1 GNU Autoconf NEWS - User visible changes.
3 * Noteworthy changes in release ?.? (????-??-??) [?]
5 ** AT_BANNER() with empty argument will cause visual separation from previous
8 ** AC_INIT again allows URLs with '?' for its BUG-REPORT argument.
9 Regression introduced in 2.66.
11 ** The macros AC_PREPROC_IFELSE, AC_COMPILE_IFELSE, AC_LINK_IFELSE, and
12 AC_RUN_IFELSE now warn if the first argument failed to use
13 AC_LANG_SOURCE or AC_LANG_PROGRAM to generate the conftest file
14 contents. A new macro AC_LANG_DEFINES_PROVIDED exists if you have
15 a compelling reason why you cannot use AC_LANG_SOURCE but must
19 * Major changes in Autoconf 2.67 (2010-07-21) [stable]
20 Released by Eric Blake, based on git versions 2.66.*.
22 ** AC_CONFIG_SUBDIRS with more than one subdirectory at a time works again.
23 Regression introduced in 2.66.
25 ** AC_CHECK_SIZEOF of a pointer type works again. Regression introduced in
28 ** New macro AC_FC_LINE_LENGTH to accept long Fortran source code lines.
30 ** AC_PREPROC_IFELSE now keeps the preprocessed output in the conftest.i
31 file for inspection by the commands in the ACTION-IF-TRUE argument.
33 ** AC_INIT again allows parentheses and other characters that are literal
34 in single- or double-quoted strings, and in quoted and unquoted
35 here-documents, for its PACKAGE and VERSION arguments. Regression
38 ** autoreconf passes warning flags to new enough versions of aclocal.
40 ** Running an Autotest testsuite in parallel mode no longer triggers a
41 race condition that could cause the testsuite run to end early,
42 fixing a sporadic failure in autoconf's own testsuite. Bug present
43 since introduction of parallel tests in 2.63b.
46 * Major changes in Autoconf 2.66 (2010-07-02) [stable]
47 Released by Eric Blake, based on git versions 2.65.*.
49 ** AC_FUNC_MMAP works in C++ mode again. Regression introduced in 2.65.
51 ** Use of m4_divert without a named diversion now issues a syntax warning,
52 since it is seldom right to change diversions behind autoconf's back.
54 ** The macros AC_TYPE_INT8_T, AC_TYPE_INT16_T, AC_TYPE_INT32_T, and
55 AC_TYPE_INT64_T work again. Regression introduced in 2.65.
57 ** AC_PROG_INSTALL correctly uses `shtool' again. Regression introduced
60 ** Autoconf should work on EBCDIC hosts.
62 ** AC_CHECK_DECL and AC_CHECK_DECLS accept optional function argument types
63 for overloaded C++ functions.
65 ** AS_SET_CATFILE accepts nonliterals in its variable name argument now.
67 ** Autotest testsuites accept an option --recheck to rerun tests that
68 failed or passed unexpectedly during the last non-debug testsuite run.
70 ** AC_ARG_ENABLE and AC_ARG_WITH now also accept `+' signs in `--enable-*'
71 and `--with-*' arguments, converting them to underscores for the variable
74 ** In configure scripts, loading CONFIG_SITE no longer searches PATH,
75 and problems in loading the configuration site files are diagnosed.
77 ** Autotest testsuites may optionally provide colored test results.
79 ** The previously undocumented Autotest macros AT_ARG_OPTION and
80 AT_ARG_OPTION_ARG have seen bug fixes and are documented now.
81 AT_ARG_OPTION has been changed in that the negative of a long option
82 --OPTION is now --no-OPTION rather than --noOPTION.
84 ** The macro AS_LITERAL_IF is slightly more conservative; text
85 containing shell quotes are no longer treated as literals.
86 Furthermore, a new macro, AS_LITERAL_WORD_IF, adds an additional
87 level of checking that no whitespace occurs in literals.
89 ** The macros AS_TR_SH and AS_TR_CPP no longer expand their results.
91 ** The following macros are now documented:
94 ** New macro AC_FC_FIXEDFORM to accept fixed-form Fortran.
97 * Major changes in Autoconf 2.65 (2009-11-21) [stable]
98 Released by Eric Blake, based on git versions 2.64.*.
100 ** Autoconf is now licensed under the General Public License version 3
101 or later (GPLv3+). As with earlier versions, the license includes
102 an exception clause so that you may release a configure script
103 generated by autoconf under the license of your own program.
105 ** New macros to support Objective C++.
106 AC_PROG_OBJCXX AC_PROG_OBJCXXCPP
108 ** The following undocumented autoconf macros, removed in Autoconf 2.64,
109 have been reinstated:
112 These macros are present only for backwards compatibility purposes.
114 ** The macro AC_LANG_COMPILER no longer fails on embedded systems that
115 lack fopen in the C library, such as AVR or RTEMS (regression
118 ** The AC_FC_FREEFORM macro no longer suffers from a whitespace bug that
119 made it fail with some Fortran compilers (regression introduced in
122 ** The AC_TYPE_UINT64_T and AC_TYPE_INT64_T macros have been fixed to no
123 longer mistakenly select a 32-bit type on some compilers (bug present
124 since macros were introduced in 2.59c).
126 ** The AC_FUNC_MMAP macro has been fixed to be portable to systems like
127 Cygwin (bug present since macro was introduced in 2.0).
129 ** The following documented autotest macros are new:
132 ** The following m4sugar macros now quote their expansion:
133 m4_toupper m4_tolower
135 ** The following m4sugar macros are new:
138 ** The m4sugar macro m4_text_wrap now copes with embedded quoting without
139 requiring quadrigraphs. For uses like AC_ARG_VAR([a], [[b c]]),
140 this gives the intuitive behavior of "[b c]" in the output (2.63
141 gave the output of "[b], [c]", and 2.64 encountered a failure).
143 ** The `$tmp' temporary directory used in config.status is documented for
146 ** config.status now provides a --config option to produce the configuration.
148 ** Many cache variables used by Autoconf's macros are now documented.
150 ** Configure scripts work better on DJGPP by avoiding a bug present in
151 the DJGPP port of bash 2.04 in handling 'return' in a shell
152 function (regression introduced in 2.64).
154 * Major changes in Autoconf 2.64 (2009-07-26) [stable]
155 Released by Eric Blake, based on git versions 2.63b.*.
157 ** Autoconf now requires GNU M4 1.4.6 or later. Earlier versions of M4
158 have a bug in regular expression handling that interferes with some
159 of the speedups provided since Autoconf 2.63. GNU M4 1.4.13 or
160 later is recommended.
162 ** AS_IF and AS_CASE have been taught to avoid syntax errors even when
163 given arguments that expand to just whitespace.
165 ** The following documented autoconf macros are new:
166 AC_ERLANG_SUBST_ERTS_VER
168 ** The autoheader tool now understands m4 macro arguments passed to
169 AC_DEFINE and AC_DEFINE_UNQUOTED.
171 ** Ensure AT_CHECK can support commands that include a # given with
172 proper m4 quoting. For shell comments, this is a new feature; for
173 non-shell comments, this fixes a regression introduced in 2.63b.
174 Additionally, AT_CHECK correctly supplies shell escapes for
175 metacharacters occurring in m4 macro expansions within the expected
176 stdout and stderr parameters.
178 ** The macro AT_CHECK now understands the concept of hard failure. If
179 a test exits with an unexpected status 99, cleanup actions for the
180 test are inhibited and the test is treated as a failure regardless
181 of AT_XFAIL_IF. It also understands the new directives
182 ignore-nolog, stdout-nolog, and stderr-nolog.
184 ** The following documented autotest macros are new:
185 AT_CHECK_UNQUOTED AT_FAIL_IF AT_SKIP_IF
187 ** The following documented m4sugar macros are new:
188 m4_argn m4_copy_force m4_default_nblank m4_default_nblank_quoted
189 m4_ifblank m4_ifnblank m4_rename_force
191 ** The autoconf testsuite now exercises all Erlang macros.
193 * Major changes in Autoconf 2.63b (2009-03-31) [beta]
194 Released by Eric Blake, based on git versions 2.63.*.
196 ** The manual is now shipped under the terms of the GNU FDL 1.3.
198 ** AC_REQUIRE now detects the case of an outer macro which first expands
199 then later indirectly requires the same inner macro. Previously,
200 this case led to silent out-of-order expansion (bug present since
201 2.50); it now issues a syntax warning, and duplicates the expansion
202 of the inner macro to guarantee dependencies have been met. See
203 the manual for advice on how to refactor macros in order to avoid
204 the bug in earlier autoconf versions and avoid increased script
205 size in the current version.
207 ** AC_DEFUN_ONCE has improved semantics. Previously, a macro declared
208 with AC_DEFUN_ONCE warned on a second invocation; and out-of-order
209 expansion was still possible. Now, dependencies are guaranteed,
210 and subsequent invocations are a silent no-op. This makes
211 AC_DEFUN_ONCE an ideal macro for silencing AC_REQUIRE warnings.
213 ** The following macros are now defined with AC_DEFUN_ONCE. This means
214 a subtle change in semantics; previously, an AC_DEFUN macro could
215 expand one of these macros multiple times or surround the macro
216 inside shell conditional text to bypass the effects of these
217 macros, but now the macro will expand exactly once, and prior to
218 the start of any enclosing AC_DEFUN macro:
219 AC_CANONICAL_BUILD AC_CANONICAL_HOST AC_CANONICAL_TARGET
220 AC_HEADER_ASSERT AC_PROG_INSTALL AC_PROG_MKDIR_P
221 AC_USE_SYSTEM_EXTENSIONS
223 ** AC_LANG_ERLANG works once again (regression introduced in 2.61a).
225 ** AC_HEADER_ASSERT is fixed so that './configure --enable-assert' no
226 longer mistakenly disables assertions.
228 ** AC_INIT now takes an optional fifth parameter that can be used to
229 set AC_PACKAGE_URL, a URL for the package's home page; the URL is
230 used in `configure --help' and is also available via AC_DEFINE.
232 ** Autotest testsuites accept an option --jobs[=N] for parallel testing.
233 This feature is still in testing, and may not work on every
234 platform, help in improving it would be appreciated.
236 ** Autotest testsuites do not attempt to write startup error messages
237 to the log file before that is opened (regression introduced in 2.63).
239 ** Configure scripts now use shell functions. This feature leads to
240 smaller configure files and faster execution.
242 ** Present But Cannot Be Compiled: Autoconf will now proceed with
243 the compiler's result if a header is present but cannot be compiled.
244 The warning is still printed, and you should really fix it by
245 providing a fourth parameter to AC_CHECK_HEADER/AC_CHECK_HEADERS.
247 ** Autoreconf added aclocal to the set of programs affected by the
248 `autoreconf -I dir' option.
250 ** The following documented m4sugar macros are new:
251 m4_chomp m4_chomp_all m4_cleardivert m4_curry m4_default_quoted
252 m4_esyscmd_s m4_map_args m4_map_args_pair m4_map_args_sep
253 m4_map_args_w m4_set_map m4_set_map_sep m4_stack_foreach
254 m4_stack_foreach_lifo m4_stack_foreach_sep
255 m4_stack_foreach_sep_lifo
257 ** The following m4sugar macros are documented now, but in some cases
258 with slightly different semantics than what the previous
259 undocumented version had:
260 m4_copy m4_dumpdefs m4_rename m4_version_prereq
262 ** The m4sugar macro m4_expand has been taught to handle unterminated
263 comments and shell case statements. As a result, it is used
264 internally in more places, such as AC_DEFINE and AT_CHECK. Most
265 uses of AC_DEFINE and AT_CHECK should not behave any differently;
266 however, it may be necessary to add double-quoting around
267 unbalanced `(' where single-quoting used to be sufficient.
269 ** The following documented m4sh macros are new:
270 AS_INIT_GENERATED AS_LINENO_PREPARE AS_ME_PREPARE AS_SET_STATUS
271 AS_VAR_APPEND AS_VAR_ARITH AS_VAR_COPY
273 ** The following m4sh macros are documented now, but in some cases
274 with slightly different semantics than what the previous
275 undocumented version had:
276 AS_ECHO AS_ECHO_N AS_ESCAPE AS_EXIT AS_LITERAL_IF AS_UNSET
277 AS_VAR_IF AS_VAR_POPDEF AS_VAR_PUSHDEF AS_VAR_SET AS_VAR_SET_IF
278 AS_VAR_TEST_SET AS_VERSION_COMPARE
280 ** The m4sh macros AS_IF and AS_CASE can now be used in shell lists.
281 The responsibility for supplying a trailing newline now belongs to
282 the call site, but since most users did not add dnl, this generally
283 results in fewer empty lines in configure.
286 * Major changes in Autoconf 2.63 (2008-09-09) [stable]
287 Released by Eric Blake, based on git versions 2.62.*.
289 ** AC_C_BIGENDIAN does not mistakenly report "universal" for some
290 bigendian hosts, a regression introduced with universal binary
293 ** AC_PATH_X now includes /lib64 and /usr/lib64 in its list of default
296 ** AC_USE_SYSTEM_EXTENSIONS no longer conflicts with an external
297 AC_DEFINE([__EXTENSIONS__]). This fixes a regression introduced in
298 2.62 when using macros such as AC_AIX that were made obsolete in
299 favor of the more portable AC_USE_SYSTEM_EXTENSIONS.
301 ** AC_CHECK_TARGET_TOOLS is usable in the non-cross-compile case.
303 ** Newly obsolete macros
304 The following macro has been marked obsolete, since current porting
305 targets can safely assume C89 semantics that signal handlers return
306 void. We have no current plans to remove the macro.
310 ** The macros m4_map and m4_map_sep now ignore any list elements
311 consisting of just empty quotes, and m4_map_sep now expands its
312 separator. This fixes a regression in 2.62 when these macros were
313 first documented, for the sake of clients expecting the semantics
314 that these macros had prior to that time. The new macros m4_mapall
315 and m4_mapall_sep, along with extra quoting of the separator, can
316 be used to get the semantics that m4_map_sep had in 2.62.
318 ** Clients of m4_expand, such as AS_HELP_STRING and AT_SETUP, can now
319 handle properly quoted but otherwise unbalanced parentheses (for
320 some macros, this fixes a regression in 2.62).
322 ** Two new quadrigraphs have been introduced: @{:@ for (, and @:}@ for ),
323 allowing the output of unbalanced parentheses in more contexts.
325 ** The following m4sugar macros are new:
326 m4_cleardivert m4_joinall m4_mapall m4_mapall_sep m4_reverse
327 m4_set_add m4_set_add_all m4_set_contains m4_set_contents
328 m4_set_delete m4_set_difference m4_set_dump m4_set_empty
329 m4_set_foreach m4_set_intersection m4_set_list m4_set_listc
330 m4_set_remove m4_set_size m4_set_union
332 ** The following m4sugar macros now accept multiple arguments, as is the
333 case with underlying m4:
334 m4_defn m4_popdef m4_undefine
336 ** The following m4sugar macros now guarantee linear scaling; they
337 previously had linear scaling with m4 1.6 but quadratic scaling
338 when using m4 1.4.x. All macros built on top of these also gain
339 the scaling improvements.
340 m4_bmatch m4_bpatsubsts m4_case m4_cond m4_do m4_dquote_elt
341 m4_foreach m4_join m4_list_cmp m4_map m4_map_sep m4_max
344 ** AT_KEYWORDS once again performs expansion on its argument, such that
345 AT_KEYWORDS([m4_if([$1], [], [default])]) no longer complains about
346 the possibly unexpanded m4_if [regression introduced in 2.62].
348 ** Config header templates `#undef UNDEFINED /* comment */' do not lead to
349 nested comments any more; regression introduced in 2.62.
352 * Major changes in Autoconf 2.62 (2008-04-05) [stable]
353 Released by Eric Blake, based on git versions 2.61a.*.
355 ** Many optimizations have been applied to make overall execution faster.
357 ** Autotest now makes use of shell functions.
359 ** config.status now uses awk instead of sed also for config headers.
361 - As a side effect, AC_DEFINE and AC_DEFINE_UNQUOTED now handle multi-line
362 values, i.e., backslash-newline combinations are handled correctly.
363 Further, for config headers, the total size of values is not limited by
364 the POSIX length limit of text lines any more, only each single line.
366 ** New config variable `top_build_prefix'.
368 ** New Autoconf macros:
369 AC_AUTOCONF_VERSION AC_OPENMP AC_PATH_PROGS_FEATURE_CHECK
371 ** AC_C_BIGENDIAN now supports universal binaries a la Mac OS X.
373 ** AC_C_RESTRICT now prefers to #define 'restrict' to a variant spelling
374 like '__restrict' if the variant spelling is available, as this is
375 more likely to work when mixing C and C++ code.
377 ** AC_CHECK_ALIGNOF's type argument T is now documented better: it must
378 be a string of tokens such that "T y;" is a valid member declaration
381 ** AC_CHECK_SIZEOF now accepts objects as well as types: the general rule
382 is that sizeof (X) works, then AC_CHECK_SIZEOF (X) should work.
384 ** AC_CHECK_TYPE and AC_CHECK_TYPES now work on any C type-name; formerly,
385 they did not work for function types. In C++, they now work on any
386 type-id that can be the operand of sizeof; this is similar to C,
387 except it excludes anonymous struct and union types. Formerly,
388 some (but not all) C++ types involving anonymous struct and union
389 were accepted, though this was not documented.
391 ** AC_CONFIG_LINKS now prefers to link against files in the build tree
392 if found, and it works to link against a file of the same name in
393 the source tree, even if both trees coincide.
395 ** AC_INIT no longer alters $@; regression introduced in 2.60.
397 ** AC_USE_SYSTEM_EXTENSIONS now defines _ALL_SOURCE for Interix platforms.
399 ** AS_HELP_STRING no longer underquotes its first argument; it also handles
400 the case where the first argument contains single-quoted commas.
401 For example, "AS_HELP_STRING([-a, [--arg[=foo]]], [bar])" produces:
402 " -a, --arg[=foo] bar"
403 Additionally, the macro now takes two additional arguments,
404 indent-column and wrap-column; these should not normally be needed,
405 but can be used to fine-tune how the output text is wrapped.
407 ** AC_PROG_INSTALL now requires an install program that can install multiple
408 files into a target directory.
410 ** The command 'autoconf -' now correctly processes a file from stdin.
412 ** 'autoreconf -m' now honors $MAKE.
414 ** For all of the directory arguments for 'configure', such as '--prefix'
415 or '--bindir', trailing slashes are stripped. As an example, if
416 tab completion in the user's shell appends trailing slashes, the
417 command './configure --prefix=/usr/' will still result in an
418 expanded libdir value of /usr/lib, not /usr//lib.
420 ** `configure --help=recursive' now works in read-only trees and from
421 unconfigured build trees.
423 ** If precious variables differ only in whitespace, then the cache consistency
424 check warns instead of fails, and reuses the old value.
426 ** AT_BANNER is now documented.
428 ** AT_SETUP now handles macro expansions properly when calculating line
431 ** Autotest now determines $srcdir correctly.
433 ** Testsuites built by autotest now accept a -C/--directory=DIR option
434 to adjust the working directory prior to creating files.
436 ** Autoconf now requires GNU M4 1.4.5 or later. Earlier versions of M4 have
437 a bug in macro tracing that interferes with the interaction between
438 Autoconf and Automake. GNU M4 1.4.11 or later is recommended. The
439 configure search for a working M4 is improved.
441 ** For portability with the eventual M4 2.0, macros should no longer use
442 anything larger than $9 to refer to arguments.
444 ** Documentation for m4sugar is improved.
446 - The following macros were previously available as undocumented
447 interfaces; the macros are now documented as stable interfaces.
449 __oline__ m4_assert m4_bmatch m4_bpatsubsts m4_car m4_case
450 m4_cdr m4_default m4_divert_once m4_divert_pop m4_divert_push
451 m4_divert_text m4_do m4_errprintn m4_fatal m4_flatten
452 m4_ifndef m4_ifset m4_ifval m4_ifvaln m4_location
453 m4_n m4_shiftn m4_strip m4_warn
455 - The following macros were previously available as undocumented
456 interfaces, but had bug fixes or semantic changes as part of this
457 release. Packages that relied on the undocumented behavior
458 should be analyzed to make sure they will still work with the
459 new documented behavior.
461 m4_cmp m4_list_cmp m4_join m4_map m4_map_sep m4_sign
462 m4_text_box m4_text_wrap m4_version_compare
464 - The m4_wrap macro used to have unspecified order, but now
465 guarantees FIFO order. m4_wrap_lifo was added to guarantee LIFO
468 - Packages using the undocumented m4sugar macro m4_PACKAGE_VERSION
469 should consider using the new AC_AUTOCONF_VERSION instead.
471 - m4sugar macros that are not documented in the manual are still
472 deemed experimental, and should not be used outside of Autoconf.
474 ** The m4sugar macros m4_append and m4_append_uniq, first documented in
475 2.60, have been fixed to treat both the string and the separator
476 arguments consistently with regards to quoting. Prior to this fix,
477 m4_append_uniq could mistakenly duplicate entries if the expansion
478 of the separator resulted in a different string (for example, if it
479 contained quotes, a comma, or a macro name). However, it means
480 that programs previously using
481 m4_append([name], [string], [[, ]])
482 are now using a four-character separator instead of the intended
483 comma and space. If you need portability to earlier versions of
484 Autoconf, you can insert the following snippet after AC_INIT but
485 before any other macro expansions, to enforce the new semantics:
486 m4_pushdef([m4_append], [m4_define([$1],
487 m4_ifdef([$1], [m4_defn([$1])[$3]])[$2])])
488 Additionally, m4_append_uniq now takes optional parameters that can
489 be used to take action depending on whether anything was appended,
490 and warns if a non-empty separator occurs within the string being
491 appended, since that can lead to duplicates.
493 ** The following m4sugar macros are new:
494 m4_append_uniq_w m4_apply m4_combine m4_cond m4_count
495 m4_dquote_elt m4_echo m4_expand m4_ignore m4_make_list m4_max
496 m4_min m4_newline m4_shift2 m4_shift3 m4_unquote m4_wrap_lifo
498 ** Warnings are now generated by default when an installer invokes
499 'configure' with an unknown --enable-* or --with-* option.
500 These warnings can be disabled with the new AC_DISABLE_OPTION_CHECKING
501 macro, or by invoking 'configure' with --disable-option-checking.
503 ** Existing obsolete macros
504 The documentation for the following macros is adjusted to make it
505 more clear that they have previously been marked obsolete, as their
506 functionality can be accomplished by other macros. We have no
507 current plans to remove them from Autoconf.
509 AC_ENABLE AC_STRUCT_ST_BLKSIZE AC_STRUCT_ST_RDEV AC_WITH
511 ** Newly obsolete macros
512 The following macros have been marked obsolete, as they only
513 perform a subset of AC_USE_SYSTEM_EXTENSIONS. We have no current
514 plans to remove them.
516 AC_AIX AC_GNU_SOURCE AC_ISC_POSIX AC_MINIX
518 ** AC_C_LONG_DOUBLE is obsolescent.
519 The documentation now says that AC_C_LONG_DOUBLE is obsolescent: it
520 tests for problems that are so old that it is no longer of
521 practical importance on current systems. New programs need not use
522 AC_C_LONG_DOUBLE. We have no current plans to remove it.
524 ** AC_DIAGNOSE, AC_WARNING, and AC_FATAL are obsolescent.
525 The documentation now favors the use of M4sugar macros m4_warn and
526 m4_fatal, since the naming makes it more obvious that the
527 diagnostics are associated with M4 expansion (ie. when running
528 `autoconf'), and offers less confusion with the AC_MSG_ERROR,
529 AC_MSG_FAILURE, and AC_MSG_WARN macros which manage diagnostics
530 when running `configure'. We have no current plans to remove these
534 * Major changes in Autoconf 2.61a (2006-12-11)
536 ** AC_FUNC_FSEEKO was broken in 2.61; it didn't make fseeko and ftello visible
537 on many platforms. This has been fixed.
539 ** AC_FUNC_SETVBUF_REVERSED is now obsolete. It is still defined for backward
540 compatibility but it does nothing. The macro was already
541 obsolescent, as the last systems to have the problem were those
542 based on SVR2, which became obsolete in 1987. The macro had bugs
543 on some modern systems and could no longer be maintained reliably
544 due to lack of ancient systems to test it on.
546 ** config.status now uses awk instead of sed for most substitutions, for speed.
548 - As a side effect multi-line values of substituted variables no
549 longer have a small limit in total size, though for portability
550 each line should not exceed the POSIX length limit for text lines.
552 - It is now documented that Makefile.in should not contain
553 overlapping variable occurrences, e.g., @VAR1@VAR2@.
554 Autoconf's behavior was always iffy in such cases, and the
555 awk implementation has changed the behavior.
557 ** Many uses of 'echo' have been rewritten so that Autoconf-generated
558 scripts have fewer problems with strings or file names containing
559 embedded special characters such as backslash or leading "-". This
560 was implemented by using `printf '%s\n' "$foo"' instead of `echo
561 "$foo"' when printf works. Due to the implementation technique
562 used, Autoconf-generated scripts now run considerably more slowly
563 on ancient implementations lacking printf. However, this should
564 not be a problem, since Autoconf-generated scripts in practice
565 invariably find a more-modern shell these days.
568 * Major changes in Autoconf 2.61 (2006-11-17)
570 ** New macros AC_C_FLEXIBLE_ARRAY_MEMBER, AC_C_VARARRAYS.
572 ** AC_ARG_ENABLE and AC_ARG_WITH now allow '.' in feature and package names.
575 * Major changes in Autoconf 2.60b (2006-10-22)
578 Autoconf-generated shell scripts no longer export BIN_SH, due to
579 configuration hassles with this. Installers who need BIN_SH in
580 their environment should set it before invoking 'configure' and
581 'make'. As far as we know, this affects only Unixware installations.
583 ** Obsolescent macros
584 The documentation now says that the following macros are obsolescent,
585 as they are superseded by Gnulib:
587 AC_FUNC_FNMATCH AC_FUNC_FNMATCH_GNU AC_FUNC_GETLOADVG AC_REPLACE_FNMATCH
589 New programs should use the Gnulib counterparts of these macros.
590 We have no current plans to remove them from Autoconf.
592 ** AC_COMPUTE_INT no longer caches or reports results.
594 ** AC_CHECK_DECL now also works with aggregate objects.
596 ** AC_USE_SYSTEM_EXTENSIONS now defines _TANDEM_SOURCE for NonStop platforms.
598 ** GNU M4 1.4.7 or later is now recommended.
601 New M4sugar macro, which is more secure than the POSIX M4 maketemp.
604 Now an alias for m4_mkstemp.
606 * Major changes in Autoconf 2.60a (2006-08-25)
608 ** GNU M4 1.4.6 or later is now recommended.
610 ** The check for C99 now tests for varargs macros, as documented.
611 It also tests that the preprocessor supports 64-bit integers.
613 ** Autoconf now uses constructs like "#ifdef HAVE_STDLIB_H" rather than
614 "#if HAVE_STDLIB_H", so that it now works with "gcc -Wundef -Werror".
616 ** The functionality of the undocumented _AC_COMPUTE_INT is now provided
617 by a public and documented macro, AC_COMPUTE_INT. The parameters to the
618 two macros are different, so autoupdate will not change the old private name
619 to the new one. _AC_COMPUTE_INT may be removed in a future release.
621 ** AC_TYPE_LONG_LONG_INT and AC_TYPE_UNSIGNED_LONG_LONG_INT now require
622 that long long types be at least 64 bits wide, as C99 and tradition
623 requires. Formerly, they accepted implementations of any width.
626 * Major changes in Autoconf 2.60
628 Released 2006-06-23, by Ralf Wildenhues.
630 ** Autoconf no longer depends on whether m4wrap is FIFO (as Posix requires)
631 or LIFO (as in GNU M4 1.4.x). GNU M4 2.0 is expected to conform to Posix
632 here, so m4wrap/m4_wrap users should no longer depend on LIFO behavior.
634 ** Provide a way to turn off warnings about the changed directory variables.
636 * Major changes in Autoconf 2.59d
638 Released 2006-06-05, by Ralf Wildenhues.
640 ** GNU make now recommended for VPATH builds
641 INSTALL now suggests VPATH builds (e.g., "sh ../srcdir/configure")
642 only if you use GNU make. In practice, other 'make' implementations
643 have too many subtle incompatibilities in their support for VPATH.
644 Many packages (including Autoconf itself) are portable to other
645 'make' implementations, but some packages are not, and recommending
646 GNU make keeps the installation instructions simpler.
648 ** Even more safety checks for the new Directory variables:
649 Warn about suspicious `${datarootdir}' found in config files output.
651 ** AC_TRY_COMMAND, AC_TRY_EVAL, ac_config_guess, ac_config_sub, ac_configure
652 These never-documented macros and variables have been marked with
653 comments saying that they may be removed in a future release,
654 because their use can lead to unintended code being executed.
655 If you need functionality that only these macros or variables
656 currently supply, please write bug-autoconf@gnu.org.
658 ** AC_SUBST, AC_DEFINE
659 Literal arguments to these are passed to m4_pattern_allow now.
662 Passing 'ac_cv_prog_cc_stdc=no' to 'configure' now sets ac_cv_prog_cc_c99
663 and ac_cv_prog_cc_c89 to 'no' as well, for backward compatibility with
664 obsolete K&R tests in the Automake test suite.
673 Now more robust with special characters in file names, or when
674 multiple processes create the same directory at the same time.
676 ** Obsolescent macros
677 The documentation now says that the following macros are obsolescent:
678 they test for problems that are so old that they are no longer of
679 practical importance on current systems.
681 AC_C_BACKSLASH_A AC_FUNC_MEMCMP AC_HEADER_DIRENT
682 AC_C_CONST AC_FUNC_SELECT_ARGTYPES AC_HEADER_STAT
683 AC_C_PROTOTYPES AC_FUNC_SETPGRP AC_HEADER_STDC
684 AC_C_STRINGIZE AC_FUNC_SETVBUF_REVERSED AC_HEADER_SYS_WAIT
685 AC_C_VOLATILE AC_FUNC_STAT AC_HEADER_TIME
686 AC_FUNC_CLOSEDIR_VOID AC_FUNC_STRFTIME AC_ISC_POSIX
687 AC_FUNC_GETPGRP AC_FUNC_UTIME_NULL AC_PROG_GCC_TRADITIONAL
688 AC_FUNC_LSTAT AC_FUNC_VPRINTF AC_STRUCT_TM
690 New programs need not use these macros. We have no current plans to
694 For compatibility with future Libtool 2.0, autoreconf will invoke
695 libtoolize with the option `--ltdl' now, if LT_CONFIG_LTDL_DIR is
698 * Major changes in Autoconf 2.59c
700 Released 2006-04-12, by Ralf Wildenhues.
702 ** The configure command now redirects standard input from /dev/null,
703 to help avoid problems with subsidiary commands that might mistakenly
704 read standard input. AS_ORIGINAL_STDIN_FD points to the original
705 standard input before this redirection, if you really want configure to
706 read from standard input.
708 ** Directory variables adjusted to recent changes in the GNU Coding Standards.
709 The following directory variables are new:
711 datarootdir read-only architecture-independent data root [PREFIX/share]
712 localedir locale-specific message catalogs [DATAROOTDIR/locale]
713 docdir documentation root [DATAROOTDIR/doc/PACKAGE]
714 htmldir html documentation [DOCDIR]
715 dvidir dvi documentation [DOCDIR]
716 pdfdir pdf documentation [DOCDIR]
717 psdir ps documentation [DOCDIR]
719 The following variables have new default values:
721 datadir read-only architecture-independent data [DATAROOTDIR]
722 infodir info documentation [DATAROOTDIR/info]
723 mandir man documentation [DATAROOTDIR/man]
725 This means that if you use any of `@datadir@', `@infodir@', or
726 `@mandir@' in a file, you will have to ensure `${datarootdir}' is
727 defined in this file. As a temporary measure, if any of those are
728 found but no mention of `datarootdir', the substitutions will be
729 replaced with values that do not contain `${datarootdir}', and a
730 warning will be issued.
732 ** @top_builddir@ is now a dir name: it is always nonempty and doesn't have
733 a trailing slash. Similar change will be made to ac_top_builddir in a
734 future release; the old style value, which matches (../)*, is (and will
735 continue to be) available as ac_top_build_prefix.
738 New macro to check for support of 'typeof' syntax a la GNU C.
740 ** AC_CHECK_DECLS_ONCE, AC_CHECK_FUNCS_ONCE, AC_CHECK_HEADERS_ONCE
741 New "once-only" variants of commonly-used macros, to make 'configure'
742 smaller and faster in common cases.
745 New macro to check for strtold with C99 semantics.
748 New macro that lets builder disable assertions at 'configure'-time.
751 Now checks for X11/Xlib.h and XrmInitialize (X proper) rather than
752 X11/Intrinsic.h and XtMalloc (Xt).
754 ** AC_PRESERVE_HELP_ORDER
755 New macro that causes `configure' to display help strings for AC_ARG_ENABLE
756 and AC_ARG_WITH arguments in one region, in the order defined. The default
757 behavior is to group options of each classes separately.
759 ** AC_PROG_CC, AC_PROG_CXX
760 No longer automatically arrange to declare the 'exit' function of C,
761 when a C++ compiler is used. Standard Autoconf macros no longer use
762 'exit', so this is no longer an issue for them. If you use C++, and
763 want to call 'exit', you'll have to arrange for its declaration
764 yourself. But we now suggest you return from 'main' instead.
766 ** AC_PROG_CC_C89, AC_PROG_CC_C99
767 New macros for ISO C99 support. AC_PROG_CC_C89 and AC_PROG_CC_C99
768 check for ANSI C89 and ISO C99 support respectively.
771 Has been unobsoleted, and will check if the compiler supports ISO
772 C99, falling back to ANSI C89 if not. ac_cv_prog_cc_stdc is
773 retained for backwards compatibility, assuming the value of
774 ac_cv_prog_cc_c99 or ac_cv_prog_cc_c89 (whichever is valid, in
777 ** AC_STRUCT_DIRENT_D_INO, AC_STRUCT_DIRENT_D_TYPE
778 New macros for checking commonly-used members of struct dirent.
781 The substituted value can now contain newlines.
784 The substitution now occurs only when @variable@ is on a line by itself,
785 optionally surrounded by spaces and tabs. The whole line is replaced.
787 ** AC_TYPE_LONG_DOUBLE, AC_TYPE_LONG_DOUBLE_WIDER
788 New macros to check for long double, and whether it is wider than double.
789 The old macro AC_C_TYPE_LONG_DOUBLE has been marked as obsolete;
790 applications should switch to the new macro.
792 ** AC_TYPE_INT8_T, AC_TYPE_INT16_T, AC_TYPE_INT32_T, AC_TYPE_INT64_T,
793 AC_TYPE_INTMAX_T, AC_TYPE_INTPTR_T, AC_TYPE_LONG_LONG_INT, AC_TYPE_SSIZE_T,
794 AC_TYPE_UINT8_T, AC_TYPE_UINT16_T, AC_TYPE_UINT32_T, AC_TYPE_UINT64_T,
795 AC_TYPE_UINTMAX_T, AC_TYPE_UINTPTR_T, AC_TYPE_UNSIGNED_LONG_LONG_INT
796 New macros to check for C99 and POSIX types.
798 ** AC_USE_SYSTEM_EXTENSIONS
799 New macro to enable extensions to Posix.
802 New macro which is defined to the name of the first declared config header
803 or undefined if no config headers have been declared yet.
806 The macro correctly handles quadrigraphs now.
808 ** AS_BOURNE_COMPATIBLE, AS_SHELL_SANITIZE, AS_CASE
809 These macros are new or published now.
812 New macro for copyright notices in testsuite files.
814 ** ALLOCA, LIBOBJS, LTLIBOBJS
815 Object names added to these variables are now prefixed with `${LIBOBJDIR}',
816 as in `${LIBOBJDIR}alloca.o'. LIBOBJDIR is meant to be defined from
817 `Makefile.in' in case the object files lie in a different directory.
818 The LIBOBJDIR feature is experimental.
821 Supports --no-recursive now.
823 ** New macros to support Erlang/OTP.
824 New macros for configuring paths to Erlang tools and libraries:
825 AC_ERLANG_PATH_ERLC, AC_ERLANG_NEED_ERLC, AC_ERLANG_PATH_ERL,
826 AC_ERLANG_NEED_ERL, AC_ERLANG_CHECK_LIB, AC_ERLANG_SUBST_ROOT_DIR,
827 AC_ERLANG_SUBST_LIB_DIR.
829 New macros for configuring installation of Erlang libraries:
830 AC_ERLANG_SUBST_INSTALL_LIB_DIR, AC_ERLANG_SUBST_INSTALL_LIB_SUBDIR.
832 ** The manual now mentions Gnulib more prominently.
834 ** New macros to support Objective C.
835 AC_PROG_OBJC, AC_PROG_OBJCPP.
837 * Major changes in Autoconf 2.59b
839 Released 2004-08-20, by Paul Eggert.
842 New macro that computes the default alignment of a type.
844 ** AC_CHECK_TOOL, AC_PATH_TOOL, AC_CHECK_TOOLS
845 When cross-compiling, these macros will give a warning if the tool
846 is not prefixed. In the future, unprefixed cross tools will not
847 be detected; please consult the info documentation for information
848 about the reason of this change.
850 ** AC_CHECK_TARGET_TOOL, AC_PATH_TARGET_TOOL, AC_CHECK_TARGET_TOOLS
851 New macros that detect programs whose name is prefixed with the
852 target type, if the build type and target type are different.
854 ** AC_REQUIRE_AUX_FILE
855 New trace macro that declares expected auxiliary files.
858 New macro that tests for a grep program that accepts as a long a line
861 ** AC_PROG_EGREP, AC_PROG_FGREP
862 These macros now require AC_PROG_GREP, and try EGREP="$GREP -E" and
863 FGREP="$GREP -F" respectively if possible, or else run a path search for
864 a program that accepts as long a line as possible.
867 New macro that tests for a sed program that truncates as few characters
870 * Major changes in Autoconf 2.59
872 Released 2003-11-04, by Akim Demaille
874 ** ac_abs_builddir etc.
875 Absolute file names were actually relative in 2.58.
877 * Major changes in Autoconf 2.58
879 Released 2003-11-04, by Akim Demaille
882 core.* files are no longer removed, as they may be valid user files.
884 ** autoreconf and auxiliary directory
885 Autoreconf creates the auxiliary directory if needed. This is
886 especially useful for initial "bootstrapping" of fresh CVS checkouts.
888 ** AC_CONFIG_MACRO_DIR
889 Use this macro to declare the directory for local M4 macros for aclocal.
892 No longer includes twice the same file in LIBOBJS if invoked
895 ** AC_CONFIG_COMMANDS
896 The directory for its first argument is automatically created. For
899 AC_CONFIG_COMMANDS([src/modules.hh], [...])
901 $top_builddir/src/ is created if needed.
903 ** Autotest and local.at
904 The optional file local.at is always included in Autotest test suites.
907 The warnings are always issued, including with cached runs.
908 This became a significant problem since aclocal and automake can
909 run autoconf behind the scene.
911 ** autoheader warnings
912 The warnings of autoheader can be turned off, using --warning.
913 For instance, -Wno-obsolete disables the complaints about acconfig.h
914 and other deprecated constructs.
917 AC_C_RESTRICT, AC_INCLUDES_DEFAULT, AC_LANG_ASSERT, AC_LANG_WERROR,
920 ** AC_DECL_SYS_SIGLIST
924 Now checks that mktime is the inverse of localtime.
926 ** Improve DJGPP portability
927 The Autoconf tools and configure behave better under DJGPP.
929 ** Present But Cannot Be Compiled
930 New FAQ section dedicated to the mystic
932 configure: WARNING: pi.h: present but cannot be compiled
933 configure: WARNING: pi.h: check for missing prerequisite headers?
934 configure: WARNING: pi.h: proceeding with the preprocessor's result
937 ** Concurrent executions of autom4te
938 autom4te now locks its internal files, which enables concurrent
939 executions of autom4te, likely to happen if automake, autoconf,
940 autoheader etc. are run simultaneously.
943 Use of Libtool 1.5 and higher is encouraged. Compatibility with
944 Libtool pre-1.4 is not checked.
947 Testsuites no longer rerun failed tests in verbose mode; instead,
948 failures are logged while the test is run.
950 In addition, expected failures can be marked as such.
952 * Major changes in Autoconf 2.57
954 Released 2002-12-03 by Paul Eggert.
956 Bug fixes for problems with AIX linker, with freestanding C compilers,
957 with GNU M4 limitations, and with obsolete copies of GNU documents.
959 The Free Documentation License has been upgraded from 1.1 to 1.2.
961 * Major changes in Autoconf 2.56
963 Released 2002-11-15 by Akim Demaille.
965 One packaging problem fixed (config/install-sh was not executable).
967 * Major changes in Autoconf 2.55
969 Released 2002-11-14 by Akim Demaille.
973 Have your configure.ac checked by autoscan ("autoscan").
974 Try the warning options ("autoreconf -fv -Wall").
978 - AC_CHECK_HEADER, AC_CHECK_HEADERS
979 More information on proper use.
981 - Writing Test Programs
983 This sections explains how to write good test sources to use with
984 AC_COMPILE_IFELSE etc. It documents AC_LANG_PROGRAM and so forth.
986 - AC_FOO_IFELSE vs. AC_TRY_FOO
988 Explains why Autoconf moves from AC_TRY_COMPILE etc. to
989 AC_COMPILE_IFELSE and AC_LANG_PROGRAM etc.
993 - Is more robust to different Gettext installations.
995 - Produces messages (when --verbose) to be understood by Emacs'
998 - Supports -W/--warnings.
1001 Once the GNU Build System reinstalled, run `./config.status
1002 --recheck && ./config.status && make' if possible.
1006 - Supports --cache, and --no-cache.
1008 - ~/.autom4te.cfg makes it possible to disable the caching mechanism
1009 (autom4te.cache). See `Customizing autom4te' in the documentation.
1016 Support for the obsoleted options -m, --macrodir, -l, --localdir is
1017 dropped in favor of the safer --include/--prepend-include scheme.
1022 AC_COMPILER_IFELSE, AC_FUNC_MBRTOWC, AC_HEADER_STDBOOL,
1023 AC_LANG_CONFTEST, AC_LANG_SOURCE, AC_LANG_PROGRAM, AC_LANG_CALL,
1024 AC_LANG_FUNC_TRY_LINK, AC_MSG_FAILURE, AC_PREPROC_IFELSE.
1027 Obsoleted macros are kept for Autoconf backward compatibility, but
1028 should be avoided in configure.ac. Running autoupdate is advised.
1029 AC_DECL_SYS_SIGLIST.
1031 - AC_DEFINE/AC_DEFINE_UNQUOTED
1033 We have to stop using the old compatibility scheme --that tried to
1034 avoid useless backslashes-- because Libtool 1.4.3 contains a
1036 AC_DEFINE([error_t], [int],
1037 [Define to a type to use for \`error_t' if it is not
1038 otherwise available.])
1040 We have to quote the single quotes and backslashes with \. The old
1041 compatibility scheme saw that ` was backslashed, and therefore did
1042 not quote the single quote... Failure. Hence, Autoconf 2.54 is not
1043 compatible with Libtool. Autoconf 2.55 is, but in some cases might
1044 produce more \ than wanted.
1046 Please, note that in the future the same problem will happen with
1047 AC_MSG_*: use `autoreconf -f -Wall'.
1051 - Portability of the Autoconf package to Solaris.
1053 - Spurious warnings caused by config.status.
1054 This bug is benign, but painful: on some systems (typically
1055 FreeBSD), warnings such as:
1057 config.status: creating Makefile
1058 mv: Makefile: set owner/group (was: 1357/0): Operation not permitted
1060 could be issued. This is fixed.
1063 Simultaneous executions of config.status are possible again.
1065 - Precious variables accumulation
1067 config.status could stack several copies of the precious variables
1071 ** Plans for later versions
1073 - ./configure <host>
1075 The compatibility hooks with the old scheme will be completely
1076 removed. Please, advice/use `--build', `--host', and `--target'
1079 - AC_CHECK_HEADER, AC_CHECK_HEADERS
1081 The tests will be stricter, please make sure your invocations are
1086 Shell functions will gradually be introduced, probably starting with
1087 Autotest. If you know machines which are in use that you suspect
1088 *not* to support shell functions, please run the test suite of
1089 Autoconf 2.55 on it, and report the results to
1090 bug-autoconf@gnu.org.
1094 Special characters in AC_MSG_* need not be quoted. Currently,
1095 Autoconf has heuristics to decide when a string is escaped, or has
1096 to be escaped. This scheme is fragile, and will be removed; the
1097 only risk is uglified messages. Please, run `autoreconf -f -Wall'
1098 to find occurrences that will be affected.
1100 * Major changes in Autoconf 2.54
1102 Released 2002-09-13 by Akim Demaille.
1106 - autoreconf no longer changes the version of the gettext/po/intl
1107 support files. It now adds the files the correspond to the
1108 AM_GNU_GETTEXT_VERSION declared in configure.ac.
1110 Warning: It now relies on the 'autopoint' program, which is part
1111 of GNU gettext 0.11.4 and newer.
1113 Please note that you need to have a GNU gettext version that
1114 corresponds at least to the AM_GNU_GETTEXT_VERSION declared
1115 in configure.ac. You can upgrade to newer GNU gettext versions,
1116 though, without needing to change configure.ac.
1118 - The -I DIR or --include=DIR option now appends DIR to the include path
1119 instead of prepending; this is for consistency with other GNU tools.
1120 The new -B DIR or --prepend-include=DIR option has the old behavior.
1125 Now handles all the gory details about LIBOBJS and LTLIBOBJS.
1126 Please, remove lines such as
1128 # This is necessary so that .o files in LIBOBJS are also
1129 # built via the ANSI2KNR-filtering rules.
1130 LIBOBJS=`echo $LIBOBJS|sed 's/\.o /\$U.o /g;s/\.o$/\$U.o/'`
1132 and read the `AC_LIBOBJ vs LIBOBJS' section. Do not define U in
1133 your Makefiles either.
1135 - AC_CONFIG_LINKS now makes copies if it can't make links.
1137 - AC_FUNC_FNMATCH now tests only for POSIX compatibility, reverting to
1138 Autoconf 2.13 behavior. The new macro AC_FUNC_FNMATCH_GNU also
1139 tests for GNU extensions to fnmatch, and replaces fnmatch if needed.
1141 - AC_FUNC_SETVBUF_REVERSED no longer fails when cross-compiling.
1143 - AC_PROG_CC_STDC is integrated into AC_PROG_CC.
1145 - AC_PROG_F77 default search no longer includes cf77 and cfg77.
1149 AC_C_BACKSLASH_A, AC_CONFIG_LIBOBJ_DIR, AC_GNU_SOURCE,
1150 AC_PROG_EGREP, AC_PROG_FGREP, AC_REPLACE_FNMATCH,
1151 AC_FUNC_FNMATCH_GNU, AC_FUNC_REALLOC, AC_TYPE_MBSTATE_T.
1153 - AC_FUNC_GETLOADAVG
1154 looks for getloadavg.c in the CONFIG_LIBOBJ_DIR.
1157 Now defines HAVE_MALLOC to 0 if `malloc' does not work, and asks
1158 for an AC_LIBOBJ replacement.
1162 - Spurious complaints from `m4_bmatch' about invalid regular
1163 expressions are suppressed.
1165 - Empty top_builddirs are properly handled.
1167 - AC_CHECK_MEMBER works correctly when the member is an aggregate.
1170 Now colon in the optional path arguments are properly handled.
1172 ** Improved portability
1174 - Both Autoconf the package, and the scripts it produces, should run
1175 more reliably with Zsh. Bear in mind it is the default Bourne shell
1178 - Autoconf and the scripts it produces no longer assume the existence of
1179 the obsolescent commands egrep and fgrep.
1183 - Limitations of Make
1187 The GNATS base moved to
1188 http://bugs.gnu.org/cgi-bin/gnatsweb.pl?database=autoconf
1189 (It is no longer available, though.)
1194 Now contains the list of ouput variables and files (AC_SUBST,
1197 * Major changes in Autoconf 2.53
1199 Released 2002-03-08 by Akim Demaille.
1203 Perl 5.005_03 or later is required: autom4te is written in Perl and is
1204 needed by autoconf. autoheader, autoreconf, ifnames, and autoscan are
1210 Argument requirements, output variables, defined macros.
1211 - M4sugar, M4sh, Autotest
1213 - Double quoting macros
1214 AC_TRY_CPP, AC_TRY_COMPILE, AC_TRY_LINK and AC_TRY_RUN.
1216 The Autoconf manual is now distributed under the terms of the GNU FDL.
1217 - Section `Hosts and Cross-Compilation'
1218 Explains the rationale for the 2.5x changes in the cross-compilation
1219 chain, and in the relationships between build, host, and target
1221 Emphasizes that `cross-compilation' == `--host is given'.
1222 If you are working on compilers etc., be sure to read this section.
1223 - Section `AC_LIBOBJ vs. LIBOBJS'
1224 Explains why assigning LIBOBJS directly is now an error.
1225 Details how to update the code.
1230 Now used instead of hard coded line numbers.
1231 This eases the comparison of `configure's, and diminishes the
1232 pressure over control version archives.
1233 Automatic replacement for shells that don't support this feature.
1234 - New output variables
1235 @builddir@, @top_builddir@, @abs_srcdir@, @abs_top_srcdir@, @abs_builddir@,
1240 Autoconf and Autotest modes are provided.
1245 New, used by the Autoconf suite to cache and speed up most processing.
1247 Supported by autom4te, autoconf and autoheader.
1249 Replaces --autoconf-dir and --localdir in autoconf, autoheader,
1250 autoupdate, and autoreconf.
1252 No longer passes --cygnus, --foreign, --gnits, --gnu, --include-deps:
1253 automake options are to be given via AUTOMAKE_OPTIONS.
1255 Runs gettextize and libtoolize when appropriate.
1257 --m4dir is no longer supported.
1259 Now runs only in the specified directories, defaulting to `.',
1260 but understands AC_CONFIG_SUBDIRS for dependent directories.
1261 Before, it used to run on all the `configure.ac' found in the
1263 Independent packages are properly updated.
1267 - The top level $prefix is propagated to the AC_CONFIG_SUBDIRS configures.
1269 Under the user pressure, $? is finally available. Probably a mistake.
1270 - AC_F77_LIBRARY_LDFLAGS now supports the HP/UX f90 compiler.
1271 - Precious variables accumulation
1272 config.status could stack several copies of the precious variables
1274 - AC_PATH_PROG and family.
1275 Works properly when given a literal path.
1277 Somewhere since 2.13, the result had been reversed.
1281 - AC_C_BIGENDIAN supports the cross-compiling case.
1282 - AC_C_BIGENDIAN accepts ACTION-IF-TRUE, ACTION-IF-FALSE, and
1283 ACTION-IF-UNKNOWN arguments. All are facultative, and the default
1284 for ACTION-IF-TRUE is to define WORDS_BIGENDIAN like AC_C_BIGENDIAN
1286 - AC_C_LONG_DOUBLE now succeeds only if `long double' has more range or
1287 precision than `double'.
1292 It now defines the preprocessor symbols PACKAGE_NAME,
1293 PACKAGE_TARNAME, PACKAGE_VERSION, PACKAGE_STRING, and
1297 Admits a fourth optional parameter: the tar name.
1299 - AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS.
1300 Provide the user with srcdir, ac_srcdir, ac_top_srcdir, ac_builddir,
1301 ac_top_builddir, ac_abs_srcdir, ac_abs_top_srcdir, ac_abs_builddir,
1302 ac_abs_top_builddir.
1304 - AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS and AC_OUTPUT.
1305 Are much less expensive when using long lists of files.
1308 Works with shell variables, and non alphanumeric names.
1312 - AC_FUNC_STRERROR_R now sets STRERROR_R_CHAR_P, not HAVE_WORKING_STRERROR_R,
1313 because POSIX 1003.1-200x draft 7 says strerror_r returns int, not char *.
1315 - AC_FUNC_STRTOD substitutes POW_LIB.
1320 * Major changes in Autoconf 2.52
1322 Released 2001-07-18 by Akim Demaille.
1327 This feature was present in autoconf 2.50 but was not documented.
1328 For example, `@<:@' is translated to `[' just before output. This
1329 is useful when writing strings that contain unbalanced quotes, or
1330 other hard-to-quote constructs.
1331 - m4_pattern_forbid, m4_pattern_allow
1332 - Tips for upgrading from 2.13.
1333 - Using autoscan to maintain a configure.ac.
1336 - Now include stdint.h.
1337 - sys/types.h and sys/stat.h are guarded.
1338 - strings.h is included if available, and not conflicting with string.h.
1341 - The test suite is more robust and presents less false failures.
1342 - Invocation of GNU M4 now robust to POSIXLY_CORRECT.
1343 - configure accepts --prefix='' again.
1344 - AC_CHECK_LIB works properly when its first argument is not a
1346 - HAVE_INTTYPES_H is defined only if not conflicting with sys/types.h.
1347 - build_, host_, and target_alias are AC_SUBST as in 2.13.
1348 - AC_ARG_VAR properly propagates precious variables inherited from the
1349 environment to ./config.status.
1350 - Using --program-suffix/--program-prefix is portable.
1351 - Failures to detect the default compiler's output extension are less
1353 - `config.status foo' works properly when `foo' depends on variables
1354 set in an AC_CONFIG_THING INIT-CMD.
1355 - autoheader is more robust to broken input.
1356 - Fixed Fortran name-mangling and link tests on a number of systems,
1357 e.g. NetBSD; see AC_F77_DUMMY_MAIN, below.
1360 - AC_CHECK_HEADER and AC_CHECK_HEADERS support a fourth argument to
1361 specify pre-includes. In this case, the headers are compiled with
1362 cc, not merely preprocessed by cpp. Therefore it is the _usability_
1363 of a header which is checked for, not just its availability.
1364 - AC_ARG_VAR refuses to run configure when precious variables have
1366 - Versions of compilers are dumped in the logs.
1367 - AC_CHECK_TYPE recognizes use of `foo_t' as a replacement type.
1370 - AC_PATH_XTRA only adds -ldnet to $LIBS if it's needed to link.
1371 - AC_FUNC_WAIT3 and AC_SYS_RESTARTABLE_SYSCALLS are obsoleted.
1372 - AM_FUNC_ERROR_AT_LINE, AM_FUNC_FNMATCH, AM_FUNC_MKTIME,
1373 AM_FUNC_OBSTACK, and AM_FUNC_STRTOD are now activated.
1374 Be sure to read `Upgrading from Version 2.13' to understand why
1375 running `autoupdate' is needed.
1376 - AC_F77_DUMMY_MAIN, AC_F77_MAIN: new macros to detect whether
1377 a main-like routine is required/possible when linking C/C++ with
1378 Fortran. Users of e.g. AC_F77_WRAPPERS should be aware of these.
1379 - AC_FUNC_GETPGRG behaves better when cross-compiling.
1381 * Major changes in Autoconf 2.51
1382 There was no release of Autoconf 2.51 since some packagers had used
1383 this version number without permission to ship intermediary versions
1384 of 2.50. The version was skipped to avoid confusion.
1386 * Major changes in Autoconf 2.50
1388 Released 2001-05-21 by Akim Demaille.
1390 ** Lots of bug fixes
1391 There have been far too many to enumerate them here. Check out
1392 ChangeLog if you really want to know more.
1394 ** Improved documentation
1395 In particular, portability issues are better covered.
1398 All the standard GNU Makefile targets are supported. The layout has
1399 changed: m4/ holds the M4 extensions Autoconf needs for its
1400 configuration, doc/ contains the documentation, and tests/ contains
1403 ** Man pages are provided
1404 For autoconf, autoreconf, autoupdate, autoheader, autoscan, ifnames,
1405 config.guess, config.sub.
1409 Provides a safe and powerful means to trace the macro uses. This
1410 provide the parsing layer for tools which need to `study'
1414 Specify what category of warnings should be enabled.
1416 - When recursing into subdirectories, try for configure.gnu before
1417 configure to adapt for packages not using autoconf on case-insensitive
1421 More errors are now caught (circular AC_REQUIRE dependencies,
1422 AC_DEFINE in the action part of an AC_CACHE_CHECK, too many pops
1423 etc.). In addition, their location and call stack are given.
1426 autoupdate is much more powerful, and is able to provide the glue code
1427 which might be needed to move from an old macro to its newer
1430 You are strongly encouraged to use it to modernize both your
1431 `configure.in' and your .m4 extension files.
1434 The internal machinery of autoheader has completely changed. As a
1435 result, using `acconfig.h' should be considered to be obsoleted, and
1436 you are encouraged to get rid of it using the AH macros.
1441 ** Fortran 77 compilers
1442 Globally, the support for Fortran 77 is considerably improved.
1444 Support for automatically determining a Fortran 77 compiler's
1445 name-mangling scheme. New CPP macros F77_FUNC and F77_FUNC_ are
1446 provided to wrap C/C++ identifiers, thus making it easier and more
1447 transparent for C/C++ to call Fortran 77 routines, and Fortran 77 to
1448 call C/C++ routines. See the Texinfo documentation for details.
1451 The test suite no longer uses DejaGNU. It should be easy to submit
1452 test cases in this new framework.
1455 - --help, --help=long, -hl
1456 no longer dumps useless items.
1458 lists only specific options.
1459 - --help=recursive, -hr
1460 displays the help of all the embedded packages.
1461 - Remembers environment variables when reconfiguring.
1462 The previous scheme to set envvar before running configure was
1464 what prevented configure from remembering the environment in which
1465 it was run, therefore --recheck was run in an inconsistent
1466 environment. Now, one should run
1468 and then --recheck will work properly. Variables declared with
1469 AC_ARG_VAR are also preserved.
1471 $build defaults to `config.guess`, $host to $build, and then $target
1473 Cross-compilation is a global status of the package, it no longer
1474 depends upon the current language.
1475 Cross compilation is enabled iff the user specified `--host'.
1476 `configure' now fails if it can't run the executables it compiles,
1477 unless cross-compilation is enabled.
1479 The cache file is disabled by default. The new options
1480 `--config-cache', `-C' set the cache to `config.cache'.
1484 Much faster on most architectures.
1485 - concurrent executions
1486 It is safe to use `make -j' with config.status.
1487 - human interface improved
1488 It is possible to invoke
1489 ./config.status foobar
1490 instead of the former form (still valid)
1491 CONFIG_COMMANDS= CONFIG_HEADERS= CONFIG_LINKS= \
1492 CONFIG_FILES=foobar:foo.in:bar.in \
1494 The same holds for configuration headers and links.
1495 You can instantiate unknown files and headers:
1496 ./config.status --header foo.h:foo.h.in --file bar:baz
1497 - has a useful --help
1498 - accepts special file name "-" for stdin/stdout
1503 Specify additional copyright information.
1506 Now expects the identity of the package as argument.
1510 Most macros, if not all, now strictly follow the `one quotation
1511 level' rule. This results in a more predictable expansion.
1514 A sly bug in the AC_REQUIRE machinery, which could produce incorrect
1515 configure scripts, was fixed by Axel Thimm.
1519 Document and ask for the registration of an envvar.
1522 Specifies the file which `configure' should look for when trying to
1523 find the source tree (used to be handled by AC_INIT).
1525 - AC_CONFIG_COMMANDS
1526 To add new actions to config.status. Should be used instead of
1530 Replaces AC_LINK_FILES.
1532 - AC_CONFIG_HEADERS, AC_CONFIG_COMMANDS, AC_CONFIG_SUBDIRS,
1533 AC_CONFIG_LINKS, and AC_CONFIG_FILES
1534 They now obey sh: you should no longer use shell variables as
1535 argument. Instead of
1537 test "$package_foo_enabled" = yes && $my_subdirs="$my_subdirs foo"
1538 AC_CONFIG_SUBDIRS($my_subdirs)
1542 if test "$package_foo_enabled" = yes; then
1543 AC_CONFIG_SUBDIRS(foo)
1547 To format an Autoconf macro's help string so that it looks pretty
1548 when the user executes `configure --help'.
1551 ** Generic Test Macros
1553 The interface of the AC_CHECK families of macros (decl, header,
1554 type, member, func) is now uniform. They support the same set of
1557 - AC_CHECK_DECL, AC_CHECK_DECLS
1558 To check whether a symbol is declared.
1560 - AC_CHECK_SIZEOF, AC_C_CHAR_UNSIGNED.
1561 No longer need a cross-compilation default.
1564 The test it performs is much more robust than previously, and makes
1565 it possible to test builtin types in addition to typedefs.
1566 It is now schizophrenic:
1567 - AC_CHECK_TYPE(TYPE, REPLACEMENT)
1568 remains for backward compatibility, but its use is discouraged.
1569 - AC_CHECK_TYPE(TYPE, IF-FOUND, IF-NOT-FOUND, INCLUDES)
1570 behaves exactly like the other AC_CHECK macros.
1573 Checks whether given types are supported by the system.
1575 - AC_CHECK_MEMBER, AC_CHECK_MEMBERS
1576 Check for given members in aggregates (e.g., pw_gecos in struct
1580 Checks if the compiler supports ISO C, included when needs special
1584 Checking whether the preprocessor indicates missing includes by the
1585 error code. stderr is checked by AC_TRY_CPP only as a fallback.
1588 Takes a language as argument and replaces AC_LANG_C,
1589 AC_LANG_CPLUSPLUS and AC_LANG_FORTRAN77.
1591 - AC_LANG_PUSH, AC_LANG_POP
1592 Are preferred to AC_LANG_SAVE, AC_LANG_RESTORE.
1595 - AC_FUNC_CHOWN, AC_FUNC_MALLOC, AC_FUNC_STRERROR_R,
1596 AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK, AC_FUNC_STAT, AC_FUNC_LSTAT,
1597 AC_FUNC_ERROR_AT_LINE, AC_FUNC_OBSTACK, AC_FUNC_STRTOD, AC_FUNC_FSEEKO.
1601 Sets GETGROUPS_LIBS.
1603 - AC_FUNC_GETLOADAVG
1604 Defines `HAVE_STRUCT_NLIST_N_UN_N_NAME' instead of `NLIST_NAME_UNION'.
1607 Now integrates `AC_DECL_YYTEXT' which is obsoleted.
1610 Arrange for large-file support.
1612 - AC_EXEEXT, AC_OBJEXT
1613 You are no longer expected to use them: their computation is
1614 performed by default.
1616 ** C++ compatibility
1617 Every macro has been revisited in order to support at best CC=c++.
1619 Major changes in Autoconf 2.14:
1620 There was no release of GNU Autoconf 2.14.
1622 Major changes in Autoconf 2.13:
1624 Released 1999-05-01 by Ben Elliston.
1626 * Support for building on Win32 systems where the only available C or
1627 C++ compiler is the Microsoft Visual C++ command line compiler
1628 (`cl'). Additional support for building on Win32 systems which are
1629 using the Cygwin or Mingw32 environments.
1630 * Support for alternative object file and executable file extensions.
1631 On Win32, for example, these are .obj and .exe. These are discovered
1632 using AC_OBJEXT and AC_EXEEXT, which substitute @OBJEXT@ and
1633 @EXEEXT@ in the output, respectively.
1634 * New macros: AC_CACHE_LOAD, AC_CACHE_SAVE, AC_FUNC_SELECT_ARGTYPES,
1635 AC_VALIDATE_CACHED_SYSTEM_TUPLE, AC_SEARCH_LIBS, AC_TRY_LINK_FUNC,
1636 AC_C_STRINGIZE, AC_CHECK_FILE(S), AC_PROG_F77 (and friends).
1637 * AC_DEFINE now has an optional third argument for a description to be
1638 placed in the config header input file (e.g. config.h.in).
1639 * The C++ code fragment compiled for the C++ compiler test had to be
1640 improved to include an explicit return type for main(). This was
1641 causing failures on systems using recent versions of the EGCS C++
1643 * Fixed an important bug in AC_CHECK_TYPE that would cause a configure
1644 script to report that `sometype_t' was present when only `type_t'
1646 * Merge of the FSF version of config.guess and config.sub to modernize
1647 these scripts. Add support for a few new hosts in config.guess.
1648 Incorporate latest versions of install-sh, mkinstalldirs and
1649 texinfo.tex from the FSF.
1650 * autoreconf is capable of running automake if necessary (and
1652 * Support for Fortran 77. See the Texinfo documentation for details.
1653 * Bug fixes and workarounds for quirky bugs in vendor utilities.
1655 Major changes in Autoconf 2.12:
1657 Released 1996-11-26 by David J. MacKenzie
1659 * AC_OUTPUT and AC_CONFIG_HEADER can create output files by
1660 concatenating multiple input files separated by colons, like so:
1661 AC_CONFIG_HEADER(config.h:conf.pre:config.h.in:conf.post)
1662 AC_OUTPUT(Makefile:Makefile.in:Makefile.rules)
1663 The arguments may be shell variables, to compute the lists on the fly.
1664 * AC_LINK_FILES and AC_CONFIG_SUBDIRS may be called multiple times.
1665 * New macro AC_OUTPUT_COMMANDS adds more commands to run in config.status.
1668 Major changes in Autoconf 2.11:
1670 Released November 18th, 1996, by David J. MacKenzie
1672 * AC_PROG_CC and AC_PROG_CXX check whether the compiler works.
1673 They also default CFLAGS/CXXFLAGS to "-g -O2" for gcc, instead of "-g -O".
1674 * AC_REPLACE_FUNCS defines HAVE_foo if the system has the function `foo'.
1675 * AC_CONFIG_HEADER expands shell variables in its argument.
1676 * New macros: AC_FUNC_FNMATCH, AC_FUNC_SETPGRP.
1677 * The "checking..." messages and the source code for test programs that
1678 fail are saved in config.log.
1679 * Another workaround has been added for seds with small command length limits.
1680 * config.sub and config.guess recognize more system types.
1683 Major changes in Autoconf 2.10:
1685 Released May 7th, 1996, by Roland McGrath
1688 * The cache variable names used by `AC_CHECK_LIB(LIB, FUNC, ...)' has
1689 changed: now $ac_cv_lib_LIB_FUNC, previously $ac_cv_lib_LIB.
1691 Major changes in Autoconf 2.9:
1693 Released March 16th, 1996, by Roland McGrath
1697 Major changes in Autoconf 2.8:
1699 Released March 8th, 1996, by Roland McGrath
1703 Major changes in Autoconf 2.7:
1705 Released November 22nd, 1995, by David J. MacKenzie
1709 Major changes in Autoconf 2.6:
1711 Released November 20th, 1995, by David J. MacKenzie
1715 Major changes in Autoconf 2.5:
1717 Released November 17th, 1995, by Roland McGrath
1719 * New configure options --bindir, --libdir, --datadir, etc., with
1720 corresponding output variables.
1721 * New macro: AC_CACHE_CHECK, to make using the cache easier.
1722 * config.log contains the command being run as well as any output from it.
1723 * AC_CHECK_LIB can check for libraries with "." or "/" or "+" in their name.
1724 * AC_PROG_INSTALL doesn't cache a name for install-sh, for sharing caches.
1725 * AC_CHECK_PROG, AC_PATH_PROG, AC_CHECK_PROGS, AC_PATH_PROGS, and
1726 AC_CHECK_TOOL can search a path other than $PATH.
1727 * AC_CHECK_SIZEOF takes an optional size to use when cross-compiling.
1729 Major changes in Autoconf 2.4:
1731 Released June 14th, 1995, by David J. MacKenzie
1733 * Fix a few bugs found by Emacs testers.
1735 Major changes in Autoconf 2.3:
1737 Released March 27th, 1995, by David J. MacKenzie
1739 * Fix the cleanup trap in several ways.
1740 * Handle C compilers that are picky about option placement.
1741 * ifnames gets the version number from the right directory.
1743 Major changes in Autoconf 2.2:
1745 Released March 8th, 1995, by David J. MacKenzie
1747 * The ifnames utility is much faster but requires a "new awk" interpreter.
1748 * AC_CHECK_LIB and AC_HAVE_LIBRARY check and add the new
1749 library before existing libs, not after, in case it uses them.
1750 * New macros: AC_FUNC_GETPGRP, AC_CHECK_TOOL.
1751 * Lots of bug fixes.
1752 * Many additions to the TODO file :-)
1754 Major changes in Autoconf 2.1:
1756 Released November 4th, 1994, by David J. MacKenzie
1759 * More explanations in the manual.
1760 * Fix a spurious failure in the testsuite.
1761 * Clarify some warning messages.
1762 * autoreconf by default only rebuilds configure and config.h.in files
1763 that are older than any of their particular input files; there is a
1764 --force option to use after installing a new version of Autoconf.
1766 Thanks to everybody who's submitted changes and additions to Autoconf!
1767 I've incorporated many of them, and am still considering others for
1768 future releases -- but I didn't want to postpone this release indefinitely.
1770 Caution: don't indiscriminately rebuild configure scripts with
1771 Autoconf version 2. Some configure.in files need minor adjustments to
1772 work with it; the documentation has a chapter on upgrading. A few
1773 configure.in files, including those for GNU Emacs and the GNU C
1774 Library, need major changes because they relied on undocumented
1775 internals of version 1. Future releases of those packages will have
1776 updated configure.in files.
1778 It's best to use GNU M4 1.3 (or later) with Autoconf version 2.
1779 Autoconf now makes heavy use of M4 diversions, which were implemented
1780 inefficiently in GNU M4 releases before 1.3.
1782 Major changes in Autoconf 2.0:
1784 Released October 26th, 1994, by David J. MacKenzie
1786 ** New copyright terms:
1787 * There are no restrictions on distribution or use of configure scripts.
1790 * Autoconf manual is reorganized to make information easier to find
1791 and has several new indexes.
1792 * INSTALL is reorganized and clearer and is now made from Texinfo source.
1795 * autoscan to generate a preliminary configure.in for a package by
1796 scanning its source code for commonly used nonportable functions,
1797 programs, and header files.
1798 * ifnames to list the symbols used in #if and #ifdef directives in a
1800 * autoupdate to update a configure.in to use the version 2 macro names.
1801 * autoreconf to recursively remake configure and configuration header
1802 files in a source tree.
1804 ** Changed utilities:
1805 * autoheader can take pieces of acconfig.h to replace config.h.{top,bot}.
1806 * autoconf and autoheader can look for package-local definition files
1807 in an alternate directory.
1810 * AC_CACHE_VAL to share results of tests between configure runs.
1811 * AC_DEFUN to define macros, automatically AC_PROVIDE them, and ensure
1812 that macros invoked with AC_REQUIRE don't interrupt other macros.
1813 * AC_CONFIG_AUX_DIR, AC_CANONICAL_SYSTEM, AC_CANONICAL_HOST, AC_LINK_FILES to
1814 support deciding unguessable features based on the host and target types.
1815 * AC_CONFIG_SUBDIRS to recursively configure a source tree.
1816 * AC_ARG_PROGRAM to use the options --program-prefix,
1817 --program-suffix, and --program-transform-name to change the names
1818 of programs being installed.
1819 * AC_PREFIX_DEFAULT to change the default installation prefix.
1820 * AC_TRY_COMPILE to compile a test program without linking it.
1821 * AC_CHECK_TYPE to check whether sys/types.h or stdlib.h defines a given type.
1822 * AC_CHECK_LIB to check for a particular function and library.
1823 * AC_MSG_CHECKING and AC_MSG_RESULT to print test results, on a single line,
1824 whether or not the test succeeds. They obsolete AC_CHECKING and AC_VERBOSE.
1825 * AC_SUBST_FILE to insert one file into another.
1826 * AC_FUNC_MEMCMP to check whether memcmp is 8-bit clean.
1827 * AC_FUNC_STRFTIME to find strftime even if it's in -lintl.
1828 * AC_FUNC_GETMNTENT to find getmntent even if it's in -lsun or -lseq.
1829 * AC_HEADER_SYS_WAIT to check whether sys/wait.h is POSIX.1 compatible.
1832 * Many macros renamed systematically, but old names are accepted for
1833 backward compatibility.
1834 * AC_OUTPUT adds the "automatically generated" comment to
1835 non-Makefiles where it finds @configure_input@ in an input file, to
1836 support files with various comment syntaxes.
1837 * AC_OUTPUT does not replace "prefix" and "exec_prefix" in generated
1838 files when they are not enclosed in @ signs.
1839 * AC_OUTPUT allows the optional environment variable CONFIG_STATUS to
1840 override the file name "config.status".
1841 * AC_OUTPUT takes an optional argument for passing variables from
1842 configure to config.status.
1843 * AC_OUTPUT and AC_CONFIG_HEADER allow you to override the input-file names.
1844 * AC_OUTPUT automatically substitutes the values of CFLAGS, CXXFLAGS,
1845 CPPFLAGS, and LDFLAGS from the environment.
1846 * AC_PROG_CC and AC_PROG_CXX now set CFLAGS and CXXFLAGS, respectively.
1847 * AC_PROG_INSTALL looks for install-sh or install.sh in the directory
1848 specified by AC_CONFIG_AUXDIR, or srcdir or srcdir/.. or
1849 srcdir/../.. by default.
1850 * AC_DEFINE, AC_DEFINE_UNQUOTED, and AC_SUBST are more robust and smaller.
1851 * AC_DEFINE no longer prints anything, because of the new result reporting
1852 mechanism (AC_MSG_CHECKING and AC_MSG_RESULT).
1853 * AC_VERBOSE pays attention to --quiet/--silent, not --verbose.
1854 * AC_ARG_ENABLE and AC_ARG_WITH support whitespace in the arguments to
1855 --enable- and --with- options.
1856 * AC_CHECK_FUNCS and AC_CHECK_HEADERS take optional shell commands to
1857 execute on success or failure.
1858 * Checking for C functions in C++ works.
1861 * AC_REMOTE_TAPE and AC_RSH removed; too specific to tar and cpio, and
1862 better maintained with them.
1863 * AC_ARG_ARRAY removed because no one was likely using it.
1864 * AC_HAVE_POUNDBANG replaced with AC_SYS_INTERPRETER, which doesn't
1865 take arguments, for consistency with all of the other specific checks.
1868 * Comes with config.sub and config.guess, and uses them optionally.
1869 * Uses config.cache to cache test results. An alternate cache file
1870 can be selected with the --cache-file=FILE option.
1871 * Uses optional shell scripts $prefix/share/config.site and
1872 $prefix/etc/config.site to perform site or system specific initializations.
1873 * configure saves compiler output to ./config.log for debugging.
1874 * New files autoconf.m4 and autoheader.m4 load the other Autoconf macros.
1875 * acsite.m4 is the new name for the system-wide aclocal.m4.
1876 * Has a DejaGnu test suite.
1878 Major changes in Autoconf 1.11:
1880 * AC_PROG_INSTALL calls install.sh with the -c option.
1881 * AC_SET_MAKE cleans up after itself.
1882 * AC_OUTPUT sets prefix and exec_prefix if they weren't set already.
1883 * AC_OUTPUT prevents shells from looking in PATH for config.status.
1885 Plus a few other bug fixes.
1887 Major changes in Autoconf 1.10:
1889 * autoheader uses config.h.bot if present, analogous to config.h.top.
1890 * AC_PROG_INSTALL looks for install.sh in srcdir or srcdir/.. and
1892 * AC_PROG_CXX looks for cxx as a C++ compiler.
1894 Plus several bugs fixed.
1896 Major changes in Autoconf 1.9:
1898 * AC_YYTEXT_POINTER replaces AC_DECLARE_YYTEXT.
1899 * AC_SIZEOF_TYPE generates the cpp symbol name automatically,
1900 and autoheader generates entries for those names automatically.
1901 * AC_FIND_X gets the result from xmkmf correctly.
1902 * AC_FIND_X assumes no X if --without-x was given.
1903 * AC_FIND_XTRA adds libraries to the variable X_EXTRA_LIBS.
1904 * AC_PROG_INSTALL finds OSF/1 installbsd.
1906 Major changes in Autoconf 1.8:
1909 * New macros AC_LANG_C, AC_LANG_CPLUSPLUS, AC_LANG_SAVE, AC_LANG_RESTORE,
1910 AC_PROG_CXX, AC_PROG_CXXCPP, AC_REQUIRE_CPP
1911 for checking both C++ and C features in one configure script.
1912 * New macros AC_CHECKING, AC_VERBOSE, AC_WARN, AC_ERROR for printing messages.
1913 * New macros AC_FIND_XTRA, AC_MMAP, AC_SIZEOF_TYPE, AC_PREREQ,
1914 AC_SET_MAKE, AC_ENABLE.
1917 * AC_FIND_X looks for X in more places.
1918 * AC_PROG_INSTALL defaults to install.sh instead of cp, if it's in srcdir.
1919 install.sh is distributed with Autoconf.
1920 * AC_DECLARE_YYTEXT has been removed because it can't work, pending
1921 a rewrite of quoting in AC_DEFINE.
1922 * AC_OUTPUT adds its comments in C format when substituting in C files.
1923 * AC_COMPILE_CHECK protects its ECHO-TEXT argument with double quotes.
1925 ** New or changed command line options:
1926 * configure accepts --enable-FEATURE[=ARG] and --disable-FEATURE options.
1927 * configure accepts --without-PACKAGE, which sets withval=no.
1928 * configure accepts --x-includes=DIR and --x-libraries=DIR.
1929 * Giving --with-PACKAGE no argument sets withval=yes instead of withval=1.
1930 * configure accepts --help, --version, --silent/--quiet, --no-create options.
1931 * configure accepts and ignores most other Cygnus configure options, and
1932 warns about unknown options.
1933 * config.status accepts --help, --version options.
1935 ** File names and other changes:
1936 * Relative srcdir values are not made absolute.
1937 * The values of @prefix@ and @exec_prefix@ and @top_srcdir@ get substituted.
1938 * Autoconf library files are installed in ${datadir}/autoconf, not ${datadir}.
1939 * autoheader optionally copies config.h.top to the beginning of config.h.in.
1940 * The example Makefile dependencies for configure et al. work better.
1941 * Namespace cleanup: all shell variables used internally by Autoconf
1942 have names beginning with `ac_'.
1944 More big improvements are in process for future releases, but have not
1945 yet been (variously) finished, integrated, tested, or documented enough
1948 Major changes in Autoconf 1.7:
1950 * New macro AC_OBSOLETE.
1951 * Bugs in Makefile.in fixed.
1952 * AC_LONG_FILE_NAMES improved.
1954 Major changes in Autoconf 1.6:
1956 * New macro AC_LONG_64_BITS.
1957 * Multiple .h files can be created.
1958 * AC_FIND_X looks for X files directly if it doesn't find xmkmf.
1959 * AC_ALLOCA defines C_ALLOCA if using alloca.c.
1960 * --with-NAME can take a value, e.g., --with-targets=sun4,hp300bsd.
1961 * Unused --no-create option to configure removed.
1962 * autoheader doesn't change the timestamp of its output file if
1963 the file didn't change.
1964 * All macros that look for libraries now use AC_HAVE_LIBRARY.
1965 * config.status checks three optional environment variables to
1966 modify its behavior.
1967 * The usual bug fixes.
1969 Major changes in Autoconf 1.5:
1971 * New macros AC_FIND_X, AC_OFF_T, AC_STAT_MACROS_BROKEN, AC_REVISION.
1972 * autoconf and autoheader scripts have GNU standards conforming
1973 --version and --help options (they print their message and exit).
1976 Major changes in Autoconf 1.4:
1978 * New macros AC_HAVE_POUNDBANG, AC_TIME_WITH_SYS_TIME, AC_LONG_DOUBLE,
1979 AC_GETGROUPS_T, AC_DEFINE_UNQUOTED.
1980 * autoconf and autoheader use the M4 environment variable to determine the
1981 name of the M4 program to use.
1982 * The --macrodir option to autoconf and autoheader specifies the directory
1983 in which acspecific.m4, acgeneral.m4, etc. reside if not the default.
1984 * autoconf and autoheader can take `-' as their file names, which means to
1985 read stdin as input.
1986 * Resulting configure scripts can take a --verbose option which causes them
1987 to print the results of their tests.
1988 * AC_DEFINE quotes its second argument in such a way that spaces, magic
1989 shell characters, etc. will be preserved during various stages of
1990 expansion done by the shell. If you don't want this, use
1991 AC_DEFINE_UNQUOTED instead.
1992 * Much textual processing done with external calls to tr and sed have been
1993 internalized with builtin M4 `patsubst' and `translit' calls.
1994 * AC_OUTPUT doesn't hardwire the file names it outputs. Instead, you can
1995 set the shell variables `gen_files' and `gen_config' to the list of
1996 file names to output.
1997 * AC_DECLARE_YYTEXT does an AC_SUBST of `LEX_OUTPUT_ROOT', which may be
1998 "lex.yy" or "lexyy", depending on the system.
1999 * AC_PROGRAMS_CHECK takes an optional third arg. If given, it is used as
2001 * If AC_ALLOCA chooses alloca.c, it also defines STACK_DIRECTION.
2002 * AC_CONST works much more reliably on more systems.
2005 Major changes in Autoconf 1.3:
2007 configure no longer requires awk for packages that use a config.h.
2008 Support handling --with-PACKAGE options.
2009 New `autoheader' script to create `config.h.in' from `configure.in'.
2010 Ignore troublesome -lucb and -lPW when searching for alloca.
2011 Rename --exec_prefix to --exec-prefix for GNU standards conformance.
2012 Improve detection of STDC library.
2013 Add AC_HAVE_LIBRARY to check for non-default libraries.
2014 Function checking should work with future GNU libc releases.
2016 Major changes in Autoconf 1.2:
2018 The --srcdir option is now usually unnecessary.
2019 Add a file containing sample comments describing CPP macros.
2020 A comment in config.status tells which host it was configured on.
2021 Substituted variable values can now contain commas.
2022 Fix bugs in various feature checks.
2024 Major changes in Autoconf 1.1:
2026 Added AC_STRCOLL macro.
2027 Made AC_GETLOADAVG check for more things.
2028 AC_OUTPUT argument is now optional.
2033 Copyright (C) 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001, 2002,
2034 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation,
2037 Copying and distribution of this file, with or without modification,
2038 are permitted in any medium without royalty provided the copyright
2039 notice and this notice are preserved. This file is offered as-is,
2040 without warranty of any kind.