1 GNU Autoconf NEWS - User visible changes.
3 * Noteworthy changes in release ?.? (????-??-??) [?]
5 ** AT_BANNER() with empty argument will cause visual separation from previous
9 * Major changes in Autoconf 2.67 (2010-07-21) [stable]
10 Released by Eric Blake, based on git versions 2.66.*.
12 ** AC_CONFIG_SUBDIRS with more than one subdirectory at a time works again.
13 Regression introduced in 2.66.
15 ** AC_CHECK_SIZEOF of a pointer type works again. Regression introduced in
18 ** New macro AC_FC_LINE_LENGTH to accept long Fortran source code lines.
20 ** AC_PREPROC_IFELSE now keeps the preprocessed output in the conftest.i
21 file for inspection by the commands in the ACTION-IF-TRUE argument.
23 ** AC_INIT again allows parentheses and other characters that are literal
24 in single- or double-quoted strings, and in quoted and unquoted
25 here-documents, for its PACKAGE and VERSION arguments. Regression
28 ** autoreconf passes warning flags to new enough versions of aclocal.
30 ** Running an Autotest testsuite in parallel mode no longer triggers a
31 race condition that could cause the testsuite run to end early,
32 fixing a sporadic failure in autoconf's own testsuite. Bug present
33 since introduction of parallel tests in 2.63b.
36 * Major changes in Autoconf 2.66 (2010-07-02) [stable]
37 Released by Eric Blake, based on git versions 2.65.*.
39 ** AC_FUNC_MMAP works in C++ mode again. Regression introduced in 2.65.
41 ** Use of m4_divert without a named diversion now issues a syntax warning,
42 since it is seldom right to change diversions behind autoconf's back.
44 ** The macros AC_TYPE_INT8_T, AC_TYPE_INT16_T, AC_TYPE_INT32_T, and
45 AC_TYPE_INT64_T work again. Regression introduced in 2.65.
47 ** AC_PROG_INSTALL correctly uses `shtool' again. Regression introduced
50 ** Autoconf should work on EBCDIC hosts.
52 ** AC_CHECK_DECL and AC_CHECK_DECLS accept optional function argument types
53 for overloaded C++ functions.
55 ** AS_SET_CATFILE accepts nonliterals in its variable name argument now.
57 ** Autotest testsuites accept an option --recheck to rerun tests that
58 failed or passed unexpectedly during the last non-debug testsuite run.
60 ** AC_ARG_ENABLE and AC_ARG_WITH now also accept `+' signs in `--enable-*'
61 and `--with-*' arguments, converting them to underscores for the variable
64 ** In configure scripts, loading CONFIG_SITE no longer searches PATH,
65 and problems in loading the configuration site files are diagnosed.
67 ** Autotest testsuites may optionally provide colored test results.
69 ** The previously undocumented Autotest macros AT_ARG_OPTION and
70 AT_ARG_OPTION_ARG have seen bug fixes and are documented now.
71 AT_ARG_OPTION has been changed in that the negative of a long option
72 --OPTION is now --no-OPTION rather than --noOPTION.
74 ** The macro AS_LITERAL_IF is slightly more conservative; text
75 containing shell quotes are no longer treated as literals.
76 Furthermore, a new macro, AS_LITERAL_WORD_IF, adds an additional
77 level of checking that no whitespace occurs in literals.
79 ** The macros AS_TR_SH and AS_TR_CPP no longer expand their results.
81 ** The following macros are now documented:
84 ** New macro AC_FC_FIXEDFORM to accept fixed-form Fortran.
87 * Major changes in Autoconf 2.65 (2009-11-21) [stable]
88 Released by Eric Blake, based on git versions 2.64.*.
90 ** Autoconf is now licensed under the General Public License version 3
91 or later (GPLv3+). As with earlier versions, the license includes
92 an exception clause so that you may release a configure script
93 generated by autoconf under the license of your own program.
95 ** New macros to support Objective C++.
96 AC_PROG_OBJCXX AC_PROG_OBJCXXCPP
98 ** The following undocumented autoconf macros, removed in Autoconf 2.64,
102 These macros are present only for backwards compatibility purposes.
104 ** The macro AC_LANG_COMPILER no longer fails on embedded systems that
105 lack fopen in the C library, such as AVR or RTEMS (regression
108 ** The AC_FC_FREEFORM macro no longer suffers from a whitespace bug that
109 made it fail with some Fortran compilers (regression introduced in
112 ** The AC_TYPE_UINT64_T and AC_TYPE_INT64_T macros have been fixed to no
113 longer mistakenly select a 32-bit type on some compilers (bug present
114 since macros were introduced in 2.59c).
116 ** The AC_FUNC_MMAP macro has been fixed to be portable to systems like
117 Cygwin (bug present since macro was introduced in 2.0).
119 ** The following documented autotest macros are new:
122 ** The following m4sugar macros now quote their expansion:
123 m4_toupper m4_tolower
125 ** The following m4sugar macros are new:
128 ** The m4sugar macro m4_text_wrap now copes with embedded quoting without
129 requiring quadrigraphs. For uses like AC_ARG_VAR([a], [[b c]]),
130 this gives the intuitive behavior of "[b c]" in the output (2.63
131 gave the output of "[b], [c]", and 2.64 encountered a failure).
133 ** The `$tmp' temporary directory used in config.status is documented for
136 ** config.status now provides a --config option to produce the configuration.
138 ** Many cache variables used by Autoconf's macros are now documented.
140 ** Configure scripts work better on DJGPP by avoiding a bug present in
141 the DJGPP port of bash 2.04 in handling 'return' in a shell
142 function (regression introduced in 2.64).
144 * Major changes in Autoconf 2.64 (2009-07-26) [stable]
145 Released by Eric Blake, based on git versions 2.63b.*.
147 ** Autoconf now requires GNU M4 1.4.6 or later. Earlier versions of M4
148 have a bug in regular expression handling that interferes with some
149 of the speedups provided since Autoconf 2.63. GNU M4 1.4.13 or
150 later is recommended.
152 ** AS_IF and AS_CASE have been taught to avoid syntax errors even when
153 given arguments that expand to just whitespace.
155 ** The following documented autoconf macros are new:
156 AC_ERLANG_SUBST_ERTS_VER
158 ** The autoheader tool now understands m4 macro arguments passed to
159 AC_DEFINE and AC_DEFINE_UNQUOTED.
161 ** Ensure AT_CHECK can support commands that include a # given with
162 proper m4 quoting. For shell comments, this is a new feature; for
163 non-shell comments, this fixes a regression introduced in 2.63b.
164 Additionally, AT_CHECK correctly supplies shell escapes for
165 metacharacters occurring in m4 macro expansions within the expected
166 stdout and stderr parameters.
168 ** The macro AT_CHECK now understands the concept of hard failure. If
169 a test exits with an unexpected status 99, cleanup actions for the
170 test are inhibited and the test is treated as a failure regardless
171 of AT_XFAIL_IF. It also understands the new directives
172 ignore-nolog, stdout-nolog, and stderr-nolog.
174 ** The following documented autotest macros are new:
175 AT_CHECK_UNQUOTED AT_FAIL_IF AT_SKIP_IF
177 ** The following documented m4sugar macros are new:
178 m4_argn m4_copy_force m4_default_nblank m4_default_nblank_quoted
179 m4_ifblank m4_ifnblank m4_rename_force
181 ** The autoconf testsuite now exercises all Erlang macros.
183 * Major changes in Autoconf 2.63b (2009-03-31) [beta]
184 Released by Eric Blake, based on git versions 2.63.*.
186 ** The manual is now shipped under the terms of the GNU FDL 1.3.
188 ** AC_REQUIRE now detects the case of an outer macro which first expands
189 then later indirectly requires the same inner macro. Previously,
190 this case led to silent out-of-order expansion (bug present since
191 2.50); it now issues a syntax warning, and duplicates the expansion
192 of the inner macro to guarantee dependencies have been met. See
193 the manual for advice on how to refactor macros in order to avoid
194 the bug in earlier autoconf versions and avoid increased script
195 size in the current version.
197 ** AC_DEFUN_ONCE has improved semantics. Previously, a macro declared
198 with AC_DEFUN_ONCE warned on a second invocation; and out-of-order
199 expansion was still possible. Now, dependencies are guaranteed,
200 and subsequent invocations are a silent no-op. This makes
201 AC_DEFUN_ONCE an ideal macro for silencing AC_REQUIRE warnings.
203 ** The following macros are now defined with AC_DEFUN_ONCE. This means
204 a subtle change in semantics; previously, an AC_DEFUN macro could
205 expand one of these macros multiple times or surround the macro
206 inside shell conditional text to bypass the effects of these
207 macros, but now the macro will expand exactly once, and prior to
208 the start of any enclosing AC_DEFUN macro:
209 AC_CANONICAL_BUILD AC_CANONICAL_HOST AC_CANONICAL_TARGET
210 AC_HEADER_ASSERT AC_PROG_INSTALL AC_PROG_MKDIR_P
211 AC_USE_SYSTEM_EXTENSIONS
213 ** AC_LANG_ERLANG works once again (regression introduced in 2.61a).
215 ** AC_HEADER_ASSERT is fixed so that './configure --enable-assert' no
216 longer mistakenly disables assertions.
218 ** AC_INIT now takes an optional fifth parameter that can be used to
219 set AC_PACKAGE_URL, a URL for the package's home page; the URL is
220 used in `configure --help' and is also available via AC_DEFINE.
222 ** Autotest testsuites accept an option --jobs[=N] for parallel testing.
223 This feature is still in testing, and may not work on every
224 platform, help in improving it would be appreciated.
226 ** Autotest testsuites do not attempt to write startup error messages
227 to the log file before that is opened (regression introduced in 2.63).
229 ** Configure scripts now use shell functions. This feature leads to
230 smaller configure files and faster execution.
232 ** Present But Cannot Be Compiled: Autoconf will now proceed with
233 the compiler's result if a header is present but cannot be compiled.
234 The warning is still printed, and you should really fix it by
235 providing a fourth parameter to AC_CHECK_HEADER/AC_CHECK_HEADERS.
237 ** Autoreconf added aclocal to the set of programs affected by the
238 `autoreconf -I dir' option.
240 ** The following documented m4sugar macros are new:
241 m4_chomp m4_chomp_all m4_cleardivert m4_curry m4_default_quoted
242 m4_esyscmd_s m4_map_args m4_map_args_pair m4_map_args_sep
243 m4_map_args_w m4_set_map m4_set_map_sep m4_stack_foreach
244 m4_stack_foreach_lifo m4_stack_foreach_sep
245 m4_stack_foreach_sep_lifo
247 ** The following m4sugar macros are documented now, but in some cases
248 with slightly different semantics than what the previous
249 undocumented version had:
250 m4_copy m4_dumpdefs m4_rename m4_version_prereq
252 ** The m4sugar macro m4_expand has been taught to handle unterminated
253 comments and shell case statements. As a result, it is used
254 internally in more places, such as AC_DEFINE and AT_CHECK. Most
255 uses of AC_DEFINE and AT_CHECK should not behave any differently;
256 however, it may be necessary to add double-quoting around
257 unbalanced `(' where single-quoting used to be sufficient.
259 ** The following documented m4sh macros are new:
260 AS_INIT_GENERATED AS_LINENO_PREPARE AS_ME_PREPARE AS_SET_STATUS
261 AS_VAR_APPEND AS_VAR_ARITH AS_VAR_COPY
263 ** The following m4sh macros are documented now, but in some cases
264 with slightly different semantics than what the previous
265 undocumented version had:
266 AS_ECHO AS_ECHO_N AS_ESCAPE AS_EXIT AS_LITERAL_IF AS_UNSET
267 AS_VAR_IF AS_VAR_POPDEF AS_VAR_PUSHDEF AS_VAR_SET AS_VAR_SET_IF
268 AS_VAR_TEST_SET AS_VERSION_COMPARE
270 ** The m4sh macros AS_IF and AS_CASE can now be used in shell lists.
271 The responsibility for supplying a trailing newline now belongs to
272 the call site, but since most users did not add dnl, this generally
273 results in fewer empty lines in configure.
276 * Major changes in Autoconf 2.63 (2008-09-09) [stable]
277 Released by Eric Blake, based on git versions 2.62.*.
279 ** AC_C_BIGENDIAN does not mistakenly report "universal" for some
280 bigendian hosts, a regression introduced with universal binary
283 ** AC_PATH_X now includes /lib64 and /usr/lib64 in its list of default
286 ** AC_USE_SYSTEM_EXTENSIONS no longer conflicts with an external
287 AC_DEFINE([__EXTENSIONS__]). This fixes a regression introduced in
288 2.62 when using macros such as AC_AIX that were made obsolete in
289 favor of the more portable AC_USE_SYSTEM_EXTENSIONS.
291 ** AC_CHECK_TARGET_TOOLS is usable in the non-cross-compile case.
293 ** Newly obsolete macros
294 The following macro has been marked obsolete, since current porting
295 targets can safely assume C89 semantics that signal handlers return
296 void. We have no current plans to remove the macro.
300 ** The macros m4_map and m4_map_sep now ignore any list elements
301 consisting of just empty quotes, and m4_map_sep now expands its
302 separator. This fixes a regression in 2.62 when these macros were
303 first documented, for the sake of clients expecting the semantics
304 that these macros had prior to that time. The new macros m4_mapall
305 and m4_mapall_sep, along with extra quoting of the separator, can
306 be used to get the semantics that m4_map_sep had in 2.62.
308 ** Clients of m4_expand, such as AS_HELP_STRING and AT_SETUP, can now
309 handle properly quoted but otherwise unbalanced parentheses (for
310 some macros, this fixes a regression in 2.62).
312 ** Two new quadrigraphs have been introduced: @{:@ for (, and @:}@ for ),
313 allowing the output of unbalanced parentheses in more contexts.
315 ** The following m4sugar macros are new:
316 m4_cleardivert m4_joinall m4_mapall m4_mapall_sep m4_reverse
317 m4_set_add m4_set_add_all m4_set_contains m4_set_contents
318 m4_set_delete m4_set_difference m4_set_dump m4_set_empty
319 m4_set_foreach m4_set_intersection m4_set_list m4_set_listc
320 m4_set_remove m4_set_size m4_set_union
322 ** The following m4sugar macros now accept multiple arguments, as is the
323 case with underlying m4:
324 m4_defn m4_popdef m4_undefine
326 ** The following m4sugar macros now guarantee linear scaling; they
327 previously had linear scaling with m4 1.6 but quadratic scaling
328 when using m4 1.4.x. All macros built on top of these also gain
329 the scaling improvements.
330 m4_bmatch m4_bpatsubsts m4_case m4_cond m4_do m4_dquote_elt
331 m4_foreach m4_join m4_list_cmp m4_map m4_map_sep m4_max
334 ** AT_KEYWORDS once again performs expansion on its argument, such that
335 AT_KEYWORDS([m4_if([$1], [], [default])]) no longer complains about
336 the possibly unexpanded m4_if [regression introduced in 2.62].
338 ** Config header templates `#undef UNDEFINED /* comment */' do not lead to
339 nested comments any more; regression introduced in 2.62.
342 * Major changes in Autoconf 2.62 (2008-04-05) [stable]
343 Released by Eric Blake, based on git versions 2.61a.*.
345 ** Many optimizations have been applied to make overall execution faster.
347 ** Autotest now makes use of shell functions.
349 ** config.status now uses awk instead of sed also for config headers.
351 - As a side effect, AC_DEFINE and AC_DEFINE_UNQUOTED now handle multi-line
352 values, i.e., backslash-newline combinations are handled correctly.
353 Further, for config headers, the total size of values is not limited by
354 the POSIX length limit of text lines any more, only each single line.
356 ** New config variable `top_build_prefix'.
358 ** New Autoconf macros:
359 AC_AUTOCONF_VERSION AC_OPENMP AC_PATH_PROGS_FEATURE_CHECK
361 ** AC_C_BIGENDIAN now supports universal binaries a la Mac OS X.
363 ** AC_C_RESTRICT now prefers to #define 'restrict' to a variant spelling
364 like '__restrict' if the variant spelling is available, as this is
365 more likely to work when mixing C and C++ code.
367 ** AC_CHECK_ALIGNOF's type argument T is now documented better: it must
368 be a string of tokens such that "T y;" is a valid member declaration
371 ** AC_CHECK_SIZEOF now accepts objects as well as types: the general rule
372 is that sizeof (X) works, then AC_CHECK_SIZEOF (X) should work.
374 ** AC_CHECK_TYPE and AC_CHECK_TYPES now work on any C type-name; formerly,
375 they did not work for function types. In C++, they now work on any
376 type-id that can be the operand of sizeof; this is similar to C,
377 except it excludes anonymous struct and union types. Formerly,
378 some (but not all) C++ types involving anonymous struct and union
379 were accepted, though this was not documented.
381 ** AC_CONFIG_LINKS now prefers to link against files in the build tree
382 if found, and it works to link against a file of the same name in
383 the source tree, even if both trees coincide.
385 ** AC_INIT no longer alters $@; regression introduced in 2.60.
387 ** AC_USE_SYSTEM_EXTENSIONS now defines _ALL_SOURCE for Interix platforms.
389 ** AS_HELP_STRING no longer underquotes its first argument; it also handles
390 the case where the first argument contains single-quoted commas.
391 For example, "AS_HELP_STRING([-a, [--arg[=foo]]], [bar])" produces:
392 " -a, --arg[=foo] bar"
393 Additionally, the macro now takes two additional arguments,
394 indent-column and wrap-column; these should not normally be needed,
395 but can be used to fine-tune how the output text is wrapped.
397 ** AC_PROG_INSTALL now requires an install program that can install multiple
398 files into a target directory.
400 ** The command 'autoconf -' now correctly processes a file from stdin.
402 ** 'autoreconf -m' now honors $MAKE.
404 ** For all of the directory arguments for 'configure', such as '--prefix'
405 or '--bindir', trailing slashes are stripped. As an example, if
406 tab completion in the user's shell appends trailing slashes, the
407 command './configure --prefix=/usr/' will still result in an
408 expanded libdir value of /usr/lib, not /usr//lib.
410 ** `configure --help=recursive' now works in read-only trees and from
411 unconfigured build trees.
413 ** If precious variables differ only in whitespace, then the cache consistency
414 check warns instead of fails, and reuses the old value.
416 ** AT_BANNER is now documented.
418 ** AT_SETUP now handles macro expansions properly when calculating line
421 ** Autotest now determines $srcdir correctly.
423 ** Testsuites built by autotest now accept a -C/--directory=DIR option
424 to adjust the working directory prior to creating files.
426 ** Autoconf now requires GNU M4 1.4.5 or later. Earlier versions of M4 have
427 a bug in macro tracing that interferes with the interaction between
428 Autoconf and Automake. GNU M4 1.4.11 or later is recommended. The
429 configure search for a working M4 is improved.
431 ** For portability with the eventual M4 2.0, macros should no longer use
432 anything larger than $9 to refer to arguments.
434 ** Documentation for m4sugar is improved.
436 - The following macros were previously available as undocumented
437 interfaces; the macros are now documented as stable interfaces.
439 __oline__ m4_assert m4_bmatch m4_bpatsubsts m4_car m4_case
440 m4_cdr m4_default m4_divert_once m4_divert_pop m4_divert_push
441 m4_divert_text m4_do m4_errprintn m4_fatal m4_flatten
442 m4_ifndef m4_ifset m4_ifval m4_ifvaln m4_location
443 m4_n m4_shiftn m4_strip m4_warn
445 - The following macros were previously available as undocumented
446 interfaces, but had bug fixes or semantic changes as part of this
447 release. Packages that relied on the undocumented behavior
448 should be analyzed to make sure they will still work with the
449 new documented behavior.
451 m4_cmp m4_list_cmp m4_join m4_map m4_map_sep m4_sign
452 m4_text_box m4_text_wrap m4_version_compare
454 - The m4_wrap macro used to have unspecified order, but now
455 guarantees FIFO order. m4_wrap_lifo was added to guarantee LIFO
458 - Packages using the undocumented m4sugar macro m4_PACKAGE_VERSION
459 should consider using the new AC_AUTOCONF_VERSION instead.
461 - m4sugar macros that are not documented in the manual are still
462 deemed experimental, and should not be used outside of Autoconf.
464 ** The m4sugar macros m4_append and m4_append_uniq, first documented in
465 2.60, have been fixed to treat both the string and the separator
466 arguments consistently with regards to quoting. Prior to this fix,
467 m4_append_uniq could mistakenly duplicate entries if the expansion
468 of the separator resulted in a different string (for example, if it
469 contained quotes, a comma, or a macro name). However, it means
470 that programs previously using
471 m4_append([name], [string], [[, ]])
472 are now using a four-character separator instead of the intended
473 comma and space. If you need portability to earlier versions of
474 Autoconf, you can insert the following snippet after AC_INIT but
475 before any other macro expansions, to enforce the new semantics:
476 m4_pushdef([m4_append], [m4_define([$1],
477 m4_ifdef([$1], [m4_defn([$1])[$3]])[$2])])
478 Additionally, m4_append_uniq now takes optional parameters that can
479 be used to take action depending on whether anything was appended,
480 and warns if a non-empty separator occurs within the string being
481 appended, since that can lead to duplicates.
483 ** The following m4sugar macros are new:
484 m4_append_uniq_w m4_apply m4_combine m4_cond m4_count
485 m4_dquote_elt m4_echo m4_expand m4_ignore m4_make_list m4_max
486 m4_min m4_newline m4_shift2 m4_shift3 m4_unquote m4_wrap_lifo
488 ** Warnings are now generated by default when an installer invokes
489 'configure' with an unknown --enable-* or --with-* option.
490 These warnings can be disabled with the new AC_DISABLE_OPTION_CHECKING
491 macro, or by invoking 'configure' with --disable-option-checking.
493 ** Existing obsolete macros
494 The documentation for the following macros is adjusted to make it
495 more clear that they have previously been marked obsolete, as their
496 functionality can be accomplished by other macros. We have no
497 current plans to remove them from Autoconf.
499 AC_ENABLE AC_STRUCT_ST_BLKSIZE AC_STRUCT_ST_RDEV AC_WITH
501 ** Newly obsolete macros
502 The following macros have been marked obsolete, as they only
503 perform a subset of AC_USE_SYSTEM_EXTENSIONS. We have no current
504 plans to remove them.
506 AC_AIX AC_GNU_SOURCE AC_ISC_POSIX AC_MINIX
508 ** AC_C_LONG_DOUBLE is obsolescent.
509 The documentation now says that AC_C_LONG_DOUBLE is obsolescent: it
510 tests for problems that are so old that it is no longer of
511 practical importance on current systems. New programs need not use
512 AC_C_LONG_DOUBLE. We have no current plans to remove it.
514 ** AC_DIAGNOSE, AC_WARNING, and AC_FATAL are obsolescent.
515 The documentation now favors the use of M4sugar macros m4_warn and
516 m4_fatal, since the naming makes it more obvious that the
517 diagnostics are associated with M4 expansion (ie. when running
518 `autoconf'), and offers less confusion with the AC_MSG_ERROR,
519 AC_MSG_FAILURE, and AC_MSG_WARN macros which manage diagnostics
520 when running `configure'. We have no current plans to remove these
524 * Major changes in Autoconf 2.61a (2006-12-11)
526 ** AC_FUNC_FSEEKO was broken in 2.61; it didn't make fseeko and ftello visible
527 on many platforms. This has been fixed.
529 ** AC_FUNC_SETVBUF_REVERSED is now obsolete. It is still defined for backward
530 compatibility but it does nothing. The macro was already
531 obsolescent, as the last systems to have the problem were those
532 based on SVR2, which became obsolete in 1987. The macro had bugs
533 on some modern systems and could no longer be maintained reliably
534 due to lack of ancient systems to test it on.
536 ** config.status now uses awk instead of sed for most substitutions, for speed.
538 - As a side effect multi-line values of substituted variables no
539 longer have a small limit in total size, though for portability
540 each line should not exceed the POSIX length limit for text lines.
542 - It is now documented that Makefile.in should not contain
543 overlapping variable occurrences, e.g., @VAR1@VAR2@.
544 Autoconf's behavior was always iffy in such cases, and the
545 awk implementation has changed the behavior.
547 ** Many uses of 'echo' have been rewritten so that Autoconf-generated
548 scripts have fewer problems with strings or file names containing
549 embedded special characters such as backslash or leading "-". This
550 was implemented by using `printf '%s\n' "$foo"' instead of `echo
551 "$foo"' when printf works. Due to the implementation technique
552 used, Autoconf-generated scripts now run considerably more slowly
553 on ancient implementations lacking printf. However, this should
554 not be a problem, since Autoconf-generated scripts in practice
555 invariably find a more-modern shell these days.
558 * Major changes in Autoconf 2.61 (2006-11-17)
560 ** New macros AC_C_FLEXIBLE_ARRAY_MEMBER, AC_C_VARARRAYS.
562 ** AC_ARG_ENABLE and AC_ARG_WITH now allow '.' in feature and package names.
565 * Major changes in Autoconf 2.60b (2006-10-22)
568 Autoconf-generated shell scripts no longer export BIN_SH, due to
569 configuration hassles with this. Installers who need BIN_SH in
570 their environment should set it before invoking 'configure' and
571 'make'. As far as we know, this affects only Unixware installations.
573 ** Obsolescent macros
574 The documentation now says that the following macros are obsolescent,
575 as they are superseded by Gnulib:
577 AC_FUNC_FNMATCH AC_FUNC_FNMATCH_GNU AC_FUNC_GETLOADVG AC_REPLACE_FNMATCH
579 New programs should use the Gnulib counterparts of these macros.
580 We have no current plans to remove them from Autoconf.
582 ** AC_COMPUTE_INT no longer caches or reports results.
584 ** AC_CHECK_DECL now also works with aggregate objects.
586 ** AC_USE_SYSTEM_EXTENSIONS now defines _TANDEM_SOURCE for NonStop platforms.
588 ** GNU M4 1.4.7 or later is now recommended.
591 New M4sugar macro, which is more secure than the POSIX M4 maketemp.
594 Now an alias for m4_mkstemp.
596 * Major changes in Autoconf 2.60a (2006-08-25)
598 ** GNU M4 1.4.6 or later is now recommended.
600 ** The check for C99 now tests for varargs macros, as documented.
601 It also tests that the preprocessor supports 64-bit integers.
603 ** Autoconf now uses constructs like "#ifdef HAVE_STDLIB_H" rather than
604 "#if HAVE_STDLIB_H", so that it now works with "gcc -Wundef -Werror".
606 ** The functionality of the undocumented _AC_COMPUTE_INT is now provided
607 by a public and documented macro, AC_COMPUTE_INT. The parameters to the
608 two macros are different, so autoupdate will not change the old private name
609 to the new one. _AC_COMPUTE_INT may be removed in a future release.
611 ** AC_TYPE_LONG_LONG_INT and AC_TYPE_UNSIGNED_LONG_LONG_INT now require
612 that long long types be at least 64 bits wide, as C99 and tradition
613 requires. Formerly, they accepted implementations of any width.
616 * Major changes in Autoconf 2.60
618 Released 2006-06-23, by Ralf Wildenhues.
620 ** Autoconf no longer depends on whether m4wrap is FIFO (as Posix requires)
621 or LIFO (as in GNU M4 1.4.x). GNU M4 2.0 is expected to conform to Posix
622 here, so m4wrap/m4_wrap users should no longer depend on LIFO behavior.
624 ** Provide a way to turn off warnings about the changed directory variables.
626 * Major changes in Autoconf 2.59d
628 Released 2006-06-05, by Ralf Wildenhues.
630 ** GNU make now recommended for VPATH builds
631 INSTALL now suggests VPATH builds (e.g., "sh ../srcdir/configure")
632 only if you use GNU make. In practice, other 'make' implementations
633 have too many subtle incompatibilities in their support for VPATH.
634 Many packages (including Autoconf itself) are portable to other
635 'make' implementations, but some packages are not, and recommending
636 GNU make keeps the installation instructions simpler.
638 ** Even more safety checks for the new Directory variables:
639 Warn about suspicious `${datarootdir}' found in config files output.
641 ** AC_TRY_COMMAND, AC_TRY_EVAL, ac_config_guess, ac_config_sub, ac_configure
642 These never-documented macros and variables have been marked with
643 comments saying that they may be removed in a future release,
644 because their use can lead to unintended code being executed.
645 If you need functionality that only these macros or variables
646 currently supply, please write bug-autoconf@gnu.org.
648 ** AC_SUBST, AC_DEFINE
649 Literal arguments to these are passed to m4_pattern_allow now.
652 Passing 'ac_cv_prog_cc_stdc=no' to 'configure' now sets ac_cv_prog_cc_c99
653 and ac_cv_prog_cc_c89 to 'no' as well, for backward compatibility with
654 obsolete K&R tests in the Automake test suite.
663 Now more robust with special characters in file names, or when
664 multiple processes create the same directory at the same time.
666 ** Obsolescent macros
667 The documentation now says that the following macros are obsolescent:
668 they test for problems that are so old that they are no longer of
669 practical importance on current systems.
671 AC_C_BACKSLASH_A AC_FUNC_MEMCMP AC_HEADER_DIRENT
672 AC_C_CONST AC_FUNC_SELECT_ARGTYPES AC_HEADER_STAT
673 AC_C_PROTOTYPES AC_FUNC_SETPGRP AC_HEADER_STDC
674 AC_C_STRINGIZE AC_FUNC_SETVBUF_REVERSED AC_HEADER_SYS_WAIT
675 AC_C_VOLATILE AC_FUNC_STAT AC_HEADER_TIME
676 AC_FUNC_CLOSEDIR_VOID AC_FUNC_STRFTIME AC_ISC_POSIX
677 AC_FUNC_GETPGRP AC_FUNC_UTIME_NULL AC_PROG_GCC_TRADITIONAL
678 AC_FUNC_LSTAT AC_FUNC_VPRINTF AC_STRUCT_TM
680 New programs need not use these macros. We have no current plans to
684 For compatibility with future Libtool 2.0, autoreconf will invoke
685 libtoolize with the option `--ltdl' now, if LT_CONFIG_LTDL_DIR is
688 * Major changes in Autoconf 2.59c
690 Released 2006-04-12, by Ralf Wildenhues.
692 ** The configure command now redirects standard input from /dev/null,
693 to help avoid problems with subsidiary commands that might mistakenly
694 read standard input. AS_ORIGINAL_STDIN_FD points to the original
695 standard input before this redirection, if you really want configure to
696 read from standard input.
698 ** Directory variables adjusted to recent changes in the GNU Coding Standards.
699 The following directory variables are new:
701 datarootdir read-only architecture-independent data root [PREFIX/share]
702 localedir locale-specific message catalogs [DATAROOTDIR/locale]
703 docdir documentation root [DATAROOTDIR/doc/PACKAGE]
704 htmldir html documentation [DOCDIR]
705 dvidir dvi documentation [DOCDIR]
706 pdfdir pdf documentation [DOCDIR]
707 psdir ps documentation [DOCDIR]
709 The following variables have new default values:
711 datadir read-only architecture-independent data [DATAROOTDIR]
712 infodir info documentation [DATAROOTDIR/info]
713 mandir man documentation [DATAROOTDIR/man]
715 This means that if you use any of `@datadir@', `@infodir@', or
716 `@mandir@' in a file, you will have to ensure `${datarootdir}' is
717 defined in this file. As a temporary measure, if any of those are
718 found but no mention of `datarootdir', the substitutions will be
719 replaced with values that do not contain `${datarootdir}', and a
720 warning will be issued.
722 ** @top_builddir@ is now a dir name: it is always nonempty and doesn't have
723 a trailing slash. Similar change will be made to ac_top_builddir in a
724 future release; the old style value, which matches (../)*, is (and will
725 continue to be) available as ac_top_build_prefix.
728 New macro to check for support of 'typeof' syntax a la GNU C.
730 ** AC_CHECK_DECLS_ONCE, AC_CHECK_FUNCS_ONCE, AC_CHECK_HEADERS_ONCE
731 New "once-only" variants of commonly-used macros, to make 'configure'
732 smaller and faster in common cases.
735 New macro to check for strtold with C99 semantics.
738 New macro that lets builder disable assertions at 'configure'-time.
741 Now checks for X11/Xlib.h and XrmInitialize (X proper) rather than
742 X11/Intrinsic.h and XtMalloc (Xt).
744 ** AC_PRESERVE_HELP_ORDER
745 New macro that causes `configure' to display help strings for AC_ARG_ENABLE
746 and AC_ARG_WITH arguments in one region, in the order defined. The default
747 behavior is to group options of each classes separately.
749 ** AC_PROG_CC, AC_PROG_CXX
750 No longer automatically arrange to declare the 'exit' function of C,
751 when a C++ compiler is used. Standard Autoconf macros no longer use
752 'exit', so this is no longer an issue for them. If you use C++, and
753 want to call 'exit', you'll have to arrange for its declaration
754 yourself. But we now suggest you return from 'main' instead.
756 ** AC_PROG_CC_C89, AC_PROG_CC_C99
757 New macros for ISO C99 support. AC_PROG_CC_C89 and AC_PROG_CC_C99
758 check for ANSI C89 and ISO C99 support respectively.
761 Has been unobsoleted, and will check if the compiler supports ISO
762 C99, falling back to ANSI C89 if not. ac_cv_prog_cc_stdc is
763 retained for backwards compatibility, assuming the value of
764 ac_cv_prog_cc_c99 or ac_cv_prog_cc_c89 (whichever is valid, in
767 ** AC_STRUCT_DIRENT_D_INO, AC_STRUCT_DIRENT_D_TYPE
768 New macros for checking commonly-used members of struct dirent.
771 The substituted value can now contain newlines.
774 The substitution now occurs only when @variable@ is on a line by itself,
775 optionally surrounded by spaces and tabs. The whole line is replaced.
777 ** AC_TYPE_LONG_DOUBLE, AC_TYPE_LONG_DOUBLE_WIDER
778 New macros to check for long double, and whether it is wider than double.
779 The old macro AC_C_TYPE_LONG_DOUBLE has been marked as obsolete;
780 applications should switch to the new macro.
782 ** AC_TYPE_INT8_T, AC_TYPE_INT16_T, AC_TYPE_INT32_T, AC_TYPE_INT64_T,
783 AC_TYPE_INTMAX_T, AC_TYPE_INTPTR_T, AC_TYPE_LONG_LONG_INT, AC_TYPE_SSIZE_T,
784 AC_TYPE_UINT8_T, AC_TYPE_UINT16_T, AC_TYPE_UINT32_T, AC_TYPE_UINT64_T,
785 AC_TYPE_UINTMAX_T, AC_TYPE_UINTPTR_T, AC_TYPE_UNSIGNED_LONG_LONG_INT
786 New macros to check for C99 and POSIX types.
788 ** AC_USE_SYSTEM_EXTENSIONS
789 New macro to enable extensions to Posix.
792 New macro which is defined to the name of the first declared config header
793 or undefined if no config headers have been declared yet.
796 The macro correctly handles quadrigraphs now.
798 ** AS_BOURNE_COMPATIBLE, AS_SHELL_SANITIZE, AS_CASE
799 These macros are new or published now.
802 New macro for copyright notices in testsuite files.
804 ** ALLOCA, LIBOBJS, LTLIBOBJS
805 Object names added to these variables are now prefixed with `${LIBOBJDIR}',
806 as in `${LIBOBJDIR}alloca.o'. LIBOBJDIR is meant to be defined from
807 `Makefile.in' in case the object files lie in a different directory.
808 The LIBOBJDIR feature is experimental.
811 Supports --no-recursive now.
813 ** New macros to support Erlang/OTP.
814 New macros for configuring paths to Erlang tools and libraries:
815 AC_ERLANG_PATH_ERLC, AC_ERLANG_NEED_ERLC, AC_ERLANG_PATH_ERL,
816 AC_ERLANG_NEED_ERL, AC_ERLANG_CHECK_LIB, AC_ERLANG_SUBST_ROOT_DIR,
817 AC_ERLANG_SUBST_LIB_DIR.
819 New macros for configuring installation of Erlang libraries:
820 AC_ERLANG_SUBST_INSTALL_LIB_DIR, AC_ERLANG_SUBST_INSTALL_LIB_SUBDIR.
822 ** The manual now mentions Gnulib more prominently.
824 ** New macros to support Objective C.
825 AC_PROG_OBJC, AC_PROG_OBJCPP.
827 * Major changes in Autoconf 2.59b
829 Released 2004-08-20, by Paul Eggert.
832 New macro that computes the default alignment of a type.
834 ** AC_CHECK_TOOL, AC_PATH_TOOL, AC_CHECK_TOOLS
835 When cross-compiling, these macros will give a warning if the tool
836 is not prefixed. In the future, unprefixed cross tools will not
837 be detected; please consult the info documentation for information
838 about the reason of this change.
840 ** AC_CHECK_TARGET_TOOL, AC_PATH_TARGET_TOOL, AC_CHECK_TARGET_TOOLS
841 New macros that detect programs whose name is prefixed with the
842 target type, if the build type and target type are different.
844 ** AC_REQUIRE_AUX_FILE
845 New trace macro that declares expected auxiliary files.
848 New macro that tests for a grep program that accepts as a long a line
851 ** AC_PROG_EGREP, AC_PROG_FGREP
852 These macros now require AC_PROG_GREP, and try EGREP="$GREP -E" and
853 FGREP="$GREP -F" respectively if possible, or else run a path search for
854 a program that accepts as long a line as possible.
857 New macro that tests for a sed program that truncates as few characters
860 * Major changes in Autoconf 2.59
862 Released 2003-11-04, by Akim Demaille
864 ** ac_abs_builddir etc.
865 Absolute file names were actually relative in 2.58.
867 * Major changes in Autoconf 2.58
869 Released 2003-11-04, by Akim Demaille
872 core.* files are no longer removed, as they may be valid user files.
874 ** autoreconf and auxiliary directory
875 Autoreconf creates the auxiliary directory if needed. This is
876 especially useful for initial "bootstrapping" of fresh CVS checkouts.
878 ** AC_CONFIG_MACRO_DIR
879 Use this macro to declare the directory for local M4 macros for aclocal.
882 No longer includes twice the same file in LIBOBJS if invoked
885 ** AC_CONFIG_COMMANDS
886 The directory for its first argument is automatically created. For
889 AC_CONFIG_COMMANDS([src/modules.hh], [...])
891 $top_builddir/src/ is created if needed.
893 ** Autotest and local.at
894 The optional file local.at is always included in Autotest test suites.
897 The warnings are always issued, including with cached runs.
898 This became a significant problem since aclocal and automake can
899 run autoconf behind the scene.
901 ** autoheader warnings
902 The warnings of autoheader can be turned off, using --warning.
903 For instance, -Wno-obsolete disables the complaints about acconfig.h
904 and other deprecated constructs.
907 AC_C_RESTRICT, AC_INCLUDES_DEFAULT, AC_LANG_ASSERT, AC_LANG_WERROR,
910 ** AC_DECL_SYS_SIGLIST
914 Now checks that mktime is the inverse of localtime.
916 ** Improve DJGPP portability
917 The Autoconf tools and configure behave better under DJGPP.
919 ** Present But Cannot Be Compiled
920 New FAQ section dedicated to the mystic
922 configure: WARNING: pi.h: present but cannot be compiled
923 configure: WARNING: pi.h: check for missing prerequisite headers?
924 configure: WARNING: pi.h: proceeding with the preprocessor's result
927 ** Concurrent executions of autom4te
928 autom4te now locks its internal files, which enables concurrent
929 executions of autom4te, likely to happen if automake, autoconf,
930 autoheader etc. are run simultaneously.
933 Use of Libtool 1.5 and higher is encouraged. Compatibility with
934 Libtool pre-1.4 is not checked.
937 Testsuites no longer rerun failed tests in verbose mode; instead,
938 failures are logged while the test is run.
940 In addition, expected failures can be marked as such.
942 * Major changes in Autoconf 2.57
944 Released 2002-12-03 by Paul Eggert.
946 Bug fixes for problems with AIX linker, with freestanding C compilers,
947 with GNU M4 limitations, and with obsolete copies of GNU documents.
949 The Free Documentation License has been upgraded from 1.1 to 1.2.
951 * Major changes in Autoconf 2.56
953 Released 2002-11-15 by Akim Demaille.
955 One packaging problem fixed (config/install-sh was not executable).
957 * Major changes in Autoconf 2.55
959 Released 2002-11-14 by Akim Demaille.
963 Have your configure.ac checked by autoscan ("autoscan").
964 Try the warning options ("autoreconf -fv -Wall").
968 - AC_CHECK_HEADER, AC_CHECK_HEADERS
969 More information on proper use.
971 - Writing Test Programs
973 This sections explains how to write good test sources to use with
974 AC_COMPILE_IFELSE etc. It documents AC_LANG_PROGRAM and so forth.
976 - AC_FOO_IFELSE vs. AC_TRY_FOO
978 Explains why Autoconf moves from AC_TRY_COMPILE etc. to
979 AC_COMPILE_IFELSE and AC_LANG_PROGRAM etc.
983 - Is more robust to different Gettext installations.
985 - Produces messages (when --verbose) to be understood by Emacs'
988 - Supports -W/--warnings.
991 Once the GNU Build System reinstalled, run `./config.status
992 --recheck && ./config.status && make' if possible.
996 - Supports --cache, and --no-cache.
998 - ~/.autom4te.cfg makes it possible to disable the caching mechanism
999 (autom4te.cache). See `Customizing autom4te' in the documentation.
1006 Support for the obsoleted options -m, --macrodir, -l, --localdir is
1007 dropped in favor of the safer --include/--prepend-include scheme.
1012 AC_COMPILER_IFELSE, AC_FUNC_MBRTOWC, AC_HEADER_STDBOOL,
1013 AC_LANG_CONFTEST, AC_LANG_SOURCE, AC_LANG_PROGRAM, AC_LANG_CALL,
1014 AC_LANG_FUNC_TRY_LINK, AC_MSG_FAILURE, AC_PREPROC_IFELSE.
1017 Obsoleted macros are kept for Autoconf backward compatibility, but
1018 should be avoided in configure.ac. Running autoupdate is advised.
1019 AC_DECL_SYS_SIGLIST.
1021 - AC_DEFINE/AC_DEFINE_UNQUOTED
1023 We have to stop using the old compatibility scheme --that tried to
1024 avoid useless backslashes-- because Libtool 1.4.3 contains a
1026 AC_DEFINE([error_t], [int],
1027 [Define to a type to use for \`error_t' if it is not
1028 otherwise available.])
1030 We have to quote the single quotes and backslashes with \. The old
1031 compatibility scheme saw that ` was backslashed, and therefore did
1032 not quote the single quote... Failure. Hence, Autoconf 2.54 is not
1033 compatible with Libtool. Autoconf 2.55 is, but in some cases might
1034 produce more \ than wanted.
1036 Please, note that in the future the same problem will happen with
1037 AC_MSG_*: use `autoreconf -f -Wall'.
1041 - Portability of the Autoconf package to Solaris.
1043 - Spurious warnings caused by config.status.
1044 This bug is benign, but painful: on some systems (typically
1045 FreeBSD), warnings such as:
1047 config.status: creating Makefile
1048 mv: Makefile: set owner/group (was: 1357/0): Operation not permitted
1050 could be issued. This is fixed.
1053 Simultaneous executions of config.status are possible again.
1055 - Precious variables accumulation
1057 config.status could stack several copies of the precious variables
1061 ** Plans for later versions
1063 - ./configure <host>
1065 The compatibility hooks with the old scheme will be completely
1066 removed. Please, advice/use `--build', `--host', and `--target'
1069 - AC_CHECK_HEADER, AC_CHECK_HEADERS
1071 The tests will be stricter, please make sure your invocations are
1076 Shell functions will gradually be introduced, probably starting with
1077 Autotest. If you know machines which are in use that you suspect
1078 *not* to support shell functions, please run the test suite of
1079 Autoconf 2.55 on it, and report the results to
1080 bug-autoconf@gnu.org.
1084 Special characters in AC_MSG_* need not be quoted. Currently,
1085 Autoconf has heuristics to decide when a string is escaped, or has
1086 to be escaped. This scheme is fragile, and will be removed; the
1087 only risk is uglified messages. Please, run `autoreconf -f -Wall'
1088 to find occurrences that will be affected.
1090 * Major changes in Autoconf 2.54
1092 Released 2002-09-13 by Akim Demaille.
1096 - autoreconf no longer changes the version of the gettext/po/intl
1097 support files. It now adds the files the correspond to the
1098 AM_GNU_GETTEXT_VERSION declared in configure.ac.
1100 Warning: It now relies on the 'autopoint' program, which is part
1101 of GNU gettext 0.11.4 and newer.
1103 Please note that you need to have a GNU gettext version that
1104 corresponds at least to the AM_GNU_GETTEXT_VERSION declared
1105 in configure.ac. You can upgrade to newer GNU gettext versions,
1106 though, without needing to change configure.ac.
1108 - The -I DIR or --include=DIR option now appends DIR to the include path
1109 instead of prepending; this is for consistency with other GNU tools.
1110 The new -B DIR or --prepend-include=DIR option has the old behavior.
1115 Now handles all the gory details about LIBOBJS and LTLIBOBJS.
1116 Please, remove lines such as
1118 # This is necessary so that .o files in LIBOBJS are also
1119 # built via the ANSI2KNR-filtering rules.
1120 LIBOBJS=`echo $LIBOBJS|sed 's/\.o /\$U.o /g;s/\.o$/\$U.o/'`
1122 and read the `AC_LIBOBJ vs LIBOBJS' section. Do not define U in
1123 your Makefiles either.
1125 - AC_CONFIG_LINKS now makes copies if it can't make links.
1127 - AC_FUNC_FNMATCH now tests only for POSIX compatibility, reverting to
1128 Autoconf 2.13 behavior. The new macro AC_FUNC_FNMATCH_GNU also
1129 tests for GNU extensions to fnmatch, and replaces fnmatch if needed.
1131 - AC_FUNC_SETVBUF_REVERSED no longer fails when cross-compiling.
1133 - AC_PROG_CC_STDC is integrated into AC_PROG_CC.
1135 - AC_PROG_F77 default search no longer includes cf77 and cfg77.
1139 AC_C_BACKSLASH_A, AC_CONFIG_LIBOBJ_DIR, AC_GNU_SOURCE,
1140 AC_PROG_EGREP, AC_PROG_FGREP, AC_REPLACE_FNMATCH,
1141 AC_FUNC_FNMATCH_GNU, AC_FUNC_REALLOC, AC_TYPE_MBSTATE_T.
1143 - AC_FUNC_GETLOADAVG
1144 looks for getloadavg.c in the CONFIG_LIBOBJ_DIR.
1147 Now defines HAVE_MALLOC to 0 if `malloc' does not work, and asks
1148 for an AC_LIBOBJ replacement.
1152 - Spurious complaints from `m4_bmatch' about invalid regular
1153 expressions are suppressed.
1155 - Empty top_builddirs are properly handled.
1157 - AC_CHECK_MEMBER works correctly when the member is an aggregate.
1160 Now colon in the optional path arguments are properly handled.
1162 ** Improved portability
1164 - Both Autoconf the package, and the scripts it produces, should run
1165 more reliably with Zsh. Bear in mind it is the default Bourne shell
1168 - Autoconf and the scripts it produces no longer assume the existence of
1169 the obsolescent commands egrep and fgrep.
1173 - Limitations of Make
1177 The GNATS base moved to
1178 http://bugs.gnu.org/cgi-bin/gnatsweb.pl?database=autoconf
1179 (It is no longer available, though.)
1184 Now contains the list of ouput variables and files (AC_SUBST,
1187 * Major changes in Autoconf 2.53
1189 Released 2002-03-08 by Akim Demaille.
1193 Perl 5.005_03 or later is required: autom4te is written in Perl and is
1194 needed by autoconf. autoheader, autoreconf, ifnames, and autoscan are
1200 Argument requirements, output variables, defined macros.
1201 - M4sugar, M4sh, Autotest
1203 - Double quoting macros
1204 AC_TRY_CPP, AC_TRY_COMPILE, AC_TRY_LINK and AC_TRY_RUN.
1206 The Autoconf manual is now distributed under the terms of the GNU FDL.
1207 - Section `Hosts and Cross-Compilation'
1208 Explains the rationale for the 2.5x changes in the cross-compilation
1209 chain, and in the relationships between build, host, and target
1211 Emphasizes that `cross-compilation' == `--host is given'.
1212 If you are working on compilers etc., be sure to read this section.
1213 - Section `AC_LIBOBJ vs. LIBOBJS'
1214 Explains why assigning LIBOBJS directly is now an error.
1215 Details how to update the code.
1220 Now used instead of hard coded line numbers.
1221 This eases the comparison of `configure's, and diminishes the
1222 pressure over control version archives.
1223 Automatic replacement for shells that don't support this feature.
1224 - New output variables
1225 @builddir@, @top_builddir@, @abs_srcdir@, @abs_top_srcdir@, @abs_builddir@,
1230 Autoconf and Autotest modes are provided.
1235 New, used by the Autoconf suite to cache and speed up most processing.
1237 Supported by autom4te, autoconf and autoheader.
1239 Replaces --autoconf-dir and --localdir in autoconf, autoheader,
1240 autoupdate, and autoreconf.
1242 No longer passes --cygnus, --foreign, --gnits, --gnu, --include-deps:
1243 automake options are to be given via AUTOMAKE_OPTIONS.
1245 Runs gettextize and libtoolize when appropriate.
1247 --m4dir is no longer supported.
1249 Now runs only in the specified directories, defaulting to `.',
1250 but understands AC_CONFIG_SUBDIRS for dependent directories.
1251 Before, it used to run on all the `configure.ac' found in the
1253 Independent packages are properly updated.
1257 - The top level $prefix is propagated to the AC_CONFIG_SUBDIRS configures.
1259 Under the user pressure, $? is finally available. Probably a mistake.
1260 - AC_F77_LIBRARY_LDFLAGS now supports the HP/UX f90 compiler.
1261 - Precious variables accumulation
1262 config.status could stack several copies of the precious variables
1264 - AC_PATH_PROG and family.
1265 Works properly when given a literal path.
1267 Somewhere since 2.13, the result had been reversed.
1271 - AC_C_BIGENDIAN supports the cross-compiling case.
1272 - AC_C_BIGENDIAN accepts ACTION-IF-TRUE, ACTION-IF-FALSE, and
1273 ACTION-IF-UNKNOWN arguments. All are facultative, and the default
1274 for ACTION-IF-TRUE is to define WORDS_BIGENDIAN like AC_C_BIGENDIAN
1276 - AC_C_LONG_DOUBLE now succeeds only if `long double' has more range or
1277 precision than `double'.
1282 It now defines the preprocessor symbols PACKAGE_NAME,
1283 PACKAGE_TARNAME, PACKAGE_VERSION, PACKAGE_STRING, and
1287 Admits a fourth optional parameter: the tar name.
1289 - AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS.
1290 Provide the user with srcdir, ac_srcdir, ac_top_srcdir, ac_builddir,
1291 ac_top_builddir, ac_abs_srcdir, ac_abs_top_srcdir, ac_abs_builddir,
1292 ac_abs_top_builddir.
1294 - AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS and AC_OUTPUT.
1295 Are much less expensive when using long lists of files.
1298 Works with shell variables, and non alphanumeric names.
1302 - AC_FUNC_STRERROR_R now sets STRERROR_R_CHAR_P, not HAVE_WORKING_STRERROR_R,
1303 because POSIX 1003.1-200x draft 7 says strerror_r returns int, not char *.
1305 - AC_FUNC_STRTOD substitutes POW_LIB.
1310 * Major changes in Autoconf 2.52
1312 Released 2001-07-18 by Akim Demaille.
1317 This feature was present in autoconf 2.50 but was not documented.
1318 For example, `@<:@' is translated to `[' just before output. This
1319 is useful when writing strings that contain unbalanced quotes, or
1320 other hard-to-quote constructs.
1321 - m4_pattern_forbid, m4_pattern_allow
1322 - Tips for upgrading from 2.13.
1323 - Using autoscan to maintain a configure.ac.
1326 - Now include stdint.h.
1327 - sys/types.h and sys/stat.h are guarded.
1328 - strings.h is included if available, and not conflicting with string.h.
1331 - The test suite is more robust and presents less false failures.
1332 - Invocation of GNU M4 now robust to POSIXLY_CORRECT.
1333 - configure accepts --prefix='' again.
1334 - AC_CHECK_LIB works properly when its first argument is not a
1336 - HAVE_INTTYPES_H is defined only if not conflicting with sys/types.h.
1337 - build_, host_, and target_alias are AC_SUBST as in 2.13.
1338 - AC_ARG_VAR properly propagates precious variables inherited from the
1339 environment to ./config.status.
1340 - Using --program-suffix/--program-prefix is portable.
1341 - Failures to detect the default compiler's output extension are less
1343 - `config.status foo' works properly when `foo' depends on variables
1344 set in an AC_CONFIG_THING INIT-CMD.
1345 - autoheader is more robust to broken input.
1346 - Fixed Fortran name-mangling and link tests on a number of systems,
1347 e.g. NetBSD; see AC_F77_DUMMY_MAIN, below.
1350 - AC_CHECK_HEADER and AC_CHECK_HEADERS support a fourth argument to
1351 specify pre-includes. In this case, the headers are compiled with
1352 cc, not merely preprocessed by cpp. Therefore it is the _usability_
1353 of a header which is checked for, not just its availability.
1354 - AC_ARG_VAR refuses to run configure when precious variables have
1356 - Versions of compilers are dumped in the logs.
1357 - AC_CHECK_TYPE recognizes use of `foo_t' as a replacement type.
1360 - AC_PATH_XTRA only adds -ldnet to $LIBS if it's needed to link.
1361 - AC_FUNC_WAIT3 and AC_SYS_RESTARTABLE_SYSCALLS are obsoleted.
1362 - AM_FUNC_ERROR_AT_LINE, AM_FUNC_FNMATCH, AM_FUNC_MKTIME,
1363 AM_FUNC_OBSTACK, and AM_FUNC_STRTOD are now activated.
1364 Be sure to read `Upgrading from Version 2.13' to understand why
1365 running `autoupdate' is needed.
1366 - AC_F77_DUMMY_MAIN, AC_F77_MAIN: new macros to detect whether
1367 a main-like routine is required/possible when linking C/C++ with
1368 Fortran. Users of e.g. AC_F77_WRAPPERS should be aware of these.
1369 - AC_FUNC_GETPGRG behaves better when cross-compiling.
1371 * Major changes in Autoconf 2.51
1372 There was no release of Autoconf 2.51 since some packagers had used
1373 this version number without permission to ship intermediary versions
1374 of 2.50. The version was skipped to avoid confusion.
1376 * Major changes in Autoconf 2.50
1378 Released 2001-05-21 by Akim Demaille.
1380 ** Lots of bug fixes
1381 There have been far too many to enumerate them here. Check out
1382 ChangeLog if you really want to know more.
1384 ** Improved documentation
1385 In particular, portability issues are better covered.
1388 All the standard GNU Makefile targets are supported. The layout has
1389 changed: m4/ holds the M4 extensions Autoconf needs for its
1390 configuration, doc/ contains the documentation, and tests/ contains
1393 ** Man pages are provided
1394 For autoconf, autoreconf, autoupdate, autoheader, autoscan, ifnames,
1395 config.guess, config.sub.
1399 Provides a safe and powerful means to trace the macro uses. This
1400 provide the parsing layer for tools which need to `study'
1404 Specify what category of warnings should be enabled.
1406 - When recursing into subdirectories, try for configure.gnu before
1407 configure to adapt for packages not using autoconf on case-insensitive
1411 More errors are now caught (circular AC_REQUIRE dependencies,
1412 AC_DEFINE in the action part of an AC_CACHE_CHECK, too many pops
1413 etc.). In addition, their location and call stack are given.
1416 autoupdate is much more powerful, and is able to provide the glue code
1417 which might be needed to move from an old macro to its newer
1420 You are strongly encouraged to use it to modernize both your
1421 `configure.in' and your .m4 extension files.
1424 The internal machinery of autoheader has completely changed. As a
1425 result, using `acconfig.h' should be considered to be obsoleted, and
1426 you are encouraged to get rid of it using the AH macros.
1431 ** Fortran 77 compilers
1432 Globally, the support for Fortran 77 is considerably improved.
1434 Support for automatically determining a Fortran 77 compiler's
1435 name-mangling scheme. New CPP macros F77_FUNC and F77_FUNC_ are
1436 provided to wrap C/C++ identifiers, thus making it easier and more
1437 transparent for C/C++ to call Fortran 77 routines, and Fortran 77 to
1438 call C/C++ routines. See the Texinfo documentation for details.
1441 The test suite no longer uses DejaGNU. It should be easy to submit
1442 test cases in this new framework.
1445 - --help, --help=long, -hl
1446 no longer dumps useless items.
1448 lists only specific options.
1449 - --help=recursive, -hr
1450 displays the help of all the embedded packages.
1451 - Remembers environment variables when reconfiguring.
1452 The previous scheme to set envvar before running configure was
1454 what prevented configure from remembering the environment in which
1455 it was run, therefore --recheck was run in an inconsistent
1456 environment. Now, one should run
1458 and then --recheck will work properly. Variables declared with
1459 AC_ARG_VAR are also preserved.
1461 $build defaults to `config.guess`, $host to $build, and then $target
1463 Cross-compilation is a global status of the package, it no longer
1464 depends upon the current language.
1465 Cross compilation is enabled iff the user specified `--host'.
1466 `configure' now fails if it can't run the executables it compiles,
1467 unless cross-compilation is enabled.
1469 The cache file is disabled by default. The new options
1470 `--config-cache', `-C' set the cache to `config.cache'.
1474 Much faster on most architectures.
1475 - concurrent executions
1476 It is safe to use `make -j' with config.status.
1477 - human interface improved
1478 It is possible to invoke
1479 ./config.status foobar
1480 instead of the former form (still valid)
1481 CONFIG_COMMANDS= CONFIG_HEADERS= CONFIG_LINKS= \
1482 CONFIG_FILES=foobar:foo.in:bar.in \
1484 The same holds for configuration headers and links.
1485 You can instantiate unknown files and headers:
1486 ./config.status --header foo.h:foo.h.in --file bar:baz
1487 - has a useful --help
1488 - accepts special file name "-" for stdin/stdout
1493 Specify additional copyright information.
1496 Now expects the identity of the package as argument.
1500 Most macros, if not all, now strictly follow the `one quotation
1501 level' rule. This results in a more predictable expansion.
1504 A sly bug in the AC_REQUIRE machinery, which could produce incorrect
1505 configure scripts, was fixed by Axel Thimm.
1509 Document and ask for the registration of an envvar.
1512 Specifies the file which `configure' should look for when trying to
1513 find the source tree (used to be handled by AC_INIT).
1515 - AC_CONFIG_COMMANDS
1516 To add new actions to config.status. Should be used instead of
1520 Replaces AC_LINK_FILES.
1522 - AC_CONFIG_HEADERS, AC_CONFIG_COMMANDS, AC_CONFIG_SUBDIRS,
1523 AC_CONFIG_LINKS, and AC_CONFIG_FILES
1524 They now obey sh: you should no longer use shell variables as
1525 argument. Instead of
1527 test "$package_foo_enabled" = yes && $my_subdirs="$my_subdirs foo"
1528 AC_CONFIG_SUBDIRS($my_subdirs)
1532 if test "$package_foo_enabled" = yes; then
1533 AC_CONFIG_SUBDIRS(foo)
1537 To format an Autoconf macro's help string so that it looks pretty
1538 when the user executes `configure --help'.
1541 ** Generic Test Macros
1543 The interface of the AC_CHECK families of macros (decl, header,
1544 type, member, func) is now uniform. They support the same set of
1547 - AC_CHECK_DECL, AC_CHECK_DECLS
1548 To check whether a symbol is declared.
1550 - AC_CHECK_SIZEOF, AC_C_CHAR_UNSIGNED.
1551 No longer need a cross-compilation default.
1554 The test it performs is much more robust than previously, and makes
1555 it possible to test builtin types in addition to typedefs.
1556 It is now schizophrenic:
1557 - AC_CHECK_TYPE(TYPE, REPLACEMENT)
1558 remains for backward compatibility, but its use is discouraged.
1559 - AC_CHECK_TYPE(TYPE, IF-FOUND, IF-NOT-FOUND, INCLUDES)
1560 behaves exactly like the other AC_CHECK macros.
1563 Checks whether given types are supported by the system.
1565 - AC_CHECK_MEMBER, AC_CHECK_MEMBERS
1566 Check for given members in aggregates (e.g., pw_gecos in struct
1570 Checks if the compiler supports ISO C, included when needs special
1574 Checking whether the preprocessor indicates missing includes by the
1575 error code. stderr is checked by AC_TRY_CPP only as a fallback.
1578 Takes a language as argument and replaces AC_LANG_C,
1579 AC_LANG_CPLUSPLUS and AC_LANG_FORTRAN77.
1581 - AC_LANG_PUSH, AC_LANG_POP
1582 Are preferred to AC_LANG_SAVE, AC_LANG_RESTORE.
1585 - AC_FUNC_CHOWN, AC_FUNC_MALLOC, AC_FUNC_STRERROR_R,
1586 AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK, AC_FUNC_STAT, AC_FUNC_LSTAT,
1587 AC_FUNC_ERROR_AT_LINE, AC_FUNC_OBSTACK, AC_FUNC_STRTOD, AC_FUNC_FSEEKO.
1591 Sets GETGROUPS_LIBS.
1593 - AC_FUNC_GETLOADAVG
1594 Defines `HAVE_STRUCT_NLIST_N_UN_N_NAME' instead of `NLIST_NAME_UNION'.
1597 Now integrates `AC_DECL_YYTEXT' which is obsoleted.
1600 Arrange for large-file support.
1602 - AC_EXEEXT, AC_OBJEXT
1603 You are no longer expected to use them: their computation is
1604 performed by default.
1606 ** C++ compatibility
1607 Every macro has been revisited in order to support at best CC=c++.
1609 Major changes in Autoconf 2.14:
1610 There was no release of GNU Autoconf 2.14.
1612 Major changes in Autoconf 2.13:
1614 Released 1999-05-01 by Ben Elliston.
1616 * Support for building on Win32 systems where the only available C or
1617 C++ compiler is the Microsoft Visual C++ command line compiler
1618 (`cl'). Additional support for building on Win32 systems which are
1619 using the Cygwin or Mingw32 environments.
1620 * Support for alternative object file and executable file extensions.
1621 On Win32, for example, these are .obj and .exe. These are discovered
1622 using AC_OBJEXT and AC_EXEEXT, which substitute @OBJEXT@ and
1623 @EXEEXT@ in the output, respectively.
1624 * New macros: AC_CACHE_LOAD, AC_CACHE_SAVE, AC_FUNC_SELECT_ARGTYPES,
1625 AC_VALIDATE_CACHED_SYSTEM_TUPLE, AC_SEARCH_LIBS, AC_TRY_LINK_FUNC,
1626 AC_C_STRINGIZE, AC_CHECK_FILE(S), AC_PROG_F77 (and friends).
1627 * AC_DEFINE now has an optional third argument for a description to be
1628 placed in the config header input file (e.g. config.h.in).
1629 * The C++ code fragment compiled for the C++ compiler test had to be
1630 improved to include an explicit return type for main(). This was
1631 causing failures on systems using recent versions of the EGCS C++
1633 * Fixed an important bug in AC_CHECK_TYPE that would cause a configure
1634 script to report that `sometype_t' was present when only `type_t'
1636 * Merge of the FSF version of config.guess and config.sub to modernize
1637 these scripts. Add support for a few new hosts in config.guess.
1638 Incorporate latest versions of install-sh, mkinstalldirs and
1639 texinfo.tex from the FSF.
1640 * autoreconf is capable of running automake if necessary (and
1642 * Support for Fortran 77. See the Texinfo documentation for details.
1643 * Bug fixes and workarounds for quirky bugs in vendor utilities.
1645 Major changes in Autoconf 2.12:
1647 Released 1996-11-26 by David J. MacKenzie
1649 * AC_OUTPUT and AC_CONFIG_HEADER can create output files by
1650 concatenating multiple input files separated by colons, like so:
1651 AC_CONFIG_HEADER(config.h:conf.pre:config.h.in:conf.post)
1652 AC_OUTPUT(Makefile:Makefile.in:Makefile.rules)
1653 The arguments may be shell variables, to compute the lists on the fly.
1654 * AC_LINK_FILES and AC_CONFIG_SUBDIRS may be called multiple times.
1655 * New macro AC_OUTPUT_COMMANDS adds more commands to run in config.status.
1658 Major changes in Autoconf 2.11:
1660 Released November 18th, 1996, by David J. MacKenzie
1662 * AC_PROG_CC and AC_PROG_CXX check whether the compiler works.
1663 They also default CFLAGS/CXXFLAGS to "-g -O2" for gcc, instead of "-g -O".
1664 * AC_REPLACE_FUNCS defines HAVE_foo if the system has the function `foo'.
1665 * AC_CONFIG_HEADER expands shell variables in its argument.
1666 * New macros: AC_FUNC_FNMATCH, AC_FUNC_SETPGRP.
1667 * The "checking..." messages and the source code for test programs that
1668 fail are saved in config.log.
1669 * Another workaround has been added for seds with small command length limits.
1670 * config.sub and config.guess recognize more system types.
1673 Major changes in Autoconf 2.10:
1675 Released May 7th, 1996, by Roland McGrath
1678 * The cache variable names used by `AC_CHECK_LIB(LIB, FUNC, ...)' has
1679 changed: now $ac_cv_lib_LIB_FUNC, previously $ac_cv_lib_LIB.
1681 Major changes in Autoconf 2.9:
1683 Released March 16th, 1996, by Roland McGrath
1687 Major changes in Autoconf 2.8:
1689 Released March 8th, 1996, by Roland McGrath
1693 Major changes in Autoconf 2.7:
1695 Released November 22nd, 1995, by David J. MacKenzie
1699 Major changes in Autoconf 2.6:
1701 Released November 20th, 1995, by David J. MacKenzie
1705 Major changes in Autoconf 2.5:
1707 Released November 17th, 1995, by Roland McGrath
1709 * New configure options --bindir, --libdir, --datadir, etc., with
1710 corresponding output variables.
1711 * New macro: AC_CACHE_CHECK, to make using the cache easier.
1712 * config.log contains the command being run as well as any output from it.
1713 * AC_CHECK_LIB can check for libraries with "." or "/" or "+" in their name.
1714 * AC_PROG_INSTALL doesn't cache a name for install-sh, for sharing caches.
1715 * AC_CHECK_PROG, AC_PATH_PROG, AC_CHECK_PROGS, AC_PATH_PROGS, and
1716 AC_CHECK_TOOL can search a path other than $PATH.
1717 * AC_CHECK_SIZEOF takes an optional size to use when cross-compiling.
1719 Major changes in Autoconf 2.4:
1721 Released June 14th, 1995, by David J. MacKenzie
1723 * Fix a few bugs found by Emacs testers.
1725 Major changes in Autoconf 2.3:
1727 Released March 27th, 1995, by David J. MacKenzie
1729 * Fix the cleanup trap in several ways.
1730 * Handle C compilers that are picky about option placement.
1731 * ifnames gets the version number from the right directory.
1733 Major changes in Autoconf 2.2:
1735 Released March 8th, 1995, by David J. MacKenzie
1737 * The ifnames utility is much faster but requires a "new awk" interpreter.
1738 * AC_CHECK_LIB and AC_HAVE_LIBRARY check and add the new
1739 library before existing libs, not after, in case it uses them.
1740 * New macros: AC_FUNC_GETPGRP, AC_CHECK_TOOL.
1741 * Lots of bug fixes.
1742 * Many additions to the TODO file :-)
1744 Major changes in Autoconf 2.1:
1746 Released November 4th, 1994, by David J. MacKenzie
1749 * More explanations in the manual.
1750 * Fix a spurious failure in the testsuite.
1751 * Clarify some warning messages.
1752 * autoreconf by default only rebuilds configure and config.h.in files
1753 that are older than any of their particular input files; there is a
1754 --force option to use after installing a new version of Autoconf.
1756 Thanks to everybody who's submitted changes and additions to Autoconf!
1757 I've incorporated many of them, and am still considering others for
1758 future releases -- but I didn't want to postpone this release indefinitely.
1760 Caution: don't indiscriminately rebuild configure scripts with
1761 Autoconf version 2. Some configure.in files need minor adjustments to
1762 work with it; the documentation has a chapter on upgrading. A few
1763 configure.in files, including those for GNU Emacs and the GNU C
1764 Library, need major changes because they relied on undocumented
1765 internals of version 1. Future releases of those packages will have
1766 updated configure.in files.
1768 It's best to use GNU M4 1.3 (or later) with Autoconf version 2.
1769 Autoconf now makes heavy use of M4 diversions, which were implemented
1770 inefficiently in GNU M4 releases before 1.3.
1772 Major changes in Autoconf 2.0:
1774 Released October 26th, 1994, by David J. MacKenzie
1776 ** New copyright terms:
1777 * There are no restrictions on distribution or use of configure scripts.
1780 * Autoconf manual is reorganized to make information easier to find
1781 and has several new indexes.
1782 * INSTALL is reorganized and clearer and is now made from Texinfo source.
1785 * autoscan to generate a preliminary configure.in for a package by
1786 scanning its source code for commonly used nonportable functions,
1787 programs, and header files.
1788 * ifnames to list the symbols used in #if and #ifdef directives in a
1790 * autoupdate to update a configure.in to use the version 2 macro names.
1791 * autoreconf to recursively remake configure and configuration header
1792 files in a source tree.
1794 ** Changed utilities:
1795 * autoheader can take pieces of acconfig.h to replace config.h.{top,bot}.
1796 * autoconf and autoheader can look for package-local definition files
1797 in an alternate directory.
1800 * AC_CACHE_VAL to share results of tests between configure runs.
1801 * AC_DEFUN to define macros, automatically AC_PROVIDE them, and ensure
1802 that macros invoked with AC_REQUIRE don't interrupt other macros.
1803 * AC_CONFIG_AUX_DIR, AC_CANONICAL_SYSTEM, AC_CANONICAL_HOST, AC_LINK_FILES to
1804 support deciding unguessable features based on the host and target types.
1805 * AC_CONFIG_SUBDIRS to recursively configure a source tree.
1806 * AC_ARG_PROGRAM to use the options --program-prefix,
1807 --program-suffix, and --program-transform-name to change the names
1808 of programs being installed.
1809 * AC_PREFIX_DEFAULT to change the default installation prefix.
1810 * AC_TRY_COMPILE to compile a test program without linking it.
1811 * AC_CHECK_TYPE to check whether sys/types.h or stdlib.h defines a given type.
1812 * AC_CHECK_LIB to check for a particular function and library.
1813 * AC_MSG_CHECKING and AC_MSG_RESULT to print test results, on a single line,
1814 whether or not the test succeeds. They obsolete AC_CHECKING and AC_VERBOSE.
1815 * AC_SUBST_FILE to insert one file into another.
1816 * AC_FUNC_MEMCMP to check whether memcmp is 8-bit clean.
1817 * AC_FUNC_STRFTIME to find strftime even if it's in -lintl.
1818 * AC_FUNC_GETMNTENT to find getmntent even if it's in -lsun or -lseq.
1819 * AC_HEADER_SYS_WAIT to check whether sys/wait.h is POSIX.1 compatible.
1822 * Many macros renamed systematically, but old names are accepted for
1823 backward compatibility.
1824 * AC_OUTPUT adds the "automatically generated" comment to
1825 non-Makefiles where it finds @configure_input@ in an input file, to
1826 support files with various comment syntaxes.
1827 * AC_OUTPUT does not replace "prefix" and "exec_prefix" in generated
1828 files when they are not enclosed in @ signs.
1829 * AC_OUTPUT allows the optional environment variable CONFIG_STATUS to
1830 override the file name "config.status".
1831 * AC_OUTPUT takes an optional argument for passing variables from
1832 configure to config.status.
1833 * AC_OUTPUT and AC_CONFIG_HEADER allow you to override the input-file names.
1834 * AC_OUTPUT automatically substitutes the values of CFLAGS, CXXFLAGS,
1835 CPPFLAGS, and LDFLAGS from the environment.
1836 * AC_PROG_CC and AC_PROG_CXX now set CFLAGS and CXXFLAGS, respectively.
1837 * AC_PROG_INSTALL looks for install-sh or install.sh in the directory
1838 specified by AC_CONFIG_AUXDIR, or srcdir or srcdir/.. or
1839 srcdir/../.. by default.
1840 * AC_DEFINE, AC_DEFINE_UNQUOTED, and AC_SUBST are more robust and smaller.
1841 * AC_DEFINE no longer prints anything, because of the new result reporting
1842 mechanism (AC_MSG_CHECKING and AC_MSG_RESULT).
1843 * AC_VERBOSE pays attention to --quiet/--silent, not --verbose.
1844 * AC_ARG_ENABLE and AC_ARG_WITH support whitespace in the arguments to
1845 --enable- and --with- options.
1846 * AC_CHECK_FUNCS and AC_CHECK_HEADERS take optional shell commands to
1847 execute on success or failure.
1848 * Checking for C functions in C++ works.
1851 * AC_REMOTE_TAPE and AC_RSH removed; too specific to tar and cpio, and
1852 better maintained with them.
1853 * AC_ARG_ARRAY removed because no one was likely using it.
1854 * AC_HAVE_POUNDBANG replaced with AC_SYS_INTERPRETER, which doesn't
1855 take arguments, for consistency with all of the other specific checks.
1858 * Comes with config.sub and config.guess, and uses them optionally.
1859 * Uses config.cache to cache test results. An alternate cache file
1860 can be selected with the --cache-file=FILE option.
1861 * Uses optional shell scripts $prefix/share/config.site and
1862 $prefix/etc/config.site to perform site or system specific initializations.
1863 * configure saves compiler output to ./config.log for debugging.
1864 * New files autoconf.m4 and autoheader.m4 load the other Autoconf macros.
1865 * acsite.m4 is the new name for the system-wide aclocal.m4.
1866 * Has a DejaGnu test suite.
1868 Major changes in Autoconf 1.11:
1870 * AC_PROG_INSTALL calls install.sh with the -c option.
1871 * AC_SET_MAKE cleans up after itself.
1872 * AC_OUTPUT sets prefix and exec_prefix if they weren't set already.
1873 * AC_OUTPUT prevents shells from looking in PATH for config.status.
1875 Plus a few other bug fixes.
1877 Major changes in Autoconf 1.10:
1879 * autoheader uses config.h.bot if present, analogous to config.h.top.
1880 * AC_PROG_INSTALL looks for install.sh in srcdir or srcdir/.. and
1882 * AC_PROG_CXX looks for cxx as a C++ compiler.
1884 Plus several bugs fixed.
1886 Major changes in Autoconf 1.9:
1888 * AC_YYTEXT_POINTER replaces AC_DECLARE_YYTEXT.
1889 * AC_SIZEOF_TYPE generates the cpp symbol name automatically,
1890 and autoheader generates entries for those names automatically.
1891 * AC_FIND_X gets the result from xmkmf correctly.
1892 * AC_FIND_X assumes no X if --without-x was given.
1893 * AC_FIND_XTRA adds libraries to the variable X_EXTRA_LIBS.
1894 * AC_PROG_INSTALL finds OSF/1 installbsd.
1896 Major changes in Autoconf 1.8:
1899 * New macros AC_LANG_C, AC_LANG_CPLUSPLUS, AC_LANG_SAVE, AC_LANG_RESTORE,
1900 AC_PROG_CXX, AC_PROG_CXXCPP, AC_REQUIRE_CPP
1901 for checking both C++ and C features in one configure script.
1902 * New macros AC_CHECKING, AC_VERBOSE, AC_WARN, AC_ERROR for printing messages.
1903 * New macros AC_FIND_XTRA, AC_MMAP, AC_SIZEOF_TYPE, AC_PREREQ,
1904 AC_SET_MAKE, AC_ENABLE.
1907 * AC_FIND_X looks for X in more places.
1908 * AC_PROG_INSTALL defaults to install.sh instead of cp, if it's in srcdir.
1909 install.sh is distributed with Autoconf.
1910 * AC_DECLARE_YYTEXT has been removed because it can't work, pending
1911 a rewrite of quoting in AC_DEFINE.
1912 * AC_OUTPUT adds its comments in C format when substituting in C files.
1913 * AC_COMPILE_CHECK protects its ECHO-TEXT argument with double quotes.
1915 ** New or changed command line options:
1916 * configure accepts --enable-FEATURE[=ARG] and --disable-FEATURE options.
1917 * configure accepts --without-PACKAGE, which sets withval=no.
1918 * configure accepts --x-includes=DIR and --x-libraries=DIR.
1919 * Giving --with-PACKAGE no argument sets withval=yes instead of withval=1.
1920 * configure accepts --help, --version, --silent/--quiet, --no-create options.
1921 * configure accepts and ignores most other Cygnus configure options, and
1922 warns about unknown options.
1923 * config.status accepts --help, --version options.
1925 ** File names and other changes:
1926 * Relative srcdir values are not made absolute.
1927 * The values of @prefix@ and @exec_prefix@ and @top_srcdir@ get substituted.
1928 * Autoconf library files are installed in ${datadir}/autoconf, not ${datadir}.
1929 * autoheader optionally copies config.h.top to the beginning of config.h.in.
1930 * The example Makefile dependencies for configure et al. work better.
1931 * Namespace cleanup: all shell variables used internally by Autoconf
1932 have names beginning with `ac_'.
1934 More big improvements are in process for future releases, but have not
1935 yet been (variously) finished, integrated, tested, or documented enough
1938 Major changes in Autoconf 1.7:
1940 * New macro AC_OBSOLETE.
1941 * Bugs in Makefile.in fixed.
1942 * AC_LONG_FILE_NAMES improved.
1944 Major changes in Autoconf 1.6:
1946 * New macro AC_LONG_64_BITS.
1947 * Multiple .h files can be created.
1948 * AC_FIND_X looks for X files directly if it doesn't find xmkmf.
1949 * AC_ALLOCA defines C_ALLOCA if using alloca.c.
1950 * --with-NAME can take a value, e.g., --with-targets=sun4,hp300bsd.
1951 * Unused --no-create option to configure removed.
1952 * autoheader doesn't change the timestamp of its output file if
1953 the file didn't change.
1954 * All macros that look for libraries now use AC_HAVE_LIBRARY.
1955 * config.status checks three optional environment variables to
1956 modify its behavior.
1957 * The usual bug fixes.
1959 Major changes in Autoconf 1.5:
1961 * New macros AC_FIND_X, AC_OFF_T, AC_STAT_MACROS_BROKEN, AC_REVISION.
1962 * autoconf and autoheader scripts have GNU standards conforming
1963 --version and --help options (they print their message and exit).
1966 Major changes in Autoconf 1.4:
1968 * New macros AC_HAVE_POUNDBANG, AC_TIME_WITH_SYS_TIME, AC_LONG_DOUBLE,
1969 AC_GETGROUPS_T, AC_DEFINE_UNQUOTED.
1970 * autoconf and autoheader use the M4 environment variable to determine the
1971 name of the M4 program to use.
1972 * The --macrodir option to autoconf and autoheader specifies the directory
1973 in which acspecific.m4, acgeneral.m4, etc. reside if not the default.
1974 * autoconf and autoheader can take `-' as their file names, which means to
1975 read stdin as input.
1976 * Resulting configure scripts can take a --verbose option which causes them
1977 to print the results of their tests.
1978 * AC_DEFINE quotes its second argument in such a way that spaces, magic
1979 shell characters, etc. will be preserved during various stages of
1980 expansion done by the shell. If you don't want this, use
1981 AC_DEFINE_UNQUOTED instead.
1982 * Much textual processing done with external calls to tr and sed have been
1983 internalized with builtin M4 `patsubst' and `translit' calls.
1984 * AC_OUTPUT doesn't hardwire the file names it outputs. Instead, you can
1985 set the shell variables `gen_files' and `gen_config' to the list of
1986 file names to output.
1987 * AC_DECLARE_YYTEXT does an AC_SUBST of `LEX_OUTPUT_ROOT', which may be
1988 "lex.yy" or "lexyy", depending on the system.
1989 * AC_PROGRAMS_CHECK takes an optional third arg. If given, it is used as
1991 * If AC_ALLOCA chooses alloca.c, it also defines STACK_DIRECTION.
1992 * AC_CONST works much more reliably on more systems.
1995 Major changes in Autoconf 1.3:
1997 configure no longer requires awk for packages that use a config.h.
1998 Support handling --with-PACKAGE options.
1999 New `autoheader' script to create `config.h.in' from `configure.in'.
2000 Ignore troublesome -lucb and -lPW when searching for alloca.
2001 Rename --exec_prefix to --exec-prefix for GNU standards conformance.
2002 Improve detection of STDC library.
2003 Add AC_HAVE_LIBRARY to check for non-default libraries.
2004 Function checking should work with future GNU libc releases.
2006 Major changes in Autoconf 1.2:
2008 The --srcdir option is now usually unnecessary.
2009 Add a file containing sample comments describing CPP macros.
2010 A comment in config.status tells which host it was configured on.
2011 Substituted variable values can now contain commas.
2012 Fix bugs in various feature checks.
2014 Major changes in Autoconf 1.1:
2016 Added AC_STRCOLL macro.
2017 Made AC_GETLOADAVG check for more things.
2018 AC_OUTPUT argument is now optional.
2023 Copyright (C) 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001, 2002,
2024 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation,
2027 Copying and distribution of this file, with or without modification,
2028 are permitted in any medium without royalty provided the copyright
2029 notice and this notice are preserved. This file is offered as-is,
2030 without warranty of any kind.