1 GNU M4 NEWS - User visible changes.
2 Copyright (C) 1992, 1993, 1994, 2004, 2005, 2006 Free Software
5 Version 1.4.8 - 20 November 2006, by Eric Blake (CVS version 1.4.7a)
7 * The `divert' macro and `-H'/`--hashsize' command line option no longer
8 cause a core dump when handed extra large values. Also, `divert' now
9 uses memory proportional to the number of diversions in use, rather than
10 to the maximum diversion number encountered, so that large diversion
11 numbers are less likely to exhaust system memory; and is no longer
12 limited by the maximum number of file descriptors.
13 * The `--help' and `--version' command line options now consistently
14 override all earlier options. For example, `m4 --debugfile=trace
15 --help' now no longer accidentally creates an empty file `trace'.
16 * The `-L'/`--nesting-limit' command line option can now be set to 0
17 to remove the default limit of 1024. However, it is still possible that
18 heavily nested input can cause abrupt program termination due to stack
20 * Problems encountered when writing to standard error, such as with the
21 `errprint' macro, now always cause a non-zero exit status.
22 * Warnings and errors issued during macro expansion are now consistently
23 reported at the line where the macro name was detected, rather than
24 where the close parenthesis resides. Text wrapped by `m4wrap' now
25 remembers the location that was in effect when m4wrap was invoked,
26 rather than changing to line 0 and the empty string for a file. The
27 macros `__line__' and `__file__' now work correctly even as the last
28 token in an included file.
29 * The `builtin' and `indir' macros now transparently handle builtin
30 tokens generated by `defn'.
31 * When diversions created by the `divert' macro collect enough text that
32 M4 must use temporary files, the environment variable $TMPDIR is now
33 consulted, and a better effort is made to clean up those files in the
34 event of a fatal signal.
35 * The `mkstemp' builtin is added with the same GNU semantics as `maketemp',
36 based on the recommendation of POSIX to deprecate the POSIX semantics of
37 `maketemp' as inherently insecure. In GNU mode (no -G supplied on the
38 command line), `maketemp' silently retains the secure GNU semantics, but
39 a future release of M4 will change this to emit a warning. In
40 traditional mode (m4 -G), `maketemp' now uses the POSIX-mandated insecure
41 semantics, and issues a warning that you should convert your script to
42 use `mkstemp' instead. Additionally, `mkstemp' and `maketemp' are now
43 well-defined even if the template argument does not end in six `X'
45 * The manual has been improved, including a new section on a composite
47 * The `changecom' and `changequote' macros now treat an empty second
48 argument the same as if it were missing, rather than using the empty
49 string and making it impossible to end a comment or quote.
50 * The `translit' macro now operates in linear instead of quadratic time,
51 and is now eight-bit clean.
52 * The `-D', `-U', `-s', and `-t' command line options now take effect
53 after any files encountered earlier on the command line, rather than up
54 front, as is done in traditional implementations and required by POSIX.
56 Version 1.4.7 - 25 September 2006, by Eric Blake (CVS version 1.4.6a)
58 * Fix regression from 1.4.5 in handling a file that ends in a macro
59 expansion without arguments instead of a newline.
60 * The define and pushdef macros now warn when the first argument is not
61 a string, rather than silently doing nothing.
62 * Standard input can now be read more than once, as in 'm4 - file -', and
63 is not closed until all wrapped text is handled. This makes a
64 difference when stdin is not a regular file, and also fixes bugs when
65 using the syscmd or esyscmd macros from wrapped text.
66 * When standard input is a seekable file, the m4exit, syscmd, and esyscmd
67 macros now restore the current position to the next unread byte rather
68 than discarding an arbitrary amount of buffered data.
69 * SysV command-line compatibility is no longer a goal of GNU M4; the
70 focus will be instead on POSIX compatibility. This release continues to
71 support previous usage, but adds warnings in areas which will allow a
72 future version of GNU M4 to use its own extensions without being tied to
73 the SysV command line interface.
74 * The no-op compatibility command line options -B, -N, -S, -T, and
75 --diversions may be withdrawn or assigned new meanings in future
76 releases, so they now issue a warning if used.
77 * A new command line option -i replaces the compatibility -e as the
78 short spelling of --interactive, for consistency with other GNU tools; a
79 warning is issued if the old spelling is used, and it may be assigned new
80 meaning in future releases.
81 * A new command line option --debugfile replaces the options -o and
82 --error-output as the preferred spelling. The old options were
83 misleading in their names and inconsistent with other GNU tools; they are
84 still silently accepted, but no longer documented in --help, and may be
85 assigned new meanings in future releases.
87 Version 1.4.6 - 25 August 2006, by Eric Blake (CVS version 1.4.5a)
89 * Fix buffer overruns in regexp and patsubst macros when handed a trailing
90 backslash in the replacement text, or when handling \n substitutions
91 beyond the number of \(\) groups.
92 * Fix memory leak in regexp, patsubst, and changeword macros.
93 * The format macro now understands %F, %g, and %G.
94 * When loading frozen files, m4 now exits with status 63 if version
96 * Fix bugs that occurred when invoked with stdout or stderr closed,
97 and detect write failures to stdout or to the target of the
98 debugfile macro. In particular, the syscmd and esyscmd macros can
99 no longer interfere with the debug stream or diversions.
100 * The m4exit macro now converts values outside the range 0-255 to 1.
101 * It is now an error if a command-line input file ends in the middle of a
102 comment, matching the behavior of mid-string and mid-argument
104 * The dnl macro now warns if end of file is encountered instead of a
106 * The error message when end of file is encountered now uses the file and
107 line where the dangling construct started, rather than `NONE:0:'.
108 * The debugmode and __file__ macros, and the -s/--synclines option, now
109 show what directory a file was found in when the -I/--include option or
110 M4PATH variable had an effect.
111 * The changequote and changecom macros now work with 8-bit characters, and
112 quotes and comments that begin with `(' are properly recognized
114 * The new macro __program__ is added, which allows the input file to issue
115 an error message that resembles messages from m4. Warning and error
116 messages have been reformatted to comply with GNU Coding Standards.
117 * The errprint, m4wrap, and shift macros are now recognized only with
119 * The index, substr, translit, regexp, and patsubst macros now produce
120 output when given only one argument, but still warn about a missing
122 * The patsubst macro now reliably finds zero-length matches at the end
125 Version 1.4.5 - 15 July 2006, by Eric Blake (CVS version 1.4.4c)
127 * Fix sysval on BeOS, OS/2, and other systems that store exit status
128 in the low-order byte. Additionally, on Unix platforms, if syscmd was
129 terminated by a signal, sysval now displays the signal number shifted
130 left by eight bits, to match traditional m4 implementations.
131 * The maketemp macro is no longer subject to platform limitations (such as
132 26 or 32 max files from a given template).
133 * Frozen files now require that the first directive be V (version), to
134 better diagnose version mismatch. Additionally, if the F directive
135 (builtin function) names an unknown builtin that existed in the m4 that
136 froze the file but not in the current m4 (for example, changeword), the
137 warning is deferred until an attempt is made to actually use the
138 builtin. This allows downgrading from beta m4-1.4o to stable m4-1.4.5
139 without breaking autoconf.
140 * The format and indir macros are now recognized only with arguments.
141 * The eval macro no longer crashes on x86 architectures when dividing the
142 minimum integer by -1.
143 * On systems with ecvt and fcvt, format no longer truncates trailing
144 zeroes on integers printed with %.0f. On systems without these
145 functions, format is no longer subject to a buffer overflow that
146 permitted arbitrary code execution.
147 * On native Windows builds, the macro __windows__ is provided instead of
148 __unix__. Likewise, on OS/2 builds, the macro __os2__ is provided. This
149 allows input files to determine when syscmd might behave differently.
150 * Fix bug in 1.4.3 patch to use \n line-endings that did not work for
152 * When given the empty string or 0, undivert is now documented as a no-op
153 rather than closing stdout, warning about a non-existent file, or trying
154 to read a directory as a file.
155 * Many documentation improvements. Also, the manual is now distributed
156 under FDL 1.2, rather than a stricter verbatim-only license.
157 * Raise the -L (--nesting-limit) command line option limit from 250 to
159 * The decr, incr, divert, m4exit, and substr macros treat an empty number
160 as 0, issue a warning, and expand as normal; rather than issuing an error
161 and expanding to the empty string.
162 * The eval macro now treats an empty radix argument as 10, handles radix 1,
163 and treats the width argument as number of digits excluding the sign,
164 for compatibility with other m4 implementations.
165 * The ifdef, divert, m4exit, substr, and translit macros now correctly
166 ignore extra arguments.
167 * The popdef and undefine macros now correctly accept multiple arguments.
168 * Although changeword is on its last leg, if enabled, it now reverts to the
169 default (faster) regexp when passed the empty string.
170 * The regexp and substr macros now warn and ignore a trailing backslash in
171 the replacement, and warn on \n for n larger than the number of
172 sub-expressions in the regexp.
174 Version 1.4.4b - 17 June 2006, by Eric Blake (CVS version 1.4.4a)
176 * Fix a recursive push_string crashing bug, which affected changequote of
177 three or more characters on some compilers.
178 * Use automake to fix build portability issues.
179 * Fix a recursive m4wrap crashing bug.
180 * Fix a 1 in 2**32 hash crashing bug.
181 * Tracing a macro by name is now persistent, even if the macro is
182 subsequently undefined or redefined. The traceon and traceoff macros no
183 longer warn about undefined symbols. This solves a crash when using
184 indir on an undefined macro traced with the -t option, as well as an
185 incorrect result of ifdef. Furthermore, tracing is no longer transferred
186 with builtins, solving the bug of "m4 -tm4_eval" failing to give trace
187 output on the input "define(`m4_eval',defn(`eval'))m4_eval(1)".
188 * Fix a crash when a macro is undefined while collecting its arguments, by
189 always using the definition that was in effect before argument
190 collection. This behavior matches the C pre-processor, and means that
191 the sequence "define(`f',`1')f(define(`f',`2'))f" is now documented to
192 result in "12", rather than the previously undocumented "22".
193 * Update the regex engine to fix several bugs.
194 * Fix a potential crash on machines where char is signed.
196 Version 1.4.4 - October 2005, by Gary V. Vaughan
198 * ./configure --infodir=/usr/share/info now works correctly.
199 * When any file named on the command line is missing exit with status 1.
201 Version 1.4.3 - March 2005, by Gary V. Vaughan
203 * DESTDIR installs now work correctly.
204 * Don't segfault with uncompilable regexps to changeword().
205 * Always use \n line-endings for frozen files (fixes a Windows bug).
206 * Portability fix for systems lacking mkstemp(3).
207 * Approximately 20% speed up in the common case of usage with autoconf.
208 * Supported on QNX 6.3.
210 Version 1.4.2 - August 2004, by Paul Eggert
212 * No user visible changes; portability bug fixes only.
214 Version 1.4.1 - June 2004, by Paul Eggert
216 * maketemp now creates an empty file with the given name, instead of merely
217 returning the name of a nonexistent file. This closes a security hole.
219 Version 1.4 - October 1994, by Franc,ois Pinard
221 (No user visible changes)
223 Version 1.3 - September 1994, by Franc,ois Pinard
225 * Diversions are created as needed. Option `-N' is still accepted, but
226 otherwise ignored. Users should use only negative diversion numbers,
227 instead of high positive numbers, for diverting to nowhere.
229 * Diversions should also work faster. No temporary files will be needed
230 at all if all diversions taken altogether do not use more than 512K.
232 * Frozen state files may be produced with the `--freeze-state' (-F)
233 option and later brought back through the `--reload-state' (-R) option.
235 Version 1.2 - July 1994, by Franc,ois Pinard
237 * In patsubst(STRING, REGEXP, REPLACEMENT), \& in REPLACEMENT has been
238 changed to represent this part of STRING matched by the whole REGEXP,
239 instead of the whole STRING as before. \0 does the same, but emits a
240 diagnostic saying it will disappear in some subsequent release.
242 * eval(EXPR) emits a diagnostic if EXPR has suffixed crumb. The same for
243 other numeric conversions in incr(), decr(), divert(), etc.
245 * `--fatal-warnings' (-E) stops execution at first warning.
247 * `--nesting-limit=LEVEL' (-L LEVEL) sets a limit to macro nesting.
248 It is initially fixed at 250.
250 * `--word-regexp=REGEXP' (-W REGEXP) modifies macro name syntax, like
251 does the new `changeword(REGEXP)' macro. This feature is experimental,
252 tell me your opinions about it. You do need --enable-changeword at
253 configure time to get these things. Do *not* depend on them yet.
255 * Trace output format is scannable by GNU Emacs' next-error function.
257 * Stack overflow is detected and diagnosed on some capable systems.
259 * Various bugs have been corrected, m4 should be more portable. See the
260 ChangeLog for details.
262 Version 1.1 - November 1993, by Franc,ois Pinard
264 Changes which might affect existing GNU m4 scripts:
266 * Option `-V' has been removed, use `--version' instead. `--version'
267 writes on standard output instead of standard error, and inhibits any
270 * `--no-gnu-extensions' has been renamed `--traditional'.
272 * In `eval', `^' used to indicate exponentiation, use `**' instead.
274 * The automatic undiversion which takes place at end of all input is
275 forced into the main output stream.
277 Changes which are unlikely to affect existing scripts:
279 * `--help' prints an usage summary on standard output. Script execution
282 * `--prefix-builtins' (-P) prefixes all builtin macros by `m4_'.
284 * Most builtin macros for which arguments are mandatory, called without
285 any arguments, are no more recognized as builtin macros: they are
286 consequently copied verbatim to the output stream.
288 * `define' and `pushdef' are usable with only one argument, they give
289 this argument an empty definition.
291 * `eval' new operators for binary representation handling: `^' for
292 exclusive-or, `~' for the bitwise negation, `<<' and `>>' for shifts.
294 * `eval' recognizes the notation 0bDIGITS for binary numbers and the
295 notation 0rRADIX:DIGITS for numbers in any radix from 1 to 36.
297 Version 1.0.3 - December 1992, by Franc,ois Pinard
299 Changes for the user:
301 * `dnl' outputs a diagnostic if immediately followed by `('. Usually,
302 `dnl' is followed by newline or whitespace.
304 * `ifelse' accepts without complaining the common idiom of having only
305 one argument. This is useful for introducing long comments.
307 * `eval' always expresses values as signed, whatever the radix.
309 * M4OPTS environment variable is no longer obeyed.
311 * `--no-warnings' option is renamed `--silent'.
313 * Debug lines use a new format more compatible with GNU standards.
315 * Various bugs have been corrected. See the ChangeLog for details.
317 Changes for the installer:
319 * GNU m4 now uses an Autoconf-generated configure script, and should be
320 more easily portable in many ways. (Cray is not supported yet).
322 * `make check' has been made more portable, expect no errors.
324 Changes for the programmer:
326 * Sources have been fully reindented to comply with GNU standards, and
327 cleaned up in many ways.
329 * Sources have been protoized. Non-ANSI compilers are automatically
330 detected, then sources are unprotoized on the fly before compilation.
332 * GNU m4 uses newer versions of obstack, regex, getopt, etc.
334 Version 1.0 - October 1991, by Rene' Seindal
336 * Uses GNU configure, taken from the gdb distribution.
338 * Uses GNU getopt(), with long option names.
340 * The -Q/+quiet option is added, which suppresses warnings about missing
341 or superflous arguments to built-in macros.
343 * Added default options via the M4OPTS environment variable.
345 * Several minor bugs have been fixed.
347 Version 0.99 - July 1991, by Rene' Seindal
349 * The builtins `incr' and `decr' are now implemented without use of
352 * The builtin `indir' is added, to allow for indirect macro calls
353 (allows use of "illegal" macro names).
355 * The debugging and tracing facilities has been enhanced considerably.
356 See the manual for details.
358 * The -tMACRO option is added, marks MACRO for tracing as soon as it
361 * Builtins are traced after renaming iff they were before.
363 * Named files can now be undiverted.
365 * The -Nnum option can be used to increase the number of divertions
368 * Calling changecom without arguments now disables all comment handling.
370 * A bug in `dnl' is fixed.
372 * A bug in the multi-character quoting code is fixed.
374 * Several typos in the manual has been corrected. More probably persist.
376 Version 0.75 - November 1990, by Rene' Seindal
378 * Implemented search path for include files (-I option and M4PATH
379 environment variable).
381 * Implemented builtin `format' for printf-like formatting.
383 * Implemented builtin `regexp' for searching for regular expressions.
385 * Implemented builtin `patsubst' for substitution with regular
388 * Implemented builtin `esyscmd', which expands to a shell commands output.
390 * Implemented `__file__' and `__line__' for use in error messages.
392 * Implemented character ranges in `translit'.
394 * Implemented control over debugging output.
396 * Implemented multi-character quotes.
398 * Implemented multi-character comment delimiters.
400 * Changed predefined macro `gnu' to `__gnu__'.
402 * Changed predefined macro `unix' to `__unix__', when the -G option is
403 not used. With -G, `unix' is still defined.
405 * Added program name to error messages.
407 * Fixed two missing null bytes bugs.
409 Version 0.50 - January 1990, by Rene' Seindal
411 * Initial beta release.