1 GNU Autoconf NEWS - User visible changes.
3 * Major changes in Autoconf 2.64 (2009-??-??) [stable]
4 Released by Eric Blake, based on git versions 2.63b.*.
6 ** Autoconf now requires GNU M4 1.4.6 or later. Earlier versions of M4
7 have a bug in regular expression handling that interferes with some
8 of the speedups provided since Autoconf 2.63. GNU M4 1.4.13 or
11 ** AS_IF and AS_CASE have been taught to avoid syntax errors even when
12 given arguments that expand to just whitespace.
14 ** The following documented autoconf macros are new:
15 AC_ERLANG_SUBST_ERTS_VER
17 ** The autoheader tool now understands m4 macro arguments passed to
18 AC_DEFINE and AC_DEFINE_UNQUOTED.
20 ** Ensure AT_CHECK can support commands that include a # given with
21 proper m4 quoting. For shell comments, this is a new feature; for
22 non-shell comments, this fixes a regression introduced in 2.63b.
23 Additionally, AT_CHECK correctly supplies shell escapes for
24 metacharacters occurring in m4 macro expansions within the expected
25 stdout and stderr parameters.
27 ** The macro AT_CHECK now understands the concept of hard failure. If
28 a test exits with an unexpected status 99, cleanup actions for the
29 test are inhibited and the test is treated as a failure regardless
30 of AT_XFAIL_IF. It also understands the new directives
31 ignore-nolog, stdout-nolog, and stderr-nolog.
33 ** The following documented autotest macros are new:
34 AT_CHECK_UNQUOTED AT_FAIL_IF AT_SKIP_IF
36 ** The following documented m4sugar macros are new:
37 m4_argn m4_copy_force m4_default_nblank m4_default_nblank_quoted
38 m4_ifblank m4_ifnblank m4_rename_force
40 ** The autoconf testsuite now exercises all Erlang macros.
42 * Major changes in Autoconf 2.63b (2009-03-31) [beta]
43 Released by Eric Blake, based on git versions 2.63.*.
45 ** The manual is now shipped under the terms of the GNU FDL 1.3.
47 ** AC_REQUIRE now detects the case of an outer macro which first expands
48 then later indirectly requires the same inner macro. Previously,
49 this case led to silent out-of-order expansion (bug present since
50 2.50); it now issues a syntax warning, and duplicates the expansion
51 of the inner macro to guarantee dependencies have been met. See
52 the manual for advice on how to refactor macros in order to avoid
53 the bug in earlier autoconf versions and avoid increased script
54 size in the current version.
56 ** AC_DEFUN_ONCE has improved semantics. Previously, a macro declared
57 with AC_DEFUN_ONCE warned on a second invocation; and out-of-order
58 expansion was still possible. Now, dependencies are guaranteed,
59 and subsequent invocations are a silent no-op. This makes
60 AC_DEFUN_ONCE an ideal macro for silencing AC_REQUIRE warnings.
62 ** The following macros are now defined with AC_DEFUN_ONCE. This means
63 a subtle change in semantics; previously, an AC_DEFUN macro could
64 expand one of these macros multiple times or surround the macro
65 inside shell conditional text to bypass the effects of these
66 macros, but now the macro will expand exactly once, and prior to
67 the start of any enclosing AC_DEFUN macro:
68 AC_CANONICAL_BUILD AC_CANONICAL_HOST AC_CANONICAL_TARGET
69 AC_HEADER_ASSERT AC_PROG_INSTALL AC_PROG_MKDIR_P
70 AC_USE_SYSTEM_EXTENSIONS
72 ** AC_LANG_ERLANG works once again (regression introduced in 2.61a).
74 ** AC_HEADER_ASSERT is fixed so that './configure --enable-assert' no
75 longer mistakenly disables assertions.
77 ** AC_INIT now takes an optional fifth parameter that can be used to
78 set AC_PACKAGE_URL, a URL for the package's home page; the URL is
79 used in `configure --help' and is also available via AC_DEFINE.
81 ** Autotest testsuites accept an option --jobs[=N] for parallel testing.
82 This feature is still in testing, and may not work on every
83 platform, help in improving it would be appreciated.
85 ** Autotest testsuites do not attempt to write startup error messages
86 to the log file before that is opened (regression introduced in 2.63).
88 ** Configure scripts now use shell functions. This feature leads to
89 smaller configure files and faster execution.
91 ** Present But Cannot Be Compiled: Autoconf will now proceed with
92 the compiler's result if a header is present but cannot be compiled.
93 The warning is still printed, and you should really fix it by
94 providing a fourth parameter to AC_CHECK_HEADER/AC_CHECK_HEADERS.
96 ** Autoreconf added aclocal to the set of programs affected by the
97 `autoreconf -I dir' option.
99 ** The following documented m4sugar macros are new:
100 m4_chomp m4_chomp_all m4_cleardivert m4_curry m4_default_quoted
101 m4_esyscmd_s m4_map_args m4_map_args_pair m4_map_args_sep
102 m4_map_args_w m4_set_map m4_set_map_sep m4_stack_foreach
103 m4_stack_foreach_lifo m4_stack_foreach_sep
104 m4_stack_foreach_sep_lifo
106 ** The following m4sugar macros are documented now, but in some cases
107 with slightly different semantics than what the previous
108 undocumented version had:
109 m4_copy m4_dumpdefs m4_rename m4_version_prereq
111 ** The m4sugar macro m4_expand has been taught to handle unterminated
112 comments and shell case statements. As a result, it is used
113 internally in more places, such as AC_DEFINE and AT_CHECK. Most
114 uses of AC_DEFINE and AT_CHECK should not behave any differently;
115 however, it may be necessary to add double-quoting around
116 unbalanced `(' where single-quoting used to be sufficient.
118 ** The following documented m4sh macros are new:
119 AS_INIT_GENERATED AS_LINENO_PREPARE AS_ME_PREPARE AS_SET_STATUS
120 AS_VAR_APPEND AS_VAR_ARITH AS_VAR_COPY
122 ** The following m4sh macros are documented now, but in some cases
123 with slightly different semantics than what the previous
124 undocumented version had:
125 AS_ECHO AS_ECHO_N AS_ESCAPE AS_EXIT AS_LITERAL_IF AS_UNSET
126 AS_VAR_IF AS_VAR_POPDEF AS_VAR_PUSHDEF AS_VAR_SET AS_VAR_SET_IF
127 AS_VAR_TEST_SET AS_VERSION_COMPARE
129 ** The m4sh macros AS_IF and AS_CASE can now be used in shell lists.
130 The responsibility for supplying a trailing newline now belongs to
131 the call site, but since most users did not add dnl, this generally
132 results in fewer empty lines in configure.
135 * Major changes in Autoconf 2.63 (2008-09-09) [stable]
136 Released by Eric Blake, based on git versions 2.62.*.
138 ** AC_C_BIGENDIAN does not mistakenly report "universal" for some
139 bigendian hosts, a regression introduced with universal binary
142 ** AC_PATH_X now includes /lib64 and /usr/lib64 in its list of default
145 ** AC_USE_SYSTEM_EXTENSIONS no longer conflicts with an external
146 AC_DEFINE([__EXTENSIONS__]). This fixes a regression introduced in
147 2.62 when using macros such as AC_AIX that were made obsolete in
148 favor of the more portable AC_USE_SYSTEM_EXTENSIONS.
150 ** AC_CHECK_TARGET_TOOLS is usable in the non-cross-compile case.
152 ** Newly obsolete macros
153 The following macro has been marked obsolete, since current porting
154 targets can safely assume C89 semantics that signal handlers return
155 void. We have no current plans to remove the macro.
159 ** The macros m4_map and m4_map_sep now ignore any list elements
160 consisting of just empty quotes, and m4_map_sep now expands its
161 separator. This fixes a regression in 2.62 when these macros were
162 first documented, for the sake of clients expecting the semantics
163 that these macros had prior to that time. The new macros m4_mapall
164 and m4_mapall_sep, along with extra quoting of the separator, can
165 be used to get the semantics that m4_map_sep had in 2.62.
167 ** Clients of m4_expand, such as AS_HELP_STRING and AT_SETUP, can now
168 handle properly quoted but otherwise unbalanced parentheses (for
169 some macros, this fixes a regression in 2.62).
171 ** Two new quadrigraphs have been introduced: @{:@ for (, and @:}@ for ),
172 allowing the output of unbalanced parentheses in more contexts.
174 ** The following m4sugar macros are new:
175 m4_cleardivert m4_joinall m4_mapall m4_mapall_sep m4_reverse
176 m4_set_add m4_set_add_all m4_set_contains m4_set_contents
177 m4_set_delete m4_set_difference m4_set_dump m4_set_empty
178 m4_set_foreach m4_set_intersection m4_set_list m4_set_listc
179 m4_set_remove m4_set_size m4_set_union
181 ** The following m4sugar macros now accept multiple arguments, as is the
182 case with underlying m4:
183 m4_defn m4_popdef m4_undefine
185 ** The following m4sugar macros now guarantee linear scaling; they
186 previously had linear scaling with m4 1.6 but quadratic scaling
187 when using m4 1.4.x. All macros built on top of these also gain
188 the scaling improvements.
189 m4_bmatch m4_bpatsubsts m4_case m4_cond m4_do m4_dquote_elt
190 m4_foreach m4_join m4_list_cmp m4_map m4_map_sep m4_max
193 ** AT_KEYWORDS once again performs expansion on its argument, such that
194 AT_KEYWORDS([m4_if([$1], [], [default])]) no longer complains about
195 the possibly unexpanded m4_if [regression introduced in 2.62].
197 ** Config header templates `#undef UNDEFINED /* comment */' do not lead to
198 nested comments any more; regression introduced in 2.62.
201 * Major changes in Autoconf 2.62 (2008-04-05) [stable]
202 Released by Eric Blake, based on git versions 2.61a.*.
204 ** Many optimizations have been applied to make overall execution faster.
206 ** Autotest now makes use of shell functions.
208 ** config.status now uses awk instead of sed also for config headers.
210 - As a side effect, AC_DEFINE and AC_DEFINE_UNQUOTED now handle multi-line
211 values, i.e., backslash-newline combinations are handled correctly.
212 Further, for config headers, the total size of values is not limited by
213 the POSIX length limit of text lines any more, only each single line.
215 ** New config variable `top_build_prefix'.
217 ** New Autoconf macros:
218 AC_AUTOCONF_VERSION AC_OPENMP AC_PATH_PROGS_FEATURE_CHECK
220 ** AC_C_BIGENDIAN now supports universal binaries a la Mac OS X.
222 ** AC_C_RESTRICT now prefers to #define 'restrict' to a variant spelling
223 like '__restrict' if the variant spelling is available, as this is
224 more likely to work when mixing C and C++ code.
226 ** AC_CHECK_ALIGNOF's type argument T is now documented better: it must
227 be a string of tokens such that "T y;" is a valid member declaration
230 ** AC_CHECK_SIZEOF now accepts objects as well as types: the general rule
231 is that sizeof (X) works, then AC_CHECK_SIZEOF (X) should work.
233 ** AC_CHECK_TYPE and AC_CHECK_TYPES now work on any C type-name; formerly,
234 they did not work for function types. In C++, they now work on any
235 type-id that can be the operand of sizeof; this is similar to C,
236 except it excludes anonymous struct and union types. Formerly,
237 some (but not all) C++ types involving anonymous struct and union
238 were accepted, though this was not documented.
240 ** AC_CONFIG_LINKS now prefers to link against files in the build tree
241 if found, and it works to link against a file of the same name in
242 the source tree, even if both trees coincide.
244 ** AC_INIT no longer alters $@; regression introduced in 2.60.
246 ** AC_USE_SYSTEM_EXTENSIONS now defines _ALL_SOURCE for Interix platforms.
248 ** AS_HELP_STRING no longer underquotes its first argument; it also handles
249 the case where the first argument contains single-quoted commas.
250 For example, "AS_HELP_STRING([-a, [--arg[=foo]]], [bar])" produces:
251 " -a, --arg[=foo] bar"
252 Additionally, the macro now takes two additional arguments,
253 indent-column and wrap-column; these should not normally be needed,
254 but can be used to fine-tune how the output text is wrapped.
256 ** AC_PROG_INSTALL now requires an install program that can install multiple
257 files into a target directory.
259 ** The command 'autoconf -' now correctly processes a file from stdin.
261 ** 'autoreconf -m' now honors $MAKE.
263 ** For all of the directory arguments for 'configure', such as '--prefix'
264 or '--bindir', trailing slashes are stripped. As an example, if
265 tab completion in the user's shell appends trailing slashes, the
266 command './configure --prefix=/usr/' will still result in an
267 expanded libdir value of /usr/lib, not /usr//lib.
269 ** `configure --help=recursive' now works in read-only trees and from
270 unconfigured build trees.
272 ** If precious variables differ only in whitespace, then the cache consistency
273 check warns instead of fails, and reuses the old value.
275 ** AT_BANNER is now documented.
277 ** AT_SETUP now handles macro expansions properly when calculating line
280 ** Autotest now determines $srcdir correctly.
282 ** Testsuites built by autotest now accept a -C/--directory=DIR option
283 to adjust the working directory prior to creating files.
285 ** Autoconf now requires GNU M4 1.4.5 or later. Earlier versions of M4 have
286 a bug in macro tracing that interferes with the interaction between
287 Autoconf and Automake. GNU M4 1.4.11 or later is recommended. The
288 configure search for a working M4 is improved.
290 ** For portability with the eventual M4 2.0, macros should no longer use
291 anything larger than $9 to refer to arguments.
293 ** Documentation for m4sugar is improved.
295 - The following macros were previously available as undocumented
296 interfaces; the macros are now documented as stable interfaces.
298 __oline__ m4_assert m4_bmatch m4_bpatsubsts m4_car m4_case
299 m4_cdr m4_default m4_divert_once m4_divert_pop m4_divert_push
300 m4_divert_text m4_do m4_errprintn m4_fatal m4_flatten
301 m4_ifndef m4_ifset m4_ifval m4_ifvaln m4_location
302 m4_n m4_shiftn m4_strip m4_warn
304 - The following macros were previously available as undocumented
305 interfaces, but had bug fixes or semantic changes as part of this
306 release. Packages that relied on the undocumented behavior
307 should be analyzed to make sure they will still work with the
308 new documented behavior.
310 m4_cmp m4_list_cmp m4_join m4_map m4_map_sep m4_sign
311 m4_text_box m4_text_wrap m4_version_compare
313 - The m4_wrap macro used to have unspecified order, but now
314 guarantees FIFO order. m4_wrap_lifo was added to guarantee LIFO
317 - Packages using the undocumented m4sugar macro m4_PACKAGE_VERSION
318 should consider using the new AC_AUTOCONF_VERSION instead.
320 - m4sugar macros that are not documented in the manual are still
321 deemed experimental, and should not be used outside of Autoconf.
323 ** The m4sugar macros m4_append and m4_append_uniq, first documented in
324 2.60, have been fixed to treat both the string and the separator
325 arguments consistently with regards to quoting. Prior to this fix,
326 m4_append_uniq could mistakenly duplicate entries if the expansion
327 of the separator resulted in a different string (for example, if it
328 contained quotes, a comma, or a macro name). However, it means
329 that programs previously using
330 m4_append([name], [string], [[, ]])
331 are now using a four-character separator instead of the intended
332 comma and space. If you need portability to earlier versions of
333 Autoconf, you can insert the following snippet after AC_INIT but
334 before any other macro expansions, to enforce the new semantics:
335 m4_pushdef([m4_append], [m4_define([$1],
336 m4_ifdef([$1], [m4_defn([$1])[$3]])[$2])])
337 Additionally, m4_append_uniq now takes optional parameters that can
338 be used to take action depending on whether anything was appended,
339 and warns if a non-empty separator occurs within the string being
340 appended, since that can lead to duplicates.
342 ** The following m4sugar macros are new:
343 m4_append_uniq_w m4_apply m4_combine m4_cond m4_count
344 m4_dquote_elt m4_echo m4_expand m4_ignore m4_make_list m4_max
345 m4_min m4_newline m4_shift2 m4_shift3 m4_unquote m4_wrap_lifo
347 ** Warnings are now generated by default when an installer invokes
348 'configure' with an unknown --enable-* or --with-* option.
349 These warnings can be disabled with the new AC_DISABLE_OPTION_CHECKING
350 macro, or by invoking 'configure' with --disable-option-checking.
352 ** Existing obsolete macros
353 The documentation for the following macros is adjusted to make it
354 more clear that they have previously been marked obsolete, as their
355 functionality can be accomplished by other macros. We have no
356 current plans to remove them from Autoconf.
358 AC_ENABLE AC_STRUCT_ST_BLKSIZE AC_STRUCT_ST_RDEV AC_WITH
360 ** Newly obsolete macros
361 The following macros have been marked obsolete, as they only
362 perform a subset of AC_USE_SYSTEM_EXTENSIONS. We have no current
363 plans to remove them.
365 AC_AIX AC_GNU_SOURCE AC_ISC_POSIX AC_MINIX
367 ** AC_C_LONG_DOUBLE is obsolescent.
368 The documentation now says that AC_C_LONG_DOUBLE is obsolescent: it
369 tests for problems that are so old that it is no longer of
370 practical importance on current systems. New programs need not use
371 AC_C_LONG_DOUBLE. We have no current plans to remove it.
373 ** AC_DIAGNOSE, AC_WARNING, and AC_FATAL are obsolescent.
374 The documentation now favors the use of M4sugar macros m4_warn and
375 m4_fatal, since the naming makes it more obvious that the
376 diagnostics are associated with M4 expansion (ie. when running
377 `autoconf'), and offers less confusion with the AC_MSG_ERROR,
378 AC_MSG_FAILURE, and AC_MSG_WARN macros which manage diagnostics
379 when running `configure'. We have no current plans to remove these
383 * Major changes in Autoconf 2.61a (2006-12-11)
385 ** AC_FUNC_FSEEKO was broken in 2.61; it didn't make fseeko and ftello visible
386 on many platforms. This has been fixed.
388 ** AC_FUNC_SETVBUF_REVERSED is now obsolete. It is still defined for backward
389 compatibility but it does nothing. The macro was already
390 obsolescent, as the last systems to have the problem were those
391 based on SVR2, which became obsolete in 1987. The macro had bugs
392 on some modern systems and could no longer be maintained reliably
393 due to lack of ancient systems to test it on.
395 ** config.status now uses awk instead of sed for most substitutions, for speed.
397 - As a side effect multi-line values of substituted variables no
398 longer have a small limit in total size, though for portability
399 each line should not exceed the POSIX length limit for text lines.
401 - It is now documented that Makefile.in should not contain
402 overlapping variable occurrences, e.g., @VAR1@VAR2@.
403 Autoconf's behavior was always iffy in such cases, and the
404 awk implementation has changed the behavior.
406 ** Many uses of 'echo' have been rewritten so that Autoconf-generated
407 scripts have fewer problems with strings or file names containing
408 embedded special characters such as backslash or leading "-". This
409 was implemented by using `printf '%s\n' "$foo"' instead of `echo
410 "$foo"' when printf works. Due to the implementation technique
411 used, Autoconf-generated scripts now run considerably more slowly
412 on ancient implementations lacking printf. However, this should
413 not be a problem, since Autoconf-generated scripts in practice
414 invariably find a more-modern shell these days.
417 * Major changes in Autoconf 2.61 (2006-11-17)
419 ** New macros AC_C_FLEXIBLE_ARRAY_MEMBER, AC_C_VARARRAYS.
421 ** AC_ARG_ENABLE and AC_ARG_WITH now allow '.' in feature and package names.
424 * Major changes in Autoconf 2.60b (2006-10-22)
427 Autoconf-generated shell scripts no longer export BIN_SH, due to
428 configuration hassles with this. Installers who need BIN_SH in
429 their environment should set it before invoking 'configure' and
430 'make'. As far as we know, this affects only Unixware installations.
432 ** Obsolescent macros
433 The documentation now says that the following macros are obsolescent,
434 as they are superseded by Gnulib:
436 AC_FUNC_FNMATCH AC_FUNC_FNMATCH_GNU AC_FUNC_GETLOADVG AC_REPLACE_FNMATCH
438 New programs should use the Gnulib counterparts of these macros.
439 We have no current plans to remove them from Autoconf.
441 ** AC_COMPUTE_INT no longer caches or reports results.
443 ** AC_CHECK_DECL now also works with aggregate objects.
445 ** AC_USE_SYSTEM_EXTENSIONS now defines _TANDEM_SOURCE for NonStop platforms.
447 ** GNU M4 1.4.7 or later is now recommended.
450 New M4sugar macro, which is more secure than the POSIX M4 maketemp.
453 Now an alias for m4_mkstemp.
455 * Major changes in Autoconf 2.60a (2006-08-25)
457 ** GNU M4 1.4.6 or later is now recommended.
459 ** The check for C99 now tests for varargs macros, as documented.
460 It also tests that the preprocessor supports 64-bit integers.
462 ** Autoconf now uses constructs like "#ifdef HAVE_STDLIB_H" rather than
463 "#if HAVE_STDLIB_H", so that it now works with "gcc -Wundef -Werror".
465 ** The functionality of the undocumented _AC_COMPUTE_INT is now provided
466 by a public and documented macro, AC_COMPUTE_INT. The parameters to the
467 two macros are different, so autoupdate will not change the old private name
468 to the new one. _AC_COMPUTE_INT may be removed in a future release.
470 ** AC_TYPE_LONG_LONG_INT and AC_TYPE_UNSIGNED_LONG_LONG_INT now require
471 that long long types be at least 64 bits wide, as C99 and tradition
472 requires. Formerly, they accepted implementations of any width.
475 * Major changes in Autoconf 2.60
477 Released 2006-06-23, by Ralf Wildenhues.
479 ** Autoconf no longer depends on whether m4wrap is FIFO (as Posix requires)
480 or LIFO (as in GNU M4 1.4.x). GNU M4 2.0 is expected to conform to Posix
481 here, so m4wrap/m4_wrap users should no longer depend on LIFO behavior.
483 ** Provide a way to turn off warnings about the changed directory variables.
485 * Major changes in Autoconf 2.59d
487 Released 2006-06-05, by Ralf Wildenhues.
489 ** GNU make now recommended for VPATH builds
490 INSTALL now suggests VPATH builds (e.g., "sh ../srcdir/configure")
491 only if you use GNU make. In practice, other 'make' implementations
492 have too many subtle incompatibilities in their support for VPATH.
493 Many packages (including Autoconf itself) are portable to other
494 'make' implementations, but some packages are not, and recommending
495 GNU make keeps the installation instructions simpler.
497 ** Even more safety checks for the new Directory variables:
498 Warn about suspicious `${datarootdir}' found in config files output.
500 ** AC_TRY_COMMAND, AC_TRY_EVAL, ac_config_guess, ac_config_sub, ac_configure
501 These never-documented macros and variables have been marked with
502 comments saying that they may be removed in a future release,
503 because their use can lead to unintended code being executed.
504 If you need functionality that only these macros or variables
505 currently supply, please write bug-autoconf@gnu.org.
507 ** AC_SUBST, AC_DEFINE
508 Literal arguments to these are passed to m4_pattern_allow now.
511 Passing 'ac_cv_prog_cc_stdc=no' to 'configure' now sets ac_cv_prog_cc_c99
512 and ac_cv_prog_cc_c89 to 'no' as well, for backward compatibility with
513 obsolete K&R tests in the Automake test suite.
522 Now more robust with special characters in file names, or when
523 multiple processes create the same directory at the same time.
525 ** Obsolescent macros
526 The documentation now says that the following macros are obsolescent:
527 they test for problems that are so old that they are no longer of
528 practical importance on current systems.
530 AC_C_BACKSLASH_A AC_FUNC_MEMCMP AC_HEADER_DIRENT
531 AC_C_CONST AC_FUNC_SELECT_ARGTYPES AC_HEADER_STAT
532 AC_C_PROTOTYPES AC_FUNC_SETPGRP AC_HEADER_STDC
533 AC_C_STRINGIZE AC_FUNC_SETVBUF_REVERSED AC_HEADER_SYS_WAIT
534 AC_C_VOLATILE AC_FUNC_STAT AC_HEADER_TIME
535 AC_FUNC_CLOSEDIR_VOID AC_FUNC_STRFTIME AC_ISC_POSIX
536 AC_FUNC_GETPGRP AC_FUNC_UTIME_NULL AC_PROG_GCC_TRADITIONAL
537 AC_FUNC_LSTAT AC_FUNC_VPRINTF AC_STRUCT_TM
539 New programs need not use these macros. We have no current plans to
543 For compatibility with future Libtool 2.0, autoreconf will invoke
544 libtoolize with the option `--ltdl' now, if LT_CONFIG_LTDL_DIR is
547 * Major changes in Autoconf 2.59c
549 Released 2006-04-12, by Ralf Wildenhues.
551 ** The configure command now redirects standard input from /dev/null,
552 to help avoid problems with subsidiary commands that might mistakenly
553 read standard input. AS_ORIGINAL_STDIN_FD points to the original
554 standard input before this redirection, if you really want configure to
555 read from standard input.
557 ** Directory variables adjusted to recent changes in the GNU Coding Standards.
558 The following directory variables are new:
560 datarootdir read-only architecture-independent data root [PREFIX/share]
561 localedir locale-specific message catalogs [DATAROOTDIR/locale]
562 docdir documentation root [DATAROOTDIR/doc/PACKAGE]
563 htmldir html documentation [DOCDIR]
564 dvidir dvi documentation [DOCDIR]
565 pdfdir pdf documentation [DOCDIR]
566 psdir ps documentation [DOCDIR]
568 The following variables have new default values:
570 datadir read-only architecture-independent data [DATAROOTDIR]
571 infodir info documentation [DATAROOTDIR/info]
572 mandir man documentation [DATAROOTDIR/man]
574 This means that if you use any of `@datadir@', `@infodir@', or
575 `@mandir@' in a file, you will have to ensure `${datarootdir}' is
576 defined in this file. As a temporary measure, if any of those are
577 found but no mention of `datarootdir', the substitutions will be
578 replaced with values that do not contain `${datarootdir}', and a
579 warning will be issued.
581 ** @top_builddir@ is now a dir name: it is always nonempty and doesn't have
582 a trailing slash. Similar change will be made to ac_top_builddir in a
583 future release; the old style value, which matches (../)*, is (and will
584 continue to be) available as ac_top_build_prefix.
587 New macro to check for support of 'typeof' syntax a la GNU C.
589 ** AC_CHECK_DECLS_ONCE, AC_CHECK_FUNCS_ONCE, AC_CHECK_HEADERS_ONCE
590 New "once-only" variants of commonly-used macros, to make 'configure'
591 smaller and faster in common cases.
594 New macro to check for strtold with C99 semantics.
597 New macro that lets builder disable assertions at 'configure'-time.
600 Now checks for X11/Xlib.h and XrmInitialize (X proper) rather than
601 X11/Intrinsic.h and XtMalloc (Xt).
603 ** AC_PRESERVE_HELP_ORDER
604 New macro that causes `configure' to display help strings for AC_ARG_ENABLE
605 and AC_ARG_WITH arguments in one region, in the order defined. The default
606 behavior is to group options of each classes separately.
608 ** AC_PROG_CC, AC_PROG_CXX
609 No longer automatically arrange to declare the 'exit' function of C,
610 when a C++ compiler is used. Standard Autoconf macros no longer use
611 'exit', so this is no longer an issue for them. If you use C++, and
612 want to call 'exit', you'll have to arrange for its declaration
613 yourself. But we now suggest you return from 'main' instead.
615 ** AC_PROG_CC_C89, AC_PROG_CC_C99
616 New macros for ISO C99 support. AC_PROG_CC_C89 and AC_PROG_CC_C99
617 check for ANSI C89 and ISO C99 support respectively.
620 Has been unobsoleted, and will check if the compiler supports ISO
621 C99, falling back to ANSI C89 if not. ac_cv_prog_cc_stdc is
622 retained for backwards compatibility, assuming the value of
623 ac_cv_prog_cc_c99 or ac_cv_prog_cc_c89 (whichever is valid, in
626 ** AC_STRUCT_DIRENT_D_INO, AC_STRUCT_DIRENT_D_TYPE
627 New macros for checking commonly-used members of struct dirent.
630 The substituted value can now contain newlines.
633 The substitution now occurs only when @variable@ is on a line by itself,
634 optionally surrounded by spaces and tabs. The whole line is replaced.
636 ** AC_TYPE_LONG_DOUBLE, AC_TYPE_LONG_DOUBLE_WIDER
637 New macros to check for long double, and whether it is wider than double.
638 The old macro AC_C_TYPE_LONG_DOUBLE has been marked as obsolete;
639 applications should switch to the new macro.
641 ** AC_TYPE_INT8_T, AC_TYPE_INT16_T, AC_TYPE_INT32_T, AC_TYPE_INT64_T,
642 AC_TYPE_INTMAX_T, AC_TYPE_INTPTR_T, AC_TYPE_LONG_LONG_INT, AC_TYPE_SSIZE_T,
643 AC_TYPE_UINT8_T, AC_TYPE_UINT16_T, AC_TYPE_UINT32_T, AC_TYPE_UINT64_T,
644 AC_TYPE_UINTMAX_T, AC_TYPE_UINTPTR_T, AC_TYPE_UNSIGNED_LONG_LONG_INT
645 New macros to check for C99 and POSIX types.
647 ** AC_USE_SYSTEM_EXTENSIONS
648 New macro to enable extensions to Posix.
651 New macro which is defined to the name of the first declared config header
652 or undefined if no config headers have been declared yet.
655 The macro correctly handles quadrigraphs now.
657 ** AS_BOURNE_COMPATIBLE, AS_SHELL_SANITIZE, AS_CASE
658 These macros are new or published now.
661 New macro for copyright notices in testsuite files.
663 ** ALLOCA, LIBOBJS, LTLIBOBJS
664 Object names added to these variables are now prefixed with `${LIBOBJDIR}',
665 as in `${LIBOBJDIR}alloca.o'. LIBOBJDIR is meant to be defined from
666 `Makefile.in' in case the object files lie in a different directory.
667 The LIBOBJDIR feature is experimental.
670 Supports --no-recursive now.
672 ** New macros to support Erlang/OTP.
673 New macros for configuring paths to Erlang tools and libraries:
674 AC_ERLANG_PATH_ERLC, AC_ERLANG_NEED_ERLC, AC_ERLANG_PATH_ERL,
675 AC_ERLANG_NEED_ERL, AC_ERLANG_CHECK_LIB, AC_ERLANG_SUBST_ROOT_DIR,
676 AC_ERLANG_SUBST_LIB_DIR.
678 New macros for configuring installation of Erlang libraries:
679 AC_ERLANG_SUBST_INSTALL_LIB_DIR, AC_ERLANG_SUBST_INSTALL_LIB_SUBDIR.
681 ** The manual now mentions Gnulib more prominently.
683 ** New macros to support Objective C.
684 AC_PROG_OBJC, AC_PROG_OBJCPP.
686 * Major changes in Autoconf 2.59b
688 Released 2004-08-20, by Paul Eggert.
691 New macro that computes the default alignment of a type.
693 ** AC_CHECK_TOOL, AC_PATH_TOOL, AC_CHECK_TOOLS
694 When cross-compiling, these macros will give a warning if the tool
695 is not prefixed. In the future, unprefixed cross tools will not
696 be detected; please consult the info documentation for information
697 about the reason of this change.
699 ** AC_CHECK_TARGET_TOOL, AC_PATH_TARGET_TOOL, AC_CHECK_TARGET_TOOLS
700 New macros that detect programs whose name is prefixed with the
701 target type, if the build type and target type are different.
703 ** AC_REQUIRE_AUX_FILE
704 New trace macro that declares expected auxiliary files.
707 New macro that tests for a grep program that accepts as a long a line
710 ** AC_PROG_EGREP, AC_PROG_FGREP
711 These macros now require AC_PROG_GREP, and try EGREP="$GREP -E" and
712 FGREP="$GREP -F" respectively if possible, or else run a path search for
713 a program that accepts as long a line as possible.
716 New macro that tests for a sed program that truncates as few characters
719 * Major changes in Autoconf 2.59
721 Released 2003-11-04, by Akim Demaille
723 ** ac_abs_builddir etc.
724 Absolute file names were actually relative in 2.58.
726 * Major changes in Autoconf 2.58
728 Released 2003-11-04, by Akim Demaille
731 core.* files are no longer removed, as they may be valid user files.
733 ** autoreconf and auxiliary directory
734 Autoreconf creates the auxiliary directory if needed. This is
735 especially useful for initial "bootstrapping" of fresh CVS checkouts.
737 ** AC_CONFIG_MACRO_DIR
738 Use this macro to declare the directory for local M4 macros for aclocal.
741 No longer includes twice the same file in LIBOBJS if invoked
744 ** AC_CONFIG_COMMANDS
745 The directory for its first argument is automatically created. For
748 AC_CONFIG_COMMANDS([src/modules.hh], [...])
750 $top_builddir/src/ is created if needed.
752 ** Autotest and local.at
753 The optional file local.at is always included in Autotest test suites.
756 The warnings are always issued, including with cached runs.
757 This became a significant problem since aclocal and automake can
758 run autoconf behind the scene.
760 ** autoheader warnings
761 The warnings of autoheader can be turned off, using --warning.
762 For instance, -Wno-obsolete disables the complaints about acconfig.h
763 and other deprecated constructs.
766 AC_C_RESTRICT, AC_INCLUDES_DEFAULT, AC_LANG_ASSERT, AC_LANG_WERROR,
769 ** AC_DECL_SYS_SIGLIST
773 Now checks that mktime is the inverse of localtime.
775 ** Improve DJGPP portability
776 The Autoconf tools and configure behave better under DJGPP.
778 ** Present But Cannot Be Compiled
779 New FAQ section dedicated to the mystic
781 configure: WARNING: pi.h: present but cannot be compiled
782 configure: WARNING: pi.h: check for missing prerequisite headers?
783 configure: WARNING: pi.h: proceeding with the preprocessor's result
786 ** Concurrent executions of autom4te
787 autom4te now locks its internal files, which enables concurrent
788 executions of autom4te, likely to happen if automake, autoconf,
789 autoheader etc. are run simultaneously.
792 Use of Libtool 1.5 and higher is encouraged. Compatibility with
793 Libtool pre-1.4 is not checked.
796 Testsuites no longer rerun failed tests in verbose mode; instead,
797 failures are logged while the test is run.
799 In addition, expected failures can be marked as such.
801 * Major changes in Autoconf 2.57
803 Released 2002-12-03 by Paul Eggert.
805 Bug fixes for problems with AIX linker, with freestanding C compilers,
806 with GNU M4 limitations, and with obsolete copies of GNU documents.
808 The Free Documentation License has been upgraded from 1.1 to 1.2.
810 * Major changes in Autoconf 2.56
812 Released 2002-11-15 by Akim Demaille.
814 One packaging problem fixed (config/install-sh was not executable).
816 * Major changes in Autoconf 2.55
818 Released 2002-11-14 by Akim Demaille.
822 Have your configure.ac checked by autoscan ("autoscan").
823 Try the warning options ("autoreconf -fv -Wall").
827 - AC_CHECK_HEADER, AC_CHECK_HEADERS
828 More information on proper use.
830 - Writing Test Programs
832 This sections explains how to write good test sources to use with
833 AC_COMPILE_IFELSE etc. It documents AC_LANG_PROGRAM and so forth.
835 - AC_FOO_IFELSE vs. AC_TRY_FOO
837 Explains why Autoconf moves from AC_TRY_COMPILE etc. to
838 AC_COMPILE_IFELSE and AC_LANG_PROGRAM etc.
842 - Is more robust to different Gettext installations.
844 - Produces messages (when --verbose) to be understood by Emacs'
847 - Supports -W/--warnings.
850 Once the GNU Build System reinstalled, run `./config.status
851 --recheck && ./config.status && make' if possible.
855 - Supports --cache, and --no-cache.
857 - ~/.autom4te.cfg makes it possible to disable the caching mechanism
858 (autom4te.cache). See `Customizing autom4te' in the documentation.
865 Support for the obsoleted options -m, --macrodir, -l, --localdir is
866 dropped in favor of the safer --include/--prepend-include scheme.
871 AC_COMPILER_IFELSE, AC_FUNC_MBRTOWC, AC_HEADER_STDBOOL,
872 AC_LANG_CONFTEST, AC_LANG_SOURCE, AC_LANG_PROGRAM, AC_LANG_CALL,
873 AC_LANG_FUNC_TRY_LINK, AC_MSG_FAILURE, AC_PREPROC_IFELSE.
876 Obsoleted macros are kept for Autoconf backward compatibility, but
877 should be avoided in configure.ac. Running autoupdate is advised.
880 - AC_DEFINE/AC_DEFINE_UNQUOTED
882 We have to stop using the old compatibility scheme --that tried to
883 avoid useless backslashes-- because Libtool 1.4.3 contains a
885 AC_DEFINE([error_t], [int],
886 [Define to a type to use for \`error_t' if it is not
887 otherwise available.])
889 We have to quote the single quotes and backslashes with \. The old
890 compatibility scheme saw that ` was backslashed, and therefore did
891 not quote the single quote... Failure. Hence, Autoconf 2.54 is not
892 compatible with Libtool. Autoconf 2.55 is, but in some cases might
893 produce more \ than wanted.
895 Please, note that in the future the same problem will happen with
896 AC_MSG_*: use `autoreconf -f -Wall'.
900 - Portability of the Autoconf package to Solaris.
902 - Spurious warnings caused by config.status.
903 This bug is benign, but painful: on some systems (typically
904 FreeBSD), warnings such as:
906 config.status: creating Makefile
907 mv: Makefile: set owner/group (was: 1357/0): Operation not permitted
909 could be issued. This is fixed.
912 Simultaneous executions of config.status are possible again.
914 - Precious variables accumulation
916 config.status could stack several copies of the precious variables
920 ** Plans for later versions
924 The compatibility hooks with the old scheme will be completely
925 removed. Please, advice/use `--build', `--host', and `--target'
928 - AC_CHECK_HEADER, AC_CHECK_HEADERS
930 The tests will be stricter, please make sure your invocations are
935 Shell functions will gradually be introduced, probably starting with
936 Autotest. If you know machines which are in use that you suspect
937 *not* to support shell functions, please run the test suite of
938 Autoconf 2.55 on it, and report the results to
939 bug-autoconf@gnu.org.
943 Special characters in AC_MSG_* need not be quoted. Currently,
944 Autoconf has heuristics to decide when a string is escaped, or has
945 to be escaped. This scheme is fragile, and will be removed; the
946 only risk is uglified messages. Please, run `autoreconf -f -Wall'
947 to find occurrences that will be affected.
949 * Major changes in Autoconf 2.54
951 Released 2002-09-13 by Akim Demaille.
955 - autoreconf no longer changes the version of the gettext/po/intl
956 support files. It now adds the files the correspond to the
957 AM_GNU_GETTEXT_VERSION declared in configure.ac.
959 Warning: It now relies on the 'autopoint' program, which is part
960 of GNU gettext 0.11.4 and newer.
962 Please note that you need to have a GNU gettext version that
963 corresponds at least to the AM_GNU_GETTEXT_VERSION declared
964 in configure.ac. You can upgrade to newer GNU gettext versions,
965 though, without needing to change configure.ac.
967 - The -I DIR or --include=DIR option now appends DIR to the include path
968 instead of prepending; this is for consistency with other GNU tools.
969 The new -B DIR or --prepend-include=DIR option has the old behavior.
974 Now handles all the gory details about LIBOBJS and LTLIBOBJS.
975 Please, remove lines such as
977 # This is necessary so that .o files in LIBOBJS are also
978 # built via the ANSI2KNR-filtering rules.
979 LIBOBJS=`echo $LIBOBJS|sed 's/\.o /\$U.o /g;s/\.o$/\$U.o/'`
981 and read the `AC_LIBOBJ vs LIBOBJS' section. Do not define U in
982 your Makefiles either.
984 - AC_CONFIG_LINKS now makes copies if it can't make links.
986 - AC_FUNC_FNMATCH now tests only for POSIX compatibility, reverting to
987 Autoconf 2.13 behavior. The new macro AC_FUNC_FNMATCH_GNU also
988 tests for GNU extensions to fnmatch, and replaces fnmatch if needed.
990 - AC_FUNC_SETVBUF_REVERSED no longer fails when cross-compiling.
992 - AC_PROG_CC_STDC is integrated into AC_PROG_CC.
994 - AC_PROG_F77 default search no longer includes cf77 and cfg77.
998 AC_C_BACKSLASH_A, AC_CONFIG_LIBOBJ_DIR, AC_GNU_SOURCE,
999 AC_PROG_EGREP, AC_PROG_FGREP, AC_REPLACE_FNMATCH,
1000 AC_FUNC_FNMATCH_GNU, AC_FUNC_REALLOC, AC_TYPE_MBSTATE_T.
1002 - AC_FUNC_GETLOADAVG
1003 looks for getloadavg.c in the CONFIG_LIBOBJ_DIR.
1006 Now defines HAVE_MALLOC to 0 if `malloc' does not work, and asks
1007 for an AC_LIBOBJ replacement.
1011 - Spurious complaints from `m4_bmatch' about invalid regular
1012 expressions are suppressed.
1014 - Empty top_builddirs are properly handled.
1016 - AC_CHECK_MEMBER works correctly when the member is an aggregate.
1019 Now colon in the optional path arguments are properly handled.
1021 ** Improved portability
1023 - Both Autoconf the package, and the scripts it produces, should run
1024 more reliably with Zsh. Bear in mind it is the default Bourne shell
1027 - Autoconf and the scripts it produces no longer assume the existence of
1028 the obsolescent commands egrep and fgrep.
1032 - Limitations of Make
1036 The GNATS base moved to
1037 http://bugs.gnu.org/cgi-bin/gnatsweb.pl?database=autoconf
1038 (It is no longer available, though.)
1043 Now contains the list of ouput variables and files (AC_SUBST,
1046 * Major changes in Autoconf 2.53
1048 Released 2002-03-08 by Akim Demaille.
1052 Perl 5.005_03 or later is required: autom4te is written in Perl and is
1053 needed by autoconf. autoheader, autoreconf, ifnames, and autoscan are
1059 Argument requirements, output variables, defined macros.
1060 - M4sugar, M4sh, Autotest
1062 - Double quoting macros
1063 AC_TRY_CPP, AC_TRY_COMPILE, AC_TRY_LINK and AC_TRY_RUN.
1065 The Autoconf manual is now distributed under the terms of the GNU FDL.
1066 - Section `Hosts and Cross-Compilation'
1067 Explains the rationale for the 2.5x changes in the cross-compilation
1068 chain, and in the relationships between build, host, and target
1070 Emphasizes that `cross-compilation' == `--host is given'.
1071 If you are working on compilers etc., be sure to read this section.
1072 - Section `AC_LIBOBJ vs. LIBOBJS'
1073 Explains why assigning LIBOBJS directly is now an error.
1074 Details how to update the code.
1079 Now used instead of hard coded line numbers.
1080 This eases the comparison of `configure's, and diminishes the
1081 pressure over control version archives.
1082 Automatic replacement for shells that don't support this feature.
1083 - New output variables
1084 @builddir@, @top_builddir@, @abs_srcdir@, @abs_top_srcdir@, @abs_builddir@,
1089 Autoconf and Autotest modes are provided.
1094 New, used by the Autoconf suite to cache and speed up most processing.
1096 Supported by autom4te, autoconf and autoheader.
1098 Replaces --autoconf-dir and --localdir in autoconf, autoheader,
1099 autoupdate, and autoreconf.
1101 No longer passes --cygnus, --foreign, --gnits, --gnu, --include-deps:
1102 automake options are to be given via AUTOMAKE_OPTIONS.
1104 Runs gettextize and libtoolize when appropriate.
1106 --m4dir is no longer supported.
1108 Now runs only in the specified directories, defaulting to `.',
1109 but understands AC_CONFIG_SUBDIRS for dependent directories.
1110 Before, it used to run on all the `configure.ac' found in the
1112 Independent packages are properly updated.
1116 - The top level $prefix is propagated to the AC_CONFIG_SUBDIRS configures.
1118 Under the user pressure, $? is finally available. Probably a mistake.
1119 - AC_F77_LIBRARY_LDFLAGS now supports the HP/UX f90 compiler.
1120 - Precious variables accumulation
1121 config.status could stack several copies of the precious variables
1123 - AC_PATH_PROG and family.
1124 Works properly when given a literal path.
1126 Somewhere since 2.13, the result had been reversed.
1130 - AC_C_BIGENDIAN supports the cross-compiling case.
1131 - AC_C_BIGENDIAN accepts ACTION-IF-TRUE, ACTION-IF-FALSE, and
1132 ACTION-IF-UNKNOWN arguments. All are facultative, and the default
1133 for ACTION-IF-TRUE is to define WORDS_BIGENDIAN like AC_C_BIGENDIAN
1135 - AC_C_LONG_DOUBLE now succeeds only if `long double' has more range or
1136 precision than `double'.
1141 It now defines the preprocessor symbols PACKAGE_NAME,
1142 PACKAGE_TARNAME, PACKAGE_VERSION, PACKAGE_STRING, and
1146 Admits a fourth optional parameter: the tar name.
1148 - AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS.
1149 Provide the user with srcdir, ac_srcdir, ac_top_srcdir, ac_builddir,
1150 ac_top_builddir, ac_abs_srcdir, ac_abs_top_srcdir, ac_abs_builddir,
1151 ac_abs_top_builddir.
1153 - AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS and AC_OUTPUT.
1154 Are much less expensive when using long lists of files.
1157 Works with shell variables, and non alphanumeric names.
1161 - AC_FUNC_STRERROR_R now sets STRERROR_R_CHAR_P, not HAVE_WORKING_STRERROR_R,
1162 because POSIX 1003.1-200x draft 7 says strerror_r returns int, not char *.
1164 - AC_FUNC_STRTOD substitutes POW_LIB.
1169 * Major changes in Autoconf 2.52
1171 Released 2001-07-18 by Akim Demaille.
1176 This feature was present in autoconf 2.50 but was not documented.
1177 For example, `@<:@' is translated to `[' just before output. This
1178 is useful when writing strings that contain unbalanced quotes, or
1179 other hard-to-quote constructs.
1180 - m4_pattern_forbid, m4_pattern_allow
1181 - Tips for upgrading from 2.13.
1182 - Using autoscan to maintain a configure.ac.
1185 - Now include stdint.h.
1186 - sys/types.h and sys/stat.h are guarded.
1187 - strings.h is included if available, and not conflicting with string.h.
1190 - The test suite is more robust and presents less false failures.
1191 - Invocation of GNU M4 now robust to POSIXLY_CORRECT.
1192 - configure accepts --prefix='' again.
1193 - AC_CHECK_LIB works properly when its first argument is not a
1195 - HAVE_INTTYPES_H is defined only if not conflicting with sys/types.h.
1196 - build_, host_, and target_alias are AC_SUBST as in 2.13.
1197 - AC_ARG_VAR properly propagates precious variables inherited from the
1198 environment to ./config.status.
1199 - Using --program-suffix/--program-prefix is portable.
1200 - Failures to detect the default compiler's output extension are less
1202 - `config.status foo' works properly when `foo' depends on variables
1203 set in an AC_CONFIG_THING INIT-CMD.
1204 - autoheader is more robust to broken input.
1205 - Fixed Fortran name-mangling and link tests on a number of systems,
1206 e.g. NetBSD; see AC_F77_DUMMY_MAIN, below.
1209 - AC_CHECK_HEADER and AC_CHECK_HEADERS support a fourth argument to
1210 specify pre-includes. In this case, the headers are compiled with
1211 cc, not merely preprocessed by cpp. Therefore it is the _usability_
1212 of a header which is checked for, not just its availability.
1213 - AC_ARG_VAR refuses to run configure when precious variables have
1215 - Versions of compilers are dumped in the logs.
1216 - AC_CHECK_TYPE recognizes use of `foo_t' as a replacement type.
1219 - AC_PATH_XTRA only adds -ldnet to $LIBS if it's needed to link.
1220 - AC_FUNC_WAIT3 and AC_SYS_RESTARTABLE_SYSCALLS are obsoleted.
1221 - AM_FUNC_ERROR_AT_LINE, AM_FUNC_FNMATCH, AM_FUNC_MKTIME,
1222 AM_FUNC_OBSTACK, and AM_FUNC_STRTOD are now activated.
1223 Be sure to read `Upgrading from Version 2.13' to understand why
1224 running `autoupdate' is needed.
1225 - AC_F77_DUMMY_MAIN, AC_F77_MAIN: new macros to detect whether
1226 a main-like routine is required/possible when linking C/C++ with
1227 Fortran. Users of e.g. AC_F77_WRAPPERS should be aware of these.
1228 - AC_FUNC_GETPGRG behaves better when cross-compiling.
1230 * Major changes in Autoconf 2.51
1231 There was no release of Autoconf 2.51 since some packagers had used
1232 this version number without permission to ship intermediary versions
1233 of 2.50. The version was skipped to avoid confusion.
1235 * Major changes in Autoconf 2.50
1237 Released 2001-05-21 by Akim Demaille.
1239 ** Lots of bug fixes
1240 There have been far too many to enumerate them here. Check out
1241 ChangeLog if you really want to know more.
1243 ** Improved documentation
1244 In particular, portability issues are better covered.
1247 All the standard GNU Makefile targets are supported. The layout has
1248 changed: m4/ holds the M4 extensions Autoconf needs for its
1249 configuration, doc/ contains the documentation, and tests/ contains
1252 ** Man pages are provided
1253 For autoconf, autoreconf, autoupdate, autoheader, autoscan, ifnames,
1254 config.guess, config.sub.
1258 Provides a safe and powerful means to trace the macro uses. This
1259 provide the parsing layer for tools which need to `study'
1263 Specify what category of warnings should be enabled.
1265 - When recursing into subdirectories, try for configure.gnu before
1266 configure to adapt for packages not using autoconf on case-insensitive
1270 More errors are now caught (circular AC_REQUIRE dependencies,
1271 AC_DEFINE in the action part of an AC_CACHE_CHECK, too many pops
1272 etc.). In addition, their location and call stack are given.
1275 autoupdate is much more powerful, and is able to provide the glue code
1276 which might be needed to move from an old macro to its newer
1279 You are strongly encouraged to use it to modernize both your
1280 `configure.in' and your .m4 extension files.
1283 The internal machinery of autoheader has completely changed. As a
1284 result, using `acconfig.h' should be considered to be obsoleted, and
1285 you are encouraged to get rid of it using the AH macros.
1290 ** Fortran 77 compilers
1291 Globally, the support for Fortran 77 is considerably improved.
1293 Support for automatically determining a Fortran 77 compiler's
1294 name-mangling scheme. New CPP macros F77_FUNC and F77_FUNC_ are
1295 provided to wrap C/C++ identifiers, thus making it easier and more
1296 transparent for C/C++ to call Fortran 77 routines, and Fortran 77 to
1297 call C/C++ routines. See the Texinfo documentation for details.
1300 The test suite no longer uses DejaGNU. It should be easy to submit
1301 test cases in this new framework.
1304 - --help, --help=long, -hl
1305 no longer dumps useless items.
1307 lists only specific options.
1308 - --help=recursive, -hr
1309 displays the help of all the embedded packages.
1310 - Remembers environment variables when reconfiguring.
1311 The previous scheme to set envvar before running configure was
1313 what prevented configure from remembering the environment in which
1314 it was run, therefore --recheck was run in an inconsistent
1315 environment. Now, one should run
1317 and then --recheck will work properly. Variables declared with
1318 AC_ARG_VAR are also preserved.
1320 $build defaults to `config.guess`, $host to $build, and then $target
1322 Cross-compilation is a global status of the package, it no longer
1323 depends upon the current language.
1324 Cross compilation is enabled iff the user specified `--host'.
1325 `configure' now fails if it can't run the executables it compiles,
1326 unless cross-compilation is enabled.
1328 The cache file is disabled by default. The new options
1329 `--config-cache', `-C' set the cache to `config.cache'.
1333 Much faster on most architectures.
1334 - concurrent executions
1335 It is safe to use `make -j' with config.status.
1336 - human interface improved
1337 It is possible to invoke
1338 ./config.status foobar
1339 instead of the former form (still valid)
1340 CONFIG_COMMANDS= CONFIG_HEADERS= CONFIG_LINKS= \
1341 CONFIG_FILES=foobar:foo.in:bar.in \
1343 The same holds for configuration headers and links.
1344 You can instantiate unknown files and headers:
1345 ./config.status --header foo.h:foo.h.in --file bar:baz
1346 - has a useful --help
1347 - accepts special file name "-" for stdin/stdout
1352 Specify additional copyright information.
1355 Now expects the identity of the package as argument.
1359 Most macros, if not all, now strictly follow the `one quotation
1360 level' rule. This results in a more predictable expansion.
1363 A sly bug in the AC_REQUIRE machinery, which could produce incorrect
1364 configure scripts, was fixed by Axel Thimm.
1368 Document and ask for the registration of an envvar.
1371 Specifies the file which `configure' should look for when trying to
1372 find the source tree (used to be handled by AC_INIT).
1374 - AC_CONFIG_COMMANDS
1375 To add new actions to config.status. Should be used instead of
1379 Replaces AC_LINK_FILES.
1381 - AC_CONFIG_HEADERS, AC_CONFIG_COMMANDS, AC_CONFIG_SUBDIRS,
1382 AC_CONFIG_LINKS, and AC_CONFIG_FILES
1383 They now obey sh: you should no longer use shell variables as
1384 argument. Instead of
1386 test "$package_foo_enabled" = yes && $my_subdirs="$my_subdirs foo"
1387 AC_CONFIG_SUBDIRS($my_subdirs)
1391 if test "$package_foo_enabled" = yes; then
1392 AC_CONFIG_SUBDIRS(foo)
1396 To format an Autoconf macro's help string so that it looks pretty
1397 when the user executes `configure --help'.
1400 ** Generic Test Macros
1402 The interface of the AC_CHECK families of macros (decl, header,
1403 type, member, func) is now uniform. They support the same set of
1406 - AC_CHECK_DECL, AC_CHECK_DECLS
1407 To check whether a symbol is declared.
1409 - AC_CHECK_SIZEOF, AC_C_CHAR_UNSIGNED.
1410 No longer need a cross-compilation default.
1413 The test it performs is much more robust than previously, and makes
1414 it possible to test builtin types in addition to typedefs.
1415 It is now schizophrenic:
1416 - AC_CHECK_TYPE(TYPE, REPLACEMENT)
1417 remains for backward compatibility, but its use is discouraged.
1418 - AC_CHECK_TYPE(TYPE, IF-FOUND, IF-NOT-FOUND, INCLUDES)
1419 behaves exactly like the other AC_CHECK macros.
1422 Checks whether given types are supported by the system.
1424 - AC_CHECK_MEMBER, AC_CHECK_MEMBERS
1425 Check for given members in aggregates (e.g., pw_gecos in struct
1429 Checks if the compiler supports ISO C, included when needs special
1433 Checking whether the preprocessor indicates missing includes by the
1434 error code. stderr is checked by AC_TRY_CPP only as a fallback.
1437 Takes a language as argument and replaces AC_LANG_C,
1438 AC_LANG_CPLUSPLUS and AC_LANG_FORTRAN77.
1440 - AC_LANG_PUSH, AC_LANG_POP
1441 Are preferred to AC_LANG_SAVE, AC_LANG_RESTORE.
1444 - AC_FUNC_CHOWN, AC_FUNC_MALLOC, AC_FUNC_STRERROR_R,
1445 AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK, AC_FUNC_STAT, AC_FUNC_LSTAT,
1446 AC_FUNC_ERROR_AT_LINE, AC_FUNC_OBSTACK, AC_FUNC_STRTOD, AC_FUNC_FSEEKO.
1450 Sets GETGROUPS_LIBS.
1452 - AC_FUNC_GETLOADAVG
1453 Defines `HAVE_STRUCT_NLIST_N_UN_N_NAME' instead of `NLIST_NAME_UNION'.
1456 Now integrates `AC_DECL_YYTEXT' which is obsoleted.
1459 Arrange for large-file support.
1461 - AC_EXEEXT, AC_OBJEXT
1462 You are no longer expected to use them: their computation is
1463 performed by default.
1465 ** C++ compatibility
1466 Every macro has been revisited in order to support at best CC=c++.
1468 Major changes in Autoconf 2.14:
1469 There was no release of GNU Autoconf 2.14.
1471 Major changes in Autoconf 2.13:
1473 Released 1999-05-01 by Ben Elliston.
1475 * Support for building on Win32 systems where the only available C or
1476 C++ compiler is the Microsoft Visual C++ command line compiler
1477 (`cl'). Additional support for building on Win32 systems which are
1478 using the Cygwin or Mingw32 environments.
1479 * Support for alternative object file and executable file extensions.
1480 On Win32, for example, these are .obj and .exe. These are discovered
1481 using AC_OBJEXT and AC_EXEEXT, which substitute @OBJEXT@ and
1482 @EXEEXT@ in the output, respectively.
1483 * New macros: AC_CACHE_LOAD, AC_CACHE_SAVE, AC_FUNC_SELECT_ARGTYPES,
1484 AC_VALIDATE_CACHED_SYSTEM_TUPLE, AC_SEARCH_LIBS, AC_TRY_LINK_FUNC,
1485 AC_C_STRINGIZE, AC_CHECK_FILE(S), AC_PROG_F77 (and friends).
1486 * AC_DEFINE now has an optional third argument for a description to be
1487 placed in the config header input file (e.g. config.h.in).
1488 * The C++ code fragment compiled for the C++ compiler test had to be
1489 improved to include an explicit return type for main(). This was
1490 causing failures on systems using recent versions of the EGCS C++
1492 * Fixed an important bug in AC_CHECK_TYPE that would cause a configure
1493 script to report that `sometype_t' was present when only `type_t'
1495 * Merge of the FSF version of config.guess and config.sub to modernize
1496 these scripts. Add support for a few new hosts in config.guess.
1497 Incorporate latest versions of install-sh, mkinstalldirs and
1498 texinfo.tex from the FSF.
1499 * autoreconf is capable of running automake if necessary (and
1501 * Support for Fortran 77. See the Texinfo documentation for details.
1502 * Bug fixes and workarounds for quirky bugs in vendor utilities.
1504 Major changes in Autoconf 2.12:
1506 Released 1996-11-26 by David J. MacKenzie
1508 * AC_OUTPUT and AC_CONFIG_HEADER can create output files by
1509 concatenating multiple input files separated by colons, like so:
1510 AC_CONFIG_HEADER(config.h:conf.pre:config.h.in:conf.post)
1511 AC_OUTPUT(Makefile:Makefile.in:Makefile.rules)
1512 The arguments may be shell variables, to compute the lists on the fly.
1513 * AC_LINK_FILES and AC_CONFIG_SUBDIRS may be called multiple times.
1514 * New macro AC_OUTPUT_COMMANDS adds more commands to run in config.status.
1517 Major changes in Autoconf 2.11:
1519 Released November 18th, 1996, by David J. MacKenzie
1521 * AC_PROG_CC and AC_PROG_CXX check whether the compiler works.
1522 They also default CFLAGS/CXXFLAGS to "-g -O2" for gcc, instead of "-g -O".
1523 * AC_REPLACE_FUNCS defines HAVE_foo if the system has the function `foo'.
1524 * AC_CONFIG_HEADER expands shell variables in its argument.
1525 * New macros: AC_FUNC_FNMATCH, AC_FUNC_SETPGRP.
1526 * The "checking..." messages and the source code for test programs that
1527 fail are saved in config.log.
1528 * Another workaround has been added for seds with small command length limits.
1529 * config.sub and config.guess recognize more system types.
1532 Major changes in Autoconf 2.10:
1534 Released May 7th, 1996, by Roland McGrath
1537 * The cache variable names used by `AC_CHECK_LIB(LIB, FUNC, ...)' has
1538 changed: now $ac_cv_lib_LIB_FUNC, previously $ac_cv_lib_LIB.
1540 Major changes in Autoconf 2.9:
1542 Released March 16th, 1996, by Roland McGrath
1546 Major changes in Autoconf 2.8:
1548 Released March 8th, 1996, by Roland McGrath
1552 Major changes in Autoconf 2.7:
1554 Released November 22nd, 1995, by David J. MacKenzie
1558 Major changes in Autoconf 2.6:
1560 Released November 20th, 1995, by David J. MacKenzie
1564 Major changes in Autoconf 2.5:
1566 Released November 17th, 1995, by Roland McGrath
1568 * New configure options --bindir, --libdir, --datadir, etc., with
1569 corresponding output variables.
1570 * New macro: AC_CACHE_CHECK, to make using the cache easier.
1571 * config.log contains the command being run as well as any output from it.
1572 * AC_CHECK_LIB can check for libraries with "." or "/" or "+" in their name.
1573 * AC_PROG_INSTALL doesn't cache a name for install-sh, for sharing caches.
1574 * AC_CHECK_PROG, AC_PATH_PROG, AC_CHECK_PROGS, AC_PATH_PROGS, and
1575 AC_CHECK_TOOL can search a path other than $PATH.
1576 * AC_CHECK_SIZEOF takes an optional size to use when cross-compiling.
1578 Major changes in Autoconf 2.4:
1580 Released June 14th, 1995, by David J. MacKenzie
1582 * Fix a few bugs found by Emacs testers.
1584 Major changes in Autoconf 2.3:
1586 Released March 27th, 1995, by David J. MacKenzie
1588 * Fix the cleanup trap in several ways.
1589 * Handle C compilers that are picky about option placement.
1590 * ifnames gets the version number from the right directory.
1592 Major changes in Autoconf 2.2:
1594 Released March 8th, 1995, by David J. MacKenzie
1596 * The ifnames utility is much faster but requires a "new awk" interpreter.
1597 * AC_CHECK_LIB and AC_HAVE_LIBRARY check and add the new
1598 library before existing libs, not after, in case it uses them.
1599 * New macros: AC_FUNC_GETPGRP, AC_CHECK_TOOL.
1600 * Lots of bug fixes.
1601 * Many additions to the TODO file :-)
1603 Major changes in Autoconf 2.1:
1605 Released November 4th, 1994, by David J. MacKenzie
1608 * More explanations in the manual.
1609 * Fix a spurious failure in the testsuite.
1610 * Clarify some warning messages.
1611 * autoreconf by default only rebuilds configure and config.h.in files
1612 that are older than any of their particular input files; there is a
1613 --force option to use after installing a new version of Autoconf.
1615 Thanks to everybody who's submitted changes and additions to Autoconf!
1616 I've incorporated many of them, and am still considering others for
1617 future releases -- but I didn't want to postpone this release indefinitely.
1619 Caution: don't indiscriminately rebuild configure scripts with
1620 Autoconf version 2. Some configure.in files need minor adjustments to
1621 work with it; the documentation has a chapter on upgrading. A few
1622 configure.in files, including those for GNU Emacs and the GNU C
1623 Library, need major changes because they relied on undocumented
1624 internals of version 1. Future releases of those packages will have
1625 updated configure.in files.
1627 It's best to use GNU M4 1.3 (or later) with Autoconf version 2.
1628 Autoconf now makes heavy use of M4 diversions, which were implemented
1629 inefficiently in GNU M4 releases before 1.3.
1631 Major changes in Autoconf 2.0:
1633 Released October 26th, 1994, by David J. MacKenzie
1635 ** New copyright terms:
1636 * There are no restrictions on distribution or use of configure scripts.
1639 * Autoconf manual is reorganized to make information easier to find
1640 and has several new indexes.
1641 * INSTALL is reorganized and clearer and is now made from Texinfo source.
1644 * autoscan to generate a preliminary configure.in for a package by
1645 scanning its source code for commonly used nonportable functions,
1646 programs, and header files.
1647 * ifnames to list the symbols used in #if and #ifdef directives in a
1649 * autoupdate to update a configure.in to use the version 2 macro names.
1650 * autoreconf to recursively remake configure and configuration header
1651 files in a source tree.
1653 ** Changed utilities:
1654 * autoheader can take pieces of acconfig.h to replace config.h.{top,bot}.
1655 * autoconf and autoheader can look for package-local definition files
1656 in an alternate directory.
1659 * AC_CACHE_VAL to share results of tests between configure runs.
1660 * AC_DEFUN to define macros, automatically AC_PROVIDE them, and ensure
1661 that macros invoked with AC_REQUIRE don't interrupt other macros.
1662 * AC_CONFIG_AUX_DIR, AC_CANONICAL_SYSTEM, AC_CANONICAL_HOST, AC_LINK_FILES to
1663 support deciding unguessable features based on the host and target types.
1664 * AC_CONFIG_SUBDIRS to recursively configure a source tree.
1665 * AC_ARG_PROGRAM to use the options --program-prefix,
1666 --program-suffix, and --program-transform-name to change the names
1667 of programs being installed.
1668 * AC_PREFIX_DEFAULT to change the default installation prefix.
1669 * AC_TRY_COMPILE to compile a test program without linking it.
1670 * AC_CHECK_TYPE to check whether sys/types.h or stdlib.h defines a given type.
1671 * AC_CHECK_LIB to check for a particular function and library.
1672 * AC_MSG_CHECKING and AC_MSG_RESULT to print test results, on a single line,
1673 whether or not the test succeeds. They obsolete AC_CHECKING and AC_VERBOSE.
1674 * AC_SUBST_FILE to insert one file into another.
1675 * AC_FUNC_MEMCMP to check whether memcmp is 8-bit clean.
1676 * AC_FUNC_STRFTIME to find strftime even if it's in -lintl.
1677 * AC_FUNC_GETMNTENT to find getmntent even if it's in -lsun or -lseq.
1678 * AC_HEADER_SYS_WAIT to check whether sys/wait.h is POSIX.1 compatible.
1681 * Many macros renamed systematically, but old names are accepted for
1682 backward compatibility.
1683 * AC_OUTPUT adds the "automatically generated" comment to
1684 non-Makefiles where it finds @configure_input@ in an input file, to
1685 support files with various comment syntaxes.
1686 * AC_OUTPUT does not replace "prefix" and "exec_prefix" in generated
1687 files when they are not enclosed in @ signs.
1688 * AC_OUTPUT allows the optional environment variable CONFIG_STATUS to
1689 override the file name "config.status".
1690 * AC_OUTPUT takes an optional argument for passing variables from
1691 configure to config.status.
1692 * AC_OUTPUT and AC_CONFIG_HEADER allow you to override the input-file names.
1693 * AC_OUTPUT automatically substitutes the values of CFLAGS, CXXFLAGS,
1694 CPPFLAGS, and LDFLAGS from the environment.
1695 * AC_PROG_CC and AC_PROG_CXX now set CFLAGS and CXXFLAGS, respectively.
1696 * AC_PROG_INSTALL looks for install-sh or install.sh in the directory
1697 specified by AC_CONFIG_AUXDIR, or srcdir or srcdir/.. or
1698 srcdir/../.. by default.
1699 * AC_DEFINE, AC_DEFINE_UNQUOTED, and AC_SUBST are more robust and smaller.
1700 * AC_DEFINE no longer prints anything, because of the new result reporting
1701 mechanism (AC_MSG_CHECKING and AC_MSG_RESULT).
1702 * AC_VERBOSE pays attention to --quiet/--silent, not --verbose.
1703 * AC_ARG_ENABLE and AC_ARG_WITH support whitespace in the arguments to
1704 --enable- and --with- options.
1705 * AC_CHECK_FUNCS and AC_CHECK_HEADERS take optional shell commands to
1706 execute on success or failure.
1707 * Checking for C functions in C++ works.
1710 * AC_REMOTE_TAPE and AC_RSH removed; too specific to tar and cpio, and
1711 better maintained with them.
1712 * AC_ARG_ARRAY removed because no one was likely using it.
1713 * AC_HAVE_POUNDBANG replaced with AC_SYS_INTERPRETER, which doesn't
1714 take arguments, for consistency with all of the other specific checks.
1717 * Comes with config.sub and config.guess, and uses them optionally.
1718 * Uses config.cache to cache test results. An alternate cache file
1719 can be selected with the --cache-file=FILE option.
1720 * Uses optional shell scripts $prefix/share/config.site and
1721 $prefix/etc/config.site to perform site or system specific initializations.
1722 * configure saves compiler output to ./config.log for debugging.
1723 * New files autoconf.m4 and autoheader.m4 load the other Autoconf macros.
1724 * acsite.m4 is the new name for the system-wide aclocal.m4.
1725 * Has a DejaGnu test suite.
1727 Major changes in Autoconf 1.11:
1729 * AC_PROG_INSTALL calls install.sh with the -c option.
1730 * AC_SET_MAKE cleans up after itself.
1731 * AC_OUTPUT sets prefix and exec_prefix if they weren't set already.
1732 * AC_OUTPUT prevents shells from looking in PATH for config.status.
1734 Plus a few other bug fixes.
1736 Major changes in Autoconf 1.10:
1738 * autoheader uses config.h.bot if present, analogous to config.h.top.
1739 * AC_PROG_INSTALL looks for install.sh in srcdir or srcdir/.. and
1741 * AC_PROG_CXX looks for cxx as a C++ compiler.
1743 Plus several bugs fixed.
1745 Major changes in Autoconf 1.9:
1747 * AC_YYTEXT_POINTER replaces AC_DECLARE_YYTEXT.
1748 * AC_SIZEOF_TYPE generates the cpp symbol name automatically,
1749 and autoheader generates entries for those names automatically.
1750 * AC_FIND_X gets the result from xmkmf correctly.
1751 * AC_FIND_X assumes no X if --without-x was given.
1752 * AC_FIND_XTRA adds libraries to the variable X_EXTRA_LIBS.
1753 * AC_PROG_INSTALL finds OSF/1 installbsd.
1755 Major changes in Autoconf 1.8:
1758 * New macros AC_LANG_C, AC_LANG_CPLUSPLUS, AC_LANG_SAVE, AC_LANG_RESTORE,
1759 AC_PROG_CXX, AC_PROG_CXXCPP, AC_REQUIRE_CPP
1760 for checking both C++ and C features in one configure script.
1761 * New macros AC_CHECKING, AC_VERBOSE, AC_WARN, AC_ERROR for printing messages.
1762 * New macros AC_FIND_XTRA, AC_MMAP, AC_SIZEOF_TYPE, AC_PREREQ,
1763 AC_SET_MAKE, AC_ENABLE.
1766 * AC_FIND_X looks for X in more places.
1767 * AC_PROG_INSTALL defaults to install.sh instead of cp, if it's in srcdir.
1768 install.sh is distributed with Autoconf.
1769 * AC_DECLARE_YYTEXT has been removed because it can't work, pending
1770 a rewrite of quoting in AC_DEFINE.
1771 * AC_OUTPUT adds its comments in C format when substituting in C files.
1772 * AC_COMPILE_CHECK protects its ECHO-TEXT argument with double quotes.
1774 ** New or changed command line options:
1775 * configure accepts --enable-FEATURE[=ARG] and --disable-FEATURE options.
1776 * configure accepts --without-PACKAGE, which sets withval=no.
1777 * configure accepts --x-includes=DIR and --x-libraries=DIR.
1778 * Giving --with-PACKAGE no argument sets withval=yes instead of withval=1.
1779 * configure accepts --help, --version, --silent/--quiet, --no-create options.
1780 * configure accepts and ignores most other Cygnus configure options, and
1781 warns about unknown options.
1782 * config.status accepts --help, --version options.
1784 ** File names and other changes:
1785 * Relative srcdir values are not made absolute.
1786 * The values of @prefix@ and @exec_prefix@ and @top_srcdir@ get substituted.
1787 * Autoconf library files are installed in ${datadir}/autoconf, not ${datadir}.
1788 * autoheader optionally copies config.h.top to the beginning of config.h.in.
1789 * The example Makefile dependencies for configure et al. work better.
1790 * Namespace cleanup: all shell variables used internally by Autoconf
1791 have names beginning with `ac_'.
1793 More big improvements are in process for future releases, but have not
1794 yet been (variously) finished, integrated, tested, or documented enough
1797 Major changes in Autoconf 1.7:
1799 * New macro AC_OBSOLETE.
1800 * Bugs in Makefile.in fixed.
1801 * AC_LONG_FILE_NAMES improved.
1803 Major changes in Autoconf 1.6:
1805 * New macro AC_LONG_64_BITS.
1806 * Multiple .h files can be created.
1807 * AC_FIND_X looks for X files directly if it doesn't find xmkmf.
1808 * AC_ALLOCA defines C_ALLOCA if using alloca.c.
1809 * --with-NAME can take a value, e.g., --with-targets=sun4,hp300bsd.
1810 * Unused --no-create option to configure removed.
1811 * autoheader doesn't change the timestamp of its output file if
1812 the file didn't change.
1813 * All macros that look for libraries now use AC_HAVE_LIBRARY.
1814 * config.status checks three optional environment variables to
1815 modify its behavior.
1816 * The usual bug fixes.
1818 Major changes in Autoconf 1.5:
1820 * New macros AC_FIND_X, AC_OFF_T, AC_STAT_MACROS_BROKEN, AC_REVISION.
1821 * autoconf and autoheader scripts have GNU standards conforming
1822 --version and --help options (they print their message and exit).
1825 Major changes in Autoconf 1.4:
1827 * New macros AC_HAVE_POUNDBANG, AC_TIME_WITH_SYS_TIME, AC_LONG_DOUBLE,
1828 AC_GETGROUPS_T, AC_DEFINE_UNQUOTED.
1829 * autoconf and autoheader use the M4 environment variable to determine the
1830 name of the M4 program to use.
1831 * The --macrodir option to autoconf and autoheader specifies the directory
1832 in which acspecific.m4, acgeneral.m4, etc. reside if not the default.
1833 * autoconf and autoheader can take `-' as their file names, which means to
1834 read stdin as input.
1835 * Resulting configure scripts can take a --verbose option which causes them
1836 to print the results of their tests.
1837 * AC_DEFINE quotes its second argument in such a way that spaces, magic
1838 shell characters, etc. will be preserved during various stages of
1839 expansion done by the shell. If you don't want this, use
1840 AC_DEFINE_UNQUOTED instead.
1841 * Much textual processing done with external calls to tr and sed have been
1842 internalized with builtin M4 `patsubst' and `translit' calls.
1843 * AC_OUTPUT doesn't hardwire the file names it outputs. Instead, you can
1844 set the shell variables `gen_files' and `gen_config' to the list of
1845 file names to output.
1846 * AC_DECLARE_YYTEXT does an AC_SUBST of `LEX_OUTPUT_ROOT', which may be
1847 "lex.yy" or "lexyy", depending on the system.
1848 * AC_PROGRAMS_CHECK takes an optional third arg. If given, it is used as
1850 * If AC_ALLOCA chooses alloca.c, it also defines STACK_DIRECTION.
1851 * AC_CONST works much more reliably on more systems.
1854 Major changes in Autoconf 1.3:
1856 configure no longer requires awk for packages that use a config.h.
1857 Support handling --with-PACKAGE options.
1858 New `autoheader' script to create `config.h.in' from `configure.in'.
1859 Ignore troublesome -lucb and -lPW when searching for alloca.
1860 Rename --exec_prefix to --exec-prefix for GNU standards conformance.
1861 Improve detection of STDC library.
1862 Add AC_HAVE_LIBRARY to check for non-default libraries.
1863 Function checking should work with future GNU libc releases.
1865 Major changes in Autoconf 1.2:
1867 The --srcdir option is now usually unnecessary.
1868 Add a file containing sample comments describing CPP macros.
1869 A comment in config.status tells which host it was configured on.
1870 Substituted variable values can now contain commas.
1871 Fix bugs in various feature checks.
1873 Major changes in Autoconf 1.1:
1875 Added AC_STRCOLL macro.
1876 Made AC_GETLOADAVG check for more things.
1877 AC_OUTPUT argument is now optional.
1882 Copyright (C) 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001, 2002,
1883 2003, 2004, 2005, 2006, 2007, 2008, 2009 Free Software Foundation,
1886 Copying and distribution of this file, with or without modification,
1887 are permitted in any medium without royalty provided the copyright
1888 notice and this notice are preserved. This file is offered as-is,
1889 without warranty of any kind.