1* Major changes in Autoconf 2.61 (2006-11-17)
2
3** New macros AC_C_FLEXIBLE_ARRAY_MEMBER, AC_C_VARARRAYS.
4
5** AC_ARG_ENABLE and AC_ARG_WITH now allow '.' in feature and package names.
6
7* Major changes in Autoconf 2.60b (2006-10-22)
8
9** BIN_SH
10  Autoconf-generated shell scripts no longer export BIN_SH, due to
11  configuration hassles with this.  Installers who need BIN_SH in
12  their environment should set it before invoking 'configure' and
13  'make'.  As far as we know, this affects only Unixware installations.
14
15** Obsolescent macros
16  The documentation now says that the following macros are obsolescent,
17  as they are superseded by Gnulib:
18
19    AC_FUNC_FNMATCH  AC_FUNC_FNMATCH_GNU  AC_FUNC_GETLOADVG  AC_REPLACE_FNMATCH
20
21  New programs should use the Gnulib counterparts of these macros.
22  We have no current plans to remove them from Autoconf.
23
24** AC_COMPUTE_INT no longer caches or reports results.
25
26** AC_CHECK_DECL now also works with aggregate objects.
27
28** AC_USE_SYSTEM_EXTENSIONS now defines _TANDEM_SOURCE for NonStop platforms.
29
30** GNU M4 1.4.7 or later is now recommended.
31
32** m4_mkstemp
33  New M4sugar macro, which is more secure than the POSIX M4 maketemp.
34
35** m4_maketemp
36  Now an alias for m4_mkstemp.
37
38* Major changes in Autoconf 2.60a (2006-08-25)
39
40** GNU M4 1.4.6 or later is now recommended.
41
42** The check for C99 now tests for varargs macros, as documented.
43  It also tests that the preprocessor supports 64-bit integers.
44
45** Autoconf now uses constructs like "#ifdef HAVE_STDLIB_H" rather than
46  "#if HAVE_STDLIB_H", so that it now works with "gcc -Wundef -Werror".
47
48** The functionality of the undocumented _AC_COMPUTE_INT is now provided
49  by a public and documented macro, AC_COMPUTE_INT.  The parameters to the
50  two macros are different, so autoupdate will not change the old private name
51  to the new one.  _AC_COMPUTE_INT may be removed in a future release.
52
53** AC_TYPE_LONG_LONG_INT and AC_TYPE_UNSIGNED_LONG_LONG_INT now require
54   that long long types be at least 64 bits wide, as C99 and tradition
55   requires.  Formerly, they accepted implementations of any width.
56
57
58* Major changes in Autoconf 2.60
59
60  Released 2006-06-23, by Ralf Wildenhues.
61
62** Autoconf no longer depends on whether m4wrap is FIFO (as Posix requires)
63  or LIFO (as in GNU M4 1.4.x).  GNU M4 2.0 is expected to conform to Posix
64  here, so m4wrap/m4_wrap users should no longer depend on LIFO behavior.
65
66** Provide a way to turn off warnings about the changed directory variables.
67
68* Major changes in Autoconf 2.59d
69
70  Released 2006-06-05, by Ralf Wildenhues.
71
72** GNU make now recommended for VPATH builds
73  INSTALL now suggests VPATH builds (e.g., "sh ../srcdir/configure")
74  only if you use GNU make.  In practice, other 'make' implementations
75  have too many subtle incompatibilities in their support for VPATH.
76  Many packages (including Autoconf itself) are portable to other
77  'make' implementations, but some packages are not, and recommending
78  GNU make keeps the installation instructions simpler.
79
80** Even more safety checks for the new Directory variables:
81  Warn about suspicious `${datarootdir}' found in config files output.
82
83** AC_TRY_COMMAND, AC_TRY_EVAL, ac_config_guess, ac_config_sub, ac_configure
84  These never-documented macros and variables have been marked with
85  comments saying that they may be removed in a future release,
86  because their use can lead to unintended code being executed.
87  If you need functionality that only these macros or variables
88  currently supply, please write bug-autoconf@gnu.org.
89
90** AC_SUBST, AC_DEFINE
91  Literal arguments to these are passed to m4_pattern_allow now.
92
93** AC_PROG_CC_STDC
94  Passing 'ac_cv_prog_cc_stdc=no' to 'configure' now sets ac_cv_prog_cc_c99
95  and ac_cv_prog_cc_c89 to 'no' as well, for backward compatibility with
96  obsolete K&R tests in the Automake test suite.
97
98** AC_PROG_CXX_C_O
99  New macro.
100
101** AC_PROG_MKDIR_P
102  New macro.
103
104** AS_MKDIR_P
105  Now more robust with special characters in file names, or when
106  multiple processes create the same directory at the same time.
107
108** Obsolescent macros
109  The documentation now says that the following macros are obsolescent:
110  they test for problems that are so old that they are no longer of
111  practical importance on current systems.
112
113    AC_C_BACKSLASH_A       AC_FUNC_MEMCMP            AC_HEADER_DIRENT
114    AC_C_CONST             AC_FUNC_SELECT_ARGTYPES   AC_HEADER_STAT
115    AC_C_PROTOTYPES        AC_FUNC_SETPGRP           AC_HEADER_STDC
116    AC_C_STRINGIZE         AC_FUNC_SETVBUF_REVERSED  AC_HEADER_SYS_WAIT
117    AC_C_VOLATILE          AC_FUNC_STAT              AC_HEADER_TIME
118    AC_FUNC_CLOSEDIR_VOID  AC_FUNC_STRFTIME          AC_ISC_POSIX
119    AC_FUNC_GETPGRP        AC_FUNC_UTIME_NULL        AC_PROG_GCC_TRADITIONAL
120    AC_FUNC_LSTAT          AC_FUNC_VPRINTF           AC_STRUCT_TM
121
122  New programs need not use these macros.  We have no current plans to
123  remove them.
124
125** autoreconf
126  For compatibility with future Libtool 2.0, autoreconf will invoke
127  libtoolize with the option `--ltdl' now, if LT_CONFIG_LTDL_DIR is
128  used.
129
130* Major changes in Autoconf 2.59c
131
132  Released 2006-04-12, by Ralf Wildenhues.
133
134** The configure command now redirects standard input from /dev/null,
135  to help avoid problems with subsidiary commands that might mistakenly
136  read standard input.  AS_ORIGINAL_STDIN_FD points to the original
137  standard input before this redirection, if you really want configure to
138  read from standard input.
139
140** Directory variables adjusted to recent changes in the GNU Coding Standards.
141  The following directory variables are new:
142
143    datarootdir   read-only architecture-independent data root [PREFIX/share]
144    localedir     locale-specific message catalogs [DATAROOTDIR/locale]
145    docdir        documentation root [DATAROOTDIR/doc/PACKAGE]
146    htmldir       html documentation [DOCDIR]
147    dvidir        dvi documentation [DOCDIR]
148    pdfdir        pdf documentation [DOCDIR]
149    psdir         ps documentation [DOCDIR]
150
151  The following variables have new default values:
152
153    datadir       read-only architecture-independent data [DATAROOTDIR]
154    infodir       info documentation [DATAROOTDIR/info]
155    mandir        man documentation [DATAROOTDIR/man]
156
157  This means that if you use any of `@datadir@', `@infodir@', or
158  `@mandir@' in a file, you will have to ensure `${datarootdir}' is
159  defined in this file.  As a temporary measure, if any of those are
160  found but no mention of `datarootdir', the substitutions will be
161  replaced with values that do not contain `${datarootdir}', and a
162  warning will be issued.
163
164** @top_builddir@ is now a dir name: it is always nonempty and doesn't have
165  a trailing slash.  Similar change will be made to ac_top_builddir in a
166  future release; the old style value, which matches (../)*, is (and will
167  continue to be) available as ac_top_build_prefix.
168
169** AC_C_TYPEOF
170  New macro to check for support of 'typeof' syntax a la GNU C.
171
172** AC_CHECK_DECLS_ONCE, AC_CHECK_FUNCS_ONCE, AC_CHECK_HEADERS_ONCE
173  New "once-only" variants of commonly-used macros, to make 'configure'
174  smaller and faster in common cases.
175
176** AC_FUNC_STRTOLD
177  New macro to check for strtold with C99 semantics.
178
179** AC_HEADER_ASSERT
180  New macro that lets builder disable assertions at 'configure'-time.
181
182** AC_PATH_X
183  Now checks for X11/Xlib.h and XrmInitialize (X proper) rather than
184  X11/Intrinsic.h and XtMalloc (Xt).
185
186** AC_PRESERVE_HELP_ORDER
187  New macro that causes `configure' to display help strings for AC_ARG_ENABLE
188  and AC_ARG_WITH arguments in one region, in the order defined.  The default
189  behavior is to group options of each classes separately.
190
191** AC_PROG_CC, AC_PROG_CXX
192  No longer automatically arrange to declare the 'exit' function of C,
193  when a C++ compiler is used.  Standard Autoconf macros no longer use
194  'exit', so this is no longer an issue for them.  If you use C++, and
195  want to call 'exit', you'll have to arrange for its declaration
196  yourself.  But we now suggest you return from 'main' instead.
197
198** AC_PROG_CC_C89, AC_PROG_CC_C99
199  New macros for ISO C99 support.  AC_PROG_CC_C89 and AC_PROG_CC_C99
200  check for ANSI C89 and ISO C99 support respectively.
201
202** AC_PROG_CC_STDC
203  Has been unobsoleted, and will check if the compiler supports ISO
204  C99, falling back to ANSI C89 if not.  ac_cv_prog_cc_stdc is
205  retained for backwards compatibility, assuming the value of
206  ac_cv_prog_cc_c99 or ac_cv_prog_cc_c89 (whichever is valid, in
207  that order).
208
209** AC_STRUCT_DIRENT_D_INO, AC_STRUCT_DIRENT_D_TYPE
210  New macros for checking commonly-used members of struct dirent.
211
212** AC_SUBST
213  The substituted value can now contain newlines.
214
215** AC_SUBST_FILE
216  The substitution now occurs only when @variable@ is on a line by itself,
217  optionally surrounded by spaces and tabs.  The whole line is replaced.
218
219** AC_TYPE_LONG_DOUBLE, AC_TYPE_LONG_DOUBLE_WIDER
220  New macros to check for long double, and whether it is wider than double.
221  The old macro AC_C_TYPE_LONG_DOUBLE has been marked as obsolete;
222  applications should switch to the new macro.
223
224** AC_TYPE_INT8_T, AC_TYPE_INT16_T, AC_TYPE_INT32_T, AC_TYPE_INT64_T,
225   AC_TYPE_INTMAX_T, AC_TYPE_INTPTR_T, AC_TYPE_LONG_LONG_INT, AC_TYPE_SSIZE_T,
226   AC_TYPE_UINT8_T, AC_TYPE_UINT16_T, AC_TYPE_UINT32_T, AC_TYPE_UINT64_T,
227   AC_TYPE_UINTMAX_T, AC_TYPE_UINTPTR_T, AC_TYPE_UNSIGNED_LONG_LONG_INT
228  New macros to check for C99 and POSIX types.
229
230** AC_USE_SYSTEM_EXTENSIONS
231  New macro to enable extensions to Posix.
232
233** AH_HEADER
234  New macro which is defined to the name of the first declared config header
235  or undefined if no config headers have been declared yet.
236
237** AS_HELP_STRING
238  The macro correctly handles quadrigraphs now.
239
240** AS_BOURNE_COMPATIBLE, AS_SHELL_SANITIZE, AS_CASE
241  These macros are new or published now.
242
243** AT_COPYRIGHT
244  New macro for copyright notices in testsuite files.
245
246** ALLOCA, LIBOBJS, LTLIBOBJS
247  Object names added to these variables are now prefixed with `${LIBOBJDIR}',
248  as in `${LIBOBJDIR}alloca.o'.  LIBOBJDIR is meant to be defined from
249  `Makefile.in' in case the object files lie in a different directory.
250  The LIBOBJDIR feature is experimental.
251
252** autoreconf
253  Supports --no-recursive now.
254
255** New macros to support Erlang/OTP.
256  New macros for configuring paths to Erlang tools and libraries:
257  AC_ERLANG_PATH_ERLC, AC_ERLANG_NEED_ERLC, AC_ERLANG_PATH_ERL,
258  AC_ERLANG_NEED_ERL, AC_ERLANG_CHECK_LIB, AC_ERLANG_SUBST_ROOT_DIR,
259  AC_ERLANG_SUBST_LIB_DIR.
260
261  New macros for configuring installation of Erlang libraries:
262  AC_ERLANG_SUBST_INSTALL_LIB_DIR, AC_ERLANG_SUBST_INSTALL_LIB_SUBDIR.
263
264** The manual now mentions Gnulib more prominently.
265
266** New macros to support Objective C.
267  AC_PROG_OBJC, AC_PROG_OBJCPP.
268
269* Major changes in Autoconf 2.59b
270
271  Released 2004-08-20, by Paul Eggert.
272
273** AC_CHECK_ALIGNOF
274  New macro that computes the default alignment of a type.
275
276** AC_CHECK_TOOL, AC_PATH_TOOL, AC_CHECK_TOOLS
277  When cross-compiling, these macros will give a warning if the tool
278  is not prefixed.  In the future, unprefixed cross tools will not
279  be detected; please consult the info documentation for information
280  about the reason of this change.
281
282** AC_CHECK_TARGET_TOOL, AC_PATH_TARGET_TOOL, AC_CHECK_TARGET_TOOLS
283  New macros that detect programs whose name is prefixed with the
284  target type, if the build type and target type are different.
285
286** AC_REQUIRE_AUX_FILE
287  New trace macro that declares expected auxiliary files.
288
289** AC_PROG_GREP
290  New macro that tests for a grep program that accepts as a long a line
291  as possible.
292
293** AC_PROG_EGREP, AC_PROG_FGREP
294  These macros now require AC_PROG_GREP, and try EGREP="$GREP -E" and
295  FGREP="$GREP -F" respectively if possible, or else run a path search for
296  a program that accepts as long a line as possible.
297
298** AC_PROG_SED
299  New macro that tests for a sed program that truncates as few characters
300  as possible.
301
302* Major changes in Autoconf 2.59
303
304  Released 2003-11-04, by Akim Demaille
305
306** ac_abs_builddir etc.
307  Absolute file names were actually relative in 2.58.
308
309* Major changes in Autoconf 2.58
310
311  Released 2003-11-04, by Akim Demaille
312
313** core.*
314  core.* files are no longer removed, as they may be valid user files.
315
316** autoreconf and auxiliary directory
317  Autoreconf creates the auxiliary directory if needed.  This is
318  especially useful for initial "bootstrapping" of fresh CVS checkouts.
319
320** AC_CONFIG_MACRO_DIR
321  Use this macro to declare the directory for local M4 macros for aclocal.
322
323** AC_LIBOBJS
324  No longer includes twice the same file in LIBOBJS if invoked
325  multiple times.
326
327** AC_CONFIG_COMMANDS
328  The directory for its first argument is automatically created.  For
329  instance, with
330
331      AC_CONFIG_COMMANDS([src/modules.hh], [...])
332
333  $top_builddir/src/ is created if needed.
334
335** Autotest and local.at
336  The optional file local.at is always included in Autotest test suites.
337
338** Warnings
339  The warnings are always issued, including with cached runs.
340  This became a significant problem since aclocal and automake can
341  run autoconf behind the scene.
342
343** autoheader warnings
344  The warnings of autoheader can be turned off, using --warning.
345  For instance, -Wno-obsolete disables the complaints about acconfig.h
346  and other deprecated constructs.
347
348** New macros
349  AC_C_RESTRICT, AC_INCLUDES_DEFAULT, AC_LANG_ASSERT, AC_LANG_WERROR,
350  AS_SET_CATFILE.
351
352** AC_DECL_SYS_SIGLIST
353  Works again.
354
355** AC_FUNC_MKTIME
356  Now checks that mktime is the inverse of localtime.
357
358** Improve DJGPP portability
359  The Autoconf tools and configure behave better under DJGPP.
360
361** Present But Cannot Be Compiled
362  New FAQ section dedicated to the mystic
363
364    configure: WARNING: pi.h: present but cannot be compiled
365    configure: WARNING: pi.h: check for missing prerequisite headers?
366    configure: WARNING: pi.h: proceeding with the preprocessor's result
367      messages.
368
369** Concurrent executions of autom4te
370  autom4te now locks its internal files, which enables concurrent
371  executions of autom4te, likely to happen if automake, autoconf,
372  autoheader etc. are run simultaneously.
373
374** Libtool
375  Use of Libtool 1.5 and higher is encouraged.  Compatibility with
376  Libtool pre-1.4 is not checked.
377
378** Autotest
379  Testsuites no longer rerun failed tests in verbose mode; instead,
380  failures are logged while the test is run.
381
382  In addition, expected failures can be marked as such.
383
384* Major changes in Autoconf 2.57
385
386  Released 2002-12-03 by Paul Eggert.
387
388Bug fixes for problems with AIX linker, with freestanding C compilers,
389with GNU M4 limitations, and with obsolete copies of GNU documents.
390
391The Free Documentation License has been upgraded from 1.1 to 1.2.
392
393* Major changes in Autoconf 2.56
394
395  Released 2002-11-15 by Akim Demaille.
396
397One packaging problem fixed (config/install-sh was not executable).
398
399* Major changes in Autoconf 2.55
400
401  Released 2002-11-14 by Akim Demaille.
402
403Release tips:
404
405           Have your configure.ac checked by autoscan ("autoscan").
406             Try the warning options ("autoreconf -fv -Wall").
407
408** Documentation
409
410- AC_CHECK_HEADER, AC_CHECK_HEADERS
411  More information on proper use.
412
413- Writing Test Programs
414
415  This sections explains how to write good test sources to use with
416  AC_COMPILE_IFELSE etc.  It documents AC_LANG_PROGRAM and so forth.
417
418- AC_FOO_IFELSE vs. AC_TRY_FOO
419
420  Explains why Autoconf moves from AC_TRY_COMPILE etc. to
421  AC_COMPILE_IFELSE and AC_LANG_PROGRAM etc.
422
423** autoreconf
424
425- Is more robust to different Gettext installations.
426
427- Produces messages (when --verbose) to be understood by Emacs'
428  compile mode.
429
430- Supports -W/--warnings.
431
432- -m/--make
433  Once the GNU Build System reinstalled, run `./config.status
434  --recheck && ./config.status && make' if possible.
435
436** autom4te
437
438- Supports --cache, and --no-cache.
439
440- ~/.autom4te.cfg makes it possible to disable the caching mechanism
441  (autom4te.cache).  See `Customizing autom4te' in the documentation.
442
443** config.status
444  Supports --quiet.
445
446** Obsolete options
447
448  Support for the obsoleted options -m, --macrodir, -l, --localdir is
449  dropped in favor of the safer --include/--prepend-include scheme.
450
451** Macros
452
453- New macros
454  AC_COMPILER_IFELSE, AC_FUNC_MBRTOWC, AC_HEADER_STDBOOL,
455  AC_LANG_CONFTEST, AC_LANG_SOURCE, AC_LANG_PROGRAM, AC_LANG_CALL,
456  AC_LANG_FUNC_TRY_LINK, AC_MSG_FAILURE, AC_PREPROC_IFELSE.
457
458- Obsoleted
459  Obsoleted macros are kept for Autoconf backward compatibility, but
460  should be avoided in configure.ac.  Running autoupdate is advised.
461  AC_DECL_SYS_SIGLIST.
462
463- AC_DEFINE/AC_DEFINE_UNQUOTED
464
465  We have to stop using the old compatibility scheme --that tried to
466  avoid useless backslashes-- because Libtool 1.4.3 contains a
467
468  AC_DEFINE([error_t], [int],
469            [Define to a type to use for \`error_t' if it is not
470             otherwise available.])
471
472  We have to quote the single quotes and backslashes with \.  The old
473  compatibility scheme saw that ` was backslashed, and therefore did
474  not quote the single quote...  Failure.  Hence, Autoconf 2.54 is not
475  compatible with Libtool.  Autoconf 2.55 is, but in some cases might
476  produce more \ than wanted.
477
478  Please, note that in the future the same problem will happen with
479  AC_MSG_*: use `autoreconf -f -Wall'.
480
481** Bug Fixes
482
483- Portability of the Autoconf package to Solaris.
484
485- Spurious warnings caused by config.status.
486  This bug is benign, but painful: on some systems (typically
487  FreeBSD), warnings such as:
488
489     config.status: creating Makefile
490     mv: Makefile: set owner/group (was: 1357/0): Operation not permitted
491
492  could be issued.  This is fixed.
493
494- Parallel Builds
495  Simultaneous executions of config.status are possible again.
496
497- Precious variables accumulation
498
499  config.status could stack several copies of the precious variables
500  assignments.
501
502
503** Plans for later versions
504
505- ./configure <host>
506
507  The compatibility hooks with the old scheme will be completely
508  removed.  Please, advice/use `--build', `--host', and `--target'
509  only.
510
511- AC_CHECK_HEADER, AC_CHECK_HEADERS
512
513  The tests will be stricter, please make sure your invocations are
514  valid.
515
516- shell functions
517
518  Shell functions will gradually be introduced, probably starting with
519  Autotest.  If you know machines which are in use that you suspect
520  *not* to support shell functions, please run the test suite of
521  Autoconf 2.55 on it, and report the results to
522  bug-autoconf@gnu.org.
523
524- AC_MSG_*
525
526  Special characters in AC_MSG_* need not be quoted.  Currently,
527  Autoconf has heuristics to decide when a string is escaped, or has
528  to be escaped.  This scheme is fragile, and will be removed; the
529  only risk is uglified messages.  Please, run `autoreconf -f -Wall'
530  to find occurrences that will be affected.
531
532* Major changes in Autoconf 2.54
533
534  Released 2002-09-13 by Akim Demaille.
535
536** Executables
537
538- autoreconf no longer changes the version of the gettext/po/intl
539  support files. It now adds the files the correspond to the
540  AM_GNU_GETTEXT_VERSION declared in configure.ac.
541
542  Warning: It now relies on the 'autopoint' program, which is part
543  of GNU gettext 0.11.4 and newer.
544
545  Please note that you need to have a GNU gettext version that
546  corresponds at least to the AM_GNU_GETTEXT_VERSION declared
547  in configure.ac. You can upgrade to newer GNU gettext versions,
548  though, without needing to change configure.ac.
549
550- The -I DIR or --include=DIR option now appends DIR to the include path
551  instead of prepending; this is for consistency with other GNU tools.
552  The new -B DIR or --prepend-include=DIR option has the old behavior.
553
554** Macros
555
556- AC_OUTPUT
557  Now handles all the gory details about LIBOBJS and LTLIBOBJS.
558  Please, remove lines such as
559
560	# This is necessary so that .o files in LIBOBJS are also
561	# built via the ANSI2KNR-filtering rules.
562	LIBOBJS=`echo $LIBOBJS|sed 's/\.o /\$U.o /g;s/\.o$/\$U.o/'`
563
564  and read the `AC_LIBOBJ vs LIBOBJS' section.  Do not define U in
565  your Makefiles either.
566
567- AC_CONFIG_LINKS now makes copies if it can't make links.
568
569- AC_FUNC_FNMATCH now tests only for POSIX compatibility, reverting to
570  Autoconf 2.13 behavior.  The new macro AC_FUNC_FNMATCH_GNU also
571  tests for GNU extensions to fnmatch, and replaces fnmatch if needed.
572
573- AC_FUNC_SETVBUF_REVERSED no longer fails when cross-compiling.
574
575- AC_PROG_CC_STDC is integrated into AC_PROG_CC.
576
577- AC_PROG_F77 default search no longer includes cf77 and cfg77.
578
579- New macros
580
581  AC_C_BACKSLASH_A, AC_CONFIG_LIBOBJ_DIR, AC_GNU_SOURCE,
582  AC_PROG_EGREP, AC_PROG_FGREP, AC_REPLACE_FNMATCH,
583  AC_FUNC_FNMATCH_GNU, AC_FUNC_REALLOC, AC_TYPE_MBSTATE_T.
584
585- AC_FUNC_GETLOADAVG
586  looks for getloadavg.c in the CONFIG_LIBOBJ_DIR.
587
588- AC_FUNC_MALLOC
589  Now defines HAVE_MALLOC to 0 if `malloc' does not work, and asks
590  for an AC_LIBOBJ replacement.
591
592** Bug fixes
593
594- Spurious complaints from `m4_bmatch' about invalid regular
595  expressions are suppressed.
596
597- Empty top_builddirs are properly handled.
598
599- AC_CHECK_MEMBER works correctly when the member is an aggregate.
600
601- AC_PATH_PROG
602  Now colon in the optional path arguments are properly handled.
603
604** Improved portability
605
606- Both Autoconf the package, and the scripts it produces, should run
607  more reliably with Zsh.  Bear in mind it is the default Bourne shell
608  on Darwin.
609
610- Autoconf and the scripts it produces no longer assume the existence of
611  the obsolescent commands egrep and fgrep.
612
613** Documentation
614
615- Limitations of Make
616  More of them.
617
618- GNATS
619  The GNATS base moved to
620  http://bugs.gnu.org/cgi-bin/gnatsweb.pl?database=autoconf
621  (It is no longer available, though.)
622
623** Misc.
624
625- config.log
626  Now contains the list of ouput variables and files (AC_SUBST,
627  AC_SUBST_FILES).
628
629* Major changes in Autoconf 2.53
630
631  Released 2002-03-08 by Akim Demaille.
632
633** Requirements
634
635  Perl 5.005_03 or later is required: autom4te is written in Perl and is
636  needed by autoconf.  autoheader, autoreconf, ifnames, and autoscan are
637  rewritten in Perl.
638
639** Documentation
640
641- AC_INIT
642  Argument requirements, output variables, defined macros.
643- M4sugar, M4sh, Autotest
644  First sketch.
645- Double quoting macros
646  AC_TRY_CPP, AC_TRY_COMPILE, AC_TRY_LINK and AC_TRY_RUN.
647- Licensing
648  The Autoconf manual is now distributed under the terms of the GNU FDL.
649- Section `Hosts and Cross-Compilation'
650  Explains the rationale for the 2.5x changes in the cross-compilation
651  chain, and in the relationships between build, host, and target
652  types.
653  Emphasizes that `cross-compilation' == `--host is given'.
654  If you are working on compilers etc., be sure to read this section.
655- Section `AC_LIBOBJ vs. LIBOBJS'
656  Explains why assigning LIBOBJS directly is now an error.
657  Details how to update the code.
658
659** configure
660
661- $LINENO
662  Now used instead of hard coded line numbers.
663  This eases the comparison of `configure's, and diminishes the
664  pressure over control version archives.
665  Automatic replacement for shells that don't support this feature.
666- New output variables
667  @builddir@, @top_builddir@, @abs_srcdir@, @abs_top_srcdir@, @abs_builddir@,
668  @abs_top_builddir@.
669
670** Emacs
671
672  Autoconf and Autotest modes are provided.
673
674** Executables
675
676- autom4te
677  New, used by the Autoconf suite to cache and speed up most processing.
678- --force, -f
679  Supported by autom4te, autoconf and autoheader.
680- --include, -I
681  Replaces --autoconf-dir and --localdir in autoconf, autoheader,
682  autoupdate, and autoreconf.
683- autoreconf
684  No longer passes --cygnus, --foreign, --gnits, --gnu, --include-deps:
685  automake options are to be given via AUTOMAKE_OPTIONS.
686- autoreconf
687  Runs gettextize and libtoolize when appropriate.
688- autoreconf
689  --m4dir is no longer supported.
690- autoreconf
691  Now runs only in the specified directories, defaulting to `.',
692  but understands AC_CONFIG_SUBDIRS for dependent directories.
693  Before, it used to run on all the `configure.ac' found in the
694  current tree.
695  Independent packages are properly updated.
696
697** Bug fixes
698
699- The top level $prefix is propagated to the AC_CONFIG_SUBDIRS configures.
700- AC_TRY_RUN
701  Under the user pressure, $? is finally available.  Probably a mistake.
702- AC_F77_LIBRARY_LDFLAGS now supports the HP/UX f90 compiler.
703- Precious variables accumulation
704  config.status could stack several copies of the precious variables
705  assignments.
706- AC_PATH_PROG and family.
707  Works properly when given a literal path.
708- AC_FUNC_SETPGRP
709  Somewhere since 2.13, the result had been reversed.
710
711** C Macros
712
713- AC_C_BIGENDIAN supports the cross-compiling case.
714- AC_C_BIGENDIAN accepts ACTION-IF-TRUE, ACTION-IF-FALSE, and
715  ACTION-IF-UNKNOWN arguments.  All are facultative, and the default
716  for ACTION-IF-TRUE is to define WORDS_BIGENDIAN like AC_C_BIGENDIAN
717  always did.
718- AC_C_LONG_DOUBLE now succeeds only if `long double' has more range or
719  precision than `double'.
720
721** Generic macros
722
723- AC_INIT
724  It now defines the preprocessor symbols PACKAGE_NAME,
725  PACKAGE_TARNAME, PACKAGE_VERSION, PACKAGE_STRING, and
726  PACKAGE_BUGREPORT.
727
728- AC_INIT
729  Admits a fourth optional parameter: the tar name.
730
731- AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS.
732  Provide the user with srcdir, ac_srcdir, ac_top_srcdir, ac_builddir,
733  ac_top_builddir, ac_abs_srcdir, ac_abs_top_srcdir, ac_abs_builddir,
734  ac_abs_top_builddir.
735
736- AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS and AC_OUTPUT.
737  Are much less expensive when using long lists of files.
738
739- AC_PREFIX_PROGRAM
740  Works with shell variables, and non alphanumeric names.
741
742** Library macros
743
744- AC_FUNC_STRERROR_R now sets STRERROR_R_CHAR_P, not HAVE_WORKING_STRERROR_R,
745  because POSIX 1003.1-200x draft 7 says strerror_r returns int, not char *.
746
747- AC_FUNC_STRTOD substitutes POW_LIB.
748
749- AC_FUNC_STRNLEN
750  New.
751
752* Major changes in Autoconf 2.52
753
754  Released 2001-07-18 by Akim Demaille.
755
756** Documentation
757- AC_ARG_VAR
758- Quadrigraphs
759  This feature was present in autoconf 2.50 but was not documented.
760  For example, `@<:@' is translated to `[' just before output.  This
761  is useful when writing strings that contain unbalanced quotes, or
762  other hard-to-quote constructs.
763- m4_pattern_forbid, m4_pattern_allow
764- Tips for upgrading from 2.13.
765- Using autoscan to maintain a configure.ac.
766
767** Default includes
768- Now include stdint.h.
769- sys/types.h and sys/stat.h are guarded.
770- strings.h is included if available, and not conflicting with string.h.
771
772** Bug fixes
773- The test suite is more robust and presents less false failures.
774- Invocation of GNU M4 now robust to POSIXLY_CORRECT.
775- configure accepts --prefix='' again.
776- AC_CHECK_LIB works properly when its first argument is not a
777  literal.
778- HAVE_INTTYPES_H is defined only if not conflicting with sys/types.h.
779- build_, host_, and target_alias are AC_SUBST as in 2.13.
780- AC_ARG_VAR properly propagates precious variables inherited from the
781  environment to ./config.status.
782- Using --program-suffix/--program-prefix is portable.
783- Failures to detect the default compiler's output extension are less
784  likely.
785- `config.status foo' works properly when `foo' depends on variables
786  set in an AC_CONFIG_THING INIT-CMD.
787- autoheader is more robust to broken input.
788- Fixed Fortran name-mangling and link tests on a number of systems,
789  e.g. NetBSD; see AC_F77_DUMMY_MAIN, below.
790
791** Generic macros
792- AC_CHECK_HEADER and AC_CHECK_HEADERS support a fourth argument to
793  specify pre-includes.  In this case, the headers are compiled with
794  cc, not merely preprocessed by cpp.  Therefore it is the _usability_
795  of a header which is checked for, not just its availability.
796- AC_ARG_VAR refuses to run configure when precious variables have
797  changed.
798- Versions of compilers are dumped in the logs.
799- AC_CHECK_TYPE recognizes use of `foo_t' as a replacement type.
800
801** Specific Macros
802- AC_PATH_XTRA only adds -ldnet to $LIBS if it's needed to link.
803- AC_FUNC_WAIT3 and AC_SYS_RESTARTABLE_SYSCALLS are obsoleted.
804- AM_FUNC_ERROR_AT_LINE, AM_FUNC_FNMATCH, AM_FUNC_MKTIME,
805  AM_FUNC_OBSTACK, and AM_FUNC_STRTOD are now activated.
806  Be sure to read `Upgrading from Version 2.13' to understand why
807  running `autoupdate' is needed.
808- AC_F77_DUMMY_MAIN, AC_F77_MAIN: new macros to detect whether
809  a main-like routine is required/possible when linking C/C++ with
810  Fortran.  Users of e.g. AC_F77_WRAPPERS should be aware of these.
811- AC_FUNC_GETPGRG behaves better when cross-compiling.
812
813* Major changes in Autoconf 2.51
814There was no release of Autoconf 2.51 since some packagers had used
815this version number without permission to ship intermediary versions
816of 2.50.  The version was skipped to avoid confusion.
817
818* Major changes in Autoconf 2.50
819
820  Released 2001-05-21 by Akim Demaille.
821
822** Lots of bug fixes
823There have been far too many to enumerate them here.  Check out
824ChangeLog if you really want to know more.
825
826** Improved documentation
827In particular, portability issues are better covered.
828
829** Use of Automake
830All the standard GNU Makefile targets are supported.  The layout has
831changed: m4/ holds the M4 extensions Autoconf needs for its
832configuration, doc/ contains the documentation, and tests/ contains
833the test suite.
834
835** Man pages are provided
836For autoconf, autoreconf, autoupdate, autoheader, autoscan, ifnames,
837config.guess, config.sub.
838
839** autoconf
840- --trace
841  Provides a safe and powerful means to trace the macro uses.  This
842  provide the parsing layer for tools which need to `study'
843  configure.in.
844
845- --warnings
846  Specify what category of warnings should be enabled.
847
848- When recursing into subdirectories, try for configure.gnu before
849  configure to adapt for packages not using autoconf on case-insensitive
850  file systems.
851
852- Diagnostics
853  More errors are now caught (circular AC_REQUIRE dependencies,
854  AC_DEFINE in the action part of an AC_CACHE_CHECK, too many pops
855  etc.).  In addition, their location and call stack are given.
856
857** autoupdate
858autoupdate is much more powerful, and is able to provide the glue code
859which might be needed to move from an old macro to its newer
860equivalent.
861
862You are strongly encouraged to use it to modernize both your
863`configure.in' and your .m4 extension files.
864
865** autoheader
866The internal machinery of autoheader has completely changed.  As a
867result, using `acconfig.h' should be considered to be obsoleted, and
868you are encouraged to get rid of it using the AH macros.
869
870** autoreconf
871Extensive overhaul.
872
873** Fortran 77 compilers
874Globally, the support for Fortran 77 is considerably improved.
875
876Support for automatically determining a Fortran 77 compiler's
877name-mangling scheme.  New CPP macros F77_FUNC and F77_FUNC_ are
878provided to wrap C/C++ identifiers, thus making it easier and more
879transparent for C/C++ to call Fortran 77 routines, and Fortran 77 to
880call C/C++ routines.  See the Texinfo documentation for details.
881
882** Test suite
883The test suite no longer uses DejaGNU.  It should be easy to submit
884test cases in this new framework.
885
886** configure
887- --help, --help=long, -hl
888  no longer dumps useless items.
889- --help=short, -hs
890  lists only specific options.
891- --help=recursive, -hr
892  displays the help of all the embedded packages.
893- Remembers environment variables when reconfiguring.
894  The previous scheme to set envvar before running configure was
895    ENV=VAL ./configure
896  what prevented configure from remembering the environment in which
897  it was run, therefore --recheck was run in an inconsistent
898  environment.  Now, one should run
899    ./configure ENV=VAR
900  and then --recheck will work properly.  Variables declared with
901  AC_ARG_VAR are also preserved.
902- cross-compilation
903  $build defaults to `config.guess`, $host to $build, and then $target
904  to $host.
905  Cross-compilation is a global status of the package, it no longer
906  depends upon the current language.
907  Cross compilation is enabled iff the user specified `--host'.
908  `configure' now fails if it can't run the executables it compiles,
909  unless cross-compilation is enabled.
910- Cache file
911  The cache file is disabled by default.  The new options
912  `--config-cache', `-C' set the cache to `config.cache'.
913
914** config.status
915- faster
916  Much faster on most architectures.
917- concurrent executions
918  It is safe to use `make -j' with config.status.
919- human interface improved
920  It is possible to invoke
921    ./config.status foobar
922  instead of the former form (still valid)
923    CONFIG_COMMANDS= CONFIG_HEADERS= CONFIG_LINKS= \
924    CONFIG_FILES=foobar:foo.in:bar.in \
925    ./config.status
926  The same holds for configuration headers and links.
927  You can instantiate unknown files and headers:
928    ./config.status --header foo.h:foo.h.in --file bar:baz
929- has a useful --help
930- accepts special file name "-" for stdin/stdout
931
932
933** Identity Macros
934- AC_COPYRIGHT
935  Specify additional copyright information.
936
937- AC_INIT
938  Now expects the identity of the package as argument.
939
940** General changes.
941- Uniform quotation
942  Most macros, if not all, now strictly follow the `one quotation
943  level' rule.  This results in a more predictable expansion.
944
945- AC_REQUIRE
946  A sly bug in the AC_REQUIRE machinery, which could produce incorrect
947  configure scripts, was fixed by Axel Thimm.
948
949** Setup Macros
950- AC_ARG_VAR
951  Document and ask for the registration of an envvar.
952
953- AC_CONFIG_SRCDIR
954  Specifies the file which `configure' should look for when trying to
955  find the source tree (used to be handled by AC_INIT).
956
957- AC_CONFIG_COMMANDS
958  To add new actions to config.status.  Should be used instead of
959  AC_OUTPUT_COMMANDS.
960
961- AC_CONFIG_LINKS
962  Replaces AC_LINK_FILES.
963
964- AC_CONFIG_HEADERS, AC_CONFIG_COMMANDS, AC_CONFIG_SUBDIRS,
965  AC_CONFIG_LINKS, and AC_CONFIG_FILES
966  They now obey sh: you should no longer use shell variables as
967  argument.  Instead of
968
969        test "$package_foo_enabled" = yes && $my_subdirs="$my_subdirs foo"
970        AC_CONFIG_SUBDIRS($my_subdirs)
971
972  write
973
974        if test "$package_foo_enabled" = yes; then
975          AC_CONFIG_SUBDIRS(foo)
976        fi
977
978- AC_HELP_STRING
979  To format an Autoconf macro's help string so that it looks pretty
980  when the user executes `configure --help'.
981
982
983** Generic Test Macros
984- AC_CHECK families
985  The interface of the AC_CHECK families of macros (decl, header,
986  type, member, func) is now uniform.  They support the same set of
987  default includes.
988
989- AC_CHECK_DECL, AC_CHECK_DECLS
990  To check whether a symbol is declared.
991
992- AC_CHECK_SIZEOF, AC_C_CHAR_UNSIGNED.
993  No longer need a cross-compilation default.
994
995- AC_CHECK_TYPE
996  The test it performs is much more robust than previously, and makes
997  it possible to test builtin types in addition to typedefs.
998  It is now schizophrenic:
999    - AC_CHECK_TYPE(TYPE, REPLACEMENT)
1000      remains for backward compatibility, but its use is discouraged.
1001    - AC_CHECK_TYPE(TYPE, IF-FOUND, IF-NOT-FOUND, INCLUDES)
1002      behaves exactly like the other AC_CHECK macros.
1003
1004- AC_CHECK_TYPES
1005  Checks whether given types are supported by the system.
1006
1007- AC_CHECK_MEMBER, AC_CHECK_MEMBERS
1008  Check for given members in aggregates (e.g., pw_gecos in struct
1009  passwd).
1010
1011- AC_PROG_CC_STDC
1012  Checks if the compiler supports ISO C, included when needs special
1013  options.
1014
1015- AC_PROG_CPP
1016  Checking whether the preprocessor indicates missing includes by the
1017  error code. stderr is checked by AC_TRY_CPP only as a fallback.
1018
1019- AC_LANG
1020  Takes a language as argument and replaces AC_LANG_C,
1021  AC_LANG_CPLUSPLUS and AC_LANG_FORTRAN77.
1022
1023- AC_LANG_PUSH, AC_LANG_POP
1024  Are preferred to AC_LANG_SAVE, AC_LANG_RESTORE.
1025
1026** Specific Macros
1027- AC_FUNC_CHOWN, AC_FUNC_MALLOC, AC_FUNC_STRERROR_R,
1028  AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK, AC_FUNC_STAT, AC_FUNC_LSTAT,
1029  AC_FUNC_ERROR_AT_LINE, AC_FUNC_OBSTACK, AC_FUNC_STRTOD, AC_FUNC_FSEEKO.
1030  New.
1031
1032- AC_FUNC_GETGROUPS
1033  Sets GETGROUPS_LIBS.
1034
1035- AC_FUNC_GETLOADAVG
1036  Defines `HAVE_STRUCT_NLIST_N_UN_N_NAME' instead of `NLIST_NAME_UNION'.
1037
1038- AC_PROG_LEX
1039  Now integrates `AC_DECL_YYTEXT' which is obsoleted.
1040
1041- AC_SYS_LARGEFILE
1042  Arrange for large-file support.
1043
1044- AC_EXEEXT, AC_OBJEXT
1045  You are no longer expected to use them: their computation is
1046  performed by default.
1047
1048** C++ compatibility
1049  Every macro has been revisited in order to support at best CC=c++.
1050
1051Major changes in Autoconf 2.14:
1052  There was no release of GNU Autoconf 2.14.
1053
1054Major changes in Autoconf 2.13:
1055
1056  Released 1999-05-01 by Ben Elliston.
1057
1058* Support for building on Win32 systems where the only available C or
1059  C++ compiler is the Microsoft Visual C++ command line compiler
1060  (`cl').  Additional support for building on Win32 systems which are
1061  using the Cygwin or Mingw32 environments.
1062* Support for alternative object file and executable file extensions.
1063  On Win32, for example, these are .obj and .exe. These are discovered
1064  using AC_OBJEXT and AC_EXEEXT, which substitute @OBJEXT@ and
1065  @EXEEXT@ in the output, respectively.
1066* New macros: AC_CACHE_LOAD, AC_CACHE_SAVE, AC_FUNC_SELECT_ARGTYPES,
1067  AC_VALIDATE_CACHED_SYSTEM_TUPLE, AC_SEARCH_LIBS, AC_TRY_LINK_FUNC,
1068  AC_C_STRINGIZE, AC_CHECK_FILE(S), AC_PROG_F77 (and friends).
1069* AC_DEFINE now has an optional third argument for a description to be
1070  placed in the config header input file (e.g. config.h.in).
1071* The C++ code fragment compiled for the C++ compiler test had to be
1072  improved to include an explicit return type for main(). This was
1073  causing failures on systems using recent versions of the EGCS C++
1074  compiler.
1075* Fixed an important bug in AC_CHECK_TYPE that would cause a configure
1076  script to report that `sometype_t' was present when only `type_t'
1077  was defined.
1078* Merge of the FSF version of config.guess and config.sub to modernize
1079  these scripts. Add support for a few new hosts in config.guess.
1080  Incorporate latest versions of install-sh, mkinstalldirs and
1081  texinfo.tex from the FSF.
1082* autoreconf is capable of running automake if necessary (and
1083  applicable).
1084* Support for Fortran 77. See the Texinfo documentation for details.
1085* Bug fixes and workarounds for quirky bugs in vendor utilities.
1086
1087Major changes in Autoconf 2.12:
1088
1089  Released 1996-11-26 by David J. MacKenzie
1090
1091* AC_OUTPUT and AC_CONFIG_HEADER can create output files by
1092  concatenating multiple input files separated by colons, like so:
1093  AC_CONFIG_HEADER(config.h:conf.pre:config.h.in:conf.post)
1094  AC_OUTPUT(Makefile:Makefile.in:Makefile.rules)
1095  The arguments may be shell variables, to compute the lists on the fly.
1096* AC_LINK_FILES and AC_CONFIG_SUBDIRS may be called multiple times.
1097* New macro AC_OUTPUT_COMMANDS adds more commands to run in config.status.
1098* Bug fixes.
1099
1100Major changes in Autoconf 2.11:
1101
1102  Released November 18th, 1996, by David J. MacKenzie
1103
1104* AC_PROG_CC and AC_PROG_CXX check whether the compiler works.
1105  They also default CFLAGS/CXXFLAGS to "-g -O2" for gcc, instead of "-g -O".
1106* AC_REPLACE_FUNCS defines HAVE_foo if the system has the function `foo'.
1107* AC_CONFIG_HEADER expands shell variables in its argument.
1108* New macros: AC_FUNC_FNMATCH, AC_FUNC_SETPGRP.
1109* The "checking..." messages and the source code for test programs that
1110  fail are saved in config.log.
1111* Another workaround has been added for seds with small command length limits.
1112* config.sub and config.guess recognize more system types.
1113* Bug fixes.
1114
1115Major changes in Autoconf 2.10:
1116
1117  Released May 7th, 1996, by Roland McGrath
1118
1119* Bug fixes.
1120* The cache variable names used by `AC_CHECK_LIB(LIB, FUNC, ...)' has
1121  changed: now $ac_cv_lib_LIB_FUNC, previously $ac_cv_lib_LIB.
1122
1123Major changes in Autoconf 2.9:
1124
1125  Released March 16th, 1996, by Roland McGrath
1126
1127* Bug fixes.
1128
1129Major changes in Autoconf 2.8:
1130
1131  Released March 8th, 1996, by Roland McGrath
1132
1133* Bug fixes.
1134
1135Major changes in Autoconf 2.7:
1136
1137  Released November 22nd, 1995, by David J. MacKenzie
1138
1139* Bug fixes.
1140
1141Major changes in Autoconf 2.6:
1142
1143  Released November 20th, 1995, by David J. MacKenzie
1144
1145* Bug fixes.
1146
1147Major changes in Autoconf 2.5:
1148
1149  Released November 17th, 1995, by Roland McGrath
1150
1151* New configure options --bindir, --libdir, --datadir, etc., with
1152  corresponding output variables.
1153* New macro: AC_CACHE_CHECK, to make using the cache easier.
1154* config.log contains the command being run as well as any output from it.
1155* AC_CHECK_LIB can check for libraries with "." or "/" or "+" in their name.
1156* AC_PROG_INSTALL doesn't cache a name for install-sh, for sharing caches.
1157* AC_CHECK_PROG, AC_PATH_PROG, AC_CHECK_PROGS, AC_PATH_PROGS, and
1158  AC_CHECK_TOOL can search a path other than $PATH.
1159* AC_CHECK_SIZEOF takes an optional size to use when cross-compiling.
1160
1161Major changes in Autoconf 2.4:
1162
1163  Released June 14th, 1995, by David J. MacKenzie
1164
1165* Fix a few bugs found by Emacs testers.
1166
1167Major changes in Autoconf 2.3:
1168
1169  Released March 27th, 1995, by David J. MacKenzie
1170
1171* Fix the cleanup trap in several ways.
1172* Handle C compilers that are picky about option placement.
1173* ifnames gets the version number from the right directory.
1174
1175Major changes in Autoconf 2.2:
1176
1177  Released March 8th, 1995, by David J. MacKenzie
1178
1179* The ifnames utility is much faster but requires a "new awk" interpreter.
1180* AC_CHECK_LIB and AC_HAVE_LIBRARY check and add the new
1181  library before existing libs, not after, in case it uses them.
1182* New macros: AC_FUNC_GETPGRP, AC_CHECK_TOOL.
1183* Lots of bug fixes.
1184* Many additions to the TODO file :-)
1185
1186Major changes in Autoconf 2.1:
1187
1188  Released November 4th, 1994, by David J. MacKenzie
1189
1190* Fix C++ problems.
1191* More explanations in the manual.
1192* Fix a spurious failure in the testsuite.
1193* Clarify some warning messages.
1194* autoreconf by default only rebuilds configure and config.h.in files
1195  that are older than any of their particular input files; there is a
1196  --force option to use after installing a new version of Autoconf.
1197
1198Thanks to everybody who's submitted changes and additions to Autoconf!
1199I've incorporated many of them, and am still considering others for
1200future releases -- but I didn't want to postpone this release indefinitely.
1201
1202Caution: don't indiscriminately rebuild configure scripts with
1203Autoconf version 2.  Some configure.in files need minor adjustments to
1204work with it; the documentation has a chapter on upgrading.  A few
1205configure.in files, including those for GNU Emacs and the GNU C
1206Library, need major changes because they relied on undocumented
1207internals of version 1.  Future releases of those packages will have
1208updated configure.in files.
1209
1210It's best to use GNU M4 1.3 (or later) with Autoconf version 2.
1211Autoconf now makes heavy use of M4 diversions, which were implemented
1212inefficiently in GNU M4 releases before 1.3.
1213
1214Major changes in Autoconf 2.0:
1215
1216  Released October 26th, 1994, by David J. MacKenzie
1217
1218** New copyright terms:
1219* There are no restrictions on distribution or use of configure scripts.
1220
1221** Documentation:
1222* Autoconf manual is reorganized to make information easier to find
1223  and has several new indexes.
1224* INSTALL is reorganized and clearer and is now made from Texinfo source.
1225
1226** New utilities:
1227* autoscan to generate a preliminary configure.in for a package by
1228  scanning its source code for commonly used nonportable functions,
1229  programs, and header files.
1230* ifnames to list the symbols used in #if and #ifdef directives in a
1231  source tree.
1232* autoupdate to update a configure.in to use the version 2 macro names.
1233* autoreconf to recursively remake configure and configuration header
1234  files in a source tree.
1235
1236** Changed utilities:
1237* autoheader can take pieces of acconfig.h to replace config.h.{top,bot}.
1238* autoconf and autoheader can look for package-local definition files
1239  in an alternate directory.
1240
1241** New macros:
1242* AC_CACHE_VAL to share results of tests between configure runs.
1243* AC_DEFUN to define macros, automatically AC_PROVIDE them, and ensure
1244  that macros invoked with AC_REQUIRE don't interrupt other macros.
1245* AC_CONFIG_AUX_DIR, AC_CANONICAL_SYSTEM, AC_CANONICAL_HOST, AC_LINK_FILES to
1246  support deciding unguessable features based on the host and target types.
1247* AC_CONFIG_SUBDIRS to recursively configure a source tree.
1248* AC_ARG_PROGRAM to use the options --program-prefix,
1249  --program-suffix, and --program-transform-name to change the names
1250  of programs being installed.
1251* AC_PREFIX_DEFAULT to change the default installation prefix.
1252* AC_TRY_COMPILE to compile a test program without linking it.
1253* AC_CHECK_TYPE to check whether sys/types.h or stdlib.h defines a given type.
1254* AC_CHECK_LIB to check for a particular function and library.
1255* AC_MSG_CHECKING and AC_MSG_RESULT to print test results, on a single line,
1256  whether or not the test succeeds.  They obsolete AC_CHECKING and AC_VERBOSE.
1257* AC_SUBST_FILE to insert one file into another.
1258* AC_FUNC_MEMCMP to check whether memcmp is 8-bit clean.
1259* AC_FUNC_STRFTIME to find strftime even if it's in -lintl.
1260* AC_FUNC_GETMNTENT to find getmntent even if it's in -lsun or -lseq.
1261* AC_HEADER_SYS_WAIT to check whether sys/wait.h is POSIX.1 compatible.
1262
1263** Changed macros:
1264* Many macros renamed systematically, but old names are accepted for
1265  backward compatibility.
1266* AC_OUTPUT adds the "automatically generated" comment to
1267  non-Makefiles where it finds @configure_input@ in an input file, to
1268  support files with various comment syntaxes.
1269* AC_OUTPUT does not replace "prefix" and "exec_prefix" in generated
1270  files when they are not enclosed in @ signs.
1271* AC_OUTPUT allows the optional environment variable CONFIG_STATUS to
1272  override the file name "config.status".
1273* AC_OUTPUT takes an optional argument for passing variables from
1274  configure to config.status.
1275* AC_OUTPUT and AC_CONFIG_HEADER allow you to override the input-file names.
1276* AC_OUTPUT automatically substitutes the values of CFLAGS, CXXFLAGS,
1277  CPPFLAGS, and LDFLAGS from the environment.
1278* AC_PROG_CC and AC_PROG_CXX now set CFLAGS and CXXFLAGS, respectively.
1279* AC_PROG_INSTALL looks for install-sh or install.sh in the directory
1280  specified by AC_CONFIG_AUXDIR, or srcdir or srcdir/.. or
1281  srcdir/../.. by default.
1282* AC_DEFINE, AC_DEFINE_UNQUOTED, and AC_SUBST are more robust and smaller.
1283* AC_DEFINE no longer prints anything, because of the new result reporting
1284  mechanism (AC_MSG_CHECKING and AC_MSG_RESULT).
1285* AC_VERBOSE pays attention to --quiet/--silent, not --verbose.
1286* AC_ARG_ENABLE and AC_ARG_WITH support whitespace in the arguments to
1287  --enable- and --with- options.
1288* AC_CHECK_FUNCS and AC_CHECK_HEADERS take optional shell commands to
1289  execute on success or failure.
1290* Checking for C functions in C++ works.
1291
1292** Removed macros:
1293* AC_REMOTE_TAPE and AC_RSH removed; too specific to tar and cpio, and
1294  better maintained with them.
1295* AC_ARG_ARRAY removed because no one was likely using it.
1296* AC_HAVE_POUNDBANG replaced with AC_SYS_INTERPRETER, which doesn't
1297  take arguments, for consistency with all of the other specific checks.
1298
1299** New files:
1300* Comes with config.sub and config.guess, and uses them optionally.
1301* Uses config.cache to cache test results.  An alternate cache file
1302  can be selected with the --cache-file=FILE option.
1303* Uses optional shell scripts $prefix/share/config.site and
1304  $prefix/etc/config.site to perform site or system specific initializations.
1305* configure saves compiler output to ./config.log for debugging.
1306* New files autoconf.m4 and autoheader.m4 load the other Autoconf macros.
1307* acsite.m4 is the new name for the system-wide aclocal.m4.
1308* Has a DejaGnu test suite.
1309
1310Major changes in Autoconf 1.11:
1311
1312* AC_PROG_INSTALL calls install.sh with the -c option.
1313* AC_SET_MAKE cleans up after itself.
1314* AC_OUTPUT sets prefix and exec_prefix if they weren't set already.
1315* AC_OUTPUT prevents shells from looking in PATH for config.status.
1316
1317Plus a few other bug fixes.
1318
1319Major changes in Autoconf 1.10:
1320
1321* autoheader uses config.h.bot if present, analogous to config.h.top.
1322* AC_PROG_INSTALL looks for install.sh in srcdir or srcdir/.. and
1323  never uses cp.
1324* AC_PROG_CXX looks for cxx as a C++ compiler.
1325
1326Plus several bugs fixed.
1327
1328Major changes in Autoconf 1.9:
1329
1330* AC_YYTEXT_POINTER replaces AC_DECLARE_YYTEXT.
1331* AC_SIZEOF_TYPE generates the cpp symbol name automatically,
1332  and autoheader generates entries for those names automatically.
1333* AC_FIND_X gets the result from xmkmf correctly.
1334* AC_FIND_X assumes no X if --without-x was given.
1335* AC_FIND_XTRA adds libraries to the variable X_EXTRA_LIBS.
1336* AC_PROG_INSTALL finds OSF/1 installbsd.
1337
1338Major changes in Autoconf 1.8:
1339
1340** New macros:
1341* New macros AC_LANG_C, AC_LANG_CPLUSPLUS, AC_LANG_SAVE, AC_LANG_RESTORE,
1342  AC_PROG_CXX, AC_PROG_CXXCPP, AC_REQUIRE_CPP
1343  for checking both C++ and C features in one configure script.
1344* New macros AC_CHECKING, AC_VERBOSE, AC_WARN, AC_ERROR for printing messages.
1345* New macros AC_FIND_XTRA, AC_MMAP, AC_SIZEOF_TYPE, AC_PREREQ,
1346  AC_SET_MAKE, AC_ENABLE.
1347
1348** Changed macros:
1349* AC_FIND_X looks for X in more places.
1350* AC_PROG_INSTALL defaults to install.sh instead of cp, if it's in srcdir.
1351  install.sh is distributed with Autoconf.
1352* AC_DECLARE_YYTEXT has been removed because it can't work, pending
1353  a rewrite of quoting in AC_DEFINE.
1354* AC_OUTPUT adds its comments in C format when substituting in C files.
1355* AC_COMPILE_CHECK protects its ECHO-TEXT argument with double quotes.
1356
1357** New or changed command line options:
1358* configure accepts --enable-FEATURE[=ARG] and --disable-FEATURE options.
1359* configure accepts --without-PACKAGE, which sets withval=no.
1360* configure accepts --x-includes=DIR and --x-libraries=DIR.
1361* Giving --with-PACKAGE no argument sets withval=yes instead of withval=1.
1362* configure accepts --help, --version, --silent/--quiet, --no-create options.
1363* configure accepts and ignores most other Cygnus configure options, and
1364  warns about unknown options.
1365* config.status accepts --help, --version options.
1366
1367** File names and other changes:
1368* Relative srcdir values are not made absolute.
1369* The values of @prefix@ and @exec_prefix@ and @top_srcdir@ get substituted.
1370* Autoconf library files are installed in ${datadir}/autoconf, not ${datadir}.
1371* autoheader optionally copies config.h.top to the beginning of config.h.in.
1372* The example Makefile dependencies for configure et al. work better.
1373* Namespace cleanup: all shell variables used internally by Autoconf
1374  have names beginning with `ac_'.
1375
1376More big improvements are in process for future releases, but have not
1377yet been (variously) finished, integrated, tested, or documented enough
1378to release yet.
1379
1380Major changes in Autoconf 1.7:
1381
1382* New macro AC_OBSOLETE.
1383* Bugs in Makefile.in fixed.
1384* AC_LONG_FILE_NAMES improved.
1385
1386Major changes in Autoconf 1.6:
1387
1388* New macro AC_LONG_64_BITS.
1389* Multiple .h files can be created.
1390* AC_FIND_X looks for X files directly if it doesn't find xmkmf.
1391* AC_ALLOCA defines C_ALLOCA if using alloca.c.
1392* --with-NAME can take a value, e.g., --with-targets=sun4,hp300bsd.
1393* Unused --no-create option to configure removed.
1394* autoheader doesn't change the timestamp of its output file if
1395  the file didn't change.
1396* All macros that look for libraries now use AC_HAVE_LIBRARY.
1397* config.status checks three optional environment variables to
1398  modify its behavior.
1399* The usual bug fixes.
1400
1401Major changes in Autoconf 1.5:
1402
1403* New macros AC_FIND_X, AC_OFF_T, AC_STAT_MACROS_BROKEN, AC_REVISION.
1404* autoconf and autoheader scripts have GNU standards conforming
1405  --version and --help options (they print their message and exit).
1406* Many bug fixes.
1407
1408Major changes in Autoconf 1.4:
1409
1410* New macros AC_HAVE_POUNDBANG, AC_TIME_WITH_SYS_TIME, AC_LONG_DOUBLE,
1411  AC_GETGROUPS_T, AC_DEFINE_UNQUOTED.
1412* autoconf and autoheader use the M4 environment variable to determine the
1413  name of the M4 program to use.
1414* The --macrodir option to autoconf and autoheader specifies the directory
1415  in which acspecific.m4, acgeneral.m4, etc. reside if not the default.
1416* autoconf and autoheader can take `-' as their file names, which means to
1417  read stdin as input.
1418* Resulting configure scripts can take a --verbose option which causes them
1419  to print the results of their tests.
1420* AC_DEFINE quotes its second argument in such a way that spaces, magic
1421  shell characters, etc. will be preserved during various stages of
1422  expansion done by the shell.  If you don't want this, use
1423  AC_DEFINE_UNQUOTED instead.
1424* Much textual processing done with external calls to tr and sed have been
1425  internalized with builtin M4 `patsubst' and `translit' calls.
1426* AC_OUTPUT doesn't hardwire the file names it outputs.  Instead, you can
1427  set the shell variables `gen_files' and `gen_config' to the list of
1428  file names to output.
1429* AC_DECLARE_YYTEXT does an AC_SUBST of `LEX_OUTPUT_ROOT', which may be
1430  "lex.yy" or "lexyy", depending on the system.
1431* AC_PROGRAMS_CHECK takes an optional third arg.  If given, it is used as
1432  the default value.
1433* If AC_ALLOCA chooses alloca.c, it also defines STACK_DIRECTION.
1434* AC_CONST works much more reliably on more systems.
1435* Many bug fixes.
1436
1437Major changes in Autoconf 1.3:
1438
1439configure no longer requires awk for packages that use a config.h.
1440Support handling --with-PACKAGE options.
1441New `autoheader' script to create `config.h.in' from `configure.in'.
1442Ignore troublesome -lucb and -lPW when searching for alloca.
1443Rename --exec_prefix to --exec-prefix for GNU standards conformance.
1444Improve detection of STDC library.
1445Add AC_HAVE_LIBRARY to check for non-default libraries.
1446Function checking should work with future GNU libc releases.
1447
1448Major changes in Autoconf 1.2:
1449
1450The --srcdir option is now usually unnecessary.
1451Add a file containing sample comments describing CPP macros.
1452A comment in config.status tells which host it was configured on.
1453Substituted variable values can now contain commas.
1454Fix bugs in various feature checks.
1455
1456Major changes in Autoconf 1.1:
1457
1458Added AC_STRCOLL macro.
1459Made AC_GETLOADAVG check for more things.
1460AC_OUTPUT argument is now optional.
1461Various bug fixes.
1462
1463-----
1464
1465Copyright (C) 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001, 2002,
14662003, 2004, 2005, 2006 Free Software Foundation, Inc.
1467
1468This file is part of GNU Autoconf.
1469
1470GNU Autoconf is free software; you can redistribute it and/or modify
1471it under the terms of the GNU General Public License as published by
1472the Free Software Foundation; either version 2, or (at your option)
1473any later version.
1474
1475GNU Autoconf is distributed in the hope that it will be useful,
1476but WITHOUT ANY WARRANTY; without even the implied warranty of
1477MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
1478GNU General Public License for more details.
1479
1480You should have received a copy of the GNU General Public License
1481along with GNU Autoconf; see the file COPYING.  If not, write to
1482the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
1483Boston, MA 02110-1301, USA.
1484
1485Local Variables:
1486mode: outline
1487End:
1488