1 GNU Autoconf NEWS - User visible changes.
3 * Major changes in Autoconf 2.64 (????-??-??) [stable]
4 Released by Eric Blake, based on git versions 2.63.*.
6 ** The manual is now shipped under the terms of the GNU FDL 1.3.
8 ** AC_REQUIRE now detects the case of an outer macro which first expands
9 then later indirectly requires the same inner macro. Previously,
10 this case led to silent out-of-order expansion (bug present since
11 2.50); it now issues a syntax warning, and duplicates the expansion
12 of the inner macro to guarantee dependencies have been met. See
13 the manual for advice on how to refactor macros in order to avoid
14 the bug in earlier autoconf versions and avoid increased script
15 size in the current version.
17 ** AC_DEFUN_ONCE has improved semantics. Previously, a macro declared
18 with AC_DEFUN_ONCE warned on a second invocation; and out-of-order
19 expansion was still possible. Now, dependencies are guaranteed,
20 and subsequent invocations are a silent no-op. This makes
21 AC_DEFUN_ONCE an ideal macro for silencing AC_REQUIRE warnings.
23 ** AC_LANG_ERLANG works once again (regression introduced in 2.61a).
25 ** AC_HEADER_ASSERT is fixed so that './configure --enable-assert' no
26 longer mistakenly disables assertions.
28 ** AC_INIT now takes an optional fifth parameter that can be used to
29 set AC_PACKAGE_URL, a URL for the package's home page; the URL is
30 used in `configure --help' and is also available via AC_DEFINE.
32 ** Autotest testsuites accept an option --jobs[=N] for parallel testing.
34 ** Autotest testsuites do not attempt to write startup error messages
35 to the log file before that is opened (regression introduced in 2.63).
37 ** Configure scripts now use shell functions.
39 ** Present But Cannot Be Compiled: Autoconf will now proceed with
40 the compiler's result if a header is present but cannot be compiled.
41 The warning is still printed, and you should really fix it by
42 providing a fourth parameter to AC_CHECK_HEADER/AC_CHECK_HEADERS.
44 ** Autoreconf added aclocal to the set of programs affected by the
45 `autoreconf -I dir' option.
47 ** The following documented m4sugar macros are new:
48 m4_chomp m4_curry m4_default_quoted m4_esyscmd_s m4_map_args
49 m4_map_args_pair m4_map_args_sep m4_map_args_w m4_set_map
50 m4_set_map_sep m4_stack_foreach m4_stack_foreach_lifo
51 m4_stack_foreach_sep m4_stack_foreach_sep_lifo
53 ** The following m4sugar macros are documented now, but in some cases
54 with slightly different semantics than what the previous
55 undocumented version had:
56 m4_copy m4_dumpdefs m4_rename m4_version_prereq
58 ** The m4sugar macro m4_expand has been taught to handle unterminated
59 comments and shell case statements. As a result, it is used
60 internally in more places, such as AC_DEFINE and AT_CHECK. Most
61 uses of AC_DEFINE and AT_CHECK should not behave any differently;
62 however, it may be necessary to add double-quoting around
63 unbalanced `(' where single-quoting used to be sufficient.
65 ** The following documented m4sh macros are new:
66 AS_LINENO_PREPARE AS_ME_PREPARE AS_SET_STATUS AS_VAR_APPEND
67 AS_VAR_ARITH AS_VAR_COPY
69 ** The following m4sh macros are documented now, but in some cases
70 with slightly different semantics than what the previous
71 undocumented version had:
72 AS_ECHO AS_ECHO_N AS_EXIT AS_LITERAL_IF AS_UNSET AS_VAR_IF
73 AS_VAR_POPDEF AS_VAR_PUSHDEF AS_VAR_SET AS_VAR_SET_IF
74 AS_VAR_TEST_SET AS_VERSION_COMPARE
76 ** The m4sh macros AS_IF and AS_CASE can now be used in shell lists.
77 The responsibility for supplying a trailing newline now belongs to
78 the call site, but since most users did not add dnl, this generally
79 results in fewer empty lines in configure.
82 * Major changes in Autoconf 2.63 (2008-09-09) [stable]
83 Released by Eric Blake, based on git versions 2.62.*.
85 ** AC_C_BIGENDIAN does not mistakenly report "universal" for some
86 bigendian hosts, a regression introduced with universal binary
89 ** AC_PATH_X now includes /lib64 and /usr/lib64 in its list of default
92 ** AC_USE_SYSTEM_EXTENSIONS no longer conflicts with an external
93 AC_DEFINE([__EXTENSIONS__]). This fixes a regression introduced in
94 2.62 when using macros such as AC_AIX that were made obsolete in
95 favor of the more portable AC_USE_SYSTEM_EXTENSIONS.
97 ** AC_CHECK_TARGET_TOOLS is usable in the non-cross-compile case.
99 ** Newly obsolete macros
100 The following macro has been marked obsolete, since current porting
101 targets can safely assume C89 semantics that signal handlers return
102 void. We have no current plans to remove the macro.
106 ** The macros m4_map and m4_map_sep now ignore any list elements
107 consisting of just empty quotes, and m4_map_sep now expands its
108 separator. This fixes a regression in 2.62 when these macros were
109 first documented, for the sake of clients expecting the semantics
110 that these macros had prior to that time. The new macros m4_mapall
111 and m4_mapall_sep, along with extra quoting of the separator, can
112 be used to get the semantics that m4_map_sep had in 2.62.
114 ** Clients of m4_expand, such as AS_HELP_STRING and AT_SETUP, can now
115 handle properly quoted but otherwise unbalanced parentheses (for
116 some macros, this fixes a regression in 2.62).
118 ** Two new quadrigraphs have been introduced: @{:@ for (, and @:}@ for ),
119 allowing the output of unbalanced parentheses in more contexts.
121 ** The following m4sugar macros are new:
122 m4_cleardivert m4_joinall m4_mapall m4_mapall_sep m4_reverse
123 m4_set_add m4_set_add_all m4_set_contains m4_set_contents
124 m4_set_delete m4_set_difference m4_set_dump m4_set_empty
125 m4_set_foreach m4_set_intersection m4_set_list m4_set_listc
126 m4_set_remove m4_set_size m4_set_union
128 ** The following m4sugar macros now accept multiple arguments, as is the
129 case with underlying m4:
130 m4_defn m4_popdef m4_undefine
132 ** The following m4sugar macros now guarantee linear scaling; they
133 previously had linear scaling with m4 1.6 but quadratic scaling
134 when using m4 1.4.x. All macros built on top of these also gain
135 the scaling improvements.
136 m4_bmatch m4_bpatsubsts m4_case m4_cond m4_do m4_dquote_elt
137 m4_foreach m4_join m4_list_cmp m4_map m4_map_sep m4_max
140 ** AT_KEYWORDS once again performs expansion on its argument, such that
141 AT_KEYWORDS([m4_if([$1], [], [default])]) no longer complains about
142 the possibly unexpanded m4_if [regression introduced in 2.62].
144 ** Config header templates `#undef UNDEFINED /* comment */' do not lead to
145 nested comments any more; regression introduced in 2.62.
148 * Major changes in Autoconf 2.62 (2008-04-05) [stable]
149 Released by Eric Blake, based on git versions 2.61a.*.
151 ** Many optimizations have been applied to make overall execution faster.
153 ** Autotest now makes use of shell functions.
155 ** config.status now uses awk instead of sed also for config headers.
157 - As a side effect, AC_DEFINE and AC_DEFINE_UNQUOTED now handle multi-line
158 values, i.e., backslash-newline combinations are handled correctly.
159 Further, for config headers, the total size of values is not limited by
160 the POSIX length limit of text lines any more, only each single line.
162 ** New config variable `top_build_prefix'.
164 ** New Autoconf macros:
165 AC_AUTOCONF_VERSION AC_OPENMP AC_PATH_PROGS_FEATURE_CHECK
167 ** AC_C_BIGENDIAN now supports universal binaries a la Mac OS X.
169 ** AC_C_RESTRICT now prefers to #define 'restrict' to a variant spelling
170 like '__restrict' if the variant spelling is available, as this is
171 more likely to work when mixing C and C++ code.
173 ** AC_CHECK_ALIGNOF's type argument T is now documented better: it must
174 be a string of tokens such that "T y;" is a valid member declaration
177 ** AC_CHECK_SIZEOF now accepts objects as well as types: the general rule
178 is that sizeof (X) works, then AC_CHECK_SIZEOF (X) should work.
180 ** AC_CHECK_TYPE and AC_CHECK_TYPES now work on any C type-name; formerly,
181 they did not work for function types. In C++, they now work on any
182 type-id that can be the operand of sizeof; this is similar to C,
183 except it excludes anonymous struct and union types. Formerly,
184 some (but not all) C++ types involving anonymous struct and union
185 were accepted, though this was not documented.
187 ** AC_CONFIG_LINKS now prefers to link against files in the build tree
188 if found, and it works to link against a file of the same name in
189 the source tree, even if both trees coincide.
191 ** AC_INIT no longer alters $@; regression introduced in 2.60.
193 ** AC_USE_SYSTEM_EXTENSIONS now defines _ALL_SOURCE for Interix platforms.
195 ** AS_HELP_STRING no longer underquotes its first argument; it also handles
196 the case where the first argument contains single-quoted commas.
197 For example, "AS_HELP_STRING([-a, [--arg[=foo]]], [bar])" produces:
198 " -a, --arg[=foo] bar"
199 Additionally, the macro now takes two additional arguments,
200 indent-column and wrap-column; these should not normally be needed,
201 but can be used to fine-tune how the output text is wrapped.
203 ** AC_PROG_INSTALL now requires an install program that can install multiple
204 files into a target directory.
206 ** The command 'autoconf -' now correctly processes a file from stdin.
208 ** 'autoreconf -m' now honors $MAKE.
210 ** For all of the directory arguments for 'configure', such as '--prefix'
211 or '--bindir', trailing slashes are stripped. As an example, if
212 tab completion in the user's shell appends trailing slashes, the
213 command './configure --prefix=/usr/' will still result in an
214 expanded libdir value of /usr/lib, not /usr//lib.
216 ** `configure --help=recursive' now works in read-only trees and from
217 unconfigured build trees.
219 ** If precious variables differ only in whitespace, then the cache consistency
220 check warns instead of fails, and reuses the old value.
222 ** AT_BANNER is now documented.
224 ** AT_SETUP now handles macro expansions properly when calculating line
227 ** Autotest now determines $srcdir correctly.
229 ** Testsuites built by autotest now accept a -C/--directory=DIR option
230 to adjust the working directory prior to creating files.
232 ** Autoconf now requires GNU M4 1.4.5 or later. Earlier versions of M4 have
233 a bug in macro tracing that interferes with the interaction between
234 Autoconf and Automake. GNU M4 1.4.11 or later is recommended. The
235 configure search for a working M4 is improved.
237 ** For portability with the eventual M4 2.0, macros should no longer use
238 anything larger than $9 to refer to arguments.
240 ** Documentation for m4sugar is improved.
242 - The following macros were previously available as undocumented
243 interfaces; the macros are now documented as stable interfaces.
245 __oline__ m4_assert m4_bmatch m4_bpatsubsts m4_car m4_case
246 m4_cdr m4_default m4_divert_once m4_divert_pop m4_divert_push
247 m4_divert_text m4_do m4_errprintn m4_fatal m4_flatten
248 m4_ifndef m4_ifset m4_ifval m4_ifvaln m4_location
249 m4_n m4_shiftn m4_strip m4_warn
251 - The following macros were previously available as undocumented
252 interfaces, but had bug fixes or semantic changes as part of this
253 release. Packages that relied on the undocumented behavior
254 should be analyzed to make sure they will still work with the
255 new documented behavior.
257 m4_cmp m4_list_cmp m4_join m4_map m4_map_sep m4_sign
258 m4_text_box m4_text_wrap m4_version_compare
260 - The m4_wrap macro used to have unspecified order, but now
261 guarantees FIFO order. m4_wrap_lifo was added to guarantee LIFO
264 - Packages using the undocumented m4sugar macro m4_PACKAGE_VERSION
265 should consider using the new AC_AUTOCONF_VERSION instead.
267 - m4sugar macros that are not documented in the manual are still
268 deemed experimental, and should not be used outside of Autoconf.
270 ** The m4sugar macros m4_append and m4_append_uniq, first documented in
271 2.60, have been fixed to treat both the string and the separator
272 arguments consistently with regards to quoting. Prior to this fix,
273 m4_append_uniq could mistakenly duplicate entries if the expansion
274 of the separator resulted in a different string (for example, if it
275 contained quotes, a comma, or a macro name). However, it means
276 that programs previously using
277 m4_append([name], [string], [[, ]])
278 are now using a four-character separator instead of the intended
279 comma and space. If you need portability to earlier versions of
280 Autoconf, you can insert the following snippet after AC_INIT but
281 before any other macro expansions, to enforce the new semantics:
282 m4_pushdef([m4_append], [m4_define([$1],
283 m4_ifdef([$1], [m4_defn([$1])[$3]])[$2])])
284 Additionally, m4_append_uniq now takes optional parameters that can
285 be used to take action depending on whether anything was appended,
286 and warns if a non-empty separator occurs within the string being
287 appended, since that can lead to duplicates.
289 ** The following m4sugar macros are new:
290 m4_append_uniq_w m4_apply m4_combine m4_cond m4_count
291 m4_dquote_elt m4_echo m4_expand m4_ignore m4_make_list m4_max
292 m4_min m4_newline m4_shift2 m4_shift3 m4_unquote m4_wrap_lifo
294 ** Warnings are now generated by default when an installer invokes
295 'configure' with an unknown --enable-* or --with-* option.
296 These warnings can be disabled with the new AC_DISABLE_OPTION_CHECKING
297 macro, or by invoking 'configure' with --disable-option-checking.
299 ** Existing obsolete macros
300 The documentation for the following macros is adjusted to make it
301 more clear that they have previously been marked obsolete, as their
302 functionality can be accomplished by other macros. We have no
303 current plans to remove them from Autoconf.
305 AC_ENABLE AC_STRUCT_ST_BLKSIZE AC_STRUCT_ST_RDEV AC_WITH
307 ** Newly obsolete macros
308 The following macros have been marked obsolete, as they only
309 perform a subset of AC_USE_SYSTEM_EXTENSIONS. We have no current
310 plans to remove them.
312 AC_AIX AC_GNU_SOURCE AC_ISC_POSIX AC_MINIX
314 ** AC_C_LONG_DOUBLE is obsolescent.
315 The documentation now says that AC_C_LONG_DOUBLE is obsolescent: it
316 tests for problems that are so old that it is no longer of
317 practical importance on current systems. New programs need not use
318 AC_C_LONG_DOUBLE. We have no current plans to remove it.
320 ** AC_DIAGNOSE, AC_WARNING, and AC_FATAL are obsolescent.
321 The documentation now favors the use of M4sugar macros m4_warn and
322 m4_fatal, since the naming makes it more obvious that the
323 diagnostics are associated with M4 expansion (ie. when running
324 `autoconf'), and offers less confusion with the AC_MSG_ERROR,
325 AC_MSG_FAILURE, and AC_MSG_WARN macros which manage diagnostics
326 when running `configure'. We have no current plans to remove these
330 * Major changes in Autoconf 2.61a (2006-12-11)
332 ** AC_FUNC_FSEEKO was broken in 2.61; it didn't make fseeko and ftello visible
333 on many platforms. This has been fixed.
335 ** AC_FUNC_SETVBUF_REVERSED is now obsolete. It is still defined for backward
336 compatibility but it does nothing. The macro was already
337 obsolescent, as the last systems to have the problem were those
338 based on SVR2, which became obsolete in 1987. The macro had bugs
339 on some modern systems and could no longer be maintained reliably
340 due to lack of ancient systems to test it on.
342 ** config.status now uses awk instead of sed for most substitutions, for speed.
344 - As a side effect multi-line values of substituted variables no
345 longer have a small limit in total size, though for portability
346 each line should not exceed the POSIX length limit for text lines.
348 - It is now documented that Makefile.in should not contain
349 overlapping variable occurrences, e.g., @VAR1@VAR2@.
350 Autoconf's behavior was always iffy in such cases, and the
351 awk implementation has changed the behavior.
353 ** Many uses of 'echo' have been rewritten so that Autoconf-generated
354 scripts have fewer problems with strings or file names containing
355 embedded special characters such as backslash or leading "-". This
356 was implemented by using `printf '%s\n' "$foo"' instead of `echo
357 "$foo"' when printf works. Due to the implementation technique
358 used, Autoconf-generated scripts now run considerably more slowly
359 on ancient implementations lacking printf. However, this should
360 not be a problem, since Autoconf-generated scripts in practice
361 invariably find a more-modern shell these days.
364 * Major changes in Autoconf 2.61 (2006-11-17)
366 ** New macros AC_C_FLEXIBLE_ARRAY_MEMBER, AC_C_VARARRAYS.
368 ** AC_ARG_ENABLE and AC_ARG_WITH now allow '.' in feature and package names.
371 * Major changes in Autoconf 2.60b (2006-10-22)
374 Autoconf-generated shell scripts no longer export BIN_SH, due to
375 configuration hassles with this. Installers who need BIN_SH in
376 their environment should set it before invoking 'configure' and
377 'make'. As far as we know, this affects only Unixware installations.
379 ** Obsolescent macros
380 The documentation now says that the following macros are obsolescent,
381 as they are superseded by Gnulib:
383 AC_FUNC_FNMATCH AC_FUNC_FNMATCH_GNU AC_FUNC_GETLOADVG AC_REPLACE_FNMATCH
385 New programs should use the Gnulib counterparts of these macros.
386 We have no current plans to remove them from Autoconf.
388 ** AC_COMPUTE_INT no longer caches or reports results.
390 ** AC_CHECK_DECL now also works with aggregate objects.
392 ** AC_USE_SYSTEM_EXTENSIONS now defines _TANDEM_SOURCE for NonStop platforms.
394 ** GNU M4 1.4.7 or later is now recommended.
397 New M4sugar macro, which is more secure than the POSIX M4 maketemp.
400 Now an alias for m4_mkstemp.
402 * Major changes in Autoconf 2.60a (2006-08-25)
404 ** GNU M4 1.4.6 or later is now recommended.
406 ** The check for C99 now tests for varargs macros, as documented.
407 It also tests that the preprocessor supports 64-bit integers.
409 ** Autoconf now uses constructs like "#ifdef HAVE_STDLIB_H" rather than
410 "#if HAVE_STDLIB_H", so that it now works with "gcc -Wundef -Werror".
412 ** The functionality of the undocumented _AC_COMPUTE_INT is now provided
413 by a public and documented macro, AC_COMPUTE_INT. The parameters to the
414 two macros are different, so autoupdate will not change the old private name
415 to the new one. _AC_COMPUTE_INT may be removed in a future release.
417 ** AC_TYPE_LONG_LONG_INT and AC_TYPE_UNSIGNED_LONG_LONG_INT now require
418 that long long types be at least 64 bits wide, as C99 and tradition
419 requires. Formerly, they accepted implementations of any width.
422 * Major changes in Autoconf 2.60
424 Released 2006-06-23, by Ralf Wildenhues.
426 ** Autoconf no longer depends on whether m4wrap is FIFO (as Posix requires)
427 or LIFO (as in GNU M4 1.4.x). GNU M4 2.0 is expected to conform to Posix
428 here, so m4wrap/m4_wrap users should no longer depend on LIFO behavior.
430 ** Provide a way to turn off warnings about the changed directory variables.
432 * Major changes in Autoconf 2.59d
434 Released 2006-06-05, by Ralf Wildenhues.
436 ** GNU make now recommended for VPATH builds
437 INSTALL now suggests VPATH builds (e.g., "sh ../srcdir/configure")
438 only if you use GNU make. In practice, other 'make' implementations
439 have too many subtle incompatibilities in their support for VPATH.
440 Many packages (including Autoconf itself) are portable to other
441 'make' implementations, but some packages are not, and recommending
442 GNU make keeps the installation instructions simpler.
444 ** Even more safety checks for the new Directory variables:
445 Warn about suspicious `${datarootdir}' found in config files output.
447 ** AC_TRY_COMMAND, AC_TRY_EVAL, ac_config_guess, ac_config_sub, ac_configure
448 These never-documented macros and variables have been marked with
449 comments saying that they may be removed in a future release,
450 because their use can lead to unintended code being executed.
451 If you need functionality that only these macros or variables
452 currently supply, please write bug-autoconf@gnu.org.
454 ** AC_SUBST, AC_DEFINE
455 Literal arguments to these are passed to m4_pattern_allow now.
458 Passing 'ac_cv_prog_cc_stdc=no' to 'configure' now sets ac_cv_prog_cc_c99
459 and ac_cv_prog_cc_c89 to 'no' as well, for backward compatibility with
460 obsolete K&R tests in the Automake test suite.
469 Now more robust with special characters in file names, or when
470 multiple processes create the same directory at the same time.
472 ** Obsolescent macros
473 The documentation now says that the following macros are obsolescent:
474 they test for problems that are so old that they are no longer of
475 practical importance on current systems.
477 AC_C_BACKSLASH_A AC_FUNC_MEMCMP AC_HEADER_DIRENT
478 AC_C_CONST AC_FUNC_SELECT_ARGTYPES AC_HEADER_STAT
479 AC_C_PROTOTYPES AC_FUNC_SETPGRP AC_HEADER_STDC
480 AC_C_STRINGIZE AC_FUNC_SETVBUF_REVERSED AC_HEADER_SYS_WAIT
481 AC_C_VOLATILE AC_FUNC_STAT AC_HEADER_TIME
482 AC_FUNC_CLOSEDIR_VOID AC_FUNC_STRFTIME AC_ISC_POSIX
483 AC_FUNC_GETPGRP AC_FUNC_UTIME_NULL AC_PROG_GCC_TRADITIONAL
484 AC_FUNC_LSTAT AC_FUNC_VPRINTF AC_STRUCT_TM
486 New programs need not use these macros. We have no current plans to
490 For compatibility with future Libtool 2.0, autoreconf will invoke
491 libtoolize with the option `--ltdl' now, if LT_CONFIG_LTDL_DIR is
494 * Major changes in Autoconf 2.59c
496 Released 2006-04-12, by Ralf Wildenhues.
498 ** The configure command now redirects standard input from /dev/null,
499 to help avoid problems with subsidiary commands that might mistakenly
500 read standard input. AS_ORIGINAL_STDIN_FD points to the original
501 standard input before this redirection, if you really want configure to
502 read from standard input.
504 ** Directory variables adjusted to recent changes in the GNU Coding Standards.
505 The following directory variables are new:
507 datarootdir read-only architecture-independent data root [PREFIX/share]
508 localedir locale-specific message catalogs [DATAROOTDIR/locale]
509 docdir documentation root [DATAROOTDIR/doc/PACKAGE]
510 htmldir html documentation [DOCDIR]
511 dvidir dvi documentation [DOCDIR]
512 pdfdir pdf documentation [DOCDIR]
513 psdir ps documentation [DOCDIR]
515 The following variables have new default values:
517 datadir read-only architecture-independent data [DATAROOTDIR]
518 infodir info documentation [DATAROOTDIR/info]
519 mandir man documentation [DATAROOTDIR/man]
521 This means that if you use any of `@datadir@', `@infodir@', or
522 `@mandir@' in a file, you will have to ensure `${datarootdir}' is
523 defined in this file. As a temporary measure, if any of those are
524 found but no mention of `datarootdir', the substitutions will be
525 replaced with values that do not contain `${datarootdir}', and a
526 warning will be issued.
528 ** @top_builddir@ is now a dir name: it is always nonempty and doesn't have
529 a trailing slash. Similar change will be made to ac_top_builddir in a
530 future release; the old style value, which matches (../)*, is (and will
531 continue to be) available as ac_top_build_prefix.
534 New macro to check for support of 'typeof' syntax a la GNU C.
536 ** AC_CHECK_DECLS_ONCE, AC_CHECK_FUNCS_ONCE, AC_CHECK_HEADERS_ONCE
537 New "once-only" variants of commonly-used macros, to make 'configure'
538 smaller and faster in common cases.
541 New macro to check for strtold with C99 semantics.
544 New macro that lets builder disable assertions at 'configure'-time.
547 Now checks for X11/Xlib.h and XrmInitialize (X proper) rather than
548 X11/Intrinsic.h and XtMalloc (Xt).
550 ** AC_PRESERVE_HELP_ORDER
551 New macro that causes `configure' to display help strings for AC_ARG_ENABLE
552 and AC_ARG_WITH arguments in one region, in the order defined. The default
553 behavior is to group options of each classes separately.
555 ** AC_PROG_CC, AC_PROG_CXX
556 No longer automatically arrange to declare the 'exit' function of C,
557 when a C++ compiler is used. Standard Autoconf macros no longer use
558 'exit', so this is no longer an issue for them. If you use C++, and
559 want to call 'exit', you'll have to arrange for its declaration
560 yourself. But we now suggest you return from 'main' instead.
562 ** AC_PROG_CC_C89, AC_PROG_CC_C99
563 New macros for ISO C99 support. AC_PROG_CC_C89 and AC_PROG_CC_C99
564 check for ANSI C89 and ISO C99 support respectively.
567 Has been unobsoleted, and will check if the compiler supports ISO
568 C99, falling back to ANSI C89 if not. ac_cv_prog_cc_stdc is
569 retained for backwards compatibility, assuming the value of
570 ac_cv_prog_cc_c99 or ac_cv_prog_cc_c89 (whichever is valid, in
573 ** AC_STRUCT_DIRENT_D_INO, AC_STRUCT_DIRENT_D_TYPE
574 New macros for checking commonly-used members of struct dirent.
577 The substituted value can now contain newlines.
580 The substitution now occurs only when @variable@ is on a line by itself,
581 optionally surrounded by spaces and tabs. The whole line is replaced.
583 ** AC_TYPE_LONG_DOUBLE, AC_TYPE_LONG_DOUBLE_WIDER
584 New macros to check for long double, and whether it is wider than double.
585 The old macro AC_C_TYPE_LONG_DOUBLE has been marked as obsolete;
586 applications should switch to the new macro.
588 ** AC_TYPE_INT8_T, AC_TYPE_INT16_T, AC_TYPE_INT32_T, AC_TYPE_INT64_T,
589 AC_TYPE_INTMAX_T, AC_TYPE_INTPTR_T, AC_TYPE_LONG_LONG_INT, AC_TYPE_SSIZE_T,
590 AC_TYPE_UINT8_T, AC_TYPE_UINT16_T, AC_TYPE_UINT32_T, AC_TYPE_UINT64_T,
591 AC_TYPE_UINTMAX_T, AC_TYPE_UINTPTR_T, AC_TYPE_UNSIGNED_LONG_LONG_INT
592 New macros to check for C99 and POSIX types.
594 ** AC_USE_SYSTEM_EXTENSIONS
595 New macro to enable extensions to Posix.
598 New macro which is defined to the name of the first declared config header
599 or undefined if no config headers have been declared yet.
602 The macro correctly handles quadrigraphs now.
604 ** AS_BOURNE_COMPATIBLE, AS_SHELL_SANITIZE, AS_CASE
605 These macros are new or published now.
608 New macro for copyright notices in testsuite files.
610 ** ALLOCA, LIBOBJS, LTLIBOBJS
611 Object names added to these variables are now prefixed with `${LIBOBJDIR}',
612 as in `${LIBOBJDIR}alloca.o'. LIBOBJDIR is meant to be defined from
613 `Makefile.in' in case the object files lie in a different directory.
614 The LIBOBJDIR feature is experimental.
617 Supports --no-recursive now.
619 ** New macros to support Erlang/OTP.
620 New macros for configuring paths to Erlang tools and libraries:
621 AC_ERLANG_PATH_ERLC, AC_ERLANG_NEED_ERLC, AC_ERLANG_PATH_ERL,
622 AC_ERLANG_NEED_ERL, AC_ERLANG_CHECK_LIB, AC_ERLANG_SUBST_ROOT_DIR,
623 AC_ERLANG_SUBST_LIB_DIR.
625 New macros for configuring installation of Erlang libraries:
626 AC_ERLANG_SUBST_INSTALL_LIB_DIR, AC_ERLANG_SUBST_INSTALL_LIB_SUBDIR.
628 ** The manual now mentions Gnulib more prominently.
630 ** New macros to support Objective C.
631 AC_PROG_OBJC, AC_PROG_OBJCPP.
633 * Major changes in Autoconf 2.59b
635 Released 2004-08-20, by Paul Eggert.
638 New macro that computes the default alignment of a type.
640 ** AC_CHECK_TOOL, AC_PATH_TOOL, AC_CHECK_TOOLS
641 When cross-compiling, these macros will give a warning if the tool
642 is not prefixed. In the future, unprefixed cross tools will not
643 be detected; please consult the info documentation for information
644 about the reason of this change.
646 ** AC_CHECK_TARGET_TOOL, AC_PATH_TARGET_TOOL, AC_CHECK_TARGET_TOOLS
647 New macros that detect programs whose name is prefixed with the
648 target type, if the build type and target type are different.
650 ** AC_REQUIRE_AUX_FILE
651 New trace macro that declares expected auxiliary files.
654 New macro that tests for a grep program that accepts as a long a line
657 ** AC_PROG_EGREP, AC_PROG_FGREP
658 These macros now require AC_PROG_GREP, and try EGREP="$GREP -E" and
659 FGREP="$GREP -F" respectively if possible, or else run a path search for
660 a program that accepts as long a line as possible.
663 New macro that tests for a sed program that truncates as few characters
666 * Major changes in Autoconf 2.59
668 Released 2003-11-04, by Akim Demaille
670 ** ac_abs_builddir etc.
671 Absolute file names were actually relative in 2.58.
673 * Major changes in Autoconf 2.58
675 Released 2003-11-04, by Akim Demaille
678 core.* files are no longer removed, as they may be valid user files.
680 ** autoreconf and auxiliary directory
681 Autoreconf creates the auxiliary directory if needed. This is
682 especially useful for initial "bootstrapping" of fresh CVS checkouts.
684 ** AC_CONFIG_MACRO_DIR
685 Use this macro to declare the directory for local M4 macros for aclocal.
688 No longer includes twice the same file in LIBOBJS if invoked
691 ** AC_CONFIG_COMMANDS
692 The directory for its first argument is automatically created. For
695 AC_CONFIG_COMMANDS([src/modules.hh], [...])
697 $top_builddir/src/ is created if needed.
699 ** Autotest and local.at
700 The optional file local.at is always included in Autotest test suites.
703 The warnings are always issued, including with cached runs.
704 This became a significant problem since aclocal and automake can
705 run autoconf behind the scene.
707 ** autoheader warnings
708 The warnings of autoheader can be turned off, using --warning.
709 For instance, -Wno-obsolete disables the complaints about acconfig.h
710 and other deprecated constructs.
713 AC_C_RESTRICT, AC_INCLUDES_DEFAULT, AC_LANG_ASSERT, AC_LANG_WERROR,
716 ** AC_DECL_SYS_SIGLIST
720 Now checks that mktime is the inverse of localtime.
722 ** Improve DJGPP portability
723 The Autoconf tools and configure behave better under DJGPP.
725 ** Present But Cannot Be Compiled
726 New FAQ section dedicated to the mystic
728 configure: WARNING: pi.h: present but cannot be compiled
729 configure: WARNING: pi.h: check for missing prerequisite headers?
730 configure: WARNING: pi.h: proceeding with the preprocessor's result
733 ** Concurrent executions of autom4te
734 autom4te now locks its internal files, which enables concurrent
735 executions of autom4te, likely to happen if automake, autoconf,
736 autoheader etc. are run simultaneously.
739 Use of Libtool 1.5 and higher is encouraged. Compatibility with
740 Libtool pre-1.4 is not checked.
743 Testsuites no longer rerun failed tests in verbose mode; instead,
744 failures are logged while the test is run.
746 In addition, expected failures can be marked as such.
748 * Major changes in Autoconf 2.57
750 Released 2002-12-03 by Paul Eggert.
752 Bug fixes for problems with AIX linker, with freestanding C compilers,
753 with GNU M4 limitations, and with obsolete copies of GNU documents.
755 The Free Documentation License has been upgraded from 1.1 to 1.2.
757 * Major changes in Autoconf 2.56
759 Released 2002-11-15 by Akim Demaille.
761 One packaging problem fixed (config/install-sh was not executable).
763 * Major changes in Autoconf 2.55
765 Released 2002-11-14 by Akim Demaille.
769 Have your configure.ac checked by autoscan ("autoscan").
770 Try the warning options ("autoreconf -fv -Wall").
774 - AC_CHECK_HEADER, AC_CHECK_HEADERS
775 More information on proper use.
777 - Writing Test Programs
779 This sections explains how to write good test sources to use with
780 AC_COMPILE_IFELSE etc. It documents AC_LANG_PROGRAM and so forth.
782 - AC_FOO_IFELSE vs. AC_TRY_FOO
784 Explains why Autoconf moves from AC_TRY_COMPILE etc. to
785 AC_COMPILE_IFELSE and AC_LANG_PROGRAM etc.
789 - Is more robust to different Gettext installations.
791 - Produces messages (when --verbose) to be understood by Emacs'
794 - Supports -W/--warnings.
797 Once the GNU Build System reinstalled, run `./config.status
798 --recheck && ./config.status && make' if possible.
802 - Supports --cache, and --no-cache.
804 - ~/.autom4te.cfg makes it possible to disable the caching mechanism
805 (autom4te.cache). See `Customizing autom4te' in the documentation.
812 Support for the obsoleted options -m, --macrodir, -l, --localdir is
813 dropped in favor of the safer --include/--prepend-include scheme.
818 AC_COMPILER_IFELSE, AC_FUNC_MBRTOWC, AC_HEADER_STDBOOL,
819 AC_LANG_CONFTEST, AC_LANG_SOURCE, AC_LANG_PROGRAM, AC_LANG_CALL,
820 AC_LANG_FUNC_TRY_LINK, AC_MSG_FAILURE, AC_PREPROC_IFELSE.
823 Obsoleted macros are kept for Autoconf backward compatibility, but
824 should be avoided in configure.ac. Running autoupdate is advised.
827 - AC_DEFINE/AC_DEFINE_UNQUOTED
829 We have to stop using the old compatibility scheme --that tried to
830 avoid useless backslashes-- because Libtool 1.4.3 contains a
832 AC_DEFINE([error_t], [int],
833 [Define to a type to use for \`error_t' if it is not
834 otherwise available.])
836 We have to quote the single quotes and backslashes with \. The old
837 compatibility scheme saw that ` was backslashed, and therefore did
838 not quote the single quote... Failure. Hence, Autoconf 2.54 is not
839 compatible with Libtool. Autoconf 2.55 is, but in some cases might
840 produce more \ than wanted.
842 Please, note that in the future the same problem will happen with
843 AC_MSG_*: use `autoreconf -f -Wall'.
847 - Portability of the Autoconf package to Solaris.
849 - Spurious warnings caused by config.status.
850 This bug is benign, but painful: on some systems (typically
851 FreeBSD), warnings such as:
853 config.status: creating Makefile
854 mv: Makefile: set owner/group (was: 1357/0): Operation not permitted
856 could be issued. This is fixed.
859 Simultaneous executions of config.status are possible again.
861 - Precious variables accumulation
863 config.status could stack several copies of the precious variables
867 ** Plans for later versions
871 The compatibility hooks with the old scheme will be completely
872 removed. Please, advice/use `--build', `--host', and `--target'
875 - AC_CHECK_HEADER, AC_CHECK_HEADERS
877 The tests will be stricter, please make sure your invocations are
882 Shell functions will gradually be introduced, probably starting with
883 Autotest. If you know machines which are in use that you suspect
884 *not* to support shell functions, please run the test suite of
885 Autoconf 2.55 on it, and report the results to
886 bug-autoconf@gnu.org.
890 Special characters in AC_MSG_* need not be quoted. Currently,
891 Autoconf has heuristics to decide when a string is escaped, or has
892 to be escaped. This scheme is fragile, and will be removed; the
893 only risk is uglified messages. Please, run `autoreconf -f -Wall'
894 to find occurrences that will be affected.
896 * Major changes in Autoconf 2.54
898 Released 2002-09-13 by Akim Demaille.
902 - autoreconf no longer changes the version of the gettext/po/intl
903 support files. It now adds the files the correspond to the
904 AM_GNU_GETTEXT_VERSION declared in configure.ac.
906 Warning: It now relies on the 'autopoint' program, which is part
907 of GNU gettext 0.11.4 and newer.
909 Please note that you need to have a GNU gettext version that
910 corresponds at least to the AM_GNU_GETTEXT_VERSION declared
911 in configure.ac. You can upgrade to newer GNU gettext versions,
912 though, without needing to change configure.ac.
914 - The -I DIR or --include=DIR option now appends DIR to the include path
915 instead of prepending; this is for consistency with other GNU tools.
916 The new -B DIR or --prepend-include=DIR option has the old behavior.
921 Now handles all the gory details about LIBOBJS and LTLIBOBJS.
922 Please, remove lines such as
924 # This is necessary so that .o files in LIBOBJS are also
925 # built via the ANSI2KNR-filtering rules.
926 LIBOBJS=`echo $LIBOBJS|sed 's/\.o /\$U.o /g;s/\.o$/\$U.o/'`
928 and read the `AC_LIBOBJ vs LIBOBJS' section. Do not define U in
929 your Makefiles either.
931 - AC_CONFIG_LINKS now makes copies if it can't make links.
933 - AC_FUNC_FNMATCH now tests only for POSIX compatibility, reverting to
934 Autoconf 2.13 behavior. The new macro AC_FUNC_FNMATCH_GNU also
935 tests for GNU extensions to fnmatch, and replaces fnmatch if needed.
937 - AC_FUNC_SETVBUF_REVERSED no longer fails when cross-compiling.
939 - AC_PROG_CC_STDC is integrated into AC_PROG_CC.
941 - AC_PROG_F77 default search no longer includes cf77 and cfg77.
945 AC_C_BACKSLASH_A, AC_CONFIG_LIBOBJ_DIR, AC_GNU_SOURCE,
946 AC_PROG_EGREP, AC_PROG_FGREP, AC_REPLACE_FNMATCH,
947 AC_FUNC_FNMATCH_GNU, AC_FUNC_REALLOC, AC_TYPE_MBSTATE_T.
950 looks for getloadavg.c in the CONFIG_LIBOBJ_DIR.
953 Now defines HAVE_MALLOC to 0 if `malloc' does not work, and asks
954 for an AC_LIBOBJ replacement.
958 - Spurious complaints from `m4_bmatch' about invalid regular
959 expressions are suppressed.
961 - Empty top_builddirs are properly handled.
963 - AC_CHECK_MEMBER works correctly when the member is an aggregate.
966 Now colon in the optional path arguments are properly handled.
968 ** Improved portability
970 - Both Autoconf the package, and the scripts it produces, should run
971 more reliably with Zsh. Bear in mind it is the default Bourne shell
974 - Autoconf and the scripts it produces no longer assume the existence of
975 the obsolescent commands egrep and fgrep.
979 - Limitations of Make
983 The GNATS base moved to
984 http://bugs.gnu.org/cgi-bin/gnatsweb.pl?database=autoconf
985 (It is no longer available, though.)
990 Now contains the list of ouput variables and files (AC_SUBST,
993 * Major changes in Autoconf 2.53
995 Released 2002-03-08 by Akim Demaille.
999 Perl 5.005_03 or later is required: autom4te is written in Perl and is
1000 needed by autoconf. autoheader, autoreconf, ifnames, and autoscan are
1006 Argument requirements, output variables, defined macros.
1007 - M4sugar, M4sh, Autotest
1009 - Double quoting macros
1010 AC_TRY_CPP, AC_TRY_COMPILE, AC_TRY_LINK and AC_TRY_RUN.
1012 The Autoconf manual is now distributed under the terms of the GNU FDL.
1013 - Section `Hosts and Cross-Compilation'
1014 Explains the rationale for the 2.5x changes in the cross-compilation
1015 chain, and in the relationships between build, host, and target
1017 Emphasizes that `cross-compilation' == `--host is given'.
1018 If you are working on compilers etc., be sure to read this section.
1019 - Section `AC_LIBOBJ vs. LIBOBJS'
1020 Explains why assigning LIBOBJS directly is now an error.
1021 Details how to update the code.
1026 Now used instead of hard coded line numbers.
1027 This eases the comparison of `configure's, and diminishes the
1028 pressure over control version archives.
1029 Automatic replacement for shells that don't support this feature.
1030 - New output variables
1031 @builddir@, @top_builddir@, @abs_srcdir@, @abs_top_srcdir@, @abs_builddir@,
1036 Autoconf and Autotest modes are provided.
1041 New, used by the Autoconf suite to cache and speed up most processing.
1043 Supported by autom4te, autoconf and autoheader.
1045 Replaces --autoconf-dir and --localdir in autoconf, autoheader,
1046 autoupdate, and autoreconf.
1048 No longer passes --cygnus, --foreign, --gnits, --gnu, --include-deps:
1049 automake options are to be given via AUTOMAKE_OPTIONS.
1051 Runs gettextize and libtoolize when appropriate.
1053 --m4dir is no longer supported.
1055 Now runs only in the specified directories, defaulting to `.',
1056 but understands AC_CONFIG_SUBDIRS for dependent directories.
1057 Before, it used to run on all the `configure.ac' found in the
1059 Independent packages are properly updated.
1063 - The top level $prefix is propagated to the AC_CONFIG_SUBDIRS configures.
1065 Under the user pressure, $? is finally available. Probably a mistake.
1066 - AC_F77_LIBRARY_LDFLAGS now supports the HP/UX f90 compiler.
1067 - Precious variables accumulation
1068 config.status could stack several copies of the precious variables
1070 - AC_PATH_PROG and family.
1071 Works properly when given a literal path.
1073 Somewhere since 2.13, the result had been reversed.
1077 - AC_C_BIGENDIAN supports the cross-compiling case.
1078 - AC_C_BIGENDIAN accepts ACTION-IF-TRUE, ACTION-IF-FALSE, and
1079 ACTION-IF-UNKNOWN arguments. All are facultative, and the default
1080 for ACTION-IF-TRUE is to define WORDS_BIGENDIAN like AC_C_BIGENDIAN
1082 - AC_C_LONG_DOUBLE now succeeds only if `long double' has more range or
1083 precision than `double'.
1088 It now defines the preprocessor symbols PACKAGE_NAME,
1089 PACKAGE_TARNAME, PACKAGE_VERSION, PACKAGE_STRING, and
1093 Admits a fourth optional parameter: the tar name.
1095 - AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS.
1096 Provide the user with srcdir, ac_srcdir, ac_top_srcdir, ac_builddir,
1097 ac_top_builddir, ac_abs_srcdir, ac_abs_top_srcdir, ac_abs_builddir,
1098 ac_abs_top_builddir.
1100 - AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS and AC_OUTPUT.
1101 Are much less expensive when using long lists of files.
1104 Works with shell variables, and non alphanumeric names.
1108 - AC_FUNC_STRERROR_R now sets STRERROR_R_CHAR_P, not HAVE_WORKING_STRERROR_R,
1109 because POSIX 1003.1-200x draft 7 says strerror_r returns int, not char *.
1111 - AC_FUNC_STRTOD substitutes POW_LIB.
1116 * Major changes in Autoconf 2.52
1118 Released 2001-07-18 by Akim Demaille.
1123 This feature was present in autoconf 2.50 but was not documented.
1124 For example, `@<:@' is translated to `[' just before output. This
1125 is useful when writing strings that contain unbalanced quotes, or
1126 other hard-to-quote constructs.
1127 - m4_pattern_forbid, m4_pattern_allow
1128 - Tips for upgrading from 2.13.
1129 - Using autoscan to maintain a configure.ac.
1132 - Now include stdint.h.
1133 - sys/types.h and sys/stat.h are guarded.
1134 - strings.h is included if available, and not conflicting with string.h.
1137 - The test suite is more robust and presents less false failures.
1138 - Invocation of GNU M4 now robust to POSIXLY_CORRECT.
1139 - configure accepts --prefix='' again.
1140 - AC_CHECK_LIB works properly when its first argument is not a
1142 - HAVE_INTTYPES_H is defined only if not conflicting with sys/types.h.
1143 - build_, host_, and target_alias are AC_SUBST as in 2.13.
1144 - AC_ARG_VAR properly propagates precious variables inherited from the
1145 environment to ./config.status.
1146 - Using --program-suffix/--program-prefix is portable.
1147 - Failures to detect the default compiler's output extension are less
1149 - `config.status foo' works properly when `foo' depends on variables
1150 set in an AC_CONFIG_THING INIT-CMD.
1151 - autoheader is more robust to broken input.
1152 - Fixed Fortran name-mangling and link tests on a number of systems,
1153 e.g. NetBSD; see AC_F77_DUMMY_MAIN, below.
1156 - AC_CHECK_HEADER and AC_CHECK_HEADERS support a fourth argument to
1157 specify pre-includes. In this case, the headers are compiled with
1158 cc, not merely preprocessed by cpp. Therefore it is the _usability_
1159 of a header which is checked for, not just its availability.
1160 - AC_ARG_VAR refuses to run configure when precious variables have
1162 - Versions of compilers are dumped in the logs.
1163 - AC_CHECK_TYPE recognizes use of `foo_t' as a replacement type.
1166 - AC_PATH_XTRA only adds -ldnet to $LIBS if it's needed to link.
1167 - AC_FUNC_WAIT3 and AC_SYS_RESTARTABLE_SYSCALLS are obsoleted.
1168 - AM_FUNC_ERROR_AT_LINE, AM_FUNC_FNMATCH, AM_FUNC_MKTIME,
1169 AM_FUNC_OBSTACK, and AM_FUNC_STRTOD are now activated.
1170 Be sure to read `Upgrading from Version 2.13' to understand why
1171 running `autoupdate' is needed.
1172 - AC_F77_DUMMY_MAIN, AC_F77_MAIN: new macros to detect whether
1173 a main-like routine is required/possible when linking C/C++ with
1174 Fortran. Users of e.g. AC_F77_WRAPPERS should be aware of these.
1175 - AC_FUNC_GETPGRG behaves better when cross-compiling.
1177 * Major changes in Autoconf 2.51
1178 There was no release of Autoconf 2.51 since some packagers had used
1179 this version number without permission to ship intermediary versions
1180 of 2.50. The version was skipped to avoid confusion.
1182 * Major changes in Autoconf 2.50
1184 Released 2001-05-21 by Akim Demaille.
1186 ** Lots of bug fixes
1187 There have been far too many to enumerate them here. Check out
1188 ChangeLog if you really want to know more.
1190 ** Improved documentation
1191 In particular, portability issues are better covered.
1194 All the standard GNU Makefile targets are supported. The layout has
1195 changed: m4/ holds the M4 extensions Autoconf needs for its
1196 configuration, doc/ contains the documentation, and tests/ contains
1199 ** Man pages are provided
1200 For autoconf, autoreconf, autoupdate, autoheader, autoscan, ifnames,
1201 config.guess, config.sub.
1205 Provides a safe and powerful means to trace the macro uses. This
1206 provide the parsing layer for tools which need to `study'
1210 Specify what category of warnings should be enabled.
1212 - When recursing into subdirectories, try for configure.gnu before
1213 configure to adapt for packages not using autoconf on case-insensitive
1217 More errors are now caught (circular AC_REQUIRE dependencies,
1218 AC_DEFINE in the action part of an AC_CACHE_CHECK, too many pops
1219 etc.). In addition, their location and call stack are given.
1222 autoupdate is much more powerful, and is able to provide the glue code
1223 which might be needed to move from an old macro to its newer
1226 You are strongly encouraged to use it to modernize both your
1227 `configure.in' and your .m4 extension files.
1230 The internal machinery of autoheader has completely changed. As a
1231 result, using `acconfig.h' should be considered to be obsoleted, and
1232 you are encouraged to get rid of it using the AH macros.
1237 ** Fortran 77 compilers
1238 Globally, the support for Fortran 77 is considerably improved.
1240 Support for automatically determining a Fortran 77 compiler's
1241 name-mangling scheme. New CPP macros F77_FUNC and F77_FUNC_ are
1242 provided to wrap C/C++ identifiers, thus making it easier and more
1243 transparent for C/C++ to call Fortran 77 routines, and Fortran 77 to
1244 call C/C++ routines. See the Texinfo documentation for details.
1247 The test suite no longer uses DejaGNU. It should be easy to submit
1248 test cases in this new framework.
1251 - --help, --help=long, -hl
1252 no longer dumps useless items.
1254 lists only specific options.
1255 - --help=recursive, -hr
1256 displays the help of all the embedded packages.
1257 - Remembers environment variables when reconfiguring.
1258 The previous scheme to set envvar before running configure was
1260 what prevented configure from remembering the environment in which
1261 it was run, therefore --recheck was run in an inconsistent
1262 environment. Now, one should run
1264 and then --recheck will work properly. Variables declared with
1265 AC_ARG_VAR are also preserved.
1267 $build defaults to `config.guess`, $host to $build, and then $target
1269 Cross-compilation is a global status of the package, it no longer
1270 depends upon the current language.
1271 Cross compilation is enabled iff the user specified `--host'.
1272 `configure' now fails if it can't run the executables it compiles,
1273 unless cross-compilation is enabled.
1275 The cache file is disabled by default. The new options
1276 `--config-cache', `-C' set the cache to `config.cache'.
1280 Much faster on most architectures.
1281 - concurrent executions
1282 It is safe to use `make -j' with config.status.
1283 - human interface improved
1284 It is possible to invoke
1285 ./config.status foobar
1286 instead of the former form (still valid)
1287 CONFIG_COMMANDS= CONFIG_HEADERS= CONFIG_LINKS= \
1288 CONFIG_FILES=foobar:foo.in:bar.in \
1290 The same holds for configuration headers and links.
1291 You can instantiate unknown files and headers:
1292 ./config.status --header foo.h:foo.h.in --file bar:baz
1293 - has a useful --help
1294 - accepts special file name "-" for stdin/stdout
1299 Specify additional copyright information.
1302 Now expects the identity of the package as argument.
1306 Most macros, if not all, now strictly follow the `one quotation
1307 level' rule. This results in a more predictable expansion.
1310 A sly bug in the AC_REQUIRE machinery, which could produce incorrect
1311 configure scripts, was fixed by Axel Thimm.
1315 Document and ask for the registration of an envvar.
1318 Specifies the file which `configure' should look for when trying to
1319 find the source tree (used to be handled by AC_INIT).
1321 - AC_CONFIG_COMMANDS
1322 To add new actions to config.status. Should be used instead of
1326 Replaces AC_LINK_FILES.
1328 - AC_CONFIG_HEADERS, AC_CONFIG_COMMANDS, AC_CONFIG_SUBDIRS,
1329 AC_CONFIG_LINKS, and AC_CONFIG_FILES
1330 They now obey sh: you should no longer use shell variables as
1331 argument. Instead of
1333 test "$package_foo_enabled" = yes && $my_subdirs="$my_subdirs foo"
1334 AC_CONFIG_SUBDIRS($my_subdirs)
1338 if test "$package_foo_enabled" = yes; then
1339 AC_CONFIG_SUBDIRS(foo)
1343 To format an Autoconf macro's help string so that it looks pretty
1344 when the user executes `configure --help'.
1347 ** Generic Test Macros
1349 The interface of the AC_CHECK families of macros (decl, header,
1350 type, member, func) is now uniform. They support the same set of
1353 - AC_CHECK_DECL, AC_CHECK_DECLS
1354 To check whether a symbol is declared.
1356 - AC_CHECK_SIZEOF, AC_C_CHAR_UNSIGNED.
1357 No longer need a cross-compilation default.
1360 The test it performs is much more robust than previously, and makes
1361 it possible to test builtin types in addition to typedefs.
1362 It is now schizophrenic:
1363 - AC_CHECK_TYPE(TYPE, REPLACEMENT)
1364 remains for backward compatibility, but its use is discouraged.
1365 - AC_CHECK_TYPE(TYPE, IF-FOUND, IF-NOT-FOUND, INCLUDES)
1366 behaves exactly like the other AC_CHECK macros.
1369 Checks whether given types are supported by the system.
1371 - AC_CHECK_MEMBER, AC_CHECK_MEMBERS
1372 Check for given members in aggregates (e.g., pw_gecos in struct
1376 Checks if the compiler supports ISO C, included when needs special
1380 Checking whether the preprocessor indicates missing includes by the
1381 error code. stderr is checked by AC_TRY_CPP only as a fallback.
1384 Takes a language as argument and replaces AC_LANG_C,
1385 AC_LANG_CPLUSPLUS and AC_LANG_FORTRAN77.
1387 - AC_LANG_PUSH, AC_LANG_POP
1388 Are preferred to AC_LANG_SAVE, AC_LANG_RESTORE.
1391 - AC_FUNC_CHOWN, AC_FUNC_MALLOC, AC_FUNC_STRERROR_R,
1392 AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK, AC_FUNC_STAT, AC_FUNC_LSTAT,
1393 AC_FUNC_ERROR_AT_LINE, AC_FUNC_OBSTACK, AC_FUNC_STRTOD, AC_FUNC_FSEEKO.
1397 Sets GETGROUPS_LIBS.
1399 - AC_FUNC_GETLOADAVG
1400 Defines `HAVE_STRUCT_NLIST_N_UN_N_NAME' instead of `NLIST_NAME_UNION'.
1403 Now integrates `AC_DECL_YYTEXT' which is obsoleted.
1406 Arrange for large-file support.
1408 - AC_EXEEXT, AC_OBJEXT
1409 You are no longer expected to use them: their computation is
1410 performed by default.
1412 ** C++ compatibility
1413 Every macro has been revisited in order to support at best CC=c++.
1415 Major changes in Autoconf 2.14:
1416 There was no release of GNU Autoconf 2.14.
1418 Major changes in Autoconf 2.13:
1420 Released 1999-05-01 by Ben Elliston.
1422 * Support for building on Win32 systems where the only available C or
1423 C++ compiler is the Microsoft Visual C++ command line compiler
1424 (`cl'). Additional support for building on Win32 systems which are
1425 using the Cygwin or Mingw32 environments.
1426 * Support for alternative object file and executable file extensions.
1427 On Win32, for example, these are .obj and .exe. These are discovered
1428 using AC_OBJEXT and AC_EXEEXT, which substitute @OBJEXT@ and
1429 @EXEEXT@ in the output, respectively.
1430 * New macros: AC_CACHE_LOAD, AC_CACHE_SAVE, AC_FUNC_SELECT_ARGTYPES,
1431 AC_VALIDATE_CACHED_SYSTEM_TUPLE, AC_SEARCH_LIBS, AC_TRY_LINK_FUNC,
1432 AC_C_STRINGIZE, AC_CHECK_FILE(S), AC_PROG_F77 (and friends).
1433 * AC_DEFINE now has an optional third argument for a description to be
1434 placed in the config header input file (e.g. config.h.in).
1435 * The C++ code fragment compiled for the C++ compiler test had to be
1436 improved to include an explicit return type for main(). This was
1437 causing failures on systems using recent versions of the EGCS C++
1439 * Fixed an important bug in AC_CHECK_TYPE that would cause a configure
1440 script to report that `sometype_t' was present when only `type_t'
1442 * Merge of the FSF version of config.guess and config.sub to modernize
1443 these scripts. Add support for a few new hosts in config.guess.
1444 Incorporate latest versions of install-sh, mkinstalldirs and
1445 texinfo.tex from the FSF.
1446 * autoreconf is capable of running automake if necessary (and
1448 * Support for Fortran 77. See the Texinfo documentation for details.
1449 * Bug fixes and workarounds for quirky bugs in vendor utilities.
1451 Major changes in Autoconf 2.12:
1453 Released 1996-11-26 by David J. MacKenzie
1455 * AC_OUTPUT and AC_CONFIG_HEADER can create output files by
1456 concatenating multiple input files separated by colons, like so:
1457 AC_CONFIG_HEADER(config.h:conf.pre:config.h.in:conf.post)
1458 AC_OUTPUT(Makefile:Makefile.in:Makefile.rules)
1459 The arguments may be shell variables, to compute the lists on the fly.
1460 * AC_LINK_FILES and AC_CONFIG_SUBDIRS may be called multiple times.
1461 * New macro AC_OUTPUT_COMMANDS adds more commands to run in config.status.
1464 Major changes in Autoconf 2.11:
1466 Released November 18th, 1996, by David J. MacKenzie
1468 * AC_PROG_CC and AC_PROG_CXX check whether the compiler works.
1469 They also default CFLAGS/CXXFLAGS to "-g -O2" for gcc, instead of "-g -O".
1470 * AC_REPLACE_FUNCS defines HAVE_foo if the system has the function `foo'.
1471 * AC_CONFIG_HEADER expands shell variables in its argument.
1472 * New macros: AC_FUNC_FNMATCH, AC_FUNC_SETPGRP.
1473 * The "checking..." messages and the source code for test programs that
1474 fail are saved in config.log.
1475 * Another workaround has been added for seds with small command length limits.
1476 * config.sub and config.guess recognize more system types.
1479 Major changes in Autoconf 2.10:
1481 Released May 7th, 1996, by Roland McGrath
1484 * The cache variable names used by `AC_CHECK_LIB(LIB, FUNC, ...)' has
1485 changed: now $ac_cv_lib_LIB_FUNC, previously $ac_cv_lib_LIB.
1487 Major changes in Autoconf 2.9:
1489 Released March 16th, 1996, by Roland McGrath
1493 Major changes in Autoconf 2.8:
1495 Released March 8th, 1996, by Roland McGrath
1499 Major changes in Autoconf 2.7:
1501 Released November 22nd, 1995, by David J. MacKenzie
1505 Major changes in Autoconf 2.6:
1507 Released November 20th, 1995, by David J. MacKenzie
1511 Major changes in Autoconf 2.5:
1513 Released November 17th, 1995, by Roland McGrath
1515 * New configure options --bindir, --libdir, --datadir, etc., with
1516 corresponding output variables.
1517 * New macro: AC_CACHE_CHECK, to make using the cache easier.
1518 * config.log contains the command being run as well as any output from it.
1519 * AC_CHECK_LIB can check for libraries with "." or "/" or "+" in their name.
1520 * AC_PROG_INSTALL doesn't cache a name for install-sh, for sharing caches.
1521 * AC_CHECK_PROG, AC_PATH_PROG, AC_CHECK_PROGS, AC_PATH_PROGS, and
1522 AC_CHECK_TOOL can search a path other than $PATH.
1523 * AC_CHECK_SIZEOF takes an optional size to use when cross-compiling.
1525 Major changes in Autoconf 2.4:
1527 Released June 14th, 1995, by David J. MacKenzie
1529 * Fix a few bugs found by Emacs testers.
1531 Major changes in Autoconf 2.3:
1533 Released March 27th, 1995, by David J. MacKenzie
1535 * Fix the cleanup trap in several ways.
1536 * Handle C compilers that are picky about option placement.
1537 * ifnames gets the version number from the right directory.
1539 Major changes in Autoconf 2.2:
1541 Released March 8th, 1995, by David J. MacKenzie
1543 * The ifnames utility is much faster but requires a "new awk" interpreter.
1544 * AC_CHECK_LIB and AC_HAVE_LIBRARY check and add the new
1545 library before existing libs, not after, in case it uses them.
1546 * New macros: AC_FUNC_GETPGRP, AC_CHECK_TOOL.
1547 * Lots of bug fixes.
1548 * Many additions to the TODO file :-)
1550 Major changes in Autoconf 2.1:
1552 Released November 4th, 1994, by David J. MacKenzie
1555 * More explanations in the manual.
1556 * Fix a spurious failure in the testsuite.
1557 * Clarify some warning messages.
1558 * autoreconf by default only rebuilds configure and config.h.in files
1559 that are older than any of their particular input files; there is a
1560 --force option to use after installing a new version of Autoconf.
1562 Thanks to everybody who's submitted changes and additions to Autoconf!
1563 I've incorporated many of them, and am still considering others for
1564 future releases -- but I didn't want to postpone this release indefinitely.
1566 Caution: don't indiscriminately rebuild configure scripts with
1567 Autoconf version 2. Some configure.in files need minor adjustments to
1568 work with it; the documentation has a chapter on upgrading. A few
1569 configure.in files, including those for GNU Emacs and the GNU C
1570 Library, need major changes because they relied on undocumented
1571 internals of version 1. Future releases of those packages will have
1572 updated configure.in files.
1574 It's best to use GNU M4 1.3 (or later) with Autoconf version 2.
1575 Autoconf now makes heavy use of M4 diversions, which were implemented
1576 inefficiently in GNU M4 releases before 1.3.
1578 Major changes in Autoconf 2.0:
1580 Released October 26th, 1994, by David J. MacKenzie
1582 ** New copyright terms:
1583 * There are no restrictions on distribution or use of configure scripts.
1586 * Autoconf manual is reorganized to make information easier to find
1587 and has several new indexes.
1588 * INSTALL is reorganized and clearer and is now made from Texinfo source.
1591 * autoscan to generate a preliminary configure.in for a package by
1592 scanning its source code for commonly used nonportable functions,
1593 programs, and header files.
1594 * ifnames to list the symbols used in #if and #ifdef directives in a
1596 * autoupdate to update a configure.in to use the version 2 macro names.
1597 * autoreconf to recursively remake configure and configuration header
1598 files in a source tree.
1600 ** Changed utilities:
1601 * autoheader can take pieces of acconfig.h to replace config.h.{top,bot}.
1602 * autoconf and autoheader can look for package-local definition files
1603 in an alternate directory.
1606 * AC_CACHE_VAL to share results of tests between configure runs.
1607 * AC_DEFUN to define macros, automatically AC_PROVIDE them, and ensure
1608 that macros invoked with AC_REQUIRE don't interrupt other macros.
1609 * AC_CONFIG_AUX_DIR, AC_CANONICAL_SYSTEM, AC_CANONICAL_HOST, AC_LINK_FILES to
1610 support deciding unguessable features based on the host and target types.
1611 * AC_CONFIG_SUBDIRS to recursively configure a source tree.
1612 * AC_ARG_PROGRAM to use the options --program-prefix,
1613 --program-suffix, and --program-transform-name to change the names
1614 of programs being installed.
1615 * AC_PREFIX_DEFAULT to change the default installation prefix.
1616 * AC_TRY_COMPILE to compile a test program without linking it.
1617 * AC_CHECK_TYPE to check whether sys/types.h or stdlib.h defines a given type.
1618 * AC_CHECK_LIB to check for a particular function and library.
1619 * AC_MSG_CHECKING and AC_MSG_RESULT to print test results, on a single line,
1620 whether or not the test succeeds. They obsolete AC_CHECKING and AC_VERBOSE.
1621 * AC_SUBST_FILE to insert one file into another.
1622 * AC_FUNC_MEMCMP to check whether memcmp is 8-bit clean.
1623 * AC_FUNC_STRFTIME to find strftime even if it's in -lintl.
1624 * AC_FUNC_GETMNTENT to find getmntent even if it's in -lsun or -lseq.
1625 * AC_HEADER_SYS_WAIT to check whether sys/wait.h is POSIX.1 compatible.
1628 * Many macros renamed systematically, but old names are accepted for
1629 backward compatibility.
1630 * AC_OUTPUT adds the "automatically generated" comment to
1631 non-Makefiles where it finds @configure_input@ in an input file, to
1632 support files with various comment syntaxes.
1633 * AC_OUTPUT does not replace "prefix" and "exec_prefix" in generated
1634 files when they are not enclosed in @ signs.
1635 * AC_OUTPUT allows the optional environment variable CONFIG_STATUS to
1636 override the file name "config.status".
1637 * AC_OUTPUT takes an optional argument for passing variables from
1638 configure to config.status.
1639 * AC_OUTPUT and AC_CONFIG_HEADER allow you to override the input-file names.
1640 * AC_OUTPUT automatically substitutes the values of CFLAGS, CXXFLAGS,
1641 CPPFLAGS, and LDFLAGS from the environment.
1642 * AC_PROG_CC and AC_PROG_CXX now set CFLAGS and CXXFLAGS, respectively.
1643 * AC_PROG_INSTALL looks for install-sh or install.sh in the directory
1644 specified by AC_CONFIG_AUXDIR, or srcdir or srcdir/.. or
1645 srcdir/../.. by default.
1646 * AC_DEFINE, AC_DEFINE_UNQUOTED, and AC_SUBST are more robust and smaller.
1647 * AC_DEFINE no longer prints anything, because of the new result reporting
1648 mechanism (AC_MSG_CHECKING and AC_MSG_RESULT).
1649 * AC_VERBOSE pays attention to --quiet/--silent, not --verbose.
1650 * AC_ARG_ENABLE and AC_ARG_WITH support whitespace in the arguments to
1651 --enable- and --with- options.
1652 * AC_CHECK_FUNCS and AC_CHECK_HEADERS take optional shell commands to
1653 execute on success or failure.
1654 * Checking for C functions in C++ works.
1657 * AC_REMOTE_TAPE and AC_RSH removed; too specific to tar and cpio, and
1658 better maintained with them.
1659 * AC_ARG_ARRAY removed because no one was likely using it.
1660 * AC_HAVE_POUNDBANG replaced with AC_SYS_INTERPRETER, which doesn't
1661 take arguments, for consistency with all of the other specific checks.
1664 * Comes with config.sub and config.guess, and uses them optionally.
1665 * Uses config.cache to cache test results. An alternate cache file
1666 can be selected with the --cache-file=FILE option.
1667 * Uses optional shell scripts $prefix/share/config.site and
1668 $prefix/etc/config.site to perform site or system specific initializations.
1669 * configure saves compiler output to ./config.log for debugging.
1670 * New files autoconf.m4 and autoheader.m4 load the other Autoconf macros.
1671 * acsite.m4 is the new name for the system-wide aclocal.m4.
1672 * Has a DejaGnu test suite.
1674 Major changes in Autoconf 1.11:
1676 * AC_PROG_INSTALL calls install.sh with the -c option.
1677 * AC_SET_MAKE cleans up after itself.
1678 * AC_OUTPUT sets prefix and exec_prefix if they weren't set already.
1679 * AC_OUTPUT prevents shells from looking in PATH for config.status.
1681 Plus a few other bug fixes.
1683 Major changes in Autoconf 1.10:
1685 * autoheader uses config.h.bot if present, analogous to config.h.top.
1686 * AC_PROG_INSTALL looks for install.sh in srcdir or srcdir/.. and
1688 * AC_PROG_CXX looks for cxx as a C++ compiler.
1690 Plus several bugs fixed.
1692 Major changes in Autoconf 1.9:
1694 * AC_YYTEXT_POINTER replaces AC_DECLARE_YYTEXT.
1695 * AC_SIZEOF_TYPE generates the cpp symbol name automatically,
1696 and autoheader generates entries for those names automatically.
1697 * AC_FIND_X gets the result from xmkmf correctly.
1698 * AC_FIND_X assumes no X if --without-x was given.
1699 * AC_FIND_XTRA adds libraries to the variable X_EXTRA_LIBS.
1700 * AC_PROG_INSTALL finds OSF/1 installbsd.
1702 Major changes in Autoconf 1.8:
1705 * New macros AC_LANG_C, AC_LANG_CPLUSPLUS, AC_LANG_SAVE, AC_LANG_RESTORE,
1706 AC_PROG_CXX, AC_PROG_CXXCPP, AC_REQUIRE_CPP
1707 for checking both C++ and C features in one configure script.
1708 * New macros AC_CHECKING, AC_VERBOSE, AC_WARN, AC_ERROR for printing messages.
1709 * New macros AC_FIND_XTRA, AC_MMAP, AC_SIZEOF_TYPE, AC_PREREQ,
1710 AC_SET_MAKE, AC_ENABLE.
1713 * AC_FIND_X looks for X in more places.
1714 * AC_PROG_INSTALL defaults to install.sh instead of cp, if it's in srcdir.
1715 install.sh is distributed with Autoconf.
1716 * AC_DECLARE_YYTEXT has been removed because it can't work, pending
1717 a rewrite of quoting in AC_DEFINE.
1718 * AC_OUTPUT adds its comments in C format when substituting in C files.
1719 * AC_COMPILE_CHECK protects its ECHO-TEXT argument with double quotes.
1721 ** New or changed command line options:
1722 * configure accepts --enable-FEATURE[=ARG] and --disable-FEATURE options.
1723 * configure accepts --without-PACKAGE, which sets withval=no.
1724 * configure accepts --x-includes=DIR and --x-libraries=DIR.
1725 * Giving --with-PACKAGE no argument sets withval=yes instead of withval=1.
1726 * configure accepts --help, --version, --silent/--quiet, --no-create options.
1727 * configure accepts and ignores most other Cygnus configure options, and
1728 warns about unknown options.
1729 * config.status accepts --help, --version options.
1731 ** File names and other changes:
1732 * Relative srcdir values are not made absolute.
1733 * The values of @prefix@ and @exec_prefix@ and @top_srcdir@ get substituted.
1734 * Autoconf library files are installed in ${datadir}/autoconf, not ${datadir}.
1735 * autoheader optionally copies config.h.top to the beginning of config.h.in.
1736 * The example Makefile dependencies for configure et al. work better.
1737 * Namespace cleanup: all shell variables used internally by Autoconf
1738 have names beginning with `ac_'.
1740 More big improvements are in process for future releases, but have not
1741 yet been (variously) finished, integrated, tested, or documented enough
1744 Major changes in Autoconf 1.7:
1746 * New macro AC_OBSOLETE.
1747 * Bugs in Makefile.in fixed.
1748 * AC_LONG_FILE_NAMES improved.
1750 Major changes in Autoconf 1.6:
1752 * New macro AC_LONG_64_BITS.
1753 * Multiple .h files can be created.
1754 * AC_FIND_X looks for X files directly if it doesn't find xmkmf.
1755 * AC_ALLOCA defines C_ALLOCA if using alloca.c.
1756 * --with-NAME can take a value, e.g., --with-targets=sun4,hp300bsd.
1757 * Unused --no-create option to configure removed.
1758 * autoheader doesn't change the timestamp of its output file if
1759 the file didn't change.
1760 * All macros that look for libraries now use AC_HAVE_LIBRARY.
1761 * config.status checks three optional environment variables to
1762 modify its behavior.
1763 * The usual bug fixes.
1765 Major changes in Autoconf 1.5:
1767 * New macros AC_FIND_X, AC_OFF_T, AC_STAT_MACROS_BROKEN, AC_REVISION.
1768 * autoconf and autoheader scripts have GNU standards conforming
1769 --version and --help options (they print their message and exit).
1772 Major changes in Autoconf 1.4:
1774 * New macros AC_HAVE_POUNDBANG, AC_TIME_WITH_SYS_TIME, AC_LONG_DOUBLE,
1775 AC_GETGROUPS_T, AC_DEFINE_UNQUOTED.
1776 * autoconf and autoheader use the M4 environment variable to determine the
1777 name of the M4 program to use.
1778 * The --macrodir option to autoconf and autoheader specifies the directory
1779 in which acspecific.m4, acgeneral.m4, etc. reside if not the default.
1780 * autoconf and autoheader can take `-' as their file names, which means to
1781 read stdin as input.
1782 * Resulting configure scripts can take a --verbose option which causes them
1783 to print the results of their tests.
1784 * AC_DEFINE quotes its second argument in such a way that spaces, magic
1785 shell characters, etc. will be preserved during various stages of
1786 expansion done by the shell. If you don't want this, use
1787 AC_DEFINE_UNQUOTED instead.
1788 * Much textual processing done with external calls to tr and sed have been
1789 internalized with builtin M4 `patsubst' and `translit' calls.
1790 * AC_OUTPUT doesn't hardwire the file names it outputs. Instead, you can
1791 set the shell variables `gen_files' and `gen_config' to the list of
1792 file names to output.
1793 * AC_DECLARE_YYTEXT does an AC_SUBST of `LEX_OUTPUT_ROOT', which may be
1794 "lex.yy" or "lexyy", depending on the system.
1795 * AC_PROGRAMS_CHECK takes an optional third arg. If given, it is used as
1797 * If AC_ALLOCA chooses alloca.c, it also defines STACK_DIRECTION.
1798 * AC_CONST works much more reliably on more systems.
1801 Major changes in Autoconf 1.3:
1803 configure no longer requires awk for packages that use a config.h.
1804 Support handling --with-PACKAGE options.
1805 New `autoheader' script to create `config.h.in' from `configure.in'.
1806 Ignore troublesome -lucb and -lPW when searching for alloca.
1807 Rename --exec_prefix to --exec-prefix for GNU standards conformance.
1808 Improve detection of STDC library.
1809 Add AC_HAVE_LIBRARY to check for non-default libraries.
1810 Function checking should work with future GNU libc releases.
1812 Major changes in Autoconf 1.2:
1814 The --srcdir option is now usually unnecessary.
1815 Add a file containing sample comments describing CPP macros.
1816 A comment in config.status tells which host it was configured on.
1817 Substituted variable values can now contain commas.
1818 Fix bugs in various feature checks.
1820 Major changes in Autoconf 1.1:
1822 Added AC_STRCOLL macro.
1823 Made AC_GETLOADAVG check for more things.
1824 AC_OUTPUT argument is now optional.
1829 Copyright (C) 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001, 2002,
1830 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
1832 This program is free software: you can redistribute it and/or modify
1833 it under the terms of the GNU General Public License as published by
1834 the Free Software Foundation, either version 3 of the License, or
1835 (at your option) any later version.
1837 This program is distributed in the hope that it will be useful,
1838 but WITHOUT ANY WARRANTY; without even the implied warranty of
1839 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
1840 GNU General Public License for more details.
1842 You should have received a copy of the GNU General Public License
1843 along with this program. If not, see <http://www.gnu.org/licenses/>.