1 GNU m4 NEWS - History of user-visible changes. -*- outline -*-
2 Copyright (C) 1992, 1993, 1994, 1998, 2000, 2001, 2006, 2007 Free Software
5 * Version beta 1.9b - ???, by ??? (CVS version 1.9a)
7 NOTE - there are still a number of FIXMEs to resolve before this can be
12 *** The build environment has been updated to modern GNU practices,
13 depending on newer features of Autoconf, Automake, Libtool, Gettext,
14 and Gnulib to be more portable to a wide variety of platforms.
16 ** New command line behavior
18 *** If the POSIXLY_CORRECT environment variable is set, it implies the
19 `-G' and `-Q' options, effectively giving a more fully POSIX-compliant
20 implementation with only compatible GNU extensions.
22 *** New `-b'/`--batch' command-line option to force non-interactive mode.
23 Also, in addition to `-e'/`--interactive' requesting interactive mode,
24 m4 now follows the lead of sh, and automatically enters interactive
25 mode when there are no files specified, and when both standard input
26 and standard error are terminals.
28 *** New `-B'/`--prepend-include' command-line option allows prepending to
29 the include path, rather than always searching `.' first.
31 *** The `-d'/`--debug' command-line option now understands `-' and `+'
32 modifiers, the way `debugmode' has always done. The option
33 `--debugmode' is added as an alias for `-d'.
35 *** New `--debuglen' command-line option matches the spelling of a new
36 macro, and the old spelling `--arglength' now issues a warning that it
37 might be withdrawn in the future.
39 *** New `-g'/`--gnu' command-line option overrides `-G'/`--traditional',
40 allowing the GNU module to be selected even when POSIXLY_CORRECT.
42 *** The `-H'/`--hashsize' command-line options, which were made no-ops in
43 a previous beta, now issue a deprecation warning.
45 *** The `-L'/`--nesting-limit' command-line option now performs argument
46 validation and accepts an optional multiplier suffix.
48 *** The `-o'/`--error-output' command-line options, which were replaced by
49 `--debugfile' in M4 1.4.7, now issue a deprecation warning. This
50 warning interferes with all versions of Autoconf prior to 2.61, so plan
51 on installing an updated Autoconf when installing M4 2.0.
53 *** New `-p'/`--pushdef' and `--popdef' command-line options allow more
54 control over macro definitions from the command line between input
57 *** New `--posix' command-line option is a synonym for `-G'/`--traditional'.
59 *** New `-r'/`--regexp-syntax' command-line option changes the default
60 regular expression syntax used by M4. Without this option, M4
61 continues to use EMACS style expressions. A new section in the info
62 docs explains the differences between them, and what builtins are
65 *** New `--safer' command-line option cripples the potentially unsafe
66 builtins `debugfile', `esyscmd', `maketemp', `mkdtemp', `mkstemp', and
69 *** New `--syncoutput' command-line option matches the builtin added in a
70 previous beta, and provides more control over sync line generation
71 from the command line between input files. The previous options
72 `-s'/`--synclines' remain as aliases for `--syncoutput=1'.
74 *** New `--traceoff' command-line option, and new spelling `--traceon' for
75 `--trace', allow more control over macro tracing from the command line
78 *** New `--unload-module' command-line option allows more control over
79 dynamic modules from the command line. Also, `-m'/`--load-module' now
80 acts between input files.
82 *** New `--warnings' command-line option re-enables warnings, overriding
83 `-Q'/`--quiet'/`--silent', allowing warnings even when POSIXLY_CORRECT.
87 *** The `defn' builtin now allows any number of arguments, as POSIX requires.
88 - FIXME: This still doesn't work with concatenating builtins with text.
90 - FIXME: POSIX recommends using ${10} instead of $10 for the tenth
91 positional argument. We should deprecate $10.
93 - FIXME: `m4wrap' semantics need an update to FIFO.
97 *** The experimental `epatsubst' and `eregexp' builtins have been removed
98 in favor of a new `changeresyntax' builtin.
102 *** New `changeresyntax' builtin allows programmatic setting of the default
103 regular expression flavor, to match `-r'/`--regexp-syntax' command-line
106 *** New `debuglen' builtin allows runtime setting of debug output length,
107 previously controlled only by the `-l' command line argument.
108 Additionally, whether using the new macro or the command line argument,
109 the length limitation now affects dumpdef output as well as trace
110 output, undergoes argument validation, and accepts an optional
112 - FIXME the multiplier suffix isn't reliable yet
114 *** New `mkdtemp' builtin parallels `mkstemp', but allows the creation of
115 temporary directories instead of files.
117 *** New `renamesyms' builtin allows programmatic renaming of all symbols
118 according to a regular expression.
119 - FIXME: This feature can cause core dumps when renaming multiple
120 symbols to the same name.
122 *** New `__traditional__' builtin identifies when the traditional module
123 is loaded instead of the gnu module.
125 *** The `modules' and `symbols' builtins, introduced in previous betas,
126 have been renamed `m4modules' and `m4symbols', in order to minimize
127 problems when upgrading from 1.4.x and processing English text. To
128 prevent future problems, any future macro added as a GNU extension will
129 either be blind (ie. be unrecognized without arguments), or begin with
130 the prefix `m4' or `__'.
132 ** Changed behavior of builtins
134 *** The `builtin' builtin now has a special form, where if the first
135 argument is exactly the special token representing defn(`builtin'), the
136 expansion is the special token representing the builtin named in the
137 second argument. This allows regenerating a macro with a more
138 efficient mapping directly to a builtin function, rather than through
139 textual indirection through further expansions of `builtin'.
141 *** The `changecom' builtin semantics now match traditional
142 implementations; if the start-comment string resembles a macro name or
143 the start-quote string, comments are effectively disabled.
145 *** The `changesyntax' builtin has been improved, to make it easier to add
146 and remove characters from a syntax class without having to specify the
147 entire set of characters in that class. It also supports new syntax
148 categories, `$', `{' and `}', for extended argument handling in macro
149 definitions. See the manual for more examples.
151 *** New `m' flag to `-d'/`--debug' command-line option or `debugmode'
152 builtin traces actions related to module loading and unloading, and
153 affects `dumpdef' and trace output to show where builtins come from.
154 New `s' flag shows the entire stack of `pushdef' definitions during
155 `dumpdef'. The `c' flag has been updated to output two lines instead
156 of three (since the last two had always been paired), and to add
157 information to the first line to show the definition of the macro being
158 expanded. The 'e' flag has been updated to output non-text expansions.
160 *** The `dumpdef' builtin now always outputs to standard error, rather than
161 the debug file specified by the `--debugfile' option or `debugfile'
164 *** The `eval' and `mpeval' builtins now support the following new
165 operators: `>>>', `\', `?:', and `,'.
167 *** The `format' builtin now supports the C99 specifiers of %a and %A, even
168 on platforms that don't yet support C99.
170 *** The `maketemp' builtin now always warns that it is obsolete, even in GNU
171 mode where it uses the same secure algorithm as `mkstemp', because of
172 the recommendation of POSIX to obsolete `maketemp' as inherently
173 insecure when obeying POSIX.
175 *** The `patsubst' and `regexp' builtins have a new optional 4th argument
176 to use a different regular expression syntax for the duration of that
179 *** The semantics of the `traceon' and `traceoff' builtins now match
180 traditional implementations: when called without arguments, they affect
181 global state rather than affecting only the macros defined at that
182 moment. The manual includes an example of how to recover 1.4.x
187 *** The syntax of frozen files format V2 has been improved to save
188 additional state. This includes the `R' directive for default regular
189 expression syntax. Also, a V2 file can now be represented completely
190 in ASCII, thanks to escape sequences. Unfortunately, files frozen by
191 M4 1.4q that contain \ in macros cannot be read by 1.9b, but since 1.4q
192 was not widely distributed, this is not expected to be much of an
193 issue, and comes with the territory of using a beta release.
194 - FIXME: format 2 still needs to catch more missing state; once 2.0 is
195 released, any further changes would introduce format 3.
197 *** Improvements made in the 1.4.x stable series have been incorporated.
199 * Version 1.4.9 - 23 Mar 2007, by Eric Blake (CVS version 1.4.8c)
201 ** Minor documentation and portability cleanups.
203 * Version 1.4.8b - 24 Feb 2007, by Eric Blake (CVS version 1.4.8a)
205 ** Fix a regression introduced in 1.4.8 that made m4 unable to process
206 files larger than 2GiB on some platforms.
208 ** Fix a regression introduced in 1.4.8 that made m4 dump core when
209 invoked as 'm4 -- file'.
211 ** The `eval' builtin now follows C precedence rules. Additionally, the
212 short-circuit operators correctly short-circuit division by zero. The
213 previously undocumented alias of '=' meaning '==' in eval now triggers a
214 deprecation warning, so that a future version of M4 can implement a form
215 of variable assignment as an extension.
217 ** The `include' builtin now affects exit status on failure, as required by
218 POSIX. Use `sinclude' if you need a successful exit status.
220 ** The `-E'/`--fatal-warnings' command-line option now has two levels. When
221 specified only once, warnings affect exit status, but execution
222 continues, so that you can see all warnings instead of fixing them one
223 at a time. To achieve 1.4.8 behavior, where the first warning
224 immediately exits, specify -E twice on the command line.
226 ** A new `--warn-macro-sequence' command-line option allows detection of
227 sequences in `define' and `pushdef' definitions that match an optional
228 regular expression. The default regular expression is
229 `\$\({[^}]*}\|[0-9][0-9]+\)', corresponding to the sequences that might
230 not behave correctly when upgrading to the eventual M4 2.0. By default,
231 M4 2.0 will follow the POSIX requirement that a macro definition
232 containing `$11' must expand to the first argument concatenated with 1,
233 rather than the eleventh argument; and will take advantage of the POSIX
234 wording that allows implementations to treat `${11}' as the eleventh
235 argument instead of literal text. Be aware that Autoconf 2.61 will not
236 work with this option enabled with the default regular expression; but
237 Autoconf 2.62 will be compatible with this option.
239 ** Improved portability to platforms such as BSD/OS and AIX.
241 * Version 1.4.8 - 20 November 2006, by Eric Blake (CVS version 1.4.7a)
243 ** The `divert' macro and `-H'/`--hashsize' command line option no longer
244 cause a core dump when handed extra large values. Also, `divert' now
245 uses memory proportional to the number of diversions in use, rather than
246 to the maximum diversion number encountered, so that large diversion
247 numbers are less likely to exhaust system memory; and is no longer
248 limited by the maximum number of file descriptors.
250 ** The `--help' and `--version' command line options now consistently
251 override all earlier options. For example, `m4 --debugfile=trace
252 --help' now no longer accidentally creates an empty file `trace'.
254 ** The `-L'/`--nesting-limit' command line option can now be set to 0
255 to remove the default limit of 1024. However, it is still possible that
256 heavily nested input can cause abrupt program termination due to stack
259 ** Problems encountered when writing to standard error, such as with the
260 `errprint' macro, now always cause a non-zero exit status.
262 ** Warnings and errors issued during macro expansion are now consistently
263 reported at the line where the macro name was detected, rather than
264 where the close parenthesis resides. Text wrapped by `m4wrap' now
265 remembers the location that was in effect when m4wrap was invoked,
266 rather than changing to line 0 and the empty string for a file. The
267 macros `__line__' and `__file__' now work correctly even as the last
268 token in an included file.
270 ** The `builtin' and `indir' macros now transparently handle builtin
271 tokens generated by `defn'.
273 ** When diversions created by the `divert' macro collect enough text that
274 M4 must use temporary files, the environment variable $TMPDIR is now
275 consulted, and a better effort is made to clean up those files in the
276 event of a fatal signal.
278 ** The `mkstemp' builtin is added with the same GNU semantics as `maketemp',
279 based on the recommendation of POSIX to deprecate the POSIX semantics of
280 `maketemp' as inherently insecure. In GNU mode (no -G supplied on the
281 command line), `maketemp' silently retains the secure GNU semantics, but
282 a future release of M4 will change this to emit a warning. In
283 traditional mode (m4 -G), `maketemp' now uses the POSIX-mandated
284 insecure semantics, and issues a warning that you should convert your
285 script to use `mkstemp' instead. Additionally, `mkstemp' and `maketemp'
286 are now well-defined even if the template argument does not end in six
289 ** The manual has been improved, including a new section on a composite
292 ** The `changecom' and `changequote' macros now treat an empty second
293 argument the same as if it were missing, rather than using the empty
294 string and making it impossible to end a comment or quote.
296 ** The `translit' macro now operates in linear instead of quadratic time,
297 and is now eight-bit clean.
299 ** The `-D', `-U', `-s', and `-t' command line options now take effect
300 after any files encountered earlier on the command line, rather than up
301 front, as is done in traditional implementations and required by POSIX.
303 * Version 1.4.7 - 25 September 2006, by Eric Blake (CVS version 1.4.6a)
305 ** Fix regression from 1.4.5 in handling a file that ends in a macro
306 expansion without arguments instead of a newline.
308 ** The define and pushdef macros now warn when the first argument is not
309 a string, rather than silently doing nothing.
311 ** Standard input can now be read more than once, as in 'm4 - file -', and
312 is not closed until all wrapped text is handled. This makes a
313 difference when stdin is not a regular file, and also fixes bugs when
314 using the syscmd or esyscmd macros from wrapped text.
316 ** When standard input is a seekable file, the m4exit, syscmd, and esyscmd
317 macros now restore the current position to the next unread byte rather
318 than discarding an arbitrary amount of buffered data.
320 ** SysV command-line compatibility is no longer a goal of GNU M4; the
321 focus will be instead on POSIX compatibility. This release continues to
322 support previous usage, but adds warnings in areas which will allow a
323 future version of GNU M4 to use its own extensions without being tied to
324 the SysV command line interface.
326 ** The no-op compatibility command line options -B, -N, -S, -T, and
327 --diversions may be withdrawn or assigned new meanings in future
328 releases, so they now issue a warning if used.
330 ** A new command line option -i replaces the compatibility -e as the
331 short spelling of --interactive, for consistency with other GNU tools; a
332 warning is issued if the old spelling is used, and it may be assigned
333 new meaning in future releases.
335 ** A new command line option --debugfile replaces the options -o and
336 --error-output as the preferred spelling. The old options were
337 misleading in their names and inconsistent with other GNU tools; they
338 are still silently accepted, but no longer documented in --help, and may
339 be assigned new meanings in future releases.
341 * Version 1.4.6 - 25 August 2006, by Eric Blake (CVS version 1.4.5a)
343 ** Fix buffer overruns in regexp and patsubst macros when handed a trailing
344 backslash in the replacement text, or when handling \n substitutions
345 beyond the number of \(\) groups.
347 ** Fix memory leak in regexp, patsubst, and changeword macros.
349 ** The format macro now understands %F, %g, and %G.
351 ** When loading frozen files, m4 now exits with status 63 if version
352 mismatch is detected.
354 ** Fix bugs that occurred when invoked with stdout or stderr closed,
355 and detect write failures to stdout or to the target of the debugfile
356 macro. In particular, the syscmd and esyscmd macros can no longer
357 interfere with the debug stream or diversions.
359 ** The m4exit macro now converts values outside the range 0-255 to 1.
361 ** It is now an error if a command-line input file ends in the middle of a
362 comment, matching the behavior of mid-string and mid-argument
365 ** The dnl macro now warns if end of file is encountered instead of a
368 ** The error message when end of file is encountered now uses the file and
369 line where the dangling construct started, rather than `NONE:0:'.
371 ** The debugmode and __file__ macros, and the -s/--synclines option, now
372 show what directory a file was found in when the -I/--include option or
373 M4PATH variable had an effect.
375 ** The changequote and changecom macros now work with 8-bit characters, and
376 quotes and comments that begin with `(' are properly recognized
379 ** The new macro __program__ is added, which allows the input file to issue
380 an error message that resembles messages from m4. Warning and error
381 messages have been reformatted to comply with GNU Coding Standards.
383 ** The errprint, m4wrap, and shift macros are now recognized only with
386 ** The index, substr, translit, regexp, and patsubst macros now produce
387 output when given only one argument, but still warn about a missing
390 ** The patsubst macro now reliably finds zero-length matches at the end
393 * Version 1.4.5 - 15 July 2006, by Eric Blake (CVS version 1.4.4c)
395 ** Fix sysval on BeOS, OS/2, and other systems that store exit status
396 in the low-order byte. Additionally, on Unix platforms, if syscmd was
397 terminated by a signal, sysval now displays the signal number shifted
398 left by eight bits, to match traditional m4 implementations.
400 ** The maketemp macro is no longer subject to platform limitations (such as
401 26 or 32 max files from a given template).
403 ** Frozen files now require that the first directive be V (version), to
404 better diagnose version mismatch. Additionally, if the F directive
405 (builtin function) names an unknown builtin that existed in the m4 that
406 froze the file but not in the current m4 (for example, changeword), the
407 warning is deferred until an attempt is made to actually use the
408 builtin. This allows downgrading from beta m4-1.4o to stable m4-1.4.5
409 without breaking autoconf.
411 ** The format and indir macros are now recognized only with arguments.
413 ** The eval macro no longer crashes on x86 architectures when dividing the
414 minimum integer by -1.
416 ** On systems with ecvt and fcvt, format no longer truncates trailing
417 zeroes on integers printed with %.0f. On systems without these
418 functions, format is no longer subject to a buffer overflow that
419 permitted arbitrary code execution.
421 ** On native Windows builds, the macro __windows__ is provided instead of
422 __unix__. Likewise, on OS/2 builds, the macro __os2__ is provided.
423 This allows input files to determine when syscmd might behave
426 ** Fix bug in 1.4.3 patch to use \n line-endings that did not work for
429 ** When given the empty string or 0, undivert is now documented as a no-op
430 rather than closing stdout, warning about a non-existent file, or trying
431 to read a directory as a file.
433 ** Many documentation improvements. Also, the manual is now distributed
434 under FDL 1.2, rather than a stricter verbatim-only license.
436 ** Raise the -L (--nesting-limit) command line option limit from 250 to
439 ** The decr, incr, divert, m4exit, and substr macros treat an empty number
440 as 0, issue a warning, and expand as normal; rather than issuing an
441 error and expanding to the empty string.
443 ** The eval macro now treats an empty radix argument as 10, handles radix 1,
444 and treats the width argument as number of digits excluding the sign,
445 for compatibility with other m4 implementations.
447 ** The ifdef, divert, m4exit, substr, and translit macros now correctly
448 ignore extra arguments.
450 ** The popdef and undefine macros now correctly accept multiple arguments.
452 ** Although changeword is on its last leg, if enabled, it now reverts to the
453 default (faster) regexp when passed the empty string.
455 ** The regexp and substr macros now warn and ignore a trailing backslash in
456 the replacement, and warn on \n for n larger than the number of
457 sub-expressions in the regexp.
459 * Version 1.4.4b - 17 June 2006, by Eric Blake (CVS version 1.4.4a)
461 ** Fix a recursive push_string crashing bug, which affected changequote of
462 three or more characters on some compilers.
464 ** Use automake to fix build portability issues.
466 ** Fix a recursive m4wrap crashing bug.
468 ** Fix a 1 in 2**32 hash crashing bug.
470 ** Tracing a macro by name is now persistent, even if the macro is
471 subsequently undefined or redefined. The traceon and traceoff macros no
472 longer warn about undefined symbols. This solves a crash when using
473 indir on an undefined macro traced with the -t option, as well as an
474 incorrect result of ifdef. Furthermore, tracing is no longer
475 transferred with builtins, solving the bug of "m4 -tm4_eval" failing to
476 give trace output on the input
477 "define(`m4_eval',defn(`eval'))m4_eval(1)".
479 ** Fix a crash when a macro is undefined while collecting its arguments, by
480 always using the definition that was in effect before argument
481 collection. This behavior matches the C pre-processor, and means that
482 the sequence "define(`f',`1')f(define(`f',`2'))f" is now documented to
483 result in "12", rather than the previously undocumented "22".
485 ** Update the regex engine to fix several bugs.
487 ** Fix a potential crash on machines where char is signed.
489 * Version 1.4.4 - October 2005, by Gary V. Vaughan
491 ** ./configure --infodir=/usr/share/info now works correctly.
493 ** When any file named on the command line is missing exit with status 1.
495 * Version 1.4.3 - March 2005, by Gary V. Vaughan
497 ** DESTDIR installs now work correctly.
499 ** Don't segfault with uncompilable regexps to changeword().
501 ** Always use \n line-endings for frozen files (fixes a Windows bug).
503 ** Portability fix for systems lacking mkstemp(3).
505 ** Approximately 20% speed up in the common case of usage with autoconf.
507 ** Supported on QNX 6.3.
509 * Version 1.4.2 - August 2004, by Paul Eggert
511 ** No user visible changes; portability bug fixes only.
513 * Version 1.4.1 - June 2004, by Paul Eggert
515 ** The 1.4.x series is intended to be stable; features added in 1.4[a-q]
516 were not backported to 1.4.x unless specifically mentioned above.
518 ** maketemp now creates an empty file with the given name, instead of merely
519 returning the name of a nonexistent file. This closes a security hole.
521 * Version beta 1.4q - August 2001, by Gary V. Vaughan
523 ** Support for the experimental `changeword' has been dropped.
525 ** `m4 --hashsize' and `-H' are still accepted, but have no effect. M4
526 will grow its internal symbol table if the symbol density is having an
527 effect on performance.
529 ** `configure --without-modules' will build an m4 binary with no preloaded
530 modules. At startup it will search for and load modules `m4' and either
531 `gnu' or `traditional'. This mode of operation can be used for
532 development and debugging of the base modules without the need to
533 recompile all of m4 with each modification.
535 ** `configure --with-modules="gnu m4 traditional load"', for example,
536 will build an m4 binary with the named modules preloaded, ready to be
537 activated (even on static lib only machines) with the `-m' option or
538 using the `load' builtin.
540 ** M4 has no builtins or macros in core, they are all loaded from modules
541 at startup. This means that modules are no longer optional, though the
542 standard build will statically link the modules `m4', `gnu' and
543 `traditional', so even on machines with no ltdl support, all of the
544 functionality from previous releases is available.
546 ** New builtin `load' to dynamically load modules which can define new
547 builtins and user macros.
549 ** New builtin `unload' to remove loaded modules (and the builtins and user
550 macros they define) from the running m4 interpreter.
552 ** New builtins `eregexp' and `epatsubst' to use Extended Regular
553 Expressions syntax in lieu of Basic Regular Expressions as used by
554 `regexp' and `patsubst'.
556 ** The names of all currently loaded modules are returned by the new
557 builtin, ``modules''.
559 ** Loadable modules can define new builtin functions or text expansion
562 ** The module code has been rewritten to use libltdl, the libtool dynamic
563 loader, which means GNU m4 can now load (and unload) modules just about
564 anywhere which it can be built. This includes obscure hosts such as
565 cygwin and BeOS, and also on hosts which do not have shared libraries,
566 through preloading (see libtool manual) and GNU dld.
568 ** Modules can now be built without the m4 source being available using the
569 installed m4module.h header file (and some other headers that it
570 includes for you), and the installed libm4.la libtool library. All
571 symbols exported from libm4.la have a prefix of `m4_' or `M4_'. See the
572 modules directory for examples of usage.
574 ** A new V2 format for frozen files that saves module and syntax information.
576 * Version beta 1.4o - January 2000, by Rene' Seindal
578 ** Modules can be loaded from the command line with --load-module
580 ** Modules now use libtool's wrapper libltdl.
582 ** New builtin `symbols' allows dynamic queries of all currently defined
585 ** Various Bug fixes.
587 * Version beta 1.4n - November 1998, by Rene' Seindal
589 ** The module code has been reorganised yet again, and now compiles
590 correctly on GNU/Linux, HPUX 9 and 10, SunOS 5 and Solaris 5.
592 ** When configured --with-gmp a new builtin `mpeval' is now defined. The
593 builtin `eval' retains its normal behaviour.
595 ** m4 --version also shows which options were used for compilation, such as:
596 "GNU m4 1.4n (options: modules gmp changeword)"
598 ** New option --import-environment defines all environment variables as
599 macros. This is done before -D and -U are handled, so the macros can be
600 changed through these options.
602 ** Error messages now always print program name before input file name as
603 specified by GNU coding standards. Reported by Akim Demaille.
605 ** Bug fixed: "undivert(0)" could cause m4 to read standard output. A call
606 of "undivert(0)" is now silently ignored.
608 ** Bug fixed: when compiling --with-included-gettext, <libintl.h> wasn't
609 found in intl/ directory. Reported by Andrew Bettison.
611 * Version beta 1.4m - November 1998, by Rene' Seindal
613 ** Using libtool for compiling modules and for linking main app.
615 ** Reorganised the dynamic module code to encapsulate system dependencies
616 better. The code for HPUX shl_load() still needs testing and debugging.
617 A dld interface is also missing. Any volunteers?
619 ** The files from the GNU m4 web-site is now in examples/WWW as a more
620 complete example of what GNU m4 can do.
622 * Version beta 1.4l - November 1998, by Rene' Seindal
624 ** GNU m4 now has an escape syntax category. If a character is marked as
625 an escape, words are only recognised as macros if preceded by an escape
626 character. It is a bit like -P, but dynamic: it can be turned on and
627 off. The GNU m4 web-site on http://www.seindal.dk/rene/gnu/ is
628 maintained with this feature - the m4 source is available on the site.
630 ** The module interface is improved, thanks to "Brian J. Fox",
631 who has contributed some code from Meta-HTML. The modules now build
632 automatically and installs properly, by default in
633 /usr/local/libexec/m4. There is a preliminary, untested support for
636 ** There is now a __m4_version__ macro that expands to the current version
639 * Version beta 1.4k - November 1998, by Erick Branderhorst and Rene' Seindal
641 ** GNU m4 now uses gettext to support internationalization.
643 ** GNU m4 now uses automake to control Makefile.in generation. This
644 should make it more consistent with the GNU standards.
646 ** GNU m4 will use the gmp library for multiple precision integral and
647 rational arithmetic in `eval' if configured with `--with-gmp'. If
648 configured without `--with-gmp' or if gmp is not available, and the type
649 `long long int' is, GNU m4 will use that for `eval' arithmetic.
651 ** GNU m4 now parses the input according to a syntax table, that can be
652 modified through the new builtin `changesyntax'. It is a generalisation
653 of the existing builtins `changecom' and `changequote'. The changes are
654 completely backwards compatible (except for the existence of
657 ** Sync lines can be turned on and off with the `syncoutput' builtin. The
658 builtin `syncoutput' is a GNU extension.
660 ** New experimental feature: dynamically loadable modules. New builtin
661 `loadmodules' loads shared libraries, that can define new builtin
662 macros, ie, new macros can be written in C. Depends on the dlopen()
663 interface, and is currently only tested on Linux. Enabled at configure
664 time with `--with-modules'. Documentation is in src/module.c and
667 ** Implement a GNU message catalog for French (Franc,ois Pinard).
669 ** Filenames found through path searches are now correctly reflected in
670 error and debug messages and through the `__file__' macro.
674 *** All 8-bit characters can now be used for quotes.
676 * Version 1.4 - October 1994, by Franc,ois Pinard
678 ** (No user visible changes)
680 * Version 1.3 - September 1994, by Franc,ois Pinard
682 ** Diversions are created as needed. Option `-N' is still accepted, but
683 otherwise ignored. Users should use only negative diversion numbers,
684 instead of high positive numbers, for diverting to nowhere.
686 ** Diversions should also work faster. No temporary files will be needed
687 at all if all diversions taken altogether do not use more than 512K.
689 ** Frozen state files may be produced with the `--freeze-state' (-F)
690 option and later brought back through the `--reload-state' (-R) option.
692 * Version 1.2 - July 1994, by Franc,ois Pinard
694 ** In patsubst(STRING, REGEXP, REPLACEMENT), \& in REPLACEMENT has been
695 changed to represent this part of STRING matched by the whole REGEXP,
696 instead of the whole STRING as before. \0 does the same, but emits a
697 diagnostic saying it will disappear in some subsequent release.
699 ** eval(EXPR) emits a diagnostic if EXPR has suffixed crumb. The same for
700 other numeric conversions in incr(), decr(), divert(), etc.
702 ** `--fatal-warnings' (-E) stops execution at first warning.
704 ** `--nesting-limit=LEVEL' (-L LEVEL) sets a limit to macro nesting.
705 It is initially fixed at 250.
707 ** `--word-regexp=REGEXP' (-W REGEXP) modifies macro name syntax, like
708 does the new `changeword(REGEXP)' macro. This feature is experimental,
709 tell me your opinions about it. You do need --enable-changeword at
710 configure time to get these things. Do *not* depend on them yet.
712 ** Trace output format is scannable by GNU Emacs' next-error function.
714 ** Stack overflow is detected and diagnosed on some capable systems.
716 ** Various bugs have been corrected, m4 should be more portable. See the
717 ChangeLog for details.
719 * Version 1.1 - November 1993, by Franc,ois Pinard
721 ** Changes which might affect existing GNU m4 scripts:
723 *** Option `-V' has been removed, use `--version' instead. `--version'
724 writes on standard output instead of standard error, and inhibits any
727 *** `--no-gnu-extensions' has been renamed `--traditional'.
729 *** In `eval', `^' used to indicate exponentiation, use `**' instead.
731 *** The automatic undiversion which takes place at end of all input is
732 forced into the main output stream.
734 ** Changes which are unlikely to affect existing scripts:
736 *** `--help' prints an usage summary on standard output. Script execution
739 *** `--prefix-builtins' (-P) prefixes all builtin macros by `m4_'.
741 *** Most builtin macros for which arguments are mandatory, called without
742 any arguments, are no more recognized as builtin macros: they are
743 consequently copied verbatim to the output stream.
745 *** `define' and `pushdef' are usable with only one argument, they give
746 this argument an empty definition.
748 *** `eval' new operators for binary representation handling: `^' for
749 exclusive-or, `~' for the bitwise negation, `<<' and `>>' for shifts.
751 *** `eval' recognizes the notation 0bDIGITS for binary numbers and the
752 notation 0rRADIX:DIGITS for numbers in any radix from 1 to 36.
754 * Version 1.0.3 - December 1992, by Franc,ois Pinard
756 ** Changes for the user:
758 *** `dnl' outputs a diagnostic if immediately followed by `('. Usually,
759 `dnl' is followed by newline or whitespace.
761 *** `ifelse' accepts without complaining the common idiom of having only
762 one argument. This is useful for introducing long comments.
764 *** `eval' always expresses values as signed, whatever the radix.
766 *** M4OPTS environment variable is no longer obeyed.
768 *** `--no-warnings' option is renamed `--silent'.
770 *** Debug lines use a new format more compatible with GNU standards.
772 *** Various bugs have been corrected. See the ChangeLog for details.
774 ** Changes for the installer:
776 *** GNU m4 now uses an Autoconf-generated configure script, and should be
777 more easily portable in many ways. (Cray is not supported yet).
779 *** `make check' has been made more portable, expect no errors.
781 ** Changes for the programmer:
783 *** Sources have been fully reindented to comply with GNU standards, and
784 cleaned up in many ways.
786 *** Sources have been protoized. Non-ANSI compilers are automatically
787 detected, then sources are unprotoized on the fly before compilation.
789 *** GNU m4 uses newer versions of obstack, regex, getopt, etc.
791 * Version 1.0 - October 1991, by Rene' Seindal
793 ** Uses GNU configure, taken from the gdb distribution.
795 ** Uses GNU getopt(), with long option names.
797 ** The -Q/+quiet option is added, which suppresses warnings about missing
798 or superflous arguments to builtin macros.
800 ** Added default options via the M4OPTS environment variable.
802 ** Several minor bugs have been fixed.
804 * Version 0.99 - July 1991, by Rene' Seindal
806 ** The builtins `incr' and `decr' are now implemented without use of
809 ** The builtin `indir' is added, to allow for indirect macro calls
810 (allows use of "illegal" macro names).
812 ** The debugging and tracing facilities has been enhanced considerably.
813 See the manual for details.
815 ** The -tMACRO option is added, marks MACRO for tracing as soon as it
818 ** Builtins are traced after renaming iff they were before.
820 ** Named files can now be undiverted.
822 ** The -Nnum option can be used to increase the number of divertions
825 ** Calling changecom without arguments now disables all comment handling.
827 ** A bug in `dnl' is fixed.
829 ** A bug in the multi-character quoting code is fixed.
831 ** Several typos in the manual has been corrected. More probably persist.
833 * Version 0.75 - November 1990, by Rene' Seindal
835 ** Implemented search path for include files (-I option and M4PATH
836 environment variable).
838 ** Implemented builtin `format' for printf-like formatting.
840 ** Implemented builtin `regexp' for searching for regular expressions.
842 ** Implemented builtin `patsubst' for substitution with regular
845 ** Implemented builtin `esyscmd', which expands to a shell commands output.
847 ** Implemented `__file__' and `__line__' for use in error messages.
849 ** Implemented character ranges in `translit'.
851 ** Implemented control over debugging output.
853 ** Implemented multi-character quotes.
855 ** Implemented multi-character comment delimiters.
857 ** Changed predefined macro `gnu' to `__gnu__'.
859 ** Changed predefined macro `unix' to `__unix__', when the -G option is
860 not used. With -G, `unix' is still defined.
862 ** Added program name to error messages.
864 ** Fixed two missing null bytes bugs.
866 * Version 0.50 - January 1990, by Rene' Seindal
868 * Initial beta release.