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 ** AC_LANG_ERLANG works once again (regression introduced in 2.61a).
8 ** Autotest testsuites accept an option --jobs[=N] for parallel testing.
10 ** Autotest testsuites do not attempt to write startup error messages
11 to the log file before that is opened (regression introduced in 2.63).
13 ** Configure scripts now use shell functions.
15 ** Present But Cannot Be Compiled: Autoconf will now proceed with
16 the compiler's result if a header is present but cannot be compiled.
17 The warning is still printed, and you should really fix it by
18 providing a fourth parameter to AC_CHECK_HEADER/AC_CHECK_HEADERS.
20 ** The following documented m4sugar macros are new:
21 m4_curry m4_default_quoted m4_map_args m4_map_args_pair
24 ** The following m4sugar macros are documented now:
25 m4_copy m4_dumpdefs m4_rename
27 ** The following documented m4sh macros are new:
28 AS_LINENO_PREPARE AS_ME_PREPARE AS_VAR_APPEND AS_VAR_ARITH
31 ** The following m4sh macros are documented now:
32 AS_ECHO AS_ECHO_N AS_EXIT AS_LITERAL_IF AS_UNSET AS_VAR_IF
33 AS_VAR_POPDEF AS_VAR_PUSHDEF AS_VAR_SET AS_VAR_SET_IF
34 AS_VAR_TEST_SET AS_VERSION_COMPARE
36 ** The m4sh macros AS_IF and AS_CASE can now be used in shell lists.
37 The responsibility for supplying a trailing newline now belongs to
38 the call site, but since most users did not add dnl, this generally
39 results in fewer empty lines in configure.
42 * Major changes in Autoconf 2.63 (2008-09-09) [stable]
43 Released by Eric Blake, based on git versions 2.62.*.
45 ** AC_C_BIGENDIAN does not mistakenly report "universal" for some
46 bigendian hosts, a regression introduced with universal binary
49 ** AC_PATH_X now includes /lib64 and /usr/lib64 in its list of default
52 ** AC_USE_SYSTEM_EXTENSIONS no longer conflicts with an external
53 AC_DEFINE([__EXTENSIONS__]). This fixes a regression introduced in
54 2.62 when using macros such as AC_AIX that were made obsolete in
55 favor of the more portable AC_USE_SYSTEM_EXTENSIONS.
57 ** AC_CHECK_TARGET_TOOLS is usable in the non-cross-compile case.
59 ** Newly obsolete macros
60 The following macro has been marked obsolete, since current porting
61 targets can safely assume C89 semantics that signal handlers return
62 void. We have no current plans to remove the macro.
66 ** The macros m4_map and m4_map_sep now ignore any list elements
67 consisting of just empty quotes, and m4_map_sep now expands its
68 separator. This fixes a regression in 2.62 when these macros were
69 first documented, for the sake of clients expecting the semantics
70 that these macros had prior to that time. The new macros m4_mapall
71 and m4_mapall_sep, along with extra quoting of the separator, can
72 be used to get the semantics that m4_map_sep had in 2.62.
74 ** Clients of m4_expand, such as AS_HELP_STRING and AT_SETUP, can now
75 handle properly quoted but otherwise unbalanced parentheses (for
76 some macros, this fixes a regression in 2.62).
78 ** Two new quadrigraphs have been introduced: @{:@ for (, and @:}@ for ),
79 allowing the output of unbalanced parentheses in more contexts.
81 ** The following m4sugar macros are new:
82 m4_joinall m4_mapall m4_mapall_sep m4_reverse m4_set_add
83 m4_set_add_all m4_set_contains m4_set_contents m4_set_delete
84 m4_set_difference m4_set_dump m4_set_empty m4_set_foreach
85 m4_set_intersection m4_set_list m4_set_listc m4_set_remove
86 m4_set_size m4_set_union
88 ** The following m4sugar macros now accept multiple arguments, as is the
89 case with underlying m4:
90 m4_defn m4_popdef m4_undefine
92 ** The following m4sugar macros now guarantee linear scaling; they
93 previously had linear scaling with m4 1.6 but quadratic scaling
94 when using m4 1.4.x. All macros built on top of these also gain
95 the scaling improvements.
96 m4_bmatch m4_bpatsubsts m4_case m4_cond m4_do m4_dquote_elt
97 m4_foreach m4_join m4_list_cmp m4_map m4_map_sep m4_max
100 ** AT_KEYWORDS once again performs expansion on its argument, such that
101 AT_KEYWORDS([m4_if([$1], [], [default])]) no longer complains about
102 the possibly unexpanded m4_if [regression introduced in 2.62].
104 ** Config header templates `#undef UNDEFINED /* comment */' do not lead to
105 nested comments any more; regression introduced in 2.62.
108 * Major changes in Autoconf 2.62 (2008-04-05) [stable]
109 Released by Eric Blake, based on git versions 2.61a.*.
111 ** Many optimizations have been applied to make overall execution faster.
113 ** Autotest now makes use of shell functions.
115 ** config.status now uses awk instead of sed also for config headers.
117 - As a side effect, AC_DEFINE and AC_DEFINE_UNQUOTED now handle multi-line
118 values, i.e., backslash-newline combinations are handled correctly.
119 Further, for config headers, the total size of values is not limited by
120 the POSIX length limit of text lines any more, only each single line.
122 ** New config variable `top_build_prefix'.
124 ** New Autoconf macros:
125 AC_AUTOCONF_VERSION AC_OPENMP AC_PATH_PROGS_FEATURE_CHECK
127 ** AC_C_BIGENDIAN now supports universal binaries a la Mac OS X.
129 ** AC_C_RESTRICT now prefers to #define 'restrict' to a variant spelling
130 like '__restrict' if the variant spelling is available, as this is
131 more likely to work when mixing C and C++ code.
133 ** AC_CHECK_ALIGNOF's type argument T is now documented better: it must
134 be a string of tokens such that "T y;" is a valid member declaration
137 ** AC_CHECK_SIZEOF now accepts objects as well as types: the general rule
138 is that sizeof (X) works, then AC_CHECK_SIZEOF (X) should work.
140 ** AC_CHECK_TYPE and AC_CHECK_TYPES now work on any C type-name; formerly,
141 they did not work for function types. In C++, they now work on any
142 type-id that can be the operand of sizeof; this is similar to C,
143 except it excludes anonymous struct and union types. Formerly,
144 some (but not all) C++ types involving anonymous struct and union
145 were accepted, though this was not documented.
147 ** AC_CONFIG_LINKS now prefers to link against files in the build tree
148 if found, and it works to link against a file of the same name in
149 the source tree, even if both trees coincide.
151 ** AC_INIT no longer alters $@; regression introduced in 2.60.
153 ** AC_USE_SYSTEM_EXTENSIONS now defines _ALL_SOURCE for Interix platforms.
155 ** AS_HELP_STRING no longer underquotes its first argument; it also handles
156 the case where the first argument contains single-quoted commas.
157 For example, "AS_HELP_STRING([-a, [--arg[=foo]]], [bar])" produces:
158 " -a, --arg[=foo] bar"
159 Additionally, the macro now takes two additional arguments,
160 indent-column and wrap-column; these should not normally be needed,
161 but can be used to fine-tune how the output text is wrapped.
163 ** AC_PROG_INSTALL now requires an install program that can install multiple
164 files into a target directory.
166 ** The command 'autoconf -' now correctly processes a file from stdin.
168 ** 'autoreconf -m' now honors $MAKE.
170 ** For all of the directory arguments for 'configure', such as '--prefix'
171 or '--bindir', trailing slashes are stripped. As an example, if
172 tab completion in the user's shell appends trailing slashes, the
173 command './configure --prefix=/usr/' will still result in an
174 expanded libdir value of /usr/lib, not /usr//lib.
176 ** `configure --help=recursive' now works in read-only trees and from
177 unconfigured build trees.
179 ** If precious variables differ only in whitespace, then the cache consistency
180 check warns instead of fails, and reuses the old value.
182 ** AT_BANNER is now documented.
184 ** AT_SETUP now handles macro expansions properly when calculating line
187 ** Autotest now determines $srcdir correctly.
189 ** Testsuites built by autotest now accept a -C/--directory=DIR option
190 to adjust the working directory prior to creating files.
192 ** Autoconf now requires GNU M4 1.4.5 or later. Earlier versions of M4 have
193 a bug in macro tracing that interferes with the interaction between
194 Autoconf and Automake. GNU M4 1.4.11 or later is recommended. The
195 configure search for a working M4 is improved.
197 ** For portability with the eventual M4 2.0, macros should no longer use
198 anything larger than $9 to refer to arguments.
200 ** Documentation for m4sugar is improved.
202 - The following macros were previously available as undocumented
203 interfaces; the macros are now documented as stable interfaces.
205 __oline__ m4_assert m4_bmatch m4_bpatsubsts m4_car m4_case
206 m4_cdr m4_default m4_divert_once m4_divert_pop m4_divert_push
207 m4_divert_text m4_do m4_errprintn m4_fatal m4_flatten
208 m4_ifndef m4_ifset m4_ifval m4_ifvaln m4_location
209 m4_n m4_shiftn m4_strip m4_warn
211 - The following macros were previously available as undocumented
212 interfaces, but had bug fixes or semantic changes as part of this
213 release. Packages that relied on the undocumented behavior
214 should be analyzed to make sure they will still work with the
215 new documented behavior.
217 m4_cmp m4_list_cmp m4_join m4_map m4_map_sep m4_sign
218 m4_text_box m4_text_wrap m4_version_compare
220 - The m4_wrap macro used to have unspecified order, but now
221 guarantees FIFO order. m4_wrap_lifo was added to guarantee LIFO
224 - Packages using the undocumented m4sugar macro m4_PACKAGE_VERSION
225 should consider using the new AC_AUTOCONF_VERSION instead.
227 - m4sugar macros that are not documented in the manual are still
228 deemed experimental, and should not be used outside of Autoconf.
230 ** The m4sugar macros m4_append and m4_append_uniq, first documented in
231 2.60, have been fixed to treat both the string and the separator
232 arguments consistently with regards to quoting. Prior to this fix,
233 m4_append_uniq could mistakenly duplicate entries if the expansion
234 of the separator resulted in a different string (for example, if it
235 contained quotes, a comma, or a macro name). However, it means
236 that programs previously using
237 m4_append([name], [string], [[, ]])
238 are now using a four-character separator instead of the intended
239 comma and space. If you need portability to earlier versions of
240 Autoconf, you can insert the following snippet after AC_INIT but
241 before any other macro expansions, to enforce the new semantics:
242 m4_pushdef([m4_append], [m4_define([$1],
243 m4_ifdef([$1], [m4_defn([$1])[$3]])[$2])])
244 Additionally, m4_append_uniq now takes optional parameters that can
245 be used to take action depending on whether anything was appended,
246 and warns if a non-empty separator occurs within the string being
247 appended, since that can lead to duplicates.
249 ** The following m4sugar macros are new:
250 m4_append_uniq_w m4_apply m4_combine m4_cond m4_count
251 m4_dquote_elt m4_echo m4_expand m4_ignore m4_make_list m4_max
252 m4_min m4_newline m4_shift2 m4_shift3 m4_unquote m4_wrap_lifo
254 ** Warnings are now generated by default when an installer invokes
255 'configure' with an unknown --enable-* or --with-* option.
256 These warnings can be disabled with the new AC_DISABLE_OPTION_CHECKING
257 macro, or by invoking 'configure' with --disable-option-checking.
259 ** Existing obsolete macros
260 The documentation for the following macros is adjusted to make it
261 more clear that they have previously been marked obsolete, as their
262 functionality can be accomplished by other macros. We have no
263 current plans to remove them from Autoconf.
265 AC_ENABLE AC_STRUCT_ST_BLKSIZE AC_STRUCT_ST_RDEV AC_WITH
267 ** Newly obsolete macros
268 The following macros have been marked obsolete, as they only
269 perform a subset of AC_USE_SYSTEM_EXTENSIONS. We have no current
270 plans to remove them.
272 AC_AIX AC_GNU_SOURCE AC_ISC_POSIX AC_MINIX
274 ** AC_C_LONG_DOUBLE is obsolescent.
275 The documentation now says that AC_C_LONG_DOUBLE is obsolescent: it
276 tests for problems that are so old that it is no longer of
277 practical importance on current systems. New programs need not use
278 AC_C_LONG_DOUBLE. We have no current plans to remove it.
280 ** AC_DIAGNOSE, AC_WARNING, and AC_FATAL are obsolescent.
281 The documentation now favors the use of M4sugar macros m4_warn and
282 m4_fatal, since the naming makes it more obvious that the
283 diagnostics are associated with M4 expansion (ie. when running
284 `autoconf'), and offers less confusion with the AC_MSG_ERROR,
285 AC_MSG_FAILURE, and AC_MSG_WARN macros which manage diagnostics
286 when running `configure'. We have no current plans to remove these
290 * Major changes in Autoconf 2.61a (2006-12-11)
292 ** AC_FUNC_FSEEKO was broken in 2.61; it didn't make fseeko and ftello visible
293 on many platforms. This has been fixed.
295 ** AC_FUNC_SETVBUF_REVERSED is now obsolete. It is still defined for backward
296 compatibility but it does nothing. The macro was already
297 obsolescent, as the last systems to have the problem were those
298 based on SVR2, which became obsolete in 1987. The macro had bugs
299 on some modern systems and could no longer be maintained reliably
300 due to lack of ancient systems to test it on.
302 ** config.status now uses awk instead of sed for most substitutions, for speed.
304 - As a side effect multi-line values of substituted variables no
305 longer have a small limit in total size, though for portability
306 each line should not exceed the POSIX length limit for text lines.
308 - It is now documented that Makefile.in should not contain
309 overlapping variable occurrences, e.g., @VAR1@VAR2@.
310 Autoconf's behavior was always iffy in such cases, and the
311 awk implementation has changed the behavior.
313 ** Many uses of 'echo' have been rewritten so that Autoconf-generated
314 scripts have fewer problems with strings or file names containing
315 embedded special characters such as backslash or leading "-". This
316 was implemented by using `printf '%s\n' "$foo"' instead of `echo
317 "$foo"' when printf works. Due to the implementation technique
318 used, Autoconf-generated scripts now run considerably more slowly
319 on ancient implementations lacking printf. However, this should
320 not be a problem, since Autoconf-generated scripts in practice
321 invariably find a more-modern shell these days.
324 * Major changes in Autoconf 2.61 (2006-11-17)
326 ** New macros AC_C_FLEXIBLE_ARRAY_MEMBER, AC_C_VARARRAYS.
328 ** AC_ARG_ENABLE and AC_ARG_WITH now allow '.' in feature and package names.
331 * Major changes in Autoconf 2.60b (2006-10-22)
334 Autoconf-generated shell scripts no longer export BIN_SH, due to
335 configuration hassles with this. Installers who need BIN_SH in
336 their environment should set it before invoking 'configure' and
337 'make'. As far as we know, this affects only Unixware installations.
339 ** Obsolescent macros
340 The documentation now says that the following macros are obsolescent,
341 as they are superseded by Gnulib:
343 AC_FUNC_FNMATCH AC_FUNC_FNMATCH_GNU AC_FUNC_GETLOADVG AC_REPLACE_FNMATCH
345 New programs should use the Gnulib counterparts of these macros.
346 We have no current plans to remove them from Autoconf.
348 ** AC_COMPUTE_INT no longer caches or reports results.
350 ** AC_CHECK_DECL now also works with aggregate objects.
352 ** AC_USE_SYSTEM_EXTENSIONS now defines _TANDEM_SOURCE for NonStop platforms.
354 ** GNU M4 1.4.7 or later is now recommended.
357 New M4sugar macro, which is more secure than the POSIX M4 maketemp.
360 Now an alias for m4_mkstemp.
362 * Major changes in Autoconf 2.60a (2006-08-25)
364 ** GNU M4 1.4.6 or later is now recommended.
366 ** The check for C99 now tests for varargs macros, as documented.
367 It also tests that the preprocessor supports 64-bit integers.
369 ** Autoconf now uses constructs like "#ifdef HAVE_STDLIB_H" rather than
370 "#if HAVE_STDLIB_H", so that it now works with "gcc -Wundef -Werror".
372 ** The functionality of the undocumented _AC_COMPUTE_INT is now provided
373 by a public and documented macro, AC_COMPUTE_INT. The parameters to the
374 two macros are different, so autoupdate will not change the old private name
375 to the new one. _AC_COMPUTE_INT may be removed in a future release.
377 ** AC_TYPE_LONG_LONG_INT and AC_TYPE_UNSIGNED_LONG_LONG_INT now require
378 that long long types be at least 64 bits wide, as C99 and tradition
379 requires. Formerly, they accepted implementations of any width.
382 * Major changes in Autoconf 2.60
384 Released 2006-06-23, by Ralf Wildenhues.
386 ** Autoconf no longer depends on whether m4wrap is FIFO (as Posix requires)
387 or LIFO (as in GNU M4 1.4.x). GNU M4 2.0 is expected to conform to Posix
388 here, so m4wrap/m4_wrap users should no longer depend on LIFO behavior.
390 ** Provide a way to turn off warnings about the changed directory variables.
392 * Major changes in Autoconf 2.59d
394 Released 2006-06-05, by Ralf Wildenhues.
396 ** GNU make now recommended for VPATH builds
397 INSTALL now suggests VPATH builds (e.g., "sh ../srcdir/configure")
398 only if you use GNU make. In practice, other 'make' implementations
399 have too many subtle incompatibilities in their support for VPATH.
400 Many packages (including Autoconf itself) are portable to other
401 'make' implementations, but some packages are not, and recommending
402 GNU make keeps the installation instructions simpler.
404 ** Even more safety checks for the new Directory variables:
405 Warn about suspicious `${datarootdir}' found in config files output.
407 ** AC_TRY_COMMAND, AC_TRY_EVAL, ac_config_guess, ac_config_sub, ac_configure
408 These never-documented macros and variables have been marked with
409 comments saying that they may be removed in a future release,
410 because their use can lead to unintended code being executed.
411 If you need functionality that only these macros or variables
412 currently supply, please write bug-autoconf@gnu.org.
414 ** AC_SUBST, AC_DEFINE
415 Literal arguments to these are passed to m4_pattern_allow now.
418 Passing 'ac_cv_prog_cc_stdc=no' to 'configure' now sets ac_cv_prog_cc_c99
419 and ac_cv_prog_cc_c89 to 'no' as well, for backward compatibility with
420 obsolete K&R tests in the Automake test suite.
429 Now more robust with special characters in file names, or when
430 multiple processes create the same directory at the same time.
432 ** Obsolescent macros
433 The documentation now says that the following macros are obsolescent:
434 they test for problems that are so old that they are no longer of
435 practical importance on current systems.
437 AC_C_BACKSLASH_A AC_FUNC_MEMCMP AC_HEADER_DIRENT
438 AC_C_CONST AC_FUNC_SELECT_ARGTYPES AC_HEADER_STAT
439 AC_C_PROTOTYPES AC_FUNC_SETPGRP AC_HEADER_STDC
440 AC_C_STRINGIZE AC_FUNC_SETVBUF_REVERSED AC_HEADER_SYS_WAIT
441 AC_C_VOLATILE AC_FUNC_STAT AC_HEADER_TIME
442 AC_FUNC_CLOSEDIR_VOID AC_FUNC_STRFTIME AC_ISC_POSIX
443 AC_FUNC_GETPGRP AC_FUNC_UTIME_NULL AC_PROG_GCC_TRADITIONAL
444 AC_FUNC_LSTAT AC_FUNC_VPRINTF AC_STRUCT_TM
446 New programs need not use these macros. We have no current plans to
450 For compatibility with future Libtool 2.0, autoreconf will invoke
451 libtoolize with the option `--ltdl' now, if LT_CONFIG_LTDL_DIR is
454 * Major changes in Autoconf 2.59c
456 Released 2006-04-12, by Ralf Wildenhues.
458 ** The configure command now redirects standard input from /dev/null,
459 to help avoid problems with subsidiary commands that might mistakenly
460 read standard input. AS_ORIGINAL_STDIN_FD points to the original
461 standard input before this redirection, if you really want configure to
462 read from standard input.
464 ** Directory variables adjusted to recent changes in the GNU Coding Standards.
465 The following directory variables are new:
467 datarootdir read-only architecture-independent data root [PREFIX/share]
468 localedir locale-specific message catalogs [DATAROOTDIR/locale]
469 docdir documentation root [DATAROOTDIR/doc/PACKAGE]
470 htmldir html documentation [DOCDIR]
471 dvidir dvi documentation [DOCDIR]
472 pdfdir pdf documentation [DOCDIR]
473 psdir ps documentation [DOCDIR]
475 The following variables have new default values:
477 datadir read-only architecture-independent data [DATAROOTDIR]
478 infodir info documentation [DATAROOTDIR/info]
479 mandir man documentation [DATAROOTDIR/man]
481 This means that if you use any of `@datadir@', `@infodir@', or
482 `@mandir@' in a file, you will have to ensure `${datarootdir}' is
483 defined in this file. As a temporary measure, if any of those are
484 found but no mention of `datarootdir', the substitutions will be
485 replaced with values that do not contain `${datarootdir}', and a
486 warning will be issued.
488 ** @top_builddir@ is now a dir name: it is always nonempty and doesn't have
489 a trailing slash. Similar change will be made to ac_top_builddir in a
490 future release; the old style value, which matches (../)*, is (and will
491 continue to be) available as ac_top_build_prefix.
494 New macro to check for support of 'typeof' syntax a la GNU C.
496 ** AC_CHECK_DECLS_ONCE, AC_CHECK_FUNCS_ONCE, AC_CHECK_HEADERS_ONCE
497 New "once-only" variants of commonly-used macros, to make 'configure'
498 smaller and faster in common cases.
501 New macro to check for strtold with C99 semantics.
504 New macro that lets builder disable assertions at 'configure'-time.
507 Now checks for X11/Xlib.h and XrmInitialize (X proper) rather than
508 X11/Intrinsic.h and XtMalloc (Xt).
510 ** AC_PRESERVE_HELP_ORDER
511 New macro that causes `configure' to display help strings for AC_ARG_ENABLE
512 and AC_ARG_WITH arguments in one region, in the order defined. The default
513 behavior is to group options of each classes separately.
515 ** AC_PROG_CC, AC_PROG_CXX
516 No longer automatically arrange to declare the 'exit' function of C,
517 when a C++ compiler is used. Standard Autoconf macros no longer use
518 'exit', so this is no longer an issue for them. If you use C++, and
519 want to call 'exit', you'll have to arrange for its declaration
520 yourself. But we now suggest you return from 'main' instead.
522 ** AC_PROG_CC_C89, AC_PROG_CC_C99
523 New macros for ISO C99 support. AC_PROG_CC_C89 and AC_PROG_CC_C99
524 check for ANSI C89 and ISO C99 support respectively.
527 Has been unobsoleted, and will check if the compiler supports ISO
528 C99, falling back to ANSI C89 if not. ac_cv_prog_cc_stdc is
529 retained for backwards compatibility, assuming the value of
530 ac_cv_prog_cc_c99 or ac_cv_prog_cc_c89 (whichever is valid, in
533 ** AC_STRUCT_DIRENT_D_INO, AC_STRUCT_DIRENT_D_TYPE
534 New macros for checking commonly-used members of struct dirent.
537 The substituted value can now contain newlines.
540 The substitution now occurs only when @variable@ is on a line by itself,
541 optionally surrounded by spaces and tabs. The whole line is replaced.
543 ** AC_TYPE_LONG_DOUBLE, AC_TYPE_LONG_DOUBLE_WIDER
544 New macros to check for long double, and whether it is wider than double.
545 The old macro AC_C_TYPE_LONG_DOUBLE has been marked as obsolete;
546 applications should switch to the new macro.
548 ** AC_TYPE_INT8_T, AC_TYPE_INT16_T, AC_TYPE_INT32_T, AC_TYPE_INT64_T,
549 AC_TYPE_INTMAX_T, AC_TYPE_INTPTR_T, AC_TYPE_LONG_LONG_INT, AC_TYPE_SSIZE_T,
550 AC_TYPE_UINT8_T, AC_TYPE_UINT16_T, AC_TYPE_UINT32_T, AC_TYPE_UINT64_T,
551 AC_TYPE_UINTMAX_T, AC_TYPE_UINTPTR_T, AC_TYPE_UNSIGNED_LONG_LONG_INT
552 New macros to check for C99 and POSIX types.
554 ** AC_USE_SYSTEM_EXTENSIONS
555 New macro to enable extensions to Posix.
558 New macro which is defined to the name of the first declared config header
559 or undefined if no config headers have been declared yet.
562 The macro correctly handles quadrigraphs now.
564 ** AS_BOURNE_COMPATIBLE, AS_SHELL_SANITIZE, AS_CASE
565 These macros are new or published now.
568 New macro for copyright notices in testsuite files.
570 ** ALLOCA, LIBOBJS, LTLIBOBJS
571 Object names added to these variables are now prefixed with `${LIBOBJDIR}',
572 as in `${LIBOBJDIR}alloca.o'. LIBOBJDIR is meant to be defined from
573 `Makefile.in' in case the object files lie in a different directory.
574 The LIBOBJDIR feature is experimental.
577 Supports --no-recursive now.
579 ** New macros to support Erlang/OTP.
580 New macros for configuring paths to Erlang tools and libraries:
581 AC_ERLANG_PATH_ERLC, AC_ERLANG_NEED_ERLC, AC_ERLANG_PATH_ERL,
582 AC_ERLANG_NEED_ERL, AC_ERLANG_CHECK_LIB, AC_ERLANG_SUBST_ROOT_DIR,
583 AC_ERLANG_SUBST_LIB_DIR.
585 New macros for configuring installation of Erlang libraries:
586 AC_ERLANG_SUBST_INSTALL_LIB_DIR, AC_ERLANG_SUBST_INSTALL_LIB_SUBDIR.
588 ** The manual now mentions Gnulib more prominently.
590 ** New macros to support Objective C.
591 AC_PROG_OBJC, AC_PROG_OBJCPP.
593 * Major changes in Autoconf 2.59b
595 Released 2004-08-20, by Paul Eggert.
598 New macro that computes the default alignment of a type.
600 ** AC_CHECK_TOOL, AC_PATH_TOOL, AC_CHECK_TOOLS
601 When cross-compiling, these macros will give a warning if the tool
602 is not prefixed. In the future, unprefixed cross tools will not
603 be detected; please consult the info documentation for information
604 about the reason of this change.
606 ** AC_CHECK_TARGET_TOOL, AC_PATH_TARGET_TOOL, AC_CHECK_TARGET_TOOLS
607 New macros that detect programs whose name is prefixed with the
608 target type, if the build type and target type are different.
610 ** AC_REQUIRE_AUX_FILE
611 New trace macro that declares expected auxiliary files.
614 New macro that tests for a grep program that accepts as a long a line
617 ** AC_PROG_EGREP, AC_PROG_FGREP
618 These macros now require AC_PROG_GREP, and try EGREP="$GREP -E" and
619 FGREP="$GREP -F" respectively if possible, or else run a path search for
620 a program that accepts as long a line as possible.
623 New macro that tests for a sed program that truncates as few characters
626 * Major changes in Autoconf 2.59
628 Released 2003-11-04, by Akim Demaille
630 ** ac_abs_builddir etc.
631 Absolute file names were actually relative in 2.58.
633 * Major changes in Autoconf 2.58
635 Released 2003-11-04, by Akim Demaille
638 core.* files are no longer removed, as they may be valid user files.
640 ** autoreconf and auxiliary directory
641 Autoreconf creates the auxiliary directory if needed. This is
642 especially useful for initial "bootstrapping" of fresh CVS checkouts.
644 ** AC_CONFIG_MACRO_DIR
645 Use this macro to declare the directory for local M4 macros for aclocal.
648 No longer includes twice the same file in LIBOBJS if invoked
651 ** AC_CONFIG_COMMANDS
652 The directory for its first argument is automatically created. For
655 AC_CONFIG_COMMANDS([src/modules.hh], [...])
657 $top_builddir/src/ is created if needed.
659 ** Autotest and local.at
660 The optional file local.at is always included in Autotest test suites.
663 The warnings are always issued, including with cached runs.
664 This became a significant problem since aclocal and automake can
665 run autoconf behind the scene.
667 ** autoheader warnings
668 The warnings of autoheader can be turned off, using --warning.
669 For instance, -Wno-obsolete disables the complaints about acconfig.h
670 and other deprecated constructs.
673 AC_C_RESTRICT, AC_INCLUDES_DEFAULT, AC_LANG_ASSERT, AC_LANG_WERROR,
676 ** AC_DECL_SYS_SIGLIST
680 Now checks that mktime is the inverse of localtime.
682 ** Improve DJGPP portability
683 The Autoconf tools and configure behave better under DJGPP.
685 ** Present But Cannot Be Compiled
686 New FAQ section dedicated to the mystic
688 configure: WARNING: pi.h: present but cannot be compiled
689 configure: WARNING: pi.h: check for missing prerequisite headers?
690 configure: WARNING: pi.h: proceeding with the preprocessor's result
693 ** Concurrent executions of autom4te
694 autom4te now locks its internal files, which enables concurrent
695 executions of autom4te, likely to happen if automake, autoconf,
696 autoheader etc. are run simultaneously.
699 Use of Libtool 1.5 and higher is encouraged. Compatibility with
700 Libtool pre-1.4 is not checked.
703 Testsuites no longer rerun failed tests in verbose mode; instead,
704 failures are logged while the test is run.
706 In addition, expected failures can be marked as such.
708 * Major changes in Autoconf 2.57
710 Released 2002-12-03 by Paul Eggert.
712 Bug fixes for problems with AIX linker, with freestanding C compilers,
713 with GNU M4 limitations, and with obsolete copies of GNU documents.
715 The Free Documentation License has been upgraded from 1.1 to 1.2.
717 * Major changes in Autoconf 2.56
719 Released 2002-11-15 by Akim Demaille.
721 One packaging problem fixed (config/install-sh was not executable).
723 * Major changes in Autoconf 2.55
725 Released 2002-11-14 by Akim Demaille.
729 Have your configure.ac checked by autoscan ("autoscan").
730 Try the warning options ("autoreconf -fv -Wall").
734 - AC_CHECK_HEADER, AC_CHECK_HEADERS
735 More information on proper use.
737 - Writing Test Programs
739 This sections explains how to write good test sources to use with
740 AC_COMPILE_IFELSE etc. It documents AC_LANG_PROGRAM and so forth.
742 - AC_FOO_IFELSE vs. AC_TRY_FOO
744 Explains why Autoconf moves from AC_TRY_COMPILE etc. to
745 AC_COMPILE_IFELSE and AC_LANG_PROGRAM etc.
749 - Is more robust to different Gettext installations.
751 - Produces messages (when --verbose) to be understood by Emacs'
754 - Supports -W/--warnings.
757 Once the GNU Build System reinstalled, run `./config.status
758 --recheck && ./config.status && make' if possible.
762 - Supports --cache, and --no-cache.
764 - ~/.autom4te.cfg makes it possible to disable the caching mechanism
765 (autom4te.cache). See `Customizing autom4te' in the documentation.
772 Support for the obsoleted options -m, --macrodir, -l, --localdir is
773 dropped in favor of the safer --include/--prepend-include scheme.
778 AC_COMPILER_IFELSE, AC_FUNC_MBRTOWC, AC_HEADER_STDBOOL,
779 AC_LANG_CONFTEST, AC_LANG_SOURCE, AC_LANG_PROGRAM, AC_LANG_CALL,
780 AC_LANG_FUNC_TRY_LINK, AC_MSG_FAILURE, AC_PREPROC_IFELSE.
783 Obsoleted macros are kept for Autoconf backward compatibility, but
784 should be avoided in configure.ac. Running autoupdate is advised.
787 - AC_DEFINE/AC_DEFINE_UNQUOTED
789 We have to stop using the old compatibility scheme --that tried to
790 avoid useless backslashes-- because Libtool 1.4.3 contains a
792 AC_DEFINE([error_t], [int],
793 [Define to a type to use for \`error_t' if it is not
794 otherwise available.])
796 We have to quote the single quotes and backslashes with \. The old
797 compatibility scheme saw that ` was backslashed, and therefore did
798 not quote the single quote... Failure. Hence, Autoconf 2.54 is not
799 compatible with Libtool. Autoconf 2.55 is, but in some cases might
800 produce more \ than wanted.
802 Please, note that in the future the same problem will happen with
803 AC_MSG_*: use `autoreconf -f -Wall'.
807 - Portability of the Autoconf package to Solaris.
809 - Spurious warnings caused by config.status.
810 This bug is benign, but painful: on some systems (typically
811 FreeBSD), warnings such as:
813 config.status: creating Makefile
814 mv: Makefile: set owner/group (was: 1357/0): Operation not permitted
816 could be issued. This is fixed.
819 Simultaneous executions of config.status are possible again.
821 - Precious variables accumulation
823 config.status could stack several copies of the precious variables
827 ** Plans for later versions
831 The compatibility hooks with the old scheme will be completely
832 removed. Please, advice/use `--build', `--host', and `--target'
835 - AC_CHECK_HEADER, AC_CHECK_HEADERS
837 The tests will be stricter, please make sure your invocations are
842 Shell functions will gradually be introduced, probably starting with
843 Autotest. If you know machines which are in use that you suspect
844 *not* to support shell functions, please run the test suite of
845 Autoconf 2.55 on it, and report the results to
846 bug-autoconf@gnu.org.
850 Special characters in AC_MSG_* need not be quoted. Currently,
851 Autoconf has heuristics to decide when a string is escaped, or has
852 to be escaped. This scheme is fragile, and will be removed; the
853 only risk is uglified messages. Please, run `autoreconf -f -Wall'
854 to find occurrences that will be affected.
856 * Major changes in Autoconf 2.54
858 Released 2002-09-13 by Akim Demaille.
862 - autoreconf no longer changes the version of the gettext/po/intl
863 support files. It now adds the files the correspond to the
864 AM_GNU_GETTEXT_VERSION declared in configure.ac.
866 Warning: It now relies on the 'autopoint' program, which is part
867 of GNU gettext 0.11.4 and newer.
869 Please note that you need to have a GNU gettext version that
870 corresponds at least to the AM_GNU_GETTEXT_VERSION declared
871 in configure.ac. You can upgrade to newer GNU gettext versions,
872 though, without needing to change configure.ac.
874 - The -I DIR or --include=DIR option now appends DIR to the include path
875 instead of prepending; this is for consistency with other GNU tools.
876 The new -B DIR or --prepend-include=DIR option has the old behavior.
881 Now handles all the gory details about LIBOBJS and LTLIBOBJS.
882 Please, remove lines such as
884 # This is necessary so that .o files in LIBOBJS are also
885 # built via the ANSI2KNR-filtering rules.
886 LIBOBJS=`echo $LIBOBJS|sed 's/\.o /\$U.o /g;s/\.o$/\$U.o/'`
888 and read the `AC_LIBOBJ vs LIBOBJS' section. Do not define U in
889 your Makefiles either.
891 - AC_CONFIG_LINKS now makes copies if it can't make links.
893 - AC_FUNC_FNMATCH now tests only for POSIX compatibility, reverting to
894 Autoconf 2.13 behavior. The new macro AC_FUNC_FNMATCH_GNU also
895 tests for GNU extensions to fnmatch, and replaces fnmatch if needed.
897 - AC_FUNC_SETVBUF_REVERSED no longer fails when cross-compiling.
899 - AC_PROG_CC_STDC is integrated into AC_PROG_CC.
901 - AC_PROG_F77 default search no longer includes cf77 and cfg77.
905 AC_C_BACKSLASH_A, AC_CONFIG_LIBOBJ_DIR, AC_GNU_SOURCE,
906 AC_PROG_EGREP, AC_PROG_FGREP, AC_REPLACE_FNMATCH,
907 AC_FUNC_FNMATCH_GNU, AC_FUNC_REALLOC, AC_TYPE_MBSTATE_T.
910 looks for getloadavg.c in the CONFIG_LIBOBJ_DIR.
913 Now defines HAVE_MALLOC to 0 if `malloc' does not work, and asks
914 for an AC_LIBOBJ replacement.
918 - Spurious complaints from `m4_bmatch' about invalid regular
919 expressions are suppressed.
921 - Empty top_builddirs are properly handled.
923 - AC_CHECK_MEMBER works correctly when the member is an aggregate.
926 Now colon in the optional path arguments are properly handled.
928 ** Improved portability
930 - Both Autoconf the package, and the scripts it produces, should run
931 more reliably with Zsh. Bear in mind it is the default Bourne shell
934 - Autoconf and the scripts it produces no longer assume the existence of
935 the obsolescent commands egrep and fgrep.
939 - Limitations of Make
943 The GNATS base moved to
944 http://bugs.gnu.org/cgi-bin/gnatsweb.pl?database=autoconf
945 (It is no longer available, though.)
950 Now contains the list of ouput variables and files (AC_SUBST,
953 * Major changes in Autoconf 2.53
955 Released 2002-03-08 by Akim Demaille.
959 Perl 5.005_03 or later is required: autom4te is written in Perl and is
960 needed by autoconf. autoheader, autoreconf, ifnames, and autoscan are
966 Argument requirements, output variables, defined macros.
967 - M4sugar, M4sh, Autotest
969 - Double quoting macros
970 AC_TRY_CPP, AC_TRY_COMPILE, AC_TRY_LINK and AC_TRY_RUN.
972 The Autoconf manual is now distributed under the terms of the GNU FDL.
973 - Section `Hosts and Cross-Compilation'
974 Explains the rationale for the 2.5x changes in the cross-compilation
975 chain, and in the relationships between build, host, and target
977 Emphasizes that `cross-compilation' == `--host is given'.
978 If you are working on compilers etc., be sure to read this section.
979 - Section `AC_LIBOBJ vs. LIBOBJS'
980 Explains why assigning LIBOBJS directly is now an error.
981 Details how to update the code.
986 Now used instead of hard coded line numbers.
987 This eases the comparison of `configure's, and diminishes the
988 pressure over control version archives.
989 Automatic replacement for shells that don't support this feature.
990 - New output variables
991 @builddir@, @top_builddir@, @abs_srcdir@, @abs_top_srcdir@, @abs_builddir@,
996 Autoconf and Autotest modes are provided.
1001 New, used by the Autoconf suite to cache and speed up most processing.
1003 Supported by autom4te, autoconf and autoheader.
1005 Replaces --autoconf-dir and --localdir in autoconf, autoheader,
1006 autoupdate, and autoreconf.
1008 No longer passes --cygnus, --foreign, --gnits, --gnu, --include-deps:
1009 automake options are to be given via AUTOMAKE_OPTIONS.
1011 Runs gettextize and libtoolize when appropriate.
1013 --m4dir is no longer supported.
1015 Now runs only in the specified directories, defaulting to `.',
1016 but understands AC_CONFIG_SUBDIRS for dependent directories.
1017 Before, it used to run on all the `configure.ac' found in the
1019 Independent packages are properly updated.
1023 - The top level $prefix is propagated to the AC_CONFIG_SUBDIRS configures.
1025 Under the user pressure, $? is finally available. Probably a mistake.
1026 - AC_F77_LIBRARY_LDFLAGS now supports the HP/UX f90 compiler.
1027 - Precious variables accumulation
1028 config.status could stack several copies of the precious variables
1030 - AC_PATH_PROG and family.
1031 Works properly when given a literal path.
1033 Somewhere since 2.13, the result had been reversed.
1037 - AC_C_BIGENDIAN supports the cross-compiling case.
1038 - AC_C_BIGENDIAN accepts ACTION-IF-TRUE, ACTION-IF-FALSE, and
1039 ACTION-IF-UNKNOWN arguments. All are facultative, and the default
1040 for ACTION-IF-TRUE is to define WORDS_BIGENDIAN like AC_C_BIGENDIAN
1042 - AC_C_LONG_DOUBLE now succeeds only if `long double' has more range or
1043 precision than `double'.
1048 It now defines the preprocessor symbols PACKAGE_NAME,
1049 PACKAGE_TARNAME, PACKAGE_VERSION, PACKAGE_STRING, and
1053 Admits a fourth optional parameter: the tar name.
1055 - AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS.
1056 Provide the user with srcdir, ac_srcdir, ac_top_srcdir, ac_builddir,
1057 ac_top_builddir, ac_abs_srcdir, ac_abs_top_srcdir, ac_abs_builddir,
1058 ac_abs_top_builddir.
1060 - AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS and AC_OUTPUT.
1061 Are much less expensive when using long lists of files.
1064 Works with shell variables, and non alphanumeric names.
1068 - AC_FUNC_STRERROR_R now sets STRERROR_R_CHAR_P, not HAVE_WORKING_STRERROR_R,
1069 because POSIX 1003.1-200x draft 7 says strerror_r returns int, not char *.
1071 - AC_FUNC_STRTOD substitutes POW_LIB.
1076 * Major changes in Autoconf 2.52
1078 Released 2001-07-18 by Akim Demaille.
1083 This feature was present in autoconf 2.50 but was not documented.
1084 For example, `@<:@' is translated to `[' just before output. This
1085 is useful when writing strings that contain unbalanced quotes, or
1086 other hard-to-quote constructs.
1087 - m4_pattern_forbid, m4_pattern_allow
1088 - Tips for upgrading from 2.13.
1089 - Using autoscan to maintain a configure.ac.
1092 - Now include stdint.h.
1093 - sys/types.h and sys/stat.h are guarded.
1094 - strings.h is included if available, and not conflicting with string.h.
1097 - The test suite is more robust and presents less false failures.
1098 - Invocation of GNU M4 now robust to POSIXLY_CORRECT.
1099 - configure accepts --prefix='' again.
1100 - AC_CHECK_LIB works properly when its first argument is not a
1102 - HAVE_INTTYPES_H is defined only if not conflicting with sys/types.h.
1103 - build_, host_, and target_alias are AC_SUBST as in 2.13.
1104 - AC_ARG_VAR properly propagates precious variables inherited from the
1105 environment to ./config.status.
1106 - Using --program-suffix/--program-prefix is portable.
1107 - Failures to detect the default compiler's output extension are less
1109 - `config.status foo' works properly when `foo' depends on variables
1110 set in an AC_CONFIG_THING INIT-CMD.
1111 - autoheader is more robust to broken input.
1112 - Fixed Fortran name-mangling and link tests on a number of systems,
1113 e.g. NetBSD; see AC_F77_DUMMY_MAIN, below.
1116 - AC_CHECK_HEADER and AC_CHECK_HEADERS support a fourth argument to
1117 specify pre-includes. In this case, the headers are compiled with
1118 cc, not merely preprocessed by cpp. Therefore it is the _usability_
1119 of a header which is checked for, not just its availability.
1120 - AC_ARG_VAR refuses to run configure when precious variables have
1122 - Versions of compilers are dumped in the logs.
1123 - AC_CHECK_TYPE recognizes use of `foo_t' as a replacement type.
1126 - AC_PATH_XTRA only adds -ldnet to $LIBS if it's needed to link.
1127 - AC_FUNC_WAIT3 and AC_SYS_RESTARTABLE_SYSCALLS are obsoleted.
1128 - AM_FUNC_ERROR_AT_LINE, AM_FUNC_FNMATCH, AM_FUNC_MKTIME,
1129 AM_FUNC_OBSTACK, and AM_FUNC_STRTOD are now activated.
1130 Be sure to read `Upgrading from Version 2.13' to understand why
1131 running `autoupdate' is needed.
1132 - AC_F77_DUMMY_MAIN, AC_F77_MAIN: new macros to detect whether
1133 a main-like routine is required/possible when linking C/C++ with
1134 Fortran. Users of e.g. AC_F77_WRAPPERS should be aware of these.
1135 - AC_FUNC_GETPGRG behaves better when cross-compiling.
1137 * Major changes in Autoconf 2.51
1138 There was no release of Autoconf 2.51 since some packagers had used
1139 this version number without permission to ship intermediary versions
1140 of 2.50. The version was skipped to avoid confusion.
1142 * Major changes in Autoconf 2.50
1144 Released 2001-05-21 by Akim Demaille.
1146 ** Lots of bug fixes
1147 There have been far too many to enumerate them here. Check out
1148 ChangeLog if you really want to know more.
1150 ** Improved documentation
1151 In particular, portability issues are better covered.
1154 All the standard GNU Makefile targets are supported. The layout has
1155 changed: m4/ holds the M4 extensions Autoconf needs for its
1156 configuration, doc/ contains the documentation, and tests/ contains
1159 ** Man pages are provided
1160 For autoconf, autoreconf, autoupdate, autoheader, autoscan, ifnames,
1161 config.guess, config.sub.
1165 Provides a safe and powerful means to trace the macro uses. This
1166 provide the parsing layer for tools which need to `study'
1170 Specify what category of warnings should be enabled.
1172 - When recursing into subdirectories, try for configure.gnu before
1173 configure to adapt for packages not using autoconf on case-insensitive
1177 More errors are now caught (circular AC_REQUIRE dependencies,
1178 AC_DEFINE in the action part of an AC_CACHE_CHECK, too many pops
1179 etc.). In addition, their location and call stack are given.
1182 autoupdate is much more powerful, and is able to provide the glue code
1183 which might be needed to move from an old macro to its newer
1186 You are strongly encouraged to use it to modernize both your
1187 `configure.in' and your .m4 extension files.
1190 The internal machinery of autoheader has completely changed. As a
1191 result, using `acconfig.h' should be considered to be obsoleted, and
1192 you are encouraged to get rid of it using the AH macros.
1197 ** Fortran 77 compilers
1198 Globally, the support for Fortran 77 is considerably improved.
1200 Support for automatically determining a Fortran 77 compiler's
1201 name-mangling scheme. New CPP macros F77_FUNC and F77_FUNC_ are
1202 provided to wrap C/C++ identifiers, thus making it easier and more
1203 transparent for C/C++ to call Fortran 77 routines, and Fortran 77 to
1204 call C/C++ routines. See the Texinfo documentation for details.
1207 The test suite no longer uses DejaGNU. It should be easy to submit
1208 test cases in this new framework.
1211 - --help, --help=long, -hl
1212 no longer dumps useless items.
1214 lists only specific options.
1215 - --help=recursive, -hr
1216 displays the help of all the embedded packages.
1217 - Remembers environment variables when reconfiguring.
1218 The previous scheme to set envvar before running configure was
1220 what prevented configure from remembering the environment in which
1221 it was run, therefore --recheck was run in an inconsistent
1222 environment. Now, one should run
1224 and then --recheck will work properly. Variables declared with
1225 AC_ARG_VAR are also preserved.
1227 $build defaults to `config.guess`, $host to $build, and then $target
1229 Cross-compilation is a global status of the package, it no longer
1230 depends upon the current language.
1231 Cross compilation is enabled iff the user specified `--host'.
1232 `configure' now fails if it can't run the executables it compiles,
1233 unless cross-compilation is enabled.
1235 The cache file is disabled by default. The new options
1236 `--config-cache', `-C' set the cache to `config.cache'.
1240 Much faster on most architectures.
1241 - concurrent executions
1242 It is safe to use `make -j' with config.status.
1243 - human interface improved
1244 It is possible to invoke
1245 ./config.status foobar
1246 instead of the former form (still valid)
1247 CONFIG_COMMANDS= CONFIG_HEADERS= CONFIG_LINKS= \
1248 CONFIG_FILES=foobar:foo.in:bar.in \
1250 The same holds for configuration headers and links.
1251 You can instantiate unknown files and headers:
1252 ./config.status --header foo.h:foo.h.in --file bar:baz
1253 - has a useful --help
1254 - accepts special file name "-" for stdin/stdout
1259 Specify additional copyright information.
1262 Now expects the identity of the package as argument.
1266 Most macros, if not all, now strictly follow the `one quotation
1267 level' rule. This results in a more predictable expansion.
1270 A sly bug in the AC_REQUIRE machinery, which could produce incorrect
1271 configure scripts, was fixed by Axel Thimm.
1275 Document and ask for the registration of an envvar.
1278 Specifies the file which `configure' should look for when trying to
1279 find the source tree (used to be handled by AC_INIT).
1281 - AC_CONFIG_COMMANDS
1282 To add new actions to config.status. Should be used instead of
1286 Replaces AC_LINK_FILES.
1288 - AC_CONFIG_HEADERS, AC_CONFIG_COMMANDS, AC_CONFIG_SUBDIRS,
1289 AC_CONFIG_LINKS, and AC_CONFIG_FILES
1290 They now obey sh: you should no longer use shell variables as
1291 argument. Instead of
1293 test "$package_foo_enabled" = yes && $my_subdirs="$my_subdirs foo"
1294 AC_CONFIG_SUBDIRS($my_subdirs)
1298 if test "$package_foo_enabled" = yes; then
1299 AC_CONFIG_SUBDIRS(foo)
1303 To format an Autoconf macro's help string so that it looks pretty
1304 when the user executes `configure --help'.
1307 ** Generic Test Macros
1309 The interface of the AC_CHECK families of macros (decl, header,
1310 type, member, func) is now uniform. They support the same set of
1313 - AC_CHECK_DECL, AC_CHECK_DECLS
1314 To check whether a symbol is declared.
1316 - AC_CHECK_SIZEOF, AC_C_CHAR_UNSIGNED.
1317 No longer need a cross-compilation default.
1320 The test it performs is much more robust than previously, and makes
1321 it possible to test builtin types in addition to typedefs.
1322 It is now schizophrenic:
1323 - AC_CHECK_TYPE(TYPE, REPLACEMENT)
1324 remains for backward compatibility, but its use is discouraged.
1325 - AC_CHECK_TYPE(TYPE, IF-FOUND, IF-NOT-FOUND, INCLUDES)
1326 behaves exactly like the other AC_CHECK macros.
1329 Checks whether given types are supported by the system.
1331 - AC_CHECK_MEMBER, AC_CHECK_MEMBERS
1332 Check for given members in aggregates (e.g., pw_gecos in struct
1336 Checks if the compiler supports ISO C, included when needs special
1340 Checking whether the preprocessor indicates missing includes by the
1341 error code. stderr is checked by AC_TRY_CPP only as a fallback.
1344 Takes a language as argument and replaces AC_LANG_C,
1345 AC_LANG_CPLUSPLUS and AC_LANG_FORTRAN77.
1347 - AC_LANG_PUSH, AC_LANG_POP
1348 Are preferred to AC_LANG_SAVE, AC_LANG_RESTORE.
1351 - AC_FUNC_CHOWN, AC_FUNC_MALLOC, AC_FUNC_STRERROR_R,
1352 AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK, AC_FUNC_STAT, AC_FUNC_LSTAT,
1353 AC_FUNC_ERROR_AT_LINE, AC_FUNC_OBSTACK, AC_FUNC_STRTOD, AC_FUNC_FSEEKO.
1357 Sets GETGROUPS_LIBS.
1359 - AC_FUNC_GETLOADAVG
1360 Defines `HAVE_STRUCT_NLIST_N_UN_N_NAME' instead of `NLIST_NAME_UNION'.
1363 Now integrates `AC_DECL_YYTEXT' which is obsoleted.
1366 Arrange for large-file support.
1368 - AC_EXEEXT, AC_OBJEXT
1369 You are no longer expected to use them: their computation is
1370 performed by default.
1372 ** C++ compatibility
1373 Every macro has been revisited in order to support at best CC=c++.
1375 Major changes in Autoconf 2.14:
1376 There was no release of GNU Autoconf 2.14.
1378 Major changes in Autoconf 2.13:
1380 Released 1999-05-01 by Ben Elliston.
1382 * Support for building on Win32 systems where the only available C or
1383 C++ compiler is the Microsoft Visual C++ command line compiler
1384 (`cl'). Additional support for building on Win32 systems which are
1385 using the Cygwin or Mingw32 environments.
1386 * Support for alternative object file and executable file extensions.
1387 On Win32, for example, these are .obj and .exe. These are discovered
1388 using AC_OBJEXT and AC_EXEEXT, which substitute @OBJEXT@ and
1389 @EXEEXT@ in the output, respectively.
1390 * New macros: AC_CACHE_LOAD, AC_CACHE_SAVE, AC_FUNC_SELECT_ARGTYPES,
1391 AC_VALIDATE_CACHED_SYSTEM_TUPLE, AC_SEARCH_LIBS, AC_TRY_LINK_FUNC,
1392 AC_C_STRINGIZE, AC_CHECK_FILE(S), AC_PROG_F77 (and friends).
1393 * AC_DEFINE now has an optional third argument for a description to be
1394 placed in the config header input file (e.g. config.h.in).
1395 * The C++ code fragment compiled for the C++ compiler test had to be
1396 improved to include an explicit return type for main(). This was
1397 causing failures on systems using recent versions of the EGCS C++
1399 * Fixed an important bug in AC_CHECK_TYPE that would cause a configure
1400 script to report that `sometype_t' was present when only `type_t'
1402 * Merge of the FSF version of config.guess and config.sub to modernize
1403 these scripts. Add support for a few new hosts in config.guess.
1404 Incorporate latest versions of install-sh, mkinstalldirs and
1405 texinfo.tex from the FSF.
1406 * autoreconf is capable of running automake if necessary (and
1408 * Support for Fortran 77. See the Texinfo documentation for details.
1409 * Bug fixes and workarounds for quirky bugs in vendor utilities.
1411 Major changes in Autoconf 2.12:
1413 Released 1996-11-26 by David J. MacKenzie
1415 * AC_OUTPUT and AC_CONFIG_HEADER can create output files by
1416 concatenating multiple input files separated by colons, like so:
1417 AC_CONFIG_HEADER(config.h:conf.pre:config.h.in:conf.post)
1418 AC_OUTPUT(Makefile:Makefile.in:Makefile.rules)
1419 The arguments may be shell variables, to compute the lists on the fly.
1420 * AC_LINK_FILES and AC_CONFIG_SUBDIRS may be called multiple times.
1421 * New macro AC_OUTPUT_COMMANDS adds more commands to run in config.status.
1424 Major changes in Autoconf 2.11:
1426 Released November 18th, 1996, by David J. MacKenzie
1428 * AC_PROG_CC and AC_PROG_CXX check whether the compiler works.
1429 They also default CFLAGS/CXXFLAGS to "-g -O2" for gcc, instead of "-g -O".
1430 * AC_REPLACE_FUNCS defines HAVE_foo if the system has the function `foo'.
1431 * AC_CONFIG_HEADER expands shell variables in its argument.
1432 * New macros: AC_FUNC_FNMATCH, AC_FUNC_SETPGRP.
1433 * The "checking..." messages and the source code for test programs that
1434 fail are saved in config.log.
1435 * Another workaround has been added for seds with small command length limits.
1436 * config.sub and config.guess recognize more system types.
1439 Major changes in Autoconf 2.10:
1441 Released May 7th, 1996, by Roland McGrath
1444 * The cache variable names used by `AC_CHECK_LIB(LIB, FUNC, ...)' has
1445 changed: now $ac_cv_lib_LIB_FUNC, previously $ac_cv_lib_LIB.
1447 Major changes in Autoconf 2.9:
1449 Released March 16th, 1996, by Roland McGrath
1453 Major changes in Autoconf 2.8:
1455 Released March 8th, 1996, by Roland McGrath
1459 Major changes in Autoconf 2.7:
1461 Released November 22nd, 1995, by David J. MacKenzie
1465 Major changes in Autoconf 2.6:
1467 Released November 20th, 1995, by David J. MacKenzie
1471 Major changes in Autoconf 2.5:
1473 Released November 17th, 1995, by Roland McGrath
1475 * New configure options --bindir, --libdir, --datadir, etc., with
1476 corresponding output variables.
1477 * New macro: AC_CACHE_CHECK, to make using the cache easier.
1478 * config.log contains the command being run as well as any output from it.
1479 * AC_CHECK_LIB can check for libraries with "." or "/" or "+" in their name.
1480 * AC_PROG_INSTALL doesn't cache a name for install-sh, for sharing caches.
1481 * AC_CHECK_PROG, AC_PATH_PROG, AC_CHECK_PROGS, AC_PATH_PROGS, and
1482 AC_CHECK_TOOL can search a path other than $PATH.
1483 * AC_CHECK_SIZEOF takes an optional size to use when cross-compiling.
1485 Major changes in Autoconf 2.4:
1487 Released June 14th, 1995, by David J. MacKenzie
1489 * Fix a few bugs found by Emacs testers.
1491 Major changes in Autoconf 2.3:
1493 Released March 27th, 1995, by David J. MacKenzie
1495 * Fix the cleanup trap in several ways.
1496 * Handle C compilers that are picky about option placement.
1497 * ifnames gets the version number from the right directory.
1499 Major changes in Autoconf 2.2:
1501 Released March 8th, 1995, by David J. MacKenzie
1503 * The ifnames utility is much faster but requires a "new awk" interpreter.
1504 * AC_CHECK_LIB and AC_HAVE_LIBRARY check and add the new
1505 library before existing libs, not after, in case it uses them.
1506 * New macros: AC_FUNC_GETPGRP, AC_CHECK_TOOL.
1507 * Lots of bug fixes.
1508 * Many additions to the TODO file :-)
1510 Major changes in Autoconf 2.1:
1512 Released November 4th, 1994, by David J. MacKenzie
1515 * More explanations in the manual.
1516 * Fix a spurious failure in the testsuite.
1517 * Clarify some warning messages.
1518 * autoreconf by default only rebuilds configure and config.h.in files
1519 that are older than any of their particular input files; there is a
1520 --force option to use after installing a new version of Autoconf.
1522 Thanks to everybody who's submitted changes and additions to Autoconf!
1523 I've incorporated many of them, and am still considering others for
1524 future releases -- but I didn't want to postpone this release indefinitely.
1526 Caution: don't indiscriminately rebuild configure scripts with
1527 Autoconf version 2. Some configure.in files need minor adjustments to
1528 work with it; the documentation has a chapter on upgrading. A few
1529 configure.in files, including those for GNU Emacs and the GNU C
1530 Library, need major changes because they relied on undocumented
1531 internals of version 1. Future releases of those packages will have
1532 updated configure.in files.
1534 It's best to use GNU M4 1.3 (or later) with Autoconf version 2.
1535 Autoconf now makes heavy use of M4 diversions, which were implemented
1536 inefficiently in GNU M4 releases before 1.3.
1538 Major changes in Autoconf 2.0:
1540 Released October 26th, 1994, by David J. MacKenzie
1542 ** New copyright terms:
1543 * There are no restrictions on distribution or use of configure scripts.
1546 * Autoconf manual is reorganized to make information easier to find
1547 and has several new indexes.
1548 * INSTALL is reorganized and clearer and is now made from Texinfo source.
1551 * autoscan to generate a preliminary configure.in for a package by
1552 scanning its source code for commonly used nonportable functions,
1553 programs, and header files.
1554 * ifnames to list the symbols used in #if and #ifdef directives in a
1556 * autoupdate to update a configure.in to use the version 2 macro names.
1557 * autoreconf to recursively remake configure and configuration header
1558 files in a source tree.
1560 ** Changed utilities:
1561 * autoheader can take pieces of acconfig.h to replace config.h.{top,bot}.
1562 * autoconf and autoheader can look for package-local definition files
1563 in an alternate directory.
1566 * AC_CACHE_VAL to share results of tests between configure runs.
1567 * AC_DEFUN to define macros, automatically AC_PROVIDE them, and ensure
1568 that macros invoked with AC_REQUIRE don't interrupt other macros.
1569 * AC_CONFIG_AUX_DIR, AC_CANONICAL_SYSTEM, AC_CANONICAL_HOST, AC_LINK_FILES to
1570 support deciding unguessable features based on the host and target types.
1571 * AC_CONFIG_SUBDIRS to recursively configure a source tree.
1572 * AC_ARG_PROGRAM to use the options --program-prefix,
1573 --program-suffix, and --program-transform-name to change the names
1574 of programs being installed.
1575 * AC_PREFIX_DEFAULT to change the default installation prefix.
1576 * AC_TRY_COMPILE to compile a test program without linking it.
1577 * AC_CHECK_TYPE to check whether sys/types.h or stdlib.h defines a given type.
1578 * AC_CHECK_LIB to check for a particular function and library.
1579 * AC_MSG_CHECKING and AC_MSG_RESULT to print test results, on a single line,
1580 whether or not the test succeeds. They obsolete AC_CHECKING and AC_VERBOSE.
1581 * AC_SUBST_FILE to insert one file into another.
1582 * AC_FUNC_MEMCMP to check whether memcmp is 8-bit clean.
1583 * AC_FUNC_STRFTIME to find strftime even if it's in -lintl.
1584 * AC_FUNC_GETMNTENT to find getmntent even if it's in -lsun or -lseq.
1585 * AC_HEADER_SYS_WAIT to check whether sys/wait.h is POSIX.1 compatible.
1588 * Many macros renamed systematically, but old names are accepted for
1589 backward compatibility.
1590 * AC_OUTPUT adds the "automatically generated" comment to
1591 non-Makefiles where it finds @configure_input@ in an input file, to
1592 support files with various comment syntaxes.
1593 * AC_OUTPUT does not replace "prefix" and "exec_prefix" in generated
1594 files when they are not enclosed in @ signs.
1595 * AC_OUTPUT allows the optional environment variable CONFIG_STATUS to
1596 override the file name "config.status".
1597 * AC_OUTPUT takes an optional argument for passing variables from
1598 configure to config.status.
1599 * AC_OUTPUT and AC_CONFIG_HEADER allow you to override the input-file names.
1600 * AC_OUTPUT automatically substitutes the values of CFLAGS, CXXFLAGS,
1601 CPPFLAGS, and LDFLAGS from the environment.
1602 * AC_PROG_CC and AC_PROG_CXX now set CFLAGS and CXXFLAGS, respectively.
1603 * AC_PROG_INSTALL looks for install-sh or install.sh in the directory
1604 specified by AC_CONFIG_AUXDIR, or srcdir or srcdir/.. or
1605 srcdir/../.. by default.
1606 * AC_DEFINE, AC_DEFINE_UNQUOTED, and AC_SUBST are more robust and smaller.
1607 * AC_DEFINE no longer prints anything, because of the new result reporting
1608 mechanism (AC_MSG_CHECKING and AC_MSG_RESULT).
1609 * AC_VERBOSE pays attention to --quiet/--silent, not --verbose.
1610 * AC_ARG_ENABLE and AC_ARG_WITH support whitespace in the arguments to
1611 --enable- and --with- options.
1612 * AC_CHECK_FUNCS and AC_CHECK_HEADERS take optional shell commands to
1613 execute on success or failure.
1614 * Checking for C functions in C++ works.
1617 * AC_REMOTE_TAPE and AC_RSH removed; too specific to tar and cpio, and
1618 better maintained with them.
1619 * AC_ARG_ARRAY removed because no one was likely using it.
1620 * AC_HAVE_POUNDBANG replaced with AC_SYS_INTERPRETER, which doesn't
1621 take arguments, for consistency with all of the other specific checks.
1624 * Comes with config.sub and config.guess, and uses them optionally.
1625 * Uses config.cache to cache test results. An alternate cache file
1626 can be selected with the --cache-file=FILE option.
1627 * Uses optional shell scripts $prefix/share/config.site and
1628 $prefix/etc/config.site to perform site or system specific initializations.
1629 * configure saves compiler output to ./config.log for debugging.
1630 * New files autoconf.m4 and autoheader.m4 load the other Autoconf macros.
1631 * acsite.m4 is the new name for the system-wide aclocal.m4.
1632 * Has a DejaGnu test suite.
1634 Major changes in Autoconf 1.11:
1636 * AC_PROG_INSTALL calls install.sh with the -c option.
1637 * AC_SET_MAKE cleans up after itself.
1638 * AC_OUTPUT sets prefix and exec_prefix if they weren't set already.
1639 * AC_OUTPUT prevents shells from looking in PATH for config.status.
1641 Plus a few other bug fixes.
1643 Major changes in Autoconf 1.10:
1645 * autoheader uses config.h.bot if present, analogous to config.h.top.
1646 * AC_PROG_INSTALL looks for install.sh in srcdir or srcdir/.. and
1648 * AC_PROG_CXX looks for cxx as a C++ compiler.
1650 Plus several bugs fixed.
1652 Major changes in Autoconf 1.9:
1654 * AC_YYTEXT_POINTER replaces AC_DECLARE_YYTEXT.
1655 * AC_SIZEOF_TYPE generates the cpp symbol name automatically,
1656 and autoheader generates entries for those names automatically.
1657 * AC_FIND_X gets the result from xmkmf correctly.
1658 * AC_FIND_X assumes no X if --without-x was given.
1659 * AC_FIND_XTRA adds libraries to the variable X_EXTRA_LIBS.
1660 * AC_PROG_INSTALL finds OSF/1 installbsd.
1662 Major changes in Autoconf 1.8:
1665 * New macros AC_LANG_C, AC_LANG_CPLUSPLUS, AC_LANG_SAVE, AC_LANG_RESTORE,
1666 AC_PROG_CXX, AC_PROG_CXXCPP, AC_REQUIRE_CPP
1667 for checking both C++ and C features in one configure script.
1668 * New macros AC_CHECKING, AC_VERBOSE, AC_WARN, AC_ERROR for printing messages.
1669 * New macros AC_FIND_XTRA, AC_MMAP, AC_SIZEOF_TYPE, AC_PREREQ,
1670 AC_SET_MAKE, AC_ENABLE.
1673 * AC_FIND_X looks for X in more places.
1674 * AC_PROG_INSTALL defaults to install.sh instead of cp, if it's in srcdir.
1675 install.sh is distributed with Autoconf.
1676 * AC_DECLARE_YYTEXT has been removed because it can't work, pending
1677 a rewrite of quoting in AC_DEFINE.
1678 * AC_OUTPUT adds its comments in C format when substituting in C files.
1679 * AC_COMPILE_CHECK protects its ECHO-TEXT argument with double quotes.
1681 ** New or changed command line options:
1682 * configure accepts --enable-FEATURE[=ARG] and --disable-FEATURE options.
1683 * configure accepts --without-PACKAGE, which sets withval=no.
1684 * configure accepts --x-includes=DIR and --x-libraries=DIR.
1685 * Giving --with-PACKAGE no argument sets withval=yes instead of withval=1.
1686 * configure accepts --help, --version, --silent/--quiet, --no-create options.
1687 * configure accepts and ignores most other Cygnus configure options, and
1688 warns about unknown options.
1689 * config.status accepts --help, --version options.
1691 ** File names and other changes:
1692 * Relative srcdir values are not made absolute.
1693 * The values of @prefix@ and @exec_prefix@ and @top_srcdir@ get substituted.
1694 * Autoconf library files are installed in ${datadir}/autoconf, not ${datadir}.
1695 * autoheader optionally copies config.h.top to the beginning of config.h.in.
1696 * The example Makefile dependencies for configure et al. work better.
1697 * Namespace cleanup: all shell variables used internally by Autoconf
1698 have names beginning with `ac_'.
1700 More big improvements are in process for future releases, but have not
1701 yet been (variously) finished, integrated, tested, or documented enough
1704 Major changes in Autoconf 1.7:
1706 * New macro AC_OBSOLETE.
1707 * Bugs in Makefile.in fixed.
1708 * AC_LONG_FILE_NAMES improved.
1710 Major changes in Autoconf 1.6:
1712 * New macro AC_LONG_64_BITS.
1713 * Multiple .h files can be created.
1714 * AC_FIND_X looks for X files directly if it doesn't find xmkmf.
1715 * AC_ALLOCA defines C_ALLOCA if using alloca.c.
1716 * --with-NAME can take a value, e.g., --with-targets=sun4,hp300bsd.
1717 * Unused --no-create option to configure removed.
1718 * autoheader doesn't change the timestamp of its output file if
1719 the file didn't change.
1720 * All macros that look for libraries now use AC_HAVE_LIBRARY.
1721 * config.status checks three optional environment variables to
1722 modify its behavior.
1723 * The usual bug fixes.
1725 Major changes in Autoconf 1.5:
1727 * New macros AC_FIND_X, AC_OFF_T, AC_STAT_MACROS_BROKEN, AC_REVISION.
1728 * autoconf and autoheader scripts have GNU standards conforming
1729 --version and --help options (they print their message and exit).
1732 Major changes in Autoconf 1.4:
1734 * New macros AC_HAVE_POUNDBANG, AC_TIME_WITH_SYS_TIME, AC_LONG_DOUBLE,
1735 AC_GETGROUPS_T, AC_DEFINE_UNQUOTED.
1736 * autoconf and autoheader use the M4 environment variable to determine the
1737 name of the M4 program to use.
1738 * The --macrodir option to autoconf and autoheader specifies the directory
1739 in which acspecific.m4, acgeneral.m4, etc. reside if not the default.
1740 * autoconf and autoheader can take `-' as their file names, which means to
1741 read stdin as input.
1742 * Resulting configure scripts can take a --verbose option which causes them
1743 to print the results of their tests.
1744 * AC_DEFINE quotes its second argument in such a way that spaces, magic
1745 shell characters, etc. will be preserved during various stages of
1746 expansion done by the shell. If you don't want this, use
1747 AC_DEFINE_UNQUOTED instead.
1748 * Much textual processing done with external calls to tr and sed have been
1749 internalized with builtin M4 `patsubst' and `translit' calls.
1750 * AC_OUTPUT doesn't hardwire the file names it outputs. Instead, you can
1751 set the shell variables `gen_files' and `gen_config' to the list of
1752 file names to output.
1753 * AC_DECLARE_YYTEXT does an AC_SUBST of `LEX_OUTPUT_ROOT', which may be
1754 "lex.yy" or "lexyy", depending on the system.
1755 * AC_PROGRAMS_CHECK takes an optional third arg. If given, it is used as
1757 * If AC_ALLOCA chooses alloca.c, it also defines STACK_DIRECTION.
1758 * AC_CONST works much more reliably on more systems.
1761 Major changes in Autoconf 1.3:
1763 configure no longer requires awk for packages that use a config.h.
1764 Support handling --with-PACKAGE options.
1765 New `autoheader' script to create `config.h.in' from `configure.in'.
1766 Ignore troublesome -lucb and -lPW when searching for alloca.
1767 Rename --exec_prefix to --exec-prefix for GNU standards conformance.
1768 Improve detection of STDC library.
1769 Add AC_HAVE_LIBRARY to check for non-default libraries.
1770 Function checking should work with future GNU libc releases.
1772 Major changes in Autoconf 1.2:
1774 The --srcdir option is now usually unnecessary.
1775 Add a file containing sample comments describing CPP macros.
1776 A comment in config.status tells which host it was configured on.
1777 Substituted variable values can now contain commas.
1778 Fix bugs in various feature checks.
1780 Major changes in Autoconf 1.1:
1782 Added AC_STRCOLL macro.
1783 Made AC_GETLOADAVG check for more things.
1784 AC_OUTPUT argument is now optional.
1789 Copyright (C) 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001, 2002,
1790 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
1792 This program is free software: you can redistribute it and/or modify
1793 it under the terms of the GNU General Public License as published by
1794 the Free Software Foundation, either version 3 of the License, or
1795 (at your option) any later version.
1797 This program is distributed in the hope that it will be useful,
1798 but WITHOUT ANY WARRANTY; without even the implied warranty of
1799 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
1800 GNU General Public License for more details.
1802 You should have received a copy of the GNU General Public License
1803 along with this program. If not, see <http://www.gnu.org/licenses/>.