1 \input texinfo @c -*-texinfo-*-
3 @setfilename automake.info
10 @c @ovar(ARG, DEFAULT)
11 @c -------------------
12 @c The ARG is an optional argument. To be used for macro arguments in
13 @c their documentation (@defmac).
15 @r{[}@var{\varname\}@r{]}
18 @set PACKAGE_BUGREPORT bug-automake@@gnu.org
22 This manual is for GNU Automake (version @value{VERSION},
23 @value{UPDATED}), a program that creates GNU standards-compliant
24 Makefiles from template files.
26 Copyright @copyright{} 1995-2012 Free Software Foundation, Inc.
29 Permission is granted to copy, distribute and/or modify this document
30 under the terms of the GNU Free Documentation License,
31 Version 1.3 or any later version published by the Free Software
32 Foundation; with no Invariant Sections, with no Front-Cover texts,
33 and with no Back-Cover Texts. A copy of the license is included in the
34 section entitled ``GNU Free Documentation License.''
39 @dircategory Software development
41 * Automake: (automake). Making GNU standards-compliant Makefiles.
44 @dircategory Individual utilities
46 * aclocal-invocation: (automake)aclocal Invocation. Generating aclocal.m4.
47 * automake-invocation: (automake)automake Invocation. Generating Makefile.in.
52 @subtitle For version @value{VERSION}, @value{UPDATED}
53 @author David MacKenzie
55 @author Alexandre Duret-Lutz
57 @vskip 0pt plus 1filll
63 @c We use the following macros to define indices:
64 @c @cindex concepts, and anything that does not fit elsewhere
65 @c @vindex Makefile variables
67 @c @acindex Autoconf/Automake/Libtool/M4/... macros
68 @c @opindex tool options
70 @c Define an index of configure macros.
72 @c Define an index of options.
74 @c Define an index of targets.
76 @c Define an index of commands.
79 @c Put the macros in the function index.
82 @c Put everything else into one index (arbitrarily chosen to be the
90 @comment node-name, next, previous, up
96 * Introduction:: Automake's purpose
97 * Autotools Introduction:: An Introduction to the Autotools
98 * Generalities:: General ideas
99 * Examples:: Some example packages
100 * automake Invocation:: Creating a Makefile.in
101 * configure:: Scanning configure.ac, using aclocal
102 * Directories:: Declaring subdirectories
103 * Programs:: Building programs and libraries
104 * Other Objects:: Other derived objects
105 * Other GNU Tools:: Other GNU Tools
106 * Documentation:: Building documentation
107 * Install:: What gets installed
108 * Clean:: What gets cleaned
109 * Dist:: What goes in a distribution
110 * Tests:: Support for test suites
111 * Rebuilding:: Automatic rebuilding of Makefile
112 * Options:: Changing Automake's behavior
113 * Miscellaneous:: Miscellaneous rules
114 * Include:: Including extra files in an Automake template
115 * Conditionals:: Conditionals
116 * Silencing Make:: Obtain less verbose output from @command{make}
117 * Gnits:: The effect of @option{--gnu} and @option{--gnits}
118 * Cygnus:: The effect of @option{--cygnus} (deprecated, soon to be removed)
119 * Not Enough:: When Automake is not Enough
120 * Distributing:: Distributing the Makefile.in
121 * API Versioning:: About compatibility between Automake versions
122 * Upgrading:: Upgrading to a Newer Automake Version
123 * FAQ:: Frequently Asked Questions
124 * Copying This Manual:: How to make copies of this manual
125 * Indices:: Indices of variables, macros, and concepts
128 --- The Detailed Node Listing ---
130 An Introduction to the Autotools
132 * GNU Build System:: Introducing the GNU Build System
133 * Use Cases:: Use Cases for the GNU Build System
134 * Why Autotools:: How Autotools Help
135 * Hello World:: A Small Hello World Package
137 Use Cases for the GNU Build System
139 * Basic Installation:: Common installation procedure
140 * Standard Targets:: A list of standard Makefile targets
141 * Standard Directory Variables:: A list of standard directory variables
142 * Standard Configuration Variables:: Using configuration variables
143 * config.site:: Using a config.site file
144 * VPATH Builds:: Parallel build trees
145 * Two-Part Install:: Installing data and programs separately
146 * Cross-Compilation:: Building for other architectures
147 * Renaming:: Renaming programs at install time
148 * DESTDIR:: Building binary packages with DESTDIR
149 * Preparing Distributions:: Rolling out tarballs
150 * Dependency Tracking:: Automatic dependency tracking
151 * Nested Packages:: The GNU Build Systems can be nested
155 * Creating amhello:: Create @file{amhello-1.0.tar.gz} from scratch
156 * amhello's configure.ac Setup Explained::
157 * amhello's Makefile.am Setup Explained::
161 * General Operation:: General operation of Automake
162 * Strictness:: Standards conformance checking
163 * Uniform:: The Uniform Naming Scheme
164 * Length Limitations:: Staying below the command line length limit
165 * Canonicalization:: How derived variables are named
166 * User Variables:: Variables reserved for the user
167 * Auxiliary Programs:: Programs automake might require
169 Some example packages
171 * Complete:: A simple example, start to finish
172 * true:: Building true and false
174 Scanning @file{configure.ac}, using @command{aclocal}
176 * Requirements:: Configuration requirements
177 * Optional:: Other things Automake recognizes
178 * aclocal Invocation:: Auto-generating aclocal.m4
179 * Macros:: Autoconf macros supplied with Automake
181 Auto-generating aclocal.m4
183 * aclocal Options:: Options supported by aclocal
184 * Macro Search Path:: How aclocal finds .m4 files
185 * Extending aclocal:: Writing your own aclocal macros
186 * Local Macros:: Organizing local macros
187 * Serials:: Serial lines in Autoconf macros
188 * Future of aclocal:: aclocal's scheduled death
190 Autoconf macros supplied with Automake
192 * Public Macros:: Macros that you can use.
193 * Obsolete Macros:: Macros that will soon be removed.
194 * Private Macros:: Macros that you should not use.
198 * Subdirectories:: Building subdirectories recursively
199 * Conditional Subdirectories:: Conditionally not building directories
200 * Alternative:: Subdirectories without recursion
201 * Subpackages:: Nesting packages
203 Conditional Subdirectories
205 * SUBDIRS vs DIST_SUBDIRS:: Two sets of directories
206 * Subdirectories with AM_CONDITIONAL:: Specifying conditional subdirectories
207 * Subdirectories with AC_SUBST:: Another way for conditional recursion
208 * Unconfigured Subdirectories:: Not even creating a @samp{Makefile}
210 Building Programs and Libraries
212 * A Program:: Building a program
213 * A Library:: Building a library
214 * A Shared Library:: Building a Libtool library
215 * Program and Library Variables:: Variables controlling program and
217 * Default _SOURCES:: Default source files
218 * LIBOBJS:: Special handling for LIBOBJS and ALLOCA
219 * Program Variables:: Variables used when building a program
220 * Yacc and Lex:: Yacc and Lex support
221 * C++ Support:: Compiling C++ sources
222 * Objective C Support:: Compiling Objective C sources
223 * Objective C++ Support:: Compiling Objective C++ sources
224 * Unified Parallel C Support:: Compiling Unified Parallel C sources
225 * Assembly Support:: Compiling assembly sources
226 * Fortran 77 Support:: Compiling Fortran 77 sources
227 * Fortran 9x Support:: Compiling Fortran 9x sources
228 * Java Support with gcj:: Compiling Java sources using gcj
229 * Vala Support:: Compiling Vala sources
230 * Support for Other Languages:: Compiling other languages
231 * Dependencies:: Automatic dependency tracking
232 * EXEEXT:: Support for executable extensions
236 * Program Sources:: Defining program sources
237 * Linking:: Linking with libraries or extra objects
238 * Conditional Sources:: Handling conditional sources
239 * Conditional Programs:: Building a program conditionally
241 Building a Shared Library
243 * Libtool Concept:: Introducing Libtool
244 * Libtool Libraries:: Declaring Libtool Libraries
245 * Conditional Libtool Libraries:: Building Libtool Libraries Conditionally
246 * Conditional Libtool Sources:: Choosing Library Sources Conditionally
247 * Libtool Convenience Libraries:: Building Convenience Libtool Libraries
248 * Libtool Modules:: Building Libtool Modules
249 * Libtool Flags:: Using _LIBADD, _LDFLAGS, and _LIBTOOLFLAGS
250 * LTLIBOBJS:: Using $(LTLIBOBJS) and $(LTALLOCA)
251 * Libtool Issues:: Common Issues Related to Libtool's Use
253 Common Issues Related to Libtool's Use
255 * Error required file ltmain.sh not found:: The need to run libtoolize
256 * Objects created both with libtool and without:: Avoid a specific build race
260 * Preprocessing Fortran 77:: Preprocessing Fortran 77 sources
261 * Compiling Fortran 77 Files:: Compiling Fortran 77 sources
262 * Mixing Fortran 77 With C and C++:: Mixing Fortran 77 With C and C++
264 Mixing Fortran 77 With C and C++
266 * How the Linker is Chosen:: Automatic linker selection
270 * Compiling Fortran 9x Files:: Compiling Fortran 9x sources
272 Other Derived Objects
274 * Scripts:: Executable scripts
275 * Headers:: Header files
276 * Data:: Architecture-independent data files
277 * Sources:: Derived sources
281 * Built Sources Example:: Several ways to handle built sources.
285 * Emacs Lisp:: Emacs Lisp
288 * Java:: Java bytecode compilation (deprecated)
291 Building documentation
294 * Man Pages:: Man pages
298 * Basics of Installation:: What gets installed where
299 * The Two Parts of Install:: Installing data and programs separately
300 * Extending Installation:: Adding your own rules for installation
301 * Staged Installs:: Installation in a temporary location
302 * Install Rules for the User:: Useful additional rules
304 What Goes in a Distribution
306 * Basics of Distribution:: Files distributed by default
307 * Fine-grained Distribution Control:: @code{dist_} and @code{nodist_} prefixes
308 * The dist Hook:: A target for last-minute distribution changes
309 * Checking the Distribution:: @samp{make distcheck} explained
310 * The Types of Distributions:: A variety of formats and compression methods
312 Support for test suites
314 * Generalities about Testing:: Generic concepts and terminology about testing
315 * Simple Tests:: Listing test scripts in @code{TESTS}
316 * Custom Test Drivers:: Writing and using custom test drivers
317 * Using the TAP test protocol:: Integrating test scripts that use the TAP protocol
318 * DejaGnu Tests:: Interfacing with the @command{dejagnu} testing framework
319 * Install Tests:: Running tests on installed packages
323 * Scripts-based Testsuites:: Automake-specific concepts and terminology
324 * Serial Test Harness:: Older (and obsolescent) serial test harness
325 * Parallel Test Harness:: Generic concurrent test harness
327 Using the TAP test protocol
329 * Introduction to TAP::
330 * Use TAP with the Automake test harness::
331 * Incompatibilities with other TAP parsers and drivers::
332 * Links and external resources on TAP::
336 * Overview of Custom Test Drivers Support::
337 * Declaring Custom Test Drivers::
338 * API for Custom Test Drivers::
340 API for Custom Test Drivers
342 * Command-line arguments for test drivers::
343 * Log files generation and test results recording::
344 * Testsuite progress output::
346 Changing Automake's Behavior
348 * Options generalities:: Semantics of Automake option
349 * List of Automake options:: A comprehensive list of Automake options
353 * Tags:: Interfacing to cscope, etags and mkid
354 * Suffixes:: Handling new file extensions
358 * Usage of Conditionals:: Declaring conditional content
359 * Limits of Conditionals:: Enclosing complete statements
363 * Make verbosity:: Make is verbose by default
364 * Tricks For Silencing Make:: Standard and generic ways to silence make
365 * Automake silent-rules Option:: How Automake can help in silencing make
367 When Automake Isn't Enough
369 * Extending:: Adding new rules or overriding existing ones.
370 * Third-Party Makefiles:: Integrating Non-Automake @file{Makefile}s.
372 Frequently Asked Questions about Automake
374 * CVS:: CVS and generated files
375 * maintainer-mode:: missing and AM_MAINTAINER_MODE
376 * Wildcards:: Why doesn't Automake support wildcards?
377 * Limitations on File Names:: Limitations on source and installed file names
378 * Errors with distclean:: Files left in build directory after distclean
379 * Flag Variables Ordering:: CFLAGS vs.@: AM_CFLAGS vs.@: mumble_CFLAGS
380 * Renamed Objects:: Why are object files sometimes renamed?
381 * Per-Object Flags:: How to simulate per-object flags?
382 * Multiple Outputs:: Writing rules for tools with many output files
383 * Hard-Coded Install Paths:: Installing to hard-coded locations
384 * Debugging Make Rules:: Strategies when things don't work as expected
385 * Reporting Bugs:: Feedback on bugs and feature requests
389 * GNU Free Documentation License:: License for copying this manual
393 * Macro Index:: Index of Autoconf macros
394 * Variable Index:: Index of Makefile variables
395 * General Index:: General index
404 @chapter Introduction
406 Automake is a tool for automatically generating @file{Makefile.in}s
407 from files called @file{Makefile.am}. Each @file{Makefile.am} is
408 basically a series of @command{make} variable
409 definitions@footnote{These variables are also called @dfn{make macros}
410 in Make terminology, however in this manual we reserve the term
411 @dfn{macro} for Autoconf's macros.}, with rules being thrown in
412 occasionally. The generated @file{Makefile.in}s are compliant with
413 the GNU Makefile standards.
415 @cindex GNU Makefile standards
417 The GNU Makefile Standards Document
418 (@pxref{Makefile Conventions, , , standards, The GNU Coding Standards})
419 is long, complicated, and subject to change. The goal of Automake is to
420 remove the burden of Makefile maintenance from the back of the
421 individual GNU maintainer (and put it on the back of the Automake
424 The typical Automake input file is simply a series of variable definitions.
425 Each such file is processed to create a @file{Makefile.in}.
427 @cindex Constraints of Automake
428 @cindex Automake constraints
430 Automake does constrain a project in certain ways; for instance, it
431 assumes that the project uses Autoconf (@pxref{Top, , Introduction,
432 autoconf, The Autoconf Manual}), and enforces certain restrictions on
433 the @file{configure.ac} contents.
435 @cindex Automake requirements
436 @cindex Requirements, Automake
438 Automake requires @command{perl} in order to generate the
439 @file{Makefile.in}s. However, the distributions created by Automake are
440 fully GNU standards-compliant, and do not require @command{perl} in order
443 @cindex Bugs, reporting
444 @cindex Reporting bugs
445 @cindex E-mail, bug reports
447 For more information on bug reports, @xref{Reporting Bugs}.
449 @node Autotools Introduction
450 @chapter An Introduction to the Autotools
452 If you are new to Automake, maybe you know that it is part of a set of
453 tools called @emph{The Autotools}. Maybe you've already delved into a
454 package full of files named @file{configure}, @file{configure.ac},
455 @file{Makefile.in}, @file{Makefile.am}, @file{aclocal.m4}, @dots{},
456 some of them claiming to be @emph{generated by} Autoconf or Automake.
457 But the exact purpose of these files and their relations is probably
458 fuzzy. The goal of this chapter is to introduce you to this machinery,
459 to show you how it works and how powerful it is. If you've never
460 installed or seen such a package, do not worry: this chapter will walk
463 If you need some teaching material, more illustrations, or a less
464 @command{automake}-centered continuation, some slides for this
465 introduction are available in Alexandre Duret-Lutz's
466 @uref{http://www.lrde.epita.fr/@/~adl/@/autotools.html,
468 This chapter is the written version of the first part of his tutorial.
471 * GNU Build System:: Introducing the GNU Build System
472 * Use Cases:: Use Cases for the GNU Build System
473 * Why Autotools:: How Autotools Help
474 * Hello World:: A Small Hello World Package
477 @node GNU Build System
478 @section Introducing the GNU Build System
479 @cindex GNU Build System, introduction
481 It is a truth universally acknowledged, that as a developer in
482 possession of a new package, you must be in want of a build system.
484 In the Unix world, such a build system is traditionally achieved using
485 the command @command{make} (@pxref{Top, , Overview, make, The GNU Make
486 Manual}). You express the recipe to build your package in a
487 @file{Makefile}. This file is a set of rules to build the files in
488 the package. For instance the program @file{prog} may be built by
489 running the linker on the files @file{main.o}, @file{foo.o}, and
490 @file{bar.o}; the file @file{main.o} may be built by running the
491 compiler on @file{main.c}; etc. Each time @command{make} is run, it
492 reads @file{Makefile}, checks the existence and modification time of
493 the files mentioned, decides what files need to be built (or rebuilt),
494 and runs the associated commands.
496 When a package needs to be built on a different platform than the one
497 it was developed on, its @file{Makefile} usually needs to be adjusted.
498 For instance the compiler may have another name or require more
499 options. In 1991, David J. MacKenzie got tired of customizing
500 @file{Makefile} for the 20 platforms he had to deal with. Instead, he
501 handcrafted a little shell script called @file{configure} to
502 automatically adjust the @file{Makefile} (@pxref{Genesis, , Genesis,
503 autoconf, The Autoconf Manual}). Compiling his package was now
504 as simple as running @code{./configure && make}.
506 @cindex GNU Coding Standards
508 Today this process has been standardized in the GNU project. The GNU
509 Coding Standards (@pxref{Managing Releases, The Release Process, ,
510 standards, The GNU Coding Standards}) explains how each package of the
511 GNU project should have a @file{configure} script, and the minimal
512 interface it should have. The @file{Makefile} too should follow some
513 established conventions. The result? A unified build system that
514 makes all packages almost indistinguishable by the installer. In its
515 simplest scenario, all the installer has to do is to unpack the
516 package, run @code{./configure && make && make install}, and repeat
517 with the next package to install.
519 We call this build system the @dfn{GNU Build System}, since it was
520 grown out of the GNU project. However it is used by a vast number of
521 other packages: following any existing convention has its advantages.
523 @cindex Autotools, introduction
525 The Autotools are tools that will create a GNU Build System for your
526 package. Autoconf mostly focuses on @file{configure} and Automake on
527 @file{Makefile}s. It is entirely possible to create a GNU Build
528 System without the help of these tools. However it is rather
529 burdensome and error-prone. We will discuss this again after some
530 illustration of the GNU Build System in action.
533 @section Use Cases for the GNU Build System
534 @cindex GNU Build System, use cases
535 @cindex GNU Build System, features
536 @cindex Features of the GNU Build System
537 @cindex Use Cases for the GNU Build System
538 @cindex @file{amhello-1.0.tar.gz}, location
539 @cindex @file{amhello-1.0.tar.gz}, use cases
541 In this section we explore several use cases for the GNU Build System.
542 You can replay all of these examples on the @file{amhello-1.0.tar.gz}
543 package distributed with Automake. If Automake is installed on your
544 system, you should find a copy of this file in
545 @file{@var{prefix}/share/doc/automake/amhello-1.0.tar.gz}, where
546 @var{prefix} is the installation prefix specified during configuration
547 (@var{prefix} defaults to @file{/usr/local}, however if Automake was
548 installed by some GNU/Linux distribution it most likely has been set
549 to @file{/usr}). If you do not have a copy of Automake installed,
550 you can find a copy of this file inside the @file{doc/} directory of
551 the Automake package.
553 Some of the following use cases present features that are in fact
554 extensions to the GNU Build System. Read: they are not specified by
555 the GNU Coding Standards, but they are nonetheless part of the build
556 system created by the Autotools. To keep things simple, we do not
557 point out the difference. Our objective is to show you many of the
558 features that the build system created by the Autotools will offer to
562 * Basic Installation:: Common installation procedure
563 * Standard Targets:: A list of standard Makefile targets
564 * Standard Directory Variables:: A list of standard directory variables
565 * Standard Configuration Variables:: Using configuration variables
566 * config.site:: Using a config.site file
567 * VPATH Builds:: Parallel build trees
568 * Two-Part Install:: Installing data and programs separately
569 * Cross-Compilation:: Building for other architectures
570 * Renaming:: Renaming programs at install time
571 * DESTDIR:: Building binary packages with DESTDIR
572 * Preparing Distributions:: Rolling out tarballs
573 * Dependency Tracking:: Automatic dependency tracking
574 * Nested Packages:: The GNU Build Systems can be nested
577 @node Basic Installation
578 @subsection Basic Installation
579 @cindex Configuration, basics
580 @cindex Installation, basics
581 @cindex GNU Build System, basics
583 The most common installation procedure looks as follows.
586 ~ % @kbd{tar zxf amhello-1.0.tar.gz}
587 ~ % @kbd{cd amhello-1.0}
588 ~/amhello-1.0 % @kbd{./configure}
590 config.status: creating Makefile
591 config.status: creating src/Makefile
593 ~/amhello-1.0 % @kbd{make}
595 ~/amhello-1.0 % @kbd{make check}
597 ~/amhello-1.0 % @kbd{su}
599 /home/adl/amhello-1.0 # @kbd{make install}
601 /home/adl/amhello-1.0 # @kbd{exit}
602 ~/amhello-1.0 % @kbd{make installcheck}
608 The user first unpacks the package. Here, and in the following
609 examples, we will use the non-portable @code{tar zxf} command for
610 simplicity. On a system without GNU @command{tar} installed, this
611 command should read @code{gunzip -c amhello-1.0.tar.gz | tar xf -}.
613 The user then enters the newly created directory to run the
614 @file{configure} script. This script probes the system for various
615 features, and finally creates the @file{Makefile}s. In this toy
616 example there are only two @file{Makefile}s, but in real-world projects,
617 there may be many more, usually one @file{Makefile} per directory.
619 It is now possible to run @code{make}. This will construct all the
620 programs, libraries, and scripts that need to be constructed for the
621 package. In our example, this compiles the @file{hello} program.
622 All files are constructed in place, in the source tree; we will see
623 later how this can be changed.
625 @code{make check} causes the package's tests to be run. This step is
626 not mandatory, but it is often good to make sure the programs that
627 have been built behave as they should, before you decide to install
628 them. Our example does not contain any tests, so running @code{make
631 @cindex su, before @code{make install}
632 After everything has been built, and maybe tested, it is time to
633 install it on the system. That means copying the programs,
634 libraries, header files, scripts, and other data files from the
635 source directory to their final destination on the system. The
636 command @code{make install} will do that. However, by default
637 everything will be installed in subdirectories of @file{/usr/local}:
638 binaries will go into @file{/usr/local/bin}, libraries will end up in
639 @file{/usr/local/lib}, etc. This destination is usually not writable
640 by any user, so we assume that we have to become root before we can
641 run @code{make install}. In our example, running @code{make install}
642 will copy the program @file{hello} into @file{/usr/local/bin}
643 and @file{README} into @file{/usr/local/share/doc/amhello}.
645 A last and optional step is to run @code{make installcheck}. This
646 command may run tests on the installed files. @code{make check} tests
647 the files in the source tree, while @code{make installcheck} tests
648 their installed copies. The tests run by the latter can be different
649 from those run by the former. For instance, there are tests that
650 cannot be run in the source tree. Conversely, some packages are set
651 up so that @code{make installcheck} will run the very same tests as
652 @code{make check}, only on different files (non-installed
653 vs.@: installed). It can make a difference, for instance when the
654 source tree's layout is different from that of the installation.
655 Furthermore it may help to diagnose an incomplete installation.
657 Presently most packages do not have any @code{installcheck} tests
658 because the existence of @code{installcheck} is little known, and its
659 usefulness is neglected. Our little toy package is no better: @code{make
660 installcheck} does nothing.
662 @node Standard Targets
663 @subsection Standard @file{Makefile} Targets
665 So far we have come across four ways to run @command{make} in the GNU
666 Build System: @code{make}, @code{make check}, @code{make install}, and
667 @code{make installcheck}. The words @code{check}, @code{install}, and
668 @code{installcheck}, passed as arguments to @command{make}, are called
669 @dfn{targets}. @code{make} is a shorthand for @code{make all},
670 @code{all} being the default target in the GNU Build System.
672 Here is a list of the most useful targets that the GNU Coding Standards
678 Build programs, libraries, documentation, etc.@: (same as @code{make}).
681 Install what needs to be installed, copying the files from the
682 package's tree to system-wide directories.
683 @item make install-strip
684 @trindex install-strip
685 Same as @code{make install}, then strip debugging symbols. Some
686 users like to trade space for useful bug reports@enddots{}
689 The opposite of @code{make install}: erase the installed files.
690 (This needs to be run from the same build tree that was installed.)
693 Erase from the build tree the files built by @code{make all}.
696 Additionally erase anything @code{./configure} created.
699 Run the test suite, if any.
700 @item make installcheck
701 @trindex installcheck
702 Check the installed programs or libraries, if supported.
705 Recreate @file{@var{package}-@var{version}.tar.gz} from all the source
709 @node Standard Directory Variables
710 @subsection Standard Directory Variables
711 @cindex directory variables
713 The GNU Coding Standards also specify a hierarchy of variables to
714 denote installation directories. Some of these are:
716 @multitable {Directory variable} {@code{$@{datarootdir@}/doc/$@{PACKAGE@}}}
717 @headitem Directory variable @tab Default value
718 @item @code{prefix} @tab @code{/usr/local}
719 @item @w{@ @ @code{exec_prefix}} @tab @code{$@{prefix@}}
720 @item @w{@ @ @ @ @code{bindir}} @tab @code{$@{exec_prefix@}/bin}
721 @item @w{@ @ @ @ @code{libdir}} @tab @code{$@{exec_prefix@}/lib}
722 @item @w{@ @ @ @ @dots{}}
723 @item @w{@ @ @code{includedir}} @tab @code{$@{prefix@}/include}
724 @item @w{@ @ @code{datarootdir}} @tab @code{$@{prefix@}/share}
725 @item @w{@ @ @ @ @code{datadir}} @tab @code{$@{datarootdir@}}
726 @item @w{@ @ @ @ @code{mandir}} @tab @code{$@{datarootdir@}/man}
727 @item @w{@ @ @ @ @code{infodir}} @tab @code{$@{datarootdir@}/info}
728 @item @w{@ @ @ @ @code{docdir}} @tab @code{$@{datarootdir@}/doc/$@{PACKAGE@}}
729 @item @w{@ @ @dots{}}
732 @c We should provide a complete table somewhere, but not here. The
733 @c complete list of directory variables it too confusing as-is. It
734 @c requires some explanations that are too complicated for this
735 @c introduction. Besides listing directories like localstatedir
736 @c would make the explanations in ``Two-Part Install'' harder.
738 Each of these directories has a role which is often obvious from its
739 name. In a package, any installable file will be installed in one of
740 these directories. For instance in @code{amhello-1.0}, the program
741 @file{hello} is to be installed in @var{bindir}, the directory for
742 binaries. The default value for this directory is
743 @file{/usr/local/bin}, but the user can supply a different value when
744 calling @command{configure}. Also the file @file{README} will be
745 installed into @var{docdir}, which defaults to
746 @file{/usr/local/share/doc/amhello}.
750 As a user, if you wish to install a package on your own account, you
751 could proceed as follows:
754 ~/amhello-1.0 % @kbd{./configure --prefix ~/usr}
756 ~/amhello-1.0 % @kbd{make}
758 ~/amhello-1.0 % @kbd{make install}
762 This would install @file{~/usr/bin/hello} and
763 @file{~/usr/share/doc/amhello/README}.
765 The list of all such directory options is shown by
766 @code{./configure --help}.
768 @node Standard Configuration Variables
769 @subsection Standard Configuration Variables
770 @cindex configuration variables, overriding
772 The GNU Coding Standards also define a set of standard configuration
773 variables used during the build. Here are some:
782 @item @code{CXXFLAGS}
786 @item @code{CPPFLAGS}
787 C/C++ preprocessor flags
791 @command{configure} usually does a good job at setting appropriate
792 values for these variables, but there are cases where you may want to
793 override them. For instance you may have several versions of a
794 compiler installed and would like to use another one, you may have
795 header files installed outside the default search path of the
796 compiler, or even libraries out of the way of the linker.
798 Here is how one would call @command{configure} to force it to use
799 @command{gcc-3} as C compiler, use header files from
800 @file{~/usr/include} when compiling, and libraries from
801 @file{~/usr/lib} when linking.
804 ~/amhello-1.0 % @kbd{./configure --prefix ~/usr CC=gcc-3 \
805 CPPFLAGS=-I$HOME/usr/include LDFLAGS=-L$HOME/usr/lib}
808 Again, a full list of these variables appears in the output of
809 @code{./configure --help}.
812 @subsection Overriding Default Configuration Setting with @file{config.site}
813 @cindex @file{config.site} example
815 When installing several packages using the same setup, it can be
816 convenient to create a file to capture common settings.
817 If a file named @file{@var{prefix}/share/config.site} exists,
818 @command{configure} will source it at the beginning of its execution.
820 Recall the command from the previous section:
823 ~/amhello-1.0 % @kbd{./configure --prefix ~/usr CC=gcc-3 \
824 CPPFLAGS=-I$HOME/usr/include LDFLAGS=-L$HOME/usr/lib}
827 Assuming we are installing many package in @file{~/usr}, and will
828 always want to use these definitions of @code{CC}, @code{CPPFLAGS}, and
829 @code{LDFLAGS}, we can automate this by creating the following
830 @file{~/usr/share/config.site} file:
833 test -z "$CC" && CC=gcc-3
834 test -z "$CPPFLAGS" && CPPFLAGS=-I$HOME/usr/include
835 test -z "$LDFLAGS" && LDFLAGS=-L$HOME/usr/lib
838 Now, any time a @file{configure} script is using the @file{~/usr}
839 prefix, it will execute the above @file{config.site} and define
840 these three variables.
843 ~/amhello-1.0 % @kbd{./configure --prefix ~/usr}
844 configure: loading site script /home/adl/usr/share/config.site
848 @xref{Site Defaults, , Setting Site Defaults, autoconf, The Autoconf
849 Manual}, for more information about this feature.
853 @subsection Parallel Build Trees (a.k.a.@: VPATH Builds)
854 @cindex Parallel build trees
856 @cindex source tree and build tree
857 @cindex build tree and source tree
858 @cindex trees, source vs.@: build
860 The GNU Build System distinguishes two trees: the source tree, and
863 The source tree is rooted in the directory containing
864 @file{configure}. It contains all the sources files (those that are
865 distributed), and may be arranged using several subdirectories.
867 The build tree is rooted in the directory in which @file{configure}
868 was run, and is populated with all object files, programs, libraries,
869 and other derived files built from the sources (and hence not
870 distributed). The build tree usually has the same subdirectory layout
871 as the source tree; its subdirectories are created automatically by
874 If @file{configure} is executed in its own directory, the source and
875 build trees are combined: derived files are constructed in the same
876 directories as their sources. This was the case in our first
877 installation example (@pxref{Basic Installation}).
879 A common request from users is that they want to confine all derived
880 files to a single directory, to keep their source directories
881 uncluttered. Here is how we could run @file{configure} to build
882 everything in a subdirectory called @file{build/}.
885 ~ % @kbd{tar zxf ~/amhello-1.0.tar.gz}
886 ~ % @kbd{cd amhello-1.0}
887 ~/amhello-1.0 % @kbd{mkdir build && cd build}
888 ~/amhello-1.0/build % @kbd{../configure}
890 ~/amhello-1.0/build % @kbd{make}
894 These setups, where source and build trees are different, are often
895 called @dfn{parallel builds} or @dfn{VPATH builds}. The expression
896 @emph{parallel build} is misleading: the word @emph{parallel} is a
897 reference to the way the build tree shadows the source tree, it is not
898 about some concurrency in the way build commands are run. For this
899 reason we refer to such setups using the name @emph{VPATH builds} in
900 the following. @emph{VPATH} is the name of the @command{make} feature
901 used by the @file{Makefile}s to allow these builds (@pxref{General
902 Search, , @code{VPATH} Search Path for All Prerequisites, make, The
905 @cindex multiple configurations, example
906 @cindex debug build, example
907 @cindex optimized build, example
909 VPATH builds have other interesting uses. One is to build the same
910 sources with multiple configurations. For instance:
912 @c Keep in sync with amhello-cflags.sh
914 ~ % @kbd{tar zxf ~/amhello-1.0.tar.gz}
915 ~ % @kbd{cd amhello-1.0}
916 ~/amhello-1.0 % @kbd{mkdir debug optim && cd debug}
917 ~/amhello-1.0/debug % @kbd{../configure CFLAGS='-g -O0'}
919 ~/amhello-1.0/debug % @kbd{make}
921 ~/amhello-1.0/debug % cd ../optim
922 ~/amhello-1.0/optim % @kbd{../configure CFLAGS='-O3 -fomit-frame-pointer'}
924 ~/amhello-1.0/optim % @kbd{make}
928 With network file systems, a similar approach can be used to build the
929 same sources on different machines. For instance, suppose that the
930 sources are installed on a directory shared by two hosts: @code{HOST1}
931 and @code{HOST2}, which may be different platforms.
934 ~ % @kbd{cd /nfs/src}
935 /nfs/src % @kbd{tar zxf ~/amhello-1.0.tar.gz}
938 On the first host, you could create a local build directory:
940 [HOST1] ~ % @kbd{mkdir /tmp/amh && cd /tmp/amh}
941 [HOST1] /tmp/amh % @kbd{/nfs/src/amhello-1.0/configure}
943 [HOST1] /tmp/amh % @kbd{make && sudo make install}
948 (Here we assume that the installer has configured @command{sudo} so it
949 can execute @code{make install} with root privileges; it is more convenient
950 than using @command{su} like in @ref{Basic Installation}).
952 On the second host, you would do exactly the same, possibly at
955 [HOST2] ~ % @kbd{mkdir /tmp/amh && cd /tmp/amh}
956 [HOST2] /tmp/amh % @kbd{/nfs/src/amhello-1.0/configure}
958 [HOST2] /tmp/amh % @kbd{make && sudo make install}
962 @cindex read-only source tree
963 @cindex source tree, read-only
965 In this scenario, nothing forbids the @file{/nfs/src/amhello-1.0}
966 directory from being read-only. In fact VPATH builds are also a means
967 of building packages from a read-only medium such as a CD-ROM. (The
968 FSF used to sell CD-ROM with unpacked source code, before the GNU
969 project grew so big.)
971 @node Two-Part Install
972 @subsection Two-Part Installation
974 In our last example (@pxref{VPATH Builds}), a source tree was shared
975 by two hosts, but compilation and installation were done separately on
978 The GNU Build System also supports networked setups where part of the
979 installed files should be shared amongst multiple hosts. It does so
980 by distinguishing architecture-dependent files from
981 architecture-independent files, and providing two @file{Makefile}
982 targets to install each of these classes of files.
984 @trindex install-exec
985 @trindex install-data
987 These targets are @code{install-exec} for architecture-dependent files
988 and @code{install-data} for architecture-independent files.
989 The command we used up to now, @code{make install}, can be thought of
990 as a shorthand for @code{make install-exec install-data}.
992 From the GNU Build System point of view, the distinction between
993 architecture-dependent files and architecture-independent files is
994 based exclusively on the directory variable used to specify their
995 installation destination. In the list of directory variables we
996 provided earlier (@pxref{Standard Directory Variables}), all the
997 variables based on @var{exec-prefix} designate architecture-dependent
998 directories whose files will be installed by @code{make install-exec}.
999 The others designate architecture-independent directories and will
1000 serve files installed by @code{make install-data}. @xref{The Two Parts
1001 of Install}, for more details.
1003 Here is how we could revisit our two-host installation example,
1004 assuming that (1) we want to install the package directly in
1005 @file{/usr}, and (2) the directory @file{/usr/share} is shared by the
1008 On the first host we would run
1010 [HOST1] ~ % @kbd{mkdir /tmp/amh && cd /tmp/amh}
1011 [HOST1] /tmp/amh % @kbd{/nfs/src/amhello-1.0/configure --prefix /usr}
1013 [HOST1] /tmp/amh % @kbd{make && sudo make install}
1017 On the second host, however, we need only install the
1018 architecture-specific files.
1020 [HOST2] ~ % @kbd{mkdir /tmp/amh && cd /tmp/amh}
1021 [HOST2] /tmp/amh % @kbd{/nfs/src/amhello-1.0/configure --prefix /usr}
1023 [HOST2] /tmp/amh % @kbd{make && sudo make install-exec}
1027 In packages that have installation checks, it would make sense to run
1028 @code{make installcheck} (@pxref{Basic Installation}) to verify that
1029 the package works correctly despite the apparent partial installation.
1031 @node Cross-Compilation
1032 @subsection Cross-Compilation
1033 @cindex cross-compilation
1035 To @dfn{cross-compile} is to build on one platform a binary that will
1036 run on another platform. When speaking of cross-compilation, it is
1037 important to distinguish between the @dfn{build platform} on which
1038 the compilation is performed, and the @dfn{host platform} on which the
1039 resulting executable is expected to run. The following
1040 @command{configure} options are used to specify each of them:
1043 @item --build=@var{build}
1044 @opindex --build=@var{build}
1045 The system on which the package is built.
1046 @item --host=@var{host}
1047 @opindex --host=@var{host}
1048 The system where built programs and libraries will run.
1051 When the @option{--host} is used, @command{configure} will search for
1052 the cross-compiling suite for this platform. Cross-compilation tools
1053 commonly have their target architecture as prefix of their name. For
1054 instance my cross-compiler for MinGW32 has its binaries called
1055 @code{i586-mingw32msvc-gcc}, @code{i586-mingw32msvc-ld},
1056 @code{i586-mingw32msvc-as}, etc.
1058 @cindex MinGW cross-compilation example
1059 @cindex cross-compilation example
1061 Here is how we could build @code{amhello-1.0} for
1062 @code{i586-mingw32msvc} on a GNU/Linux PC.
1064 @c Keep in sync with amhello-cross-compile.sh
1066 ~/amhello-1.0 % @kbd{./configure --build i686-pc-linux-gnu --host i586-mingw32msvc}
1067 checking for a BSD-compatible install... /usr/bin/install -c
1068 checking whether build environment is sane... yes
1069 checking for gawk... gawk
1070 checking whether make sets $(MAKE)... yes
1071 checking for i586-mingw32msvc-strip... i586-mingw32msvc-strip
1072 checking for i586-mingw32msvc-gcc... i586-mingw32msvc-gcc
1073 checking for C compiler default output file name... a.exe
1074 checking whether the C compiler works... yes
1075 checking whether we are cross compiling... yes
1076 checking for suffix of executables... .exe
1077 checking for suffix of object files... o
1078 checking whether we are using the GNU C compiler... yes
1079 checking whether i586-mingw32msvc-gcc accepts -g... yes
1080 checking for i586-mingw32msvc-gcc option to accept ANSI C...
1082 ~/amhello-1.0 % @kbd{make}
1084 ~/amhello-1.0 % @kbd{cd src; file hello.exe}
1085 hello.exe: MS Windows PE 32-bit Intel 80386 console executable not relocatable
1088 The @option{--host} and @option{--build} options are usually all we
1089 need for cross-compiling. The only exception is if the package being
1090 built is itself a cross-compiler: we need a third option to specify
1091 its target architecture.
1094 @item --target=@var{target}
1095 @opindex --target=@var{target}
1096 When building compiler tools: the system for which the tools will
1100 For instance when installing GCC, the GNU Compiler Collection, we can
1101 use @option{--target=@/@var{target}} to specify that we want to build
1102 GCC as a cross-compiler for @var{target}. Mixing @option{--build} and
1103 @option{--target}, we can actually cross-compile a cross-compiler;
1104 such a three-way cross-compilation is known as a @dfn{Canadian cross}.
1106 @xref{Specifying Names, , Specifying the System Type, autoconf, The
1107 Autoconf Manual}, for more information about these @command{configure}
1111 @subsection Renaming Programs at Install Time
1112 @cindex Renaming programs
1113 @cindex Transforming program names
1114 @cindex Programs, renaming during installation
1116 The GNU Build System provides means to automatically rename
1117 executables and manpages before they are installed (@pxref{Man Pages}).
1118 This is especially convenient
1119 when installing a GNU package on a system that already has a
1120 proprietary implementation you do not want to overwrite. For instance,
1121 you may want to install GNU @command{tar} as @command{gtar} so you can
1122 distinguish it from your vendor's @command{tar}.
1124 This can be done using one of these three @command{configure} options.
1127 @item --program-prefix=@var{prefix}
1128 @opindex --program-prefix=@var{prefix}
1129 Prepend @var{prefix} to installed program names.
1130 @item --program-suffix=@var{suffix}
1131 @opindex --program-suffix=@var{suffix}
1132 Append @var{suffix} to installed program names.
1133 @item --program-transform-name=@var{program}
1134 @opindex --program-transform-name=@var{program}
1135 Run @code{sed @var{program}} on installed program names.
1138 The following commands would install @file{hello}
1139 as @file{/usr/local/bin/test-hello}, for instance.
1142 ~/amhello-1.0 % @kbd{./configure --program-prefix test-}
1144 ~/amhello-1.0 % @kbd{make}
1146 ~/amhello-1.0 % @kbd{sudo make install}
1151 @subsection Building Binary Packages Using DESTDIR
1154 The GNU Build System's @code{make install} and @code{make uninstall}
1155 interface does not exactly fit the needs of a system administrator
1156 who has to deploy and upgrade packages on lots of hosts. In other
1157 words, the GNU Build System does not replace a package manager.
1159 Such package managers usually need to know which files have been
1160 installed by a package, so a mere @code{make install} is
1163 @cindex Staged installation
1165 The @code{DESTDIR} variable can be used to perform a staged
1166 installation. The package should be configured as if it was going to
1167 be installed in its final location (e.g., @code{--prefix /usr}), but
1168 when running @code{make install}, the @code{DESTDIR} should be set to
1169 the absolute name of a directory into which the installation will be
1170 diverted. From this directory it is easy to review which files are
1171 being installed where, and finally copy them to their final location
1174 @cindex Binary package
1176 For instance here is how we could create a binary package containing a
1177 snapshot of all the files to be installed.
1179 @c Keep in sync with amhello-binpkg.sh
1181 ~/amhello-1.0 % @kbd{./configure --prefix /usr}
1183 ~/amhello-1.0 % @kbd{make}
1185 ~/amhello-1.0 % @kbd{make DESTDIR=$HOME/inst install}
1187 ~/amhello-1.0 % @kbd{cd ~/inst}
1188 ~/inst % @kbd{find . -type f -print > ../files.lst}
1189 ~/inst % @kbd{tar zcvf ~/amhello-1.0-i686.tar.gz `cat ../files.lst`}
1191 ./usr/share/doc/amhello/README
1194 After this example, @code{amhello-1.0-i686.tar.gz} is ready to be
1195 uncompressed in @file{/} on many hosts. (Using @code{`cat ../files.lst`}
1196 instead of @samp{.} as argument for @command{tar} avoids entries for
1197 each subdirectory in the archive: we would not like @command{tar} to
1198 restore the modification time of @file{/}, @file{/usr/}, etc.)
1200 Note that when building packages for several architectures, it might
1201 be convenient to use @code{make install-data} and @code{make
1202 install-exec} (@pxref{Two-Part Install}) to gather
1203 architecture-independent files in a single package.
1205 @xref{Install}, for more information.
1207 @c We should document PRE_INSTALL/POST_INSTALL/NORMAL_INSTALL and their
1208 @c UNINSTALL counterparts.
1210 @node Preparing Distributions
1211 @subsection Preparing Distributions
1212 @cindex Preparing distributions
1213 @cindex Packages, preparation
1214 @cindex Distributions, preparation
1216 We have already mentioned @code{make dist}. This target collects all
1217 your source files and the necessary parts of the build system to
1218 create a tarball named @file{@var{package}-@var{version}.tar.gz}.
1220 @cindex @code{distcheck} better than @code{dist}
1222 Another, more useful command is @code{make distcheck}. The
1223 @code{distcheck} target constructs
1224 @file{@var{package}-@var{version}.tar.gz} just as well as @code{dist},
1225 but it additionally ensures most of the use cases presented so far
1230 It attempts a full compilation of the package (@pxref{Basic
1231 Installation}), unpacking the newly constructed tarball, running
1232 @code{make}, @code{make check}, @code{make install}, as well as
1233 @code{make installcheck}, and even @code{make dist},
1235 it tests VPATH builds with read-only source tree (@pxref{VPATH Builds}),
1237 it makes sure @code{make clean}, @code{make distclean}, and @code{make
1238 uninstall} do not omit any file (@pxref{Standard Targets}),
1240 and it checks that @code{DESTDIR} installations work (@pxref{DESTDIR}).
1243 All of these actions are performed in a temporary subdirectory, so
1244 that no root privileges are required.
1246 Releasing a package that fails @code{make distcheck} means that one of
1247 the scenarios we presented will not work and some users will be
1248 disappointed. Therefore it is a good practice to release a package
1249 only after a successful @code{make distcheck}. This of course does
1250 not imply that the package will be flawless, but at least it will
1251 prevent some of the embarrassing errors you may find in packages
1252 released by people who have never heard about @code{distcheck} (like
1253 @code{DESTDIR} not working because of a typo, or a distributed file
1254 being erased by @code{make clean}, or even @code{VPATH} builds not
1257 @xref{Creating amhello}, to recreate @file{amhello-1.0.tar.gz} using
1258 @code{make distcheck}. @xref{Checking the Distribution}, for more
1259 information about @code{distcheck}.
1261 @node Dependency Tracking
1262 @subsection Automatic Dependency Tracking
1263 @cindex Dependency tracking
1265 Dependency tracking is performed as a side-effect of compilation.
1266 Each time the build system compiles a source file, it computes its
1267 list of dependencies (in C these are the header files included by the
1268 source being compiled). Later, any time @command{make} is run and a
1269 dependency appears to have changed, the dependent files will be
1272 Automake generates code for automatic dependency tracking by default,
1273 unless the developer chooses to override it; for more information,
1274 @pxref{Dependencies}.
1276 When @command{configure} is executed, you can see it probing each
1277 compiler for the dependency mechanism it supports (several mechanisms
1281 ~/amhello-1.0 % @kbd{./configure --prefix /usr}
1283 checking dependency style of gcc... gcc3
1287 Because dependencies are only computed as a side-effect of the
1288 compilation, no dependency information exists the first time a package
1289 is built. This is OK because all the files need to be built anyway:
1290 @code{make} does not have to decide which files need to be rebuilt.
1291 In fact, dependency tracking is completely useless for one-time builds
1292 and there is a @command{configure} option to disable this:
1295 @item --disable-dependency-tracking
1296 @opindex --disable-dependency-tracking
1297 Speed up one-time builds.
1300 Some compilers do not offer any practical way to derive the list of
1301 dependencies as a side-effect of the compilation, requiring a separate
1302 run (maybe of another tool) to compute these dependencies. The
1303 performance penalty implied by these methods is important enough to
1304 disable them by default. The option @option{--enable-dependency-tracking}
1305 must be passed to @command{configure} to activate them.
1308 @item --enable-dependency-tracking
1309 @opindex --enable-dependency-tracking
1310 Do not reject slow dependency extractors.
1313 @xref{Dependency Tracking Evolution, , Dependency Tracking Evolution,
1314 automake-history, Brief History of Automake}, for some discussion about
1315 the different dependency tracking schemes used by Automake over the years.
1317 @node Nested Packages
1318 @subsection Nested Packages
1319 @cindex Nested packages
1320 @cindex Packages, nested
1323 Although nesting packages isn't something we would recommend to
1324 someone who is discovering the Autotools, it is a nice feature worthy
1325 of mention in this small advertising tour.
1327 Autoconfiscated packages (that means packages whose build system have
1328 been created by Autoconf and friends) can be nested to arbitrary
1331 A typical setup is that package A will distribute one of the libraries
1332 it needs in a subdirectory. This library B is a complete package with
1333 its own GNU Build System. The @command{configure} script of A will
1334 run the @command{configure} script of B as part of its execution,
1335 building and installing A will also build and install B. Generating a
1336 distribution for A will also include B.
1338 It is possible to gather several packages like this. GCC is a heavy
1339 user of this feature. This gives installers a single package to
1340 configure, build and install, while it allows developers to work on
1341 subpackages independently.
1343 When configuring nested packages, the @command{configure} options
1344 given to the top-level @command{configure} are passed recursively to
1345 nested @command{configure}s. A package that does not understand an
1346 option will ignore it, assuming it is meaningful to some other
1349 @opindex --help=recursive
1351 The command @code{configure --help=recursive} can be used to display
1352 the options supported by all the included packages.
1354 @xref{Subpackages}, for an example setup.
1357 @section How Autotools Help
1358 @cindex Autotools, purpose
1360 There are several reasons why you may not want to implement the GNU
1361 Build System yourself (read: write a @file{configure} script and
1362 @file{Makefile}s yourself).
1366 As we have seen, the GNU Build System has a lot of
1367 features (@pxref{Use Cases}).
1368 Some users may expect features you have not implemented because
1369 you did not need them.
1371 Implementing these features portably is difficult and exhausting.
1372 Think of writing portable shell scripts, and portable
1373 @file{Makefile}s, for systems you may not have handy. @xref{Portable
1374 Shell, , Portable Shell Programming, autoconf, The Autoconf Manual}, to
1377 You will have to upgrade your setup to follow changes to the GNU
1381 The GNU Autotools take all this burden off your back and provide:
1385 Tools to create a portable, complete, and self-contained GNU Build
1386 System, from simple instructions.
1387 @emph{Self-contained} meaning the resulting build system does not
1388 require the GNU Autotools.
1390 A central place where fixes and improvements are made:
1391 a bug-fix for a portability issue will benefit every package.
1394 Yet there also exist reasons why you may want NOT to use the
1395 Autotools@enddots{} For instance you may be already using (or used to)
1396 another incompatible build system. Autotools will only be useful if
1397 you do accept the concepts of the GNU Build System. People who have their
1398 own idea of how a build system should work will feel frustrated by the
1402 @section A Small Hello World
1403 @cindex Example Hello World
1404 @cindex Hello World example
1405 @cindex @file{amhello-1.0.tar.gz}, creation
1407 In this section we recreate the @file{amhello-1.0} package from
1408 scratch. The first subsection shows how to call the Autotools to
1409 instantiate the GNU Build System, while the second explains the
1410 meaning of the @file{configure.ac} and @file{Makefile.am} files read
1413 @anchor{amhello Explained}
1415 * Creating amhello:: Create @file{amhello-1.0.tar.gz} from scratch
1416 * amhello's configure.ac Setup Explained::
1417 * amhello's Makefile.am Setup Explained::
1420 @node Creating amhello
1421 @subsection Creating @file{amhello-1.0.tar.gz}
1423 Here is how we can recreate @file{amhello-1.0.tar.gz} from scratch.
1424 The package is simple enough so that we will only need to write 5
1425 files. (You may copy them from the final @file{amhello-1.0.tar.gz}
1426 that is distributed with Automake if you do not want to write them.)
1428 Create the following files in an empty directory.
1433 @file{src/main.c} is the source file for the @file{hello} program. We
1434 store it in the @file{src/} subdirectory, because later, when the package
1435 evolves, it will ease the addition of a @file{man/} directory for man
1436 pages, a @file{data/} directory for data files, etc.
1438 ~/amhello % @kbd{cat src/main.c}
1445 puts ("Hello World!");
1446 puts ("This is " PACKAGE_STRING ".");
1452 @file{README} contains some very limited documentation for our little
1455 ~/amhello % @kbd{cat README}
1456 This is a demonstration package for GNU Automake.
1457 Type 'info Automake' to read the Automake manual.
1461 @file{Makefile.am} and @file{src/Makefile.am} contain Automake
1462 instructions for these two directories.
1465 ~/amhello % @kbd{cat src/Makefile.am}
1466 bin_PROGRAMS = hello
1467 hello_SOURCES = main.c
1468 ~/amhello % @kbd{cat Makefile.am}
1470 dist_doc_DATA = README
1474 Finally, @file{configure.ac} contains Autoconf instructions to
1475 create the @command{configure} script.
1478 ~/amhello % @kbd{cat configure.ac}
1479 AC_INIT([amhello], [1.0], [@value{PACKAGE_BUGREPORT}])
1480 AM_INIT_AUTOMAKE([-Wall -Werror foreign])
1482 AC_CONFIG_HEADERS([config.h])
1491 @cindex @command{autoreconf}, example
1493 Once you have these five files, it is time to run the Autotools to
1494 instantiate the build system. Do this using the @command{autoreconf}
1498 ~/amhello % @kbd{autoreconf --install}
1499 configure.ac: installing './install-sh'
1500 configure.ac: installing './missing'
1501 src/Makefile.am: installing './depcomp'
1504 At this point the build system is complete.
1506 In addition to the three scripts mentioned in its output, you can see
1507 that @command{autoreconf} created four other files: @file{configure},
1508 @file{config.h.in}, @file{Makefile.in}, and @file{src/Makefile.in}.
1509 The latter three files are templates that will be adapted to the
1510 system by @command{configure} under the names @file{config.h},
1511 @file{Makefile}, and @file{src/Makefile}. Let's do this:
1514 ~/amhello % @kbd{./configure}
1515 checking for a BSD-compatible install... /usr/bin/install -c
1516 checking whether build environment is sane... yes
1517 checking for gawk... no
1518 checking for mawk... mawk
1519 checking whether make sets $(MAKE)... yes
1520 checking for gcc... gcc
1521 checking for C compiler default output file name... a.out
1522 checking whether the C compiler works... yes
1523 checking whether we are cross compiling... no
1524 checking for suffix of executables...
1525 checking for suffix of object files... o
1526 checking whether we are using the GNU C compiler... yes
1527 checking whether gcc accepts -g... yes
1528 checking for gcc option to accept ISO C89... none needed
1529 checking for style of include used by make... GNU
1530 checking dependency style of gcc... gcc3
1531 configure: creating ./config.status
1532 config.status: creating Makefile
1533 config.status: creating src/Makefile
1534 config.status: creating config.h
1535 config.status: executing depfiles commands
1539 @cindex @code{distcheck} example
1541 You can see @file{Makefile}, @file{src/Makefile}, and @file{config.h}
1542 being created at the end after @command{configure} has probed the
1543 system. It is now possible to run all the targets we wish
1544 (@pxref{Standard Targets}). For instance:
1547 ~/amhello % @kbd{make}
1549 ~/amhello % @kbd{src/hello}
1551 This is amhello 1.0.
1552 ~/amhello % @kbd{make distcheck}
1554 =============================================
1555 amhello-1.0 archives ready for distribution:
1557 =============================================
1560 Note that running @command{autoreconf} is only needed initially when
1561 the GNU Build System does not exist. When you later change some
1562 instructions in a @file{Makefile.am} or @file{configure.ac}, the
1563 relevant part of the build system will be regenerated automatically
1564 when you execute @command{make}.
1566 @command{autoreconf} is a script that calls @command{autoconf},
1567 @command{automake}, and a bunch of other commands in the right order.
1568 If you are beginning with these tools, it is not important to figure
1569 out in which order all of these tools should be invoked and why. However,
1570 because Autoconf and Automake have separate manuals, the important
1571 point to understand is that @command{autoconf} is in charge of
1572 creating @file{configure} from @file{configure.ac}, while
1573 @command{automake} is in charge of creating @file{Makefile.in}s from
1574 @file{Makefile.am}s and @file{configure.ac}. This should at least
1575 direct you to the right manual when seeking answers.
1578 @node amhello's configure.ac Setup Explained
1579 @subsection @code{amhello}'s @file{configure.ac} Setup Explained
1581 @cindex @file{configure.ac}, Hello World
1583 Let us begin with the contents of @file{configure.ac}.
1586 AC_INIT([amhello], [1.0], [@value{PACKAGE_BUGREPORT}])
1587 AM_INIT_AUTOMAKE([-Wall -Werror foreign])
1589 AC_CONFIG_HEADERS([config.h])
1597 This file is read by both @command{autoconf} (to create
1598 @file{configure}) and @command{automake} (to create the various
1599 @file{Makefile.in}s). It contains a series of M4 macros that will be
1600 expanded as shell code to finally form the @file{configure} script.
1601 We will not elaborate on the syntax of this file, because the Autoconf
1602 manual has a whole section about it (@pxref{Writing Autoconf Input, ,
1603 Writing @file{configure.ac}, autoconf, The Autoconf Manual}).
1605 The macros prefixed with @code{AC_} are Autoconf macros, documented
1606 in the Autoconf manual (@pxref{Autoconf Macro Index, , Autoconf Macro
1607 Index, autoconf, The Autoconf Manual}). The macros that start with
1608 @code{AM_} are Automake macros, documented later in this manual
1609 (@pxref{Macro Index}).
1611 The first two lines of @file{configure.ac} initialize Autoconf and
1612 Automake. @code{AC_INIT} takes in as parameters the name of the package,
1613 its version number, and a contact address for bug-reports about the
1614 package (this address is output at the end of @code{./configure
1615 --help}, for instance). When adapting this setup to your own package,
1616 by all means please do not blindly copy Automake's address: use the
1617 mailing list of your package, or your own mail address.
1623 The argument to @code{AM_INIT_AUTOMAKE} is a list of options for
1624 @command{automake} (@pxref{Options}). @option{-Wall} and
1625 @option{-Werror} ask @command{automake} to turn on all warnings and
1626 report them as errors. We are speaking of @strong{Automake} warnings
1627 here, such as dubious instructions in @file{Makefile.am}. This has
1628 absolutely nothing to do with how the compiler will be called, even
1629 though it may support options with similar names. Using @option{-Wall
1630 -Werror} is a safe setting when starting to work on a package: you do
1631 not want to miss any issues. Later you may decide to relax things a
1632 bit. The @option{foreign} option tells Automake that this package
1633 will not follow the GNU Standards. GNU packages should always
1634 distribute additional files such as @file{ChangeLog}, @file{AUTHORS},
1635 etc. We do not want @command{automake} to complain about these
1636 missing files in our small example.
1638 The @code{AC_PROG_CC} line causes the @command{configure} script to
1639 search for a C compiler and define the variable @code{CC} with its
1640 name. The @file{src/Makefile.in} file generated by Automake uses the
1641 variable @code{CC} to build @file{hello}, so when @command{configure}
1642 creates @file{src/Makefile} from @file{src/Makefile.in}, it will define
1643 @code{CC} with the value it has found. If Automake is asked to create
1644 a @file{Makefile.in} that uses @code{CC} but @file{configure.ac} does
1645 not define it, it will suggest you add a call to @code{AC_PROG_CC}.
1647 The @code{AC_CONFIG_HEADERS([config.h])} invocation causes the
1648 @command{configure} script to create a @file{config.h} file gathering
1649 @samp{#define}s defined by other macros in @file{configure.ac}. In our
1650 case, the @code{AC_INIT} macro already defined a few of them. Here
1651 is an excerpt of @file{config.h} after @command{configure} has run:
1655 /* Define to the address where bug reports for this package should be sent. */
1656 #define PACKAGE_BUGREPORT "@value{PACKAGE_BUGREPORT}"
1658 /* Define to the full name and version of this package. */
1659 #define PACKAGE_STRING "amhello 1.0"
1663 As you probably noticed, @file{src/main.c} includes @file{config.h} so
1664 it can use @code{PACKAGE_STRING}. In a real-world project,
1665 @file{config.h} can grow really big, with one @samp{#define} per
1666 feature probed on the system.
1668 The @code{AC_CONFIG_FILES} macro declares the list of files that
1669 @command{configure} should create from their @file{*.in} templates.
1670 Automake also scans this list to find the @file{Makefile.am} files it must
1671 process. (This is important to remember: when adding a new directory
1672 to your project, you should add its @file{Makefile} to this list,
1673 otherwise Automake will never process the new @file{Makefile.am} you
1674 wrote in that directory.)
1676 Finally, the @code{AC_OUTPUT} line is a closing command that actually
1677 produces the part of the script in charge of creating the files
1678 registered with @code{AC_CONFIG_HEADERS} and @code{AC_CONFIG_FILES}.
1680 @cindex @command{autoscan}
1682 When starting a new project, we suggest you start with such a simple
1683 @file{configure.ac}, and gradually add the other tests it requires.
1684 The command @command{autoscan} can also suggest a few of the tests
1685 your package may need (@pxref{autoscan Invocation, , Using
1686 @command{autoscan} to Create @file{configure.ac}, autoconf, The
1690 @node amhello's Makefile.am Setup Explained
1691 @subsection @code{amhello}'s @file{Makefile.am} Setup Explained
1693 @cindex @file{Makefile.am}, Hello World
1695 We now turn to @file{src/Makefile.am}. This file contains
1696 Automake instructions to build and install @file{hello}.
1699 bin_PROGRAMS = hello
1700 hello_SOURCES = main.c
1703 A @file{Makefile.am} has the same syntax as an ordinary
1704 @file{Makefile}. When @command{automake} processes a
1705 @file{Makefile.am} it copies the entire file into the output
1706 @file{Makefile.in} (that will be later turned into @file{Makefile} by
1707 @command{configure}) but will react to certain variable definitions
1708 by generating some build rules and other variables.
1709 Often @file{Makefile.am}s contain only a list of variable definitions as
1710 above, but they can also contain other variable and rule definitions that
1711 @command{automake} will pass along without interpretation.
1713 Variables that end with @code{_PROGRAMS} are special variables
1714 that list programs that the resulting @file{Makefile} should build.
1715 In Automake speak, this @code{_PROGRAMS} suffix is called a
1716 @dfn{primary}; Automake recognizes other primaries such as
1717 @code{_SCRIPTS}, @code{_DATA}, @code{_LIBRARIES}, etc.@: corresponding
1718 to different types of files.
1720 The @samp{bin} part of the @code{bin_PROGRAMS} tells
1721 @command{automake} that the resulting programs should be installed in
1722 @var{bindir}. Recall that the GNU Build System uses a set of variables
1723 to denote destination directories and allow users to customize these
1724 locations (@pxref{Standard Directory Variables}). Any such directory
1725 variable can be put in front of a primary (omitting the @code{dir}
1726 suffix) to tell @command{automake} where to install the listed files.
1728 Programs need to be built from source files, so for each program
1729 @code{@var{prog}} listed in a @code{@w{_PROGRAMS}} variable,
1730 @command{automake} will look for another variable named
1731 @code{@var{prog}_SOURCES} listing its source files. There may be more
1732 than one source file: they will all be compiled and linked together.
1734 Automake also knows that source files need to be distributed when
1735 creating a tarball (unlike built programs). So a side-effect of this
1736 @code{hello_SOURCES} declaration is that @file{main.c} will be
1737 part of the tarball created by @code{make dist}.
1739 Finally here are some explanations regarding the top-level
1744 dist_doc_DATA = README
1747 @code{SUBDIRS} is a special variable listing all directories that
1748 @command{make} should recurse into before processing the current
1749 directory. So this line is responsible for @command{make} building
1750 @file{src/hello} even though we run it from the top-level. This line
1751 also causes @code{make install} to install @file{src/hello} before
1752 installing @file{README} (not that this order matters).
1754 The line @code{dist_doc_DATA = README} causes @file{README} to be
1755 distributed and installed in @var{docdir}. Files listed with the
1756 @code{_DATA} primary are not automatically part of the tarball built
1757 with @code{make dist}, so we add the @code{dist_} prefix so they get
1758 distributed. However, for @file{README} it would not have been
1759 necessary: @command{automake} automatically distributes any
1760 @file{README} file it encounters (the list of other files
1761 automatically distributed is presented by @code{automake --help}).
1762 The only important effect of this second line is therefore to install
1763 @file{README} during @code{make install}.
1765 One thing not covered in this example is accessing the installation
1766 directory values (@pxref{Standard Directory Variables}) from your
1767 program code, that is, converting them into defined macros. For this,
1768 @pxref{Defining Directories,,, autoconf, The Autoconf Manual}.
1772 @chapter General ideas
1774 The following sections cover a few basic ideas that will help you
1775 understand how Automake works.
1778 * General Operation:: General operation of Automake
1779 * Strictness:: Standards conformance checking
1780 * Uniform:: The Uniform Naming Scheme
1781 * Length Limitations:: Staying below the command line length limit
1782 * Canonicalization:: How derived variables are named
1783 * User Variables:: Variables reserved for the user
1784 * Auxiliary Programs:: Programs automake might require
1788 @node General Operation
1789 @section General Operation
1791 Automake works by reading a @file{Makefile.am} and generating a
1792 @file{Makefile.in}. Certain variables and rules defined in the
1793 @file{Makefile.am} instruct Automake to generate more specialized code;
1794 for instance, a @code{bin_PROGRAMS} variable definition will cause rules
1795 for compiling and linking programs to be generated.
1797 @cindex Non-standard targets
1798 @cindex @code{git-dist}, non-standard example
1801 The variable definitions and rules in the @file{Makefile.am} are
1802 copied mostly verbatim into the generated file, with all variable
1803 definitions preceding all rules. This allows you to add almost
1804 arbitrary code into the generated @file{Makefile.in}. For instance,
1805 the Automake distribution includes a non-standard rule for the
1806 @code{git-dist} target, which the Automake maintainer uses to make
1807 distributions from the source control system.
1809 @cindex GNU make extensions
1811 Note that most GNU make extensions are not recognized by Automake. Using
1812 such extensions in a @file{Makefile.am} will lead to errors or confusing
1815 @cindex Append operator
1817 A special exception is that the GNU make append operator, @samp{+=}, is
1818 supported. This operator appends its right hand argument to the variable
1819 specified on the left. Automake will translate the operator into
1820 an ordinary @samp{=} operator; @samp{+=} will thus work with any make program.
1822 Automake tries to keep comments grouped with any adjoining rules or
1823 variable definitions.
1825 @cindex Limitations of automake parser
1826 @cindex Automake parser, limitations of
1827 @cindex indentation in Makefile.am
1828 Generally, Automake is not particularly smart in the parsing of unusual
1829 Makefile constructs, so you're advised to avoid fancy constructs or
1830 ``creative'' use of whitespaces.
1831 @c Keep this in sync with doc-parsing-buglets-tabs.sh
1832 For example, @key{TAB} characters cannot be used between a target name
1833 and the following ``@code{:}'' character, and variable assignments
1834 shouldn't be indented with @key{TAB} characters.
1835 @c Keep this in sync with doc-parsing-buglets-colneq-subst.sh
1836 Also, using more complex macro in target names can cause trouble:
1839 % @kbd{cat Makefile.am}
1842 Makefile.am:1: bad characters in variable name '$(FOO'
1843 Makefile.am:1: ':='-style assignments are not portable
1846 @cindex Make targets, overriding
1847 @cindex Make rules, overriding
1848 @cindex Overriding make rules
1849 @cindex Overriding make targets
1851 A rule defined in @file{Makefile.am} generally overrides any such
1852 rule of a similar name that would be automatically generated by
1853 @command{automake}. Although this is a supported feature, it is generally
1854 best to avoid making use of it, as sometimes the generated rules are
1857 @cindex Variables, overriding
1858 @cindex Overriding make variables
1860 Similarly, a variable defined in @file{Makefile.am} or
1861 @code{AC_SUBST}ed from @file{configure.ac} will override any
1862 definition of the variable that @command{automake} would ordinarily
1863 create. This feature is more often useful than the ability to
1864 override a rule. Be warned that many of the variables generated by
1865 @command{automake} are considered to be for internal use only, and their
1866 names might change in future releases.
1868 @cindex Recursive operation of Automake
1869 @cindex Automake, recursive operation
1870 @cindex Example of recursive operation
1872 When examining a variable definition, Automake will recursively examine
1873 variables referenced in the definition. For example, if Automake is
1874 looking at the content of @code{foo_SOURCES} in this snippet
1876 @c Keep in sync with interp.sh
1879 foo_SOURCES = c.c $(xs)
1882 it would use the files @file{a.c}, @file{b.c}, and @file{c.c} as the
1883 contents of @code{foo_SOURCES}.
1885 @cindex @code{##} (special Automake comment)
1886 @cindex Special Automake comment
1887 @cindex Comment, special to Automake
1889 Automake also allows a form of comment that is @emph{not} copied into
1890 the output; all lines beginning with @samp{##} (leading spaces allowed)
1891 are completely ignored by Automake.
1893 It is customary to make the first line of @file{Makefile.am} read:
1895 @cindex Makefile.am, first line
1896 @cindex First line of Makefile.am
1899 ## Process this file with automake to produce Makefile.in
1902 @c FIXME discuss putting a copyright into Makefile.am here? I would but
1903 @c I don't know quite what to say.
1905 @c FIXME document customary ordering of Makefile.am here!
1911 @cindex Non-GNU packages
1913 While Automake is intended to be used by maintainers of GNU packages, it
1914 does make some effort to accommodate those who wish to use it, but do
1915 not want to use all the GNU conventions.
1917 @cindex Strictness, defined
1918 @cindex Strictness, @option{foreign}
1919 @cindex @option{foreign} strictness
1920 @cindex Strictness, @option{gnu}
1921 @cindex @option{gnu} strictness
1922 @cindex Strictness, @option{gnits}
1923 @cindex @option{gnits} strictness
1925 To this end, Automake supports three levels of @dfn{strictness}---the
1926 strictness indicating how stringently Automake should check standards
1929 The valid strictness levels are:
1933 Automake will check for only those things that are absolutely
1934 required for proper operations. For instance, whereas GNU standards
1935 dictate the existence of a @file{NEWS} file, it will not be required in
1936 this mode. This strictness will also turn off some warnings by default
1937 (among them, portability warnings).
1938 The name comes from the fact that Automake is intended to be
1939 used for GNU programs; these relaxed rules are not the standard mode of
1943 Automake will check---as much as possible---for compliance to the GNU
1944 standards for packages. This is the default.
1947 Automake will check for compliance to the as-yet-unwritten @dfn{Gnits
1948 standards}. These are based on the GNU standards, but are even more
1949 detailed. Unless you are a Gnits standards contributor, it is
1950 recommended that you avoid this option until such time as the Gnits
1951 standard is actually published (which may never happen).
1954 @xref{Gnits}, for more information on the precise implications of the
1957 Automake also has a special (and @emph{today deprecated}) ``cygnus'' mode
1958 that is similar to strictness but handled differently. This mode is
1959 useful for packages that are put into a ``Cygnus'' style tree (e.g., older
1960 versions of the GCC and gdb trees). @xref{Cygnus}, for more information
1961 on this mode. Please note that this mode @emph{is deprecated and will be
1962 removed in the next major Automake release (1.13)}; you must avoid its use
1963 in new packages, and should stop using it in existing packages as well.
1967 @section The Uniform Naming Scheme
1969 @cindex Uniform naming scheme
1971 Automake variables generally follow a @dfn{uniform naming scheme} that
1972 makes it easy to decide how programs (and other derived objects) are
1973 built, and how they are installed. This scheme also supports
1974 @command{configure} time determination of what should be built.
1976 @cindex @code{_PROGRAMS} primary variable
1977 @cindex @code{PROGRAMS} primary variable
1978 @cindex Primary variable, @code{PROGRAMS}
1979 @cindex Primary variable, defined
1982 At @command{make} time, certain variables are used to determine which
1983 objects are to be built. The variable names are made of several pieces
1984 that are concatenated together.
1986 The piece that tells @command{automake} what is being built is commonly called
1987 the @dfn{primary}. For instance, the primary @code{PROGRAMS} holds a
1988 list of programs that are to be compiled and linked.
1991 @cindex @code{pkgdatadir}, defined
1992 @cindex @code{pkgincludedir}, defined
1993 @cindex @code{pkglibdir}, defined
1994 @cindex @code{pkglibexecdir}, defined
1997 @vindex pkgincludedir
1999 @vindex pkglibexecdir
2001 @cindex @code{PACKAGE}, directory
2002 A different set of names is used to decide where the built objects
2003 should be installed. These names are prefixes to the primary, and they
2004 indicate which standard directory should be used as the installation
2005 directory. The standard directory names are given in the GNU standards
2006 (@pxref{Directory Variables, , , standards, The GNU Coding Standards}).
2007 Automake extends this list with @code{pkgdatadir}, @code{pkgincludedir},
2008 @code{pkglibdir}, and @code{pkglibexecdir}; these are the same as the
2009 non-@samp{pkg} versions, but with @samp{$(PACKAGE)} appended. For instance,
2010 @code{pkglibdir} is defined as @samp{$(libdir)/$(PACKAGE)}.
2012 @cindex @code{EXTRA_}, prepending
2013 For each primary, there is one additional variable named by prepending
2014 @samp{EXTRA_} to the primary name. This variable is used to list
2015 objects that may or may not be built, depending on what
2016 @command{configure} decides. This variable is required because Automake
2017 must statically know the entire list of objects that may be built in
2018 order to generate a @file{Makefile.in} that will work in all cases.
2020 @cindex @code{EXTRA_PROGRAMS}, defined
2021 @cindex Example, @code{EXTRA_PROGRAMS}
2022 @cindex @command{cpio} example
2024 For instance, @command{cpio} decides at configure time which programs
2025 should be built. Some of the programs are installed in @code{bindir},
2026 and some are installed in @code{sbindir}:
2029 EXTRA_PROGRAMS = mt rmt
2030 bin_PROGRAMS = cpio pax
2031 sbin_PROGRAMS = $(MORE_PROGRAMS)
2034 Defining a primary without a prefix as a variable, e.g.,
2035 @samp{PROGRAMS}, is an error.
2037 Note that the common @samp{dir} suffix is left off when constructing the
2038 variable names; thus one writes @samp{bin_PROGRAMS} and not
2039 @samp{bindir_PROGRAMS}.
2041 Not every sort of object can be installed in every directory. Automake
2042 will flag those attempts it finds in error (but see below how to override
2043 the check if you really need to).
2044 Automake will also diagnose obvious misspellings in directory names.
2046 @cindex Extending list of installation directories
2047 @cindex Installation directories, extending list
2049 Sometimes the standard directories---even as augmented by
2050 Automake---are not enough. In particular it is sometimes useful, for
2051 clarity, to install objects in a subdirectory of some predefined
2052 directory. To this end, Automake allows you to extend the list of
2053 possible installation directories. A given prefix (e.g., @samp{zar})
2054 is valid if a variable of the same name with @samp{dir} appended is
2055 defined (e.g., @samp{zardir}).
2057 For instance, the following snippet will install @file{file.xml} into
2058 @samp{$(datadir)/xml}.
2060 @c Keep in sync with primary-prefix-couples-documented-valid.sh
2062 xmldir = $(datadir)/xml
2066 This feature can also be used to override the sanity checks Automake
2067 performs to diagnose suspicious directory/primary couples (in the
2068 unlikely case these checks are undesirable, and you really know what
2069 you're doing). For example, Automake would error out on this input:
2071 @c Should be tested in primary-prefix-invalid-couples.sh
2073 # Forbidden directory combinations, automake will error out on this.
2074 pkglib_PROGRAMS = foo
2075 doc_LIBRARIES = libquux.a
2079 but it will succeed with this:
2081 @c Keep in sync with primary-prefix-couples-documented-valid.sh
2083 # Work around forbidden directory combinations. Do not use this
2084 # without a very good reason!
2085 my_execbindir = $(pkglibdir)
2086 my_doclibdir = $(docdir)
2087 my_execbin_PROGRAMS = foo
2088 my_doclib_LIBRARIES = libquux.a
2091 The @samp{exec} substring of the @samp{my_execbindir} variable lets
2092 the files be installed at the right time (@pxref{The Two Parts of
2095 @cindex @samp{noinst_} primary prefix, definition
2098 The special prefix @samp{noinst_} indicates that the objects in question
2099 should be built but not installed at all. This is usually used for
2100 objects required to build the rest of your package, for instance static
2101 libraries (@pxref{A Library}), or helper scripts.
2103 @cindex @samp{check_} primary prefix, definition
2106 The special prefix @samp{check_} indicates that the objects in question
2107 should not be built until the @samp{make check} command is run. Those
2108 objects are not installed either.
2110 The current primary names are @samp{PROGRAMS}, @samp{LIBRARIES},
2111 @samp{LTLIBRARIES}, @samp{LISP}, @samp{PYTHON}, @samp{JAVA},
2112 @samp{SCRIPTS}, @samp{DATA}, @samp{HEADERS}, @samp{MANS}, and
2126 Some primaries also allow additional prefixes that control other
2127 aspects of @command{automake}'s behavior. The currently defined prefixes
2128 are @samp{dist_}, @samp{nodist_}, @samp{nobase_}, and @samp{notrans_}.
2129 These prefixes are explained later (@pxref{Program and Library Variables})
2130 (@pxref{Man Pages}).
2133 @node Length Limitations
2134 @section Staying below the command line length limit
2136 @cindex command line length limit
2139 Traditionally, most unix-like systems have a length limitation for the
2140 command line arguments and environment contents when creating new
2141 processes (see for example
2142 @uref{http://www.in-ulm.de/@/~mascheck/@/various/@/argmax/} for an
2143 overview on this issue),
2144 which of course also applies to commands spawned by @command{make}.
2145 POSIX requires this limit to be at least 4096 bytes, and most modern
2146 systems have quite high limits (or are unlimited).
2148 In order to create portable Makefiles that do not trip over these
2149 limits, it is necessary to keep the length of file lists bounded.
2150 Unfortunately, it is not possible to do so fully transparently within
2151 Automake, so your help may be needed. Typically, you can split long
2152 file lists manually and use different installation directory names for
2153 each list. For example,
2156 data_DATA = file1 @dots{} file@var{N} file@var{N+1} @dots{} file@var{2N}
2160 may also be written as
2162 @c Keep in sync with primary-prefix-couples-documented-valid.sh
2164 data_DATA = file1 @dots{} file@var{N}
2165 data2dir = $(datadir)
2166 data2_DATA = file@var{N+1} @dots{} file@var{2N}
2170 and will cause Automake to treat the two lists separately during
2171 @code{make install}. See @ref{The Two Parts of Install} for choosing
2172 directory names that will keep the ordering of the two parts of
2173 installation Note that @code{make dist} may still only work on a host
2174 with a higher length limit in this example.
2176 Automake itself employs a couple of strategies to avoid long command
2177 lines. For example, when @samp{$@{srcdir@}/} is prepended to file
2178 names, as can happen with above @code{$(data_DATA)} lists, it limits
2179 the amount of arguments passed to external commands.
2181 Unfortunately, some system's @command{make} commands may prepend
2182 @code{VPATH} prefixes like @samp{$@{srcdir@}/} to file names from the
2183 source tree automatically (@pxref{Automatic Rule Rewriting, , Automatic
2184 Rule Rewriting, autoconf, The Autoconf Manual}). In this case, the user
2185 may have to switch to use GNU Make, or refrain from using VPATH builds,
2186 in order to stay below the length limit.
2188 For libraries and programs built from many sources, convenience archives
2189 may be used as intermediates in order to limit the object list length
2190 (@pxref{Libtool Convenience Libraries}).
2193 @node Canonicalization
2194 @section How derived variables are named
2196 @cindex canonicalizing Automake variables
2198 Sometimes a Makefile variable name is derived from some text the
2199 maintainer supplies. For instance, a program name listed in
2200 @samp{_PROGRAMS} is rewritten into the name of a @samp{_SOURCES}
2201 variable. In cases like this, Automake canonicalizes the text, so that
2202 program names and the like do not have to follow Makefile variable naming
2203 rules. All characters in the name except for letters, numbers, the
2204 strudel (@@), and the underscore are turned into underscores when making
2205 variable references.
2207 For example, if your program is named @file{sniff-glue}, the derived
2208 variable name would be @samp{sniff_glue_SOURCES}, not
2209 @samp{sniff-glue_SOURCES}. Similarly the sources for a library named
2210 @file{libmumble++.a} should be listed in the
2211 @samp{libmumble___a_SOURCES} variable.
2213 The strudel is an addition, to make the use of Autoconf substitutions in
2214 variable names less obfuscating.
2217 @node User Variables
2218 @section Variables reserved for the user
2220 @cindex variables, reserved for the user
2221 @cindex user variables
2223 Some @file{Makefile} variables are reserved by the GNU Coding Standards
2224 for the use of the ``user''---the person building the package. For
2225 instance, @code{CFLAGS} is one such variable.
2227 Sometimes package developers are tempted to set user variables such as
2228 @code{CFLAGS} because it appears to make their job easier. However,
2229 the package itself should never set a user variable, particularly not
2230 to include switches that are required for proper compilation of the
2231 package. Since these variables are documented as being for the
2232 package builder, that person rightfully expects to be able to override
2233 any of these variables at build time.
2235 To get around this problem, Automake introduces an automake-specific
2236 shadow variable for each user flag variable. (Shadow variables are
2237 not introduced for variables like @code{CC}, where they would make no
2238 sense.) The shadow variable is named by prepending @samp{AM_} to the
2239 user variable's name. For instance, the shadow variable for
2240 @code{YFLAGS} is @code{AM_YFLAGS}. The package maintainer---that is,
2241 the author(s) of the @file{Makefile.am} and @file{configure.ac}
2242 files---may adjust these shadow variables however necessary.
2244 @xref{Flag Variables Ordering}, for more discussion about these
2245 variables and how they interact with per-target variables.
2247 @node Auxiliary Programs
2248 @section Programs automake might require
2250 @cindex Programs, auxiliary
2251 @cindex Auxiliary programs
2253 Automake sometimes requires helper programs so that the generated
2254 @file{Makefile} can do its work properly. There are a fairly large
2255 number of them, and we list them here.
2257 Although all of these files are distributed and installed with
2258 Automake, a couple of them are maintained separately. The Automake
2259 copies are updated before each release, but we mention the original
2260 source in case you need more recent versions.
2264 This is a wrapper primarily for the Microsoft lib archiver, to make
2268 This is a wrapper for compilers that do not accept options @option{-c}
2269 and @option{-o} at the same time. It is only used when absolutely
2270 required. Such compilers are rare, with the Microsoft C/C++ Compiler
2271 as the most notable exception. This wrapper also makes the following
2272 common options available for that compiler, while performing file name
2273 translation where needed: @option{-I}, @option{-L}, @option{-l},
2274 @option{-Wl,} and @option{-Xlinker}.
2278 These two programs compute the canonical triplets for the given build,
2279 host, or target architecture. These programs are updated regularly to
2280 support new architectures and fix probes broken by changes in new
2281 kernel versions. Each new release of Automake comes with up-to-date
2282 copies of these programs. If your copy of Automake is getting old,
2283 you are encouraged to fetch the latest versions of these files from
2284 @url{http://savannah.gnu.org/git/?group=config} before making a
2288 This program understands how to run a compiler so that it will
2289 generate not only the desired output but also dependency information
2290 that is then used by the automatic dependency tracking feature
2291 (@pxref{Dependencies}).
2294 This program is used to byte-compile Emacs Lisp code.
2297 This is a replacement for the @command{install} program that works on
2298 platforms where @command{install} is unavailable or unusable.
2301 This script is used to generate a @file{version.texi} file. It examines
2302 a file and prints some date information about it.
2305 This wraps a number of programs that are typically only required by
2306 maintainers. If the program in question doesn't exist,
2307 @command{missing} prints an informative warning and attempts to fix
2308 things so that the build can continue.
2311 This script used to be a wrapper around @samp{mkdir -p}, which is not
2312 portable. Now we prefer to use @samp{install-sh -d} when @command{configure}
2313 finds that @samp{mkdir -p} does not work, this makes one less script to
2316 For backward compatibility @file{mkinstalldirs} is still used and
2317 distributed when @command{automake} finds it in a package. But it is no
2318 longer installed automatically, and it should be safe to remove it.
2321 This is used to byte-compile Python scripts.
2324 This implements the default test driver offered by the parallel
2328 Not a program, this file is required for @samp{make dvi}, @samp{make
2329 ps} and @samp{make pdf} to work when Texinfo sources are in the
2330 package. The latest version can be downloaded from
2331 @url{http://www.gnu.org/software/texinfo/}.
2334 This program wraps @command{lex} and @command{yacc} to rename their
2335 output files. It also ensures that, for instance, multiple
2336 @command{yacc} instances can be invoked in a single directory in
2343 @chapter Some example packages
2345 This section contains two small examples.
2347 The first example (@pxref{Complete}) assumes you have an existing
2348 project already using Autoconf, with handcrafted @file{Makefile}s, and
2349 that you want to convert it to using Automake. If you are discovering
2350 both tools, it is probably better that you look at the Hello World
2351 example presented earlier (@pxref{Hello World}).
2353 The second example (@pxref{true}) shows how two programs can be built
2354 from the same file, using different compilation parameters. It
2355 contains some technical digressions that are probably best skipped on
2359 * Complete:: A simple example, start to finish
2360 * true:: Building true and false
2365 @section A simple example, start to finish
2367 @cindex Complete example
2369 Let's suppose you just finished writing @code{zardoz}, a program to make
2370 your head float from vortex to vortex. You've been using Autoconf to
2371 provide a portability framework, but your @file{Makefile.in}s have been
2372 ad-hoc. You want to make them bulletproof, so you turn to Automake.
2374 @cindex @code{AM_INIT_AUTOMAKE}, example use
2376 The first step is to update your @file{configure.ac} to include the
2377 commands that @command{automake} needs. The way to do this is to add an
2378 @code{AM_INIT_AUTOMAKE} call just after @code{AC_INIT}:
2381 AC_INIT([zardoz], [1.0])
2386 Since your program doesn't have any complicating factors (e.g., it
2387 doesn't use @code{gettext}, it doesn't want to build a shared library),
2388 you're done with this part. That was easy!
2390 @cindex @command{aclocal} program, introduction
2391 @cindex @file{aclocal.m4}, preexisting
2392 @cindex @file{acinclude.m4}, defined
2394 Now you must regenerate @file{configure}. But to do that, you'll need
2395 to tell @command{autoconf} how to find the new macro you've used. The
2396 easiest way to do this is to use the @command{aclocal} program to
2397 generate your @file{aclocal.m4} for you. But wait@dots{} maybe you
2398 already have an @file{aclocal.m4}, because you had to write some hairy
2399 macros for your program. The @command{aclocal} program lets you put
2400 your own macros into @file{acinclude.m4}, so simply rename and then
2404 mv aclocal.m4 acinclude.m4
2409 @cindex @command{zardoz} example
2411 Now it is time to write your @file{Makefile.am} for @code{zardoz}.
2412 Since @code{zardoz} is a user program, you want to install it where the
2413 rest of the user programs go: @code{bindir}. Additionally,
2414 @code{zardoz} has some Texinfo documentation. Your @file{configure.ac}
2415 script uses @code{AC_REPLACE_FUNCS}, so you need to link against
2416 @samp{$(LIBOBJS)}. So here's what you'd write:
2419 bin_PROGRAMS = zardoz
2420 zardoz_SOURCES = main.c head.c float.c vortex9.c gun.c
2421 zardoz_LDADD = $(LIBOBJS)
2423 info_TEXINFOS = zardoz.texi
2426 Now you can run @samp{automake --add-missing} to generate your
2427 @file{Makefile.in} and grab any auxiliary files you might need, and
2432 @section Building true and false
2434 @cindex Example, @command{false} and @command{true}
2435 @cindex @command{false} Example
2436 @cindex @command{true} Example
2438 Here is another, trickier example. It shows how to generate two
2439 programs (@code{true} and @code{false}) from the same source file
2440 (@file{true.c}). The difficult part is that each compilation of
2441 @file{true.c} requires different @code{cpp} flags.
2444 bin_PROGRAMS = true false
2446 false_LDADD = false.o
2449 $(COMPILE) -DEXIT_CODE=0 -c true.c
2452 $(COMPILE) -DEXIT_CODE=1 -o false.o -c true.c
2455 Note that there is no @code{true_SOURCES} definition. Automake will
2456 implicitly assume that there is a source file named @file{true.c}
2457 (@pxref{Default _SOURCES}), and
2458 define rules to compile @file{true.o} and link @file{true}. The
2459 @samp{true.o: true.c} rule supplied by the above @file{Makefile.am},
2460 will override the Automake generated rule to build @file{true.o}.
2462 @code{false_SOURCES} is defined to be empty---that way no implicit value
2463 is substituted. Because we have not listed the source of
2464 @file{false}, we have to tell Automake how to link the program. This is
2465 the purpose of the @code{false_LDADD} line. A @code{false_DEPENDENCIES}
2466 variable, holding the dependencies of the @file{false} target will be
2467 automatically generated by Automake from the content of
2470 The above rules won't work if your compiler doesn't accept both
2471 @option{-c} and @option{-o}. The simplest fix for this is to introduce a
2472 bogus dependency (to avoid problems with a parallel @command{make}):
2475 true.o: true.c false.o
2476 $(COMPILE) -DEXIT_CODE=0 -c true.c
2479 $(COMPILE) -DEXIT_CODE=1 -c true.c && mv true.o false.o
2482 As it turns out, there is also a much easier way to do this same task.
2483 Some of the above technique is useful enough that we've kept the
2484 example in the manual. However if you were to build @code{true} and
2485 @code{false} in real life, you would probably use per-program
2486 compilation flags, like so:
2488 @c Keep in sync with specflg7.sh and specflg8.sh
2490 bin_PROGRAMS = false true
2492 false_SOURCES = true.c
2493 false_CPPFLAGS = -DEXIT_CODE=1
2495 true_SOURCES = true.c
2496 true_CPPFLAGS = -DEXIT_CODE=0
2499 In this case Automake will cause @file{true.c} to be compiled twice,
2500 with different flags. In this instance, the names of the object files
2501 would be chosen by automake; they would be @file{false-true.o} and
2502 @file{true-true.o}. (The name of the object files rarely matters.)
2504 @node automake Invocation
2505 @chapter Creating a @file{Makefile.in}
2506 @c This node used to be named "Invoking automake". This @anchor
2507 @c allows old links to still work.
2508 @anchor{Invoking automake}
2510 @cindex Multiple @file{configure.ac} files
2511 @cindex Invoking @command{automake}
2512 @cindex @command{automake}, invoking
2513 @cindex Invocation of @command{automake}
2514 @cindex @command{automake}, invocation
2516 To create all the @file{Makefile.in}s for a package, run the
2517 @command{automake} program in the top level directory, with no
2518 arguments. @command{automake} will automatically find each
2519 appropriate @file{Makefile.am} (by scanning @file{configure.ac};
2520 @pxref{configure}) and generate the corresponding @file{Makefile.in}.
2521 Note that @command{automake} has a rather simplistic view of what
2522 constitutes a package; it assumes that a package has only one
2523 @file{configure.ac}, at the top. If your package has multiple
2524 @file{configure.ac}s, then you must run @command{automake} in each
2525 directory holding a @file{configure.ac}. (Alternatively, you may rely
2526 on Autoconf's @command{autoreconf}, which is able to recurse your
2527 package tree and run @command{automake} where appropriate.)
2529 You can optionally give @command{automake} an argument; @file{.am} is
2530 appended to the argument and the result is used as the name of the
2531 input file. This feature is generally only used to automatically
2532 rebuild an out-of-date @file{Makefile.in}. Note that
2533 @command{automake} must always be run from the topmost directory of a
2534 project, even if being used to regenerate the @file{Makefile.in} in
2535 some subdirectory. This is necessary because @command{automake} must
2536 scan @file{configure.ac}, and because @command{automake} uses the
2537 knowledge that a @file{Makefile.in} is in a subdirectory to change its
2538 behavior in some cases.
2541 Automake will run @command{autoconf} to scan @file{configure.ac} and
2542 its dependencies (i.e., @file{aclocal.m4} and any included file),
2543 therefore @command{autoconf} must be in your @env{PATH}. If there is
2544 an @env{AUTOCONF} variable in your environment it will be used
2545 instead of @command{autoconf}, this allows you to select a particular
2546 version of Autoconf. By the way, don't misunderstand this paragraph:
2547 @command{automake} runs @command{autoconf} to @strong{scan} your
2548 @file{configure.ac}, this won't build @file{configure} and you still
2549 have to run @command{autoconf} yourself for this purpose.
2551 @cindex @command{automake} options
2552 @cindex Options, @command{automake}
2553 @cindex Strictness, command line
2555 @command{automake} accepts the following options:
2557 @cindex Extra files distributed with Automake
2558 @cindex Files distributed with Automake
2559 @cindex @file{config.guess}
2563 @itemx --add-missing
2565 @opindex --add-missing
2566 Automake requires certain common files to exist in certain situations;
2567 for instance, @file{config.guess} is required if @file{configure.ac} invokes
2568 @code{AC_CANONICAL_HOST}. Automake is distributed with several of these
2569 files (@pxref{Auxiliary Programs}); this option will cause the missing
2570 ones to be automatically added to the package, whenever possible. In
2571 general if Automake tells you a file is missing, try using this option.
2572 By default Automake tries to make a symbolic link pointing to its own
2573 copy of the missing file; this can be changed with @option{--copy}.
2575 Many of the potentially-missing files are common scripts whose
2576 location may be specified via the @code{AC_CONFIG_AUX_DIR} macro.
2577 Therefore, @code{AC_CONFIG_AUX_DIR}'s setting affects whether a
2578 file is considered missing, and where the missing file is added
2581 In some strictness modes, additional files are installed, see @ref{Gnits}
2582 for more information.
2584 @item --libdir=@var{dir}
2586 Look for Automake data files in directory @var{dir} instead of in the
2587 installation directory. This is typically used for debugging.
2589 @item --print-libdir
2590 @opindex --print-libdir
2591 Print the path of the installation directory containing Automake-provided
2592 scripts and data files (like e.g., @file{texinfo.texi} and
2599 When used with @option{--add-missing}, causes installed files to be
2600 copied. The default is to make a symbolic link.
2604 Causes the generated @file{Makefile.in}s to follow Cygnus rules, instead
2605 of GNU or Gnits rules. For more information, see @ref{Cygnus}.
2606 Note that @emph{this mode of operation is deprecated, and will be removed}
2607 in the next major Automake release (1.13).
2611 @itemx --force-missing
2612 @opindex --force-missing
2613 When used with @option{--add-missing}, causes standard files to be reinstalled
2614 even if they already exist in the source tree. This involves removing
2615 the file from the source tree before creating the new symlink (or, with
2616 @option{--copy}, copying the new file).
2620 Set the global strictness to @option{foreign}. For more information, see
2625 Set the global strictness to @option{gnits}. For more information, see
2630 Set the global strictness to @option{gnu}. For more information, see
2631 @ref{Gnits}. This is the default strictness.
2635 Print a summary of the command line options and exit.
2638 @itemx --ignore-deps
2640 This disables the dependency tracking feature in generated
2641 @file{Makefile}s; see @ref{Dependencies}.
2643 @item --include-deps
2644 @opindex --include-deps
2645 This enables the dependency tracking feature. This feature is enabled
2646 by default. This option is provided for historical reasons only and
2647 probably should not be used.
2651 Ordinarily @command{automake} creates all @file{Makefile.in}s mentioned in
2652 @file{configure.ac}. This option causes it to only update those
2653 @file{Makefile.in}s that are out of date with respect to one of their
2657 @itemx --output-dir=@var{dir}
2659 @opindex --output-dir
2660 Put the generated @file{Makefile.in} in the directory @var{dir}.
2661 Ordinarily each @file{Makefile.in} is created in the directory of the
2662 corresponding @file{Makefile.am}. This option is deprecated and will be
2663 removed in a future release.
2669 Cause Automake to print information about which files are being read or
2674 Print the version number of Automake and exit.
2677 @itemx --warnings=@var{category}
2680 Output warnings falling in @var{category}. @var{category} can be
2684 warnings related to the GNU Coding Standards
2685 (@pxref{Top, , , standards, The GNU Coding Standards}).
2687 obsolete features or constructions
2689 user redefinitions of Automake rules or variables
2691 portability issues (e.g., use of @command{make} features that are
2692 known to be not portable)
2693 @item extra-portability
2694 extra portability issues related to obscure tools. One example of such
2695 a tool is the Microsoft @command{lib} archiver.
2697 weird syntax, unused variables, typos
2699 unsupported or incomplete features
2703 turn off all the warnings
2705 treat warnings as errors
2708 A category can be turned off by prefixing its name with @samp{no-}. For
2709 instance, @option{-Wno-syntax} will hide the warnings about unused
2712 The categories output by default are @samp{obsolete}, @samp{syntax} and
2713 @samp{unsupported}. Additionally, @samp{gnu} and @samp{portability}
2714 are enabled in @option{--gnu} and @option{--gnits} strictness.
2715 On the other hand, the @option{silent-rules} options (@pxref{Options})
2716 turns off portability warnings about recursive variable expansions.
2718 @c Checked by extra-portability.sh
2719 Turning off @samp{portability} will also turn off @samp{extra-portability},
2720 and similarly turning on @samp{extra-portability} will also turn on
2721 @samp{portability}. However, turning on @samp{portability} or turning
2722 off @samp{extra-portability} will not affect the other category.
2725 The environment variable @env{WARNINGS} can contain a comma separated
2726 list of categories to enable. It will be taken into account before the
2727 command-line switches, this way @option{-Wnone} will also ignore any
2728 warning category enabled by @env{WARNINGS}. This variable is also used
2729 by other tools like @command{autoconf}; unknown categories are ignored
2734 @vindex AUTOMAKE_JOBS
2735 If the environment variable @env{AUTOMAKE_JOBS} contains a positive
2736 number, it is taken as the maximum number of Perl threads to use in
2737 @command{automake} for generating multiple @file{Makefile.in} files
2738 concurrently. This is an experimental feature.
2742 @chapter Scanning @file{configure.ac}, using @command{aclocal}
2744 @cindex @file{configure.ac}, scanning
2745 @cindex Scanning @file{configure.ac}
2746 @cindex Using @command{aclocal}
2747 @cindex @command{aclocal}, using
2749 Automake scans the package's @file{configure.ac} to determine certain
2750 information about the package. Some @command{autoconf} macros are required
2751 and some variables must be defined in @file{configure.ac}. Automake
2752 will also use information from @file{configure.ac} to further tailor its
2755 Automake also supplies some Autoconf macros to make the maintenance
2756 easier. These macros can automatically be put into your
2757 @file{aclocal.m4} using the @command{aclocal} program.
2760 * Requirements:: Configuration requirements
2761 * Optional:: Other things Automake recognizes
2762 * aclocal Invocation:: Auto-generating aclocal.m4
2763 * Macros:: Autoconf macros supplied with Automake
2768 @section Configuration requirements
2770 @cindex Automake requirements
2771 @cindex Requirements of Automake
2773 @acindex AM_INIT_AUTOMAKE
2774 The one real requirement of Automake is that your @file{configure.ac}
2775 call @code{AM_INIT_AUTOMAKE}. This macro does several things that are
2776 required for proper Automake operation (@pxref{Macros}).
2778 Here are the other macros that Automake requires but which are not run
2779 by @code{AM_INIT_AUTOMAKE}:
2782 @item AC_CONFIG_FILES
2784 @acindex AC_CONFIG_FILES
2786 These two macros are usually invoked as follows near the end of
2787 @file{configure.ac}.
2801 Automake uses these to determine which files to create (@pxref{Output, ,
2802 Creating Output Files, autoconf, The Autoconf Manual}). A listed file
2803 is considered to be an Automake generated @file{Makefile} if there
2804 exists a file with the same name and the @file{.am} extension appended.
2805 Typically, @samp{AC_CONFIG_FILES([foo/Makefile])} will cause Automake to
2806 generate @file{foo/Makefile.in} if @file{foo/Makefile.am} exists.
2808 When using @code{AC_CONFIG_FILES} with multiple input files, as in
2811 AC_CONFIG_FILES([Makefile:top.in:Makefile.in:bot.in])
2815 @command{automake} will generate the first @file{.in} input file for
2816 which a @file{.am} file exists. If no such file exists the output
2817 file is not considered to be generated by Automake.
2819 Files created by @code{AC_CONFIG_FILES}, be they Automake
2820 @file{Makefile}s or not, are all removed by @samp{make distclean}.
2821 Their inputs are automatically distributed, unless they
2822 are the output of prior @code{AC_CONFIG_FILES} commands.
2823 Finally, rebuild rules are generated in the Automake @file{Makefile}
2824 existing in the subdirectory of the output file, if there is one, or
2825 in the top-level @file{Makefile} otherwise.
2827 The above machinery (cleaning, distributing, and rebuilding) works
2828 fine if the @code{AC_CONFIG_FILES} specifications contain only
2829 literals. If part of the specification uses shell variables,
2830 @command{automake} will not be able to fulfill this setup, and you will
2831 have to complete the missing bits by hand. For instance, on
2833 @c Keep in sync with output11.sh
2837 AC_CONFIG_FILES([output:$file],, [file=$file])
2841 @command{automake} will output rules to clean @file{output}, and
2842 rebuild it. However the rebuild rule will not depend on @file{input},
2843 and this file will not be distributed either. (You must add
2844 @samp{EXTRA_DIST = input} to your @file{Makefile.am} if @file{input} is a
2849 @c Keep in sync with output11.sh
2854 AC_CONFIG_FILES([$file:input],, [file=$file])
2855 AC_CONFIG_FILES([$file2],, [file2=$file2])
2859 will only cause @file{input} to be distributed. No file will be
2860 cleaned automatically (add @samp{DISTCLEANFILES = output out}
2861 yourself), and no rebuild rule will be output.
2863 Obviously @command{automake} cannot guess what value @samp{$file} is
2864 going to hold later when @file{configure} is run, and it cannot use
2865 the shell variable @samp{$file} in a @file{Makefile}. However, if you
2866 make reference to @samp{$file} as @samp{$@{file@}} (i.e., in a way
2867 that is compatible with @command{make}'s syntax) and furthermore use
2868 @code{AC_SUBST} to ensure that @samp{$@{file@}} is meaningful in a
2869 @file{Makefile}, then @command{automake} will be able to use
2870 @samp{$@{file@}} to generate all of these rules. For instance, here is
2871 how the Automake package itself generates versioned scripts for its
2875 AC_SUBST([APIVERSION], @dots{})
2878 [tests/aclocal-$@{APIVERSION@}:tests/aclocal.in],
2879 [chmod +x tests/aclocal-$@{APIVERSION@}],
2880 [APIVERSION=$APIVERSION])
2882 [tests/automake-$@{APIVERSION@}:tests/automake.in],
2883 [chmod +x tests/automake-$@{APIVERSION@}])
2887 Here cleaning, distributing, and rebuilding are done automatically,
2888 because @samp{$@{APIVERSION@}} is known at @command{make}-time.
2890 Note that you should not use shell variables to declare
2891 @file{Makefile} files for which @command{automake} must create
2892 @file{Makefile.in}. Even @code{AC_SUBST} does not help here, because
2893 @command{automake} needs to know the file name when it runs in order
2894 to check whether @file{Makefile.am} exists. (In the very hairy case
2895 that your setup requires such use of variables, you will have to tell
2896 Automake which @file{Makefile.in}s to generate on the command-line.)
2898 It is possible to let @command{automake} emit conditional rules for
2899 @code{AC_CONFIG_FILES} with the help of @code{AM_COND_IF}
2905 Use literals for @file{Makefile}s, and for other files whenever possible.
2907 Use @samp{$file} (or @samp{$@{file@}} without @samp{AC_SUBST([file])})
2908 for files that @command{automake} should ignore.
2910 Use @samp{$@{file@}} and @samp{AC_SUBST([file])} for files
2911 that @command{automake} should not ignore.
2918 @section Other things Automake recognizes
2920 @cindex Macros Automake recognizes
2921 @cindex Recognized macros by Automake
2923 Every time Automake is run it calls Autoconf to trace
2924 @file{configure.ac}. This way it can recognize the use of certain
2925 macros and tailor the generated @file{Makefile.in} appropriately.
2926 Currently recognized macros and their effects are:
2929 @item AC_CANONICAL_BUILD
2930 @itemx AC_CANONICAL_HOST
2931 @itemx AC_CANONICAL_TARGET
2932 @vindex build_triplet
2933 @vindex host_triplet
2934 @vindex target_triplet
2935 Automake will ensure that @file{config.guess} and @file{config.sub}
2936 exist. Also, the @file{Makefile} variables @code{build_triplet},
2937 @code{host_triplet} and @code{target_triplet} are introduced. See
2938 @ref{Canonicalizing, , Getting the Canonical System Type, autoconf,
2939 The Autoconf Manual}.
2941 @item AC_CONFIG_AUX_DIR
2942 Automake will look for various helper scripts, such as
2943 @file{install-sh}, in the directory named in this macro invocation.
2944 @c This list is accurate relative to version 1.11
2945 (The full list of scripts is:
2947 @file{config.guess},
2956 @file{mkinstalldirs},
2961 Not all scripts are always searched for; some scripts
2962 will only be sought if the generated @file{Makefile.in} requires them.
2964 If @code{AC_CONFIG_AUX_DIR} is not given, the scripts are looked for in
2965 their standard locations. For @file{mdate-sh},
2966 @file{texinfo.tex}, and @file{ylwrap}, the standard location is the
2967 source directory corresponding to the current @file{Makefile.am}. For
2968 the rest, the standard location is the first one of @file{.}, @file{..},
2969 or @file{../..} (relative to the top source directory) that provides any
2970 one of the helper scripts. @xref{Input, , Finding `configure' Input,
2971 autoconf, The Autoconf Manual}.
2973 Required files from @code{AC_CONFIG_AUX_DIR} are automatically
2974 distributed, even if there is no @file{Makefile.am} in this directory.
2976 @item AC_CONFIG_LIBOBJ_DIR
2977 Automake will require the sources file declared with
2978 @code{AC_LIBSOURCE} (see below) in the directory specified by this
2981 @item AC_CONFIG_HEADERS
2982 Automake will generate rules to rebuild these headers from the
2983 corresponding templates (usually, the template for a @file{foo.h}
2984 header being @file{foo.h.in}). Older versions of Automake required
2985 the use of @code{AM_CONFIG_HEADER} (@pxref{Macros}); this is no
2988 As with @code{AC_CONFIG_FILES} (@pxref{Requirements}), parts of the
2989 specification using shell variables will be ignored as far as
2990 cleaning, distributing, and rebuilding is concerned.
2992 @item AC_CONFIG_LINKS
2993 Automake will generate rules to remove @file{configure} generated
2994 links on @samp{make distclean} and to distribute named source files as
2995 part of @samp{make dist}.
2997 As for @code{AC_CONFIG_FILES} (@pxref{Requirements}), parts of the
2998 specification using shell variables will be ignored as far as cleaning
2999 and distributing is concerned. (There are no rebuild rules for links.)
3003 @itemx AC_LIBSOURCES
3005 Automake will automatically distribute any file listed in
3006 @code{AC_LIBSOURCE} or @code{AC_LIBSOURCES}.
3008 Note that the @code{AC_LIBOBJ} macro calls @code{AC_LIBSOURCE}. So if
3009 an Autoconf macro is documented to call @samp{AC_LIBOBJ([file])}, then
3010 @file{file.c} will be distributed automatically by Automake. This
3011 encompasses many macros like @code{AC_FUNC_ALLOCA},
3012 @code{AC_FUNC_MEMCMP}, @code{AC_REPLACE_FUNCS}, and others.
3014 By the way, direct assignments to @code{LIBOBJS} are no longer
3015 supported. You should always use @code{AC_LIBOBJ} for this purpose.
3016 @xref{AC_LIBOBJ vs LIBOBJS, , @code{AC_LIBOBJ} vs.@: @code{LIBOBJS},
3017 autoconf, The Autoconf Manual}.
3019 @item AC_PROG_RANLIB
3020 This is required if any libraries are built in the package.
3021 @xref{Particular Programs, , Particular Program Checks, autoconf, The
3025 This is required if any C++ source is included. @xref{Particular
3026 Programs, , Particular Program Checks, autoconf, The Autoconf Manual}.
3029 This is required if any Objective C source is included. @xref{Particular
3030 Programs, , Particular Program Checks, autoconf, The Autoconf Manual}.
3032 @item AC_PROG_OBJCXX
3033 This is required if any Objective C++ source is included. @xref{Particular
3034 Programs, , Particular Program Checks, autoconf, The Autoconf Manual}.
3037 This is required if any Fortran 77 source is included. @xref{Particular
3038 Programs, , Particular Program Checks, autoconf, The Autoconf Manual}.
3040 @item AC_F77_LIBRARY_LDFLAGS
3041 This is required for programs and shared libraries that are a mixture of
3042 languages that include Fortran 77 (@pxref{Mixing Fortran 77 With C and
3043 C++}). @xref{Macros, , Autoconf macros supplied with Automake}.
3046 Automake will add the flags computed by @code{AC_FC_SRCEXT} to compilation
3047 of files with the respective source extension (@pxref{Fortran Compiler, ,
3048 Fortran Compiler Characteristics, autoconf, The Autoconf Manual}).
3051 This is required if any Fortran 90/95 source is included. This macro is
3052 distributed with Autoconf version 2.58 and later. @xref{Particular
3053 Programs, , Particular Program Checks, autoconf, The Autoconf Manual}.
3055 @item AC_PROG_LIBTOOL
3056 Automake will turn on processing for @command{libtool} (@pxref{Top, ,
3057 Introduction, libtool, The Libtool Manual}).
3061 If a Yacc source file is seen, then you must either use this macro or
3062 define the variable @code{YACC} in @file{configure.ac}. The former is
3063 preferred (@pxref{Particular Programs, , Particular Program Checks,
3064 autoconf, The Autoconf Manual}).
3067 If a Lex source file is seen, then this macro must be used.
3068 @xref{Particular Programs, , Particular Program Checks, autoconf, The
3071 @item AC_REQUIRE_AUX_FILE
3072 For each @code{AC_REQUIRE_AUX_FILE([@var{file}])},
3073 @command{automake} will ensure that @file{@var{file}} exists in the
3074 aux directory, and will complain otherwise. It
3075 will also automatically distribute the file. This macro should be
3076 used by third-party Autoconf macros that require some supporting
3077 files in the aux directory specified with @code{AC_CONFIG_AUX_DIR}
3078 above. @xref{Input, , Finding @command{configure} Input, autoconf,
3079 The Autoconf Manual}.
3082 The first argument is automatically defined as a variable in each
3083 generated @file{Makefile.in}, unless @code{AM_SUBST_NOTMAKE} is also
3084 used for this variable. @xref{Setting Output Variables, , Setting
3085 Output Variables, autoconf, The Autoconf Manual}.
3087 For every substituted variable @var{var}, @command{automake} will add
3088 a line @code{@var{var} = @var{value}} to each @file{Makefile.in} file.
3089 Many Autoconf macros invoke @code{AC_SUBST} to set output variables
3090 this way, e.g., @code{AC_PATH_XTRA} defines @code{X_CFLAGS} and
3091 @code{X_LIBS}. Thus, you can access these variables as
3092 @code{$(X_CFLAGS)} and @code{$(X_LIBS)} in any @file{Makefile.am}
3093 if @code{AC_PATH_XTRA} is called.
3095 @item AM_CONDITIONAL
3096 This introduces an Automake conditional (@pxref{Conditionals}).
3099 This macro allows @code{automake} to detect subsequent access within
3100 @file{configure.ac} to a conditional previously introduced with
3101 @code{AM_CONDITIONAL}, thus enabling conditional @code{AC_CONFIG_FILES}
3102 (@pxref{Usage of Conditionals}).
3104 @item AM_GNU_GETTEXT
3105 This macro is required for packages that use GNU gettext
3106 (@pxref{gettext}). It is distributed with gettext. If Automake sees
3107 this macro it ensures that the package meets some of gettext's
3110 @item AM_GNU_GETTEXT_INTL_SUBDIR
3111 This macro specifies that the @file{intl/} subdirectory is to be built,
3112 even if the @code{AM_GNU_GETTEXT} macro was invoked with a first argument
3115 @item AM_MAINTAINER_MODE(@ovar{default-mode})
3116 @opindex --enable-maintainer-mode
3117 @opindex --disable-maintainer-mode
3118 This macro adds an @option{--enable-maintainer-mode} option to
3119 @command{configure}. If this is used, @command{automake} will cause
3120 ``maintainer-only'' rules to be turned off by default in the
3121 generated @file{Makefile.in}s, unless @var{default-mode} is
3122 @samp{enable}. This macro defines the @code{MAINTAINER_MODE}
3123 conditional, which you can use in your own @file{Makefile.am}.
3124 @xref{maintainer-mode}.
3126 @item AM_SUBST_NOTMAKE(@var{var})
3127 Prevent Automake from defining a variable @var{var}, even if it is
3128 substituted by @command{config.status}. Normally, Automake defines a
3129 @command{make} variable for each @command{configure} substitution,
3130 i.e., for each @code{AC_SUBST([@var{var}])}. This macro prevents that
3131 definition from Automake. If @code{AC_SUBST} has not been called
3132 for this variable, then @code{AM_SUBST_NOTMAKE} has no effects.
3133 Preventing variable definitions may be useful for substitution of
3134 multi-line values, where @code{@var{var} = @@@var{value}@@} might yield
3138 Files included by @file{configure.ac} using this macro will be
3139 detected by Automake and automatically distributed. They will also
3140 appear as dependencies in @file{Makefile} rules.
3142 @code{m4_include} is seldom used by @file{configure.ac} authors, but
3143 can appear in @file{aclocal.m4} when @command{aclocal} detects that
3144 some required macros come from files local to your package (as opposed to
3145 macros installed in a system-wide directory, @pxref{aclocal Invocation}).
3149 @node aclocal Invocation
3150 @section Auto-generating aclocal.m4
3151 @c This node used to be named "Invoking automake". This @anchor
3152 @c allows old links to still work.
3153 @anchor{Invoking aclocal}
3155 @cindex Invocation of @command{aclocal}
3156 @cindex @command{aclocal}, Invocation
3157 @cindex Invoking @command{aclocal}
3158 @cindex @command{aclocal}, Invoking
3160 Automake includes a number of Autoconf macros that can be used in
3161 your package (@pxref{Macros}); some of them are actually required by
3162 Automake in certain situations. These macros must be defined in your
3163 @file{aclocal.m4}; otherwise they will not be seen by
3166 The @command{aclocal} program will automatically generate
3167 @file{aclocal.m4} files based on the contents of @file{configure.ac}.
3168 This provides a convenient way to get Automake-provided macros,
3169 without having to search around. The @command{aclocal} mechanism
3170 allows other packages to supply their own macros (@pxref{Extending
3171 aclocal}). You can also use it to maintain your own set of custom
3172 macros (@pxref{Local Macros}).
3174 At startup, @command{aclocal} scans all the @file{.m4} files it can
3175 find, looking for macro definitions (@pxref{Macro Search Path}). Then
3176 it scans @file{configure.ac}. Any mention of one of the macros found
3177 in the first step causes that macro, and any macros it in turn
3178 requires, to be put into @file{aclocal.m4}.
3180 @emph{Putting} the file that contains the macro definition into
3181 @file{aclocal.m4} is usually done by copying the entire text of this
3182 file, including unused macro definitions as well as both @samp{#} and
3183 @samp{dnl} comments. If you want to make a comment that will be
3184 completely ignored by @command{aclocal}, use @samp{##} as the comment
3187 When a file selected by @command{aclocal} is located in a subdirectory
3188 specified as a relative search path with @command{aclocal}'s @option{-I}
3189 argument, @command{aclocal} assumes the file belongs to the package
3190 and uses @code{m4_include} instead of copying it into
3191 @file{aclocal.m4}. This makes the package smaller, eases dependency
3192 tracking, and cause the file to be distributed automatically.
3193 (@xref{Local Macros}, for an example.) Any macro that is found in a
3194 system-wide directory, or via an absolute search path will be copied.
3195 So use @samp{-I `pwd`/reldir} instead of @samp{-I reldir} whenever
3196 some relative directory should be considered outside the package.
3198 The contents of @file{acinclude.m4}, if this file exists, are also
3199 automatically included in @file{aclocal.m4}. We recommend against
3200 using @file{acinclude.m4} in new packages (@pxref{Local Macros}).
3204 While computing @file{aclocal.m4}, @command{aclocal} runs
3205 @command{autom4te} (@pxref{Using autom4te, , Using @command{Autom4te},
3206 autoconf, The Autoconf Manual}) in order to trace the macros that are
3207 really used, and omit from @file{aclocal.m4} all macros that are
3208 mentioned but otherwise unexpanded (this can happen when a macro is
3209 called conditionally). @command{autom4te} is expected to be in the
3210 @env{PATH}, just as @command{autoconf}. Its location can be
3211 overridden using the @env{AUTOM4TE} environment variable.
3214 * aclocal Options:: Options supported by aclocal
3215 * Macro Search Path:: How aclocal finds .m4 files
3216 * Extending aclocal:: Writing your own aclocal macros
3217 * Local Macros:: Organizing local macros
3218 * Serials:: Serial lines in Autoconf macros
3219 * Future of aclocal:: aclocal's scheduled death
3222 @node aclocal Options
3223 @subsection aclocal Options
3225 @cindex @command{aclocal}, Options
3226 @cindex Options, @command{aclocal}
3228 @command{aclocal} accepts the following options:
3231 @item --automake-acdir=@var{dir}
3232 @opindex --automake-acdir
3233 Look for the automake-provided macro files in @var{dir} instead of
3234 in the installation directory. This is typically used for debugging.
3236 @item --system-acdir=@var{dir}
3237 @opindex --system-acdir
3238 Look for the system-wide third-party macro files (and the special
3239 @file{dirlist} file) in @var{dir} instead of in the installation
3240 directory. This is typically used for debugging.
3242 @item --diff[=@var{command}]
3244 Run @var{command} on M4 file that would be installed or overwritten
3245 by @option{--install}. The default @var{command} is @samp{diff -u}.
3246 This option implies @option{--install} and @option{--dry-run}.
3250 Do not actually overwrite (or create) @file{aclocal.m4} and M4
3251 files installed by @option{--install}.
3255 Print a summary of the command line options and exit.
3259 Add the directory @var{dir} to the list of directories searched for
3264 Install system-wide third-party macros into the first directory
3265 specified with @samp{-I @var{dir}} instead of copying them in the
3267 @c Keep in sync with aclocal-install-absdir.sh
3268 Note that this will happen also if @var{dir} is an absolute path.
3270 @cindex serial number and @option{--install}
3271 When this option is used, and only when this option is used,
3272 @command{aclocal} will also honor @samp{#serial @var{number}} lines
3273 that appear in macros: an M4 file is ignored if there exists another
3274 M4 file with the same basename and a greater serial number in the
3275 search path (@pxref{Serials}).
3279 Always overwrite the output file. The default is to overwrite the output
3280 file only when really needed, i.e., when its contents changes or if one
3281 of its dependencies is younger.
3283 This option forces the update of @file{aclocal.m4} (or the file
3284 specified with @file{--output} below) and only this file, it has
3285 absolutely no influence on files that may need to be installed by
3288 @item --output=@var{file}
3290 Cause the output to be put into @var{file} instead of @file{aclocal.m4}.
3292 @item --print-ac-dir
3293 @opindex --print-ac-dir
3294 Prints the name of the directory that @command{aclocal} will search to
3295 find third-party @file{.m4} files. When this option is given, normal
3296 processing is suppressed. This option was used @emph{in the past} by
3297 third-party packages to determine where to install @file{.m4} macro
3298 files, but @emph{this usage is today discouraged}, since it causes
3299 @samp{$(prefix)} not to be thoroughly honoured (which violates the
3300 GNU Coding Standards), and a similar semantics can be better obtained
3301 with the @env{ACLOCAL_PATH} environment variable; @pxref{Extending aclocal}.
3305 Print the names of the files it examines.
3309 Print the version number of Automake and exit.
3312 @item --warnings=@var{category}
3315 Output warnings falling in @var{category}. @var{category} can be
3319 dubious syntactic constructs, underquoted macros, unused macros, etc.
3323 all the warnings, this is the default
3325 turn off all the warnings
3327 treat warnings as errors
3330 All warnings are output by default.
3333 The environment variable @env{WARNINGS} is honored in the same
3334 way as it is for @command{automake} (@pxref{automake Invocation}).
3338 @node Macro Search Path
3339 @subsection Macro Search Path
3341 @cindex Macro search path
3342 @cindex @command{aclocal} search path
3344 By default, @command{aclocal} searches for @file{.m4} files in the following
3345 directories, in this order:
3348 @item @var{acdir-APIVERSION}
3349 This is where the @file{.m4} macros distributed with Automake itself
3350 are stored. @var{APIVERSION} depends on the Automake release used;
3351 for example, for Automake 1.11.x, @var{APIVERSION} = @code{1.11}.
3354 This directory is intended for third party @file{.m4} files, and is
3355 configured when @command{automake} itself is built. This is
3356 @file{@@datadir@@/aclocal/}, which typically
3357 expands to @file{$@{prefix@}/share/aclocal/}. To find the compiled-in
3358 value of @var{acdir}, use the @option{--print-ac-dir} option
3359 (@pxref{aclocal Options}).
3362 As an example, suppose that @command{automake-1.11.2} was configured with
3363 @option{--prefix=@-/usr/local}. Then, the search path would be:
3366 @item @file{/usr/local/share/aclocal-1.11.2/}
3367 @item @file{/usr/local/share/aclocal/}
3370 The paths for the @var{acdir} and @var{acdir-APIVERSION} directories can
3371 be changed respectively through aclocal options @option{--system-acdir}
3372 and @option{--automake-acdir} (@pxref{aclocal Options}). Note however
3373 that these options are only intended for use by the internal Automake
3374 test suite, or for debugging under highly unusual situations; they are
3375 not ordinarily needed by end-users.
3377 As explained in (@pxref{aclocal Options}), there are several options that
3378 can be used to change or extend this search path.
3380 @subsubheading Modifying the Macro Search Path: @samp{-I @var{dir}}
3382 Any extra directories specified using @option{-I} options
3383 (@pxref{aclocal Options}) are @emph{prepended} to this search list. Thus,
3384 @samp{aclocal -I /foo -I /bar} results in the following search path:
3389 @item @var{acdir}-@var{APIVERSION}
3393 @subsubheading Modifying the Macro Search Path: @file{dirlist}
3394 @cindex @file{dirlist}
3396 There is a third mechanism for customizing the search path. If a
3397 @file{dirlist} file exists in @var{acdir}, then that file is assumed to
3398 contain a list of directory patterns, one per line. @command{aclocal}
3399 expands these patterns to directory names, and adds them to the search
3400 list @emph{after} all other directories. @file{dirlist} entries may
3401 use shell wildcards such as @samp{*}, @samp{?}, or @code{[...]}.
3403 For example, suppose
3404 @file{@var{acdir}/dirlist} contains the following:
3413 and that @command{aclocal} was called with the @samp{-I /foo -I /bar} options.
3414 Then, the search path would be
3416 @c @code looks better than @file here
3420 @item @var{acdir}-@var{APIVERSION}
3427 and all directories with path names starting with @code{/test3}.
3429 If the @option{--system-acdir=@var{dir}} option is used, then
3430 @command{aclocal} will search for the @file{dirlist} file in
3431 @var{dir}; but remember the warnings above against the use of
3432 @option{--system-acdir}.
3434 @file{dirlist} is useful in the following situation: suppose that
3435 @command{automake} version @code{1.11.2} is installed with
3436 @samp{--prefix=/usr} by the system vendor. Thus, the default search
3439 @c @code looks better than @file here
3441 @item @code{/usr/share/aclocal-1.11/}
3442 @item @code{/usr/share/aclocal/}
3445 However, suppose further that many packages have been manually
3446 installed on the system, with $prefix=/usr/local, as is typical. In
3447 that case, many of these ``extra'' @file{.m4} files are in
3448 @file{/usr/local/share/aclocal}. The only way to force
3449 @file{/usr/bin/aclocal} to find these ``extra'' @file{.m4} files is to
3450 always call @samp{aclocal -I /usr/local/share/aclocal}. This is
3451 inconvenient. With @file{dirlist}, one may create a file
3452 @file{/usr/share/aclocal/dirlist} containing only the single line
3455 /usr/local/share/aclocal
3458 Now, the ``default'' search path on the affected system is
3460 @c @code looks better than @file here
3462 @item @code{/usr/share/aclocal-1.11/}
3463 @item @code{/usr/share/aclocal/}
3464 @item @code{/usr/local/share/aclocal/}
3467 without the need for @option{-I} options; @option{-I} options can be reserved
3468 for project-specific needs (@file{my-source-dir/m4/}), rather than
3469 using it to work around local system-dependent tool installation
3472 Similarly, @file{dirlist} can be handy if you have installed a local
3473 copy of Automake in your account and want @command{aclocal} to look for
3474 macros installed at other places on the system.
3476 @anchor{ACLOCAL_PATH}
3477 @subsubheading Modifying the Macro Search Path: @file{ACLOCAL_PATH}
3478 @cindex @env{ACLOCAL_PATH}
3480 The fourth and last mechanism to customize the macro search path is
3481 also the simplest. Any directory included in the colon-separated
3482 environment variable @env{ACLOCAL_PATH} is added to the search path
3483 @c Keep in sync with aclocal-path-precedence.sh
3484 and takes precedence over system directories (including those found via
3485 @file{dirlist}), with the exception of the versioned directory
3486 @var{acdir-APIVERSION} (@pxref{Macro Search Path}). However, directories
3487 passed via @option{-I} will take precedence over directories in
3490 @c Keep in sync with aclocal-path-installed.sh
3491 Also note that, if the @option{--install} option is used, any @file{.m4}
3492 file containing a required macro that is found in a directory listed in
3493 @env{ACLOCAL_PATH} will be installed locally.
3494 @c Keep in sync with aclocal-path-installed-serial.sh
3495 In this case, serial numbers in @file{.m4} are honoured too,
3498 Conversely to @file{dirlist}, @env{ACLOCAL_PATH} is useful if you are
3499 using a global copy of Automake and want @command{aclocal} to look for
3500 macros somewhere under your home directory.
3502 @subsubheading Planned future incompatibilities
3504 The order in which the directories in the macro search path are currently
3505 looked up is confusing and/or suboptimal in various aspects, and is
3506 probably going to be changed in the future Automake release. In
3507 particular, directories in @env{ACLOCAL_PATH} and @file{@var{acdir}}
3508 might end up taking precedence over @file{@var{acdir-APIVERSION}}, and
3509 directories in @file{@var{acdir}/dirlist} might end up taking precedence
3510 over @file{@var{acdir}}. @emph{This is a possible future incompatibility!}
3512 @node Extending aclocal
3513 @subsection Writing your own aclocal macros
3515 @cindex @command{aclocal}, extending
3516 @cindex Extending @command{aclocal}
3518 The @command{aclocal} program doesn't have any built-in knowledge of any
3519 macros, so it is easy to extend it with your own macros.
3521 This can be used by libraries that want to supply their own Autoconf
3522 macros for use by other programs. For instance, the @command{gettext}
3523 library supplies a macro @code{AM_GNU_GETTEXT} that should be used by
3524 any package using @command{gettext}. When the library is installed, it
3525 installs this macro so that @command{aclocal} will find it.
3527 A macro file's name should end in @file{.m4}. Such files should be
3528 installed in @file{$(datadir)/aclocal}. This is as simple as writing:
3530 @c Keep in sync with primary-prefix-couples-documented-valid.sh
3532 aclocaldir = $(datadir)/aclocal
3533 aclocal_DATA = mymacro.m4 myothermacro.m4
3537 Please do use @file{$(datadir)/aclocal}, and not something based on
3538 the result of @samp{aclocal --print-ac-dir} (@pxref{Hard-Coded Install
3539 Paths}, for arguments). It might also be helpful to suggest to
3540 the user to add the @file{$(datadir)/aclocal} directory to his
3541 @env{ACLOCAL_PATH} variable (@pxref{ACLOCAL_PATH}) so that
3542 @command{aclocal} will find the @file{.m4} files installed by your
3543 package automatically.
3545 A file of macros should be a series of properly quoted
3546 @code{AC_DEFUN}'s (@pxref{Macro Definitions, , , autoconf, The
3547 Autoconf Manual}). The @command{aclocal} programs also understands
3548 @code{AC_REQUIRE} (@pxref{Prerequisite Macros, , , autoconf, The
3549 Autoconf Manual}), so it is safe to put each macro in a separate file.
3550 Each file should have no side effects but macro definitions.
3551 Especially, any call to @code{AC_PREREQ} should be done inside the
3552 defined macro, not at the beginning of the file.
3554 @cindex underquoted @code{AC_DEFUN}
3558 Starting with Automake 1.8, @command{aclocal} will warn about all
3559 underquoted calls to @code{AC_DEFUN}. We realize this will annoy a
3560 lot of people, because @command{aclocal} was not so strict in the past
3561 and many third party macros are underquoted; and we have to apologize
3562 for this temporary inconvenience. The reason we have to be stricter
3563 is that a future implementation of @command{aclocal} (@pxref{Future of
3564 aclocal}) will have to temporarily include all of these third party
3565 @file{.m4} files, maybe several times, including even files that are
3566 not actually needed. Doing so should alleviate many problems of the
3567 current implementation, however it requires a stricter style from the
3568 macro authors. Hopefully it is easy to revise the existing macros.
3575 [AC_REQUIRE([AX_SOMETHING])dnl
3582 should be rewritten as
3585 AC_DEFUN([AX_FOOBAR],
3586 [AC_PREREQ([2.68])dnl
3587 AC_REQUIRE([AX_SOMETHING])dnl
3593 Wrapping the @code{AC_PREREQ} call inside the macro ensures that
3594 Autoconf 2.68 will not be required if @code{AX_FOOBAR} is not actually
3595 used. Most importantly, quoting the first argument of @code{AC_DEFUN}
3596 allows the macro to be redefined or included twice (otherwise this
3597 first argument would be expanded during the second definition). For
3598 consistency we like to quote even arguments such as @code{2.68} that
3601 If you have been directed here by the @command{aclocal} diagnostic but
3602 are not the maintainer of the implicated macro, you will want to
3603 contact the maintainer of that macro. Please make sure you have the
3604 latest version of the macro and that the problem hasn't already been
3605 reported before doing so: people tend to work faster when they aren't
3608 Another situation where @command{aclocal} is commonly used is to
3609 manage macros that are used locally by the package, @ref{Local
3613 @subsection Handling Local Macros
3615 Feature tests offered by Autoconf do not cover all needs. People
3616 often have to supplement existing tests with their own macros, or
3617 with third-party macros.
3619 There are two ways to organize custom macros in a package.
3621 The first possibility (the historical practice) is to list all your
3622 macros in @file{acinclude.m4}. This file will be included in
3623 @file{aclocal.m4} when you run @command{aclocal}, and its macro(s) will
3624 henceforth be visible to @command{autoconf}. However if it contains
3625 numerous macros, it will rapidly become difficult to maintain, and it
3626 will be almost impossible to share macros between packages.
3628 @vindex ACLOCAL_AMFLAGS
3629 The second possibility, which we do recommend, is to write each macro
3630 in its own file and gather all of these files in a directory. This
3631 directory is usually called @file{m4/}. To build @file{aclocal.m4},
3632 one should therefore instruct @command{aclocal} to scan @file{m4/}.
3633 From the command line, this is done with @samp{aclocal -I m4}. The
3634 top-level @file{Makefile.am} should also be updated to define
3637 ACLOCAL_AMFLAGS = -I m4
3640 @code{ACLOCAL_AMFLAGS} contains options to pass to @command{aclocal}
3641 when @file{aclocal.m4} is to be rebuilt by @command{make}. This line is
3642 also used by @command{autoreconf} (@pxref{autoreconf Invocation, ,
3643 Using @command{autoreconf} to Update @file{configure} Scripts,
3644 autoconf, The Autoconf Manual}) to run @command{aclocal} with suitable
3645 options, or by @command{autopoint} (@pxref{autopoint Invocation, ,
3646 Invoking the @command{autopoint} Program, gettext, GNU gettext tools})
3647 and @command{gettextize} (@pxref{gettextize Invocation, , Invoking the
3648 @command{gettextize} Program, gettext, GNU gettext tools}) to locate
3649 the place where Gettext's macros should be installed. So even if you
3650 do not really care about the rebuild rules, you should define
3651 @code{ACLOCAL_AMFLAGS}.
3653 When @samp{aclocal -I m4} is run, it will build an @file{aclocal.m4}
3654 that @code{m4_include}s any file from @file{m4/} that defines a
3655 required macro. Macros not found locally will still be searched in
3656 system-wide directories, as explained in @ref{Macro Search Path}.
3658 Custom macros should be distributed for the same reason that
3659 @file{configure.ac} is: so that other people have all the sources of
3660 your package if they want to work on it. Actually, this distribution
3661 happens automatically because all @code{m4_include}d files are
3664 However there is no consensus on the distribution of third-party
3665 macros that your package may use. Many libraries install their own
3666 macro in the system-wide @command{aclocal} directory (@pxref{Extending
3667 aclocal}). For instance, Guile ships with a file called
3668 @file{guile.m4} that contains the macro @code{GUILE_FLAGS} that can
3669 be used to define setup compiler and linker flags appropriate for
3670 using Guile. Using @code{GUILE_FLAGS} in @file{configure.ac} will
3671 cause @command{aclocal} to copy @file{guile.m4} into
3672 @file{aclocal.m4}, but as @file{guile.m4} is not part of the project,
3673 it will not be distributed. Technically, that means a user who
3674 needs to rebuild @file{aclocal.m4} will have to install Guile first.
3675 This is probably OK, if Guile already is a requirement to build the
3676 package. However, if Guile is only an optional feature, or if your
3677 package might run on architectures where Guile cannot be installed,
3678 this requirement will hinder development. An easy solution is to copy
3679 such third-party macros in your local @file{m4/} directory so they get
3682 Since Automake 1.10, @command{aclocal} offers an option to copy these
3683 system-wide third-party macros in your local macro directory, solving
3684 the above problem. Simply use:
3687 ACLOCAL_AMFLAGS = -I m4 --install
3691 With this setup, system-wide macros will be copied to @file{m4/}
3692 the first time you run @command{autoreconf}. Then the locally
3693 installed macros will have precedence over the system-wide installed
3694 macros each time @command{aclocal} is run again.
3696 One reason why you should keep @option{--install} in the flags even
3697 after the first run is that when you later edit @file{configure.ac}
3698 and depend on a new macro, this macro will be installed in your
3699 @file{m4/} automatically. Another one is that serial numbers
3700 (@pxref{Serials}) can be used to update the macros in your source tree
3701 automatically when new system-wide versions are installed. A serial
3702 number should be a single line of the form
3709 where @var{nnn} contains only digits and dots. It should appear in
3710 the M4 file before any macro definition. It is a good practice to
3711 maintain a serial number for each macro you distribute, even if you do
3712 not use the @option{--install} option of @command{aclocal}: this allows
3713 other people to use it.
3717 @subsection Serial Numbers
3718 @cindex serial numbers in macros
3719 @cindex macro serial numbers
3720 @cindex @code{#serial} syntax
3721 @cindex @command{aclocal} and serial numbers
3723 Because third-party macros defined in @file{*.m4} files are naturally
3724 shared between multiple projects, some people like to version them.
3725 This makes it easier to tell which of two M4 files is newer. Since at
3726 least 1996, the tradition is to use a @samp{#serial} line for this.
3728 A serial number should be a single line of the form
3731 # serial @var{version}
3735 where @var{version} is a version number containing only digits and
3736 dots. Usually people use a single integer, and they increment it each
3737 time they change the macro (hence the name of ``serial''). Such a
3738 line should appear in the M4 file before any macro definition.
3740 The @samp{#} must be the first character on the line,
3741 and it is OK to have extra words after the version, as in
3744 #serial @var{version} @var{garbage}
3747 Normally these serial numbers are completely ignored by
3748 @command{aclocal} and @command{autoconf}, like any genuine comment.
3749 However when using @command{aclocal}'s @option{--install} feature, these
3750 serial numbers will modify the way @command{aclocal} selects the
3751 macros to install in the package: if two files with the same basename
3752 exist in your search path, and if at least one of them uses a
3753 @samp{#serial} line, @command{aclocal} will ignore the file that has
3754 the older @samp{#serial} line (or the file that has none).
3756 Note that a serial number applies to a whole M4 file, not to any macro
3757 it contains. A file can contains multiple macros, but only one
3760 Here is a use case that illustrates the use of @option{--install} and
3761 its interaction with serial numbers. Let's assume we maintain a
3762 package called MyPackage, the @file{configure.ac} of which requires a
3763 third-party macro @code{AX_THIRD_PARTY} defined in
3764 @file{/usr/share/aclocal/thirdparty.m4} as follows:
3768 AC_DEFUN([AX_THIRD_PARTY], [...])
3771 MyPackage uses an @file{m4/} directory to store local macros as
3772 explained in @ref{Local Macros}, and has
3775 ACLOCAL_AMFLAGS = -I m4 --install
3779 in its top-level @file{Makefile.am}.
3781 Initially the @file{m4/} directory is empty. The first time we run
3782 @command{autoreconf}, it will fetch the options to pass to
3783 @command{aclocal} in @file{Makefile.am}, and run @samp{aclocal -I m4
3784 --install}. @command{aclocal} will notice that
3788 @file{configure.ac} uses @code{AX_THIRD_PARTY}
3790 No local macros define @code{AX_THIRD_PARTY}
3792 @file{/usr/share/aclocal/thirdparty.m4} defines @code{AX_THIRD_PARTY}
3797 Because @file{/usr/share/aclocal/thirdparty.m4} is a system-wide macro
3798 and @command{aclocal} was given the @option{--install} option, it will
3799 copy this file in @file{m4/thirdparty.m4}, and output an
3800 @file{aclocal.m4} that contains @samp{m4_include([m4/thirdparty.m4])}.
3802 The next time @samp{aclocal -I m4 --install} is run (either via
3803 @command{autoreconf}, by hand, or from the @file{Makefile} rebuild
3804 rules) something different happens. @command{aclocal} notices that
3808 @file{configure.ac} uses @code{AX_THIRD_PARTY}
3810 @file{m4/thirdparty.m4} defines @code{AX_THIRD_PARTY}
3813 @file{/usr/share/aclocal/thirdparty.m4} defines @code{AX_THIRD_PARTY}
3818 Because both files have the same serial number, @command{aclocal} uses
3819 the first it found in its search path order (@pxref{Macro Search
3820 Path}). @command{aclocal} therefore ignores
3821 @file{/usr/share/aclocal/thirdparty.m4} and outputs an
3822 @file{aclocal.m4} that contains @samp{m4_include([m4/thirdparty.m4])}.
3824 Local directories specified with @option{-I} are always searched before
3825 system-wide directories, so a local file will always be preferred to
3826 the system-wide file in case of equal serial numbers.
3828 Now suppose the system-wide third-party macro is changed. This can
3829 happen if the package installing this macro is updated. Let's suppose
3830 the new macro has serial number 2. The next time @samp{aclocal -I m4
3831 --install} is run the situation is the following:
3835 @file{configure.ac} uses @code{AX_THIRD_PARTY}
3837 @file{m4/thirdparty.m4} defines @code{AX_THIRD_PARTY}
3840 @file{/usr/share/aclocal/thirdparty.m4} defines @code{AX_THIRD_PARTY}
3845 When @command{aclocal} sees a greater serial number, it immediately
3846 forgets anything it knows from files that have the same basename and a
3847 smaller serial number. So after it has found
3848 @file{/usr/share/aclocal/thirdparty.m4} with serial 2,
3849 @command{aclocal} will proceed as if it had never seen
3850 @file{m4/thirdparty.m4}. This brings us back to a situation similar
3851 to that at the beginning of our example, where no local file defined
3852 the macro. @command{aclocal} will install the new version of the
3853 macro in @file{m4/thirdparty.m4}, in this case overriding the old
3854 version. MyPackage just had its macro updated as a side effect of
3855 running @command{aclocal}.
3857 If you are leery of letting @command{aclocal} update your local macro,
3858 you can run @samp{aclocal -I m4 --diff} to review the changes
3859 @samp{aclocal -I m4 --install} would perform on these macros.
3861 Finally, note that the @option{--force} option of @command{aclocal} has
3862 absolutely no effect on the files installed by @option{--install}. For
3863 instance, if you have modified your local macros, do not expect
3864 @option{--install --force} to replace the local macros by their
3865 system-wide versions. If you want to do so, simply erase the local
3866 macros you want to revert, and run @samp{aclocal -I m4 --install}.
3869 @node Future of aclocal
3870 @subsection The Future of @command{aclocal}
3871 @cindex @command{aclocal}'s scheduled death
3873 @command{aclocal} is expected to disappear. This feature really
3874 should not be offered by Automake. Automake should focus on
3875 generating @file{Makefile}s; dealing with M4 macros really is
3876 Autoconf's job. The fact that some people install Automake just to use
3877 @command{aclocal}, but do not use @command{automake} otherwise is an
3878 indication of how that feature is misplaced.
3880 The new implementation will probably be done slightly differently.
3881 For instance, it could enforce the @file{m4/}-style layout discussed in
3884 We have no idea when and how this will happen. This has been
3885 discussed several times in the past, but someone still has to commit
3886 to that non-trivial task.
3888 From the user point of view, @command{aclocal}'s removal might turn
3889 out to be painful. There is a simple precaution that you may take to
3890 make that switch more seamless: never call @command{aclocal} yourself.
3891 Keep this guy under the exclusive control of @command{autoreconf} and
3892 Automake's rebuild rules. Hopefully you won't need to worry about
3893 things breaking, when @command{aclocal} disappears, because everything
3894 will have been taken care of. If otherwise you used to call
3895 @command{aclocal} directly yourself or from some script, you will
3896 quickly notice the change.
3898 Many packages come with a script called @file{bootstrap.sh} or
3899 @file{autogen.sh}, that will just call @command{aclocal},
3900 @command{libtoolize}, @command{gettextize} or @command{autopoint},
3901 @command{autoconf}, @command{autoheader}, and @command{automake} in
3902 the right order. Actually this is precisely what @command{autoreconf}
3903 can do for you. If your package has such a @file{bootstrap.sh} or
3904 @file{autogen.sh} script, consider using @command{autoreconf}. That
3905 should simplify its logic a lot (less things to maintain, yum!), it's
3906 even likely you will not need the script anymore, and more to the point
3907 you will not call @command{aclocal} directly anymore.
3909 For the time being, third-party packages should continue to install
3910 public macros into @file{/usr/share/aclocal/}. If @command{aclocal}
3911 is replaced by another tool it might make sense to rename the
3912 directory, but supporting @file{/usr/share/aclocal/} for backward
3913 compatibility should be really easy provided all macros are properly
3914 written (@pxref{Extending aclocal}).
3919 @section Autoconf macros supplied with Automake
3921 Automake ships with several Autoconf macros that you can use from your
3922 @file{configure.ac}. When you use one of them it will be included by
3923 @command{aclocal} in @file{aclocal.m4}.
3926 * Public Macros:: Macros that you can use.
3927 * Obsolete Macros:: Macros that will soon be removed.
3928 * Private Macros:: Macros that you should not use.
3931 @c consider generating the following subsections automatically from m4 files.
3934 @subsection Public Macros
3938 @item AM_INIT_AUTOMAKE([OPTIONS])
3939 @acindex AM_INIT_AUTOMAKE
3940 Runs many macros required for proper operation of the generated Makefiles.
3942 @vindex AUTOMAKE_OPTIONS
3943 Today, @code{AM_INIT_AUTOMAKE} is called with a single argument: a
3944 space-separated list of Automake options that should
3945 be applied to every @file{Makefile.am} in the tree. The effect is as if
3946 each option were listed in @code{AUTOMAKE_OPTIONS} (@pxref{Options}).
3949 This macro can also be called in @emph{another, deprecated form} (support
3950 for which will be @emph{removed in the next major Automake release (1.13)}):
3951 @code{AM_INIT_AUTOMAKE(PACKAGE, VERSION, [NO-DEFINE])}. In this form,
3952 there are two required arguments: the package and the version number.
3953 This form is obsolete because the @var{package} and @var{version} can
3954 be obtained from Autoconf's @code{AC_INIT} macro (which itself has an
3955 old and a new form).
3957 @anchor{Modernize AM_INIT_AUTOMAKE invocation}
3958 If your @file{configure.ac} has:
3961 AC_INIT([src/foo.c])
3962 AM_INIT_AUTOMAKE([mumble], [1.5])
3966 you should modernize it as follows:
3969 AC_INIT([mumble], [1.5])
3970 AC_CONFIG_SRCDIR([src/foo.c])
3974 Note that if you're upgrading your @file{configure.ac} from an earlier
3975 version of Automake, it is not always correct to simply move the
3976 package and version arguments from @code{AM_INIT_AUTOMAKE} directly to
3977 @code{AC_INIT}, as in the example above. The first argument to
3978 @code{AC_INIT} should be the name of your package (e.g., @samp{GNU
3979 Automake}), not the tarball name (e.g., @samp{automake}) that you used
3980 to pass to @code{AM_INIT_AUTOMAKE}. Autoconf tries to derive a
3981 tarball name from the package name, which should work for most but not
3982 all package names. (If it doesn't work for yours, you can use the
3983 four-argument form of @code{AC_INIT} to provide the tarball name
3986 @cindex @code{PACKAGE}, prevent definition
3987 @cindex @code{VERSION}, prevent definition
3989 By default this macro @code{AC_DEFINE}'s @code{PACKAGE} and
3990 @code{VERSION}. This can be avoided by passing the @option{no-define}
3993 AM_INIT_AUTOMAKE([gnits 1.5 no-define dist-bzip2])
3996 @item AM_PATH_LISPDIR
3997 @acindex AM_PATH_LISPDIR
4000 Searches for the program @command{emacs}, and, if found, sets the
4001 output variable @code{lispdir} to the full path to Emacs' site-lisp
4004 Note that this test assumes the @command{emacs} found to be a version
4005 that supports Emacs Lisp (such as GNU Emacs or XEmacs). Other
4006 emacsen can cause this test to hang (some, like old versions of
4007 MicroEmacs, start up in interactive mode, requiring @kbd{C-x C-c} to
4008 exit, which is hardly obvious for a non-emacs user). In most cases,
4009 however, you should be able to use @kbd{C-c} to kill the test. In
4010 order to avoid problems, you can set @env{EMACS} to ``no'' in the
4011 environment, or use the @option{--with-lispdir} option to
4012 @command{configure} to explicitly set the correct path (if you're sure
4013 you have an @command{emacs} that supports Emacs Lisp).
4015 @item AM_PROG_AR(@ovar{act-if-fail})
4018 You must use this macro when you use the archiver in your project, if
4019 you want support for unusual archivers such as Microsoft @command{lib}.
4020 The content of the optional argument is executed if the archiver
4021 interface is not recognized; the default action is to abort configure
4022 with an error message.
4028 Use this macro when you have assembly code in your project. This will
4029 choose the assembler for you (by default the C compiler) and set
4030 @code{CCAS}, and will also set @code{CCASFLAGS} if required.
4032 @item AM_PROG_CC_C_O
4033 @acindex AM_PROG_CC_C_O
4034 @acindex AC_PROG_CC_C_O
4035 This is like @code{AC_PROG_CC_C_O}, but it generates its results in
4036 the manner required by Automake. You must use this instead of
4037 @code{AC_PROG_CC_C_O} when you need this functionality, that is, when
4038 using per-target flags or subdir-objects with C sources.
4041 @acindex AM_PROG_LEX
4042 @acindex AC_PROG_LEX
4043 @cindex HP-UX 10, @command{lex} problems
4044 @cindex @command{lex} problems with HP-UX 10
4045 Like @code{AC_PROG_LEX} (@pxref{Particular Programs, , Particular
4046 Program Checks, autoconf, The Autoconf Manual}), but uses the
4047 @command{missing} script on systems that do not have @command{lex}.
4048 HP-UX 10 is one such system.
4051 @acindex AM_PROG_GCJ
4054 This macro finds the @command{gcj} program or causes an error. It sets
4055 @code{GCJ} and @code{GCJFLAGS}. @command{gcj} is the Java front-end to the
4056 GNU Compiler Collection.
4058 @item AM_PROG_UPC([@var{compiler-search-list}])
4059 @acindex AM_PROG_UPC
4061 Find a compiler for Unified Parallel C and define the @code{UPC}
4062 variable. The default @var{compiler-search-list} is @samp{upcc upc}.
4063 This macro will abort @command{configure} if no Unified Parallel C
4066 @item AM_MISSING_PROG(@var{name}, @var{program})
4067 @acindex AM_MISSING_PROG
4069 Find a maintainer tool @var{program} and define the @var{name}
4070 environment variable with its location. If @var{program} is not
4071 detected, then @var{name} will instead invoke the @command{missing}
4072 script, in order to give useful advice to the user about the missing
4073 maintainer tool. @xref{maintainer-mode}, for more information on when
4074 the @command{missing} script is appropriate.
4076 @item AM_SILENT_RULES
4077 @acindex AM_SILENT_RULES
4078 Enable the machinery for less verbose build output (@pxref{Options}).
4080 @item AM_WITH_DMALLOC
4081 @acindex AM_WITH_DMALLOC
4082 @cindex @command{dmalloc}, support for
4083 @vindex WITH_DMALLOC
4084 @opindex --with-dmalloc
4085 Add support for the @uref{http://dmalloc.com/, Dmalloc package}. If
4086 the user runs @command{configure} with @option{--with-dmalloc}, then
4087 define @code{WITH_DMALLOC} and add @option{-ldmalloc} to @code{LIBS}.
4092 @node Obsolete Macros
4093 @subsection Obsolete Macros
4094 @cindex obsolete macros
4097 Although using some of the following macros was required in past
4098 releases, you should not use any of them in new code. @emph{All
4099 these macros will be removed in the next major Automake version};
4100 if you are still using them, running @command{autoupdate} should
4101 adjust your @file{configure.ac} automatically (@pxref{autoupdate
4102 Invocation, , Using @command{autoupdate} to Modernize
4103 @file{configure.ac}, autoconf, The Autoconf Manual}).
4108 @item AM_CONFIG_HEADER
4109 @acindex AM_CONFIG_HEADER
4110 Automake will generate rules to automatically regenerate the config
4111 header. This obsolete macro is a synonym of @code{AC_CONFIG_HEADERS}
4112 today (@pxref{Optional}).
4114 @item AM_HEADER_TIOCGWINSZ_NEEDS_SYS_IOCTL
4115 @acindex AM_HEADER_TIOCGWINSZ_NEEDS_SYS_IOCTL
4116 If the use of @code{TIOCGWINSZ} requires @file{<sys/ioctl.h>}, then
4117 define @code{GWINSZ_IN_SYS_IOCTL}. Otherwise @code{TIOCGWINSZ} can be
4118 found in @file{<termios.h>}. This macro is obsolete, you should
4119 use Autoconf's @code{AC_HEADER_TIOCGWINSZ} instead.
4121 @item AM_PROG_MKDIR_P
4122 @acindex AM_PROG_MKDIR_P
4123 @cindex @code{mkdir -p}, macro check
4127 From Automake 1.8 to 1.9.6 this macro used to define the output
4128 variable @code{mkdir_p} to one of @code{mkdir -p}, @code{install-sh
4129 -d}, or @code{mkinstalldirs}.
4131 Nowadays Autoconf provides a similar functionality with
4132 @code{AC_PROG_MKDIR_P} (@pxref{Particular Programs, , Particular
4133 Program Checks, autoconf, The Autoconf Manual}), however this defines
4134 the output variable @code{MKDIR_P} instead. In case you are still
4135 using the @code{AM_PROG_MKDIR_P} macro in your @file{configure.ac},
4136 or its provided variable @code{$(mkdir_p)} in your @file{Makefile.am},
4137 you are advised to switch ASAP to the more modern Autoconf-provided
4138 interface instead; both the macro and the variable @emph{will be
4139 removed} in the next major Automake release.
4141 @item AM_SYS_POSIX_TERMIOS
4142 @acindex AM_SYS_POSIX_TERMIOS
4143 @cindex POSIX termios headers
4144 @cindex termios POSIX headers
4145 Check to see if POSIX termios headers and functions are available on the
4146 system. If so, set the shell variable @code{am_cv_sys_posix_termios} to
4147 @samp{yes}. If not, set the variable to @samp{no}. This macro is obsolete,
4148 you should use Autoconf's @code{AC_SYS_POSIX_TERMIOS} instead.
4153 @node Private Macros
4154 @subsection Private Macros
4156 The following macros are private macros you should not call directly.
4157 They are called by the other public macros when appropriate. Do not
4158 rely on them, as they might be changed in a future version. Consider
4159 them as implementation details; or better, do not consider them at all:
4163 @item _AM_DEPENDENCIES
4164 @itemx AM_SET_DEPDIR
4166 @itemx AM_OUTPUT_DEPENDENCY_COMMANDS
4167 These macros are used to implement Automake's automatic dependency
4168 tracking scheme. They are called automatically by Automake when
4169 required, and there should be no need to invoke them manually.
4171 @item AM_MAKE_INCLUDE
4172 This macro is used to discover how the user's @command{make} handles
4173 @code{include} statements. This macro is automatically invoked when
4174 needed; there should be no need to invoke it manually.
4176 @item AM_PROG_INSTALL_STRIP
4177 This is used to find a version of @code{install} that can be used to
4178 strip a program at installation time. This macro is automatically
4179 included when required.
4181 @item AM_SANITY_CHECK
4182 This checks to make sure that a file created in the build directory is
4183 newer than a file in the source directory. This can fail on systems
4184 where the clock is set incorrectly. This macro is automatically run
4185 from @code{AM_INIT_AUTOMAKE}.
4191 @chapter Directories
4193 For simple projects that distribute all files in the same directory
4194 it is enough to have a single @file{Makefile.am} that builds
4195 everything in place.
4197 In larger projects, it is common to organize files in different
4198 directories, in a tree. For example, there could be a directory
4199 for the program's source, one for the testsuite, and one for the
4200 documentation; or, for very large projects, there could be one
4201 directory per program, per library or per module.
4203 The traditional approach is to build these subdirectories recursively,
4204 employing @emph{make recursion}: each directory contains its
4205 own @file{Makefile}, and when @command{make} is run from the top-level
4206 directory, it enters each subdirectory in turn, and invokes there a
4207 new @command{make} instance to build the directory's contents.
4209 Because this approach is very widespread, Automake offers built-in
4210 support for it. However, it is worth nothing that the use of make
4211 recursion has its own serious issues and drawbacks, and that it's
4212 well possible to have packages with a multi directory layout that
4213 make little or no use of such recursion (examples of such packages
4214 are GNU Bison and GNU Automake itself); see also the @ref{Alternative}
4218 * Subdirectories:: Building subdirectories recursively
4219 * Conditional Subdirectories:: Conditionally not building directories
4220 * Alternative:: Subdirectories without recursion
4221 * Subpackages:: Nesting packages
4224 @node Subdirectories
4225 @section Recursing subdirectories
4227 @cindex @code{SUBDIRS}, explained
4229 In packages using make recursion, the top level @file{Makefile.am} must
4230 tell Automake which subdirectories are to be built. This is done via
4231 the @code{SUBDIRS} variable.
4234 The @code{SUBDIRS} variable holds a list of subdirectories in which
4235 building of various sorts can occur. The rules for many targets
4236 (e.g., @code{all}) in the generated @file{Makefile} will run commands
4237 both locally and in all specified subdirectories. Note that the
4238 directories listed in @code{SUBDIRS} are not required to contain
4239 @file{Makefile.am}s; only @file{Makefile}s (after configuration).
4240 This allows inclusion of libraries from packages that do not use
4241 Automake (such as @code{gettext}; see also @ref{Third-Party
4244 In packages that use subdirectories, the top-level @file{Makefile.am} is
4245 often very short. For instance, here is the @file{Makefile.am} from the
4246 GNU Hello distribution:
4249 EXTRA_DIST = BUGS ChangeLog.O README-alpha
4250 SUBDIRS = doc intl po src tests
4253 When Automake invokes @command{make} in a subdirectory, it uses the value
4254 of the @code{MAKE} variable. It passes the value of the variable
4255 @code{AM_MAKEFLAGS} to the @command{make} invocation; this can be set in
4256 @file{Makefile.am} if there are flags you must always pass to
4259 @vindex AM_MAKEFLAGS
4261 The directories mentioned in @code{SUBDIRS} are usually direct
4262 children of the current directory, each subdirectory containing its
4263 own @file{Makefile.am} with a @code{SUBDIRS} pointing to deeper
4264 subdirectories. Automake can be used to construct packages of
4265 arbitrary depth this way.
4267 By default, Automake generates @file{Makefiles} that work depth-first
4268 in postfix order: the subdirectories are built before the current
4269 directory. However, it is possible to change this ordering. You can
4270 do this by putting @samp{.} into @code{SUBDIRS}. For instance,
4271 putting @samp{.} first will cause a prefix ordering of
4277 SUBDIRS = lib src . test
4281 will cause @file{lib/} to be built before @file{src/}, then the
4282 current directory will be built, finally the @file{test/} directory
4283 will be built. It is customary to arrange test directories to be
4284 built after everything else since they are meant to test what has
4287 @node Conditional Subdirectories
4288 @section Conditional Subdirectories
4289 @cindex Subdirectories, building conditionally
4290 @cindex Conditional subdirectories
4291 @cindex @code{SUBDIRS}, conditional
4292 @cindex Conditional @code{SUBDIRS}
4294 It is possible to define the @code{SUBDIRS} variable conditionally if,
4295 like in the case of GNU Inetutils, you want to only build a subset of
4298 To illustrate how this works, let's assume we have two directories
4299 @file{src/} and @file{opt/}. @file{src/} should always be built, but we
4300 want to decide in @command{configure} whether @file{opt/} will be built
4301 or not. (For this example we will assume that @file{opt/} should be
4302 built when the variable @samp{$want_opt} was set to @samp{yes}.)
4304 Running @command{make} should thus recurse into @file{src/} always, and
4305 then maybe in @file{opt/}.
4307 However @samp{make dist} should always recurse into both @file{src/}
4308 and @file{opt/}. Because @file{opt/} should be distributed even if it
4309 is not needed in the current configuration. This means
4310 @file{opt/Makefile} should be created @emph{unconditionally}.
4312 There are two ways to setup a project like this. You can use Automake
4313 conditionals (@pxref{Conditionals}) or use Autoconf @code{AC_SUBST}
4314 variables (@pxref{Setting Output Variables, , Setting Output
4315 Variables, autoconf, The Autoconf Manual}). Using Automake
4316 conditionals is the preferred solution. Before we illustrate these
4317 two possibilities, let's introduce @code{DIST_SUBDIRS}.
4320 * SUBDIRS vs DIST_SUBDIRS:: Two sets of directories
4321 * Subdirectories with AM_CONDITIONAL:: Specifying conditional subdirectories
4322 * Subdirectories with AC_SUBST:: Another way for conditional recursion
4323 * Unconfigured Subdirectories:: Not even creating a @samp{Makefile}
4326 @node SUBDIRS vs DIST_SUBDIRS
4327 @subsection @code{SUBDIRS} vs.@: @code{DIST_SUBDIRS}
4328 @cindex @code{DIST_SUBDIRS}, explained
4330 Automake considers two sets of directories, defined by the variables
4331 @code{SUBDIRS} and @code{DIST_SUBDIRS}.
4333 @code{SUBDIRS} contains the subdirectories of the current directory
4334 that must be built (@pxref{Subdirectories}). It must be defined
4335 manually; Automake will never guess a directory is to be built. As we
4336 will see in the next two sections, it is possible to define it
4337 conditionally so that some directory will be omitted from the build.
4339 @code{DIST_SUBDIRS} is used in rules that need to recurse in all
4340 directories, even those that have been conditionally left out of the
4341 build. Recall our example where we may not want to build subdirectory
4342 @file{opt/}, but yet we want to distribute it? This is where
4343 @code{DIST_SUBDIRS} comes into play: @samp{opt} may not appear in
4344 @code{SUBDIRS}, but it must appear in @code{DIST_SUBDIRS}.
4346 Precisely, @code{DIST_SUBDIRS} is used by @samp{make
4347 maintainer-clean}, @samp{make distclean} and @samp{make dist}. All
4348 other recursive rules use @code{SUBDIRS}.
4350 If @code{SUBDIRS} is defined conditionally using Automake
4351 conditionals, Automake will define @code{DIST_SUBDIRS} automatically
4352 from the possible values of @code{SUBDIRS} in all conditions.
4354 If @code{SUBDIRS} contains @code{AC_SUBST} variables,
4355 @code{DIST_SUBDIRS} will not be defined correctly because Automake
4356 does not know the possible values of these variables. In this case
4357 @code{DIST_SUBDIRS} needs to be defined manually.
4359 @node Subdirectories with AM_CONDITIONAL
4360 @subsection Subdirectories with @code{AM_CONDITIONAL}
4361 @cindex @code{SUBDIRS} and @code{AM_CONDITIONAL}
4362 @cindex @code{AM_CONDITIONAL} and @code{SUBDIRS}
4364 @c Keep in sync with subdir-am-cond.sh
4366 @file{configure} should output the @file{Makefile} for each directory
4367 and define a condition into which @file{opt/} should be built.
4371 AM_CONDITIONAL([COND_OPT], [test "$want_opt" = yes])
4372 AC_CONFIG_FILES([Makefile src/Makefile opt/Makefile])
4376 Then @code{SUBDIRS} can be defined in the top-level @file{Makefile.am}
4383 SUBDIRS = src $(MAYBE_OPT)
4386 As you can see, running @command{make} will rightly recurse into
4387 @file{src/} and maybe @file{opt/}.
4389 @vindex DIST_SUBDIRS
4390 As you can't see, running @samp{make dist} will recurse into both
4391 @file{src/} and @file{opt/} directories because @samp{make dist}, unlike
4392 @samp{make all}, doesn't use the @code{SUBDIRS} variable. It uses the
4393 @code{DIST_SUBDIRS} variable.
4395 In this case Automake will define @samp{DIST_SUBDIRS = src opt}
4396 automatically because it knows that @code{MAYBE_OPT} can contain
4397 @samp{opt} in some condition.
4399 @node Subdirectories with AC_SUBST
4400 @subsection Subdirectories with @code{AC_SUBST}
4401 @cindex @code{SUBDIRS} and @code{AC_SUBST}
4402 @cindex @code{AC_SUBST} and @code{SUBDIRS}
4404 @c Keep in sync with subdir-ac-subst.sh
4406 Another possibility is to define @code{MAYBE_OPT} from
4407 @file{./configure} using @code{AC_SUBST}:
4411 if test "$want_opt" = yes; then
4416 AC_SUBST([MAYBE_OPT])
4417 AC_CONFIG_FILES([Makefile src/Makefile opt/Makefile])
4421 In this case the top-level @file{Makefile.am} should look as follows.
4424 SUBDIRS = src $(MAYBE_OPT)
4425 DIST_SUBDIRS = src opt
4428 The drawback is that since Automake cannot guess what the possible
4429 values of @code{MAYBE_OPT} are, it is necessary to define
4430 @code{DIST_SUBDIRS}.
4432 @node Unconfigured Subdirectories
4433 @subsection Unconfigured Subdirectories
4434 @cindex Subdirectories, configured conditionally
4436 The semantics of @code{DIST_SUBDIRS} are often misunderstood by some
4437 users that try to @emph{configure and build} subdirectories
4438 conditionally. Here by configuring we mean creating the
4439 @file{Makefile} (it might also involve running a nested
4440 @command{configure} script: this is a costly operation that explains
4441 why people want to do it conditionally, but only the @file{Makefile}
4442 is relevant to the discussion).
4444 The above examples all assume that every @file{Makefile} is created,
4445 even in directories that are not going to be built. The simple reason
4446 is that we want @samp{make dist} to distribute even the directories
4447 that are not being built (e.g., platform-dependent code), hence
4448 @file{make dist} must recurse into the subdirectory, hence this
4449 directory must be configured and appear in @code{DIST_SUBDIRS}.
4451 Building packages that do not configure every subdirectory is a tricky
4452 business, and we do not recommend it to the novice as it is easy to
4453 produce an incomplete tarball by mistake. We will not discuss this
4454 topic in depth here, yet for the adventurous here are a few rules to
4459 @item @code{SUBDIRS} should always be a subset of @code{DIST_SUBDIRS}.
4461 It makes little sense to have a directory in @code{SUBDIRS} that
4462 is not in @code{DIST_SUBDIRS}. Think of the former as a way to tell
4463 which directories listed in the latter should be built.
4464 @item Any directory listed in @code{DIST_SUBDIRS} and @code{SUBDIRS}
4467 I.e., the @file{Makefile} must exists or the recursive @command{make}
4468 rules will not be able to process the directory.
4469 @item Any configured directory must be listed in @code{DIST_SUBDIRS}.
4471 So that the cleaning rules remove the generated @file{Makefile}s.
4472 It would be correct to see @code{DIST_SUBDIRS} as a variable that
4473 lists all the directories that have been configured.
4477 In order to prevent recursion in some unconfigured directory you
4478 must therefore ensure that this directory does not appear in
4479 @code{DIST_SUBDIRS} (and @code{SUBDIRS}). For instance, if you define
4480 @code{SUBDIRS} conditionally using @code{AC_SUBST} and do not define
4481 @code{DIST_SUBDIRS} explicitly, it will be default to
4482 @samp{$(SUBDIRS)}; another possibility is to force @code{DIST_SUBDIRS
4485 Of course, directories that are omitted from @code{DIST_SUBDIRS} will
4486 not be distributed unless you make other arrangements for this to
4487 happen (for instance, always running @samp{make dist} in a
4488 configuration where all directories are known to appear in
4489 @code{DIST_SUBDIRS}; or writing a @code{dist-hook} target to
4490 distribute these directories).
4492 @cindex Subdirectories, not distributed
4493 In few packages, unconfigured directories are not even expected to
4494 be distributed. Although these packages do not require the
4495 aforementioned extra arrangements, there is another pitfall. If the
4496 name of a directory appears in @code{SUBDIRS} or @code{DIST_SUBDIRS},
4497 @command{automake} will make sure the directory exists. Consequently
4498 @command{automake} cannot be run on such a distribution when one
4499 directory has been omitted. One way to avoid this check is to use the
4500 @code{AC_SUBST} method to declare conditional directories; since
4501 @command{automake} does not know the values of @code{AC_SUBST}
4502 variables it cannot ensure the corresponding directory exists.
4505 @section An Alternative Approach to Subdirectories
4507 If you've ever read Peter Miller's excellent paper,
4508 @uref{http://miller.emu.id.au/pmiller/books/rmch/,
4509 Recursive Make Considered Harmful}, the preceding sections on the use of
4510 make recursion will probably come as unwelcome advice. For those who
4511 haven't read the paper, Miller's main thesis is that recursive
4512 @command{make} invocations are both slow and error-prone.
4514 Automake provides sufficient cross-directory support @footnote{We
4515 believe. This work is new and there are probably warts.
4516 @xref{Introduction}, for information on reporting bugs.} to enable you
4517 to write a single @file{Makefile.am} for a complex multi-directory
4520 By default an installable file specified in a subdirectory will have its
4521 directory name stripped before installation. For instance, in this
4522 example, the header file will be installed as
4523 @file{$(includedir)/stdio.h}:
4526 include_HEADERS = inc/stdio.h
4530 @cindex @code{nobase_} prefix
4531 @cindex Path stripping, avoiding
4532 @cindex Avoiding path stripping
4534 However, the @samp{nobase_} prefix can be used to circumvent this path
4535 stripping. In this example, the header file will be installed as
4536 @file{$(includedir)/sys/types.h}:
4539 nobase_include_HEADERS = sys/types.h
4542 @cindex @code{nobase_} and @code{dist_} or @code{nodist_}
4543 @cindex @code{dist_} and @code{nobase_}
4544 @cindex @code{nodist_} and @code{nobase_}
4548 @samp{nobase_} should be specified first when used in conjunction with
4549 either @samp{dist_} or @samp{nodist_} (@pxref{Fine-grained Distribution
4550 Control}). For instance:
4553 nobase_dist_pkgdata_DATA = images/vortex.pgm sounds/whirl.ogg
4556 Finally, note that a variable using the @samp{nobase_} prefix can
4557 often be replaced by several variables, one for each destination
4558 directory (@pxref{Uniform}). For instance, the last example could be
4559 rewritten as follows:
4561 @c Keep in sync with primary-prefix-couples-documented-valid.sh
4563 imagesdir = $(pkgdatadir)/images
4564 soundsdir = $(pkgdatadir)/sounds
4565 dist_images_DATA = images/vortex.pgm
4566 dist_sounds_DATA = sounds/whirl.ogg
4570 This latter syntax makes it possible to change one destination
4571 directory without changing the layout of the source tree.
4573 Currently, @samp{nobase_*_LTLIBRARIES} are the only exception to this
4574 rule, in that there is no particular installation order guarantee for
4575 an otherwise equivalent set of variables without @samp{nobase_} prefix.
4578 @section Nesting Packages
4579 @cindex Nesting packages
4581 @acindex AC_CONFIG_SUBDIRS
4582 @acindex AC_CONFIG_AUX_DIR
4585 In the GNU Build System, packages can be nested to arbitrary depth.
4586 This means that a package can embed other packages with their own
4587 @file{configure}, @file{Makefile}s, etc.
4589 These other packages should just appear as subdirectories of their
4590 parent package. They must be listed in @code{SUBDIRS} like other
4591 ordinary directories. However the subpackage's @file{Makefile}s
4592 should be output by its own @file{configure} script, not by the
4593 parent's @file{configure}. This is achieved using the
4594 @code{AC_CONFIG_SUBDIRS} Autoconf macro (@pxref{Subdirectories,
4595 AC_CONFIG_SUBDIRS, Configuring Other Packages in Subdirectories,
4596 autoconf, The Autoconf Manual}).
4598 Here is an example package for an @code{arm} program that links with
4599 a @code{hand} library that is a nested package in subdirectory
4602 @code{arm}'s @file{configure.ac}:
4605 AC_INIT([arm], [1.0])
4606 AC_CONFIG_AUX_DIR([.])
4609 AC_CONFIG_FILES([Makefile])
4610 # Call hand's ./configure script recursively.
4611 AC_CONFIG_SUBDIRS([hand])
4615 @code{arm}'s @file{Makefile.am}:
4618 # Build the library in the hand subdirectory first.
4621 # Include hand's header when compiling this directory.
4622 AM_CPPFLAGS = -I$(srcdir)/hand
4626 # link with the hand library.
4627 arm_LDADD = hand/libhand.a
4630 Now here is @code{hand}'s @file{hand/configure.ac}:
4633 AC_INIT([hand], [1.2])
4634 AC_CONFIG_AUX_DIR([.])
4639 AC_CONFIG_FILES([Makefile])
4644 and its @file{hand/Makefile.am}:
4647 lib_LIBRARIES = libhand.a
4648 libhand_a_SOURCES = hand.c
4651 When @samp{make dist} is run from the top-level directory it will
4652 create an archive @file{arm-1.0.tar.gz} that contains the @code{arm}
4653 code as well as the @file{hand} subdirectory. This package can be
4654 built and installed like any ordinary package, with the usual
4655 @samp{./configure && make && make install} sequence (the @code{hand}
4656 subpackage will be built and installed by the process).
4658 When @samp{make dist} is run from the hand directory, it will create a
4659 self-contained @file{hand-1.2.tar.gz} archive. So although it appears
4660 to be embedded in another package, it can still be used separately.
4662 The purpose of the @samp{AC_CONFIG_AUX_DIR([.])} instruction is to
4663 force Automake and Autoconf to search for auxiliary scripts in the
4664 current directory. For instance, this means that there will be two
4665 copies of @file{install-sh}: one in the top-level of the @code{arm}
4666 package, and another one in the @file{hand/} subdirectory for the
4667 @code{hand} package.
4669 The historical default is to search for these auxiliary scripts in
4670 the parent directory and the grandparent directory. So if the
4671 @samp{AC_CONFIG_AUX_DIR([.])} line was removed from
4672 @file{hand/configure.ac}, that subpackage would share the auxiliary
4673 script of the @code{arm} package. This may looks like a gain in size
4674 (a few kilobytes), but it is actually a loss of modularity as the
4675 @code{hand} subpackage is no longer self-contained (@samp{make dist}
4676 in the subdirectory will not work anymore).
4678 Packages that do not use Automake need more work to be integrated this
4679 way. @xref{Third-Party Makefiles}.
4682 @chapter Building Programs and Libraries
4684 A large part of Automake's functionality is dedicated to making it easy
4685 to build programs and libraries.
4688 * A Program:: Building a program
4689 * A Library:: Building a library
4690 * A Shared Library:: Building a Libtool library
4691 * Program and Library Variables:: Variables controlling program and
4693 * Default _SOURCES:: Default source files
4694 * LIBOBJS:: Special handling for LIBOBJS and ALLOCA
4695 * Program Variables:: Variables used when building a program
4696 * Yacc and Lex:: Yacc and Lex support
4697 * C++ Support:: Compiling C++ sources
4698 * Objective C Support:: Compiling Objective C sources
4699 * Objective C++ Support:: Compiling Objective C++ sources
4700 * Unified Parallel C Support:: Compiling Unified Parallel C sources
4701 * Assembly Support:: Compiling assembly sources
4702 * Fortran 77 Support:: Compiling Fortran 77 sources
4703 * Fortran 9x Support:: Compiling Fortran 9x sources
4704 * Java Support with gcj:: Compiling Java sources using gcj
4705 * Vala Support:: Compiling Vala sources
4706 * Support for Other Languages:: Compiling other languages
4707 * Dependencies:: Automatic dependency tracking
4708 * EXEEXT:: Support for executable extensions
4713 @section Building a program
4715 In order to build a program, you need to tell Automake which sources
4716 are part of it, and which libraries it should be linked with.
4718 This section also covers conditional compilation of sources or
4719 programs. Most of the comments about these also apply to libraries
4720 (@pxref{A Library}) and libtool libraries (@pxref{A Shared Library}).
4723 * Program Sources:: Defining program sources
4724 * Linking:: Linking with libraries or extra objects
4725 * Conditional Sources:: Handling conditional sources
4726 * Conditional Programs:: Building a program conditionally
4729 @node Program Sources
4730 @subsection Defining program sources
4732 @cindex @code{PROGRAMS}, @code{bindir}
4734 @vindex bin_PROGRAMS
4735 @vindex sbin_PROGRAMS
4736 @vindex libexec_PROGRAMS
4737 @vindex pkglibexec_PROGRAMS
4738 @vindex noinst_PROGRAMS
4739 @vindex check_PROGRAMS
4741 In a directory containing source that gets built into a program (as
4742 opposed to a library or a script), the @code{PROGRAMS} primary is used.
4743 Programs can be installed in @code{bindir}, @code{sbindir},
4744 @code{libexecdir}, @code{pkglibexecdir}, or not at all
4745 (@code{noinst_}). They can also be built only for @samp{make check}, in
4746 which case the prefix is @samp{check_}.
4751 bin_PROGRAMS = hello
4754 In this simple case, the resulting @file{Makefile.in} will contain code
4755 to generate a program named @code{hello}.
4757 Associated with each program are several assisting variables that are
4758 named after the program. These variables are all optional, and have
4759 reasonable defaults. Each variable, its use, and default is spelled out
4760 below; we use the ``hello'' example throughout.
4762 The variable @code{hello_SOURCES} is used to specify which source files
4763 get built into an executable:
4766 hello_SOURCES = hello.c version.c getopt.c getopt1.c getopt.h system.h
4769 This causes each mentioned @file{.c} file to be compiled into the
4770 corresponding @file{.o}. Then all are linked to produce @file{hello}.
4772 @cindex @code{_SOURCES} primary, defined
4773 @cindex @code{SOURCES} primary, defined
4774 @cindex Primary variable, @code{SOURCES}
4777 If @code{hello_SOURCES} is not specified, then it defaults to the single
4778 file @file{hello.c} (@pxref{Default _SOURCES}).
4782 Multiple programs can be built in a single directory. Multiple programs
4783 can share a single source file, which must be listed in each
4784 @code{_SOURCES} definition.
4786 @cindex Header files in @code{_SOURCES}
4787 @cindex @code{_SOURCES} and header files
4789 Header files listed in a @code{_SOURCES} definition will be included in
4790 the distribution but otherwise ignored. In case it isn't obvious, you
4791 should not include the header file generated by @file{configure} in a
4792 @code{_SOURCES} variable; this file should not be distributed. Lex
4793 (@file{.l}) and Yacc (@file{.y}) files can also be listed; see @ref{Yacc
4798 @subsection Linking the program
4800 If you need to link against libraries that are not found by
4801 @command{configure}, you can use @code{LDADD} to do so. This variable is
4802 used to specify additional objects or libraries to link with; it is
4803 inappropriate for specifying specific linker flags, you should use
4804 @code{AM_LDFLAGS} for this purpose.
4808 @cindex @code{prog_LDADD}, defined
4810 Sometimes, multiple programs are built in one directory but do not share
4811 the same link-time requirements. In this case, you can use the
4812 @code{@var{prog}_LDADD} variable (where @var{prog} is the name of the
4813 program as it appears in some @code{_PROGRAMS} variable, and usually
4814 written in lowercase) to override @code{LDADD}. If this variable exists
4815 for a given program, then that program is not linked using @code{LDADD}.
4818 For instance, in GNU cpio, @code{pax}, @code{cpio} and @code{mt} are
4819 linked against the library @file{libcpio.a}. However, @code{rmt} is
4820 built in the same directory, and has no such link requirement. Also,
4821 @code{mt} and @code{rmt} are only built on certain architectures. Here
4822 is what cpio's @file{src/Makefile.am} looks like (abridged):
4825 bin_PROGRAMS = cpio pax $(MT)
4826 libexec_PROGRAMS = $(RMT)
4827 EXTRA_PROGRAMS = mt rmt
4829 LDADD = ../lib/libcpio.a $(INTLLIBS)
4832 cpio_SOURCES = @dots{}
4833 pax_SOURCES = @dots{}
4834 mt_SOURCES = @dots{}
4835 rmt_SOURCES = @dots{}
4838 @cindex @code{_LDFLAGS}, defined
4839 @vindex maude_LDFLAGS
4840 @code{@var{prog}_LDADD} is inappropriate for passing program-specific
4841 linker flags (except for @option{-l}, @option{-L}, @option{-dlopen} and
4842 @option{-dlpreopen}). So, use the @code{@var{prog}_LDFLAGS} variable for
4845 @cindex @code{_DEPENDENCIES}, defined
4846 @vindex maude_DEPENDENCIES
4847 @vindex EXTRA_maude_DEPENDENCIES
4848 It is also occasionally useful to have a program depend on some other
4849 target that is not actually part of that program. This can be done
4850 using either the @code{@var{prog}_DEPENDENCIES} or the
4851 @code{EXTRA_@var{prog}_DEPENDENCIES} variable. Each program depends on
4852 the contents both variables, but no further interpretation is done.
4854 Since these dependencies are associated to the link rule used to
4855 create the programs they should normally list files used by the link
4856 command. That is @file{*.$(OBJEXT)}, @file{*.a}, or @file{*.la}
4857 files. In rare cases you may need to add other kinds of files such as
4858 linker scripts, but @emph{listing a source file in
4859 @code{_DEPENDENCIES} is wrong}. If some source file needs to be built
4860 before all the components of a program are built, consider using the
4861 @code{BUILT_SOURCES} variable instead (@pxref{Sources}).
4863 If @code{@var{prog}_DEPENDENCIES} is not supplied, it is computed by
4864 Automake. The automatically-assigned value is the contents of
4865 @code{@var{prog}_LDADD}, with most configure substitutions, @option{-l},
4866 @option{-L}, @option{-dlopen} and @option{-dlpreopen} options removed. The
4867 configure substitutions that are left in are only @samp{$(LIBOBJS)} and
4868 @samp{$(ALLOCA)}; these are left because it is known that they will not
4869 cause an invalid value for @code{@var{prog}_DEPENDENCIES} to be
4872 @ref{Conditional Sources} shows a situation where @code{_DEPENDENCIES}
4875 The @code{EXTRA_@var{prog}_DEPENDENCIES} may be useful for cases where
4876 you merely want to augment the @command{automake}-generated
4877 @code{@var{prog}_DEPENDENCIES} rather than replacing it.
4879 @cindex @code{LDADD} and @option{-l}
4880 @cindex @option{-l} and @code{LDADD}
4881 We recommend that you avoid using @option{-l} options in @code{LDADD}
4882 or @code{@var{prog}_LDADD} when referring to libraries built by your
4883 package. Instead, write the file name of the library explicitly as in
4884 the above @code{cpio} example. Use @option{-l} only to list
4885 third-party libraries. If you follow this rule, the default value of
4886 @code{@var{prog}_DEPENDENCIES} will list all your local libraries and
4887 omit the other ones.
4890 @node Conditional Sources
4891 @subsection Conditional compilation of sources
4893 You can't put a configure substitution (e.g., @samp{@@FOO@@} or
4894 @samp{$(FOO)} where @code{FOO} is defined via @code{AC_SUBST}) into a
4895 @code{_SOURCES} variable. The reason for this is a bit hard to
4896 explain, but suffice to say that it simply won't work. Automake will
4897 give an error if you try to do this.
4899 Fortunately there are two other ways to achieve the same result. One is
4900 to use configure substitutions in @code{_LDADD} variables, the other is
4901 to use an Automake conditional.
4903 @subsubheading Conditional Compilation using @code{_LDADD} Substitutions
4905 @cindex @code{EXTRA_prog_SOURCES}, defined
4907 Automake must know all the source files that could possibly go into a
4908 program, even if not all the files are built in every circumstance. Any
4909 files that are only conditionally built should be listed in the
4910 appropriate @code{EXTRA_} variable. For instance, if
4911 @file{hello-linux.c} or @file{hello-generic.c} were conditionally included
4912 in @code{hello}, the @file{Makefile.am} would contain:
4915 bin_PROGRAMS = hello
4916 hello_SOURCES = hello-common.c
4917 EXTRA_hello_SOURCES = hello-linux.c hello-generic.c
4918 hello_LDADD = $(HELLO_SYSTEM)
4919 hello_DEPENDENCIES = $(HELLO_SYSTEM)
4923 You can then setup the @samp{$(HELLO_SYSTEM)} substitution from
4924 @file{configure.ac}:
4929 *linux*) HELLO_SYSTEM='hello-linux.$(OBJEXT)' ;;
4930 *) HELLO_SYSTEM='hello-generic.$(OBJEXT)' ;;
4932 AC_SUBST([HELLO_SYSTEM])
4936 In this case, the variable @code{HELLO_SYSTEM} should be replaced by
4937 either @file{hello-linux.o} or @file{hello-generic.o}, and added to
4938 both @code{hello_DEPENDENCIES} and @code{hello_LDADD} in order to be
4939 built and linked in.
4941 @subsubheading Conditional Compilation using Automake Conditionals
4943 An often simpler way to compile source files conditionally is to use
4944 Automake conditionals. For instance, you could use this
4945 @file{Makefile.am} construct to build the same @file{hello} example:
4948 bin_PROGRAMS = hello
4950 hello_SOURCES = hello-linux.c hello-common.c
4952 hello_SOURCES = hello-generic.c hello-common.c
4956 In this case, @file{configure.ac} should setup the @code{LINUX}
4957 conditional using @code{AM_CONDITIONAL} (@pxref{Conditionals}).
4959 When using conditionals like this you don't need to use the
4960 @code{EXTRA_} variable, because Automake will examine the contents of
4961 each variable to construct the complete list of source files.
4963 If your program uses a lot of files, you will probably prefer a
4964 conditional @samp{+=}.
4967 bin_PROGRAMS = hello
4968 hello_SOURCES = hello-common.c
4970 hello_SOURCES += hello-linux.c
4972 hello_SOURCES += hello-generic.c
4976 @node Conditional Programs
4977 @subsection Conditional compilation of programs
4978 @cindex Conditional programs
4979 @cindex Programs, conditional
4981 Sometimes it is useful to determine the programs that are to be built
4982 at configure time. For instance, GNU @code{cpio} only builds
4983 @code{mt} and @code{rmt} under special circumstances. The means to
4984 achieve conditional compilation of programs are the same you can use
4985 to compile source files conditionally: substitutions or conditionals.
4987 @subsubheading Conditional Programs using @command{configure} Substitutions
4989 @vindex EXTRA_PROGRAMS
4990 @cindex @code{EXTRA_PROGRAMS}, defined
4991 In this case, you must notify Automake of all the programs that can
4992 possibly be built, but at the same time cause the generated
4993 @file{Makefile.in} to use the programs specified by @command{configure}.
4994 This is done by having @command{configure} substitute values into each
4995 @code{_PROGRAMS} definition, while listing all optionally built programs
4996 in @code{EXTRA_PROGRAMS}.
4999 bin_PROGRAMS = cpio pax $(MT)
5000 libexec_PROGRAMS = $(RMT)
5001 EXTRA_PROGRAMS = mt rmt
5004 As explained in @ref{EXEEXT}, Automake will rewrite
5005 @code{bin_PROGRAMS}, @code{libexec_PROGRAMS}, and
5006 @code{EXTRA_PROGRAMS}, appending @samp{$(EXEEXT)} to each binary.
5007 Obviously it cannot rewrite values obtained at run-time through
5008 @command{configure} substitutions, therefore you should take care of
5009 appending @samp{$(EXEEXT)} yourself, as in @samp{AC_SUBST([MT],
5010 ['mt$@{EXEEXT@}'])}.
5012 @subsubheading Conditional Programs using Automake Conditionals
5014 You can also use Automake conditionals (@pxref{Conditionals}) to
5015 select programs to be built. In this case you don't have to worry
5016 about @samp{$(EXEEXT)} or @code{EXTRA_PROGRAMS}.
5018 @c Keep in sync with exeext.sh
5020 bin_PROGRAMS = cpio pax
5025 libexec_PROGRAMS = rmt
5031 @section Building a library
5033 @cindex @code{_LIBRARIES} primary, defined
5034 @cindex @code{LIBRARIES} primary, defined
5035 @cindex Primary variable, @code{LIBRARIES}
5038 @vindex lib_LIBRARIES
5039 @vindex pkglib_LIBRARIES
5040 @vindex noinst_LIBRARIES
5042 Building a library is much like building a program. In this case, the
5043 name of the primary is @code{LIBRARIES}. Libraries can be installed in
5044 @code{libdir} or @code{pkglibdir}.
5046 @xref{A Shared Library}, for information on how to build shared
5047 libraries using libtool and the @code{LTLIBRARIES} primary.
5049 Each @code{_LIBRARIES} variable is a list of the libraries to be built.
5050 For instance, to create a library named @file{libcpio.a}, but not install
5051 it, you would write:
5054 noinst_LIBRARIES = libcpio.a
5055 libcpio_a_SOURCES = @dots{}
5058 The sources that go into a library are determined exactly as they are
5059 for programs, via the @code{_SOURCES} variables. Note that the library
5060 name is canonicalized (@pxref{Canonicalization}), so the @code{_SOURCES}
5061 variable corresponding to @file{libcpio.a} is @samp{libcpio_a_SOURCES},
5062 not @samp{libcpio.a_SOURCES}.
5064 @vindex maude_LIBADD
5065 Extra objects can be added to a library using the
5066 @code{@var{library}_LIBADD} variable. This should be used for objects
5067 determined by @command{configure}. Again from @code{cpio}:
5069 @c Keep in sync with pr401c.sh
5071 libcpio_a_LIBADD = $(LIBOBJS) $(ALLOCA)
5074 In addition, sources for extra objects that will not exist until
5075 configure-time must be added to the @code{BUILT_SOURCES} variable
5078 Building a static library is done by compiling all object files, then
5079 by invoking @samp{$(AR) $(ARFLAGS)} followed by the name of the
5080 library and the list of objects, and finally by calling
5081 @samp{$(RANLIB)} on that library. You should call
5082 @code{AC_PROG_RANLIB} from your @file{configure.ac} to define
5083 @code{RANLIB} (Automake will complain otherwise). You should also
5084 call @code{AM_PROG_AR} to define @code{AR}, in order to support unusual
5085 archivers such as Microsoft lib. @code{ARFLAGS} will default to
5086 @code{cru}; you can override this variable by setting it in your
5087 @file{Makefile.am} or by @code{AC_SUBST}ing it from your
5088 @file{configure.ac}. You can override the @code{AR} variable by
5089 defining a per-library @code{maude_AR} variable (@pxref{Program and
5090 Library Variables}).
5092 @cindex Empty libraries
5093 Be careful when selecting library components conditionally. Because
5094 building an empty library is not portable, you should ensure that any
5095 library always contains at least one object.
5097 To use a static library when building a program, add it to
5098 @code{LDADD} for this program. In the following example, the program
5099 @file{cpio} is statically linked with the library @file{libcpio.a}.
5102 noinst_LIBRARIES = libcpio.a
5103 libcpio_a_SOURCES = @dots{}
5106 cpio_SOURCES = cpio.c @dots{}
5107 cpio_LDADD = libcpio.a
5111 @node A Shared Library
5112 @section Building a Shared Library
5114 @cindex Shared libraries, support for
5116 Building shared libraries portably is a relatively complex matter.
5117 For this reason, GNU Libtool (@pxref{Top, , Introduction, libtool, The
5118 Libtool Manual}) was created to help build shared libraries in a
5119 platform-independent way.
5122 * Libtool Concept:: Introducing Libtool
5123 * Libtool Libraries:: Declaring Libtool Libraries
5124 * Conditional Libtool Libraries:: Building Libtool Libraries Conditionally
5125 * Conditional Libtool Sources:: Choosing Library Sources Conditionally
5126 * Libtool Convenience Libraries:: Building Convenience Libtool Libraries
5127 * Libtool Modules:: Building Libtool Modules
5128 * Libtool Flags:: Using _LIBADD, _LDFLAGS, and _LIBTOOLFLAGS
5129 * LTLIBOBJS:: Using $(LTLIBOBJS) and $(LTALLOCA)
5130 * Libtool Issues:: Common Issues Related to Libtool's Use
5133 @node Libtool Concept
5134 @subsection The Libtool Concept
5136 @cindex @command{libtool}, introduction
5137 @cindex libtool library, definition
5138 @cindex suffix @file{.la}, defined
5139 @cindex @file{.la} suffix, defined
5141 Libtool abstracts shared and static libraries into a unified concept
5142 henceforth called @dfn{libtool libraries}. Libtool libraries are
5143 files using the @file{.la} suffix, and can designate a static library,
5144 a shared library, or maybe both. Their exact nature cannot be
5145 determined until @file{./configure} is run: not all platforms support
5146 all kinds of libraries, and users can explicitly select which
5147 libraries should be built. (However the package's maintainers can
5148 tune the default, @pxref{AC_PROG_LIBTOOL, , The @code{AC_PROG_LIBTOOL}
5149 macro, libtool, The Libtool Manual}.)
5151 @cindex suffix @file{.lo}, defined
5152 Because object files for shared and static libraries must be compiled
5153 differently, libtool is also used during compilation. Object files
5154 built by libtool are called @dfn{libtool objects}: these are files
5155 using the @file{.lo} suffix. Libtool libraries are built from these
5158 You should not assume anything about the structure of @file{.la} or
5159 @file{.lo} files and how libtool constructs them: this is libtool's
5160 concern, and the last thing one wants is to learn about libtool's
5161 guts. However the existence of these files matters, because they are
5162 used as targets and dependencies in @file{Makefile}s rules when
5163 building libtool libraries. There are situations where you may have
5164 to refer to these, for instance when expressing dependencies for
5165 building source files conditionally (@pxref{Conditional Libtool
5168 @cindex @file{libltdl}, introduction
5170 People considering writing a plug-in system, with dynamically loaded
5171 modules, should look into @file{libltdl}: libtool's dlopening library
5172 (@pxref{Using libltdl, , Using libltdl, libtool, The Libtool Manual}).
5173 This offers a portable dlopening facility to load libtool libraries
5174 dynamically, and can also achieve static linking where unavoidable.
5176 Before we discuss how to use libtool with Automake in details, it
5177 should be noted that the libtool manual also has a section about how
5178 to use Automake with libtool (@pxref{Using Automake, , Using Automake
5179 with Libtool, libtool, The Libtool Manual}).
5181 @node Libtool Libraries
5182 @subsection Building Libtool Libraries
5184 @cindex @code{_LTLIBRARIES} primary, defined
5185 @cindex @code{LTLIBRARIES} primary, defined
5186 @cindex Primary variable, @code{LTLIBRARIES}
5187 @cindex Example of shared libraries
5188 @vindex lib_LTLIBRARIES
5189 @vindex pkglib_LTLIBRARIES
5190 @vindex _LTLIBRARIES
5192 Automake uses libtool to build libraries declared with the
5193 @code{LTLIBRARIES} primary. Each @code{_LTLIBRARIES} variable is a
5194 list of libtool libraries to build. For instance, to create a libtool
5195 library named @file{libgettext.la}, and install it in @code{libdir},
5199 lib_LTLIBRARIES = libgettext.la
5200 libgettext_la_SOURCES = gettext.c gettext.h @dots{}
5203 Automake predefines the variable @code{pkglibdir}, so you can use
5204 @code{pkglib_LTLIBRARIES} to install libraries in
5205 @samp{$(libdir)/@@PACKAGE@@/}.
5207 If @file{gettext.h} is a public header file that needs to be installed
5208 in order for people to use the library, it should be declared using a
5209 @code{_HEADERS} variable, not in @code{libgettext_la_SOURCES}.
5210 Headers listed in the latter should be internal headers that are not
5211 part of the public interface.
5214 lib_LTLIBRARIES = libgettext.la
5215 libgettext_la_SOURCES = gettext.c @dots{}
5216 include_HEADERS = gettext.h @dots{}
5219 A package can build and install such a library along with other
5220 programs that use it. This dependency should be specified using
5221 @code{LDADD}. The following example builds a program named
5222 @file{hello} that is linked with @file{libgettext.la}.
5225 lib_LTLIBRARIES = libgettext.la
5226 libgettext_la_SOURCES = gettext.c @dots{}
5228 bin_PROGRAMS = hello
5229 hello_SOURCES = hello.c @dots{}
5230 hello_LDADD = libgettext.la
5234 Whether @file{hello} is statically or dynamically linked with
5235 @file{libgettext.la} is not yet known: this will depend on the
5236 configuration of libtool and the capabilities of the host.
5239 @node Conditional Libtool Libraries
5240 @subsection Building Libtool Libraries Conditionally
5241 @cindex libtool libraries, conditional
5242 @cindex conditional libtool libraries
5244 Like conditional programs (@pxref{Conditional Programs}), there are
5245 two main ways to build conditional libraries: using Automake
5246 conditionals or using Autoconf @code{AC_SUBST}itutions.
5248 The important implementation detail you have to be aware of is that
5249 the place where a library will be installed matters to libtool: it
5250 needs to be indicated @emph{at link-time} using the @option{-rpath}
5253 For libraries whose destination directory is known when Automake runs,
5254 Automake will automatically supply the appropriate @option{-rpath}
5255 option to libtool. This is the case for libraries listed explicitly in
5256 some installable @code{_LTLIBRARIES} variables such as
5257 @code{lib_LTLIBRARIES}.
5259 However, for libraries determined at configure time (and thus
5260 mentioned in @code{EXTRA_LTLIBRARIES}), Automake does not know the
5261 final installation directory. For such libraries you must add the
5262 @option{-rpath} option to the appropriate @code{_LDFLAGS} variable by
5265 The examples below illustrate the differences between these two methods.
5267 Here is an example where @code{WANTEDLIBS} is an @code{AC_SUBST}ed
5268 variable set at @file{./configure}-time to either @file{libfoo.la},
5269 @file{libbar.la}, both, or none. Although @samp{$(WANTEDLIBS)}
5270 appears in the @code{lib_LTLIBRARIES}, Automake cannot guess it
5271 relates to @file{libfoo.la} or @file{libbar.la} at the time it creates
5272 the link rule for these two libraries. Therefore the @option{-rpath}
5273 argument must be explicitly supplied.
5275 @c Keep in sync with ltcond.sh
5277 EXTRA_LTLIBRARIES = libfoo.la libbar.la
5278 lib_LTLIBRARIES = $(WANTEDLIBS)
5279 libfoo_la_SOURCES = foo.c @dots{}
5280 libfoo_la_LDFLAGS = -rpath '$(libdir)'
5281 libbar_la_SOURCES = bar.c @dots{}
5282 libbar_la_LDFLAGS = -rpath '$(libdir)'
5285 Here is how the same @file{Makefile.am} would look using Automake
5286 conditionals named @code{WANT_LIBFOO} and @code{WANT_LIBBAR}. Now
5287 Automake is able to compute the @option{-rpath} setting itself, because
5288 it's clear that both libraries will end up in @samp{$(libdir)} if they
5291 @c Keep in sync with ltcond.sh
5295 lib_LTLIBRARIES += libfoo.la
5298 lib_LTLIBRARIES += libbar.la
5300 libfoo_la_SOURCES = foo.c @dots{}
5301 libbar_la_SOURCES = bar.c @dots{}
5304 @node Conditional Libtool Sources
5305 @subsection Libtool Libraries with Conditional Sources
5307 Conditional compilation of sources in a library can be achieved in the
5308 same way as conditional compilation of sources in a program
5309 (@pxref{Conditional Sources}). The only difference is that
5310 @code{_LIBADD} should be used instead of @code{_LDADD} and that it
5311 should mention libtool objects (@file{.lo} files).
5313 So, to mimic the @file{hello} example from @ref{Conditional Sources},
5314 we could build a @file{libhello.la} library using either
5315 @file{hello-linux.c} or @file{hello-generic.c} with the following
5318 @c Keep in sync with ltcond2.sh
5320 lib_LTLIBRARIES = libhello.la
5321 libhello_la_SOURCES = hello-common.c
5322 EXTRA_libhello_la_SOURCES = hello-linux.c hello-generic.c
5323 libhello_la_LIBADD = $(HELLO_SYSTEM)
5324 libhello_la_DEPENDENCIES = $(HELLO_SYSTEM)
5328 And make sure @command{configure} defines @code{HELLO_SYSTEM} as
5329 either @file{hello-linux.lo} or @file{hello-@-generic.lo}.
5331 Or we could simply use an Automake conditional as follows.
5333 @c Keep in sync with ltcond2.sh
5335 lib_LTLIBRARIES = libhello.la
5336 libhello_la_SOURCES = hello-common.c
5338 libhello_la_SOURCES += hello-linux.c
5340 libhello_la_SOURCES += hello-generic.c
5344 @node Libtool Convenience Libraries
5345 @subsection Libtool Convenience Libraries
5346 @cindex convenience libraries, libtool
5347 @cindex libtool convenience libraries
5348 @vindex noinst_LTLIBRARIES
5349 @vindex check_LTLIBRARIES
5351 Sometimes you want to build libtool libraries that should not be
5352 installed. These are called @dfn{libtool convenience libraries} and
5353 are typically used to encapsulate many sublibraries, later gathered
5354 into one big installed library.
5356 Libtool convenience libraries are declared by directory-less variables
5357 such as @code{noinst_LTLIBRARIES}, @code{check_LTLIBRARIES}, or even
5358 @code{EXTRA_LTLIBRARIES}. Unlike installed libtool libraries they do
5359 not need an @option{-rpath} flag at link time (actually this is the only
5362 Convenience libraries listed in @code{noinst_LTLIBRARIES} are always
5363 built. Those listed in @code{check_LTLIBRARIES} are built only upon
5364 @samp{make check}. Finally, libraries listed in
5365 @code{EXTRA_LTLIBRARIES} are never built explicitly: Automake outputs
5366 rules to build them, but if the library does not appear as a Makefile
5367 dependency anywhere it won't be built (this is why
5368 @code{EXTRA_LTLIBRARIES} is used for conditional compilation).
5370 Here is a sample setup merging libtool convenience libraries from
5371 subdirectories into one main @file{libtop.la} library.
5373 @c Keep in sync with ltconv.sh
5375 # -- Top-level Makefile.am --
5376 SUBDIRS = sub1 sub2 @dots{}
5377 lib_LTLIBRARIES = libtop.la
5379 libtop_la_LIBADD = \
5384 # -- sub1/Makefile.am --
5385 noinst_LTLIBRARIES = libsub1.la
5386 libsub1_la_SOURCES = @dots{}
5388 # -- sub2/Makefile.am --
5389 # showing nested convenience libraries
5390 SUBDIRS = sub2.1 sub2.2 @dots{}
5391 noinst_LTLIBRARIES = libsub2.la
5392 libsub2_la_SOURCES =
5393 libsub2_la_LIBADD = \
5399 When using such setup, beware that @command{automake} will assume
5400 @file{libtop.la} is to be linked with the C linker. This is because
5401 @code{libtop_la_SOURCES} is empty, so @command{automake} picks C as
5402 default language. If @code{libtop_la_SOURCES} was not empty,
5403 @command{automake} would select the linker as explained in @ref{How
5404 the Linker is Chosen}.
5406 If one of the sublibraries contains non-C source, it is important that
5407 the appropriate linker be chosen. One way to achieve this is to
5408 pretend that there is such a non-C file among the sources of the
5409 library, thus forcing @command{automake} to select the appropriate
5410 linker. Here is the top-level @file{Makefile} of our example updated
5411 to force C++ linking.
5414 SUBDIRS = sub1 sub2 @dots{}
5415 lib_LTLIBRARIES = libtop.la
5417 # Dummy C++ source to cause C++ linking.
5418 nodist_EXTRA_libtop_la_SOURCES = dummy.cxx
5419 libtop_la_LIBADD = \
5425 @samp{EXTRA_*_SOURCES} variables are used to keep track of source
5426 files that might be compiled (this is mostly useful when doing
5427 conditional compilation using @code{AC_SUBST}, @pxref{Conditional
5428 Libtool Sources}), and the @code{nodist_} prefix means the listed
5429 sources are not to be distributed (@pxref{Program and Library
5430 Variables}). In effect the file @file{dummy.cxx} does not need to
5431 exist in the source tree. Of course if you have some real source file
5432 to list in @code{libtop_la_SOURCES} there is no point in cheating with
5433 @code{nodist_EXTRA_libtop_la_SOURCES}.
5436 @node Libtool Modules
5437 @subsection Libtool Modules
5438 @cindex modules, libtool
5439 @cindex libtool modules
5440 @cindex @option{-module}, libtool
5442 These are libtool libraries meant to be dlopened. They are
5443 indicated to libtool by passing @option{-module} at link-time.
5446 pkglib_LTLIBRARIES = mymodule.la
5447 mymodule_la_SOURCES = doit.c
5448 mymodule_la_LDFLAGS = -module
5451 Ordinarily, Automake requires that a library's name start with
5452 @code{lib}. However, when building a dynamically loadable module you
5453 might wish to use a "nonstandard" name. Automake will not complain
5454 about such nonstandard names if it knows the library being built is a
5455 libtool module, i.e., if @option{-module} explicitly appears in the
5456 library's @code{_LDFLAGS} variable (or in the common @code{AM_LDFLAGS}
5457 variable when no per-library @code{_LDFLAGS} variable is defined).
5459 As always, @code{AC_SUBST} variables are black boxes to Automake since
5460 their values are not yet known when @command{automake} is run.
5461 Therefore if @option{-module} is set via such a variable, Automake
5462 cannot notice it and will proceed as if the library was an ordinary
5463 libtool library, with strict naming.
5465 If @code{mymodule_la_SOURCES} is not specified, then it defaults to
5466 the single file @file{mymodule.c} (@pxref{Default _SOURCES}).
5469 @subsection @code{_LIBADD}, @code{_LDFLAGS}, and @code{_LIBTOOLFLAGS}
5470 @cindex @code{_LIBADD}, libtool
5471 @cindex @code{_LDFLAGS}, libtool
5472 @cindex @code{_LIBTOOLFLAGS}, libtool
5473 @vindex AM_LIBTOOLFLAGS
5474 @vindex LIBTOOLFLAGS
5475 @vindex maude_LIBTOOLFLAGS
5477 As shown in previous sections, the @samp{@var{library}_LIBADD}
5478 variable should be used to list extra libtool objects (@file{.lo}
5479 files) or libtool libraries (@file{.la}) to add to @var{library}.
5481 The @samp{@var{library}_LDFLAGS} variable is the place to list
5482 additional libtool linking flags, such as @option{-version-info},
5483 @option{-static}, and a lot more. @xref{Link mode, , Link mode,
5484 libtool, The Libtool Manual}.
5486 The @command{libtool} command has two kinds of options: mode-specific
5487 options and generic options. Mode-specific options such as the
5488 aforementioned linking flags should be lumped with the other flags
5489 passed to the tool invoked by @command{libtool} (hence the use of
5490 @samp{@var{library}_LDFLAGS} for libtool linking flags). Generic
5491 options include @option{--tag=@var{tag}} and @option{--silent}
5492 (@pxref{Invoking libtool, , Invoking @command{libtool}, libtool, The
5493 Libtool Manual} for more options) should appear before the mode
5494 selection on the command line; in @file{Makefile.am}s they should
5495 be listed in the @samp{@var{library}_LIBTOOLFLAGS} variable.
5497 If @samp{@var{library}_LIBTOOLFLAGS} is not defined, then the variable
5498 @code{AM_LIBTOOLFLAGS} is used instead.
5500 These flags are passed to libtool after the @option{--tag=@var{tag}}
5501 option computed by Automake (if any), so
5502 @samp{@var{library}_LIBTOOLFLAGS} (or @code{AM_LIBTOOLFLAGS}) is a
5503 good place to override or supplement the @option{--tag=@var{tag}}
5506 The libtool rules also use a @code{LIBTOOLFLAGS} variable that should
5507 not be set in @file{Makefile.am}: this is a user variable (@pxref{Flag
5508 Variables Ordering}. It allows users to run @samp{make
5509 LIBTOOLFLAGS=--silent}, for instance. Note that the verbosity of
5510 @command{libtool} can also be influenced with the Automake
5511 @option{silent-rules} option (@pxref{Options}).
5514 @node LTLIBOBJS, Libtool Issues, Libtool Flags, A Shared Library
5515 @subsection @code{LTLIBOBJS} and @code{LTALLOCA}
5516 @cindex @code{LTLIBOBJS}, special handling
5517 @cindex @code{LIBOBJS}, and Libtool
5518 @cindex @code{LTALLOCA}, special handling
5519 @cindex @code{ALLOCA}, and Libtool
5526 Where an ordinary library might include @samp{$(LIBOBJS)} or
5527 @samp{$(ALLOCA)} (@pxref{LIBOBJS}), a libtool library must use
5528 @samp{$(LTLIBOBJS)} or @samp{$(LTALLOCA)}. This is required because
5529 the object files that libtool operates on do not necessarily end in
5532 Nowadays, the computation of @code{LTLIBOBJS} from @code{LIBOBJS} is
5533 performed automatically by Autoconf (@pxref{AC_LIBOBJ vs LIBOBJS, ,
5534 @code{AC_LIBOBJ} vs.@: @code{LIBOBJS}, autoconf, The Autoconf Manual}).
5536 @node Libtool Issues
5537 @subsection Common Issues Related to Libtool's Use
5540 * Error required file ltmain.sh not found:: The need to run libtoolize
5541 * Objects created both with libtool and without:: Avoid a specific build race
5544 @node Error required file ltmain.sh not found
5545 @subsubsection Error: @samp{required file `./ltmain.sh' not found}
5546 @cindex @file{ltmain.sh} not found
5547 @cindex @command{libtoolize}, no longer run by @command{automake}
5548 @cindex @command{libtoolize} and @command{autoreconf}
5549 @cindex @command{autoreconf} and @command{libtoolize}
5550 @cindex @file{bootstrap.sh} and @command{autoreconf}
5551 @cindex @file{autogen.sh} and @command{autoreconf}
5553 Libtool comes with a tool called @command{libtoolize} that will
5554 install libtool's supporting files into a package. Running this
5555 command will install @file{ltmain.sh}. You should execute it before
5556 @command{aclocal} and @command{automake}.
5558 People upgrading old packages to newer autotools are likely to face
5559 this issue because older Automake versions used to call
5560 @command{libtoolize}. Therefore old build scripts do not call
5561 @command{libtoolize}.
5563 Since Automake 1.6, it has been decided that running
5564 @command{libtoolize} was none of Automake's business. Instead, that
5565 functionality has been moved into the @command{autoreconf} command
5566 (@pxref{autoreconf Invocation, , Using @command{autoreconf}, autoconf,
5567 The Autoconf Manual}). If you do not want to remember what to run and
5568 when, just learn the @command{autoreconf} command. Hopefully,
5569 replacing existing @file{bootstrap.sh} or @file{autogen.sh} scripts by
5570 a call to @command{autoreconf} should also free you from any similar
5571 incompatible change in the future.
5573 @node Objects created both with libtool and without
5574 @subsubsection Objects @samp{created with both libtool and without}
5576 Sometimes, the same source file is used both to build a libtool
5577 library and to build another non-libtool target (be it a program or
5580 Let's consider the following @file{Makefile.am}.
5584 prog_SOURCES = prog.c foo.c @dots{}
5586 lib_LTLIBRARIES = libfoo.la
5587 libfoo_la_SOURCES = foo.c @dots{}
5591 (In this trivial case the issue could be avoided by linking
5592 @file{libfoo.la} with @file{prog} instead of listing @file{foo.c} in
5593 @code{prog_SOURCES}. But let's assume we really want to keep
5594 @file{prog} and @file{libfoo.la} separate.)
5596 Technically, it means that we should build @file{foo.$(OBJEXT)} for
5597 @file{prog}, and @file{foo.lo} for @file{libfoo.la}. The problem is
5598 that in the course of creating @file{foo.lo}, libtool may erase (or
5599 replace) @file{foo.$(OBJEXT)}, and this cannot be avoided.
5601 Therefore, when Automake detects this situation it will complain
5602 with a message such as
5604 object 'foo.$(OBJEXT)' created both with libtool and without
5607 A workaround for this issue is to ensure that these two objects get
5608 different basenames. As explained in @ref{Renamed Objects}, this
5609 happens automatically when per-targets flags are used.
5613 prog_SOURCES = prog.c foo.c @dots{}
5614 prog_CFLAGS = $(AM_CFLAGS)
5616 lib_LTLIBRARIES = libfoo.la
5617 libfoo_la_SOURCES = foo.c @dots{}
5621 Adding @samp{prog_CFLAGS = $(AM_CFLAGS)} is almost a no-op, because
5622 when the @code{prog_CFLAGS} is defined, it is used instead of
5623 @code{AM_CFLAGS}. However as a side effect it will cause
5624 @file{prog.c} and @file{foo.c} to be compiled as
5625 @file{prog-prog.$(OBJEXT)} and @file{prog-foo.$(OBJEXT)}, which solves
5628 @node Program and Library Variables
5629 @section Program and Library Variables
5631 Associated with each program is a collection of variables that can be
5632 used to modify how that program is built. There is a similar list of
5633 such variables for each library. The canonical name of the program (or
5634 library) is used as a base for naming these variables.
5636 In the list below, we use the name ``maude'' to refer to the program or
5637 library. In your @file{Makefile.am} you would replace this with the
5638 canonical name of your program. This list also refers to ``maude'' as a
5639 program, but in general the same rules apply for both static and dynamic
5640 libraries; the documentation below notes situations where programs and
5645 This variable, if it exists, lists all the source files that are
5646 compiled to build the program. These files are added to the
5647 distribution by default. When building the program, Automake will cause
5648 each source file to be compiled to a single @file{.o} file (or
5649 @file{.lo} when using libtool). Normally these object files are named
5650 after the source file, but other factors can change this. If a file in
5651 the @code{_SOURCES} variable has an unrecognized extension, Automake
5652 will do one of two things with it. If a suffix rule exists for turning
5653 files with the unrecognized extension into @file{.o} files, then
5654 @command{automake} will treat this file as it will any other source file
5655 (@pxref{Support for Other Languages}). Otherwise, the file will be
5656 ignored as though it were a header file.
5658 The prefixes @code{dist_} and @code{nodist_} can be used to control
5659 whether files listed in a @code{_SOURCES} variable are distributed.
5660 @code{dist_} is redundant, as sources are distributed by default, but it
5661 can be specified for clarity if desired.
5663 It is possible to have both @code{dist_} and @code{nodist_} variants of
5664 a given @code{_SOURCES} variable at once; this lets you easily
5665 distribute some files and not others, for instance:
5668 nodist_maude_SOURCES = nodist.c
5669 dist_maude_SOURCES = dist-me.c
5672 By default the output file (on Unix systems, the @file{.o} file) will
5673 be put into the current build directory. However, if the option
5674 @option{subdir-objects} is in effect in the current directory then the
5675 @file{.o} file will be put into the subdirectory named after the
5676 source file. For instance, with @option{subdir-objects} enabled,
5677 @file{sub/dir/file.c} will be compiled to @file{sub/dir/file.o}. Some
5678 people prefer this mode of operation. You can specify
5679 @option{subdir-objects} in @code{AUTOMAKE_OPTIONS} (@pxref{Options}).
5680 @cindex Subdirectory, objects in
5681 @cindex Objects in subdirectory
5684 @item EXTRA_maude_SOURCES
5685 Automake needs to know the list of files you intend to compile
5686 @emph{statically}. For one thing, this is the only way Automake has of
5687 knowing what sort of language support a given @file{Makefile.in}
5688 requires. @footnote{There are other, more obscure reasons for
5689 this limitation as well.} This means that, for example, you can't put a
5690 configure substitution like @samp{@@my_sources@@} into a @samp{_SOURCES}
5691 variable. If you intend to conditionally compile source files and use
5692 @file{configure} to substitute the appropriate object names into, e.g.,
5693 @code{_LDADD} (see below), then you should list the corresponding source
5694 files in the @code{EXTRA_} variable.
5696 This variable also supports @code{dist_} and @code{nodist_} prefixes.
5697 For instance, @code{nodist_EXTRA_maude_SOURCES} would list extra
5698 sources that may need to be built, but should not be distributed.
5701 A static library is created by default by invoking @samp{$(AR)
5702 $(ARFLAGS)} followed by the name of the library and then the objects
5703 being put into the library. You can override this by setting the
5704 @code{_AR} variable. This is usually used with C++; some C++
5705 compilers require a special invocation in order to instantiate all the
5706 templates that should go into a library. For instance, the SGI C++
5707 compiler likes this variable set like so:
5709 libmaude_a_AR = $(CXX) -ar -o
5713 Extra objects can be added to a @emph{library} using the @code{_LIBADD}
5714 variable. For instance, this should be used for objects determined by
5715 @command{configure} (@pxref{A Library}).
5717 In the case of libtool libraries, @code{maude_LIBADD} can also refer
5718 to other libtool libraries.
5721 Extra objects (@file{*.$(OBJEXT)}) and libraries (@file{*.a},
5722 @file{*.la}) can be added to a @emph{program} by listing them in the
5723 @code{_LDADD} variable. For instance, this should be used for objects
5724 determined by @command{configure} (@pxref{Linking}).
5726 @code{_LDADD} and @code{_LIBADD} are inappropriate for passing
5727 program-specific linker flags (except for @option{-l}, @option{-L},
5728 @option{-dlopen} and @option{-dlpreopen}). Use the @code{_LDFLAGS} variable
5731 For instance, if your @file{configure.ac} uses @code{AC_PATH_XTRA}, you
5732 could link your program against the X libraries like so:
5735 maude_LDADD = $(X_PRE_LIBS) $(X_LIBS) $(X_EXTRA_LIBS)
5738 We recommend that you use @option{-l} and @option{-L} only when
5739 referring to third-party libraries, and give the explicit file names
5740 of any library built by your package. Doing so will ensure that
5741 @code{maude_DEPENDENCIES} (see below) is correctly defined by default.
5744 This variable is used to pass extra flags to the link step of a program
5745 or a shared library. It overrides the @code{AM_LDFLAGS} variable.
5747 @item maude_LIBTOOLFLAGS
5748 This variable is used to pass extra options to @command{libtool}.
5749 It overrides the @code{AM_LIBTOOLFLAGS} variable.
5750 These options are output before @command{libtool}'s @option{--mode=@var{mode}}
5751 option, so they should not be mode-specific options (those belong to
5752 the compiler or linker flags). @xref{Libtool Flags}.
5754 @item maude_DEPENDENCIES
5755 @itemx EXTRA_maude_DEPENDENCIES
5756 It is also occasionally useful to have a target (program or library)
5757 depend on some other file that is not actually part of that target.
5758 This can be done using the @code{_DEPENDENCIES} variable. Each
5759 target depends on the contents of such a variable, but no further
5760 interpretation is done.
5762 Since these dependencies are associated to the link rule used to
5763 create the programs they should normally list files used by the link
5764 command. That is @file{*.$(OBJEXT)}, @file{*.a}, or @file{*.la} files
5765 for programs; @file{*.lo} and @file{*.la} files for Libtool libraries;
5766 and @file{*.$(OBJEXT)} files for static libraries. In rare cases you
5767 may need to add other kinds of files such as linker scripts, but
5768 @emph{listing a source file in @code{_DEPENDENCIES} is wrong}. If
5769 some source file needs to be built before all the components of a
5770 program are built, consider using the @code{BUILT_SOURCES} variable
5773 If @code{_DEPENDENCIES} is not supplied, it is computed by Automake.
5774 The automatically-assigned value is the contents of @code{_LDADD} or
5775 @code{_LIBADD}, with most configure substitutions, @option{-l}, @option{-L},
5776 @option{-dlopen} and @option{-dlpreopen} options removed. The configure
5777 substitutions that are left in are only @samp{$(LIBOBJS)} and
5778 @samp{$(ALLOCA)}; these are left because it is known that they will not
5779 cause an invalid value for @code{_DEPENDENCIES} to be generated.
5781 @code{_DEPENDENCIES} is more likely used to perform conditional
5782 compilation using an @code{AC_SUBST} variable that contains a list of
5783 objects. @xref{Conditional Sources}, and @ref{Conditional Libtool
5786 The @code{EXTRA_*_DEPENDENCIES} variable may be useful for cases where
5787 you merely want to augment the @command{automake}-generated
5788 @code{_DEPENDENCIES} variable rather than replacing it.
5791 You can override the linker on a per-program basis. By default the
5792 linker is chosen according to the languages used by the program. For
5793 instance, a program that includes C++ source code would use the C++
5794 compiler to link. The @code{_LINK} variable must hold the name of a
5795 command that can be passed all the @file{.o} file names and libraries
5796 to link against as arguments. Note that the name of the underlying
5797 program is @emph{not} passed to @code{_LINK}; typically one uses
5801 maude_LINK = $(CCLD) -magic -o $@@
5804 If a @code{_LINK} variable is not supplied, it may still be generated
5805 and used by Automake due to the use of per-target link flags such as
5806 @code{_CFLAGS}, @code{_LDFLAGS} or @code{_LIBTOOLFLAGS}, in cases where
5809 @item maude_CCASFLAGS
5811 @itemx maude_CPPFLAGS
5812 @itemx maude_CXXFLAGS
5814 @itemx maude_GCJFLAGS
5816 @itemx maude_OBJCFLAGS
5817 @itemx maude_OBJCXXFLAGS
5819 @itemx maude_UPCFLAGS
5821 @cindex per-target compilation flags, defined
5822 Automake allows you to set compilation flags on a per-program (or
5823 per-library) basis. A single source file can be included in several
5824 programs, and it will potentially be compiled with different flags for
5825 each program. This works for any language directly supported by
5826 Automake. These @dfn{per-target compilation flags} are
5835 @samp{_OBJCXXFLAGS},
5837 @samp{_UPCFLAGS}, and
5840 When using a per-target compilation flag, Automake will choose a
5841 different name for the intermediate object files. Ordinarily a file
5842 like @file{sample.c} will be compiled to produce @file{sample.o}.
5843 However, if the program's @code{_CFLAGS} variable is set, then the
5844 object file will be named, for instance, @file{maude-sample.o}. (See
5845 also @ref{Renamed Objects}.) The use of per-target compilation flags
5846 with C sources requires that the macro @code{AM_PROG_CC_C_O} be called
5847 from @file{configure.ac}.
5849 In compilations with per-target flags, the ordinary @samp{AM_} form of
5850 the flags variable is @emph{not} automatically included in the
5851 compilation (however, the user form of the variable @emph{is} included).
5852 So for instance, if you want the hypothetical @file{maude} compilations
5853 to also use the value of @code{AM_CFLAGS}, you would need to write:
5856 maude_CFLAGS = @dots{} your flags @dots{} $(AM_CFLAGS)
5859 @xref{Flag Variables Ordering}, for more discussion about the
5860 interaction between user variables, @samp{AM_} shadow variables, and
5861 per-target variables.
5863 @item maude_SHORTNAME
5864 On some platforms the allowable file names are very short. In order to
5865 support these systems and per-target compilation flags at the same
5866 time, Automake allows you to set a ``short name'' that will influence
5867 how intermediate object files are named. For instance, in the following
5871 bin_PROGRAMS = maude
5872 maude_CPPFLAGS = -DSOMEFLAG
5874 maude_SOURCES = sample.c @dots{}
5878 the object file would be named @file{m-sample.o} rather than
5879 @file{maude-sample.o}.
5881 This facility is rarely needed in practice,
5882 and we recommend avoiding it until you find it is required.
5885 @node Default _SOURCES
5886 @section Default @code{_SOURCES}
5890 @cindex @code{_SOURCES}, default
5891 @cindex default @code{_SOURCES}
5892 @vindex AM_DEFAULT_SOURCE_EXT
5894 @code{_SOURCES} variables are used to specify source files of programs
5895 (@pxref{A Program}), libraries (@pxref{A Library}), and Libtool
5896 libraries (@pxref{A Shared Library}).
5898 When no such variable is specified for a target, Automake will define
5899 one itself. The default is to compile a single C file whose base name
5900 is the name of the target itself, with any extension replaced by
5901 @code{AM_DEFAULT_SOURCE_EXT}, which defaults to @file{.c}.
5903 For example if you have the following somewhere in your
5904 @file{Makefile.am} with no corresponding @code{libfoo_a_SOURCES}:
5907 lib_LIBRARIES = libfoo.a sub/libc++.a
5911 @file{libfoo.a} will be built using a default source file named
5912 @file{libfoo.c}, and @file{sub/libc++.a} will be built from
5913 @file{sub/libc++.c}. (In older versions @file{sub/libc++.a}
5914 would be built from @file{sub_libc___a.c}, i.e., the default source
5915 was the canonized name of the target, with @file{.c} appended.
5916 We believe the new behavior is more sensible, but for backward
5917 compatibility @command{automake} will use the old name if a file or a rule
5918 with that name exists and @code{AM_DEFAULT_SOURCE_EXT} is not used.)
5920 @cindex @code{check_PROGRAMS} example
5921 @vindex check_PROGRAMS
5922 Default sources are mainly useful in test suites, when building many
5923 test programs each from a single source. For instance, in
5926 check_PROGRAMS = test1 test2 test3
5927 AM_DEFAULT_SOURCE_EXT = .cpp
5931 @file{test1}, @file{test2}, and @file{test3} will be built
5932 from @file{test1.cpp}, @file{test2.cpp}, and @file{test3.cpp}.
5933 Without the last line, they will be built from @file{test1.c},
5934 @file{test2.c}, and @file{test3.c}.
5936 @cindex Libtool modules, default source example
5937 @cindex default source, Libtool modules example
5938 Another case where this is convenient is building many Libtool modules
5939 (@file{module@var{n}.la}), each defined in its own file
5940 (@file{module@var{n}.c}).
5943 AM_LDFLAGS = -module
5944 lib_LTLIBRARIES = module1.la module2.la module3.la
5947 @cindex empty @code{_SOURCES}
5948 @cindex @code{_SOURCES}, empty
5949 Finally, there is one situation where this default source computation
5950 needs to be avoided: when a target should not be built from sources.
5951 We already saw such an example in @ref{true}; this happens when all
5952 the constituents of a target have already been compiled and just need
5953 to be combined using a @code{_LDADD} variable. Then it is necessary
5954 to define an empty @code{_SOURCES} variable, so that @command{automake}
5955 does not compute a default.
5958 bin_PROGRAMS = target
5960 target_LDADD = libmain.a libmisc.a
5964 @section Special handling for @code{LIBOBJS} and @code{ALLOCA}
5966 @cindex @code{LIBOBJS}, example
5967 @cindex @code{ALLOCA}, example
5968 @cindex @code{LIBOBJS}, special handling
5969 @cindex @code{ALLOCA}, special handling
5975 The @samp{$(LIBOBJS)} and @samp{$(ALLOCA)} variables list object
5976 files that should be compiled into the project to provide an
5977 implementation for functions that are missing or broken on the host
5978 system. They are substituted by @file{configure}.
5982 These variables are defined by Autoconf macros such as
5983 @code{AC_LIBOBJ}, @code{AC_REPLACE_FUNCS} (@pxref{Generic Functions, ,
5984 Generic Function Checks, autoconf, The Autoconf Manual}), or
5985 @code{AC_FUNC_ALLOCA} (@pxref{Particular Functions, , Particular
5986 Function Checks, autoconf, The Autoconf Manual}). Many other Autoconf
5987 macros call @code{AC_LIBOBJ} or @code{AC_REPLACE_FUNCS} to
5988 populate @samp{$(LIBOBJS)}.
5990 @acindex AC_LIBSOURCE
5992 Using these variables is very similar to doing conditional compilation
5993 using @code{AC_SUBST} variables, as described in @ref{Conditional
5994 Sources}. That is, when building a program, @samp{$(LIBOBJS)} and
5995 @samp{$(ALLOCA)} should be added to the associated @samp{*_LDADD}
5996 variable, or to the @samp{*_LIBADD} variable when building a library.
5997 However there is no need to list the corresponding sources in
5998 @samp{EXTRA_*_SOURCES} nor to define @samp{*_DEPENDENCIES}. Automake
5999 automatically adds @samp{$(LIBOBJS)} and @samp{$(ALLOCA)} to the
6000 dependencies, and it will discover the list of corresponding source
6001 files automatically (by tracing the invocations of the
6002 @code{AC_LIBSOURCE} Autoconf macros). If you have already defined
6003 @samp{*_DEPENDENCIES} explicitly for an unrelated reason, then you
6004 either need to add these variables manually, or use
6005 @samp{EXTRA_*_DEPENDENCIES} instead of @samp{*_DEPENDENCIES}.
6007 These variables are usually used to build a portability library that
6008 is linked with all the programs of the project. We now review a
6009 sample setup. First, @file{configure.ac} contains some checks that
6010 affect either @code{LIBOBJS} or @code{ALLOCA}.
6015 AC_CONFIG_LIBOBJ_DIR([lib])
6017 AC_FUNC_MALLOC dnl May add malloc.$(OBJEXT) to LIBOBJS
6018 AC_FUNC_MEMCMP dnl May add memcmp.$(OBJEXT) to LIBOBJS
6019 AC_REPLACE_FUNCS([strdup]) dnl May add strdup.$(OBJEXT) to LIBOBJS
6020 AC_FUNC_ALLOCA dnl May add alloca.$(OBJEXT) to ALLOCA
6029 @acindex AC_CONFIG_LIBOBJ_DIR
6031 The @code{AC_CONFIG_LIBOBJ_DIR} tells Autoconf that the source files
6032 of these object files are to be found in the @file{lib/} directory.
6033 Automake can also use this information, otherwise it expects the
6034 source files are to be in the directory where the @samp{$(LIBOBJS)}
6035 and @samp{$(ALLOCA)} variables are used.
6037 The @file{lib/} directory should therefore contain @file{malloc.c},
6038 @file{memcmp.c}, @file{strdup.c}, @file{alloca.c}. Here is its
6044 noinst_LIBRARIES = libcompat.a
6045 libcompat_a_SOURCES =
6046 libcompat_a_LIBADD = $(LIBOBJS) $(ALLOCA)
6049 The library can have any name, of course, and anyway it is not going
6050 to be installed: it just holds the replacement versions of the missing
6051 or broken functions so we can later link them in. Many projects
6052 also include extra functions, specific to the project, in that
6053 library: they are simply added on the @code{_SOURCES} line.
6055 @cindex Empty libraries and @samp{$(LIBOBJS)}
6056 @cindex @samp{$(LIBOBJS)} and empty libraries
6057 There is a small trap here, though: @samp{$(LIBOBJS)} and
6058 @samp{$(ALLOCA)} might be empty, and building an empty library is not
6059 portable. You should ensure that there is always something to put in
6060 @file{libcompat.a}. Most projects will also add some utility
6061 functions in that directory, and list them in
6062 @code{libcompat_a_SOURCES}, so in practice @file{libcompat.a} cannot
6065 Finally here is how this library could be used from the @file{src/}
6071 # Link all programs in this directory with libcompat.a
6072 LDADD = ../lib/libcompat.a
6074 bin_PROGRAMS = tool1 tool2 @dots{}
6075 tool1_SOURCES = @dots{}
6076 tool2_SOURCES = @dots{}
6079 When option @option{subdir-objects} is not used, as in the above
6080 example, the variables @samp{$(LIBOBJS)} or @samp{$(ALLOCA)} can only
6081 be used in the directory where their sources lie. E.g., here it would
6082 be wrong to use @samp{$(LIBOBJS)} or @samp{$(ALLOCA)} in
6083 @file{src/Makefile.am}. However if both @option{subdir-objects} and
6084 @code{AC_CONFIG_LIBOBJ_DIR} are used, it is OK to use these variables
6085 in other directories. For instance @file{src/Makefile.am} could be
6091 AUTOMAKE_OPTIONS = subdir-objects
6092 LDADD = $(LIBOBJS) $(ALLOCA)
6094 bin_PROGRAMS = tool1 tool2 @dots{}
6095 tool1_SOURCES = @dots{}
6096 tool2_SOURCES = @dots{}
6099 Because @samp{$(LIBOBJS)} and @samp{$(ALLOCA)} contain object
6100 file names that end with @samp{.$(OBJEXT)}, they are not suitable for
6101 Libtool libraries (where the expected object extension is @file{.lo}):
6102 @code{LTLIBOBJS} and @code{LTALLOCA} should be used instead.
6104 @code{LTLIBOBJS} is defined automatically by Autoconf and should not
6105 be defined by hand (as in the past), however at the time of writing
6106 @code{LTALLOCA} still needs to be defined from @code{ALLOCA} manually.
6107 @xref{AC_LIBOBJ vs LIBOBJS, , @code{AC_LIBOBJ} vs.@: @code{LIBOBJS},
6108 autoconf, The Autoconf Manual}.
6111 @node Program Variables
6112 @section Variables used when building a program
6114 Occasionally it is useful to know which @file{Makefile} variables
6115 Automake uses for compilations, and in which order (@pxref{Flag
6116 Variables Ordering}); for instance, you might need to do your own
6117 compilation in some special cases.
6119 Some variables are inherited from Autoconf; these are @code{CC},
6120 @code{CFLAGS}, @code{CPPFLAGS}, @code{DEFS}, @code{LDFLAGS}, and
6129 There are some additional variables that Automake defines on its own:
6133 The contents of this variable are passed to every compilation that invokes
6134 the C preprocessor; it is a list of arguments to the preprocessor. For
6135 instance, @option{-I} and @option{-D} options should be listed here.
6137 Automake already provides some @option{-I} options automatically, in a
6138 separate variable that is also passed to every compilation that invokes
6139 the C preprocessor. In particular it generates @samp{-I.},
6140 @samp{-I$(srcdir)}, and a @option{-I} pointing to the directory holding
6141 @file{config.h} (if you've used @code{AC_CONFIG_HEADERS} or
6142 @code{AM_CONFIG_HEADER}). You can disable the default @option{-I}
6143 options using the @option{nostdinc} option.
6145 When a file to be included is generated during the build and not part
6146 of a distribution tarball, its location is under @code{$(builddir)},
6147 not under @code{$(srcdir)}. This matters especially for packages that
6148 use header files placed in sub-directories and want to allow builds
6149 outside the source tree (@pxref{VPATH Builds}). In that case we
6150 recommend to use a pair of @option{-I} options, such as, e.g.,
6151 @samp{-Isome/subdir -I$(srcdir)/some/subdir} or
6152 @samp{-I$(top_builddir)/some/subdir -I$(top_srcdir)/some/subdir}.
6153 Note that the reference to the build tree should come before the
6154 reference to the source tree, so that accidentally leftover generated
6155 files in the source directory are ignored.
6157 @code{AM_CPPFLAGS} is ignored in preference to a per-executable (or
6158 per-library) @code{_CPPFLAGS} variable if it is defined.
6161 This does the same job as @code{AM_CPPFLAGS} (or any per-target
6162 @code{_CPPFLAGS} variable if it is used). It is an older name for the
6163 same functionality. This variable is deprecated; we suggest using
6164 @code{AM_CPPFLAGS} and per-target @code{_CPPFLAGS} instead.
6167 This is the variable the @file{Makefile.am} author can use to pass
6168 in additional C compiler flags. In some situations, this is
6169 not used, in preference to the per-executable (or per-library)
6173 This is the command used to actually compile a C source file. The
6174 file name is appended to form the complete command line.
6177 This is the variable the @file{Makefile.am} author can use to pass
6178 in additional linker flags. In some situations, this is not used, in
6179 preference to the per-executable (or per-library) @code{_LDFLAGS}.
6182 This is the command used to actually link a C program. It already
6183 includes @samp{-o $@@} and the usual variable references (for instance,
6184 @code{CFLAGS}); it takes as ``arguments'' the names of the object files
6185 and libraries to link in. This variable is not used when the linker is
6186 overridden with a per-target @code{_LINK} variable or per-target flags
6187 cause Automake to define such a @code{_LINK} variable.
6192 @section Yacc and Lex support
6194 Automake has somewhat idiosyncratic support for Yacc and Lex.
6196 Automake assumes that the @file{.c} file generated by @command{yacc}
6197 (or @command{lex}) should be named using the basename of the input
6198 file. That is, for a yacc source file @file{foo.y}, Automake will
6199 cause the intermediate file to be named @file{foo.c} (as opposed to
6200 @file{y.tab.c}, which is more traditional).
6202 The extension of a yacc source file is used to determine the extension
6203 of the resulting C or C++ source and header files. Note that header
6204 files are generated only when the @option{-d} Yacc option is used; see
6205 below for more information about this flag, and how to specify it.
6206 Files with the extension @file{.y} will thus be turned into @file{.c}
6207 sources and @file{.h} headers; likewise, @file{.yy} will become
6208 @file{.cc} and @file{.hh}, @file{.y++} will become @file{c++} and
6209 @file{h++}, @file{.yxx} will become @file{.cxx} and @file{.hxx},
6210 and @file{.ypp} will become @file{.cpp} and @file{.hpp}.
6212 Similarly, lex source files can be used to generate C or C++; the
6213 extensions @file{.l}, @file{.ll}, @file{.l++}, @file{.lxx}, and
6214 @file{.lpp} are recognized.
6216 You should never explicitly mention the intermediate (C or C++) file
6217 in any @code{SOURCES} variable; only list the source file.
6219 The intermediate files generated by @command{yacc} (or @command{lex})
6220 will be included in any distribution that is made. That way the user
6221 doesn't need to have @command{yacc} or @command{lex}.
6223 If a @command{yacc} source file is seen, then your @file{configure.ac} must
6224 define the variable @code{YACC}. This is most easily done by invoking
6225 the macro @code{AC_PROG_YACC} (@pxref{Particular Programs, , Particular
6226 Program Checks, autoconf, The Autoconf Manual}).
6230 When @code{yacc} is invoked, it is passed @code{AM_YFLAGS} and
6231 @code{YFLAGS}. The latter is a user variable and the former is
6232 intended for the @file{Makefile.am} author.
6234 @code{AM_YFLAGS} is usually used to pass the @option{-d} option to
6235 @command{yacc}. Automake knows what this means and will automatically
6236 adjust its rules to update and distribute the header file built by
6237 @samp{yacc -d}@footnote{Please note that @command{automake} recognizes
6238 @option{-d} in @code{AM_YFLAGS} only if it is not clustered with other
6239 options; for example, it won't be recognized if @code{AM_YFLAGS} is
6240 @option{-dt}, but it will be if @code{AM_YFLAGS} is @option{-d -t} or
6242 What Automake cannot guess, though, is where this
6243 header will be used: it is up to you to ensure the header gets built
6244 before it is first used. Typically this is necessary in order for
6245 dependency tracking to work when the header is included by another
6246 file. The common solution is listing the header file in
6247 @code{BUILT_SOURCES} (@pxref{Sources}) as follows.
6250 BUILT_SOURCES = parser.h
6253 foo_SOURCES = @dots{} parser.y @dots{}
6256 If a @command{lex} source file is seen, then your @file{configure.ac}
6257 must define the variable @code{LEX}. You can use @code{AC_PROG_LEX}
6258 to do this (@pxref{Particular Programs, , Particular Program Checks,
6259 autoconf, The Autoconf Manual}), but using @code{AM_PROG_LEX} macro
6260 (@pxref{Macros}) is recommended.
6264 When @command{lex} is invoked, it is passed @code{AM_LFLAGS} and
6265 @code{LFLAGS}. The latter is a user variable and the former is
6266 intended for the @file{Makefile.am} author.
6268 When @code{AM_MAINTAINER_MODE} (@pxref{maintainer-mode}) is used, the
6269 rebuild rule for distributed Yacc and Lex sources are only used when
6270 @code{maintainer-mode} is enabled, or when the files have been erased.
6272 @cindex @command{ylwrap}
6273 @cindex @command{yacc}, multiple parsers
6274 @cindex Multiple @command{yacc} parsers
6275 @cindex Multiple @command{lex} lexers
6276 @cindex @command{lex}, multiple lexers
6278 When @command{lex} or @command{yacc} sources are used, @code{automake
6279 -i} automatically installs an auxiliary program called
6280 @command{ylwrap} in your package (@pxref{Auxiliary Programs}). This
6281 program is used by the build rules to rename the output of these
6282 tools, and makes it possible to include multiple @command{yacc} (or
6283 @command{lex}) source files in a single directory. (This is necessary
6284 because yacc's output file name is fixed, and a parallel make could
6285 conceivably invoke more than one instance of @command{yacc}
6288 For @command{yacc}, simply managing locking is insufficient. The output of
6289 @command{yacc} always uses the same symbol names internally, so it isn't
6290 possible to link two @command{yacc} parsers into the same executable.
6292 We recommend using the following renaming hack used in @command{gdb}:
6294 #define yymaxdepth c_maxdepth
6295 #define yyparse c_parse
6297 #define yyerror c_error
6298 #define yylval c_lval
6299 #define yychar c_char
6300 #define yydebug c_debug
6301 #define yypact c_pact
6308 #define yyexca c_exca
6309 #define yyerrflag c_errflag
6310 #define yynerrs c_nerrs
6314 #define yy_yys c_yys
6315 #define yystate c_state
6318 #define yy_yyv c_yyv
6320 #define yylloc c_lloc
6321 #define yyreds c_reds
6322 #define yytoks c_toks
6323 #define yylhs c_yylhs
6324 #define yylen c_yylen
6325 #define yydefred c_yydefred
6326 #define yydgoto c_yydgoto
6327 #define yysindex c_yysindex
6328 #define yyrindex c_yyrindex
6329 #define yygindex c_yygindex
6330 #define yytable c_yytable
6331 #define yycheck c_yycheck
6332 #define yyname c_yyname
6333 #define yyrule c_yyrule
6336 For each define, replace the @samp{c_} prefix with whatever you like.
6337 These defines work for @command{bison}, @command{byacc}, and
6338 traditional @code{yacc}s. If you find a parser generator that uses a
6339 symbol not covered here, please report the new name so it can be added
6344 @section C++ Support
6347 @cindex Support for C++
6349 Automake includes full support for C++.
6351 Any package including C++ code must define the output variable
6352 @code{CXX} in @file{configure.ac}; the simplest way to do this is to use
6353 the @code{AC_PROG_CXX} macro (@pxref{Particular Programs, , Particular
6354 Program Checks, autoconf, The Autoconf Manual}).
6356 A few additional variables are defined when a C++ source file is seen:
6360 The name of the C++ compiler.
6363 Any flags to pass to the C++ compiler.
6366 The maintainer's variant of @code{CXXFLAGS}.
6369 The command used to actually compile a C++ source file. The file name
6370 is appended to form the complete command line.
6373 The command used to actually link a C++ program.
6377 @node Objective C Support
6378 @section Objective C Support
6380 @cindex Objective C support
6381 @cindex Support for Objective C
6383 Automake includes some support for Objective C.
6385 Any package including Objective C code must define the output variable
6386 @code{OBJC} in @file{configure.ac}; the simplest way to do this is to use
6387 the @code{AC_PROG_OBJC} macro (@pxref{Particular Programs, , Particular
6388 Program Checks, autoconf, The Autoconf Manual}).
6390 A few additional variables are defined when an Objective C source file
6395 The name of the Objective C compiler.
6398 Any flags to pass to the Objective C compiler.
6401 The maintainer's variant of @code{OBJCFLAGS}.
6404 The command used to actually compile an Objective C source file. The
6405 file name is appended to form the complete command line.
6408 The command used to actually link an Objective C program.
6412 @node Objective C++ Support
6413 @section Objective C++ Support
6415 @cindex Objective C++ support
6416 @cindex Support for Objective C++
6418 Automake includes some support for Objective C++.
6420 Any package including Objective C++ code must define the output variable
6421 @code{OBJCXX} in @file{configure.ac}; the simplest way to do this is to use
6422 the @code{AC_PROG_OBJCXX} macro (@pxref{Particular Programs, , Particular
6423 Program Checks, autoconf, The Autoconf Manual}).
6425 A few additional variables are defined when an Objective C++ source file
6430 The name of the Objective C++ compiler.
6433 Any flags to pass to the Objective C++ compiler.
6435 @item AM_OBJCXXFLAGS
6436 The maintainer's variant of @code{OBJCXXFLAGS}.
6439 The command used to actually compile an Objective C++ source file. The
6440 file name is appended to form the complete command line.
6443 The command used to actually link an Objective C++ program.
6447 @node Unified Parallel C Support
6448 @section Unified Parallel C Support
6450 @cindex Unified Parallel C support
6451 @cindex Support for Unified Parallel C
6453 Automake includes some support for Unified Parallel C.
6455 Any package including Unified Parallel C code must define the output
6456 variable @code{UPC} in @file{configure.ac}; the simplest way to do
6457 this is to use the @code{AM_PROG_UPC} macro (@pxref{Public Macros}).
6459 A few additional variables are defined when a Unified Parallel C
6460 source file is seen:
6464 The name of the Unified Parallel C compiler.
6467 Any flags to pass to the Unified Parallel C compiler.
6470 The maintainer's variant of @code{UPCFLAGS}.
6473 The command used to actually compile a Unified Parallel C source file.
6474 The file name is appended to form the complete command line.
6477 The command used to actually link a Unified Parallel C program.
6481 @node Assembly Support
6482 @section Assembly Support
6484 Automake includes some support for assembly code. There are two forms
6485 of assembler files: normal (@file{*.s}) and preprocessed by @code{CPP}
6486 (@file{*.S} or @file{*.sx}).
6491 @vindex AM_CCASFLAGS
6493 The variable @code{CCAS} holds the name of the compiler used to build
6494 assembly code. This compiler must work a bit like a C compiler; in
6495 particular it must accept @option{-c} and @option{-o}. The values of
6496 @code{CCASFLAGS} and @code{AM_CCASFLAGS} (or its per-target
6497 definition) is passed to the compilation. For preprocessed files,
6498 @code{DEFS}, @code{DEFAULT_INCLUDES}, @code{INCLUDES}, @code{CPPFLAGS}
6499 and @code{AM_CPPFLAGS} are also used.
6501 The autoconf macro @code{AM_PROG_AS} will define @code{CCAS} and
6502 @code{CCASFLAGS} for you (unless they are already set, it simply sets
6503 @code{CCAS} to the C compiler and @code{CCASFLAGS} to the C compiler
6504 flags), but you are free to define these variables by other means.
6506 Only the suffixes @file{.s}, @file{.S}, and @file{.sx} are recognized by
6507 @command{automake} as being files containing assembly code.
6510 @node Fortran 77 Support
6511 @comment node-name, next, previous, up
6512 @section Fortran 77 Support
6514 @cindex Fortran 77 support
6515 @cindex Support for Fortran 77
6517 Automake includes full support for Fortran 77.
6519 Any package including Fortran 77 code must define the output variable
6520 @code{F77} in @file{configure.ac}; the simplest way to do this is to use
6521 the @code{AC_PROG_F77} macro (@pxref{Particular Programs, , Particular
6522 Program Checks, autoconf, The Autoconf Manual}).
6524 A few additional variables are defined when a Fortran 77 source file is
6530 The name of the Fortran 77 compiler.
6533 Any flags to pass to the Fortran 77 compiler.
6536 The maintainer's variant of @code{FFLAGS}.
6539 Any flags to pass to the Ratfor compiler.
6542 The maintainer's variant of @code{RFLAGS}.
6545 The command used to actually compile a Fortran 77 source file. The file
6546 name is appended to form the complete command line.
6549 The command used to actually link a pure Fortran 77 program or shared
6554 Automake can handle preprocessing Fortran 77 and Ratfor source files in
6555 addition to compiling them@footnote{Much, if not most, of the
6556 information in the following sections pertaining to preprocessing
6557 Fortran 77 programs was taken almost verbatim from @ref{Catalogue of
6558 Rules, , Catalogue of Rules, make, The GNU Make Manual}.}. Automake
6559 also contains some support for creating programs and shared libraries
6560 that are a mixture of Fortran 77 and other languages (@pxref{Mixing
6561 Fortran 77 With C and C++}).
6563 These issues are covered in the following sections.
6566 * Preprocessing Fortran 77:: Preprocessing Fortran 77 sources
6567 * Compiling Fortran 77 Files:: Compiling Fortran 77 sources
6568 * Mixing Fortran 77 With C and C++:: Mixing Fortran 77 With C and C++
6572 @node Preprocessing Fortran 77
6573 @comment node-name, next, previous, up
6574 @subsection Preprocessing Fortran 77
6576 @cindex Preprocessing Fortran 77
6577 @cindex Fortran 77, Preprocessing
6578 @cindex Ratfor programs
6580 @file{N.f} is made automatically from @file{N.F} or @file{N.r}. This
6581 rule runs just the preprocessor to convert a preprocessable Fortran 77
6582 or Ratfor source file into a strict Fortran 77 source file. The precise
6583 command used is as follows:
6588 @code{$(F77) -F $(DEFS) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS)@*
6589 $(AM_FFLAGS) $(FFLAGS)}
6592 @code{$(F77) -F $(AM_FFLAGS) $(FFLAGS) $(AM_RFLAGS) $(RFLAGS)}
6597 @node Compiling Fortran 77 Files
6598 @comment node-name, next, previous, up
6599 @subsection Compiling Fortran 77 Files
6601 @file{N.o} is made automatically from @file{N.f}, @file{N.F} or
6602 @file{N.r} by running the Fortran 77 compiler. The precise command used
6608 @code{$(F77) -c $(AM_FFLAGS) $(FFLAGS)}
6611 @code{$(F77) -c $(DEFS) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS)@*
6612 $(AM_FFLAGS) $(FFLAGS)}
6615 @code{$(F77) -c $(AM_FFLAGS) $(FFLAGS) $(AM_RFLAGS) $(RFLAGS)}
6620 @node Mixing Fortran 77 With C and C++
6621 @comment node-name, next, previous, up
6622 @subsection Mixing Fortran 77 With C and C++
6624 @cindex Fortran 77, mixing with C and C++
6625 @cindex Mixing Fortran 77 with C and C++
6626 @cindex Linking Fortran 77 with C and C++
6628 @cindex Mixing Fortran 77 with C and/or C++
6630 Automake currently provides @emph{limited} support for creating programs
6631 and shared libraries that are a mixture of Fortran 77 and C and/or C++.
6632 However, there are many other issues related to mixing Fortran 77 with
6633 other languages that are @emph{not} (currently) handled by Automake, but
6634 that are handled by other packages@footnote{For example,
6635 @uref{http://www-zeus.desy.de/~burow/cfortran/, the cfortran package}
6636 addresses all of these inter-language issues, and runs under nearly all
6637 Fortran 77, C and C++ compilers on nearly all platforms. However,
6638 @command{cfortran} is not yet Free Software, but it will be in the next
6641 Automake can help in two ways:
6645 Automatic selection of the linker depending on which combinations of
6649 Automatic selection of the appropriate linker flags (e.g., @option{-L} and
6650 @option{-l}) to pass to the automatically selected linker in order to link
6651 in the appropriate Fortran 77 intrinsic and run-time libraries.
6653 @cindex @code{FLIBS}, defined
6655 These extra Fortran 77 linker flags are supplied in the output variable
6656 @code{FLIBS} by the @code{AC_F77_LIBRARY_LDFLAGS} Autoconf macro.
6657 @xref{Fortran Compiler, , Fortran Compiler Characteristics, autoconf,
6658 The Autoconf Manual}.
6661 If Automake detects that a program or shared library (as mentioned in
6662 some @code{_PROGRAMS} or @code{_LTLIBRARIES} primary) contains source
6663 code that is a mixture of Fortran 77 and C and/or C++, then it requires
6664 that the macro @code{AC_F77_LIBRARY_LDFLAGS} be called in
6665 @file{configure.ac}, and that either @code{$(FLIBS)}
6666 appear in the appropriate @code{_LDADD} (for programs) or @code{_LIBADD}
6667 (for shared libraries) variables. It is the responsibility of the
6668 person writing the @file{Makefile.am} to make sure that @samp{$(FLIBS)}
6669 appears in the appropriate @code{_LDADD} or
6670 @code{_LIBADD} variable.
6672 @cindex Mixed language example
6673 @cindex Example, mixed language
6675 For example, consider the following @file{Makefile.am}:
6679 foo_SOURCES = main.cc foo.f
6680 foo_LDADD = libfoo.la $(FLIBS)
6682 pkglib_LTLIBRARIES = libfoo.la
6683 libfoo_la_SOURCES = bar.f baz.c zardoz.cc
6684 libfoo_la_LIBADD = $(FLIBS)
6687 In this case, Automake will insist that @code{AC_F77_LIBRARY_LDFLAGS}
6688 is mentioned in @file{configure.ac}. Also, if @samp{$(FLIBS)} hadn't
6689 been mentioned in @code{foo_LDADD} and @code{libfoo_la_LIBADD}, then
6690 Automake would have issued a warning.
6693 * How the Linker is Chosen:: Automatic linker selection
6696 @node How the Linker is Chosen
6697 @comment node-name, next, previous, up
6698 @subsubsection How the Linker is Chosen
6700 @cindex Automatic linker selection
6701 @cindex Selecting the linker automatically
6703 When a program or library mixes several languages, Automake choose the
6704 linker according to the following priorities. (The names in
6705 parentheses are the variables containing the link command.)
6710 Native Java (@code{GCJLINK})
6713 Objective C++ (@code{OBJCXXLINK})
6716 C++ (@code{CXXLINK})
6719 Fortran 77 (@code{F77LINK})
6722 Fortran (@code{FCLINK})
6725 Objective C (@code{OBJCLINK})
6728 Unified Parallel C (@code{UPCLINK})
6734 For example, if Fortran 77, C and C++ source code is compiled
6735 into a program, then the C++ linker will be used. In this case, if the
6736 C or Fortran 77 linkers required any special libraries that weren't
6737 included by the C++ linker, then they must be manually added to an
6738 @code{_LDADD} or @code{_LIBADD} variable by the user writing the
6741 Automake only looks at the file names listed in @file{_SOURCES}
6742 variables to choose the linker, and defaults to the C linker.
6743 Sometimes this is inconvenient because you are linking against a
6744 library written in another language and would like to set the linker
6745 more appropriately. @xref{Libtool Convenience Libraries}, for a
6746 trick with @code{nodist_EXTRA_@dots{}_SOURCES}.
6748 A per-target @code{_LINK} variable will override the above selection.
6749 Per-target link flags will cause Automake to write a per-target
6750 @code{_LINK} variable according to the language chosen as above.
6753 @node Fortran 9x Support
6754 @comment node-name, next, previous, up
6755 @section Fortran 9x Support
6757 @cindex Fortran 9x support
6758 @cindex Support for Fortran 9x
6760 Automake includes support for Fortran 9x.
6762 Any package including Fortran 9x code must define the output variable
6763 @code{FC} in @file{configure.ac}; the simplest way to do this is to use
6764 the @code{AC_PROG_FC} macro (@pxref{Particular Programs, , Particular
6765 Program Checks, autoconf, The Autoconf Manual}).
6767 A few additional variables are defined when a Fortran 9x source file is
6773 The name of the Fortran 9x compiler.
6776 Any flags to pass to the Fortran 9x compiler.
6779 The maintainer's variant of @code{FCFLAGS}.
6782 The command used to actually compile a Fortran 9x source file. The file
6783 name is appended to form the complete command line.
6786 The command used to actually link a pure Fortran 9x program or shared
6792 * Compiling Fortran 9x Files:: Compiling Fortran 9x sources
6795 @node Compiling Fortran 9x Files
6796 @comment node-name, next, previous, up
6797 @subsection Compiling Fortran 9x Files
6799 @file{@var{file}.o} is made automatically from @file{@var{file}.f90},
6800 @file{@var{file}.f95}, @file{@var{file}.f03}, or @file{@var{file}.f08}
6801 by running the Fortran 9x compiler. The precise command used
6807 @code{$(FC) $(AM_FCFLAGS) $(FCFLAGS) -c $(FCFLAGS_f90) $<}
6810 @code{$(FC) $(AM_FCFLAGS) $(FCFLAGS) -c $(FCFLAGS_f95) $<}
6813 @code{$(FC) $(AM_FCFLAGS) $(FCFLAGS) -c $(FCFLAGS_f03) $<}
6816 @code{$(FC) $(AM_FCFLAGS) $(FCFLAGS) -c $(FCFLAGS_f08) $<}
6820 @node Java Support with gcj
6821 @comment node-name, next, previous, up
6822 @section Compiling Java sources using gcj
6824 @cindex Java support with gcj
6825 @cindex Support for Java with gcj
6826 @cindex Java to native code, compilation
6827 @cindex Compilation of Java to native code
6829 Automake includes support for natively compiled Java, using @command{gcj},
6830 the Java front end to the GNU Compiler Collection (rudimentary support
6831 for compiling Java to bytecode using the @command{javac} compiler is
6832 also present, @emph{albeit deprecated}; @pxref{Java}).
6834 Any package including Java code to be compiled must define the output
6835 variable @code{GCJ} in @file{configure.ac}; the variable @code{GCJFLAGS}
6836 must also be defined somehow (either in @file{configure.ac} or
6837 @file{Makefile.am}). The simplest way to do this is to use the
6838 @code{AM_PROG_GCJ} macro.
6842 By default, programs including Java source files are linked with
6845 As always, the contents of @code{AM_GCJFLAGS} are passed to every
6846 compilation invoking @command{gcj} (in its role as an ahead-of-time
6847 compiler, when invoking it to create @file{.class} files,
6848 @code{AM_JAVACFLAGS} is used instead). If it is necessary to pass
6849 options to @command{gcj} from @file{Makefile.am}, this variable, and not
6850 the user variable @code{GCJFLAGS}, should be used.
6854 @command{gcj} can be used to compile @file{.java}, @file{.class},
6855 @file{.zip}, or @file{.jar} files.
6857 When linking, @command{gcj} requires that the main class be specified
6858 using the @option{--main=} option. The easiest way to do this is to use
6859 the @code{_LDFLAGS} variable for the program.
6863 @comment node-name, next, previous, up
6864 @section Vala Support
6866 @cindex Vala Support
6867 @cindex Support for Vala
6869 Automake provides initial support for Vala
6870 (@uref{http://www.vala-project.org/}).
6871 This requires valac version 0.7.0 or later, and currently requires
6872 the user to use GNU @command{make}.
6875 foo_SOURCES = foo.vala bar.vala zardoc.c
6878 Any @file{.vala} file listed in a @code{_SOURCES} variable will be
6879 compiled into C code by the Vala compiler. The generated @file{.c} files
6880 are distributed. The end user does not need to have a Vala compiler installed.
6882 Automake ships with an Autoconf macro called @code{AM_PROG_VALAC}
6883 that will locate the Vala compiler and optionally check its version
6886 @defmac AM_PROG_VALAC (@ovar{minimum-version}, @ovar{action-if-found},
6887 @ovar{action-if-not-found})
6888 Search for a Vala compiler in @env{PATH}. If it is found, the variable
6889 @code{VALAC} is set to point to it (see below for more details). This
6890 macro takes three optional arguments. The first argument, if present,
6891 is the minimum version of the Vala compiler required to compile this
6892 package. If a compiler is found and satisfies @var{minimum-version},
6893 then @var{action-if-found} is run (this defaults to do nothing).
6894 Otherwise, @var{action-if-not-found} is run. If @var{action-if-not-found}
6895 is not specified, the default value is to print a warning in case no
6896 compiler is found, or if a too-old version of the compiler is found.
6899 There are a few variables that are used when compiling Vala sources:
6903 Absolute path to the Vala compiler, or simply @samp{valac} if no
6904 suitable compiler Vala could be found at configure runtime.
6907 Additional arguments for the Vala compiler.
6910 The maintainer's variant of @code{VALAFLAGS}.
6913 lib_LTLIBRARIES = libfoo.la
6914 libfoo_la_SOURCES = foo.vala
6918 Note that currently, you cannot use per-target @code{*_VALAFLAGS}
6919 (@pxref{Renamed Objects}) to produce different C files from one Vala
6923 @node Support for Other Languages
6924 @comment node-name, next, previous, up
6925 @section Support for Other Languages
6927 Automake currently only includes full support for C, C++ (@pxref{C++
6928 Support}), Objective C (@pxref{Objective C Support}),
6929 Objective C++ (@pxref{Objective C++ Support}),
6931 (@pxref{Fortran 77 Support}), Fortran 9x (@pxref{Fortran 9x Support}),
6932 and Java (@pxref{Java Support with gcj}). There is only rudimentary
6933 support for other languages, support for which will be improved based
6936 Some limited support for adding your own languages is available via the
6937 suffix rule handling (@pxref{Suffixes}).
6940 @section Automatic dependency tracking
6942 As a developer it is often painful to continually update the
6943 @file{Makefile.am} whenever the include-file dependencies change in a
6944 project. Automake supplies a way to automatically track dependency
6945 changes (@pxref{Dependency Tracking}).
6947 @cindex Dependency tracking
6948 @cindex Automatic dependency tracking
6950 Automake always uses complete dependencies for a compilation,
6951 including system headers. Automake's model is that dependency
6952 computation should be a side effect of the build. To this end,
6953 dependencies are computed by running all compilations through a
6954 special wrapper program called @command{depcomp}. @command{depcomp}
6955 understands how to coax many different C and C++ compilers into
6956 generating dependency information in the format it requires.
6957 @samp{automake -a} will install @command{depcomp} into your source
6958 tree for you. If @command{depcomp} can't figure out how to properly
6959 invoke your compiler, dependency tracking will simply be disabled for
6962 @cindex @command{depcomp}
6964 Experience with earlier versions of Automake (@pxref{Dependency Tracking
6965 Evolution, , Dependency Tracking Evolution, automake-history, Brief History
6966 of Automake}) taught us that it is not reliable to generate dependencies
6967 only on the maintainer's system, as configurations vary too much. So
6968 instead Automake implements dependency tracking at build time.
6970 Automatic dependency tracking can be suppressed by putting
6971 @option{no-dependencies} in the variable @code{AUTOMAKE_OPTIONS}, or
6972 passing @option{no-dependencies} as an argument to @code{AM_INIT_AUTOMAKE}
6973 (this should be the preferred way). Or, you can invoke @command{automake}
6974 with the @option{-i} option. Dependency tracking is enabled by default.
6976 @vindex AUTOMAKE_OPTIONS
6977 @opindex no-dependencies
6979 The person building your package also can choose to disable dependency
6980 tracking by configuring with @option{--disable-dependency-tracking}.
6982 @cindex Disabling dependency tracking
6983 @cindex Dependency tracking, disabling
6987 @section Support for executable extensions
6989 @cindex Executable extension
6990 @cindex Extension, executable
6993 On some platforms, such as Windows, executables are expected to have an
6994 extension such as @file{.exe}. On these platforms, some compilers (GCC
6995 among them) will automatically generate @file{foo.exe} when asked to
6996 generate @file{foo}.
6998 Automake provides mostly-transparent support for this. Unfortunately
6999 @emph{mostly} doesn't yet mean @emph{fully}. Until the English
7000 dictionary is revised, you will have to assist Automake if your package
7001 must support those platforms.
7003 One thing you must be aware of is that, internally, Automake rewrites
7004 something like this:
7007 bin_PROGRAMS = liver
7013 bin_PROGRAMS = liver$(EXEEXT)
7016 The targets Automake generates are likewise given the @samp{$(EXEEXT)}
7019 The variables @code{TESTS} and @code{XFAIL_TESTS} (@pxref{Simple Tests})
7020 are also rewritten if they contain filenames that have been declared as
7021 programs in the same @file{Makefile}. (This is mostly useful when some
7022 programs from @code{check_PROGRAMS} are listed in @code{TESTS}.)
7024 However, Automake cannot apply this rewriting to @command{configure}
7025 substitutions. This means that if you are conditionally building a
7026 program using such a substitution, then your @file{configure.ac} must
7027 take care to add @samp{$(EXEEXT)} when constructing the output variable.
7029 Sometimes maintainers like to write an explicit link rule for their
7030 program. Without executable extension support, this is easy---you
7031 simply write a rule whose target is the name of the program. However,
7032 when executable extension support is enabled, you must instead add the
7033 @samp{$(EXEEXT)} suffix.
7035 This might be a nuisance for maintainers who know their package will
7036 never run on a platform that has
7037 executable extensions. For those maintainers, the @option{no-exeext}
7038 option (@pxref{Options}) will disable this feature. This works in a
7039 fairly ugly way; if @option{no-exeext} is seen, then the presence of a
7040 rule for a target named @code{foo} in @file{Makefile.am} will override
7041 an @command{automake}-generated rule for @samp{foo$(EXEEXT)}. Without
7042 the @option{no-exeext} option, this use will give a diagnostic.
7046 @chapter Other Derived Objects
7048 Automake can handle derived objects that are not C programs. Sometimes
7049 the support for actually building such objects must be explicitly
7050 supplied, but Automake will still automatically handle installation and
7054 * Scripts:: Executable scripts
7055 * Headers:: Header files
7056 * Data:: Architecture-independent data files
7057 * Sources:: Derived sources
7062 @section Executable Scripts
7064 @cindex @code{_SCRIPTS} primary, defined
7065 @cindex @code{SCRIPTS} primary, defined
7066 @cindex Primary variable, @code{SCRIPTS}
7068 @cindex Installing scripts
7070 It is possible to define and install programs that are scripts. Such
7071 programs are listed using the @code{SCRIPTS} primary name. When the
7072 script is distributed in its final, installable form, the
7073 @file{Makefile} usually looks as follows:
7077 # Install my_script in $(bindir) and distribute it.
7078 dist_bin_SCRIPTS = my_script
7081 Scripts are not distributed by default; as we have just seen, those
7082 that should be distributed can be specified using a @code{dist_}
7083 prefix as with other primaries.
7085 @cindex @code{SCRIPTS}, installation directories
7087 @vindex sbin_SCRIPTS
7088 @vindex libexec_SCRIPTS
7089 @vindex pkgdata_SCRIPTS
7090 @vindex pkglibexec_SCRIPTS
7091 @vindex noinst_SCRIPTS
7092 @vindex check_SCRIPTS
7094 Scripts can be installed in @code{bindir}, @code{sbindir},
7095 @code{libexecdir}, @code{pkglibexecdir}, or @code{pkgdatadir}.
7097 Scripts that need not be installed can be listed in
7098 @code{noinst_SCRIPTS}, and among them, those which are needed only by
7099 @samp{make check} should go in @code{check_SCRIPTS}.
7101 When a script needs to be built, the @file{Makefile.am} should include
7102 the appropriate rules. For instance the @command{automake} program
7103 itself is a Perl script that is generated from @file{automake.in}.
7104 Here is how this is handled:
7107 bin_SCRIPTS = automake
7108 CLEANFILES = $(bin_SCRIPTS)
7109 EXTRA_DIST = automake.in
7111 do_subst = sed -e 's,[@@]datadir[@@],$(datadir),g' \
7112 -e 's,[@@]PERL[@@],$(PERL),g' \
7113 -e 's,[@@]PACKAGE[@@],$(PACKAGE),g' \
7114 -e 's,[@@]VERSION[@@],$(VERSION),g' \
7117 automake: automake.in Makefile
7118 $(do_subst) < $(srcdir)/automake.in > automake
7122 Such scripts for which a build rule has been supplied need to be
7123 deleted explicitly using @code{CLEANFILES} (@pxref{Clean}), and their
7124 sources have to be distributed, usually with @code{EXTRA_DIST}
7125 (@pxref{Basics of Distribution}).
7127 Another common way to build scripts is to process them from
7128 @file{configure} with @code{AC_CONFIG_FILES}. In this situation
7129 Automake knows which files should be cleaned and distributed, and what
7130 the rebuild rules should look like.
7132 For instance if @file{configure.ac} contains
7135 AC_CONFIG_FILES([src/my_script], [chmod +x src/my_script])
7139 to build @file{src/my_script} from @file{src/my_script.in}, then a
7140 @file{src/Makefile.am} to install this script in @code{$(bindir)} can
7144 bin_SCRIPTS = my_script
7145 CLEANFILES = $(bin_SCRIPTS)
7149 There is no need for @code{EXTRA_DIST} or any build rule: Automake
7150 infers them from @code{AC_CONFIG_FILES} (@pxref{Requirements}).
7151 @code{CLEANFILES} is still useful, because by default Automake will
7152 clean targets of @code{AC_CONFIG_FILES} in @code{distclean}, not
7155 Although this looks simpler, building scripts this way has one
7156 drawback: directory variables such as @code{$(datadir)} are not fully
7157 expanded and may refer to other directory variables.
7160 @section Header files
7162 @cindex @code{_HEADERS} primary, defined
7163 @cindex @code{HEADERS} primary, defined
7164 @cindex Primary variable, @code{HEADERS}
7166 @vindex noinst_HEADERS
7167 @cindex @code{HEADERS}, installation directories
7168 @cindex Installing headers
7169 @vindex include_HEADERS
7170 @vindex oldinclude_HEADERS
7171 @vindex pkginclude_HEADERS
7174 Header files that must be installed are specified by the
7175 @code{HEADERS} family of variables. Headers can be installed in
7176 @code{includedir}, @code{oldincludedir}, @code{pkgincludedir} or any
7177 other directory you may have defined (@pxref{Uniform}). For instance,
7180 include_HEADERS = foo.h bar/bar.h
7184 will install the two files as @file{$(includedir)/foo.h} and
7185 @file{$(includedir)/bar.h}.
7187 The @code{nobase_} prefix is also supported,
7190 nobase_include_HEADERS = foo.h bar/bar.h
7194 will install the two files as @file{$(includedir)/foo.h} and
7195 @file{$(includedir)/bar/bar.h} (@pxref{Alternative}).
7197 @vindex noinst_HEADERS
7198 Usually, only header files that accompany installed libraries need to
7199 be installed. Headers used by programs or convenience libraries are
7200 not installed. The @code{noinst_HEADERS} variable can be used for
7201 such headers. However when the header actually belongs to a single
7202 convenience library or program, we recommend listing it in the
7203 program's or library's @code{_SOURCES} variable (@pxref{Program
7204 Sources}) instead of in @code{noinst_HEADERS}. This is clearer for
7205 the @file{Makefile.am} reader. @code{noinst_HEADERS} would be the
7206 right variable to use in a directory containing only headers and no
7207 associated library or program.
7209 All header files must be listed somewhere; in a @code{_SOURCES}
7210 variable or in a @code{_HEADERS} variable. Missing ones will not
7211 appear in the distribution.
7213 For header files that are built and must not be distributed, use the
7214 @code{nodist_} prefix as in @code{nodist_include_HEADERS} or
7215 @code{nodist_prog_SOURCES}. If these generated headers are needed
7216 during the build, you must also ensure they exist before they are
7217 used (@pxref{Sources}).
7221 @section Architecture-independent data files
7223 @cindex @code{_DATA} primary, defined
7224 @cindex @code{DATA} primary, defined
7225 @cindex Primary variable, @code{DATA}
7228 Automake supports the installation of miscellaneous data files using the
7229 @code{DATA} family of variables.
7233 @vindex sysconf_DATA
7234 @vindex sharedstate_DATA
7235 @vindex localstate_DATA
7236 @vindex pkgdata_DATA
7238 Such data can be installed in the directories @code{datadir},
7239 @code{sysconfdir}, @code{sharedstatedir}, @code{localstatedir}, or
7242 By default, data files are @emph{not} included in a distribution. Of
7243 course, you can use the @code{dist_} prefix to change this on a
7246 Here is how Automake declares its auxiliary data files:
7249 dist_pkgdata_DATA = clean-kr.am clean.am @dots{}
7254 @section Built Sources
7256 Because Automake's automatic dependency tracking works as a side-effect
7257 of compilation (@pxref{Dependencies}) there is a bootstrap issue: a
7258 target should not be compiled before its dependencies are made, but
7259 these dependencies are unknown until the target is first compiled.
7261 Ordinarily this is not a problem, because dependencies are distributed
7262 sources: they preexist and do not need to be built. Suppose that
7263 @file{foo.c} includes @file{foo.h}. When it first compiles
7264 @file{foo.o}, @command{make} only knows that @file{foo.o} depends on
7265 @file{foo.c}. As a side-effect of this compilation @command{depcomp}
7266 records the @file{foo.h} dependency so that following invocations of
7267 @command{make} will honor it. In these conditions, it's clear there is
7268 no problem: either @file{foo.o} doesn't exist and has to be built
7269 (regardless of the dependencies), or accurate dependencies exist and
7270 they can be used to decide whether @file{foo.o} should be rebuilt.
7272 It's a different story if @file{foo.h} doesn't exist by the first
7273 @command{make} run. For instance, there might be a rule to build
7274 @file{foo.h}. This time @file{file.o}'s build will fail because the
7275 compiler can't find @file{foo.h}. @command{make} failed to trigger the
7276 rule to build @file{foo.h} first by lack of dependency information.
7278 @vindex BUILT_SOURCES
7279 @cindex @code{BUILT_SOURCES}, defined
7281 The @code{BUILT_SOURCES} variable is a workaround for this problem. A
7282 source file listed in @code{BUILT_SOURCES} is made on @samp{make all}
7283 or @samp{make check} (or even @samp{make install}) before other
7284 targets are processed. However, such a source file is not
7285 @emph{compiled} unless explicitly requested by mentioning it in some
7286 other @code{_SOURCES} variable.
7288 So, to conclude our introductory example, we could use
7289 @samp{BUILT_SOURCES = foo.h} to ensure @file{foo.h} gets built before
7290 any other target (including @file{foo.o}) during @samp{make all} or
7293 @code{BUILT_SOURCES} is actually a bit of a misnomer, as any file which
7294 must be created early in the build process can be listed in this
7295 variable. Moreover, all built sources do not necessarily have to be
7296 listed in @code{BUILT_SOURCES}. For instance, a generated @file{.c} file
7297 doesn't need to appear in @code{BUILT_SOURCES} (unless it is included by
7298 another source), because it's a known dependency of the associated
7301 It might be important to emphasize that @code{BUILT_SOURCES} is
7302 honored only by @samp{make all}, @samp{make check} and @samp{make
7303 install}. This means you cannot build a specific target (e.g.,
7304 @samp{make foo}) in a clean tree if it depends on a built source.
7305 However it will succeed if you have run @samp{make all} earlier,
7306 because accurate dependencies are already available.
7308 The next section illustrates and discusses the handling of built sources
7312 * Built Sources Example:: Several ways to handle built sources.
7315 @node Built Sources Example
7316 @subsection Built Sources Example
7318 Suppose that @file{foo.c} includes @file{bindir.h}, which is
7319 installation-dependent and not distributed: it needs to be built. Here
7320 @file{bindir.h} defines the preprocessor macro @code{bindir} to the
7321 value of the @command{make} variable @code{bindir} (inherited from
7324 We suggest several implementations below. It's not meant to be an
7325 exhaustive listing of all ways to handle built sources, but it will give
7326 you a few ideas if you encounter this issue.
7328 @subsubheading First Try
7330 This first implementation will illustrate the bootstrap issue mentioned
7331 in the previous section (@pxref{Sources}).
7333 Here is a tentative @file{Makefile.am}.
7339 nodist_foo_SOURCES = bindir.h
7340 CLEANFILES = bindir.h
7342 echo '#define bindir "$(bindir)"' >$@@
7345 This setup doesn't work, because Automake doesn't know that @file{foo.c}
7346 includes @file{bindir.h}. Remember, automatic dependency tracking works
7347 as a side-effect of compilation, so the dependencies of @file{foo.o} will
7348 be known only after @file{foo.o} has been compiled (@pxref{Dependencies}).
7349 The symptom is as follows.
7353 source='foo.c' object='foo.o' libtool=no \
7354 depfile='.deps/foo.Po' tmpdepfile='.deps/foo.TPo' \
7355 depmode=gcc /bin/sh ./depcomp \
7356 gcc -I. -I. -g -O2 -c `test -f 'foo.c' || echo './'`foo.c
7357 foo.c:2: bindir.h: No such file or directory
7358 make: *** [foo.o] Error 1
7361 In this example @file{bindir.h} is not distributed nor installed, and
7362 it is not even being built on-time. One may wonder if the
7363 @samp{nodist_foo_SOURCES = bindir.h} line has any use at all. This
7364 line simply states that @file{bindir.h} is a source of @code{foo}, so
7365 for instance, it should be inspected while generating tags
7366 (@pxref{Tags}). In other words, it does not help our present problem,
7367 and the build would fail identically without it.
7369 @subsubheading Using @code{BUILT_SOURCES}
7371 A solution is to require @file{bindir.h} to be built before anything
7372 else. This is what @code{BUILT_SOURCES} is meant for (@pxref{Sources}).
7377 nodist_foo_SOURCES = bindir.h
7378 BUILT_SOURCES = bindir.h
7379 CLEANFILES = bindir.h
7381 echo '#define bindir "$(bindir)"' >$@@
7384 See how @file{bindir.h} gets built first:
7388 echo '#define bindir "/usr/local/bin"' >bindir.h
7390 make[1]: Entering directory `/home/adl/tmp'
7391 source='foo.c' object='foo.o' libtool=no \
7392 depfile='.deps/foo.Po' tmpdepfile='.deps/foo.TPo' \
7393 depmode=gcc /bin/sh ./depcomp \
7394 gcc -I. -I. -g -O2 -c `test -f 'foo.c' || echo './'`foo.c
7395 gcc -g -O2 -o foo foo.o
7396 make[1]: Leaving directory `/home/adl/tmp'
7399 However, as said earlier, @code{BUILT_SOURCES} applies only to the
7400 @code{all}, @code{check}, and @code{install} targets. It still fails
7401 if you try to run @samp{make foo} explicitly:
7405 test -z "bindir.h" || rm -f bindir.h
7406 test -z "foo" || rm -f foo
7408 % : > .deps/foo.Po # Suppress previously recorded dependencies
7410 source='foo.c' object='foo.o' libtool=no \
7411 depfile='.deps/foo.Po' tmpdepfile='.deps/foo.TPo' \
7412 depmode=gcc /bin/sh ./depcomp \
7413 gcc -I. -I. -g -O2 -c `test -f 'foo.c' || echo './'`foo.c
7414 foo.c:2: bindir.h: No such file or directory
7415 make: *** [foo.o] Error 1
7418 @subsubheading Recording Dependencies manually
7420 Usually people are happy enough with @code{BUILT_SOURCES} because they
7421 never build targets such as @samp{make foo} before @samp{make all}, as
7422 in the previous example. However if this matters to you, you can
7423 avoid @code{BUILT_SOURCES} and record such dependencies explicitly in
7424 the @file{Makefile.am}.
7429 nodist_foo_SOURCES = bindir.h
7430 foo.$(OBJEXT): bindir.h
7431 CLEANFILES = bindir.h
7433 echo '#define bindir "$(bindir)"' >$@@
7436 You don't have to list @emph{all} the dependencies of @file{foo.o}
7437 explicitly, only those that might need to be built. If a dependency
7438 already exists, it will not hinder the first compilation and will be
7439 recorded by the normal dependency tracking code. (Note that after
7440 this first compilation the dependency tracking code will also have
7441 recorded the dependency between @file{foo.o} and
7442 @file{bindir.h}; so our explicit dependency is really useful to
7443 the first build only.)
7445 Adding explicit dependencies like this can be a bit dangerous if you are
7446 not careful enough. This is due to the way Automake tries not to
7447 overwrite your rules (it assumes you know better than it).
7448 @samp{foo.$(OBJEXT): bindir.h} supersedes any rule Automake may want to
7449 output to build @samp{foo.$(OBJEXT)}. It happens to work in this case
7450 because Automake doesn't have to output any @samp{foo.$(OBJEXT):}
7451 target: it relies on a suffix rule instead (i.e., @samp{.c.$(OBJEXT):}).
7452 Always check the generated @file{Makefile.in} if you do this.
7454 @subsubheading Build @file{bindir.h} from @file{configure}
7456 It's possible to define this preprocessor macro from @file{configure},
7457 either in @file{config.h} (@pxref{Defining Directories, , Defining
7458 Directories, autoconf, The Autoconf Manual}), or by processing a
7459 @file{bindir.h.in} file using @code{AC_CONFIG_FILES}
7460 (@pxref{Configuration Actions, ,Configuration Actions, autoconf, The
7463 At this point it should be clear that building @file{bindir.h} from
7464 @file{configure} works well for this example. @file{bindir.h} will exist
7465 before you build any target, hence will not cause any dependency issue.
7467 The Makefile can be shrunk as follows. We do not even have to mention
7475 However, it's not always possible to build sources from
7476 @file{configure}, especially when these sources are generated by a tool
7477 that needs to be built first.
7479 @subsubheading Build @file{bindir.c}, not @file{bindir.h}.
7481 Another attractive idea is to define @code{bindir} as a variable or
7482 function exported from @file{bindir.o}, and build @file{bindir.c}
7483 instead of @file{bindir.h}.
7486 noinst_PROGRAMS = foo
7487 foo_SOURCES = foo.c bindir.h
7488 nodist_foo_SOURCES = bindir.c
7489 CLEANFILES = bindir.c
7491 echo 'const char bindir[] = "$(bindir)";' >$@@
7494 @file{bindir.h} contains just the variable's declaration and doesn't
7495 need to be built, so it won't cause any trouble. @file{bindir.o} is
7496 always dependent on @file{bindir.c}, so @file{bindir.c} will get built
7499 @subsubheading Which is best?
7501 There is no panacea, of course. Each solution has its merits and
7504 You cannot use @code{BUILT_SOURCES} if the ability to run @samp{make
7505 foo} on a clean tree is important to you.
7507 You won't add explicit dependencies if you are leery of overriding
7508 an Automake rule by mistake.
7510 Building files from @file{./configure} is not always possible, neither
7511 is converting @file{.h} files into @file{.c} files.
7514 @node Other GNU Tools
7515 @chapter Other GNU Tools
7517 Since Automake is primarily intended to generate @file{Makefile.in}s for
7518 use in GNU programs, it tries hard to interoperate with other GNU tools.
7521 * Emacs Lisp:: Emacs Lisp
7524 * Java:: Java bytecode compilation (deprecated)
7532 @cindex @code{_LISP} primary, defined
7533 @cindex @code{LISP} primary, defined
7534 @cindex Primary variable, @code{LISP}
7540 Automake provides some support for Emacs Lisp. The @code{LISP} primary
7541 is used to hold a list of @file{.el} files. Possible prefixes for this
7542 primary are @code{lisp_} and @code{noinst_}. Note that if
7543 @code{lisp_LISP} is defined, then @file{configure.ac} must run
7544 @code{AM_PATH_LISPDIR} (@pxref{Macros}).
7546 @vindex dist_lisp_LISP
7547 @vindex dist_noinst_LISP
7548 Lisp sources are not distributed by default. You can prefix the
7549 @code{LISP} primary with @code{dist_}, as in @code{dist_lisp_LISP} or
7550 @code{dist_noinst_LISP}, to indicate that these files should be
7553 Automake will byte-compile all Emacs Lisp source files using the Emacs
7554 found by @code{AM_PATH_LISPDIR}, if any was found.
7556 Byte-compiled Emacs Lisp files are not portable among all versions of
7557 Emacs, so it makes sense to turn this off if you expect sites to have
7558 more than one version of Emacs installed. Furthermore, many packages
7559 don't actually benefit from byte-compilation. Still, we recommend
7560 that you byte-compile your Emacs Lisp sources. It is probably better
7561 for sites with strange setups to cope for themselves than to make the
7562 installation less nice for everybody else.
7564 There are two ways to avoid byte-compiling. Historically, we have
7565 recommended the following construct.
7568 lisp_LISP = file1.el file2.el
7573 @code{ELCFILES} is an internal Automake variable that normally lists
7574 all @file{.elc} files that must be byte-compiled. Automake defines
7575 @code{ELCFILES} automatically from @code{lisp_LISP}. Emptying this
7576 variable explicitly prevents byte-compilation.
7578 Since Automake 1.8, we now recommend using @code{lisp_DATA} instead:
7580 @c Keep in sync with primary-prefix-couples-documented-valid.sh
7582 lisp_DATA = file1.el file2.el
7585 Note that these two constructs are not equivalent. @code{_LISP} will
7586 not install a file if Emacs is not installed, while @code{_DATA} will
7587 always install its files.
7592 @cindex GNU Gettext support
7593 @cindex Gettext support
7594 @cindex Support for GNU Gettext
7596 If @code{AM_GNU_GETTEXT} is seen in @file{configure.ac}, then Automake
7597 turns on support for GNU gettext, a message catalog system for
7598 internationalization
7599 (@pxref{Top, , Introduction, gettext, GNU gettext utilities}).
7601 The @code{gettext} support in Automake requires the addition of one or
7602 two subdirectories to the package: @file{po} and possibly also @file{intl}.
7603 The latter is needed if @code{AM_GNU_GETTEXT} is not invoked with the
7604 @samp{external} argument, or if @code{AM_GNU_GETTEXT_INTL_SUBDIR} is used.
7605 Automake ensures that these directories exist and are mentioned in
7611 Automake provides support for GNU Libtool (@pxref{Top, , Introduction,
7612 libtool, The Libtool Manual}) with the @code{LTLIBRARIES} primary.
7613 @xref{A Shared Library}.
7617 @section Java bytecode compilation (deprecated)
7619 @cindex @code{_JAVA} primary, defined
7620 @cindex @code{JAVA} primary, defined
7621 @cindex Primary variable, @code{JAVA}
7622 @cindex Java to bytecode, compilation
7623 @cindex Compilation of Java to bytecode
7625 Automake provides some minimal support for Java bytecode compilation with
7626 the @code{JAVA} primary (in addition to the support for compiling Java to
7627 native machine code; @pxref{Java Support with gcj}). Note however that
7628 @emph{the interface and most features described here are deprecated}; the
7629 next automake release will strive to provide a better and cleaner
7630 interface, which however @emph{won't be backward-compatible}; the present
7631 interface will probably be removed altogether in future automake releases
7632 (1.13 or later), so don't use it in new code.
7634 Any @file{.java} files listed in a @code{_JAVA} variable will be
7635 compiled with @code{JAVAC} at build time. By default, @file{.java}
7636 files are not included in the distribution, you should use the
7637 @code{dist_} prefix to distribute them.
7639 Here is a typical setup for distributing @file{.java} files and
7640 installing the @file{.class} files resulting from their compilation.
7642 @c Keep in sync with primary-prefix-couples-documented-valid.sh
7644 javadir = $(datadir)/java
7645 dist_java_JAVA = a.java b.java @dots{}
7648 @cindex @code{JAVA} restrictions
7649 @cindex Restrictions for @code{JAVA}
7651 Currently Automake enforces the restriction that only one @code{_JAVA}
7652 primary can be used in a given @file{Makefile.am}. The reason for this
7653 restriction is that, in general, it isn't possible to know which
7654 @file{.class} files were generated from which @file{.java} files, so
7655 it would be impossible to know which files to install where. For
7656 instance, a @file{.java} file can define multiple classes; the resulting
7657 @file{.class} file names cannot be predicted without parsing the
7660 There are a few variables that are used when compiling Java sources:
7664 The name of the Java compiler. This defaults to @samp{javac}.
7667 The flags to pass to the compiler. This is considered to be a user
7668 variable (@pxref{User Variables}).
7671 More flags to pass to the Java compiler. This, and not
7672 @code{JAVACFLAGS}, should be used when it is necessary to put Java
7673 compiler flags into @file{Makefile.am}.
7676 The value of this variable is passed to the @option{-d} option to
7677 @code{javac}. It defaults to @samp{$(top_builddir)}.
7680 This variable is a shell expression that is used to set the
7681 @env{CLASSPATH} environment variable on the @code{javac} command line.
7682 (In the future we will probably handle class path setting differently.)
7689 @cindex @code{_PYTHON} primary, defined
7690 @cindex @code{PYTHON} primary, defined
7691 @cindex Primary variable, @code{PYTHON}
7694 Automake provides support for Python compilation with the
7695 @code{PYTHON} primary. A typical setup is to call
7696 @code{AM_PATH_PYTHON} in @file{configure.ac} and use a line like the
7697 following in @file{Makefile.am}:
7700 python_PYTHON = tree.py leave.py
7703 Any files listed in a @code{_PYTHON} variable will be byte-compiled
7704 with @command{py-compile} at install time. @command{py-compile}
7705 actually creates both standard (@file{.pyc}) and optimized
7706 (@file{.pyo}) byte-compiled versions of the source files. Note that
7707 because byte-compilation occurs at install time, any files listed in
7708 @code{noinst_PYTHON} will not be compiled. Python source files are
7709 included in the distribution by default, prepend @code{nodist_} (as in
7710 @code{nodist_python_PYTHON}) to omit them.
7712 Automake ships with an Autoconf macro called @code{AM_PATH_PYTHON}
7713 that will determine some Python-related directory variables (see
7714 below). If you have called @code{AM_PATH_PYTHON} from
7715 @file{configure.ac}, then you may use the variables
7716 @c Keep in sync with primary-prefix-couples-documented-valid.sh
7717 @code{python_PYTHON} or @code{pkgpython_PYTHON} to list Python source
7718 files in your @file{Makefile.am}, depending on where you want your files
7719 installed (see the definitions of @code{pythondir} and
7720 @code{pkgpythondir} below).
7722 @defmac AM_PATH_PYTHON (@ovar{version}, @ovar{action-if-found},
7723 @ovar{action-if-not-found})
7725 Search for a Python interpreter on the system. This macro takes three
7726 optional arguments. The first argument, if present, is the minimum
7727 version of Python required for this package: @code{AM_PATH_PYTHON}
7728 will skip any Python interpreter that is older than @var{version}.
7729 If an interpreter is found and satisfies @var{version}, then
7730 @var{action-if-found} is run. Otherwise, @var{action-if-not-found} is
7733 If @var{action-if-not-found} is not specified, as in the following
7734 example, the default is to abort @command{configure}.
7737 AM_PATH_PYTHON([2.2])
7741 This is fine when Python is an absolute requirement for the package.
7742 If Python >= 2.5 was only @emph{optional} to the package,
7743 @code{AM_PATH_PYTHON} could be called as follows.
7746 AM_PATH_PYTHON([2.5],, [:])
7749 If the @env{PYTHON} variable is set when @code{AM_PATH_PYTHON} is
7750 called, then that will be the only Python interpreter that is tried.
7752 @code{AM_PATH_PYTHON} creates the following output variables based on
7753 the Python installation found during configuration.
7758 The name of the Python executable, or @samp{:} if no suitable
7759 interpreter could be found.
7761 Assuming @var{action-if-not-found} is used (otherwise @file{./configure}
7762 will abort if Python is absent), the value of @code{PYTHON} can be used
7763 to setup a conditional in order to disable the relevant part of a build
7767 AM_PATH_PYTHON(,, [:])
7768 AM_CONDITIONAL([HAVE_PYTHON], [test "$PYTHON" != :])
7771 @item PYTHON_VERSION
7772 The Python version number, in the form @var{major}.@var{minor}
7773 (e.g., @samp{2.5}). This is currently the value of
7774 @samp{sys.version[:3]}.
7777 The string @samp{$@{prefix@}}. This term may be used in future work
7778 that needs the contents of Python's @samp{sys.prefix}, but general
7779 consensus is to always use the value from @command{configure}.
7781 @item PYTHON_EXEC_PREFIX
7782 The string @samp{$@{exec_prefix@}}. This term may be used in future work
7783 that needs the contents of Python's @samp{sys.exec_prefix}, but general
7784 consensus is to always use the value from @command{configure}.
7786 @item PYTHON_PLATFORM
7787 The canonical name used by Python to describe the operating system, as
7788 given by @samp{sys.platform}. This value is sometimes needed when
7789 building Python extensions.
7792 The directory name for the @file{site-packages} subdirectory of the
7793 standard Python install tree.
7796 This is the directory under @code{pythondir} that is named after the
7797 package. That is, it is @samp{$(pythondir)/$(PACKAGE)}. It is provided
7801 This is the directory where Python extension modules (shared libraries)
7802 should be installed. An extension module written in C could be declared
7803 as follows to Automake:
7805 @c Keep in sync with primary-prefix-couples-documented-valid.sh
7807 pyexec_LTLIBRARIES = quaternion.la
7808 quaternion_la_SOURCES = quaternion.c support.c support.h
7809 quaternion_la_LDFLAGS = -avoid-version -module
7813 This is a convenience variable that is defined as
7814 @samp{$(pyexecdir)/$(PACKAGE)}.
7817 All of these directory variables have values that start with either
7818 @samp{$@{prefix@}} or @samp{$@{exec_prefix@}} unexpanded. This works
7819 fine in @file{Makefiles}, but it makes these variables hard to use in
7820 @file{configure}. This is mandated by the GNU coding standards, so
7821 that the user can run @samp{make prefix=/foo install}. The Autoconf
7822 manual has a section with more details on this topic
7823 (@pxref{Installation Directory Variables, , Installation Directory
7824 Variables, autoconf, The Autoconf Manual}). See also @ref{Hard-Coded
7829 @chapter Building documentation
7831 Currently Automake provides support for Texinfo and man pages.
7835 * Man Pages:: Man pages
7842 @cindex @code{_TEXINFOS} primary, defined
7843 @cindex @code{TEXINFOS} primary, defined
7844 @cindex Primary variable, @code{TEXINFOS}
7845 @cindex HTML output using Texinfo
7846 @cindex PDF output using Texinfo
7847 @cindex PS output using Texinfo
7848 @cindex DVI output using Texinfo
7850 @vindex info_TEXINFOS
7852 If the current directory contains Texinfo source, you must declare it
7853 with the @code{TEXINFOS} primary. Generally Texinfo files are converted
7854 into info, and thus the @code{info_TEXINFOS} variable is most commonly used
7855 here. Any Texinfo source file must end in the @file{.texi},
7856 @file{.txi}, or @file{.texinfo} extension. We recommend @file{.texi}
7859 Automake generates rules to build @file{.info}, @file{.dvi},
7860 @file{.ps}, @file{.pdf} and @file{.html} files from your Texinfo
7861 sources. Following the GNU Coding Standards, only the @file{.info}
7862 files are built by @samp{make all} and installed by @samp{make
7863 install} (unless you use @option{no-installinfo}, see below).
7864 Furthermore, @file{.info} files are automatically distributed so that
7865 Texinfo is not a prerequisite for installing your package.
7871 @trindex install-dvi
7872 @trindex install-html
7873 @trindex install-pdf
7875 Other documentation formats can be built on request by @samp{make
7876 dvi}, @samp{make ps}, @samp{make pdf} and @samp{make html}, and they
7877 can be installed with @samp{make install-dvi}, @samp{make install-ps},
7878 @samp{make install-pdf} and @samp{make install-html} explicitly.
7879 @samp{make uninstall} will remove everything: the Texinfo
7880 documentation installed by default as well as all the above optional
7883 All of these targets can be extended using @samp{-local} rules
7884 (@pxref{Extending}).
7886 @cindex Texinfo flag, @code{VERSION}
7887 @cindex Texinfo flag, @code{UPDATED}
7888 @cindex Texinfo flag, @code{EDITION}
7889 @cindex Texinfo flag, @code{UPDATED-MONTH}
7891 @cindex @code{VERSION} Texinfo flag
7892 @cindex @code{UPDATED} Texinfo flag
7893 @cindex @code{EDITION} Texinfo flag
7894 @cindex @code{UPDATED-MONTH} Texinfo flag
7896 @cindex @file{mdate-sh}
7898 If the @file{.texi} file @code{@@include}s @file{version.texi}, then
7899 that file will be automatically generated. The file @file{version.texi}
7900 defines four Texinfo flag you can reference using
7901 @code{@@value@{EDITION@}}, @code{@@value@{VERSION@}},
7902 @code{@@value@{UPDATED@}}, and @code{@@value@{UPDATED-MONTH@}}.
7907 Both of these flags hold the version number of your program. They are
7908 kept separate for clarity.
7911 This holds the date the primary @file{.texi} file was last modified.
7914 This holds the name of the month in which the primary @file{.texi} file
7918 The @file{version.texi} support requires the @command{mdate-sh}
7919 script; this script is supplied with Automake and automatically
7920 included when @command{automake} is invoked with the
7921 @option{--add-missing} option.
7923 If you have multiple Texinfo files, and you want to use the
7924 @file{version.texi} feature, then you have to have a separate version
7925 file for each Texinfo file. Automake will treat any include in a
7926 Texinfo file that matches @file{vers*.texi} just as an automatically
7927 generated version file.
7929 Sometimes an info file actually depends on more than one @file{.texi}
7930 file. For instance, in GNU Hello, @file{hello.texi} includes the file
7931 @file{fdl.texi}. You can tell Automake about these dependencies using
7932 the @code{@var{texi}_TEXINFOS} variable. Here is how GNU Hello does it:
7937 info_TEXINFOS = hello.texi
7938 hello_TEXINFOS = fdl.texi
7941 @cindex @file{texinfo.tex}
7943 By default, Automake requires the file @file{texinfo.tex} to appear in
7944 the same directory as the @file{Makefile.am} file that lists the
7945 @file{.texi} files. If you used @code{AC_CONFIG_AUX_DIR} in
7946 @file{configure.ac} (@pxref{Input, , Finding `configure' Input,
7947 autoconf, The Autoconf Manual}), then @file{texinfo.tex} is looked for
7948 there. In both cases, @command{automake} then supplies @file{texinfo.tex} if
7949 @option{--add-missing} is given, and takes care of its distribution.
7950 However, if you set the @code{TEXINFO_TEX} variable (see below),
7951 it overrides the location of the file and turns off its installation
7952 into the source as well as its distribution.
7954 The option @option{no-texinfo.tex} can be used to eliminate the
7955 requirement for the file @file{texinfo.tex}. Use of the variable
7956 @code{TEXINFO_TEX} is preferable, however, because that allows the
7957 @code{dvi}, @code{ps}, and @code{pdf} targets to still work.
7959 @cindex Option, @code{no-installinfo}
7960 @cindex Target, @code{install-info}
7961 @cindex @code{install-info} target
7962 @cindex @code{no-installinfo} option
7964 @opindex no-installinfo
7965 @trindex install-info
7967 Automake generates an @code{install-info} rule; some people apparently
7968 use this. By default, info pages are installed by @samp{make
7969 install}, so running @code{make install-info} is pointless. This can
7970 be prevented via the @code{no-installinfo} option. In this case,
7971 @file{.info} files are not installed by default, and user must
7972 request this explicitly using @samp{make install-info}.
7974 @vindex AM_UPDATE_INFO_DIR
7975 By default, @code{make install-info} and @code{make uninstall-info}
7976 will try to run the @command{install-info} program (if available) to
7977 update (or create/remove) the @file{@code{$@{infodir@}}/dir} index.
7978 If this is undesired, it can be prevented by exporting the
7979 @code{AM_UPDATE_INFO_DIR} variable to "@code{no}".
7981 The following variables are used by the Texinfo build rules.
7985 The name of the program invoked to build @file{.info} files. This
7986 variable is defined by Automake. If the @command{makeinfo} program is
7987 found on the system then it will be used by default; otherwise
7988 @command{missing} will be used instead.
7991 The command invoked to build @file{.html} files. Automake
7992 defines this to @samp{$(MAKEINFO) --html}.
7995 User flags passed to each invocation of @samp{$(MAKEINFO)} and
7996 @samp{$(MAKEINFOHTML)}. This user variable (@pxref{User Variables}) is
7997 not expected to be defined in any @file{Makefile}; it can be used by
7998 users to pass extra flags to suit their needs.
8000 @item AM_MAKEINFOFLAGS
8001 @itemx AM_MAKEINFOHTMLFLAGS
8002 Maintainer flags passed to each @command{makeinfo} invocation. Unlike
8003 @code{MAKEINFOFLAGS}, these variables are meant to be defined by
8004 maintainers in @file{Makefile.am}. @samp{$(AM_MAKEINFOFLAGS)} is
8005 passed to @code{makeinfo} when building @file{.info} files; and
8006 @samp{$(AM_MAKEINFOHTMLFLAGS)} is used when building @file{.html}
8009 @c Keep in sync with txinfo21.sh
8010 For instance, the following setting can be used to obtain one single
8011 @file{.html} file per manual, without node separators.
8013 AM_MAKEINFOHTMLFLAGS = --no-headers --no-split
8016 @code{AM_MAKEINFOHTMLFLAGS} defaults to @samp{$(AM_MAKEINFOFLAGS)}.
8017 This means that defining @code{AM_MAKEINFOFLAGS} without defining
8018 @code{AM_MAKEINFOHTMLFLAGS} will impact builds of both @file{.info}
8019 and @file{.html} files.
8022 The name of the command that converts a @file{.texi} file into a
8023 @file{.dvi} file. This defaults to @samp{texi2dvi}, a script that ships
8024 with the Texinfo package.
8027 The name of the command that translates a @file{.texi} file into a
8028 @file{.pdf} file. This defaults to @samp{$(TEXI2DVI) --pdf --batch}.
8031 The name of the command that builds a @file{.ps} file out of a
8032 @file{.dvi} file. This defaults to @samp{dvips}.
8036 If your package has Texinfo files in many directories, you can use the
8037 variable @code{TEXINFO_TEX} to tell Automake where to find the canonical
8038 @file{texinfo.tex} for your package. The value of this variable should
8039 be the relative path from the current @file{Makefile.am} to
8043 TEXINFO_TEX = ../doc/texinfo.tex
8051 @cindex @code{_MANS} primary, defined
8052 @cindex @code{MANS} primary, defined
8053 @cindex Primary variable, @code{MANS}
8057 A package can also include man pages (but see the GNU standards on this
8058 matter, @ref{Man Pages, , , standards, The GNU Coding Standards}.) Man
8059 pages are declared using the @code{MANS} primary. Generally the
8060 @code{man_MANS} variable is used. Man pages are automatically installed in
8061 the correct subdirectory of @code{mandir}, based on the file extension.
8063 File extensions such as @file{.1c} are handled by looking for the valid
8064 part of the extension and using that to determine the correct
8065 subdirectory of @code{mandir}. Valid section names are the digits
8066 @samp{0} through @samp{9}, and the letters @samp{l} and @samp{n}.
8068 Sometimes developers prefer to name a man page something like
8069 @file{foo.man} in the source, and then rename it to have the correct
8070 suffix, for example @file{foo.1}, when installing the file. Automake
8071 also supports this mode. For a valid section named @var{section},
8072 there is a corresponding directory named @samp{man@var{section}dir},
8073 and a corresponding @code{_MANS} variable. Files listed in such a
8074 variable are installed in the indicated section. If the file already
8075 has a valid suffix, then it is installed as-is; otherwise the file
8076 suffix is changed to match the section.
8078 For instance, consider this example:
8080 man1_MANS = rename.man thesame.1 alsothesame.1c
8084 In this case, @file{rename.man} will be renamed to @file{rename.1} when
8085 installed, but the other files will keep their names.
8087 @cindex Target, @code{install-man}
8088 @cindex Option, @option{no-installman}
8089 @cindex @code{install-man} target
8090 @cindex @option{no-installman} option
8091 @opindex no-installman
8092 @trindex install-man
8094 By default, man pages are installed by @samp{make install}. However,
8095 since the GNU project does not require man pages, many maintainers do
8096 not expend effort to keep the man pages up to date. In these cases, the
8097 @option{no-installman} option will prevent the man pages from being
8098 installed by default. The user can still explicitly install them via
8099 @samp{make install-man}.
8101 For fast installation, with many files it is preferable to use
8102 @samp{man@var{section}_MANS} over @samp{man_MANS} as well as files that
8103 do not need to be renamed.
8105 Man pages are not currently considered to be source, because it is not
8106 uncommon for man pages to be automatically generated. Therefore they
8107 are not automatically included in the distribution. However, this can
8108 be changed by use of the @code{dist_} prefix. For instance here is
8109 how to distribute and install the two man pages of GNU @command{cpio}
8110 (which includes both Texinfo documentation and man pages):
8113 dist_man_MANS = cpio.1 mt.1
8116 The @code{nobase_} prefix is meaningless for man pages and is
8120 @cindex @code{notrans_} prefix
8121 @cindex Man page renaming, avoiding
8122 @cindex Avoiding man page renaming
8124 Executables and manpages may be renamed upon installation
8125 (@pxref{Renaming}). For manpages this can be avoided by use of the
8126 @code{notrans_} prefix. For instance, suppose an executable @samp{foo}
8127 allowing to access a library function @samp{foo} from the command line.
8128 The way to avoid renaming of the @file{foo.3} manpage is:
8132 notrans_man_MANS = foo.3
8135 @cindex @code{notrans_} and @code{dist_} or @code{nodist_}
8136 @cindex @code{dist_} and @code{notrans_}
8137 @cindex @code{nodist_} and @code{notrans_}
8139 @samp{notrans_} must be specified first when used in conjunction with
8140 either @samp{dist_} or @samp{nodist_} (@pxref{Fine-grained Distribution
8141 Control}). For instance:
8144 notrans_dist_man3_MANS = bar.3
8148 @chapter What Gets Installed
8150 @cindex Installation support
8151 @cindex @samp{make install} support
8153 Naturally, Automake handles the details of actually installing your
8154 program once it has been built. All files named by the various
8155 primaries are automatically installed in the appropriate places when the
8156 user runs @samp{make install}.
8159 * Basics of Installation:: What gets installed where
8160 * The Two Parts of Install:: Installing data and programs separately
8161 * Extending Installation:: Adding your own rules for installation
8162 * Staged Installs:: Installation in a temporary location
8163 * Install Rules for the User:: Useful additional rules
8166 @node Basics of Installation
8167 @section Basics of Installation
8169 A file named in a primary is installed by copying the built file into
8170 the appropriate directory. The base name of the file is used when
8174 bin_PROGRAMS = hello subdir/goodbye
8177 In this example, both @samp{hello} and @samp{goodbye} will be installed
8178 in @samp{$(bindir)}.
8180 Sometimes it is useful to avoid the basename step at install time. For
8181 instance, you might have a number of header files in subdirectories of
8182 the source tree that are laid out precisely how you want to install
8183 them. In this situation you can use the @code{nobase_} prefix to
8184 suppress the base name step. For example:
8187 nobase_include_HEADERS = stdio.h sys/types.h
8191 will install @file{stdio.h} in @samp{$(includedir)} and @file{types.h}
8192 in @samp{$(includedir)/sys}.
8194 For most file types, Automake will install multiple files at once, while
8195 avoiding command line length issues (@pxref{Length Limitations}). Since
8196 some @command{install} programs will not install the same file twice in
8197 one invocation, you may need to ensure that file lists are unique within
8198 one variable such as @samp{nobase_include_HEADERS} above.
8200 You should not rely on the order in which files listed in one variable
8201 are installed. Likewise, to cater for parallel make, you should not
8202 rely on any particular file installation order even among different
8203 file types (library dependencies are an exception here).
8206 @node The Two Parts of Install
8207 @section The Two Parts of Install
8209 Automake generates separate @code{install-data} and @code{install-exec}
8210 rules, in case the installer is installing on multiple machines that
8211 share directory structure---these targets allow the machine-independent
8212 parts to be installed only once. @code{install-exec} installs
8213 platform-dependent files, and @code{install-data} installs
8214 platform-independent files. The @code{install} target depends on both
8215 of these targets. While Automake tries to automatically segregate
8216 objects into the correct category, the @file{Makefile.am} author is, in
8217 the end, responsible for making sure this is done correctly.
8218 @trindex install-data
8219 @trindex install-exec
8221 @cindex Install, two parts of
8223 Variables using the standard directory prefixes @samp{data},
8224 @samp{info}, @samp{man}, @samp{include}, @samp{oldinclude},
8225 @samp{pkgdata}, or @samp{pkginclude} are installed by
8226 @code{install-data}.
8228 Variables using the standard directory prefixes @samp{bin},
8229 @samp{sbin}, @samp{libexec}, @samp{sysconf}, @samp{localstate},
8230 @samp{lib}, or @samp{pkglib} are installed by @code{install-exec}.
8232 For instance, @code{data_DATA} files are installed by @code{install-data},
8233 while @code{bin_PROGRAMS} files are installed by @code{install-exec}.
8235 Any variable using a user-defined directory prefix with
8236 @samp{exec} in the name (e.g.,
8237 @c Keep in sync with primary-prefix-couples-documented-valid.sh
8238 @code{myexecbin_PROGRAMS}) is installed by @code{install-exec}. All
8239 other user-defined prefixes are installed by @code{install-data}.
8241 @node Extending Installation
8242 @section Extending Installation
8244 It is possible to extend this mechanism by defining an
8245 @code{install-exec-local} or @code{install-data-local} rule. If these
8246 rules exist, they will be run at @samp{make install} time. These
8247 rules can do almost anything; care is required.
8248 @trindex install-exec-local
8249 @trindex install-data-local
8251 Automake also supports two install hooks, @code{install-exec-hook} and
8252 @code{install-data-hook}. These hooks are run after all other install
8253 rules of the appropriate type, exec or data, have completed. So, for
8254 instance, it is possible to perform post-installation modifications
8255 using an install hook. @xref{Extending}, for some examples.
8256 @cindex Install hook
8258 @node Staged Installs
8259 @section Staged Installs
8262 Automake generates support for the @code{DESTDIR} variable in all
8263 install rules. @code{DESTDIR} is used during the @samp{make install}
8264 step to relocate install objects into a staging area. Each object and
8265 path is prefixed with the value of @code{DESTDIR} before being copied
8266 into the install area. Here is an example of typical DESTDIR usage:
8269 mkdir /tmp/staging &&
8270 make DESTDIR=/tmp/staging install
8273 The @command{mkdir} command avoids a security problem if the attacker
8274 creates a symbolic link from @file{/tmp/staging} to a victim area;
8275 then @command{make} places install objects in a directory tree built under
8276 @file{/tmp/staging}. If @file{/gnu/bin/foo} and
8277 @file{/gnu/share/aclocal/foo.m4} are to be installed, the above command
8278 would install @file{/tmp/staging/gnu/bin/foo} and
8279 @file{/tmp/staging/gnu/share/aclocal/foo.m4}.
8281 This feature is commonly used to build install images and packages
8284 Support for @code{DESTDIR} is implemented by coding it directly into
8285 the install rules. If your @file{Makefile.am} uses a local install
8286 rule (e.g., @code{install-exec-local}) or an install hook, then you
8287 must write that code to respect @code{DESTDIR}.
8289 @xref{Makefile Conventions, , , standards, The GNU Coding Standards},
8290 for another usage example.
8292 @node Install Rules for the User
8293 @section Install Rules for the User
8295 Automake also generates rules for targets @code{uninstall},
8296 @code{installdirs}, and @code{install-strip}.
8298 @trindex installdirs
8299 @trindex install-strip
8301 Automake supports @code{uninstall-local} and @code{uninstall-hook}.
8302 There is no notion of separate uninstalls for ``exec'' and ``data'', as
8303 these features would not provide additional functionality.
8305 Note that @code{uninstall} is not meant as a replacement for a real
8310 @chapter What Gets Cleaned
8312 @cindex @samp{make clean} support
8314 The GNU Makefile Standards specify a number of different clean rules.
8315 @xref{Standard Targets, , Standard Targets for Users, standards,
8316 The GNU Coding Standards}.
8318 Generally the files that can be cleaned are determined automatically by
8319 Automake. Of course, Automake also recognizes some variables that can
8320 be defined to specify additional files to clean. These variables are
8321 @code{MOSTLYCLEANFILES}, @code{CLEANFILES}, @code{DISTCLEANFILES}, and
8322 @code{MAINTAINERCLEANFILES}.
8323 @vindex MOSTLYCLEANFILES
8325 @vindex DISTCLEANFILES
8326 @vindex MAINTAINERCLEANFILES
8328 @trindex mostlyclean-local
8329 @trindex clean-local
8330 @trindex distclean-local
8331 @trindex maintainer-clean-local
8332 When cleaning involves more than deleting some hard-coded list of
8333 files, it is also possible to supplement the cleaning rules with your
8334 own commands. Simply define a rule for any of the
8335 @code{mostlyclean-local}, @code{clean-local}, @code{distclean-local},
8336 or @code{maintainer-clean-local} targets (@pxref{Extending}). A common
8337 case is deleting a directory, for instance, a directory created by the
8345 Since @command{make} allows only one set of rules for a given target,
8346 a more extensible way of writing this is to use a separate target
8347 listed as a dependency:
8350 clean-local: clean-local-check
8351 .PHONY: clean-local-check
8356 As the GNU Standards aren't always explicit as to which files should
8357 be removed by which rule, we've adopted a heuristic that we believe
8358 was first formulated by Fran@,{c}ois Pinard:
8362 If @command{make} built it, and it is commonly something that one would
8363 want to rebuild (for instance, a @file{.o} file), then
8364 @code{mostlyclean} should delete it.
8367 Otherwise, if @command{make} built it, then @code{clean} should delete it.
8370 If @command{configure} built it, then @code{distclean} should delete it.
8373 If the maintainer built it (for instance, a @file{.info} file), then
8374 @code{maintainer-clean} should delete it. However
8375 @code{maintainer-clean} should not delete anything that needs to exist
8376 in order to run @samp{./configure && make}.
8379 We recommend that you follow this same set of heuristics in your
8384 @chapter What Goes in a Distribution
8387 * Basics of Distribution:: Files distributed by default
8388 * Fine-grained Distribution Control:: @code{dist_} and @code{nodist_} prefixes
8389 * The dist Hook:: A target for last-minute distribution changes
8390 * Checking the Distribution:: @samp{make distcheck} explained
8391 * The Types of Distributions:: A variety of formats and compression methods
8394 @node Basics of Distribution
8395 @section Basics of Distribution
8397 @cindex @samp{make dist}
8402 The @code{dist} rule in the generated @file{Makefile.in} can be used
8403 to generate a gzipped @code{tar} file and other flavors of archive for
8404 distribution. The file is named based on the @code{PACKAGE} and
8405 @code{VERSION} variables defined by @code{AM_INIT_AUTOMAKE}
8406 (@pxref{Macros}); more precisely the gzipped @code{tar} file is named
8407 @samp{@var{package}-@var{version}.tar.gz}.
8409 You can use the @command{make} variable @code{GZIP_ENV} to control how gzip
8410 is run. The default setting is @option{--best}.
8412 @cindex @code{m4_include}, distribution
8413 @cindex @code{include}, distribution
8416 For the most part, the files to distribute are automatically found by
8417 Automake: all source files are automatically included in a distribution,
8418 as are all @file{Makefile.am} and @file{Makefile.in} files. Automake also
8419 has a built-in list of commonly used files that are automatically
8420 included if they are found in the current directory (either physically,
8421 or as the target of a @file{Makefile.am} rule); this list is printed by
8422 @samp{automake --help}. Note that some files in this list are actually
8423 distributed only if other certain conditions hold (for example,
8424 @c Keep in sync with autodist-config-headers.sh
8425 the @file{config.h.top} and @file{config.h.bot} files are automatically
8426 distributed only if, e.g., @samp{AC_CONFIG_HEADERS([config.h])} is used
8427 in @file{configure.ac}). Also, files that are read by @command{configure}
8428 (i.e.@: the source files corresponding to the files specified in various
8429 Autoconf macros such as @code{AC_CONFIG_FILES} and siblings) are
8430 automatically distributed. Files included in a @file{Makefile.am} (using
8431 @code{include}) or in @file{configure.ac} (using @code{m4_include}), and
8432 helper scripts installed with @samp{automake --add-missing} are also
8436 Still, sometimes there are files that must be distributed, but which
8437 are not covered in the automatic rules. These files should be listed in
8438 the @code{EXTRA_DIST} variable. You can mention files from
8439 subdirectories in @code{EXTRA_DIST}.
8441 You can also mention a directory in @code{EXTRA_DIST}; in this case the
8442 entire directory will be recursively copied into the distribution.
8443 Please note that this will also copy @emph{everything} in the directory,
8444 including, e.g., Subversion's @file{.svn} private directories or CVS/RCS
8445 version control files. We recommend against using this feature.
8448 @vindex DIST_SUBDIRS
8449 If you define @code{SUBDIRS}, Automake will recursively include the
8450 subdirectories in the distribution. If @code{SUBDIRS} is defined
8451 conditionally (@pxref{Conditionals}), Automake will normally include
8452 all directories that could possibly appear in @code{SUBDIRS} in the
8453 distribution. If you need to specify the set of directories
8454 conditionally, you can set the variable @code{DIST_SUBDIRS} to the
8455 exact list of subdirectories to include in the distribution
8456 (@pxref{Conditional Subdirectories}).
8459 @node Fine-grained Distribution Control
8460 @section Fine-grained Distribution Control
8464 Sometimes you need tighter control over what does @emph{not} go into the
8465 distribution; for instance, you might have source files that are
8466 generated and that you do not want to distribute. In this case
8467 Automake gives fine-grained control using the @code{dist} and
8468 @code{nodist} prefixes. Any primary or @code{_SOURCES} variable can be
8469 prefixed with @code{dist_} to add the listed files to the distribution.
8470 Similarly, @code{nodist_} can be used to omit the files from the
8473 As an example, here is how you would cause some data to be distributed
8474 while leaving some source code out of the distribution:
8477 dist_data_DATA = distribute-this
8479 nodist_foo_SOURCES = do-not-distribute.c
8483 @section The dist Hook
8487 Occasionally it is useful to be able to change the distribution before
8488 it is packaged up. If the @code{dist-hook} rule exists, it is run
8489 after the distribution directory is filled, but before the actual
8490 distribution archives are created. One way to use this is for
8491 removing unnecessary files that get recursively included by specifying
8492 a directory in @code{EXTRA_DIST}:
8497 rm -rf `find $(distdir)/doc -type d -name .svn`
8500 @c The caveates described here should be documented in 'disthook.sh'.
8502 Note that the @code{dist-hook} recipe shouldn't assume that the regular
8503 files in the distribution directory are writable; this might not be the
8504 case if one is packaging from a read-only source tree, or when a
8505 @code{make distcheck} is being done. For similar reasons, the recipe
8506 shouldn't assume that the subdirectories put into the distribution
8507 directory as effect of having them listed in @code{EXTRA_DIST} are
8508 writable. So, if the @code{dist-hook} recipe wants to modify the
8509 content of an existing file (or @code{EXTRA_DIST} subdirectory) in the
8510 distribution directory, it should explicitly to make it writable first:
8513 EXTRA_DIST = README doc
8515 chmod u+w $(distdir)/README $(distdir)/doc
8516 echo "Distribution date: `date`" >> README
8517 rm -f $(distdir)/doc/HACKING
8522 Two variables that come handy when writing @code{dist-hook} rules are
8523 @samp{$(distdir)} and @samp{$(top_distdir)}.
8525 @samp{$(distdir)} points to the directory where the @code{dist} rule
8526 will copy files from the current directory before creating the
8527 tarball. If you are at the top-level directory, then @samp{distdir =
8528 $(PACKAGE)-$(VERSION)}. When used from subdirectory named
8529 @file{foo/}, then @samp{distdir = ../$(PACKAGE)-$(VERSION)/foo}.
8530 @samp{$(distdir)} can be a relative or absolute path, do not assume
8533 @samp{$(top_distdir)} always points to the root directory of the
8534 distributed tree. At the top-level it's equal to @samp{$(distdir)}.
8535 In the @file{foo/} subdirectory
8536 @samp{top_distdir = ../$(PACKAGE)-$(VERSION)}.
8537 @samp{$(top_distdir)} too can be a relative or absolute path.
8539 Note that when packages are nested using @code{AC_CONFIG_SUBDIRS}
8540 (@pxref{Subpackages}), then @samp{$(distdir)} and
8541 @samp{$(top_distdir)} are relative to the package where @samp{make
8542 dist} was run, not to any sub-packages involved.
8544 @node Checking the Distribution
8545 @section Checking the Distribution
8547 @cindex @samp{make distcheck}
8549 Automake also generates a @code{distcheck} rule that can be of help
8550 to ensure that a given distribution will actually work. Simplifying
8551 a bit, we can say this rule first makes a distribution, and then,
8552 @emph{operating from it}, takes the following steps:
8555 tries to do a @code{VPATH} build (@pxref{VPATH Builds}), with the
8556 @code{srcdir} and all its content made @emph{read-only};
8558 runs the test suite (with @command{make check}) on this fresh build;
8560 installs the package in a temporary directory (with @command{make
8561 install}), and tries runs the test suite on the resulting installation
8562 (with @command{make installcheck});
8564 checks that the package can be correctly uninstalled (by @command{make
8565 uninstall}) and cleaned (by @code{make distclean});
8567 finally, makes another tarball to ensure the distribution is
8571 @vindex AM_DISTCHECK_CONFIGURE_FLAGS
8572 @vindex DISTCHECK_CONFIGURE_FLAGS
8573 @subheading DISTCHECK_CONFIGURE_FLAGS
8574 Building the package involves running @samp{./configure}. If you need
8575 to supply additional flags to @command{configure}, define them in the
8576 @code{AM_DISTCHECK_CONFIGURE_FLAGS} variable in your top-level
8577 @file{Makefile.am}. The user can still extend or override the flags
8578 provided there by defining the @code{DISTCHECK_CONFIGURE_FLAGS} variable,
8579 on the command line when invoking @command{make}.
8581 Still, developers are encouraged to strive to make their code buildable
8582 without requiring any special configure option; thus, in general, you
8583 shouldn't define @code{AM_DISTCHECK_CONFIGURE_FLAGS}. However, there
8584 might be few scenarios in which the use of this variable is justified.
8585 GNU @command{m4} offers an example. GNU @command{m4} configures by
8586 default with its experimental and seldom used "changeword" feature
8587 disabled; so in its case it is useful to have @command{make distcheck}
8588 run configure with the @option{--with-changeword} option, to ensure that
8589 the code for changeword support still compiles correctly.
8590 GNU @command{m4} also employs the @code{AM_DISTCHECK_CONFIGURE_FLAGS}
8591 variable to stress-test the use of @option{--program-prefix=g}, since at
8592 one point the @command{m4} build system had a bug where @command{make
8593 installcheck} was wrongly assuming it could blindly test "@command{m4}",
8594 rather than the just-installed "@command{gm4}".
8596 @trindex distcheck-hook
8597 @subheading distcheck-hook
8598 If the @code{distcheck-hook} rule is defined in your top-level
8599 @file{Makefile.am}, then it will be invoked by @code{distcheck} after
8600 the new distribution has been unpacked, but before the unpacked copy
8601 is configured and built. Your @code{distcheck-hook} can do almost
8602 anything, though as always caution is advised. Generally this hook is
8603 used to check for potential distribution errors not caught by the
8604 standard mechanism. Note that @code{distcheck-hook} as well as
8605 @code{AM_DISTCHECK_CONFIGURE_FLAGS} and @code{DISTCHECK_CONFIGURE_FLAGS}
8606 are not honored in a subpackage @file{Makefile.am}, but the flags from
8607 @code{AM_DISTCHECK_CONFIGURE_FLAGS} and @code{DISTCHECK_CONFIGURE_FLAGS}
8608 are passed down to the @command{configure} script of the subpackage.
8610 @cindex @samp{make distcleancheck}
8611 @trindex distcleancheck
8612 @vindex DISTCLEANFILES
8613 @vindex distcleancheck_listfiles
8615 @subheading distcleancheck
8616 Speaking of potential distribution errors, @code{distcheck} also
8617 ensures that the @code{distclean} rule actually removes all built
8618 files. This is done by running @samp{make distcleancheck} at the end of
8619 the @code{VPATH} build. By default, @code{distcleancheck} will run
8620 @code{distclean} and then make sure the build tree has been emptied by
8621 running @samp{$(distcleancheck_listfiles)}. Usually this check will
8622 find generated files that you forgot to add to the @code{DISTCLEANFILES}
8623 variable (@pxref{Clean}).
8625 The @code{distcleancheck} behavior should be OK for most packages,
8626 otherwise you have the possibility to override the definition of
8627 either the @code{distcleancheck} rule, or the
8628 @samp{$(distcleancheck_listfiles)} variable. For instance, to disable
8629 @code{distcleancheck} completely, add the following rule to your
8630 top-level @file{Makefile.am}:
8637 If you want @code{distcleancheck} to ignore built files that have not
8638 been cleaned because they are also part of the distribution, add the
8639 following definition instead:
8641 @c Keep in sync with distcleancheck.sh
8643 distcleancheck_listfiles = \
8644 find . -type f -exec sh -c 'test -f $(srcdir)/$$1 || echo $$1' \
8648 The above definition is not the default because it's usually an error if
8649 your Makefiles cause some distributed files to be rebuilt when the user
8650 build the package. (Think about the user missing the tool required to
8651 build the file; or if the required tool is built by your package,
8652 consider the cross-compilation case where it can't be run.) There is
8653 an entry in the FAQ about this (@pxref{Errors with distclean}), make
8654 sure you read it before playing with @code{distcleancheck_listfiles}.
8656 @cindex @samp{make distuninstallcheck}
8657 @trindex distuninstallcheck
8658 @vindex distuninstallcheck_listfiles
8660 @subheading distuninstallcheck
8661 @code{distcheck} also checks that the @code{uninstall} rule works
8662 properly, both for ordinary and @code{DESTDIR} builds. It does this
8663 by invoking @samp{make uninstall}, and then it checks the install tree
8664 to see if any files are left over. This check will make sure that you
8665 correctly coded your @code{uninstall}-related rules.
8667 By default, the checking is done by the @code{distuninstallcheck} rule,
8668 and the list of files in the install tree is generated by
8669 @samp{$(distuninstallcheck_listfiles)} (this is a variable whose value is
8670 a shell command to run that prints the list of files to stdout).
8672 Either of these can be overridden to modify the behavior of
8673 @code{distcheck}. For instance, to disable this check completely, you
8681 @node The Types of Distributions
8682 @section The Types of Distributions
8684 Automake generates rules to provide archives of the project for
8685 distributions in various formats. Their targets are:
8689 @item @code{dist-bzip2}
8690 Generate a bzip2 tar archive of the distribution. bzip2 archives are
8691 frequently smaller than gzipped archives.
8692 By default, this rule makes @samp{bzip2} use a compression option of @option{-9}.
8693 To make it use a different one, set the @env{BZIP2} environment variable.
8694 For example, @samp{make dist-bzip2 BZIP2=-7}.
8697 @item @code{dist-gzip}
8698 Generate a gzip tar archive of the distribution.
8701 @item @code{dist-lzip}
8702 Generate an @samp{lzip} tar archive of the distribution. @command{lzip}
8703 archives are frequently smaller than @command{bzip2}-compressed archives.
8706 @item @code{dist-shar}
8707 Generate a shar archive of the distribution.
8711 @item @code{dist-xz}
8712 Generate an @samp{xz} tar archive of the distribution. @command{xz}
8713 archives are frequently smaller than @command{bzip2}-compressed archives.
8714 By default, this rule makes @samp{xz} use a compression option of
8715 @option{-e}. To make it use a different one, set the @env{XZ_OPT}
8716 environment variable. For example, run this command to use the
8717 default compression ratio, but with a progress indicator:
8718 @samp{make dist-xz XZ_OPT=-7e}.
8721 @item @code{dist-zip}
8722 Generate a zip archive of the distribution.
8725 @item @code{dist-tarZ}
8726 Generate a compressed tar archive of
8731 The rule @code{dist} (and its historical synonym @code{dist-all}) will
8732 create archives in all the enabled formats, @ref{Options}. By
8733 default, only the @code{dist-gzip} target is hooked to @code{dist}.
8737 @chapter Support for test suites
8740 @cindex @code{make check}
8743 Automake can generate code to handle two kinds of test suites. One is
8744 based on integration with the @command{dejagnu} framework. The other
8745 (and most used) form is based on the use of generic test scripts, and
8746 its activation is triggered by the definition of the special @code{TESTS}
8747 variable. This second form allows for various degrees of sophistication
8748 and customization; in particular, it allows for concurrent execution
8749 of test scripts, use of established test protocols such as TAP, and
8750 definition of custom test drivers and test runners.
8753 In either case, the testsuite is invoked via @samp{make check}.
8756 * Generalities about Testing:: Concepts and terminology about testing
8757 * Simple Tests:: Listing test scripts in @code{TESTS}
8758 * Custom Test Drivers:: Writing and using custom test drivers
8759 * Using the TAP test protocol:: Integrating test scripts that use the TAP protocol
8760 * DejaGnu Tests:: Interfacing with the @command{dejagnu} testing framework
8761 * Install Tests:: Running tests on installed packages
8764 @node Generalities about Testing
8765 @section Generalities about Testing
8767 The purpose of testing is to determine whether a program or system behaves
8768 as expected (e.g., known inputs produce the expected outputs, error
8769 conditions are correctly handled or reported, and older bugs do not
8773 The minimal unit of testing is usually called @emph{test case}, or simply
8774 @emph{test}. How a test case is defined or delimited, and even what
8775 exactly @emph{constitutes} a test case, depends heavily on the testing
8776 paradigm and/or framework in use, so we won't attempt any more precise
8777 definition. The set of the test cases for a given program or system
8778 constitutes its @emph{testsuite}.
8780 @cindex test harness
8781 @cindex testsuite harness
8782 A @emph{test harness} (also @emph{testsuite harness}) is a program or
8783 software component that executes all (or part of) the defined test cases,
8784 analyzes their outcomes, and report or register these outcomes
8785 appropriately. Again, the details of how this is accomplished (and how
8786 the developer and user can influence it or interface with it) varies
8787 wildly, and we'll attempt no precise definition.
8790 @cindex test failure
8791 A test is said to @emph{pass} when it can determine that the condition or
8792 behaviour it means to verify holds, and is said to @emph{fail} when it can
8793 determine that such condition of behaviour does @emph{not} hold.
8796 Sometimes, tests can rely on non-portable tools or prerequisites, or
8797 simply make no sense on a given system (for example, a test checking a
8798 Windows-specific feature makes no sense on a GNU/Linux system). In this
8799 case, accordingly to the definition above, the tests can neither be
8800 considered passed nor failed; instead, they are @emph{skipped} -- i.e.,
8801 they are not run, or their result is anyway ignored for what concerns
8802 the count of failures an successes. Skips are usually explicitly
8803 reported though, so that the user will be aware that not all of the
8804 testsuite has really run.
8807 @cindex expected failure
8808 @cindex expected test failure
8810 @cindex unexpected pass
8811 @cindex unexpected test pass
8812 It's not uncommon, especially during early development stages, that some
8813 tests fail for known reasons, and that the developer doesn't want to
8814 tackle these failures immediately (this is especially true when the
8815 failing tests deal with corner cases). In this situation, the better
8816 policy is to declare that each of those failures is an @emph{expected
8817 failure} (or @emph{xfail}). In case a test that is expected to fail ends
8818 up passing instead, many testing environments will flag the result as a
8819 special kind of failure called @emph{unexpected pass} (or @emph{xpass}).
8822 @cindex Distinction between errors and failures in testsuites
8823 Many testing environments and frameworks distinguish between test failures
8824 and hard errors. As we've seen, a test failure happens when some invariant
8825 or expected behaviour of the software under test is not met. An @emph{hard
8826 error} happens when e.g., the set-up of a test case scenario fails, or when
8827 some other unexpected or highly undesirable condition is encountered (for
8828 example, the program under test experiences a segmentation fault).
8830 @emph{TODO}: Links to other test harnesses (esp. those sharing our
8834 @section Simple Tests
8837 * Scripts-based Testsuites:: Automake-specific concepts and terminology
8838 * Serial Test Harness:: Older (and obsolescent) serial test harness
8839 * Parallel Test Harness:: Generic concurrent test harness
8842 @node Scripts-based Testsuites
8843 @subsection Scripts-based Testsuites
8845 If the special variable @code{TESTS} is defined, its value is taken to be
8846 a list of programs or scripts to run in order to do the testing. Under
8847 the appropriate circumstances, it's possible for @code{TESTS} to list
8848 also data files to be passed to one or more test scripts defined by
8849 different means (the so-called ``log compilers'', @pxref{Parallel Test
8852 Test scripts can be executed serially or concurrently. Automake
8853 supports both these kinds of test execution, with the serial test harness
8854 being the default (for backward-compatibility reasons only, as its use
8855 is nowadays discouraged). The concurrent test harness relies on the
8856 concurrence capabilities (if any) offered by the underlying @command{make}
8857 implementation, and can thus only be as good as those are.
8859 By default, only the exit statuses of the test scripts are considered when
8860 determining the testsuite outcome. But Automake allows also the use of
8861 more complex test protocols, either standard (@pxref{Using the TAP test
8862 protocol}) or custom (@pxref{Custom Test Drivers}). Note that you can
8863 enable such protocols only when the parallel harness is used: they won't
8864 work with the serial test harness. In the rest of this section we are
8865 going to concentrate mostly on protocol-less tests, since we cover
8866 test protocols in a later section (again, @pxref{Custom Test Drivers}).
8868 @cindex Exit status 77, special interpretation
8869 @cindex Exit status 99, special interpretation
8870 When no test protocol is in use, an exit status of 0 from a test script will
8871 denote a success, an exit status of 77 a skipped test, an exit status of 99
8872 an hard error, and any other exit status will denote a failure.
8874 @cindex Tests, expected failure
8875 @cindex Expected test failure
8877 @vindex DISABLE_HARD_ERRORS
8878 @cindex Disabling hard errors
8879 You may define the variable @code{XFAIL_TESTS} to a list of tests
8880 (usually a subset of @code{TESTS}) that are expected to fail; this will
8881 effectively reverse the result of those tests (with the provision that
8882 skips and hard errors remain untouched). You may also instruct the
8883 testsuite harness to treat hard errors like simple failures, by defining
8884 the @code{DISABLE_HARD_ERRORS} make variable to a nonempty value.
8886 Note however that, for tests based on more complex test protocols,
8887 the exact effects of @code{XFAIL_TESTS} and @code{DISABLE_HARD_ERRORS}
8888 might change, or they might even have no effect at all (for example,
8889 @c Keep this in sync with tap-no-disable-hard-errors.sh
8890 in tests using TAP, there is not way to disable hard errors, and the
8891 @code{DISABLE_HARD_ERRORS} variable has no effect on them).
8893 @anchor{Testsuite progress on console}
8894 @cindex Testsuite progress on console
8895 The result of each test case run by the scripts in @code{TESTS} will be
8896 printed on standard output, along with the test name. For test protocols
8897 that allow more test cases per test script (such as TAP), a number,
8898 identifier and/or brief description specific for the single test case is
8899 expected to be printed in addition to the name of the test script. The
8900 possible results (whose meanings should be clear from the previous
8901 @ref{Generalities about Testing}) are @code{PASS}, @code{FAIL},
8902 @code{SKIP}, @code{XFAIL}, @code{XPASS} and @code{ERROR}. Here is an
8903 example of output from an hypothetical testsuite that uses both plain
8905 @c Keep in sync with tap-doc.sh
8908 PASS: zardoz.tap 1 - Daemon started
8909 PASS: zardoz.tap 2 - Daemon responding
8910 SKIP: zardoz.tap 3 - Daemon uses /proc # SKIP /proc is not mounted
8911 PASS: zardoz.tap 4 - Daemon stopped
8914 XFAIL: mu.tap 2 # TODO frobnication not yet implemented
8918 A testsuite summary (expected to report at least the number of run,
8919 skipped and failed tests) will be printed at the end of the testsuite
8922 @anchor{Simple tests and color-tests}
8923 @vindex AM_COLOR_TESTS
8924 @cindex Colorized testsuite output
8925 If the Automake option @code{color-tests} is used (@pxref{Options})
8926 and standard output is connected to a capable terminal, then the test
8927 results and the summary are colored appropriately. The user can disable
8928 colored output by setting the @command{make} variable
8929 @samp{AM_COLOR_TESTS=no}, or force colored output even without a connecting
8930 terminal with @samp{AM_COLOR_TESTS=always}. It's also worth noting that
8931 some @command{make} implementations, when used in parallel mode, have
8932 slightly different semantics (@pxref{Parallel make,,, autoconf,
8933 The Autoconf Manual}), which can break the automatic detection of a
8934 connection to a capable terminal. If this is the case, you'll have to
8935 resort to the use of @samp{AM_COLOR_TESTS=always} in order to have the
8936 testsuite output colorized.
8938 Test programs that need data files should look for them in @code{srcdir}
8939 (which is both a make variable and an environment variable made available
8940 to the tests), so that they work when building in a separate directory
8941 (@pxref{Build Directories, , Build Directories , autoconf,
8942 The Autoconf Manual}), and in particular for the @code{distcheck} rule
8943 (@pxref{Checking the Distribution}).
8946 @vindex TESTS_ENVIRONMENT
8947 @vindex AM_TESTS_ENVIRONMENT
8948 The @code{AM_TESTS_ENVIRONMENT} and @code{TESTS_ENVIRONMENT} variables can
8949 be used to run initialization code and set environment variables for the
8950 test scripts. The former variable is developer-reserved, and can be
8951 defined in the @file{Makefile.am}, while the latter is reserved for the
8952 user, which can employ it to extend or override the settings in the
8953 former; for this to work portably, however, the contents of a non-empty
8954 @code{AM_TESTS_ENVIRONMENT} @emph{must} be terminated by a semicolon.
8956 @vindex AM_TESTS_FD_REDIRECT
8957 The @code{AM_TESTS_FD_REDIRECT} variable can be used to define file
8958 descriptor redirections for the test scripts. One might think that
8959 @code{AM_TESTS_ENVIRONMENT} could be used for this purpose, but experience
8960 has shown that doing so portably is practically impossible. The main
8961 hurdle is constituted by Korn shells, which usually set the close-on-exec
8962 flag on file descriptors opened with the @command{exec} builtin, thus
8963 rendering an idiom like @code{AM_TESTS_ENVIRONMENT = exec 9>&2;}
8964 ineffectual. This issue also affects some Bourne shells, such as the
8965 HP-UX's @command{/bin/sh},
8966 @c FIXME: should we offer a link to the relevant discussions on the
8967 @c bug-autoconf list?
8969 @c Keep in sync with tests-environment-backcompat.sh
8971 AM_TESTS_ENVIRONMENT = \
8972 ## Some environment initializations are kept in a separate shell
8973 ## file 'tests-env.sh', which can make it easier to also run tests
8974 ## from the command line.
8975 . $(srcdir)/tests-env.sh; \
8976 ## On Solaris, prefer more POSIX-compliant versions of the standard
8977 ## tools by default.
8978 if test -d /usr/xpg4/bin; then \
8979 PATH=/usr/xpg4/bin:$$PATH; export PATH; \
8981 @c $$ restore font-lock
8982 ## With this, the test scripts will be able to print diagnostic
8983 ## messages to the original standard error stream, even if the test
8984 ## driver redirects the stderr of the test scripts to a log file
8985 ## before executing them.
8986 AM_TESTS_FD_REDIRECT = 9>&2
8990 Note however that @code{AM_TESTS_ENVIRONMENT} is, for historical and
8991 implementation reasons, @emph{not} supported by the serial harness
8992 (@pxref{Serial Test Harness}).
8994 Automake ensures that each file listed in @code{TESTS} is built before
8995 it is run; you can list both source and derived programs (or scripts)
8996 in @code{TESTS}; the generated rule will look both in @code{srcdir} and
8997 @file{.}. For instance, you might want to run a C program as a test.
8998 To do this you would list its name in @code{TESTS} and also in
8999 @code{check_PROGRAMS}, and then specify it as you would any other
9002 Programs listed in @code{check_PROGRAMS} (and @code{check_LIBRARIES},
9003 @code{check_LTLIBRARIES}...) are only built during @code{make check},
9004 not during @code{make all}. You should list there any program needed
9005 by your tests that does not need to be built by @code{make all}. Note
9006 that @code{check_PROGRAMS} are @emph{not} automatically added to
9007 @code{TESTS} because @code{check_PROGRAMS} usually lists programs used
9008 by the tests, not the tests themselves. Of course you can set
9009 @code{TESTS = $(check_PROGRAMS)} if all your programs are test cases.
9011 @node Serial Test Harness
9012 @subsection Serial Test Harness
9013 @cindex @option{serial-tests}, Using
9015 @emph{NOTE:} This harness, while still being the default one, is
9016 obsolescent, and kept mostly for backward-compatibility reasons. The user
9017 is advised to use the parallel test harness instead (@pxref{Parallel Test
9018 Harness}). Be warned that future Automake versions might switch to use
9019 that more modern and feature-rich harness by default.
9021 The serial test harness is enabled by the Automake option
9022 @option{serial-tests}. It operates by simply running the tests serially,
9023 one at the time, without any I/O redirection. It's up to the user to
9024 implement logging of tests' output, if that's requited or desired.
9025 @c TODO: give an example of how this can be done.
9027 For historical and implementation reasons, the @code{AM_TESTS_ENVIRONMENT}
9028 variable is @emph{not} supported by this harness (it will be silently
9029 ignored if defined); only @code{TESTS_ENVIRONMENT} is, and it is to be
9030 considered a developer-reserved variable. This is done so that, when
9031 using the serial harness, @code{TESTS_ENVIRONMENT} can be defined to an
9032 invocation of an interpreter through which the tests are to be run.
9033 For instance, the following setup may be used to run tests with Perl:
9036 TESTS_ENVIRONMENT = $(PERL) -Mstrict -w
9037 TESTS = foo.pl bar.pl baz.pl
9041 It's important to note that the use of @code{TESTS_ENVIRONMENT} endorsed
9042 here would be @emph{invalid} with the parallel harness. That harness
9043 provides a more elegant way to achieve the same effect, with the further
9044 benefit of freeing the @code{TESTS_ENVIRONMENT} variable for the user
9045 (@pxref{Parallel Test Harness}).
9047 Another, less serious limit of the serial harness is that it doesn't
9048 really distinguish between simple failures and hard errors; this is
9049 due to historical reasons only, and might be fixed in future Automake
9052 @node Parallel Test Harness
9053 @subsection Parallel Test Harness
9054 @cindex @option{parallel-tests}, Using
9056 The parallel (or concurrent) test harness is enabled by the Automake option
9057 @option{parallel-tests}. It features automatic collection of the test
9058 scripts output in @file{.log} files, concurrent execution of tests with
9059 @code{make -j}, specification of inter-test dependencies, lazy reruns of
9060 tests that have not completed in a prior run, and hard errors for exceptional
9063 This harness is still somewhat experimental and may undergo changes in
9064 order to satisfy additional portability requirements.
9066 @anchor{Basics of test metadata}
9067 @vindex TEST_SUITE_LOG
9069 @cindex @file{.log} files
9070 @cindex @file{.trs} files
9071 @cindex test metadata
9072 The parallel test harness operates by defining a set of @command{make}
9073 rules that run the test scripts listed in @code{TESTS}, and, for each
9074 such script, save its output in a corresponding @file{.log} file and
9075 its results (and other ``metadata'', @pxref{API for Custom Test Drivers})
9076 in a corresponding @file{.trs} (as in @b{T}est @b{R}e@b{S}ults) file.
9077 @c We choose the '.trs' extension also because, at the time of writing,
9078 @c it isn't already used for other significant purposes; see e.g.:
9079 @c - http://filext.com/file-extension/trs
9080 @c - http://www.file-extensions.org/search/?searchstring=trs
9081 The @file{.log} file will contain all the output emitted by the test on
9082 its standard output and its standard error. The @file{.trs} file will
9083 contain, among the other things, the results of the test cases run by
9086 The parallel test harness will also create a summary log file,
9087 @code{TEST_SUITE_LOG}, which defaults to @file{test-suite.log} and requires
9088 a @file{.log} suffix. This file depends upon all the @file{.log} and
9089 @file{.trs} files created for the test scripts listed in @code{TESTS}.
9092 As with the serial harness above, by default one status line is printed
9093 per completed test, and a short summary after the suite has completed.
9094 However, standard output and standard error of the test are redirected
9095 to a per-test log file, so that parallel execution does not produce
9096 intermingled output. The output from failed tests is collected in the
9097 @file{test-suite.log} file. If the variable @samp{VERBOSE} is set, this
9098 file is output after the summary.
9099 @c FIXME: we should be clearer about what we mean exactly here ...
9100 For best results, the tests should be verbose by default now.
9102 @vindex TEST_EXTENSIONS
9104 Each couple of @file{.log} and @file{.trs} files is created when the
9105 corresponding test has completed. The set of log files is listed in
9106 the read-only variable @code{TEST_LOGS}, and defaults to @code{TESTS},
9107 with the executable extension if any (@pxref{EXEEXT}), as well as any
9108 suffix listed in @code{TEST_EXTENSIONS} removed, and @file{.log} appended.
9109 Results are undefined if a test file name ends in several concatenated
9110 suffixes. @code{TEST_EXTENSIONS} defaults to @file{.test}; it can be
9111 overridden by the user, in which case any extension listed in it must be
9112 constituted by a dot, followed by a non-digit alphabetic character,
9113 followed by any number of alphabetic characters.
9114 @c Keep in sync with test-extensions.sh
9115 For example, @samp{.sh}, @samp{.T} and @samp{.t1} are valid extensions,
9116 while @samp{.x-y}, @samp{.6c} and @samp{.t.1} are not.
9118 @vindex _LOG_COMPILE
9119 @vindex _LOG_COMPILER
9122 @vindex LOG_COMPILER
9124 @vindex @var{ext}_LOG_COMPILE
9125 @vindex @var{ext}_LOG_COMPILER
9126 @vindex @var{ext}_LOG_FLAGS
9127 @vindex AM_@var{ext}_LOG_FLAGS
9128 @vindex AM_LOG_FLAGS
9129 For tests that match an extension @code{.@var{ext}} listed in
9130 @code{TEST_EXTENSIONS}, you can provide a custom ``test runner'' using
9131 the variable @code{@var{ext}_LOG_COMPILER} (note the upper-case
9132 extension) and pass options in @code{AM_@var{ext}_LOG_FLAGS} and allow
9133 the user to pass options in @code{@var{ext}_LOG_FLAGS}. It will cause
9134 all tests with this extension to be called with this runner. For all
9135 tests without a registered extension, the variables @code{LOG_COMPILER},
9136 @code{AM_LOG_FLAGS}, and @code{LOG_FLAGS} may be used. For example,
9138 @c Keep in sync with parallel-tests-log-compiler-example.sh
9140 TESTS = foo.pl bar.py baz
9141 TEST_EXTENSIONS = .pl .py
9142 PL_LOG_COMPILER = $(PERL)
9143 AM_PL_LOG_FLAGS = -w
9144 PY_LOG_COMPILER = $(PYTHON)
9145 AM_PY_LOG_FLAGS = -v
9146 LOG_COMPILER = ./wrapper-script
9151 will invoke @samp{$(PERL) -w foo.pl}, @samp{$(PYTHON) -v bar.py},
9152 and @samp{./wrapper-script -d baz} to produce @file{foo.log},
9153 @file{bar.log}, and @file{baz.log}, respectively. The @file{foo.trs},
9154 @file{bar.trs} and @file{baz.trs} files will be automatically produced
9157 It's important to note that, differently from what we've seen for the
9158 serial test harness (@pxref{Parallel Test Harness}), the
9159 @code{AM_TESTS_ENVIRONMENT} and @code{TESTS_ENVIRONMENT} variables
9160 @emph{cannot} be use to define a custom test runner; the
9161 @code{LOG_COMPILER} and @code{LOG_FLAGS} (or their extension-specific
9162 counterparts) should be used instead:
9166 AM_TESTS_ENVIRONMENT = PERL5LIB='$(srcdir)/lib' $(PERL) -Mstrict -w
9171 AM_TESTS_ENVIRONMENT = PERL5LIB='$(srcdir)/lib'; export PERL5LIB;
9172 LOG_COMPILER = $(PERL)
9173 AM_LOG_FLAGS = -Mstrict -w
9176 By default, the test suite harness will run all tests, but there are
9177 several ways to limit the set of tests that are run:
9181 You can set the @code{TESTS} variable. For example, you can use a
9182 command like this to run only a subset of the tests:
9185 env TESTS="foo.test bar.test" make -e check
9188 Note however that the command above will unconditionally overwrite the
9189 @file{test-suite.log} file, thus clobbering the recorded results
9190 of any previous testsuite run. This might be undesirable for packages
9191 whose testsuite takes long time to execute. Luckily, this problem can
9192 easily be avoided by overriding also @code{TEST_SUITE_LOG} at runtime;
9195 @c Keep in sync with parallel-tests-log-override-2.sh
9197 env TEST_SUITE_LOG=partial.log TESTS="..." make -e check
9200 will write the result of the partial testsuite runs to the
9201 @file{partial.log}, without touching @file{test-suite.log}.
9204 You can set the @code{TEST_LOGS} variable. By default, this variable is
9205 computed at @command{make} run time from the value of @code{TESTS} as
9206 described above. For example, you can use the following:
9209 set x subset*.log; shift
9210 env TEST_LOGS="foo.log $*" make -e check
9213 The comments made above about @code{TEST_SUITE_LOG} overriding applies
9217 @vindex RECHECK_LOGS
9218 @cindex lazy test execution
9219 By default, the test harness removes all old per-test @file{.log} and
9220 @file{.trs} files before it starts running tests to regenerate them. The
9221 variable @code{RECHECK_LOGS} contains the set of @file{.log} (and, by
9222 implication, @file{.trs}) files which are removed. @code{RECHECK_LOGS}
9223 defaults to @code{TEST_LOGS}, which means all tests need to be rechecked.
9224 By overriding this variable, you can choose which tests need to be
9225 reconsidered. For example, you can lazily rerun only those tests which
9226 are outdated, i.e., older than their prerequisite test files, by setting
9227 this variable to the empty value:
9230 env RECHECK_LOGS= make -e check
9235 You can ensure that all tests are rerun which have failed or passed
9236 unexpectedly, by running @code{make recheck} in the test directory.
9237 This convenience target will set @code{RECHECK_LOGS} appropriately
9238 before invoking the main test harness.
9242 In order to guarantee an ordering between tests even with @code{make
9243 -j@var{N}}, dependencies between the corresponding @file{.log} files
9244 may be specified through usual @command{make} dependencies. For example,
9245 the following snippet lets the test named @file{foo-execute.test} depend
9246 upon completion of the test @file{foo-compile.test}:
9249 TESTS = foo-compile.test foo-execute.test
9250 foo-execute.log: foo-compile.log
9254 Please note that this ordering ignores the @emph{results} of required
9255 tests, thus the test @file{foo-execute.test} is run even if the test
9256 @file{foo-compile.test} failed or was skipped beforehand. Further,
9257 please note that specifying such dependencies currently works only for
9258 tests that end in one of the suffixes listed in @code{TEST_EXTENSIONS}.
9260 Tests without such specified dependencies may be run concurrently with
9261 parallel @command{make -j@var{N}}, so be sure they are prepared for
9262 concurrent execution.
9265 @c Keep in sync with 'parallel-tests-extra-programs.sh'.
9266 The combination of lazy test execution and correct dependencies between
9267 tests and their sources may be exploited for efficient unit testing
9268 during development. To further speed up the edit-compile-test cycle, it
9269 may even be useful to specify compiled programs in @code{EXTRA_PROGRAMS}
9270 instead of with @code{check_PROGRAMS}, as the former allows intertwined
9271 compilation and test execution (but note that @code{EXTRA_PROGRAMS} are
9272 not cleaned automatically, @pxref{Uniform}).
9274 The variables @code{TESTS} and @code{XFAIL_TESTS} may contain
9275 conditional parts as well as configure substitutions. In the latter
9276 case, however, certain restrictions apply: substituted test names
9277 must end with a nonempty test suffix like @file{.test}, so that one of
9278 the inference rules generated by @command{automake} can apply. For
9279 literal test names, @command{automake} can generate per-target rules
9280 to avoid this limitation.
9282 Please note that it is currently not possible to use @code{$(srcdir)/}
9283 or @code{$(top_srcdir)/} in the @code{TESTS} variable. This technical
9284 limitation is necessary to avoid generating test logs in the source tree
9285 and has the unfortunate consequence that it is not possible to specify
9286 distributed tests that are themselves generated by means of explicit
9287 rules, in a way that is portable to all @command{make} implementations
9288 (@pxref{Make Target Lookup,,, autoconf, The Autoconf Manual}, the
9289 semantics of FreeBSD and OpenBSD @command{make} conflict with this).
9290 In case of doubt you may want to require to use GNU @command{make},
9291 or work around the issue with inference rules to generate the tests.
9293 @node Custom Test Drivers
9294 @section Custom Test Drivers
9297 * Overview of Custom Test Drivers Support::
9298 * Declaring Custom Test Drivers::
9299 * API for Custom Test Drivers::
9302 @node Overview of Custom Test Drivers Support
9303 @subsection Overview of Custom Test Drivers Support
9305 Starting from Automake version 1.12, the parallel test harness allows
9306 the package authors to use third-party custom test drivers, in case the
9307 default ones are inadequate for their purposes, or do not support their
9308 testing protocol of choice.
9310 A custom test driver is expected to properly run the test programs passed
9311 to it (including the command-line arguments passed to those programs, if
9312 any), to analyze their execution and outcome, to create the @file{.log}
9313 and @file{.trs} files associated to these test runs, and to display the test
9314 results on the console. It is responsibility of the author of the test
9315 driver to ensure that it implements all the above steps meaningfully and
9316 correctly; Automake isn't and can't be of any help here. On the other
9317 hand, the Automake-provided code for testsuite summary generation offers
9318 support for test drivers allowing several test results per test script,
9319 if they take care to register such results properly (@pxref{Log files
9320 generation and test results recording}).
9322 The exact details of how test scripts' results are to be determined and
9323 analyzed is left to the individual drivers. Some drivers might only
9324 consider the test script exit status (this is done for example by the
9325 default test driver used by the parallel test harness, described
9326 in the previous section). Other drivers might implement more complex and
9327 advanced test protocols, which might require them to parse and interpreter
9328 the output emitted by the test script they're running (examples of such
9329 protocols are TAP and SubUnit).
9331 It's very important to note that, even when using custom test drivers,
9332 most of the infrastructure described in the previous section about the
9333 parallel harness remains in place; this includes:
9337 list of test scripts defined in @code{TESTS}, and overridable at
9338 runtime through the redefinition of @code{TESTS} or @code{TEST_LOGS};
9340 concurrency through the use of @command{make}'s option @option{-j};
9342 per-test @file{.log} and @file{.trs} files, and generation of a summary
9343 @file{.log} file from them;
9345 @code{recheck} target, @code{RECHECK_LOGS} variable, and lazy reruns
9348 inter-test dependencies;
9350 support for @code{check_*} variables (@code{check_PROGRAMS},
9351 @code{check_LIBRARIES}, ...);
9353 use of @code{VERBOSE} environment variable to get verbose output on
9356 definition and honoring of @code{TESTS_ENVIRONMENT},
9357 @code{AM_TESTS_ENVIRONMENT} and @code{AM_TESTS_FD_REDIRECT}
9360 definition of generic and extension-specific @code{LOG_COMPILER} and
9361 @code{LOG_FLAGS} variables.
9365 On the other hand, the exact semantics of how (and if)
9366 @option{color-tests}, @code{XFAIL_TESTS}, and hard errors are supported
9367 and handled is left to the individual test drivers.
9369 @c TODO: We should really add a working example in the doc/ directory,
9370 @c TODO: and reference if from here.
9372 @node Declaring Custom Test Drivers
9373 @subsection Declaring Custom Test Drivers
9376 @vindex _LOG_DRIVER_FLAGS
9378 @vindex LOG_DRIVER_FLAGS
9379 @vindex @var{ext}_LOG_DRIVER
9380 @vindex @var{ext}_LOG_DRIVER_FLAGS
9381 @vindex AM_@var{ext}_LOG_DRIVER_FLAGS
9382 @vindex AM_LOG_DRIVER_FLAGS
9383 Custom testsuite drivers are declared by defining the make variables
9384 @code{LOG_DRIVER} or @code{@var{ext}_LOG_DRIVER} (where @var{ext} must
9385 be declared in @code{TEST_EXTENSIONS}). They must be defined to
9386 programs or scripts that will be used to drive the execution, logging,
9387 and outcome report of the tests with corresponding extensions (or of
9388 those with no registered extension in the case of @code{LOG_DRIVER}).
9389 Clearly, multiple distinct test drivers can be declared in the same
9390 @file{Makefile.am}. Note moreover that the @code{LOG_DRIVER} variables
9391 are @emph{not} a substitute for the @code{LOG_COMPILER} variables: the
9392 two sets of variables can, and often do, usefully and legitimately
9395 @c TODO: We should really be able to point to a clarifying example here!
9397 The developer-reserved variable @code{AM_LOG_DRIVER_FLAGS} and the
9398 user-reserved variable @code{LOG_DRIVER_FLAGS} can be used to define
9399 flags that will be passed to each invocation of @code{LOG_DRIVER},
9400 with the user-defined flags obviously taking precedence over the
9401 developer-reserved ones. Similarly, for each extension @var{ext}
9402 declared in @code{TEST_EXTENSIONS}, flags listed in
9403 @code{AM_@var{ext}_LOG_DRIVER_FLAGS} and
9404 @code{@var{ext}_LOG_DRIVER_FLAGS} will be passed to
9405 invocations of @code{@var{ext}_LOG_DRIVER}.
9407 @node API for Custom Test Drivers
9408 @subsection API for Custom Test Drivers
9410 Note that @emph{the APIs described here are still highly experimental},
9411 and will very likely undergo tightenings and likely also extensive changes
9412 in the future, to accommodate for new features or to satisfy additional
9413 portability requirements.
9415 The main characteristic of these APIs is that they are designed to share
9416 as much infrastructure, semantics, and implementation details as possible
9417 with the parallel test harness and its default driver.
9420 * Command-line arguments for test drivers::
9421 * Log files generation and test results recording::
9422 * Testsuite progress output::
9425 @node Command-line arguments for test drivers
9426 @subsubsection Command-line arguments for test drivers
9428 A custom driver can rely on various command-line options and arguments
9429 being passed to it automatically by the Automake's @option{parallel-tests}
9430 harness. It is @emph{mandatory} that it understands all of them (even
9431 if the exact interpretation of the associated semantics can legitimately
9432 change between a test driver and another, and even be a no-op in some
9436 Here is the list of options:
9439 @item --test-name=@var{NAME}
9440 The name of the test, with VPATH prefix (if any) removed. This can have a
9441 suffix and a directory component (as in e.g., @file{sub/foo.test}), and is
9442 mostly meant to be used in console reports about testsuite advancements and
9443 results (@pxref{Testsuite progress output}).
9444 @item --log-file=@file{@var{PATH}.log}
9445 The @file{.log} file the test driver must create (@pxref{Basics of
9446 test metadata}). If it has a directory component (as in e.g.,
9447 @file{sub/foo.log}), the test harness will ensure that such directory
9448 exists @emph{before} the test driver is called.
9449 @item --trs-file=@file{@var{PATH}.trs}
9450 The @file{.trs} file the test driver must create (@pxref{Basics of
9451 test metadata}). If it has a directory component (as in e.g.,
9452 @file{sub/foo.trs}), the test harness will ensure that such directory
9453 exists @emph{before} the test driver is called.
9454 @item --color-tests=@{yes|no@}
9455 Whether the console output should be colorized or not (@pxref{Simple
9456 tests and color-tests}, to learn when this option gets activated and
9458 @item --expect-failure=@{yes|no@}
9459 Whether the tested program is expected to fail.
9460 @item --enable-hard-errors=@{yes|no@}
9461 Whether ``hard errors'' in the tested program should be treated differently
9462 from normal failures or not (the default should be @code{yes}). The exact
9463 meaning of ``hard error'' is highly dependent from the test protocols or
9466 Explicitly terminate the list of options.
9470 The first non-option argument passed to the test driver is the program to
9471 be run, and all the following ones are command-line options and arguments
9474 Note that the exact semantics attached to the @option{--color-tests},
9475 @option{--expect-failure} and @option{--enable-hard-errors} options are
9476 left up to the individual test drivers. Still, having a behaviour
9477 compatible or at least similar to that provided by the default
9478 @option{parallel-tests} driver is advised, as that would offer a better
9479 consistency and a more pleasant user experience.
9481 @node Log files generation and test results recording
9482 @subsubsection Log files generation and test results recording
9484 The test driver must correctly generate the files specified by the
9485 @option{--log-file} and @option{--trs-file} option (even when the tested
9486 program fails or crashes).
9488 The @file{.log} file should ideally contain all the output produced by the
9489 tested program, plus optionally other information that might facilitate
9490 debugging or analysis of bug reports. Apart from that, its format is
9493 The @file{.trs} file is used to register some metadata through the use
9494 of custom reStructuredText fields. This metadata is expected to be
9495 employed in various ways by the parallel test harness; for example, to
9496 count the test results when printing the testsuite summary, or to decide
9497 which tests to re-run upon @command{make reheck}. Unrecognized metadata
9498 in a @file{.trs} file is currently ignored by the harness, but this might
9499 change in the future. The list of currently recognized metadata follows.
9504 @cindex Register test result
9505 @cindex Register test case result
9506 @cindex Test result, registering
9507 @cindex Test case result, registering
9508 @cindex @code{:test-result:}
9509 @cindex reStructuredText field, @code{:test-result:}
9510 The test driver must use this field to register the results of @emph{each}
9511 test case run by a test script file. Several @code{:test-result:} fields
9512 can be present in the same @file{.trs} file; this is done in order to
9513 support test protocols that allow a single test script to run more test
9516 @c Keep this in sync with lib/am/check-am:$(TEST_SUITE_LOG).
9517 The only recognized test results are currently @code{PASS}, @code{XFAIL},
9518 @code{SKIP}, @code{FAIL}, @code{XPASS} and @code{ERROR}. These results,
9519 when declared with @code{:test-result:}, can be optionally followed by
9520 text holding the name and/or a brief description of the corresponding
9521 test; the @option{parallel-tests} harness will ignore such extra text when
9522 generating @file{test-suite.log} and preparing the testsuite summary.
9524 @c Keep in sync with 'test-metadata-recheck.sh'.
9525 @item @code{:recheck:}
9527 @cindex reStructuredText field, @code{:recheck:}
9528 If this field is present and defined to @code{no}, then the corresponding
9529 test script will @emph{not} be run upon a @command{make recheck}. What
9530 happens when two or more @code{:recheck:} fields are present in the same
9531 @file{.trs} file is undefined behaviour.
9533 @c Keep in sync with 'test-metadata-global-log.sh'.
9534 @item @code{:copy-in-global-log:}
9535 @cindex :copy-in-global-log:
9536 @cindex reStructuredText field, @code{:copy-in-global-log:}
9537 If this field is present and defined to @code{no}, then the content
9538 of the @file{.log} file will @emph{not} be copied into the global
9539 @file{test-suite.log}. We allow to forsake such copying because, while
9540 it can be useful in debugging and analysis of bug report, it can also be
9541 just a waste of space in normal situations, e.g., when a test script is
9542 successful. What happens when two or more @code{:copy-in-global-log:}
9543 fields are present in the same @file{.trs} file is undefined behaviour.
9545 @c Keep in sync with 'test-metadata-global-result.sh'.
9546 @item @code{:test-global-result:}
9547 @cindex :test-global-result:
9548 @cindex reStructuredText field, @code{:test-global-result:}
9549 This is used to declare the "global result" of the script. Currently,
9550 the value of this field is needed only to be reported (more or less
9551 verbatim) in the generated global log file @code{$(TEST_SUITE_LOG)},
9552 so it's quite free-form. For example, a test script which run 10 test
9553 cases, 6 of which pass and 4 of which are skipped, could reasonably have
9554 a @code{PASS/SKIP} value for this field, while a test script which run
9555 19 successful tests and one failed test could have an @code{ALMOST
9556 PASSED} value. What happens when two or more @code{:test-global-result:}
9557 fields are present in the same @file{.trs} file is undefined behaviour.
9561 Let's see a small example. Assume a @file{.trs} file contains the
9565 :test-result: PASS server starts
9566 :global-log-copy: no
9567 :test-result: PASS HTTP/1.1 request
9568 :test-result: FAIL HTTP/1.0 request
9570 :test-result: SKIP HTTPS request (TLS library wasn't available)
9571 :test-result: PASS server stops
9575 Then the corresponding test script will be re-run by @command{make check},
9576 will contribute with @emph{five} test results to the testsuite summary
9577 (three of these tests being successful, one failed, and one skipped), and
9578 the content of the corresponding @file{.log} file will @emph{not} be
9579 copied in the global log file @file{test-suite.log}.
9581 @node Testsuite progress output
9582 @subsubsection Testsuite progress output
9584 A custom test driver also has the task of displaying, on the standard
9585 output, the test results as soon as they become available. Depending on
9586 the protocol in use, it can also display the reasons for failures and
9587 skips, and, more generally, any useful diagnostic output (but remember
9588 that each line on the screen is precious, so that cluttering the screen
9589 with overly verbose information is bad idea). The exact format of this
9590 progress output is left up to the test driver; in fact, a custom test
9591 driver might @emph{theoretically} even decide not to do any such report,
9592 leaving it all to the testsuite summary (that would be a very lousy idea,
9593 of course, and serves only to illustrate the flexibility that is
9596 Remember that consistency is good; so, if possible, try to be consistent
9597 with the output of the built-in Automake test drivers, providing a similar
9598 ``look & feel''. In particular, the testsuite progress output should be
9599 colorized when the @option{--color-tests} is passed to the driver. On the
9600 other end, if you are using a known and widespread test protocol with
9601 well-established implementations, being consistent with those
9602 implementations' output might be a good idea too.
9604 @c TODO: Give an example, maybe inspired to py.test-style output.
9605 @c TODO: That is a good idea because it shows a test driver that allows
9606 @c TODO: for different levels of verbosity in the progress output (could
9607 @c TODO: be implemented either using a driver cmdline flag, or an
9608 @c TODO: environment variable, or both).
9610 @node Using the TAP test protocol
9611 @section Using the TAP test protocol
9614 * Introduction to TAP::
9615 * Use TAP with the Automake test harness::
9616 * Incompatibilities with other TAP parsers and drivers::
9617 * Links and external resources on TAP::
9620 @node Introduction to TAP
9621 @subsection Introduction to TAP
9623 TAP, the Test Anything Protocol, is a simple text-based interface between
9624 testing modules or programs and a test harness. The tests (also called
9625 ``TAP producers'' in this context) write test results in a simple format
9626 on standard output; a test harness (also called ``TAP consumer'') will
9627 parse and interpret these results, and properly present them to the user,
9628 and/or register them for later analysis. The exact details of how this
9629 is accomplished can vary among different test harnesses. The Automake
9630 parallel harness will present the results on the console in the usual
9631 fashion (@pxref{Testsuite progress on console}), and will use the
9632 @file{.trs} files (@pxref{Basics of test metadata}) to store the test
9633 results and related metadata. Apart from that, it will try to remain
9634 as much compatible as possible with pre-existing and widespread utilities,
9635 such as the @uref{http://search.cpan.org/~andya/Test-Harness/bin/prove,
9636 @command{prove} utility}, at least for the simpler usages.
9638 TAP started its life as part of the test harness for Perl, but today
9639 it has been (mostly) standardized, and has various independent
9640 implementations in different languages; among them, C, C++, Perl,
9641 Python, PHP, and Java. For a semi-official specification of the
9642 TAP protocol, please refer to the documentation of
9643 @uref{http://search.cpan.org/~petdance/Test-Harness/lib/Test/Harness/TAP.pod,
9644 @samp{Test::Harness::TAP}}.
9646 The most relevant real-world usages of TAP are obviously in the testsuites
9647 of @command{perl} and of many perl modules. Still, also other important
9648 third-party packages, such as @uref{http://git-scm.com/, @command{git}},
9649 use TAP in their testsuite.
9651 @node Use TAP with the Automake test harness
9652 @subsection Use TAP with the Automake test harness
9654 Currently, the TAP driver that comes with Automake requires some by-hand
9655 steps on the developer's part (this situation should hopefully be improved
9656 in future Automake versions). You'll have to grab the @file{tap-driver.sh}
9657 script from the Automake distribution by hand, copy it in your source tree,
9658 add a call to @code{AC_PROG_AWK} in @file{configure.ac} to search for a
9659 proper awk program, and use the Automake support for third-party test
9660 drivers to instruct the harness to use the @file{tap-driver.sh} script
9661 and that awk program to run your TAP-producing tests. See the example
9662 below for clarification.
9664 Apart from the options common to all the Automake test drivers
9665 (@pxref{Command-line arguments for test drivers}), the @file{tap-driver.sh}
9666 supports the following options, whose names are chosen for enhanced
9667 compatibility with the @command{prove} utility.
9670 @c Keep in sync with 'tap-exit.sh' and 'tap-signal.tap'.
9672 Causes the test driver to ignore the exit status of the test scripts;
9673 by default, the driver will report an error if the script exits with a
9674 non-zero status. This option has effect also on non-zero exit statuses
9675 due to termination by a signal.
9677 Instruct the test driver to display TAP diagnostic (i.e., lines beginning
9678 with the @samp{#} character) in the testsuite progress output too; by
9679 default, TAP diagnostic is only copied to the @file{.log} file.
9681 Revert the effects of @option{--comments}.
9683 Instruct the test driver to merge the test scripts' standard error into
9684 their standard output. This is necessary if you want to ensure that
9685 diagnostics from the test scripts are displayed in the correct order
9686 relative to test results; this can be of great help in debugging
9687 (especially if your test scripts are shell scripts run with shell
9688 tracing active). As a downside, this option might cause the test
9689 harness to get confused if anything that appears on standard error
9690 looks like a test result.
9692 Revert the effects of @option{--merge}.
9693 @item --diagnostic-string=@var{STRING}
9694 Change the string that introduces TAP diagnostic from the default value
9695 of ``@code{#}'' to @code{@var{STRING}}. This can be useful if your
9696 TAP-based test scripts produce verbose output on which they have limited
9697 control (because, say, the output comes from other tools invoked in the
9698 scripts), and it might contain text that gets spuriously interpreted as
9699 TAP diagnostic: such an issue can be solved by redefining the string that
9700 activates TAP diagnostic to a value you know won't appear by chance in
9701 the tests' output. Note however that this feature is non-standard, as
9702 the ``official'' TAP protocol does not allow for such a customization; so
9703 don't use it if you can avoid it.
9707 Here is an example of how the TAP driver can be set up and used.
9709 @c Keep in sync with tap-doc2.sh
9711 % @kbd{cat configure.ac}
9712 AC_INIT([GNU Try Tap], [1.0], [bug-automake@@gnu.org])
9713 AC_CONFIG_AUX_DIR([build-aux])
9714 AM_INIT_AUTOMAKE([foreign parallel-tests -Wall -Werror])
9715 AC_CONFIG_FILES([Makefile])
9716 AC_REQUIRE_AUX_FILE([tap-driver.sh])
9720 % @kbd{cat Makefile.am}
9721 TEST_LOG_DRIVER = env AM_TAP_AWK='$(AWK)' $(SHELL) \
9722 $(top_srcdir)/build-aux/tap-driver.sh
9723 TESTS = foo.test bar.test baz.test
9724 EXTRA_DIST = $(TESTS)
9726 % @kbd{cat foo.test}
9728 echo 1..4 # Number of tests to be executed.
9729 echo 'ok 1 - Swallows fly'
9730 echo 'not ok 2 - Caterpillars fly # TODO metamorphosis in progress'
9731 echo 'ok 3 - Pigs fly # SKIP not enough acid'
9732 echo '# I just love word plays ...'
9733 echo 'ok 4 - Flies fly too :-)'
9735 % @kbd{cat bar.test}
9738 echo 'not ok 1 - Bummer, this test has failed.'
9739 echo 'ok 2 - This passed though.'
9740 echo 'Bail out! Ennui kicking in, sorry...'
9741 echo 'ok 3 - This will not be seen.'
9743 % @kbd{cat baz.test}
9747 # Exit with error, even if all the tests have been successful.
9750 % @kbd{cp @var{PREFIX}/share/automake-@var{APIVERSION}/tap-driver.pl .}
9751 % @kbd{autoreconf -vi && ./configure && make check}
9753 PASS: foo.test 1 - Swallows fly
9754 XFAIL: foo.test 2 - Caterpillars fly # TODO metamorphosis in progress
9755 SKIP: foo.test 3 - Pigs fly # SKIP not enough acid
9756 PASS: foo.test 4 - Flies fly too :-)
9757 FAIL: bar.test 1 - Bummer, this test has failed.
9758 PASS: bar.test 2 - This passed though.
9759 ERROR: bar.test - Bail out! Ennui kicking in, sorry...
9761 ERROR: baz.test - exited with status 7
9763 Please report to bug-automake@@gnu.org
9765 % @kbd{echo exit status: $?}
9768 @c Keep the "skewed" indentation below, it produces pretty PDF output.
9769 % @kbd{env TEST_LOG_DRIVER_FLAGS='--comments --ignore-exit' \
9770 TESTS='foo.test baz.test' make -e check}
9772 PASS: foo.test 1 - Swallows fly
9773 XFAIL: foo.test 2 - Caterpillars fly # TODO metamorphosis in progress
9774 SKIP: foo.test 3 - Pigs fly # SKIP not enough acid
9775 # foo.test: I just love word plays...
9776 PASS: foo.test 4 - Flies fly too :-)
9779 % @kbd{echo exit status: $?}
9783 @node Incompatibilities with other TAP parsers and drivers
9784 @subsection Incompatibilities with other TAP parsers and drivers
9786 For implementation or historical reasons, the TAP driver and harness as
9787 implemented by Automake have some minors incompatibilities with the
9788 mainstream versions, which you should be aware of.
9792 A @code{Bail out!} directive doesn't stop the whole testsuite, but only
9793 the test script it occurs in. This doesn't follow TAP specifications,
9794 but on the other hand it maximizes compatibility (and code sharing) with
9795 the ``hard error'' concept of the default @option{parallel-tests} driver.
9797 The @code{version} and @code{pragma} directives are not supported.
9799 The @option{--diagnostic-string} option of our driver allows to modify
9800 the string that introduces TAP diagnostic from the default value
9801 of ``@code{#}''. The standard TAP protocol has currently no way to
9802 allow this, so if you use it your diagnostic will be lost to more
9803 compliant tools like @command{prove} and @code{Test::Harness}
9805 And there are probably some other small and yet undiscovered
9806 incompatibilities, especially in corner cases or with rare usages.
9809 @node Links and external resources on TAP
9810 @subsection Links and external resources on TAP
9813 Here are some links to more extensive official or third-party
9814 documentation and resources about the TAP protocol and related
9815 tools and libraries.
9818 @uref{http://search.cpan.org/~petdance/Test-Harness/lib/Test/Harness/TAP.pod,
9819 @samp{Test::Harness::TAP}},
9820 the (mostly) official documentation about the TAP format and protocol.
9822 @uref{http://search.cpan.org/~andya/Test-Harness/bin/prove,
9824 the most famous command-line TAP test driver, included in the distribution
9825 of @command{perl} and
9826 @uref{http://search.cpan.org/~andya/Test-Harness/lib/Test/Harness.pm,
9827 @samp{Test::Harness}}.
9829 The @uref{http://testanything.org/wiki/index.php/Main_Page,TAP wiki}.
9831 A ``gentle introduction'' to testing for perl coders:
9832 @uref{http://search.cpan.org/dist/Test-Simple/lib/Test/Tutorial.pod,
9833 @samp{Test::Tutorial}}.
9835 @uref{http://search.cpan.org/~mschwern/Test-Simple/lib/Test/Simple.pm,
9836 @samp{Test::Simple}}
9838 @uref{http://search.cpan.org/~mschwern/Test-Simple/lib/Test/More.pm,
9840 the standard perl testing libraries, which are based on TAP.
9842 @uref{http://www.eyrie.org/~eagle/software/c-tap-harness/,C TAP Harness},
9843 a C-based project implementing both a TAP producer and a TAP consumer.
9845 @uref{http://www.tap4j.org/,tap4j},
9846 a Java-based project implementing both a TAP producer and a TAP consumer.
9850 @section DejaGnu Tests
9852 If @uref{ftp://ftp.gnu.org/gnu/dejagnu/, @command{dejagnu}} appears in
9853 @code{AUTOMAKE_OPTIONS}, then a @command{dejagnu}-based test suite is
9854 assumed. The variable @code{DEJATOOL} is a list of names that are
9855 passed, one at a time, as the @option{--tool} argument to
9856 @command{runtest} invocations; it defaults to the name of the package.
9858 The variable @code{RUNTESTDEFAULTFLAGS} holds the @option{--tool} and
9859 @option{--srcdir} flags that are passed to dejagnu by default; this can be
9860 overridden if necessary.
9861 @vindex RUNTESTDEFAULTFLAGS
9863 The variables @code{EXPECT} and @code{RUNTEST} can
9864 also be overridden to provide project-specific values. For instance,
9865 you will need to do this if you are testing a compiler toolchain,
9866 because the default values do not take into account host and target
9873 The contents of the variable @code{RUNTESTFLAGS} are passed to the
9874 @code{runtest} invocation. This is considered a ``user variable''
9875 (@pxref{User Variables}). If you need to set @command{runtest} flags in
9876 @file{Makefile.am}, you can use @code{AM_RUNTESTFLAGS} instead.
9877 @vindex RUNTESTFLAGS
9878 @vindex AM_RUNTESTFLAGS
9880 @cindex @file{site.exp}
9881 Automake will generate rules to create a local @file{site.exp} file,
9882 defining various variables detected by @command{configure}. This file
9883 is automatically read by DejaGnu. It is OK for the user of a package
9884 to edit this file in order to tune the test suite. However this is
9885 not the place where the test suite author should define new variables:
9886 this should be done elsewhere in the real test suite code.
9887 Especially, @file{site.exp} should not be distributed.
9889 Still, if the package author has legitimate reasons to extend
9890 @file{site.exp} at @command{make} time, he can do so by defining
9891 the variable @code{EXTRA_DEJAGNU_SITE_CONFIG}; the files listed
9892 there will be considered @file{site.exp} prerequisites, and their
9893 content will be appended to it (in the same order in which they
9894 appear in @code{EXTRA_DEJAGNU_SITE_CONFIG}). Note that files are
9895 @emph{not} distributed by default.
9897 For more information regarding DejaGnu test suites, see @ref{Top, , ,
9898 dejagnu, The DejaGnu Manual}.
9901 @section Install Tests
9903 The @code{installcheck} target is available to the user as a way to
9904 run any tests after the package has been installed. You can add tests
9905 to this by writing an @code{installcheck-local} rule.
9909 @chapter Rebuilding Makefiles
9910 @cindex rebuild rules
9912 Automake generates rules to automatically rebuild @file{Makefile}s,
9913 @file{configure}, and other derived files like @file{Makefile.in}.
9915 @acindex AM_MAINTAINER_MODE
9916 If you are using @code{AM_MAINTAINER_MODE} in @file{configure.ac}, then
9917 these automatic rebuilding rules are only enabled in maintainer mode.
9919 @vindex ACLOCAL_AMFLAGS
9920 Sometimes you need to run @command{aclocal} with an argument like
9921 @option{-I} to tell it where to find @file{.m4} files. Since
9922 sometimes @command{make} will automatically run @command{aclocal}, you
9923 need a way to specify these arguments. You can do this by defining
9924 @code{ACLOCAL_AMFLAGS}; this holds arguments that are passed verbatim
9925 to @command{aclocal}. This variable is only useful in the top-level
9928 @vindex CONFIG_STATUS_DEPENDENCIES
9929 @vindex CONFIGURE_DEPENDENCIES
9930 @cindex @file{version.sh}, example
9931 @cindex @file{version.m4}, example
9933 Sometimes it is convenient to supplement the rebuild rules for
9934 @file{configure} or @file{config.status} with additional dependencies.
9935 The variables @code{CONFIGURE_DEPENDENCIES} and
9936 @code{CONFIG_STATUS_DEPENDENCIES} can be used to list these extra
9937 dependencies. These variables should be defined in all
9938 @file{Makefile}s of the tree (because these two rebuild rules are
9939 output in all them), so it is safer and easier to @code{AC_SUBST} them
9940 from @file{configure.ac}. For instance, the following statement will
9941 cause @file{configure} to be rerun each time @file{version.sh} is
9945 AC_SUBST([CONFIG_STATUS_DEPENDENCIES], ['$(top_srcdir)/version.sh'])
9949 Note the @samp{$(top_srcdir)/} in the file name. Since this variable
9950 is to be used in all @file{Makefile}s, its value must be sensible at
9951 any level in the build hierarchy.
9953 Beware not to mistake @code{CONFIGURE_DEPENDENCIES} for
9954 @code{CONFIG_STATUS_DEPENDENCIES}.
9956 @code{CONFIGURE_DEPENDENCIES} adds dependencies to the
9957 @file{configure} rule, whose effect is to run @command{autoconf}. This
9958 variable should be seldom used, because @command{automake} already tracks
9959 @code{m4_include}d files. However it can be useful when playing
9960 tricky games with @code{m4_esyscmd} or similar non-recommendable
9961 macros with side effects.
9963 @code{CONFIG_STATUS_DEPENDENCIES} adds dependencies to the
9964 @file{config.status} rule, whose effect is to run @file{configure}.
9965 This variable should therefore carry any non-standard source that may
9966 be read as a side effect of running @command{configure}, like @file{version.sh}
9967 in the example above.
9969 Speaking of @file{version.sh} scripts, we recommend against them
9970 today. They are mainly used when the version of a package is updated
9971 automatically by a script (e.g., in daily builds). Here is what some
9972 old-style @file{configure.ac}s may look like:
9976 . $srcdir/version.sh
9977 AM_INIT_AUTOMAKE([name], $VERSION_NUMBER)
9982 Here, @file{version.sh} is a shell fragment that sets
9983 @code{VERSION_NUMBER}. The problem with this example is that
9984 @command{automake} cannot track dependencies (listing @file{version.sh}
9985 in @command{CONFIG_STATUS_DEPENDENCIES}, and distributing this file is up
9986 to the user), and that it uses the obsolete form of @code{AC_INIT} and
9987 @code{AM_INIT_AUTOMAKE}. Upgrading to the new syntax is not
9988 straightforward, because shell variables are not allowed in
9989 @code{AC_INIT}'s arguments. We recommend that @file{version.sh} be
9990 replaced by an M4 file that is included by @file{configure.ac}:
9993 m4_include([version.m4])
9994 AC_INIT([name], VERSION_NUMBER)
10000 Here @file{version.m4} could contain something like
10001 @samp{m4_define([VERSION_NUMBER], [1.2])}. The advantage of this
10002 second form is that @command{automake} will take care of the
10003 dependencies when defining the rebuild rule, and will also distribute
10004 the file automatically. An inconvenience is that @command{autoconf}
10005 will now be rerun each time the version number is bumped, when only
10006 @file{configure} had to be rerun in the previous setup.
10010 @chapter Changing Automake's Behavior
10013 * Options generalities:: Semantics of Automake option
10014 * List of Automake options:: A comprehensive list of Automake options
10017 @node Options generalities
10018 @section Options generalities
10020 Various features of Automake can be controlled by options. Except where
10021 noted otherwise, options can be specified in one of several ways. Most
10022 options can be applied on a per-@file{Makefile} basis when listed in a
10023 special @file{Makefile} variable named @code{AUTOMAKE_OPTIONS}. Some
10024 of these options only make sense when specified in the toplevel
10025 @file{Makefile.am} file. Options are applied globally to all processed
10026 @file{Makefile} files when listed in the first argument of
10027 @code{AM_INIT_AUTOMAKE} in @file{configure.ac}, and some options which
10028 require changes to the @command{configure} script can only be specified
10029 there. These are annotated below.
10031 As a general rule, options specified in @code{AUTOMAKE_OPTIONS} take
10032 precedence over those specified in @code{AM_INIT_AUTOMAKE}, which in
10033 turn take precedence over those specified on the command line.
10035 Also, some care must be taken about the interactions among strictness
10036 level and warning categories. As a general rule, strictness-implied
10037 warnings are overridden by those specified by explicit options. For
10038 example, even if @samp{portability} warnings are disabled by default
10039 in @option{foreign} strictness, an usage like this will end up enabling
10043 AUTOMAKE_OPTIONS = -Wportability foreign
10046 However, a strictness level specified in a higher-priority context
10047 will override all the explicit warnings specified in a lower-priority
10048 context. For example, if @file{configure.ac} contains:
10051 AM_INIT_AUTOMAKE([-Wportability])
10055 and @file{Makefile.am} contains:
10058 AUTOMAKE_OPTIONS = foreign
10062 then @samp{portability} warnings will be @emph{disabled} in
10063 @file{Makefile.am}.
10065 @node List of Automake options
10066 @section List of Automake options
10068 @vindex AUTOMAKE_OPTIONS
10071 @item @option{gnits}
10072 @itemx @option{gnu}
10073 @itemx @option{foreign}
10074 @itemx @option{cygnus}
10075 @cindex Option, @option{gnits}
10076 @cindex Option, @option{gnu}
10077 @cindex Option, @option{foreign}
10078 @cindex Option, @option{cygnus}
10084 Set the strictness as appropriate. The @option{gnits} option also
10085 implies options @option{readme-alpha} and @option{check-news}.
10087 @item @option{check-news}
10088 @cindex Option, @option{check-news}
10089 @opindex check-news
10090 Cause @samp{make dist} to fail unless the current version number appears
10091 in the first few lines of the @file{NEWS} file.
10093 @item @option{color-tests}
10094 @cindex Option, @option{color-tests}
10095 @opindex color-tests
10096 Cause output of the serial and parallel test harnesses (see @ref{Simple
10097 Tests}) and of properly-written custom test drivers (@pxref{Custom Test
10098 Drivers}) to be colorized on capable terminals.
10100 @item @option{dejagnu}
10101 @cindex Option, @option{dejagnu}
10103 Cause @command{dejagnu}-specific rules to be generated. @xref{DejaGnu Tests}.
10105 @item @option{dist-bzip2}
10106 @cindex Option, @option{dist-bzip2}
10107 @opindex dist-bzip2
10108 Hook @code{dist-bzip2} to @code{dist}.
10109 @trindex dist-bzip2
10111 @item @option{dist-lzip}
10112 @cindex Option, @option{dist-lzip}
10114 Hook @code{dist-lzip} to @code{dist}.
10117 @item @option{dist-shar}
10118 @cindex Option, @option{dist-shar}
10120 Hook @code{dist-shar} to @code{dist}.
10123 @item @option{dist-zip}
10124 @cindex Option, @option{dist-zip}
10126 Hook @code{dist-zip} to @code{dist}.
10129 @item @option{dist-tarZ}
10130 @cindex Option, @option{dist-tarZ}
10132 Hook @code{dist-tarZ} to @code{dist}.
10135 @item @option{filename-length-max=99}
10136 @cindex Option, @option{filename-length-max=99}
10137 @opindex filename-length-max=99
10138 Abort if file names longer than 99 characters are found during
10139 @samp{make dist}. Such long file names are generally considered not to
10140 be portable in tarballs. See the @option{tar-v7} and @option{tar-ustar}
10141 options below. This option should be used in the top-level
10142 @file{Makefile.am} or as an argument of @code{AM_INIT_AUTOMAKE} in
10143 @file{configure.ac}, it will be ignored otherwise. It will also be
10144 ignored in sub-packages of nested packages (@pxref{Subpackages}).
10146 @item @option{no-define}
10147 @cindex Option, @option{no-define}
10149 This option is meaningful only when passed as an argument to
10150 @code{AM_INIT_AUTOMAKE}. It will prevent the @code{PACKAGE} and
10151 @code{VERSION} variables from being @code{AC_DEFINE}d.
10153 @item @option{no-dependencies}
10154 @cindex Option, @option{no-dependencies}
10155 @opindex no-dependencies
10156 This is similar to using @option{--ignore-deps} on the command line,
10157 but is useful for those situations where you don't have the necessary
10158 bits to make automatic dependency tracking work
10159 (@pxref{Dependencies}). In this case the effect is to effectively
10160 disable automatic dependency tracking.
10162 @item @option{no-dist}
10163 @cindex Option, @option{no-dist}
10165 Don't emit any code related to @code{dist} target. This is useful
10166 when a package has its own method for making distributions.
10168 @item @option{no-dist-gzip}
10169 @cindex Option, @option{no-dist-gzip}
10170 @opindex no-dist-gzip
10171 Do not hook @code{dist-gzip} to @code{dist}.
10172 @trindex no-dist-gzip
10174 @item @option{no-exeext}
10175 @cindex Option, @option{no-exeext}
10177 If your @file{Makefile.am} defines a rule for target @code{foo}, it
10178 will override a rule for a target named @samp{foo$(EXEEXT)}. This is
10179 necessary when @code{EXEEXT} is found to be empty. However, by
10180 default @command{automake} will generate an error for this use. The
10181 @option{no-exeext} option will disable this error. This is intended for
10182 use only where it is known in advance that the package will not be
10183 ported to Windows, or any other operating system using extensions on
10186 @item @option{no-installinfo}
10187 @cindex Option, @option{no-installinfo}
10188 @opindex no-installinfo
10189 The generated @file{Makefile.in} will not cause info pages to be built
10190 or installed by default. However, @code{info} and @code{install-info}
10191 targets will still be available. This option is disallowed at
10192 @option{gnu} strictness and above.
10194 @trindex install-info
10196 @item @option{no-installman}
10197 @cindex Option, @option{no-installman}
10198 @opindex no-installman
10199 The generated @file{Makefile.in} will not cause man pages to be
10200 installed by default. However, an @code{install-man} target will still
10201 be available for optional installation. This option is disallowed at
10202 @option{gnu} strictness and above.
10203 @trindex install-man
10205 @item @option{nostdinc}
10206 @cindex Option, @option{nostdinc}
10208 This option can be used to disable the standard @option{-I} options that
10209 are ordinarily automatically provided by Automake.
10211 @item @option{no-texinfo.tex}
10212 @cindex Option, @option{no-texinfo.tex}
10213 @opindex no-texinfo.tex
10214 Don't require @file{texinfo.tex}, even if there are texinfo files in
10217 @item @option{parallel-tests}
10218 @cindex Option, @option{parallel-tests}
10219 @opindex parallel-tests
10220 Enable test suite harness for @code{TESTS} that can run tests in parallel
10221 (@pxref{Parallel Test Harness}, for more information).
10223 @item @option{serial-tests}
10224 @cindex Option, @option{serial-tests}
10225 @opindex serial-tests
10226 Enable the older serial test suite harness for @code{TESTS} (@pxref{Serial
10227 Test Harness}, for more information). This is still the default for the
10230 @item @option{readme-alpha}
10231 @cindex Option, @option{readme-alpha}
10232 @opindex readme-alpha
10233 If this release is an alpha release, and the file @file{README-alpha}
10234 exists, then it will be added to the distribution. If this option is
10235 given, version numbers are expected to follow one of two forms. The
10236 first form is @samp{@var{major}.@var{minor}.@var{alpha}}, where each
10237 element is a number; the final period and number should be left off for
10238 non-alpha releases. The second form is
10239 @samp{@var{major}.@var{minor}@var{alpha}}, where @var{alpha} is a
10240 letter; it should be omitted for non-alpha releases.
10242 @item @option{silent-rules}
10243 @cindex Option, @option{silent-rules}
10244 @opindex silent-rules
10245 Enable less verbose build rules. This can be used to let build rules
10246 output status lines of the form:
10248 GEN @var{output-file}
10249 CC @var{object-file}
10252 instead of printing the command that will be executed to update
10253 @var{output-file} or to compile @var{object-file}. It can also
10254 silence @command{libtool} output.
10256 For more information about how to use, enable, or disable silent
10257 rules, @pxref{Automake silent-rules Option}.
10259 @item @option{std-options}
10260 @cindex Options, @option{std-options}
10261 @cindex @samp{make installcheck}, testing @option{--help} and @option{--version}
10262 @cindex @option{--help} check
10263 @cindex @option{--version} check
10264 @opindex std-options
10266 Make the @code{installcheck} rule check that installed scripts and
10267 programs support the @option{--help} and @option{--version} options.
10268 This also provides a basic check that the program's
10269 run-time dependencies are satisfied after installation.
10271 @vindex AM_INSTALLCHECK_STD_OPTIONS_EXEMPT
10272 In a few situations, programs (or scripts) have to be exempted from this
10273 test. For instance, @command{false} (from GNU coreutils) is never
10274 successful, even for @option{--help} or @option{--version}. You can list
10275 such programs in the variable @code{AM_INSTALLCHECK_STD_OPTIONS_EXEMPT}.
10276 Programs (not scripts) listed in this variable should be suffixed by
10277 @samp{$(EXEEXT)} for the sake of Windows or OS/2. For instance, suppose we
10278 build @file{false} as a program but @file{true.sh} as a script, and that
10279 neither of them support @option{--help} or @option{--version}:
10282 AUTOMAKE_OPTIONS = std-options
10283 bin_PROGRAMS = false ...
10284 bin_SCRIPTS = true.sh ...
10285 AM_INSTALLCHECK_STD_OPTIONS_EXEMPT = false$(EXEEXT) true.sh
10288 @item @option{subdir-objects}
10289 @cindex Options, @option{subdir-objects}
10290 @opindex subdir-objects
10291 If this option is specified, then objects are placed into the
10292 subdirectory of the build directory corresponding to the subdirectory of
10293 the source file. For instance, if the source file is
10294 @file{subdir/file.cxx}, then the output file would be
10295 @file{subdir/file.o}.
10297 In order to use this option with C sources, you should add
10298 @code{AM_PROG_CC_C_O} to @file{configure.ac}.
10300 @anchor{tar-formats}
10301 @item @option{tar-v7}
10302 @itemx @option{tar-ustar}
10303 @itemx @option{tar-pax}
10304 @cindex Option, @option{tar-v7}
10305 @cindex Option, @option{tar-ustar}
10306 @cindex Option, @option{tar-pax}
10307 @cindex @command{tar} formats
10308 @cindex v7 @command{tar} format
10309 @cindex ustar format
10315 These three mutually exclusive options select the tar format to use
10316 when generating tarballs with @samp{make dist}. (The tar file created
10317 is then compressed according to the set of @option{no-dist-gzip},
10318 @option{dist-bzip2}, @option{dist-lzip}, @option{dist-xz} and
10319 @option{dist-tarZ} options in use.)
10321 These options must be passed as arguments to @code{AM_INIT_AUTOMAKE}
10322 (@pxref{Macros}) because they can require additional configure checks.
10323 Automake will complain if it sees such options in an
10324 @code{AUTOMAKE_OPTIONS} variable.
10326 @option{tar-v7} selects the old V7 tar format. This is the historical
10327 default. This antiquated format is understood by all tar
10328 implementations and supports file names with up to 99 characters. When
10329 given longer file names some tar implementations will diagnose the
10330 problem while other will generate broken tarballs or use non-portable
10331 extensions. Furthermore, the V7 format cannot store empty
10332 directories. When using this format, consider using the
10333 @option{filename-length-max=99} option to catch file names too long.
10335 @option{tar-ustar} selects the ustar format defined by POSIX
10336 1003.1-1988. This format is believed to be old enough to be portable.
10337 It fully supports empty directories. It can store file names with up
10338 to 256 characters, provided that the file name can be split at
10339 directory separator in two parts, first of them being at most 155
10340 bytes long. So, in most cases the maximum file name length will be
10341 shorter than 256 characters. However you may run against broken tar
10342 implementations that incorrectly handle file names longer than 99
10343 characters (please report them to @email{@value{PACKAGE_BUGREPORT}} so we
10344 can document this accurately).
10346 @option{tar-pax} selects the new pax interchange format defined by POSIX
10347 1003.1-2001. It does not limit the length of file names. However,
10348 this format is very young and should probably be restricted to
10349 packages that target only very modern platforms. There are moves to
10350 change the pax format in an upward-compatible way, so this option may
10351 refer to a more recent version in the future.
10353 @xref{Formats, , Controlling the Archive Format, tar, GNU Tar}, for
10354 further discussion about tar formats.
10356 @command{configure} knows several ways to construct these formats. It
10357 will not abort if it cannot find a tool up to the task (so that the
10358 package can still be built), but @samp{make dist} will fail.
10360 @item @var{version}
10361 @cindex Option, @var{version}
10362 A version number (e.g., @samp{0.30}) can be specified. If Automake is not
10363 newer than the version specified, creation of the @file{Makefile.in}
10364 will be suppressed.
10366 @item @option{-W@var{category}} or @option{--warnings=@var{category}}
10367 @cindex Option, warnings
10368 @cindex Option, @option{-W@var{category}}
10369 @cindex Option, @option{--warnings=@var{category}}
10370 These options behave exactly like their command-line counterpart
10371 (@pxref{automake Invocation}). This allows you to enable or disable some
10372 warning categories on a per-file basis. You can also setup some warnings
10373 for your entire project; for instance, try @samp{AM_INIT_AUTOMAKE([-Wall])}
10374 in your @file{configure.ac}.
10378 Unrecognized options are diagnosed by @command{automake}.
10380 If you want an option to apply to all the files in the tree, you can use
10381 the @code{AM_INIT_AUTOMAKE} macro in @file{configure.ac}.
10385 @node Miscellaneous
10386 @chapter Miscellaneous Rules
10388 There are a few rules and variables that didn't fit anywhere else.
10391 * Tags:: Interfacing to cscope, etags and mkid
10392 * Suffixes:: Handling new file extensions
10397 @section Interfacing to @command{etags}
10399 @cindex @file{TAGS} support
10401 Automake will generate rules to generate @file{TAGS} files for use with
10402 GNU Emacs under some circumstances.
10405 If any C, C++ or Fortran 77 source code or headers are present, then
10406 @code{tags} and @code{TAGS} rules will be generated for the directory.
10407 All files listed using the @code{_SOURCES}, @code{_HEADERS}, and
10408 @code{_LISP} primaries will be used to generate tags. Note that
10409 generated source files that are not distributed must be declared in
10410 variables like @code{nodist_noinst_HEADERS} or
10411 @code{nodist_@var{prog}_SOURCES} or they will be ignored.
10413 A @code{tags} rule will be output at the topmost directory of a
10414 multi-directory package. When run from this topmost directory,
10415 @samp{make tags} will generate a @file{TAGS} file that includes by
10416 reference all @file{TAGS} files from subdirectories.
10418 The @code{tags} rule will also be generated if the variable
10419 @code{ETAGS_ARGS} is defined. This variable is intended for use in
10420 directories that contain taggable source that @command{etags} does
10421 not understand. The user can use the @code{ETAGSFLAGS} to pass
10422 additional flags to @command{etags}; @code{AM_ETAGSFLAGS} is also
10423 available for use in @file{Makefile.am}.
10426 @vindex AM_ETAGSFLAGS
10428 Here is how Automake generates tags for its source, and for nodes in its
10432 ETAGS_ARGS = automake.in --lang=none \
10433 --regex='/^@@node[ \t]+\([^,]+\)/\1/' automake.texi
10436 If you add file names to @code{ETAGS_ARGS}, you will probably also
10437 want to define @code{TAGS_DEPENDENCIES}. The contents of this variable
10438 are added directly to the dependencies for the @code{tags} rule.
10439 @vindex TAGS_DEPENDENCIES
10441 Automake also generates a @code{ctags} rule that can be used to
10442 build @command{vi}-style @file{tags} files. The variable @code{CTAGS}
10443 is the name of the program to invoke (by default @command{ctags});
10444 @code{CTAGSFLAGS} can be used by the user to pass additional flags,
10445 and @code{AM_CTAGSFLAGS} can be used by the @file{Makefile.am}.
10448 Automake will also generate an @code{ID} rule that will run
10449 @command{mkid} on the source. This is only supported on a
10450 directory-by-directory basis.
10452 Similarly, the @code{cscope} rule will create a list of all the source
10453 files in the tree and run @command{cscope} to build an inverted index
10454 database. The variable @code{CSCOPE} is the name of the program to invoke
10455 (by default @command{cscope}); @code{CSCOPEFLAGS} and
10456 @code{CSCOPE_ARGS} can be used by the user to pass additional flags and
10457 file names respectively, while @code{AM_CSCOPEFLAGS} can be used by the
10458 @file{Makefile.am}. Note that, currently, the Automake-provided
10459 @code{cscope} support, when used in a VPATH build, might not work well
10460 with non-GNU make implementations (especially with make implementations
10461 performing @ref{Automatic Rule Rewriting, , VPATH rewrites, autoconf,
10462 The Autoconf Manual}).
10464 Finally, Automake also emits rules to support the
10465 @uref{http://www.gnu.org/software/global/, GNU Global Tags program}.
10466 The @code{GTAGS} rule runs Global Tags and puts the
10467 result in the top build directory. The variable @code{GTAGS_ARGS}
10468 holds arguments that are passed to @command{gtags}.
10473 @section Handling new file extensions
10475 @cindex Adding new @code{SUFFIXES}
10476 @cindex @code{SUFFIXES}, adding
10479 It is sometimes useful to introduce a new implicit rule to handle a file
10480 type that Automake does not know about.
10482 For instance, suppose you had a compiler that could compile @file{.foo}
10483 files to @file{.o} files. You would simply define a suffix rule for
10491 Then you could directly use a @file{.foo} file in a @code{_SOURCES}
10492 variable and expect the correct results:
10495 bin_PROGRAMS = doit
10496 doit_SOURCES = doit.foo
10499 This was the simpler and more common case. In other cases, you will
10500 have to help Automake to figure out which extensions you are defining your
10501 suffix rule for. This usually happens when your extension does not
10502 start with a dot. Then, all you have to do is to put a list of new
10503 suffixes in the @code{SUFFIXES} variable @strong{before} you define your
10506 For instance, the following definition prevents Automake from misinterpreting
10507 the @samp{.idlC.cpp:} rule as an attempt to transform @file{.idlC} files into
10510 @c Keep in sync with suffix7.sh
10512 SUFFIXES = .idl C.cpp
10517 As you may have noted, the @code{SUFFIXES} variable behaves like the
10518 @code{.SUFFIXES} special target of @command{make}. You should not touch
10519 @code{.SUFFIXES} yourself, but use @code{SUFFIXES} instead and let
10520 Automake generate the suffix list for @code{.SUFFIXES}. Any given
10521 @code{SUFFIXES} go at the start of the generated suffixes list, followed
10522 by Automake generated suffixes not already in the list.
10528 @cindex Including @file{Makefile} fragment
10529 @cindex @file{Makefile} fragment, including
10531 Automake supports an @code{include} directive that can be used to
10532 include other @file{Makefile} fragments when @command{automake} is run.
10533 Note that these fragments are read and interpreted by @command{automake},
10534 not by @command{make}. As with conditionals, @command{make} has no idea that
10535 @code{include} is in use.
10537 There are two forms of @code{include}:
10540 @item include $(srcdir)/file
10541 Include a fragment that is found relative to the current source
10544 @item include $(top_srcdir)/file
10545 Include a fragment that is found relative to the top source directory.
10548 Note that if a fragment is included inside a conditional, then the
10549 condition applies to the entire contents of that fragment.
10551 Makefile fragments included this way are always distributed because
10552 they are needed to rebuild @file{Makefile.in}.
10555 @chapter Conditionals
10557 @cindex Conditionals
10559 Automake supports a simple type of conditionals.
10561 These conditionals are not the same as conditionals in
10562 GNU Make. Automake conditionals are checked at configure time by the
10563 @file{configure} script, and affect the translation from
10564 @file{Makefile.in} to @file{Makefile}. They are based on options passed
10565 to @file{configure} and on results that @file{configure} has discovered
10566 about the host system. GNU Make conditionals are checked at @command{make}
10567 time, and are based on variables passed to the make program or defined
10568 in the @file{Makefile}.
10570 Automake conditionals will work with any make program.
10573 * Usage of Conditionals:: Declaring conditional content
10574 * Limits of Conditionals:: Enclosing complete statements
10577 @node Usage of Conditionals
10578 @section Usage of Conditionals
10580 @acindex AM_CONDITIONAL
10581 Before using a conditional, you must define it by using
10582 @code{AM_CONDITIONAL} in the @file{configure.ac} file (@pxref{Macros}).
10584 @defmac AM_CONDITIONAL (@var{conditional}, @var{condition})
10585 The conditional name, @var{conditional}, should be a simple string
10586 starting with a letter and containing only letters, digits, and
10587 underscores. It must be different from @samp{TRUE} and @samp{FALSE}
10588 that are reserved by Automake.
10590 The shell @var{condition} (suitable for use in a shell @code{if}
10591 statement) is evaluated when @command{configure} is run. Note that you
10592 must arrange for @emph{every} @code{AM_CONDITIONAL} to be invoked every
10593 time @command{configure} is run. If @code{AM_CONDITIONAL} is run
10594 conditionally (e.g., in a shell @code{if} statement), then the result
10595 will confuse @command{automake}.
10598 @cindex @option{--enable-debug}, example
10599 @cindex Example conditional @option{--enable-debug}
10600 @cindex Conditional example, @option{--enable-debug}
10602 Conditionals typically depend upon options that the user provides to
10603 the @command{configure} script. Here is an example of how to write a
10604 conditional that is true if the user uses the @option{--enable-debug}
10608 AC_ARG_ENABLE([debug],
10609 [ --enable-debug Turn on debugging],
10610 [case "$@{enableval@}" in
10613 *) AC_MSG_ERROR([bad value $@{enableval@} for --enable-debug]) ;;
10614 esac],[debug=false])
10615 AM_CONDITIONAL([DEBUG], [test x$debug = xtrue])
10618 Here is an example of how to use that conditional in @file{Makefile.am}:
10630 noinst_PROGRAMS = $(DBG)
10633 This trivial example could also be handled using @code{EXTRA_PROGRAMS}
10634 (@pxref{Conditional Programs}).
10636 You may only test a single variable in an @code{if} statement, possibly
10637 negated using @samp{!}. The @code{else} statement may be omitted.
10638 Conditionals may be nested to any depth. You may specify an argument to
10639 @code{else} in which case it must be the negation of the condition used
10640 for the current @code{if}. Similarly you may specify the condition
10641 that is closed on the @code{endif} line:
10652 Unbalanced conditions are errors. The @code{if}, @code{else}, and
10653 @code{endif} statements should not be indented, i.e., start on column
10656 The @code{else} branch of the above two examples could be omitted,
10657 since assigning the empty string to an otherwise undefined variable
10658 makes no difference.
10660 @acindex AM_COND_IF
10661 In order to allow access to the condition registered by
10662 @code{AM_CONDITIONAL} inside @file{configure.ac}, and to allow
10663 conditional @code{AC_CONFIG_FILES}, @code{AM_COND_IF} may be used:
10665 @defmac AM_COND_IF (@var{conditional}, @ovar{if-true}, @ovar{if-false})
10666 If @var{conditional} is fulfilled, execute @var{if-true}, otherwise
10667 execute @var{if-false}. If either branch contains @code{AC_CONFIG_FILES},
10668 it will cause @command{automake} to output the rules for the respective
10669 files only for the given condition.
10672 @code{AM_COND_IF} macros may be nested when m4 quotation is used
10673 properly (@pxref{M4 Quotation, ,, autoconf, The Autoconf Manual}).
10675 @cindex Example conditional @code{AC_CONFIG_FILES}
10676 @cindex @code{AC_CONFIG_FILES}, conditional
10678 Here is an example of how to define a conditional config file:
10681 AM_CONDITIONAL([SHELL_WRAPPER], [test "x$with_wrapper" = xtrue])
10682 AM_COND_IF([SHELL_WRAPPER],
10683 [AC_CONFIG_FILES([wrapper:wrapper.in])])
10686 @node Limits of Conditionals
10687 @section Limits of Conditionals
10689 Conditionals should enclose complete statements like variables or
10690 rules definitions. Automake cannot deal with conditionals used inside
10691 a variable definition, for instance, and is not even able to diagnose
10692 this situation. The following example would not work:
10695 # This syntax is not understood by Automake
10704 However the intended definition of @code{AM_CPPFLAGS} can be achieved
10709 DEBUGFLAGS = -DDEBUG
10711 AM_CPPFLAGS = -DFEATURE_A $(DEBUGFLAGS) -DFEATURE_B
10718 AM_CPPFLAGS = -DFEATURE_A
10720 AM_CPPFLAGS += -DDEBUG
10722 AM_CPPFLAGS += -DFEATURE_B
10725 More details and examples of conditionals are described alongside
10726 various Automake features in this manual (@pxref{Conditional
10727 Subdirectories}, @pxref{Conditional Sources}, @pxref{Conditional
10728 Programs}, @pxref{Conditional Libtool Libraries}, @pxref{Conditional
10731 @node Silencing Make
10732 @chapter Silencing @command{make}
10734 @cindex Silent @command{make}
10735 @cindex Silencing @command{make}
10736 @cindex Silent rules
10737 @cindex Silent @command{make} rules
10740 * Make verbosity:: Make is verbose by default
10741 * Tricks For Silencing Make:: Standard and generic ways to silence make
10742 * Automake silent-rules Option:: How Automake can help in silencing make
10745 @node Make verbosity
10746 @section Make is verbose by default
10748 Normally, when executing the set of rules associated with a target,
10749 @command{make} prints each rule before it is executed. This behaviour,
10750 while having been in place for a long time, and being even mandated by
10751 the POSIX standard, starkly violates the ``silence is golden'' UNIX
10752 principle@footnote{See also
10753 @uref{http://catb.org/~esr/writings/taoup/html/ch11s09.html}.}:
10756 When a program has nothing interesting or surprising to say, it should
10757 say nothing. Well-behaved Unix programs do their jobs unobtrusively,
10758 with a minimum of fuss and bother. Silence is golden.
10761 In fact, while such verbosity of @command{make} can theoretically be
10762 useful to track bugs and understand reasons of failures right away, it
10763 can also hide warning and error messages from @command{make}-invoked
10764 tools, drowning them in a flood of uninteresting and seldom useful
10765 messages, and thus allowing them to go easily undetected.
10767 This problem can be very annoying, especially for developers, who usually
10768 know quite well what's going on behind the scenes, and for whom the
10769 verbose output from @command{make} ends up being mostly noise that hampers
10770 the easy detection of potentially important warning messages.
10772 @node Tricks For Silencing Make
10773 @section Standard and generic ways to silence make
10775 Here we describe some common idioms/tricks to obtain a quieter make
10776 output, with their relative advantages and drawbacks. In the next
10777 section (@ref{Automake silent-rules Option}) we'll see how Automake
10778 can help in this respect.
10782 @item @command{make -s}
10784 This simply causes @command{make} not to print @emph{any} rule before
10787 The @option{-s} flag is mandated by POSIX, universally supported, and
10788 its purpose and function are easy to understand.
10790 But it also has its serious limitations too. First of all, it embodies
10791 an ``all or nothing'' strategy, i.e., either everything is silenced, or
10792 nothing is; this lack of granularity can sometimes be a fatal flaw.
10793 Moreover, when the @option{-s} flag is used, the @command{make} output
10794 might turn out to be too much terse; in case of errors, the user won't
10795 be able to easily see what rule or command have caused them, or even,
10796 in case of tools with poor error reporting, what the errors were!
10798 @item @command{make >/dev/null || make}
10800 Apparently, this perfectly obeys the ``silence is golden'' rule: warnings
10801 from stderr are passed through, output reporting is done only in case of
10802 error, and in that case it should provide a verbose-enough report to allow
10803 an easy determination of the error location and causes.
10805 However, calling @command{make} two times in a row might hide errors
10806 (especially intermittent ones), or subtly change the expected semantic
10807 of the @command{make} calls --- things these which can clearly make
10808 debugging and error assessment very difficult.
10810 @item @command{make --no-print-directory}
10812 This is GNU @command{make} specific. When called with the
10813 @option{--no-print-directory} option, GNU @command{make} will disable
10814 printing of the working directory by invoked sub-@command{make}s (the
10815 well-known ``@i{Entering/Leaving directory ...}'' messages). This helps
10816 to decrease the verbosity of the output, but experience has shown that
10817 it can also often render debugging considerably harder in projects using
10818 deeply-nested @command{make} recursion.
10820 As an aside, notice that the @option{--no-print-directory} option is
10821 automatically activated if the @option{-s} flag is used.
10823 @c TODO: Other tricks?
10824 @c TODO: Maybe speak about the @code{.SILENT} target?
10825 @c TODO: - Pros: More granularity on what to silence.
10826 @c TODO: - Cons: No easy way to temporarily override.
10830 @node Automake silent-rules Option
10831 @section How Automake can help in silencing make
10833 The tricks and idioms for silencing @command{make} described in the
10834 previous section can be useful from time to time, but we've seen that
10835 they all have their serious drawbacks and limitations. That's why
10836 automake provides support for a more advanced and flexible way of
10837 obtaining quieter output from @command{make}: the @option{silent-rules}
10840 @c TODO: Maybe describe in brief the precedent set by the build system
10841 @c of the Linux Kernel, from which Automake took inspiration ... Links?
10843 To give the gist of what @option{silent-rules} can do, here is a simple
10844 comparison between a typical @command{make} output (where silent rules
10845 are disabled) and one with silent rules enabled:
10848 % @kbd{cat Makefile.am}
10850 foo_SOURCES = main.c func.c
10852 int main (void) @{ return func (); @} /* func used undeclared */
10854 int func (void) @{ int i; return i; @} /* i used uninitialized */
10856 @i{The make output is by default very verbose. This causes warnings
10857 from the compiler to be somewhat hidden, and not immediate to spot.}
10858 % @kbd{make CFLAGS=-Wall}
10859 gcc -DPACKAGE_NAME=\"foo\" -DPACKAGE_TARNAME=\"foo\" ...
10860 -DPACKAGE_STRING=\"foo\ 1.0\" -DPACKAGE_BUGREPORT=\"\" ...
10861 -DPACKAGE=\"foo\" -DVERSION=\"1.0\" -I. -Wall -MT main.o
10862 -MD -MP -MF .deps/main.Tpo -c -o main.o main.c
10863 main.c: In function ‘main’:
10864 main.c:3:3: warning: implicit declaration of function ‘func’
10865 mv -f .deps/main.Tpo .deps/main.Po
10866 gcc -DPACKAGE_NAME=\"foo\" -DPACKAGE_TARNAME=\"foo\" ...
10867 -DPACKAGE_STRING=\"foo\ 1.0\" -DPACKAGE_BUGREPORT=\"\" ...
10868 -DPACKAGE=\"foo\" -DVERSION=\"1.0\" -I. -Wall -MT func.o
10869 -MD -MP -MF .deps/func.Tpo -c -o func.o func.c
10870 func.c: In function ‘func’:
10871 func.c:4:3: warning: ‘i’ used uninitialized in this function
10872 mv -f .deps/func.Tpo .deps/func.Po
10873 gcc -Wall -o foo main.o func.o
10875 @i{Clean up, so that we we can rebuild everything from scratch.}
10877 test -z "foo" || rm -f foo
10880 @i{Silent rules enabled: the output is minimal but informative. In
10881 particular, the warnings from the compiler stick out very clearly.}
10882 % @kbd{make V=0 CFLAGS=-Wall}
10884 main.c: In function ‘main’:
10885 main.c:3:3: warning: implicit declaration of function ‘func’
10887 func.c: In function ‘func’:
10888 func.c:4:3: warning: ‘i’ used uninitialized in this function
10892 @cindex silent-rules and libtool
10893 Also, in projects using @command{libtool}, the use of silent rules can
10894 automatically enable the @command{libtool}'s @option{--silent} option:
10897 % @kbd{cat Makefile.am}
10898 lib_LTLIBRARIES = libx.la
10900 % @kbd{make # Both make and libtool are verbose by default.}
10902 libtool: compile: gcc -DPACKAGE_NAME=\"foo\" ... -DLT_OBJDIR=\".libs/\"
10903 -I. -g -O2 -MT libx.lo -MD -MP -MF .deps/libx.Tpo -c libx.c -fPIC
10904 -DPIC -o .libs/libx.o
10905 mv -f .deps/libx.Tpo .deps/libx.Plo
10906 /bin/sh ./libtool --tag=CC --mode=link gcc -g -O2 -o libx.la -rpath
10907 /usr/local/lib libx.lo
10908 libtool: link: gcc -shared .libs/libx.o -Wl,-soname -Wl,libx.so.0
10909 -o .libs/libx.so.0.0.0
10910 libtool: link: cd .libs && rm -f libx.so && ln -s libx.so.0.0.0 libx.so
10918 Let's now see how the @option{silent-rules} mode interfaces with the
10919 package developer and the package user.
10921 To enable the use of @option{silent-rules} in his package, a developer
10922 needs to do either of the following:
10926 Add the @option{silent-rules} option as argument to @code{AM_INIT_AUTOMAKE}.
10928 Call the @code{AM_SILENT_RULES} macro from within the @file{configure.ac}
10932 It is not possible to instead specify @option{silent-rules} in a
10933 @file{Makefile.am} file.
10935 If the developer has done either of the above, then the user of the
10936 package may influence the verbosity at @command{configure} run time as
10937 well as at @command{make} run time:
10941 @opindex --enable-silent-rules
10942 @opindex --disable-silent-rules
10943 Passing @option{--enable-silent-rules} to @command{configure} will cause
10944 build rules to be less verbose; the option @option{--disable-silent-rules}
10945 will cause normal verbose output.
10948 At @command{make} run time, the default chosen at @command{configure}
10949 time may be overridden: @code{make V=1} will produce verbose output,
10950 @code{make V=0} less verbose output.
10953 @cindex default verbosity for silent-rules
10954 Note that silent rules are @emph{disabled} by default; the user must
10955 enable them explicitly at either @command{configure} run time or at
10956 @command{make} run time. We think that this is a good policy, since
10957 it provides the casual user with enough information to prepare a good
10958 bug report in case anything breaks.
10960 Still, notwithstanding the rationales above, a developer who wants to
10961 make silent rules enabled by default in his own package can do so by
10962 adding a @samp{yes} argument to the @code{AM_SILENT_RULES} call in
10963 @file{configure.ac}. We advise against this approach, though.
10965 @c Keep in sync with silent-configsite.sh
10966 Users who prefer to have silent rules enabled by default can edit their
10967 @file{config.site} file to make the variable @code{enable_silent_rules}
10968 default to @samp{yes}. This should still allow disabling silent rules
10969 at @command{configure} time and at @command{make} time.
10971 @c FIXME: there's really a need to specify this explicitly?
10972 For portability to different @command{make} implementations, package authors
10973 are advised to not set the variable @code{V} inside the @file{Makefile.am}
10974 file, to allow the user to override the value for subdirectories as well.
10976 The current implementation of this feature normally uses nested
10977 variable expansion @samp{$(@var{var1}$(V))}, a @file{Makefile} feature
10978 that is not required by POSIX 2008 but is widely supported in
10979 practice. The @option{silent-rules} option thus turns off warnings
10980 about recursive variable expansion, which are in turn enabled by
10981 @option{-Wportability} (@pxref{automake Invocation}). On the rare
10982 @command{make} implementations that do not support nested variable
10983 expansion, whether rules are silent is always determined at configure
10984 time, and cannot be overridden at make time. Future versions of POSIX
10985 are likely to require nested variable expansion, so this minor
10986 limitation should go away with time.
10988 @vindex @code{AM_V_GEN}
10989 @vindex @code{AM_V_at}
10990 @vindex @code{AM_DEFAULT_VERBOSITY}
10991 @vindex @code{AM_V}
10992 @vindex @code{AM_DEFAULT_V}
10993 To extend the silent mode to your own rules, you have few choices:
10998 You can use the predefined variable @code{AM_V_GEN} as a prefix to
10999 commands that should output a status line in silent mode, and
11000 @code{AM_V_at} as a prefix to commands that should not output anything
11001 in silent mode. When output is to be verbose, both of these variables
11002 will expand to the empty string.
11005 You can silence a recipe unconditionally with @code{@@}, and then use
11006 the predefined variable @code{AM_V_P} to know whether make is being run
11007 in silent or verbose mode, adjust the verbose information your recipe
11008 displays accordingly:
11013 ... [commands defining a shell variable '$headers'] ...; \
11014 if $(AM_V_P); then set -x; else echo " GEN [headers]"; fi; \
11015 rm -f $$headers && generate-header --flags $$headers
11019 You can add your own variables, so strings of your own choice are shown.
11020 The following snippet shows how you would define your own equivalent of
11024 pkg_verbose = $(pkg_verbose_@@AM_V@@)
11025 pkg_verbose_ = $(pkg_verbose_@@AM_DEFAULT_V@@)
11026 pkg_verbose_0 = @@echo PKG-GEN $@@;
11029 $(pkg_verbose)cp $(srcdir)/foo.in $@@
11034 As a final note, observe that, even when silent rules are enabled,
11035 the @option{--no-print-directory} option is still required with GNU
11036 @command{make} if the ``@i{Entering/Leaving directory ...}'' messages
11037 are to be disabled.
11040 @chapter The effect of @option{--gnu} and @option{--gnits}
11042 @cindex @option{--gnu}, required files
11043 @cindex @option{--gnu}, complete description
11045 The @option{--gnu} option (or @option{gnu} in the
11046 @code{AUTOMAKE_OPTIONS} variable) causes @command{automake} to check
11051 The files @file{INSTALL}, @file{NEWS}, @file{README}, @file{AUTHORS},
11052 and @file{ChangeLog}, plus one of @file{COPYING.LIB}, @file{COPYING.LESSER}
11053 or @file{COPYING}, are required at the topmost directory of the package.
11055 If the @option{--add-missing} option is given, @command{automake} will
11056 add a generic version of the @file{INSTALL} file as well as the
11057 @file{COPYING} file containing the text of the current version of the
11058 GNU General Public License existing at the time of this Automake release
11059 (version 3 as this is written, @uref{http://www.gnu.org/@/copyleft/@/gpl.html}).
11060 However, an existing @file{COPYING} file will never be overwritten by
11061 @command{automake}.
11064 The options @option{no-installman} and @option{no-installinfo} are
11068 Note that this option will be extended in the future to do even more
11069 checking; it is advisable to be familiar with the precise requirements
11070 of the GNU standards. Also, @option{--gnu} can require certain
11071 non-standard GNU programs to exist for use by various maintainer-only
11072 rules; for instance, in the future @command{pathchk} might be required for
11075 @cindex @option{--gnits}, complete description
11077 The @option{--gnits} option does everything that @option{--gnu} does, and
11078 checks the following as well:
11082 @samp{make installcheck} will check to make sure that the @option{--help}
11083 and @option{--version} really print a usage message and a version string,
11084 respectively. This is the @option{std-options} option (@pxref{Options}).
11087 @samp{make dist} will check to make sure the @file{NEWS} file has been
11088 updated to the current version.
11091 @code{VERSION} is checked to make sure its format complies with Gnits
11093 @c FIXME xref when standards are finished
11096 @cindex @file{README-alpha}
11097 If @code{VERSION} indicates that this is an alpha release, and the file
11098 @file{README-alpha} appears in the topmost directory of a package, then
11099 it is included in the distribution. This is done in @option{--gnits}
11100 mode, and no other, because this mode is the only one where version
11101 number formats are constrained, and hence the only mode where Automake
11102 can automatically determine whether @file{README-alpha} should be
11106 The file @file{THANKS} is required.
11111 @chapter The effect of @option{--cygnus}
11113 @cindex @option{cygnus} strictness
11115 @emph{The features described in this section are deprecated; you must
11116 not use any of them in new code, and should remove their use from older
11117 but still maintained code: they will be withdrawn the next major Automake
11120 Some packages, notably GNU GCC and GNU gdb, used to have a build
11121 environment originally written at Cygnus Support (subsequently renamed
11122 Cygnus Solutions, and then later purchased by Red Hat). Packages with
11123 this ancestry are sometimes referred to as ``Cygnus'' trees.
11125 A Cygnus tree has slightly different rules for how a
11126 @file{Makefile.in} is to be constructed. Passing @option{--cygnus} to
11127 @command{automake} will cause any generated @file{Makefile.in} to
11128 comply with Cygnus rules.
11130 Here are the precise effects of @option{--cygnus}:
11135 The @option{foreign} strictness is implied.
11138 The options @option{no-installinfo}, @option{no-dependencies} and
11139 @option{no-dist} are implied (@pxref{Options}).
11142 The macro @code{AM_MAINTAINER_MODE} is required.
11145 Info files are always created in the build directory, and not in the
11146 source directory. Packages that don't use the @option{cygnus} option
11147 can emulate this effect by using the @option{no-installinfo} option
11148 and listing the generated info files in the @code{CLEANFILES} variable.
11151 @file{texinfo.tex} is not required if a Texinfo source file is
11152 specified. The assumption is that the file will be supplied, but in a
11153 place that Automake cannot find -- it is an artifact of how Cygnus
11154 packages are typically bundled. This effect can be emulated in
11155 packages not using the @option{cygnus} option with a proper definition
11156 of the @code{TEXINFO_TEX} variable (@pxref{Texinfo}).
11159 Certain tools will be searched for in the build tree as well as in the
11160 user's @env{PATH}. These tools are @command{runtest}, @command{expect},
11161 @command{makeinfo} and @command{texi2dvi}.
11164 The @code{check} target doesn't depend on @code{all}.
11169 @chapter When Automake Isn't Enough
11171 In some situations, where Automake is not up to one task, one has to
11172 resort to handwritten rules or even handwritten @file{Makefile}s.
11175 * Extending:: Adding new rules or overriding existing ones.
11176 * Third-Party Makefiles:: Integrating Non-Automake @file{Makefile}s.
11180 @section Extending Automake Rules
11182 With some minor exceptions (for example @code{_PROGRAMS} variables,
11183 @code{TESTS}, or @code{XFAIL_TESTS}) being rewritten to append
11184 @samp{$(EXEEXT)}), the contents of a @file{Makefile.am} is copied to
11185 @file{Makefile.in} verbatim.
11187 @cindex copying semantics
11189 These copying semantics mean that many problems can be worked around
11190 by simply adding some @command{make} variables and rules to
11191 @file{Makefile.am}. Automake will ignore these additions.
11193 @cindex conflicting definitions
11194 @cindex rules, conflicting
11195 @cindex variables, conflicting
11196 @cindex definitions, conflicts
11198 Since a @file{Makefile.in} is built from data gathered from three
11199 different places (@file{Makefile.am}, @file{configure.ac}, and
11200 @command{automake} itself), it is possible to have conflicting
11201 definitions of rules or variables. When building @file{Makefile.in}
11202 the following priorities are respected by @command{automake} to ensure
11203 the user always has the last word:
11207 User defined variables in @file{Makefile.am} have priority over
11208 variables @code{AC_SUBST}ed from @file{configure.ac}, and
11209 @code{AC_SUBST}ed variables have priority over
11210 @command{automake}-defined variables.
11212 As far as rules are concerned, a user-defined rule overrides any
11213 @command{automake}-defined rule for the same target.
11216 @cindex overriding rules
11217 @cindex overriding semantics
11218 @cindex rules, overriding
11220 These overriding semantics make it possible to fine tune some default
11221 settings of Automake, or replace some of its rules. Overriding
11222 Automake rules is often inadvisable, particularly in the topmost
11223 directory of a package with subdirectories. The @option{-Woverride}
11224 option (@pxref{automake Invocation}) comes in handy to catch overridden
11227 Note that Automake does not make any distinction between rules with
11228 commands and rules that only specify dependencies. So it is not
11229 possible to append new dependencies to an @command{automake}-defined
11230 target without redefining the entire rule.
11232 @cindex @option{-local} targets
11233 @cindex local targets
11235 However, various useful targets have a @samp{-local} version you can
11236 specify in your @file{Makefile.am}. Automake will supplement the
11237 standard target with these user-supplied targets.
11242 @trindex info-local
11250 @trindex html-local
11252 @trindex check-local
11254 @trindex install-data
11255 @trindex install-data-local
11256 @trindex install-dvi
11257 @trindex install-dvi-local
11258 @trindex install-exec
11259 @trindex install-exec-local
11260 @trindex install-html
11261 @trindex install-html-local
11262 @trindex install-info
11263 @trindex install-info-local
11264 @trindex install-pdf
11265 @trindex install-pdf-local
11266 @trindex install-ps
11267 @trindex install-ps-local
11269 @trindex uninstall-local
11270 @trindex mostlyclean
11271 @trindex mostlyclean-local
11273 @trindex clean-local
11275 @trindex distclean-local
11276 @trindex installdirs
11277 @trindex installdirs-local
11278 @trindex installcheck
11279 @trindex installcheck-local
11281 The targets that support a local version are @code{all}, @code{info},
11282 @code{dvi}, @code{ps}, @code{pdf}, @code{html}, @code{check},
11283 @code{install-data}, @code{install-dvi}, @code{install-exec},
11284 @code{install-html}, @code{install-info}, @code{install-pdf},
11285 @code{install-ps}, @code{uninstall}, @code{installdirs},
11286 @code{installcheck} and the various @code{clean} targets
11287 (@code{mostlyclean}, @code{clean}, @code{distclean}, and
11288 @code{maintainer-clean}).
11290 Note that there are no @code{uninstall-exec-local} or
11291 @code{uninstall-data-local} targets; just use @code{uninstall-local}.
11292 It doesn't make sense to uninstall just data or just executables.
11294 For instance, here is one way to erase a subdirectory during
11295 @samp{make clean} (@pxref{Clean}).
11302 You may be tempted to use @code{install-data-local} to install a file
11303 to some hard-coded location, but you should avoid this
11304 (@pxref{Hard-Coded Install Paths}).
11306 With the @code{-local} targets, there is no particular guarantee of
11307 execution order; typically, they are run early, but with parallel
11308 make, there is no way to be sure of that.
11310 @cindex @option{-hook} targets
11311 @cindex hook targets
11312 @trindex install-data-hook
11313 @trindex install-exec-hook
11314 @trindex uninstall-hook
11317 In contrast, some rules also have a way to run another rule, called a
11318 @dfn{hook}; hooks are always executed after the main rule's work is done.
11319 The hook is named after the principal target, with @samp{-hook} appended.
11320 The targets allowing hooks are @code{install-data},
11321 @code{install-exec}, @code{uninstall}, @code{dist}, and
11324 For instance, here is how to create a hard link to an installed program:
11328 ln $(DESTDIR)$(bindir)/program$(EXEEXT) \
11329 $(DESTDIR)$(bindir)/proglink$(EXEEXT)
11332 Although cheaper and more portable than symbolic links, hard links
11333 will not work everywhere (for instance, OS/2 does not have
11334 @command{ln}). Ideally you should fall back to @samp{cp -p} when
11335 @command{ln} does not work. An easy way, if symbolic links are
11336 acceptable to you, is to add @code{AC_PROG_LN_S} to
11337 @file{configure.ac} (@pxref{Particular Programs, , Particular Program
11338 Checks, autoconf, The Autoconf Manual}) and use @samp{$(LN_S)} in
11339 @file{Makefile.am}.
11341 @cindex versioned binaries, installing
11342 @cindex installing versioned binaries
11343 @cindex @code{LN_S} example
11344 For instance, here is how you could install a versioned copy of a
11345 program using @samp{$(LN_S)}:
11347 @c Keep in sync with insthook.sh
11350 cd $(DESTDIR)$(bindir) && \
11351 mv -f prog$(EXEEXT) prog-$(VERSION)$(EXEEXT) && \
11352 $(LN_S) prog-$(VERSION)$(EXEEXT) prog$(EXEEXT)
11355 Note that we rename the program so that a new version will erase the
11356 symbolic link, not the real binary. Also we @command{cd} into the
11357 destination directory in order to create relative links.
11359 When writing @code{install-exec-hook} or @code{install-data-hook},
11360 please bear in mind that the exec/data distinction is based on the
11361 installation directory, not on the primary used (@pxref{The Two Parts of
11363 @c Keep in sync with primary-prefix-couples-documented-valid.sh
11364 So a @code{foo_SCRIPTS} will be installed by
11365 @code{install-data}, and a @code{barexec_SCRIPTS} will be installed by
11366 @code{install-exec}. You should define your hooks consequently.
11368 @c FIXME should include discussion of variables you can use in these
11371 @node Third-Party Makefiles
11372 @section Third-Party @file{Makefile}s
11374 @cindex Third-party packages, interfacing with
11375 @cindex Interfacing with third-party packages
11377 In most projects all @file{Makefile}s are generated by Automake. In
11378 some cases, however, projects need to embed subdirectories with
11379 handwritten @file{Makefile}s. For instance, one subdirectory could be
11380 a third-party project with its own build system, not using Automake.
11382 It is possible to list arbitrary directories in @code{SUBDIRS} or
11383 @code{DIST_SUBDIRS} provided each of these directories has a
11384 @file{Makefile} that recognizes all the following recursive targets.
11386 @cindex recursive targets and third-party @file{Makefile}s
11387 When a user runs one of these targets, that target is run recursively
11388 in all subdirectories. This is why it is important that even
11389 third-party @file{Makefile}s support them.
11393 Compile the entire package. This is the default target in
11394 Automake-generated @file{Makefile}s, but it does not need to be the
11395 default in third-party @file{Makefile}s.
11400 @vindex top_distdir
11401 Copy files to distribute into @samp{$(distdir)}, before a tarball is
11402 constructed. Of course this target is not required if the
11403 @option{no-dist} option (@pxref{Options}) is used.
11405 The variables @samp{$(top_distdir)} and @samp{$(distdir)}
11406 (@pxref{The dist Hook}) will be passed from the outer package to the subpackage
11407 when the @code{distdir} target is invoked. These two variables have
11408 been adjusted for the directory that is being recursed into, so they
11412 @itemx install-data
11413 @itemx install-exec
11415 Install or uninstall files (@pxref{Install}).
11418 @itemx install-html
11419 @itemx install-info
11422 Install only some specific documentation format (@pxref{Texinfo}).
11425 Create install directories, but do not install any files.
11428 @itemx installcheck
11429 Check the package (@pxref{Tests}).
11434 @itemx maintainer-clean
11435 Cleaning rules (@pxref{Clean}).
11442 Build the documentation in various formats (@pxref{Texinfo}).
11446 Build @file{TAGS} and @file{CTAGS} (@pxref{Tags}).
11449 If you have ever used Gettext in a project, this is a good example of
11450 how third-party @file{Makefile}s can be used with Automake. The
11451 @file{Makefile}s @command{gettextize} puts in the @file{po/} and
11452 @file{intl/} directories are handwritten @file{Makefile}s that
11453 implement all of these targets. That way they can be added to
11454 @code{SUBDIRS} in Automake packages.
11456 Directories that are only listed in @code{DIST_SUBDIRS} but not in
11457 @code{SUBDIRS} need only the @code{distclean},
11458 @code{maintainer-clean}, and @code{distdir} rules (@pxref{Conditional
11461 Usually, many of these rules are irrelevant to the third-party
11462 subproject, but they are required for the whole package to work. It's
11463 OK to have a rule that does nothing, so if you are integrating a
11464 third-party project with no documentation or tag support, you could
11465 simply augment its @file{Makefile} as follows:
11468 EMPTY_AUTOMAKE_TARGETS = dvi pdf ps info html tags ctags
11469 .PHONY: $(EMPTY_AUTOMAKE_TARGETS)
11470 $(EMPTY_AUTOMAKE_TARGETS):
11473 Another aspect of integrating third-party build systems is whether
11474 they support VPATH builds (@pxref{VPATH Builds}). Obviously if the
11475 subpackage does not support VPATH builds the whole package will not
11476 support VPATH builds. This in turns means that @samp{make distcheck}
11477 will not work, because it relies on VPATH builds. Some people can
11478 live without this (actually, many Automake users have never heard of
11479 @samp{make distcheck}). Other people may prefer to revamp the
11480 existing @file{Makefile}s to support VPATH@. Doing so does not
11481 necessarily require Automake, only Autoconf is needed (@pxref{Build
11482 Directories, , Build Directories, autoconf, The Autoconf Manual}).
11483 The necessary substitutions: @samp{@@srcdir@@}, @samp{@@top_srcdir@@},
11484 and @samp{@@top_builddir@@} are defined by @file{configure} when it
11485 processes a @file{Makefile} (@pxref{Preset Output Variables, , Preset
11486 Output Variables, autoconf, The Autoconf Manual}), they are not
11487 computed by the Makefile like the aforementioned @samp{$(distdir)} and
11488 @samp{$(top_distdir)} variables.
11490 It is sometimes inconvenient to modify a third-party @file{Makefile}
11491 to introduce the above required targets. For instance, one may want to
11492 keep the third-party sources untouched to ease upgrades to new
11495 @cindex @file{GNUmakefile} including @file{Makefile}
11496 Here are two other ideas. If GNU make is assumed, one possibility is
11497 to add to that subdirectory a @file{GNUmakefile} that defines the
11498 required targets and includes the third-party @file{Makefile}. For
11499 this to work in VPATH builds, @file{GNUmakefile} must lie in the build
11500 directory; the easiest way to do this is to write a
11501 @file{GNUmakefile.in} instead, and have it processed with
11502 @code{AC_CONFIG_FILES} from the outer package. For example if we
11503 assume @file{Makefile} defines all targets except the documentation
11504 targets, and that the @code{check} target is actually called
11505 @code{test}, we could write @file{GNUmakefile} (or
11506 @file{GNUmakefile.in}) like this:
11509 # First, include the real Makefile
11511 # Then, define the other targets needed by Automake Makefiles.
11512 .PHONY: dvi pdf ps info html check
11513 dvi pdf ps info html:
11517 @cindex Proxy @file{Makefile} for third-party packages
11518 A similar idea that does not use @code{include} is to write a proxy
11519 @file{Makefile} that dispatches rules to the real @file{Makefile},
11520 either with @samp{$(MAKE) -f Makefile.real $(AM_MAKEFLAGS) target} (if
11521 it's OK to rename the original @file{Makefile}) or with @samp{cd
11522 subdir && $(MAKE) $(AM_MAKEFLAGS) target} (if it's OK to store the
11523 subdirectory project one directory deeper). The good news is that
11524 this proxy @file{Makefile} can be generated with Automake. All we
11525 need are @option{-local} targets (@pxref{Extending}) that perform the
11526 dispatch. Of course the other Automake features are available, so you
11527 could decide to let Automake perform distribution or installation.
11528 Here is a possible @file{Makefile.am}:
11532 cd subdir && $(MAKE) $(AM_MAKEFLAGS) all
11534 cd subdir && $(MAKE) $(AM_MAKEFLAGS) test
11536 cd subdir && $(MAKE) $(AM_MAKEFLAGS) clean
11538 # Assuming the package knows how to install itself
11539 install-data-local:
11540 cd subdir && $(MAKE) $(AM_MAKEFLAGS) install-data
11541 install-exec-local:
11542 cd subdir && $(MAKE) $(AM_MAKEFLAGS) install-exec
11544 cd subdir && $(MAKE) $(AM_MAKEFLAGS) uninstall
11546 # Distribute files from here.
11547 EXTRA_DIST = subdir/Makefile subdir/program.c ...
11550 Pushing this idea to the extreme, it is also possible to ignore the
11551 subproject build system and build everything from this proxy
11552 @file{Makefile.am}. This might sound very sensible if you need VPATH
11553 builds but the subproject does not support them.
11556 @chapter Distributing @file{Makefile.in}s
11558 Automake places no restrictions on the distribution of the resulting
11559 @file{Makefile.in}s. We still encourage software authors to
11560 distribute their work under terms like those of the GPL, but doing so
11561 is not required to use Automake.
11563 Some of the files that can be automatically installed via the
11564 @option{--add-missing} switch do fall under the GPL@. However, these also
11565 have a special exception allowing you to distribute them with your
11566 package, regardless of the licensing you choose.
11569 @node API Versioning
11570 @chapter Automake API Versioning
11572 New Automake releases usually include bug fixes and new features.
11573 Unfortunately they may also introduce new bugs and incompatibilities.
11574 This makes four reasons why a package may require a particular Automake
11577 Things get worse when maintaining a large tree of packages, each one
11578 requiring a different version of Automake. In the past, this meant that
11579 any developer (and sometimes users) had to install several versions of
11580 Automake in different places, and switch @samp{$PATH} appropriately for
11583 Starting with version 1.6, Automake installs versioned binaries. This
11584 means you can install several versions of Automake in the same
11585 @samp{$prefix}, and can select an arbitrary Automake version by running
11586 @command{automake-1.6} or @command{automake-1.7} without juggling with
11587 @samp{$PATH}. Furthermore, @file{Makefile}'s generated by Automake 1.6
11588 will use @command{automake-1.6} explicitly in their rebuild rules.
11590 The number @samp{1.6} in @command{automake-1.6} is Automake's API version,
11591 not Automake's version. If a bug fix release is made, for instance
11592 Automake 1.6.1, the API version will remain 1.6. This means that a
11593 package that works with Automake 1.6 should also work with 1.6.1; after
11594 all, this is what people expect from bug fix releases.
11596 If your package relies on a feature or a bug fix introduced in
11597 a release, you can pass this version as an option to Automake to ensure
11598 older releases will not be used. For instance, use this in your
11599 @file{configure.ac}:
11602 AM_INIT_AUTOMAKE([1.6.1]) dnl Require Automake 1.6.1 or better.
11606 or, in a particular @file{Makefile.am}:
11609 AUTOMAKE_OPTIONS = 1.6.1 # Require Automake 1.6.1 or better.
11613 Automake will print an error message if its version is
11614 older than the requested version.
11617 @heading What is in the API
11619 Automake's programming interface is not easy to define. Basically it
11620 should include at least all @strong{documented} variables and targets
11621 that a @file{Makefile.am} author can use, any behavior associated with
11622 them (e.g., the places where @samp{-hook}'s are run), the command line
11623 interface of @command{automake} and @command{aclocal}, @dots{}
11625 @heading What is not in the API
11627 Every undocumented variable, target, or command line option, is not part
11628 of the API@. You should avoid using them, as they could change from one
11629 version to the other (even in bug fix releases, if this helps to fix a
11632 If it turns out you need to use such an undocumented feature, contact
11633 @email{automake@@gnu.org} and try to get it documented and exercised by
11637 @chapter Upgrading a Package to a Newer Automake Version
11639 Automake maintains three kind of files in a package.
11642 @item @file{aclocal.m4}
11643 @item @file{Makefile.in}s
11644 @item auxiliary tools like @file{install-sh} or @file{py-compile}
11647 @file{aclocal.m4} is generated by @command{aclocal} and contains some
11648 Automake-supplied M4 macros. Auxiliary tools are installed by
11649 @samp{automake --add-missing} when needed. @file{Makefile.in}s are
11650 built from @file{Makefile.am} by @command{automake}, and rely on the
11651 definitions of the M4 macros put in @file{aclocal.m4} as well as the
11652 behavior of the auxiliary tools installed.
11654 Because all of these files are closely related, it is important to
11655 regenerate all of them when upgrading to a newer Automake release.
11656 The usual way to do that is
11659 aclocal # with any option needed (such a -I m4)
11661 automake --add-missing --force-missing
11665 or more conveniently:
11671 The use of @option{--force-missing} ensures that auxiliary tools will be
11672 overridden by new versions (@pxref{automake Invocation}).
11674 It is important to regenerate all of these files each time Automake is
11675 upgraded, even between bug fixes releases. For instance, it is not
11676 unusual for a bug fix to involve changes to both the rules generated
11677 in @file{Makefile.in} and the supporting M4 macros copied to
11680 Presently @command{automake} is able to diagnose situations where
11681 @file{aclocal.m4} has been generated with another version of
11682 @command{aclocal}. However it never checks whether auxiliary scripts
11683 are up-to-date. In other words, @command{automake} will tell you when
11684 @command{aclocal} needs to be rerun, but it will never diagnose a
11685 missing @option{--force-missing}.
11687 Before upgrading to a new major release, it is a good idea to read the
11688 file @file{NEWS}. This file lists all changes between releases: new
11689 features, obsolete constructs, known incompatibilities, and
11693 @chapter Frequently Asked Questions about Automake
11695 This chapter covers some questions that often come up on the mailing
11699 * CVS:: CVS and generated files
11700 * maintainer-mode:: missing and AM_MAINTAINER_MODE
11701 * Wildcards:: Why doesn't Automake support wildcards?
11702 * Limitations on File Names:: Limitations on source and installed file names
11703 * Errors with distclean:: Files left in build directory after distclean
11704 * Flag Variables Ordering:: CFLAGS vs.@: AM_CFLAGS vs.@: mumble_CFLAGS
11705 * Renamed Objects:: Why are object files sometimes renamed?
11706 * Per-Object Flags:: How to simulate per-object flags?
11707 * Multiple Outputs:: Writing rules for tools with many output files
11708 * Hard-Coded Install Paths:: Installing to hard-coded locations
11709 * Debugging Make Rules:: Strategies when things don't work as expected
11710 * Reporting Bugs:: Feedback on bugs and feature requests
11714 @section CVS and generated files
11716 @subheading Background: distributed generated Files
11717 @cindex generated files, distributed
11718 @cindex rebuild rules
11720 Packages made with Autoconf and Automake ship with some generated
11721 files like @file{configure} or @file{Makefile.in}. These files were
11722 generated on the developer's host and are distributed so that
11723 end-users do not have to install the maintainer tools required to
11724 rebuild them. Other generated files like Lex scanners, Yacc parsers,
11725 or Info documentation, are usually distributed on similar grounds.
11727 Automake outputs rules in @file{Makefile}s to rebuild these files. For
11728 instance, @command{make} will run @command{autoconf} to rebuild
11729 @file{configure} whenever @file{configure.ac} is changed. This makes
11730 development safer by ensuring a @file{configure} is never out-of-date
11731 with respect to @file{configure.ac}.
11733 As generated files shipped in packages are up-to-date, and because
11734 @command{tar} preserves times-tamps, these rebuild rules are not
11735 triggered when a user unpacks and builds a package.
11737 @subheading Background: CVS and Timestamps
11738 @cindex timestamps and CVS
11739 @cindex CVS and timestamps
11741 Unless you use CVS keywords (in which case files must be updated at
11742 commit time), CVS preserves timestamp during @samp{cvs commit} and
11743 @samp{cvs import -d} operations.
11745 When you check out a file using @samp{cvs checkout} its timestamp is
11746 set to that of the revision that is being checked out.
11748 However, during @command{cvs update}, files will have the date of the
11749 update, not the original timestamp of this revision. This is meant to
11750 make sure that @command{make} notices sources files have been updated.
11752 This timestamp shift is troublesome when both sources and generated
11753 files are kept under CVS@. Because CVS processes files in lexical
11754 order, @file{configure.ac} will appear newer than @file{configure}
11755 after a @command{cvs update} that updates both files, even if
11756 @file{configure} was newer than @file{configure.ac} when it was
11757 checked in. Calling @command{make} will then trigger a spurious rebuild
11758 of @file{configure}.
11760 @subheading Living with CVS in Autoconfiscated Projects
11761 @cindex CVS and generated files
11762 @cindex generated files and CVS
11764 There are basically two clans amongst maintainers: those who keep all
11765 distributed files under CVS, including generated files, and those who
11766 keep generated files @emph{out} of CVS.
11768 @subsubheading All Files in CVS
11772 The CVS repository contains all distributed files so you know exactly
11773 what is distributed, and you can checkout any prior version entirely.
11776 Maintainers can see how generated files evolve (for instance, you can
11777 see what happens to your @file{Makefile.in}s when you upgrade Automake
11778 and make sure they look OK).
11781 Users do not need the autotools to build a checkout of the project, it
11782 works just like a released tarball.
11785 If users use @command{cvs update} to update their copy, instead of
11786 @command{cvs checkout} to fetch a fresh one, timestamps will be
11787 inaccurate. Some rebuild rules will be triggered and attempt to
11788 run developer tools such as @command{autoconf} or @command{automake}.
11790 Actually, calls to such tools are all wrapped into a call to the
11791 @command{missing} script discussed later (@pxref{maintainer-mode}).
11792 @command{missing} will take care of fixing the timestamps when these
11793 tools are not installed, so that the build can continue.
11796 In distributed development, developers are likely to have different
11797 version of the maintainer tools installed. In this case rebuilds
11798 triggered by timestamp lossage will lead to spurious changes
11799 to generated files. There are several solutions to this:
11803 All developers should use the same versions, so that the rebuilt files
11804 are identical to files in CVS@. (This starts to be difficult when each
11805 project you work on uses different versions.)
11807 Or people use a script to fix the timestamp after a checkout (the GCC
11808 folks have such a script).
11810 Or @file{configure.ac} uses @code{AM_MAINTAINER_MODE}, which will
11811 disable all of these rebuild rules by default. This is further discussed
11812 in @ref{maintainer-mode}.
11816 Although we focused on spurious rebuilds, the converse can also
11817 happen. CVS's timestamp handling can also let you think an
11818 out-of-date file is up-to-date.
11820 For instance, suppose a developer has modified @file{Makefile.am} and
11821 has rebuilt @file{Makefile.in}, and then decides to do a last-minute
11822 change to @file{Makefile.am} right before checking in both files
11823 (without rebuilding @file{Makefile.in} to account for the change).
11825 This last change to @file{Makefile.am} makes the copy of
11826 @file{Makefile.in} out-of-date. Since CVS processes files
11827 alphabetically, when another developer @samp{cvs update}s his or her
11828 tree, @file{Makefile.in} will happen to be newer than
11829 @file{Makefile.am}. This other developer will not see that
11830 @file{Makefile.in} is out-of-date.
11834 @subsubheading Generated Files out of CVS
11836 One way to get CVS and @command{make} working peacefully is to never
11837 store generated files in CVS, i.e., do not CVS-control files that
11838 are @file{Makefile} targets (also called @emph{derived} files).
11840 This way developers are not annoyed by changes to generated files. It
11841 does not matter if they all have different versions (assuming they are
11842 compatible, of course). And finally, timestamps are not lost, changes
11843 to sources files can't be missed as in the
11844 @file{Makefile.am}/@file{Makefile.in} example discussed earlier.
11846 The drawback is that the CVS repository is not an exact copy of what
11847 is distributed and that users now need to install various development
11848 tools (maybe even specific versions) before they can build a checkout.
11849 But, after all, CVS's job is versioning, not distribution.
11851 Allowing developers to use different versions of their tools can also
11852 hide bugs during distributed development. Indeed, developers will be
11853 using (hence testing) their own generated files, instead of the
11854 generated files that will be released actually. The developer who
11855 prepares the tarball might be using a version of the tool that
11856 produces bogus output (for instance a non-portable C file), something
11857 other developers could have noticed if they weren't using their own
11858 versions of this tool.
11860 @subheading Third-party Files
11861 @cindex CVS and third-party files
11862 @cindex third-party files and CVS
11864 Another class of files not discussed here (because they do not cause
11865 timestamp issues) are files that are shipped with a package, but
11866 maintained elsewhere. For instance, tools like @command{gettextize}
11867 and @command{autopoint} (from Gettext) or @command{libtoolize} (from
11868 Libtool), will install or update files in your package.
11870 These files, whether they are kept under CVS or not, raise similar
11871 concerns about version mismatch between developers' tools. The
11872 Gettext manual has a section about this, see @ref{CVS Issues, CVS
11873 Issues, Integrating with CVS, gettext, GNU gettext tools}.
11875 @node maintainer-mode
11876 @section @command{missing} and @code{AM_MAINTAINER_MODE}
11878 @subheading @command{missing}
11879 @cindex @command{missing}, purpose
11881 The @command{missing} script is a wrapper around several maintainer
11882 tools, designed to warn users if a maintainer tool is required but
11883 missing. Typical maintainer tools are @command{autoconf},
11884 @command{automake}, @command{bison}, etc. Because file generated by
11885 these tools are shipped with the other sources of a package, these
11886 tools shouldn't be required during a user build and they are not
11887 checked for in @file{configure}.
11889 However, if for some reason a rebuild rule is triggered and involves a
11890 missing tool, @command{missing} will notice it and warn the user.
11891 Besides the warning, when a tool is missing, @command{missing} will
11892 attempt to fix timestamps in a way that allows the build to continue.
11893 For instance, @command{missing} will touch @file{configure} if
11894 @command{autoconf} is not installed. When all distributed files are
11895 kept under version control, this feature of @command{missing} allows a
11896 user @emph{with no maintainer tools} to build a package off its version
11897 control repository, bypassing any timestamp inconsistency (implied by
11898 e.g.@: @samp{cvs update} or @samp{git clone}).
11900 If the required tool is installed, @command{missing} will run it and
11901 won't attempt to continue after failures. This is correct during
11902 development: developers love fixing failures. However, users with
11903 wrong versions of maintainer tools may get an error when the rebuild
11904 rule is spuriously triggered, halting the build. This failure to let
11905 the build continue is one of the arguments of the
11906 @code{AM_MAINTAINER_MODE} advocates.
11908 @subheading @code{AM_MAINTAINER_MODE}
11909 @cindex @code{AM_MAINTAINER_MODE}, purpose
11910 @acindex AM_MAINTAINER_MODE
11912 @code{AM_MAINTAINER_MODE} allows you to choose whether the so called
11913 "rebuild rules" should be enabled or disabled. With
11914 @code{AM_MAINTAINER_MODE([enable])}, they are enabled by default,
11915 otherwise they are disabled by default. In the latter case, if
11916 you have @code{AM_MAINTAINER_MODE} in @file{configure.ac}, and run
11917 @samp{./configure && make}, then @command{make} will *never* attempt to
11918 rebuild @file{configure}, @file{Makefile.in}s, Lex or Yacc outputs, etc.
11919 I.e., this disables build rules for files that are usually distributed
11920 and that users should normally not have to update.
11922 The user can override the default setting by passing either
11923 @samp{--enable-maintainer-mode} or @samp{--disable-maintainer-mode}
11924 to @command{configure}.
11926 People use @code{AM_MAINTAINER_MODE} either because they do not want their
11927 users (or themselves) annoyed by timestamps lossage (@pxref{CVS}), or
11928 because they simply can't stand the rebuild rules and prefer running
11929 maintainer tools explicitly.
11931 @code{AM_MAINTAINER_MODE} also allows you to disable some custom build
11932 rules conditionally. Some developers use this feature to disable
11933 rules that need exotic tools that users may not have available.
11935 Several years ago Fran@,{c}ois Pinard pointed out several arguments
11936 against this @code{AM_MAINTAINER_MODE} macro. Most of them relate to
11937 insecurity. By removing dependencies you get non-dependable builds:
11938 changes to sources files can have no effect on generated files and this
11939 can be very confusing when unnoticed. He adds that security shouldn't
11940 be reserved to maintainers (what @option{--enable-maintainer-mode}
11941 suggests), on the contrary. If one user has to modify a
11942 @file{Makefile.am}, then either @file{Makefile.in} should be updated
11943 or a warning should be output (this is what Automake uses
11944 @command{missing} for) but the last thing you want is that nothing
11945 happens and the user doesn't notice it (this is what happens when
11946 rebuild rules are disabled by @code{AM_MAINTAINER_MODE}).
11948 Jim Meyering, the inventor of the @code{AM_MAINTAINER_MODE} macro was
11949 swayed by Fran@,{c}ois's arguments, and got rid of
11950 @code{AM_MAINTAINER_MODE} in all of his packages.
11952 Still many people continue to use @code{AM_MAINTAINER_MODE}, because
11953 it helps them working on projects where all files are kept under version
11954 control, and because @command{missing} isn't enough if you have the
11955 wrong version of the tools.
11959 @section Why doesn't Automake support wildcards?
11962 Developers are lazy. They would often like to use wildcards in
11963 @file{Makefile.am}s, so that they would not need to remember to
11964 update @file{Makefile.am}s every time they add, delete, or rename
11967 There are several objections to this:
11970 When using CVS (or similar) developers need to remember they have to
11971 run @samp{cvs add} or @samp{cvs rm} anyway. Updating
11972 @file{Makefile.am} accordingly quickly becomes a reflex.
11974 Conversely, if your application doesn't compile
11975 because you forgot to add a file in @file{Makefile.am}, it will help
11976 you remember to @samp{cvs add} it.
11979 Using wildcards makes it easy to distribute files by mistake. For
11980 instance, some code a developer is experimenting with (a test case,
11981 say) that should not be part of the distribution.
11984 Using wildcards it's easy to omit some files by mistake. For
11985 instance, one developer creates a new file, uses it in many places,
11986 but forgets to commit it. Another developer then checks out the
11987 incomplete project and is able to run @samp{make dist} successfully,
11988 even though a file is missing. By listing files, @samp{make dist}
11989 @emph{will} complain.
11992 Wildcards are not portable to some non-GNU @command{make} implementations,
11993 e.g., NetBSD @command{make} will not expand globs such as @samp{*} in
11994 prerequisites of a target.
11997 Finally, it's really hard to @emph{forget} to add a file to
11998 @file{Makefile.am}: files that are not listed in @file{Makefile.am} are
11999 not compiled or installed, so you can't even test them.
12002 Still, these are philosophical objections, and as such you may disagree,
12003 or find enough value in wildcards to dismiss all of them. Before you
12004 start writing a patch against Automake to teach it about wildcards,
12005 let's see the main technical issue: portability.
12007 Although @samp{$(wildcard ...)} works with GNU @command{make}, it is
12008 not portable to other @command{make} implementations.
12010 The only way Automake could support @command{$(wildcard ...)} is by
12011 expanding @command{$(wildcard ...)} when @command{automake} is run.
12012 The resulting @file{Makefile.in}s would be portable since they would
12013 list all files and not use @samp{$(wildcard ...)}. However that
12014 means developers would need to remember to run @command{automake} each
12015 time they add, delete, or rename files.
12017 Compared to editing @file{Makefile.am}, this is a very small gain. Sure,
12018 it's easier and faster to type @samp{automake; make} than to type
12019 @samp{emacs Makefile.am; make}. But nobody bothered enough to write a
12020 patch to add support for this syntax. Some people use scripts to
12021 generate file lists in @file{Makefile.am} or in separate
12022 @file{Makefile} fragments.
12024 Even if you don't care about portability, and are tempted to use
12025 @samp{$(wildcard ...)} anyway because you target only GNU Make, you
12026 should know there are many places where Automake needs to know exactly
12027 which files should be processed. As Automake doesn't know how to
12028 expand @samp{$(wildcard ...)}, you cannot use it in these places.
12029 @samp{$(wildcard ...)} is a black box comparable to @code{AC_SUBST}ed
12030 variables as far Automake is concerned.
12032 You can get warnings about @samp{$(wildcard ...}) constructs using the
12033 @option{-Wportability} flag.
12035 @node Limitations on File Names
12036 @section Limitations on File Names
12037 @cindex file names, limitations on
12039 Automake attempts to support all kinds of file names, even those that
12040 contain unusual characters or are unusually long. However, some
12041 limitations are imposed by the underlying operating system and tools.
12043 Most operating systems prohibit the use of the null byte in file
12044 names, and reserve @samp{/} as a directory separator. Also, they
12045 require that file names are properly encoded for the user's locale.
12046 Automake is subject to these limits.
12048 Portable packages should limit themselves to POSIX file
12049 names. These can contain ASCII letters and digits,
12050 @samp{_}, @samp{.}, and @samp{-}. File names consist of components
12051 separated by @samp{/}. File name components cannot begin with
12054 Portable POSIX file names cannot contain components that exceed a
12055 14-byte limit, but nowadays it's normally safe to assume the
12056 more-generous XOPEN limit of 255 bytes. POSIX
12057 limits file names to 255 bytes (XOPEN allows 1023 bytes),
12058 but you may want to limit a source tarball to file names of 99 bytes
12059 to avoid interoperability problems with old versions of @command{tar}.
12061 If you depart from these rules (e.g., by using non-ASCII
12062 characters in file names, or by using lengthy file names), your
12063 installers may have problems for reasons unrelated to Automake.
12064 However, if this does not concern you, you should know about the
12065 limitations imposed by Automake itself. These limitations are
12066 undesirable, but some of them seem to be inherent to underlying tools
12067 like Autoconf, Make, M4, and the shell. They fall into three
12068 categories: install directories, build directories, and file names.
12070 The following characters:
12073 @r{newline} " # $ ' `
12076 should not appear in the names of install directories. For example,
12077 the operand of @command{configure}'s @option{--prefix} option should
12078 not contain these characters.
12080 Build directories suffer the same limitations as install directories,
12081 and in addition should not contain the following characters:
12087 For example, the full name of the directory containing the source
12088 files should not contain these characters.
12090 Source and installation file names like @file{main.c} are limited even
12091 further: they should conform to the POSIX/XOPEN
12092 rules described above. In addition, if you plan to port to
12093 non-POSIX environments, you should avoid file names that
12094 differ only in case (e.g., @file{makefile} and @file{Makefile}).
12095 Nowadays it is no longer worth worrying about the 8.3 limits of
12098 @c FIXME This should probably be moved in the "Checking the Distribution"
12099 @c FIXME section...
12100 @node Errors with distclean
12101 @section Errors with distclean
12102 @cindex @code{distclean}, diagnostic
12103 @cindex @samp{make distclean}, diagnostic
12104 @cindex dependencies and distributed files
12107 This is a diagnostic you might encounter while running @samp{make
12110 As explained in @ref{Checking the Distribution}, @samp{make distcheck}
12111 attempts to build and check your package for errors like this one.
12113 @samp{make distcheck} will perform a @code{VPATH} build of your
12114 package (@pxref{VPATH Builds}), and then call @samp{make distclean}.
12115 Files left in the build directory after @samp{make distclean} has run
12116 are listed after this error.
12118 This diagnostic really covers two kinds of errors:
12122 files that are forgotten by distclean;
12124 distributed files that are erroneously rebuilt.
12127 The former left-over files are not distributed, so the fix is to mark
12128 them for cleaning (@pxref{Clean}), this is obvious and doesn't deserve
12131 The latter bug is not always easy to understand and fix, so let's
12132 proceed with an example. Suppose our package contains a program for
12133 which we want to build a man page using @command{help2man}. GNU
12134 @command{help2man} produces simple manual pages from the @option{--help}
12135 and @option{--version} output of other commands (@pxref{Top, , Overview,
12136 help2man, The Help2man Manual}). Because we don't want to force our
12137 users to install @command{help2man}, we decide to distribute the
12138 generated man page using the following setup.
12141 # This Makefile.am is bogus.
12143 foo_SOURCES = foo.c
12144 dist_man_MANS = foo.1
12146 foo.1: foo$(EXEEXT)
12147 help2man --output=foo.1 ./foo$(EXEEXT)
12150 This will effectively distribute the man page. However,
12151 @samp{make distcheck} will fail with:
12154 ERROR: files left in build directory after distclean:
12158 Why was @file{foo.1} rebuilt? Because although distributed,
12159 @file{foo.1} depends on a non-distributed built file:
12160 @file{foo$(EXEEXT)}. @file{foo$(EXEEXT)} is built by the user, so it
12161 will always appear to be newer than the distributed @file{foo.1}.
12163 @samp{make distcheck} caught an inconsistency in our package. Our
12164 intent was to distribute @file{foo.1} so users do not need to install
12165 @command{help2man}, however since this rule causes this file to be
12166 always rebuilt, users @emph{do} need @command{help2man}. Either we
12167 should ensure that @file{foo.1} is not rebuilt by users, or there is
12168 no point in distributing @file{foo.1}.
12170 More generally, the rule is that distributed files should never depend
12171 on non-distributed built files. If you distribute something
12172 generated, distribute its sources.
12174 One way to fix the above example, while still distributing
12175 @file{foo.1} is to not depend on @file{foo$(EXEEXT)}. For instance,
12176 assuming @command{foo --version} and @command{foo --help} do not
12177 change unless @file{foo.c} or @file{configure.ac} change, we could
12178 write the following @file{Makefile.am}:
12182 foo_SOURCES = foo.c
12183 dist_man_MANS = foo.1
12185 foo.1: foo.c $(top_srcdir)/configure.ac
12186 $(MAKE) $(AM_MAKEFLAGS) foo$(EXEEXT)
12187 help2man --output=foo.1 ./foo$(EXEEXT)
12190 This way, @file{foo.1} will not get rebuilt every time
12191 @file{foo$(EXEEXT)} changes. The @command{make} call makes sure
12192 @file{foo$(EXEEXT)} is up-to-date before @command{help2man}. Another
12193 way to ensure this would be to use separate directories for binaries
12194 and man pages, and set @code{SUBDIRS} so that binaries are built
12197 We could also decide not to distribute @file{foo.1}. In
12198 this case it's fine to have @file{foo.1} dependent upon
12199 @file{foo$(EXEEXT)}, since both will have to be rebuilt.
12200 However it would be impossible to build the package in a
12201 cross-compilation, because building @file{foo.1} involves
12202 an @emph{execution} of @file{foo$(EXEEXT)}.
12204 Another context where such errors are common is when distributed files
12205 are built by tools that are built by the package. The pattern is
12209 distributed-file: built-tools distributed-sources
12214 should be changed to
12217 distributed-file: distributed-sources
12218 $(MAKE) $(AM_MAKEFLAGS) built-tools
12223 or you could choose not to distribute @file{distributed-file}, if
12224 cross-compilation does not matter.
12226 The points made through these examples are worth a summary:
12231 Distributed files should never depend upon non-distributed built
12234 Distributed files should be distributed with all their dependencies.
12236 If a file is @emph{intended} to be rebuilt by users, then there is no point
12237 in distributing it.
12241 @vrindex distcleancheck_listfiles
12242 For desperate cases, it's always possible to disable this check by
12243 setting @code{distcleancheck_listfiles} as documented in @ref{Checking
12245 Make sure you do understand the reason why @samp{make distcheck}
12246 complains before you do this. @code{distcleancheck_listfiles} is a
12247 way to @emph{hide} errors, not to fix them. You can always do better.
12249 @node Flag Variables Ordering
12250 @section Flag Variables Ordering
12251 @cindex Ordering flag variables
12252 @cindex Flag variables, ordering
12255 What is the difference between @code{AM_CFLAGS}, @code{CFLAGS}, and
12256 @code{mumble_CFLAGS}?
12260 Why does @command{automake} output @code{CPPFLAGS} after
12261 @code{AM_CPPFLAGS} on compile lines? Shouldn't it be the converse?
12265 My @file{configure} adds some warning flags into @code{CXXFLAGS}. In
12266 one @file{Makefile.am} I would like to append a new flag, however if I
12267 put the flag into @code{AM_CXXFLAGS} it is prepended to the other
12268 flags, not appended.
12271 @subheading Compile Flag Variables
12272 @cindex Flag Variables, Ordering
12273 @cindex Compile Flag Variables
12274 @cindex @code{AM_CCASFLAGS} and @code{CCASFLAGS}
12275 @cindex @code{AM_CFLAGS} and @code{CFLAGS}
12276 @cindex @code{AM_CPPFLAGS} and @code{CPPFLAGS}
12277 @cindex @code{AM_CXXFLAGS} and @code{CXXFLAGS}
12278 @cindex @code{AM_FCFLAGS} and @code{FCFLAGS}
12279 @cindex @code{AM_FFLAGS} and @code{FFLAGS}
12280 @cindex @code{AM_GCJFLAGS} and @code{GCJFLAGS}
12281 @cindex @code{AM_LDFLAGS} and @code{LDFLAGS}
12282 @cindex @code{AM_LFLAGS} and @code{LFLAGS}
12283 @cindex @code{AM_LIBTOOLFLAGS} and @code{LIBTOOLFLAGS}
12284 @cindex @code{AM_OBJCFLAGS} and @code{OBJCFLAGS}
12285 @cindex @code{AM_OBJCXXFLAGS} and @code{OBJXXCFLAGS}
12286 @cindex @code{AM_RFLAGS} and @code{RFLAGS}
12287 @cindex @code{AM_UPCFLAGS} and @code{UPCFLAGS}
12288 @cindex @code{AM_YFLAGS} and @code{YFLAGS}
12289 @cindex @code{CCASFLAGS} and @code{AM_CCASFLAGS}
12290 @cindex @code{CFLAGS} and @code{AM_CFLAGS}
12291 @cindex @code{CPPFLAGS} and @code{AM_CPPFLAGS}
12292 @cindex @code{CXXFLAGS} and @code{AM_CXXFLAGS}
12293 @cindex @code{FCFLAGS} and @code{AM_FCFLAGS}
12294 @cindex @code{FFLAGS} and @code{AM_FFLAGS}
12295 @cindex @code{GCJFLAGS} and @code{AM_GCJFLAGS}
12296 @cindex @code{LDFLAGS} and @code{AM_LDFLAGS}
12297 @cindex @code{LFLAGS} and @code{AM_LFLAGS}
12298 @cindex @code{LIBTOOLFLAGS} and @code{AM_LIBTOOLFLAGS}
12299 @cindex @code{OBJCFLAGS} and @code{AM_OBJCFLAGS}
12300 @cindex @code{OBJCXXFLAGS} and @code{AM_OBJCXXFLAGS}
12301 @cindex @code{RFLAGS} and @code{AM_RFLAGS}
12302 @cindex @code{UPCFLAGS} and @code{AM_UPCFLAGS}
12303 @cindex @code{YFLAGS} and @code{AM_YFLAGS}
12305 This section attempts to answer all the above questions. We will
12306 mostly discuss @code{CPPFLAGS} in our examples, but actually the
12307 answer holds for all the compile flags used in Automake:
12308 @code{CCASFLAGS}, @code{CFLAGS}, @code{CPPFLAGS}, @code{CXXFLAGS},
12309 @code{FCFLAGS}, @code{FFLAGS}, @code{GCJFLAGS}, @code{LDFLAGS},
12310 @code{LFLAGS}, @code{LIBTOOLFLAGS}, @code{OBJCFLAGS}, @code{OBJCXXFLAGS},
12311 @code{RFLAGS}, @code{UPCFLAGS}, and @code{YFLAGS}.
12313 @code{CPPFLAGS}, @code{AM_CPPFLAGS}, and @code{mumble_CPPFLAGS} are
12314 three variables that can be used to pass flags to the C preprocessor
12315 (actually these variables are also used for other languages like C++
12316 or preprocessed Fortran). @code{CPPFLAGS} is the user variable
12317 (@pxref{User Variables}), @code{AM_CPPFLAGS} is the Automake variable,
12318 and @code{mumble_CPPFLAGS} is the variable specific to the
12319 @code{mumble} target (we call this a per-target variable,
12320 @pxref{Program and Library Variables}).
12322 Automake always uses two of these variables when compiling C sources
12323 files. When compiling an object file for the @code{mumble} target,
12324 the first variable will be @code{mumble_CPPFLAGS} if it is defined, or
12325 @code{AM_CPPFLAGS} otherwise. The second variable is always
12328 In the following example,
12331 bin_PROGRAMS = foo bar
12332 foo_SOURCES = xyz.c
12333 bar_SOURCES = main.c
12334 foo_CPPFLAGS = -DFOO
12335 AM_CPPFLAGS = -DBAZ
12339 @file{xyz.o} will be compiled with @samp{$(foo_CPPFLAGS) $(CPPFLAGS)},
12340 (because @file{xyz.o} is part of the @code{foo} target), while
12341 @file{main.o} will be compiled with @samp{$(AM_CPPFLAGS) $(CPPFLAGS)}
12342 (because there is no per-target variable for target @code{bar}).
12344 The difference between @code{mumble_CPPFLAGS} and @code{AM_CPPFLAGS}
12345 being clear enough, let's focus on @code{CPPFLAGS}. @code{CPPFLAGS}
12346 is a user variable, i.e., a variable that users are entitled to modify
12347 in order to compile the package. This variable, like many others,
12348 is documented at the end of the output of @samp{configure --help}.
12350 For instance, someone who needs to add @file{/home/my/usr/include} to
12351 the C compiler's search path would configure a package with
12354 ./configure CPPFLAGS='-I /home/my/usr/include'
12358 and this flag would be propagated to the compile rules of all
12361 It is also not uncommon to override a user variable at
12362 @command{make}-time. Many installers do this with @code{prefix}, but
12363 this can be useful with compiler flags too. For instance, if, while
12364 debugging a C++ project, you need to disable optimization in one
12365 specific object file, you can run something like
12369 make CXXFLAGS=-O0 file.o
12373 The reason @samp{$(CPPFLAGS)} appears after @samp{$(AM_CPPFLAGS)} or
12374 @samp{$(mumble_CPPFLAGS)} in the compile command is that users
12375 should always have the last say. It probably makes more sense if you
12376 think about it while looking at the @samp{CXXFLAGS=-O0} above, which
12377 should supersede any other switch from @code{AM_CXXFLAGS} or
12378 @code{mumble_CXXFLAGS} (and this of course replaces the previous value
12379 of @code{CXXFLAGS}).
12381 You should never redefine a user variable such as @code{CPPFLAGS} in
12382 @file{Makefile.am}. Use @samp{automake -Woverride} to diagnose such
12383 mistakes. Even something like
12386 CPPFLAGS = -DDATADIR=\"$(datadir)\" @@CPPFLAGS@@
12390 is erroneous. Although this preserves @file{configure}'s value of
12391 @code{CPPFLAGS}, the definition of @code{DATADIR} will disappear if a
12392 user attempts to override @code{CPPFLAGS} from the @command{make}
12396 AM_CPPFLAGS = -DDATADIR=\"$(datadir)\"
12400 is all that is needed here if no per-target flags are used.
12402 You should not add options to these user variables within
12403 @file{configure} either, for the same reason. Occasionally you need
12404 to modify these variables to perform a test, but you should reset
12405 their values afterwards. In contrast, it is OK to modify the
12406 @samp{AM_} variables within @file{configure} if you @code{AC_SUBST}
12407 them, but it is rather rare that you need to do this, unless you
12408 really want to change the default definitions of the @samp{AM_}
12409 variables in all @file{Makefile}s.
12411 What we recommend is that you define extra flags in separate
12412 variables. For instance, you may write an Autoconf macro that computes
12413 a set of warning options for the C compiler, and @code{AC_SUBST} them
12414 in @code{WARNINGCFLAGS}; you may also have an Autoconf macro that
12415 determines which compiler and which linker flags should be used to
12416 link with library @file{libfoo}, and @code{AC_SUBST} these in
12417 @code{LIBFOOCFLAGS} and @code{LIBFOOLDFLAGS}. Then, a
12418 @file{Makefile.am} could use these variables as follows:
12421 AM_CFLAGS = $(WARNINGCFLAGS)
12422 bin_PROGRAMS = prog1 prog2
12423 prog1_SOURCES = @dots{}
12424 prog2_SOURCES = @dots{}
12425 prog2_CFLAGS = $(LIBFOOCFLAGS) $(AM_CFLAGS)
12426 prog2_LDFLAGS = $(LIBFOOLDFLAGS)
12429 In this example both programs will be compiled with the flags
12430 substituted into @samp{$(WARNINGCFLAGS)}, and @code{prog2} will
12431 additionally be compiled with the flags required to link with
12434 Note that listing @code{AM_CFLAGS} in a per-target @code{CFLAGS}
12435 variable is a common idiom to ensure that @code{AM_CFLAGS} applies to
12436 every target in a @file{Makefile.in}.
12438 Using variables like this gives you full control over the ordering of
12439 the flags. For instance, if there is a flag in $(WARNINGCFLAGS) that
12440 you want to negate for a particular target, you can use something like
12441 @samp{prog1_CFLAGS = $(AM_CFLAGS) -no-flag}. If all of these flags had
12442 been forcefully appended to @code{CFLAGS}, there would be no way to
12443 disable one flag. Yet another reason to leave user variables to
12446 Finally, we have avoided naming the variable of the example
12447 @code{LIBFOO_LDFLAGS} (with an underscore) because that would cause
12448 Automake to think that this is actually a per-target variable (like
12449 @code{mumble_LDFLAGS}) for some non-declared @code{LIBFOO} target.
12451 @subheading Other Variables
12453 There are other variables in Automake that follow similar principles
12454 to allow user options. For instance, Texinfo rules (@pxref{Texinfo})
12455 use @code{MAKEINFOFLAGS} and @code{AM_MAKEINFOFLAGS}. Similarly,
12456 DejaGnu tests (@pxref{DejaGnu Tests}) use @code{RUNTESTDEFAULTFLAGS} and
12457 @code{AM_RUNTESTDEFAULTFLAGS}. The tags and ctags rules
12458 (@pxref{Tags}) use @code{ETAGSFLAGS}, @code{AM_ETAGSFLAGS},
12459 @code{CTAGSFLAGS}, and @code{AM_CTAGSFLAGS}. Java rules
12460 (@pxref{Java}) use @code{JAVACFLAGS} and @code{AM_JAVACFLAGS}. None
12461 of these rules support per-target flags (yet).
12463 To some extent, even @code{AM_MAKEFLAGS} (@pxref{Subdirectories})
12464 obeys this naming scheme. The slight difference is that
12465 @code{MAKEFLAGS} is passed to sub-@command{make}s implicitly by
12466 @command{make} itself.
12468 However you should not think that all variables ending with
12469 @code{FLAGS} follow this convention. For instance,
12470 @code{DISTCHECK_CONFIGURE_FLAGS} (@pxref{Checking the Distribution}) and
12471 @code{ACLOCAL_AMFLAGS} (see @ref{Rebuilding} and @ref{Local Macros}),
12472 are two variables that are only useful to the maintainer and have no
12475 @code{ARFLAGS} (@pxref{A Library}) is usually defined by Automake and
12476 has neither @code{AM_} nor per-target cousin.
12478 Finally you should not think that the existence of a per-target
12479 variable implies the existence of an @code{AM_} variable or of a user
12480 variable. For instance, the @code{mumble_LDADD} per-target variable
12481 overrides the makefile-wide @code{LDADD} variable (which is not a user
12482 variable), and @code{mumble_LIBADD} exists only as a per-target
12483 variable. @xref{Program and Library Variables}.
12486 @node Renamed Objects
12487 @section Why are object files sometimes renamed?
12489 This happens when per-target compilation flags are used. Object
12490 files need to be renamed just in case they would clash with object
12491 files compiled from the same sources, but with different flags.
12492 Consider the following example.
12495 bin_PROGRAMS = true false
12496 true_SOURCES = generic.c
12497 true_CPPFLAGS = -DEXIT_CODE=0
12498 false_SOURCES = generic.c
12499 false_CPPFLAGS = -DEXIT_CODE=1
12503 Obviously the two programs are built from the same source, but it
12504 would be bad if they shared the same object, because @file{generic.o}
12505 cannot be built with both @samp{-DEXIT_CODE=0} @emph{and}
12506 @samp{-DEXIT_CODE=1}. Therefore @command{automake} outputs rules to
12507 build two different objects: @file{true-generic.o} and
12508 @file{false-generic.o}.
12510 @command{automake} doesn't actually look whether source files are
12511 shared to decide if it must rename objects. It will just rename all
12512 objects of a target as soon as it sees per-target compilation flags
12515 It's OK to share object files when per-target compilation flags are not
12516 used. For instance, @file{true} and @file{false} will both use
12517 @file{version.o} in the following example.
12520 AM_CPPFLAGS = -DVERSION=1.0
12521 bin_PROGRAMS = true false
12522 true_SOURCES = true.c version.c
12523 false_SOURCES = false.c version.c
12526 Note that the renaming of objects is also affected by the
12527 @code{_SHORTNAME} variable (@pxref{Program and Library Variables}).
12530 @node Per-Object Flags
12531 @section Per-Object Flags Emulation
12532 @cindex Per-object flags, emulated
12535 One of my source files needs to be compiled with different flags. How
12539 Automake supports per-program and per-library compilation flags (see
12540 @ref{Program and Library Variables} and @ref{Flag Variables
12541 Ordering}). With this you can define compilation flags that apply to
12542 all files compiled for a target. For instance, in
12546 foo_SOURCES = foo.c foo.h bar.c bar.h main.c
12547 foo_CFLAGS = -some -flags
12551 @file{foo-foo.o}, @file{foo-bar.o}, and @file{foo-main.o} will all be
12552 compiled with @samp{-some -flags}. (If you wonder about the names of
12553 these object files, see @ref{Renamed Objects}.) Note that
12554 @code{foo_CFLAGS} gives the flags to use when compiling all the C
12555 sources of the @emph{program} @code{foo}, it has nothing to do with
12556 @file{foo.c} or @file{foo-foo.o} specifically.
12558 What if @file{foo.c} needs to be compiled into @file{foo.o} using some
12559 specific flags, that none of the other files requires? Obviously
12560 per-program flags are not directly applicable here. Something like
12561 per-object flags are expected, i.e., flags that would be used only
12562 when creating @file{foo-foo.o}. Automake does not support that,
12563 however this is easy to simulate using a library that contains only
12564 that object, and compiling this library with per-library flags.
12568 foo_SOURCES = bar.c bar.h main.c
12569 foo_CFLAGS = -some -flags
12570 foo_LDADD = libfoo.a
12571 noinst_LIBRARIES = libfoo.a
12572 libfoo_a_SOURCES = foo.c foo.h
12573 libfoo_a_CFLAGS = -some -other -flags
12576 Here @file{foo-bar.o} and @file{foo-main.o} will all be
12577 compiled with @samp{-some -flags}, while @file{libfoo_a-foo.o} will
12578 be compiled using @samp{-some -other -flags}. Eventually, all
12579 three objects will be linked to form @file{foo}.
12581 This trick can also be achieved using Libtool convenience libraries,
12582 for instance @samp{noinst_LTLIBRARIES = libfoo.la} (@pxref{Libtool
12583 Convenience Libraries}).
12585 Another tempting idea to implement per-object flags is to override the
12586 compile rules @command{automake} would output for these files.
12587 Automake will not define a rule for a target you have defined, so you
12588 could think about defining the @samp{foo-foo.o: foo.c} rule yourself.
12589 We recommend against this, because this is error prone. For instance,
12590 if you add such a rule to the first example, it will break the day you
12591 decide to remove @code{foo_CFLAGS} (because @file{foo.c} will then be
12592 compiled as @file{foo.o} instead of @file{foo-foo.o}, @pxref{Renamed
12593 Objects}). Also in order to support dependency tracking, the two
12594 @file{.o}/@file{.obj} extensions, and all the other flags variables
12595 involved in a compilation, you will end up modifying a copy of the
12596 rule previously output by @command{automake} for this file. If a new
12597 release of Automake generates a different rule, your copy will need to
12598 be updated by hand.
12600 @node Multiple Outputs
12601 @section Handling Tools that Produce Many Outputs
12602 @cindex multiple outputs, rules with
12603 @cindex many outputs, rules with
12604 @cindex rules with multiple outputs
12606 This section describes a @command{make} idiom that can be used when a
12607 tool produces multiple output files. It is not specific to Automake
12608 and can be used in ordinary @file{Makefile}s.
12610 Suppose we have a program called @command{foo} that will read one file
12611 called @file{data.foo} and produce two files named @file{data.c} and
12612 @file{data.h}. We want to write a @file{Makefile} rule that captures
12613 this one-to-two dependency.
12615 The naive rule is incorrect:
12618 # This is incorrect.
12619 data.c data.h: data.foo
12624 What the above rule really says is that @file{data.c} and
12625 @file{data.h} each depend on @file{data.foo}, and can each be built by
12626 running @samp{foo data.foo}. In other words it is equivalent to:
12629 # We do not want this.
12637 which means that @command{foo} can be run twice. Usually it will not
12638 be run twice, because @command{make} implementations are smart enough
12639 to check for the existence of the second file after the first one has
12640 been built; they will therefore detect that it already exists.
12641 However there are a few situations where it can run twice anyway:
12645 The most worrying case is when running a parallel @command{make}. If
12646 @file{data.c} and @file{data.h} are built in parallel, two @samp{foo
12647 data.foo} commands will run concurrently. This is harmful.
12649 Another case is when the dependency (here @file{data.foo}) is
12650 (or depends upon) a phony target.
12653 A solution that works with parallel @command{make} but not with
12654 phony dependencies is the following:
12657 data.c data.h: data.foo
12663 The above rules are equivalent to
12668 data.h: data.foo data.c
12673 therefore a parallel @command{make} will have to serialize the builds
12674 of @file{data.c} and @file{data.h}, and will detect that the second is
12675 no longer needed once the first is over.
12677 Using this pattern is probably enough for most cases. However it does
12678 not scale easily to more output files (in this scheme all output files
12679 must be totally ordered by the dependency relation), so we will
12680 explore a more complicated solution.
12682 Another idea is to write the following:
12685 # There is still a problem with this one.
12692 The idea is that @samp{foo data.foo} is run only when @file{data.c}
12693 needs to be updated, but we further state that @file{data.h} depends
12694 upon @file{data.c}. That way, if @file{data.h} is required and
12695 @file{data.foo} is out of date, the dependency on @file{data.c} will
12698 This is almost perfect, but suppose we have built @file{data.h} and
12699 @file{data.c}, and then we erase @file{data.h}. Then, running
12700 @samp{make data.h} will not rebuild @file{data.h}. The above rules
12701 just state that @file{data.c} must be up-to-date with respect to
12702 @file{data.foo}, and this is already the case.
12704 What we need is a rule that forces a rebuild when @file{data.h} is
12705 missing. Here it is:
12711 ## Recover from the removal of $@@
12712 @@if test -f $@@; then :; else \
12714 $(MAKE) $(AM_MAKEFLAGS) data.c; \
12718 The above scheme can be extended to handle more outputs and more
12719 inputs. One of the outputs is selected to serve as a witness to the
12720 successful completion of the command, it depends upon all inputs, and
12721 all other outputs depend upon it. For instance, if @command{foo}
12722 should additionally read @file{data.bar} and also produce
12723 @file{data.w} and @file{data.x}, we would write:
12726 data.c: data.foo data.bar
12727 foo data.foo data.bar
12728 data.h data.w data.x: data.c
12729 ## Recover from the removal of $@@
12730 @@if test -f $@@; then :; else \
12732 $(MAKE) $(AM_MAKEFLAGS) data.c; \
12736 However there are now three minor problems in this setup. One is related
12737 to the timestamp ordering of @file{data.h}, @file{data.w},
12738 @file{data.x}, and @file{data.c}. Another one is a race condition
12739 if a parallel @command{make} attempts to run multiple instances of the
12740 recover block at once. Finally, the recursive rule breaks @samp{make -n}
12741 when run with GNU @command{make} (as well as some other @command{make}
12742 implementations), as it may remove @file{data.h} even when it should not
12743 (@pxref{MAKE Variable, , How the @code{MAKE} Variable Works, make,
12744 The GNU Make Manual}).
12746 Let us deal with the first problem. @command{foo} outputs four files,
12747 but we do not know in which order these files are created. Suppose
12748 that @file{data.h} is created before @file{data.c}. Then we have a
12749 weird situation. The next time @command{make} is run, @file{data.h}
12750 will appear older than @file{data.c}, the second rule will be
12751 triggered, a shell will be started to execute the @samp{if@dots{}fi}
12752 command, but actually it will just execute the @code{then} branch,
12753 that is: nothing. In other words, because the witness we selected is
12754 not the first file created by @command{foo}, @command{make} will start
12755 a shell to do nothing each time it is run.
12757 A simple riposte is to fix the timestamps when this happens.
12760 data.c: data.foo data.bar
12761 foo data.foo data.bar
12762 data.h data.w data.x: data.c
12763 @@if test -f $@@; then \
12766 ## Recover from the removal of $@@
12768 $(MAKE) $(AM_MAKEFLAGS) data.c; \
12772 Another solution is to use a different and dedicated file as witness,
12773 rather than using any of @command{foo}'s outputs.
12776 data.stamp: data.foo data.bar
12779 foo data.foo data.bar
12780 @@mv -f data.tmp $@@
12781 data.c data.h data.w data.x: data.stamp
12782 ## Recover from the removal of $@@
12783 @@if test -f $@@; then :; else \
12784 rm -f data.stamp; \
12785 $(MAKE) $(AM_MAKEFLAGS) data.stamp; \
12789 @file{data.tmp} is created before @command{foo} is run, so it has a
12790 timestamp older than output files output by @command{foo}. It is then
12791 renamed to @file{data.stamp} after @command{foo} has run, because we
12792 do not want to update @file{data.stamp} if @command{foo} fails.
12794 This solution still suffers from the second problem: the race
12795 condition in the recover rule. If, after a successful build, a user
12796 erases @file{data.c} and @file{data.h}, and runs @samp{make -j}, then
12797 @command{make} may start both recover rules in parallel. If the two
12798 instances of the rule execute @samp{$(MAKE) $(AM_MAKEFLAGS)
12799 data.stamp} concurrently the build is likely to fail (for instance, the
12800 two rules will create @file{data.tmp}, but only one can rename it).
12802 Admittedly, such a weird situation does not arise during ordinary
12803 builds. It occurs only when the build tree is mutilated. Here
12804 @file{data.c} and @file{data.h} have been explicitly removed without
12805 also removing @file{data.stamp} and the other output files.
12806 @code{make clean; make} will always recover from these situations even
12807 with parallel makes, so you may decide that the recover rule is solely
12808 to help non-parallel make users and leave things as-is. Fixing this
12809 requires some locking mechanism to ensure only one instance of the
12810 recover rule rebuilds @file{data.stamp}. One could imagine something
12811 along the following lines.
12814 data.c data.h data.w data.x: data.stamp
12815 ## Recover from the removal of $@@
12816 @@if test -f $@@; then :; else \
12817 trap 'rm -rf data.lock data.stamp' 1 2 13 15; \
12818 ## mkdir is a portable test-and-set
12819 if mkdir data.lock 2>/dev/null; then \
12820 ## This code is being executed by the first process.
12821 rm -f data.stamp; \
12822 $(MAKE) $(AM_MAKEFLAGS) data.stamp; \
12823 result=$$?; rm -rf data.lock; exit $$result; \
12825 ## This code is being executed by the follower processes.
12826 ## Wait until the first process is done.
12827 while test -d data.lock; do sleep 1; done; \
12828 ## Succeed if and only if the first process succeeded.
12829 test -f data.stamp; \
12834 Using a dedicated witness, like @file{data.stamp}, is very handy when
12835 the list of output files is not known beforehand. As an illustration,
12836 consider the following rules to compile many @file{*.el} files into
12837 @file{*.elc} files in a single command. It does not matter how
12838 @code{ELFILES} is defined (as long as it is not empty: empty targets
12839 are not accepted by POSIX).
12842 ELFILES = one.el two.el three.el @dots{}
12843 ELCFILES = $(ELFILES:=c)
12845 elc-stamp: $(ELFILES)
12848 $(elisp_comp) $(ELFILES)
12849 @@mv -f elc-temp $@@
12851 $(ELCFILES): elc-stamp
12852 @@if test -f $@@; then :; else \
12853 ## Recover from the removal of $@@
12854 trap 'rm -rf elc-lock elc-stamp' 1 2 13 15; \
12855 if mkdir elc-lock 2>/dev/null; then \
12856 ## This code is being executed by the first process.
12858 $(MAKE) $(AM_MAKEFLAGS) elc-stamp; \
12861 ## This code is being executed by the follower processes.
12862 ## Wait until the first process is done.
12863 while test -d elc-lock; do sleep 1; done; \
12864 ## Succeed if and only if the first process succeeded.
12865 test -f elc-stamp; exit $$?; \
12871 These solutions all still suffer from the third problem, namely that
12872 they break the promise that @samp{make -n} should not cause any actual
12873 changes to the tree. For those solutions that do not create lock files,
12874 it is possible to split the recover rules into two separate recipe
12875 commands, one of which does all work but the recursion, and the
12876 other invokes the recursive @samp{$(MAKE)}. The solutions involving
12877 locking could act upon the contents of the @samp{MAKEFLAGS} variable,
12878 but parsing that portably is not easy (@pxref{The Make Macro MAKEFLAGS,,,
12879 autoconf, The Autoconf Manual}). Here is an example:
12882 ELFILES = one.el two.el three.el @dots{}
12883 ELCFILES = $(ELFILES:=c)
12885 elc-stamp: $(ELFILES)
12888 $(elisp_comp) $(ELFILES)
12889 @@mv -f elc-temp $@@
12891 $(ELCFILES): elc-stamp
12892 ## Recover from the removal of $@@
12893 @@dry=; for f in x $$MAKEFLAGS; do \
12899 if test -f $@@; then :; else \
12900 $$dry trap 'rm -rf elc-lock elc-stamp' 1 2 13 15; \
12901 if $$dry mkdir elc-lock 2>/dev/null; then \
12902 ## This code is being executed by the first process.
12903 $$dry rm -f elc-stamp; \
12904 $(MAKE) $(AM_MAKEFLAGS) elc-stamp; \
12905 $$dry rmdir elc-lock; \
12907 ## This code is being executed by the follower processes.
12908 ## Wait until the first process is done.
12909 while test -d elc-lock && test -z "$$dry"; do \
12913 ## Succeed if and only if the first process succeeded.
12914 $$dry test -f elc-stamp; exit $$?; \
12919 For completeness it should be noted that GNU @command{make} is able to
12920 express rules with multiple output files using pattern rules
12921 (@pxref{Pattern Examples, , Pattern Rule Examples, make, The GNU Make
12922 Manual}). We do not discuss pattern rules here because they are not
12923 portable, but they can be convenient in packages that assume GNU
12927 @node Hard-Coded Install Paths
12928 @section Installing to Hard-Coded Locations
12931 My package needs to install some configuration file. I tried to use
12932 the following rule, but @samp{make distcheck} fails. Why?
12936 install-data-local:
12937 $(INSTALL_DATA) $(srcdir)/afile $(DESTDIR)/etc/afile
12942 My package needs to populate the installation directory of another
12943 package at install-time. I can easily compute that installation
12944 directory in @file{configure}, but if I install files therein,
12945 @samp{make distcheck} fails. How else should I do?
12948 These two setups share their symptoms: @samp{make distcheck} fails
12949 because they are installing files to hard-coded paths. In the later
12950 case the path is not really hard-coded in the package, but we can
12951 consider it to be hard-coded in the system (or in whichever tool that
12952 supplies the path). As long as the path does not use any of the
12953 standard directory variables (@samp{$(prefix)}, @samp{$(bindir)},
12954 @samp{$(datadir)}, etc.), the effect will be the same:
12955 user-installations are impossible.
12957 As a (non-root) user who wants to install a package, you usually have no
12958 right to install anything in @file{/usr} or @file{/usr/local}. So you
12959 do something like @samp{./configure --prefix ~/usr} to install a
12960 package in your own @file{~/usr} tree.
12962 If a package attempts to install something to some hard-coded path
12963 (e.g., @file{/etc/afile}), regardless of this @option{--prefix} setting,
12964 then the installation will fail. @samp{make distcheck} performs such
12965 a @option{--prefix} installation, hence it will fail too.
12967 Now, there are some easy solutions.
12969 The above @code{install-data-local} example for installing
12970 @file{/etc/afile} would be better replaced by
12973 sysconf_DATA = afile
12977 by default @code{sysconfdir} will be @samp{$(prefix)/etc}, because
12978 this is what the GNU Standards require. When such a package is
12979 installed on an FHS compliant system, the installer will have to set
12980 @samp{--sysconfdir=/etc}. As the maintainer of the package you
12981 should not be concerned by such site policies: use the appropriate
12982 standard directory variable to install your files so that the installer
12983 can easily redefine these variables to match their site conventions.
12985 Installing files that should be used by another package is slightly
12986 more involved. Let's take an example and assume you want to install
12987 a shared library that is a Python extension module. If you ask Python
12988 where to install the library, it will answer something like this:
12991 % @kbd{python -c 'from distutils import sysconfig;
12992 print sysconfig.get_python_lib(1,0)'}
12993 /usr/lib/python2.5/site-packages
12996 If you indeed use this absolute path to install your shared library,
12997 non-root users will not be able to install the package, hence
13000 Let's do better. The @samp{sysconfig.get_python_lib()} function
13001 actually accepts a third argument that will replace Python's
13002 installation prefix.
13005 % @kbd{python -c 'from distutils import sysconfig;
13006 print sysconfig.get_python_lib(1,0,"$@{exec_prefix@}")'}
13007 $@{exec_prefix@}/lib/python2.5/site-packages
13010 You can also use this new path. If you do
13013 root users can install your package with the same @option{--prefix}
13014 as Python (you get the behavior of the previous attempt)
13017 non-root users can install your package too, they will have the
13018 extension module in a place that is not searched by Python but they
13019 can work around this using environment variables (and if you installed
13020 scripts that use this shared library, it's easy to tell Python were to
13021 look in the beginning of your script, so the script works in both
13025 The @code{AM_PATH_PYTHON} macro uses similar commands to define
13026 @samp{$(pythondir)} and @samp{$(pyexecdir)} (@pxref{Python}).
13028 Of course not all tools are as advanced as Python regarding that
13029 substitution of @var{prefix}. So another strategy is to figure the
13030 part of the installation directory that must be preserved. For
13031 instance, here is how @code{AM_PATH_LISPDIR} (@pxref{Emacs Lisp})
13032 computes @samp{$(lispdir)}:
13035 $EMACS -batch -q -eval '(while load-path
13036 (princ (concat (car load-path) "\n"))
13037 (setq load-path (cdr load-path)))' >conftest.out
13040 -e '/.*\/lib\/x*emacs\/site-lisp$/@{
13041 s,.*/lib/\(x*emacs/site-lisp\)$,$@{libdir@}/\1,;p;q;
13043 -e '/.*\/share\/x*emacs\/site-lisp$/@{
13044 s,.*/share/\(x*emacs/site-lisp\),$@{datarootdir@}/\1,;p;q;
13049 I.e., it just picks the first directory that looks like
13050 @file{*/lib/*emacs/site-lisp} or @file{*/share/*emacs/site-lisp} in
13051 the search path of emacs, and then substitutes @samp{$@{libdir@}} or
13052 @samp{$@{datadir@}} appropriately.
13054 The emacs case looks complicated because it processes a list and
13055 expects two possible layouts, otherwise it's easy, and the benefits for
13056 non-root users are really worth the extra @command{sed} invocation.
13059 @node Debugging Make Rules
13060 @section Debugging Make Rules
13061 @cindex debugging rules
13062 @cindex rules, debugging
13064 The rules and dependency trees generated by @command{automake} can get
13065 rather complex, and leave the developer head-scratching when things
13066 don't work as expected. Besides the debug options provided by the
13067 @command{make} command (@pxref{Options Summary,,, make, The GNU Make
13068 Manual}), here's a couple of further hints for debugging makefiles
13069 generated by @command{automake} effectively:
13073 If less verbose output has been enabled in the package with the
13074 @samp{silent-rules} option (@pxref{Options}), you can use
13075 @code{make V=1} to see the commands being executed.
13077 @code{make -n} can help show what would be done without actually doing
13078 it. Note however, that this will @emph{still execute} commands prefixed
13079 with @samp{+}, and, when using GNU @command{make}, commands that contain
13080 the strings @samp{$(MAKE)} or @samp{$@{MAKE@}} (@pxref{Instead of
13081 Execution,,, make, The GNU Make Manual}).
13082 Typically, this is helpful to show what recursive rules would do, but it
13083 means that, in your own rules, you should not mix such recursion with
13084 actions that change any files.@footnote{Automake's @samp{dist} and
13085 @samp{distcheck} rules had a bug in this regard in that they created
13086 directories even with @option{-n}, but this has been fixed in Automake
13087 1.11.} Furthermore, note that GNU @command{make} will update
13088 prerequisites for the @file{Makefile} file itself even with @option{-n}
13089 (@pxref{Remaking Makefiles,,, make, The GNU Make Manual}).
13091 @code{make SHELL="/bin/bash -vx"} can help debug complex rules.
13092 @xref{The Make Macro SHELL,,, autoconf, The Autoconf Manual}, for some
13093 portability quirks associated with this construct.
13095 @code{echo 'print: ; @@echo "$(VAR)"' | make -f Makefile -f - print}
13096 can be handy to examine the expanded value of variables. You may need
13097 to use a target other than @samp{print} if that is already used or a
13098 file with that name exists.
13100 @url{http://bashdb.sourceforge.net/@/remake/} provides a modified
13101 GNU @command{make} command called @command{remake} that copes with
13102 complex GNU @command{make}-specific Makefiles and allows to trace
13103 execution, examine variables, and call rules interactively, much like
13108 @node Reporting Bugs
13109 @section Reporting Bugs
13111 Most nontrivial software has bugs. Automake is no exception. Although
13112 we cannot promise we can or will fix a bug, and we might not even agree
13113 that it is a bug, we want to hear about problems you encounter. Often we
13114 agree they are bugs and want to fix them.
13116 To make it possible for us to fix a bug, please report it. In order to
13117 do so effectively, it helps to know when and how to do it.
13119 Before reporting a bug, it is a good idea to see if it is already known.
13120 You can look at the @uref{http://debbugs.gnu.org/, GNU Bug Tracker}
13121 and the @uref{http://lists.gnu.org/@/archive/@/html/@/bug-automake/,
13122 bug-automake mailing list archives} for previous bug reports. We
13124 @uref{http://sourceware.org/@/cgi-bin/@/gnatsweb.pl?database=automake,
13125 Gnats database} for bug tracking, so some bugs might have been reported
13126 there already. Please do not use it for new bug reports, however.
13128 If the bug is not already known, it should be reported. It is very
13129 important to report bugs in a way that is useful and efficient. For
13130 this, please familiarize yourself with
13131 @uref{http://www.chiark.greenend.org.uk/@/~sgtatham/@/bugs.html, How to
13132 Report Bugs Effectively} and
13133 @uref{http://catb.org/@/~esr/@/faqs/@/smart-questions.html, How to Ask
13134 Questions the Smart Way}. This helps you and developers to save time
13135 which can then be spent on fixing more bugs and implementing more
13138 For a bug report, a feature request or other suggestions, please send
13139 email to @email{@value{PACKAGE_BUGREPORT}}. This will then open a new
13140 bug in the @uref{http://debbugs.gnu.org/@/automake, bug tracker}. Be
13141 sure to include the versions of Autoconf and Automake that you use.
13142 Ideally, post a minimal @file{Makefile.am} and @file{configure.ac} that
13143 reproduces the problem you encounter. If you have encountered test
13144 suite failures, please attach the @file{test-suite.log} file.
13146 @c ========================================================== Appendices
13149 @node Copying This Manual
13150 @appendix Copying This Manual
13153 * GNU Free Documentation License:: License for copying this manual
13156 @node GNU Free Documentation License
13157 @appendixsec GNU Free Documentation License
13165 * Macro Index:: Index of Autoconf macros
13166 * Variable Index:: Index of Makefile variables
13167 * General Index:: General index
13171 @appendixsec Macro Index
13175 @node Variable Index
13176 @appendixsec Variable Index
13180 @node General Index
13181 @appendixsec General Index
13188 @c LocalWords: texinfo setfilename settitle setchapternewpage texi direntry
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13191 @c LocalWords: dir Automake's ac Dist Gnits gnits cygnus dfn Autoconf's pxref
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13207 @c LocalWords: GWINSZ termios SRCDIR tarball bzip LISPDIR lispdir XEmacs CCAS
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13230 @c LocalWords: JAVAC javac JAVAROOT builddir CLASSPATH ENV pyc pyo pkgpython
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13232 @c LocalWords: installinfo vers MAKEINFO makeinfo MAKEINFOFLAGS noinstall rf
13233 @c LocalWords: mandir thesame alsothesame installman myexecbin DESTDIR Pinard
13234 @c LocalWords: uninstall installdirs uninstalls MOSTLYCLEANFILES mostlyclean
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13236 @c LocalWords: distdir distcheck distcleancheck listfiles distuninstallcheck
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13238 @c LocalWords: RUNTESTDEFAULTFLAGS toolchain RUNTESTFLAGS asis readme DVIPS
13239 @c LocalWords: installcheck gzipped tarZ std utils etags mkid cd
13240 @c LocalWords: ARGS taggable ETAGSFLAGS lang ctags CTAGSFLAGS GTAGS gtags idl
13241 @c LocalWords: foocc doit idlC multilibs ABIs cmindex defmac ARG enableval FC
13242 @c LocalWords: MSG xtrue DBG pathchk CYGWIN afile proglink versioned CVS's TE
13243 @c LocalWords: wildcards Autoconfiscated subsubheading autotools Meyering API
13244 @c LocalWords: ois's wildcard Wportability cartouche vrindex printindex Duret
13245 @c LocalWords: DSOMEFLAG DVERSION automake Lutz insertcopying versioning FAQ
13246 @c LocalWords: LTLIBOBJ Libtool's libtool's libltdl dlopening itutions libbar
13247 @c LocalWords: WANTEDLIBS libhello sublibraries libtop libsub dlopened Ratfor
13248 @c LocalWords: mymodule timestamps timestamp underquoted MAKEINFOHTMLFLAGS te
13249 @c LocalWords: GNUmakefile Subpackages subpackage's subpackages aux
13250 @c LocalWords: detailmenu Timeline pwd reldir AUTOM autom PREREQ FOOBAR libc
13251 @c LocalWords: libhand subpackage moduleN libmain libmisc FCFLAGS FCCOMPILE
13252 @c LocalWords: FCLINK subst sed ELCFILES elc MAKEINFOHTML dvips esyscmd ustar
13253 @c LocalWords: tarballs Woverride vfi ELFILES djm AutoMake honkin FSF
13254 @c LocalWords: fileutils precanned MacKenzie's reimplement termutils Tromey's
13255 @c LocalWords: cois gnitsians LIBPROGRAMS progs LIBLIBRARIES Textutils Ulrich
13256 @c LocalWords: Matzigkeit Drepper's Gord Matzigkeit's jm Dalley Debian org
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13261 @c LocalWords: syscalls perlhist acl pm multitable headitem fdl appendixsec
13262 @c LocalWords: LTALLOCA MALLOC malloc memcmp strdup alloca libcompat xyz DFOO
13263 @c LocalWords: unprefixed buildable preprocessed DBAZ DDATADIR WARNINGCFLAGS
13264 @c LocalWords: LIBFOOCFLAGS LIBFOOLDFLAGS ftable testSubDir obj LIBTOOLFLAGS
13265 @c LocalWords: barexec Pinard's automatize initialize lzip xz cscope