1 # gnulib-common.m4 serial 80
2 dnl Copyright (C) 2007-2023 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 __clang__ && __clang_major__ < 16 \
42 && defined _GL_WORK_AROUND_LLVM_BUG_59792)
43 /* Compile with -D_GL_WORK_AROUND_LLVM_BUG_59792 to work around
44 that rare LLVM bug, though you may get many false-alarm warnings. */
46 # elif ((!defined __cplusplus || defined __clang__) \
47 && (201112 <= (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) \
48 || (!defined __STRICT_ANSI__ \
49 && (_GL_GNUC_PREREQ (4, 7) \
50 || (defined __apple_build_version__ \
51 ? 6000000 <= __apple_build_version__ \
52 : 3 < __clang_major__ + (5 <= __clang_minor__))))))
53 /* _Noreturn works as-is. */
54 # elif _GL_GNUC_PREREQ (2, 8) || defined __clang__ || 0x5110 <= __SUNPRO_C
55 # define _Noreturn __attribute__ ((__noreturn__))
56 # elif 1200 <= (defined _MSC_VER ? _MSC_VER : 0)
57 # define _Noreturn __declspec (noreturn)
63 AH_VERBATIM([isoc99_inline],
64 [/* Work around a bug in Apple GCC 4.0.1 build 5465: In C99 mode, it supports
65 the ISO C 99 semantics of 'extern inline' (unlike the GNU C semantics of
66 earlier versions), but does not display it by setting __GNUC_STDC_INLINE__.
67 __APPLE__ && __MACH__ test for Mac OS X.
68 __APPLE_CC__ tests for the Apple compiler and its version.
69 __STDC_VERSION__ tests for the C99 mode. */
70 #if defined __APPLE__ && defined __MACH__ && __APPLE_CC__ >= 5465 && !defined __cplusplus && __STDC_VERSION__ >= 199901L && !defined __GNUC_STDC_INLINE__
71 # define __GNUC_STDC_INLINE__ 1
73 AH_VERBATIM([attribute],
75 #if (defined __has_attribute \
76 && (!defined __clang_minor__ \
77 || (defined __apple_build_version__ \
78 ? 6000000 <= __apple_build_version__ \
79 : 5 <= __clang_major__)))
80 # define _GL_HAS_ATTRIBUTE(attr) __has_attribute (__##attr##__)
82 # define _GL_HAS_ATTRIBUTE(attr) _GL_ATTR_##attr
83 # define _GL_ATTR_alloc_size _GL_GNUC_PREREQ (4, 3)
84 # define _GL_ATTR_always_inline _GL_GNUC_PREREQ (3, 2)
85 # define _GL_ATTR_artificial _GL_GNUC_PREREQ (4, 3)
86 # define _GL_ATTR_cold _GL_GNUC_PREREQ (4, 3)
87 # define _GL_ATTR_const _GL_GNUC_PREREQ (2, 95)
88 # define _GL_ATTR_deprecated _GL_GNUC_PREREQ (3, 1)
89 # define _GL_ATTR_diagnose_if 0
90 # define _GL_ATTR_error _GL_GNUC_PREREQ (4, 3)
91 # define _GL_ATTR_externally_visible _GL_GNUC_PREREQ (4, 1)
92 # define _GL_ATTR_fallthrough _GL_GNUC_PREREQ (7, 0)
93 # define _GL_ATTR_format _GL_GNUC_PREREQ (2, 7)
94 # define _GL_ATTR_leaf _GL_GNUC_PREREQ (4, 6)
95 # define _GL_ATTR_malloc _GL_GNUC_PREREQ (3, 0)
97 # define _GL_ATTR_may_alias 0
99 # define _GL_ATTR_may_alias _GL_GNUC_PREREQ (3, 3)
101 # define _GL_ATTR_noinline _GL_GNUC_PREREQ (3, 1)
102 # define _GL_ATTR_nonnull _GL_GNUC_PREREQ (3, 3)
103 # define _GL_ATTR_nonstring _GL_GNUC_PREREQ (8, 0)
104 # define _GL_ATTR_nothrow _GL_GNUC_PREREQ (3, 3)
105 # define _GL_ATTR_packed _GL_GNUC_PREREQ (2, 7)
106 # define _GL_ATTR_pure _GL_GNUC_PREREQ (2, 96)
107 # define _GL_ATTR_returns_nonnull _GL_GNUC_PREREQ (4, 9)
108 # define _GL_ATTR_sentinel _GL_GNUC_PREREQ (4, 0)
109 # define _GL_ATTR_unused _GL_GNUC_PREREQ (2, 7)
110 # define _GL_ATTR_warn_unused_result _GL_GNUC_PREREQ (3, 4)
113 /* Disable GCC -Wpedantic if using __has_c_attribute and this is not C23+. */
114 #if (defined __has_c_attribute && _GL_GNUC_PREREQ (4, 6) \
115 && (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) <= 201710)
116 # pragma GCC diagnostic ignored "-Wpedantic"
119 ]dnl There is no _GL_ATTRIBUTE_ALIGNED; use stdalign's alignas instead.
121 /* _GL_ATTRIBUTE_ALLOC_SIZE ((N)) declares that the Nth argument of the function
122 is the size of the returned memory block.
123 _GL_ATTRIBUTE_ALLOC_SIZE ((M, N)) declares that the Mth argument multiplied
124 by the Nth argument of the function is the size of the returned memory block.
126 /* Applies to: function, pointer to function, function types. */
127 #ifndef _GL_ATTRIBUTE_ALLOC_SIZE
128 # if _GL_HAS_ATTRIBUTE (alloc_size)
129 # define _GL_ATTRIBUTE_ALLOC_SIZE(args) __attribute__ ((__alloc_size__ args))
131 # define _GL_ATTRIBUTE_ALLOC_SIZE(args)
135 /* _GL_ATTRIBUTE_ALWAYS_INLINE tells that the compiler should always inline the
136 function and report an error if it cannot do so. */
137 /* Applies to: function. */
138 #ifndef _GL_ATTRIBUTE_ALWAYS_INLINE
139 # if _GL_HAS_ATTRIBUTE (always_inline)
140 # define _GL_ATTRIBUTE_ALWAYS_INLINE __attribute__ ((__always_inline__))
142 # define _GL_ATTRIBUTE_ALWAYS_INLINE
146 /* _GL_ATTRIBUTE_ARTIFICIAL declares that the function is not important to show
147 in stack traces when debugging. The compiler should omit the function from
149 /* Applies to: function. */
150 #ifndef _GL_ATTRIBUTE_ARTIFICIAL
151 # if _GL_HAS_ATTRIBUTE (artificial)
152 # define _GL_ATTRIBUTE_ARTIFICIAL __attribute__ ((__artificial__))
154 # define _GL_ATTRIBUTE_ARTIFICIAL
158 /* _GL_ATTRIBUTE_COLD declares that the function is rarely executed. */
159 /* Applies to: functions. */
160 /* Avoid __attribute__ ((cold)) on MinGW; see thread starting at
161 <https://lists.gnu.org/r/emacs-devel/2019-04/msg01152.html>.
162 Also, Oracle Studio 12.6 requires 'cold' not '__cold__'. */
163 #ifndef _GL_ATTRIBUTE_COLD
164 # if _GL_HAS_ATTRIBUTE (cold) && !defined __MINGW32__
166 # define _GL_ATTRIBUTE_COLD __attribute__ ((__cold__))
168 # define _GL_ATTRIBUTE_COLD __attribute__ ((cold))
171 # define _GL_ATTRIBUTE_COLD
175 /* _GL_ATTRIBUTE_CONST declares that it is OK for a compiler to omit duplicate
176 calls to the function with the same arguments.
177 This attribute is safe for a function that neither depends on nor affects
178 observable state, and always returns exactly once - e.g., does not loop
179 forever, and does not call longjmp.
180 (This attribute is stricter than _GL_ATTRIBUTE_PURE.) */
181 /* Applies to: functions. */
182 #ifndef _GL_ATTRIBUTE_CONST
183 # if _GL_HAS_ATTRIBUTE (const)
184 # define _GL_ATTRIBUTE_CONST __attribute__ ((__const__))
186 # define _GL_ATTRIBUTE_CONST
190 /* _GL_ATTRIBUTE_DEALLOC (F, I) declares that the function returns pointers
191 that can be freed by passing them as the Ith argument to the
193 _GL_ATTRIBUTE_DEALLOC_FREE declares that the function returns pointers that
194 can be freed via 'free'; it can be used only after declaring 'free'. */
195 /* Applies to: functions. Cannot be used on inline functions. */
196 #ifndef _GL_ATTRIBUTE_DEALLOC
197 # if _GL_GNUC_PREREQ (11, 0)
198 # define _GL_ATTRIBUTE_DEALLOC(f, i) __attribute__ ((__malloc__ (f, i)))
200 # define _GL_ATTRIBUTE_DEALLOC(f, i)
203 /* If gnulib's <string.h> or <wchar.h> has already defined this macro, continue
204 to use this earlier definition, since <stdlib.h> may not have been included
206 #ifndef _GL_ATTRIBUTE_DEALLOC_FREE
207 # if defined __cplusplus && defined __GNUC__ && !defined __clang__
208 /* Work around GCC bug <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108231> */
209 # define _GL_ATTRIBUTE_DEALLOC_FREE \
210 _GL_ATTRIBUTE_DEALLOC ((void (*) (void *)) free, 1)
212 # define _GL_ATTRIBUTE_DEALLOC_FREE \
213 _GL_ATTRIBUTE_DEALLOC (free, 1)
217 /* _GL_ATTRIBUTE_DEPRECATED: Declares that an entity is deprecated.
218 The compiler may warn if the entity is used. */
220 - function, variable,
221 - struct, union, struct/union member,
222 - enumeration, enumeration item,
224 in C++ also: namespace, class, template specialization. */
225 #ifndef _GL_ATTRIBUTE_DEPRECATED
226 # ifdef __has_c_attribute
227 # if __has_c_attribute (__deprecated__)
228 # define _GL_ATTRIBUTE_DEPRECATED [[__deprecated__]]
231 # if !defined _GL_ATTRIBUTE_DEPRECATED && _GL_HAS_ATTRIBUTE (deprecated)
232 # define _GL_ATTRIBUTE_DEPRECATED __attribute__ ((__deprecated__))
234 # ifndef _GL_ATTRIBUTE_DEPRECATED
235 # define _GL_ATTRIBUTE_DEPRECATED
239 /* _GL_ATTRIBUTE_ERROR(msg) requests an error if a function is called and
240 the function call is not optimized away.
241 _GL_ATTRIBUTE_WARNING(msg) requests a warning if a function is called and
242 the function call is not optimized away. */
243 /* Applies to: functions. */
244 #if !(defined _GL_ATTRIBUTE_ERROR && defined _GL_ATTRIBUTE_WARNING)
245 # if _GL_HAS_ATTRIBUTE (error)
246 # define _GL_ATTRIBUTE_ERROR(msg) __attribute__ ((__error__ (msg)))
247 # define _GL_ATTRIBUTE_WARNING(msg) __attribute__ ((__warning__ (msg)))
248 # elif _GL_HAS_ATTRIBUTE (diagnose_if)
249 # define _GL_ATTRIBUTE_ERROR(msg) __attribute__ ((__diagnose_if__ (1, msg, "error")))
250 # define _GL_ATTRIBUTE_WARNING(msg) __attribute__ ((__diagnose_if__ (1, msg, "warning")))
252 # define _GL_ATTRIBUTE_ERROR(msg)
253 # define _GL_ATTRIBUTE_WARNING(msg)
257 /* _GL_ATTRIBUTE_EXTERNALLY_VISIBLE declares that the entity should remain
258 visible to debuggers etc., even with '-fwhole-program'. */
259 /* Applies to: functions, variables. */
260 #ifndef _GL_ATTRIBUTE_EXTERNALLY_VISIBLE
261 # if _GL_HAS_ATTRIBUTE (externally_visible)
262 # define _GL_ATTRIBUTE_EXTERNALLY_VISIBLE __attribute__ ((externally_visible))
264 # define _GL_ATTRIBUTE_EXTERNALLY_VISIBLE
268 /* _GL_ATTRIBUTE_FALLTHROUGH declares that it is not a programming mistake if
269 the control flow falls through to the immediately following 'case' or
270 'default' label. The compiler should not warn in this case. */
271 /* Applies to: Empty statement (;), inside a 'switch' statement. */
272 /* Always expands to something. */
273 #ifndef _GL_ATTRIBUTE_FALLTHROUGH
274 # ifdef __has_c_attribute
275 # if __has_c_attribute (__fallthrough__)
276 # define _GL_ATTRIBUTE_FALLTHROUGH [[__fallthrough__]]
279 # if !defined _GL_ATTRIBUTE_FALLTHROUGH && _GL_HAS_ATTRIBUTE (fallthrough)
280 # define _GL_ATTRIBUTE_FALLTHROUGH __attribute__ ((__fallthrough__))
282 # ifndef _GL_ATTRIBUTE_FALLTHROUGH
283 # define _GL_ATTRIBUTE_FALLTHROUGH ((void) 0)
287 /* _GL_ATTRIBUTE_FORMAT ((ARCHETYPE, STRING-INDEX, FIRST-TO-CHECK))
288 declares that the STRING-INDEXth function argument is a format string of
289 style ARCHETYPE, which is one of:
292 strftime, gnu_strftime,
294 or the same thing prefixed and suffixed with '__'.
295 If FIRST-TO-CHECK is not 0, arguments starting at FIRST-TO_CHECK
296 are suitable for the format string. */
297 /* Applies to: functions. */
298 #ifndef _GL_ATTRIBUTE_FORMAT
299 # if _GL_HAS_ATTRIBUTE (format)
300 # define _GL_ATTRIBUTE_FORMAT(spec) __attribute__ ((__format__ spec))
302 # define _GL_ATTRIBUTE_FORMAT(spec)
306 /* _GL_ATTRIBUTE_LEAF declares that if the function is called from some other
307 compilation unit, it executes code from that unit only by return or by
308 exception handling. This declaration lets the compiler optimize that unit
309 more aggressively. */
310 /* Applies to: functions. */
311 #ifndef _GL_ATTRIBUTE_LEAF
312 # if _GL_HAS_ATTRIBUTE (leaf)
313 # define _GL_ATTRIBUTE_LEAF __attribute__ ((__leaf__))
315 # define _GL_ATTRIBUTE_LEAF
319 /* _GL_ATTRIBUTE_MALLOC declares that the function returns a pointer to freshly
321 /* Applies to: functions. */
322 #ifndef _GL_ATTRIBUTE_MALLOC
323 # if _GL_HAS_ATTRIBUTE (malloc)
324 # define _GL_ATTRIBUTE_MALLOC __attribute__ ((__malloc__))
326 # define _GL_ATTRIBUTE_MALLOC
330 /* _GL_ATTRIBUTE_MAY_ALIAS declares that pointers to the type may point to the
331 same storage as pointers to other types. Thus this declaration disables
332 strict aliasing optimization. */
333 /* Applies to: types. */
334 /* Oracle Studio 12.6 mishandles may_alias despite __has_attribute OK. */
335 #ifndef _GL_ATTRIBUTE_MAY_ALIAS
336 # if _GL_HAS_ATTRIBUTE (may_alias) && !defined __SUNPRO_C
337 # define _GL_ATTRIBUTE_MAY_ALIAS __attribute__ ((__may_alias__))
339 # define _GL_ATTRIBUTE_MAY_ALIAS
343 /* _GL_ATTRIBUTE_MAYBE_UNUSED declares that it is not a programming mistake if
344 the entity is not used. The compiler should not warn if the entity is not
347 - function, variable,
348 - struct, union, struct/union member,
349 - enumeration, enumeration item,
351 in C++ also: class. */
352 /* In C++ and C23, this is spelled [[__maybe_unused__]].
353 GCC's syntax is __attribute__ ((__unused__)).
354 clang supports both syntaxes. Except that with clang ≥ 6, < 10, in C++ mode,
355 __has_c_attribute (__maybe_unused__) yields true but the use of
356 [[__maybe_unused__]] nevertheless produces a warning. */
357 #ifndef _GL_ATTRIBUTE_MAYBE_UNUSED
358 # if defined __clang__ && defined __cplusplus
359 # if __clang_major__ >= 10
360 # define _GL_ATTRIBUTE_MAYBE_UNUSED [[__maybe_unused__]]
362 # elif defined __has_c_attribute
363 # if __has_c_attribute (__maybe_unused__)
364 # define _GL_ATTRIBUTE_MAYBE_UNUSED [[__maybe_unused__]]
367 # ifndef _GL_ATTRIBUTE_MAYBE_UNUSED
368 # define _GL_ATTRIBUTE_MAYBE_UNUSED _GL_ATTRIBUTE_UNUSED
371 /* Alternative spelling of this macro, for convenience and for
372 compatibility with glibc/include/libc-symbols.h. */
373 #define _GL_UNUSED _GL_ATTRIBUTE_MAYBE_UNUSED
374 /* Earlier spellings of this macro. */
375 #define _UNUSED_PARAMETER_ _GL_ATTRIBUTE_MAYBE_UNUSED
377 /* _GL_ATTRIBUTE_NODISCARD declares that the caller of the function should not
378 discard the return value. The compiler may warn if the caller does not use
379 the return value, unless the caller uses something like ignore_value. */
380 /* Applies to: function, enumeration, class. */
381 #ifndef _GL_ATTRIBUTE_NODISCARD
382 # if defined __clang__ && defined __cplusplus
383 /* With clang up to 15.0.6 (at least), in C++ mode, [[__nodiscard__]] produces
385 The 1000 below means a yet unknown threshold. When clang++ version X
386 starts supporting [[__nodiscard__]] without warning about it, you can
387 replace the 1000 with X. */
388 # if __clang_major__ >= 1000
389 # define _GL_ATTRIBUTE_NODISCARD [[__nodiscard__]]
391 # elif defined __has_c_attribute
392 # if __has_c_attribute (__nodiscard__)
393 # define _GL_ATTRIBUTE_NODISCARD [[__nodiscard__]]
396 # if !defined _GL_ATTRIBUTE_NODISCARD && _GL_HAS_ATTRIBUTE (warn_unused_result)
397 # define _GL_ATTRIBUTE_NODISCARD __attribute__ ((__warn_unused_result__))
399 # ifndef _GL_ATTRIBUTE_NODISCARD
400 # define _GL_ATTRIBUTE_NODISCARD
404 /* _GL_ATTRIBUTE_NOINLINE tells that the compiler should not inline the
406 /* Applies to: functions. */
407 #ifndef _GL_ATTRIBUTE_NOINLINE
408 # if _GL_HAS_ATTRIBUTE (noinline)
409 # define _GL_ATTRIBUTE_NOINLINE __attribute__ ((__noinline__))
411 # define _GL_ATTRIBUTE_NOINLINE
415 /* _GL_ATTRIBUTE_NONNULL ((N1, N2,...)) declares that the arguments N1, N2,...
417 _GL_ATTRIBUTE_NONNULL () declares that all pointer arguments must not be
419 /* Applies to: functions. */
420 #ifndef _GL_ATTRIBUTE_NONNULL
421 # if _GL_HAS_ATTRIBUTE (nonnull)
422 # define _GL_ATTRIBUTE_NONNULL(args) __attribute__ ((__nonnull__ args))
424 # define _GL_ATTRIBUTE_NONNULL(args)
428 /* _GL_ATTRIBUTE_NONSTRING declares that the contents of a character array is
429 not meant to be NUL-terminated. */
430 /* Applies to: struct/union members and variables that are arrays of element
431 type '[[un]signed] char'. */
432 #ifndef _GL_ATTRIBUTE_NONSTRING
433 # if _GL_HAS_ATTRIBUTE (nonstring)
434 # define _GL_ATTRIBUTE_NONSTRING __attribute__ ((__nonstring__))
436 # define _GL_ATTRIBUTE_NONSTRING
440 /* There is no _GL_ATTRIBUTE_NORETURN; use _Noreturn instead. */
442 /* _GL_ATTRIBUTE_NOTHROW declares that the function does not throw exceptions.
444 /* Applies to: functions. */
445 #ifndef _GL_ATTRIBUTE_NOTHROW
446 # if _GL_HAS_ATTRIBUTE (nothrow) && !defined __cplusplus
447 # define _GL_ATTRIBUTE_NOTHROW __attribute__ ((__nothrow__))
449 # define _GL_ATTRIBUTE_NOTHROW
453 /* _GL_ATTRIBUTE_PACKED declares:
454 For struct members: The member has the smallest possible alignment.
455 For struct, union, class: All members have the smallest possible alignment,
456 minimizing the memory required. */
457 /* Applies to: struct members, struct, union,
458 in C++ also: class. */
459 #ifndef _GL_ATTRIBUTE_PACKED
460 # if _GL_HAS_ATTRIBUTE (packed)
461 # define _GL_ATTRIBUTE_PACKED __attribute__ ((__packed__))
463 # define _GL_ATTRIBUTE_PACKED
467 /* _GL_ATTRIBUTE_PURE declares that It is OK for a compiler to omit duplicate
468 calls to the function with the same arguments if observable state is not
469 changed between calls.
470 This attribute is safe for a function that does not affect
471 observable state, and always returns exactly once.
472 (This attribute is looser than _GL_ATTRIBUTE_CONST.) */
473 /* Applies to: functions. */
474 #ifndef _GL_ATTRIBUTE_PURE
475 # if _GL_HAS_ATTRIBUTE (pure)
476 # define _GL_ATTRIBUTE_PURE __attribute__ ((__pure__))
478 # define _GL_ATTRIBUTE_PURE
482 /* _GL_ATTRIBUTE_RETURNS_NONNULL declares that the function's return value is
483 a non-NULL pointer. */
484 /* Applies to: functions. */
485 #ifndef _GL_ATTRIBUTE_RETURNS_NONNULL
486 # if _GL_HAS_ATTRIBUTE (returns_nonnull)
487 # define _GL_ATTRIBUTE_RETURNS_NONNULL __attribute__ ((__returns_nonnull__))
489 # define _GL_ATTRIBUTE_RETURNS_NONNULL
493 /* _GL_ATTRIBUTE_SENTINEL(pos) declares that the variadic function expects a
494 trailing NULL argument.
495 _GL_ATTRIBUTE_SENTINEL () - The last argument is NULL (requires C99).
496 _GL_ATTRIBUTE_SENTINEL ((N)) - The (N+1)st argument from the end is NULL. */
497 /* Applies to: functions. */
498 #ifndef _GL_ATTRIBUTE_SENTINEL
499 # if _GL_HAS_ATTRIBUTE (sentinel)
500 # define _GL_ATTRIBUTE_SENTINEL(pos) __attribute__ ((__sentinel__ pos))
502 # define _GL_ATTRIBUTE_SENTINEL(pos)
506 /* A helper macro. Don't use it directly. */
507 #ifndef _GL_ATTRIBUTE_UNUSED
508 # if _GL_HAS_ATTRIBUTE (unused)
509 # define _GL_ATTRIBUTE_UNUSED __attribute__ ((__unused__))
511 # define _GL_ATTRIBUTE_UNUSED
515 ]dnl There is no _GL_ATTRIBUTE_VISIBILITY; see m4/visibility.m4 instead.
517 /* _GL_UNUSED_LABEL; declares that it is not a programming mistake if the
518 immediately preceding label is not used. The compiler should not warn
519 if the label is not used. */
520 /* Applies to: label (both in C and C++). */
521 /* Note that g++ < 4.5 does not support the '__attribute__ ((__unused__)) ;'
522 syntax. But clang does. */
523 #ifndef _GL_UNUSED_LABEL
524 # if !(defined __cplusplus && !_GL_GNUC_PREREQ (4, 5)) || defined __clang__
525 # define _GL_UNUSED_LABEL _GL_ATTRIBUTE_UNUSED
527 # define _GL_UNUSED_LABEL
531 AH_VERBATIM([async_safe],
532 [/* The _GL_ASYNC_SAFE marker should be attached to functions that are
533 signal handlers (for signals other than SIGABRT, SIGPIPE) or can be
534 invoked from such signal handlers. Such functions have some restrictions:
535 * All functions that it calls should be marked _GL_ASYNC_SAFE as well,
536 or should be listed as async-signal-safe in POSIX
537 <https://pubs.opengroup.org/onlinepubs/9699919799/functions/V2_chap02.html#tag_15_04>
538 section 2.4.3. Note that malloc(), sprintf(), and fwrite(), in
539 particular, are NOT async-signal-safe.
540 * All memory locations (variables and struct fields) that these functions
541 access must be marked 'volatile'. This holds for both read and write
542 accesses. Otherwise the compiler might optimize away stores to and
543 reads from such locations that occur in the program, depending on its
544 data flow analysis. For example, when the program contains a loop
545 that is intended to inspect a variable set from within a signal handler
546 while (!signal_occurred)
548 the compiler is allowed to transform this into an endless loop if the
549 variable 'signal_occurred' is not declared 'volatile'.
550 Additionally, recall that:
551 * A signal handler should not modify errno (except if it is a handler
552 for a fatal signal and ends by raising the same signal again, thus
553 provoking the termination of the process). If it invokes a function
554 that may clobber errno, it needs to save and restore the value of
556 #define _GL_ASYNC_SAFE
558 AH_VERBATIM([micro_optimizations],
559 [/* _GL_CMP (n1, n2) performs a three-valued comparison on n1 vs. n2, where
560 n1 and n2 are expressions without side effects, that evaluate to real
561 numbers (excluding NaN).
566 The naïve code (n1 > n2 ? 1 : n1 < n2 ? -1 : 0) produces a conditional
567 jump with nearly all GCC versions up to GCC 10.
568 This variant (n1 < n2 ? -1 : n1 > n2) produces a conditional with many
569 GCC versions up to GCC 9.
570 The better code (n1 > n2) - (n1 < n2) from Hacker's Delight § 2-9
571 avoids conditional jumps in all GCC versions >= 3.4. */
572 #define _GL_CMP(n1, n2) (((n1) > (n2)) - ((n1) < (n2)))
574 dnl Hint which direction to take regarding cross-compilation guesses:
575 dnl When a user installs a program on a platform they are not intimately
576 dnl familiar with, --enable-cross-guesses=conservative is the appropriate
577 dnl choice. It implements the "If we don't know, assume the worst" principle.
578 dnl However, when an operating system developer (on a platform which is not
579 dnl yet known to gnulib) builds packages for their platform, they want to
580 dnl expose, not hide, possible platform bugs; in this case,
581 dnl --enable-cross-guesses=risky is the appropriate choice.
582 dnl Sets the variables
583 dnl gl_cross_guess_normal (to be used when 'yes' is good and 'no' is bad),
584 dnl gl_cross_guess_inverted (to be used when 'no' is good and 'yes' is bad).
585 AC_ARG_ENABLE([cross-guesses],
586 [AS_HELP_STRING([--enable-cross-guesses={conservative|risky}],
587 [specify policy for cross-compilation guesses])],
588 [if test "x$enableval" != xconservative && test "x$enableval" != xrisky; then
589 AC_MSG_WARN([invalid argument supplied to --enable-cross-guesses])
590 enableval=conservative
592 gl_cross_guesses="$enableval"],
593 [gl_cross_guesses=conservative])
594 if test $gl_cross_guesses = risky; then
595 gl_cross_guess_normal="guessing yes"
596 gl_cross_guess_inverted="guessing no"
598 gl_cross_guess_normal="guessing no"
599 gl_cross_guess_inverted="guessing yes"
601 dnl Preparation for running test programs:
602 dnl Tell glibc to write diagnostics from -D_FORTIFY_SOURCE=2 to stderr, not
603 dnl to /dev/tty, so they can be redirected to log files. Such diagnostics
604 dnl arise e.g., in the macros gl_PRINTF_DIRECTIVE_N, gl_SNPRINTF_DIRECTIVE_N.
606 export LIBC_FATAL_STDERR_
609 # gl_MODULE_INDICATOR_INIT_VARIABLE([variablename])
610 # gl_MODULE_INDICATOR_INIT_VARIABLE([variablename], [initialvalue])
611 # initializes the shell variable that indicates the presence of the given module
612 # as a C preprocessor expression.
613 AC_DEFUN([gl_MODULE_INDICATOR_INIT_VARIABLE],
615 GL_MODULE_INDICATOR_PREFIX[]_[$1]=m4_if([$2], , [0], [$2])
616 AC_SUBST(GL_MODULE_INDICATOR_PREFIX[]_[$1])
619 # gl_MODULE_INDICATOR_CONDITION
620 # expands to a C preprocessor expression that evaluates to 1 or 0, depending
621 # whether a gnulib module that has been requested shall be considered present
623 m4_define([gl_MODULE_INDICATOR_CONDITION], [1])
625 # gl_MODULE_INDICATOR_SET_VARIABLE([modulename])
626 # sets the shell variable that indicates the presence of the given module to
627 # a C preprocessor expression that will evaluate to 1.
628 AC_DEFUN([gl_MODULE_INDICATOR_SET_VARIABLE],
630 gl_MODULE_INDICATOR_SET_VARIABLE_AUX(
631 [GL_MODULE_INDICATOR_PREFIX[]_GNULIB_[]m4_translit([[$1]],
632 [abcdefghijklmnopqrstuvwxyz./-],
633 [ABCDEFGHIJKLMNOPQRSTUVWXYZ___])],
634 [gl_MODULE_INDICATOR_CONDITION])
637 # gl_MODULE_INDICATOR_SET_VARIABLE_AUX([variable])
638 # modifies the shell variable to include the gl_MODULE_INDICATOR_CONDITION.
639 # The shell variable's value is a C preprocessor expression that evaluates
641 AC_DEFUN([gl_MODULE_INDICATOR_SET_VARIABLE_AUX],
643 m4_if(m4_defn([gl_MODULE_INDICATOR_CONDITION]), [1],
645 dnl Simplify the expression VALUE || 1 to 1.
648 [gl_MODULE_INDICATOR_SET_VARIABLE_AUX_OR([$1],
649 [gl_MODULE_INDICATOR_CONDITION])])
652 # gl_MODULE_INDICATOR_SET_VARIABLE_AUX_OR([variable], [condition])
653 # modifies the shell variable to include the given condition. The shell
654 # variable's value is a C preprocessor expression that evaluates to 0 or 1.
655 AC_DEFUN([gl_MODULE_INDICATOR_SET_VARIABLE_AUX_OR],
657 dnl Simplify the expression 1 || CONDITION to 1.
658 if test "$[]$1" != 1; then
659 dnl Simplify the expression 0 || CONDITION to CONDITION.
660 if test "$[]$1" = 0; then
668 # gl_MODULE_INDICATOR([modulename])
669 # defines a C macro indicating the presence of the given module
670 # in a location where it can be used.
672 # | in lib/ | in tests/ |
673 # --------------------------------------------+---------+-----------+
674 # Module present among main modules: | 1 | 1 |
675 # --------------------------------------------+---------+-----------+
676 # Module present among tests-related modules: | 0 | 1 |
677 # --------------------------------------------+---------+-----------+
678 # Module not present at all: | 0 | 0 |
679 # --------------------------------------------+---------+-----------+
680 AC_DEFUN([gl_MODULE_INDICATOR],
682 AC_DEFINE_UNQUOTED([GNULIB_]m4_translit([[$1]],
683 [abcdefghijklmnopqrstuvwxyz./-],
684 [ABCDEFGHIJKLMNOPQRSTUVWXYZ___]),
685 [gl_MODULE_INDICATOR_CONDITION],
686 [Define to a C preprocessor expression that evaluates to 1 or 0,
687 depending whether the gnulib module $1 shall be considered present.])
690 # gl_MODULE_INDICATOR_FOR_TESTS([modulename])
691 # defines a C macro indicating the presence of the given module
692 # in lib or tests. This is useful to determine whether the module
695 # | in lib/ | in tests/ |
696 # --------------------------------------------+---------+-----------+
697 # Module present among main modules: | 1 | 1 |
698 # --------------------------------------------+---------+-----------+
699 # Module present among tests-related modules: | 1 | 1 |
700 # --------------------------------------------+---------+-----------+
701 # Module not present at all: | 0 | 0 |
702 # --------------------------------------------+---------+-----------+
703 AC_DEFUN([gl_MODULE_INDICATOR_FOR_TESTS],
705 AC_DEFINE([GNULIB_TEST_]m4_translit([[$1]],
706 [abcdefghijklmnopqrstuvwxyz./-],
707 [ABCDEFGHIJKLMNOPQRSTUVWXYZ___]), [1],
708 [Define to 1 when the gnulib module $1 should be tested.])
711 # gl_ASSERT_NO_GNULIB_POSIXCHECK
712 # asserts that there will never be a need to #define GNULIB_POSIXCHECK.
713 # and thereby enables an optimization of configure and config.h.
715 AC_DEFUN([gl_ASSERT_NO_GNULIB_POSIXCHECK],
717 dnl Override gl_WARN_ON_USE_PREPARE.
718 dnl But hide this definition from 'aclocal'.
719 AC_DEFUN([gl_W][ARN_ON_USE_PREPARE], [])
722 # gl_ASSERT_NO_GNULIB_TESTS
723 # asserts that there will be no gnulib tests in the scope of the configure.ac
724 # and thereby enables an optimization of config.h.
726 AC_DEFUN([gl_ASSERT_NO_GNULIB_TESTS],
728 dnl Override gl_MODULE_INDICATOR_FOR_TESTS.
729 AC_DEFUN([gl_MODULE_INDICATOR_FOR_TESTS], [])
732 # Test whether <features.h> exists.
733 # Set HAVE_FEATURES_H.
734 AC_DEFUN([gl_FEATURES_H],
736 AC_CHECK_HEADERS_ONCE([features.h])
737 if test $ac_cv_header_features_h = yes; then
742 AC_SUBST([HAVE_FEATURES_H])
746 # Modifies the value of the shell variable CC in an attempt to make $CC
747 # understand ISO C99 source code.
748 AC_DEFUN([gl_PROG_CC_C99],
750 dnl Just use AC_PROG_CC_C99.
751 dnl When AC_PROG_CC_C99 and AC_PROG_CC_STDC are used together, the substituted
752 dnl value of CC will contain the C99 enabling options twice. But this is only
753 dnl a cosmetic problem.
754 dnl With Autoconf >= 2.70, use AC_PROG_CC since it implies AC_PROG_CC_C99;
755 dnl this avoids a "warning: The macro `AC_PROG_CC_C99' is obsolete."
756 m4_version_prereq([2.70],
757 [AC_REQUIRE([AC_PROG_CC])],
758 [AC_REQUIRE([AC_PROG_CC_C99])])
762 # Determines the values for AR, ARFLAGS, RANLIB that fit with the compiler.
763 # The user can set the variables AR, ARFLAGS, RANLIB if he wants to override
765 AC_DEFUN([gl_PROG_AR_RANLIB],
767 dnl Minix 3 comes with two toolchains: The Amsterdam Compiler Kit compiler
768 dnl as "cc", and GCC as "gcc". They have different object file formats and
769 dnl library formats. In particular, the GNU binutils programs ar and ranlib
770 dnl produce libraries that work only with gcc, not with cc.
771 AC_REQUIRE([AC_PROG_CC])
772 dnl The '][' hides this use from 'aclocal'.
773 AC_BEFORE([$0], [A][M_PROG_AR])
774 AC_CACHE_CHECK([for Minix Amsterdam compiler], [gl_cv_c_amsterdam_compiler],
776 AC_EGREP_CPP([Amsterdam],
782 [gl_cv_c_amsterdam_compiler=yes],
783 [gl_cv_c_amsterdam_compiler=no])
786 dnl Don't compete with AM_PROG_AR's decision about AR/ARFLAGS if we are not
787 dnl building with __ACK__.
788 if test $gl_cv_c_amsterdam_compiler = yes; then
789 if test -z "$AR"; then
792 if test -z "$ARFLAGS"; then
796 dnl AM_PROG_AR was added in automake v1.11.2. AM_PROG_AR does not AC_SUBST
797 dnl ARFLAGS variable (it is filed into Makefile.in directly by automake
798 dnl script on-demand, if not specified by ./configure of course).
799 dnl Don't AC_REQUIRE the AM_PROG_AR otherwise the code for __ACK__ above
800 dnl will be ignored. Also, pay attention to call AM_PROG_AR in else block
801 dnl because AM_PROG_AR is written so it could re-set AR variable even for
802 dnl __ACK__. It may seem like its easier to avoid calling the macro here,
803 dnl but we need to AC_SUBST both AR/ARFLAGS (thus those must have some good
804 dnl default value and automake should usually know them).
806 dnl The '][' hides this use from 'aclocal'.
807 m4_ifdef([A][M_PROG_AR], [A][M_PROG_AR], [:])
810 dnl In case the code above has not helped with setting AR/ARFLAGS, use
811 dnl Automake-documented default values for AR and ARFLAGS, but prefer
812 dnl ${host}-ar over ar (useful for cross-compiling).
813 AC_CHECK_TOOL([AR], [ar], [ar])
814 if test -z "$ARFLAGS"; then
820 if test -z "$RANLIB"; then
821 if test $gl_cv_c_amsterdam_compiler = yes; then
824 dnl Use the ranlib program if it is available.
832 # This definition is copied from post-2.70 Autoconf and overrides the
833 # AC_C_RESTRICT macro from autoconf 2.60..2.70.
834 m4_version_prereq([2.70.1], [], [
835 AC_DEFUN([AC_C_RESTRICT],
836 [AC_CACHE_CHECK([for C/C++ restrict keyword], [ac_cv_c_restrict],
838 # Put '__restrict__' first, to avoid problems with glibc and non-GCC; see:
839 # https://lists.gnu.org/archive/html/bug-autoconf/2016-02/msg00006.html
840 # Put 'restrict' last, because C++ lacks it.
841 for ac_kw in __restrict__ __restrict _Restrict restrict; do
844 [[typedef int *int_ptr;
845 int foo (int_ptr $ac_kw ip) { return ip[0]; }
846 int bar (int [$ac_kw]); /* Catch GCC bug 14050. */
847 int bar (int ip[$ac_kw]) { return ip[0]; }
852 return foo (t) + bar (t);
854 [ac_cv_c_restrict=$ac_kw])
855 test "$ac_cv_c_restrict" != no && break
858 AH_VERBATIM([restrict],
859 [/* Define to the equivalent of the C99 'restrict' keyword, or to
860 nothing if this is not supported. Do not define if restrict is
861 supported only directly. */
863 /* Work around a bug in older versions of Sun C++, which did not
864 #define __restrict__ or support _Restrict or __restrict__
865 even though the corresponding Sun C compiler ended up with
866 "#define restrict _Restrict" or "#define restrict __restrict__"
867 in the previous line. This workaround can be removed once
868 we assume Oracle Developer Studio 12.5 (2016) or later. */
869 #if defined __SUNPRO_CC && !defined __RESTRICT && !defined __restrict__
871 # define __restrict__
873 case $ac_cv_c_restrict in
875 no) AC_DEFINE([restrict], []) ;;
876 *) AC_DEFINE_UNQUOTED([restrict], [$ac_cv_c_restrict]) ;;
882 # is like AC_C_BIGENDIAN, except that it can be AC_REQUIREd.
883 # Note that AC_REQUIRE([AC_C_BIGENDIAN]) does not work reliably because some
884 # macros invoke AC_C_BIGENDIAN with arguments.
885 AC_DEFUN([gl_BIGENDIAN],
890 # A temporary file descriptor.
891 # Must be less than 10, because dash 0.5.8 does not support redirections
892 # with multi-digit file descriptors.
893 m4_define([GL_TMP_FD], 9)
896 # executes command, but without the normal configure output.
897 # This is useful when you want to invoke AC_CACHE_CHECK (or AC_CHECK_FUNC etc.)
898 # inside another AC_CACHE_CHECK.
899 AC_DEFUN([gl_SILENT],
901 exec GL_TMP_FD>&AS_MESSAGE_FD AS_MESSAGE_FD>/dev/null
903 exec AS_MESSAGE_FD>&GL_TMP_FD GL_TMP_FD>&-
906 # gl_CACHE_VAL_SILENT(cache-id, command-to-set-it)
907 # is like AC_CACHE_VAL(cache-id, command-to-set-it), except that it does not
908 # output a spurious "(cached)" mark in the midst of other configure output.
909 # This macro should be used instead of AC_CACHE_VAL when it is not surrounded
910 # by an AC_MSG_CHECKING/AC_MSG_RESULT pair.
911 AC_DEFUN([gl_CACHE_VAL_SILENT],
914 AC_CACHE_VAL([$1], [$2])
918 # gl_CONDITIONAL(conditional, condition)
919 # is like AM_CONDITIONAL(conditional, condition), except that it does not
921 # configure: error: conditional "..." was never defined.
922 # Usually this means the macro was only invoked conditionally.
923 # when only invoked conditionally. Instead, in that case, both the _TRUE
924 # and the _FALSE case are disabled.
925 AC_DEFUN([gl_CONDITIONAL],
927 pushdef([AC_CONFIG_COMMANDS_PRE], [:])dnl
928 AM_CONDITIONAL([$1], [$2])
929 popdef([AC_CONFIG_COMMANDS_PRE])dnl
930 if test -z "${[$1]_TRUE}" && test -z "${[$1]_FALSE}"; then
936 # gl_CC_ALLOW_WARNINGS
937 # sets and substitutes a variable GL_CFLAG_ALLOW_WARNINGS, to a $(CC) option
938 # that reverts a preceding '-Werror' option, if available.
939 # This is expected to be '-Wno-error' on gcc, clang (except clang/MSVC), xlclang
940 # and empty otherwise.
941 AC_DEFUN([gl_CC_ALLOW_WARNINGS],
943 AC_REQUIRE([AC_PROG_CC])
944 AC_CACHE_CHECK([for C compiler option to allow warnings],
947 echo 'int dummy;' > conftest.c
948 AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS -c conftest.c 2>conftest1.err]) >/dev/null
949 AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS -Wno-error -c conftest.c 2>conftest2.err]) >/dev/null
950 dnl Test the number of error output lines, because AIX xlc accepts the
951 dnl option '-Wno-error', just to produce a warning
952 dnl "Option -Wno-error was incorrectly specified. The option will be ignored."
954 if test $? = 0 && test `wc -l < conftest1.err` = `wc -l < conftest2.err`; then
955 gl_cv_cc_wallow='-Wno-error'
961 case "$gl_cv_cc_wallow" in
962 none) GL_CFLAG_ALLOW_WARNINGS='' ;;
963 *) GL_CFLAG_ALLOW_WARNINGS="$gl_cv_cc_wallow" ;;
965 AC_SUBST([GL_CFLAG_ALLOW_WARNINGS])
968 # gl_CXX_ALLOW_WARNINGS
969 # sets and substitutes a variable GL_CXXFLAG_ALLOW_WARNINGS, to a $(CC) option
970 # that reverts a preceding '-Werror' option, if available.
971 AC_DEFUN([gl_CXX_ALLOW_WARNINGS],
973 dnl Requires AC_PROG_CXX or gl_PROG_ANSI_CXX.
974 if test -n "$CXX" && test "$CXX" != no; then
975 AC_CACHE_CHECK([for C++ compiler option to allow warnings],
978 echo 'int dummy;' > conftest.cc
979 AC_TRY_COMMAND([${CXX-c++} $CXXFLAGS $CPPFLAGS -c conftest.cc 2>conftest1.err]) >/dev/null
980 AC_TRY_COMMAND([${CXX-c++} $CXXFLAGS $CPPFLAGS -Wno-error -c conftest.cc 2>conftest2.err]) >/dev/null
981 dnl Test the number of error output lines, because AIX xlC accepts the
982 dnl option '-Wno-error', just to produce a warning
983 dnl "Option -Wno-error was incorrectly specified. The option will be ignored."
985 if test $? = 0 && test `wc -l < conftest1.err` = `wc -l < conftest2.err`; then
986 gl_cv_cxx_wallow='-Wno-error'
988 gl_cv_cxx_wallow=none
992 case "$gl_cv_cxx_wallow" in
993 none) GL_CXXFLAG_ALLOW_WARNINGS='' ;;
994 *) GL_CXXFLAG_ALLOW_WARNINGS="$gl_cv_cxx_wallow" ;;
997 GL_CXXFLAG_ALLOW_WARNINGS=''
999 AC_SUBST([GL_CXXFLAG_ALLOW_WARNINGS])
1002 # gl_CC_GNULIB_WARNINGS
1003 # sets and substitutes a variable GL_CFLAG_GNULIB_WARNINGS, to a $(CC) option
1004 # set that enables or disables warnings as suitable for the Gnulib coding style.
1005 AC_DEFUN([gl_CC_GNULIB_WARNINGS],
1007 AC_REQUIRE([gl_CC_ALLOW_WARNINGS])
1008 dnl Assume that the compiler supports -Wno-* options only if it also supports
1010 GL_CFLAG_GNULIB_WARNINGS=''
1011 if test -n "$GL_CFLAG_ALLOW_WARNINGS"; then
1012 dnl Enable these warning options:
1015 dnl -Wno-cast-qual >= 3 >= 3.9
1016 dnl -Wno-conversion >= 3 >= 3.9
1017 dnl -Wno-float-conversion >= 4.9 >= 3.9
1018 dnl -Wno-float-equal >= 3 >= 3.9
1019 dnl -Wimplicit-fallthrough >= 7 >= 3.9
1020 dnl -Wno-pedantic >= 4.8 >= 3.9
1021 dnl -Wno-sign-compare >= 3 >= 3.9
1022 dnl -Wno-sign-conversion >= 4.3 >= 3.9
1023 dnl -Wno-type-limits >= 4.3 >= 3.9
1024 dnl -Wno-undef >= 3 >= 3.9
1025 dnl -Wno-unsuffixed-float-constants >= 4.5
1026 dnl -Wno-unused-function >= 3 >= 3.9
1027 dnl -Wno-unused-parameter >= 3 >= 3.9
1029 cat > conftest.c <<\EOF
1030 #if __GNUC__ >= 3 || (__clang_major__ + (__clang_minor__ >= 9) > 3)
1036 -Wno-unused-function
1037 -Wno-unused-parameter
1039 #if __GNUC__ + (__GNUC_MINOR__ >= 9) > 4 || (__clang_major__ + (__clang_minor__ >= 9) > 3)
1040 -Wno-float-conversion
1042 #if __GNUC__ >= 7 || (__clang_major__ + (__clang_minor__ >= 9) > 3)
1043 -Wimplicit-fallthrough
1045 #if __GNUC__ + (__GNUC_MINOR__ >= 8) > 4 || (__clang_major__ + (__clang_minor__ >= 9) > 3)
1048 #if __GNUC__ + (__GNUC_MINOR__ >= 3) > 4 || (__clang_major__ + (__clang_minor__ >= 9) > 3)
1049 -Wno-sign-conversion
1052 #if __GNUC__ + (__GNUC_MINOR__ >= 5) > 4
1053 -Wno-unsuffixed-float-constants
1056 gl_command="$CC $CFLAGS $CPPFLAGS -E conftest.c > conftest.out"
1057 if AC_TRY_EVAL([gl_command]); then
1058 gl_options=`grep -v '#' conftest.out`
1059 for word in $gl_options; do
1060 GL_CFLAG_GNULIB_WARNINGS="$GL_CFLAG_GNULIB_WARNINGS $word"
1063 rm -f conftest.c conftest.out
1065 AC_SUBST([GL_CFLAG_GNULIB_WARNINGS])
1068 dnl gl_CONDITIONAL_HEADER([foo.h])
1069 dnl takes a shell variable GL_GENERATE_FOO_H (with value true or false) as input
1071 dnl - an AC_SUBSTed variable FOO_H that is either a file name or empty, based
1072 dnl on whether GL_GENERATE_FOO_H is true or false,
1073 dnl - an Automake conditional GL_GENERATE_FOO_H that evaluates to the value of
1074 dnl the shell variable GL_GENERATE_FOO_H.
1075 AC_DEFUN([gl_CONDITIONAL_HEADER],
1077 m4_pushdef([gl_header_name], AS_TR_SH(m4_toupper($1)))
1078 m4_pushdef([gl_generate_var], [GL_GENERATE_]AS_TR_SH(m4_toupper($1)))
1079 m4_pushdef([gl_generate_cond], [GL_GENERATE_]AS_TR_SH(m4_toupper($1)))
1080 case "$gl_generate_var" in
1081 false) gl_header_name='' ;;
1083 dnl It is OK to use a .h file in lib/ from within tests/, but not vice
1085 if test -z "$gl_header_name"; then
1086 gl_header_name="${gl_source_base_prefix}$1"
1089 *) echo "*** gl_generate_var is not set correctly" 1>&2; exit 1 ;;
1091 AC_SUBST(gl_header_name)
1092 gl_CONDITIONAL(gl_generate_cond, [$gl_generate_var])
1093 m4_popdef([gl_generate_cond])
1094 m4_popdef([gl_generate_var])
1095 m4_popdef([gl_header_name])
1098 dnl gl_CHECK_FUNCS_ANDROID([func], [[#include <foo.h>]])
1099 dnl is like AC_CHECK_FUNCS([func]), taking into account a portability problem
1102 dnl When code is compiled on Android, it is in the context of a certain
1103 dnl "Android API level", which indicates the minimum version of Android on
1104 dnl which the app can be installed. In other words, you don't compile for a
1105 dnl specific version of Android. You compile for all versions of Android,
1106 dnl onwards from the given API level.
1107 dnl Thus, the question "does the OS have the function func" has three possible
1109 dnl - yes, in all versions starting from the given API level,
1110 dnl - no, in no version,
1111 dnl - not in the given API level, but in a later version of Android.
1113 dnl In detail, this works as follows:
1114 dnl If func was added to Android API level, say, 28, then the libc.so has the
1115 dnl symbol func always, whereas the header file <foo.h> declares func
1117 dnl #if __ANDROID_API__ >= 28
1118 dnl ... func (...) __INTRODUCED_IN(28);
1120 dnl Thus, when compiling with "clang -target armv7a-unknown-linux-android28",
1121 dnl the function func is declared and exists in libc.
1122 dnl Whereas when compiling with "clang -target armv7a-unknown-linux-android27",
1123 dnl the function func is not declared but exists in libc.
1125 dnl This macro sets two variables:
1126 dnl - gl_cv_onwards_func_<func> to yes / no / "future OS version"
1127 dnl - ac_cv_func_<func> to yes / no / no
1128 dnl The first variable allows to distinguish all three cases.
1129 dnl The second variable is set, so that an invocation
1130 dnl gl_CHECK_FUNCS_ANDROID([func], [[#include <foo.h>]])
1131 dnl can be used as a drop-in replacement for
1132 dnl AC_CHECK_FUNCS([func]).
1133 AC_DEFUN([gl_CHECK_FUNCS_ANDROID],
1135 AC_REQUIRE([AC_CANONICAL_HOST])
1136 AC_CACHE_CHECK([for [$1]],
1137 [[gl_cv_onwards_func_][$1]],
1141 AC_CHECK_DECL([$1], , , [$2])
1142 if test $[ac_cv_have_decl_][$1] = yes; then
1143 AC_CHECK_FUNC([[$1]])
1144 if test $[ac_cv_func_][$1] = yes; then
1145 [gl_cv_onwards_func_][$1]=yes
1147 dnl The function is declared but does not exist. This should not
1148 dnl happen normally. But anyway, we know that a future version
1149 dnl of Android will have the function.
1150 [gl_cv_onwards_func_][$1]='future OS version'
1153 [gl_cv_onwards_func_][$1]='future OS version'
1158 [gl_cv_onwards_func_][$1]=$[ac_cv_func_][$1]
1163 case "$[gl_cv_onwards_func_][$1]" in
1164 future*) [ac_cv_func_][$1]=no ;;
1165 *) [ac_cv_func_][$1]=$[gl_cv_onwards_func_][$1] ;;
1167 if test $[ac_cv_func_][$1] = yes; then
1168 AC_DEFINE([HAVE_]m4_translit([[$1]],
1169 [abcdefghijklmnopqrstuvwxyz],
1170 [ABCDEFGHIJKLMNOPQRSTUVWXYZ]),
1171 [1], [Define to 1 if you have the `$1' function.])
1175 dnl Expands to some code for use in .c programs that, on native Windows, defines
1176 dnl the Microsoft deprecated alias function names to the underscore-prefixed
1177 dnl actual function names. With this macro, these function names are available
1178 dnl without linking with '-loldnames' and without generating warnings.
1179 dnl Usage: Use it after all system header files are included.
1182 dnl ]GL_MDA_DEFINES[
1184 AC_DEFUN([GL_MDA_DEFINES],[
1185 AC_REQUIRE([_GL_MDA_DEFINES])
1188 AC_DEFUN([_GL_MDA_DEFINES],
1190 #if defined _WIN32 && !defined __CYGWIN__
1191 #define access _access
1192 #define chdir _chdir
1193 #define chmod _chmod
1194 #define close _close
1195 #define creat _creat
1199 #define execl _execl
1200 #define execle _execle
1201 #define execlp _execlp
1202 #define execv _execv
1203 #define execve _execve
1204 #define execvp _execvp
1205 #define execvpe _execvpe
1206 #define fcloseall _fcloseall
1208 #define fdopen _fdopen
1209 #define fileno _fileno
1211 #define getcwd _getcwd
1212 #define getpid _getpid
1214 #define isatty _isatty
1218 #define lfind _lfind
1219 #define lsearch _lsearch
1220 #define lseek _lseek
1221 #define memccpy _memccpy
1222 #define mkdir _mkdir
1223 #define mktemp _mktemp
1225 #define putenv _putenv
1228 #define rmdir _rmdir
1229 #define strdup _strdup
1231 #define tempnam _tempnam
1232 #define tzset _tzset
1233 #define umask _umask
1234 #define unlink _unlink
1235 #define utime _utime
1236 #define wcsdup _wcsdup
1237 #define write _write