1 \input texinfo @c -*- Texinfo -*-
2 @setfilename binutils.info
3 @settitle @sc{gnu} Binary Utilities
12 @c man begin COPYRIGHT
13 Copyright @copyright{} 1991-2019 Free Software Foundation, Inc.
15 Permission is granted to copy, distribute and/or modify this document
16 under the terms of the GNU Free Documentation License, Version 1.3
17 or any later version published by the Free Software Foundation;
18 with no Invariant Sections, with no Front-Cover Texts, and with no
19 Back-Cover Texts. A copy of the license is included in the
20 section entitled ``GNU Free Documentation License''.
25 @dircategory Software development
27 * Binutils: (binutils). The GNU binary utilities.
30 @dircategory Individual utilities
32 * addr2line: (binutils)addr2line. Convert addresses to file and line.
33 * ar: (binutils)ar. Create, modify, and extract from archives.
34 * c++filt: (binutils)c++filt. Filter to demangle encoded C++ symbols.
35 * cxxfilt: (binutils)c++filt. MS-DOS name for c++filt.
36 * dlltool: (binutils)dlltool. Create files needed to build and use DLLs.
37 * nm: (binutils)nm. List symbols from object files.
38 * objcopy: (binutils)objcopy. Copy and translate object files.
39 * objdump: (binutils)objdump. Display information from object files.
40 * ranlib: (binutils)ranlib. Generate index to archive contents.
41 * readelf: (binutils)readelf. Display the contents of ELF format files.
42 * size: (binutils)size. List section sizes and total size.
43 * strings: (binutils)strings. List printable strings from files.
44 * strip: (binutils)strip. Discard symbols.
45 * elfedit: (binutils)elfedit. Update ELF header and property of ELF files.
46 * windmc: (binutils)windmc. Generator for Windows message resources.
47 * windres: (binutils)windres. Manipulate Windows resources.
51 @title The @sc{gnu} Binary Utilities
52 @ifset VERSION_PACKAGE
53 @subtitle @value{VERSION_PACKAGE}
55 @subtitle Version @value{VERSION}
57 @subtitle @value{UPDATED}
58 @author Roland H. Pesch
59 @author Jeffrey M. Osier
60 @author Cygnus Support
64 {\parskip=0pt \hfill Cygnus Support\par \hfill
65 Texinfo \texinfoversion\par }
68 @vskip 0pt plus 1filll
77 This brief manual contains documentation for the @sc{gnu} binary
79 @ifset VERSION_PACKAGE
80 @value{VERSION_PACKAGE}
82 version @value{VERSION}:
87 Create, modify, and extract from archives
90 List symbols from object files
93 Copy and translate object files
96 Display information from object files
99 Generate index to archive contents
102 Display the contents of ELF format files.
105 List file section sizes and total size
108 List printable strings from files
114 Update the ELF header and program property of ELF files.
117 Demangle encoded C++ symbols (on MS-DOS, this program is named
121 Convert addresses into file names and line numbers
124 Manipulate Windows resources
127 Generator for Windows message resources
130 Create the files needed to build and use Dynamic Link Libraries
134 This document is distributed under the terms of the GNU Free
135 Documentation License version 1.3. A copy of the license is included
136 in the section entitled ``GNU Free Documentation License''.
139 * ar:: Create, modify, and extract from archives
140 * nm:: List symbols from object files
141 * objcopy:: Copy and translate object files
142 * objdump:: Display information from object files
143 * ranlib:: Generate index to archive contents
144 * size:: List section sizes and total size
145 * strings:: List printable strings from files
146 * strip:: Discard symbols
147 * c++filt:: Filter to demangle encoded C++ symbols
148 * cxxfilt: c++filt. MS-DOS name for c++filt
149 * addr2line:: Convert addresses to file and line
150 * windmc:: Generator for Windows message resources
151 * windres:: Manipulate Windows resources
152 * dlltool:: Create files needed to build and use DLLs
153 * readelf:: Display the contents of ELF format files
154 * elfedit:: Update ELF header and property of ELF files
155 * Common Options:: Command-line options for all utilities
156 * Selecting the Target System:: How these utilities determine the target
157 * Reporting Bugs:: Reporting Bugs
158 * GNU Free Documentation License:: GNU Free Documentation License
159 * Binutils Index:: Binutils Index
167 @cindex collections of files
169 @c man title ar create, modify, and extract from archives
172 ar [-]@var{p}[@var{mod}] [@option{--plugin} @var{name}] [@option{--target} @var{bfdname}] [@var{relpos}] [@var{count}] @var{archive} [@var{member}@dots{}]
173 ar -M [ <mri-script ]
176 @c man begin DESCRIPTION ar
178 The @sc{gnu} @command{ar} program creates, modifies, and extracts from
179 archives. An @dfn{archive} is a single file holding a collection of
180 other files in a structure that makes it possible to retrieve
181 the original individual files (called @dfn{members} of the archive).
183 The original files' contents, mode (permissions), timestamp, owner, and
184 group are preserved in the archive, and can be restored on
188 @sc{gnu} @command{ar} can maintain archives whose members have names of any
189 length; however, depending on how @command{ar} is configured on your
190 system, a limit on member-name length may be imposed for compatibility
191 with archive formats maintained with other tools. If it exists, the
192 limit is often 15 characters (typical of formats related to a.out) or 16
193 characters (typical of formats related to coff).
196 @command{ar} is considered a binary utility because archives of this sort
197 are most often used as @dfn{libraries} holding commonly needed
201 @command{ar} creates an index to the symbols defined in relocatable
202 object modules in the archive when you specify the modifier @samp{s}.
203 Once created, this index is updated in the archive whenever @command{ar}
204 makes a change to its contents (save for the @samp{q} update operation).
205 An archive with such an index speeds up linking to the library, and
206 allows routines in the library to call each other without regard to
207 their placement in the archive.
209 You may use @samp{nm -s} or @samp{nm --print-armap} to list this index
210 table. If an archive lacks the table, another form of @command{ar} called
211 @command{ranlib} can be used to add just the table.
213 @cindex thin archives
214 @sc{gnu} @command{ar} can optionally create a @emph{thin} archive,
215 which contains a symbol index and references to the original copies
216 of the member files of the archive. This is useful for building
217 libraries for use within a local build tree, where the relocatable
218 objects are expected to remain available, and copying the contents of
219 each object would only waste time and space.
221 An archive can either be @emph{thin} or it can be normal. It cannot
222 be both at the same time. Once an archive is created its format
223 cannot be changed without first deleting it and then creating a new
224 archive in its place.
226 Thin archives are also @emph{flattened}, so that adding one thin
227 archive to another thin archive does not nest it, as would happen with
228 a normal archive. Instead the elements of the first archive are added
229 individually to the second archive.
231 The paths to the elements of the archive are stored relative to the
234 @cindex compatibility, @command{ar}
235 @cindex @command{ar} compatibility
236 @sc{gnu} @command{ar} is designed to be compatible with two different
237 facilities. You can control its activity using command-line options,
238 like the different varieties of @command{ar} on Unix systems; or, if you
239 specify the single command-line option @option{-M}, you can control it
240 with a script supplied via standard input, like the MRI ``librarian''
246 * ar cmdline:: Controlling @command{ar} on the command line
247 * ar scripts:: Controlling @command{ar} with a script
252 @section Controlling @command{ar} on the Command Line
255 @c man begin SYNOPSIS ar
256 ar [@option{-X32_64}] [@option{-}]@var{p}[@var{mod}] [@option{--plugin} @var{name}] [@option{--target} @var{bfdname}] [@var{relpos}] [@var{count}] @var{archive} [@var{member}@dots{}]
260 @cindex Unix compatibility, @command{ar}
261 When you use @command{ar} in the Unix style, @command{ar} insists on at least two
262 arguments to execute: one keyletter specifying the @emph{operation}
263 (optionally accompanied by other keyletters specifying
264 @emph{modifiers}), and the archive name to act on.
266 Most operations can also accept further @var{member} arguments,
267 specifying particular files to operate on.
269 @c man begin OPTIONS ar
271 @sc{gnu} @command{ar} allows you to mix the operation code @var{p} and modifier
272 flags @var{mod} in any order, within the first command-line argument.
274 If you wish, you may begin the first command-line argument with a
277 @cindex operations on archive
278 The @var{p} keyletter specifies what operation to execute; it may be
279 any of the following, but you must specify only one of them:
283 @cindex deleting from archive
284 @emph{Delete} modules from the archive. Specify the names of modules to
285 be deleted as @var{member}@dots{}; the archive is untouched if you
286 specify no files to delete.
288 If you specify the @samp{v} modifier, @command{ar} lists each module
292 @cindex moving in archive
293 Use this operation to @emph{move} members in an archive.
295 The ordering of members in an archive can make a difference in how
296 programs are linked using the library, if a symbol is defined in more
299 If no modifiers are used with @code{m}, any members you name in the
300 @var{member} arguments are moved to the @emph{end} of the archive;
301 you can use the @samp{a}, @samp{b}, or @samp{i} modifiers to move them to a
302 specified place instead.
305 @cindex printing from archive
306 @emph{Print} the specified members of the archive, to the standard
307 output file. If the @samp{v} modifier is specified, show the member
308 name before copying its contents to standard output.
310 If you specify no @var{member} arguments, all the files in the archive are
314 @cindex quick append to archive
315 @emph{Quick append}; Historically, add the files @var{member}@dots{} to the end of
316 @var{archive}, without checking for replacement.
318 The modifiers @samp{a}, @samp{b}, and @samp{i} do @emph{not} affect this
319 operation; new members are always placed at the end of the archive.
321 The modifier @samp{v} makes @command{ar} list each file as it is appended.
323 Since the point of this operation is speed, implementations of
324 @command{ar} have the option of not updating the archive's symbol
325 table if one exists. Too many different systems however assume that
326 symbol tables are always up-to-date, so @sc{gnu} @command{ar} will
327 rebuild the table even with a quick append.
329 Note - @sc{gnu} @command{ar} treats the command @samp{qs} as a
330 synonym for @samp{r} - replacing already existing files in the
331 archive and appending new ones at the end.
334 @cindex replacement in archive
335 Insert the files @var{member}@dots{} into @var{archive} (with
336 @emph{replacement}). This operation differs from @samp{q} in that any
337 previously existing members are deleted if their names match those being
340 If one of the files named in @var{member}@dots{} does not exist, @command{ar}
341 displays an error message, and leaves undisturbed any existing members
342 of the archive matching that name.
344 By default, new members are added at the end of the file; but you may
345 use one of the modifiers @samp{a}, @samp{b}, or @samp{i} to request
346 placement relative to some existing member.
348 The modifier @samp{v} used with this operation elicits a line of
349 output for each file inserted, along with one of the letters @samp{a} or
350 @samp{r} to indicate whether the file was appended (no old member
351 deleted) or replaced.
355 Add an index to the archive, or update it if it already exists. Note
356 this command is an exception to the rule that there can only be one
357 command letter, as it is possible to use it as either a command or a
358 modifier. In either case it does the same thing.
361 @cindex contents of archive
362 Display a @emph{table} listing the contents of @var{archive}, or those
363 of the files listed in @var{member}@dots{} that are present in the
364 archive. Normally only the member name is shown, but if the modifier
365 @samp{O} is specified, then the corresponding offset of the member is also
366 displayed. Finally, in order to see the modes (permissions), timestamp,
367 owner, group, and size the @samp{v} modifier should be included.
369 If you do not specify a @var{member}, all files in the archive
372 @cindex repeated names in archive
373 @cindex name duplication in archive
374 If there is more than one file with the same name (say, @samp{fie}) in
375 an archive (say @samp{b.a}), @samp{ar t b.a fie} lists only the
376 first instance; to see them all, you must ask for a complete
377 listing---in our example, @samp{ar t b.a}.
378 @c WRS only; per Gumby, this is implementation-dependent, and in a more
379 @c recent case in fact works the other way.
382 @cindex extract from archive
383 @emph{Extract} members (named @var{member}) from the archive. You can
384 use the @samp{v} modifier with this operation, to request that
385 @command{ar} list each name as it extracts it.
387 If you do not specify a @var{member}, all files in the archive
390 Files cannot be extracted from a thin archive.
393 A number of modifiers (@var{mod}) may immediately follow the @var{p}
394 keyletter, to specify variations on an operation's behavior:
398 @cindex relative placement in archive
399 Add new files @emph{after} an existing member of the
400 archive. If you use the modifier @samp{a}, the name of an existing archive
401 member must be present as the @var{relpos} argument, before the
402 @var{archive} specification.
405 Add new files @emph{before} an existing member of the
406 archive. If you use the modifier @samp{b}, the name of an existing archive
407 member must be present as the @var{relpos} argument, before the
408 @var{archive} specification. (same as @samp{i}).
411 @cindex creating archives
412 @emph{Create} the archive. The specified @var{archive} is always
413 created if it did not exist, when you request an update. But a warning is
414 issued unless you specify in advance that you expect to create it, by
418 @cindex deterministic archives
419 @kindex --enable-deterministic-archives
420 Operate in @emph{deterministic} mode. When adding files and the archive
421 index use zero for UIDs, GIDs, timestamps, and use consistent file modes
422 for all files. When this option is used, if @command{ar} is used with
423 identical options and identical input files, multiple runs will create
424 identical output files regardless of the input files' owners, groups,
425 file modes, or modification times.
427 If @file{binutils} was configured with
428 @option{--enable-deterministic-archives}, then this mode is on by default.
429 It can be disabled with the @samp{U} modifier, below.
432 Truncate names in the archive. @sc{gnu} @command{ar} will normally permit file
433 names of any length. This will cause it to create archives which are
434 not compatible with the native @command{ar} program on some systems. If
435 this is a concern, the @samp{f} modifier may be used to truncate file
436 names when putting them in the archive.
439 Insert new files @emph{before} an existing member of the
440 archive. If you use the modifier @samp{i}, the name of an existing archive
441 member must be present as the @var{relpos} argument, before the
442 @var{archive} specification. (same as @samp{b}).
445 This modifier is accepted but not used.
446 @c whaffor ar l modifier??? presumably compat; with
447 @c what???---doc@@cygnus.com, 25jan91
450 Uses the @var{count} parameter. This is used if there are multiple
451 entries in the archive with the same name. Extract or delete instance
452 @var{count} of the given name from the archive.
455 @cindex dates in archive
456 Preserve the @emph{original} dates of members when extracting them. If
457 you do not specify this modifier, files extracted from the archive
458 are stamped with the time of extraction.
461 @cindex offsets of files
462 Display member offsets inside the archive. Use together with the @samp{t}
466 Use the full path name when matching names in the archive. @sc{gnu}
467 @command{ar} can not create an archive with a full path name (such archives
468 are not POSIX complaint), but other archive creators can. This option
469 will cause @sc{gnu} @command{ar} to match file names using a complete path
470 name, which can be convenient when extracting a single file from an
471 archive created by another tool.
474 @cindex writing archive index
475 Write an object-file index into the archive, or update an existing one,
476 even if no other change is made to the archive. You may use this modifier
477 flag either with any operation, or alone. Running @samp{ar s} on an
478 archive is equivalent to running @samp{ranlib} on it.
481 @cindex not writing archive index
482 Do not generate an archive symbol table. This can speed up building a
483 large library in several steps. The resulting archive can not be used
484 with the linker. In order to build a symbol table, you must omit the
485 @samp{S} modifier on the last execution of @samp{ar}, or you must run
486 @samp{ranlib} on the archive.
489 @cindex creating thin archive
490 Make the specified @var{archive} a @emph{thin} archive. If it already
491 exists and is a regular archive, the existing members must be present
492 in the same directory as @var{archive}.
495 @cindex updating an archive
496 Normally, @samp{ar r}@dots{} inserts all files
497 listed into the archive. If you would like to insert @emph{only} those
498 of the files you list that are newer than existing members of the same
499 names, use this modifier. The @samp{u} modifier is allowed only for the
500 operation @samp{r} (replace). In particular, the combination @samp{qu} is
501 not allowed, since checking the timestamps would lose any speed
502 advantage from the operation @samp{q}.
505 @cindex deterministic archives
506 @kindex --enable-deterministic-archives
507 Do @emph{not} operate in @emph{deterministic} mode. This is the inverse
508 of the @samp{D} modifier, above: added files and the archive index will
509 get their actual UID, GID, timestamp, and file mode values.
511 This is the default unless @file{binutils} was configured with
512 @option{--enable-deterministic-archives}.
515 This modifier requests the @emph{verbose} version of an operation. Many
516 operations display additional information, such as filenames processed,
517 when the modifier @samp{v} is appended.
520 This modifier shows the version number of @command{ar}.
523 The @command{ar} program also supports some command-line options which
524 are neither modifiers nor actions, but which do change its behaviour
529 Displays the list of command-line options supported by @command{ar}
533 Displays the version information of @command{ar} and then exits.
536 @command{ar} ignores an initial option spelt @samp{-X32_64}, for
537 compatibility with AIX. The behaviour produced by this option is the
538 default for @sc{gnu} @command{ar}. @command{ar} does not support any
539 of the other @samp{-X} options; in particular, it does not support
540 @option{-X32} which is the default for AIX @command{ar}.
542 @item --plugin @var{name}
544 The optional command-line switch @option{--plugin @var{name}} causes
545 @command{ar} to load the plugin called @var{name} which adds support
546 for more file formats, including object files with link-time
547 optimization information.
549 This option is only available if the toolchain has been built with
550 plugin support enabled.
552 If @option{--plugin} is not provided, but plugin support has been
553 enabled then @command{ar} iterates over the files in
554 @file{$@{libdir@}/bfd-plugins} in alphabetic order and the first
555 plugin that claims the object in question is used.
557 Please note that this plugin search directory is @emph{not} the one
558 used by @command{ld}'s @option{-plugin} option. In order to make
559 @command{ar} use the linker plugin it must be copied into the
560 @file{$@{libdir@}/bfd-plugins} directory. For GCC based compilations
561 the linker plugin is called @file{liblto_plugin.so.0.0.0}. For Clang
562 based compilations it is called @file{LLVMgold.so}. The GCC plugin
563 is always backwards compatible with earlier versions, so it is
564 sufficient to just copy the newest one.
566 @item --target @var{target}
567 The optional command-line switch @option{--target @var{bfdname}}
568 specifies that the archive members are in an object code format
569 different from your system's default format. See
570 @xref{Target Selection}, for more information.
575 @c man begin SEEALSO ar
576 nm(1), ranlib(1), and the Info entries for @file{binutils}.
581 @section Controlling @command{ar} with a Script
584 ar -M [ <@var{script} ]
587 @cindex MRI compatibility, @command{ar}
588 @cindex scripts, @command{ar}
589 If you use the single command-line option @samp{-M} with @command{ar}, you
590 can control its operation with a rudimentary command language. This
591 form of @command{ar} operates interactively if standard input is coming
592 directly from a terminal. During interactive use, @command{ar} prompts for
593 input (the prompt is @samp{AR >}), and continues executing even after
594 errors. If you redirect standard input to a script file, no prompts are
595 issued, and @command{ar} abandons execution (with a nonzero exit code)
598 The @command{ar} command language is @emph{not} designed to be equivalent
599 to the command-line options; in fact, it provides somewhat less control
600 over archives. The only purpose of the command language is to ease the
601 transition to @sc{gnu} @command{ar} for developers who already have scripts
602 written for the MRI ``librarian'' program.
604 The syntax for the @command{ar} command language is straightforward:
607 commands are recognized in upper or lower case; for example, @code{LIST}
608 is the same as @code{list}. In the following descriptions, commands are
609 shown in upper case for clarity.
612 a single command may appear on each line; it is the first word on the
616 empty lines are allowed, and have no effect.
619 comments are allowed; text after either of the characters @samp{*}
620 or @samp{;} is ignored.
623 Whenever you use a list of names as part of the argument to an @command{ar}
624 command, you can separate the individual names with either commas or
625 blanks. Commas are shown in the explanations below, for clarity.
628 @samp{+} is used as a line continuation character; if @samp{+} appears
629 at the end of a line, the text on the following line is considered part
630 of the current command.
633 Here are the commands you can use in @command{ar} scripts, or when using
634 @command{ar} interactively. Three of them have special significance:
636 @code{OPEN} or @code{CREATE} specify a @dfn{current archive}, which is
637 a temporary file required for most of the other commands.
639 @code{SAVE} commits the changes so far specified by the script. Prior
640 to @code{SAVE}, commands affect only the temporary copy of the current
644 @item ADDLIB @var{archive}
645 @itemx ADDLIB @var{archive} (@var{module}, @var{module}, @dots{} @var{module})
646 Add all the contents of @var{archive} (or, if specified, each named
647 @var{module} from @var{archive}) to the current archive.
649 Requires prior use of @code{OPEN} or @code{CREATE}.
651 @item ADDMOD @var{member}, @var{member}, @dots{} @var{member}
652 @c FIXME! w/Replacement?? If so, like "ar r @var{archive} @var{names}"
653 @c else like "ar q..."
654 Add each named @var{member} as a module in the current archive.
656 Requires prior use of @code{OPEN} or @code{CREATE}.
659 Discard the contents of the current archive, canceling the effect of
660 any operations since the last @code{SAVE}. May be executed (with no
661 effect) even if no current archive is specified.
663 @item CREATE @var{archive}
664 Creates an archive, and makes it the current archive (required for many
665 other commands). The new archive is created with a temporary name; it
666 is not actually saved as @var{archive} until you use @code{SAVE}.
667 You can overwrite existing archives; similarly, the contents of any
668 existing file named @var{archive} will not be destroyed until @code{SAVE}.
670 @item DELETE @var{module}, @var{module}, @dots{} @var{module}
671 Delete each listed @var{module} from the current archive; equivalent to
672 @samp{ar -d @var{archive} @var{module} @dots{} @var{module}}.
674 Requires prior use of @code{OPEN} or @code{CREATE}.
676 @item DIRECTORY @var{archive} (@var{module}, @dots{} @var{module})
677 @itemx DIRECTORY @var{archive} (@var{module}, @dots{} @var{module}) @var{outputfile}
678 List each named @var{module} present in @var{archive}. The separate
679 command @code{VERBOSE} specifies the form of the output: when verbose
680 output is off, output is like that of @samp{ar -t @var{archive}
681 @var{module}@dots{}}. When verbose output is on, the listing is like
682 @samp{ar -tv @var{archive} @var{module}@dots{}}.
684 Output normally goes to the standard output stream; however, if you
685 specify @var{outputfile} as a final argument, @command{ar} directs the
689 Exit from @command{ar}, with a @code{0} exit code to indicate successful
690 completion. This command does not save the output file; if you have
691 changed the current archive since the last @code{SAVE} command, those
694 @item EXTRACT @var{module}, @var{module}, @dots{} @var{module}
695 Extract each named @var{module} from the current archive, writing them
696 into the current directory as separate files. Equivalent to @samp{ar -x
697 @var{archive} @var{module}@dots{}}.
699 Requires prior use of @code{OPEN} or @code{CREATE}.
702 @c FIXME Tokens but no commands???
709 Display full contents of the current archive, in ``verbose'' style
710 regardless of the state of @code{VERBOSE}. The effect is like @samp{ar
711 tv @var{archive}}. (This single command is a @sc{gnu} @command{ar}
712 enhancement, rather than present for MRI compatibility.)
714 Requires prior use of @code{OPEN} or @code{CREATE}.
716 @item OPEN @var{archive}
717 Opens an existing archive for use as the current archive (required for
718 many other commands). Any changes as the result of subsequent commands
719 will not actually affect @var{archive} until you next use @code{SAVE}.
721 @item REPLACE @var{module}, @var{module}, @dots{} @var{module}
722 In the current archive, replace each existing @var{module} (named in
723 the @code{REPLACE} arguments) from files in the current working directory.
724 To execute this command without errors, both the file, and the module in
725 the current archive, must exist.
727 Requires prior use of @code{OPEN} or @code{CREATE}.
730 Toggle an internal flag governing the output from @code{DIRECTORY}.
731 When the flag is on, @code{DIRECTORY} output matches output from
732 @samp{ar -tv }@dots{}.
735 Commit your changes to the current archive, and actually save it as a
736 file with the name specified in the last @code{CREATE} or @code{OPEN}
739 Requires prior use of @code{OPEN} or @code{CREATE}.
748 The @sc{gnu} linker @command{ld} is now described in a separate manual.
749 @xref{Top,, Overview,, Using LD: the @sc{gnu} linker}.
757 @c man title nm list symbols from object files
760 @c man begin SYNOPSIS nm
761 nm [@option{-A}|@option{-o}|@option{--print-file-name}] [@option{-a}|@option{--debug-syms}]
762 [@option{-B}|@option{--format=bsd}] [@option{-C}|@option{--demangle}[=@var{style}]]
763 [@option{-D}|@option{--dynamic}] [@option{-f}@var{format}|@option{--format=}@var{format}]
764 [@option{-g}|@option{--extern-only}] [@option{-h}|@option{--help}]
765 [@option{-l}|@option{--line-numbers}] [@option{--inlines}]
766 [@option{-n}|@option{-v}|@option{--numeric-sort}]
767 [@option{-P}|@option{--portability}] [@option{-p}|@option{--no-sort}]
768 [@option{-r}|@option{--reverse-sort}] [@option{-S}|@option{--print-size}]
769 [@option{-s}|@option{--print-armap}] [@option{-t} @var{radix}|@option{--radix=}@var{radix}]
770 [@option{-u}|@option{--undefined-only}] [@option{-V}|@option{--version}]
771 [@option{-X 32_64}] [@option{--defined-only}] [@option{--no-demangle}]
772 [@option{--plugin} @var{name}]
773 [@option{--no-recurse-limit}|@option{--recurse-limit}]]
774 [@option{--size-sort}] [@option{--special-syms}]
775 [@option{--synthetic}] [@option{--with-symbol-versions}] [@option{--target=}@var{bfdname}]
776 [@var{objfile}@dots{}]
780 @c man begin DESCRIPTION nm
781 @sc{gnu} @command{nm} lists the symbols from object files @var{objfile}@dots{}.
782 If no object files are listed as arguments, @command{nm} assumes the file
785 For each symbol, @command{nm} shows:
789 The symbol value, in the radix selected by options (see below), or
790 hexadecimal by default.
793 The symbol type. At least the following types are used; others are, as
794 well, depending on the object file format. If lowercase, the symbol is
795 usually local; if uppercase, the symbol is global (external). There
796 are however a few lowercase symbols that are shown for special global
797 symbols (@code{u}, @code{v} and @code{w}).
799 @c Some more detail on exactly what these symbol types are used for
803 The symbol's value is absolute, and will not be changed by further
808 The symbol is in the BSS data section. This section typically
809 contains zero-initialized or uninitialized data, although the exact
810 behavior is system dependent.
813 The symbol is common. Common symbols are uninitialized data. When
814 linking, multiple common symbols may appear with the same name. If the
815 symbol is defined anywhere, the common symbols are treated as undefined
818 For more details on common symbols, see the discussion of
819 --warn-common in @ref{Options,,Linker options,ld.info,The GNU linker}.
824 The symbol is in the initialized data section.
828 The symbol is in an initialized data section for small objects. Some
829 object file formats permit more efficient access to small data objects,
830 such as a global int variable as opposed to a large global array.
833 For PE format files this indicates that the symbol is in a section
834 specific to the implementation of DLLs. For ELF format files this
835 indicates that the symbol is an indirect function. This is a GNU
836 extension to the standard set of ELF symbol types. It indicates a
837 symbol which if referenced by a relocation does not evaluate to its
838 address, but instead must be invoked at runtime. The runtime
839 execution will then return the value to be used in the relocation.
842 The symbol is an indirect reference to another symbol.
845 The symbol is a debugging symbol.
848 The symbols is in a stack unwind section.
852 The symbol is in a read only data section.
856 The symbol is in an uninitialized or zero-initialized data section
861 The symbol is in the text (code) section.
864 The symbol is undefined.
867 The symbol is a unique global symbol. This is a GNU extension to the
868 standard set of ELF symbol bindings. For such a symbol the dynamic linker
869 will make sure that in the entire process there is just one symbol with
870 this name and type in use.
874 The symbol is a weak object. When a weak defined symbol is linked with
875 a normal defined symbol, the normal defined symbol is used with no error.
876 When a weak undefined symbol is linked and the symbol is not defined,
877 the value of the weak symbol becomes zero with no error. On some
878 systems, uppercase indicates that a default value has been specified.
882 The symbol is a weak symbol that has not been specifically tagged as a
883 weak object symbol. When a weak defined symbol is linked with a normal
884 defined symbol, the normal defined symbol is used with no error.
885 When a weak undefined symbol is linked and the symbol is not defined,
886 the value of the symbol is determined in a system-specific manner without
887 error. On some systems, uppercase indicates that a default value has been
891 The symbol is a stabs symbol in an a.out object file. In this case, the
892 next values printed are the stabs other field, the stabs desc field, and
893 the stab type. Stabs symbols are used to hold debugging information.
896 The symbol type is unknown, or object file format specific.
905 @c man begin OPTIONS nm
906 The long and short forms of options, shown here as alternatives, are
912 @itemx --print-file-name
913 @cindex input file name
915 @cindex source file name
916 Precede each symbol by the name of the input file (or archive member)
917 in which it was found, rather than identifying the input file once only,
918 before all of its symbols.
922 @cindex debugging symbols
923 Display all symbols, even debugger-only symbols; normally these are not
927 @cindex @command{nm} format
928 @cindex @command{nm} compatibility
929 The same as @option{--format=bsd} (for compatibility with the MIPS @command{nm}).
932 @itemx --demangle[=@var{style}]
933 @cindex demangling in nm
934 Decode (@dfn{demangle}) low-level symbol names into user-level names.
935 Besides removing any initial underscore prepended by the system, this
936 makes C++ function names readable. Different compilers have different
937 mangling styles. The optional demangling style argument can be used to
938 choose an appropriate demangling style for your compiler. @xref{c++filt},
939 for more information on demangling.
942 Do not demangle low-level symbol names. This is the default.
944 @item --recurse-limit
945 @itemx --no-recurse-limit
946 @itemx --recursion-limit
947 @itemx --no-recursion-limit
948 Enables or disables a limit on the amount of recursion performed
949 whilst demangling strings. Since the name mangling formats allow for
950 an inifinite level of recursion it is possible to create strings whose
951 decoding will exhaust the amount of stack space available on the host
952 machine, triggering a memory fault. The limit tries to prevent this
953 from happening by restricting recursion to 2048 levels of nesting.
955 The default is for this limit to be enabled, but disabling it may be
956 necessary in order to demangle truly complicated names. Note however
957 that if the recursion limit is disabled then stack exhaustion is
958 possible and any bug reports about such an event will be rejected.
962 @cindex dynamic symbols
963 Display the dynamic symbols rather than the normal symbols. This is
964 only meaningful for dynamic objects, such as certain types of shared
967 @item -f @var{format}
968 @itemx --format=@var{format}
969 @cindex @command{nm} format
970 @cindex @command{nm} compatibility
971 Use the output format @var{format}, which can be @code{bsd},
972 @code{sysv}, or @code{posix}. The default is @code{bsd}.
973 Only the first character of @var{format} is significant; it can be
974 either upper or lower case.
978 @cindex external symbols
979 Display only external symbols.
983 Show a summary of the options to @command{nm} and exit.
986 @itemx --line-numbers
987 @cindex symbol line numbers
988 For each symbol, use debugging information to try to find a filename and
989 line number. For a defined symbol, look for the line number of the
990 address of the symbol. For an undefined symbol, look for the line
991 number of a relocation entry which refers to the symbol. If line number
992 information can be found, print it after the other symbol information.
995 @cindex objdump inlines
996 When option @option{-l} is active, if the address belongs to a
997 function that was inlined, then this option causes the source
998 information for all enclosing scopes back to the first non-inlined
999 function to be printed as well. For example, if @code{main} inlines
1000 @code{callee1} which inlines @code{callee2}, and address is from
1001 @code{callee2}, the source information for @code{callee1} and @code{main}
1002 will also be printed.
1006 @itemx --numeric-sort
1007 Sort symbols numerically by their addresses, rather than alphabetically
1012 @cindex sorting symbols
1013 Do not bother to sort the symbols in any order; print them in the order
1017 @itemx --portability
1018 Use the POSIX.2 standard output format instead of the default format.
1019 Equivalent to @samp{-f posix}.
1022 @itemx --reverse-sort
1023 Reverse the order of the sort (whether numeric or alphabetic); let the
1028 Print both value and size of defined symbols for the @code{bsd} output style.
1029 This option has no effect for object formats that do not record symbol
1030 sizes, unless @samp{--size-sort} is also used in which case a
1031 calculated size is displayed.
1034 @itemx --print-armap
1035 @cindex symbol index, listing
1036 When listing symbols from archive members, include the index: a mapping
1037 (stored in the archive by @command{ar} or @command{ranlib}) of which modules
1038 contain definitions for which names.
1040 @item -t @var{radix}
1041 @itemx --radix=@var{radix}
1042 Use @var{radix} as the radix for printing the symbol values. It must be
1043 @samp{d} for decimal, @samp{o} for octal, or @samp{x} for hexadecimal.
1046 @itemx --undefined-only
1047 @cindex external symbols
1048 @cindex undefined symbols
1049 Display only undefined symbols (those external to each object file).
1053 Show the version number of @command{nm} and exit.
1056 This option is ignored for compatibility with the AIX version of
1057 @command{nm}. It takes one parameter which must be the string
1058 @option{32_64}. The default mode of AIX @command{nm} corresponds
1059 to @option{-X 32}, which is not supported by @sc{gnu} @command{nm}.
1061 @item --defined-only
1062 @cindex external symbols
1063 @cindex undefined symbols
1064 Display only defined symbols for each object file.
1066 @item --plugin @var{name}
1068 Load the plugin called @var{name} to add support for extra target
1069 types. This option is only available if the toolchain has been built
1070 with plugin support enabled.
1072 If @option{--plugin} is not provided, but plugin support has been
1073 enabled then @command{nm} iterates over the files in
1074 @file{$@{libdir@}/bfd-plugins} in alphabetic order and the first
1075 plugin that claims the object in question is used.
1077 Please note that this plugin search directory is @emph{not} the one
1078 used by @command{ld}'s @option{-plugin} option. In order to make
1079 @command{nm} use the linker plugin it must be copied into the
1080 @file{$@{libdir@}/bfd-plugins} directory. For GCC based compilations
1081 the linker plugin is called @file{liblto_plugin.so.0.0.0}. For Clang
1082 based compilations it is called @file{LLVMgold.so}. The GCC plugin
1083 is always backwards compatible with earlier versions, so it is
1084 sufficient to just copy the newest one.
1087 Sort symbols by size. For ELF objects symbol sizes are read from the
1088 ELF, for other object types the symbol sizes are computed as the
1089 difference between the value of the symbol and the value of the symbol
1090 with the next higher value. If the @code{bsd} output format is used
1091 the size of the symbol is printed, rather than the value, and
1092 @samp{-S} must be used in order both size and value to be printed.
1094 @item --special-syms
1095 Display symbols which have a target-specific special meaning. These
1096 symbols are usually used by the target for some special processing and
1097 are not normally helpful when included in the normal symbol lists.
1098 For example for ARM targets this option would skip the mapping symbols
1099 used to mark transitions between ARM code, THUMB code and data.
1102 Include synthetic symbols in the output. These are special symbols
1103 created by the linker for various purposes. They are not shown by
1104 default since they are not part of the binary's original source code.
1106 @item --with-symbol-versions
1107 Enables the display of symbol version information if any exists. The
1108 version string is displayed as a suffix to the symbol name, preceeded by
1109 an @@ character. For example @samp{foo@@VER_1}. If the version is
1110 the default version to be used when resolving unversioned references
1111 to the symbol then it is displayed as a suffix preceeded by two @@
1112 characters. For example @samp{foo@@@@VER_2}.
1114 @item --target=@var{bfdname}
1115 @cindex object code format
1116 Specify an object code format other than your system's default format.
1117 @xref{Target Selection}, for more information.
1124 @c man begin SEEALSO nm
1125 ar(1), objdump(1), ranlib(1), and the Info entries for @file{binutils}.
1132 @c man title objcopy copy and translate object files
1135 @c man begin SYNOPSIS objcopy
1136 objcopy [@option{-F} @var{bfdname}|@option{--target=}@var{bfdname}]
1137 [@option{-I} @var{bfdname}|@option{--input-target=}@var{bfdname}]
1138 [@option{-O} @var{bfdname}|@option{--output-target=}@var{bfdname}]
1139 [@option{-B} @var{bfdarch}|@option{--binary-architecture=}@var{bfdarch}]
1140 [@option{-S}|@option{--strip-all}]
1141 [@option{-g}|@option{--strip-debug}]
1142 [@option{--strip-unneeded}]
1143 [@option{-K} @var{symbolname}|@option{--keep-symbol=}@var{symbolname}]
1144 [@option{-N} @var{symbolname}|@option{--strip-symbol=}@var{symbolname}]
1145 [@option{--strip-unneeded-symbol=}@var{symbolname}]
1146 [@option{-G} @var{symbolname}|@option{--keep-global-symbol=}@var{symbolname}]
1147 [@option{--localize-hidden}]
1148 [@option{-L} @var{symbolname}|@option{--localize-symbol=}@var{symbolname}]
1149 [@option{--globalize-symbol=}@var{symbolname}]
1150 [@option{--globalize-symbols=}@var{filename}]
1151 [@option{-W} @var{symbolname}|@option{--weaken-symbol=}@var{symbolname}]
1152 [@option{-w}|@option{--wildcard}]
1153 [@option{-x}|@option{--discard-all}]
1154 [@option{-X}|@option{--discard-locals}]
1155 [@option{-b} @var{byte}|@option{--byte=}@var{byte}]
1156 [@option{-i} [@var{breadth}]|@option{--interleave}[=@var{breadth}]]
1157 [@option{--interleave-width=}@var{width}]
1158 [@option{-j} @var{sectionpattern}|@option{--only-section=}@var{sectionpattern}]
1159 [@option{-R} @var{sectionpattern}|@option{--remove-section=}@var{sectionpattern}]
1160 [@option{--remove-relocations=}@var{sectionpattern}]
1161 [@option{-p}|@option{--preserve-dates}]
1162 [@option{-D}|@option{--enable-deterministic-archives}]
1163 [@option{-U}|@option{--disable-deterministic-archives}]
1164 [@option{--debugging}]
1165 [@option{--gap-fill=}@var{val}]
1166 [@option{--pad-to=}@var{address}]
1167 [@option{--set-start=}@var{val}]
1168 [@option{--adjust-start=}@var{incr}]
1169 [@option{--change-addresses=}@var{incr}]
1170 [@option{--change-section-address} @var{sectionpattern}@{=,+,-@}@var{val}]
1171 [@option{--change-section-lma} @var{sectionpattern}@{=,+,-@}@var{val}]
1172 [@option{--change-section-vma} @var{sectionpattern}@{=,+,-@}@var{val}]
1173 [@option{--change-warnings}] [@option{--no-change-warnings}]
1174 [@option{--set-section-flags} @var{sectionpattern}=@var{flags}]
1175 [@option{--add-section} @var{sectionname}=@var{filename}]
1176 [@option{--dump-section} @var{sectionname}=@var{filename}]
1177 [@option{--update-section} @var{sectionname}=@var{filename}]
1178 [@option{--rename-section} @var{oldname}=@var{newname}[,@var{flags}]]
1179 [@option{--long-section-names} @{enable,disable,keep@}]
1180 [@option{--change-leading-char}] [@option{--remove-leading-char}]
1181 [@option{--reverse-bytes=}@var{num}]
1182 [@option{--srec-len=}@var{ival}] [@option{--srec-forceS3}]
1183 [@option{--redefine-sym} @var{old}=@var{new}]
1184 [@option{--redefine-syms=}@var{filename}]
1186 [@option{--keep-symbols=}@var{filename}]
1187 [@option{--strip-symbols=}@var{filename}]
1188 [@option{--strip-unneeded-symbols=}@var{filename}]
1189 [@option{--keep-global-symbols=}@var{filename}]
1190 [@option{--localize-symbols=}@var{filename}]
1191 [@option{--weaken-symbols=}@var{filename}]
1192 [@option{--add-symbol} @var{name}=[@var{section}:]@var{value}[,@var{flags}]]
1193 [@option{--alt-machine-code=}@var{index}]
1194 [@option{--prefix-symbols=}@var{string}]
1195 [@option{--prefix-sections=}@var{string}]
1196 [@option{--prefix-alloc-sections=}@var{string}]
1197 [@option{--add-gnu-debuglink=}@var{path-to-file}]
1198 [@option{--keep-file-symbols}]
1199 [@option{--only-keep-debug}]
1200 [@option{--strip-dwo}]
1201 [@option{--extract-dwo}]
1202 [@option{--extract-symbol}]
1203 [@option{--writable-text}]
1204 [@option{--readonly-text}]
1207 [@option{--file-alignment=}@var{num}]
1208 [@option{--heap=}@var{size}]
1209 [@option{--image-base=}@var{address}]
1210 [@option{--section-alignment=}@var{num}]
1211 [@option{--stack=}@var{size}]
1212 [@option{--subsystem=}@var{which}:@var{major}.@var{minor}]
1213 [@option{--compress-debug-sections}]
1214 [@option{--decompress-debug-sections}]
1215 [@option{--elf-stt-common=@var{val}}]
1216 [@option{--merge-notes}]
1217 [@option{--no-merge-notes}]
1218 [@option{-v}|@option{--verbose}]
1219 [@option{-V}|@option{--version}]
1220 [@option{--help}] [@option{--info}]
1221 @var{infile} [@var{outfile}]
1225 @c man begin DESCRIPTION objcopy
1226 The @sc{gnu} @command{objcopy} utility copies the contents of an object
1227 file to another. @command{objcopy} uses the @sc{gnu} @sc{bfd} Library to
1228 read and write the object files. It can write the destination object
1229 file in a format different from that of the source object file. The
1230 exact behavior of @command{objcopy} is controlled by command-line options.
1231 Note that @command{objcopy} should be able to copy a fully linked file
1232 between any two formats. However, copying a relocatable object file
1233 between any two formats may not work as expected.
1235 @command{objcopy} creates temporary files to do its translations and
1236 deletes them afterward. @command{objcopy} uses @sc{bfd} to do all its
1237 translation work; it has access to all the formats described in @sc{bfd}
1238 and thus is able to recognize most formats without being told
1239 explicitly. @xref{BFD,,BFD,ld.info,Using LD}.
1241 @command{objcopy} can be used to generate S-records by using an output
1242 target of @samp{srec} (e.g., use @samp{-O srec}).
1244 @command{objcopy} can be used to generate a raw binary file by using an
1245 output target of @samp{binary} (e.g., use @option{-O binary}). When
1246 @command{objcopy} generates a raw binary file, it will essentially produce
1247 a memory dump of the contents of the input object file. All symbols and
1248 relocation information will be discarded. The memory dump will start at
1249 the load address of the lowest section copied into the output file.
1251 When generating an S-record or a raw binary file, it may be helpful to
1252 use @option{-S} to remove sections containing debugging information. In
1253 some cases @option{-R} will be useful to remove sections which contain
1254 information that is not needed by the binary file.
1256 Note---@command{objcopy} is not able to change the endianness of its input
1257 files. If the input format has an endianness (some formats do not),
1258 @command{objcopy} can only copy the inputs into file formats that have the
1259 same endianness or which have no endianness (e.g., @samp{srec}).
1260 (However, see the @option{--reverse-bytes} option.)
1264 @c man begin OPTIONS objcopy
1268 @itemx @var{outfile}
1269 The input and output files, respectively.
1270 If you do not specify @var{outfile}, @command{objcopy} creates a
1271 temporary file and destructively renames the result with
1272 the name of @var{infile}.
1274 @item -I @var{bfdname}
1275 @itemx --input-target=@var{bfdname}
1276 Consider the source file's object format to be @var{bfdname}, rather than
1277 attempting to deduce it. @xref{Target Selection}, for more information.
1279 @item -O @var{bfdname}
1280 @itemx --output-target=@var{bfdname}
1281 Write the output file using the object format @var{bfdname}.
1282 @xref{Target Selection}, for more information.
1284 @item -F @var{bfdname}
1285 @itemx --target=@var{bfdname}
1286 Use @var{bfdname} as the object format for both the input and the output
1287 file; i.e., simply transfer data from source to destination with no
1288 translation. @xref{Target Selection}, for more information.
1290 @item -B @var{bfdarch}
1291 @itemx --binary-architecture=@var{bfdarch}
1292 Useful when transforming a architecture-less input file into an object file.
1293 In this case the output architecture can be set to @var{bfdarch}. This
1294 option will be ignored if the input file has a known @var{bfdarch}. You
1295 can access this binary data inside a program by referencing the special
1296 symbols that are created by the conversion process. These symbols are
1297 called _binary_@var{objfile}_start, _binary_@var{objfile}_end and
1298 _binary_@var{objfile}_size. e.g. you can transform a picture file into
1299 an object file and then access it in your code using these symbols.
1301 @item -j @var{sectionpattern}
1302 @itemx --only-section=@var{sectionpattern}
1303 Copy only the indicated sections from the input file to the output file.
1304 This option may be given more than once. Note that using this option
1305 inappropriately may make the output file unusable. Wildcard
1306 characters are accepted in @var{sectionpattern}.
1308 If the first character of @var{sectionpattern} is the exclamation
1309 point (!) then matching sections will not be copied, even if earlier
1310 use of @option{--only-section} on the same command line would
1311 otherwise copy it. For example:
1314 --only-section=.text.* --only-section=!.text.foo
1317 will copy all sectinos maching '.text.*' but not the section
1320 @item -R @var{sectionpattern}
1321 @itemx --remove-section=@var{sectionpattern}
1322 Remove any section matching @var{sectionpattern} from the output file.
1323 This option may be given more than once. Note that using this option
1324 inappropriately may make the output file unusable. Wildcard
1325 characters are accepted in @var{sectionpattern}. Using both the
1326 @option{-j} and @option{-R} options together results in undefined
1329 If the first character of @var{sectionpattern} is the exclamation
1330 point (!) then matching sections will not be removed even if an
1331 earlier use of @option{--remove-section} on the same command line
1332 would otherwise remove it. For example:
1335 --remove-section=.text.* --remove-section=!.text.foo
1338 will remove all sections matching the pattern '.text.*', but will not
1339 remove the section '.text.foo'.
1341 @item --remove-relocations=@var{sectionpattern}
1342 Remove non-dynamic relocations from the output file for any section
1343 matching @var{sectionpattern}. This option may be given more than
1344 once. Note that using this option inappropriately may make the output
1345 file unusable, and attempting to remove a dynamic relocation section
1346 such as @samp{.rela.plt} from an executable or shared library with
1347 @option{--remove-relocations=.plt} will not work. Wildcard characters
1348 are accepted in @var{sectionpattern}.
1352 --remove-relocations=.text.*
1355 will remove the relocations for all sections matching the pattern
1358 If the first character of @var{sectionpattern} is the exclamation
1359 point (!) then matching sections will not have their relocation
1360 removed even if an earlier use of @option{--remove-relocations} on the
1361 same command line would otherwise cause the relocations to be removed.
1365 --remove-relocations=.text.* --remove-relocations=!.text.foo
1368 will remove all relocations for sections matching the pattern
1369 '.text.*', but will not remove relocations for the section
1374 Do not copy relocation and symbol information from the source file.
1377 @itemx --strip-debug
1378 Do not copy debugging symbols or sections from the source file.
1380 @item --strip-unneeded
1381 Strip all symbols that are not needed for relocation processing.
1383 @item -K @var{symbolname}
1384 @itemx --keep-symbol=@var{symbolname}
1385 When stripping symbols, keep symbol @var{symbolname} even if it would
1386 normally be stripped. This option may be given more than once.
1388 @item -N @var{symbolname}
1389 @itemx --strip-symbol=@var{symbolname}
1390 Do not copy symbol @var{symbolname} from the source file. This option
1391 may be given more than once.
1393 @item --strip-unneeded-symbol=@var{symbolname}
1394 Do not copy symbol @var{symbolname} from the source file unless it is needed
1395 by a relocation. This option may be given more than once.
1397 @item -G @var{symbolname}
1398 @itemx --keep-global-symbol=@var{symbolname}
1399 Keep only symbol @var{symbolname} global. Make all other symbols local
1400 to the file, so that they are not visible externally. This option may
1401 be given more than once. Note: this option cannot be used in
1402 conjunction with the @option{--globalize-symbol} or
1403 @option{--globalize-symbols} options.
1405 @item --localize-hidden
1406 In an ELF object, mark all symbols that have hidden or internal visibility
1407 as local. This option applies on top of symbol-specific localization options
1408 such as @option{-L}.
1410 @item -L @var{symbolname}
1411 @itemx --localize-symbol=@var{symbolname}
1412 Convert a global or weak symbol called @var{symbolname} into a local
1413 symbol, so that it is not visible externally. This option may be
1414 given more than once. Note - unique symbols are not converted.
1416 @item -W @var{symbolname}
1417 @itemx --weaken-symbol=@var{symbolname}
1418 Make symbol @var{symbolname} weak. This option may be given more than once.
1420 @item --globalize-symbol=@var{symbolname}
1421 Give symbol @var{symbolname} global scoping so that it is visible
1422 outside of the file in which it is defined. This option may be given
1423 more than once. Note: this option cannot be used in conjunction with
1424 the @option{-G} or @option{--keep-global-symbol} options.
1428 Permit regular expressions in @var{symbolname}s used in other command
1429 line options. The question mark (?), asterisk (*), backslash (\) and
1430 square brackets ([]) operators can be used anywhere in the symbol
1431 name. If the first character of the symbol name is the exclamation
1432 point (!) then the sense of the switch is reversed for that symbol.
1439 would cause objcopy to weaken all symbols that start with ``fo''
1440 except for the symbol ``foo''.
1443 @itemx --discard-all
1444 Do not copy non-global symbols from the source file.
1445 @c FIXME any reason to prefer "non-global" to "local" here?
1448 @itemx --discard-locals
1449 Do not copy compiler-generated local symbols.
1450 (These usually start with @samp{L} or @samp{.}.)
1453 @itemx --byte=@var{byte}
1454 If interleaving has been enabled via the @option{--interleave} option
1455 then start the range of bytes to keep at the @var{byte}th byte.
1456 @var{byte} can be in the range from 0 to @var{breadth}-1, where
1457 @var{breadth} is the value given by the @option{--interleave} option.
1459 @item -i [@var{breadth}]
1460 @itemx --interleave[=@var{breadth}]
1461 Only copy a range out of every @var{breadth} bytes. (Header data is
1462 not affected). Select which byte in the range begins the copy with
1463 the @option{--byte} option. Select the width of the range with the
1464 @option{--interleave-width} option.
1466 This option is useful for creating files to program @sc{rom}. It is
1467 typically used with an @code{srec} output target. Note that
1468 @command{objcopy} will complain if you do not specify the
1469 @option{--byte} option as well.
1471 The default interleave breadth is 4, so with @option{--byte} set to 0,
1472 @command{objcopy} would copy the first byte out of every four bytes
1473 from the input to the output.
1475 @item --interleave-width=@var{width}
1476 When used with the @option{--interleave} option, copy @var{width}
1477 bytes at a time. The start of the range of bytes to be copied is set
1478 by the @option{--byte} option, and the extent of the range is set with
1479 the @option{--interleave} option.
1481 The default value for this option is 1. The value of @var{width} plus
1482 the @var{byte} value set by the @option{--byte} option must not exceed
1483 the interleave breadth set by the @option{--interleave} option.
1485 This option can be used to create images for two 16-bit flashes interleaved
1486 in a 32-bit bus by passing @option{-b 0 -i 4 --interleave-width=2}
1487 and @option{-b 2 -i 4 --interleave-width=2} to two @command{objcopy}
1488 commands. If the input was '12345678' then the outputs would be
1489 '1256' and '3478' respectively.
1492 @itemx --preserve-dates
1493 Set the access and modification dates of the output file to be the same
1494 as those of the input file.
1497 @itemx --enable-deterministic-archives
1498 @cindex deterministic archives
1499 @kindex --enable-deterministic-archives
1500 Operate in @emph{deterministic} mode. When copying archive members
1501 and writing the archive index, use zero for UIDs, GIDs, timestamps,
1502 and use consistent file modes for all files.
1504 If @file{binutils} was configured with
1505 @option{--enable-deterministic-archives}, then this mode is on by default.
1506 It can be disabled with the @samp{-U} option, below.
1509 @itemx --disable-deterministic-archives
1510 @cindex deterministic archives
1511 @kindex --enable-deterministic-archives
1512 Do @emph{not} operate in @emph{deterministic} mode. This is the
1513 inverse of the @option{-D} option, above: when copying archive members
1514 and writing the archive index, use their actual UID, GID, timestamp,
1515 and file mode values.
1517 This is the default unless @file{binutils} was configured with
1518 @option{--enable-deterministic-archives}.
1521 Convert debugging information, if possible. This is not the default
1522 because only certain debugging formats are supported, and the
1523 conversion process can be time consuming.
1525 @item --gap-fill @var{val}
1526 Fill gaps between sections with @var{val}. This operation applies to
1527 the @emph{load address} (LMA) of the sections. It is done by increasing
1528 the size of the section with the lower address, and filling in the extra
1529 space created with @var{val}.
1531 @item --pad-to @var{address}
1532 Pad the output file up to the load address @var{address}. This is
1533 done by increasing the size of the last section. The extra space is
1534 filled in with the value specified by @option{--gap-fill} (default zero).
1536 @item --set-start @var{val}
1537 Set the start address of the new file to @var{val}. Not all object file
1538 formats support setting the start address.
1540 @item --change-start @var{incr}
1541 @itemx --adjust-start @var{incr}
1542 @cindex changing start address
1543 Change the start address by adding @var{incr}. Not all object file
1544 formats support setting the start address.
1546 @item --change-addresses @var{incr}
1547 @itemx --adjust-vma @var{incr}
1548 @cindex changing object addresses
1549 Change the VMA and LMA addresses of all sections, as well as the start
1550 address, by adding @var{incr}. Some object file formats do not permit
1551 section addresses to be changed arbitrarily. Note that this does not
1552 relocate the sections; if the program expects sections to be loaded at a
1553 certain address, and this option is used to change the sections such
1554 that they are loaded at a different address, the program may fail.
1556 @item --change-section-address @var{sectionpattern}@{=,+,-@}@var{val}
1557 @itemx --adjust-section-vma @var{sectionpattern}@{=,+,-@}@var{val}
1558 @cindex changing section address
1559 Set or change both the VMA address and the LMA address of any section
1560 matching @var{sectionpattern}. If @samp{=} is used, the section
1561 address is set to @var{val}. Otherwise, @var{val} is added to or
1562 subtracted from the section address. See the comments under
1563 @option{--change-addresses}, above. If @var{sectionpattern} does not
1564 match any sections in the input file, a warning will be issued, unless
1565 @option{--no-change-warnings} is used.
1567 @item --change-section-lma @var{sectionpattern}@{=,+,-@}@var{val}
1568 @cindex changing section LMA
1569 Set or change the LMA address of any sections matching
1570 @var{sectionpattern}. The LMA address is the address where the
1571 section will be loaded into memory at program load time. Normally
1572 this is the same as the VMA address, which is the address of the
1573 section at program run time, but on some systems, especially those
1574 where a program is held in ROM, the two can be different. If @samp{=}
1575 is used, the section address is set to @var{val}. Otherwise,
1576 @var{val} is added to or subtracted from the section address. See the
1577 comments under @option{--change-addresses}, above. If
1578 @var{sectionpattern} does not match any sections in the input file, a
1579 warning will be issued, unless @option{--no-change-warnings} is used.
1581 @item --change-section-vma @var{sectionpattern}@{=,+,-@}@var{val}
1582 @cindex changing section VMA
1583 Set or change the VMA address of any section matching
1584 @var{sectionpattern}. The VMA address is the address where the
1585 section will be located once the program has started executing.
1586 Normally this is the same as the LMA address, which is the address
1587 where the section will be loaded into memory, but on some systems,
1588 especially those where a program is held in ROM, the two can be
1589 different. If @samp{=} is used, the section address is set to
1590 @var{val}. Otherwise, @var{val} is added to or subtracted from the
1591 section address. See the comments under @option{--change-addresses},
1592 above. If @var{sectionpattern} does not match any sections in the
1593 input file, a warning will be issued, unless
1594 @option{--no-change-warnings} is used.
1596 @item --change-warnings
1597 @itemx --adjust-warnings
1598 If @option{--change-section-address} or @option{--change-section-lma} or
1599 @option{--change-section-vma} is used, and the section pattern does not
1600 match any sections, issue a warning. This is the default.
1602 @item --no-change-warnings
1603 @itemx --no-adjust-warnings
1604 Do not issue a warning if @option{--change-section-address} or
1605 @option{--adjust-section-lma} or @option{--adjust-section-vma} is used, even
1606 if the section pattern does not match any sections.
1608 @item --set-section-flags @var{sectionpattern}=@var{flags}
1609 Set the flags for any sections matching @var{sectionpattern}. The
1610 @var{flags} argument is a comma separated string of flag names. The
1611 recognized names are @samp{alloc}, @samp{contents}, @samp{load},
1612 @samp{noload}, @samp{readonly}, @samp{code}, @samp{data}, @samp{rom},
1613 @samp{share}, and @samp{debug}. You can set the @samp{contents} flag
1614 for a section which does not have contents, but it is not meaningful
1615 to clear the @samp{contents} flag of a section which does have
1616 contents--just remove the section instead. Not all flags are
1617 meaningful for all object file formats.
1619 @item --add-section @var{sectionname}=@var{filename}
1620 Add a new section named @var{sectionname} while copying the file. The
1621 contents of the new section are taken from the file @var{filename}. The
1622 size of the section will be the size of the file. This option only
1623 works on file formats which can support sections with arbitrary names.
1624 Note - it may be necessary to use the @option{--set-section-flags}
1625 option to set the attributes of the newly created section.
1627 @item --dump-section @var{sectionname}=@var{filename}
1628 Place the contents of section named @var{sectionname} into the file
1629 @var{filename}, overwriting any contents that may have been there
1630 previously. This option is the inverse of @option{--add-section}.
1631 This option is similar to the @option{--only-section} option except
1632 that it does not create a formatted file, it just dumps the contents
1633 as raw binary data, without applying any relocations. The option can
1634 be specified more than once.
1636 @item --update-section @var{sectionname}=@var{filename}
1637 Replace the existing contents of a section named @var{sectionname}
1638 with the contents of file @var{filename}. The size of the section
1639 will be adjusted to the size of the file. The section flags for
1640 @var{sectionname} will be unchanged. For ELF format files the section
1641 to segment mapping will also remain unchanged, something which is not
1642 possible using @option{--remove-section} followed by
1643 @option{--add-section}. The option can be specified more than once.
1645 Note - it is possible to use @option{--rename-section} and
1646 @option{--update-section} to both update and rename a section from one
1647 command line. In this case, pass the original section name to
1648 @option{--update-section}, and the original and new section names to
1649 @option{--rename-section}.
1651 @item --add-symbol @var{name}=[@var{section}:]@var{value}[,@var{flags}]
1652 Add a new symbol named @var{name} while copying the file. This option may be
1653 specified multiple times. If the @var{section} is given, the symbol will be
1654 associated with and relative to that section, otherwise it will be an ABS
1655 symbol. Specifying an undefined section will result in a fatal error. There
1656 is no check for the value, it will be taken as specified. Symbol flags can
1657 be specified and not all flags will be meaningful for all object file
1658 formats. By default, the symbol will be global. The special flag
1659 'before=@var{othersym}' will insert the new symbol in front of the specified
1660 @var{othersym}, otherwise the symbol(s) will be added at the end of the
1661 symbol table in the order they appear.
1663 @item --rename-section @var{oldname}=@var{newname}[,@var{flags}]
1664 Rename a section from @var{oldname} to @var{newname}, optionally
1665 changing the section's flags to @var{flags} in the process. This has
1666 the advantage over using a linker script to perform the rename in that
1667 the output stays as an object file and does not become a linked
1670 This option is particularly helpful when the input format is binary,
1671 since this will always create a section called .data. If for example,
1672 you wanted instead to create a section called .rodata containing binary
1673 data you could use the following command line to achieve it:
1676 objcopy -I binary -O <output_format> -B <architecture> \
1677 --rename-section .data=.rodata,alloc,load,readonly,data,contents \
1678 <input_binary_file> <output_object_file>
1681 @item --long-section-names @{enable,disable,keep@}
1682 Controls the handling of long section names when processing @code{COFF}
1683 and @code{PE-COFF} object formats. The default behaviour, @samp{keep},
1684 is to preserve long section names if any are present in the input file.
1685 The @samp{enable} and @samp{disable} options forcibly enable or disable
1686 the use of long section names in the output object; when @samp{disable}
1687 is in effect, any long section names in the input object will be truncated.
1688 The @samp{enable} option will only emit long section names if any are
1689 present in the inputs; this is mostly the same as @samp{keep}, but it
1690 is left undefined whether the @samp{enable} option might force the
1691 creation of an empty string table in the output file.
1693 @item --change-leading-char
1694 Some object file formats use special characters at the start of
1695 symbols. The most common such character is underscore, which compilers
1696 often add before every symbol. This option tells @command{objcopy} to
1697 change the leading character of every symbol when it converts between
1698 object file formats. If the object file formats use the same leading
1699 character, this option has no effect. Otherwise, it will add a
1700 character, or remove a character, or change a character, as
1703 @item --remove-leading-char
1704 If the first character of a global symbol is a special symbol leading
1705 character used by the object file format, remove the character. The
1706 most common symbol leading character is underscore. This option will
1707 remove a leading underscore from all global symbols. This can be useful
1708 if you want to link together objects of different file formats with
1709 different conventions for symbol names. This is different from
1710 @option{--change-leading-char} because it always changes the symbol name
1711 when appropriate, regardless of the object file format of the output
1714 @item --reverse-bytes=@var{num}
1715 Reverse the bytes in a section with output contents. A section length must
1716 be evenly divisible by the value given in order for the swap to be able to
1717 take place. Reversing takes place before the interleaving is performed.
1719 This option is used typically in generating ROM images for problematic
1720 target systems. For example, on some target boards, the 32-bit words
1721 fetched from 8-bit ROMs are re-assembled in little-endian byte order
1722 regardless of the CPU byte order. Depending on the programming model, the
1723 endianness of the ROM may need to be modified.
1725 Consider a simple file with a section containing the following eight
1726 bytes: @code{12345678}.
1728 Using @samp{--reverse-bytes=2} for the above example, the bytes in the
1729 output file would be ordered @code{21436587}.
1731 Using @samp{--reverse-bytes=4} for the above example, the bytes in the
1732 output file would be ordered @code{43218765}.
1734 By using @samp{--reverse-bytes=2} for the above example, followed by
1735 @samp{--reverse-bytes=4} on the output file, the bytes in the second
1736 output file would be ordered @code{34127856}.
1738 @item --srec-len=@var{ival}
1739 Meaningful only for srec output. Set the maximum length of the Srecords
1740 being produced to @var{ival}. This length covers both address, data and
1743 @item --srec-forceS3
1744 Meaningful only for srec output. Avoid generation of S1/S2 records,
1745 creating S3-only record format.
1747 @item --redefine-sym @var{old}=@var{new}
1748 Change the name of a symbol @var{old}, to @var{new}. This can be useful
1749 when one is trying link two things together for which you have no
1750 source, and there are name collisions.
1752 @item --redefine-syms=@var{filename}
1753 Apply @option{--redefine-sym} to each symbol pair "@var{old} @var{new}"
1754 listed in the file @var{filename}. @var{filename} is simply a flat file,
1755 with one symbol pair per line. Line comments may be introduced by the hash
1756 character. This option may be given more than once.
1759 Change all global symbols in the file to be weak. This can be useful
1760 when building an object which will be linked against other objects using
1761 the @option{-R} option to the linker. This option is only effective when
1762 using an object file format which supports weak symbols.
1764 @item --keep-symbols=@var{filename}
1765 Apply @option{--keep-symbol} option to each symbol listed in the file
1766 @var{filename}. @var{filename} is simply a flat file, with one symbol
1767 name per line. Line comments may be introduced by the hash character.
1768 This option may be given more than once.
1770 @item --strip-symbols=@var{filename}
1771 Apply @option{--strip-symbol} option to each symbol listed in the file
1772 @var{filename}. @var{filename} is simply a flat file, with one symbol
1773 name per line. Line comments may be introduced by the hash character.
1774 This option may be given more than once.
1776 @item --strip-unneeded-symbols=@var{filename}
1777 Apply @option{--strip-unneeded-symbol} option to each symbol listed in
1778 the file @var{filename}. @var{filename} is simply a flat file, with one
1779 symbol name per line. Line comments may be introduced by the hash
1780 character. This option may be given more than once.
1782 @item --keep-global-symbols=@var{filename}
1783 Apply @option{--keep-global-symbol} option to each symbol listed in the
1784 file @var{filename}. @var{filename} is simply a flat file, with one
1785 symbol name per line. Line comments may be introduced by the hash
1786 character. This option may be given more than once.
1788 @item --localize-symbols=@var{filename}
1789 Apply @option{--localize-symbol} option to each symbol listed in the file
1790 @var{filename}. @var{filename} is simply a flat file, with one symbol
1791 name per line. Line comments may be introduced by the hash character.
1792 This option may be given more than once.
1794 @item --globalize-symbols=@var{filename}
1795 Apply @option{--globalize-symbol} option to each symbol listed in the file
1796 @var{filename}. @var{filename} is simply a flat file, with one symbol
1797 name per line. Line comments may be introduced by the hash character.
1798 This option may be given more than once. Note: this option cannot be
1799 used in conjunction with the @option{-G} or @option{--keep-global-symbol}
1802 @item --weaken-symbols=@var{filename}
1803 Apply @option{--weaken-symbol} option to each symbol listed in the file
1804 @var{filename}. @var{filename} is simply a flat file, with one symbol
1805 name per line. Line comments may be introduced by the hash character.
1806 This option may be given more than once.
1808 @item --alt-machine-code=@var{index}
1809 If the output architecture has alternate machine codes, use the
1810 @var{index}th code instead of the default one. This is useful in case
1811 a machine is assigned an official code and the tool-chain adopts the
1812 new code, but other applications still depend on the original code
1813 being used. For ELF based architectures if the @var{index}
1814 alternative does not exist then the value is treated as an absolute
1815 number to be stored in the e_machine field of the ELF header.
1817 @item --writable-text
1818 Mark the output text as writable. This option isn't meaningful for all
1819 object file formats.
1821 @item --readonly-text
1822 Make the output text write protected. This option isn't meaningful for all
1823 object file formats.
1826 Mark the output file as demand paged. This option isn't meaningful for all
1827 object file formats.
1830 Mark the output file as impure. This option isn't meaningful for all
1831 object file formats.
1833 @item --prefix-symbols=@var{string}
1834 Prefix all symbols in the output file with @var{string}.
1836 @item --prefix-sections=@var{string}
1837 Prefix all section names in the output file with @var{string}.
1839 @item --prefix-alloc-sections=@var{string}
1840 Prefix all the names of all allocated sections in the output file with
1843 @item --add-gnu-debuglink=@var{path-to-file}
1844 Creates a .gnu_debuglink section which contains a reference to
1845 @var{path-to-file} and adds it to the output file. Note: the file at
1846 @var{path-to-file} must exist. Part of the process of adding the
1847 .gnu_debuglink section involves embedding a checksum of the contents
1848 of the debug info file into the section.
1850 If the debug info file is built in one location but it is going to be
1851 installed at a later time into a different location then do not use
1852 the path to the installed location. The @option{--add-gnu-debuglink}
1853 option will fail because the installed file does not exist yet.
1854 Instead put the debug info file in the current directory and use the
1855 @option{--add-gnu-debuglink} option without any directory components,
1859 objcopy --add-gnu-debuglink=foo.debug
1862 At debug time the debugger will attempt to look for the separate debug
1863 info file in a set of known locations. The exact set of these
1864 locations varies depending upon the distribution being used, but it
1869 @item * The same directory as the executable.
1871 @item * A sub-directory of the directory containing the executable
1874 @item * A global debug directory such as /usr/lib/debug.
1877 As long as the debug info file has been installed into one of these
1878 locations before the debugger is run everything should work
1881 @item --keep-file-symbols
1882 When stripping a file, perhaps with @option{--strip-debug} or
1883 @option{--strip-unneeded}, retain any symbols specifying source file names,
1884 which would otherwise get stripped.
1886 @item --only-keep-debug
1887 Strip a file, removing contents of any sections that would not be
1888 stripped by @option{--strip-debug} and leaving the debugging sections
1889 intact. In ELF files, this preserves all note sections in the output.
1891 Note - the section headers of the stripped sections are preserved,
1892 including their sizes, but the contents of the section are discarded.
1893 The section headers are preserved so that other tools can match up the
1894 debuginfo file with the real executable, even if that executable has
1895 been relocated to a different address space.
1897 The intention is that this option will be used in conjunction with
1898 @option{--add-gnu-debuglink} to create a two part executable. One a
1899 stripped binary which will occupy less space in RAM and in a
1900 distribution and the second a debugging information file which is only
1901 needed if debugging abilities are required. The suggested procedure
1902 to create these files is as follows:
1905 @item Link the executable as normal. Assuming that it is called
1907 @item Run @code{objcopy --only-keep-debug foo foo.dbg} to
1908 create a file containing the debugging info.
1909 @item Run @code{objcopy --strip-debug foo} to create a
1910 stripped executable.
1911 @item Run @code{objcopy --add-gnu-debuglink=foo.dbg foo}
1912 to add a link to the debugging info into the stripped executable.
1915 Note---the choice of @code{.dbg} as an extension for the debug info
1916 file is arbitrary. Also the @code{--only-keep-debug} step is
1917 optional. You could instead do this:
1920 @item Link the executable as normal.
1921 @item Copy @code{foo} to @code{foo.full}
1922 @item Run @code{objcopy --strip-debug foo}
1923 @item Run @code{objcopy --add-gnu-debuglink=foo.full foo}
1926 i.e., the file pointed to by the @option{--add-gnu-debuglink} can be the
1927 full executable. It does not have to be a file created by the
1928 @option{--only-keep-debug} switch.
1930 Note---this switch is only intended for use on fully linked files. It
1931 does not make sense to use it on object files where the debugging
1932 information may be incomplete. Besides the gnu_debuglink feature
1933 currently only supports the presence of one filename containing
1934 debugging information, not multiple filenames on a one-per-object-file
1938 Remove the contents of all DWARF .dwo sections, leaving the
1939 remaining debugging sections and all symbols intact.
1940 This option is intended for use by the compiler as part of
1941 the @option{-gsplit-dwarf} option, which splits debug information
1942 between the .o file and a separate .dwo file. The compiler
1943 generates all debug information in the same file, then uses
1944 the @option{--extract-dwo} option to copy the .dwo sections to
1945 the .dwo file, then the @option{--strip-dwo} option to remove
1946 those sections from the original .o file.
1949 Extract the contents of all DWARF .dwo sections. See the
1950 @option{--strip-dwo} option for more information.
1952 @item --file-alignment @var{num}
1953 Specify the file alignment. Sections in the file will always begin at
1954 file offsets which are multiples of this number. This defaults to
1956 [This option is specific to PE targets.]
1958 @item --heap @var{reserve}
1959 @itemx --heap @var{reserve},@var{commit}
1960 Specify the number of bytes of memory to reserve (and optionally commit)
1961 to be used as heap for this program.
1962 [This option is specific to PE targets.]
1964 @item --image-base @var{value}
1965 Use @var{value} as the base address of your program or dll. This is
1966 the lowest memory location that will be used when your program or dll
1967 is loaded. To reduce the need to relocate and improve performance of
1968 your dlls, each should have a unique base address and not overlap any
1969 other dlls. The default is 0x400000 for executables, and 0x10000000
1971 [This option is specific to PE targets.]
1973 @item --section-alignment @var{num}
1974 Sets the section alignment. Sections in memory will always begin at
1975 addresses which are a multiple of this number. Defaults to 0x1000.
1976 [This option is specific to PE targets.]
1978 @item --stack @var{reserve}
1979 @itemx --stack @var{reserve},@var{commit}
1980 Specify the number of bytes of memory to reserve (and optionally commit)
1981 to be used as stack for this program.
1982 [This option is specific to PE targets.]
1984 @item --subsystem @var{which}
1985 @itemx --subsystem @var{which}:@var{major}
1986 @itemx --subsystem @var{which}:@var{major}.@var{minor}
1987 Specifies the subsystem under which your program will execute. The
1988 legal values for @var{which} are @code{native}, @code{windows},
1989 @code{console}, @code{posix}, @code{efi-app}, @code{efi-bsd},
1990 @code{efi-rtd}, @code{sal-rtd}, and @code{xbox}. You may optionally set
1991 the subsystem version also. Numeric values are also accepted for
1993 [This option is specific to PE targets.]
1995 @item --extract-symbol
1996 Keep the file's section flags and symbols but remove all section data.
1997 Specifically, the option:
2000 @item removes the contents of all sections;
2001 @item sets the size of every section to zero; and
2002 @item sets the file's start address to zero.
2005 This option is used to build a @file{.sym} file for a VxWorks kernel.
2006 It can also be a useful way of reducing the size of a @option{--just-symbols}
2009 @item --compress-debug-sections
2010 Compress DWARF debug sections using zlib with SHF_COMPRESSED from the
2011 ELF ABI. Note - if compression would actually make a section
2012 @emph{larger}, then it is not compressed.
2014 @item --compress-debug-sections=none
2015 @itemx --compress-debug-sections=zlib
2016 @itemx --compress-debug-sections=zlib-gnu
2017 @itemx --compress-debug-sections=zlib-gabi
2018 For ELF files, these options control how DWARF debug sections are
2019 compressed. @option{--compress-debug-sections=none} is equivalent
2020 to @option{--decompress-debug-sections}.
2021 @option{--compress-debug-sections=zlib} and
2022 @option{--compress-debug-sections=zlib-gabi} are equivalent to
2023 @option{--compress-debug-sections}.
2024 @option{--compress-debug-sections=zlib-gnu} compresses DWARF debug
2025 sections using zlib. The debug sections are renamed to begin with
2026 @samp{.zdebug} instead of @samp{.debug}. Note - if compression would
2027 actually make a section @emph{larger}, then it is not compressed nor
2030 @item --decompress-debug-sections
2031 Decompress DWARF debug sections using zlib. The original section
2032 names of the compressed sections are restored.
2034 @item --elf-stt-common=yes
2035 @itemx --elf-stt-common=no
2036 For ELF files, these options control whether common symbols should be
2037 converted to the @code{STT_COMMON} or @code{STT_OBJECT} type.
2038 @option{--elf-stt-common=yes} converts common symbol type to
2039 @code{STT_COMMON}. @option{--elf-stt-common=no} converts common symbol
2040 type to @code{STT_OBJECT}.
2043 @itemx --no-merge-notes
2044 For ELF files, attempt (or do not attempt) to reduce the size of any
2045 SHT_NOTE type sections by removing duplicate notes.
2049 Show the version number of @command{objcopy}.
2053 Verbose output: list all object files modified. In the case of
2054 archives, @samp{objcopy -V} lists all members of the archive.
2057 Show a summary of the options to @command{objcopy}.
2060 Display a list showing all architectures and object formats available.
2066 @c man begin SEEALSO objcopy
2067 ld(1), objdump(1), and the Info entries for @file{binutils}.
2074 @cindex object file information
2077 @c man title objdump display information from object files.
2080 @c man begin SYNOPSIS objdump
2081 objdump [@option{-a}|@option{--archive-headers}]
2082 [@option{-b} @var{bfdname}|@option{--target=@var{bfdname}}]
2083 [@option{-C}|@option{--demangle}[=@var{style}] ]
2084 [@option{-d}|@option{--disassemble}[=@var{symbol}]]
2085 [@option{-D}|@option{--disassemble-all}]
2086 [@option{-z}|@option{--disassemble-zeroes}]
2087 [@option{-EB}|@option{-EL}|@option{--endian=}@{big | little @}]
2088 [@option{-f}|@option{--file-headers}]
2089 [@option{-F}|@option{--file-offsets}]
2090 [@option{--file-start-context}]
2091 [@option{-g}|@option{--debugging}]
2092 [@option{-e}|@option{--debugging-tags}]
2093 [@option{-h}|@option{--section-headers}|@option{--headers}]
2094 [@option{-i}|@option{--info}]
2095 [@option{-j} @var{section}|@option{--section=}@var{section}]
2096 [@option{-l}|@option{--line-numbers}]
2097 [@option{-S}|@option{--source}]
2098 [@option{-m} @var{machine}|@option{--architecture=}@var{machine}]
2099 [@option{-M} @var{options}|@option{--disassembler-options=}@var{options}]
2100 [@option{-p}|@option{--private-headers}]
2101 [@option{-P} @var{options}|@option{--private=}@var{options}]
2102 [@option{-r}|@option{--reloc}]
2103 [@option{-R}|@option{--dynamic-reloc}]
2104 [@option{-s}|@option{--full-contents}]
2105 [@option{-W[lLiaprmfFsoRtUuTgAckK]}|
2106 @option{--dwarf}[=rawline,=decodedline,=info,=abbrev,=pubnames,=aranges,=macro,=frames,=frames-interp,=str,=loc,=Ranges,=pubtypes,=trace_info,=trace_abbrev,=trace_aranges,=gdb_index,=addr,=cu_index,=links,=follow-links]]
2107 [@option{-G}|@option{--stabs}]
2108 [@option{-t}|@option{--syms}]
2109 [@option{-T}|@option{--dynamic-syms}]
2110 [@option{-x}|@option{--all-headers}]
2111 [@option{-w}|@option{--wide}]
2112 [@option{--start-address=}@var{address}]
2113 [@option{--stop-address=}@var{address}]
2114 [@option{--prefix-addresses}]
2115 [@option{--[no-]show-raw-insn}]
2116 [@option{--adjust-vma=}@var{offset}]
2117 [@option{--dwarf-depth=@var{n}}]
2118 [@option{--dwarf-start=@var{n}}]
2119 [@option{--no-recurse-limit}|@option{--recurse-limit}]
2120 [@option{--special-syms}]
2121 [@option{--prefix=}@var{prefix}]
2122 [@option{--prefix-strip=}@var{level}]
2123 [@option{--insn-width=}@var{width}]
2124 [@option{-V}|@option{--version}]
2125 [@option{-H}|@option{--help}]
2126 @var{objfile}@dots{}
2130 @c man begin DESCRIPTION objdump
2132 @command{objdump} displays information about one or more object files.
2133 The options control what particular information to display. This
2134 information is mostly useful to programmers who are working on the
2135 compilation tools, as opposed to programmers who just want their
2136 program to compile and work.
2138 @var{objfile}@dots{} are the object files to be examined. When you
2139 specify archives, @command{objdump} shows information on each of the member
2144 @c man begin OPTIONS objdump
2146 The long and short forms of options, shown here as alternatives, are
2147 equivalent. At least one option from the list
2148 @option{-a,-d,-D,-e,-f,-g,-G,-h,-H,-p,-P,-r,-R,-s,-S,-t,-T,-V,-x} must be given.
2152 @itemx --archive-header
2153 @cindex archive headers
2154 If any of the @var{objfile} files are archives, display the archive
2155 header information (in a format similar to @samp{ls -l}). Besides the
2156 information you could list with @samp{ar tv}, @samp{objdump -a} shows
2157 the object file format of each archive member.
2159 @item --adjust-vma=@var{offset}
2160 @cindex section addresses in objdump
2161 @cindex VMA in objdump
2162 When dumping information, first add @var{offset} to all the section
2163 addresses. This is useful if the section addresses do not correspond to
2164 the symbol table, which can happen when putting sections at particular
2165 addresses when using a format which can not represent section addresses,
2168 @item -b @var{bfdname}
2169 @itemx --target=@var{bfdname}
2170 @cindex object code format
2171 Specify that the object-code format for the object files is
2172 @var{bfdname}. This option may not be necessary; @var{objdump} can
2173 automatically recognize many formats.
2177 objdump -b oasys -m vax -h fu.o
2180 displays summary information from the section headers (@option{-h}) of
2181 @file{fu.o}, which is explicitly identified (@option{-m}) as a VAX object
2182 file in the format produced by Oasys compilers. You can list the
2183 formats available with the @option{-i} option.
2184 @xref{Target Selection}, for more information.
2187 @itemx --demangle[=@var{style}]
2188 @cindex demangling in objdump
2189 Decode (@dfn{demangle}) low-level symbol names into user-level names.
2190 Besides removing any initial underscore prepended by the system, this
2191 makes C++ function names readable. Different compilers have different
2192 mangling styles. The optional demangling style argument can be used to
2193 choose an appropriate demangling style for your compiler. @xref{c++filt},
2194 for more information on demangling.
2196 @item --recurse-limit
2197 @itemx --no-recurse-limit
2198 @itemx --recursion-limit
2199 @itemx --no-recursion-limit
2200 Enables or disables a limit on the amount of recursion performed
2201 whilst demangling strings. Since the name mangling formats allow for
2202 an inifinite level of recursion it is possible to create strings whose
2203 decoding will exhaust the amount of stack space available on the host
2204 machine, triggering a memory fault. The limit tries to prevent this
2205 from happening by restricting recursion to 2048 levels of nesting.
2207 The default is for this limit to be enabled, but disabling it may be
2208 necessary in order to demangle truly complicated names. Note however
2209 that if the recursion limit is disabled then stack exhaustion is
2210 possible and any bug reports about such an event will be rejected.
2214 Display debugging information. This attempts to parse STABS
2215 debugging format information stored in the file and print it out using
2216 a C like syntax. If no STABS debuging was found this option
2217 falls back on the @option{-W} option to print any DWARF information in
2221 @itemx --debugging-tags
2222 Like @option{-g}, but the information is generated in a format compatible
2226 @itemx --disassemble
2227 @itemx --disassemble=@var{symbol}
2228 @cindex disassembling object code
2229 @cindex machine instructions
2230 Display the assembler mnemonics for the machine instructions from the
2231 input file. This option only disassembles those sections which are
2232 expected to contain instructions. If the optional @var{symbol}
2233 argument is given, then display the assembler mnemonics starting at
2234 @var{symbol}. If @var{symbol} is a function name then disassembly
2235 will stop at the end of the function, otherwise it will stop when the
2236 next symbol is encountered. If there are no matches for @var{symbol}
2237 then nothing will be displayed.
2240 @itemx --disassemble-all
2241 Like @option{-d}, but disassemble the contents of all sections, not just
2242 those expected to contain instructions.
2244 This option also has a subtle effect on the disassembly of
2245 instructions in code sections. When option @option{-d} is in effect
2246 objdump will assume that any symbols present in a code section occur
2247 on the boundary between instructions and it will refuse to disassemble
2248 across such a boundary. When option @option{-D} is in effect however
2249 this assumption is supressed. This means that it is possible for the
2250 output of @option{-d} and @option{-D} to differ if, for example, data
2251 is stored in code sections.
2253 If the target is an ARM architecture this switch also has the effect
2254 of forcing the disassembler to decode pieces of data found in code
2255 sections as if they were instructions.
2257 @item --prefix-addresses
2258 When disassembling, print the complete address on each line. This is
2259 the older disassembly format.
2263 @itemx --endian=@{big|little@}
2265 @cindex disassembly endianness
2266 Specify the endianness of the object files. This only affects
2267 disassembly. This can be useful when disassembling a file format which
2268 does not describe endianness information, such as S-records.
2271 @itemx --file-headers
2272 @cindex object file header
2273 Display summary information from the overall header of
2274 each of the @var{objfile} files.
2277 @itemx --file-offsets
2278 @cindex object file offsets
2279 When disassembling sections, whenever a symbol is displayed, also
2280 display the file offset of the region of data that is about to be
2281 dumped. If zeroes are being skipped, then when disassembly resumes,
2282 tell the user how many zeroes were skipped and the file offset of the
2283 location from where the disassembly resumes. When dumping sections,
2284 display the file offset of the location from where the dump starts.
2286 @item --file-start-context
2287 @cindex source code context
2288 Specify that when displaying interlisted source code/disassembly
2289 (assumes @option{-S}) from a file that has not yet been displayed, extend the
2290 context to the start of the file.
2293 @itemx --section-headers
2295 @cindex section headers
2296 Display summary information from the section headers of the
2299 File segments may be relocated to nonstandard addresses, for example by
2300 using the @option{-Ttext}, @option{-Tdata}, or @option{-Tbss} options to
2301 @command{ld}. However, some object file formats, such as a.out, do not
2302 store the starting address of the file segments. In those situations,
2303 although @command{ld} relocates the sections correctly, using @samp{objdump
2304 -h} to list the file section headers cannot show the correct addresses.
2305 Instead, it shows the usual addresses, which are implicit for the
2308 Note, in some cases it is possible for a section to have both the
2309 READONLY and the NOREAD attributes set. In such cases the NOREAD
2310 attribute takes precedence, but @command{objdump} will report both
2311 since the exact setting of the flag bits might be important.
2315 Print a summary of the options to @command{objdump} and exit.
2319 @cindex architectures available
2320 @cindex object formats available
2321 Display a list showing all architectures and object formats available
2322 for specification with @option{-b} or @option{-m}.
2325 @itemx --section=@var{name}
2326 @cindex section information
2327 Display information only for section @var{name}.
2330 @itemx --line-numbers
2331 @cindex source filenames for object files
2332 Label the display (using debugging information) with the filename and
2333 source line numbers corresponding to the object code or relocs shown.
2334 Only useful with @option{-d}, @option{-D}, or @option{-r}.
2336 @item -m @var{machine}
2337 @itemx --architecture=@var{machine}
2338 @cindex architecture
2339 @cindex disassembly architecture
2340 Specify the architecture to use when disassembling object files. This
2341 can be useful when disassembling object files which do not describe
2342 architecture information, such as S-records. You can list the available
2343 architectures with the @option{-i} option.
2345 If the target is an ARM architecture then this switch has an
2346 additional effect. It restricts the disassembly to only those
2347 instructions supported by the architecture specified by @var{machine}.
2348 If it is necessary to use this switch because the input file does not
2349 contain any architecture information, but it is also desired to
2350 disassemble all the instructions use @option{-marm}.
2352 @item -M @var{options}
2353 @itemx --disassembler-options=@var{options}
2354 Pass target specific information to the disassembler. Only supported on
2355 some targets. If it is necessary to specify more than one
2356 disassembler option then multiple @option{-M} options can be used or
2357 can be placed together into a comma separated list.
2359 For ARC, @option{dsp} controls the printing of DSP instructions,
2360 @option{spfp} selects the printing of FPX single precision FP
2361 instructions, @option{dpfp} selects the printing of FPX double
2362 precision FP instructions, @option{quarkse_em} selects the printing of
2363 special QuarkSE-EM instructions, @option{fpuda} selects the printing
2364 of double precision assist instructions, @option{fpus} selects the
2365 printing of FPU single precision FP instructions, while @option{fpud}
2366 selects the printing of FPU double precision FP instructions.
2367 Additionally, one can choose to have all the immediates printed in
2368 hexadecimal using @option{hex}. By default, the short immediates are
2369 printed using the decimal representation, while the long immediate
2370 values are printed as hexadecimal.
2372 @option{cpu=...} allows to enforce a particular ISA when disassembling
2373 instructions, overriding the @option{-m} value or whatever is in the ELF file.
2374 This might be useful to select ARC EM or HS ISA, because architecture is same
2375 for those and disassembler relies on private ELF header data to decide if code
2376 is for EM or HS. This option might be specified multiple times - only the
2377 latest value will be used. Valid values are same as for the assembler
2378 @option{-mcpu=...} option.
2380 If the target is an ARM architecture then this switch can be used to
2381 select which register name set is used during disassembler. Specifying
2382 @option{-M reg-names-std} (the default) will select the register names as
2383 used in ARM's instruction set documentation, but with register 13 called
2384 'sp', register 14 called 'lr' and register 15 called 'pc'. Specifying
2385 @option{-M reg-names-apcs} will select the name set used by the ARM
2386 Procedure Call Standard, whilst specifying @option{-M reg-names-raw} will
2387 just use @samp{r} followed by the register number.
2389 There are also two variants on the APCS register naming scheme enabled
2390 by @option{-M reg-names-atpcs} and @option{-M reg-names-special-atpcs} which
2391 use the ARM/Thumb Procedure Call Standard naming conventions. (Either
2392 with the normal register names or the special register names).
2394 This option can also be used for ARM architectures to force the
2395 disassembler to interpret all instructions as Thumb instructions by
2396 using the switch @option{--disassembler-options=force-thumb}. This can be
2397 useful when attempting to disassemble thumb code produced by other
2400 For AArch64 targets this switch can be used to set whether instructions are
2401 disassembled as the most general instruction using the @option{-M no-aliases}
2402 option or whether instruction notes should be generated as comments in the
2403 disasssembly using @option{-M notes}.
2405 For the x86, some of the options duplicate functions of the @option{-m}
2406 switch, but allow finer grained control. Multiple selections from the
2407 following may be specified as a comma separated string.
2412 Select disassembly for the given architecture.
2416 Select between intel syntax mode and AT&T syntax mode.
2420 Select between AMD64 ISA and Intel64 ISA.
2422 @item intel-mnemonic
2424 Select between intel mnemonic mode and AT&T mnemonic mode.
2425 Note: @code{intel-mnemonic} implies @code{intel} and
2426 @code{att-mnemonic} implies @code{att}.
2433 Specify the default address size and operand size. These four options
2434 will be overridden if @code{x86-64}, @code{i386} or @code{i8086}
2435 appear later in the option string.
2438 When in AT&T mode, instructs the disassembler to print a mnemonic
2439 suffix even when the suffix could be inferred by the operands.
2442 For PowerPC, the @option{-M} argument @option{raw} selects
2443 disasssembly of hardware insns rather than aliases. For example, you
2444 will see @code{rlwinm} rather than @code{clrlwi}, and @code{addi}
2445 rather than @code{li}. All of the @option{-m} arguments for
2446 @command{gas} that select a CPU are supported. These are:
2447 @option{403}, @option{405}, @option{440}, @option{464}, @option{476},
2448 @option{601}, @option{603}, @option{604}, @option{620}, @option{7400},
2449 @option{7410}, @option{7450}, @option{7455}, @option{750cl},
2450 @option{821}, @option{850}, @option{860}, @option{a2}, @option{booke},
2451 @option{booke32}, @option{cell}, @option{com}, @option{e200z4},
2452 @option{e300}, @option{e500}, @option{e500mc}, @option{e500mc64},
2453 @option{e500x2}, @option{e5500}, @option{e6500}, @option{efs},
2454 @option{power4}, @option{power5}, @option{power6}, @option{power7},
2455 @option{power8}, @option{power9}, @option{ppc}, @option{ppc32},
2456 @option{ppc64}, @option{ppc64bridge}, @option{ppcps}, @option{pwr},
2457 @option{pwr2}, @option{pwr4}, @option{pwr5}, @option{pwr5x},
2458 @option{pwr6}, @option{pwr7}, @option{pwr8}, @option{pwr9},
2459 @option{pwrx}, @option{titan}, and @option{vle}.
2460 @option{32} and @option{64} modify the default or a prior CPU
2461 selection, disabling and enabling 64-bit insns respectively. In
2462 addition, @option{altivec}, @option{any}, @option{htm}, @option{vsx},
2463 and @option{spe} add capabilities to a previous @emph{or later} CPU
2464 selection. @option{any} will disassemble any opcode known to
2465 binutils, but in cases where an opcode has two different meanings or
2466 different arguments, you may not see the disassembly you expect.
2467 If you disassemble without giving a CPU selection, a default will be
2468 chosen from information gleaned by BFD from the object files headers,
2469 but the result again may not be as you expect.
2471 For MIPS, this option controls the printing of instruction mnemonic
2472 names and register names in disassembled instructions. Multiple
2473 selections from the following may be specified as a comma separated
2474 string, and invalid options are ignored:
2478 Print the 'raw' instruction mnemonic instead of some pseudo
2479 instruction mnemonic. I.e., print 'daddu' or 'or' instead of 'move',
2480 'sll' instead of 'nop', etc.
2483 Disassemble MSA instructions.
2486 Disassemble the virtualization ASE instructions.
2489 Disassemble the eXtended Physical Address (XPA) ASE instructions.
2491 @item gpr-names=@var{ABI}
2492 Print GPR (general-purpose register) names as appropriate
2493 for the specified ABI. By default, GPR names are selected according to
2494 the ABI of the binary being disassembled.
2496 @item fpr-names=@var{ABI}
2497 Print FPR (floating-point register) names as
2498 appropriate for the specified ABI. By default, FPR numbers are printed
2501 @item cp0-names=@var{ARCH}
2502 Print CP0 (system control coprocessor; coprocessor 0) register names
2503 as appropriate for the CPU or architecture specified by
2504 @var{ARCH}. By default, CP0 register names are selected according to
2505 the architecture and CPU of the binary being disassembled.
2507 @item hwr-names=@var{ARCH}
2508 Print HWR (hardware register, used by the @code{rdhwr} instruction) names
2509 as appropriate for the CPU or architecture specified by
2510 @var{ARCH}. By default, HWR names are selected according to
2511 the architecture and CPU of the binary being disassembled.
2513 @item reg-names=@var{ABI}
2514 Print GPR and FPR names as appropriate for the selected ABI.
2516 @item reg-names=@var{ARCH}
2517 Print CPU-specific register names (CP0 register and HWR names)
2518 as appropriate for the selected CPU or architecture.
2521 For any of the options listed above, @var{ABI} or
2522 @var{ARCH} may be specified as @samp{numeric} to have numbers printed
2523 rather than names, for the selected types of registers.
2524 You can list the available values of @var{ABI} and @var{ARCH} using
2525 the @option{--help} option.
2527 For VAX, you can specify function entry addresses with @option{-M
2528 entry:0xf00ba}. You can use this multiple times to properly
2529 disassemble VAX binary files that don't contain symbol tables (like
2530 ROM dumps). In these cases, the function entry mask would otherwise
2531 be decoded as VAX instructions, which would probably lead the rest
2532 of the function being wrongly disassembled.
2535 @itemx --private-headers
2536 Print information that is specific to the object file format. The exact
2537 information printed depends upon the object file format. For some
2538 object file formats, no additional information is printed.
2540 @item -P @var{options}
2541 @itemx --private=@var{options}
2542 Print information that is specific to the object file format. The
2543 argument @var{options} is a comma separated list that depends on the
2544 format (the lists of options is displayed with the help).
2546 For XCOFF, the available options are:
2562 Not all object formats support this option. In particular the ELF
2563 format does not use it.
2567 @cindex relocation entries, in object file
2568 Print the relocation entries of the file. If used with @option{-d} or
2569 @option{-D}, the relocations are printed interspersed with the
2573 @itemx --dynamic-reloc
2574 @cindex dynamic relocation entries, in object file
2575 Print the dynamic relocation entries of the file. This is only
2576 meaningful for dynamic objects, such as certain types of shared
2577 libraries. As for @option{-r}, if used with @option{-d} or
2578 @option{-D}, the relocations are printed interspersed with the
2582 @itemx --full-contents
2583 @cindex sections, full contents
2584 @cindex object file sections
2585 Display the full contents of any sections requested. By default all
2586 non-empty sections are displayed.
2590 @cindex source disassembly
2591 @cindex disassembly, with source
2592 Display source code intermixed with disassembly, if possible. Implies
2595 @item --prefix=@var{prefix}
2596 @cindex Add prefix to absolute paths
2597 Specify @var{prefix} to add to the absolute paths when used with
2600 @item --prefix-strip=@var{level}
2601 @cindex Strip absolute paths
2602 Indicate how many initial directory names to strip off the hardwired
2603 absolute paths. It has no effect without @option{--prefix=}@var{prefix}.
2605 @item --show-raw-insn
2606 When disassembling instructions, print the instruction in hex as well as
2607 in symbolic form. This is the default except when
2608 @option{--prefix-addresses} is used.
2610 @item --no-show-raw-insn
2611 When disassembling instructions, do not print the instruction bytes.
2612 This is the default when @option{--prefix-addresses} is used.
2614 @item --insn-width=@var{width}
2615 @cindex Instruction width
2616 Display @var{width} bytes on a single line when disassembling
2619 @item -W[lLiaprmfFsoRtUuTgAckK]
2620 @itemx --dwarf[=rawline,=decodedline,=info,=abbrev,=pubnames,=aranges,=macro,=frames,=frames-interp,=str,=loc,=Ranges,=pubtypes,=trace_info,=trace_abbrev,=trace_aranges,=gdb_index,=addr,=cu_index,=links,=follow-links]
2621 @include debug.options.texi
2624 Enable additional checks for consistency of Dwarf information.
2630 @cindex debug symbols
2631 @cindex ELF object file format
2632 Display the full contents of any sections requested. Display the
2633 contents of the .stab and .stab.index and .stab.excl sections from an
2634 ELF file. This is only useful on systems (such as Solaris 2.0) in which
2635 @code{.stab} debugging symbol-table entries are carried in an ELF
2636 section. In most other file formats, debugging symbol-table entries are
2637 interleaved with linkage symbols, and are visible in the @option{--syms}
2640 @item --start-address=@var{address}
2641 @cindex start-address
2642 Start displaying data at the specified address. This affects the output
2643 of the @option{-d}, @option{-r} and @option{-s} options.
2645 @item --stop-address=@var{address}
2646 @cindex stop-address
2647 Stop displaying data at the specified address. This affects the output
2648 of the @option{-d}, @option{-r} and @option{-s} options.
2652 @cindex symbol table entries, printing
2653 Print the symbol table entries of the file.
2654 This is similar to the information provided by the @samp{nm} program,
2655 although the display format is different. The format of the output
2656 depends upon the format of the file being dumped, but there are two main
2657 types. One looks like this:
2660 [ 4](sec 3)(fl 0x00)(ty 0)(scl 3) (nx 1) 0x00000000 .bss
2661 [ 6](sec 1)(fl 0x00)(ty 0)(scl 2) (nx 0) 0x00000000 fred
2664 where the number inside the square brackets is the number of the entry
2665 in the symbol table, the @var{sec} number is the section number, the
2666 @var{fl} value are the symbol's flag bits, the @var{ty} number is the
2667 symbol's type, the @var{scl} number is the symbol's storage class and
2668 the @var{nx} value is the number of auxilary entries associated with
2669 the symbol. The last two fields are the symbol's value and its name.
2671 The other common output format, usually seen with ELF based files,
2675 00000000 l d .bss 00000000 .bss
2676 00000000 g .text 00000000 fred
2679 Here the first number is the symbol's value (sometimes refered to as
2680 its address). The next field is actually a set of characters and
2681 spaces indicating the flag bits that are set on the symbol. These
2682 characters are described below. Next is the section with which the
2683 symbol is associated or @emph{*ABS*} if the section is absolute (ie
2684 not connected with any section), or @emph{*UND*} if the section is
2685 referenced in the file being dumped, but not defined there.
2687 After the section name comes another field, a number, which for common
2688 symbols is the alignment and for other symbol is the size. Finally
2689 the symbol's name is displayed.
2691 The flag characters are divided into 7 groups as follows:
2697 The symbol is a local (l), global (g), unique global (u), neither
2698 global nor local (a space) or both global and local (!). A
2699 symbol can be neither local or global for a variety of reasons, e.g.,
2700 because it is used for debugging, but it is probably an indication of
2701 a bug if it is ever both local and global. Unique global symbols are
2702 a GNU extension to the standard set of ELF symbol bindings. For such
2703 a symbol the dynamic linker will make sure that in the entire process
2704 there is just one symbol with this name and type in use.
2707 The symbol is weak (w) or strong (a space).
2710 The symbol denotes a constructor (C) or an ordinary symbol (a space).
2713 The symbol is a warning (W) or a normal symbol (a space). A warning
2714 symbol's name is a message to be displayed if the symbol following the
2715 warning symbol is ever referenced.
2719 The symbol is an indirect reference to another symbol (I), a function
2720 to be evaluated during reloc processing (i) or a normal symbol (a
2725 The symbol is a debugging symbol (d) or a dynamic symbol (D) or a
2726 normal symbol (a space).
2731 The symbol is the name of a function (F) or a file (f) or an object
2732 (O) or just a normal symbol (a space).
2736 @itemx --dynamic-syms
2737 @cindex dynamic symbol table entries, printing
2738 Print the dynamic symbol table entries of the file. This is only
2739 meaningful for dynamic objects, such as certain types of shared
2740 libraries. This is similar to the information provided by the @samp{nm}
2741 program when given the @option{-D} (@option{--dynamic}) option.
2743 The output format is similar to that produced by the @option{--syms}
2744 option, except that an extra field is inserted before the symbol's
2745 name, giving the version information associated with the symbol.
2746 If the version is the default version to be used when resolving
2747 unversioned references to the symbol then it's displayed as is,
2748 otherwise it's put into parentheses.
2750 @item --special-syms
2751 When displaying symbols include those which the target considers to be
2752 special in some way and which would not normally be of interest to the
2757 Print the version number of @command{objdump} and exit.
2760 @itemx --all-headers
2761 @cindex all header information, object file
2762 @cindex header information, all
2763 Display all available header information, including the symbol table and
2764 relocation entries. Using @option{-x} is equivalent to specifying all of
2765 @option{-a -f -h -p -r -t}.
2769 @cindex wide output, printing
2770 Format some lines for output devices that have more than 80 columns.
2771 Also do not truncate symbol names when they are displayed.
2774 @itemx --disassemble-zeroes
2775 Normally the disassembly output will skip blocks of zeroes. This
2776 option directs the disassembler to disassemble those blocks, just like
2783 @c man begin SEEALSO objdump
2784 nm(1), readelf(1), and the Info entries for @file{binutils}.
2792 @cindex archive contents
2793 @cindex symbol index
2795 @c man title ranlib generate index to archive.
2798 @c man begin SYNOPSIS ranlib
2799 ranlib [@option{--plugin} @var{name}] [@option{-DhHvVt}] @var{archive}
2803 @c man begin DESCRIPTION ranlib
2805 @command{ranlib} generates an index to the contents of an archive and
2806 stores it in the archive. The index lists each symbol defined by a
2807 member of an archive that is a relocatable object file.
2809 You may use @samp{nm -s} or @samp{nm --print-armap} to list this index.
2811 An archive with such an index speeds up linking to the library and
2812 allows routines in the library to call each other without regard to
2813 their placement in the archive.
2815 The @sc{gnu} @command{ranlib} program is another form of @sc{gnu} @command{ar}; running
2816 @command{ranlib} is completely equivalent to executing @samp{ar -s}.
2821 @c man begin OPTIONS ranlib
2827 Show usage information for @command{ranlib}.
2832 Show the version number of @command{ranlib}.
2835 @cindex deterministic archives
2836 @kindex --enable-deterministic-archives
2837 Operate in @emph{deterministic} mode. The symbol map archive member's
2838 header will show zero for the UID, GID, and timestamp. When this
2839 option is used, multiple runs will produce identical output files.
2841 If @file{binutils} was configured with
2842 @option{--enable-deterministic-archives}, then this mode is on by
2843 default. It can be disabled with the @samp{-U} option, described
2847 Update the timestamp of the symbol map of an archive.
2850 @cindex deterministic archives
2851 @kindex --enable-deterministic-archives
2852 Do @emph{not} operate in @emph{deterministic} mode. This is the
2853 inverse of the @samp{-D} option, above: the archive index will get
2854 actual UID, GID, timestamp, and file mode values.
2856 If @file{binutils} was configured @emph{without}
2857 @option{--enable-deterministic-archives}, then this mode is on by
2865 @c man begin SEEALSO ranlib
2866 ar(1), nm(1), and the Info entries for @file{binutils}.
2874 @cindex section sizes
2876 @c man title size list section sizes and total size.
2879 @c man begin SYNOPSIS size
2880 size [@option{-A}|@option{-B}|@option{--format=}@var{compatibility}]
2882 [@option{-d}|@option{-o}|@option{-x}|@option{--radix=}@var{number}]
2884 [@option{-t}|@option{--totals}]
2885 [@option{--target=}@var{bfdname}] [@option{-V}|@option{--version}]
2886 [@var{objfile}@dots{}]
2890 @c man begin DESCRIPTION size
2892 The @sc{gnu} @command{size} utility lists the section sizes---and the total
2893 size---for each of the object or archive files @var{objfile} in its
2894 argument list. By default, one line of output is generated for each
2895 object file or each module in an archive.
2897 @var{objfile}@dots{} are the object files to be examined.
2898 If none are specified, the file @code{a.out} will be used.
2902 @c man begin OPTIONS size
2904 The command-line options have the following meanings:
2909 @itemx --format=@var{compatibility}
2910 @cindex @command{size} display format
2911 Using one of these options, you can choose whether the output from @sc{gnu}
2912 @command{size} resembles output from System V @command{size} (using @option{-A},
2913 or @option{--format=sysv}), or Berkeley @command{size} (using @option{-B}, or
2914 @option{--format=berkeley}). The default is the one-line format similar to
2916 @c Bonus for doc-source readers: you can also say --format=strange (or
2917 @c anything else that starts with 's') for sysv, and --format=boring (or
2918 @c anything else that starts with 'b') for Berkeley.
2920 Here is an example of the Berkeley (default) format of output from
2923 $ size --format=Berkeley ranlib size
2924 text data bss dec hex filename
2925 294880 81920 11592 388392 5ed28 ranlib
2926 294880 81920 11888 388688 5ee50 size
2930 This is the same data, but displayed closer to System V conventions:
2933 $ size --format=SysV ranlib size
2951 Show a summary of acceptable arguments and options.
2956 @itemx --radix=@var{number}
2957 @cindex @command{size} number format
2958 @cindex radix for section sizes
2959 Using one of these options, you can control whether the size of each
2960 section is given in decimal (@option{-d}, or @option{--radix=10}); octal
2961 (@option{-o}, or @option{--radix=8}); or hexadecimal (@option{-x}, or
2962 @option{--radix=16}). In @option{--radix=@var{number}}, only the three
2963 values (8, 10, 16) are supported. The total size is always given in two
2964 radices; decimal and hexadecimal for @option{-d} or @option{-x} output, or
2965 octal and hexadecimal if you're using @option{-o}.
2968 Print total size of common symbols in each file. When using Berkeley
2969 format these are included in the bss size.
2973 Show totals of all objects listed (Berkeley format listing mode only).
2975 @item --target=@var{bfdname}
2976 @cindex object code format
2977 Specify that the object-code format for @var{objfile} is
2978 @var{bfdname}. This option may not be necessary; @command{size} can
2979 automatically recognize many formats.
2980 @xref{Target Selection}, for more information.
2984 Display the version number of @command{size}.
2990 @c man begin SEEALSO size
2991 ar(1), objdump(1), readelf(1), and the Info entries for @file{binutils}.
2998 @cindex listings strings
2999 @cindex printing strings
3000 @cindex strings, printing
3002 @c man title strings print the strings of printable characters in files.
3005 @c man begin SYNOPSIS strings
3006 strings [@option{-afovV}] [@option{-}@var{min-len}]
3007 [@option{-n} @var{min-len}] [@option{--bytes=}@var{min-len}]
3008 [@option{-t} @var{radix}] [@option{--radix=}@var{radix}]
3009 [@option{-e} @var{encoding}] [@option{--encoding=}@var{encoding}]
3010 [@option{-}] [@option{--all}] [@option{--print-file-name}]
3011 [@option{-T} @var{bfdname}] [@option{--target=}@var{bfdname}]
3012 [@option{-w}] [@option{--include-all-whitespace}]
3013 [@option{-s}] [@option{--output-separator}@var{sep_string}]
3014 [@option{--help}] [@option{--version}] @var{file}@dots{}
3018 @c man begin DESCRIPTION strings
3020 For each @var{file} given, @sc{gnu} @command{strings} prints the
3021 printable character sequences that are at least 4 characters long (or
3022 the number given with the options below) and are followed by an
3023 unprintable character.
3025 Depending upon how the strings program was configured it will default
3026 to either displaying all the printable sequences that it can find in
3027 each file, or only those sequences that are in loadable, initialized
3028 data sections. If the file type in unrecognizable, or if strings is
3029 reading from stdin then it will always display all of the printable
3030 sequences that it can find.
3032 For backwards compatibility any file that occurs after a command-line
3033 option of just @option{-} will also be scanned in full, regardless of
3034 the presence of any @option{-d} option.
3036 @command{strings} is mainly useful for determining the contents of
3041 @c man begin OPTIONS strings
3047 Scan the whole file, regardless of what sections it contains or
3048 whether those sections are loaded or initialized. Normally this is
3049 the default behaviour, but strings can be configured so that the
3050 @option{-d} is the default instead.
3052 The @option{-} option is position dependent and forces strings to
3053 perform full scans of any file that is mentioned after the @option{-}
3054 on the command line, even if the @option{-d} option has been
3059 Only print strings from initialized, loaded data sections in the
3060 file. This may reduce the amount of garbage in the output, but it
3061 also exposes the strings program to any security flaws that may be
3062 present in the BFD library used to scan and load sections. Strings
3063 can be configured so that this option is the default behaviour. In
3064 such cases the @option{-a} option can be used to avoid using the BFD
3065 library and instead just print all of the strings found in the file.
3068 @itemx --print-file-name
3069 Print the name of the file before each string.
3072 Print a summary of the program usage on the standard output and exit.
3074 @item -@var{min-len}
3075 @itemx -n @var{min-len}
3076 @itemx --bytes=@var{min-len}
3077 Print sequences of characters that are at least @var{min-len} characters
3078 long, instead of the default 4.
3081 Like @samp{-t o}. Some other versions of @command{strings} have @option{-o}
3082 act like @samp{-t d} instead. Since we can not be compatible with both
3083 ways, we simply chose one.
3085 @item -t @var{radix}
3086 @itemx --radix=@var{radix}
3087 Print the offset within the file before each string. The single
3088 character argument specifies the radix of the offset---@samp{o} for
3089 octal, @samp{x} for hexadecimal, or @samp{d} for decimal.
3091 @item -e @var{encoding}
3092 @itemx --encoding=@var{encoding}
3093 Select the character encoding of the strings that are to be found.
3094 Possible values for @var{encoding} are: @samp{s} = single-7-bit-byte
3095 characters (ASCII, ISO 8859, etc., default), @samp{S} =
3096 single-8-bit-byte characters, @samp{b} = 16-bit bigendian, @samp{l} =
3097 16-bit littleendian, @samp{B} = 32-bit bigendian, @samp{L} = 32-bit
3098 littleendian. Useful for finding wide character strings. (@samp{l}
3099 and @samp{b} apply to, for example, Unicode UTF-16/UCS-2 encodings).
3101 @item -T @var{bfdname}
3102 @itemx --target=@var{bfdname}
3103 @cindex object code format
3104 Specify an object code format other than your system's default format.
3105 @xref{Target Selection}, for more information.
3110 Print the program version number on the standard output and exit.
3113 @itemx --include-all-whitespace
3114 By default tab and space characters are included in the strings that
3115 are displayed, but other whitespace characters, such a newlines and
3116 carriage returns, are not. The @option{-w} option changes this so
3117 that all whitespace characters are considered to be part of a string.
3120 @itemx --output-separator
3121 By default, output strings are delimited by a new-line. This option
3122 allows you to supply any string to be used as the output record
3123 separator. Useful with --include-all-whitespace where strings
3124 may contain new-lines internally.
3130 @c man begin SEEALSO strings
3131 ar(1), nm(1), objdump(1), ranlib(1), readelf(1)
3132 and the Info entries for @file{binutils}.
3140 @cindex removing symbols
3141 @cindex discarding symbols
3142 @cindex symbols, discarding
3144 @c man title strip Discard symbols from object files.
3147 @c man begin SYNOPSIS strip
3148 strip [@option{-F} @var{bfdname} |@option{--target=}@var{bfdname}]
3149 [@option{-I} @var{bfdname} |@option{--input-target=}@var{bfdname}]
3150 [@option{-O} @var{bfdname} |@option{--output-target=}@var{bfdname}]
3151 [@option{-s}|@option{--strip-all}]
3152 [@option{-S}|@option{-g}|@option{-d}|@option{--strip-debug}]
3153 [@option{--strip-dwo}]
3154 [@option{-K} @var{symbolname}|@option{--keep-symbol=}@var{symbolname}]
3155 [@option{-M}|@option{--merge-notes}][@option{--no-merge-notes}]
3156 [@option{-N} @var{symbolname} |@option{--strip-symbol=}@var{symbolname}]
3157 [@option{-w}|@option{--wildcard}]
3158 [@option{-x}|@option{--discard-all}] [@option{-X} |@option{--discard-locals}]
3159 [@option{-R} @var{sectionname} |@option{--remove-section=}@var{sectionname}]
3160 [@option{--remove-relocations=}@var{sectionpattern}]
3161 [@option{-o} @var{file}] [@option{-p}|@option{--preserve-dates}]
3162 [@option{-D}|@option{--enable-deterministic-archives}]
3163 [@option{-U}|@option{--disable-deterministic-archives}]
3164 [@option{--keep-file-symbols}]
3165 [@option{--only-keep-debug}]
3166 [@option{-v} |@option{--verbose}] [@option{-V}|@option{--version}]
3167 [@option{--help}] [@option{--info}]
3168 @var{objfile}@dots{}
3172 @c man begin DESCRIPTION strip
3174 @sc{gnu} @command{strip} discards all symbols from object files
3175 @var{objfile}. The list of object files may include archives.
3176 At least one object file must be given.
3178 @command{strip} modifies the files named in its argument,
3179 rather than writing modified copies under different names.
3183 @c man begin OPTIONS strip
3186 @item -F @var{bfdname}
3187 @itemx --target=@var{bfdname}
3188 Treat the original @var{objfile} as a file with the object
3189 code format @var{bfdname}, and rewrite it in the same format.
3190 @xref{Target Selection}, for more information.
3193 Show a summary of the options to @command{strip} and exit.
3196 Display a list showing all architectures and object formats available.
3198 @item -I @var{bfdname}
3199 @itemx --input-target=@var{bfdname}
3200 Treat the original @var{objfile} as a file with the object
3201 code format @var{bfdname}.
3202 @xref{Target Selection}, for more information.
3204 @item -O @var{bfdname}
3205 @itemx --output-target=@var{bfdname}
3206 Replace @var{objfile} with a file in the output format @var{bfdname}.
3207 @xref{Target Selection}, for more information.
3209 @item -R @var{sectionname}
3210 @itemx --remove-section=@var{sectionname}
3211 Remove any section named @var{sectionname} from the output file, in
3212 addition to whatever sections would otherwise be removed. This
3213 option may be given more than once. Note that using this option
3214 inappropriately may make the output file unusable. The wildcard
3215 character @samp{*} may be given at the end of @var{sectionname}. If
3216 so, then any section starting with @var{sectionname} will be removed.
3218 If the first character of @var{sectionpattern} is the exclamation
3219 point (!) then matching sections will not be removed even if an
3220 earlier use of @option{--remove-section} on the same command line
3221 would otherwise remove it. For example:
3224 --remove-section=.text.* --remove-section=!.text.foo
3227 will remove all sections matching the pattern '.text.*', but will not
3228 remove the section '.text.foo'.
3230 @item --remove-relocations=@var{sectionpattern}
3231 Remove relocations from the output file for any section matching
3232 @var{sectionpattern}. This option may be given more than once. Note
3233 that using this option inappropriately may make the output file
3234 unusable. Wildcard characters are accepted in @var{sectionpattern}.
3238 --remove-relocations=.text.*
3241 will remove the relocations for all sections matching the patter
3244 If the first character of @var{sectionpattern} is the exclamation
3245 point (!) then matching sections will not have their relocation
3246 removed even if an earlier use of @option{--remove-relocations} on the
3247 same command line would otherwise cause the relocations to be removed.
3251 --remove-relocations=.text.* --remove-relocations=!.text.foo
3254 will remove all relocations for sections matching the pattern
3255 '.text.*', but will not remove relocations for the section
3265 @itemx --strip-debug
3266 Remove debugging symbols only.
3269 Remove the contents of all DWARF .dwo sections, leaving the
3270 remaining debugging sections and all symbols intact.
3271 See the description of this option in the @command{objcopy} section
3272 for more information.
3274 @item --strip-unneeded
3275 Remove all symbols that are not needed for relocation processing.
3277 @item -K @var{symbolname}
3278 @itemx --keep-symbol=@var{symbolname}
3279 When stripping symbols, keep symbol @var{symbolname} even if it would
3280 normally be stripped. This option may be given more than once.
3283 @itemx --merge-notes
3284 @itemx --no-merge-notes
3285 For ELF files, attempt (or do not attempt) to reduce the size of any
3286 SHT_NOTE type sections by removing duplicate notes. The default is to
3287 attempt this reduction.
3289 @item -N @var{symbolname}
3290 @itemx --strip-symbol=@var{symbolname}
3291 Remove symbol @var{symbolname} from the source file. This option may be
3292 given more than once, and may be combined with strip options other than
3296 Put the stripped output in @var{file}, rather than replacing the
3297 existing file. When this argument is used, only one @var{objfile}
3298 argument may be specified.
3301 @itemx --preserve-dates
3302 Preserve the access and modification dates of the file.
3305 @itemx --enable-deterministic-archives
3306 @cindex deterministic archives
3307 @kindex --enable-deterministic-archives
3308 Operate in @emph{deterministic} mode. When copying archive members
3309 and writing the archive index, use zero for UIDs, GIDs, timestamps,
3310 and use consistent file modes for all files.
3312 If @file{binutils} was configured with
3313 @option{--enable-deterministic-archives}, then this mode is on by default.
3314 It can be disabled with the @samp{-U} option, below.
3317 @itemx --disable-deterministic-archives
3318 @cindex deterministic archives
3319 @kindex --enable-deterministic-archives
3320 Do @emph{not} operate in @emph{deterministic} mode. This is the
3321 inverse of the @option{-D} option, above: when copying archive members
3322 and writing the archive index, use their actual UID, GID, timestamp,
3323 and file mode values.
3325 This is the default unless @file{binutils} was configured with
3326 @option{--enable-deterministic-archives}.
3330 Permit regular expressions in @var{symbolname}s used in other command
3331 line options. The question mark (?), asterisk (*), backslash (\) and
3332 square brackets ([]) operators can be used anywhere in the symbol
3333 name. If the first character of the symbol name is the exclamation
3334 point (!) then the sense of the switch is reversed for that symbol.
3341 would cause strip to only keep symbols that start with the letters
3342 ``fo'', but to discard the symbol ``foo''.
3345 @itemx --discard-all
3346 Remove non-global symbols.
3349 @itemx --discard-locals
3350 Remove compiler-generated local symbols.
3351 (These usually start with @samp{L} or @samp{.}.)
3353 @item --keep-file-symbols
3354 When stripping a file, perhaps with @option{--strip-debug} or
3355 @option{--strip-unneeded}, retain any symbols specifying source file names,
3356 which would otherwise get stripped.
3358 @item --only-keep-debug
3359 Strip a file, emptying the contents of any sections that would not be
3360 stripped by @option{--strip-debug} and leaving the debugging sections
3361 intact. In ELF files, this preserves all the note sections in the
3364 Note - the section headers of the stripped sections are preserved,
3365 including their sizes, but the contents of the section are discarded.
3366 The section headers are preserved so that other tools can match up the
3367 debuginfo file with the real executable, even if that executable has
3368 been relocated to a different address space.
3370 The intention is that this option will be used in conjunction with
3371 @option{--add-gnu-debuglink} to create a two part executable. One a
3372 stripped binary which will occupy less space in RAM and in a
3373 distribution and the second a debugging information file which is only
3374 needed if debugging abilities are required. The suggested procedure
3375 to create these files is as follows:
3378 @item Link the executable as normal. Assuming that it is called
3380 @item Run @code{objcopy --only-keep-debug foo foo.dbg} to
3381 create a file containing the debugging info.
3382 @item Run @code{objcopy --strip-debug foo} to create a
3383 stripped executable.
3384 @item Run @code{objcopy --add-gnu-debuglink=foo.dbg foo}
3385 to add a link to the debugging info into the stripped executable.
3388 Note---the choice of @code{.dbg} as an extension for the debug info
3389 file is arbitrary. Also the @code{--only-keep-debug} step is
3390 optional. You could instead do this:
3393 @item Link the executable as normal.
3394 @item Copy @code{foo} to @code{foo.full}
3395 @item Run @code{strip --strip-debug foo}
3396 @item Run @code{objcopy --add-gnu-debuglink=foo.full foo}
3399 i.e., the file pointed to by the @option{--add-gnu-debuglink} can be the
3400 full executable. It does not have to be a file created by the
3401 @option{--only-keep-debug} switch.
3403 Note---this switch is only intended for use on fully linked files. It
3404 does not make sense to use it on object files where the debugging
3405 information may be incomplete. Besides the gnu_debuglink feature
3406 currently only supports the presence of one filename containing
3407 debugging information, not multiple filenames on a one-per-object-file
3412 Show the version number for @command{strip}.
3416 Verbose output: list all object files modified. In the case of
3417 archives, @samp{strip -v} lists all members of the archive.
3423 @c man begin SEEALSO strip
3424 the Info entries for @file{binutils}.
3428 @node c++filt, addr2line, strip, Top
3432 @cindex demangling C++ symbols
3434 @c man title cxxfilt Demangle C++ and Java symbols.
3437 @c man begin SYNOPSIS cxxfilt
3438 c++filt [@option{-_}|@option{--strip-underscore}]
3439 [@option{-n}|@option{--no-strip-underscore}]
3440 [@option{-p}|@option{--no-params}]
3441 [@option{-t}|@option{--types}]
3442 [@option{-i}|@option{--no-verbose}]
3443 [@option{-r}|@option{--no-recurse-limit}]
3444 [@option{-R}|@option{--recurse-limit}]
3445 [@option{-s} @var{format}|@option{--format=}@var{format}]
3446 [@option{--help}] [@option{--version}] [@var{symbol}@dots{}]
3450 @c man begin DESCRIPTION cxxfilt
3453 The C++ and Java languages provide function overloading, which means
3454 that you can write many functions with the same name, providing that
3455 each function takes parameters of different types. In order to be
3456 able to distinguish these similarly named functions C++ and Java
3457 encode them into a low-level assembler name which uniquely identifies
3458 each different version. This process is known as @dfn{mangling}. The
3460 @footnote{MS-DOS does not allow @kbd{+} characters in file names, so on
3461 MS-DOS this program is named @command{CXXFILT}.}
3462 program does the inverse mapping: it decodes (@dfn{demangles}) low-level
3463 names into user-level names so that they can be read.
3465 Every alphanumeric word (consisting of letters, digits, underscores,
3466 dollars, or periods) seen in the input is a potential mangled name.
3467 If the name decodes into a C++ name, the C++ name replaces the
3468 low-level name in the output, otherwise the original word is output.
3469 In this way you can pass an entire assembler source file, containing
3470 mangled names, through @command{c++filt} and see the same source file
3471 containing demangled names.
3473 You can also use @command{c++filt} to decipher individual symbols by
3474 passing them on the command line:
3477 c++filt @var{symbol}
3480 If no @var{symbol} arguments are given, @command{c++filt} reads symbol
3481 names from the standard input instead. All the results are printed on
3482 the standard output. The difference between reading names from the
3483 command line versus reading names from the standard input is that
3484 command-line arguments are expected to be just mangled names and no
3485 checking is performed to separate them from surrounding text. Thus
3492 will work and demangle the name to ``f()'' whereas:
3498 will not work. (Note the extra comma at the end of the mangled
3499 name which makes it invalid). This command however will work:
3502 echo _Z1fv, | c++filt -n
3505 and will display ``f(),'', i.e., the demangled name followed by a
3506 trailing comma. This behaviour is because when the names are read
3507 from the standard input it is expected that they might be part of an
3508 assembler source file where there might be extra, extraneous
3509 characters trailing after a mangled name. For example:
3512 .type _Z1fv, @@function
3517 @c man begin OPTIONS cxxfilt
3521 @itemx --strip-underscore
3522 On some systems, both the C and C++ compilers put an underscore in front
3523 of every name. For example, the C name @code{foo} gets the low-level
3524 name @code{_foo}. This option removes the initial underscore. Whether
3525 @command{c++filt} removes the underscore by default is target dependent.
3528 @itemx --no-strip-underscore
3529 Do not remove the initial underscore.
3533 When demangling the name of a function, do not display the types of
3534 the function's parameters.
3538 Attempt to demangle types as well as function names. This is disabled
3539 by default since mangled types are normally only used internally in
3540 the compiler, and they can be confused with non-mangled names. For example,
3541 a function called ``a'' treated as a mangled type name would be
3542 demangled to ``signed char''.
3546 Do not include implementation details (if any) in the demangled
3551 @itemx --recurse-limit
3552 @itemx --no-recurse-limit
3553 @itemx --recursion-limit
3554 @itemx --no-recursion-limit
3555 Enables or disables a limit on the amount of recursion performed
3556 whilst demangling strings. Since the name mangling formats allow for
3557 an inifinite level of recursion it is possible to create strings whose
3558 decoding will exhaust the amount of stack space available on the host
3559 machine, triggering a memory fault. The limit tries to prevent this
3560 from happening by restricting recursion to 2048 levels of nesting.
3562 The default is for this limit to be enabled, but disabling it may be
3563 necessary in order to demangle truly complicated names. Note however
3564 that if the recursion limit is disabled then stack exhaustion is
3565 possible and any bug reports about such an event will be rejected.
3567 The @option{-r} option is a synonym for the
3568 @option{--no-recurse-limit} option. The @option{-R} option is a
3569 synonym for the @option{--recurse-limit} option.
3571 @item -s @var{format}
3572 @itemx --format=@var{format}
3573 @command{c++filt} can decode various methods of mangling, used by
3574 different compilers. The argument to this option selects which
3579 Automatic selection based on executable (the default method)
3581 the one used by the @sc{gnu} C++ compiler (g++)
3583 the one used by the Lucid compiler (lcc)
3585 the one specified by the C++ Annotated Reference Manual
3587 the one used by the HP compiler (aCC)
3589 the one used by the EDG compiler
3591 the one used by the @sc{gnu} C++ compiler (g++) with the V3 ABI.
3593 the one used by the @sc{gnu} Java compiler (gcj)
3595 the one used by the @sc{gnu} Ada compiler (GNAT).
3599 Print a summary of the options to @command{c++filt} and exit.
3602 Print the version number of @command{c++filt} and exit.
3608 @c man begin SEEALSO cxxfilt
3609 the Info entries for @file{binutils}.
3614 @emph{Warning:} @command{c++filt} is a new utility, and the details of its
3615 user interface are subject to change in future releases. In particular,
3616 a command-line option may be required in the future to decode a name
3617 passed as an argument on the command line; in other words,
3620 c++filt @var{symbol}
3624 may in a future release become
3627 c++filt @var{option} @var{symbol}
3635 @cindex address to file name and line number
3637 @c man title addr2line convert addresses into file names and line numbers.
3640 @c man begin SYNOPSIS addr2line
3641 addr2line [@option{-a}|@option{--addresses}]
3642 [@option{-b} @var{bfdname}|@option{--target=}@var{bfdname}]
3643 [@option{-C}|@option{--demangle}[=@var{style}]]
3644 [@option{-r}|@option{--no-recurse-limit}]
3645 [@option{-R}|@option{--recurse-limit}]
3646 [@option{-e} @var{filename}|@option{--exe=}@var{filename}]
3647 [@option{-f}|@option{--functions}] [@option{-s}|@option{--basename}]
3648 [@option{-i}|@option{--inlines}]
3649 [@option{-p}|@option{--pretty-print}]
3650 [@option{-j}|@option{--section=}@var{name}]
3651 [@option{-H}|@option{--help}] [@option{-V}|@option{--version}]
3656 @c man begin DESCRIPTION addr2line
3658 @command{addr2line} translates addresses into file names and line numbers.
3659 Given an address in an executable or an offset in a section of a relocatable
3660 object, it uses the debugging information to figure out which file name and
3661 line number are associated with it.
3663 The executable or relocatable object to use is specified with the @option{-e}
3664 option. The default is the file @file{a.out}. The section in the relocatable
3665 object to use is specified with the @option{-j} option.
3667 @command{addr2line} has two modes of operation.
3669 In the first, hexadecimal addresses are specified on the command line,
3670 and @command{addr2line} displays the file name and line number for each
3673 In the second, @command{addr2line} reads hexadecimal addresses from
3674 standard input, and prints the file name and line number for each
3675 address on standard output. In this mode, @command{addr2line} may be used
3676 in a pipe to convert dynamically chosen addresses.
3678 The format of the output is @samp{FILENAME:LINENO}. By default
3679 each input address generates one line of output.
3681 Two options can generate additional lines before each
3682 @samp{FILENAME:LINENO} line (in that order).
3684 If the @option{-a} option is used then a line with the input address
3687 If the @option{-f} option is used, then a line with the
3688 @samp{FUNCTIONNAME} is displayed. This is the name of the function
3689 containing the address.
3691 One option can generate additional lines after the
3692 @samp{FILENAME:LINENO} line.
3694 If the @option{-i} option is used and the code at the given address is
3695 present there because of inlining by the compiler then additional
3696 lines are displayed afterwards. One or two extra lines (if the
3697 @option{-f} option is used) are displayed for each inlined function.
3699 Alternatively if the @option{-p} option is used then each input
3700 address generates a single, long, output line containing the address,
3701 the function name, the file name and the line number. If the
3702 @option{-i} option has also been used then any inlined functions will
3703 be displayed in the same manner, but on separate lines, and prefixed
3704 by the text @samp{(inlined by)}.
3706 If the file name or function name can not be determined,
3707 @command{addr2line} will print two question marks in their place. If the
3708 line number can not be determined, @command{addr2line} will print 0.
3712 @c man begin OPTIONS addr2line
3714 The long and short forms of options, shown here as alternatives, are
3720 Display the address before the function name, file and line number
3721 information. The address is printed with a @samp{0x} prefix to easily
3724 @item -b @var{bfdname}
3725 @itemx --target=@var{bfdname}
3726 @cindex object code format
3727 Specify that the object-code format for the object files is
3731 @itemx --demangle[=@var{style}]
3732 @cindex demangling in objdump
3733 Decode (@dfn{demangle}) low-level symbol names into user-level names.
3734 Besides removing any initial underscore prepended by the system, this
3735 makes C++ function names readable. Different compilers have different
3736 mangling styles. The optional demangling style argument can be used to
3737 choose an appropriate demangling style for your compiler. @xref{c++filt},
3738 for more information on demangling.
3740 @item -e @var{filename}
3741 @itemx --exe=@var{filename}
3742 Specify the name of the executable for which addresses should be
3743 translated. The default file is @file{a.out}.
3747 Display function names as well as file and line number information.
3751 Display only the base of each file name.
3755 If the address belongs to a function that was inlined, the source
3756 information for all enclosing scopes back to the first non-inlined
3757 function will also be printed. For example, if @code{main} inlines
3758 @code{callee1} which inlines @code{callee2}, and address is from
3759 @code{callee2}, the source information for @code{callee1} and @code{main}
3760 will also be printed.
3764 Read offsets relative to the specified section instead of absolute addresses.
3767 @itemx --pretty-print
3768 Make the output more human friendly: each location are printed on one line.
3769 If option @option{-i} is specified, lines for all enclosing scopes are
3770 prefixed with @samp{(inlined by)}.
3774 @itemx --recurse-limit
3775 @itemx --no-recurse-limit
3776 @itemx --recursion-limit
3777 @itemx --no-recursion-limit
3778 Enables or disables a limit on the amount of recursion performed
3779 whilst demangling strings. Since the name mangling formats allow for
3780 an inifinite level of recursion it is possible to create strings whose
3781 decoding will exhaust the amount of stack space available on the host
3782 machine, triggering a memory fault. The limit tries to prevent this
3783 from happening by restricting recursion to 2048 levels of nesting.
3785 The default is for this limit to be enabled, but disabling it may be
3786 necessary in order to demangle truly complicated names. Note however
3787 that if the recursion limit is disabled then stack exhaustion is
3788 possible and any bug reports about such an event will be rejected.
3790 The @option{-r} option is a synonym for the
3791 @option{--no-recurse-limit} option. The @option{-R} option is a
3792 synonym for the @option{--recurse-limit} option.
3794 Note this option is only effective if the @option{-C} or
3795 @option{--demangle} option has been enabled.
3802 @c man begin SEEALSO addr2line
3803 Info entries for @file{binutils}.
3810 @command{windmc} may be used to generator Windows message resources.
3813 @emph{Warning:} @command{windmc} is not always built as part of the binary
3814 utilities, since it is only useful for Windows targets.
3817 @c man title windmc generates Windows message resources.
3820 @c man begin SYNOPSIS windmc
3821 windmc [options] input-file
3825 @c man begin DESCRIPTION windmc
3827 @command{windmc} reads message definitions from an input file (.mc) and
3828 translate them into a set of output files. The output files may be of
3833 A C header file containing the message definitions.
3836 A resource file compilable by the @command{windres} tool.
3839 One or more binary files containing the resource data for a specific
3843 A C include file that maps message id's to their symbolic name.
3846 The exact description of these different formats is available in
3847 documentation from Microsoft.
3849 When @command{windmc} converts from the @code{mc} format to the @code{bin}
3850 format, @code{rc}, @code{h}, and optional @code{dbg} it is acting like the
3851 Windows Message Compiler.
3855 @c man begin OPTIONS windmc
3860 Specifies that the input file specified is ASCII. This is the default
3865 Specifies that messages in the output @code{bin} files should be in ASCII
3870 Specifies that @code{bin} filenames should have to be prefixed by the
3871 basename of the source file.
3875 Sets the customer bit in all message id's.
3877 @item -C @var{codepage}
3878 @itemx --codepage_in @var{codepage}
3879 Sets the default codepage to be used to convert input file to UTF16. The
3880 default is ocdepage 1252.
3883 @itemx --decimal_values
3884 Outputs the constants in the header file in decimal. Default is using
3888 @itemx --extension @var{ext}
3889 The extension for the header file. The default is .h extension.
3891 @item -F @var{target}
3892 @itemx --target @var{target}
3893 Specify the BFD format to use for a bin file as output. This
3894 is a BFD target name; you can use the @option{--help} option to see a list
3895 of supported targets. Normally @command{windmc} will use the default
3896 format, which is the first one listed by the @option{--help} option.
3898 @ref{Target Selection}.
3902 @itemx --headerdir @var{path}
3903 The target directory of the generated header file. The default is the
3908 Displays a list of command-line options and then exits.
3910 @item -m @var{characters}
3911 @itemx --maxlength @var{characters}
3912 Instructs @command{windmc} to generate a warning if the length
3913 of any message exceeds the number specified.
3916 @itemx --nullterminate
3917 Terminate message text in @code{bin} files by zero. By default they are
3918 terminated by CR/LF.
3921 @itemx --hresult_use
3922 Not yet implemented. Instructs @code{windmc} to generate an OLE2 header
3923 file, using HRESULT definitions. Status codes are used if the flag is not
3926 @item -O @var{codepage}
3927 @itemx --codepage_out @var{codepage}
3928 Sets the default codepage to be used to output text files. The default
3932 @itemx --rcdir @var{path}
3933 The target directory for the generated @code{rc} script and the generated
3934 @code{bin} files that the resource compiler script includes. The default
3935 is the current directory.
3939 Specifies that the input file is UTF16.
3942 @itemx --unicode_out
3943 Specifies that messages in the output @code{bin} file should be in UTF16
3944 format. This is the default behaviour.
3948 Enable verbose mode.
3952 Prints the version number for @command{windmc}.
3955 @itemx --xdgb @var{path}
3956 The path of the @code{dbg} C include file that maps message id's to the
3957 symbolic name. No such file is generated without specifying the switch.
3963 @c man begin SEEALSO windmc
3964 the Info entries for @file{binutils}.
3971 @command{windres} may be used to manipulate Windows resources.
3974 @emph{Warning:} @command{windres} is not always built as part of the binary
3975 utilities, since it is only useful for Windows targets.
3978 @c man title windres manipulate Windows resources.
3981 @c man begin SYNOPSIS windres
3982 windres [options] [input-file] [output-file]
3986 @c man begin DESCRIPTION windres
3988 @command{windres} reads resources from an input file and copies them into
3989 an output file. Either file may be in one of three formats:
3993 A text format read by the Resource Compiler.
3996 A binary format generated by the Resource Compiler.
3999 A COFF object or executable.
4002 The exact description of these different formats is available in
4003 documentation from Microsoft.
4005 When @command{windres} converts from the @code{rc} format to the @code{res}
4006 format, it is acting like the Windows Resource Compiler. When
4007 @command{windres} converts from the @code{res} format to the @code{coff}
4008 format, it is acting like the Windows @code{CVTRES} program.
4010 When @command{windres} generates an @code{rc} file, the output is similar
4011 but not identical to the format expected for the input. When an input
4012 @code{rc} file refers to an external filename, an output @code{rc} file
4013 will instead include the file contents.
4015 If the input or output format is not specified, @command{windres} will
4016 guess based on the file name, or, for the input file, the file contents.
4017 A file with an extension of @file{.rc} will be treated as an @code{rc}
4018 file, a file with an extension of @file{.res} will be treated as a
4019 @code{res} file, and a file with an extension of @file{.o} or
4020 @file{.exe} will be treated as a @code{coff} file.
4022 If no output file is specified, @command{windres} will print the resources
4023 in @code{rc} format to standard output.
4025 The normal use is for you to write an @code{rc} file, use @command{windres}
4026 to convert it to a COFF object file, and then link the COFF file into
4027 your application. This will make the resources described in the
4028 @code{rc} file available to Windows.
4032 @c man begin OPTIONS windres
4035 @item -i @var{filename}
4036 @itemx --input @var{filename}
4037 The name of the input file. If this option is not used, then
4038 @command{windres} will use the first non-option argument as the input file
4039 name. If there are no non-option arguments, then @command{windres} will
4040 read from standard input. @command{windres} can not read a COFF file from
4043 @item -o @var{filename}
4044 @itemx --output @var{filename}
4045 The name of the output file. If this option is not used, then
4046 @command{windres} will use the first non-option argument, after any used
4047 for the input file name, as the output file name. If there is no
4048 non-option argument, then @command{windres} will write to standard output.
4049 @command{windres} can not write a COFF file to standard output. Note,
4050 for compatibility with @command{rc} the option @option{-fo} is also
4051 accepted, but its use is not recommended.
4053 @item -J @var{format}
4054 @itemx --input-format @var{format}
4055 The input format to read. @var{format} may be @samp{res}, @samp{rc}, or
4056 @samp{coff}. If no input format is specified, @command{windres} will
4057 guess, as described above.
4059 @item -O @var{format}
4060 @itemx --output-format @var{format}
4061 The output format to generate. @var{format} may be @samp{res},
4062 @samp{rc}, or @samp{coff}. If no output format is specified,
4063 @command{windres} will guess, as described above.
4065 @item -F @var{target}
4066 @itemx --target @var{target}
4067 Specify the BFD format to use for a COFF file as input or output. This
4068 is a BFD target name; you can use the @option{--help} option to see a list
4069 of supported targets. Normally @command{windres} will use the default
4070 format, which is the first one listed by the @option{--help} option.
4072 @ref{Target Selection}.
4075 @item --preprocessor @var{program}
4076 When @command{windres} reads an @code{rc} file, it runs it through the C
4077 preprocessor first. This option may be used to specify the preprocessor
4078 to use, including any leading arguments. The default preprocessor
4079 argument is @code{gcc -E -xc-header -DRC_INVOKED}.
4081 @item --preprocessor-arg @var{option}
4082 When @command{windres} reads an @code{rc} file, it runs it through
4083 the C preprocessor first. This option may be used to specify additional
4084 text to be passed to preprocessor on its command line.
4085 This option can be used multiple times to add multiple options to the
4086 preprocessor command line.
4088 @item -I @var{directory}
4089 @itemx --include-dir @var{directory}
4090 Specify an include directory to use when reading an @code{rc} file.
4091 @command{windres} will pass this to the preprocessor as an @option{-I}
4092 option. @command{windres} will also search this directory when looking for
4093 files named in the @code{rc} file. If the argument passed to this command
4094 matches any of the supported @var{formats} (as described in the @option{-J}
4095 option), it will issue a deprecation warning, and behave just like the
4096 @option{-J} option. New programs should not use this behaviour. If a
4097 directory happens to match a @var{format}, simple prefix it with @samp{./}
4098 to disable the backward compatibility.
4100 @item -D @var{target}
4101 @itemx --define @var{sym}[=@var{val}]
4102 Specify a @option{-D} option to pass to the preprocessor when reading an
4105 @item -U @var{target}
4106 @itemx --undefine @var{sym}
4107 Specify a @option{-U} option to pass to the preprocessor when reading an
4111 Ignored for compatibility with rc.
4114 Enable verbose mode. This tells you what the preprocessor is if you
4118 @item --codepage @var{val}
4119 Specify the default codepage to use when reading an @code{rc} file.
4120 @var{val} should be a hexadecimal prefixed by @samp{0x} or decimal
4121 codepage code. The valid range is from zero up to 0xffff, but the
4122 validity of the codepage is host and configuration dependent.
4125 @item --language @var{val}
4126 Specify the default language to use when reading an @code{rc} file.
4127 @var{val} should be a hexadecimal language code. The low eight bits are
4128 the language, and the high eight bits are the sublanguage.
4130 @item --use-temp-file
4131 Use a temporary file to instead of using popen to read the output of
4132 the preprocessor. Use this option if the popen implementation is buggy
4133 on the host (eg., certain non-English language versions of Windows 95 and
4134 Windows 98 are known to have buggy popen where the output will instead
4137 @item --no-use-temp-file
4138 Use popen, not a temporary file, to read the output of the preprocessor.
4139 This is the default behaviour.
4143 Prints a usage summary.
4147 Prints the version number for @command{windres}.
4150 If @command{windres} is compiled with @code{YYDEBUG} defined as @code{1},
4151 this will turn on parser debugging.
4157 @c man begin SEEALSO windres
4158 the Info entries for @file{binutils}.
4167 @command{dlltool} is used to create the files needed to create dynamic
4168 link libraries (DLLs) on systems which understand PE format image
4169 files such as Windows. A DLL contains an export table which contains
4170 information that the runtime loader needs to resolve references from a
4171 referencing program.
4173 The export table is generated by this program by reading in a
4174 @file{.def} file or scanning the @file{.a} and @file{.o} files which
4175 will be in the DLL. A @file{.o} file can contain information in
4176 special @samp{.drectve} sections with export information.
4179 @emph{Note:} @command{dlltool} is not always built as part of the
4180 binary utilities, since it is only useful for those targets which
4184 @c man title dlltool Create files needed to build and use DLLs.
4187 @c man begin SYNOPSIS dlltool
4188 dlltool [@option{-d}|@option{--input-def} @var{def-file-name}]
4189 [@option{-b}|@option{--base-file} @var{base-file-name}]
4190 [@option{-e}|@option{--output-exp} @var{exports-file-name}]
4191 [@option{-z}|@option{--output-def} @var{def-file-name}]
4192 [@option{-l}|@option{--output-lib} @var{library-file-name}]
4193 [@option{-y}|@option{--output-delaylib} @var{library-file-name}]
4194 [@option{--export-all-symbols}] [@option{--no-export-all-symbols}]
4195 [@option{--exclude-symbols} @var{list}]
4196 [@option{--no-default-excludes}]
4197 [@option{-S}|@option{--as} @var{path-to-assembler}] [@option{-f}|@option{--as-flags} @var{options}]
4198 [@option{-D}|@option{--dllname} @var{name}] [@option{-m}|@option{--machine} @var{machine}]
4199 [@option{-a}|@option{--add-indirect}]
4200 [@option{-U}|@option{--add-underscore}] [@option{--add-stdcall-underscore}]
4201 [@option{-k}|@option{--kill-at}] [@option{-A}|@option{--add-stdcall-alias}]
4202 [@option{-p}|@option{--ext-prefix-alias} @var{prefix}]
4203 [@option{-x}|@option{--no-idata4}] [@option{-c}|@option{--no-idata5}]
4204 [@option{--use-nul-prefixed-import-tables}]
4205 [@option{-I}|@option{--identify} @var{library-file-name}] [@option{--identify-strict}]
4206 [@option{-i}|@option{--interwork}]
4207 [@option{-n}|@option{--nodelete}] [@option{-t}|@option{--temp-prefix} @var{prefix}]
4208 [@option{-v}|@option{--verbose}]
4209 [@option{-h}|@option{--help}] [@option{-V}|@option{--version}]
4210 [@option{--no-leading-underscore}] [@option{--leading-underscore}]
4211 [object-file @dots{}]
4215 @c man begin DESCRIPTION dlltool
4217 @command{dlltool} reads its inputs, which can come from the @option{-d} and
4218 @option{-b} options as well as object files specified on the command
4219 line. It then processes these inputs and if the @option{-e} option has
4220 been specified it creates a exports file. If the @option{-l} option
4221 has been specified it creates a library file and if the @option{-z} option
4222 has been specified it creates a def file. Any or all of the @option{-e},
4223 @option{-l} and @option{-z} options can be present in one invocation of
4226 When creating a DLL, along with the source for the DLL, it is necessary
4227 to have three other files. @command{dlltool} can help with the creation of
4230 The first file is a @file{.def} file which specifies which functions are
4231 exported from the DLL, which functions the DLL imports, and so on. This
4232 is a text file and can be created by hand, or @command{dlltool} can be used
4233 to create it using the @option{-z} option. In this case @command{dlltool}
4234 will scan the object files specified on its command line looking for
4235 those functions which have been specially marked as being exported and
4236 put entries for them in the @file{.def} file it creates.
4238 In order to mark a function as being exported from a DLL, it needs to
4239 have an @option{-export:<name_of_function>} entry in the @samp{.drectve}
4240 section of the object file. This can be done in C by using the
4244 asm (".section .drectve");
4245 asm (".ascii \"-export:my_func\"");
4247 int my_func (void) @{ @dots{} @}
4250 The second file needed for DLL creation is an exports file. This file
4251 is linked with the object files that make up the body of the DLL and it
4252 handles the interface between the DLL and the outside world. This is a
4253 binary file and it can be created by giving the @option{-e} option to
4254 @command{dlltool} when it is creating or reading in a @file{.def} file.
4256 The third file needed for DLL creation is the library file that programs
4257 will link with in order to access the functions in the DLL (an `import
4258 library'). This file can be created by giving the @option{-l} option to
4259 dlltool when it is creating or reading in a @file{.def} file.
4261 If the @option{-y} option is specified, dlltool generates a delay-import
4262 library that can be used instead of the normal import library to allow
4263 a program to link to the dll only as soon as an imported function is
4264 called for the first time. The resulting executable will need to be
4265 linked to the static delayimp library containing __delayLoadHelper2(),
4266 which in turn will import LoadLibraryA and GetProcAddress from kernel32.
4268 @command{dlltool} builds the library file by hand, but it builds the
4269 exports file by creating temporary files containing assembler statements
4270 and then assembling these. The @option{-S} command-line option can be
4271 used to specify the path to the assembler that dlltool will use,
4272 and the @option{-f} option can be used to pass specific flags to that
4273 assembler. The @option{-n} can be used to prevent dlltool from deleting
4274 these temporary assembler files when it is done, and if @option{-n} is
4275 specified twice then this will prevent dlltool from deleting the
4276 temporary object files it used to build the library.
4278 Here is an example of creating a DLL from a source file @samp{dll.c} and
4279 also creating a program (from an object file called @samp{program.o})
4284 dlltool -e exports.o -l dll.lib dll.o
4285 gcc dll.o exports.o -o dll.dll
4286 gcc program.o dll.lib -o program
4290 @command{dlltool} may also be used to query an existing import library
4291 to determine the name of the DLL to which it is associated. See the
4292 description of the @option{-I} or @option{--identify} option.
4296 @c man begin OPTIONS dlltool
4298 The command-line options have the following meanings:
4302 @item -d @var{filename}
4303 @itemx --input-def @var{filename}
4304 @cindex input .def file
4305 Specifies the name of a @file{.def} file to be read in and processed.
4307 @item -b @var{filename}
4308 @itemx --base-file @var{filename}
4310 Specifies the name of a base file to be read in and processed. The
4311 contents of this file will be added to the relocation section in the
4312 exports file generated by dlltool.
4314 @item -e @var{filename}
4315 @itemx --output-exp @var{filename}
4316 Specifies the name of the export file to be created by dlltool.
4318 @item -z @var{filename}
4319 @itemx --output-def @var{filename}
4320 Specifies the name of the @file{.def} file to be created by dlltool.
4322 @item -l @var{filename}
4323 @itemx --output-lib @var{filename}
4324 Specifies the name of the library file to be created by dlltool.
4326 @item -y @var{filename}
4327 @itemx --output-delaylib @var{filename}
4328 Specifies the name of the delay-import library file to be created by dlltool.
4330 @item --export-all-symbols
4331 Treat all global and weak defined symbols found in the input object
4332 files as symbols to be exported. There is a small list of symbols which
4333 are not exported by default; see the @option{--no-default-excludes}
4334 option. You may add to the list of symbols to not export by using the
4335 @option{--exclude-symbols} option.
4337 @item --no-export-all-symbols
4338 Only export symbols explicitly listed in an input @file{.def} file or in
4339 @samp{.drectve} sections in the input object files. This is the default
4340 behaviour. The @samp{.drectve} sections are created by @samp{dllexport}
4341 attributes in the source code.
4343 @item --exclude-symbols @var{list}
4344 Do not export the symbols in @var{list}. This is a list of symbol names
4345 separated by comma or colon characters. The symbol names should not
4346 contain a leading underscore. This is only meaningful when
4347 @option{--export-all-symbols} is used.
4349 @item --no-default-excludes
4350 When @option{--export-all-symbols} is used, it will by default avoid
4351 exporting certain special symbols. The current list of symbols to avoid
4352 exporting is @samp{DllMain@@12}, @samp{DllEntryPoint@@0},
4353 @samp{impure_ptr}. You may use the @option{--no-default-excludes} option
4354 to go ahead and export these special symbols. This is only meaningful
4355 when @option{--export-all-symbols} is used.
4358 @itemx --as @var{path}
4359 Specifies the path, including the filename, of the assembler to be used
4360 to create the exports file.
4362 @item -f @var{options}
4363 @itemx --as-flags @var{options}
4364 Specifies any specific command-line options to be passed to the
4365 assembler when building the exports file. This option will work even if
4366 the @option{-S} option is not used. This option only takes one argument,
4367 and if it occurs more than once on the command line, then later
4368 occurrences will override earlier occurrences. So if it is necessary to
4369 pass multiple options to the assembler they should be enclosed in
4373 @itemx --dll-name @var{name}
4374 Specifies the name to be stored in the @file{.def} file as the name of
4375 the DLL when the @option{-e} option is used. If this option is not
4376 present, then the filename given to the @option{-e} option will be
4377 used as the name of the DLL.
4379 @item -m @var{machine}
4380 @itemx -machine @var{machine}
4381 Specifies the type of machine for which the library file should be
4382 built. @command{dlltool} has a built in default type, depending upon how
4383 it was created, but this option can be used to override that. This is
4384 normally only useful when creating DLLs for an ARM processor, when the
4385 contents of the DLL are actually encode using Thumb instructions.
4388 @itemx --add-indirect
4389 Specifies that when @command{dlltool} is creating the exports file it
4390 should add a section which allows the exported functions to be
4391 referenced without using the import library. Whatever the hell that
4395 @itemx --add-underscore
4396 Specifies that when @command{dlltool} is creating the exports file it
4397 should prepend an underscore to the names of @emph{all} exported symbols.
4399 @item --no-leading-underscore
4400 @item --leading-underscore
4401 Specifies whether standard symbol should be forced to be prefixed, or
4404 @item --add-stdcall-underscore
4405 Specifies that when @command{dlltool} is creating the exports file it
4406 should prepend an underscore to the names of exported @emph{stdcall}
4407 functions. Variable names and non-stdcall function names are not modified.
4408 This option is useful when creating GNU-compatible import libs for third
4409 party DLLs that were built with MS-Windows tools.
4413 Specifies that @samp{@@<number>} suffixes should be omitted from the names
4414 of stdcall functions that will be imported from the DLL. This is
4415 useful when creating an import library for a DLL which exports stdcall
4416 functions but without the usual @samp{@@<number>} symbol name suffix.
4418 This does not change the naming of symbols provided by the import library
4419 to programs linked against it, but only the entries in the import table
4420 (ie the .idata section).
4423 @itemx --add-stdcall-alias
4424 Specifies that when @command{dlltool} is creating the exports file it
4425 should add aliases for stdcall symbols without @samp{@@ <number>}
4426 in addition to the symbols with @samp{@@ <number>}.
4429 @itemx --ext-prefix-alias @var{prefix}
4430 Causes @command{dlltool} to create external aliases for all DLL
4431 imports with the specified prefix. The aliases are created for both
4432 external and import symbols with no leading underscore.
4436 Specifies that when @command{dlltool} is creating the exports and library
4437 files it should omit the @code{.idata4} section. This is for compatibility
4438 with certain operating systems.
4440 @item --use-nul-prefixed-import-tables
4441 Specifies that when @command{dlltool} is creating the exports and library
4442 files it should prefix the @code{.idata4} and @code{.idata5} by zero an
4443 element. This emulates old gnu import library generation of
4444 @code{dlltool}. By default this option is turned off.
4448 Specifies that when @command{dlltool} is creating the exports and library
4449 files it should omit the @code{.idata5} section. This is for compatibility
4450 with certain operating systems.
4452 @item -I @var{filename}
4453 @itemx --identify @var{filename}
4454 Specifies that @command{dlltool} should inspect the import library
4455 indicated by @var{filename} and report, on @code{stdout}, the name(s)
4456 of the associated DLL(s). This can be performed in addition to any
4457 other operations indicated by the other options and arguments.
4458 @command{dlltool} fails if the import library does not exist or is not
4459 actually an import library. See also @option{--identify-strict}.
4461 @item --identify-strict
4462 Modifies the behavior of the @option{--identify} option, such
4463 that an error is reported if @var{filename} is associated with
4468 Specifies that @command{dlltool} should mark the objects in the library
4469 file and exports file that it produces as supporting interworking
4470 between ARM and Thumb code.
4474 Makes @command{dlltool} preserve the temporary assembler files it used to
4475 create the exports file. If this option is repeated then dlltool will
4476 also preserve the temporary object files it uses to create the library
4479 @item -t @var{prefix}
4480 @itemx --temp-prefix @var{prefix}
4481 Makes @command{dlltool} use @var{prefix} when constructing the names of
4482 temporary assembler and object files. By default, the temp file prefix
4483 is generated from the pid.
4487 Make dlltool describe what it is doing.
4491 Displays a list of command-line options and then exits.
4495 Displays dlltool's version number and then exits.
4502 * def file format:: The format of the dlltool @file{.def} file
4505 @node def file format
4506 @section The format of the @command{dlltool} @file{.def} file
4508 A @file{.def} file contains any number of the following commands:
4512 @item @code{NAME} @var{name} @code{[ ,} @var{base} @code{]}
4513 The result is going to be named @var{name}@code{.exe}.
4515 @item @code{LIBRARY} @var{name} @code{[ ,} @var{base} @code{]}
4516 The result is going to be named @var{name}@code{.dll}.
4517 Note: If you want to use LIBRARY as name then you need to quote. Otherwise
4518 this will fail due a necessary hack for libtool (see PR binutils/13710 for more
4521 @item @code{EXPORTS ( ( (} @var{name1} @code{[ = } @var{name2} @code{] ) | ( } @var{name1} @code{=} @var{module-name} @code{.} @var{external-name} @code{) ) [ == } @var{its_name} @code{]}
4522 @item @code{[} @var{integer} @code{] [ NONAME ] [ CONSTANT ] [ DATA ] [ PRIVATE ] ) *}
4523 Declares @var{name1} as an exported symbol from the DLL, with optional
4524 ordinal number @var{integer}, or declares @var{name1} as an alias
4525 (forward) of the function @var{external-name} in the DLL.
4526 If @var{its_name} is specified, this name is used as string in export table.
4528 Note: The @code{EXPORTS} has to be the last command in .def file, as keywords
4529 are treated - beside @code{LIBRARY} - as simple name-identifiers.
4530 If you want to use LIBRARY as name then you need to quote it.
4532 @item @code{IMPORTS ( (} @var{internal-name} @code{=} @var{module-name} @code{.} @var{integer} @code{) | [} @var{internal-name} @code{= ]} @var{module-name} @code{.} @var{external-name} @code{) [ == ) @var{its_name} @code{]} *}
4533 Declares that @var{external-name} or the exported function whose
4534 ordinal number is @var{integer} is to be imported from the file
4535 @var{module-name}. If @var{internal-name} is specified then this is
4536 the name that the imported function will be referred to in the body of
4538 If @var{its_name} is specified, this name is used as string in import table.
4539 Note: The @code{IMPORTS} has to be the last command in .def file, as keywords
4540 are treated - beside @code{LIBRARY} - as simple name-identifiers.
4541 If you want to use LIBRARY as name then you need to quote it.
4543 @item @code{DESCRIPTION} @var{string}
4544 Puts @var{string} into the output @file{.exp} file in the
4545 @code{.rdata} section.
4547 @item @code{STACKSIZE} @var{number-reserve} @code{[, } @var{number-commit} @code{]}
4548 @item @code{HEAPSIZE} @var{number-reserve} @code{[, } @var{number-commit} @code{]}
4549 Generates @code{--stack} or @code{--heap}
4550 @var{number-reserve},@var{number-commit} in the output @code{.drectve}
4551 section. The linker will see this and act upon it.
4553 @item @code{CODE} @var{attr} @code{+}
4554 @item @code{DATA} @var{attr} @code{+}
4555 @item @code{SECTIONS (} @var{section-name} @var{attr}@code{ + ) *}
4556 Generates @code{--attr} @var{section-name} @var{attr} in the output
4557 @code{.drectve} section, where @var{attr} is one of @code{READ},
4558 @code{WRITE}, @code{EXECUTE} or @code{SHARED}. The linker will see
4559 this and act upon it.
4564 @c man begin SEEALSO dlltool
4565 The Info pages for @file{binutils}.
4572 @cindex ELF file information
4575 @c man title readelf Displays information about ELF files.
4578 @c man begin SYNOPSIS readelf
4579 readelf [@option{-a}|@option{--all}]
4580 [@option{-h}|@option{--file-header}]
4581 [@option{-l}|@option{--program-headers}|@option{--segments}]
4582 [@option{-S}|@option{--section-headers}|@option{--sections}]
4583 [@option{-g}|@option{--section-groups}]
4584 [@option{-t}|@option{--section-details}]
4585 [@option{-e}|@option{--headers}]
4586 [@option{-s}|@option{--syms}|@option{--symbols}]
4587 [@option{--dyn-syms}]
4588 [@option{-n}|@option{--notes}]
4589 [@option{-r}|@option{--relocs}]
4590 [@option{-u}|@option{--unwind}]
4591 [@option{-d}|@option{--dynamic}]
4592 [@option{-V}|@option{--version-info}]
4593 [@option{-A}|@option{--arch-specific}]
4594 [@option{-D}|@option{--use-dynamic}]
4595 [@option{-x} <number or name>|@option{--hex-dump=}<number or name>]
4596 [@option{-p} <number or name>|@option{--string-dump=}<number or name>]
4597 [@option{-R} <number or name>|@option{--relocated-dump=}<number or name>]
4598 [@option{-z}|@option{--decompress}]
4599 [@option{-c}|@option{--archive-index}]
4600 [@option{-w[lLiaprmfFsoRtUuTgAckK]}|
4601 @option{--debug-dump}[=rawline,=decodedline,=info,=abbrev,=pubnames,=aranges,=macro,=frames,=frames-interp,=str,=loc,=Ranges,=pubtypes,=trace_info,=trace_abbrev,=trace_aranges,=gdb_index,=addr,=cu_index,=links,=follow-links]]
4602 [@option{--dwarf-depth=@var{n}}]
4603 [@option{--dwarf-start=@var{n}}]
4604 [@option{-I}|@option{--histogram}]
4605 [@option{-v}|@option{--version}]
4606 [@option{-W}|@option{--wide}]
4607 [@option{-H}|@option{--help}]
4608 @var{elffile}@dots{}
4612 @c man begin DESCRIPTION readelf
4614 @command{readelf} displays information about one or more ELF format object
4615 files. The options control what particular information to display.
4617 @var{elffile}@dots{} are the object files to be examined. 32-bit and
4618 64-bit ELF files are supported, as are archives containing ELF files.
4620 This program performs a similar function to @command{objdump} but it
4621 goes into more detail and it exists independently of the @sc{bfd}
4622 library, so if there is a bug in @sc{bfd} then readelf will not be
4627 @c man begin OPTIONS readelf
4629 The long and short forms of options, shown here as alternatives, are
4630 equivalent. At least one option besides @samp{-v} or @samp{-H} must be
4636 Equivalent to specifying @option{--file-header},
4637 @option{--program-headers}, @option{--sections}, @option{--symbols},
4638 @option{--relocs}, @option{--dynamic}, @option{--notes},
4639 @option{--version-info}, @option{--arch-specific}, @option{--unwind},
4640 @option{--section-groups} and @option{--histogram}.
4642 Note - this option does not enable @option{--use-dynamic} itself, so
4643 if that option is not present on the command line then dynamic symbols
4644 and dynamic relocs will not be displayed.
4647 @itemx --file-header
4648 @cindex ELF file header information
4649 Displays the information contained in the ELF header at the start of the
4653 @itemx --program-headers
4655 @cindex ELF program header information
4656 @cindex ELF segment information
4657 Displays the information contained in the file's segment headers, if it
4662 @itemx --section-headers
4663 @cindex ELF section information
4664 Displays the information contained in the file's section headers, if it
4668 @itemx --section-groups
4669 @cindex ELF section group information
4670 Displays the information contained in the file's section groups, if it
4674 @itemx --section-details
4675 @cindex ELF section information
4676 Displays the detailed section information. Implies @option{-S}.
4681 @cindex ELF symbol table information
4682 Displays the entries in symbol table section of the file, if it has one.
4683 If a symbol has version information associated with it then this is
4684 displayed as well. The version string is displayed as a suffix to the
4685 symbol name, preceeded by an @@ character. For example
4686 @samp{foo@@VER_1}. If the version is the default version to be used
4687 when resolving unversioned references to the symbol then it is
4688 displayed as a suffix preceeded by two @@ characters. For example
4689 @samp{foo@@@@VER_2}.
4692 @cindex ELF dynamic symbol table information
4693 Displays the entries in dynamic symbol table section of the file, if it
4694 has one. The output format is the same as the format used by the
4695 @option{--syms} option.
4699 Display all the headers in the file. Equivalent to @option{-h -l -S}.
4704 Displays the contents of the NOTE segments and/or sections, if any.
4708 @cindex ELF reloc information
4709 Displays the contents of the file's relocation section, if it has one.
4713 @cindex unwind information
4714 Displays the contents of the file's unwind section, if it has one. Only
4715 the unwind sections for IA64 ELF files, as well as ARM unwind tables
4716 (@code{.ARM.exidx} / @code{.ARM.extab}) are currently supported. If
4717 support is not yet implemented for your architecture you could try
4718 dumping the contents of the @var{.eh_frames} section using the
4719 @option{--debug-dump=frames} or @option{--debug-dump=frames-interp}
4724 @cindex ELF dynamic section information
4725 Displays the contents of the file's dynamic section, if it has one.
4728 @itemx --version-info
4729 @cindex ELF version sections information
4730 Displays the contents of the version sections in the file, it they
4734 @itemx --arch-specific
4735 Displays architecture-specific information in the file, if there
4739 @itemx --use-dynamic
4740 When displaying symbols, this option makes @command{readelf} use the
4741 symbol hash tables in the file's dynamic section, rather than the
4742 symbol table sections.
4744 When displaying relocations, this option makes @command{readelf}
4745 display the dynamic relocations rather than the static relocations.
4747 @item -x <number or name>
4748 @itemx --hex-dump=<number or name>
4749 Displays the contents of the indicated section as a hexadecimal bytes.
4750 A number identifies a particular section by index in the section table;
4751 any other string identifies all sections with that name in the object file.
4753 @item -R <number or name>
4754 @itemx --relocated-dump=<number or name>
4755 Displays the contents of the indicated section as a hexadecimal
4756 bytes. A number identifies a particular section by index in the
4757 section table; any other string identifies all sections with that name
4758 in the object file. The contents of the section will be relocated
4759 before they are displayed.
4761 @item -p <number or name>
4762 @itemx --string-dump=<number or name>
4763 Displays the contents of the indicated section as printable strings.
4764 A number identifies a particular section by index in the section table;
4765 any other string identifies all sections with that name in the object file.
4769 Requests that the section(s) being dumped by @option{x}, @option{R} or
4770 @option{p} options are decompressed before being displayed. If the
4771 section(s) are not compressed then they are displayed as is.
4774 @itemx --archive-index
4775 @cindex Archive file symbol index information
4776 Displays the file symbol index information contained in the header part
4777 of binary archives. Performs the same function as the @option{t}
4778 command to @command{ar}, but without using the BFD library. @xref{ar}.
4780 @item -w[lLiaprmfFsoRtUuTgAckK]
4781 @itemx --debug-dump[=rawline,=decodedline,=info,=abbrev,=pubnames,=aranges,=macro,=frames,=frames-interp,=str,=loc,=Ranges,=pubtypes,=trace_info,=trace_abbrev,=trace_aranges,=gdb_index,=addr,=cu_index,=links,=follow-links]
4782 @include debug.options.texi
4786 Display a histogram of bucket list lengths when displaying the contents
4787 of the symbol tables.
4791 Display the version number of readelf.
4795 Don't break output lines to fit into 80 columns. By default
4796 @command{readelf} breaks section header and segment listing lines for
4797 64-bit ELF files, so that they fit into 80 columns. This option causes
4798 @command{readelf} to print each section header resp. each segment one a
4799 single line, which is far more readable on terminals wider than 80 columns.
4803 Display the command-line options understood by @command{readelf}.
4810 @c man begin SEEALSO readelf
4811 objdump(1), and the Info entries for @file{binutils}.
4818 @cindex Update ELF header
4821 @c man title elfedit Update ELF header and program property of ELF files.
4824 @c man begin SYNOPSIS elfedit
4825 elfedit [@option{--input-mach=}@var{machine}]
4826 [@option{--input-type=}@var{type}]
4827 [@option{--input-osabi=}@var{osabi}]
4828 @option{--output-mach=}@var{machine}
4829 @option{--output-type=}@var{type}
4830 @option{--output-osabi=}@var{osabi}
4831 @option{--enable-x86-feature=}@var{feature}
4832 @option{--disable-x86-feature=}@var{feature}
4833 [@option{-v}|@option{--version}]
4834 [@option{-h}|@option{--help}]
4835 @var{elffile}@dots{}
4839 @c man begin DESCRIPTION elfedit
4841 @command{elfedit} updates the ELF header and program property of ELF
4842 files which have the matching ELF machine and file types. The options
4843 control how and which fields in the ELF header and program property
4846 @var{elffile}@dots{} are the ELF files to be updated. 32-bit and
4847 64-bit ELF files are supported, as are archives containing ELF files.
4850 @c man begin OPTIONS elfedit
4852 The long and short forms of options, shown here as alternatives, are
4853 equivalent. At least one of the @option{--output-mach},
4854 @option{--output-type}, @option{--output-osabi},
4855 @option{--enable-x86-feature} and @option{--disable-x86-feature}
4856 options must be given.
4860 @item --input-mach=@var{machine}
4861 Set the matching input ELF machine type to @var{machine}. If
4862 @option{--input-mach} isn't specified, it will match any ELF
4865 The supported ELF machine types are, @var{i386}, @var{IAMCU}, @var{L1OM},
4866 @var{K1OM} and @var{x86-64}.
4868 @item --output-mach=@var{machine}
4869 Change the ELF machine type in the ELF header to @var{machine}. The
4870 supported ELF machine types are the same as @option{--input-mach}.
4872 @item --input-type=@var{type}
4873 Set the matching input ELF file type to @var{type}. If
4874 @option{--input-type} isn't specified, it will match any ELF file types.
4876 The supported ELF file types are, @var{rel}, @var{exec} and @var{dyn}.
4878 @item --output-type=@var{type}
4879 Change the ELF file type in the ELF header to @var{type}. The
4880 supported ELF types are the same as @option{--input-type}.
4882 @item --input-osabi=@var{osabi}
4883 Set the matching input ELF file OSABI to @var{osabi}. If
4884 @option{--input-osabi} isn't specified, it will match any ELF OSABIs.
4886 The supported ELF OSABIs are, @var{none}, @var{HPUX}, @var{NetBSD},
4887 @var{GNU}, @var{Linux} (alias for @var{GNU}),
4888 @var{Solaris}, @var{AIX}, @var{Irix},
4889 @var{FreeBSD}, @var{TRU64}, @var{Modesto}, @var{OpenBSD}, @var{OpenVMS},
4890 @var{NSK}, @var{AROS} and @var{FenixOS}.
4892 @item --output-osabi=@var{osabi}
4893 Change the ELF OSABI in the ELF header to @var{osabi}. The
4894 supported ELF OSABI are the same as @option{--input-osabi}.
4896 @item --enable-x86-feature=@var{feature}
4897 Set the @var{feature} bit in program property in @var{exec} or @var{dyn}
4898 ELF files with machine types of @var{i386} or @var{x86-64}. The
4899 supported features are, @var{ibt} and @var{shstk}.
4901 @item --disable-x86-feature=@var{feature}
4902 Clear the @var{feature} bit in program property in @var{exec} or
4903 @var{dyn} ELF files with machine types of @var{i386} or @var{x86-64}.
4904 The supported features are the same as @option{--enable-x86-feature}.
4906 Note: @option{--enable-x86-feature} and @option{--disable-x86-feature}
4907 are available only on hosts with @samp{mmap} support.
4911 Display the version number of @command{elfedit}.
4915 Display the command-line options understood by @command{elfedit}.
4922 @c man begin SEEALSO elfedit
4923 readelf(1), and the Info entries for @file{binutils}.
4927 @node Common Options
4928 @chapter Common Options
4930 The following command-line options are supported by all of the
4931 programs described in this manual.
4933 @c man begin OPTIONS
4935 @include at-file.texi
4939 Display the command-line options supported by the program.
4942 Display the version number of the program.
4944 @c man begin OPTIONS
4948 @node Selecting the Target System
4949 @chapter Selecting the Target System
4951 You can specify two aspects of the target system to the @sc{gnu}
4952 binary file utilities, each in several ways:
4962 In the following summaries, the lists of ways to specify values are in
4963 order of decreasing precedence. The ways listed first override those
4966 The commands to list valid values only list the values for which the
4967 programs you are running were configured. If they were configured with
4968 @option{--enable-targets=all}, the commands list most of the available
4969 values, but a few are left out; not all targets can be configured in at
4970 once because some of them can only be configured @dfn{native} (on hosts
4971 with the same type as the target system).
4974 * Target Selection::
4975 * Architecture Selection::
4978 @node Target Selection
4979 @section Target Selection
4981 A @dfn{target} is an object file format. A given target may be
4982 supported for multiple architectures (@pxref{Architecture Selection}).
4983 A target selection may also have variations for different operating
4984 systems or architectures.
4986 The command to list valid target values is @samp{objdump -i}
4987 (the first column of output contains the relevant information).
4989 Some sample values are: @samp{a.out-hp300bsd}, @samp{ecoff-littlemips},
4990 @samp{a.out-sunos-big}.
4992 You can also specify a target using a configuration triplet. This is
4993 the same sort of name that is passed to @file{configure} to specify a
4994 target. When you use a configuration triplet as an argument, it must be
4995 fully canonicalized. You can see the canonical version of a triplet by
4996 running the shell script @file{config.sub} which is included with the
4999 Some sample configuration triplets are: @samp{m68k-hp-bsd},
5000 @samp{mips-dec-ultrix}, @samp{sparc-sun-sunos}.
5002 @subheading @command{objdump} Target
5008 command-line option: @option{-b} or @option{--target}
5011 environment variable @code{GNUTARGET}
5014 deduced from the input file
5017 @subheading @command{objcopy} and @command{strip} Input Target
5023 command-line options: @option{-I} or @option{--input-target}, or @option{-F} or @option{--target}
5026 environment variable @code{GNUTARGET}
5029 deduced from the input file
5032 @subheading @command{objcopy} and @command{strip} Output Target
5038 command-line options: @option{-O} or @option{--output-target}, or @option{-F} or @option{--target}
5041 the input target (see ``@command{objcopy} and @command{strip} Input Target'' above)
5044 environment variable @code{GNUTARGET}
5047 deduced from the input file
5050 @subheading @command{nm}, @command{size}, and @command{strings} Target
5056 command-line option: @option{--target}
5059 environment variable @code{GNUTARGET}
5062 deduced from the input file
5065 @node Architecture Selection
5066 @section Architecture Selection
5068 An @dfn{architecture} is a type of @sc{cpu} on which an object file is
5069 to run. Its name may contain a colon, separating the name of the
5070 processor family from the name of the particular @sc{cpu}.
5072 The command to list valid architecture values is @samp{objdump -i} (the
5073 second column contains the relevant information).
5075 Sample values: @samp{m68k:68020}, @samp{mips:3000}, @samp{sparc}.
5077 @subheading @command{objdump} Architecture
5083 command-line option: @option{-m} or @option{--architecture}
5086 deduced from the input file
5089 @subheading @command{objcopy}, @command{nm}, @command{size}, @command{strings} Architecture
5095 deduced from the input file
5098 @node Reporting Bugs
5099 @chapter Reporting Bugs
5101 @cindex reporting bugs
5103 Your bug reports play an essential role in making the binary utilities
5106 Reporting a bug may help you by bringing a solution to your problem, or
5107 it may not. But in any case the principal function of a bug report is
5108 to help the entire community by making the next version of the binary
5109 utilities work better. Bug reports are your contribution to their
5112 In order for a bug report to serve its purpose, you must include the
5113 information that enables us to fix the bug.
5116 * Bug Criteria:: Have you found a bug?
5117 * Bug Reporting:: How to report bugs
5121 @section Have You Found a Bug?
5122 @cindex bug criteria
5124 If you are not sure whether you have found a bug, here are some guidelines:
5127 @cindex fatal signal
5130 If a binary utility gets a fatal signal, for any input whatever, that is
5131 a bug. Reliable utilities never crash.
5133 @cindex error on valid input
5135 If a binary utility produces an error message for valid input, that is a
5139 If you are an experienced user of binary utilities, your suggestions for
5140 improvement are welcome in any case.
5144 @section How to Report Bugs
5146 @cindex bugs, reporting
5148 A number of companies and individuals offer support for @sc{gnu}
5149 products. If you obtained the binary utilities from a support
5150 organization, we recommend you contact that organization first.
5152 You can find contact information for many support companies and
5153 individuals in the file @file{etc/SERVICE} in the @sc{gnu} Emacs
5157 In any event, we also recommend that you send bug reports for the binary
5158 utilities to @value{BUGURL}.
5161 The fundamental principle of reporting bugs usefully is this:
5162 @strong{report all the facts}. If you are not sure whether to state a
5163 fact or leave it out, state it!
5165 Often people omit facts because they think they know what causes the
5166 problem and assume that some details do not matter. Thus, you might
5167 assume that the name of a file you use in an example does not matter.
5168 Well, probably it does not, but one cannot be sure. Perhaps the bug is
5169 a stray memory reference which happens to fetch from the location where
5170 that pathname is stored in memory; perhaps, if the pathname were
5171 different, the contents of that location would fool the utility into
5172 doing the right thing despite the bug. Play it safe and give a
5173 specific, complete example. That is the easiest thing for you to do,
5174 and the most helpful.
5176 Keep in mind that the purpose of a bug report is to enable us to fix the bug if
5177 it is new to us. Therefore, always write your bug reports on the assumption
5178 that the bug has not been reported previously.
5180 Sometimes people give a few sketchy facts and ask, ``Does this ring a
5181 bell?'' This cannot help us fix a bug, so it is basically useless. We
5182 respond by asking for enough details to enable us to investigate.
5183 You might as well expedite matters by sending them to begin with.
5185 To enable us to fix the bug, you should include all these things:
5189 The version of the utility. Each utility announces it if you start it
5190 with the @option{--version} argument.
5192 Without this, we will not know whether there is any point in looking for
5193 the bug in the current version of the binary utilities.
5196 Any patches you may have applied to the source, including any patches
5197 made to the @code{BFD} library.
5200 The type of machine you are using, and the operating system name and
5204 What compiler (and its version) was used to compile the utilities---e.g.
5208 The command arguments you gave the utility to observe the bug. To
5209 guarantee you will not omit something important, list them all. A copy
5210 of the Makefile (or the output from make) is sufficient.
5212 If we were to try to guess the arguments, we would probably guess wrong
5213 and then we might not encounter the bug.
5216 A complete input file, or set of input files, that will reproduce the
5217 bug. If the utility is reading an object file or files, then it is
5218 generally most helpful to send the actual object files.
5220 If the source files were produced exclusively using @sc{gnu} programs
5221 (e.g., @command{gcc}, @command{gas}, and/or the @sc{gnu} @command{ld}), then it
5222 may be OK to send the source files rather than the object files. In
5223 this case, be sure to say exactly what version of @command{gcc}, or
5224 whatever, was used to produce the object files. Also say how
5225 @command{gcc}, or whatever, was configured.
5228 A description of what behavior you observe that you believe is
5229 incorrect. For example, ``It gets a fatal signal.''
5231 Of course, if the bug is that the utility gets a fatal signal, then we
5232 will certainly notice it. But if the bug is incorrect output, we might
5233 not notice unless it is glaringly wrong. You might as well not give us
5234 a chance to make a mistake.
5236 Even if the problem you experience is a fatal signal, you should still
5237 say so explicitly. Suppose something strange is going on, such as your
5238 copy of the utility is out of sync, or you have encountered a bug in
5239 the C library on your system. (This has happened!) Your copy might
5240 crash and ours would not. If you told us to expect a crash, then when
5241 ours fails to crash, we would know that the bug was not happening for
5242 us. If you had not told us to expect a crash, then we would not be able
5243 to draw any conclusion from our observations.
5246 If you wish to suggest changes to the source, send us context diffs, as
5247 generated by @command{diff} with the @option{-u}, @option{-c}, or @option{-p}
5248 option. Always send diffs from the old file to the new file. If you
5249 wish to discuss something in the @command{ld} source, refer to it by
5250 context, not by line number.
5252 The line numbers in our development sources will not match those in your
5253 sources. Your line numbers would convey no useful information to us.
5256 Here are some things that are not necessary:
5260 A description of the envelope of the bug.
5262 Often people who encounter a bug spend a lot of time investigating
5263 which changes to the input file will make the bug go away and which
5264 changes will not affect it.
5266 This is often time consuming and not very useful, because the way we
5267 will find the bug is by running a single example under the debugger
5268 with breakpoints, not by pure deduction from a series of examples.
5269 We recommend that you save your time for something else.
5271 Of course, if you can find a simpler example to report @emph{instead}
5272 of the original one, that is a convenience for us. Errors in the
5273 output will be easier to spot, running under the debugger will take
5274 less time, and so on.
5276 However, simplification is not vital; if you do not want to do this,
5277 report the bug anyway and send us the entire test case you used.
5280 A patch for the bug.
5282 A patch for the bug does help us if it is a good one. But do not omit
5283 the necessary information, such as the test case, on the assumption that
5284 a patch is all we need. We might see problems with your patch and decide
5285 to fix the problem another way, or we might not understand it at all.
5287 Sometimes with programs as complicated as the binary utilities it is
5288 very hard to construct an example that will make the program follow a
5289 certain path through the code. If you do not send us the example, we
5290 will not be able to construct one, so we will not be able to verify that
5293 And if we cannot understand what bug you are trying to fix, or why your
5294 patch should be an improvement, we will not install it. A test case will
5295 help us to understand.
5298 A guess about what the bug is or what it depends on.
5300 Such guesses are usually wrong. Even we cannot guess right about such
5301 things without first using the debugger to find the facts.
5304 @node GNU Free Documentation License
5305 @appendix GNU Free Documentation License
5309 @node Binutils Index
5310 @unnumbered Binutils Index