1 GNU Autoconf NEWS - User visible changes.
3 * Noteworthy changes in release ?.? (????-??-??) [?]
5 ** config.log properly escapes arguments in the header comment;
6 config.status --config output is now quoted in a more readable fashion
8 ** Configure scripts now support a '--runstatedir' option, which
9 defaults to '${localstatedir}/run', and which can be used to place
10 per-process temporary runtime files (such as pid files) into '/run'
11 instead of '/var/run'.
13 ** The use of the long-deprecated name 'configure.in' for the autoconf
14 input file now elicits a warning in the 'obsolete' category.
16 ** Older version of automake and aclocal (< 1.8) are no longer supported
19 ** Use of printf is now recommended instead of working around bugs in
20 echo. Macros AS_ECHO and AS_ECHO_N now expand unconditionally to
21 'printf "%s\n"' and 'printf %s'.
23 ** AC_CHECK_HEADER and AC_CHECK_HEADERS now default to doing only a
24 compilation test. This completes the transition from preprocessor-
25 based header tests begun in Autoconf 2.56.
27 The double test that was the default since Autoconf 2.64 is no
28 longer available. You can still request a preprocessor-only test
29 by specifying '-' as the fourth argument to either macro, but this
30 is now deprecated. If you really need that behavior use
33 ** When checking for missing templates, autoheader now takes any
34 templates defined in the inputs of secondary config headers into
35 account. This makes it possible to use AC_DEFINE for secondary
36 headers without duplicating the template in the main config header.
40 - New macro AC_C__GENERIC.
42 - AC_C_VARARRAYS now defines __STDC_NO_VLA__ if variable-length
43 arrays are not supported and if the compiler does not already
44 define __STDC_NO_VLA__. This is for compatibility with C11.
45 For backward compatibility with Autoconf 2.61-2.69 AC_C_VARARRAYS
46 still defines HAVE_C_VARARRAYS, but this usage is obsolescent.
48 - AC_CONFIG_MACRO_DIRS
49 New macro, used to declare multiple directories when looking for
50 local M4 macros. This macro overcomes some of the shortfalls in the
51 older AC_CONFIG_MACRO_DIR, which could only be used once; although
52 the older macro remains for compatibility with older tools. The
53 newer macro will be used by the upcoming Automake 1.13 release to
54 eliminate the need to specify ACLOCAL_AMFLAGS in Makefile.am.
56 - AC_PROG_CC now prefers C11 if available, falling back on C99 and
57 then on C89 as before. Similarly, AC_PROG_CXX now prefers C++11
58 if available, falling back on C++98.
60 - AC_PROG_CC is now defined via AC_DEFUN_ONCE, to avoid bloat in 'configure'.
62 - AC_PROG_CC_STDC, AC_PROG_CC_C89, AC_PROG_CC_C99 have been marked as obsolete.
63 Applications should use AC_PROG_CC.
65 - AC_PROG_YACC now uses 'bison -o y.tab.c' instead of 'bison -y', so that
66 by default it no longer warns about Bison extensions. Add -Wyacc to
67 YFLAGS to enable these warnings.
69 - AC_USE_SYSTEM_EXTENSIONS now enables more extensions on HP-UX,
70 macOS, and MINIX, as well as on systems conforming to recent
71 ISO/IEC C technical reports and specifications.
73 - AC_CHECK_DECL and AC_CHECK_DECLS can now report missing declarations for
74 functions that are also Clang compiler builtins.
76 - AC_FUNC_VFORK now checks for the signal-handling bug in Solaris 2.4 'vfork'.
77 Formerly, it ignored this bug, so that Emacs could use some tricky
78 code on that platform. Solaris 2.4 has not been supported since
79 2003 and nowadays it's better to omit that old trick.
81 - Autotest provides a new macro AT_DATA_UNQUOTED, similar to AT_DATA
82 but processing variable substitutions, command substitutions and
83 backslashes in the contents argument.
85 - AC_CONFIG_TESTDIR will automatically pass EXEEXT to a testsuite (via
88 - AT_TESTED arguments can use variable or command substitutions, including
91 - AC_INCLUDES_DEFAULT has been streamlined. It now assumes that the
92 ISO C90 headers 'stdlib.h' and 'string.h' are unconditionally
93 available, and does not include the pre-standard header 'memory.h'
94 at all. If the POSIX header 'strings.h' exists, it will be
95 included; it is assumed to be safe to include both 'string.h' and
96 'strings.h' in the same source file. We are not aware of any
97 current system that violates any of the above assumptions.
99 For compatibility's sake, the C preprocessor macros STDC_HEADERS,
100 HAVE_STDLIB_H, and HAVE_STRING_H are defined unconditionally.
101 These preprocessor macros should be considered obsolescent.
103 Future releases of Autoconf may reduce the set of headers checked
104 for by AC_INCLUDES_DEFAULT.
106 - AC_HEADER_STDC and AC_HEADER_TIME are now stubs which will be
107 removed from 'configure.ac' by 'autoupdate'. For compatibility's
108 sake, the stubs (and their 'autoupdate' replacements) continue to
109 define the C preprocessor macros STDC_HEADERS and TIME_WITH_SYS_TIME,
110 respectively, but without actually checking for the ancient systems
111 where formerly those macros would not be defined.
113 These macros were already labeled obsolescent in the manual.
115 - New macro, AC_CHECK_INCLUDES_DEFAULT. It causes the checks normally
116 performed as a side-effect by AC_INCLUDES_DEFAULT to happen at that
117 point in 'configure', if they haven't already been done. Autoupdate
118 will replace certain obsolete constructs, whose only remaining
119 useful effect is to trigger those checks, with this macro. It is
120 unlikely to be useful otherwise.
122 - The AC_CHECK_FUNCS_ONCE and AC_CHECK_HEADERS_ONCE macros now support
123 use with multiple languages, rather than forcing all checks in the
124 language used by the first encounter of the macro.
126 ** Man pages for config.guess and config.sub are no longer provided.
127 They were moved to the master source tree for config.guess and config.sub.
129 * Noteworthy changes in release 2.69 (2012-04-24) [stable]
131 ** Autoconf now requires perl 5.6 or better (but generated configure
132 scripts continue to run without perl).
134 * Noteworthy changes in release 2.68b (2012-03-01) [beta]
135 Released by Eric Blake, based on git versions 2.68.*.
137 ** Autoconf-generated configure scripts now unconditionally re-execute
138 themselves with $CONFIG_SHELL, if that's set in the environment.
140 ** The texinfo documentation no longer specifies "front-cover" or
141 "back-cover" texts, so that it may now be included in Debian's
144 ** Support for the Go programming language has been added. The new macro
145 AC_LANG_GO sets variables GOC and GOFLAGS.
147 ** AS_LITERAL_IF again treats '=' as a literal. Regression introduced in
150 ** The macro AS_EXECUTABLE_P, present since 2.50, is now documented.
154 - AC_PROG_LN_S and AS_LN_S now fall back on 'cp -pR' (not 'cp -p') if 'ln -s'
155 does not work. This works better for symlinks to directories.
157 - New macro AC_HEADER_CHECK_STDBOOL.
159 - New and updated macros for Fortran support:
161 AC_FC_CHECK_BOUNDS to enable array bounds checking
162 AC_F77_IMPLICIT_NONE and AC_FC_IMPLICIT_NONE to disable implicit integer
163 AC_FC_MODULE_EXTENSION to compute the Fortran 90 module name extension
164 AC_FC_MODULE_FLAG for the Fortran 90 module search path flag
165 AC_FC_MODULE_OUTPUT_FLAG for the Fortran 90 module output directory flag
166 AC_FC_PP_SRCEXT for preprocessed Fortran source files extensions
167 AC_FC_PP_DEFINE for the Fortran preprocessor define flag
169 * Noteworthy changes in release 2.68 (2010-09-22) [stable]
170 Released by Eric Blake, based on git versions 2.67.*.
172 ** AC_MSG_ERROR (and AS_ERROR) can once again be followed immediately by
173 `dnl'. Regression introduced in 2.66.
175 ** AC_INIT again allows URLs with '?' for its BUG-REPORT argument.
176 Regression introduced in 2.66.
178 ** AC_REPLACE_FUNCS again allows a non-literal argument, such as a shell
179 variable that expands to a list of functions to check. Regression
182 ** AT_BANNER() with empty argument will cause visual separation from previous
185 ** The macros AC_PREPROC_IFELSE, AC_COMPILE_IFELSE, AC_LINK_IFELSE, and
186 AC_RUN_IFELSE now warn if the first argument failed to use
187 AC_LANG_SOURCE or AC_LANG_PROGRAM to generate the conftest file
188 contents. A new macro AC_LANG_DEFINES_PROVIDED exists if you have
189 a compelling reason why you cannot use AC_LANG_SOURCE but must
192 ** The macro m4_define_default is now documented.
194 ** Symlinked config.cache files are supported; configure now tries to
195 update non-symlinked cache files atomically, so that concurrent configure
196 runs do not leave behind broken cache files. It is still unspecified
197 which subset or union of results is cached though.
199 ** Autotest testsuites should not contain long text lines any more, and be
200 portable even when very many test groups are used.
202 ** AT_CHECK semantics with respect to the Autotest variable $at_status and
203 shell execution environment of the arguments are documented now.
205 ** AC_FC_LIBRARY_LDFLAGS now tolerates output from newer gfortran.
207 ** Newly obsolete macros
208 The following macros have been marked obsolete. New programs
209 should use the corresponding Gnulib modules. Gnulib not only
210 detects a larger set of portability problems with these functions,
211 but also provides complete workarounds.
213 AC_FUNC_ERROR_AT_LINE AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK
214 AC_FUNC_MKTIME AC_FUNC_STRTOD
217 * Major changes in Autoconf 2.67 (2010-07-21) [stable]
218 Released by Eric Blake, based on git versions 2.66.*.
220 ** AC_CONFIG_SUBDIRS with more than one subdirectory at a time works again.
221 Regression introduced in 2.66.
223 ** AC_CHECK_SIZEOF of a pointer type works again. Regression introduced in
226 ** New macro AC_FC_LINE_LENGTH to accept long Fortran source code lines.
228 ** AC_PREPROC_IFELSE now keeps the preprocessed output in the conftest.i
229 file for inspection by the commands in the ACTION-IF-TRUE argument.
231 ** AC_INIT again allows parentheses and other characters that are literal
232 in single- or double-quoted strings, and in quoted and unquoted
233 here-documents, for its PACKAGE and VERSION arguments. Regression
236 ** autoreconf passes warning flags to new enough versions of aclocal.
238 ** Running an Autotest testsuite in parallel mode no longer triggers a
239 race condition that could cause the testsuite run to end early,
240 fixing a sporadic failure in autoconf's own testsuite. Bug present
241 since introduction of parallel tests in 2.63b.
244 * Major changes in Autoconf 2.66 (2010-07-02) [stable]
245 Released by Eric Blake, based on git versions 2.65.*.
247 ** AC_FUNC_MMAP works in C++ mode again. Regression introduced in 2.65.
249 ** Use of m4_divert without a named diversion now issues a syntax warning,
250 since it is seldom right to change diversions behind autoconf's back.
252 ** The macros AC_TYPE_INT8_T, AC_TYPE_INT16_T, AC_TYPE_INT32_T, and
253 AC_TYPE_INT64_T work again. Regression introduced in 2.65.
255 ** AC_PROG_INSTALL correctly uses `shtool' again. Regression introduced
258 ** Autoconf should work on EBCDIC hosts.
260 ** AC_CHECK_DECL and AC_CHECK_DECLS accept optional function argument types
261 for overloaded C++ functions.
263 ** AS_SET_CATFILE accepts nonliterals in its variable name argument now.
265 ** Autotest testsuites accept an option --recheck to rerun tests that
266 failed or passed unexpectedly during the last non-debug testsuite run.
268 ** AC_ARG_ENABLE and AC_ARG_WITH now also accept `+' signs in `--enable-*'
269 and `--with-*' arguments, converting them to underscores for the variable
272 ** In configure scripts, loading CONFIG_SITE no longer searches PATH,
273 and problems in loading the configuration site files are diagnosed.
275 ** Autotest testsuites may optionally provide colored test results.
277 ** The previously undocumented Autotest macros AT_ARG_OPTION and
278 AT_ARG_OPTION_ARG have seen bug fixes and are documented now.
279 AT_ARG_OPTION has been changed in that the negative of a long option
280 --OPTION is now --no-OPTION rather than --noOPTION.
282 ** The macro AS_LITERAL_IF is slightly more conservative; text
283 containing shell quotes are no longer treated as literals.
284 Furthermore, a new macro, AS_LITERAL_WORD_IF, adds an additional
285 level of checking that no whitespace occurs in literals.
287 ** The macros AS_TR_SH and AS_TR_CPP no longer expand their results.
289 ** The following macros are now documented:
292 ** New macro AC_FC_FIXEDFORM to accept fixed-form Fortran.
295 * Major changes in Autoconf 2.65 (2009-11-21) [stable]
296 Released by Eric Blake, based on git versions 2.64.*.
298 ** Autoconf is now licensed under the General Public License version 3
299 or later (GPLv3+). As with earlier versions, the license includes
300 an exception clause so that you may release a configure script
301 generated by autoconf under the license of your own program.
303 ** New macros to support Objective C++.
304 AC_PROG_OBJCXX AC_PROG_OBJCXXCPP
306 ** The following undocumented autoconf macros, removed in Autoconf 2.64,
307 have been reinstated:
310 These macros are present only for backwards compatibility purposes.
312 ** The macro AC_LANG_COMPILER no longer fails on embedded systems that
313 lack fopen in the C library, such as AVR or RTEMS (regression
316 ** The AC_FC_FREEFORM macro no longer suffers from a whitespace bug that
317 made it fail with some Fortran compilers (regression introduced in
320 ** The AC_TYPE_UINT64_T and AC_TYPE_INT64_T macros have been fixed to no
321 longer mistakenly select a 32-bit type on some compilers (bug present
322 since macros were introduced in 2.59c).
324 ** The AC_FUNC_MMAP macro has been fixed to be portable to systems like
325 Cygwin (bug present since macro was introduced in 2.0).
327 ** The following documented autotest macros are new:
330 ** The following m4sugar macros now quote their expansion:
331 m4_toupper m4_tolower
333 ** The following m4sugar macros are new:
336 ** The m4sugar macro m4_text_wrap now copes with embedded quoting without
337 requiring quadrigraphs. For uses like AC_ARG_VAR([a], [[b c]]),
338 this gives the intuitive behavior of "[b c]" in the output (2.63
339 gave the output of "[b], [c]", and 2.64 encountered a failure).
341 ** The `$tmp' temporary directory used in config.status is documented for
344 ** config.status now provides a --config option to produce the configuration.
346 ** Many cache variables used by Autoconf's macros are now documented.
348 ** Configure scripts work better on DJGPP by avoiding a bug present in
349 the DJGPP port of bash 2.04 in handling 'return' in a shell
350 function (regression introduced in 2.64).
352 * Major changes in Autoconf 2.64 (2009-07-26) [stable]
353 Released by Eric Blake, based on git versions 2.63b.*.
355 ** Autoconf now requires GNU M4 1.4.6 or later. Earlier versions of M4
356 have a bug in regular expression handling that interferes with some
357 of the speedups provided since Autoconf 2.63. GNU M4 1.4.13 or
358 later is recommended.
360 ** AS_IF and AS_CASE have been taught to avoid syntax errors even when
361 given arguments that expand to just whitespace.
363 ** The following documented autoconf macros are new:
364 AC_ERLANG_SUBST_ERTS_VER
366 ** The autoheader tool now understands m4 macro arguments passed to
367 AC_DEFINE and AC_DEFINE_UNQUOTED.
369 ** Ensure AT_CHECK can support commands that include a # given with
370 proper m4 quoting. For shell comments, this is a new feature; for
371 non-shell comments, this fixes a regression introduced in 2.63b.
372 Additionally, AT_CHECK correctly supplies shell escapes for
373 metacharacters occurring in m4 macro expansions within the expected
374 stdout and stderr parameters.
376 ** The macro AT_CHECK now understands the concept of hard failure. If
377 a test exits with an unexpected status 99, cleanup actions for the
378 test are inhibited and the test is treated as a failure regardless
379 of AT_XFAIL_IF. It also understands the new directives
380 ignore-nolog, stdout-nolog, and stderr-nolog.
382 ** The following documented autotest macros are new:
383 AT_CHECK_UNQUOTED AT_FAIL_IF AT_SKIP_IF
385 ** The following documented m4sugar macros are new:
386 m4_argn m4_copy_force m4_default_nblank m4_default_nblank_quoted
387 m4_ifblank m4_ifnblank m4_rename_force
389 ** The autoconf testsuite now exercises all Erlang macros.
391 * Major changes in Autoconf 2.63b (2009-03-31) [beta]
392 Released by Eric Blake, based on git versions 2.63.*.
394 ** The manual is now shipped under the terms of the GNU FDL 1.3.
396 ** AC_REQUIRE now detects the case of an outer macro which first expands
397 then later indirectly requires the same inner macro. Previously,
398 this case led to silent out-of-order expansion (bug present since
399 2.50); it now issues a syntax warning, and duplicates the expansion
400 of the inner macro to guarantee dependencies have been met. See
401 the manual for advice on how to refactor macros in order to avoid
402 the bug in earlier autoconf versions and avoid increased script
403 size in the current version.
405 ** AC_DEFUN_ONCE has improved semantics. Previously, a macro declared
406 with AC_DEFUN_ONCE warned on a second invocation; and out-of-order
407 expansion was still possible. Now, dependencies are guaranteed,
408 and subsequent invocations are a silent no-op. This makes
409 AC_DEFUN_ONCE an ideal macro for silencing AC_REQUIRE warnings.
411 ** The following macros are now defined with AC_DEFUN_ONCE. This means
412 a subtle change in semantics; previously, an AC_DEFUN macro could
413 expand one of these macros multiple times or surround the macro
414 inside shell conditional text to bypass the effects of these
415 macros, but now the macro will expand exactly once, and prior to
416 the start of any enclosing AC_DEFUN macro:
417 AC_CANONICAL_BUILD AC_CANONICAL_HOST AC_CANONICAL_TARGET
418 AC_HEADER_ASSERT AC_PROG_INSTALL AC_PROG_MKDIR_P
419 AC_USE_SYSTEM_EXTENSIONS
421 ** AC_LANG_ERLANG works once again (regression introduced in 2.61a).
423 ** AC_HEADER_ASSERT is fixed so that './configure --enable-assert' no
424 longer mistakenly disables assertions.
426 ** AC_INIT now takes an optional fifth parameter that can be used to
427 set AC_PACKAGE_URL, a URL for the package's home page; the URL is
428 used in `configure --help' and is also available via AC_DEFINE.
430 ** Autotest testsuites accept an option --jobs[=N] for parallel testing.
431 This feature is still in testing, and may not work on every
432 platform, help in improving it would be appreciated.
434 ** Autotest testsuites do not attempt to write startup error messages
435 to the log file before that is opened (regression introduced in 2.63).
437 ** Configure scripts now use shell functions. This feature leads to
438 smaller configure files and faster execution.
440 ** Present But Cannot Be Compiled: Autoconf will now proceed with
441 the compiler's result if a header is present but cannot be compiled.
442 The warning is still printed, and you should really fix it by
443 providing a fourth parameter to AC_CHECK_HEADER/AC_CHECK_HEADERS.
445 ** Autoreconf added aclocal to the set of programs affected by the
446 `autoreconf -I dir' option.
448 ** The following documented m4sugar macros are new:
449 m4_chomp m4_chomp_all m4_cleardivert m4_curry m4_default_quoted
450 m4_esyscmd_s m4_map_args m4_map_args_pair m4_map_args_sep
451 m4_map_args_w m4_set_map m4_set_map_sep m4_stack_foreach
452 m4_stack_foreach_lifo m4_stack_foreach_sep
453 m4_stack_foreach_sep_lifo
455 ** The following m4sugar macros are documented now, but in some cases
456 with slightly different semantics than what the previous
457 undocumented version had:
458 m4_copy m4_dumpdefs m4_rename m4_version_prereq
460 ** The m4sugar macro m4_expand has been taught to handle unterminated
461 comments and shell case statements. As a result, it is used
462 internally in more places, such as AC_DEFINE and AT_CHECK. Most
463 uses of AC_DEFINE and AT_CHECK should not behave any differently;
464 however, it may be necessary to add double-quoting around
465 unbalanced `(' where single-quoting used to be sufficient.
467 ** The following documented m4sh macros are new:
468 AS_INIT_GENERATED AS_LINENO_PREPARE AS_ME_PREPARE AS_SET_STATUS
469 AS_VAR_APPEND AS_VAR_ARITH AS_VAR_COPY
471 ** The following m4sh macros are documented now, but in some cases
472 with slightly different semantics than what the previous
473 undocumented version had:
474 AS_ECHO AS_ECHO_N AS_ESCAPE AS_EXIT AS_LITERAL_IF AS_UNSET
475 AS_VAR_IF AS_VAR_POPDEF AS_VAR_PUSHDEF AS_VAR_SET AS_VAR_SET_IF
476 AS_VAR_TEST_SET AS_VERSION_COMPARE
478 ** The m4sh macros AS_IF and AS_CASE can now be used in shell lists.
479 The responsibility for supplying a trailing newline now belongs to
480 the call site, but since most users did not add dnl, this generally
481 results in fewer empty lines in configure.
484 * Major changes in Autoconf 2.63 (2008-09-09) [stable]
485 Released by Eric Blake, based on git versions 2.62.*.
487 ** AC_C_BIGENDIAN does not mistakenly report "universal" for some
488 bigendian hosts, a regression introduced with universal binary
491 ** AC_PATH_X now includes /lib64 and /usr/lib64 in its list of default
494 ** AC_USE_SYSTEM_EXTENSIONS no longer conflicts with an external
495 AC_DEFINE([__EXTENSIONS__]). This fixes a regression introduced in
496 2.62 when using macros such as AC_AIX that were made obsolete in
497 favor of the more portable AC_USE_SYSTEM_EXTENSIONS.
499 ** AC_CHECK_TARGET_TOOLS is usable in the non-cross-compile case.
501 ** Newly obsolete macros
502 The following macro has been marked obsolete, since current porting
503 targets can safely assume C89 semantics that signal handlers return
504 void. We have no current plans to remove the macro.
508 ** The macros m4_map and m4_map_sep now ignore any list elements
509 consisting of just empty quotes, and m4_map_sep now expands its
510 separator. This fixes a regression in 2.62 when these macros were
511 first documented, for the sake of clients expecting the semantics
512 that these macros had prior to that time. The new macros m4_mapall
513 and m4_mapall_sep, along with extra quoting of the separator, can
514 be used to get the semantics that m4_map_sep had in 2.62.
516 ** Clients of m4_expand, such as AS_HELP_STRING and AT_SETUP, can now
517 handle properly quoted but otherwise unbalanced parentheses (for
518 some macros, this fixes a regression in 2.62).
520 ** Two new quadrigraphs have been introduced: @{:@ for (, and @:}@ for ),
521 allowing the output of unbalanced parentheses in more contexts.
523 ** The following m4sugar macros are new:
524 m4_cleardivert m4_joinall m4_mapall m4_mapall_sep m4_reverse
525 m4_set_add m4_set_add_all m4_set_contains m4_set_contents
526 m4_set_delete m4_set_difference m4_set_dump m4_set_empty
527 m4_set_foreach m4_set_intersection m4_set_list m4_set_listc
528 m4_set_remove m4_set_size m4_set_union
530 ** The following m4sugar macros now accept multiple arguments, as is the
531 case with underlying m4:
532 m4_defn m4_popdef m4_undefine
534 ** The following m4sugar macros now guarantee linear scaling; they
535 previously had linear scaling with m4 1.6 but quadratic scaling
536 when using m4 1.4.x. All macros built on top of these also gain
537 the scaling improvements.
538 m4_bmatch m4_bpatsubsts m4_case m4_cond m4_do m4_dquote_elt
539 m4_foreach m4_join m4_list_cmp m4_map m4_map_sep m4_max
542 ** AT_KEYWORDS once again performs expansion on its argument, such that
543 AT_KEYWORDS([m4_if([$1], [], [default])]) no longer complains about
544 the possibly unexpanded m4_if [regression introduced in 2.62].
546 ** Config header templates `#undef UNDEFINED /* comment */' do not lead to
547 nested comments any more; regression introduced in 2.62.
550 * Major changes in Autoconf 2.62 (2008-04-05) [stable]
551 Released by Eric Blake, based on git versions 2.61a.*.
553 ** Many optimizations have been applied to make overall execution faster.
555 ** Autotest now makes use of shell functions.
557 ** config.status now uses awk instead of sed also for config headers.
559 - As a side effect, AC_DEFINE and AC_DEFINE_UNQUOTED now handle multi-line
560 values, i.e., backslash-newline combinations are handled correctly.
561 Further, for config headers, the total size of values is not limited by
562 the POSIX length limit of text lines any more, only each single line.
564 ** New config variable `top_build_prefix'.
566 ** New Autoconf macros:
567 AC_AUTOCONF_VERSION AC_OPENMP AC_PATH_PROGS_FEATURE_CHECK
569 ** AC_C_BIGENDIAN now supports universal binaries a la Mac OS X.
571 ** AC_C_RESTRICT now prefers to #define 'restrict' to a variant spelling
572 like '__restrict' if the variant spelling is available, as this is
573 more likely to work when mixing C and C++ code.
575 ** AC_CHECK_ALIGNOF's type argument T is now documented better: it must
576 be a string of tokens such that "T y;" is a valid member declaration
579 ** AC_CHECK_SIZEOF now accepts objects as well as types: the general rule
580 is that sizeof (X) works, then AC_CHECK_SIZEOF (X) should work.
582 ** AC_CHECK_TYPE and AC_CHECK_TYPES now work on any C type-name; formerly,
583 they did not work for function types. In C++, they now work on any
584 type-id that can be the operand of sizeof; this is similar to C,
585 except it excludes anonymous struct and union types. Formerly,
586 some (but not all) C++ types involving anonymous struct and union
587 were accepted, though this was not documented.
589 ** AC_CONFIG_LINKS now prefers to link against files in the build tree
590 if found, and it works to link against a file of the same name in
591 the source tree, even if both trees coincide.
593 ** AC_INIT no longer alters $@; regression introduced in 2.60.
595 ** AC_USE_SYSTEM_EXTENSIONS now defines _ALL_SOURCE for Interix platforms.
597 ** AS_HELP_STRING no longer underquotes its first argument; it also handles
598 the case where the first argument contains single-quoted commas.
599 For example, "AS_HELP_STRING([-a, [--arg[=foo]]], [bar])" produces:
600 " -a, --arg[=foo] bar"
601 Additionally, the macro now takes two additional arguments,
602 indent-column and wrap-column; these should not normally be needed,
603 but can be used to fine-tune how the output text is wrapped.
605 ** AC_PROG_INSTALL now requires an install program that can install multiple
606 files into a target directory.
608 ** The command 'autoconf -' now correctly processes a file from stdin.
610 ** 'autoreconf -m' now honors $MAKE.
612 ** For all of the directory arguments for 'configure', such as '--prefix'
613 or '--bindir', trailing slashes are stripped. As an example, if
614 tab completion in the user's shell appends trailing slashes, the
615 command './configure --prefix=/usr/' will still result in an
616 expanded libdir value of /usr/lib, not /usr//lib.
618 ** `configure --help=recursive' now works in read-only trees and from
619 unconfigured build trees.
621 ** If precious variables differ only in whitespace, then the cache consistency
622 check warns instead of fails, and reuses the old value.
624 ** AT_BANNER is now documented.
626 ** AT_SETUP now handles macro expansions properly when calculating line
629 ** Autotest now determines $srcdir correctly.
631 ** Testsuites built by autotest now accept a -C/--directory=DIR option
632 to adjust the working directory prior to creating files.
634 ** Autoconf now requires GNU M4 1.4.5 or later. Earlier versions of M4 have
635 a bug in macro tracing that interferes with the interaction between
636 Autoconf and Automake. GNU M4 1.4.11 or later is recommended. The
637 configure search for a working M4 is improved.
639 ** For portability with the eventual M4 2.0, macros should no longer use
640 anything larger than $9 to refer to arguments.
642 ** Documentation for m4sugar is improved.
644 - The following macros were previously available as undocumented
645 interfaces; the macros are now documented as stable interfaces.
647 __oline__ m4_assert m4_bmatch m4_bpatsubsts m4_car m4_case
648 m4_cdr m4_default m4_divert_once m4_divert_pop m4_divert_push
649 m4_divert_text m4_do m4_errprintn m4_fatal m4_flatten
650 m4_ifndef m4_ifset m4_ifval m4_ifvaln m4_location
651 m4_n m4_shiftn m4_strip m4_warn
653 - The following macros were previously available as undocumented
654 interfaces, but had bug fixes or semantic changes as part of this
655 release. Packages that relied on the undocumented behavior
656 should be analyzed to make sure they will still work with the
657 new documented behavior.
659 m4_cmp m4_list_cmp m4_join m4_map m4_map_sep m4_sign
660 m4_text_box m4_text_wrap m4_version_compare
662 - The m4_wrap macro used to have unspecified order, but now
663 guarantees FIFO order. m4_wrap_lifo was added to guarantee LIFO
666 - Packages using the undocumented m4sugar macro m4_PACKAGE_VERSION
667 should consider using the new AC_AUTOCONF_VERSION instead.
669 - m4sugar macros that are not documented in the manual are still
670 deemed experimental, and should not be used outside of Autoconf.
672 ** The m4sugar macros m4_append and m4_append_uniq, first documented in
673 2.60, have been fixed to treat both the string and the separator
674 arguments consistently with regards to quoting. Prior to this fix,
675 m4_append_uniq could mistakenly duplicate entries if the expansion
676 of the separator resulted in a different string (for example, if it
677 contained quotes, a comma, or a macro name). However, it means
678 that programs previously using
679 m4_append([name], [string], [[, ]])
680 are now using a four-character separator instead of the intended
681 comma and space. If you need portability to earlier versions of
682 Autoconf, you can insert the following snippet after AC_INIT but
683 before any other macro expansions, to enforce the new semantics:
684 m4_pushdef([m4_append], [m4_define([$1],
685 m4_ifdef([$1], [m4_defn([$1])[$3]])[$2])])
686 Additionally, m4_append_uniq now takes optional parameters that can
687 be used to take action depending on whether anything was appended,
688 and warns if a non-empty separator occurs within the string being
689 appended, since that can lead to duplicates.
691 ** The following m4sugar macros are new:
692 m4_append_uniq_w m4_apply m4_combine m4_cond m4_count
693 m4_dquote_elt m4_echo m4_expand m4_ignore m4_make_list m4_max
694 m4_min m4_newline m4_shift2 m4_shift3 m4_unquote m4_wrap_lifo
696 ** Warnings are now generated by default when an installer invokes
697 'configure' with an unknown --enable-* or --with-* option.
698 These warnings can be disabled with the new AC_DISABLE_OPTION_CHECKING
699 macro, or by invoking 'configure' with --disable-option-checking.
701 ** Existing obsolete macros
702 The documentation for the following macros is adjusted to make it
703 more clear that they have previously been marked obsolete, as their
704 functionality can be accomplished by other macros. We have no
705 current plans to remove them from Autoconf.
707 AC_ENABLE AC_STRUCT_ST_BLKSIZE AC_STRUCT_ST_RDEV AC_WITH
709 ** Newly obsolete macros
710 The following macros have been marked obsolete, as they only
711 perform a subset of AC_USE_SYSTEM_EXTENSIONS. We have no current
712 plans to remove them.
714 AC_AIX AC_GNU_SOURCE AC_ISC_POSIX AC_MINIX
716 ** AC_C_LONG_DOUBLE is obsolescent.
717 The documentation now says that AC_C_LONG_DOUBLE is obsolescent: it
718 tests for problems that are so old that it is no longer of
719 practical importance on current systems. New programs need not use
720 AC_C_LONG_DOUBLE. We have no current plans to remove it.
722 ** AC_DIAGNOSE, AC_WARNING, and AC_FATAL are obsolescent.
723 The documentation now favors the use of M4sugar macros m4_warn and
724 m4_fatal, since the naming makes it more obvious that the
725 diagnostics are associated with M4 expansion (ie. when running
726 `autoconf'), and offers less confusion with the AC_MSG_ERROR,
727 AC_MSG_FAILURE, and AC_MSG_WARN macros which manage diagnostics
728 when running `configure'. We have no current plans to remove these
732 * Major changes in Autoconf 2.61a (2006-12-11)
734 ** AC_FUNC_FSEEKO was broken in 2.61; it didn't make fseeko and ftello visible
735 on many platforms. This has been fixed.
737 ** AC_FUNC_SETVBUF_REVERSED is now obsolete. It is still defined for backward
738 compatibility but it does nothing. The macro was already
739 obsolescent, as the last systems to have the problem were those
740 based on SVR2, which became obsolete in 1987. The macro had bugs
741 on some modern systems and could no longer be maintained reliably
742 due to lack of ancient systems to test it on.
744 ** config.status now uses awk instead of sed for most substitutions, for speed.
746 - As a side effect multi-line values of substituted variables no
747 longer have a small limit in total size, though for portability
748 each line should not exceed the POSIX length limit for text lines.
750 - It is now documented that Makefile.in should not contain
751 overlapping variable occurrences, e.g., @VAR1@VAR2@.
752 Autoconf's behavior was always iffy in such cases, and the
753 awk implementation has changed the behavior.
755 ** Many uses of 'echo' have been rewritten so that Autoconf-generated
756 scripts have fewer problems with strings or file names containing
757 embedded special characters such as backslash or leading "-". This
758 was implemented by using `printf '%s\n' "$foo"' instead of `echo
759 "$foo"' when printf works. Due to the implementation technique
760 used, Autoconf-generated scripts now run considerably more slowly
761 on ancient implementations lacking printf. However, this should
762 not be a problem, since Autoconf-generated scripts in practice
763 invariably find a more-modern shell these days.
766 * Major changes in Autoconf 2.61 (2006-11-17)
768 ** New macros AC_C_FLEXIBLE_ARRAY_MEMBER, AC_C_VARARRAYS.
770 ** AC_ARG_ENABLE and AC_ARG_WITH now allow '.' in feature and package names.
773 * Major changes in Autoconf 2.60b (2006-10-22)
776 Autoconf-generated shell scripts no longer export BIN_SH, due to
777 configuration hassles with this. Installers who need BIN_SH in
778 their environment should set it before invoking 'configure' and
779 'make'. As far as we know, this affects only Unixware installations.
781 ** Obsolescent macros
782 The documentation now says that the following macros are obsolescent,
783 as they are superseded by Gnulib:
785 AC_FUNC_FNMATCH AC_FUNC_FNMATCH_GNU AC_FUNC_GETLOADVG AC_REPLACE_FNMATCH
787 New programs should use the Gnulib counterparts of these macros.
788 We have no current plans to remove them from Autoconf.
790 ** AC_COMPUTE_INT no longer caches or reports results.
792 ** AC_CHECK_DECL now also works with aggregate objects.
794 ** AC_USE_SYSTEM_EXTENSIONS now defines _TANDEM_SOURCE for NonStop platforms.
796 ** GNU M4 1.4.7 or later is now recommended.
799 New M4sugar macro, which is more secure than the POSIX M4 maketemp.
802 Now an alias for m4_mkstemp.
804 * Major changes in Autoconf 2.60a (2006-08-25)
806 ** GNU M4 1.4.6 or later is now recommended.
808 ** The check for C99 now tests for varargs macros, as documented.
809 It also tests that the preprocessor supports 64-bit integers.
811 ** Autoconf now uses constructs like "#ifdef HAVE_STDLIB_H" rather than
812 "#if HAVE_STDLIB_H", so that it now works with "gcc -Wundef -Werror".
814 ** The functionality of the undocumented _AC_COMPUTE_INT is now provided
815 by a public and documented macro, AC_COMPUTE_INT. The parameters to the
816 two macros are different, so autoupdate will not change the old private name
817 to the new one. _AC_COMPUTE_INT may be removed in a future release.
819 ** AC_TYPE_LONG_LONG_INT and AC_TYPE_UNSIGNED_LONG_LONG_INT now require
820 that long long types be at least 64 bits wide, as C99 and tradition
821 requires. Formerly, they accepted implementations of any width.
824 * Major changes in Autoconf 2.60
826 Released 2006-06-23, by Ralf Wildenhues.
828 ** Autoconf no longer depends on whether m4wrap is FIFO (as Posix requires)
829 or LIFO (as in GNU M4 1.4.x). GNU M4 2.0 is expected to conform to Posix
830 here, so m4wrap/m4_wrap users should no longer depend on LIFO behavior.
832 ** Provide a way to turn off warnings about the changed directory variables.
834 * Major changes in Autoconf 2.59d
836 Released 2006-06-05, by Ralf Wildenhues.
838 ** GNU make now recommended for VPATH builds
839 INSTALL now suggests VPATH builds (e.g., "sh ../srcdir/configure")
840 only if you use GNU make. In practice, other 'make' implementations
841 have too many subtle incompatibilities in their support for VPATH.
842 Many packages (including Autoconf itself) are portable to other
843 'make' implementations, but some packages are not, and recommending
844 GNU make keeps the installation instructions simpler.
846 ** Even more safety checks for the new Directory variables:
847 Warn about suspicious `${datarootdir}' found in config files output.
849 ** AC_TRY_COMMAND, AC_TRY_EVAL, ac_config_guess, ac_config_sub, ac_configure
850 These never-documented macros and variables have been marked with
851 comments saying that they may be removed in a future release,
852 because their use can lead to unintended code being executed.
853 If you need functionality that only these macros or variables
854 currently supply, please write bug-autoconf@gnu.org.
856 ** AC_SUBST, AC_DEFINE
857 Literal arguments to these are passed to m4_pattern_allow now.
860 Passing 'ac_cv_prog_cc_stdc=no' to 'configure' now sets ac_cv_prog_cc_c99
861 and ac_cv_prog_cc_c89 to 'no' as well, for backward compatibility with
862 obsolete K&R tests in the Automake test suite.
871 Now more robust with special characters in file names, or when
872 multiple processes create the same directory at the same time.
874 ** Obsolescent macros
875 The documentation now says that the following macros are obsolescent:
876 they test for problems that are so old that they are no longer of
877 practical importance on current systems.
879 AC_C_BACKSLASH_A AC_FUNC_MEMCMP AC_HEADER_DIRENT
880 AC_C_CONST AC_FUNC_SELECT_ARGTYPES AC_HEADER_STAT
881 AC_C_PROTOTYPES AC_FUNC_SETPGRP AC_HEADER_STDC
882 AC_C_STRINGIZE AC_FUNC_SETVBUF_REVERSED AC_HEADER_SYS_WAIT
883 AC_C_VOLATILE AC_FUNC_STAT AC_HEADER_TIME
884 AC_FUNC_CLOSEDIR_VOID AC_FUNC_STRFTIME AC_ISC_POSIX
885 AC_FUNC_GETPGRP AC_FUNC_UTIME_NULL AC_PROG_GCC_TRADITIONAL
886 AC_FUNC_LSTAT AC_FUNC_VPRINTF AC_STRUCT_TM
888 New programs need not use these macros. We have no current plans to
892 For compatibility with future Libtool 2.0, autoreconf will invoke
893 libtoolize with the option `--ltdl' now, if LT_CONFIG_LTDL_DIR is
896 * Major changes in Autoconf 2.59c
898 Released 2006-04-12, by Ralf Wildenhues.
900 ** The configure command now redirects standard input from /dev/null,
901 to help avoid problems with subsidiary commands that might mistakenly
902 read standard input. AS_ORIGINAL_STDIN_FD points to the original
903 standard input before this redirection, if you really want configure to
904 read from standard input.
906 ** Directory variables adjusted to recent changes in the GNU Coding Standards.
907 The following directory variables are new:
909 datarootdir read-only architecture-independent data root [PREFIX/share]
910 localedir locale-specific message catalogs [DATAROOTDIR/locale]
911 docdir documentation root [DATAROOTDIR/doc/PACKAGE]
912 htmldir html documentation [DOCDIR]
913 dvidir dvi documentation [DOCDIR]
914 pdfdir pdf documentation [DOCDIR]
915 psdir ps documentation [DOCDIR]
917 The following variables have new default values:
919 datadir read-only architecture-independent data [DATAROOTDIR]
920 infodir info documentation [DATAROOTDIR/info]
921 mandir man documentation [DATAROOTDIR/man]
923 This means that if you use any of `@datadir@', `@infodir@', or
924 `@mandir@' in a file, you will have to ensure `${datarootdir}' is
925 defined in this file. As a temporary measure, if any of those are
926 found but no mention of `datarootdir', the substitutions will be
927 replaced with values that do not contain `${datarootdir}', and a
928 warning will be issued.
930 ** @top_builddir@ is now a dir name: it is always nonempty and doesn't have
931 a trailing slash. Similar change will be made to ac_top_builddir in a
932 future release; the old style value, which matches (../)*, is (and will
933 continue to be) available as ac_top_build_prefix.
936 New macro to check for support of 'typeof' syntax a la GNU C.
938 ** AC_CHECK_DECLS_ONCE, AC_CHECK_FUNCS_ONCE, AC_CHECK_HEADERS_ONCE
939 New "once-only" variants of commonly-used macros, to make 'configure'
940 smaller and faster in common cases.
943 New macro to check for strtold with C99 semantics.
946 New macro that lets builder disable assertions at 'configure'-time.
949 Now checks for X11/Xlib.h and XrmInitialize (X proper) rather than
950 X11/Intrinsic.h and XtMalloc (Xt).
952 ** AC_PRESERVE_HELP_ORDER
953 New macro that causes `configure' to display help strings for AC_ARG_ENABLE
954 and AC_ARG_WITH arguments in one region, in the order defined. The default
955 behavior is to group options of each classes separately.
957 ** AC_PROG_CC, AC_PROG_CXX
958 No longer automatically arrange to declare the 'exit' function of C,
959 when a C++ compiler is used. Standard Autoconf macros no longer use
960 'exit', so this is no longer an issue for them. If you use C++, and
961 want to call 'exit', you'll have to arrange for its declaration
962 yourself. But we now suggest you return from 'main' instead.
964 ** AC_PROG_CC_C89, AC_PROG_CC_C99
965 New macros for ISO C99 support. AC_PROG_CC_C89 and AC_PROG_CC_C99
966 check for ANSI C89 and ISO C99 support respectively.
969 Has been unobsoleted, and will check if the compiler supports ISO
970 C99, falling back to ANSI C89 if not. ac_cv_prog_cc_stdc is
971 retained for backwards compatibility, assuming the value of
972 ac_cv_prog_cc_c99 or ac_cv_prog_cc_c89 (whichever is valid, in
975 ** AC_STRUCT_DIRENT_D_INO, AC_STRUCT_DIRENT_D_TYPE
976 New macros for checking commonly-used members of struct dirent.
979 The substituted value can now contain newlines.
982 The substitution now occurs only when @variable@ is on a line by itself,
983 optionally surrounded by spaces and tabs. The whole line is replaced.
985 ** AC_TYPE_LONG_DOUBLE, AC_TYPE_LONG_DOUBLE_WIDER
986 New macros to check for long double, and whether it is wider than double.
987 The old macro AC_C_TYPE_LONG_DOUBLE has been marked as obsolete;
988 applications should switch to the new macro.
990 ** AC_TYPE_INT8_T, AC_TYPE_INT16_T, AC_TYPE_INT32_T, AC_TYPE_INT64_T,
991 AC_TYPE_INTMAX_T, AC_TYPE_INTPTR_T, AC_TYPE_LONG_LONG_INT, AC_TYPE_SSIZE_T,
992 AC_TYPE_UINT8_T, AC_TYPE_UINT16_T, AC_TYPE_UINT32_T, AC_TYPE_UINT64_T,
993 AC_TYPE_UINTMAX_T, AC_TYPE_UINTPTR_T, AC_TYPE_UNSIGNED_LONG_LONG_INT
994 New macros to check for C99 and POSIX types.
996 ** AC_USE_SYSTEM_EXTENSIONS
997 New macro to enable extensions to Posix.
1000 New macro which is defined to the name of the first declared config header
1001 or undefined if no config headers have been declared yet.
1004 The macro correctly handles quadrigraphs now.
1006 ** AS_BOURNE_COMPATIBLE, AS_SHELL_SANITIZE, AS_CASE
1007 These macros are new or published now.
1010 New macro for copyright notices in testsuite files.
1012 ** ALLOCA, LIBOBJS, LTLIBOBJS
1013 Object names added to these variables are now prefixed with `${LIBOBJDIR}',
1014 as in `${LIBOBJDIR}alloca.o'. LIBOBJDIR is meant to be defined from
1015 `Makefile.in' in case the object files lie in a different directory.
1016 The LIBOBJDIR feature is experimental.
1019 Supports --no-recursive now.
1021 ** New macros to support Erlang/OTP.
1022 New macros for configuring paths to Erlang tools and libraries:
1023 AC_ERLANG_PATH_ERLC, AC_ERLANG_NEED_ERLC, AC_ERLANG_PATH_ERL,
1024 AC_ERLANG_NEED_ERL, AC_ERLANG_CHECK_LIB, AC_ERLANG_SUBST_ROOT_DIR,
1025 AC_ERLANG_SUBST_LIB_DIR.
1027 New macros for configuring installation of Erlang libraries:
1028 AC_ERLANG_SUBST_INSTALL_LIB_DIR, AC_ERLANG_SUBST_INSTALL_LIB_SUBDIR.
1030 ** The manual now mentions Gnulib more prominently.
1032 ** New macros to support Objective C.
1033 AC_PROG_OBJC, AC_PROG_OBJCPP.
1035 * Major changes in Autoconf 2.59b
1037 Released 2004-08-20, by Paul Eggert.
1040 New macro that computes the default alignment of a type.
1042 ** AC_CHECK_TOOL, AC_PATH_TOOL, AC_CHECK_TOOLS
1043 When cross-compiling, these macros will give a warning if the tool
1044 is not prefixed. In the future, unprefixed cross tools will not
1045 be detected; please consult the info documentation for information
1046 about the reason of this change.
1048 ** AC_CHECK_TARGET_TOOL, AC_PATH_TARGET_TOOL, AC_CHECK_TARGET_TOOLS
1049 New macros that detect programs whose name is prefixed with the
1050 target type, if the build type and target type are different.
1052 ** AC_REQUIRE_AUX_FILE
1053 New trace macro that declares expected auxiliary files.
1056 New macro that tests for a grep program that accepts as a long a line
1059 ** AC_PROG_EGREP, AC_PROG_FGREP
1060 These macros now require AC_PROG_GREP, and try EGREP="$GREP -E" and
1061 FGREP="$GREP -F" respectively if possible, or else run a path search for
1062 a program that accepts as long a line as possible.
1065 New macro that tests for a sed program that truncates as few characters
1068 * Major changes in Autoconf 2.59
1070 Released 2003-11-04, by Akim Demaille
1072 ** ac_abs_builddir etc.
1073 Absolute file names were actually relative in 2.58.
1075 * Major changes in Autoconf 2.58
1077 Released 2003-11-04, by Akim Demaille
1080 core.* files are no longer removed, as they may be valid user files.
1082 ** autoreconf and auxiliary directory
1083 Autoreconf creates the auxiliary directory if needed. This is
1084 especially useful for initial "bootstrapping" of fresh CVS checkouts.
1086 ** AC_CONFIG_MACRO_DIR
1087 Use this macro to declare the directory for local M4 macros for aclocal.
1090 No longer includes twice the same file in LIBOBJS if invoked
1093 ** AC_CONFIG_COMMANDS
1094 The directory for its first argument is automatically created. For
1097 AC_CONFIG_COMMANDS([src/modules.hh], [...])
1099 $top_builddir/src/ is created if needed.
1101 ** Autotest and local.at
1102 The optional file local.at is always included in Autotest test suites.
1105 The warnings are always issued, including with cached runs.
1106 This became a significant problem since aclocal and automake can
1107 run autoconf behind the scene.
1109 ** autoheader warnings
1110 The warnings of autoheader can be turned off, using --warning.
1111 For instance, -Wno-obsolete disables the complaints about acconfig.h
1112 and other deprecated constructs.
1115 AC_C_RESTRICT, AC_INCLUDES_DEFAULT, AC_LANG_ASSERT, AC_LANG_WERROR,
1118 ** AC_DECL_SYS_SIGLIST
1122 Now checks that mktime is the inverse of localtime.
1124 ** Improve DJGPP portability
1125 The Autoconf tools and configure behave better under DJGPP.
1127 ** Present But Cannot Be Compiled
1128 New FAQ section dedicated to the mystic
1130 configure: WARNING: pi.h: present but cannot be compiled
1131 configure: WARNING: pi.h: check for missing prerequisite headers?
1132 configure: WARNING: pi.h: proceeding with the preprocessor's result
1135 ** Concurrent executions of autom4te
1136 autom4te now locks its internal files, which enables concurrent
1137 executions of autom4te, likely to happen if automake, autoconf,
1138 autoheader etc. are run simultaneously.
1141 Use of Libtool 1.5 and higher is encouraged. Compatibility with
1142 Libtool pre-1.4 is not checked.
1145 Testsuites no longer rerun failed tests in verbose mode; instead,
1146 failures are logged while the test is run.
1148 In addition, expected failures can be marked as such.
1150 * Major changes in Autoconf 2.57
1152 Released 2002-12-03 by Paul Eggert.
1154 Bug fixes for problems with AIX linker, with freestanding C compilers,
1155 with GNU M4 limitations, and with obsolete copies of GNU documents.
1157 The Free Documentation License has been upgraded from 1.1 to 1.2.
1159 * Major changes in Autoconf 2.56
1161 Released 2002-11-15 by Akim Demaille.
1163 One packaging problem fixed (config/install-sh was not executable).
1165 * Major changes in Autoconf 2.55
1167 Released 2002-11-14 by Akim Demaille.
1171 Have your configure.ac checked by autoscan ("autoscan").
1172 Try the warning options ("autoreconf -fv -Wall").
1176 - AC_CHECK_HEADER, AC_CHECK_HEADERS
1177 More information on proper use.
1179 - Writing Test Programs
1181 This sections explains how to write good test sources to use with
1182 AC_COMPILE_IFELSE etc. It documents AC_LANG_PROGRAM and so forth.
1184 - AC_FOO_IFELSE vs. AC_TRY_FOO
1186 Explains why Autoconf moves from AC_TRY_COMPILE etc. to
1187 AC_COMPILE_IFELSE and AC_LANG_PROGRAM etc.
1191 - Is more robust to different Gettext installations.
1193 - Produces messages (when --verbose) to be understood by Emacs'
1196 - Supports -W/--warnings.
1199 Once the GNU Build System reinstalled, run `./config.status
1200 --recheck && ./config.status && make' if possible.
1204 - Supports --cache, and --no-cache.
1206 - ~/.autom4te.cfg makes it possible to disable the caching mechanism
1207 (autom4te.cache). See `Customizing autom4te' in the documentation.
1214 Support for the obsoleted options -m, --macrodir, -l, --localdir is
1215 dropped in favor of the safer --include/--prepend-include scheme.
1220 AC_COMPILER_IFELSE, AC_FUNC_MBRTOWC, AC_HEADER_STDBOOL,
1221 AC_LANG_CONFTEST, AC_LANG_SOURCE, AC_LANG_PROGRAM, AC_LANG_CALL,
1222 AC_LANG_FUNC_TRY_LINK, AC_MSG_FAILURE, AC_PREPROC_IFELSE.
1225 Obsoleted macros are kept for Autoconf backward compatibility, but
1226 should be avoided in configure.ac. Running autoupdate is advised.
1227 AC_DECL_SYS_SIGLIST.
1229 - AC_DEFINE/AC_DEFINE_UNQUOTED
1231 We have to stop using the old compatibility scheme --that tried to
1232 avoid useless backslashes-- because Libtool 1.4.3 contains a
1234 AC_DEFINE([error_t], [int],
1235 [Define to a type to use for \`error_t' if it is not
1236 otherwise available.])
1238 We have to quote the single quotes and backslashes with \. The old
1239 compatibility scheme saw that ` was backslashed, and therefore did
1240 not quote the single quote... Failure. Hence, Autoconf 2.54 is not
1241 compatible with Libtool. Autoconf 2.55 is, but in some cases might
1242 produce more \ than wanted.
1244 Please, note that in the future the same problem will happen with
1245 AC_MSG_*: use `autoreconf -f -Wall'.
1249 - Portability of the Autoconf package to Solaris.
1251 - Spurious warnings caused by config.status.
1252 This bug is benign, but painful: on some systems (typically
1253 FreeBSD), warnings such as:
1255 config.status: creating Makefile
1256 mv: Makefile: set owner/group (was: 1357/0): Operation not permitted
1258 could be issued. This is fixed.
1261 Simultaneous executions of config.status are possible again.
1263 - Precious variables accumulation
1265 config.status could stack several copies of the precious variables
1269 ** Plans for later versions
1271 - ./configure <host>
1273 The compatibility hooks with the old scheme will be completely
1274 removed. Please, advice/use `--build', `--host', and `--target'
1277 - AC_CHECK_HEADER, AC_CHECK_HEADERS
1279 The tests will be stricter, please make sure your invocations are
1284 Shell functions will gradually be introduced, probably starting with
1285 Autotest. If you know machines which are in use that you suspect
1286 *not* to support shell functions, please run the test suite of
1287 Autoconf 2.55 on it, and report the results to
1288 bug-autoconf@gnu.org.
1292 Special characters in AC_MSG_* need not be quoted. Currently,
1293 Autoconf has heuristics to decide when a string is escaped, or has
1294 to be escaped. This scheme is fragile, and will be removed; the
1295 only risk is uglified messages. Please, run `autoreconf -f -Wall'
1296 to find occurrences that will be affected.
1298 * Major changes in Autoconf 2.54
1300 Released 2002-09-13 by Akim Demaille.
1304 - autoreconf no longer changes the version of the gettext/po/intl
1305 support files. It now adds the files the correspond to the
1306 AM_GNU_GETTEXT_VERSION declared in configure.ac.
1308 Warning: It now relies on the 'autopoint' program, which is part
1309 of GNU gettext 0.11.4 and newer.
1311 Please note that you need to have a GNU gettext version that
1312 corresponds at least to the AM_GNU_GETTEXT_VERSION declared
1313 in configure.ac. You can upgrade to newer GNU gettext versions,
1314 though, without needing to change configure.ac.
1316 - The -I DIR or --include=DIR option now appends DIR to the include path
1317 instead of prepending; this is for consistency with other GNU tools.
1318 The new -B DIR or --prepend-include=DIR option has the old behavior.
1323 Now handles all the gory details about LIBOBJS and LTLIBOBJS.
1324 Please, remove lines such as
1326 # This is necessary so that .o files in LIBOBJS are also
1327 # built via the ANSI2KNR-filtering rules.
1328 LIBOBJS=`echo $LIBOBJS|sed 's/\.o /\$U.o /g;s/\.o$/\$U.o/'`
1330 and read the `AC_LIBOBJ vs LIBOBJS' section. Do not define U in
1331 your Makefiles either.
1333 - AC_CONFIG_LINKS now makes copies if it can't make links.
1335 - AC_FUNC_FNMATCH now tests only for POSIX compatibility, reverting to
1336 Autoconf 2.13 behavior. The new macro AC_FUNC_FNMATCH_GNU also
1337 tests for GNU extensions to fnmatch, and replaces fnmatch if needed.
1339 - AC_FUNC_SETVBUF_REVERSED no longer fails when cross-compiling.
1341 - AC_PROG_CC_STDC is integrated into AC_PROG_CC.
1343 - AC_PROG_F77 default search no longer includes cf77 and cfg77.
1347 AC_C_BACKSLASH_A, AC_CONFIG_LIBOBJ_DIR, AC_GNU_SOURCE,
1348 AC_PROG_EGREP, AC_PROG_FGREP, AC_REPLACE_FNMATCH,
1349 AC_FUNC_FNMATCH_GNU, AC_FUNC_REALLOC, AC_TYPE_MBSTATE_T.
1351 - AC_FUNC_GETLOADAVG
1352 looks for getloadavg.c in the CONFIG_LIBOBJ_DIR.
1355 Now defines HAVE_MALLOC to 0 if `malloc' does not work, and asks
1356 for an AC_LIBOBJ replacement.
1360 - Spurious complaints from `m4_bmatch' about invalid regular
1361 expressions are suppressed.
1363 - Empty top_builddirs are properly handled.
1365 - AC_CHECK_MEMBER works correctly when the member is an aggregate.
1368 Now colon in the optional path arguments are properly handled.
1370 ** Improved portability
1372 - Both Autoconf the package, and the scripts it produces, should run
1373 more reliably with Zsh. Bear in mind it is the default Bourne shell
1376 - Autoconf and the scripts it produces no longer assume the existence of
1377 the obsolescent commands egrep and fgrep.
1381 - Limitations of Make
1385 The GNATS base moved to
1386 https://bugs.gnu.org/cgi-bin/gnatsweb.pl?database=autoconf
1387 (It is no longer available, though.)
1392 Now contains the list of output variables and files (AC_SUBST,
1395 * Major changes in Autoconf 2.53
1397 Released 2002-03-08 by Akim Demaille.
1401 Perl 5.005_03 or later is required: autom4te is written in Perl and is
1402 needed by autoconf. autoheader, autoreconf, ifnames, and autoscan are
1408 Argument requirements, output variables, defined macros.
1409 - M4sugar, M4sh, Autotest
1411 - Double quoting macros
1412 AC_TRY_CPP, AC_TRY_COMPILE, AC_TRY_LINK and AC_TRY_RUN.
1414 The Autoconf manual is now distributed under the terms of the GNU FDL.
1415 - Section `Hosts and Cross-Compilation'
1416 Explains the rationale for the 2.5x changes in the cross-compilation
1417 chain, and in the relationships between build, host, and target
1419 Emphasizes that `cross-compilation' == `--host is given'.
1420 If you are working on compilers etc., be sure to read this section.
1421 - Section `AC_LIBOBJ vs. LIBOBJS'
1422 Explains why assigning LIBOBJS directly is now an error.
1423 Details how to update the code.
1428 Now used instead of hard coded line numbers.
1429 This eases the comparison of `configure's, and diminishes the
1430 pressure over control version archives.
1431 Automatic replacement for shells that don't support this feature.
1432 - New output variables
1433 @builddir@, @top_builddir@, @abs_srcdir@, @abs_top_srcdir@, @abs_builddir@,
1438 Autoconf and Autotest modes are provided.
1443 New, used by the Autoconf suite to cache and speed up most processing.
1445 Supported by autom4te, autoconf and autoheader.
1447 Replaces --autoconf-dir and --localdir in autoconf, autoheader,
1448 autoupdate, and autoreconf.
1450 No longer passes --cygnus, --foreign, --gnits, --gnu, --include-deps:
1451 automake options are to be given via AUTOMAKE_OPTIONS.
1453 Runs gettextize and libtoolize when appropriate.
1455 --m4dir is no longer supported.
1457 Now runs only in the specified directories, defaulting to `.',
1458 but understands AC_CONFIG_SUBDIRS for dependent directories.
1459 Before, it used to run on all the `configure.ac' found in the
1461 Independent packages are properly updated.
1465 - The top level $prefix is propagated to the AC_CONFIG_SUBDIRS configures.
1467 Under the user pressure, $? is finally available. Probably a mistake.
1468 - AC_F77_LIBRARY_LDFLAGS now supports the HP/UX f90 compiler.
1469 - Precious variables accumulation
1470 config.status could stack several copies of the precious variables
1472 - AC_PATH_PROG and family.
1473 Works properly when given a literal path.
1475 Somewhere since 2.13, the result had been reversed.
1479 - AC_C_BIGENDIAN supports the cross-compiling case.
1480 - AC_C_BIGENDIAN accepts ACTION-IF-TRUE, ACTION-IF-FALSE, and
1481 ACTION-IF-UNKNOWN arguments. All are optional, and the default
1482 for ACTION-IF-TRUE is to define WORDS_BIGENDIAN like AC_C_BIGENDIAN
1484 - AC_C_LONG_DOUBLE now succeeds only if `long double' has more range or
1485 precision than `double'.
1490 It now defines the preprocessor symbols PACKAGE_NAME,
1491 PACKAGE_TARNAME, PACKAGE_VERSION, PACKAGE_STRING, and
1495 Admits a fourth optional parameter: the tar name.
1497 - AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS.
1498 Provide the user with srcdir, ac_srcdir, ac_top_srcdir, ac_builddir,
1499 ac_top_builddir, ac_abs_srcdir, ac_abs_top_srcdir, ac_abs_builddir,
1500 ac_abs_top_builddir.
1502 - AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS and AC_OUTPUT.
1503 Are much less expensive when using long lists of files.
1506 Works with shell variables, and non alphanumeric names.
1510 - AC_FUNC_STRERROR_R now sets STRERROR_R_CHAR_P, not HAVE_WORKING_STRERROR_R,
1511 because POSIX 1003.1-200x draft 7 says strerror_r returns int, not char *.
1513 - AC_FUNC_STRTOD substitutes POW_LIB.
1518 * Major changes in Autoconf 2.52
1520 Released 2001-07-18 by Akim Demaille.
1525 This feature was present in autoconf 2.50 but was not documented.
1526 For example, `@<:@' is translated to `[' just before output. This
1527 is useful when writing strings that contain unbalanced quotes, or
1528 other hard-to-quote constructs.
1529 - m4_pattern_forbid, m4_pattern_allow
1530 - Tips for upgrading from 2.13.
1531 - Using autoscan to maintain a configure.ac.
1534 - Now include stdint.h.
1535 - sys/types.h and sys/stat.h are guarded.
1536 - strings.h is included if available, and not conflicting with string.h.
1539 - The test suite is more robust and presents less false failures.
1540 - Invocation of GNU M4 now robust to POSIXLY_CORRECT.
1541 - configure accepts --prefix='' again.
1542 - AC_CHECK_LIB works properly when its first argument is not a
1544 - HAVE_INTTYPES_H is defined only if not conflicting with sys/types.h.
1545 - build_, host_, and target_alias are AC_SUBST as in 2.13.
1546 - AC_ARG_VAR properly propagates precious variables inherited from the
1547 environment to ./config.status.
1548 - Using --program-suffix/--program-prefix is portable.
1549 - Failures to detect the default compiler's output extension are less
1551 - `config.status foo' works properly when `foo' depends on variables
1552 set in an AC_CONFIG_THING INIT-CMD.
1553 - autoheader is more robust to broken input.
1554 - Fixed Fortran name-mangling and link tests on a number of systems,
1555 e.g. NetBSD; see AC_F77_DUMMY_MAIN, below.
1558 - AC_CHECK_HEADER and AC_CHECK_HEADERS support a fourth argument to
1559 specify pre-includes. In this case, the headers are compiled with
1560 cc, not merely preprocessed by cpp. Therefore it is the _usability_
1561 of a header which is checked for, not just its availability.
1562 - AC_ARG_VAR refuses to run configure when precious variables have
1564 - Versions of compilers are dumped in the logs.
1565 - AC_CHECK_TYPE recognizes use of `foo_t' as a replacement type.
1568 - AC_PATH_XTRA only adds -ldnet to $LIBS if it's needed to link.
1569 - AC_FUNC_WAIT3 and AC_SYS_RESTARTABLE_SYSCALLS are obsoleted.
1570 - AM_FUNC_ERROR_AT_LINE, AM_FUNC_FNMATCH, AM_FUNC_MKTIME,
1571 AM_FUNC_OBSTACK, and AM_FUNC_STRTOD are now activated.
1572 Be sure to read `Upgrading from Version 2.13' to understand why
1573 running `autoupdate' is needed.
1574 - AC_F77_DUMMY_MAIN, AC_F77_MAIN: new macros to detect whether
1575 a main-like routine is required/possible when linking C/C++ with
1576 Fortran. Users of e.g. AC_F77_WRAPPERS should be aware of these.
1577 - AC_FUNC_GETPGRG behaves better when cross-compiling.
1579 * Major changes in Autoconf 2.51
1580 There was no release of Autoconf 2.51 since some packagers had used
1581 this version number without permission to ship intermediary versions
1582 of 2.50. The version was skipped to avoid confusion.
1584 * Major changes in Autoconf 2.50
1586 Released 2001-05-21 by Akim Demaille.
1588 ** Lots of bug fixes
1589 There have been far too many to enumerate them here. Check out
1590 ChangeLog if you really want to know more.
1592 ** Improved documentation
1593 In particular, portability issues are better covered.
1596 All the standard GNU Makefile targets are supported. The layout has
1597 changed: m4/ holds the M4 extensions Autoconf needs for its
1598 configuration, doc/ contains the documentation, and tests/ contains
1601 ** Man pages are provided
1602 For autoconf, autoreconf, autoupdate, autoheader, autoscan, ifnames,
1603 config.guess, config.sub.
1607 Provides a safe and powerful means to trace the macro uses. This
1608 provide the parsing layer for tools which need to `study'
1612 Specify what category of warnings should be enabled.
1614 - When recursing into subdirectories, try for configure.gnu before
1615 configure to adapt for packages not using autoconf on case-insensitive
1619 More errors are now caught (circular AC_REQUIRE dependencies,
1620 AC_DEFINE in the action part of an AC_CACHE_CHECK, too many pops
1621 etc.). In addition, their location and call stack are given.
1624 autoupdate is much more powerful, and is able to provide the glue code
1625 which might be needed to move from an old macro to its newer
1628 You are strongly encouraged to use it to modernize both your
1629 `configure.in' and your .m4 extension files.
1632 The internal machinery of autoheader has completely changed. As a
1633 result, using `acconfig.h' should be considered to be obsoleted, and
1634 you are encouraged to get rid of it using the AH macros.
1639 ** Fortran 77 compilers
1640 Globally, the support for Fortran 77 is considerably improved.
1642 Support for automatically determining a Fortran 77 compiler's
1643 name-mangling scheme. New CPP macros F77_FUNC and F77_FUNC_ are
1644 provided to wrap C/C++ identifiers, thus making it easier and more
1645 transparent for C/C++ to call Fortran 77 routines, and Fortran 77 to
1646 call C/C++ routines. See the Texinfo documentation for details.
1649 The test suite no longer uses DejaGNU. It should be easy to submit
1650 test cases in this new framework.
1653 - --help, --help=long, -hl
1654 no longer dumps useless items.
1656 lists only specific options.
1657 - --help=recursive, -hr
1658 displays the help of all the embedded packages.
1659 - Remembers environment variables when reconfiguring.
1660 The previous scheme to set envvar before running configure was
1662 what prevented configure from remembering the environment in which
1663 it was run, therefore --recheck was run in an inconsistent
1664 environment. Now, one should run
1666 and then --recheck will work properly. Variables declared with
1667 AC_ARG_VAR are also preserved.
1669 $build defaults to `config.guess`, $host to $build, and then $target
1671 Cross-compilation is a global status of the package, it no longer
1672 depends upon the current language.
1673 Cross compilation is enabled iff the user specified `--host'.
1674 `configure' now fails if it can't run the executables it compiles,
1675 unless cross-compilation is enabled.
1677 The cache file is disabled by default. The new options
1678 `--config-cache', `-C' set the cache to `config.cache'.
1682 Much faster on most architectures.
1683 - concurrent executions
1684 It is safe to use `make -j' with config.status.
1685 - human interface improved
1686 It is possible to invoke
1687 ./config.status foobar
1688 instead of the former form (still valid)
1689 CONFIG_COMMANDS= CONFIG_HEADERS= CONFIG_LINKS= \
1690 CONFIG_FILES=foobar:foo.in:bar.in \
1692 The same holds for configuration headers and links.
1693 You can instantiate unknown files and headers:
1694 ./config.status --header foo.h:foo.h.in --file bar:baz
1695 - has a useful --help
1696 - accepts special file name "-" for stdin/stdout
1701 Specify additional copyright information.
1704 Now expects the identity of the package as argument.
1708 Most macros, if not all, now strictly follow the `one quotation
1709 level' rule. This results in a more predictable expansion.
1712 A sly bug in the AC_REQUIRE machinery, which could produce incorrect
1713 configure scripts, was fixed by Axel Thimm.
1717 Document and ask for the registration of an envvar.
1720 Specifies the file which `configure' should look for when trying to
1721 find the source tree (used to be handled by AC_INIT).
1723 - AC_CONFIG_COMMANDS
1724 To add new actions to config.status. Should be used instead of
1728 Replaces AC_LINK_FILES.
1730 - AC_CONFIG_HEADERS, AC_CONFIG_COMMANDS, AC_CONFIG_SUBDIRS,
1731 AC_CONFIG_LINKS, and AC_CONFIG_FILES
1732 They now obey sh: you should no longer use shell variables as
1733 argument. Instead of
1735 test "$package_foo_enabled" = yes && $my_subdirs="$my_subdirs foo"
1736 AC_CONFIG_SUBDIRS($my_subdirs)
1740 if test "$package_foo_enabled" = yes; then
1741 AC_CONFIG_SUBDIRS(foo)
1745 To format an Autoconf macro's help string so that it looks pretty
1746 when the user executes `configure --help'.
1749 ** Generic Test Macros
1751 The interface of the AC_CHECK families of macros (decl, header,
1752 type, member, func) is now uniform. They support the same set of
1755 - AC_CHECK_DECL, AC_CHECK_DECLS
1756 To check whether a symbol is declared.
1758 - AC_CHECK_SIZEOF, AC_C_CHAR_UNSIGNED.
1759 No longer need a cross-compilation default.
1762 The test it performs is much more robust than previously, and makes
1763 it possible to test builtin types in addition to typedefs.
1764 It is now schizophrenic:
1765 - AC_CHECK_TYPE(TYPE, REPLACEMENT)
1766 remains for backward compatibility, but its use is discouraged.
1767 - AC_CHECK_TYPE(TYPE, IF-FOUND, IF-NOT-FOUND, INCLUDES)
1768 behaves exactly like the other AC_CHECK macros.
1771 Checks whether given types are supported by the system.
1773 - AC_CHECK_MEMBER, AC_CHECK_MEMBERS
1774 Check for given members in aggregates (e.g., pw_gecos in struct
1778 Checks if the compiler supports ISO C, included when needs special
1782 Checking whether the preprocessor indicates missing includes by the
1783 error code. stderr is checked by AC_TRY_CPP only as a fallback.
1786 Takes a language as argument and replaces AC_LANG_C,
1787 AC_LANG_CPLUSPLUS and AC_LANG_FORTRAN77.
1789 - AC_LANG_PUSH, AC_LANG_POP
1790 Are preferred to AC_LANG_SAVE, AC_LANG_RESTORE.
1793 - AC_FUNC_CHOWN, AC_FUNC_MALLOC, AC_FUNC_STRERROR_R,
1794 AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK, AC_FUNC_STAT, AC_FUNC_LSTAT,
1795 AC_FUNC_ERROR_AT_LINE, AC_FUNC_OBSTACK, AC_FUNC_STRTOD, AC_FUNC_FSEEKO.
1799 Sets GETGROUPS_LIBS.
1801 - AC_FUNC_GETLOADAVG
1802 Defines `HAVE_STRUCT_NLIST_N_UN_N_NAME' instead of `NLIST_NAME_UNION'.
1805 Now integrates `AC_DECL_YYTEXT' which is obsoleted.
1808 Arrange for large-file support.
1810 - AC_EXEEXT, AC_OBJEXT
1811 You are no longer expected to use them: their computation is
1812 performed by default.
1814 ** C++ compatibility
1815 Every macro has been revisited in order to support at best CC=c++.
1817 Major changes in Autoconf 2.14:
1818 There was no release of GNU Autoconf 2.14.
1820 Major changes in Autoconf 2.13:
1822 Released 1999-05-01 by Ben Elliston.
1824 * Support for building on 32-bit Windows systems where the only available C or
1825 C++ compiler is the Microsoft Visual C++ command line compiler
1826 (`cl'). Additional support for building on 32-bit Windows systems which are
1827 using the Cygwin or Mingw32 environments.
1828 * Support for alternative object file and executable file extensions.
1829 On 32-bit Windows, for example, these are .obj and .exe. These are discovered
1830 using AC_OBJEXT and AC_EXEEXT, which substitute @OBJEXT@ and
1831 @EXEEXT@ in the output, respectively.
1832 * New macros: AC_CACHE_LOAD, AC_CACHE_SAVE, AC_FUNC_SELECT_ARGTYPES,
1833 AC_VALIDATE_CACHED_SYSTEM_TUPLE, AC_SEARCH_LIBS, AC_TRY_LINK_FUNC,
1834 AC_C_STRINGIZE, AC_CHECK_FILE(S), AC_PROG_F77 (and friends).
1835 * AC_DEFINE now has an optional third argument for a description to be
1836 placed in the config header input file (e.g. config.h.in).
1837 * The C++ code fragment compiled for the C++ compiler test had to be
1838 improved to include an explicit return type for main(). This was
1839 causing failures on systems using recent versions of the EGCS C++
1841 * Fixed an important bug in AC_CHECK_TYPE that would cause a configure
1842 script to report that `sometype_t' was present when only `type_t'
1844 * Merge of the FSF version of config.guess and config.sub to modernize
1845 these scripts. Add support for a few new hosts in config.guess.
1846 Incorporate latest versions of install-sh, mkinstalldirs and
1847 texinfo.tex from the FSF.
1848 * autoreconf is capable of running automake if necessary (and
1850 * Support for Fortran 77. See the Texinfo documentation for details.
1851 * Bug fixes and workarounds for quirky bugs in vendor utilities.
1853 Major changes in Autoconf 2.12:
1855 Released 1996-11-26 by David J. MacKenzie
1857 * AC_OUTPUT and AC_CONFIG_HEADER can create output files by
1858 concatenating multiple input files separated by colons, like so:
1859 AC_CONFIG_HEADER(config.h:conf.pre:config.h.in:conf.post)
1860 AC_OUTPUT(Makefile:Makefile.in:Makefile.rules)
1861 The arguments may be shell variables, to compute the lists on the fly.
1862 * AC_LINK_FILES and AC_CONFIG_SUBDIRS may be called multiple times.
1863 * New macro AC_OUTPUT_COMMANDS adds more commands to run in config.status.
1866 Major changes in Autoconf 2.11:
1868 Released November 18th, 1996, by David J. MacKenzie
1870 * AC_PROG_CC and AC_PROG_CXX check whether the compiler works.
1871 They also default CFLAGS/CXXFLAGS to "-g -O2" for gcc, instead of "-g -O".
1872 * AC_REPLACE_FUNCS defines HAVE_foo if the system has the function `foo'.
1873 * AC_CONFIG_HEADER expands shell variables in its argument.
1874 * New macros: AC_FUNC_FNMATCH, AC_FUNC_SETPGRP.
1875 * The "checking..." messages and the source code for test programs that
1876 fail are saved in config.log.
1877 * Another workaround has been added for seds with small command length limits.
1878 * config.sub and config.guess recognize more system types.
1881 Major changes in Autoconf 2.10:
1883 Released May 7th, 1996, by Roland McGrath
1886 * The cache variable names used by `AC_CHECK_LIB(LIB, FUNC, ...)' has
1887 changed: now $ac_cv_lib_LIB_FUNC, previously $ac_cv_lib_LIB.
1889 Major changes in Autoconf 2.9:
1891 Released March 16th, 1996, by Roland McGrath
1895 Major changes in Autoconf 2.8:
1897 Released March 8th, 1996, by Roland McGrath
1901 Major changes in Autoconf 2.7:
1903 Released November 22nd, 1995, by David J. MacKenzie
1907 Major changes in Autoconf 2.6:
1909 Released November 20th, 1995, by David J. MacKenzie
1913 Major changes in Autoconf 2.5:
1915 Released November 17th, 1995, by Roland McGrath
1917 * New configure options --bindir, --libdir, --datadir, etc., with
1918 corresponding output variables.
1919 * New macro: AC_CACHE_CHECK, to make using the cache easier.
1920 * config.log contains the command being run as well as any output from it.
1921 * AC_CHECK_LIB can check for libraries with "." or "/" or "+" in their name.
1922 * AC_PROG_INSTALL doesn't cache a name for install-sh, for sharing caches.
1923 * AC_CHECK_PROG, AC_PATH_PROG, AC_CHECK_PROGS, AC_PATH_PROGS, and
1924 AC_CHECK_TOOL can search a path other than $PATH.
1925 * AC_CHECK_SIZEOF takes an optional size to use when cross-compiling.
1927 Major changes in Autoconf 2.4:
1929 Released June 14th, 1995, by David J. MacKenzie
1931 * Fix a few bugs found by Emacs testers.
1933 Major changes in Autoconf 2.3:
1935 Released March 27th, 1995, by David J. MacKenzie
1937 * Fix the cleanup trap in several ways.
1938 * Handle C compilers that are picky about option placement.
1939 * ifnames gets the version number from the right directory.
1941 Major changes in Autoconf 2.2:
1943 Released March 8th, 1995, by David J. MacKenzie
1945 * The ifnames utility is much faster but requires a "new awk" interpreter.
1946 * AC_CHECK_LIB and AC_HAVE_LIBRARY check and add the new
1947 library before existing libs, not after, in case it uses them.
1948 * New macros: AC_FUNC_GETPGRP, AC_CHECK_TOOL.
1949 * Lots of bug fixes.
1950 * Many additions to the TODO file :-)
1952 Major changes in Autoconf 2.1:
1954 Released November 4th, 1994, by David J. MacKenzie
1957 * More explanations in the manual.
1958 * Fix a spurious failure in the testsuite.
1959 * Clarify some warning messages.
1960 * autoreconf by default only rebuilds configure and config.h.in files
1961 that are older than any of their particular input files; there is a
1962 --force option to use after installing a new version of Autoconf.
1964 Thanks to everybody who's submitted changes and additions to Autoconf!
1965 I've incorporated many of them, and am still considering others for
1966 future releases -- but I didn't want to postpone this release indefinitely.
1968 Caution: don't indiscriminately rebuild configure scripts with
1969 Autoconf version 2. Some configure.in files need minor adjustments to
1970 work with it; the documentation has a chapter on upgrading. A few
1971 configure.in files, including those for GNU Emacs and the GNU C
1972 Library, need major changes because they relied on undocumented
1973 internals of version 1. Future releases of those packages will have
1974 updated configure.in files.
1976 It's best to use GNU M4 1.3 (or later) with Autoconf version 2.
1977 Autoconf now makes heavy use of M4 diversions, which were implemented
1978 inefficiently in GNU M4 releases before 1.3.
1980 Major changes in Autoconf 2.0:
1982 Released October 26th, 1994, by David J. MacKenzie
1984 ** New copyright terms:
1985 * There are no restrictions on distribution or use of configure scripts.
1988 * Autoconf manual is reorganized to make information easier to find
1989 and has several new indexes.
1990 * INSTALL is reorganized and clearer and is now made from Texinfo source.
1993 * autoscan to generate a preliminary configure.in for a package by
1994 scanning its source code for commonly used nonportable functions,
1995 programs, and header files.
1996 * ifnames to list the symbols used in #if and #ifdef directives in a
1998 * autoupdate to update a configure.in to use the version 2 macro names.
1999 * autoreconf to recursively remake configure and configuration header
2000 files in a source tree.
2002 ** Changed utilities:
2003 * autoheader can take pieces of acconfig.h to replace config.h.{top,bot}.
2004 * autoconf and autoheader can look for package-local definition files
2005 in an alternate directory.
2008 * AC_CACHE_VAL to share results of tests between configure runs.
2009 * AC_DEFUN to define macros, automatically AC_PROVIDE them, and ensure
2010 that macros invoked with AC_REQUIRE don't interrupt other macros.
2011 * AC_CONFIG_AUX_DIR, AC_CANONICAL_SYSTEM, AC_CANONICAL_HOST, AC_LINK_FILES to
2012 support deciding unguessable features based on the host and target types.
2013 * AC_CONFIG_SUBDIRS to recursively configure a source tree.
2014 * AC_ARG_PROGRAM to use the options --program-prefix,
2015 --program-suffix, and --program-transform-name to change the names
2016 of programs being installed.
2017 * AC_PREFIX_DEFAULT to change the default installation prefix.
2018 * AC_TRY_COMPILE to compile a test program without linking it.
2019 * AC_CHECK_TYPE to check whether sys/types.h or stdlib.h defines a given type.
2020 * AC_CHECK_LIB to check for a particular function and library.
2021 * AC_MSG_CHECKING and AC_MSG_RESULT to print test results, on a single line,
2022 whether or not the test succeeds. They obsolete AC_CHECKING and AC_VERBOSE.
2023 * AC_SUBST_FILE to insert one file into another.
2024 * AC_FUNC_MEMCMP to check whether memcmp is 8-bit clean.
2025 * AC_FUNC_STRFTIME to find strftime even if it's in -lintl.
2026 * AC_FUNC_GETMNTENT to find getmntent even if it's in -lsun or -lseq.
2027 * AC_HEADER_SYS_WAIT to check whether sys/wait.h is POSIX.1 compatible.
2030 * Many macros renamed systematically, but old names are accepted for
2031 backward compatibility.
2032 * AC_OUTPUT adds the "automatically generated" comment to
2033 non-Makefiles where it finds @configure_input@ in an input file, to
2034 support files with various comment syntaxes.
2035 * AC_OUTPUT does not replace "prefix" and "exec_prefix" in generated
2036 files when they are not enclosed in @ signs.
2037 * AC_OUTPUT allows the optional environment variable CONFIG_STATUS to
2038 override the file name "config.status".
2039 * AC_OUTPUT takes an optional argument for passing variables from
2040 configure to config.status.
2041 * AC_OUTPUT and AC_CONFIG_HEADER allow you to override the input-file names.
2042 * AC_OUTPUT automatically substitutes the values of CFLAGS, CXXFLAGS,
2043 CPPFLAGS, and LDFLAGS from the environment.
2044 * AC_PROG_CC and AC_PROG_CXX now set CFLAGS and CXXFLAGS, respectively.
2045 * AC_PROG_INSTALL looks for install-sh or install.sh in the directory
2046 specified by AC_CONFIG_AUXDIR, or srcdir or srcdir/.. or
2047 srcdir/../.. by default.
2048 * AC_DEFINE, AC_DEFINE_UNQUOTED, and AC_SUBST are more robust and smaller.
2049 * AC_DEFINE no longer prints anything, because of the new result reporting
2050 mechanism (AC_MSG_CHECKING and AC_MSG_RESULT).
2051 * AC_VERBOSE pays attention to --quiet/--silent, not --verbose.
2052 * AC_ARG_ENABLE and AC_ARG_WITH support whitespace in the arguments to
2053 --enable- and --with- options.
2054 * AC_CHECK_FUNCS and AC_CHECK_HEADERS take optional shell commands to
2055 execute on success or failure.
2056 * Checking for C functions in C++ works.
2059 * AC_REMOTE_TAPE and AC_RSH removed; too specific to tar and cpio, and
2060 better maintained with them.
2061 * AC_ARG_ARRAY removed because no one was likely using it.
2062 * AC_HAVE_POUNDBANG replaced with AC_SYS_INTERPRETER, which doesn't
2063 take arguments, for consistency with all of the other specific checks.
2066 * Comes with config.sub and config.guess, and uses them optionally.
2067 * Uses config.cache to cache test results. An alternate cache file
2068 can be selected with the --cache-file=FILE option.
2069 * Uses optional shell scripts $prefix/share/config.site and
2070 $prefix/etc/config.site to perform site or system specific initializations.
2071 * configure saves compiler output to ./config.log for debugging.
2072 * New files autoconf.m4 and autoheader.m4 load the other Autoconf macros.
2073 * acsite.m4 is the new name for the system-wide aclocal.m4.
2074 * Has a DejaGnu test suite.
2076 Major changes in Autoconf 1.11:
2078 * AC_PROG_INSTALL calls install.sh with the -c option.
2079 * AC_SET_MAKE cleans up after itself.
2080 * AC_OUTPUT sets prefix and exec_prefix if they weren't set already.
2081 * AC_OUTPUT prevents shells from looking in PATH for config.status.
2083 Plus a few other bug fixes.
2085 Major changes in Autoconf 1.10:
2087 * autoheader uses config.h.bot if present, analogous to config.h.top.
2088 * AC_PROG_INSTALL looks for install.sh in srcdir or srcdir/.. and
2090 * AC_PROG_CXX looks for cxx as a C++ compiler.
2092 Plus several bugs fixed.
2094 Major changes in Autoconf 1.9:
2096 * AC_YYTEXT_POINTER replaces AC_DECLARE_YYTEXT.
2097 * AC_SIZEOF_TYPE generates the cpp symbol name automatically,
2098 and autoheader generates entries for those names automatically.
2099 * AC_FIND_X gets the result from xmkmf correctly.
2100 * AC_FIND_X assumes no X if --without-x was given.
2101 * AC_FIND_XTRA adds libraries to the variable X_EXTRA_LIBS.
2102 * AC_PROG_INSTALL finds OSF/1 installbsd.
2104 Major changes in Autoconf 1.8:
2107 * New macros AC_LANG_C, AC_LANG_CPLUSPLUS, AC_LANG_SAVE, AC_LANG_RESTORE,
2108 AC_PROG_CXX, AC_PROG_CXXCPP, AC_REQUIRE_CPP
2109 for checking both C++ and C features in one configure script.
2110 * New macros AC_CHECKING, AC_VERBOSE, AC_WARN, AC_ERROR for printing messages.
2111 * New macros AC_FIND_XTRA, AC_MMAP, AC_SIZEOF_TYPE, AC_PREREQ,
2112 AC_SET_MAKE, AC_ENABLE.
2115 * AC_FIND_X looks for X in more places.
2116 * AC_PROG_INSTALL defaults to install.sh instead of cp, if it's in srcdir.
2117 install.sh is distributed with Autoconf.
2118 * AC_DECLARE_YYTEXT has been removed because it can't work, pending
2119 a rewrite of quoting in AC_DEFINE.
2120 * AC_OUTPUT adds its comments in C format when substituting in C files.
2121 * AC_COMPILE_CHECK protects its ECHO-TEXT argument with double quotes.
2123 ** New or changed command line options:
2124 * configure accepts --enable-FEATURE[=ARG] and --disable-FEATURE options.
2125 * configure accepts --without-PACKAGE, which sets withval=no.
2126 * configure accepts --x-includes=DIR and --x-libraries=DIR.
2127 * Giving --with-PACKAGE no argument sets withval=yes instead of withval=1.
2128 * configure accepts --help, --version, --silent/--quiet, --no-create options.
2129 * configure accepts and ignores most other Cygnus configure options, and
2130 warns about unknown options.
2131 * config.status accepts --help, --version options.
2133 ** File names and other changes:
2134 * Relative srcdir values are not made absolute.
2135 * The values of @prefix@ and @exec_prefix@ and @top_srcdir@ get substituted.
2136 * Autoconf library files are installed in ${datadir}/autoconf, not ${datadir}.
2137 * autoheader optionally copies config.h.top to the beginning of config.h.in.
2138 * The example Makefile dependencies for configure et al. work better.
2139 * Namespace cleanup: all shell variables used internally by Autoconf
2140 have names beginning with `ac_'.
2142 More big improvements are in process for future releases, but have not
2143 yet been (variously) finished, integrated, tested, or documented enough
2146 Major changes in Autoconf 1.7:
2148 * New macro AC_OBSOLETE.
2149 * Bugs in Makefile.in fixed.
2150 * AC_LONG_FILE_NAMES improved.
2152 Major changes in Autoconf 1.6:
2154 * New macro AC_LONG_64_BITS.
2155 * Multiple .h files can be created.
2156 * AC_FIND_X looks for X files directly if it doesn't find xmkmf.
2157 * AC_ALLOCA defines C_ALLOCA if using alloca.c.
2158 * --with-NAME can take a value, e.g., --with-targets=sun4,hp300bsd.
2159 * Unused --no-create option to configure removed.
2160 * autoheader doesn't change the timestamp of its output file if
2161 the file didn't change.
2162 * All macros that look for libraries now use AC_HAVE_LIBRARY.
2163 * config.status checks three optional environment variables to
2164 modify its behavior.
2165 * The usual bug fixes.
2167 Major changes in Autoconf 1.5:
2169 * New macros AC_FIND_X, AC_OFF_T, AC_STAT_MACROS_BROKEN, AC_REVISION.
2170 * autoconf and autoheader scripts have GNU standards conforming
2171 --version and --help options (they print their message and exit).
2174 Major changes in Autoconf 1.4:
2176 * New macros AC_HAVE_POUNDBANG, AC_TIME_WITH_SYS_TIME, AC_LONG_DOUBLE,
2177 AC_GETGROUPS_T, AC_DEFINE_UNQUOTED.
2178 * autoconf and autoheader use the M4 environment variable to determine the
2179 name of the M4 program to use.
2180 * The --macrodir option to autoconf and autoheader specifies the directory
2181 in which acspecific.m4, acgeneral.m4, etc. reside if not the default.
2182 * autoconf and autoheader can take `-' as their file names, which means to
2183 read stdin as input.
2184 * Resulting configure scripts can take a --verbose option which causes them
2185 to print the results of their tests.
2186 * AC_DEFINE quotes its second argument in such a way that spaces, magic
2187 shell characters, etc. will be preserved during various stages of
2188 expansion done by the shell. If you don't want this, use
2189 AC_DEFINE_UNQUOTED instead.
2190 * Much textual processing done with external calls to tr and sed have been
2191 internalized with builtin M4 `patsubst' and `translit' calls.
2192 * AC_OUTPUT doesn't hardwire the file names it outputs. Instead, you can
2193 set the shell variables `gen_files' and `gen_config' to the list of
2194 file names to output.
2195 * AC_DECLARE_YYTEXT does an AC_SUBST of `LEX_OUTPUT_ROOT', which may be
2196 "lex.yy" or "lexyy", depending on the system.
2197 * AC_PROGRAMS_CHECK takes an optional third arg. If given, it is used as
2199 * If AC_ALLOCA chooses alloca.c, it also defines STACK_DIRECTION.
2200 * AC_CONST works much more reliably on more systems.
2203 Major changes in Autoconf 1.3:
2205 configure no longer requires awk for packages that use a config.h.
2206 Support handling --with-PACKAGE options.
2207 New `autoheader' script to create `config.h.in' from `configure.in'.
2208 Ignore troublesome -lucb and -lPW when searching for alloca.
2209 Rename --exec_prefix to --exec-prefix for GNU standards conformance.
2210 Improve detection of STDC library.
2211 Add AC_HAVE_LIBRARY to check for non-default libraries.
2212 Function checking should work with future GNU libc releases.
2214 Major changes in Autoconf 1.2:
2216 The --srcdir option is now usually unnecessary.
2217 Add a file containing sample comments describing CPP macros.
2218 A comment in config.status tells which host it was configured on.
2219 Substituted variable values can now contain commas.
2220 Fix bugs in various feature checks.
2222 Major changes in Autoconf 1.1:
2224 Added AC_STRCOLL macro.
2225 Made AC_GETLOADAVG check for more things.
2226 AC_OUTPUT argument is now optional.
2231 Copyright (C) 1993-1996, 1998-2017 Free Software Foundation, Inc.
2233 Copying and distribution of this file, with or without modification,
2234 are permitted in any medium without royalty provided the copyright
2235 notice and this notice are preserved. This file is offered as-is,
2236 without warranty of any kind.