1 GNU Autoconf NEWS - User visible changes.
3 * Major changes in Autoconf 2.62a (2008-??-??)
5 ** AC_PATH_X now includes /lib64 and /usr/lib64 in its list of default
8 ** AC_USE_SYSTEM_EXTENSIONS no longer conflicts with an external
9 AC_DEFINE([__EXTENSIONS__]). This fixes a regression introduced in
10 2.62 when using macros such as AC_AIX that were made obsolete in
11 favor of the more portable AC_USE_SYSTEM_EXTENSIONS.
13 ** Newly obsolete macros
14 The following macro has been marked obsolete, since current porting
15 targets can safely assume C89 semantics that signal handlers return
16 void. We have no current plans to remove the macro.
20 ** Clients of m4_expand, such as AS_HELP_STRING and AT_SETUP, can now
21 handle properly quoted but otherwise unbalanced parentheses (for
22 some macros, this fixes a regression in 2.62).
24 ** Two new quadrigraphs have been introduced: @{:@ for (, and @:}@ for ),
25 allowing the output of unbalanced parantheses in more contexts.
27 ** The following m4sugar macros are new:
28 m4_joinall m4_reverse m4_set_add m4_set_add_all m4_set_contains
29 m4_set_contents m4_set_delete m4_set_difference m4_set_dump
30 m4_set_empty m4_set_foreach m4_set_intersection m4_set_list
31 m4_set_listc m4_set_remove m4_set_size m4_set_union
33 ** The following m4sugar macros now accept multiple arguments, as is the
34 case with underlying m4:
35 m4_defn m4_popdef m4_undefine
37 ** The following m4sugar macros now guarantee linear scaling; they
38 previously had linear scaling with m4 1.6 but quadratic scaling
39 when using m4 1.4.x. All macros built on top of these also gain
40 the scaling improvements.
41 m4_bmatch m4_bpatsubsts m4_case m4_cond m4_do m4_dquote_elt
42 m4_foreach m4_join m4_list_cmp m4_map m4_map_sep m4_max
45 ** AT_KEYWORDS once again performs expansion on its argument, such that
46 AT_KEYWORDS([m4_if([$1], [], [default])]) no longer complains about
47 the possibly unexpanded m4_if [regression introduced in 2.62].
49 ** Config header templates `#undef UNDEFINED /* comment */' do not lead to
50 nested comments any more; regression introduced in 2.62.
53 * Major changes in Autoconf 2.62 (2008-04-05) [stable]
54 Released by Eric Blake, based on git versions 2.61a.*.
56 ** Many optimizations have been applied to make overall execution faster.
58 ** Autotest now makes use of shell functions.
60 ** config.status now uses awk instead of sed also for config headers.
62 - As a side effect, AC_DEFINE and AC_DEFINE_UNQUOTED now handle multi-line
63 values, i.e., backslash-newline combinations are handled correctly.
64 Further, for config headers, the total size of values is not limited by
65 the POSIX length limit of text lines any more, only each single line.
67 ** New config variable `top_build_prefix'.
69 ** New Autoconf macros:
70 AC_AUTOCONF_VERSION AC_OPENMP AC_PATH_PROGS_FEATURE_CHECK
72 ** AC_C_BIGENDIAN now supports universal binaries a la Mac OS X.
74 ** AC_C_RESTRICT now prefers to #define 'restrict' to a variant spelling
75 like '__restrict' if the variant spelling is available, as this is
76 more likely to work when mixing C and C++ code.
78 ** AC_CHECK_ALIGNOF's type argument T is now documented better: it must
79 be a string of tokens such that "T y;" is a valid member declaration
82 ** AC_CHECK_SIZEOF now accepts objects as well as types: the general rule
83 is that sizeof (X) works, then AC_CHECK_SIZEOF (X) should work.
85 ** AC_CHECK_TYPE and AC_CHECK_TYPES now work on any C type-name; formerly,
86 they did not work for function types. In C++, they now work on any
87 type-id that can be the operand of sizeof; this is similar to C,
88 except it excludes anonymous struct and union types. Formerly,
89 some (but not all) C++ types involving anonymous struct and union
90 were accepted, though this was not documented.
92 ** AC_CONFIG_LINKS now prefers to link against files in the build tree
93 if found, and it works to link against a file of the same name in
94 the source tree, even if both trees coincide.
96 ** AC_INIT no longer alters $@; regression introduced in 2.60.
98 ** AC_USE_SYSTEM_EXTENSIONS now defines _ALL_SOURCE for Interix platforms.
100 ** AS_HELP_STRING no longer underquotes its first argument; it also handles
101 the case where the first argument contains single-quoted commas.
102 For example, "AS_HELP_STRING([-a, [--arg[=foo]]], [bar])" produces:
103 " -a, --arg[=foo] bar"
104 Additionally, the macro now takes two additional arguments,
105 indent-column and wrap-column; these should not normally be needed,
106 but can be used to fine-tune how the output text is wrapped.
108 ** AC_PROG_INSTALL now requires an install program that can install multiple
109 files into a target directory.
111 ** The command 'autoconf -' now correctly processes a file from stdin.
113 ** 'autoreconf -m' now honors $MAKE.
115 ** For all of the directory arguments for 'configure', such as '--prefix'
116 or '--bindir', trailing slashes are stripped. As an example, if
117 tab completion in the user's shell appends trailing slashes, the
118 command './configure --prefix=/usr/' will still result in an
119 expanded libdir value of /usr/lib, not /usr//lib.
121 ** `configure --help=recursive' now works in read-only trees and from
122 unconfigured build trees.
124 ** If precious variables differ only in whitespace, then the cache consistency
125 check warns instead of fails, and reuses the old value.
127 ** AT_BANNER is now documented.
129 ** AT_SETUP now handles macro expansions properly when calculating line
132 ** Autotest now determines $srcdir correctly.
134 ** Testsuites built by autotest now accept a -C/--directory=DIR option
135 to adjust the working directory prior to creating files.
137 ** Autoconf now requires GNU M4 1.4.5 or later. Earlier versions of M4 have
138 a bug in macro tracing that interferes with the interaction between
139 Autoconf and Automake. GNU M4 1.4.11 or later is recommended. The
140 configure search for a working M4 is improved.
142 ** For portability with the eventual M4 2.0, macros should no longer use
143 anything larger than $9 to refer to arguments.
145 ** Documentation for m4sugar is improved.
147 - The following macros were previously available as undocumented
148 interfaces; the macros are now documented as stable interfaces.
150 __oline__ m4_assert m4_bmatch m4_bpatsubsts m4_car m4_case
151 m4_cdr m4_default m4_divert_once m4_divert_pop m4_divert_push
152 m4_divert_text m4_do m4_errprintn m4_fatal m4_flatten
153 m4_ifndef m4_ifset m4_ifval m4_ifvaln m4_location
154 m4_n m4_shiftn m4_strip m4_warn
156 - The following macros were previously available as undocumented
157 interfaces, but had bug fixes or semantic changes as part of this
158 release. Packages that relied on the undocumented behavior
159 should be analyzed to make sure they will still work with the
160 new documented behavior.
162 m4_cmp m4_list_cmp m4_join m4_map m4_map_sep m4_sign
163 m4_text_box m4_text_wrap m4_version_compare
165 - The m4_wrap macro used to have unspecified order, but now
166 guarantees FIFO order. m4_wrap_lifo was added to guarantee LIFO
169 - Packages using the undocumented m4sugar macro m4_PACKAGE_VERSION
170 should consider using the new AC_AUTOCONF_VERSION instead.
172 - m4sugar macros that are not documented in the manual are still
173 deemed experimental, and should not be used outside of Autoconf.
175 ** The m4sugar macros m4_append and m4_append_uniq, first documented in
176 2.60, have been fixed to treat both the string and the separator
177 arguments consistently with regards to quoting. Prior to this fix,
178 m4_append_uniq could mistakenly duplicate entries if the expansion
179 of the separator resulted in a different string (for example, if it
180 contained quotes, a comma, or a macro name). However, it means
181 that programs previously using
182 m4_append([name], [string], [[, ]])
183 are now using a four-character separator instead of the intended
184 comma and space. If you need portability to earlier versions of
185 Autoconf, you can insert the following snippet after AC_INIT but
186 before any other macro expansions, to enforce the new semantics:
187 m4_pushdef([m4_append], [m4_define([$1],
188 m4_ifdef([$1], [m4_defn([$1])[$3]])[$2])])
189 Additionally, m4_append_uniq now takes optional parameters that can
190 be used to take action depending on whether anything was appended,
191 and warns if a non-empty separator occurs within the string being
192 appended, since that can lead to duplicates.
194 ** The following m4sugar macros are new:
195 m4_append_uniq_w m4_apply m4_combine m4_cond m4_count
196 m4_dquote_elt m4_echo m4_expand m4_ignore m4_make_list m4_max
197 m4_min m4_newline m4_shift2 m4_shift3 m4_unquote m4_wrap_lifo
199 ** Warnings are now generated by default when an installer invokes
200 'configure' with an unknown --enable-* or --with-* option.
201 These warnings can be disabled with the new AC_DISABLE_OPTION_CHECKING
202 macro, or by invoking 'configure' with --disable-option-checking.
204 ** Existing obsolete macros
205 The documentation for the following macros is adjusted to make it
206 more clear that they have previously been marked obsolete, as their
207 functionality can be accomplished by other macros. We have no
208 current plans to remove them from Autoconf.
210 AC_ENABLE AC_STRUCT_ST_BLKSIZE AC_STRUCT_ST_RDEV AC_WITH
212 ** Newly obsolete macros
213 The following macros have been marked obsolete, as they only
214 perform a subset of AC_USE_SYSTEM_EXTENSIONS. We have no current
215 plans to remove them.
217 AC_AIX AC_GNU_SOURCE AC_ISC_POSIX AC_MINIX
219 ** AC_C_LONG_DOUBLE is obsolescent.
220 The documentation now says that AC_C_LONG_DOUBLE is obsolescent: it
221 tests for problems that are so old that it is no longer of
222 practical importance on current systems. New programs need not use
223 AC_C_LONG_DOUBLE. We have no current plans to remove it.
225 ** AC_DIAGNOSE, AC_WARNING, and AC_FATAL are obsolescent.
226 The documentation now favors the use of M4sugar macros m4_warn and
227 m4_fatal, since the naming makes it more obvious that the
228 diagnostics are associated with M4 expansion (ie. when running
229 `autoconf'), and offers less confusion with the AC_MSG_ERROR,
230 AC_MSG_FAILURE, and AC_MSG_WARN macros which manage diagnostics
231 when running `configure'. We have no current plans to remove these
235 * Major changes in Autoconf 2.61a (2006-12-11)
237 ** AC_FUNC_FSEEKO was broken in 2.61; it didn't make fseeko and ftello visible
238 on many platforms. This has been fixed.
240 ** AC_FUNC_SETVBUF_REVERSED is now obsolete. It is still defined for backward
241 compatibility but it does nothing. The macro was already
242 obsolescent, as the last systems to have the problem were those
243 based on SVR2, which became obsolete in 1987. The macro had bugs
244 on some modern systems and could no longer be maintained reliably
245 due to lack of ancient systems to test it on.
247 ** config.status now uses awk instead of sed for most substitutions, for speed.
249 - As a side effect multi-line values of substituted variables no
250 longer have a small limit in total size, though for portability
251 each line should not exceed the POSIX length limit for text lines.
253 - It is now documented that Makefile.in should not contain
254 overlapping variable occurrences, e.g., @VAR1@VAR2@.
255 Autoconf's behavior was always iffy in such cases, and the
256 awk implementation has changed the behavior.
258 ** Many uses of 'echo' have been rewritten so that Autoconf-generated
259 scripts have fewer problems with strings or file names containing
260 embedded special characters such as backslash or leading "-". This
261 was implemented by using `printf '%s\n' "$foo"' instead of `echo
262 "$foo"' when printf works. Due to the implementation technique
263 used, Autoconf-generated scripts now run considerably more slowly
264 on ancient implementations lacking printf. However, this should
265 not be a problem, since Autoconf-generated scripts in practice
266 invariably find a more-modern shell these days.
269 * Major changes in Autoconf 2.61 (2006-11-17)
271 ** New macros AC_C_FLEXIBLE_ARRAY_MEMBER, AC_C_VARARRAYS.
273 ** AC_ARG_ENABLE and AC_ARG_WITH now allow '.' in feature and package names.
276 * Major changes in Autoconf 2.60b (2006-10-22)
279 Autoconf-generated shell scripts no longer export BIN_SH, due to
280 configuration hassles with this. Installers who need BIN_SH in
281 their environment should set it before invoking 'configure' and
282 'make'. As far as we know, this affects only Unixware installations.
284 ** Obsolescent macros
285 The documentation now says that the following macros are obsolescent,
286 as they are superseded by Gnulib:
288 AC_FUNC_FNMATCH AC_FUNC_FNMATCH_GNU AC_FUNC_GETLOADVG AC_REPLACE_FNMATCH
290 New programs should use the Gnulib counterparts of these macros.
291 We have no current plans to remove them from Autoconf.
293 ** AC_COMPUTE_INT no longer caches or reports results.
295 ** AC_CHECK_DECL now also works with aggregate objects.
297 ** AC_USE_SYSTEM_EXTENSIONS now defines _TANDEM_SOURCE for NonStop platforms.
299 ** GNU M4 1.4.7 or later is now recommended.
302 New M4sugar macro, which is more secure than the POSIX M4 maketemp.
305 Now an alias for m4_mkstemp.
307 * Major changes in Autoconf 2.60a (2006-08-25)
309 ** GNU M4 1.4.6 or later is now recommended.
311 ** The check for C99 now tests for varargs macros, as documented.
312 It also tests that the preprocessor supports 64-bit integers.
314 ** Autoconf now uses constructs like "#ifdef HAVE_STDLIB_H" rather than
315 "#if HAVE_STDLIB_H", so that it now works with "gcc -Wundef -Werror".
317 ** The functionality of the undocumented _AC_COMPUTE_INT is now provided
318 by a public and documented macro, AC_COMPUTE_INT. The parameters to the
319 two macros are different, so autoupdate will not change the old private name
320 to the new one. _AC_COMPUTE_INT may be removed in a future release.
322 ** AC_TYPE_LONG_LONG_INT and AC_TYPE_UNSIGNED_LONG_LONG_INT now require
323 that long long types be at least 64 bits wide, as C99 and tradition
324 requires. Formerly, they accepted implementations of any width.
327 * Major changes in Autoconf 2.60
329 Released 2006-06-23, by Ralf Wildenhues.
331 ** Autoconf no longer depends on whether m4wrap is FIFO (as Posix requires)
332 or LIFO (as in GNU M4 1.4.x). GNU M4 2.0 is expected to conform to Posix
333 here, so m4wrap/m4_wrap users should no longer depend on LIFO behavior.
335 ** Provide a way to turn off warnings about the changed directory variables.
337 * Major changes in Autoconf 2.59d
339 Released 2006-06-05, by Ralf Wildenhues.
341 ** GNU make now recommended for VPATH builds
342 INSTALL now suggests VPATH builds (e.g., "sh ../srcdir/configure")
343 only if you use GNU make. In practice, other 'make' implementations
344 have too many subtle incompatibilities in their support for VPATH.
345 Many packages (including Autoconf itself) are portable to other
346 'make' implementations, but some packages are not, and recommending
347 GNU make keeps the installation instructions simpler.
349 ** Even more safety checks for the new Directory variables:
350 Warn about suspicious `${datarootdir}' found in config files output.
352 ** AC_TRY_COMMAND, AC_TRY_EVAL, ac_config_guess, ac_config_sub, ac_configure
353 These never-documented macros and variables have been marked with
354 comments saying that they may be removed in a future release,
355 because their use can lead to unintended code being executed.
356 If you need functionality that only these macros or variables
357 currently supply, please write bug-autoconf@gnu.org.
359 ** AC_SUBST, AC_DEFINE
360 Literal arguments to these are passed to m4_pattern_allow now.
363 Passing 'ac_cv_prog_cc_stdc=no' to 'configure' now sets ac_cv_prog_cc_c99
364 and ac_cv_prog_cc_c89 to 'no' as well, for backward compatibility with
365 obsolete K&R tests in the Automake test suite.
374 Now more robust with special characters in file names, or when
375 multiple processes create the same directory at the same time.
377 ** Obsolescent macros
378 The documentation now says that the following macros are obsolescent:
379 they test for problems that are so old that they are no longer of
380 practical importance on current systems.
382 AC_C_BACKSLASH_A AC_FUNC_MEMCMP AC_HEADER_DIRENT
383 AC_C_CONST AC_FUNC_SELECT_ARGTYPES AC_HEADER_STAT
384 AC_C_PROTOTYPES AC_FUNC_SETPGRP AC_HEADER_STDC
385 AC_C_STRINGIZE AC_FUNC_SETVBUF_REVERSED AC_HEADER_SYS_WAIT
386 AC_C_VOLATILE AC_FUNC_STAT AC_HEADER_TIME
387 AC_FUNC_CLOSEDIR_VOID AC_FUNC_STRFTIME AC_ISC_POSIX
388 AC_FUNC_GETPGRP AC_FUNC_UTIME_NULL AC_PROG_GCC_TRADITIONAL
389 AC_FUNC_LSTAT AC_FUNC_VPRINTF AC_STRUCT_TM
391 New programs need not use these macros. We have no current plans to
395 For compatibility with future Libtool 2.0, autoreconf will invoke
396 libtoolize with the option `--ltdl' now, if LT_CONFIG_LTDL_DIR is
399 * Major changes in Autoconf 2.59c
401 Released 2006-04-12, by Ralf Wildenhues.
403 ** The configure command now redirects standard input from /dev/null,
404 to help avoid problems with subsidiary commands that might mistakenly
405 read standard input. AS_ORIGINAL_STDIN_FD points to the original
406 standard input before this redirection, if you really want configure to
407 read from standard input.
409 ** Directory variables adjusted to recent changes in the GNU Coding Standards.
410 The following directory variables are new:
412 datarootdir read-only architecture-independent data root [PREFIX/share]
413 localedir locale-specific message catalogs [DATAROOTDIR/locale]
414 docdir documentation root [DATAROOTDIR/doc/PACKAGE]
415 htmldir html documentation [DOCDIR]
416 dvidir dvi documentation [DOCDIR]
417 pdfdir pdf documentation [DOCDIR]
418 psdir ps documentation [DOCDIR]
420 The following variables have new default values:
422 datadir read-only architecture-independent data [DATAROOTDIR]
423 infodir info documentation [DATAROOTDIR/info]
424 mandir man documentation [DATAROOTDIR/man]
426 This means that if you use any of `@datadir@', `@infodir@', or
427 `@mandir@' in a file, you will have to ensure `${datarootdir}' is
428 defined in this file. As a temporary measure, if any of those are
429 found but no mention of `datarootdir', the substitutions will be
430 replaced with values that do not contain `${datarootdir}', and a
431 warning will be issued.
433 ** @top_builddir@ is now a dir name: it is always nonempty and doesn't have
434 a trailing slash. Similar change will be made to ac_top_builddir in a
435 future release; the old style value, which matches (../)*, is (and will
436 continue to be) available as ac_top_build_prefix.
439 New macro to check for support of 'typeof' syntax a la GNU C.
441 ** AC_CHECK_DECLS_ONCE, AC_CHECK_FUNCS_ONCE, AC_CHECK_HEADERS_ONCE
442 New "once-only" variants of commonly-used macros, to make 'configure'
443 smaller and faster in common cases.
446 New macro to check for strtold with C99 semantics.
449 New macro that lets builder disable assertions at 'configure'-time.
452 Now checks for X11/Xlib.h and XrmInitialize (X proper) rather than
453 X11/Intrinsic.h and XtMalloc (Xt).
455 ** AC_PRESERVE_HELP_ORDER
456 New macro that causes `configure' to display help strings for AC_ARG_ENABLE
457 and AC_ARG_WITH arguments in one region, in the order defined. The default
458 behavior is to group options of each classes separately.
460 ** AC_PROG_CC, AC_PROG_CXX
461 No longer automatically arrange to declare the 'exit' function of C,
462 when a C++ compiler is used. Standard Autoconf macros no longer use
463 'exit', so this is no longer an issue for them. If you use C++, and
464 want to call 'exit', you'll have to arrange for its declaration
465 yourself. But we now suggest you return from 'main' instead.
467 ** AC_PROG_CC_C89, AC_PROG_CC_C99
468 New macros for ISO C99 support. AC_PROG_CC_C89 and AC_PROG_CC_C99
469 check for ANSI C89 and ISO C99 support respectively.
472 Has been unobsoleted, and will check if the compiler supports ISO
473 C99, falling back to ANSI C89 if not. ac_cv_prog_cc_stdc is
474 retained for backwards compatibility, assuming the value of
475 ac_cv_prog_cc_c99 or ac_cv_prog_cc_c89 (whichever is valid, in
478 ** AC_STRUCT_DIRENT_D_INO, AC_STRUCT_DIRENT_D_TYPE
479 New macros for checking commonly-used members of struct dirent.
482 The substituted value can now contain newlines.
485 The substitution now occurs only when @variable@ is on a line by itself,
486 optionally surrounded by spaces and tabs. The whole line is replaced.
488 ** AC_TYPE_LONG_DOUBLE, AC_TYPE_LONG_DOUBLE_WIDER
489 New macros to check for long double, and whether it is wider than double.
490 The old macro AC_C_TYPE_LONG_DOUBLE has been marked as obsolete;
491 applications should switch to the new macro.
493 ** AC_TYPE_INT8_T, AC_TYPE_INT16_T, AC_TYPE_INT32_T, AC_TYPE_INT64_T,
494 AC_TYPE_INTMAX_T, AC_TYPE_INTPTR_T, AC_TYPE_LONG_LONG_INT, AC_TYPE_SSIZE_T,
495 AC_TYPE_UINT8_T, AC_TYPE_UINT16_T, AC_TYPE_UINT32_T, AC_TYPE_UINT64_T,
496 AC_TYPE_UINTMAX_T, AC_TYPE_UINTPTR_T, AC_TYPE_UNSIGNED_LONG_LONG_INT
497 New macros to check for C99 and POSIX types.
499 ** AC_USE_SYSTEM_EXTENSIONS
500 New macro to enable extensions to Posix.
503 New macro which is defined to the name of the first declared config header
504 or undefined if no config headers have been declared yet.
507 The macro correctly handles quadrigraphs now.
509 ** AS_BOURNE_COMPATIBLE, AS_SHELL_SANITIZE, AS_CASE
510 These macros are new or published now.
513 New macro for copyright notices in testsuite files.
515 ** ALLOCA, LIBOBJS, LTLIBOBJS
516 Object names added to these variables are now prefixed with `${LIBOBJDIR}',
517 as in `${LIBOBJDIR}alloca.o'. LIBOBJDIR is meant to be defined from
518 `Makefile.in' in case the object files lie in a different directory.
519 The LIBOBJDIR feature is experimental.
522 Supports --no-recursive now.
524 ** New macros to support Erlang/OTP.
525 New macros for configuring paths to Erlang tools and libraries:
526 AC_ERLANG_PATH_ERLC, AC_ERLANG_NEED_ERLC, AC_ERLANG_PATH_ERL,
527 AC_ERLANG_NEED_ERL, AC_ERLANG_CHECK_LIB, AC_ERLANG_SUBST_ROOT_DIR,
528 AC_ERLANG_SUBST_LIB_DIR.
530 New macros for configuring installation of Erlang libraries:
531 AC_ERLANG_SUBST_INSTALL_LIB_DIR, AC_ERLANG_SUBST_INSTALL_LIB_SUBDIR.
533 ** The manual now mentions Gnulib more prominently.
535 ** New macros to support Objective C.
536 AC_PROG_OBJC, AC_PROG_OBJCPP.
538 * Major changes in Autoconf 2.59b
540 Released 2004-08-20, by Paul Eggert.
543 New macro that computes the default alignment of a type.
545 ** AC_CHECK_TOOL, AC_PATH_TOOL, AC_CHECK_TOOLS
546 When cross-compiling, these macros will give a warning if the tool
547 is not prefixed. In the future, unprefixed cross tools will not
548 be detected; please consult the info documentation for information
549 about the reason of this change.
551 ** AC_CHECK_TARGET_TOOL, AC_PATH_TARGET_TOOL, AC_CHECK_TARGET_TOOLS
552 New macros that detect programs whose name is prefixed with the
553 target type, if the build type and target type are different.
555 ** AC_REQUIRE_AUX_FILE
556 New trace macro that declares expected auxiliary files.
559 New macro that tests for a grep program that accepts as a long a line
562 ** AC_PROG_EGREP, AC_PROG_FGREP
563 These macros now require AC_PROG_GREP, and try EGREP="$GREP -E" and
564 FGREP="$GREP -F" respectively if possible, or else run a path search for
565 a program that accepts as long a line as possible.
568 New macro that tests for a sed program that truncates as few characters
571 * Major changes in Autoconf 2.59
573 Released 2003-11-04, by Akim Demaille
575 ** ac_abs_builddir etc.
576 Absolute file names were actually relative in 2.58.
578 * Major changes in Autoconf 2.58
580 Released 2003-11-04, by Akim Demaille
583 core.* files are no longer removed, as they may be valid user files.
585 ** autoreconf and auxiliary directory
586 Autoreconf creates the auxiliary directory if needed. This is
587 especially useful for initial "bootstrapping" of fresh CVS checkouts.
589 ** AC_CONFIG_MACRO_DIR
590 Use this macro to declare the directory for local M4 macros for aclocal.
593 No longer includes twice the same file in LIBOBJS if invoked
596 ** AC_CONFIG_COMMANDS
597 The directory for its first argument is automatically created. For
600 AC_CONFIG_COMMANDS([src/modules.hh], [...])
602 $top_builddir/src/ is created if needed.
604 ** Autotest and local.at
605 The optional file local.at is always included in Autotest test suites.
608 The warnings are always issued, including with cached runs.
609 This became a significant problem since aclocal and automake can
610 run autoconf behind the scene.
612 ** autoheader warnings
613 The warnings of autoheader can be turned off, using --warning.
614 For instance, -Wno-obsolete disables the complaints about acconfig.h
615 and other deprecated constructs.
618 AC_C_RESTRICT, AC_INCLUDES_DEFAULT, AC_LANG_ASSERT, AC_LANG_WERROR,
621 ** AC_DECL_SYS_SIGLIST
625 Now checks that mktime is the inverse of localtime.
627 ** Improve DJGPP portability
628 The Autoconf tools and configure behave better under DJGPP.
630 ** Present But Cannot Be Compiled
631 New FAQ section dedicated to the mystic
633 configure: WARNING: pi.h: present but cannot be compiled
634 configure: WARNING: pi.h: check for missing prerequisite headers?
635 configure: WARNING: pi.h: proceeding with the preprocessor's result
638 ** Concurrent executions of autom4te
639 autom4te now locks its internal files, which enables concurrent
640 executions of autom4te, likely to happen if automake, autoconf,
641 autoheader etc. are run simultaneously.
644 Use of Libtool 1.5 and higher is encouraged. Compatibility with
645 Libtool pre-1.4 is not checked.
648 Testsuites no longer rerun failed tests in verbose mode; instead,
649 failures are logged while the test is run.
651 In addition, expected failures can be marked as such.
653 * Major changes in Autoconf 2.57
655 Released 2002-12-03 by Paul Eggert.
657 Bug fixes for problems with AIX linker, with freestanding C compilers,
658 with GNU M4 limitations, and with obsolete copies of GNU documents.
660 The Free Documentation License has been upgraded from 1.1 to 1.2.
662 * Major changes in Autoconf 2.56
664 Released 2002-11-15 by Akim Demaille.
666 One packaging problem fixed (config/install-sh was not executable).
668 * Major changes in Autoconf 2.55
670 Released 2002-11-14 by Akim Demaille.
674 Have your configure.ac checked by autoscan ("autoscan").
675 Try the warning options ("autoreconf -fv -Wall").
679 - AC_CHECK_HEADER, AC_CHECK_HEADERS
680 More information on proper use.
682 - Writing Test Programs
684 This sections explains how to write good test sources to use with
685 AC_COMPILE_IFELSE etc. It documents AC_LANG_PROGRAM and so forth.
687 - AC_FOO_IFELSE vs. AC_TRY_FOO
689 Explains why Autoconf moves from AC_TRY_COMPILE etc. to
690 AC_COMPILE_IFELSE and AC_LANG_PROGRAM etc.
694 - Is more robust to different Gettext installations.
696 - Produces messages (when --verbose) to be understood by Emacs'
699 - Supports -W/--warnings.
702 Once the GNU Build System reinstalled, run `./config.status
703 --recheck && ./config.status && make' if possible.
707 - Supports --cache, and --no-cache.
709 - ~/.autom4te.cfg makes it possible to disable the caching mechanism
710 (autom4te.cache). See `Customizing autom4te' in the documentation.
717 Support for the obsoleted options -m, --macrodir, -l, --localdir is
718 dropped in favor of the safer --include/--prepend-include scheme.
723 AC_COMPILER_IFELSE, AC_FUNC_MBRTOWC, AC_HEADER_STDBOOL,
724 AC_LANG_CONFTEST, AC_LANG_SOURCE, AC_LANG_PROGRAM, AC_LANG_CALL,
725 AC_LANG_FUNC_TRY_LINK, AC_MSG_FAILURE, AC_PREPROC_IFELSE.
728 Obsoleted macros are kept for Autoconf backward compatibility, but
729 should be avoided in configure.ac. Running autoupdate is advised.
732 - AC_DEFINE/AC_DEFINE_UNQUOTED
734 We have to stop using the old compatibility scheme --that tried to
735 avoid useless backslashes-- because Libtool 1.4.3 contains a
737 AC_DEFINE([error_t], [int],
738 [Define to a type to use for \`error_t' if it is not
739 otherwise available.])
741 We have to quote the single quotes and backslashes with \. The old
742 compatibility scheme saw that ` was backslashed, and therefore did
743 not quote the single quote... Failure. Hence, Autoconf 2.54 is not
744 compatible with Libtool. Autoconf 2.55 is, but in some cases might
745 produce more \ than wanted.
747 Please, note that in the future the same problem will happen with
748 AC_MSG_*: use `autoreconf -f -Wall'.
752 - Portability of the Autoconf package to Solaris.
754 - Spurious warnings caused by config.status.
755 This bug is benign, but painful: on some systems (typically
756 FreeBSD), warnings such as:
758 config.status: creating Makefile
759 mv: Makefile: set owner/group (was: 1357/0): Operation not permitted
761 could be issued. This is fixed.
764 Simultaneous executions of config.status are possible again.
766 - Precious variables accumulation
768 config.status could stack several copies of the precious variables
772 ** Plans for later versions
776 The compatibility hooks with the old scheme will be completely
777 removed. Please, advice/use `--build', `--host', and `--target'
780 - AC_CHECK_HEADER, AC_CHECK_HEADERS
782 The tests will be stricter, please make sure your invocations are
787 Shell functions will gradually be introduced, probably starting with
788 Autotest. If you know machines which are in use that you suspect
789 *not* to support shell functions, please run the test suite of
790 Autoconf 2.55 on it, and report the results to
791 bug-autoconf@gnu.org.
795 Special characters in AC_MSG_* need not be quoted. Currently,
796 Autoconf has heuristics to decide when a string is escaped, or has
797 to be escaped. This scheme is fragile, and will be removed; the
798 only risk is uglified messages. Please, run `autoreconf -f -Wall'
799 to find occurrences that will be affected.
801 * Major changes in Autoconf 2.54
803 Released 2002-09-13 by Akim Demaille.
807 - autoreconf no longer changes the version of the gettext/po/intl
808 support files. It now adds the files the correspond to the
809 AM_GNU_GETTEXT_VERSION declared in configure.ac.
811 Warning: It now relies on the 'autopoint' program, which is part
812 of GNU gettext 0.11.4 and newer.
814 Please note that you need to have a GNU gettext version that
815 corresponds at least to the AM_GNU_GETTEXT_VERSION declared
816 in configure.ac. You can upgrade to newer GNU gettext versions,
817 though, without needing to change configure.ac.
819 - The -I DIR or --include=DIR option now appends DIR to the include path
820 instead of prepending; this is for consistency with other GNU tools.
821 The new -B DIR or --prepend-include=DIR option has the old behavior.
826 Now handles all the gory details about LIBOBJS and LTLIBOBJS.
827 Please, remove lines such as
829 # This is necessary so that .o files in LIBOBJS are also
830 # built via the ANSI2KNR-filtering rules.
831 LIBOBJS=`echo $LIBOBJS|sed 's/\.o /\$U.o /g;s/\.o$/\$U.o/'`
833 and read the `AC_LIBOBJ vs LIBOBJS' section. Do not define U in
834 your Makefiles either.
836 - AC_CONFIG_LINKS now makes copies if it can't make links.
838 - AC_FUNC_FNMATCH now tests only for POSIX compatibility, reverting to
839 Autoconf 2.13 behavior. The new macro AC_FUNC_FNMATCH_GNU also
840 tests for GNU extensions to fnmatch, and replaces fnmatch if needed.
842 - AC_FUNC_SETVBUF_REVERSED no longer fails when cross-compiling.
844 - AC_PROG_CC_STDC is integrated into AC_PROG_CC.
846 - AC_PROG_F77 default search no longer includes cf77 and cfg77.
850 AC_C_BACKSLASH_A, AC_CONFIG_LIBOBJ_DIR, AC_GNU_SOURCE,
851 AC_PROG_EGREP, AC_PROG_FGREP, AC_REPLACE_FNMATCH,
852 AC_FUNC_FNMATCH_GNU, AC_FUNC_REALLOC, AC_TYPE_MBSTATE_T.
855 looks for getloadavg.c in the CONFIG_LIBOBJ_DIR.
858 Now defines HAVE_MALLOC to 0 if `malloc' does not work, and asks
859 for an AC_LIBOBJ replacement.
863 - Spurious complaints from `m4_bmatch' about invalid regular
864 expressions are suppressed.
866 - Empty top_builddirs are properly handled.
868 - AC_CHECK_MEMBER works correctly when the member is an aggregate.
871 Now colon in the optional path arguments are properly handled.
873 ** Improved portability
875 - Both Autoconf the package, and the scripts it produces, should run
876 more reliably with Zsh. Bear in mind it is the default Bourne shell
879 - Autoconf and the scripts it produces no longer assume the existence of
880 the obsolescent commands egrep and fgrep.
884 - Limitations of Make
888 The GNATS base moved to
889 http://bugs.gnu.org/cgi-bin/gnatsweb.pl?database=autoconf
890 (It is no longer available, though.)
895 Now contains the list of ouput variables and files (AC_SUBST,
898 * Major changes in Autoconf 2.53
900 Released 2002-03-08 by Akim Demaille.
904 Perl 5.005_03 or later is required: autom4te is written in Perl and is
905 needed by autoconf. autoheader, autoreconf, ifnames, and autoscan are
911 Argument requirements, output variables, defined macros.
912 - M4sugar, M4sh, Autotest
914 - Double quoting macros
915 AC_TRY_CPP, AC_TRY_COMPILE, AC_TRY_LINK and AC_TRY_RUN.
917 The Autoconf manual is now distributed under the terms of the GNU FDL.
918 - Section `Hosts and Cross-Compilation'
919 Explains the rationale for the 2.5x changes in the cross-compilation
920 chain, and in the relationships between build, host, and target
922 Emphasizes that `cross-compilation' == `--host is given'.
923 If you are working on compilers etc., be sure to read this section.
924 - Section `AC_LIBOBJ vs. LIBOBJS'
925 Explains why assigning LIBOBJS directly is now an error.
926 Details how to update the code.
931 Now used instead of hard coded line numbers.
932 This eases the comparison of `configure's, and diminishes the
933 pressure over control version archives.
934 Automatic replacement for shells that don't support this feature.
935 - New output variables
936 @builddir@, @top_builddir@, @abs_srcdir@, @abs_top_srcdir@, @abs_builddir@,
941 Autoconf and Autotest modes are provided.
946 New, used by the Autoconf suite to cache and speed up most processing.
948 Supported by autom4te, autoconf and autoheader.
950 Replaces --autoconf-dir and --localdir in autoconf, autoheader,
951 autoupdate, and autoreconf.
953 No longer passes --cygnus, --foreign, --gnits, --gnu, --include-deps:
954 automake options are to be given via AUTOMAKE_OPTIONS.
956 Runs gettextize and libtoolize when appropriate.
958 --m4dir is no longer supported.
960 Now runs only in the specified directories, defaulting to `.',
961 but understands AC_CONFIG_SUBDIRS for dependent directories.
962 Before, it used to run on all the `configure.ac' found in the
964 Independent packages are properly updated.
968 - The top level $prefix is propagated to the AC_CONFIG_SUBDIRS configures.
970 Under the user pressure, $? is finally available. Probably a mistake.
971 - AC_F77_LIBRARY_LDFLAGS now supports the HP/UX f90 compiler.
972 - Precious variables accumulation
973 config.status could stack several copies of the precious variables
975 - AC_PATH_PROG and family.
976 Works properly when given a literal path.
978 Somewhere since 2.13, the result had been reversed.
982 - AC_C_BIGENDIAN supports the cross-compiling case.
983 - AC_C_BIGENDIAN accepts ACTION-IF-TRUE, ACTION-IF-FALSE, and
984 ACTION-IF-UNKNOWN arguments. All are facultative, and the default
985 for ACTION-IF-TRUE is to define WORDS_BIGENDIAN like AC_C_BIGENDIAN
987 - AC_C_LONG_DOUBLE now succeeds only if `long double' has more range or
988 precision than `double'.
993 It now defines the preprocessor symbols PACKAGE_NAME,
994 PACKAGE_TARNAME, PACKAGE_VERSION, PACKAGE_STRING, and
998 Admits a fourth optional parameter: the tar name.
1000 - AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS.
1001 Provide the user with srcdir, ac_srcdir, ac_top_srcdir, ac_builddir,
1002 ac_top_builddir, ac_abs_srcdir, ac_abs_top_srcdir, ac_abs_builddir,
1003 ac_abs_top_builddir.
1005 - AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS and AC_OUTPUT.
1006 Are much less expensive when using long lists of files.
1009 Works with shell variables, and non alphanumeric names.
1013 - AC_FUNC_STRERROR_R now sets STRERROR_R_CHAR_P, not HAVE_WORKING_STRERROR_R,
1014 because POSIX 1003.1-200x draft 7 says strerror_r returns int, not char *.
1016 - AC_FUNC_STRTOD substitutes POW_LIB.
1021 * Major changes in Autoconf 2.52
1023 Released 2001-07-18 by Akim Demaille.
1028 This feature was present in autoconf 2.50 but was not documented.
1029 For example, `@<:@' is translated to `[' just before output. This
1030 is useful when writing strings that contain unbalanced quotes, or
1031 other hard-to-quote constructs.
1032 - m4_pattern_forbid, m4_pattern_allow
1033 - Tips for upgrading from 2.13.
1034 - Using autoscan to maintain a configure.ac.
1037 - Now include stdint.h.
1038 - sys/types.h and sys/stat.h are guarded.
1039 - strings.h is included if available, and not conflicting with string.h.
1042 - The test suite is more robust and presents less false failures.
1043 - Invocation of GNU M4 now robust to POSIXLY_CORRECT.
1044 - configure accepts --prefix='' again.
1045 - AC_CHECK_LIB works properly when its first argument is not a
1047 - HAVE_INTTYPES_H is defined only if not conflicting with sys/types.h.
1048 - build_, host_, and target_alias are AC_SUBST as in 2.13.
1049 - AC_ARG_VAR properly propagates precious variables inherited from the
1050 environment to ./config.status.
1051 - Using --program-suffix/--program-prefix is portable.
1052 - Failures to detect the default compiler's output extension are less
1054 - `config.status foo' works properly when `foo' depends on variables
1055 set in an AC_CONFIG_THING INIT-CMD.
1056 - autoheader is more robust to broken input.
1057 - Fixed Fortran name-mangling and link tests on a number of systems,
1058 e.g. NetBSD; see AC_F77_DUMMY_MAIN, below.
1061 - AC_CHECK_HEADER and AC_CHECK_HEADERS support a fourth argument to
1062 specify pre-includes. In this case, the headers are compiled with
1063 cc, not merely preprocessed by cpp. Therefore it is the _usability_
1064 of a header which is checked for, not just its availability.
1065 - AC_ARG_VAR refuses to run configure when precious variables have
1067 - Versions of compilers are dumped in the logs.
1068 - AC_CHECK_TYPE recognizes use of `foo_t' as a replacement type.
1071 - AC_PATH_XTRA only adds -ldnet to $LIBS if it's needed to link.
1072 - AC_FUNC_WAIT3 and AC_SYS_RESTARTABLE_SYSCALLS are obsoleted.
1073 - AM_FUNC_ERROR_AT_LINE, AM_FUNC_FNMATCH, AM_FUNC_MKTIME,
1074 AM_FUNC_OBSTACK, and AM_FUNC_STRTOD are now activated.
1075 Be sure to read `Upgrading from Version 2.13' to understand why
1076 running `autoupdate' is needed.
1077 - AC_F77_DUMMY_MAIN, AC_F77_MAIN: new macros to detect whether
1078 a main-like routine is required/possible when linking C/C++ with
1079 Fortran. Users of e.g. AC_F77_WRAPPERS should be aware of these.
1080 - AC_FUNC_GETPGRG behaves better when cross-compiling.
1082 * Major changes in Autoconf 2.51
1083 There was no release of Autoconf 2.51 since some packagers had used
1084 this version number without permission to ship intermediary versions
1085 of 2.50. The version was skipped to avoid confusion.
1087 * Major changes in Autoconf 2.50
1089 Released 2001-05-21 by Akim Demaille.
1091 ** Lots of bug fixes
1092 There have been far too many to enumerate them here. Check out
1093 ChangeLog if you really want to know more.
1095 ** Improved documentation
1096 In particular, portability issues are better covered.
1099 All the standard GNU Makefile targets are supported. The layout has
1100 changed: m4/ holds the M4 extensions Autoconf needs for its
1101 configuration, doc/ contains the documentation, and tests/ contains
1104 ** Man pages are provided
1105 For autoconf, autoreconf, autoupdate, autoheader, autoscan, ifnames,
1106 config.guess, config.sub.
1110 Provides a safe and powerful means to trace the macro uses. This
1111 provide the parsing layer for tools which need to `study'
1115 Specify what category of warnings should be enabled.
1117 - When recursing into subdirectories, try for configure.gnu before
1118 configure to adapt for packages not using autoconf on case-insensitive
1122 More errors are now caught (circular AC_REQUIRE dependencies,
1123 AC_DEFINE in the action part of an AC_CACHE_CHECK, too many pops
1124 etc.). In addition, their location and call stack are given.
1127 autoupdate is much more powerful, and is able to provide the glue code
1128 which might be needed to move from an old macro to its newer
1131 You are strongly encouraged to use it to modernize both your
1132 `configure.in' and your .m4 extension files.
1135 The internal machinery of autoheader has completely changed. As a
1136 result, using `acconfig.h' should be considered to be obsoleted, and
1137 you are encouraged to get rid of it using the AH macros.
1142 ** Fortran 77 compilers
1143 Globally, the support for Fortran 77 is considerably improved.
1145 Support for automatically determining a Fortran 77 compiler's
1146 name-mangling scheme. New CPP macros F77_FUNC and F77_FUNC_ are
1147 provided to wrap C/C++ identifiers, thus making it easier and more
1148 transparent for C/C++ to call Fortran 77 routines, and Fortran 77 to
1149 call C/C++ routines. See the Texinfo documentation for details.
1152 The test suite no longer uses DejaGNU. It should be easy to submit
1153 test cases in this new framework.
1156 - --help, --help=long, -hl
1157 no longer dumps useless items.
1159 lists only specific options.
1160 - --help=recursive, -hr
1161 displays the help of all the embedded packages.
1162 - Remembers environment variables when reconfiguring.
1163 The previous scheme to set envvar before running configure was
1165 what prevented configure from remembering the environment in which
1166 it was run, therefore --recheck was run in an inconsistent
1167 environment. Now, one should run
1169 and then --recheck will work properly. Variables declared with
1170 AC_ARG_VAR are also preserved.
1172 $build defaults to `config.guess`, $host to $build, and then $target
1174 Cross-compilation is a global status of the package, it no longer
1175 depends upon the current language.
1176 Cross compilation is enabled iff the user specified `--host'.
1177 `configure' now fails if it can't run the executables it compiles,
1178 unless cross-compilation is enabled.
1180 The cache file is disabled by default. The new options
1181 `--config-cache', `-C' set the cache to `config.cache'.
1185 Much faster on most architectures.
1186 - concurrent executions
1187 It is safe to use `make -j' with config.status.
1188 - human interface improved
1189 It is possible to invoke
1190 ./config.status foobar
1191 instead of the former form (still valid)
1192 CONFIG_COMMANDS= CONFIG_HEADERS= CONFIG_LINKS= \
1193 CONFIG_FILES=foobar:foo.in:bar.in \
1195 The same holds for configuration headers and links.
1196 You can instantiate unknown files and headers:
1197 ./config.status --header foo.h:foo.h.in --file bar:baz
1198 - has a useful --help
1199 - accepts special file name "-" for stdin/stdout
1204 Specify additional copyright information.
1207 Now expects the identity of the package as argument.
1211 Most macros, if not all, now strictly follow the `one quotation
1212 level' rule. This results in a more predictable expansion.
1215 A sly bug in the AC_REQUIRE machinery, which could produce incorrect
1216 configure scripts, was fixed by Axel Thimm.
1220 Document and ask for the registration of an envvar.
1223 Specifies the file which `configure' should look for when trying to
1224 find the source tree (used to be handled by AC_INIT).
1226 - AC_CONFIG_COMMANDS
1227 To add new actions to config.status. Should be used instead of
1231 Replaces AC_LINK_FILES.
1233 - AC_CONFIG_HEADERS, AC_CONFIG_COMMANDS, AC_CONFIG_SUBDIRS,
1234 AC_CONFIG_LINKS, and AC_CONFIG_FILES
1235 They now obey sh: you should no longer use shell variables as
1236 argument. Instead of
1238 test "$package_foo_enabled" = yes && $my_subdirs="$my_subdirs foo"
1239 AC_CONFIG_SUBDIRS($my_subdirs)
1243 if test "$package_foo_enabled" = yes; then
1244 AC_CONFIG_SUBDIRS(foo)
1248 To format an Autoconf macro's help string so that it looks pretty
1249 when the user executes `configure --help'.
1252 ** Generic Test Macros
1254 The interface of the AC_CHECK families of macros (decl, header,
1255 type, member, func) is now uniform. They support the same set of
1258 - AC_CHECK_DECL, AC_CHECK_DECLS
1259 To check whether a symbol is declared.
1261 - AC_CHECK_SIZEOF, AC_C_CHAR_UNSIGNED.
1262 No longer need a cross-compilation default.
1265 The test it performs is much more robust than previously, and makes
1266 it possible to test builtin types in addition to typedefs.
1267 It is now schizophrenic:
1268 - AC_CHECK_TYPE(TYPE, REPLACEMENT)
1269 remains for backward compatibility, but its use is discouraged.
1270 - AC_CHECK_TYPE(TYPE, IF-FOUND, IF-NOT-FOUND, INCLUDES)
1271 behaves exactly like the other AC_CHECK macros.
1274 Checks whether given types are supported by the system.
1276 - AC_CHECK_MEMBER, AC_CHECK_MEMBERS
1277 Check for given members in aggregates (e.g., pw_gecos in struct
1281 Checks if the compiler supports ISO C, included when needs special
1285 Checking whether the preprocessor indicates missing includes by the
1286 error code. stderr is checked by AC_TRY_CPP only as a fallback.
1289 Takes a language as argument and replaces AC_LANG_C,
1290 AC_LANG_CPLUSPLUS and AC_LANG_FORTRAN77.
1292 - AC_LANG_PUSH, AC_LANG_POP
1293 Are preferred to AC_LANG_SAVE, AC_LANG_RESTORE.
1296 - AC_FUNC_CHOWN, AC_FUNC_MALLOC, AC_FUNC_STRERROR_R,
1297 AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK, AC_FUNC_STAT, AC_FUNC_LSTAT,
1298 AC_FUNC_ERROR_AT_LINE, AC_FUNC_OBSTACK, AC_FUNC_STRTOD, AC_FUNC_FSEEKO.
1302 Sets GETGROUPS_LIBS.
1304 - AC_FUNC_GETLOADAVG
1305 Defines `HAVE_STRUCT_NLIST_N_UN_N_NAME' instead of `NLIST_NAME_UNION'.
1308 Now integrates `AC_DECL_YYTEXT' which is obsoleted.
1311 Arrange for large-file support.
1313 - AC_EXEEXT, AC_OBJEXT
1314 You are no longer expected to use them: their computation is
1315 performed by default.
1317 ** C++ compatibility
1318 Every macro has been revisited in order to support at best CC=c++.
1320 Major changes in Autoconf 2.14:
1321 There was no release of GNU Autoconf 2.14.
1323 Major changes in Autoconf 2.13:
1325 Released 1999-05-01 by Ben Elliston.
1327 * Support for building on Win32 systems where the only available C or
1328 C++ compiler is the Microsoft Visual C++ command line compiler
1329 (`cl'). Additional support for building on Win32 systems which are
1330 using the Cygwin or Mingw32 environments.
1331 * Support for alternative object file and executable file extensions.
1332 On Win32, for example, these are .obj and .exe. These are discovered
1333 using AC_OBJEXT and AC_EXEEXT, which substitute @OBJEXT@ and
1334 @EXEEXT@ in the output, respectively.
1335 * New macros: AC_CACHE_LOAD, AC_CACHE_SAVE, AC_FUNC_SELECT_ARGTYPES,
1336 AC_VALIDATE_CACHED_SYSTEM_TUPLE, AC_SEARCH_LIBS, AC_TRY_LINK_FUNC,
1337 AC_C_STRINGIZE, AC_CHECK_FILE(S), AC_PROG_F77 (and friends).
1338 * AC_DEFINE now has an optional third argument for a description to be
1339 placed in the config header input file (e.g. config.h.in).
1340 * The C++ code fragment compiled for the C++ compiler test had to be
1341 improved to include an explicit return type for main(). This was
1342 causing failures on systems using recent versions of the EGCS C++
1344 * Fixed an important bug in AC_CHECK_TYPE that would cause a configure
1345 script to report that `sometype_t' was present when only `type_t'
1347 * Merge of the FSF version of config.guess and config.sub to modernize
1348 these scripts. Add support for a few new hosts in config.guess.
1349 Incorporate latest versions of install-sh, mkinstalldirs and
1350 texinfo.tex from the FSF.
1351 * autoreconf is capable of running automake if necessary (and
1353 * Support for Fortran 77. See the Texinfo documentation for details.
1354 * Bug fixes and workarounds for quirky bugs in vendor utilities.
1356 Major changes in Autoconf 2.12:
1358 Released 1996-11-26 by David J. MacKenzie
1360 * AC_OUTPUT and AC_CONFIG_HEADER can create output files by
1361 concatenating multiple input files separated by colons, like so:
1362 AC_CONFIG_HEADER(config.h:conf.pre:config.h.in:conf.post)
1363 AC_OUTPUT(Makefile:Makefile.in:Makefile.rules)
1364 The arguments may be shell variables, to compute the lists on the fly.
1365 * AC_LINK_FILES and AC_CONFIG_SUBDIRS may be called multiple times.
1366 * New macro AC_OUTPUT_COMMANDS adds more commands to run in config.status.
1369 Major changes in Autoconf 2.11:
1371 Released November 18th, 1996, by David J. MacKenzie
1373 * AC_PROG_CC and AC_PROG_CXX check whether the compiler works.
1374 They also default CFLAGS/CXXFLAGS to "-g -O2" for gcc, instead of "-g -O".
1375 * AC_REPLACE_FUNCS defines HAVE_foo if the system has the function `foo'.
1376 * AC_CONFIG_HEADER expands shell variables in its argument.
1377 * New macros: AC_FUNC_FNMATCH, AC_FUNC_SETPGRP.
1378 * The "checking..." messages and the source code for test programs that
1379 fail are saved in config.log.
1380 * Another workaround has been added for seds with small command length limits.
1381 * config.sub and config.guess recognize more system types.
1384 Major changes in Autoconf 2.10:
1386 Released May 7th, 1996, by Roland McGrath
1389 * The cache variable names used by `AC_CHECK_LIB(LIB, FUNC, ...)' has
1390 changed: now $ac_cv_lib_LIB_FUNC, previously $ac_cv_lib_LIB.
1392 Major changes in Autoconf 2.9:
1394 Released March 16th, 1996, by Roland McGrath
1398 Major changes in Autoconf 2.8:
1400 Released March 8th, 1996, by Roland McGrath
1404 Major changes in Autoconf 2.7:
1406 Released November 22nd, 1995, by David J. MacKenzie
1410 Major changes in Autoconf 2.6:
1412 Released November 20th, 1995, by David J. MacKenzie
1416 Major changes in Autoconf 2.5:
1418 Released November 17th, 1995, by Roland McGrath
1420 * New configure options --bindir, --libdir, --datadir, etc., with
1421 corresponding output variables.
1422 * New macro: AC_CACHE_CHECK, to make using the cache easier.
1423 * config.log contains the command being run as well as any output from it.
1424 * AC_CHECK_LIB can check for libraries with "." or "/" or "+" in their name.
1425 * AC_PROG_INSTALL doesn't cache a name for install-sh, for sharing caches.
1426 * AC_CHECK_PROG, AC_PATH_PROG, AC_CHECK_PROGS, AC_PATH_PROGS, and
1427 AC_CHECK_TOOL can search a path other than $PATH.
1428 * AC_CHECK_SIZEOF takes an optional size to use when cross-compiling.
1430 Major changes in Autoconf 2.4:
1432 Released June 14th, 1995, by David J. MacKenzie
1434 * Fix a few bugs found by Emacs testers.
1436 Major changes in Autoconf 2.3:
1438 Released March 27th, 1995, by David J. MacKenzie
1440 * Fix the cleanup trap in several ways.
1441 * Handle C compilers that are picky about option placement.
1442 * ifnames gets the version number from the right directory.
1444 Major changes in Autoconf 2.2:
1446 Released March 8th, 1995, by David J. MacKenzie
1448 * The ifnames utility is much faster but requires a "new awk" interpreter.
1449 * AC_CHECK_LIB and AC_HAVE_LIBRARY check and add the new
1450 library before existing libs, not after, in case it uses them.
1451 * New macros: AC_FUNC_GETPGRP, AC_CHECK_TOOL.
1452 * Lots of bug fixes.
1453 * Many additions to the TODO file :-)
1455 Major changes in Autoconf 2.1:
1457 Released November 4th, 1994, by David J. MacKenzie
1460 * More explanations in the manual.
1461 * Fix a spurious failure in the testsuite.
1462 * Clarify some warning messages.
1463 * autoreconf by default only rebuilds configure and config.h.in files
1464 that are older than any of their particular input files; there is a
1465 --force option to use after installing a new version of Autoconf.
1467 Thanks to everybody who's submitted changes and additions to Autoconf!
1468 I've incorporated many of them, and am still considering others for
1469 future releases -- but I didn't want to postpone this release indefinitely.
1471 Caution: don't indiscriminately rebuild configure scripts with
1472 Autoconf version 2. Some configure.in files need minor adjustments to
1473 work with it; the documentation has a chapter on upgrading. A few
1474 configure.in files, including those for GNU Emacs and the GNU C
1475 Library, need major changes because they relied on undocumented
1476 internals of version 1. Future releases of those packages will have
1477 updated configure.in files.
1479 It's best to use GNU M4 1.3 (or later) with Autoconf version 2.
1480 Autoconf now makes heavy use of M4 diversions, which were implemented
1481 inefficiently in GNU M4 releases before 1.3.
1483 Major changes in Autoconf 2.0:
1485 Released October 26th, 1994, by David J. MacKenzie
1487 ** New copyright terms:
1488 * There are no restrictions on distribution or use of configure scripts.
1491 * Autoconf manual is reorganized to make information easier to find
1492 and has several new indexes.
1493 * INSTALL is reorganized and clearer and is now made from Texinfo source.
1496 * autoscan to generate a preliminary configure.in for a package by
1497 scanning its source code for commonly used nonportable functions,
1498 programs, and header files.
1499 * ifnames to list the symbols used in #if and #ifdef directives in a
1501 * autoupdate to update a configure.in to use the version 2 macro names.
1502 * autoreconf to recursively remake configure and configuration header
1503 files in a source tree.
1505 ** Changed utilities:
1506 * autoheader can take pieces of acconfig.h to replace config.h.{top,bot}.
1507 * autoconf and autoheader can look for package-local definition files
1508 in an alternate directory.
1511 * AC_CACHE_VAL to share results of tests between configure runs.
1512 * AC_DEFUN to define macros, automatically AC_PROVIDE them, and ensure
1513 that macros invoked with AC_REQUIRE don't interrupt other macros.
1514 * AC_CONFIG_AUX_DIR, AC_CANONICAL_SYSTEM, AC_CANONICAL_HOST, AC_LINK_FILES to
1515 support deciding unguessable features based on the host and target types.
1516 * AC_CONFIG_SUBDIRS to recursively configure a source tree.
1517 * AC_ARG_PROGRAM to use the options --program-prefix,
1518 --program-suffix, and --program-transform-name to change the names
1519 of programs being installed.
1520 * AC_PREFIX_DEFAULT to change the default installation prefix.
1521 * AC_TRY_COMPILE to compile a test program without linking it.
1522 * AC_CHECK_TYPE to check whether sys/types.h or stdlib.h defines a given type.
1523 * AC_CHECK_LIB to check for a particular function and library.
1524 * AC_MSG_CHECKING and AC_MSG_RESULT to print test results, on a single line,
1525 whether or not the test succeeds. They obsolete AC_CHECKING and AC_VERBOSE.
1526 * AC_SUBST_FILE to insert one file into another.
1527 * AC_FUNC_MEMCMP to check whether memcmp is 8-bit clean.
1528 * AC_FUNC_STRFTIME to find strftime even if it's in -lintl.
1529 * AC_FUNC_GETMNTENT to find getmntent even if it's in -lsun or -lseq.
1530 * AC_HEADER_SYS_WAIT to check whether sys/wait.h is POSIX.1 compatible.
1533 * Many macros renamed systematically, but old names are accepted for
1534 backward compatibility.
1535 * AC_OUTPUT adds the "automatically generated" comment to
1536 non-Makefiles where it finds @configure_input@ in an input file, to
1537 support files with various comment syntaxes.
1538 * AC_OUTPUT does not replace "prefix" and "exec_prefix" in generated
1539 files when they are not enclosed in @ signs.
1540 * AC_OUTPUT allows the optional environment variable CONFIG_STATUS to
1541 override the file name "config.status".
1542 * AC_OUTPUT takes an optional argument for passing variables from
1543 configure to config.status.
1544 * AC_OUTPUT and AC_CONFIG_HEADER allow you to override the input-file names.
1545 * AC_OUTPUT automatically substitutes the values of CFLAGS, CXXFLAGS,
1546 CPPFLAGS, and LDFLAGS from the environment.
1547 * AC_PROG_CC and AC_PROG_CXX now set CFLAGS and CXXFLAGS, respectively.
1548 * AC_PROG_INSTALL looks for install-sh or install.sh in the directory
1549 specified by AC_CONFIG_AUXDIR, or srcdir or srcdir/.. or
1550 srcdir/../.. by default.
1551 * AC_DEFINE, AC_DEFINE_UNQUOTED, and AC_SUBST are more robust and smaller.
1552 * AC_DEFINE no longer prints anything, because of the new result reporting
1553 mechanism (AC_MSG_CHECKING and AC_MSG_RESULT).
1554 * AC_VERBOSE pays attention to --quiet/--silent, not --verbose.
1555 * AC_ARG_ENABLE and AC_ARG_WITH support whitespace in the arguments to
1556 --enable- and --with- options.
1557 * AC_CHECK_FUNCS and AC_CHECK_HEADERS take optional shell commands to
1558 execute on success or failure.
1559 * Checking for C functions in C++ works.
1562 * AC_REMOTE_TAPE and AC_RSH removed; too specific to tar and cpio, and
1563 better maintained with them.
1564 * AC_ARG_ARRAY removed because no one was likely using it.
1565 * AC_HAVE_POUNDBANG replaced with AC_SYS_INTERPRETER, which doesn't
1566 take arguments, for consistency with all of the other specific checks.
1569 * Comes with config.sub and config.guess, and uses them optionally.
1570 * Uses config.cache to cache test results. An alternate cache file
1571 can be selected with the --cache-file=FILE option.
1572 * Uses optional shell scripts $prefix/share/config.site and
1573 $prefix/etc/config.site to perform site or system specific initializations.
1574 * configure saves compiler output to ./config.log for debugging.
1575 * New files autoconf.m4 and autoheader.m4 load the other Autoconf macros.
1576 * acsite.m4 is the new name for the system-wide aclocal.m4.
1577 * Has a DejaGnu test suite.
1579 Major changes in Autoconf 1.11:
1581 * AC_PROG_INSTALL calls install.sh with the -c option.
1582 * AC_SET_MAKE cleans up after itself.
1583 * AC_OUTPUT sets prefix and exec_prefix if they weren't set already.
1584 * AC_OUTPUT prevents shells from looking in PATH for config.status.
1586 Plus a few other bug fixes.
1588 Major changes in Autoconf 1.10:
1590 * autoheader uses config.h.bot if present, analogous to config.h.top.
1591 * AC_PROG_INSTALL looks for install.sh in srcdir or srcdir/.. and
1593 * AC_PROG_CXX looks for cxx as a C++ compiler.
1595 Plus several bugs fixed.
1597 Major changes in Autoconf 1.9:
1599 * AC_YYTEXT_POINTER replaces AC_DECLARE_YYTEXT.
1600 * AC_SIZEOF_TYPE generates the cpp symbol name automatically,
1601 and autoheader generates entries for those names automatically.
1602 * AC_FIND_X gets the result from xmkmf correctly.
1603 * AC_FIND_X assumes no X if --without-x was given.
1604 * AC_FIND_XTRA adds libraries to the variable X_EXTRA_LIBS.
1605 * AC_PROG_INSTALL finds OSF/1 installbsd.
1607 Major changes in Autoconf 1.8:
1610 * New macros AC_LANG_C, AC_LANG_CPLUSPLUS, AC_LANG_SAVE, AC_LANG_RESTORE,
1611 AC_PROG_CXX, AC_PROG_CXXCPP, AC_REQUIRE_CPP
1612 for checking both C++ and C features in one configure script.
1613 * New macros AC_CHECKING, AC_VERBOSE, AC_WARN, AC_ERROR for printing messages.
1614 * New macros AC_FIND_XTRA, AC_MMAP, AC_SIZEOF_TYPE, AC_PREREQ,
1615 AC_SET_MAKE, AC_ENABLE.
1618 * AC_FIND_X looks for X in more places.
1619 * AC_PROG_INSTALL defaults to install.sh instead of cp, if it's in srcdir.
1620 install.sh is distributed with Autoconf.
1621 * AC_DECLARE_YYTEXT has been removed because it can't work, pending
1622 a rewrite of quoting in AC_DEFINE.
1623 * AC_OUTPUT adds its comments in C format when substituting in C files.
1624 * AC_COMPILE_CHECK protects its ECHO-TEXT argument with double quotes.
1626 ** New or changed command line options:
1627 * configure accepts --enable-FEATURE[=ARG] and --disable-FEATURE options.
1628 * configure accepts --without-PACKAGE, which sets withval=no.
1629 * configure accepts --x-includes=DIR and --x-libraries=DIR.
1630 * Giving --with-PACKAGE no argument sets withval=yes instead of withval=1.
1631 * configure accepts --help, --version, --silent/--quiet, --no-create options.
1632 * configure accepts and ignores most other Cygnus configure options, and
1633 warns about unknown options.
1634 * config.status accepts --help, --version options.
1636 ** File names and other changes:
1637 * Relative srcdir values are not made absolute.
1638 * The values of @prefix@ and @exec_prefix@ and @top_srcdir@ get substituted.
1639 * Autoconf library files are installed in ${datadir}/autoconf, not ${datadir}.
1640 * autoheader optionally copies config.h.top to the beginning of config.h.in.
1641 * The example Makefile dependencies for configure et al. work better.
1642 * Namespace cleanup: all shell variables used internally by Autoconf
1643 have names beginning with `ac_'.
1645 More big improvements are in process for future releases, but have not
1646 yet been (variously) finished, integrated, tested, or documented enough
1649 Major changes in Autoconf 1.7:
1651 * New macro AC_OBSOLETE.
1652 * Bugs in Makefile.in fixed.
1653 * AC_LONG_FILE_NAMES improved.
1655 Major changes in Autoconf 1.6:
1657 * New macro AC_LONG_64_BITS.
1658 * Multiple .h files can be created.
1659 * AC_FIND_X looks for X files directly if it doesn't find xmkmf.
1660 * AC_ALLOCA defines C_ALLOCA if using alloca.c.
1661 * --with-NAME can take a value, e.g., --with-targets=sun4,hp300bsd.
1662 * Unused --no-create option to configure removed.
1663 * autoheader doesn't change the timestamp of its output file if
1664 the file didn't change.
1665 * All macros that look for libraries now use AC_HAVE_LIBRARY.
1666 * config.status checks three optional environment variables to
1667 modify its behavior.
1668 * The usual bug fixes.
1670 Major changes in Autoconf 1.5:
1672 * New macros AC_FIND_X, AC_OFF_T, AC_STAT_MACROS_BROKEN, AC_REVISION.
1673 * autoconf and autoheader scripts have GNU standards conforming
1674 --version and --help options (they print their message and exit).
1677 Major changes in Autoconf 1.4:
1679 * New macros AC_HAVE_POUNDBANG, AC_TIME_WITH_SYS_TIME, AC_LONG_DOUBLE,
1680 AC_GETGROUPS_T, AC_DEFINE_UNQUOTED.
1681 * autoconf and autoheader use the M4 environment variable to determine the
1682 name of the M4 program to use.
1683 * The --macrodir option to autoconf and autoheader specifies the directory
1684 in which acspecific.m4, acgeneral.m4, etc. reside if not the default.
1685 * autoconf and autoheader can take `-' as their file names, which means to
1686 read stdin as input.
1687 * Resulting configure scripts can take a --verbose option which causes them
1688 to print the results of their tests.
1689 * AC_DEFINE quotes its second argument in such a way that spaces, magic
1690 shell characters, etc. will be preserved during various stages of
1691 expansion done by the shell. If you don't want this, use
1692 AC_DEFINE_UNQUOTED instead.
1693 * Much textual processing done with external calls to tr and sed have been
1694 internalized with builtin M4 `patsubst' and `translit' calls.
1695 * AC_OUTPUT doesn't hardwire the file names it outputs. Instead, you can
1696 set the shell variables `gen_files' and `gen_config' to the list of
1697 file names to output.
1698 * AC_DECLARE_YYTEXT does an AC_SUBST of `LEX_OUTPUT_ROOT', which may be
1699 "lex.yy" or "lexyy", depending on the system.
1700 * AC_PROGRAMS_CHECK takes an optional third arg. If given, it is used as
1702 * If AC_ALLOCA chooses alloca.c, it also defines STACK_DIRECTION.
1703 * AC_CONST works much more reliably on more systems.
1706 Major changes in Autoconf 1.3:
1708 configure no longer requires awk for packages that use a config.h.
1709 Support handling --with-PACKAGE options.
1710 New `autoheader' script to create `config.h.in' from `configure.in'.
1711 Ignore troublesome -lucb and -lPW when searching for alloca.
1712 Rename --exec_prefix to --exec-prefix for GNU standards conformance.
1713 Improve detection of STDC library.
1714 Add AC_HAVE_LIBRARY to check for non-default libraries.
1715 Function checking should work with future GNU libc releases.
1717 Major changes in Autoconf 1.2:
1719 The --srcdir option is now usually unnecessary.
1720 Add a file containing sample comments describing CPP macros.
1721 A comment in config.status tells which host it was configured on.
1722 Substituted variable values can now contain commas.
1723 Fix bugs in various feature checks.
1725 Major changes in Autoconf 1.1:
1727 Added AC_STRCOLL macro.
1728 Made AC_GETLOADAVG check for more things.
1729 AC_OUTPUT argument is now optional.
1734 Copyright (C) 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001, 2002,
1735 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
1737 This program is free software: you can redistribute it and/or modify
1738 it under the terms of the GNU General Public License as published by
1739 the Free Software Foundation, either version 3 of the License, or
1740 (at your option) any later version.
1742 This program is distributed in the hope that it will be useful,
1743 but WITHOUT ANY WARRANTY; without even the implied warranty of
1744 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
1745 GNU General Public License for more details.
1747 You should have received a copy of the GNU General Public License
1748 along with this program. If not, see <http://www.gnu.org/licenses/>.