1 GNU M4 NEWS - User visible changes.
3 * Noteworthy changes in release 1.4.19 (2021-05-28) [stable]
5 ** A number of portability improvements inherited from gnulib, including
6 the ability to perform stack overflow detection on more platforms
7 without linking to GNU libsigsegv.
9 * Noteworthy changes in release 1.4.18d (2021-05-11) [beta]
11 ** A number of portability improvements inherited from gnulib.
14 * Noteworthy changes in release 1.4.18b (2021-05-07) [beta]
16 ** The symbol hash table now defaults to 65537 buckets instead of 509, as
17 modern systems have enough memory to benefit from fewer hash collisions
20 ** Introduce the use of gettext, with the immediate benefit of nicer
21 UTF-8 author names. Over time, more translations of program messages
22 will become available.
24 ** A number of portability improvements inherited from gnulib.
27 * Noteworthy changes in release 1.4.18 (2016-12-31) [stable]
29 ** Diagnose --word-regexp as unsupported if it was not configured.
31 ** Preliminary support for OS/2.
33 ** A number of portability improvements inherited from gnulib.
36 * Noteworthy changes in release 1.4.17 (2013-09-22) [stable]
38 ** Fix compilation with newer glibc headers.
40 ** Fix a failure with diverting large amounts of text on mingw (does
41 not affect platforms that can rename an open file).
43 ** A number of portability improvements inherited from gnulib.
46 * Noteworthy changes in release 1.4.16 (2011-03-01) [stable]
48 ** Fix regressions in the `index' builtin. On glibc platforms, this
49 avoids false positives from a strstr bug in glibc 2.9 through 2.12;
50 on many other platforms, it fixes two separate regressions, a false
51 positive introduced in 1.4.11 and a false negative in 1.4.15.
53 ** A number of portability improvements inherited from gnulib.
56 * Noteworthy changes in release 1.4.15 (2010-08-31) [stable]
58 ** Fix regression introduced in 1.4.9b where the `format' builtin could
59 crash on an invalid format string.
61 ** Fix compilation against newer glibc, and on AIX 7.1BETA.
63 ** A number of portability improvements inherited from gnulib.
66 * Noteworthy changes in Version 1.4.14 (2010-02-24) [stable]
67 Released by Eric Blake, based on git version 1.4.13.*
69 ** Fix regression introduced in 1.4.12 where executing with stdout closed
70 could crash m4 on exit on some platforms.
72 ** Fix regressions introduced in 1.4.13 in the `esyscmd' builtin, where
73 closed file descriptors could interfere with child execution, and where
74 a child status of 127 made m4 print a spurious message to stderr.
76 ** Fix a security hole in 'make dist', present since at least M4 1.4, that
77 could affect anybody attempting to redistribute modified sources (see
78 Automake CVE-2009-4029).
80 ** A number of portability improvements inherited from gnulib.
82 * Noteworthy changes in Version 1.4.13 (2009-04-01) [stable]
83 Released by Eric Blake, based on git version 1.4.12.*
85 ** The manual is now distributed under the terms of FDL 1.3.
87 ** The `divert' and `undivert' builtins have been made more efficient
88 when using temporary files for large diversions.
90 ** The `translit' builtin has been made more efficient when the second
93 ** The input engine has been optimized for faster processing.
95 ** The command line option `--debugfile', introduced in 1.4.7, now
96 treats its argument as optional, in order to allow setting the debug
97 output back to stderr when used without an argument; and order is now
98 significant with respect to command line files. You must therefore use
99 `m4 --debugfile=trace file', not `m4 file --debugfile trace'. This
100 change does not affect the deprecated `-o'/`--error-output' option.
102 ** The `syscmd' and `esyscmd' builtins can be configured to use an
103 alternate shell, via the new `configure' option `--with-syscmd-shell'.
105 ** A number of portability improvements inherited from gnulib.
107 * Noteworthy changes in Version 1.4.12 (2008-10-10) [stable]
108 Released by Eric Blake, based on git version 1.4.11.*
110 ** Fix regression introduced in 1.4.4b where using `traceon' could delete
111 a macro. This was most noticeable with `traceon(`traceon')', but
112 would also happen in cases such as `foo(traceon(`foo'))'.
114 ** Fix regression introduced in 1.4.7 where `m4 -N9' died with an assertion
117 ** Fix regression introduced in 1.4.11 where `defn' died with an assertion
118 failure on a traced but undefined macro.
120 ** New `-g'/`--gnu' command-line option overrides `-G'/`--traditional'.
121 For now, the environment variable POSIXLY_CORRECT has no effect on M4
122 behavior; but a future release of M4 will behave as though --traditional
123 is implied if POSIXLY_CORRECT is set (this future change is necessary,
124 because in the current release, there is no way to disable GNU
125 extensions that conflict with POSIX without the use of a non-POSIX
126 command-line argument). Clients of M4 that want to use GNU extensions,
127 even when POSIXLY_CORRECT is set, should start using the -g command-line
128 argument, even though it is currently a no-op if -G did not appear
129 earlier in the command line, so that the client will not break in the
130 face of an upgraded m4 and a POSIXLY_CORRECT execution environment.
132 ** The `-L'/`--nesting-limit' command-line option now defaults to 0 for
133 unlimited on platforms that can detect and deal with stack overflow. On
134 systems that lack alternate stack support, such as Cygwin, and on
135 systems that do not obey the POSIX semantics for distinguishing stack
136 overflow from other exceptions, such as Linux, you can optionally
137 install the libsigsegv library (version 2.6 or newer recommended) to
138 enhance m4's ability to accurately report stack overflow:
139 https://www.gnu.org/software/libsigsegv/
141 ** A number of portability improvements inherited from gnulib.
143 * Noteworthy changes in Version 1.4.11 (2008-04-02) [stable]
144 Released by Eric Blake, based on git version 1.4.10a
146 ** Security fixes for the -F option, for bugs present since -F was
147 introduced in 1.3: Avoid core dump with 'm4 -F file -t undefined', and
148 avoid arbitrary code execution with certain file names.
150 ** Fix regression introduced in 1.4.9b in the `divert' builtin when more
151 than 512 kibibytes are saved in diversions on platforms like NetBSD
152 or darwin where fopen(name,"a+") seeks to the end of the file.
154 ** The output of the `maketemp' and `mkstemp' builtins is now quoted if a
155 file was created. This is a minor security fix, because it was possible
156 (although rather unlikely) that an unquoted string could match an
157 existing macro name, such that use of the `mkstemp' output would trigger
158 inadvertent macro expansion and operate on the wrong file name.
160 ** Enhance the `defn' builtin to support concatenation of multiple text
161 arguments, as required by POSIX. However, at this time, it is not
162 possible to concatenate a builtin macro with anything else; a warning is
163 now issued if this is attempted, although a future version of M4 may
164 lift this restriction to match other implementations.
166 ** Enhance the `format' builtin to parse all C99 floating point numbers,
167 even on platforms where strtod(3) is buggy, although the replacement
168 function does have the known issue of rounding errors when parsing
169 some decimal floating point values. This fixes testsuite failures
170 introduced in 1.4.9b.
172 ** Enhance the `index' builtin to guarantee linear behavior, in spite of
173 the surprisingly large number of systems with a brain-dead quadratic
176 ** A number of portability improvements inherited from gnulib.
178 * Noteworthy changes in Version 1.4.10 (2007-07-09) [stable]
179 Released by Eric Blake, based on CVS version 1.4.9c
181 ** Upgrade from GPL version 2 to GPL version 3 or later.
183 ** A number of portability improvements inherited from gnulib.
185 ** Avoid undefined behavior introduced in 1.4.9b in the `format' builtin
186 when handling %c. However, this area of code has never been documented,
187 and currently does not match the POSIX behavior of printf(1), so it may
188 have further changes in the next version.
190 * Noteworthy changes in Version 1.4.9b (2007-05-29) [beta]
191 Released by Eric Blake, based on CVS version 1.4.9a
193 ** Fix regression introduced in 1.4.9 in the `eval' builtin when performing
196 ** Fix regression introduced in 1.4.8 in the `-F' option that made it
197 impossible to freeze more than 512 kibibytes of diverted text.
199 ** The synclines option `-s' no longer generates sync lines in the middle of
200 multiline comments or quoted strings.
202 ** Work around a number of corner-case POSIX compliance bugs in various
203 broken stdio libraries. In particular, the `syscmd' builtin behaves
204 more predictably when stdin is seekable.
206 ** The `format' builtin now understands formats such as %a, %A, and %'hhd,
207 and works around a number of platform printf bugs. Furthermore, the
208 sequence format(%*.*d,-1,-1,1) no longer outputs random data. However,
209 some non-compliant platforms such as mingw still have known bugs in
210 strtod that may cause testsuite failures.
212 ** The testsuite is improved to also run gnulib portability tests for the
213 features that M4 imports from gnulib.
215 * Noteworthy changes in Version 1.4.9 (2007-03-23) [stable]
216 Released by Eric Blake, based on CVS version 1.4.8c
218 ** Minor documentation and portability cleanups.
220 * Noteworthy changes in Version 1.4.8b (2007-02-24) [beta]
221 Released by Eric Blake, based on CVS version 1.4.8a
223 ** Fix a regression introduced in 1.4.8 that made m4 unable to process
224 files larger than 2GiB on some platforms.
226 ** Fix a regression introduced in 1.4.8 that made m4 dump core when
227 invoked as 'm4 -- file'.
229 ** The `eval' builtin now follows C precedence rules. Additionally, the
230 short-circuit operators correctly short-circuit division by zero. The
231 previously undocumented alias of '=' meaning '==' in eval now triggers a
232 deprecation warning, so that a future version of M4 can implement a form
233 of variable assignment as an extension.
235 ** The `include' builtin now affects exit status on failure, as required by
236 POSIX. Use `sinclude' if you need a successful exit status.
238 ** The `-E'/`--fatal-warnings' command-line option now has two levels. When
239 specified only once, warnings affect exit status, but execution
240 continues, so that you can see all warnings instead of fixing them one
241 at a time. To achieve 1.4.8 behavior, where the first warning
242 immediately exits, specify -E twice on the command line.
244 ** A new `--warn-macro-sequence' command-line option allows detection of
245 sequences in `define' and `pushdef' definitions that match an optional
246 regular expression. The default regular expression is
247 `\$\({[^}]*}\|[0-9][0-9]+\)', corresponding to the sequences that might
248 not behave correctly when upgrading to the eventual M4 2.0. By default,
249 M4 2.0 will follow the POSIX requirement that a macro definition
250 containing `$11' must expand to the first argument concatenated with 1,
251 rather than the eleventh argument; and will take advantage of the POSIX
252 wording that allows implementations to treat `${11}' as the eleventh
253 argument instead of literal text. Be aware that Autoconf 2.61 will not
254 work with this option enabled with the default regular expression; but
255 Autoconf 2.62 will be compatible with this option.
257 ** Improved portability to platforms such as BSD/OS and AIX.
259 * Noteworthy changes in Version 1.4.8 (2006-11-20) [stable]
260 Released by Eric Blake, based on CVS version 1.4.7a
262 ** The `divert' macro and `-H'/`--hashsize' command line option no longer
263 cause a core dump when handed extra large values. Also, `divert' now
264 uses memory proportional to the number of diversions in use, rather than
265 to the maximum diversion number encountered, so that large diversion
266 numbers are less likely to exhaust system memory; and is no longer
267 limited by the maximum number of file descriptors.
269 ** The `--help' and `--version' command line options now consistently
270 override all earlier options. For example, `m4 --debugfile=trace
271 --help' now no longer accidentally creates an empty file `trace'.
273 ** The `-L'/`--nesting-limit' command line option can now be set to 0
274 to remove the default limit of 1024. However, it is still possible that
275 heavily nested input can cause abrupt program termination due to stack
278 ** Problems encountered when writing to standard error, such as with the
279 `errprint' macro, now always cause a non-zero exit status.
281 ** Warnings and errors issued during macro expansion are now consistently
282 reported at the line where the macro name was detected, rather than
283 where the close parenthesis resides. Text wrapped by `m4wrap' now
284 remembers the location that was in effect when m4wrap was invoked,
285 rather than changing to line 0 and the empty string for a file. The
286 macros `__line__' and `__file__' now work correctly even as the last
287 token in an included file.
289 ** The `builtin' and `indir' macros now transparently handle builtin
290 tokens generated by `defn'.
292 ** When diversions created by the `divert' macro collect enough text that
293 M4 must use temporary files, the environment variable $TMPDIR is now
294 consulted, and a better effort is made to clean up those files in the
295 event of a fatal signal.
297 ** The `mkstemp' builtin is added with the same GNU semantics as `maketemp',
298 based on the recommendation of POSIX to deprecate the POSIX semantics of
299 `maketemp' as inherently insecure. In GNU mode (no -G supplied on the
300 command line), `maketemp' silently retains the secure GNU semantics, but
301 a future release of M4 will change this to emit a warning. In
302 traditional mode (m4 -G), `maketemp' now uses the POSIX-mandated
303 insecure semantics, and issues a warning that you should convert your
304 script to use `mkstemp' instead. Additionally, `mkstemp' and `maketemp'
305 are now well-defined even if the template argument does not end in six
308 ** The manual has been improved, including a new section on a composite
311 ** The `changecom' and `changequote' macros now treat an empty second
312 argument the same as if it were missing, rather than using the empty
313 string and making it impossible to end a comment or quote.
315 ** The `translit' macro now operates in linear instead of quadratic time,
316 and is now eight-bit clean.
318 ** The `-D', `-U', `-s', and `-t' command line options now take effect
319 after any files encountered earlier on the command line, rather than up
320 front, as is done in traditional implementations and required by POSIX.
322 * Noteworthy changes in Version 1.4.7 (2006-09-25) [stable]
323 Released by Eric Blake, based on CVS version 1.4.6a
325 ** Fix regression from 1.4.5 in handling a file that ends in a macro
326 expansion without arguments instead of a newline.
328 ** The define and pushdef macros now warn when the first argument is not
329 a string, rather than silently doing nothing.
331 ** Standard input can now be read more than once, as in 'm4 - file -', and
332 is not closed until all wrapped text is handled. This makes a
333 difference when stdin is not a regular file, and also fixes bugs when
334 using the syscmd or esyscmd macros from wrapped text.
336 ** When standard input is a seekable file, the m4exit, syscmd, and esyscmd
337 macros now restore the current position to the next unread byte rather
338 than discarding an arbitrary amount of buffered data.
340 ** SysV command-line compatibility is no longer a goal of GNU M4; the
341 focus will be instead on POSIX compatibility. This release continues to
342 support previous usage, but adds warnings in areas which will allow a
343 future version of GNU M4 to use its own extensions without being tied to
344 the SysV command line interface.
346 ** The no-op compatibility command line options -B, -N, -S, -T, and
347 --diversions may be withdrawn or assigned new meanings in future
348 releases, so they now issue a warning if used.
350 ** A new command line option -i replaces the compatibility -e as the
351 short spelling of --interactive, for consistency with other GNU tools; a
352 warning is issued if the old spelling is used, and it may be assigned
353 new meaning in future releases.
355 ** A new command line option --debugfile replaces the options -o and
356 --error-output as the preferred spelling. The old options were
357 misleading in their names and inconsistent with other GNU tools; they
358 are still silently accepted, but no longer documented in --help, and may
359 be assigned new meanings in future releases.
361 * Noteworthy changes in Version 1.4.6 (2006-08-25) [stable]
362 Released by Eric Blake, based on CVS version 1.4.5a
364 ** Fix buffer overruns in regexp and patsubst macros when handed a trailing
365 backslash in the replacement text, or when handling \n substitutions
366 beyond the number of \(\) groups.
368 ** Fix memory leak in regexp, patsubst, and changeword macros.
370 ** The format macro now understands %F, %g, and %G.
372 ** When loading frozen files, m4 now exits with status 63 if version
373 mismatch is detected.
375 ** Fix bugs that occurred when invoked with stdout or stderr closed,
376 and detect write failures to stdout or to the target of the debugfile
377 macro. In particular, the syscmd and esyscmd macros can no longer
378 interfere with the debug stream or diversions.
380 ** The m4exit macro now converts values outside the range 0-255 to 1.
382 ** It is now an error if a command-line input file ends in the middle of a
383 comment, matching the behavior of mid-string and mid-argument
386 ** The dnl macro now warns if end of file is encountered instead of a
389 ** The error message when end of file is encountered now uses the file and
390 line where the dangling construct started, rather than `NONE:0:'.
392 ** The debugmode and __file__ macros, and the -s/--synclines option, now
393 show what directory a file was found in when the -I/--include option or
394 M4PATH variable had an effect.
396 ** The changequote and changecom macros now work with 8-bit characters, and
397 quotes and comments that begin with `(' are properly recognized
400 ** The new macro __program__ is added, which allows the input file to issue
401 an error message that resembles messages from m4. Warning and error
402 messages have been reformatted to comply with GNU Coding Standards.
404 ** The errprint, m4wrap, and shift macros are now recognized only with
407 ** The index, substr, translit, regexp, and patsubst macros now produce
408 output when given only one argument, but still warn about a missing
411 ** The patsubst macro now reliably finds zero-length matches at the end
414 * Noteworthy changes in Version 1.4.5 (2006-07-15) [stable]
415 Released by Eric Blake, based on CVS version 1.4.4c
417 ** Fix sysval on BeOS, OS/2, and other systems that store exit status
418 in the low-order byte. Additionally, on Unix platforms, if syscmd was
419 terminated by a signal, sysval now displays the signal number shifted
420 left by eight bits, to match traditional m4 implementations.
422 ** The maketemp macro is no longer subject to platform limitations (such as
423 26 or 32 max files from a given template).
425 ** Frozen files now require that the first directive be V (version), to
426 better diagnose version mismatch. Additionally, if the F directive
427 (builtin function) names an unknown builtin that existed in the m4 that
428 froze the file but not in the current m4 (for example, changeword), the
429 warning is deferred until an attempt is made to actually use the
430 builtin. This allows downgrading from beta m4-1.4o to stable m4-1.4.5
431 without breaking autoconf.
433 ** The format and indir macros are now recognized only with arguments.
435 ** The eval macro no longer crashes on x86 architectures when dividing the
436 minimum integer by -1.
438 ** On systems with ecvt and fcvt, format no longer truncates trailing
439 zeroes on integers printed with %.0f. On systems without these
440 functions, format is no longer subject to a buffer overflow that
441 permitted arbitrary code execution.
443 ** On native Windows builds, the macro __windows__ is provided instead of
444 __unix__. Likewise, on OS/2 builds, the macro __os2__ is provided.
445 This allows input files to determine when syscmd might behave
448 ** Fix bug in 1.4.3 patch to use \n line-endings that did not work for
451 ** When given the empty string or 0, undivert is now documented as a no-op
452 rather than closing stdout, warning about a non-existent file, or trying
453 to read a directory as a file.
455 ** Many documentation improvements. Also, the manual is now distributed
456 under FDL 1.2, rather than a stricter verbatim-only license.
458 ** Raise the -L (--nesting-limit) command line option limit from 250 to
461 ** The decr, incr, divert, m4exit, and substr macros treat an empty number
462 as 0, issue a warning, and expand as normal; rather than issuing an
463 error and expanding to the empty string.
465 ** The eval macro now treats an empty radix argument as 10, handles radix 1,
466 and treats the width argument as number of digits excluding the sign,
467 for compatibility with other m4 implementations.
469 ** The ifdef, divert, m4exit, substr, and translit macros now correctly
470 ignore extra arguments.
472 ** The popdef and undefine macros now correctly accept multiple arguments.
474 ** Although changeword is on its last leg, if enabled, it now reverts to the
475 default (faster) regexp when passed the empty string.
477 ** The regexp and substr macros now warn and ignore a trailing backslash in
478 the replacement, and warn on \n for n larger than the number of
479 sub-expressions in the regexp.
481 * Noteworthy changes in Version 1.4.4b (2006-06-17) [beta]
482 Released by Eric Blake, based on CVS version 1.4.4a
484 ** Fix a recursive push_string crashing bug, which affected changequote of
485 three or more characters on some compilers.
487 ** Use automake to fix build portability issues.
489 ** Fix a recursive m4wrap crashing bug.
491 ** Fix a 1 in 2**32 hash crashing bug.
493 ** Tracing a macro by name is now persistent, even if the macro is
494 subsequently undefined or redefined. The traceon and traceoff macros no
495 longer warn about undefined symbols. This solves a crash when using
496 indir on an undefined macro traced with the -t option, as well as an
497 incorrect result of ifdef. Furthermore, tracing is no longer
498 transferred with builtins, solving the bug of "m4 -tm4_eval" failing to
499 give trace output on the input
500 "define(`m4_eval',defn(`eval'))m4_eval(1)".
502 ** Fix a crash when a macro is undefined while collecting its arguments, by
503 always using the definition that was in effect before argument
504 collection. This behavior matches the C pre-processor, and means that
505 the sequence "define(`f',`1')f(define(`f',`2'))f" is now documented to
506 result in "12", rather than the previously undocumented "22".
508 ** Update the regex engine to fix several bugs.
510 ** Fix a potential crash on machines where char is signed.
512 * Noteworthy changes in Version 1.4.4 (Oct 2005) [stable]
513 Released by Gary V. Vaughan
515 ** ./configure --infodir=/usr/share/info now works correctly.
517 ** When any file named on the command line is missing exit with status 1.
519 * Noteworthy changes in Version 1.4.3 (Mar 2005) [stable]
520 Released by Gary V. Vaughan
522 ** DESTDIR installs now work correctly.
524 ** Don't segfault with uncompilable regexps to changeword().
526 ** Always use \n line-endings for frozen files (fixes a Windows bug).
528 ** Portability fix for systems lacking mkstemp(3).
530 ** Approximately 20% speed up in the common case of usage with autoconf.
532 ** Supported on QNX 6.3.
534 * Noteworthy changes in Version 1.4.2 (Aug 2004) [stable]
535 Released by Paul Eggert
537 ** No user visible changes; portability bug fixes only.
539 * Noteworthy changes in Version 1.4.1 (Jun 2004) [stable]
540 Released by Paul Eggert
542 ** maketemp now creates an empty file with the given name, instead of merely
543 returning the name of a nonexistent file. This closes a security hole.
545 * Noteworthy changes in Version 1.4 (Oct 1994) [stable]
546 Released by Franc,ois Pinard
548 ** (No user visible changes)
551 Version 1.3 - September 1994, by Franc,ois Pinard
553 * Diversions are created as needed. Option `-N' is still accepted, but
554 otherwise ignored. Users should use only negative diversion numbers,
555 instead of high positive numbers, for diverting to nowhere.
557 * Diversions should also work faster. No temporary files will be needed
558 at all if all diversions taken altogether do not use more than 512K.
560 * Frozen state files may be produced with the `--freeze-state' (-F)
561 option and later brought back through the `--reload-state' (-R) option.
563 Version 1.2 - July 1994, by Franc,ois Pinard
565 * In patsubst(STRING, REGEXP, REPLACEMENT), \& in REPLACEMENT has been
566 changed to represent this part of STRING matched by the whole REGEXP,
567 instead of the whole STRING as before. \0 does the same, but emits a
568 diagnostic saying it will disappear in some subsequent release.
570 * eval(EXPR) emits a diagnostic if EXPR has suffixed crumb. The same for
571 other numeric conversions in incr(), decr(), divert(), etc.
573 * `--fatal-warnings' (-E) stops execution at first warning.
575 * `--nesting-limit=LEVEL' (-L LEVEL) sets a limit to macro nesting.
576 It is initially fixed at 250.
578 * `--word-regexp=REGEXP' (-W REGEXP) modifies macro name syntax, like
579 does the new `changeword(REGEXP)' macro. This feature is experimental,
580 tell me your opinions about it. You do need --enable-changeword at
581 configure time to get these things. Do *not* depend on them yet.
583 * Trace output format is scannable by GNU Emacs' next-error function.
585 * Stack overflow is detected and diagnosed on some capable systems.
587 * Various bugs have been corrected, m4 should be more portable. See the
588 ChangeLog for details.
590 Version 1.1 - November 1993, by Franc,ois Pinard
592 Changes which might affect existing GNU m4 scripts:
594 * Option `-V' has been removed, use `--version' instead. `--version'
595 writes on standard output instead of standard error, and inhibits any
598 * `--no-gnu-extensions' has been renamed `--traditional'.
600 * In `eval', `^' used to indicate exponentiation, use `**' instead.
602 * The automatic undiversion which takes place at end of all input is
603 forced into the main output stream.
605 Changes which are unlikely to affect existing scripts:
607 * `--help' prints an usage summary on standard output. Script execution
610 * `--prefix-builtins' (-P) prefixes all builtin macros by `m4_'.
612 * Most builtin macros for which arguments are mandatory, called without
613 any arguments, are no more recognized as builtin macros: they are
614 consequently copied verbatim to the output stream.
616 * `define' and `pushdef' are usable with only one argument, they give
617 this argument an empty definition.
619 * `eval' new operators for binary representation handling: `^' for
620 exclusive-or, `~' for the bitwise negation, `<<' and `>>' for shifts.
622 * `eval' recognizes the notation 0bDIGITS for binary numbers and the
623 notation 0rRADIX:DIGITS for numbers in any radix from 1 to 36.
625 Version 1.0.3 - December 1992, by Franc,ois Pinard
627 Changes for the user:
629 * `dnl' outputs a diagnostic if immediately followed by `('. Usually,
630 `dnl' is followed by newline or whitespace.
632 * `ifelse' accepts without complaining the common idiom of having only
633 one argument. This is useful for introducing long comments.
635 * `eval' always expresses values as signed, whatever the radix.
637 * M4OPTS environment variable is no longer obeyed.
639 * `--no-warnings' option is renamed `--silent'.
641 * Debug lines use a new format more compatible with GNU standards.
643 * Various bugs have been corrected. See the ChangeLog for details.
645 Changes for the installer:
647 * GNU m4 now uses an Autoconf-generated configure script, and should be
648 more easily portable in many ways. (Cray is not supported yet).
650 * `make check' has been made more portable, expect no errors.
652 Changes for the programmer:
654 * Sources have been fully reindented to comply with GNU standards, and
655 cleaned up in many ways.
657 * Sources have been protoized. Non-ANSI compilers are automatically
658 detected, then sources are unprotoized on the fly before compilation.
660 * GNU m4 uses newer versions of obstack, regex, getopt, etc.
662 Version 1.0 - October 1991, by René Seindal
664 * Uses GNU configure, taken from the gdb distribution.
666 * Uses GNU getopt(), with long option names.
668 * The -Q/+quiet option is added, which suppresses warnings about missing
669 or superflous arguments to built-in macros.
671 * Added default options via the M4OPTS environment variable.
673 * Several minor bugs have been fixed.
675 Version 0.99 - July 1991, by René Seindal
677 * The builtins `incr' and `decr' are now implemented without use of
680 * The builtin `indir' is added, to allow for indirect macro calls
681 (allows use of "illegal" macro names).
683 * The debugging and tracing facilities has been enhanced considerably.
684 See the manual for details.
686 * The -tMACRO option is added, marks MACRO for tracing as soon as it
689 * Builtins are traced after renaming iff they were before.
691 * Named files can now be undiverted.
693 * The -Nnum option can be used to increase the number of divertions
696 * Calling changecom without arguments now disables all comment handling.
698 * A bug in `dnl' is fixed.
700 * A bug in the multi-character quoting code is fixed.
702 * Several typos in the manual has been corrected. More probably persist.
704 Version 0.75 - November 1990, by René Seindal
706 * Implemented search path for include files (-I option and M4PATH
707 environment variable).
709 * Implemented builtin `format' for printf-like formatting.
711 * Implemented builtin `regexp' for searching for regular expressions.
713 * Implemented builtin `patsubst' for substitution with regular
716 * Implemented builtin `esyscmd', which expands to a shell commands output.
718 * Implemented `__file__' and `__line__' for use in error messages.
720 * Implemented character ranges in `translit'.
722 * Implemented control over debugging output.
724 * Implemented multi-character quotes.
726 * Implemented multi-character comment delimiters.
728 * Changed predefined macro `gnu' to `__gnu__'.
730 * Changed predefined macro `unix' to `__unix__', when the -G option is
731 not used. With -G, `unix' is still defined.
733 * Added program name to error messages.
735 * Fixed two missing null bytes bugs.
737 Version 0.50 - January 1990, by René Seindal
739 * Initial beta release.
741 ========================================================================
748 Copyright (C) 1992-1994, 2004-2014, 2016-2017, 2020-2021 Free Software
751 Permission is granted to copy, distribute and/or modify this document
752 under the terms of the GNU Free Documentation License, Version 1.3 or
753 any later version published by the Free Software Foundation; with no
754 Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
755 Texts. A copy of the license is included in the ``GNU Free
756 Documentation License'' file as part of this distribution.