* ltdl/m4/.cvsignore: Update.

[m4.git] / NEWS

GNU m4 NEWS - History of user-visible changes.          -*- outline -*-
Copyright (C) 1992, 1993, 1994, 1998, 2000, 2001, 2006, 2007 Free Software
Foundation, Inc.

* Version beta 1.9b - ???, by ??? (CVS version 1.9a)

NOTE - there are still a number of FIXMEs to resolve before this can be
promoted to 2.0.

** Building M4

*** The build environment has been updated to modern GNU practices,
    depending on newer features of Autoconf, Automake, Libtool, Gettext,
    and Gnulib to be more portable to a wide variety of platforms.

** New command line behavior

*** If the POSIXLY_CORRECT environment variable is set, it implies the
    `-G' and `-Q' options, effectively giving a more fully POSIX-compliant
    implementation with only compatible GNU extensions.

*** New `-b'/`--batch' command-line option to force non-interactive mode.
    Also, in addition to `-e'/`--interactive' requesting interactive mode,
    m4 now follows the lead of sh, and automatically enters interactive
    mode when there are no files specified, and when both standard input
    and standard error are terminals.

*** New `-B'/`--prepend-include' command-line option allows prepending to
    the include path, rather than always searching `.' first.

*** The `-d'/`--debug' command-line option now understands `-' and `+'
     modifiers, the way `debugmode' has always done.  The option
    `--debugmode' is added as an alias for `-d'.

*** New `--debuglen' command-line option matches the spelling of a new
    macro, and the old spelling `--arglength' now issues a warning that it
    might be withdrawn in the future.

*** New `-g'/`--gnu' command-line option overrides `-G'/`--traditional',
    allowing the GNU module to be selected even when POSIXLY_CORRECT.

*** The `-H'/`--hashsize' command-line options, which were made no-ops in
    a previous beta, now issue a deprecation warning.

*** The `-L'/`--nesting-limit' command-line option now performs argument
    validation and accepts an optional multiplier suffix.

*** The `-o'/`--error-output' command-line options, which were replaced by
    `--debugfile' in M4 1.4.7, now issue a deprecation warning.  This
    warning interferes with all versions of Autoconf prior to 2.61, so plan
    on installing an updated Autoconf when installing M4 2.0.

*** New `-p'/`--pushdef' and `--popdef' command-line options allow more
    control over macro definitions from the command line between input
    files.

*** New `--posix' command-line option is a synonym for `-G'/`--traditional'.

*** New `-r'/`--regexp-syntax' command-line option changes the default
    regular expression syntax used by M4.  Without this option, M4
    continues to use EMACS style expressions.  A new section in the info
    docs explains the differences between them, and what builtins are
    affected.

*** New `--safer' command-line option cripples the potentially unsafe
    builtins `debugfile', `esyscmd', `maketemp', `mkdtemp', `mkstemp', and
    `syscmd'.

*** New `--syncoutput' command-line option matches the builtin added in a
    previous beta, and provides more control over sync line generation
    from the command line between input files.  The previous options
    `-s'/`--synclines' remain as aliases for `--syncoutput=1'.

*** New `--traceoff' command-line option, and new spelling `--traceon' for
    `--trace', allow more control over macro tracing from the command line
    between input files.

*** New `--unload-module' command-line option allows more control over
    dynamic modules from the command line.  Also, `-m'/`--load-module' now
    acts between input files.

*** New `--warnings' command-line option re-enables warnings, overriding
    `-Q'/`--quiet'/`--silent', allowing warnings even when POSIXLY_CORRECT.

** POSIX conformance

*** POSIXLY_CORRECT and `m4 --traditional' now makes the `define' builtin
  replace all `pushdef'ed values of a macro.
  - FIXME: The Austin group clarified that this was never a POSIX
  requirement; consider reverting this change.

*** The `defn' builtin now allows any number of arguments, as POSIX requires.
  - FIXME: This still doesn't work with concatenating builtins with text.

*** The `eval' builtin now follows C precedence rules.  Additionally,
    short-circuit operators correctly short-circuit division by zero.

  - FIXME: POSIX recommends using ${10} instead of $10 for the tenth
  positional argument.  We should deprecate $10.

 - FIXME: `m4wrap' semantics need an update to FIFO.

** Removed builtins

*** The experimental `epatsubst' and `eregexp' builtins have been removed
    in favor of a new `changeresyntax' builtin.

** New builtins

*** New `changeresyntax' builtin allows programmtic setting of the default
    regular expression flavor, to match `-r'/`--regexp-syntax' command-line
    option.

*** New `debuglen' builtin is introduced which allows runtime setting of
    debug output length, previously controlled only by the `-l' command
    line argument.  Additionally, whether using the new macro or the
    command line argument, the length limitation now affects dumpdef output
    as well as trace output, undergoes argument validation, and accepts an
    optional multiplier suffix.
  - FIXME the multiplier suffix isn't reliable yet

*** New `mkdtemp' builtin parallels `mkstemp', but allows the creation of
    temporary directories instead of files.

*** New `renamesyms' builtin allows programmatic renaming of all symbols
    according to a regular expression.
  - FIXME: This feature can cause core dumps when renaming multiple
  symbols to the same name.

*** New `__traditional__' builtin identifies when the traditional module
    is loaded instead of the gnu module.

*** The `modules' and `symbols' builtins, introduced in previous betas,
    have been renamed `m4modules' and `m4symbols', in order to minimize
    problems when upgrading from 1.4.x and processing English text.  To
    prevent future problems, any future macro added as a GNU extension will
    either be blind (ie. be unrecognized without arguments), or begin with
    the prefix `m4' or `__'.

** Changed behavior of builtins

*** The '$' syntax class to the `changeresyntax' builtin is now enabled.
    See the manual for examples.

*** The `builtin' builtin now has a special form, where if the first
    argument is exactly the special token representing defn(`builtin'), the
    expansion is the special token representing the builtin named in the
    second argument.  This allows regenerating a macro with a more
    efficient mapping directly to a builtin function, rather than through
    textual indirection through further expansions of `builtin'.

*** The `changecom' builtin semantics now match traditional
    implementations; if the start-comment string resembles a macro name or
    the start-quote string, comments are effectively disabled.

*** The `changesyntax' builtin has been improved, to make it easier to add
    and remove characters from a syntax class without having to specify the
    entire set of characters in that class.

*** New `m' flag to `-d'/`--debug' command-line option or `debugmode'
    builtin traces actions related to module loading and unloading, and
    affects `dumpdef' and trace output to show where builtins come from.
    New `s' flag shows the entire stack of `pushdef' definitions during
    `dumpdef'.  The `c' flag has been updated to output two lines instead
    of three (since the last two had always been paired), and to add
    information to the first line to show the definition of the macro being
    expanded.  The 'e' flag has been updated to output non-text expansions.

*** The `dumpdef' builtin now always outputs to standard error, rather than
    the debug file specified by the `--debugfile' option or `debugfile'
    macro.

*** The `eval' and `mpeval' builtins now support the following new
    operators: `>>>', `\', `?:', and  `,'.  However, when complying
    strictly with POSIX, `?:' and `,' are rejected inside `eval'.

*** The `maketemp' builtin now always warns that it is obsolete, even in GNU
    mode where it uses the same secure algorithm as `mkstemp', because of
    the recommendation of POSIX to obsolete `maketemp' as inherently
    insecure when obeying POSIX.

*** The `patsubst' and `regexp' builtins have a new optional 4th argument
    to use a different regular expression syntax for the duration of that
    invocation.

*** The semantics of the `traceon' and `traceoff' builtins now match
    traditional implementations: when called without arguments, they affect
    global state rather than affecting only the macros defined at that
    moment.  The manual includes an example of how to recover 1.4.x
    semantics.

** Other changes

*** The syntax of frozen files format V2 has been improved to save
    additional state.
  - FIXME: format 2 still needs to be tweaked to allow complete ASCII
  representation and to catch any more missing state; once 2.0 is released,
  any further changes would introduce format 3.

FIXME: include the (long) list of changes in 1.4.x that were not already
  in earlier betas.
* Version 1.4.9
* Version 1.4.8
* Version 1.4.7
* Version 1.4.6
* Version 1.4.5

* 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 `patsubst'.

** The names of all currently loaded modules are returned by the new
   builtin, ``modules''.

** Loadable modules can define new builtin functions or text expansion
   macros.

** 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.

** New builtin `symbols' allows dynamic queries of all currently defined
   macros.

** Various 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",
   who has 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
   shl_load().

** There is now a __m4_version__ macro that expands to the current version
   number.

* 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
   `changesyntax').

** 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
   module/README.

** 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.

** Bugs fixed:

*** All 8-bit characters can now be used for quotes.

FIXME: include the (long) list of changes in 1.4.x that were not already
  in earlier betas.
* Version 1.4.4
* Version 1.4.3
* Version 1.4.2
* Version 1.4.1

* 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
    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 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
   `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.
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