1 # gnulib-common.m4 serial 66
2 dnl Copyright (C) 2007-2021 Free Software Foundation, Inc.
3 dnl This file is free software; the Free Software Foundation
4 dnl gives unlimited permission to copy and/or distribute it,
5 dnl with or without modifications, as long as this notice is preserved.
10 # is expanded unconditionally through gnulib-tool magic.
11 AC_DEFUN([gl_COMMON], [
12 dnl Use AC_REQUIRE here, so that the code is expanded once only.
13 AC_REQUIRE([gl_00GNULIB])
14 AC_REQUIRE([gl_COMMON_BODY])
15 AC_REQUIRE([gl_ZZGNULIB])
17 AC_DEFUN([gl_COMMON_BODY], [
18 AH_VERBATIM([_GL_GNUC_PREREQ],
19 [/* True if the compiler says it groks GNU C version MAJOR.MINOR. */
20 #if defined __GNUC__ && defined __GNUC_MINOR__
21 # define _GL_GNUC_PREREQ(major, minor) \
22 ((major) < __GNUC__ + ((minor) <= __GNUC_MINOR__))
24 # define _GL_GNUC_PREREQ(major, minor) 0
27 AH_VERBATIM([_Noreturn],
28 [/* The _Noreturn keyword of C11. */
30 # if (defined __cplusplus \
31 && ((201103 <= __cplusplus && !(__GNUC__ == 4 && __GNUC_MINOR__ == 7)) \
32 || (defined _MSC_VER && 1900 <= _MSC_VER)) \
34 /* [[noreturn]] is not practically usable, because with it the syntax
35 extern _Noreturn void func (...);
36 would not be valid; such a declaration would only be valid with 'extern'
37 and '_Noreturn' swapped, or without the 'extern' keyword. However, some
38 AIX system header files and several gnulib header files use precisely
39 this syntax with 'extern'. */
40 # define _Noreturn [[noreturn]]
41 # elif ((!defined __cplusplus || defined __clang__) \
42 && (201112 <= (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) \
43 || (!defined __STRICT_ANSI__ \
44 && (_GL_GNUC_PREREQ (4, 7) \
45 || (defined __apple_build_version__ \
46 ? 6000000 <= __apple_build_version__ \
47 : 3 < __clang_major__ + (5 <= __clang_minor__))))))
48 /* _Noreturn works as-is. */
49 # elif _GL_GNUC_PREREQ (2, 8) || defined __clang__ || 0x5110 <= __SUNPRO_C
50 # define _Noreturn __attribute__ ((__noreturn__))
51 # elif 1200 <= (defined _MSC_VER ? _MSC_VER : 0)
52 # define _Noreturn __declspec (noreturn)
58 AH_VERBATIM([isoc99_inline],
59 [/* Work around a bug in Apple GCC 4.0.1 build 5465: In C99 mode, it supports
60 the ISO C 99 semantics of 'extern inline' (unlike the GNU C semantics of
61 earlier versions), but does not display it by setting __GNUC_STDC_INLINE__.
62 __APPLE__ && __MACH__ test for Mac OS X.
63 __APPLE_CC__ tests for the Apple compiler and its version.
64 __STDC_VERSION__ tests for the C99 mode. */
65 #if defined __APPLE__ && defined __MACH__ && __APPLE_CC__ >= 5465 && !defined __cplusplus && __STDC_VERSION__ >= 199901L && !defined __GNUC_STDC_INLINE__
66 # define __GNUC_STDC_INLINE__ 1
68 AH_VERBATIM([attribute],
70 #if (defined __has_attribute \
71 && (!defined __clang_minor__ \
72 || 3 < __clang_major__ + (5 <= __clang_minor__)))
73 # define _GL_HAS_ATTRIBUTE(attr) __has_attribute (__##attr##__)
75 # define _GL_HAS_ATTRIBUTE(attr) _GL_ATTR_##attr
76 # define _GL_ATTR_alloc_size _GL_GNUC_PREREQ (4, 3)
77 # define _GL_ATTR_always_inline _GL_GNUC_PREREQ (3, 2)
78 # define _GL_ATTR_artificial _GL_GNUC_PREREQ (4, 3)
79 # define _GL_ATTR_cold _GL_GNUC_PREREQ (4, 3)
80 # define _GL_ATTR_const _GL_GNUC_PREREQ (2, 95)
81 # define _GL_ATTR_deprecated _GL_GNUC_PREREQ (3, 1)
82 # define _GL_ATTR_diagnose_if 0
83 # define _GL_ATTR_error _GL_GNUC_PREREQ (4, 3)
84 # define _GL_ATTR_externally_visible _GL_GNUC_PREREQ (4, 1)
85 # define _GL_ATTR_fallthrough _GL_GNUC_PREREQ (7, 0)
86 # define _GL_ATTR_format _GL_GNUC_PREREQ (2, 7)
87 # define _GL_ATTR_leaf _GL_GNUC_PREREQ (4, 6)
89 # define _GL_ATTR_may_alias 0
91 # define _GL_ATTR_may_alias _GL_GNUC_PREREQ (3, 3)
93 # define _GL_ATTR_malloc _GL_GNUC_PREREQ (3, 0)
94 # define _GL_ATTR_noinline _GL_GNUC_PREREQ (3, 1)
95 # define _GL_ATTR_nonnull _GL_GNUC_PREREQ (3, 3)
96 # define _GL_ATTR_nonstring _GL_GNUC_PREREQ (8, 0)
97 # define _GL_ATTR_nothrow _GL_GNUC_PREREQ (3, 3)
98 # define _GL_ATTR_packed _GL_GNUC_PREREQ (2, 7)
99 # define _GL_ATTR_pure _GL_GNUC_PREREQ (2, 96)
100 # define _GL_ATTR_returns_nonnull _GL_GNUC_PREREQ (4, 9)
101 # define _GL_ATTR_sentinel _GL_GNUC_PREREQ (4, 0)
102 # define _GL_ATTR_unused _GL_GNUC_PREREQ (2, 7)
103 # define _GL_ATTR_warn_unused_result _GL_GNUC_PREREQ (3, 4)
106 #ifdef __has_c_attribute
107 # define _GL_HAS_C_ATTRIBUTE(attr) __has_c_attribute (__##attr##__)
109 # define _GL_HAS_C_ATTRIBUTE(attr) 0
112 ]dnl There is no _GL_ATTRIBUTE_ALIGNED; use stdalign's _Alignas instead.
114 #if _GL_HAS_ATTRIBUTE (alloc_size)
115 # define _GL_ATTRIBUTE_ALLOC_SIZE(args) __attribute__ ((__alloc_size__ args))
117 # define _GL_ATTRIBUTE_ALLOC_SIZE(args)
120 #if _GL_HAS_ATTRIBUTE (always_inline)
121 # define _GL_ATTRIBUTE_ALWAYS_INLINE __attribute__ ((__always_inline__))
123 # define _GL_ATTRIBUTE_ALWAYS_INLINE
126 #if _GL_HAS_ATTRIBUTE (artificial)
127 # define _GL_ATTRIBUTE_ARTIFICIAL __attribute__ ((__artificial__))
129 # define _GL_ATTRIBUTE_ARTIFICIAL
132 /* Avoid __attribute__ ((cold)) on MinGW; see thread starting at
133 <https://lists.gnu.org/r/emacs-devel/2019-04/msg01152.html>.
134 Also, Oracle Studio 12.6 requires 'cold' not '__cold__'. */
135 #if _GL_HAS_ATTRIBUTE (cold) && !defined __MINGW32__
137 # define _GL_ATTRIBUTE_COLD __attribute__ ((__cold__))
139 # define _GL_ATTRIBUTE_COLD __attribute__ ((cold))
142 # define _GL_ATTRIBUTE_COLD
145 #if _GL_HAS_ATTRIBUTE (const)
146 # define _GL_ATTRIBUTE_CONST __attribute__ ((__const__))
148 # define _GL_ATTRIBUTE_CONST
151 /* _GL_ATTRIBUTE_DEALLOC (F, I) is for functions returning pointers
152 that can be freed by passing them as the Ith argument to the
153 function F. _GL_ATTRIBUTE_DEALLOC_FREE is for functions that
154 return pointers that can be freed via 'free'; it can be used
155 only after including stdlib.h. */
156 #if _GL_GNUC_PREREQ (11, 0)
157 # define _GL_ATTRIBUTE_DEALLOC(f, i) __attribute__ ((__malloc__ (f, i)))
159 # define _GL_ATTRIBUTE_DEALLOC(f, i)
161 #define _GL_ATTRIBUTE_DEALLOC_FREE _GL_ATTRIBUTE_DEALLOC (free, 1)
163 #if _GL_HAS_C_ATTRIBUTE (deprecated)
164 # define _GL_ATTRIBUTE_DEPRECATED [[__deprecated__]]
165 #elif _GL_HAS_ATTRIBUTE (deprecated)
166 # define _GL_ATTRIBUTE_DEPRECATED __attribute__ ((__deprecated__))
168 # define _GL_ATTRIBUTE_DEPRECATED
171 #if _GL_HAS_ATTRIBUTE (error)
172 # define _GL_ATTRIBUTE_ERROR(msg) __attribute__ ((__error__ (msg)))
173 # define _GL_ATTRIBUTE_WARNING(msg) __attribute__ ((__warning__ (msg)))
174 #elif _GL_HAS_ATTRIBUTE (diagnose_if)
175 # define _GL_ATTRIBUTE_ERROR(msg) __attribute__ ((__diagnose_if__ (1, msg, "error")))
176 # define _GL_ATTRIBUTE_WARNING(msg) __attribute__ ((__diagnose_if__ (1, msg, "warning")))
178 # define _GL_ATTRIBUTE_ERROR(msg)
179 # define _GL_ATTRIBUTE_WARNING(msg)
182 #if _GL_HAS_ATTRIBUTE (externally_visible)
183 # define _GL_ATTRIBUTE_EXTERNALLY_VISIBLE __attribute__ ((externally_visible))
185 # define _GL_ATTRIBUTE_EXTERNALLY_VISIBLE
188 /* FALLTHROUGH is special, because it always expands to something. */
189 #if _GL_HAS_C_ATTRIBUTE (fallthrough)
190 # define _GL_ATTRIBUTE_FALLTHROUGH [[__fallthrough__]]
191 #elif _GL_HAS_ATTRIBUTE (fallthrough)
192 # define _GL_ATTRIBUTE_FALLTHROUGH __attribute__ ((__fallthrough__))
194 # define _GL_ATTRIBUTE_FALLTHROUGH ((void) 0)
197 #if _GL_HAS_ATTRIBUTE (format)
198 # define _GL_ATTRIBUTE_FORMAT(spec) __attribute__ ((__format__ spec))
200 # define _GL_ATTRIBUTE_FORMAT(spec)
203 #if _GL_HAS_ATTRIBUTE (leaf)
204 # define _GL_ATTRIBUTE_LEAF __attribute__ ((__leaf__))
206 # define _GL_ATTRIBUTE_LEAF
209 /* Oracle Studio 12.6 mishandles may_alias despite __has_attribute OK. */
210 #if _GL_HAS_ATTRIBUTE (may_alias) && !defined __SUNPRO_C
211 # define _GL_ATTRIBUTE_MAY_ALIAS __attribute__ ((__may_alias__))
213 # define _GL_ATTRIBUTE_MAY_ALIAS
216 #if _GL_HAS_C_ATTRIBUTE (maybe_unused)
217 # define _GL_ATTRIBUTE_MAYBE_UNUSED [[__maybe_unused__]]
219 # define _GL_ATTRIBUTE_MAYBE_UNUSED _GL_ATTRIBUTE_UNUSED
221 /* Earlier spellings of this macro. */
222 #define _UNUSED_PARAMETER_ _GL_ATTRIBUTE_MAYBE_UNUSED
224 #if _GL_HAS_ATTRIBUTE (malloc)
225 # define _GL_ATTRIBUTE_MALLOC __attribute__ ((__malloc__))
227 # define _GL_ATTRIBUTE_MALLOC
230 #if _GL_HAS_C_ATTRIBUTE (nodiscard)
231 # define _GL_ATTRIBUTE_NODISCARD [[__nodiscard__]]
232 #elif _GL_HAS_ATTRIBUTE (warn_unused_result)
233 # define _GL_ATTRIBUTE_NODISCARD __attribute__ ((__warn_unused_result__))
235 # define _GL_ATTRIBUTE_NODISCARD
238 #if _GL_HAS_ATTRIBUTE (noinline)
239 # define _GL_ATTRIBUTE_NOINLINE __attribute__ ((__noinline__))
241 # define _GL_ATTRIBUTE_NOINLINE
244 #if _GL_HAS_ATTRIBUTE (nonnull)
245 # define _GL_ATTRIBUTE_NONNULL(args) __attribute__ ((__nonnull__ args))
247 # define _GL_ATTRIBUTE_NONNULL(args)
250 #if _GL_HAS_ATTRIBUTE (nonstring)
251 # define _GL_ATTRIBUTE_NONSTRING __attribute__ ((__nonstring__))
253 # define _GL_ATTRIBUTE_NONSTRING
256 /* There is no _GL_ATTRIBUTE_NORETURN; use _Noreturn instead. */
258 #if _GL_HAS_ATTRIBUTE (nothrow) && !defined __cplusplus
259 # define _GL_ATTRIBUTE_NOTHROW __attribute__ ((__nothrow__))
261 # define _GL_ATTRIBUTE_NOTHROW
264 #if _GL_HAS_ATTRIBUTE (packed)
265 # define _GL_ATTRIBUTE_PACKED __attribute__ ((__packed__))
267 # define _GL_ATTRIBUTE_PACKED
270 #if _GL_HAS_ATTRIBUTE (pure)
271 # define _GL_ATTRIBUTE_PURE __attribute__ ((__pure__))
273 # define _GL_ATTRIBUTE_PURE
276 #if _GL_HAS_ATTRIBUTE (returns_nonnull)
277 # define _GL_ATTRIBUTE_RETURNS_NONNULL __attribute__ ((__returns_nonnull__))
279 # define _GL_ATTRIBUTE_RETURNS_NONNULL
282 #if _GL_HAS_ATTRIBUTE (sentinel)
283 # define _GL_ATTRIBUTE_SENTINEL(pos) __attribute__ ((__sentinel__ pos))
285 # define _GL_ATTRIBUTE_SENTINEL(pos)
288 #if _GL_HAS_ATTRIBUTE (unused)
289 # define _GL_ATTRIBUTE_UNUSED __attribute__ ((__unused__))
291 # define _GL_ATTRIBUTE_UNUSED
293 /* Earlier spellings of this macro. */
294 #define _GL_UNUSED _GL_ATTRIBUTE_UNUSED
296 ]dnl There is no _GL_ATTRIBUTE_VISIBILITY; see m4/visibility.m4 instead.
298 /* To support C++ as well as C, use _GL_UNUSED_LABEL with trailing ';'. */
299 #if !defined __cplusplus || _GL_GNUC_PREREQ (4, 5)
300 # define _GL_UNUSED_LABEL _GL_ATTRIBUTE_UNUSED
302 # define _GL_UNUSED_LABEL
305 AH_VERBATIM([async_safe],
306 [/* The _GL_ASYNC_SAFE marker should be attached to functions that are
307 signal handlers (for signals other than SIGABRT, SIGPIPE) or can be
308 invoked from such signal handlers. Such functions have some restrictions:
309 * All functions that it calls should be marked _GL_ASYNC_SAFE as well,
310 or should be listed as async-signal-safe in POSIX
311 <https://pubs.opengroup.org/onlinepubs/9699919799/functions/V2_chap02.html#tag_15_04>
312 section 2.4.3. Note that malloc(), sprintf(), and fwrite(), in
313 particular, are NOT async-signal-safe.
314 * All memory locations (variables and struct fields) that these functions
315 access must be marked 'volatile'. This holds for both read and write
316 accesses. Otherwise the compiler might optimize away stores to and
317 reads from such locations that occur in the program, depending on its
318 data flow analysis. For example, when the program contains a loop
319 that is intended to inspect a variable set from within a signal handler
320 while (!signal_occurred)
322 the compiler is allowed to transform this into an endless loop if the
323 variable 'signal_occurred' is not declared 'volatile'.
324 Additionally, recall that:
325 * A signal handler should not modify errno (except if it is a handler
326 for a fatal signal and ends by raising the same signal again, thus
327 provoking the termination of the process). If it invokes a function
328 that may clobber errno, it needs to save and restore the value of
330 #define _GL_ASYNC_SAFE
332 AH_VERBATIM([micro_optimizations],
333 [/* _GL_CMP (n1, n2) performs a three-valued comparison on n1 vs. n2, where
334 n1 and n2 are expressions without side effects, that evaluate to real
335 numbers (excluding NaN).
340 The naïve code (n1 > n2 ? 1 : n1 < n2 ? -1 : 0) produces a conditional
341 jump with nearly all GCC versions up to GCC 10.
342 This variant (n1 < n2 ? -1 : n1 > n2) produces a conditional with many
343 GCC versions up to GCC 9.
344 The better code (n1 > n2) - (n1 < n2) from Hacker's Delight § 2-9
345 avoids conditional jumps in all GCC versions >= 3.4. */
346 #define _GL_CMP(n1, n2) (((n1) > (n2)) - ((n1) < (n2)))
348 dnl Hint which direction to take regarding cross-compilation guesses:
349 dnl When a user installs a program on a platform they are not intimately
350 dnl familiar with, --enable-cross-guesses=conservative is the appropriate
351 dnl choice. It implements the "If we don't know, assume the worst" principle.
352 dnl However, when an operating system developer (on a platform which is not
353 dnl yet known to gnulib) builds packages for their platform, they want to
354 dnl expose, not hide, possible platform bugs; in this case,
355 dnl --enable-cross-guesses=risky is the appropriate choice.
356 dnl Sets the variables
357 dnl gl_cross_guess_normal (to be used when 'yes' is good and 'no' is bad),
358 dnl gl_cross_guess_inverted (to be used when 'no' is good and 'yes' is bad).
359 AC_ARG_ENABLE([cross-guesses],
360 [AS_HELP_STRING([--enable-cross-guesses={conservative|risky}],
361 [specify policy for cross-compilation guesses])],
362 [if test "x$enableval" != xconservative && test "x$enableval" != xrisky; then
363 AC_MSG_WARN([invalid argument supplied to --enable-cross-guesses])
364 enableval=conservative
366 gl_cross_guesses="$enableval"],
367 [gl_cross_guesses=conservative])
368 if test $gl_cross_guesses = risky; then
369 gl_cross_guess_normal="guessing yes"
370 gl_cross_guess_inverted="guessing no"
372 gl_cross_guess_normal="guessing no"
373 gl_cross_guess_inverted="guessing yes"
375 dnl Preparation for running test programs:
376 dnl Tell glibc to write diagnostics from -D_FORTIFY_SOURCE=2 to stderr, not
377 dnl to /dev/tty, so they can be redirected to log files. Such diagnostics
378 dnl arise e.g., in the macros gl_PRINTF_DIRECTIVE_N, gl_SNPRINTF_DIRECTIVE_N.
380 export LIBC_FATAL_STDERR_
383 # gl_MODULE_INDICATOR_INIT_VARIABLE([variablename])
384 # gl_MODULE_INDICATOR_INIT_VARIABLE([variablename], [initialvalue])
385 # initializes the shell variable that indicates the presence of the given module
386 # as a C preprocessor expression.
387 AC_DEFUN([gl_MODULE_INDICATOR_INIT_VARIABLE],
389 GL_MODULE_INDICATOR_PREFIX[]_[$1]=m4_if([$2], , [0], [$2])
390 AC_SUBST(GL_MODULE_INDICATOR_PREFIX[]_[$1])
393 # gl_MODULE_INDICATOR_CONDITION
394 # expands to a C preprocessor expression that evaluates to 1 or 0, depending
395 # whether a gnulib module that has been requested shall be considered present
397 m4_define([gl_MODULE_INDICATOR_CONDITION], [1])
399 # gl_MODULE_INDICATOR_SET_VARIABLE([modulename])
400 # sets the shell variable that indicates the presence of the given module to
401 # a C preprocessor expression that will evaluate to 1.
402 AC_DEFUN([gl_MODULE_INDICATOR_SET_VARIABLE],
404 gl_MODULE_INDICATOR_SET_VARIABLE_AUX(
405 [GL_MODULE_INDICATOR_PREFIX[]_GNULIB_[]m4_translit([[$1]],
406 [abcdefghijklmnopqrstuvwxyz./-],
407 [ABCDEFGHIJKLMNOPQRSTUVWXYZ___])],
408 [gl_MODULE_INDICATOR_CONDITION])
411 # gl_MODULE_INDICATOR_SET_VARIABLE_AUX([variable])
412 # modifies the shell variable to include the gl_MODULE_INDICATOR_CONDITION.
413 # The shell variable's value is a C preprocessor expression that evaluates
415 AC_DEFUN([gl_MODULE_INDICATOR_SET_VARIABLE_AUX],
417 m4_if(m4_defn([gl_MODULE_INDICATOR_CONDITION]), [1],
419 dnl Simplify the expression VALUE || 1 to 1.
422 [gl_MODULE_INDICATOR_SET_VARIABLE_AUX_OR([$1],
423 [gl_MODULE_INDICATOR_CONDITION])])
426 # gl_MODULE_INDICATOR_SET_VARIABLE_AUX_OR([variable], [condition])
427 # modifies the shell variable to include the given condition. The shell
428 # variable's value is a C preprocessor expression that evaluates to 0 or 1.
429 AC_DEFUN([gl_MODULE_INDICATOR_SET_VARIABLE_AUX_OR],
431 dnl Simplify the expression 1 || CONDITION to 1.
432 if test "$[]$1" != 1; then
433 dnl Simplify the expression 0 || CONDITION to CONDITION.
434 if test "$[]$1" = 0; then
442 # gl_MODULE_INDICATOR([modulename])
443 # defines a C macro indicating the presence of the given module
444 # in a location where it can be used.
446 # | in lib/ | in tests/ |
447 # --------------------------------------------+---------+-----------+
448 # Module present among main modules: | 1 | 1 |
449 # --------------------------------------------+---------+-----------+
450 # Module present among tests-related modules: | 0 | 1 |
451 # --------------------------------------------+---------+-----------+
452 # Module not present at all: | 0 | 0 |
453 # --------------------------------------------+---------+-----------+
454 AC_DEFUN([gl_MODULE_INDICATOR],
456 AC_DEFINE_UNQUOTED([GNULIB_]m4_translit([[$1]],
457 [abcdefghijklmnopqrstuvwxyz./-],
458 [ABCDEFGHIJKLMNOPQRSTUVWXYZ___]),
459 [gl_MODULE_INDICATOR_CONDITION],
460 [Define to a C preprocessor expression that evaluates to 1 or 0,
461 depending whether the gnulib module $1 shall be considered present.])
464 # gl_MODULE_INDICATOR_FOR_TESTS([modulename])
465 # defines a C macro indicating the presence of the given module
466 # in lib or tests. This is useful to determine whether the module
469 # | in lib/ | in tests/ |
470 # --------------------------------------------+---------+-----------+
471 # Module present among main modules: | 1 | 1 |
472 # --------------------------------------------+---------+-----------+
473 # Module present among tests-related modules: | 1 | 1 |
474 # --------------------------------------------+---------+-----------+
475 # Module not present at all: | 0 | 0 |
476 # --------------------------------------------+---------+-----------+
477 AC_DEFUN([gl_MODULE_INDICATOR_FOR_TESTS],
479 AC_DEFINE([GNULIB_TEST_]m4_translit([[$1]],
480 [abcdefghijklmnopqrstuvwxyz./-],
481 [ABCDEFGHIJKLMNOPQRSTUVWXYZ___]), [1],
482 [Define to 1 when the gnulib module $1 should be tested.])
485 # gl_ASSERT_NO_GNULIB_POSIXCHECK
486 # asserts that there will never be a need to #define GNULIB_POSIXCHECK.
487 # and thereby enables an optimization of configure and config.h.
489 AC_DEFUN([gl_ASSERT_NO_GNULIB_POSIXCHECK],
491 dnl Override gl_WARN_ON_USE_PREPARE.
492 dnl But hide this definition from 'aclocal'.
493 AC_DEFUN([gl_W][ARN_ON_USE_PREPARE], [])
496 # gl_ASSERT_NO_GNULIB_TESTS
497 # asserts that there will be no gnulib tests in the scope of the configure.ac
498 # and thereby enables an optimization of config.h.
500 AC_DEFUN([gl_ASSERT_NO_GNULIB_TESTS],
502 dnl Override gl_MODULE_INDICATOR_FOR_TESTS.
503 AC_DEFUN([gl_MODULE_INDICATOR_FOR_TESTS], [])
506 # Test whether <features.h> exists.
507 # Set HAVE_FEATURES_H.
508 AC_DEFUN([gl_FEATURES_H],
510 AC_CHECK_HEADERS_ONCE([features.h])
511 if test $ac_cv_header_features_h = yes; then
516 AC_SUBST([HAVE_FEATURES_H])
520 # Modifies the value of the shell variable CC in an attempt to make $CC
521 # understand ISO C99 source code.
522 AC_DEFUN([gl_PROG_CC_C99],
524 dnl Just use AC_PROG_CC_C99.
525 dnl When AC_PROG_CC_C99 and AC_PROG_CC_STDC are used together, the substituted
526 dnl value of CC will contain the C99 enabling options twice. But this is only
527 dnl a cosmetic problem.
528 dnl With Autoconf >= 2.70, use AC_PROG_CC since it implies AC_PROG_CC_C99;
529 dnl this avoids a "warning: The macro `AC_PROG_CC_C99' is obsolete."
530 m4_version_prereq([2.70],
531 [AC_REQUIRE([AC_PROG_CC])],
532 [AC_REQUIRE([AC_PROG_CC_C99])])
536 # Determines the values for AR, ARFLAGS, RANLIB that fit with the compiler.
537 # The user can set the variables AR, ARFLAGS, RANLIB if he wants to override
539 AC_DEFUN([gl_PROG_AR_RANLIB],
541 dnl Minix 3 comes with two toolchains: The Amsterdam Compiler Kit compiler
542 dnl as "cc", and GCC as "gcc". They have different object file formats and
543 dnl library formats. In particular, the GNU binutils programs ar and ranlib
544 dnl produce libraries that work only with gcc, not with cc.
545 AC_REQUIRE([AC_PROG_CC])
546 dnl The '][' hides this use from 'aclocal'.
547 AC_BEFORE([$0], [A][M_PROG_AR])
548 AC_CACHE_CHECK([for Minix Amsterdam compiler], [gl_cv_c_amsterdam_compiler],
550 AC_EGREP_CPP([Amsterdam],
556 [gl_cv_c_amsterdam_compiler=yes],
557 [gl_cv_c_amsterdam_compiler=no])
560 dnl Don't compete with AM_PROG_AR's decision about AR/ARFLAGS if we are not
561 dnl building with __ACK__.
562 if test $gl_cv_c_amsterdam_compiler = yes; then
563 if test -z "$AR"; then
566 if test -z "$ARFLAGS"; then
570 dnl AM_PROG_AR was added in automake v1.11.2. AM_PROG_AR does not AC_SUBST
571 dnl ARFLAGS variable (it is filed into Makefile.in directly by automake
572 dnl script on-demand, if not specified by ./configure of course).
573 dnl Don't AC_REQUIRE the AM_PROG_AR otherwise the code for __ACK__ above
574 dnl will be ignored. Also, pay attention to call AM_PROG_AR in else block
575 dnl because AM_PROG_AR is written so it could re-set AR variable even for
576 dnl __ACK__. It may seem like its easier to avoid calling the macro here,
577 dnl but we need to AC_SUBST both AR/ARFLAGS (thus those must have some good
578 dnl default value and automake should usually know them).
580 dnl The '][' hides this use from 'aclocal'.
581 m4_ifdef([A][M_PROG_AR], [A][M_PROG_AR], [:])
584 dnl In case the code above has not helped with setting AR/ARFLAGS, use
585 dnl Automake-documented default values for AR and ARFLAGS, but prefer
586 dnl ${host}-ar over ar (useful for cross-compiling).
587 AC_CHECK_TOOL([AR], [ar], [ar])
588 if test -z "$ARFLAGS"; then
594 if test -z "$RANLIB"; then
595 if test $gl_cv_c_amsterdam_compiler = yes; then
598 dnl Use the ranlib program if it is available.
606 # This definition is copied from post-2.70 Autoconf and overrides the
607 # AC_C_RESTRICT macro from autoconf 2.60..2.70.
608 m4_version_prereq([2.70.1], [], [
609 AC_DEFUN([AC_C_RESTRICT],
610 [AC_CACHE_CHECK([for C/C++ restrict keyword], [ac_cv_c_restrict],
612 # Put '__restrict__' first, to avoid problems with glibc and non-GCC; see:
613 # https://lists.gnu.org/archive/html/bug-autoconf/2016-02/msg00006.html
614 # Put 'restrict' last, because C++ lacks it.
615 for ac_kw in __restrict__ __restrict _Restrict restrict; do
618 [[typedef int *int_ptr;
619 int foo (int_ptr $ac_kw ip) { return ip[0]; }
620 int bar (int [$ac_kw]); /* Catch GCC bug 14050. */
621 int bar (int ip[$ac_kw]) { return ip[0]; }
626 return foo (t) + bar (t);
628 [ac_cv_c_restrict=$ac_kw])
629 test "$ac_cv_c_restrict" != no && break
632 AH_VERBATIM([restrict],
633 [/* Define to the equivalent of the C99 'restrict' keyword, or to
634 nothing if this is not supported. Do not define if restrict is
635 supported only directly. */
637 /* Work around a bug in older versions of Sun C++, which did not
638 #define __restrict__ or support _Restrict or __restrict__
639 even though the corresponding Sun C compiler ended up with
640 "#define restrict _Restrict" or "#define restrict __restrict__"
641 in the previous line. This workaround can be removed once
642 we assume Oracle Developer Studio 12.5 (2016) or later. */
643 #if defined __SUNPRO_CC && !defined __RESTRICT && !defined __restrict__
645 # define __restrict__
647 case $ac_cv_c_restrict in
649 no) AC_DEFINE([restrict], []) ;;
650 *) AC_DEFINE_UNQUOTED([restrict], [$ac_cv_c_restrict]) ;;
656 # is like AC_C_BIGENDIAN, except that it can be AC_REQUIREd.
657 # Note that AC_REQUIRE([AC_C_BIGENDIAN]) does not work reliably because some
658 # macros invoke AC_C_BIGENDIAN with arguments.
659 AC_DEFUN([gl_BIGENDIAN],
664 # A temporary file descriptor.
665 # Must be less than 10, because dash 0.5.8 does not support redirections
666 # with multi-digit file descriptors.
667 m4_define([GL_TMP_FD], 9)
670 # executes command, but without the normal configure output.
671 # This is useful when you want to invoke AC_CACHE_CHECK (or AC_CHECK_FUNC etc.)
672 # inside another AC_CACHE_CHECK.
673 AC_DEFUN([gl_SILENT],
675 exec GL_TMP_FD>&AS_MESSAGE_FD AS_MESSAGE_FD>/dev/null
677 exec AS_MESSAGE_FD>&GL_TMP_FD GL_TMP_FD>&-
680 # gl_CACHE_VAL_SILENT(cache-id, command-to-set-it)
681 # is like AC_CACHE_VAL(cache-id, command-to-set-it), except that it does not
682 # output a spurious "(cached)" mark in the midst of other configure output.
683 # This macro should be used instead of AC_CACHE_VAL when it is not surrounded
684 # by an AC_MSG_CHECKING/AC_MSG_RESULT pair.
685 AC_DEFUN([gl_CACHE_VAL_SILENT],
688 AC_CACHE_VAL([$1], [$2])
692 # gl_CC_ALLOW_WARNINGS
693 # sets and substitutes a variable GL_CFLAG_ALLOW_WARNINGS, to a $(CC) option
694 # that reverts a preceding '-Werror' option, if available.
695 # This is expected to be '-Wno-error' on gcc, clang (except clang/MSVC), xlclang
696 # and empty otherwise.
697 AC_DEFUN([gl_CC_ALLOW_WARNINGS],
699 AC_REQUIRE([AC_PROG_CC])
700 AC_CACHE_CHECK([for C compiler option to allow warnings],
703 echo 'int dummy;' > conftest.c
704 AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS -c conftest.c 2>conftest1.err]) >/dev/null
705 AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS -Wno-error -c conftest.c 2>conftest2.err]) >/dev/null
706 dnl Test the number of error output lines, because AIX xlc accepts the
707 dnl option '-Wno-error', just to produce a warning
708 dnl "Option -Wno-error was incorrectly specified. The option will be ignored."
710 if test $? = 0 && test `wc -l < conftest1.err` = `wc -l < conftest2.err`; then
711 gl_cv_cc_wallow='-Wno-error'
717 case "$gl_cv_cc_wallow" in
718 none) GL_CFLAG_ALLOW_WARNINGS='' ;;
719 *) GL_CFLAG_ALLOW_WARNINGS="$gl_cv_cc_wallow" ;;
721 AC_SUBST([GL_CFLAG_ALLOW_WARNINGS])
724 # gl_CXX_ALLOW_WARNINGS
725 # sets and substitutes a variable GL_CXXFLAG_ALLOW_WARNINGS, to a $(CC) option
726 # that reverts a preceding '-Werror' option, if available.
727 AC_DEFUN([gl_CXX_ALLOW_WARNINGS],
729 dnl Requires AC_PROG_CXX or gl_PROG_ANSI_CXX.
730 if test -n "$CXX" && test "$CXX" != no; then
731 AC_CACHE_CHECK([for C++ compiler option to allow warnings],
734 echo 'int dummy;' > conftest.cc
735 AC_TRY_COMMAND([${CXX-c++} $CXXFLAGS $CPPFLAGS -c conftest.cc 2>conftest1.err]) >/dev/null
736 AC_TRY_COMMAND([${CXX-c++} $CXXFLAGS $CPPFLAGS -Wno-error -c conftest.cc 2>conftest2.err]) >/dev/null
737 dnl Test the number of error output lines, because AIX xlC accepts the
738 dnl option '-Wno-error', just to produce a warning
739 dnl "Option -Wno-error was incorrectly specified. The option will be ignored."
741 if test $? = 0 && test `wc -l < conftest1.err` = `wc -l < conftest2.err`; then
742 gl_cv_cxx_wallow='-Wno-error'
744 gl_cv_cxx_wallow=none
748 case "$gl_cv_cxx_wallow" in
749 none) GL_CXXFLAG_ALLOW_WARNINGS='' ;;
750 *) GL_CXXFLAG_ALLOW_WARNINGS="$gl_cv_cxx_wallow" ;;
753 GL_CXXFLAG_ALLOW_WARNINGS=''
755 AC_SUBST([GL_CXXFLAG_ALLOW_WARNINGS])
758 dnl Expands to some code for use in .c programs that, on native Windows, defines
759 dnl the Microsoft deprecated alias function names to the underscore-prefixed
760 dnl actual function names. With this macro, these function names are available
761 dnl without linking with '-loldnames' and without generating warnings.
762 dnl Usage: Use it after all system header files are included.
767 AC_DEFUN([GL_MDA_DEFINES],[
768 AC_REQUIRE([_GL_MDA_DEFINES])
771 AC_DEFUN([_GL_MDA_DEFINES],
773 #if defined _WIN32 && !defined __CYGWIN__
774 #define access _access
783 #define execle _execle
784 #define execlp _execlp
786 #define execve _execve
787 #define execvp _execvp
788 #define execvpe _execvpe
789 #define fcloseall _fcloseall
791 #define fdopen _fdopen
792 #define fileno _fileno
794 #define getcwd _getcwd
795 #define getpid _getpid
797 #define isatty _isatty
802 #define lsearch _lsearch
804 #define memccpy _memccpy
806 #define mktemp _mktemp
808 #define putenv _putenv
812 #define strdup _strdup
814 #define tempnam _tempnam
817 #define unlink _unlink
819 #define wcsdup _wcsdup