1 GNU Autoconf NEWS - User visible changes.
3 * Major changes in Autoconf 2.64 (2009-??-??) [stable]
4 Released by Eric Blake, based on git versions 2.63b.*.
6 ** AS_IF, AS_CASE, and AS_FOR have been taught to avoid syntax errors
7 even when given arguments that expand to just whitespace.
9 ** Ensure AT_CHECK can support commands that include a # given with
10 proper m4 quoting. For shell comments, this is a new feature; for
11 non-shell comments, this fixes a regression introduced in 2.63b.
12 Additionally, AT_CHECK correctly supplies shell escapes for
13 metacharacters occurring in m4 macro expansions within the expected
14 stdout and stderr parameters.
16 ** The macro AT_CHECK now understands the concept of hard failure. If
17 a test exits with an unexpected status 99, cleanup actions for the
18 test are inhibited and the test is treated as a failure regardless
19 of AT_XFAIL_IF. It also understands the new directives
20 ignore-nolog, stdout-nolog, and stderr-nolog.
22 ** The following documented autotest macros are new:
25 ** The following documented m4sugar macros are new:
26 m4_argn m4_default_nblank m4_default_nblank_quoted m4_ifblank
29 * Major changes in Autoconf 2.63b (2009-03-31) [beta]
30 Released by Eric Blake, based on git versions 2.63.*.
32 ** The manual is now shipped under the terms of the GNU FDL 1.3.
34 ** AC_REQUIRE now detects the case of an outer macro which first expands
35 then later indirectly requires the same inner macro. Previously,
36 this case led to silent out-of-order expansion (bug present since
37 2.50); it now issues a syntax warning, and duplicates the expansion
38 of the inner macro to guarantee dependencies have been met. See
39 the manual for advice on how to refactor macros in order to avoid
40 the bug in earlier autoconf versions and avoid increased script
41 size in the current version.
43 ** AC_DEFUN_ONCE has improved semantics. Previously, a macro declared
44 with AC_DEFUN_ONCE warned on a second invocation; and out-of-order
45 expansion was still possible. Now, dependencies are guaranteed,
46 and subsequent invocations are a silent no-op. This makes
47 AC_DEFUN_ONCE an ideal macro for silencing AC_REQUIRE warnings.
49 ** The following macros are now defined with AC_DEFUN_ONCE. This means
50 a subtle change in semantics; previously, an AC_DEFUN macro could
51 expand one of these macros multiple times or surround the macro
52 inside shell conditional text to bypass the effects of these
53 macros, but now the macro will expand exactly once, and prior to
54 the start of any enclosing AC_DEFUN macro:
55 AC_CANONICAL_BUILD AC_CANONICAL_HOST AC_CANONICAL_TARGET
56 AC_HEADER_ASSERT AC_PROG_INSTALL AC_PROG_MKDIR_P
57 AC_USE_SYSTEM_EXTENSIONS
59 ** AC_LANG_ERLANG works once again (regression introduced in 2.61a).
61 ** AC_HEADER_ASSERT is fixed so that './configure --enable-assert' no
62 longer mistakenly disables assertions.
64 ** AC_INIT now takes an optional fifth parameter that can be used to
65 set AC_PACKAGE_URL, a URL for the package's home page; the URL is
66 used in `configure --help' and is also available via AC_DEFINE.
68 ** Autotest testsuites accept an option --jobs[=N] for parallel testing.
69 This feature is still in testing, and may not work on every
70 platform, help in improving it would be appreciated.
72 ** Autotest testsuites do not attempt to write startup error messages
73 to the log file before that is opened (regression introduced in 2.63).
75 ** Configure scripts now use shell functions. This feature leads to
76 smaller configure files and faster execution.
78 ** Present But Cannot Be Compiled: Autoconf will now proceed with
79 the compiler's result if a header is present but cannot be compiled.
80 The warning is still printed, and you should really fix it by
81 providing a fourth parameter to AC_CHECK_HEADER/AC_CHECK_HEADERS.
83 ** Autoreconf added aclocal to the set of programs affected by the
84 `autoreconf -I dir' option.
86 ** The following documented m4sugar macros are new:
87 m4_chomp m4_chomp_all m4_cleardivert m4_curry m4_default_quoted
88 m4_esyscmd_s m4_map_args m4_map_args_pair m4_map_args_sep
89 m4_map_args_w m4_set_map m4_set_map_sep m4_stack_foreach
90 m4_stack_foreach_lifo m4_stack_foreach_sep
91 m4_stack_foreach_sep_lifo
93 ** The following m4sugar macros are documented now, but in some cases
94 with slightly different semantics than what the previous
95 undocumented version had:
96 m4_copy m4_dumpdefs m4_rename m4_version_prereq
98 ** The m4sugar macro m4_expand has been taught to handle unterminated
99 comments and shell case statements. As a result, it is used
100 internally in more places, such as AC_DEFINE and AT_CHECK. Most
101 uses of AC_DEFINE and AT_CHECK should not behave any differently;
102 however, it may be necessary to add double-quoting around
103 unbalanced `(' where single-quoting used to be sufficient.
105 ** The following documented m4sh macros are new:
106 AS_INIT_GENERATED AS_LINENO_PREPARE AS_ME_PREPARE AS_SET_STATUS
107 AS_VAR_APPEND AS_VAR_ARITH AS_VAR_COPY
109 ** The following m4sh macros are documented now, but in some cases
110 with slightly different semantics than what the previous
111 undocumented version had:
112 AS_ECHO AS_ECHO_N AS_ESCAPE AS_EXIT AS_LITERAL_IF AS_UNSET
113 AS_VAR_IF AS_VAR_POPDEF AS_VAR_PUSHDEF AS_VAR_SET AS_VAR_SET_IF
114 AS_VAR_TEST_SET AS_VERSION_COMPARE
116 ** The m4sh macros AS_IF and AS_CASE can now be used in shell lists.
117 The responsibility for supplying a trailing newline now belongs to
118 the call site, but since most users did not add dnl, this generally
119 results in fewer empty lines in configure.
122 * Major changes in Autoconf 2.63 (2008-09-09) [stable]
123 Released by Eric Blake, based on git versions 2.62.*.
125 ** AC_C_BIGENDIAN does not mistakenly report "universal" for some
126 bigendian hosts, a regression introduced with universal binary
129 ** AC_PATH_X now includes /lib64 and /usr/lib64 in its list of default
132 ** AC_USE_SYSTEM_EXTENSIONS no longer conflicts with an external
133 AC_DEFINE([__EXTENSIONS__]). This fixes a regression introduced in
134 2.62 when using macros such as AC_AIX that were made obsolete in
135 favor of the more portable AC_USE_SYSTEM_EXTENSIONS.
137 ** AC_CHECK_TARGET_TOOLS is usable in the non-cross-compile case.
139 ** Newly obsolete macros
140 The following macro has been marked obsolete, since current porting
141 targets can safely assume C89 semantics that signal handlers return
142 void. We have no current plans to remove the macro.
146 ** The macros m4_map and m4_map_sep now ignore any list elements
147 consisting of just empty quotes, and m4_map_sep now expands its
148 separator. This fixes a regression in 2.62 when these macros were
149 first documented, for the sake of clients expecting the semantics
150 that these macros had prior to that time. The new macros m4_mapall
151 and m4_mapall_sep, along with extra quoting of the separator, can
152 be used to get the semantics that m4_map_sep had in 2.62.
154 ** Clients of m4_expand, such as AS_HELP_STRING and AT_SETUP, can now
155 handle properly quoted but otherwise unbalanced parentheses (for
156 some macros, this fixes a regression in 2.62).
158 ** Two new quadrigraphs have been introduced: @{:@ for (, and @:}@ for ),
159 allowing the output of unbalanced parentheses in more contexts.
161 ** The following m4sugar macros are new:
162 m4_cleardivert m4_joinall m4_mapall m4_mapall_sep m4_reverse
163 m4_set_add m4_set_add_all m4_set_contains m4_set_contents
164 m4_set_delete m4_set_difference m4_set_dump m4_set_empty
165 m4_set_foreach m4_set_intersection m4_set_list m4_set_listc
166 m4_set_remove m4_set_size m4_set_union
168 ** The following m4sugar macros now accept multiple arguments, as is the
169 case with underlying m4:
170 m4_defn m4_popdef m4_undefine
172 ** The following m4sugar macros now guarantee linear scaling; they
173 previously had linear scaling with m4 1.6 but quadratic scaling
174 when using m4 1.4.x. All macros built on top of these also gain
175 the scaling improvements.
176 m4_bmatch m4_bpatsubsts m4_case m4_cond m4_do m4_dquote_elt
177 m4_foreach m4_join m4_list_cmp m4_map m4_map_sep m4_max
180 ** AT_KEYWORDS once again performs expansion on its argument, such that
181 AT_KEYWORDS([m4_if([$1], [], [default])]) no longer complains about
182 the possibly unexpanded m4_if [regression introduced in 2.62].
184 ** Config header templates `#undef UNDEFINED /* comment */' do not lead to
185 nested comments any more; regression introduced in 2.62.
188 * Major changes in Autoconf 2.62 (2008-04-05) [stable]
189 Released by Eric Blake, based on git versions 2.61a.*.
191 ** Many optimizations have been applied to make overall execution faster.
193 ** Autotest now makes use of shell functions.
195 ** config.status now uses awk instead of sed also for config headers.
197 - As a side effect, AC_DEFINE and AC_DEFINE_UNQUOTED now handle multi-line
198 values, i.e., backslash-newline combinations are handled correctly.
199 Further, for config headers, the total size of values is not limited by
200 the POSIX length limit of text lines any more, only each single line.
202 ** New config variable `top_build_prefix'.
204 ** New Autoconf macros:
205 AC_AUTOCONF_VERSION AC_OPENMP AC_PATH_PROGS_FEATURE_CHECK
207 ** AC_C_BIGENDIAN now supports universal binaries a la Mac OS X.
209 ** AC_C_RESTRICT now prefers to #define 'restrict' to a variant spelling
210 like '__restrict' if the variant spelling is available, as this is
211 more likely to work when mixing C and C++ code.
213 ** AC_CHECK_ALIGNOF's type argument T is now documented better: it must
214 be a string of tokens such that "T y;" is a valid member declaration
217 ** AC_CHECK_SIZEOF now accepts objects as well as types: the general rule
218 is that sizeof (X) works, then AC_CHECK_SIZEOF (X) should work.
220 ** AC_CHECK_TYPE and AC_CHECK_TYPES now work on any C type-name; formerly,
221 they did not work for function types. In C++, they now work on any
222 type-id that can be the operand of sizeof; this is similar to C,
223 except it excludes anonymous struct and union types. Formerly,
224 some (but not all) C++ types involving anonymous struct and union
225 were accepted, though this was not documented.
227 ** AC_CONFIG_LINKS now prefers to link against files in the build tree
228 if found, and it works to link against a file of the same name in
229 the source tree, even if both trees coincide.
231 ** AC_INIT no longer alters $@; regression introduced in 2.60.
233 ** AC_USE_SYSTEM_EXTENSIONS now defines _ALL_SOURCE for Interix platforms.
235 ** AS_HELP_STRING no longer underquotes its first argument; it also handles
236 the case where the first argument contains single-quoted commas.
237 For example, "AS_HELP_STRING([-a, [--arg[=foo]]], [bar])" produces:
238 " -a, --arg[=foo] bar"
239 Additionally, the macro now takes two additional arguments,
240 indent-column and wrap-column; these should not normally be needed,
241 but can be used to fine-tune how the output text is wrapped.
243 ** AC_PROG_INSTALL now requires an install program that can install multiple
244 files into a target directory.
246 ** The command 'autoconf -' now correctly processes a file from stdin.
248 ** 'autoreconf -m' now honors $MAKE.
250 ** For all of the directory arguments for 'configure', such as '--prefix'
251 or '--bindir', trailing slashes are stripped. As an example, if
252 tab completion in the user's shell appends trailing slashes, the
253 command './configure --prefix=/usr/' will still result in an
254 expanded libdir value of /usr/lib, not /usr//lib.
256 ** `configure --help=recursive' now works in read-only trees and from
257 unconfigured build trees.
259 ** If precious variables differ only in whitespace, then the cache consistency
260 check warns instead of fails, and reuses the old value.
262 ** AT_BANNER is now documented.
264 ** AT_SETUP now handles macro expansions properly when calculating line
267 ** Autotest now determines $srcdir correctly.
269 ** Testsuites built by autotest now accept a -C/--directory=DIR option
270 to adjust the working directory prior to creating files.
272 ** Autoconf now requires GNU M4 1.4.5 or later. Earlier versions of M4 have
273 a bug in macro tracing that interferes with the interaction between
274 Autoconf and Automake. GNU M4 1.4.11 or later is recommended. The
275 configure search for a working M4 is improved.
277 ** For portability with the eventual M4 2.0, macros should no longer use
278 anything larger than $9 to refer to arguments.
280 ** Documentation for m4sugar is improved.
282 - The following macros were previously available as undocumented
283 interfaces; the macros are now documented as stable interfaces.
285 __oline__ m4_assert m4_bmatch m4_bpatsubsts m4_car m4_case
286 m4_cdr m4_default m4_divert_once m4_divert_pop m4_divert_push
287 m4_divert_text m4_do m4_errprintn m4_fatal m4_flatten
288 m4_ifndef m4_ifset m4_ifval m4_ifvaln m4_location
289 m4_n m4_shiftn m4_strip m4_warn
291 - The following macros were previously available as undocumented
292 interfaces, but had bug fixes or semantic changes as part of this
293 release. Packages that relied on the undocumented behavior
294 should be analyzed to make sure they will still work with the
295 new documented behavior.
297 m4_cmp m4_list_cmp m4_join m4_map m4_map_sep m4_sign
298 m4_text_box m4_text_wrap m4_version_compare
300 - The m4_wrap macro used to have unspecified order, but now
301 guarantees FIFO order. m4_wrap_lifo was added to guarantee LIFO
304 - Packages using the undocumented m4sugar macro m4_PACKAGE_VERSION
305 should consider using the new AC_AUTOCONF_VERSION instead.
307 - m4sugar macros that are not documented in the manual are still
308 deemed experimental, and should not be used outside of Autoconf.
310 ** The m4sugar macros m4_append and m4_append_uniq, first documented in
311 2.60, have been fixed to treat both the string and the separator
312 arguments consistently with regards to quoting. Prior to this fix,
313 m4_append_uniq could mistakenly duplicate entries if the expansion
314 of the separator resulted in a different string (for example, if it
315 contained quotes, a comma, or a macro name). However, it means
316 that programs previously using
317 m4_append([name], [string], [[, ]])
318 are now using a four-character separator instead of the intended
319 comma and space. If you need portability to earlier versions of
320 Autoconf, you can insert the following snippet after AC_INIT but
321 before any other macro expansions, to enforce the new semantics:
322 m4_pushdef([m4_append], [m4_define([$1],
323 m4_ifdef([$1], [m4_defn([$1])[$3]])[$2])])
324 Additionally, m4_append_uniq now takes optional parameters that can
325 be used to take action depending on whether anything was appended,
326 and warns if a non-empty separator occurs within the string being
327 appended, since that can lead to duplicates.
329 ** The following m4sugar macros are new:
330 m4_append_uniq_w m4_apply m4_combine m4_cond m4_count
331 m4_dquote_elt m4_echo m4_expand m4_ignore m4_make_list m4_max
332 m4_min m4_newline m4_shift2 m4_shift3 m4_unquote m4_wrap_lifo
334 ** Warnings are now generated by default when an installer invokes
335 'configure' with an unknown --enable-* or --with-* option.
336 These warnings can be disabled with the new AC_DISABLE_OPTION_CHECKING
337 macro, or by invoking 'configure' with --disable-option-checking.
339 ** Existing obsolete macros
340 The documentation for the following macros is adjusted to make it
341 more clear that they have previously been marked obsolete, as their
342 functionality can be accomplished by other macros. We have no
343 current plans to remove them from Autoconf.
345 AC_ENABLE AC_STRUCT_ST_BLKSIZE AC_STRUCT_ST_RDEV AC_WITH
347 ** Newly obsolete macros
348 The following macros have been marked obsolete, as they only
349 perform a subset of AC_USE_SYSTEM_EXTENSIONS. We have no current
350 plans to remove them.
352 AC_AIX AC_GNU_SOURCE AC_ISC_POSIX AC_MINIX
354 ** AC_C_LONG_DOUBLE is obsolescent.
355 The documentation now says that AC_C_LONG_DOUBLE is obsolescent: it
356 tests for problems that are so old that it is no longer of
357 practical importance on current systems. New programs need not use
358 AC_C_LONG_DOUBLE. We have no current plans to remove it.
360 ** AC_DIAGNOSE, AC_WARNING, and AC_FATAL are obsolescent.
361 The documentation now favors the use of M4sugar macros m4_warn and
362 m4_fatal, since the naming makes it more obvious that the
363 diagnostics are associated with M4 expansion (ie. when running
364 `autoconf'), and offers less confusion with the AC_MSG_ERROR,
365 AC_MSG_FAILURE, and AC_MSG_WARN macros which manage diagnostics
366 when running `configure'. We have no current plans to remove these
370 * Major changes in Autoconf 2.61a (2006-12-11)
372 ** AC_FUNC_FSEEKO was broken in 2.61; it didn't make fseeko and ftello visible
373 on many platforms. This has been fixed.
375 ** AC_FUNC_SETVBUF_REVERSED is now obsolete. It is still defined for backward
376 compatibility but it does nothing. The macro was already
377 obsolescent, as the last systems to have the problem were those
378 based on SVR2, which became obsolete in 1987. The macro had bugs
379 on some modern systems and could no longer be maintained reliably
380 due to lack of ancient systems to test it on.
382 ** config.status now uses awk instead of sed for most substitutions, for speed.
384 - As a side effect multi-line values of substituted variables no
385 longer have a small limit in total size, though for portability
386 each line should not exceed the POSIX length limit for text lines.
388 - It is now documented that Makefile.in should not contain
389 overlapping variable occurrences, e.g., @VAR1@VAR2@.
390 Autoconf's behavior was always iffy in such cases, and the
391 awk implementation has changed the behavior.
393 ** Many uses of 'echo' have been rewritten so that Autoconf-generated
394 scripts have fewer problems with strings or file names containing
395 embedded special characters such as backslash or leading "-". This
396 was implemented by using `printf '%s\n' "$foo"' instead of `echo
397 "$foo"' when printf works. Due to the implementation technique
398 used, Autoconf-generated scripts now run considerably more slowly
399 on ancient implementations lacking printf. However, this should
400 not be a problem, since Autoconf-generated scripts in practice
401 invariably find a more-modern shell these days.
404 * Major changes in Autoconf 2.61 (2006-11-17)
406 ** New macros AC_C_FLEXIBLE_ARRAY_MEMBER, AC_C_VARARRAYS.
408 ** AC_ARG_ENABLE and AC_ARG_WITH now allow '.' in feature and package names.
411 * Major changes in Autoconf 2.60b (2006-10-22)
414 Autoconf-generated shell scripts no longer export BIN_SH, due to
415 configuration hassles with this. Installers who need BIN_SH in
416 their environment should set it before invoking 'configure' and
417 'make'. As far as we know, this affects only Unixware installations.
419 ** Obsolescent macros
420 The documentation now says that the following macros are obsolescent,
421 as they are superseded by Gnulib:
423 AC_FUNC_FNMATCH AC_FUNC_FNMATCH_GNU AC_FUNC_GETLOADVG AC_REPLACE_FNMATCH
425 New programs should use the Gnulib counterparts of these macros.
426 We have no current plans to remove them from Autoconf.
428 ** AC_COMPUTE_INT no longer caches or reports results.
430 ** AC_CHECK_DECL now also works with aggregate objects.
432 ** AC_USE_SYSTEM_EXTENSIONS now defines _TANDEM_SOURCE for NonStop platforms.
434 ** GNU M4 1.4.7 or later is now recommended.
437 New M4sugar macro, which is more secure than the POSIX M4 maketemp.
440 Now an alias for m4_mkstemp.
442 * Major changes in Autoconf 2.60a (2006-08-25)
444 ** GNU M4 1.4.6 or later is now recommended.
446 ** The check for C99 now tests for varargs macros, as documented.
447 It also tests that the preprocessor supports 64-bit integers.
449 ** Autoconf now uses constructs like "#ifdef HAVE_STDLIB_H" rather than
450 "#if HAVE_STDLIB_H", so that it now works with "gcc -Wundef -Werror".
452 ** The functionality of the undocumented _AC_COMPUTE_INT is now provided
453 by a public and documented macro, AC_COMPUTE_INT. The parameters to the
454 two macros are different, so autoupdate will not change the old private name
455 to the new one. _AC_COMPUTE_INT may be removed in a future release.
457 ** AC_TYPE_LONG_LONG_INT and AC_TYPE_UNSIGNED_LONG_LONG_INT now require
458 that long long types be at least 64 bits wide, as C99 and tradition
459 requires. Formerly, they accepted implementations of any width.
462 * Major changes in Autoconf 2.60
464 Released 2006-06-23, by Ralf Wildenhues.
466 ** Autoconf no longer depends on whether m4wrap is FIFO (as Posix requires)
467 or LIFO (as in GNU M4 1.4.x). GNU M4 2.0 is expected to conform to Posix
468 here, so m4wrap/m4_wrap users should no longer depend on LIFO behavior.
470 ** Provide a way to turn off warnings about the changed directory variables.
472 * Major changes in Autoconf 2.59d
474 Released 2006-06-05, by Ralf Wildenhues.
476 ** GNU make now recommended for VPATH builds
477 INSTALL now suggests VPATH builds (e.g., "sh ../srcdir/configure")
478 only if you use GNU make. In practice, other 'make' implementations
479 have too many subtle incompatibilities in their support for VPATH.
480 Many packages (including Autoconf itself) are portable to other
481 'make' implementations, but some packages are not, and recommending
482 GNU make keeps the installation instructions simpler.
484 ** Even more safety checks for the new Directory variables:
485 Warn about suspicious `${datarootdir}' found in config files output.
487 ** AC_TRY_COMMAND, AC_TRY_EVAL, ac_config_guess, ac_config_sub, ac_configure
488 These never-documented macros and variables have been marked with
489 comments saying that they may be removed in a future release,
490 because their use can lead to unintended code being executed.
491 If you need functionality that only these macros or variables
492 currently supply, please write bug-autoconf@gnu.org.
494 ** AC_SUBST, AC_DEFINE
495 Literal arguments to these are passed to m4_pattern_allow now.
498 Passing 'ac_cv_prog_cc_stdc=no' to 'configure' now sets ac_cv_prog_cc_c99
499 and ac_cv_prog_cc_c89 to 'no' as well, for backward compatibility with
500 obsolete K&R tests in the Automake test suite.
509 Now more robust with special characters in file names, or when
510 multiple processes create the same directory at the same time.
512 ** Obsolescent macros
513 The documentation now says that the following macros are obsolescent:
514 they test for problems that are so old that they are no longer of
515 practical importance on current systems.
517 AC_C_BACKSLASH_A AC_FUNC_MEMCMP AC_HEADER_DIRENT
518 AC_C_CONST AC_FUNC_SELECT_ARGTYPES AC_HEADER_STAT
519 AC_C_PROTOTYPES AC_FUNC_SETPGRP AC_HEADER_STDC
520 AC_C_STRINGIZE AC_FUNC_SETVBUF_REVERSED AC_HEADER_SYS_WAIT
521 AC_C_VOLATILE AC_FUNC_STAT AC_HEADER_TIME
522 AC_FUNC_CLOSEDIR_VOID AC_FUNC_STRFTIME AC_ISC_POSIX
523 AC_FUNC_GETPGRP AC_FUNC_UTIME_NULL AC_PROG_GCC_TRADITIONAL
524 AC_FUNC_LSTAT AC_FUNC_VPRINTF AC_STRUCT_TM
526 New programs need not use these macros. We have no current plans to
530 For compatibility with future Libtool 2.0, autoreconf will invoke
531 libtoolize with the option `--ltdl' now, if LT_CONFIG_LTDL_DIR is
534 * Major changes in Autoconf 2.59c
536 Released 2006-04-12, by Ralf Wildenhues.
538 ** The configure command now redirects standard input from /dev/null,
539 to help avoid problems with subsidiary commands that might mistakenly
540 read standard input. AS_ORIGINAL_STDIN_FD points to the original
541 standard input before this redirection, if you really want configure to
542 read from standard input.
544 ** Directory variables adjusted to recent changes in the GNU Coding Standards.
545 The following directory variables are new:
547 datarootdir read-only architecture-independent data root [PREFIX/share]
548 localedir locale-specific message catalogs [DATAROOTDIR/locale]
549 docdir documentation root [DATAROOTDIR/doc/PACKAGE]
550 htmldir html documentation [DOCDIR]
551 dvidir dvi documentation [DOCDIR]
552 pdfdir pdf documentation [DOCDIR]
553 psdir ps documentation [DOCDIR]
555 The following variables have new default values:
557 datadir read-only architecture-independent data [DATAROOTDIR]
558 infodir info documentation [DATAROOTDIR/info]
559 mandir man documentation [DATAROOTDIR/man]
561 This means that if you use any of `@datadir@', `@infodir@', or
562 `@mandir@' in a file, you will have to ensure `${datarootdir}' is
563 defined in this file. As a temporary measure, if any of those are
564 found but no mention of `datarootdir', the substitutions will be
565 replaced with values that do not contain `${datarootdir}', and a
566 warning will be issued.
568 ** @top_builddir@ is now a dir name: it is always nonempty and doesn't have
569 a trailing slash. Similar change will be made to ac_top_builddir in a
570 future release; the old style value, which matches (../)*, is (and will
571 continue to be) available as ac_top_build_prefix.
574 New macro to check for support of 'typeof' syntax a la GNU C.
576 ** AC_CHECK_DECLS_ONCE, AC_CHECK_FUNCS_ONCE, AC_CHECK_HEADERS_ONCE
577 New "once-only" variants of commonly-used macros, to make 'configure'
578 smaller and faster in common cases.
581 New macro to check for strtold with C99 semantics.
584 New macro that lets builder disable assertions at 'configure'-time.
587 Now checks for X11/Xlib.h and XrmInitialize (X proper) rather than
588 X11/Intrinsic.h and XtMalloc (Xt).
590 ** AC_PRESERVE_HELP_ORDER
591 New macro that causes `configure' to display help strings for AC_ARG_ENABLE
592 and AC_ARG_WITH arguments in one region, in the order defined. The default
593 behavior is to group options of each classes separately.
595 ** AC_PROG_CC, AC_PROG_CXX
596 No longer automatically arrange to declare the 'exit' function of C,
597 when a C++ compiler is used. Standard Autoconf macros no longer use
598 'exit', so this is no longer an issue for them. If you use C++, and
599 want to call 'exit', you'll have to arrange for its declaration
600 yourself. But we now suggest you return from 'main' instead.
602 ** AC_PROG_CC_C89, AC_PROG_CC_C99
603 New macros for ISO C99 support. AC_PROG_CC_C89 and AC_PROG_CC_C99
604 check for ANSI C89 and ISO C99 support respectively.
607 Has been unobsoleted, and will check if the compiler supports ISO
608 C99, falling back to ANSI C89 if not. ac_cv_prog_cc_stdc is
609 retained for backwards compatibility, assuming the value of
610 ac_cv_prog_cc_c99 or ac_cv_prog_cc_c89 (whichever is valid, in
613 ** AC_STRUCT_DIRENT_D_INO, AC_STRUCT_DIRENT_D_TYPE
614 New macros for checking commonly-used members of struct dirent.
617 The substituted value can now contain newlines.
620 The substitution now occurs only when @variable@ is on a line by itself,
621 optionally surrounded by spaces and tabs. The whole line is replaced.
623 ** AC_TYPE_LONG_DOUBLE, AC_TYPE_LONG_DOUBLE_WIDER
624 New macros to check for long double, and whether it is wider than double.
625 The old macro AC_C_TYPE_LONG_DOUBLE has been marked as obsolete;
626 applications should switch to the new macro.
628 ** AC_TYPE_INT8_T, AC_TYPE_INT16_T, AC_TYPE_INT32_T, AC_TYPE_INT64_T,
629 AC_TYPE_INTMAX_T, AC_TYPE_INTPTR_T, AC_TYPE_LONG_LONG_INT, AC_TYPE_SSIZE_T,
630 AC_TYPE_UINT8_T, AC_TYPE_UINT16_T, AC_TYPE_UINT32_T, AC_TYPE_UINT64_T,
631 AC_TYPE_UINTMAX_T, AC_TYPE_UINTPTR_T, AC_TYPE_UNSIGNED_LONG_LONG_INT
632 New macros to check for C99 and POSIX types.
634 ** AC_USE_SYSTEM_EXTENSIONS
635 New macro to enable extensions to Posix.
638 New macro which is defined to the name of the first declared config header
639 or undefined if no config headers have been declared yet.
642 The macro correctly handles quadrigraphs now.
644 ** AS_BOURNE_COMPATIBLE, AS_SHELL_SANITIZE, AS_CASE
645 These macros are new or published now.
648 New macro for copyright notices in testsuite files.
650 ** ALLOCA, LIBOBJS, LTLIBOBJS
651 Object names added to these variables are now prefixed with `${LIBOBJDIR}',
652 as in `${LIBOBJDIR}alloca.o'. LIBOBJDIR is meant to be defined from
653 `Makefile.in' in case the object files lie in a different directory.
654 The LIBOBJDIR feature is experimental.
657 Supports --no-recursive now.
659 ** New macros to support Erlang/OTP.
660 New macros for configuring paths to Erlang tools and libraries:
661 AC_ERLANG_PATH_ERLC, AC_ERLANG_NEED_ERLC, AC_ERLANG_PATH_ERL,
662 AC_ERLANG_NEED_ERL, AC_ERLANG_CHECK_LIB, AC_ERLANG_SUBST_ROOT_DIR,
663 AC_ERLANG_SUBST_LIB_DIR.
665 New macros for configuring installation of Erlang libraries:
666 AC_ERLANG_SUBST_INSTALL_LIB_DIR, AC_ERLANG_SUBST_INSTALL_LIB_SUBDIR.
668 ** The manual now mentions Gnulib more prominently.
670 ** New macros to support Objective C.
671 AC_PROG_OBJC, AC_PROG_OBJCPP.
673 * Major changes in Autoconf 2.59b
675 Released 2004-08-20, by Paul Eggert.
678 New macro that computes the default alignment of a type.
680 ** AC_CHECK_TOOL, AC_PATH_TOOL, AC_CHECK_TOOLS
681 When cross-compiling, these macros will give a warning if the tool
682 is not prefixed. In the future, unprefixed cross tools will not
683 be detected; please consult the info documentation for information
684 about the reason of this change.
686 ** AC_CHECK_TARGET_TOOL, AC_PATH_TARGET_TOOL, AC_CHECK_TARGET_TOOLS
687 New macros that detect programs whose name is prefixed with the
688 target type, if the build type and target type are different.
690 ** AC_REQUIRE_AUX_FILE
691 New trace macro that declares expected auxiliary files.
694 New macro that tests for a grep program that accepts as a long a line
697 ** AC_PROG_EGREP, AC_PROG_FGREP
698 These macros now require AC_PROG_GREP, and try EGREP="$GREP -E" and
699 FGREP="$GREP -F" respectively if possible, or else run a path search for
700 a program that accepts as long a line as possible.
703 New macro that tests for a sed program that truncates as few characters
706 * Major changes in Autoconf 2.59
708 Released 2003-11-04, by Akim Demaille
710 ** ac_abs_builddir etc.
711 Absolute file names were actually relative in 2.58.
713 * Major changes in Autoconf 2.58
715 Released 2003-11-04, by Akim Demaille
718 core.* files are no longer removed, as they may be valid user files.
720 ** autoreconf and auxiliary directory
721 Autoreconf creates the auxiliary directory if needed. This is
722 especially useful for initial "bootstrapping" of fresh CVS checkouts.
724 ** AC_CONFIG_MACRO_DIR
725 Use this macro to declare the directory for local M4 macros for aclocal.
728 No longer includes twice the same file in LIBOBJS if invoked
731 ** AC_CONFIG_COMMANDS
732 The directory for its first argument is automatically created. For
735 AC_CONFIG_COMMANDS([src/modules.hh], [...])
737 $top_builddir/src/ is created if needed.
739 ** Autotest and local.at
740 The optional file local.at is always included in Autotest test suites.
743 The warnings are always issued, including with cached runs.
744 This became a significant problem since aclocal and automake can
745 run autoconf behind the scene.
747 ** autoheader warnings
748 The warnings of autoheader can be turned off, using --warning.
749 For instance, -Wno-obsolete disables the complaints about acconfig.h
750 and other deprecated constructs.
753 AC_C_RESTRICT, AC_INCLUDES_DEFAULT, AC_LANG_ASSERT, AC_LANG_WERROR,
756 ** AC_DECL_SYS_SIGLIST
760 Now checks that mktime is the inverse of localtime.
762 ** Improve DJGPP portability
763 The Autoconf tools and configure behave better under DJGPP.
765 ** Present But Cannot Be Compiled
766 New FAQ section dedicated to the mystic
768 configure: WARNING: pi.h: present but cannot be compiled
769 configure: WARNING: pi.h: check for missing prerequisite headers?
770 configure: WARNING: pi.h: proceeding with the preprocessor's result
773 ** Concurrent executions of autom4te
774 autom4te now locks its internal files, which enables concurrent
775 executions of autom4te, likely to happen if automake, autoconf,
776 autoheader etc. are run simultaneously.
779 Use of Libtool 1.5 and higher is encouraged. Compatibility with
780 Libtool pre-1.4 is not checked.
783 Testsuites no longer rerun failed tests in verbose mode; instead,
784 failures are logged while the test is run.
786 In addition, expected failures can be marked as such.
788 * Major changes in Autoconf 2.57
790 Released 2002-12-03 by Paul Eggert.
792 Bug fixes for problems with AIX linker, with freestanding C compilers,
793 with GNU M4 limitations, and with obsolete copies of GNU documents.
795 The Free Documentation License has been upgraded from 1.1 to 1.2.
797 * Major changes in Autoconf 2.56
799 Released 2002-11-15 by Akim Demaille.
801 One packaging problem fixed (config/install-sh was not executable).
803 * Major changes in Autoconf 2.55
805 Released 2002-11-14 by Akim Demaille.
809 Have your configure.ac checked by autoscan ("autoscan").
810 Try the warning options ("autoreconf -fv -Wall").
814 - AC_CHECK_HEADER, AC_CHECK_HEADERS
815 More information on proper use.
817 - Writing Test Programs
819 This sections explains how to write good test sources to use with
820 AC_COMPILE_IFELSE etc. It documents AC_LANG_PROGRAM and so forth.
822 - AC_FOO_IFELSE vs. AC_TRY_FOO
824 Explains why Autoconf moves from AC_TRY_COMPILE etc. to
825 AC_COMPILE_IFELSE and AC_LANG_PROGRAM etc.
829 - Is more robust to different Gettext installations.
831 - Produces messages (when --verbose) to be understood by Emacs'
834 - Supports -W/--warnings.
837 Once the GNU Build System reinstalled, run `./config.status
838 --recheck && ./config.status && make' if possible.
842 - Supports --cache, and --no-cache.
844 - ~/.autom4te.cfg makes it possible to disable the caching mechanism
845 (autom4te.cache). See `Customizing autom4te' in the documentation.
852 Support for the obsoleted options -m, --macrodir, -l, --localdir is
853 dropped in favor of the safer --include/--prepend-include scheme.
858 AC_COMPILER_IFELSE, AC_FUNC_MBRTOWC, AC_HEADER_STDBOOL,
859 AC_LANG_CONFTEST, AC_LANG_SOURCE, AC_LANG_PROGRAM, AC_LANG_CALL,
860 AC_LANG_FUNC_TRY_LINK, AC_MSG_FAILURE, AC_PREPROC_IFELSE.
863 Obsoleted macros are kept for Autoconf backward compatibility, but
864 should be avoided in configure.ac. Running autoupdate is advised.
867 - AC_DEFINE/AC_DEFINE_UNQUOTED
869 We have to stop using the old compatibility scheme --that tried to
870 avoid useless backslashes-- because Libtool 1.4.3 contains a
872 AC_DEFINE([error_t], [int],
873 [Define to a type to use for \`error_t' if it is not
874 otherwise available.])
876 We have to quote the single quotes and backslashes with \. The old
877 compatibility scheme saw that ` was backslashed, and therefore did
878 not quote the single quote... Failure. Hence, Autoconf 2.54 is not
879 compatible with Libtool. Autoconf 2.55 is, but in some cases might
880 produce more \ than wanted.
882 Please, note that in the future the same problem will happen with
883 AC_MSG_*: use `autoreconf -f -Wall'.
887 - Portability of the Autoconf package to Solaris.
889 - Spurious warnings caused by config.status.
890 This bug is benign, but painful: on some systems (typically
891 FreeBSD), warnings such as:
893 config.status: creating Makefile
894 mv: Makefile: set owner/group (was: 1357/0): Operation not permitted
896 could be issued. This is fixed.
899 Simultaneous executions of config.status are possible again.
901 - Precious variables accumulation
903 config.status could stack several copies of the precious variables
907 ** Plans for later versions
911 The compatibility hooks with the old scheme will be completely
912 removed. Please, advice/use `--build', `--host', and `--target'
915 - AC_CHECK_HEADER, AC_CHECK_HEADERS
917 The tests will be stricter, please make sure your invocations are
922 Shell functions will gradually be introduced, probably starting with
923 Autotest. If you know machines which are in use that you suspect
924 *not* to support shell functions, please run the test suite of
925 Autoconf 2.55 on it, and report the results to
926 bug-autoconf@gnu.org.
930 Special characters in AC_MSG_* need not be quoted. Currently,
931 Autoconf has heuristics to decide when a string is escaped, or has
932 to be escaped. This scheme is fragile, and will be removed; the
933 only risk is uglified messages. Please, run `autoreconf -f -Wall'
934 to find occurrences that will be affected.
936 * Major changes in Autoconf 2.54
938 Released 2002-09-13 by Akim Demaille.
942 - autoreconf no longer changes the version of the gettext/po/intl
943 support files. It now adds the files the correspond to the
944 AM_GNU_GETTEXT_VERSION declared in configure.ac.
946 Warning: It now relies on the 'autopoint' program, which is part
947 of GNU gettext 0.11.4 and newer.
949 Please note that you need to have a GNU gettext version that
950 corresponds at least to the AM_GNU_GETTEXT_VERSION declared
951 in configure.ac. You can upgrade to newer GNU gettext versions,
952 though, without needing to change configure.ac.
954 - The -I DIR or --include=DIR option now appends DIR to the include path
955 instead of prepending; this is for consistency with other GNU tools.
956 The new -B DIR or --prepend-include=DIR option has the old behavior.
961 Now handles all the gory details about LIBOBJS and LTLIBOBJS.
962 Please, remove lines such as
964 # This is necessary so that .o files in LIBOBJS are also
965 # built via the ANSI2KNR-filtering rules.
966 LIBOBJS=`echo $LIBOBJS|sed 's/\.o /\$U.o /g;s/\.o$/\$U.o/'`
968 and read the `AC_LIBOBJ vs LIBOBJS' section. Do not define U in
969 your Makefiles either.
971 - AC_CONFIG_LINKS now makes copies if it can't make links.
973 - AC_FUNC_FNMATCH now tests only for POSIX compatibility, reverting to
974 Autoconf 2.13 behavior. The new macro AC_FUNC_FNMATCH_GNU also
975 tests for GNU extensions to fnmatch, and replaces fnmatch if needed.
977 - AC_FUNC_SETVBUF_REVERSED no longer fails when cross-compiling.
979 - AC_PROG_CC_STDC is integrated into AC_PROG_CC.
981 - AC_PROG_F77 default search no longer includes cf77 and cfg77.
985 AC_C_BACKSLASH_A, AC_CONFIG_LIBOBJ_DIR, AC_GNU_SOURCE,
986 AC_PROG_EGREP, AC_PROG_FGREP, AC_REPLACE_FNMATCH,
987 AC_FUNC_FNMATCH_GNU, AC_FUNC_REALLOC, AC_TYPE_MBSTATE_T.
990 looks for getloadavg.c in the CONFIG_LIBOBJ_DIR.
993 Now defines HAVE_MALLOC to 0 if `malloc' does not work, and asks
994 for an AC_LIBOBJ replacement.
998 - Spurious complaints from `m4_bmatch' about invalid regular
999 expressions are suppressed.
1001 - Empty top_builddirs are properly handled.
1003 - AC_CHECK_MEMBER works correctly when the member is an aggregate.
1006 Now colon in the optional path arguments are properly handled.
1008 ** Improved portability
1010 - Both Autoconf the package, and the scripts it produces, should run
1011 more reliably with Zsh. Bear in mind it is the default Bourne shell
1014 - Autoconf and the scripts it produces no longer assume the existence of
1015 the obsolescent commands egrep and fgrep.
1019 - Limitations of Make
1023 The GNATS base moved to
1024 http://bugs.gnu.org/cgi-bin/gnatsweb.pl?database=autoconf
1025 (It is no longer available, though.)
1030 Now contains the list of ouput variables and files (AC_SUBST,
1033 * Major changes in Autoconf 2.53
1035 Released 2002-03-08 by Akim Demaille.
1039 Perl 5.005_03 or later is required: autom4te is written in Perl and is
1040 needed by autoconf. autoheader, autoreconf, ifnames, and autoscan are
1046 Argument requirements, output variables, defined macros.
1047 - M4sugar, M4sh, Autotest
1049 - Double quoting macros
1050 AC_TRY_CPP, AC_TRY_COMPILE, AC_TRY_LINK and AC_TRY_RUN.
1052 The Autoconf manual is now distributed under the terms of the GNU FDL.
1053 - Section `Hosts and Cross-Compilation'
1054 Explains the rationale for the 2.5x changes in the cross-compilation
1055 chain, and in the relationships between build, host, and target
1057 Emphasizes that `cross-compilation' == `--host is given'.
1058 If you are working on compilers etc., be sure to read this section.
1059 - Section `AC_LIBOBJ vs. LIBOBJS'
1060 Explains why assigning LIBOBJS directly is now an error.
1061 Details how to update the code.
1066 Now used instead of hard coded line numbers.
1067 This eases the comparison of `configure's, and diminishes the
1068 pressure over control version archives.
1069 Automatic replacement for shells that don't support this feature.
1070 - New output variables
1071 @builddir@, @top_builddir@, @abs_srcdir@, @abs_top_srcdir@, @abs_builddir@,
1076 Autoconf and Autotest modes are provided.
1081 New, used by the Autoconf suite to cache and speed up most processing.
1083 Supported by autom4te, autoconf and autoheader.
1085 Replaces --autoconf-dir and --localdir in autoconf, autoheader,
1086 autoupdate, and autoreconf.
1088 No longer passes --cygnus, --foreign, --gnits, --gnu, --include-deps:
1089 automake options are to be given via AUTOMAKE_OPTIONS.
1091 Runs gettextize and libtoolize when appropriate.
1093 --m4dir is no longer supported.
1095 Now runs only in the specified directories, defaulting to `.',
1096 but understands AC_CONFIG_SUBDIRS for dependent directories.
1097 Before, it used to run on all the `configure.ac' found in the
1099 Independent packages are properly updated.
1103 - The top level $prefix is propagated to the AC_CONFIG_SUBDIRS configures.
1105 Under the user pressure, $? is finally available. Probably a mistake.
1106 - AC_F77_LIBRARY_LDFLAGS now supports the HP/UX f90 compiler.
1107 - Precious variables accumulation
1108 config.status could stack several copies of the precious variables
1110 - AC_PATH_PROG and family.
1111 Works properly when given a literal path.
1113 Somewhere since 2.13, the result had been reversed.
1117 - AC_C_BIGENDIAN supports the cross-compiling case.
1118 - AC_C_BIGENDIAN accepts ACTION-IF-TRUE, ACTION-IF-FALSE, and
1119 ACTION-IF-UNKNOWN arguments. All are facultative, and the default
1120 for ACTION-IF-TRUE is to define WORDS_BIGENDIAN like AC_C_BIGENDIAN
1122 - AC_C_LONG_DOUBLE now succeeds only if `long double' has more range or
1123 precision than `double'.
1128 It now defines the preprocessor symbols PACKAGE_NAME,
1129 PACKAGE_TARNAME, PACKAGE_VERSION, PACKAGE_STRING, and
1133 Admits a fourth optional parameter: the tar name.
1135 - AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS.
1136 Provide the user with srcdir, ac_srcdir, ac_top_srcdir, ac_builddir,
1137 ac_top_builddir, ac_abs_srcdir, ac_abs_top_srcdir, ac_abs_builddir,
1138 ac_abs_top_builddir.
1140 - AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS and AC_OUTPUT.
1141 Are much less expensive when using long lists of files.
1144 Works with shell variables, and non alphanumeric names.
1148 - AC_FUNC_STRERROR_R now sets STRERROR_R_CHAR_P, not HAVE_WORKING_STRERROR_R,
1149 because POSIX 1003.1-200x draft 7 says strerror_r returns int, not char *.
1151 - AC_FUNC_STRTOD substitutes POW_LIB.
1156 * Major changes in Autoconf 2.52
1158 Released 2001-07-18 by Akim Demaille.
1163 This feature was present in autoconf 2.50 but was not documented.
1164 For example, `@<:@' is translated to `[' just before output. This
1165 is useful when writing strings that contain unbalanced quotes, or
1166 other hard-to-quote constructs.
1167 - m4_pattern_forbid, m4_pattern_allow
1168 - Tips for upgrading from 2.13.
1169 - Using autoscan to maintain a configure.ac.
1172 - Now include stdint.h.
1173 - sys/types.h and sys/stat.h are guarded.
1174 - strings.h is included if available, and not conflicting with string.h.
1177 - The test suite is more robust and presents less false failures.
1178 - Invocation of GNU M4 now robust to POSIXLY_CORRECT.
1179 - configure accepts --prefix='' again.
1180 - AC_CHECK_LIB works properly when its first argument is not a
1182 - HAVE_INTTYPES_H is defined only if not conflicting with sys/types.h.
1183 - build_, host_, and target_alias are AC_SUBST as in 2.13.
1184 - AC_ARG_VAR properly propagates precious variables inherited from the
1185 environment to ./config.status.
1186 - Using --program-suffix/--program-prefix is portable.
1187 - Failures to detect the default compiler's output extension are less
1189 - `config.status foo' works properly when `foo' depends on variables
1190 set in an AC_CONFIG_THING INIT-CMD.
1191 - autoheader is more robust to broken input.
1192 - Fixed Fortran name-mangling and link tests on a number of systems,
1193 e.g. NetBSD; see AC_F77_DUMMY_MAIN, below.
1196 - AC_CHECK_HEADER and AC_CHECK_HEADERS support a fourth argument to
1197 specify pre-includes. In this case, the headers are compiled with
1198 cc, not merely preprocessed by cpp. Therefore it is the _usability_
1199 of a header which is checked for, not just its availability.
1200 - AC_ARG_VAR refuses to run configure when precious variables have
1202 - Versions of compilers are dumped in the logs.
1203 - AC_CHECK_TYPE recognizes use of `foo_t' as a replacement type.
1206 - AC_PATH_XTRA only adds -ldnet to $LIBS if it's needed to link.
1207 - AC_FUNC_WAIT3 and AC_SYS_RESTARTABLE_SYSCALLS are obsoleted.
1208 - AM_FUNC_ERROR_AT_LINE, AM_FUNC_FNMATCH, AM_FUNC_MKTIME,
1209 AM_FUNC_OBSTACK, and AM_FUNC_STRTOD are now activated.
1210 Be sure to read `Upgrading from Version 2.13' to understand why
1211 running `autoupdate' is needed.
1212 - AC_F77_DUMMY_MAIN, AC_F77_MAIN: new macros to detect whether
1213 a main-like routine is required/possible when linking C/C++ with
1214 Fortran. Users of e.g. AC_F77_WRAPPERS should be aware of these.
1215 - AC_FUNC_GETPGRG behaves better when cross-compiling.
1217 * Major changes in Autoconf 2.51
1218 There was no release of Autoconf 2.51 since some packagers had used
1219 this version number without permission to ship intermediary versions
1220 of 2.50. The version was skipped to avoid confusion.
1222 * Major changes in Autoconf 2.50
1224 Released 2001-05-21 by Akim Demaille.
1226 ** Lots of bug fixes
1227 There have been far too many to enumerate them here. Check out
1228 ChangeLog if you really want to know more.
1230 ** Improved documentation
1231 In particular, portability issues are better covered.
1234 All the standard GNU Makefile targets are supported. The layout has
1235 changed: m4/ holds the M4 extensions Autoconf needs for its
1236 configuration, doc/ contains the documentation, and tests/ contains
1239 ** Man pages are provided
1240 For autoconf, autoreconf, autoupdate, autoheader, autoscan, ifnames,
1241 config.guess, config.sub.
1245 Provides a safe and powerful means to trace the macro uses. This
1246 provide the parsing layer for tools which need to `study'
1250 Specify what category of warnings should be enabled.
1252 - When recursing into subdirectories, try for configure.gnu before
1253 configure to adapt for packages not using autoconf on case-insensitive
1257 More errors are now caught (circular AC_REQUIRE dependencies,
1258 AC_DEFINE in the action part of an AC_CACHE_CHECK, too many pops
1259 etc.). In addition, their location and call stack are given.
1262 autoupdate is much more powerful, and is able to provide the glue code
1263 which might be needed to move from an old macro to its newer
1266 You are strongly encouraged to use it to modernize both your
1267 `configure.in' and your .m4 extension files.
1270 The internal machinery of autoheader has completely changed. As a
1271 result, using `acconfig.h' should be considered to be obsoleted, and
1272 you are encouraged to get rid of it using the AH macros.
1277 ** Fortran 77 compilers
1278 Globally, the support for Fortran 77 is considerably improved.
1280 Support for automatically determining a Fortran 77 compiler's
1281 name-mangling scheme. New CPP macros F77_FUNC and F77_FUNC_ are
1282 provided to wrap C/C++ identifiers, thus making it easier and more
1283 transparent for C/C++ to call Fortran 77 routines, and Fortran 77 to
1284 call C/C++ routines. See the Texinfo documentation for details.
1287 The test suite no longer uses DejaGNU. It should be easy to submit
1288 test cases in this new framework.
1291 - --help, --help=long, -hl
1292 no longer dumps useless items.
1294 lists only specific options.
1295 - --help=recursive, -hr
1296 displays the help of all the embedded packages.
1297 - Remembers environment variables when reconfiguring.
1298 The previous scheme to set envvar before running configure was
1300 what prevented configure from remembering the environment in which
1301 it was run, therefore --recheck was run in an inconsistent
1302 environment. Now, one should run
1304 and then --recheck will work properly. Variables declared with
1305 AC_ARG_VAR are also preserved.
1307 $build defaults to `config.guess`, $host to $build, and then $target
1309 Cross-compilation is a global status of the package, it no longer
1310 depends upon the current language.
1311 Cross compilation is enabled iff the user specified `--host'.
1312 `configure' now fails if it can't run the executables it compiles,
1313 unless cross-compilation is enabled.
1315 The cache file is disabled by default. The new options
1316 `--config-cache', `-C' set the cache to `config.cache'.
1320 Much faster on most architectures.
1321 - concurrent executions
1322 It is safe to use `make -j' with config.status.
1323 - human interface improved
1324 It is possible to invoke
1325 ./config.status foobar
1326 instead of the former form (still valid)
1327 CONFIG_COMMANDS= CONFIG_HEADERS= CONFIG_LINKS= \
1328 CONFIG_FILES=foobar:foo.in:bar.in \
1330 The same holds for configuration headers and links.
1331 You can instantiate unknown files and headers:
1332 ./config.status --header foo.h:foo.h.in --file bar:baz
1333 - has a useful --help
1334 - accepts special file name "-" for stdin/stdout
1339 Specify additional copyright information.
1342 Now expects the identity of the package as argument.
1346 Most macros, if not all, now strictly follow the `one quotation
1347 level' rule. This results in a more predictable expansion.
1350 A sly bug in the AC_REQUIRE machinery, which could produce incorrect
1351 configure scripts, was fixed by Axel Thimm.
1355 Document and ask for the registration of an envvar.
1358 Specifies the file which `configure' should look for when trying to
1359 find the source tree (used to be handled by AC_INIT).
1361 - AC_CONFIG_COMMANDS
1362 To add new actions to config.status. Should be used instead of
1366 Replaces AC_LINK_FILES.
1368 - AC_CONFIG_HEADERS, AC_CONFIG_COMMANDS, AC_CONFIG_SUBDIRS,
1369 AC_CONFIG_LINKS, and AC_CONFIG_FILES
1370 They now obey sh: you should no longer use shell variables as
1371 argument. Instead of
1373 test "$package_foo_enabled" = yes && $my_subdirs="$my_subdirs foo"
1374 AC_CONFIG_SUBDIRS($my_subdirs)
1378 if test "$package_foo_enabled" = yes; then
1379 AC_CONFIG_SUBDIRS(foo)
1383 To format an Autoconf macro's help string so that it looks pretty
1384 when the user executes `configure --help'.
1387 ** Generic Test Macros
1389 The interface of the AC_CHECK families of macros (decl, header,
1390 type, member, func) is now uniform. They support the same set of
1393 - AC_CHECK_DECL, AC_CHECK_DECLS
1394 To check whether a symbol is declared.
1396 - AC_CHECK_SIZEOF, AC_C_CHAR_UNSIGNED.
1397 No longer need a cross-compilation default.
1400 The test it performs is much more robust than previously, and makes
1401 it possible to test builtin types in addition to typedefs.
1402 It is now schizophrenic:
1403 - AC_CHECK_TYPE(TYPE, REPLACEMENT)
1404 remains for backward compatibility, but its use is discouraged.
1405 - AC_CHECK_TYPE(TYPE, IF-FOUND, IF-NOT-FOUND, INCLUDES)
1406 behaves exactly like the other AC_CHECK macros.
1409 Checks whether given types are supported by the system.
1411 - AC_CHECK_MEMBER, AC_CHECK_MEMBERS
1412 Check for given members in aggregates (e.g., pw_gecos in struct
1416 Checks if the compiler supports ISO C, included when needs special
1420 Checking whether the preprocessor indicates missing includes by the
1421 error code. stderr is checked by AC_TRY_CPP only as a fallback.
1424 Takes a language as argument and replaces AC_LANG_C,
1425 AC_LANG_CPLUSPLUS and AC_LANG_FORTRAN77.
1427 - AC_LANG_PUSH, AC_LANG_POP
1428 Are preferred to AC_LANG_SAVE, AC_LANG_RESTORE.
1431 - AC_FUNC_CHOWN, AC_FUNC_MALLOC, AC_FUNC_STRERROR_R,
1432 AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK, AC_FUNC_STAT, AC_FUNC_LSTAT,
1433 AC_FUNC_ERROR_AT_LINE, AC_FUNC_OBSTACK, AC_FUNC_STRTOD, AC_FUNC_FSEEKO.
1437 Sets GETGROUPS_LIBS.
1439 - AC_FUNC_GETLOADAVG
1440 Defines `HAVE_STRUCT_NLIST_N_UN_N_NAME' instead of `NLIST_NAME_UNION'.
1443 Now integrates `AC_DECL_YYTEXT' which is obsoleted.
1446 Arrange for large-file support.
1448 - AC_EXEEXT, AC_OBJEXT
1449 You are no longer expected to use them: their computation is
1450 performed by default.
1452 ** C++ compatibility
1453 Every macro has been revisited in order to support at best CC=c++.
1455 Major changes in Autoconf 2.14:
1456 There was no release of GNU Autoconf 2.14.
1458 Major changes in Autoconf 2.13:
1460 Released 1999-05-01 by Ben Elliston.
1462 * Support for building on Win32 systems where the only available C or
1463 C++ compiler is the Microsoft Visual C++ command line compiler
1464 (`cl'). Additional support for building on Win32 systems which are
1465 using the Cygwin or Mingw32 environments.
1466 * Support for alternative object file and executable file extensions.
1467 On Win32, for example, these are .obj and .exe. These are discovered
1468 using AC_OBJEXT and AC_EXEEXT, which substitute @OBJEXT@ and
1469 @EXEEXT@ in the output, respectively.
1470 * New macros: AC_CACHE_LOAD, AC_CACHE_SAVE, AC_FUNC_SELECT_ARGTYPES,
1471 AC_VALIDATE_CACHED_SYSTEM_TUPLE, AC_SEARCH_LIBS, AC_TRY_LINK_FUNC,
1472 AC_C_STRINGIZE, AC_CHECK_FILE(S), AC_PROG_F77 (and friends).
1473 * AC_DEFINE now has an optional third argument for a description to be
1474 placed in the config header input file (e.g. config.h.in).
1475 * The C++ code fragment compiled for the C++ compiler test had to be
1476 improved to include an explicit return type for main(). This was
1477 causing failures on systems using recent versions of the EGCS C++
1479 * Fixed an important bug in AC_CHECK_TYPE that would cause a configure
1480 script to report that `sometype_t' was present when only `type_t'
1482 * Merge of the FSF version of config.guess and config.sub to modernize
1483 these scripts. Add support for a few new hosts in config.guess.
1484 Incorporate latest versions of install-sh, mkinstalldirs and
1485 texinfo.tex from the FSF.
1486 * autoreconf is capable of running automake if necessary (and
1488 * Support for Fortran 77. See the Texinfo documentation for details.
1489 * Bug fixes and workarounds for quirky bugs in vendor utilities.
1491 Major changes in Autoconf 2.12:
1493 Released 1996-11-26 by David J. MacKenzie
1495 * AC_OUTPUT and AC_CONFIG_HEADER can create output files by
1496 concatenating multiple input files separated by colons, like so:
1497 AC_CONFIG_HEADER(config.h:conf.pre:config.h.in:conf.post)
1498 AC_OUTPUT(Makefile:Makefile.in:Makefile.rules)
1499 The arguments may be shell variables, to compute the lists on the fly.
1500 * AC_LINK_FILES and AC_CONFIG_SUBDIRS may be called multiple times.
1501 * New macro AC_OUTPUT_COMMANDS adds more commands to run in config.status.
1504 Major changes in Autoconf 2.11:
1506 Released November 18th, 1996, by David J. MacKenzie
1508 * AC_PROG_CC and AC_PROG_CXX check whether the compiler works.
1509 They also default CFLAGS/CXXFLAGS to "-g -O2" for gcc, instead of "-g -O".
1510 * AC_REPLACE_FUNCS defines HAVE_foo if the system has the function `foo'.
1511 * AC_CONFIG_HEADER expands shell variables in its argument.
1512 * New macros: AC_FUNC_FNMATCH, AC_FUNC_SETPGRP.
1513 * The "checking..." messages and the source code for test programs that
1514 fail are saved in config.log.
1515 * Another workaround has been added for seds with small command length limits.
1516 * config.sub and config.guess recognize more system types.
1519 Major changes in Autoconf 2.10:
1521 Released May 7th, 1996, by Roland McGrath
1524 * The cache variable names used by `AC_CHECK_LIB(LIB, FUNC, ...)' has
1525 changed: now $ac_cv_lib_LIB_FUNC, previously $ac_cv_lib_LIB.
1527 Major changes in Autoconf 2.9:
1529 Released March 16th, 1996, by Roland McGrath
1533 Major changes in Autoconf 2.8:
1535 Released March 8th, 1996, by Roland McGrath
1539 Major changes in Autoconf 2.7:
1541 Released November 22nd, 1995, by David J. MacKenzie
1545 Major changes in Autoconf 2.6:
1547 Released November 20th, 1995, by David J. MacKenzie
1551 Major changes in Autoconf 2.5:
1553 Released November 17th, 1995, by Roland McGrath
1555 * New configure options --bindir, --libdir, --datadir, etc., with
1556 corresponding output variables.
1557 * New macro: AC_CACHE_CHECK, to make using the cache easier.
1558 * config.log contains the command being run as well as any output from it.
1559 * AC_CHECK_LIB can check for libraries with "." or "/" or "+" in their name.
1560 * AC_PROG_INSTALL doesn't cache a name for install-sh, for sharing caches.
1561 * AC_CHECK_PROG, AC_PATH_PROG, AC_CHECK_PROGS, AC_PATH_PROGS, and
1562 AC_CHECK_TOOL can search a path other than $PATH.
1563 * AC_CHECK_SIZEOF takes an optional size to use when cross-compiling.
1565 Major changes in Autoconf 2.4:
1567 Released June 14th, 1995, by David J. MacKenzie
1569 * Fix a few bugs found by Emacs testers.
1571 Major changes in Autoconf 2.3:
1573 Released March 27th, 1995, by David J. MacKenzie
1575 * Fix the cleanup trap in several ways.
1576 * Handle C compilers that are picky about option placement.
1577 * ifnames gets the version number from the right directory.
1579 Major changes in Autoconf 2.2:
1581 Released March 8th, 1995, by David J. MacKenzie
1583 * The ifnames utility is much faster but requires a "new awk" interpreter.
1584 * AC_CHECK_LIB and AC_HAVE_LIBRARY check and add the new
1585 library before existing libs, not after, in case it uses them.
1586 * New macros: AC_FUNC_GETPGRP, AC_CHECK_TOOL.
1587 * Lots of bug fixes.
1588 * Many additions to the TODO file :-)
1590 Major changes in Autoconf 2.1:
1592 Released November 4th, 1994, by David J. MacKenzie
1595 * More explanations in the manual.
1596 * Fix a spurious failure in the testsuite.
1597 * Clarify some warning messages.
1598 * autoreconf by default only rebuilds configure and config.h.in files
1599 that are older than any of their particular input files; there is a
1600 --force option to use after installing a new version of Autoconf.
1602 Thanks to everybody who's submitted changes and additions to Autoconf!
1603 I've incorporated many of them, and am still considering others for
1604 future releases -- but I didn't want to postpone this release indefinitely.
1606 Caution: don't indiscriminately rebuild configure scripts with
1607 Autoconf version 2. Some configure.in files need minor adjustments to
1608 work with it; the documentation has a chapter on upgrading. A few
1609 configure.in files, including those for GNU Emacs and the GNU C
1610 Library, need major changes because they relied on undocumented
1611 internals of version 1. Future releases of those packages will have
1612 updated configure.in files.
1614 It's best to use GNU M4 1.3 (or later) with Autoconf version 2.
1615 Autoconf now makes heavy use of M4 diversions, which were implemented
1616 inefficiently in GNU M4 releases before 1.3.
1618 Major changes in Autoconf 2.0:
1620 Released October 26th, 1994, by David J. MacKenzie
1622 ** New copyright terms:
1623 * There are no restrictions on distribution or use of configure scripts.
1626 * Autoconf manual is reorganized to make information easier to find
1627 and has several new indexes.
1628 * INSTALL is reorganized and clearer and is now made from Texinfo source.
1631 * autoscan to generate a preliminary configure.in for a package by
1632 scanning its source code for commonly used nonportable functions,
1633 programs, and header files.
1634 * ifnames to list the symbols used in #if and #ifdef directives in a
1636 * autoupdate to update a configure.in to use the version 2 macro names.
1637 * autoreconf to recursively remake configure and configuration header
1638 files in a source tree.
1640 ** Changed utilities:
1641 * autoheader can take pieces of acconfig.h to replace config.h.{top,bot}.
1642 * autoconf and autoheader can look for package-local definition files
1643 in an alternate directory.
1646 * AC_CACHE_VAL to share results of tests between configure runs.
1647 * AC_DEFUN to define macros, automatically AC_PROVIDE them, and ensure
1648 that macros invoked with AC_REQUIRE don't interrupt other macros.
1649 * AC_CONFIG_AUX_DIR, AC_CANONICAL_SYSTEM, AC_CANONICAL_HOST, AC_LINK_FILES to
1650 support deciding unguessable features based on the host and target types.
1651 * AC_CONFIG_SUBDIRS to recursively configure a source tree.
1652 * AC_ARG_PROGRAM to use the options --program-prefix,
1653 --program-suffix, and --program-transform-name to change the names
1654 of programs being installed.
1655 * AC_PREFIX_DEFAULT to change the default installation prefix.
1656 * AC_TRY_COMPILE to compile a test program without linking it.
1657 * AC_CHECK_TYPE to check whether sys/types.h or stdlib.h defines a given type.
1658 * AC_CHECK_LIB to check for a particular function and library.
1659 * AC_MSG_CHECKING and AC_MSG_RESULT to print test results, on a single line,
1660 whether or not the test succeeds. They obsolete AC_CHECKING and AC_VERBOSE.
1661 * AC_SUBST_FILE to insert one file into another.
1662 * AC_FUNC_MEMCMP to check whether memcmp is 8-bit clean.
1663 * AC_FUNC_STRFTIME to find strftime even if it's in -lintl.
1664 * AC_FUNC_GETMNTENT to find getmntent even if it's in -lsun or -lseq.
1665 * AC_HEADER_SYS_WAIT to check whether sys/wait.h is POSIX.1 compatible.
1668 * Many macros renamed systematically, but old names are accepted for
1669 backward compatibility.
1670 * AC_OUTPUT adds the "automatically generated" comment to
1671 non-Makefiles where it finds @configure_input@ in an input file, to
1672 support files with various comment syntaxes.
1673 * AC_OUTPUT does not replace "prefix" and "exec_prefix" in generated
1674 files when they are not enclosed in @ signs.
1675 * AC_OUTPUT allows the optional environment variable CONFIG_STATUS to
1676 override the file name "config.status".
1677 * AC_OUTPUT takes an optional argument for passing variables from
1678 configure to config.status.
1679 * AC_OUTPUT and AC_CONFIG_HEADER allow you to override the input-file names.
1680 * AC_OUTPUT automatically substitutes the values of CFLAGS, CXXFLAGS,
1681 CPPFLAGS, and LDFLAGS from the environment.
1682 * AC_PROG_CC and AC_PROG_CXX now set CFLAGS and CXXFLAGS, respectively.
1683 * AC_PROG_INSTALL looks for install-sh or install.sh in the directory
1684 specified by AC_CONFIG_AUXDIR, or srcdir or srcdir/.. or
1685 srcdir/../.. by default.
1686 * AC_DEFINE, AC_DEFINE_UNQUOTED, and AC_SUBST are more robust and smaller.
1687 * AC_DEFINE no longer prints anything, because of the new result reporting
1688 mechanism (AC_MSG_CHECKING and AC_MSG_RESULT).
1689 * AC_VERBOSE pays attention to --quiet/--silent, not --verbose.
1690 * AC_ARG_ENABLE and AC_ARG_WITH support whitespace in the arguments to
1691 --enable- and --with- options.
1692 * AC_CHECK_FUNCS and AC_CHECK_HEADERS take optional shell commands to
1693 execute on success or failure.
1694 * Checking for C functions in C++ works.
1697 * AC_REMOTE_TAPE and AC_RSH removed; too specific to tar and cpio, and
1698 better maintained with them.
1699 * AC_ARG_ARRAY removed because no one was likely using it.
1700 * AC_HAVE_POUNDBANG replaced with AC_SYS_INTERPRETER, which doesn't
1701 take arguments, for consistency with all of the other specific checks.
1704 * Comes with config.sub and config.guess, and uses them optionally.
1705 * Uses config.cache to cache test results. An alternate cache file
1706 can be selected with the --cache-file=FILE option.
1707 * Uses optional shell scripts $prefix/share/config.site and
1708 $prefix/etc/config.site to perform site or system specific initializations.
1709 * configure saves compiler output to ./config.log for debugging.
1710 * New files autoconf.m4 and autoheader.m4 load the other Autoconf macros.
1711 * acsite.m4 is the new name for the system-wide aclocal.m4.
1712 * Has a DejaGnu test suite.
1714 Major changes in Autoconf 1.11:
1716 * AC_PROG_INSTALL calls install.sh with the -c option.
1717 * AC_SET_MAKE cleans up after itself.
1718 * AC_OUTPUT sets prefix and exec_prefix if they weren't set already.
1719 * AC_OUTPUT prevents shells from looking in PATH for config.status.
1721 Plus a few other bug fixes.
1723 Major changes in Autoconf 1.10:
1725 * autoheader uses config.h.bot if present, analogous to config.h.top.
1726 * AC_PROG_INSTALL looks for install.sh in srcdir or srcdir/.. and
1728 * AC_PROG_CXX looks for cxx as a C++ compiler.
1730 Plus several bugs fixed.
1732 Major changes in Autoconf 1.9:
1734 * AC_YYTEXT_POINTER replaces AC_DECLARE_YYTEXT.
1735 * AC_SIZEOF_TYPE generates the cpp symbol name automatically,
1736 and autoheader generates entries for those names automatically.
1737 * AC_FIND_X gets the result from xmkmf correctly.
1738 * AC_FIND_X assumes no X if --without-x was given.
1739 * AC_FIND_XTRA adds libraries to the variable X_EXTRA_LIBS.
1740 * AC_PROG_INSTALL finds OSF/1 installbsd.
1742 Major changes in Autoconf 1.8:
1745 * New macros AC_LANG_C, AC_LANG_CPLUSPLUS, AC_LANG_SAVE, AC_LANG_RESTORE,
1746 AC_PROG_CXX, AC_PROG_CXXCPP, AC_REQUIRE_CPP
1747 for checking both C++ and C features in one configure script.
1748 * New macros AC_CHECKING, AC_VERBOSE, AC_WARN, AC_ERROR for printing messages.
1749 * New macros AC_FIND_XTRA, AC_MMAP, AC_SIZEOF_TYPE, AC_PREREQ,
1750 AC_SET_MAKE, AC_ENABLE.
1753 * AC_FIND_X looks for X in more places.
1754 * AC_PROG_INSTALL defaults to install.sh instead of cp, if it's in srcdir.
1755 install.sh is distributed with Autoconf.
1756 * AC_DECLARE_YYTEXT has been removed because it can't work, pending
1757 a rewrite of quoting in AC_DEFINE.
1758 * AC_OUTPUT adds its comments in C format when substituting in C files.
1759 * AC_COMPILE_CHECK protects its ECHO-TEXT argument with double quotes.
1761 ** New or changed command line options:
1762 * configure accepts --enable-FEATURE[=ARG] and --disable-FEATURE options.
1763 * configure accepts --without-PACKAGE, which sets withval=no.
1764 * configure accepts --x-includes=DIR and --x-libraries=DIR.
1765 * Giving --with-PACKAGE no argument sets withval=yes instead of withval=1.
1766 * configure accepts --help, --version, --silent/--quiet, --no-create options.
1767 * configure accepts and ignores most other Cygnus configure options, and
1768 warns about unknown options.
1769 * config.status accepts --help, --version options.
1771 ** File names and other changes:
1772 * Relative srcdir values are not made absolute.
1773 * The values of @prefix@ and @exec_prefix@ and @top_srcdir@ get substituted.
1774 * Autoconf library files are installed in ${datadir}/autoconf, not ${datadir}.
1775 * autoheader optionally copies config.h.top to the beginning of config.h.in.
1776 * The example Makefile dependencies for configure et al. work better.
1777 * Namespace cleanup: all shell variables used internally by Autoconf
1778 have names beginning with `ac_'.
1780 More big improvements are in process for future releases, but have not
1781 yet been (variously) finished, integrated, tested, or documented enough
1784 Major changes in Autoconf 1.7:
1786 * New macro AC_OBSOLETE.
1787 * Bugs in Makefile.in fixed.
1788 * AC_LONG_FILE_NAMES improved.
1790 Major changes in Autoconf 1.6:
1792 * New macro AC_LONG_64_BITS.
1793 * Multiple .h files can be created.
1794 * AC_FIND_X looks for X files directly if it doesn't find xmkmf.
1795 * AC_ALLOCA defines C_ALLOCA if using alloca.c.
1796 * --with-NAME can take a value, e.g., --with-targets=sun4,hp300bsd.
1797 * Unused --no-create option to configure removed.
1798 * autoheader doesn't change the timestamp of its output file if
1799 the file didn't change.
1800 * All macros that look for libraries now use AC_HAVE_LIBRARY.
1801 * config.status checks three optional environment variables to
1802 modify its behavior.
1803 * The usual bug fixes.
1805 Major changes in Autoconf 1.5:
1807 * New macros AC_FIND_X, AC_OFF_T, AC_STAT_MACROS_BROKEN, AC_REVISION.
1808 * autoconf and autoheader scripts have GNU standards conforming
1809 --version and --help options (they print their message and exit).
1812 Major changes in Autoconf 1.4:
1814 * New macros AC_HAVE_POUNDBANG, AC_TIME_WITH_SYS_TIME, AC_LONG_DOUBLE,
1815 AC_GETGROUPS_T, AC_DEFINE_UNQUOTED.
1816 * autoconf and autoheader use the M4 environment variable to determine the
1817 name of the M4 program to use.
1818 * The --macrodir option to autoconf and autoheader specifies the directory
1819 in which acspecific.m4, acgeneral.m4, etc. reside if not the default.
1820 * autoconf and autoheader can take `-' as their file names, which means to
1821 read stdin as input.
1822 * Resulting configure scripts can take a --verbose option which causes them
1823 to print the results of their tests.
1824 * AC_DEFINE quotes its second argument in such a way that spaces, magic
1825 shell characters, etc. will be preserved during various stages of
1826 expansion done by the shell. If you don't want this, use
1827 AC_DEFINE_UNQUOTED instead.
1828 * Much textual processing done with external calls to tr and sed have been
1829 internalized with builtin M4 `patsubst' and `translit' calls.
1830 * AC_OUTPUT doesn't hardwire the file names it outputs. Instead, you can
1831 set the shell variables `gen_files' and `gen_config' to the list of
1832 file names to output.
1833 * AC_DECLARE_YYTEXT does an AC_SUBST of `LEX_OUTPUT_ROOT', which may be
1834 "lex.yy" or "lexyy", depending on the system.
1835 * AC_PROGRAMS_CHECK takes an optional third arg. If given, it is used as
1837 * If AC_ALLOCA chooses alloca.c, it also defines STACK_DIRECTION.
1838 * AC_CONST works much more reliably on more systems.
1841 Major changes in Autoconf 1.3:
1843 configure no longer requires awk for packages that use a config.h.
1844 Support handling --with-PACKAGE options.
1845 New `autoheader' script to create `config.h.in' from `configure.in'.
1846 Ignore troublesome -lucb and -lPW when searching for alloca.
1847 Rename --exec_prefix to --exec-prefix for GNU standards conformance.
1848 Improve detection of STDC library.
1849 Add AC_HAVE_LIBRARY to check for non-default libraries.
1850 Function checking should work with future GNU libc releases.
1852 Major changes in Autoconf 1.2:
1854 The --srcdir option is now usually unnecessary.
1855 Add a file containing sample comments describing CPP macros.
1856 A comment in config.status tells which host it was configured on.
1857 Substituted variable values can now contain commas.
1858 Fix bugs in various feature checks.
1860 Major changes in Autoconf 1.1:
1862 Added AC_STRCOLL macro.
1863 Made AC_GETLOADAVG check for more things.
1864 AC_OUTPUT argument is now optional.
1869 Copyright (C) 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001, 2002,
1870 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
1872 This program is free software: you can redistribute it and/or modify
1873 it under the terms of the GNU General Public License as published by
1874 the Free Software Foundation, either version 3 of the License, or
1875 (at your option) any later version.
1877 This program is distributed in the hope that it will be useful,
1878 but WITHOUT ANY WARRANTY; without even the implied warranty of
1879 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
1880 GNU General Public License for more details.
1882 You should have received a copy of the GNU General Public License
1883 along with this program. If not, see <http://www.gnu.org/licenses/>.