GNU m4 NEWS - History of user-visible changes. -*- outline -*-
Copyright 1992, 1993, 1994, 1998, 2000, 2001 Free Software Foundation, Inc.
Version beta 1.4q - August 2001, by Gary V. Vaughan
* Support for the experimental `changeword' has been dropped.
* `m4 --hashsize' and `-H' are still accepted, but have no effect. M4
will grow its internal symbol table if the symbol density is having
an effect on performance.
* `configure --without-modules' will build an m4 binary with no preloaded
modules. At startup it will search for and load modules `m4' and either
`gnu' or `traditional'. This mode of operation can be used for
development and debugging of the base modules without the need to
recompile all of m4 with each modification.
* `configure --with-modules="gnu m4 traditional load"', for example,
will build an m4 binary with the named modules preloaded, ready to
be activated (even on static lib only machines) with the `-m' option
or using the `load' builtin.
* M4 has no builtins or macros in core, they are all loaded from modules
at startup. This means that modules are no longer optional, though
the standard build will statically link the modules `m4', `gnu' and
`traditional', so even on machines with no ltdl support, all of the
functionality from previous releases is available.
* New builtin `load' to dynamically load modules which can define new
builtins and user macros.
* New builtin `unload' to remove loaded modules (and the builtins and user
macros they define) from the running m4 interpreter.
* New builtins `eregexp' and `epatsubst' to use Extended Regular Expressions
syntax in lieu of Basic Regular Expressions as used by `regexp' and
* The names of all currently loaded modules are returned by the new
* Loadable modules can define new builtin functions or text expansion
* The module code has been rewritten to use libltdl, the libtool dynamic
loader, which means GNU m4 can now load (and unload) modules just about
anywhere which it can be built. This includes obscure hosts such as
cygwin and BeOS, and also on hosts which do not have shared libraries,
through preloading (see libtool manual) and GNU dld.
* Modules can now be built without the m4 source being available using the
installed m4module.h header file (and some other headers that it includes
for you), and the installed libm4.la libtool library. All symbols
exported from libm4.la have a prefix of `m4_' or `M4_'. See the modules
directory for examples of usage.
* A new V2 format for frozen files that saves module and syntax information.
Version beta 1.4o - January 2000, by Rene' Seindal
* Modules can be loaded from the command line with --load-module
* Modules now use libtool's wrapper libltdl.
* Bug fixes.
Version beta 1.4n - November 1998, by Rene' Seindal
* The module code has been reorganised yet again, and now compiles
correctly on GNU/Linux, HPUX 9 and 10, SunOS 5 and Solaris 5.
* When configured --with-gmp a new builtin `mpeval' is now defined. The
builtin `eval' retains its normal behaviour.
* m4 --version also shows which options were used for compilation, such as:
"GNU m4 1.4n (options: modules gmp changeword)"
* New option --import-environment defines all environment variables as
macros. This is done before -D and -U are handled, so the macros can be
changed through these options.
* Error messages now always print program name before input file name as
specified by GNU coding standards. Reported by Akim Demaille
* Bug fixed: "undivert(0)" could cause m4 to read standard output. A call
of "undivert(0)" is now silently ignored.
* Bug fixed: when compiling --with-included-gettext, <libintl.h> wasn't
found in intl/ directory. Reported by Andrew Bettison
Version beta 1.4m - November 1998, by Rene' Seindal
* Using libtool for compiling modules and for linking main app.
* Reorganised the dynamic module code to encapsulate system dependencies
better. The code for HPUX shl_load() still needs testing and debugging.
A dld interface is also missing. Any volunteers?
* The files from the GNU m4 web-site is now in examples/WWW as a more
complete example of what GNU m4 can do.
Version beta 1.4l - November 1998, by Rene' Seindal
* GNU m4 now has an escape syntax category. If a character is marked as
an escape, words are only recognised as macros if preceded by an escape
character. It is a bit like -P, but dynamic: it can be turned on and
off. The GNU m4 web-site on http://www.seindal.dk/rene/gnu/ is
maintained with this feature - the m4 source is available on the site.
* The module interface is improved, thanks to "Brian J. Fox"
<firstname.lastname@example.org>, who have contributed some code from Meta-HTML. The
modules now build automatically and installs properly, by default in
/usr/local/libexec/m4. There is a preliminary, untested support for
* There is now a __m4_version__ macro that expands to the current version
Version beta 1.4k - November 1998, by Erick Branderhorst and Rene' Seindal
* GNU m4 now uses gettext to support internationalization.
* GNU m4 now uses automake to control Makefile.in generation. This
should make it more consistent with the GNU standards.
* GNU m4 will use the gmp library for multiple precision integral and
rational arithmetic in `eval' if configured with `--with-gmp'. If
configured without `--with-gmp' or if gmp is not available, and the type
`long long int' is, GNU m4 will use that for `eval' arithmetic.
* GNU m4 now parses the input according to a syntax table, that can be
modified through the new builtin `changesyntax'. It is a generalisation
of the existing builtins `changecom' and `changequote'. The changes are
completely backwards compatible (except for the existence of
* Sync lines can be turned on and off with the `syncoutput' builtin. The
builtin `syncoutput' is a GNU extension.
* New experimental feature: dynamically loadable modules. New builtin
`loadmodules' loads shared libraries, that can define new builtin
macros, ie, new macros can be written in C. Depends on the dlopen()
interface, and is currently only tested on Linux. Enabled at configure
time with `--with-modules'. Documentation is in src/module.c and
* Implement a GNU message catalog for French (Franc,ois Pinard).
* Filenames found through path searches are now correctly reflected in
error and debug messages and through the `__file__' macro.
* All 8-bit characters can now be used for quotes.
Version 1.4 - October 1994, 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
* `--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 builtin 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
* 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
* 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
* 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
* Implemented builtin `format' for printf-like formatting.
* Implemented builtin `regexp' for searching for regular expressions.
* Implemented builtin `patsubst' for substitution with regular
* 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.