GNU M4 NEWS - User visible changes. * Noteworthy changes in release 1.4.16 (2011-03-01) [stable] ** Fix regressions in the `index' builtin. On glibc platforms, this avoids false positives from a strstr bug in glibc 2.9 through 2.12; on many other platforms, it fixes two separate regressions, a false positive introduced in 1.4.11 and a false negative in 1.4.15. ** A number of portability improvements inherited from gnulib. * Noteworthy changes in release 1.4.15 (2010-08-31) [stable] ** Fix regression introduced in 1.4.9b where the `format' builtin could crash on an invalid format string. ** Fix compilation against newer glibc, and on AIX 7.1BETA. ** A number of portability improvements inherited from gnulib. * Noteworthy changes in Version 1.4.14 (2010-02-24) [stable] Released by Eric Blake, based on git version 1.4.13.* ** Fix regression introduced in 1.4.12 where executing with stdout closed could crash m4 on exit on some platforms. ** Fix regressions introduced in 1.4.13 in the `esyscmd' builtin, where closed file descriptors could interfere with child execution, and where a child status of 127 made m4 print a spurious message to stderr. ** Fix a security hole in 'make dist', present since at least M4 1.4, that could affect anybody attempting to redistribute modified sources (see Automake CVE-2009-4029). ** A number of portability improvements inherited from gnulib. * Noteworthy changes in Version 1.4.13 (2009-04-01) [stable] Released by Eric Blake, based on git version 1.4.12.* ** The manual is now distributed under the terms of FDL 1.3. ** The `divert' and `undivert' builtins have been made more efficient when using temporary files for large diversions. ** The `translit' builtin has been made more efficient when the second argument is short. ** The input engine has been optimized for faster processing. ** The command line option `--debugfile', introduced in 1.4.7, now treats its argument as optional, in order to allow setting the debug output back to stderr when used without an argument; and order is now significant with respect to command line files. You must therefore use `m4 --debugfile=trace file', not `m4 file --debugfile trace'. This change does not affect the deprecated `-o'/`--error-output' option. ** The `syscmd' and `esyscmd' builtins can be configured to use an alternate shell, via the new `configure' option `--with-syscmd-shell'. ** A number of portability improvements inherited from gnulib. * Noteworthy changes in Version 1.4.12 (2008-10-10) [stable] Released by Eric Blake, based on git version 1.4.11.* ** Fix regression introduced in 1.4.4b where using `traceon' could delete a macro. This was most noticeable with `traceon(`traceon')', but would also happen in cases such as `foo(traceon(`foo'))'. ** Fix regression introduced in 1.4.7 where `m4 -N9' died with an assertion failure. ** Fix regression introduced in 1.4.11 where `defn' died with an assertion failure on a traced but undefined macro. ** New `-g'/`--gnu' command-line option overrides `-G'/`--traditional'. For now, the environment variable POSIXLY_CORRECT has no effect on M4 behavior; but a future release of M4 will behave as though --traditional is implied if POSIXLY_CORRECT is set (this future change is necessary, because in the current release, there is no way to disable GNU extensions that conflict with POSIX without the use of a non-POSIX command-line argument). Clients of M4 that want to use GNU extensions, even when POSIXLY_CORRECT is set, should start using the -g command-line argument, even though it is currently a no-op if -G did not appear earlier in the command line, so that the client will not break in the face of an upgraded m4 and a POSIXLY_CORRECT execution environment. ** The `-L'/`--nesting-limit' command-line option now defaults to 0 for unlimited on platforms that can detect and deal with stack overflow. On systems that lack alternate stack support, such as Cygwin, and on systems that do not obey the POSIX semantics for distinguishing stack overflow from other exceptions, such as Linux, you can optionally install the libsigsegv library (version 2.6 or newer recommended) to enhance m4's ability to accurately report stack overflow: http://www.gnu.org/software/libsigsegv/ ** A number of portability improvements inherited from gnulib. * Noteworthy changes in Version 1.4.11 (2008-04-02) [stable] Released by Eric Blake, based on git version 1.4.10a ** Security fixes for the -F option, for bugs present since -F was introduced in 1.3: Avoid core dump with 'm4 -F file -t undefined', and avoid arbitrary code execution with certain file names. ** Fix regression introduced in 1.4.9b in the `divert' builtin when more than 512 kibibytes are saved in diversions on platforms like NetBSD or darwin where fopen(name,"a+") seeks to the end of the file. ** The output of the `maketemp' and `mkstemp' builtins is now quoted if a file was created. This is a minor security fix, because it was possible (although rather unlikely) that an unquoted string could match an existing macro name, such that use of the `mkstemp' output would trigger inadvertent macro expansion and operate on the wrong file name. ** Enhance the `defn' builtin to support concatenation of multiple text arguments, as required by POSIX. However, at this time, it is not possible to concatenate a builtin macro with anything else; a warning is now issued if this is attempted, although a future version of M4 may lift this restriction to match other implementations. ** Enhance the `format' builtin to parse all C99 floating point numbers, even on platforms where strtod(3) is buggy, although the replacement function does have the known issue of rounding errors when parsing some decimal floating point values. This fixes testsuite failures introduced in 1.4.9b. ** Enhance the `index' builtin to guarantee linear behavior, in spite of the surprisingly large number of systems with a brain-dead quadratic strstr(3). ** A number of portability improvements inherited from gnulib. * Noteworthy changes in Version 1.4.10 (2007-07-09) [stable] Released by Eric Blake, based on CVS version 1.4.9c ** Upgrade from GPL version 2 to GPL version 3 or later. ** A number of portability improvements inherited from gnulib. ** Avoid undefined behavior introduced in 1.4.9b in the `format' builtin when handling %c. However, this area of code has never been documented, and currently does not match the POSIX behavior of printf(1), so it may have further changes in the next version. * Noteworthy changes in Version 1.4.9b (2007-05-29) [beta] Released by Eric Blake, based on CVS version 1.4.9a ** Fix regression introduced in 1.4.9 in the `eval' builtin when performing division. ** Fix regression introduced in 1.4.8 in the `-F' option that made it impossible to freeze more than 512 kibibytes of diverted text. ** The synclines option `-s' no longer generates sync lines in the middle of multiline comments or quoted strings. ** Work around a number of corner-case POSIX compliance bugs in various broken stdio libraries. In particular, the `syscmd' builtin behaves more predictably when stdin is seekable. ** The `format' builtin now understands formats such as %a, %A, and %'hhd, and works around a number of platform printf bugs. Furthermore, the sequence format(%*.*d,-1,-1,1) no longer outputs random data. However, some non-compliant platforms such as mingw still have known bugs in strtod that may cause testsuite failures. ** The testsuite is improved to also run gnulib portability tests for the features that M4 imports from gnulib. * Noteworthy changes in Version 1.4.9 (2007-03-23) [stable] Released by Eric Blake, based on CVS version 1.4.8c ** Minor documentation and portability cleanups. * Noteworthy changes in Version 1.4.8b (2007-02-24) [beta] Released by Eric Blake, based on CVS version 1.4.8a ** Fix a regression introduced in 1.4.8 that made m4 unable to process files larger than 2GiB on some platforms. ** Fix a regression introduced in 1.4.8 that made m4 dump core when invoked as 'm4 -- file'. ** The `eval' builtin now follows C precedence rules. Additionally, the short-circuit operators correctly short-circuit division by zero. The previously undocumented alias of '=' meaning '==' in eval now triggers a deprecation warning, so that a future version of M4 can implement a form of variable assignment as an extension. ** The `include' builtin now affects exit status on failure, as required by POSIX. Use `sinclude' if you need a successful exit status. ** The `-E'/`--fatal-warnings' command-line option now has two levels. When specified only once, warnings affect exit status, but execution continues, so that you can see all warnings instead of fixing them one at a time. To achieve 1.4.8 behavior, where the first warning immediately exits, specify -E twice on the command line. ** A new `--warn-macro-sequence' command-line option allows detection of sequences in `define' and `pushdef' definitions that match an optional regular expression. The default regular expression is `\$\({[^}]*}\|[0-9][0-9]+\)', corresponding to the sequences that might not behave correctly when upgrading to the eventual M4 2.0. By default, M4 2.0 will follow the POSIX requirement that a macro definition containing `$11' must expand to the first argument concatenated with 1, rather than the eleventh argument; and will take advantage of the POSIX wording that allows implementations to treat `${11}' as the eleventh argument instead of literal text. Be aware that Autoconf 2.61 will not work with this option enabled with the default regular expression; but Autoconf 2.62 will be compatible with this option. ** Improved portability to platforms such as BSD/OS and AIX. * Noteworthy changes in Version 1.4.8 (2006-11-20) [stable] Released by Eric Blake, based on CVS version 1.4.7a ** The `divert' macro and `-H'/`--hashsize' command line option no longer cause a core dump when handed extra large values. Also, `divert' now uses memory proportional to the number of diversions in use, rather than to the maximum diversion number encountered, so that large diversion numbers are less likely to exhaust system memory; and is no longer limited by the maximum number of file descriptors. ** The `--help' and `--version' command line options now consistently override all earlier options. For example, `m4 --debugfile=trace --help' now no longer accidentally creates an empty file `trace'. ** The `-L'/`--nesting-limit' command line option can now be set to 0 to remove the default limit of 1024. However, it is still possible that heavily nested input can cause abrupt program termination due to stack overflow. ** Problems encountered when writing to standard error, such as with the `errprint' macro, now always cause a non-zero exit status. ** Warnings and errors issued during macro expansion are now consistently reported at the line where the macro name was detected, rather than where the close parenthesis resides. Text wrapped by `m4wrap' now remembers the location that was in effect when m4wrap was invoked, rather than changing to line 0 and the empty string for a file. The macros `__line__' and `__file__' now work correctly even as the last token in an included file. ** The `builtin' and `indir' macros now transparently handle builtin tokens generated by `defn'. ** When diversions created by the `divert' macro collect enough text that M4 must use temporary files, the environment variable $TMPDIR is now consulted, and a better effort is made to clean up those files in the event of a fatal signal. ** The `mkstemp' builtin is added with the same GNU semantics as `maketemp', based on the recommendation of POSIX to deprecate the POSIX semantics of `maketemp' as inherently insecure. In GNU mode (no -G supplied on the command line), `maketemp' silently retains the secure GNU semantics, but a future release of M4 will change this to emit a warning. In traditional mode (m4 -G), `maketemp' now uses the POSIX-mandated insecure semantics, and issues a warning that you should convert your script to use `mkstemp' instead. Additionally, `mkstemp' and `maketemp' are now well-defined even if the template argument does not end in six `X' characters. ** The manual has been improved, including a new section on a composite macro `foreach'. ** The `changecom' and `changequote' macros now treat an empty second argument the same as if it were missing, rather than using the empty string and making it impossible to end a comment or quote. ** The `translit' macro now operates in linear instead of quadratic time, and is now eight-bit clean. ** The `-D', `-U', `-s', and `-t' command line options now take effect after any files encountered earlier on the command line, rather than up front, as is done in traditional implementations and required by POSIX. * Noteworthy changes in Version 1.4.7 (2006-09-25) [stable] Released by Eric Blake, based on CVS version 1.4.6a ** Fix regression from 1.4.5 in handling a file that ends in a macro expansion without arguments instead of a newline. ** The define and pushdef macros now warn when the first argument is not a string, rather than silently doing nothing. ** Standard input can now be read more than once, as in 'm4 - file -', and is not closed until all wrapped text is handled. This makes a difference when stdin is not a regular file, and also fixes bugs when using the syscmd or esyscmd macros from wrapped text. ** When standard input is a seekable file, the m4exit, syscmd, and esyscmd macros now restore the current position to the next unread byte rather than discarding an arbitrary amount of buffered data. ** SysV command-line compatibility is no longer a goal of GNU M4; the focus will be instead on POSIX compatibility. This release continues to support previous usage, but adds warnings in areas which will allow a future version of GNU M4 to use its own extensions without being tied to the SysV command line interface. ** The no-op compatibility command line options -B, -N, -S, -T, and --diversions may be withdrawn or assigned new meanings in future releases, so they now issue a warning if used. ** A new command line option -i replaces the compatibility -e as the short spelling of --interactive, for consistency with other GNU tools; a warning is issued if the old spelling is used, and it may be assigned new meaning in future releases. ** A new command line option --debugfile replaces the options -o and --error-output as the preferred spelling. The old options were misleading in their names and inconsistent with other GNU tools; they are still silently accepted, but no longer documented in --help, and may be assigned new meanings in future releases. * Noteworthy changes in Version 1.4.6 (2006-08-25) [stable] Released by Eric Blake, based on CVS version 1.4.5a ** Fix buffer overruns in regexp and patsubst macros when handed a trailing backslash in the replacement text, or when handling \n substitutions beyond the number of \(\) groups. ** Fix memory leak in regexp, patsubst, and changeword macros. ** The format macro now understands %F, %g, and %G. ** When loading frozen files, m4 now exits with status 63 if version mismatch is detected. ** Fix bugs that occurred when invoked with stdout or stderr closed, and detect write failures to stdout or to the target of the debugfile macro. In particular, the syscmd and esyscmd macros can no longer interfere with the debug stream or diversions. ** The m4exit macro now converts values outside the range 0-255 to 1. ** It is now an error if a command-line input file ends in the middle of a comment, matching the behavior of mid-string and mid-argument collection. ** The dnl macro now warns if end of file is encountered instead of a newline. ** The error message when end of file is encountered now uses the file and line where the dangling construct started, rather than `NONE:0:'. ** The debugmode and __file__ macros, and the -s/--synclines option, now show what directory a file was found in when the -I/--include option or M4PATH variable had an effect. ** The changequote and changecom macros now work with 8-bit characters, and quotes and comments that begin with `(' are properly recognized following a word. ** The new macro __program__ is added, which allows the input file to issue an error message that resembles messages from m4. Warning and error messages have been reformatted to comply with GNU Coding Standards. ** The errprint, m4wrap, and shift macros are now recognized only with arguments. ** The index, substr, translit, regexp, and patsubst macros now produce output when given only one argument, but still warn about a missing second argument. ** The patsubst macro now reliably finds zero-length matches at the end of a string. * Noteworthy changes in Version 1.4.5 (2006-07-15) [stable] Released by Eric Blake, based on CVS version 1.4.4c ** Fix sysval on BeOS, OS/2, and other systems that store exit status in the low-order byte. Additionally, on Unix platforms, if syscmd was terminated by a signal, sysval now displays the signal number shifted left by eight bits, to match traditional m4 implementations. ** The maketemp macro is no longer subject to platform limitations (such as 26 or 32 max files from a given template). ** Frozen files now require that the first directive be V (version), to better diagnose version mismatch. Additionally, if the F directive (builtin function) names an unknown builtin that existed in the m4 that froze the file but not in the current m4 (for example, changeword), the warning is deferred until an attempt is made to actually use the builtin. This allows downgrading from beta m4-1.4o to stable m4-1.4.5 without breaking autoconf. ** The format and indir macros are now recognized only with arguments. ** The eval macro no longer crashes on x86 architectures when dividing the minimum integer by -1. ** On systems with ecvt and fcvt, format no longer truncates trailing zeroes on integers printed with %.0f. On systems without these functions, format is no longer subject to a buffer overflow that permitted arbitrary code execution. ** On native Windows builds, the macro __windows__ is provided instead of __unix__. Likewise, on OS/2 builds, the macro __os2__ is provided. This allows input files to determine when syscmd might behave differently. ** Fix bug in 1.4.3 patch to use \n line-endings that did not work for cygwin. ** When given the empty string or 0, undivert is now documented as a no-op rather than closing stdout, warning about a non-existent file, or trying to read a directory as a file. ** Many documentation improvements. Also, the manual is now distributed under FDL 1.2, rather than a stricter verbatim-only license. ** Raise the -L (--nesting-limit) command line option limit from 250 to 1024. ** The decr, incr, divert, m4exit, and substr macros treat an empty number as 0, issue a warning, and expand as normal; rather than issuing an error and expanding to the empty string. ** The eval macro now treats an empty radix argument as 10, handles radix 1, and treats the width argument as number of digits excluding the sign, for compatibility with other m4 implementations. ** The ifdef, divert, m4exit, substr, and translit macros now correctly ignore extra arguments. ** The popdef and undefine macros now correctly accept multiple arguments. ** Although changeword is on its last leg, if enabled, it now reverts to the default (faster) regexp when passed the empty string. ** The regexp and substr macros now warn and ignore a trailing backslash in the replacement, and warn on \n for n larger than the number of sub-expressions in the regexp. * Noteworthy changes in Version 1.4.4b (2006-06-17) [beta] Released by Eric Blake, based on CVS version 1.4.4a ** Fix a recursive push_string crashing bug, which affected changequote of three or more characters on some compilers. ** Use automake to fix build portability issues. ** Fix a recursive m4wrap crashing bug. ** Fix a 1 in 2**32 hash crashing bug. ** Tracing a macro by name is now persistent, even if the macro is subsequently undefined or redefined. The traceon and traceoff macros no longer warn about undefined symbols. This solves a crash when using indir on an undefined macro traced with the -t option, as well as an incorrect result of ifdef. Furthermore, tracing is no longer transferred with builtins, solving the bug of "m4 -tm4_eval" failing to give trace output on the input "define(`m4_eval',defn(`eval'))m4_eval(1)". ** Fix a crash when a macro is undefined while collecting its arguments, by always using the definition that was in effect before argument collection. This behavior matches the C pre-processor, and means that the sequence "define(`f',`1')f(define(`f',`2'))f" is now documented to result in "12", rather than the previously undocumented "22". ** Update the regex engine to fix several bugs. ** Fix a potential crash on machines where char is signed. * Noteworthy changes in Version 1.4.4 (Oct 2005) [stable] Released by Gary V. Vaughan ** ./configure --infodir=/usr/share/info now works correctly. ** When any file named on the command line is missing exit with status 1. * Noteworthy changes in Version 1.4.3 (Mar 2005) [stable] Released by Gary V. Vaughan ** DESTDIR installs now work correctly. ** Don't segfault with uncompilable regexps to changeword(). ** Always use \n line-endings for frozen files (fixes a Windows bug). ** Portability fix for systems lacking mkstemp(3). ** Approximately 20% speed up in the common case of usage with autoconf. ** Supported on QNX 6.3. * Noteworthy changes in Version 1.4.2 (Aug 2004) [stable] Released by Paul Eggert ** No user visible changes; portability bug fixes only. * Noteworthy changes in Version 1.4.1 (Jun 2004) [stable] Released by Paul Eggert ** maketemp now creates an empty file with the given name, instead of merely returning the name of a nonexistent file. This closes a security hole. * Noteworthy changes in Version 1.4 (Oct 1994) [stable] Released by Franc,ois Pinard ** (No user visible changes) Version 1.3 - September 1994, by Franc,ois Pinard * Diversions are created as needed. Option `-N' is still accepted, but otherwise ignored. Users should use only negative diversion numbers, instead of high positive numbers, for diverting to nowhere. * Diversions should also work faster. No temporary files will be needed at all if all diversions taken altogether do not use more than 512K. * Frozen state files may be produced with the `--freeze-state' (-F) option and later brought back through the `--reload-state' (-R) option. Version 1.2 - July 1994, by Franc,ois Pinard * In patsubst(STRING, REGEXP, REPLACEMENT), \& in REPLACEMENT has been changed to represent this part of STRING matched by the whole REGEXP, instead of the whole STRING as before. \0 does the same, but emits a diagnostic saying it will disappear in some subsequent release. * eval(EXPR) emits a diagnostic if EXPR has suffixed crumb. The same for other numeric conversions in incr(), decr(), divert(), etc. * `--fatal-warnings' (-E) stops execution at first warning. * `--nesting-limit=LEVEL' (-L LEVEL) sets a limit to macro nesting. It is initially fixed at 250. * `--word-regexp=REGEXP' (-W REGEXP) modifies macro name syntax, like does the new `changeword(REGEXP)' macro. This feature is experimental, tell me your opinions about it. You do need --enable-changeword at configure time to get these things. Do *not* depend on them yet. * Trace output format is scannable by GNU Emacs' next-error function. * Stack overflow is detected and diagnosed on some capable systems. * Various bugs have been corrected, m4 should be more portable. See the ChangeLog for details. Version 1.1 - November 1993, by Franc,ois Pinard Changes which might affect existing GNU m4 scripts: * Option `-V' has been removed, use `--version' instead. `--version' writes on standard output instead of standard error, and inhibits any script execution. * `--no-gnu-extensions' has been renamed `--traditional'. * In `eval', `^' used to indicate exponentiation, use `**' instead. * The automatic undiversion which takes place at end of all input is forced into the main output stream. Changes which are unlikely to affect existing scripts: * `--help' prints an usage summary on standard output. Script execution is then inhibited. * `--prefix-builtins' (-P) prefixes all builtin macros by `m4_'. * Most builtin macros for which arguments are mandatory, called without any arguments, are no more recognized as builtin macros: they are consequently copied verbatim to the output stream. * `define' and `pushdef' are usable with only one argument, they give this argument an empty definition. * `eval' new operators for binary representation handling: `^' for exclusive-or, `~' for the bitwise negation, `<<' and `>>' for shifts. * `eval' recognizes the notation 0bDIGITS for binary numbers and the notation 0rRADIX:DIGITS for numbers in any radix from 1 to 36. Version 1.0.3 - December 1992, by Franc,ois Pinard Changes for the user: * `dnl' outputs a diagnostic if immediately followed by `('. Usually, `dnl' is followed by newline or whitespace. * `ifelse' accepts without complaining the common idiom of having only one argument. This is useful for introducing long comments. * `eval' always expresses values as signed, whatever the radix. * M4OPTS environment variable is no longer obeyed. * `--no-warnings' option is renamed `--silent'. * Debug lines use a new format more compatible with GNU standards. * Various bugs have been corrected. See the ChangeLog for details. Changes for the installer: * GNU m4 now uses an Autoconf-generated configure script, and should be more easily portable in many ways. (Cray is not supported yet). * `make check' has been made more portable, expect no errors. Changes for the programmer: * Sources have been fully reindented to comply with GNU standards, and cleaned up in many ways. * Sources have been protoized. Non-ANSI compilers are automatically detected, then sources are unprotoized on the fly before compilation. * GNU m4 uses newer versions of obstack, regex, getopt, etc. Version 1.0 - October 1991, by Rene' Seindal * Uses GNU configure, taken from the gdb distribution. * Uses GNU getopt(), with long option names. * The -Q/+quiet option is added, which suppresses warnings about missing or superflous arguments to built-in macros. * Added default options via the M4OPTS environment variable. * Several minor bugs have been fixed. Version 0.99 - July 1991, by Rene' Seindal * The builtins `incr' and `decr' are now implemented without use of `eval'. * The builtin `indir' is added, to allow for indirect macro calls (allows use of "illegal" macro names). * The debugging and tracing facilities has been enhanced considerably. See the manual for details. * The -tMACRO option is added, marks MACRO for tracing as soon as it is defined. * Builtins are traced after renaming iff they were before. * Named files can now be undiverted. * The -Nnum option can be used to increase the number of divertions available. * Calling changecom without arguments now disables all comment handling. * A bug in `dnl' is fixed. * A bug in the multi-character quoting code is fixed. * Several typos in the manual has been corrected. More probably persist. Version 0.75 - November 1990, by Rene' Seindal * Implemented search path for include files (-I option and M4PATH environment variable). * Implemented builtin `format' for printf-like formatting. * Implemented builtin `regexp' for searching for regular expressions. * Implemented builtin `patsubst' for substitution with regular expressions. * Implemented builtin `esyscmd', which expands to a shell commands output. * Implemented `__file__' and `__line__' for use in error messages. * Implemented character ranges in `translit'. * Implemented control over debugging output. * Implemented multi-character quotes. * Implemented multi-character comment delimiters. * Changed predefined macro `gnu' to `__gnu__'. * Changed predefined macro `unix' to `__unix__', when the -G option is not used. With -G, `unix' is still defined. * Added program name to error messages. * Fixed two missing null bytes bugs. Version 0.50 - January 1990, by Rene' Seindal * Initial beta release. ======================================================================== Local Variables: mode: outline fill-column: 75 End: Copyright (C) 1992-1994, 2004-2011 Free Software Foundation, Inc. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, with no Front-Cover Texts, and with no Back-Cover Texts. A copy of the license is included in the ``GNU Free Documentation License'' file as part of this distribution.