1 GNU Autoconf NEWS - User visible changes.
3 * Major changes in Autoconf 2.64a (????-??-??) [experimental]
6 ** Autoconf is now licensed under the General Public License version 3
7 or later (GPLv3+). As with earlier versions, the license includes
8 an exception clause so that you may release a configure script
9 generated by autoconf under the license of your own program.
11 ** New macros to support Objective C++.
12 AC_PROG_OBJCXX AC_PROG_OBJCXXCPP
14 ** The following undocumented autoconf macros, removed in Autoconf 2.64,
18 These macros are present only for backwards compatibility purposes.
20 ** The AC_FC_FREEFORM macro no longer suffers from a whitespace bug that
21 made it fail with some Fortran compilers (regression introduced in
24 ** The following documented autotest macros are new:
27 ** The following m4sugar macros now quote their expansion:
30 ** The `$tmp' temporary directory used in config.status is documented for
33 ** config.status now provides a --config option to produce the configuration.
35 ** Many cache variables used by Autoconf's macros are now documented.
37 * Major changes in Autoconf 2.64 (2009-07-26) [stable]
38 Released by Eric Blake, based on git versions 2.63b.*.
40 ** Autoconf now requires GNU M4 1.4.6 or later. Earlier versions of M4
41 have a bug in regular expression handling that interferes with some
42 of the speedups provided since Autoconf 2.63. GNU M4 1.4.13 or
45 ** AS_IF and AS_CASE have been taught to avoid syntax errors even when
46 given arguments that expand to just whitespace.
48 ** The following documented autoconf macros are new:
49 AC_ERLANG_SUBST_ERTS_VER
51 ** The autoheader tool now understands m4 macro arguments passed to
52 AC_DEFINE and AC_DEFINE_UNQUOTED.
54 ** Ensure AT_CHECK can support commands that include a # given with
55 proper m4 quoting. For shell comments, this is a new feature; for
56 non-shell comments, this fixes a regression introduced in 2.63b.
57 Additionally, AT_CHECK correctly supplies shell escapes for
58 metacharacters occurring in m4 macro expansions within the expected
59 stdout and stderr parameters.
61 ** The macro AT_CHECK now understands the concept of hard failure. If
62 a test exits with an unexpected status 99, cleanup actions for the
63 test are inhibited and the test is treated as a failure regardless
64 of AT_XFAIL_IF. It also understands the new directives
65 ignore-nolog, stdout-nolog, and stderr-nolog.
67 ** The following documented autotest macros are new:
68 AT_CHECK_UNQUOTED AT_FAIL_IF AT_SKIP_IF
70 ** The following documented m4sugar macros are new:
71 m4_argn m4_copy_force m4_default_nblank m4_default_nblank_quoted
72 m4_ifblank m4_ifnblank m4_rename_force
74 ** The autoconf testsuite now exercises all Erlang macros.
76 * Major changes in Autoconf 2.63b (2009-03-31) [beta]
77 Released by Eric Blake, based on git versions 2.63.*.
79 ** The manual is now shipped under the terms of the GNU FDL 1.3.
81 ** AC_REQUIRE now detects the case of an outer macro which first expands
82 then later indirectly requires the same inner macro. Previously,
83 this case led to silent out-of-order expansion (bug present since
84 2.50); it now issues a syntax warning, and duplicates the expansion
85 of the inner macro to guarantee dependencies have been met. See
86 the manual for advice on how to refactor macros in order to avoid
87 the bug in earlier autoconf versions and avoid increased script
88 size in the current version.
90 ** AC_DEFUN_ONCE has improved semantics. Previously, a macro declared
91 with AC_DEFUN_ONCE warned on a second invocation; and out-of-order
92 expansion was still possible. Now, dependencies are guaranteed,
93 and subsequent invocations are a silent no-op. This makes
94 AC_DEFUN_ONCE an ideal macro for silencing AC_REQUIRE warnings.
96 ** The following macros are now defined with AC_DEFUN_ONCE. This means
97 a subtle change in semantics; previously, an AC_DEFUN macro could
98 expand one of these macros multiple times or surround the macro
99 inside shell conditional text to bypass the effects of these
100 macros, but now the macro will expand exactly once, and prior to
101 the start of any enclosing AC_DEFUN macro:
102 AC_CANONICAL_BUILD AC_CANONICAL_HOST AC_CANONICAL_TARGET
103 AC_HEADER_ASSERT AC_PROG_INSTALL AC_PROG_MKDIR_P
104 AC_USE_SYSTEM_EXTENSIONS
106 ** AC_LANG_ERLANG works once again (regression introduced in 2.61a).
108 ** AC_HEADER_ASSERT is fixed so that './configure --enable-assert' no
109 longer mistakenly disables assertions.
111 ** AC_INIT now takes an optional fifth parameter that can be used to
112 set AC_PACKAGE_URL, a URL for the package's home page; the URL is
113 used in `configure --help' and is also available via AC_DEFINE.
115 ** Autotest testsuites accept an option --jobs[=N] for parallel testing.
116 This feature is still in testing, and may not work on every
117 platform, help in improving it would be appreciated.
119 ** Autotest testsuites do not attempt to write startup error messages
120 to the log file before that is opened (regression introduced in 2.63).
122 ** Configure scripts now use shell functions. This feature leads to
123 smaller configure files and faster execution.
125 ** Present But Cannot Be Compiled: Autoconf will now proceed with
126 the compiler's result if a header is present but cannot be compiled.
127 The warning is still printed, and you should really fix it by
128 providing a fourth parameter to AC_CHECK_HEADER/AC_CHECK_HEADERS.
130 ** Autoreconf added aclocal to the set of programs affected by the
131 `autoreconf -I dir' option.
133 ** The following documented m4sugar macros are new:
134 m4_chomp m4_chomp_all m4_cleardivert m4_curry m4_default_quoted
135 m4_esyscmd_s m4_map_args m4_map_args_pair m4_map_args_sep
136 m4_map_args_w m4_set_map m4_set_map_sep m4_stack_foreach
137 m4_stack_foreach_lifo m4_stack_foreach_sep
138 m4_stack_foreach_sep_lifo
140 ** The following m4sugar macros are documented now, but in some cases
141 with slightly different semantics than what the previous
142 undocumented version had:
143 m4_copy m4_dumpdefs m4_rename m4_version_prereq
145 ** The m4sugar macro m4_expand has been taught to handle unterminated
146 comments and shell case statements. As a result, it is used
147 internally in more places, such as AC_DEFINE and AT_CHECK. Most
148 uses of AC_DEFINE and AT_CHECK should not behave any differently;
149 however, it may be necessary to add double-quoting around
150 unbalanced `(' where single-quoting used to be sufficient.
152 ** The following documented m4sh macros are new:
153 AS_INIT_GENERATED AS_LINENO_PREPARE AS_ME_PREPARE AS_SET_STATUS
154 AS_VAR_APPEND AS_VAR_ARITH AS_VAR_COPY
156 ** The following m4sh macros are documented now, but in some cases
157 with slightly different semantics than what the previous
158 undocumented version had:
159 AS_ECHO AS_ECHO_N AS_ESCAPE AS_EXIT AS_LITERAL_IF AS_UNSET
160 AS_VAR_IF AS_VAR_POPDEF AS_VAR_PUSHDEF AS_VAR_SET AS_VAR_SET_IF
161 AS_VAR_TEST_SET AS_VERSION_COMPARE
163 ** The m4sh macros AS_IF and AS_CASE can now be used in shell lists.
164 The responsibility for supplying a trailing newline now belongs to
165 the call site, but since most users did not add dnl, this generally
166 results in fewer empty lines in configure.
169 * Major changes in Autoconf 2.63 (2008-09-09) [stable]
170 Released by Eric Blake, based on git versions 2.62.*.
172 ** AC_C_BIGENDIAN does not mistakenly report "universal" for some
173 bigendian hosts, a regression introduced with universal binary
176 ** AC_PATH_X now includes /lib64 and /usr/lib64 in its list of default
179 ** AC_USE_SYSTEM_EXTENSIONS no longer conflicts with an external
180 AC_DEFINE([__EXTENSIONS__]). This fixes a regression introduced in
181 2.62 when using macros such as AC_AIX that were made obsolete in
182 favor of the more portable AC_USE_SYSTEM_EXTENSIONS.
184 ** AC_CHECK_TARGET_TOOLS is usable in the non-cross-compile case.
186 ** Newly obsolete macros
187 The following macro has been marked obsolete, since current porting
188 targets can safely assume C89 semantics that signal handlers return
189 void. We have no current plans to remove the macro.
193 ** The macros m4_map and m4_map_sep now ignore any list elements
194 consisting of just empty quotes, and m4_map_sep now expands its
195 separator. This fixes a regression in 2.62 when these macros were
196 first documented, for the sake of clients expecting the semantics
197 that these macros had prior to that time. The new macros m4_mapall
198 and m4_mapall_sep, along with extra quoting of the separator, can
199 be used to get the semantics that m4_map_sep had in 2.62.
201 ** Clients of m4_expand, such as AS_HELP_STRING and AT_SETUP, can now
202 handle properly quoted but otherwise unbalanced parentheses (for
203 some macros, this fixes a regression in 2.62).
205 ** Two new quadrigraphs have been introduced: @{:@ for (, and @:}@ for ),
206 allowing the output of unbalanced parentheses in more contexts.
208 ** The following m4sugar macros are new:
209 m4_cleardivert m4_joinall m4_mapall m4_mapall_sep m4_reverse
210 m4_set_add m4_set_add_all m4_set_contains m4_set_contents
211 m4_set_delete m4_set_difference m4_set_dump m4_set_empty
212 m4_set_foreach m4_set_intersection m4_set_list m4_set_listc
213 m4_set_remove m4_set_size m4_set_union
215 ** The following m4sugar macros now accept multiple arguments, as is the
216 case with underlying m4:
217 m4_defn m4_popdef m4_undefine
219 ** The following m4sugar macros now guarantee linear scaling; they
220 previously had linear scaling with m4 1.6 but quadratic scaling
221 when using m4 1.4.x. All macros built on top of these also gain
222 the scaling improvements.
223 m4_bmatch m4_bpatsubsts m4_case m4_cond m4_do m4_dquote_elt
224 m4_foreach m4_join m4_list_cmp m4_map m4_map_sep m4_max
227 ** AT_KEYWORDS once again performs expansion on its argument, such that
228 AT_KEYWORDS([m4_if([$1], [], [default])]) no longer complains about
229 the possibly unexpanded m4_if [regression introduced in 2.62].
231 ** Config header templates `#undef UNDEFINED /* comment */' do not lead to
232 nested comments any more; regression introduced in 2.62.
235 * Major changes in Autoconf 2.62 (2008-04-05) [stable]
236 Released by Eric Blake, based on git versions 2.61a.*.
238 ** Many optimizations have been applied to make overall execution faster.
240 ** Autotest now makes use of shell functions.
242 ** config.status now uses awk instead of sed also for config headers.
244 - As a side effect, AC_DEFINE and AC_DEFINE_UNQUOTED now handle multi-line
245 values, i.e., backslash-newline combinations are handled correctly.
246 Further, for config headers, the total size of values is not limited by
247 the POSIX length limit of text lines any more, only each single line.
249 ** New config variable `top_build_prefix'.
251 ** New Autoconf macros:
252 AC_AUTOCONF_VERSION AC_OPENMP AC_PATH_PROGS_FEATURE_CHECK
254 ** AC_C_BIGENDIAN now supports universal binaries a la Mac OS X.
256 ** AC_C_RESTRICT now prefers to #define 'restrict' to a variant spelling
257 like '__restrict' if the variant spelling is available, as this is
258 more likely to work when mixing C and C++ code.
260 ** AC_CHECK_ALIGNOF's type argument T is now documented better: it must
261 be a string of tokens such that "T y;" is a valid member declaration
264 ** AC_CHECK_SIZEOF now accepts objects as well as types: the general rule
265 is that sizeof (X) works, then AC_CHECK_SIZEOF (X) should work.
267 ** AC_CHECK_TYPE and AC_CHECK_TYPES now work on any C type-name; formerly,
268 they did not work for function types. In C++, they now work on any
269 type-id that can be the operand of sizeof; this is similar to C,
270 except it excludes anonymous struct and union types. Formerly,
271 some (but not all) C++ types involving anonymous struct and union
272 were accepted, though this was not documented.
274 ** AC_CONFIG_LINKS now prefers to link against files in the build tree
275 if found, and it works to link against a file of the same name in
276 the source tree, even if both trees coincide.
278 ** AC_INIT no longer alters $@; regression introduced in 2.60.
280 ** AC_USE_SYSTEM_EXTENSIONS now defines _ALL_SOURCE for Interix platforms.
282 ** AS_HELP_STRING no longer underquotes its first argument; it also handles
283 the case where the first argument contains single-quoted commas.
284 For example, "AS_HELP_STRING([-a, [--arg[=foo]]], [bar])" produces:
285 " -a, --arg[=foo] bar"
286 Additionally, the macro now takes two additional arguments,
287 indent-column and wrap-column; these should not normally be needed,
288 but can be used to fine-tune how the output text is wrapped.
290 ** AC_PROG_INSTALL now requires an install program that can install multiple
291 files into a target directory.
293 ** The command 'autoconf -' now correctly processes a file from stdin.
295 ** 'autoreconf -m' now honors $MAKE.
297 ** For all of the directory arguments for 'configure', such as '--prefix'
298 or '--bindir', trailing slashes are stripped. As an example, if
299 tab completion in the user's shell appends trailing slashes, the
300 command './configure --prefix=/usr/' will still result in an
301 expanded libdir value of /usr/lib, not /usr//lib.
303 ** `configure --help=recursive' now works in read-only trees and from
304 unconfigured build trees.
306 ** If precious variables differ only in whitespace, then the cache consistency
307 check warns instead of fails, and reuses the old value.
309 ** AT_BANNER is now documented.
311 ** AT_SETUP now handles macro expansions properly when calculating line
314 ** Autotest now determines $srcdir correctly.
316 ** Testsuites built by autotest now accept a -C/--directory=DIR option
317 to adjust the working directory prior to creating files.
319 ** Autoconf now requires GNU M4 1.4.5 or later. Earlier versions of M4 have
320 a bug in macro tracing that interferes with the interaction between
321 Autoconf and Automake. GNU M4 1.4.11 or later is recommended. The
322 configure search for a working M4 is improved.
324 ** For portability with the eventual M4 2.0, macros should no longer use
325 anything larger than $9 to refer to arguments.
327 ** Documentation for m4sugar is improved.
329 - The following macros were previously available as undocumented
330 interfaces; the macros are now documented as stable interfaces.
332 __oline__ m4_assert m4_bmatch m4_bpatsubsts m4_car m4_case
333 m4_cdr m4_default m4_divert_once m4_divert_pop m4_divert_push
334 m4_divert_text m4_do m4_errprintn m4_fatal m4_flatten
335 m4_ifndef m4_ifset m4_ifval m4_ifvaln m4_location
336 m4_n m4_shiftn m4_strip m4_warn
338 - The following macros were previously available as undocumented
339 interfaces, but had bug fixes or semantic changes as part of this
340 release. Packages that relied on the undocumented behavior
341 should be analyzed to make sure they will still work with the
342 new documented behavior.
344 m4_cmp m4_list_cmp m4_join m4_map m4_map_sep m4_sign
345 m4_text_box m4_text_wrap m4_version_compare
347 - The m4_wrap macro used to have unspecified order, but now
348 guarantees FIFO order. m4_wrap_lifo was added to guarantee LIFO
351 - Packages using the undocumented m4sugar macro m4_PACKAGE_VERSION
352 should consider using the new AC_AUTOCONF_VERSION instead.
354 - m4sugar macros that are not documented in the manual are still
355 deemed experimental, and should not be used outside of Autoconf.
357 ** The m4sugar macros m4_append and m4_append_uniq, first documented in
358 2.60, have been fixed to treat both the string and the separator
359 arguments consistently with regards to quoting. Prior to this fix,
360 m4_append_uniq could mistakenly duplicate entries if the expansion
361 of the separator resulted in a different string (for example, if it
362 contained quotes, a comma, or a macro name). However, it means
363 that programs previously using
364 m4_append([name], [string], [[, ]])
365 are now using a four-character separator instead of the intended
366 comma and space. If you need portability to earlier versions of
367 Autoconf, you can insert the following snippet after AC_INIT but
368 before any other macro expansions, to enforce the new semantics:
369 m4_pushdef([m4_append], [m4_define([$1],
370 m4_ifdef([$1], [m4_defn([$1])[$3]])[$2])])
371 Additionally, m4_append_uniq now takes optional parameters that can
372 be used to take action depending on whether anything was appended,
373 and warns if a non-empty separator occurs within the string being
374 appended, since that can lead to duplicates.
376 ** The following m4sugar macros are new:
377 m4_append_uniq_w m4_apply m4_combine m4_cond m4_count
378 m4_dquote_elt m4_echo m4_expand m4_ignore m4_make_list m4_max
379 m4_min m4_newline m4_shift2 m4_shift3 m4_unquote m4_wrap_lifo
381 ** Warnings are now generated by default when an installer invokes
382 'configure' with an unknown --enable-* or --with-* option.
383 These warnings can be disabled with the new AC_DISABLE_OPTION_CHECKING
384 macro, or by invoking 'configure' with --disable-option-checking.
386 ** Existing obsolete macros
387 The documentation for the following macros is adjusted to make it
388 more clear that they have previously been marked obsolete, as their
389 functionality can be accomplished by other macros. We have no
390 current plans to remove them from Autoconf.
392 AC_ENABLE AC_STRUCT_ST_BLKSIZE AC_STRUCT_ST_RDEV AC_WITH
394 ** Newly obsolete macros
395 The following macros have been marked obsolete, as they only
396 perform a subset of AC_USE_SYSTEM_EXTENSIONS. We have no current
397 plans to remove them.
399 AC_AIX AC_GNU_SOURCE AC_ISC_POSIX AC_MINIX
401 ** AC_C_LONG_DOUBLE is obsolescent.
402 The documentation now says that AC_C_LONG_DOUBLE is obsolescent: it
403 tests for problems that are so old that it is no longer of
404 practical importance on current systems. New programs need not use
405 AC_C_LONG_DOUBLE. We have no current plans to remove it.
407 ** AC_DIAGNOSE, AC_WARNING, and AC_FATAL are obsolescent.
408 The documentation now favors the use of M4sugar macros m4_warn and
409 m4_fatal, since the naming makes it more obvious that the
410 diagnostics are associated with M4 expansion (ie. when running
411 `autoconf'), and offers less confusion with the AC_MSG_ERROR,
412 AC_MSG_FAILURE, and AC_MSG_WARN macros which manage diagnostics
413 when running `configure'. We have no current plans to remove these
417 * Major changes in Autoconf 2.61a (2006-12-11)
419 ** AC_FUNC_FSEEKO was broken in 2.61; it didn't make fseeko and ftello visible
420 on many platforms. This has been fixed.
422 ** AC_FUNC_SETVBUF_REVERSED is now obsolete. It is still defined for backward
423 compatibility but it does nothing. The macro was already
424 obsolescent, as the last systems to have the problem were those
425 based on SVR2, which became obsolete in 1987. The macro had bugs
426 on some modern systems and could no longer be maintained reliably
427 due to lack of ancient systems to test it on.
429 ** config.status now uses awk instead of sed for most substitutions, for speed.
431 - As a side effect multi-line values of substituted variables no
432 longer have a small limit in total size, though for portability
433 each line should not exceed the POSIX length limit for text lines.
435 - It is now documented that Makefile.in should not contain
436 overlapping variable occurrences, e.g., @VAR1@VAR2@.
437 Autoconf's behavior was always iffy in such cases, and the
438 awk implementation has changed the behavior.
440 ** Many uses of 'echo' have been rewritten so that Autoconf-generated
441 scripts have fewer problems with strings or file names containing
442 embedded special characters such as backslash or leading "-". This
443 was implemented by using `printf '%s\n' "$foo"' instead of `echo
444 "$foo"' when printf works. Due to the implementation technique
445 used, Autoconf-generated scripts now run considerably more slowly
446 on ancient implementations lacking printf. However, this should
447 not be a problem, since Autoconf-generated scripts in practice
448 invariably find a more-modern shell these days.
451 * Major changes in Autoconf 2.61 (2006-11-17)
453 ** New macros AC_C_FLEXIBLE_ARRAY_MEMBER, AC_C_VARARRAYS.
455 ** AC_ARG_ENABLE and AC_ARG_WITH now allow '.' in feature and package names.
458 * Major changes in Autoconf 2.60b (2006-10-22)
461 Autoconf-generated shell scripts no longer export BIN_SH, due to
462 configuration hassles with this. Installers who need BIN_SH in
463 their environment should set it before invoking 'configure' and
464 'make'. As far as we know, this affects only Unixware installations.
466 ** Obsolescent macros
467 The documentation now says that the following macros are obsolescent,
468 as they are superseded by Gnulib:
470 AC_FUNC_FNMATCH AC_FUNC_FNMATCH_GNU AC_FUNC_GETLOADVG AC_REPLACE_FNMATCH
472 New programs should use the Gnulib counterparts of these macros.
473 We have no current plans to remove them from Autoconf.
475 ** AC_COMPUTE_INT no longer caches or reports results.
477 ** AC_CHECK_DECL now also works with aggregate objects.
479 ** AC_USE_SYSTEM_EXTENSIONS now defines _TANDEM_SOURCE for NonStop platforms.
481 ** GNU M4 1.4.7 or later is now recommended.
484 New M4sugar macro, which is more secure than the POSIX M4 maketemp.
487 Now an alias for m4_mkstemp.
489 * Major changes in Autoconf 2.60a (2006-08-25)
491 ** GNU M4 1.4.6 or later is now recommended.
493 ** The check for C99 now tests for varargs macros, as documented.
494 It also tests that the preprocessor supports 64-bit integers.
496 ** Autoconf now uses constructs like "#ifdef HAVE_STDLIB_H" rather than
497 "#if HAVE_STDLIB_H", so that it now works with "gcc -Wundef -Werror".
499 ** The functionality of the undocumented _AC_COMPUTE_INT is now provided
500 by a public and documented macro, AC_COMPUTE_INT. The parameters to the
501 two macros are different, so autoupdate will not change the old private name
502 to the new one. _AC_COMPUTE_INT may be removed in a future release.
504 ** AC_TYPE_LONG_LONG_INT and AC_TYPE_UNSIGNED_LONG_LONG_INT now require
505 that long long types be at least 64 bits wide, as C99 and tradition
506 requires. Formerly, they accepted implementations of any width.
509 * Major changes in Autoconf 2.60
511 Released 2006-06-23, by Ralf Wildenhues.
513 ** Autoconf no longer depends on whether m4wrap is FIFO (as Posix requires)
514 or LIFO (as in GNU M4 1.4.x). GNU M4 2.0 is expected to conform to Posix
515 here, so m4wrap/m4_wrap users should no longer depend on LIFO behavior.
517 ** Provide a way to turn off warnings about the changed directory variables.
519 * Major changes in Autoconf 2.59d
521 Released 2006-06-05, by Ralf Wildenhues.
523 ** GNU make now recommended for VPATH builds
524 INSTALL now suggests VPATH builds (e.g., "sh ../srcdir/configure")
525 only if you use GNU make. In practice, other 'make' implementations
526 have too many subtle incompatibilities in their support for VPATH.
527 Many packages (including Autoconf itself) are portable to other
528 'make' implementations, but some packages are not, and recommending
529 GNU make keeps the installation instructions simpler.
531 ** Even more safety checks for the new Directory variables:
532 Warn about suspicious `${datarootdir}' found in config files output.
534 ** AC_TRY_COMMAND, AC_TRY_EVAL, ac_config_guess, ac_config_sub, ac_configure
535 These never-documented macros and variables have been marked with
536 comments saying that they may be removed in a future release,
537 because their use can lead to unintended code being executed.
538 If you need functionality that only these macros or variables
539 currently supply, please write bug-autoconf@gnu.org.
541 ** AC_SUBST, AC_DEFINE
542 Literal arguments to these are passed to m4_pattern_allow now.
545 Passing 'ac_cv_prog_cc_stdc=no' to 'configure' now sets ac_cv_prog_cc_c99
546 and ac_cv_prog_cc_c89 to 'no' as well, for backward compatibility with
547 obsolete K&R tests in the Automake test suite.
556 Now more robust with special characters in file names, or when
557 multiple processes create the same directory at the same time.
559 ** Obsolescent macros
560 The documentation now says that the following macros are obsolescent:
561 they test for problems that are so old that they are no longer of
562 practical importance on current systems.
564 AC_C_BACKSLASH_A AC_FUNC_MEMCMP AC_HEADER_DIRENT
565 AC_C_CONST AC_FUNC_SELECT_ARGTYPES AC_HEADER_STAT
566 AC_C_PROTOTYPES AC_FUNC_SETPGRP AC_HEADER_STDC
567 AC_C_STRINGIZE AC_FUNC_SETVBUF_REVERSED AC_HEADER_SYS_WAIT
568 AC_C_VOLATILE AC_FUNC_STAT AC_HEADER_TIME
569 AC_FUNC_CLOSEDIR_VOID AC_FUNC_STRFTIME AC_ISC_POSIX
570 AC_FUNC_GETPGRP AC_FUNC_UTIME_NULL AC_PROG_GCC_TRADITIONAL
571 AC_FUNC_LSTAT AC_FUNC_VPRINTF AC_STRUCT_TM
573 New programs need not use these macros. We have no current plans to
577 For compatibility with future Libtool 2.0, autoreconf will invoke
578 libtoolize with the option `--ltdl' now, if LT_CONFIG_LTDL_DIR is
581 * Major changes in Autoconf 2.59c
583 Released 2006-04-12, by Ralf Wildenhues.
585 ** The configure command now redirects standard input from /dev/null,
586 to help avoid problems with subsidiary commands that might mistakenly
587 read standard input. AS_ORIGINAL_STDIN_FD points to the original
588 standard input before this redirection, if you really want configure to
589 read from standard input.
591 ** Directory variables adjusted to recent changes in the GNU Coding Standards.
592 The following directory variables are new:
594 datarootdir read-only architecture-independent data root [PREFIX/share]
595 localedir locale-specific message catalogs [DATAROOTDIR/locale]
596 docdir documentation root [DATAROOTDIR/doc/PACKAGE]
597 htmldir html documentation [DOCDIR]
598 dvidir dvi documentation [DOCDIR]
599 pdfdir pdf documentation [DOCDIR]
600 psdir ps documentation [DOCDIR]
602 The following variables have new default values:
604 datadir read-only architecture-independent data [DATAROOTDIR]
605 infodir info documentation [DATAROOTDIR/info]
606 mandir man documentation [DATAROOTDIR/man]
608 This means that if you use any of `@datadir@', `@infodir@', or
609 `@mandir@' in a file, you will have to ensure `${datarootdir}' is
610 defined in this file. As a temporary measure, if any of those are
611 found but no mention of `datarootdir', the substitutions will be
612 replaced with values that do not contain `${datarootdir}', and a
613 warning will be issued.
615 ** @top_builddir@ is now a dir name: it is always nonempty and doesn't have
616 a trailing slash. Similar change will be made to ac_top_builddir in a
617 future release; the old style value, which matches (../)*, is (and will
618 continue to be) available as ac_top_build_prefix.
621 New macro to check for support of 'typeof' syntax a la GNU C.
623 ** AC_CHECK_DECLS_ONCE, AC_CHECK_FUNCS_ONCE, AC_CHECK_HEADERS_ONCE
624 New "once-only" variants of commonly-used macros, to make 'configure'
625 smaller and faster in common cases.
628 New macro to check for strtold with C99 semantics.
631 New macro that lets builder disable assertions at 'configure'-time.
634 Now checks for X11/Xlib.h and XrmInitialize (X proper) rather than
635 X11/Intrinsic.h and XtMalloc (Xt).
637 ** AC_PRESERVE_HELP_ORDER
638 New macro that causes `configure' to display help strings for AC_ARG_ENABLE
639 and AC_ARG_WITH arguments in one region, in the order defined. The default
640 behavior is to group options of each classes separately.
642 ** AC_PROG_CC, AC_PROG_CXX
643 No longer automatically arrange to declare the 'exit' function of C,
644 when a C++ compiler is used. Standard Autoconf macros no longer use
645 'exit', so this is no longer an issue for them. If you use C++, and
646 want to call 'exit', you'll have to arrange for its declaration
647 yourself. But we now suggest you return from 'main' instead.
649 ** AC_PROG_CC_C89, AC_PROG_CC_C99
650 New macros for ISO C99 support. AC_PROG_CC_C89 and AC_PROG_CC_C99
651 check for ANSI C89 and ISO C99 support respectively.
654 Has been unobsoleted, and will check if the compiler supports ISO
655 C99, falling back to ANSI C89 if not. ac_cv_prog_cc_stdc is
656 retained for backwards compatibility, assuming the value of
657 ac_cv_prog_cc_c99 or ac_cv_prog_cc_c89 (whichever is valid, in
660 ** AC_STRUCT_DIRENT_D_INO, AC_STRUCT_DIRENT_D_TYPE
661 New macros for checking commonly-used members of struct dirent.
664 The substituted value can now contain newlines.
667 The substitution now occurs only when @variable@ is on a line by itself,
668 optionally surrounded by spaces and tabs. The whole line is replaced.
670 ** AC_TYPE_LONG_DOUBLE, AC_TYPE_LONG_DOUBLE_WIDER
671 New macros to check for long double, and whether it is wider than double.
672 The old macro AC_C_TYPE_LONG_DOUBLE has been marked as obsolete;
673 applications should switch to the new macro.
675 ** AC_TYPE_INT8_T, AC_TYPE_INT16_T, AC_TYPE_INT32_T, AC_TYPE_INT64_T,
676 AC_TYPE_INTMAX_T, AC_TYPE_INTPTR_T, AC_TYPE_LONG_LONG_INT, AC_TYPE_SSIZE_T,
677 AC_TYPE_UINT8_T, AC_TYPE_UINT16_T, AC_TYPE_UINT32_T, AC_TYPE_UINT64_T,
678 AC_TYPE_UINTMAX_T, AC_TYPE_UINTPTR_T, AC_TYPE_UNSIGNED_LONG_LONG_INT
679 New macros to check for C99 and POSIX types.
681 ** AC_USE_SYSTEM_EXTENSIONS
682 New macro to enable extensions to Posix.
685 New macro which is defined to the name of the first declared config header
686 or undefined if no config headers have been declared yet.
689 The macro correctly handles quadrigraphs now.
691 ** AS_BOURNE_COMPATIBLE, AS_SHELL_SANITIZE, AS_CASE
692 These macros are new or published now.
695 New macro for copyright notices in testsuite files.
697 ** ALLOCA, LIBOBJS, LTLIBOBJS
698 Object names added to these variables are now prefixed with `${LIBOBJDIR}',
699 as in `${LIBOBJDIR}alloca.o'. LIBOBJDIR is meant to be defined from
700 `Makefile.in' in case the object files lie in a different directory.
701 The LIBOBJDIR feature is experimental.
704 Supports --no-recursive now.
706 ** New macros to support Erlang/OTP.
707 New macros for configuring paths to Erlang tools and libraries:
708 AC_ERLANG_PATH_ERLC, AC_ERLANG_NEED_ERLC, AC_ERLANG_PATH_ERL,
709 AC_ERLANG_NEED_ERL, AC_ERLANG_CHECK_LIB, AC_ERLANG_SUBST_ROOT_DIR,
710 AC_ERLANG_SUBST_LIB_DIR.
712 New macros for configuring installation of Erlang libraries:
713 AC_ERLANG_SUBST_INSTALL_LIB_DIR, AC_ERLANG_SUBST_INSTALL_LIB_SUBDIR.
715 ** The manual now mentions Gnulib more prominently.
717 ** New macros to support Objective C.
718 AC_PROG_OBJC, AC_PROG_OBJCPP.
720 * Major changes in Autoconf 2.59b
722 Released 2004-08-20, by Paul Eggert.
725 New macro that computes the default alignment of a type.
727 ** AC_CHECK_TOOL, AC_PATH_TOOL, AC_CHECK_TOOLS
728 When cross-compiling, these macros will give a warning if the tool
729 is not prefixed. In the future, unprefixed cross tools will not
730 be detected; please consult the info documentation for information
731 about the reason of this change.
733 ** AC_CHECK_TARGET_TOOL, AC_PATH_TARGET_TOOL, AC_CHECK_TARGET_TOOLS
734 New macros that detect programs whose name is prefixed with the
735 target type, if the build type and target type are different.
737 ** AC_REQUIRE_AUX_FILE
738 New trace macro that declares expected auxiliary files.
741 New macro that tests for a grep program that accepts as a long a line
744 ** AC_PROG_EGREP, AC_PROG_FGREP
745 These macros now require AC_PROG_GREP, and try EGREP="$GREP -E" and
746 FGREP="$GREP -F" respectively if possible, or else run a path search for
747 a program that accepts as long a line as possible.
750 New macro that tests for a sed program that truncates as few characters
753 * Major changes in Autoconf 2.59
755 Released 2003-11-04, by Akim Demaille
757 ** ac_abs_builddir etc.
758 Absolute file names were actually relative in 2.58.
760 * Major changes in Autoconf 2.58
762 Released 2003-11-04, by Akim Demaille
765 core.* files are no longer removed, as they may be valid user files.
767 ** autoreconf and auxiliary directory
768 Autoreconf creates the auxiliary directory if needed. This is
769 especially useful for initial "bootstrapping" of fresh CVS checkouts.
771 ** AC_CONFIG_MACRO_DIR
772 Use this macro to declare the directory for local M4 macros for aclocal.
775 No longer includes twice the same file in LIBOBJS if invoked
778 ** AC_CONFIG_COMMANDS
779 The directory for its first argument is automatically created. For
782 AC_CONFIG_COMMANDS([src/modules.hh], [...])
784 $top_builddir/src/ is created if needed.
786 ** Autotest and local.at
787 The optional file local.at is always included in Autotest test suites.
790 The warnings are always issued, including with cached runs.
791 This became a significant problem since aclocal and automake can
792 run autoconf behind the scene.
794 ** autoheader warnings
795 The warnings of autoheader can be turned off, using --warning.
796 For instance, -Wno-obsolete disables the complaints about acconfig.h
797 and other deprecated constructs.
800 AC_C_RESTRICT, AC_INCLUDES_DEFAULT, AC_LANG_ASSERT, AC_LANG_WERROR,
803 ** AC_DECL_SYS_SIGLIST
807 Now checks that mktime is the inverse of localtime.
809 ** Improve DJGPP portability
810 The Autoconf tools and configure behave better under DJGPP.
812 ** Present But Cannot Be Compiled
813 New FAQ section dedicated to the mystic
815 configure: WARNING: pi.h: present but cannot be compiled
816 configure: WARNING: pi.h: check for missing prerequisite headers?
817 configure: WARNING: pi.h: proceeding with the preprocessor's result
820 ** Concurrent executions of autom4te
821 autom4te now locks its internal files, which enables concurrent
822 executions of autom4te, likely to happen if automake, autoconf,
823 autoheader etc. are run simultaneously.
826 Use of Libtool 1.5 and higher is encouraged. Compatibility with
827 Libtool pre-1.4 is not checked.
830 Testsuites no longer rerun failed tests in verbose mode; instead,
831 failures are logged while the test is run.
833 In addition, expected failures can be marked as such.
835 * Major changes in Autoconf 2.57
837 Released 2002-12-03 by Paul Eggert.
839 Bug fixes for problems with AIX linker, with freestanding C compilers,
840 with GNU M4 limitations, and with obsolete copies of GNU documents.
842 The Free Documentation License has been upgraded from 1.1 to 1.2.
844 * Major changes in Autoconf 2.56
846 Released 2002-11-15 by Akim Demaille.
848 One packaging problem fixed (config/install-sh was not executable).
850 * Major changes in Autoconf 2.55
852 Released 2002-11-14 by Akim Demaille.
856 Have your configure.ac checked by autoscan ("autoscan").
857 Try the warning options ("autoreconf -fv -Wall").
861 - AC_CHECK_HEADER, AC_CHECK_HEADERS
862 More information on proper use.
864 - Writing Test Programs
866 This sections explains how to write good test sources to use with
867 AC_COMPILE_IFELSE etc. It documents AC_LANG_PROGRAM and so forth.
869 - AC_FOO_IFELSE vs. AC_TRY_FOO
871 Explains why Autoconf moves from AC_TRY_COMPILE etc. to
872 AC_COMPILE_IFELSE and AC_LANG_PROGRAM etc.
876 - Is more robust to different Gettext installations.
878 - Produces messages (when --verbose) to be understood by Emacs'
881 - Supports -W/--warnings.
884 Once the GNU Build System reinstalled, run `./config.status
885 --recheck && ./config.status && make' if possible.
889 - Supports --cache, and --no-cache.
891 - ~/.autom4te.cfg makes it possible to disable the caching mechanism
892 (autom4te.cache). See `Customizing autom4te' in the documentation.
899 Support for the obsoleted options -m, --macrodir, -l, --localdir is
900 dropped in favor of the safer --include/--prepend-include scheme.
905 AC_COMPILER_IFELSE, AC_FUNC_MBRTOWC, AC_HEADER_STDBOOL,
906 AC_LANG_CONFTEST, AC_LANG_SOURCE, AC_LANG_PROGRAM, AC_LANG_CALL,
907 AC_LANG_FUNC_TRY_LINK, AC_MSG_FAILURE, AC_PREPROC_IFELSE.
910 Obsoleted macros are kept for Autoconf backward compatibility, but
911 should be avoided in configure.ac. Running autoupdate is advised.
914 - AC_DEFINE/AC_DEFINE_UNQUOTED
916 We have to stop using the old compatibility scheme --that tried to
917 avoid useless backslashes-- because Libtool 1.4.3 contains a
919 AC_DEFINE([error_t], [int],
920 [Define to a type to use for \`error_t' if it is not
921 otherwise available.])
923 We have to quote the single quotes and backslashes with \. The old
924 compatibility scheme saw that ` was backslashed, and therefore did
925 not quote the single quote... Failure. Hence, Autoconf 2.54 is not
926 compatible with Libtool. Autoconf 2.55 is, but in some cases might
927 produce more \ than wanted.
929 Please, note that in the future the same problem will happen with
930 AC_MSG_*: use `autoreconf -f -Wall'.
934 - Portability of the Autoconf package to Solaris.
936 - Spurious warnings caused by config.status.
937 This bug is benign, but painful: on some systems (typically
938 FreeBSD), warnings such as:
940 config.status: creating Makefile
941 mv: Makefile: set owner/group (was: 1357/0): Operation not permitted
943 could be issued. This is fixed.
946 Simultaneous executions of config.status are possible again.
948 - Precious variables accumulation
950 config.status could stack several copies of the precious variables
954 ** Plans for later versions
958 The compatibility hooks with the old scheme will be completely
959 removed. Please, advice/use `--build', `--host', and `--target'
962 - AC_CHECK_HEADER, AC_CHECK_HEADERS
964 The tests will be stricter, please make sure your invocations are
969 Shell functions will gradually be introduced, probably starting with
970 Autotest. If you know machines which are in use that you suspect
971 *not* to support shell functions, please run the test suite of
972 Autoconf 2.55 on it, and report the results to
973 bug-autoconf@gnu.org.
977 Special characters in AC_MSG_* need not be quoted. Currently,
978 Autoconf has heuristics to decide when a string is escaped, or has
979 to be escaped. This scheme is fragile, and will be removed; the
980 only risk is uglified messages. Please, run `autoreconf -f -Wall'
981 to find occurrences that will be affected.
983 * Major changes in Autoconf 2.54
985 Released 2002-09-13 by Akim Demaille.
989 - autoreconf no longer changes the version of the gettext/po/intl
990 support files. It now adds the files the correspond to the
991 AM_GNU_GETTEXT_VERSION declared in configure.ac.
993 Warning: It now relies on the 'autopoint' program, which is part
994 of GNU gettext 0.11.4 and newer.
996 Please note that you need to have a GNU gettext version that
997 corresponds at least to the AM_GNU_GETTEXT_VERSION declared
998 in configure.ac. You can upgrade to newer GNU gettext versions,
999 though, without needing to change configure.ac.
1001 - The -I DIR or --include=DIR option now appends DIR to the include path
1002 instead of prepending; this is for consistency with other GNU tools.
1003 The new -B DIR or --prepend-include=DIR option has the old behavior.
1008 Now handles all the gory details about LIBOBJS and LTLIBOBJS.
1009 Please, remove lines such as
1011 # This is necessary so that .o files in LIBOBJS are also
1012 # built via the ANSI2KNR-filtering rules.
1013 LIBOBJS=`echo $LIBOBJS|sed 's/\.o /\$U.o /g;s/\.o$/\$U.o/'`
1015 and read the `AC_LIBOBJ vs LIBOBJS' section. Do not define U in
1016 your Makefiles either.
1018 - AC_CONFIG_LINKS now makes copies if it can't make links.
1020 - AC_FUNC_FNMATCH now tests only for POSIX compatibility, reverting to
1021 Autoconf 2.13 behavior. The new macro AC_FUNC_FNMATCH_GNU also
1022 tests for GNU extensions to fnmatch, and replaces fnmatch if needed.
1024 - AC_FUNC_SETVBUF_REVERSED no longer fails when cross-compiling.
1026 - AC_PROG_CC_STDC is integrated into AC_PROG_CC.
1028 - AC_PROG_F77 default search no longer includes cf77 and cfg77.
1032 AC_C_BACKSLASH_A, AC_CONFIG_LIBOBJ_DIR, AC_GNU_SOURCE,
1033 AC_PROG_EGREP, AC_PROG_FGREP, AC_REPLACE_FNMATCH,
1034 AC_FUNC_FNMATCH_GNU, AC_FUNC_REALLOC, AC_TYPE_MBSTATE_T.
1036 - AC_FUNC_GETLOADAVG
1037 looks for getloadavg.c in the CONFIG_LIBOBJ_DIR.
1040 Now defines HAVE_MALLOC to 0 if `malloc' does not work, and asks
1041 for an AC_LIBOBJ replacement.
1045 - Spurious complaints from `m4_bmatch' about invalid regular
1046 expressions are suppressed.
1048 - Empty top_builddirs are properly handled.
1050 - AC_CHECK_MEMBER works correctly when the member is an aggregate.
1053 Now colon in the optional path arguments are properly handled.
1055 ** Improved portability
1057 - Both Autoconf the package, and the scripts it produces, should run
1058 more reliably with Zsh. Bear in mind it is the default Bourne shell
1061 - Autoconf and the scripts it produces no longer assume the existence of
1062 the obsolescent commands egrep and fgrep.
1066 - Limitations of Make
1070 The GNATS base moved to
1071 http://bugs.gnu.org/cgi-bin/gnatsweb.pl?database=autoconf
1072 (It is no longer available, though.)
1077 Now contains the list of ouput variables and files (AC_SUBST,
1080 * Major changes in Autoconf 2.53
1082 Released 2002-03-08 by Akim Demaille.
1086 Perl 5.005_03 or later is required: autom4te is written in Perl and is
1087 needed by autoconf. autoheader, autoreconf, ifnames, and autoscan are
1093 Argument requirements, output variables, defined macros.
1094 - M4sugar, M4sh, Autotest
1096 - Double quoting macros
1097 AC_TRY_CPP, AC_TRY_COMPILE, AC_TRY_LINK and AC_TRY_RUN.
1099 The Autoconf manual is now distributed under the terms of the GNU FDL.
1100 - Section `Hosts and Cross-Compilation'
1101 Explains the rationale for the 2.5x changes in the cross-compilation
1102 chain, and in the relationships between build, host, and target
1104 Emphasizes that `cross-compilation' == `--host is given'.
1105 If you are working on compilers etc., be sure to read this section.
1106 - Section `AC_LIBOBJ vs. LIBOBJS'
1107 Explains why assigning LIBOBJS directly is now an error.
1108 Details how to update the code.
1113 Now used instead of hard coded line numbers.
1114 This eases the comparison of `configure's, and diminishes the
1115 pressure over control version archives.
1116 Automatic replacement for shells that don't support this feature.
1117 - New output variables
1118 @builddir@, @top_builddir@, @abs_srcdir@, @abs_top_srcdir@, @abs_builddir@,
1123 Autoconf and Autotest modes are provided.
1128 New, used by the Autoconf suite to cache and speed up most processing.
1130 Supported by autom4te, autoconf and autoheader.
1132 Replaces --autoconf-dir and --localdir in autoconf, autoheader,
1133 autoupdate, and autoreconf.
1135 No longer passes --cygnus, --foreign, --gnits, --gnu, --include-deps:
1136 automake options are to be given via AUTOMAKE_OPTIONS.
1138 Runs gettextize and libtoolize when appropriate.
1140 --m4dir is no longer supported.
1142 Now runs only in the specified directories, defaulting to `.',
1143 but understands AC_CONFIG_SUBDIRS for dependent directories.
1144 Before, it used to run on all the `configure.ac' found in the
1146 Independent packages are properly updated.
1150 - The top level $prefix is propagated to the AC_CONFIG_SUBDIRS configures.
1152 Under the user pressure, $? is finally available. Probably a mistake.
1153 - AC_F77_LIBRARY_LDFLAGS now supports the HP/UX f90 compiler.
1154 - Precious variables accumulation
1155 config.status could stack several copies of the precious variables
1157 - AC_PATH_PROG and family.
1158 Works properly when given a literal path.
1160 Somewhere since 2.13, the result had been reversed.
1164 - AC_C_BIGENDIAN supports the cross-compiling case.
1165 - AC_C_BIGENDIAN accepts ACTION-IF-TRUE, ACTION-IF-FALSE, and
1166 ACTION-IF-UNKNOWN arguments. All are facultative, and the default
1167 for ACTION-IF-TRUE is to define WORDS_BIGENDIAN like AC_C_BIGENDIAN
1169 - AC_C_LONG_DOUBLE now succeeds only if `long double' has more range or
1170 precision than `double'.
1175 It now defines the preprocessor symbols PACKAGE_NAME,
1176 PACKAGE_TARNAME, PACKAGE_VERSION, PACKAGE_STRING, and
1180 Admits a fourth optional parameter: the tar name.
1182 - AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS.
1183 Provide the user with srcdir, ac_srcdir, ac_top_srcdir, ac_builddir,
1184 ac_top_builddir, ac_abs_srcdir, ac_abs_top_srcdir, ac_abs_builddir,
1185 ac_abs_top_builddir.
1187 - AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS and AC_OUTPUT.
1188 Are much less expensive when using long lists of files.
1191 Works with shell variables, and non alphanumeric names.
1195 - AC_FUNC_STRERROR_R now sets STRERROR_R_CHAR_P, not HAVE_WORKING_STRERROR_R,
1196 because POSIX 1003.1-200x draft 7 says strerror_r returns int, not char *.
1198 - AC_FUNC_STRTOD substitutes POW_LIB.
1203 * Major changes in Autoconf 2.52
1205 Released 2001-07-18 by Akim Demaille.
1210 This feature was present in autoconf 2.50 but was not documented.
1211 For example, `@<:@' is translated to `[' just before output. This
1212 is useful when writing strings that contain unbalanced quotes, or
1213 other hard-to-quote constructs.
1214 - m4_pattern_forbid, m4_pattern_allow
1215 - Tips for upgrading from 2.13.
1216 - Using autoscan to maintain a configure.ac.
1219 - Now include stdint.h.
1220 - sys/types.h and sys/stat.h are guarded.
1221 - strings.h is included if available, and not conflicting with string.h.
1224 - The test suite is more robust and presents less false failures.
1225 - Invocation of GNU M4 now robust to POSIXLY_CORRECT.
1226 - configure accepts --prefix='' again.
1227 - AC_CHECK_LIB works properly when its first argument is not a
1229 - HAVE_INTTYPES_H is defined only if not conflicting with sys/types.h.
1230 - build_, host_, and target_alias are AC_SUBST as in 2.13.
1231 - AC_ARG_VAR properly propagates precious variables inherited from the
1232 environment to ./config.status.
1233 - Using --program-suffix/--program-prefix is portable.
1234 - Failures to detect the default compiler's output extension are less
1236 - `config.status foo' works properly when `foo' depends on variables
1237 set in an AC_CONFIG_THING INIT-CMD.
1238 - autoheader is more robust to broken input.
1239 - Fixed Fortran name-mangling and link tests on a number of systems,
1240 e.g. NetBSD; see AC_F77_DUMMY_MAIN, below.
1243 - AC_CHECK_HEADER and AC_CHECK_HEADERS support a fourth argument to
1244 specify pre-includes. In this case, the headers are compiled with
1245 cc, not merely preprocessed by cpp. Therefore it is the _usability_
1246 of a header which is checked for, not just its availability.
1247 - AC_ARG_VAR refuses to run configure when precious variables have
1249 - Versions of compilers are dumped in the logs.
1250 - AC_CHECK_TYPE recognizes use of `foo_t' as a replacement type.
1253 - AC_PATH_XTRA only adds -ldnet to $LIBS if it's needed to link.
1254 - AC_FUNC_WAIT3 and AC_SYS_RESTARTABLE_SYSCALLS are obsoleted.
1255 - AM_FUNC_ERROR_AT_LINE, AM_FUNC_FNMATCH, AM_FUNC_MKTIME,
1256 AM_FUNC_OBSTACK, and AM_FUNC_STRTOD are now activated.
1257 Be sure to read `Upgrading from Version 2.13' to understand why
1258 running `autoupdate' is needed.
1259 - AC_F77_DUMMY_MAIN, AC_F77_MAIN: new macros to detect whether
1260 a main-like routine is required/possible when linking C/C++ with
1261 Fortran. Users of e.g. AC_F77_WRAPPERS should be aware of these.
1262 - AC_FUNC_GETPGRG behaves better when cross-compiling.
1264 * Major changes in Autoconf 2.51
1265 There was no release of Autoconf 2.51 since some packagers had used
1266 this version number without permission to ship intermediary versions
1267 of 2.50. The version was skipped to avoid confusion.
1269 * Major changes in Autoconf 2.50
1271 Released 2001-05-21 by Akim Demaille.
1273 ** Lots of bug fixes
1274 There have been far too many to enumerate them here. Check out
1275 ChangeLog if you really want to know more.
1277 ** Improved documentation
1278 In particular, portability issues are better covered.
1281 All the standard GNU Makefile targets are supported. The layout has
1282 changed: m4/ holds the M4 extensions Autoconf needs for its
1283 configuration, doc/ contains the documentation, and tests/ contains
1286 ** Man pages are provided
1287 For autoconf, autoreconf, autoupdate, autoheader, autoscan, ifnames,
1288 config.guess, config.sub.
1292 Provides a safe and powerful means to trace the macro uses. This
1293 provide the parsing layer for tools which need to `study'
1297 Specify what category of warnings should be enabled.
1299 - When recursing into subdirectories, try for configure.gnu before
1300 configure to adapt for packages not using autoconf on case-insensitive
1304 More errors are now caught (circular AC_REQUIRE dependencies,
1305 AC_DEFINE in the action part of an AC_CACHE_CHECK, too many pops
1306 etc.). In addition, their location and call stack are given.
1309 autoupdate is much more powerful, and is able to provide the glue code
1310 which might be needed to move from an old macro to its newer
1313 You are strongly encouraged to use it to modernize both your
1314 `configure.in' and your .m4 extension files.
1317 The internal machinery of autoheader has completely changed. As a
1318 result, using `acconfig.h' should be considered to be obsoleted, and
1319 you are encouraged to get rid of it using the AH macros.
1324 ** Fortran 77 compilers
1325 Globally, the support for Fortran 77 is considerably improved.
1327 Support for automatically determining a Fortran 77 compiler's
1328 name-mangling scheme. New CPP macros F77_FUNC and F77_FUNC_ are
1329 provided to wrap C/C++ identifiers, thus making it easier and more
1330 transparent for C/C++ to call Fortran 77 routines, and Fortran 77 to
1331 call C/C++ routines. See the Texinfo documentation for details.
1334 The test suite no longer uses DejaGNU. It should be easy to submit
1335 test cases in this new framework.
1338 - --help, --help=long, -hl
1339 no longer dumps useless items.
1341 lists only specific options.
1342 - --help=recursive, -hr
1343 displays the help of all the embedded packages.
1344 - Remembers environment variables when reconfiguring.
1345 The previous scheme to set envvar before running configure was
1347 what prevented configure from remembering the environment in which
1348 it was run, therefore --recheck was run in an inconsistent
1349 environment. Now, one should run
1351 and then --recheck will work properly. Variables declared with
1352 AC_ARG_VAR are also preserved.
1354 $build defaults to `config.guess`, $host to $build, and then $target
1356 Cross-compilation is a global status of the package, it no longer
1357 depends upon the current language.
1358 Cross compilation is enabled iff the user specified `--host'.
1359 `configure' now fails if it can't run the executables it compiles,
1360 unless cross-compilation is enabled.
1362 The cache file is disabled by default. The new options
1363 `--config-cache', `-C' set the cache to `config.cache'.
1367 Much faster on most architectures.
1368 - concurrent executions
1369 It is safe to use `make -j' with config.status.
1370 - human interface improved
1371 It is possible to invoke
1372 ./config.status foobar
1373 instead of the former form (still valid)
1374 CONFIG_COMMANDS= CONFIG_HEADERS= CONFIG_LINKS= \
1375 CONFIG_FILES=foobar:foo.in:bar.in \
1377 The same holds for configuration headers and links.
1378 You can instantiate unknown files and headers:
1379 ./config.status --header foo.h:foo.h.in --file bar:baz
1380 - has a useful --help
1381 - accepts special file name "-" for stdin/stdout
1386 Specify additional copyright information.
1389 Now expects the identity of the package as argument.
1393 Most macros, if not all, now strictly follow the `one quotation
1394 level' rule. This results in a more predictable expansion.
1397 A sly bug in the AC_REQUIRE machinery, which could produce incorrect
1398 configure scripts, was fixed by Axel Thimm.
1402 Document and ask for the registration of an envvar.
1405 Specifies the file which `configure' should look for when trying to
1406 find the source tree (used to be handled by AC_INIT).
1408 - AC_CONFIG_COMMANDS
1409 To add new actions to config.status. Should be used instead of
1413 Replaces AC_LINK_FILES.
1415 - AC_CONFIG_HEADERS, AC_CONFIG_COMMANDS, AC_CONFIG_SUBDIRS,
1416 AC_CONFIG_LINKS, and AC_CONFIG_FILES
1417 They now obey sh: you should no longer use shell variables as
1418 argument. Instead of
1420 test "$package_foo_enabled" = yes && $my_subdirs="$my_subdirs foo"
1421 AC_CONFIG_SUBDIRS($my_subdirs)
1425 if test "$package_foo_enabled" = yes; then
1426 AC_CONFIG_SUBDIRS(foo)
1430 To format an Autoconf macro's help string so that it looks pretty
1431 when the user executes `configure --help'.
1434 ** Generic Test Macros
1436 The interface of the AC_CHECK families of macros (decl, header,
1437 type, member, func) is now uniform. They support the same set of
1440 - AC_CHECK_DECL, AC_CHECK_DECLS
1441 To check whether a symbol is declared.
1443 - AC_CHECK_SIZEOF, AC_C_CHAR_UNSIGNED.
1444 No longer need a cross-compilation default.
1447 The test it performs is much more robust than previously, and makes
1448 it possible to test builtin types in addition to typedefs.
1449 It is now schizophrenic:
1450 - AC_CHECK_TYPE(TYPE, REPLACEMENT)
1451 remains for backward compatibility, but its use is discouraged.
1452 - AC_CHECK_TYPE(TYPE, IF-FOUND, IF-NOT-FOUND, INCLUDES)
1453 behaves exactly like the other AC_CHECK macros.
1456 Checks whether given types are supported by the system.
1458 - AC_CHECK_MEMBER, AC_CHECK_MEMBERS
1459 Check for given members in aggregates (e.g., pw_gecos in struct
1463 Checks if the compiler supports ISO C, included when needs special
1467 Checking whether the preprocessor indicates missing includes by the
1468 error code. stderr is checked by AC_TRY_CPP only as a fallback.
1471 Takes a language as argument and replaces AC_LANG_C,
1472 AC_LANG_CPLUSPLUS and AC_LANG_FORTRAN77.
1474 - AC_LANG_PUSH, AC_LANG_POP
1475 Are preferred to AC_LANG_SAVE, AC_LANG_RESTORE.
1478 - AC_FUNC_CHOWN, AC_FUNC_MALLOC, AC_FUNC_STRERROR_R,
1479 AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK, AC_FUNC_STAT, AC_FUNC_LSTAT,
1480 AC_FUNC_ERROR_AT_LINE, AC_FUNC_OBSTACK, AC_FUNC_STRTOD, AC_FUNC_FSEEKO.
1484 Sets GETGROUPS_LIBS.
1486 - AC_FUNC_GETLOADAVG
1487 Defines `HAVE_STRUCT_NLIST_N_UN_N_NAME' instead of `NLIST_NAME_UNION'.
1490 Now integrates `AC_DECL_YYTEXT' which is obsoleted.
1493 Arrange for large-file support.
1495 - AC_EXEEXT, AC_OBJEXT
1496 You are no longer expected to use them: their computation is
1497 performed by default.
1499 ** C++ compatibility
1500 Every macro has been revisited in order to support at best CC=c++.
1502 Major changes in Autoconf 2.14:
1503 There was no release of GNU Autoconf 2.14.
1505 Major changes in Autoconf 2.13:
1507 Released 1999-05-01 by Ben Elliston.
1509 * Support for building on Win32 systems where the only available C or
1510 C++ compiler is the Microsoft Visual C++ command line compiler
1511 (`cl'). Additional support for building on Win32 systems which are
1512 using the Cygwin or Mingw32 environments.
1513 * Support for alternative object file and executable file extensions.
1514 On Win32, for example, these are .obj and .exe. These are discovered
1515 using AC_OBJEXT and AC_EXEEXT, which substitute @OBJEXT@ and
1516 @EXEEXT@ in the output, respectively.
1517 * New macros: AC_CACHE_LOAD, AC_CACHE_SAVE, AC_FUNC_SELECT_ARGTYPES,
1518 AC_VALIDATE_CACHED_SYSTEM_TUPLE, AC_SEARCH_LIBS, AC_TRY_LINK_FUNC,
1519 AC_C_STRINGIZE, AC_CHECK_FILE(S), AC_PROG_F77 (and friends).
1520 * AC_DEFINE now has an optional third argument for a description to be
1521 placed in the config header input file (e.g. config.h.in).
1522 * The C++ code fragment compiled for the C++ compiler test had to be
1523 improved to include an explicit return type for main(). This was
1524 causing failures on systems using recent versions of the EGCS C++
1526 * Fixed an important bug in AC_CHECK_TYPE that would cause a configure
1527 script to report that `sometype_t' was present when only `type_t'
1529 * Merge of the FSF version of config.guess and config.sub to modernize
1530 these scripts. Add support for a few new hosts in config.guess.
1531 Incorporate latest versions of install-sh, mkinstalldirs and
1532 texinfo.tex from the FSF.
1533 * autoreconf is capable of running automake if necessary (and
1535 * Support for Fortran 77. See the Texinfo documentation for details.
1536 * Bug fixes and workarounds for quirky bugs in vendor utilities.
1538 Major changes in Autoconf 2.12:
1540 Released 1996-11-26 by David J. MacKenzie
1542 * AC_OUTPUT and AC_CONFIG_HEADER can create output files by
1543 concatenating multiple input files separated by colons, like so:
1544 AC_CONFIG_HEADER(config.h:conf.pre:config.h.in:conf.post)
1545 AC_OUTPUT(Makefile:Makefile.in:Makefile.rules)
1546 The arguments may be shell variables, to compute the lists on the fly.
1547 * AC_LINK_FILES and AC_CONFIG_SUBDIRS may be called multiple times.
1548 * New macro AC_OUTPUT_COMMANDS adds more commands to run in config.status.
1551 Major changes in Autoconf 2.11:
1553 Released November 18th, 1996, by David J. MacKenzie
1555 * AC_PROG_CC and AC_PROG_CXX check whether the compiler works.
1556 They also default CFLAGS/CXXFLAGS to "-g -O2" for gcc, instead of "-g -O".
1557 * AC_REPLACE_FUNCS defines HAVE_foo if the system has the function `foo'.
1558 * AC_CONFIG_HEADER expands shell variables in its argument.
1559 * New macros: AC_FUNC_FNMATCH, AC_FUNC_SETPGRP.
1560 * The "checking..." messages and the source code for test programs that
1561 fail are saved in config.log.
1562 * Another workaround has been added for seds with small command length limits.
1563 * config.sub and config.guess recognize more system types.
1566 Major changes in Autoconf 2.10:
1568 Released May 7th, 1996, by Roland McGrath
1571 * The cache variable names used by `AC_CHECK_LIB(LIB, FUNC, ...)' has
1572 changed: now $ac_cv_lib_LIB_FUNC, previously $ac_cv_lib_LIB.
1574 Major changes in Autoconf 2.9:
1576 Released March 16th, 1996, by Roland McGrath
1580 Major changes in Autoconf 2.8:
1582 Released March 8th, 1996, by Roland McGrath
1586 Major changes in Autoconf 2.7:
1588 Released November 22nd, 1995, by David J. MacKenzie
1592 Major changes in Autoconf 2.6:
1594 Released November 20th, 1995, by David J. MacKenzie
1598 Major changes in Autoconf 2.5:
1600 Released November 17th, 1995, by Roland McGrath
1602 * New configure options --bindir, --libdir, --datadir, etc., with
1603 corresponding output variables.
1604 * New macro: AC_CACHE_CHECK, to make using the cache easier.
1605 * config.log contains the command being run as well as any output from it.
1606 * AC_CHECK_LIB can check for libraries with "." or "/" or "+" in their name.
1607 * AC_PROG_INSTALL doesn't cache a name for install-sh, for sharing caches.
1608 * AC_CHECK_PROG, AC_PATH_PROG, AC_CHECK_PROGS, AC_PATH_PROGS, and
1609 AC_CHECK_TOOL can search a path other than $PATH.
1610 * AC_CHECK_SIZEOF takes an optional size to use when cross-compiling.
1612 Major changes in Autoconf 2.4:
1614 Released June 14th, 1995, by David J. MacKenzie
1616 * Fix a few bugs found by Emacs testers.
1618 Major changes in Autoconf 2.3:
1620 Released March 27th, 1995, by David J. MacKenzie
1622 * Fix the cleanup trap in several ways.
1623 * Handle C compilers that are picky about option placement.
1624 * ifnames gets the version number from the right directory.
1626 Major changes in Autoconf 2.2:
1628 Released March 8th, 1995, by David J. MacKenzie
1630 * The ifnames utility is much faster but requires a "new awk" interpreter.
1631 * AC_CHECK_LIB and AC_HAVE_LIBRARY check and add the new
1632 library before existing libs, not after, in case it uses them.
1633 * New macros: AC_FUNC_GETPGRP, AC_CHECK_TOOL.
1634 * Lots of bug fixes.
1635 * Many additions to the TODO file :-)
1637 Major changes in Autoconf 2.1:
1639 Released November 4th, 1994, by David J. MacKenzie
1642 * More explanations in the manual.
1643 * Fix a spurious failure in the testsuite.
1644 * Clarify some warning messages.
1645 * autoreconf by default only rebuilds configure and config.h.in files
1646 that are older than any of their particular input files; there is a
1647 --force option to use after installing a new version of Autoconf.
1649 Thanks to everybody who's submitted changes and additions to Autoconf!
1650 I've incorporated many of them, and am still considering others for
1651 future releases -- but I didn't want to postpone this release indefinitely.
1653 Caution: don't indiscriminately rebuild configure scripts with
1654 Autoconf version 2. Some configure.in files need minor adjustments to
1655 work with it; the documentation has a chapter on upgrading. A few
1656 configure.in files, including those for GNU Emacs and the GNU C
1657 Library, need major changes because they relied on undocumented
1658 internals of version 1. Future releases of those packages will have
1659 updated configure.in files.
1661 It's best to use GNU M4 1.3 (or later) with Autoconf version 2.
1662 Autoconf now makes heavy use of M4 diversions, which were implemented
1663 inefficiently in GNU M4 releases before 1.3.
1665 Major changes in Autoconf 2.0:
1667 Released October 26th, 1994, by David J. MacKenzie
1669 ** New copyright terms:
1670 * There are no restrictions on distribution or use of configure scripts.
1673 * Autoconf manual is reorganized to make information easier to find
1674 and has several new indexes.
1675 * INSTALL is reorganized and clearer and is now made from Texinfo source.
1678 * autoscan to generate a preliminary configure.in for a package by
1679 scanning its source code for commonly used nonportable functions,
1680 programs, and header files.
1681 * ifnames to list the symbols used in #if and #ifdef directives in a
1683 * autoupdate to update a configure.in to use the version 2 macro names.
1684 * autoreconf to recursively remake configure and configuration header
1685 files in a source tree.
1687 ** Changed utilities:
1688 * autoheader can take pieces of acconfig.h to replace config.h.{top,bot}.
1689 * autoconf and autoheader can look for package-local definition files
1690 in an alternate directory.
1693 * AC_CACHE_VAL to share results of tests between configure runs.
1694 * AC_DEFUN to define macros, automatically AC_PROVIDE them, and ensure
1695 that macros invoked with AC_REQUIRE don't interrupt other macros.
1696 * AC_CONFIG_AUX_DIR, AC_CANONICAL_SYSTEM, AC_CANONICAL_HOST, AC_LINK_FILES to
1697 support deciding unguessable features based on the host and target types.
1698 * AC_CONFIG_SUBDIRS to recursively configure a source tree.
1699 * AC_ARG_PROGRAM to use the options --program-prefix,
1700 --program-suffix, and --program-transform-name to change the names
1701 of programs being installed.
1702 * AC_PREFIX_DEFAULT to change the default installation prefix.
1703 * AC_TRY_COMPILE to compile a test program without linking it.
1704 * AC_CHECK_TYPE to check whether sys/types.h or stdlib.h defines a given type.
1705 * AC_CHECK_LIB to check for a particular function and library.
1706 * AC_MSG_CHECKING and AC_MSG_RESULT to print test results, on a single line,
1707 whether or not the test succeeds. They obsolete AC_CHECKING and AC_VERBOSE.
1708 * AC_SUBST_FILE to insert one file into another.
1709 * AC_FUNC_MEMCMP to check whether memcmp is 8-bit clean.
1710 * AC_FUNC_STRFTIME to find strftime even if it's in -lintl.
1711 * AC_FUNC_GETMNTENT to find getmntent even if it's in -lsun or -lseq.
1712 * AC_HEADER_SYS_WAIT to check whether sys/wait.h is POSIX.1 compatible.
1715 * Many macros renamed systematically, but old names are accepted for
1716 backward compatibility.
1717 * AC_OUTPUT adds the "automatically generated" comment to
1718 non-Makefiles where it finds @configure_input@ in an input file, to
1719 support files with various comment syntaxes.
1720 * AC_OUTPUT does not replace "prefix" and "exec_prefix" in generated
1721 files when they are not enclosed in @ signs.
1722 * AC_OUTPUT allows the optional environment variable CONFIG_STATUS to
1723 override the file name "config.status".
1724 * AC_OUTPUT takes an optional argument for passing variables from
1725 configure to config.status.
1726 * AC_OUTPUT and AC_CONFIG_HEADER allow you to override the input-file names.
1727 * AC_OUTPUT automatically substitutes the values of CFLAGS, CXXFLAGS,
1728 CPPFLAGS, and LDFLAGS from the environment.
1729 * AC_PROG_CC and AC_PROG_CXX now set CFLAGS and CXXFLAGS, respectively.
1730 * AC_PROG_INSTALL looks for install-sh or install.sh in the directory
1731 specified by AC_CONFIG_AUXDIR, or srcdir or srcdir/.. or
1732 srcdir/../.. by default.
1733 * AC_DEFINE, AC_DEFINE_UNQUOTED, and AC_SUBST are more robust and smaller.
1734 * AC_DEFINE no longer prints anything, because of the new result reporting
1735 mechanism (AC_MSG_CHECKING and AC_MSG_RESULT).
1736 * AC_VERBOSE pays attention to --quiet/--silent, not --verbose.
1737 * AC_ARG_ENABLE and AC_ARG_WITH support whitespace in the arguments to
1738 --enable- and --with- options.
1739 * AC_CHECK_FUNCS and AC_CHECK_HEADERS take optional shell commands to
1740 execute on success or failure.
1741 * Checking for C functions in C++ works.
1744 * AC_REMOTE_TAPE and AC_RSH removed; too specific to tar and cpio, and
1745 better maintained with them.
1746 * AC_ARG_ARRAY removed because no one was likely using it.
1747 * AC_HAVE_POUNDBANG replaced with AC_SYS_INTERPRETER, which doesn't
1748 take arguments, for consistency with all of the other specific checks.
1751 * Comes with config.sub and config.guess, and uses them optionally.
1752 * Uses config.cache to cache test results. An alternate cache file
1753 can be selected with the --cache-file=FILE option.
1754 * Uses optional shell scripts $prefix/share/config.site and
1755 $prefix/etc/config.site to perform site or system specific initializations.
1756 * configure saves compiler output to ./config.log for debugging.
1757 * New files autoconf.m4 and autoheader.m4 load the other Autoconf macros.
1758 * acsite.m4 is the new name for the system-wide aclocal.m4.
1759 * Has a DejaGnu test suite.
1761 Major changes in Autoconf 1.11:
1763 * AC_PROG_INSTALL calls install.sh with the -c option.
1764 * AC_SET_MAKE cleans up after itself.
1765 * AC_OUTPUT sets prefix and exec_prefix if they weren't set already.
1766 * AC_OUTPUT prevents shells from looking in PATH for config.status.
1768 Plus a few other bug fixes.
1770 Major changes in Autoconf 1.10:
1772 * autoheader uses config.h.bot if present, analogous to config.h.top.
1773 * AC_PROG_INSTALL looks for install.sh in srcdir or srcdir/.. and
1775 * AC_PROG_CXX looks for cxx as a C++ compiler.
1777 Plus several bugs fixed.
1779 Major changes in Autoconf 1.9:
1781 * AC_YYTEXT_POINTER replaces AC_DECLARE_YYTEXT.
1782 * AC_SIZEOF_TYPE generates the cpp symbol name automatically,
1783 and autoheader generates entries for those names automatically.
1784 * AC_FIND_X gets the result from xmkmf correctly.
1785 * AC_FIND_X assumes no X if --without-x was given.
1786 * AC_FIND_XTRA adds libraries to the variable X_EXTRA_LIBS.
1787 * AC_PROG_INSTALL finds OSF/1 installbsd.
1789 Major changes in Autoconf 1.8:
1792 * New macros AC_LANG_C, AC_LANG_CPLUSPLUS, AC_LANG_SAVE, AC_LANG_RESTORE,
1793 AC_PROG_CXX, AC_PROG_CXXCPP, AC_REQUIRE_CPP
1794 for checking both C++ and C features in one configure script.
1795 * New macros AC_CHECKING, AC_VERBOSE, AC_WARN, AC_ERROR for printing messages.
1796 * New macros AC_FIND_XTRA, AC_MMAP, AC_SIZEOF_TYPE, AC_PREREQ,
1797 AC_SET_MAKE, AC_ENABLE.
1800 * AC_FIND_X looks for X in more places.
1801 * AC_PROG_INSTALL defaults to install.sh instead of cp, if it's in srcdir.
1802 install.sh is distributed with Autoconf.
1803 * AC_DECLARE_YYTEXT has been removed because it can't work, pending
1804 a rewrite of quoting in AC_DEFINE.
1805 * AC_OUTPUT adds its comments in C format when substituting in C files.
1806 * AC_COMPILE_CHECK protects its ECHO-TEXT argument with double quotes.
1808 ** New or changed command line options:
1809 * configure accepts --enable-FEATURE[=ARG] and --disable-FEATURE options.
1810 * configure accepts --without-PACKAGE, which sets withval=no.
1811 * configure accepts --x-includes=DIR and --x-libraries=DIR.
1812 * Giving --with-PACKAGE no argument sets withval=yes instead of withval=1.
1813 * configure accepts --help, --version, --silent/--quiet, --no-create options.
1814 * configure accepts and ignores most other Cygnus configure options, and
1815 warns about unknown options.
1816 * config.status accepts --help, --version options.
1818 ** File names and other changes:
1819 * Relative srcdir values are not made absolute.
1820 * The values of @prefix@ and @exec_prefix@ and @top_srcdir@ get substituted.
1821 * Autoconf library files are installed in ${datadir}/autoconf, not ${datadir}.
1822 * autoheader optionally copies config.h.top to the beginning of config.h.in.
1823 * The example Makefile dependencies for configure et al. work better.
1824 * Namespace cleanup: all shell variables used internally by Autoconf
1825 have names beginning with `ac_'.
1827 More big improvements are in process for future releases, but have not
1828 yet been (variously) finished, integrated, tested, or documented enough
1831 Major changes in Autoconf 1.7:
1833 * New macro AC_OBSOLETE.
1834 * Bugs in Makefile.in fixed.
1835 * AC_LONG_FILE_NAMES improved.
1837 Major changes in Autoconf 1.6:
1839 * New macro AC_LONG_64_BITS.
1840 * Multiple .h files can be created.
1841 * AC_FIND_X looks for X files directly if it doesn't find xmkmf.
1842 * AC_ALLOCA defines C_ALLOCA if using alloca.c.
1843 * --with-NAME can take a value, e.g., --with-targets=sun4,hp300bsd.
1844 * Unused --no-create option to configure removed.
1845 * autoheader doesn't change the timestamp of its output file if
1846 the file didn't change.
1847 * All macros that look for libraries now use AC_HAVE_LIBRARY.
1848 * config.status checks three optional environment variables to
1849 modify its behavior.
1850 * The usual bug fixes.
1852 Major changes in Autoconf 1.5:
1854 * New macros AC_FIND_X, AC_OFF_T, AC_STAT_MACROS_BROKEN, AC_REVISION.
1855 * autoconf and autoheader scripts have GNU standards conforming
1856 --version and --help options (they print their message and exit).
1859 Major changes in Autoconf 1.4:
1861 * New macros AC_HAVE_POUNDBANG, AC_TIME_WITH_SYS_TIME, AC_LONG_DOUBLE,
1862 AC_GETGROUPS_T, AC_DEFINE_UNQUOTED.
1863 * autoconf and autoheader use the M4 environment variable to determine the
1864 name of the M4 program to use.
1865 * The --macrodir option to autoconf and autoheader specifies the directory
1866 in which acspecific.m4, acgeneral.m4, etc. reside if not the default.
1867 * autoconf and autoheader can take `-' as their file names, which means to
1868 read stdin as input.
1869 * Resulting configure scripts can take a --verbose option which causes them
1870 to print the results of their tests.
1871 * AC_DEFINE quotes its second argument in such a way that spaces, magic
1872 shell characters, etc. will be preserved during various stages of
1873 expansion done by the shell. If you don't want this, use
1874 AC_DEFINE_UNQUOTED instead.
1875 * Much textual processing done with external calls to tr and sed have been
1876 internalized with builtin M4 `patsubst' and `translit' calls.
1877 * AC_OUTPUT doesn't hardwire the file names it outputs. Instead, you can
1878 set the shell variables `gen_files' and `gen_config' to the list of
1879 file names to output.
1880 * AC_DECLARE_YYTEXT does an AC_SUBST of `LEX_OUTPUT_ROOT', which may be
1881 "lex.yy" or "lexyy", depending on the system.
1882 * AC_PROGRAMS_CHECK takes an optional third arg. If given, it is used as
1884 * If AC_ALLOCA chooses alloca.c, it also defines STACK_DIRECTION.
1885 * AC_CONST works much more reliably on more systems.
1888 Major changes in Autoconf 1.3:
1890 configure no longer requires awk for packages that use a config.h.
1891 Support handling --with-PACKAGE options.
1892 New `autoheader' script to create `config.h.in' from `configure.in'.
1893 Ignore troublesome -lucb and -lPW when searching for alloca.
1894 Rename --exec_prefix to --exec-prefix for GNU standards conformance.
1895 Improve detection of STDC library.
1896 Add AC_HAVE_LIBRARY to check for non-default libraries.
1897 Function checking should work with future GNU libc releases.
1899 Major changes in Autoconf 1.2:
1901 The --srcdir option is now usually unnecessary.
1902 Add a file containing sample comments describing CPP macros.
1903 A comment in config.status tells which host it was configured on.
1904 Substituted variable values can now contain commas.
1905 Fix bugs in various feature checks.
1907 Major changes in Autoconf 1.1:
1909 Added AC_STRCOLL macro.
1910 Made AC_GETLOADAVG check for more things.
1911 AC_OUTPUT argument is now optional.
1916 Copyright (C) 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001, 2002,
1917 2003, 2004, 2005, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
1919 Copying and distribution of this file, with or without modification,
1920 are permitted in any medium without royalty provided the copyright
1921 notice and this notice are preserved. This file is offered as-is,
1922 without warranty of any kind.