diff options
| author | NIIBE Yutaka <[email protected]> | 2026-09-01 03:38:12 +0200 |
|---|---|---|
| committer | NIIBE Yutaka <[email protected]> | 2026-09-01 03:38:12 +0200 |
| commit | d89d5546db953cc4a36e2a0237aecf048b0d16e0 (patch) | |
| tree | eb31a49a77338d0417280d91e5db4bbebdd13070 /m4 | |
| parent | tests: Fix gpgrt_bsprintf test for PowerPC 32. (diff) | |
| download | libgpg-error-d89d5546db953cc4a36e2a0237aecf048b0d16e0.tar.gz libgpg-error-d89d5546db953cc4a36e2a0237aecf048b0d16e0.zip | |
build: Update threadlib from gnulib.
* m4/threadlib.m4: Update.
* m4/gnulib-common.m4: New for gl_CHECK_FUNCS_ANDROID.
--
Signed-off-by: NIIBE Yutaka <[email protected]>
Diffstat (limited to 'm4')
| -rw-r--r-- | m4/gnulib-common.m4 | 1845 | ||||
| -rw-r--r-- | m4/threadlib.m4 | 495 |
2 files changed, 2094 insertions, 246 deletions
diff --git a/m4/gnulib-common.m4 b/m4/gnulib-common.m4 new file mode 100644 index 0000000..d8a6c9b --- /dev/null +++ b/m4/gnulib-common.m4 @@ -0,0 +1,1845 @@ +# gnulib-common.m4 +# serial 122 +dnl Copyright (C) 2007-2026 Free Software Foundation, Inc. +dnl This file is free software; the Free Software Foundation +dnl gives unlimited permission to copy and/or distribute it, +dnl with or without modifications, as long as this notice is preserved. +dnl This file is offered as-is, without any warranty. + +AC_PREREQ([2.62]) + +# gl_COMMON +# is expanded unconditionally through gnulib-tool magic. +AC_DEFUN([gl_COMMON], [ + dnl Use AC_REQUIRE here, so that the code is expanded once only. + AC_REQUIRE([gl_00GNULIB]) + AC_REQUIRE([gl_COMMON_BODY]) + AC_REQUIRE([gl_ZZGNULIB]) +]) +AC_DEFUN([gl_COMMON_BODY], [ + AH_VERBATIM([0witness], +[/* Witness that <config.h> has been included. */ +#define _GL_CONFIG_H_INCLUDED 1 +]) + dnl Avoid warnings from gcc -Wtrailing-whitespace. + dnl This is a temporary workaround until Autoconf fixes it. + dnl Test case: + dnl empty1=; empty2=; AC_DEFINE_UNQUOTED([FOO], [$empty1$empty2], [...]) + dnl should produce "#define FOO /**/", not "#define FOO ". + AH_TOP([#if defined __GNUC__ && __GNUC__ >= 15 && !defined __clang__ +# pragma GCC diagnostic push +# pragma GCC diagnostic ignored "-Wtrailing-whitespace" +#endif +]) + AH_BOTTOM([#if defined __GNUC__ && __GNUC__ >= 15 && !defined __clang__ +# pragma GCC diagnostic pop +#endif +]) + AH_VERBATIM([_GL_GNUC_PREREQ], +[/* True if the compiler says it groks GNU C version MAJOR.MINOR. + Except that + - clang groks GNU C 4.2, even on Windows, where it does not define + __GNUC__. + - The OpenMandriva-modified clang compiler pretends that it groks + GNU C version 13.1, but it doesn't: It does not support + __attribute__ ((__malloc__ (f, i))), nor does it support + __attribute__ ((__warning__ (message))) on a function redeclaration. + - Users can make clang lie as well, through the -fgnuc-version option. */ +#if defined __GNUC__ && defined __GNUC_MINOR__ && !defined __clang__ +# define _GL_GNUC_PREREQ(major, minor) \ + ((major) < __GNUC__ + ((minor) <= __GNUC_MINOR__)) +#elif defined __clang__ + /* clang really only groks GNU C 4.2. */ +# define _GL_GNUC_PREREQ(major, minor) \ + ((major) < 4 + ((minor) <= 2)) +#else +# define _GL_GNUC_PREREQ(major, minor) 0 +#endif +]) + AH_VERBATIM([_Noreturn], +[/* The _Noreturn keyword of C11. + Do not use [[noreturn]], because with it the syntax + extern _Noreturn void func (...); + would not be valid; such a declaration would be valid only with 'extern' + and '_Noreturn' swapped, or without the 'extern' keyword. However, some + AIX system header files and several gnulib header files use precisely + this syntax with 'extern'. So even though C23 deprecates _Noreturn, + it is currently more portable to prefer it to [[noreturn]]. + + Also, do not try to work around LLVM bug 59792 (clang 15 or earlier). + This rare bug can be worked around by compiling with 'clang -D_Noreturn=', + though the workaround may generate many false-alarm warnings. */ +#ifndef _Noreturn +# if ((!defined __cplusplus || defined __clang__) \ + && (201112 <= (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0))) + /* _Noreturn works as-is. */ +# elif _GL_GNUC_PREREQ (2, 8) || defined __clang__ || 0x5110 <= __SUNPRO_C + /* Prefer __attribute__ ((__noreturn__)) to plain _Noreturn even if the + latter works, as 'gcc -std=gnu99 -Wpedantic' warns about _Noreturn. */ +# define _Noreturn __attribute__ ((__noreturn__)) +# elif 1200 <= (defined _MSC_VER ? _MSC_VER : 0) +# define _Noreturn __declspec (noreturn) +# else +# define _Noreturn +# endif +#endif +]) + AH_VERBATIM([isoc99_inline], +[/* Work around a bug in Apple GCC 4.0.1 build 5465: In C99 mode, it supports + the ISO C 99 semantics of 'extern inline' (unlike the GNU C semantics of + earlier versions), but does not display it by setting __GNUC_STDC_INLINE__. + __APPLE__ && __MACH__ test for Mac OS X. + __APPLE_CC__ tests for the Apple compiler and its version. + __STDC_VERSION__ tests for the C99 mode. */ +#if defined __APPLE__ && defined __MACH__ && __APPLE_CC__ >= 5465 && !defined __cplusplus && __STDC_VERSION__ >= 199901L && !defined __GNUC_STDC_INLINE__ +# define __GNUC_STDC_INLINE__ 1 +#endif]) + AH_VERBATIM([attribute], +[/* Attributes. */ +/* Define _GL_HAS_ATTRIBUTE only once, because on FreeBSD, with gcc < 5, if + <config.h> gets included once again after <sys/cdefs.h>, __has_attribute(x) + expands to 0 always, and redefining _GL_HAS_ATTRIBUTE would turn off all + attributes. */ +#ifndef _GL_HAS_ATTRIBUTE +# if (defined __has_attribute \ + && (!defined __clang_minor__ \ + || (defined __apple_build_version__ \ + ? 7000000 <= __apple_build_version__ \ + : 5 <= __clang_major__))) +# define _GL_HAS_ATTRIBUTE(attr) __has_attribute (__##attr##__) +# else +# define _GL_HAS_ATTRIBUTE(attr) _GL_ATTR_##attr +/* The following lines list the first GCC version that supports the attribute. + Although the lines are not used in GCC 5 and later (as GCC 5 introduced + __has_attribute support), list GCC versions 5+ anyway for completeness. */ +# define _GL_ATTR_alloc_size _GL_GNUC_PREREQ (4, 3) +# define _GL_ATTR_always_inline _GL_GNUC_PREREQ (3, 2) +# define _GL_ATTR_artificial _GL_GNUC_PREREQ (4, 3) +# define _GL_ATTR_cold _GL_GNUC_PREREQ (4, 3) +# define _GL_ATTR_const _GL_GNUC_PREREQ (2, 95) +# define _GL_ATTR_deprecated _GL_GNUC_PREREQ (3, 1) +# define _GL_ATTR_diagnose_if 0 +# define _GL_ATTR_error _GL_GNUC_PREREQ (4, 3) +# define _GL_ATTR_externally_visible _GL_GNUC_PREREQ (4, 1) +# define _GL_ATTR_fallthrough _GL_GNUC_PREREQ (7, 0) +# define _GL_ATTR_format _GL_GNUC_PREREQ (2, 7) +# define _GL_ATTR_leaf _GL_GNUC_PREREQ (4, 6) +# define _GL_ATTR_malloc _GL_GNUC_PREREQ (3, 0) +# ifdef _ICC +# define _GL_ATTR_may_alias 0 +# else +# define _GL_ATTR_may_alias _GL_GNUC_PREREQ (3, 3) +# endif +# define _GL_ATTR_noinline _GL_GNUC_PREREQ (3, 1) +# define _GL_ATTR_nonnull _GL_GNUC_PREREQ (3, 3) +# define _GL_ATTR_nonnull_if_nonzero _GL_GNUC_PREREQ (15, 1) +# define _GL_ATTR_nonstring _GL_GNUC_PREREQ (8, 0) +# define _GL_ATTR_nothrow _GL_GNUC_PREREQ (3, 3) +# define _GL_ATTR_packed _GL_GNUC_PREREQ (2, 7) +# define _GL_ATTR_pure _GL_GNUC_PREREQ (2, 96) +# define _GL_ATTR_reproducible _GL_GNUC_PREREQ (15, 1) +# define _GL_ATTR_returns_nonnull _GL_GNUC_PREREQ (4, 9) +# define _GL_ATTR_sentinel _GL_GNUC_PREREQ (4, 0) +# define _GL_ATTR_unsequenced _GL_GNUC_PREREQ (15, 1) +# define _GL_ATTR_unused _GL_GNUC_PREREQ (2, 7) +# define _GL_ATTR_warn_unused_result _GL_GNUC_PREREQ (3, 4) +# endif +#endif + +/* Use __has_c_attribute if available. However, do not use with + pre-C23 GCC, which can issue false positives if -Wpedantic. */ +#if (defined __has_c_attribute \ + && ! (_GL_GNUC_PREREQ (4, 6) \ + && (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) <= 201710)) +# define _GL_HAVE___HAS_C_ATTRIBUTE 1 +#else +# define _GL_HAVE___HAS_C_ATTRIBUTE 0 +#endif + +/* Attributes in bracket syntax [[...]] vs. attributes in __attribute__((...)) + syntax, in function declarations. There are two problems here. + (Last tested with gcc/g++ 14 and clang/clang++ 18.) + + 1) We want that the _GL_ATTRIBUTE_* can be cumulated on the same declaration + in any order. + =========================== foo.c = foo.cc =========================== + __attribute__ ((__deprecated__)) [[__nodiscard__]] int bar1 (int); + [[__nodiscard__]] __attribute__ ((__deprecated__)) int bar2 (int); + ====================================================================== + This gives a syntax error + - in C mode with gcc + <https://gcc.gnu.org/PR108796>, and + - in C++ mode with clang++ version < 16, and + - in C++ mode, inside extern "C" {}, still in newer clang++ versions + <https://github.com/llvm/llvm-project/issues/101990>. + */ +/* Define if, in a function declaration, the attributes in bracket syntax + [[...]] must come before the attributes in __attribute__((...)) syntax. + If this is defined, it is best to avoid the bracket syntax, so that the + various _GL_ATTRIBUTE_* can be cumulated on the same declaration in any + order. */ +#ifdef __cplusplus +# if defined __clang__ +# define _GL_BRACKET_BEFORE_ATTRIBUTE 1 +# endif +#else +# if defined __GNUC__ && !defined __clang__ +# define _GL_BRACKET_BEFORE_ATTRIBUTE 1 +# endif +#endif +/* + 2) We want that the _GL_ATTRIBUTE_* can be placed in a declaration + - without 'extern', in C as well as in C++, + - with 'extern', in C, + - with 'extern "C"', in C++ + in the same position. That is, we don't want to be forced to use a + macro which arranges for the attribute to come before 'extern' in + one case and after 'extern' in the other case, because such a macro + would make the source code of .h files pretty ugly. + =========================== foo.c = foo.cc =========================== + #ifdef __cplusplus + # define CC "C" + #else + # define CC + #endif + + #define ND [[__nodiscard__]] + #define WUR __attribute__((__warn_unused_result__)) + + #ifdef __cplusplus + extern "C" { + #endif + // gcc clang g++ clang++ + + ND int foo (int); + int ND foo (int); // warn error warn error + int foo ND (int); + int foo (int) ND; // warn error warn error + + WUR int foo (int); + int WUR foo (int); + int fo1 WUR (int); // error error error error + int foo (int) WUR; + + #ifdef __cplusplus + } + #endif + + // gcc clang g++ clang++ + + ND extern CC int foo (int); // error error + extern CC ND int foo (int); // error error + extern CC int ND foo (int); // warn error warn error + extern CC int foo ND (int); + extern CC int foo (int) ND; // warn error warn error + + WUR extern CC int foo (int); // warn + extern CC WUR int foo (int); + extern CC int WUR foo (int); + extern CC int foo WUR (int); // error error error error + extern CC int foo (int) WUR; + + ND EXTERN_C_FUNC int foo (int); // error error + EXTERN_C_FUNC ND int foo (int); + EXTERN_C_FUNC int ND foo (int); // warn error warn error + EXTERN_C_FUNC int foo ND (int); + EXTERN_C_FUNC int foo (int) ND; // warn error warn error + + WUR EXTERN_C_FUNC int foo (int); // warn + EXTERN_C_FUNC WUR int foo (int); + EXTERN_C_FUNC int WUR foo (int); + EXTERN_C_FUNC int fo2 WUR (int); // error error error error + EXTERN_C_FUNC int foo (int) WUR; + ====================================================================== + So, if we insist on using the 'extern' keyword ('extern CC' idiom): + * If _GL_ATTRIBUTE_* expands to bracket syntax [[...]] + in both C and C++, there is one available position: + - between the function name and the parameter list. + * If _GL_ATTRIBUTE_* expands to __attribute__((...)) syntax + in both C and C++, there are several available positions: + - before the return type, + - between return type and function name, + - at the end of the declaration. + * If _GL_ATTRIBUTE_* expands to bracket syntax [[...]] in C and to + __attribute__((...)) syntax in C++, there is no available position: + it would need to come before 'extern' in C but after 'extern "C"' + in C++. + * If _GL_ATTRIBUTE_* expands to __attribute__((...)) syntax in C and + to bracket syntax [[...]] in C++, there is one available position: + - before the return type. + Whereas, if we use the 'EXTERN_C_FUNC' idiom, which conditionally + omits the 'extern' keyword: + * If _GL_ATTRIBUTE_* expands to bracket syntax [[...]] + in both C and C++, there are two available positions: + - before the return type, + - between the function name and the parameter list. + * If _GL_ATTRIBUTE_* expands to __attribute__((...)) syntax + in both C and C++, there are several available positions: + - before the return type, + - between return type and function name, + - at the end of the declaration. + * If _GL_ATTRIBUTE_* expands to bracket syntax [[...]] in C and to + __attribute__((...)) syntax in C++, there is one available position: + - before the return type. + * If _GL_ATTRIBUTE_* expands to __attribute__((...)) syntax in C and + to bracket syntax [[...]] in C++, there is one available position: + - before the return type. + The best choice is therefore to use the 'EXTERN_C_FUNC' idiom and + put the attributes before the return type. This works regardless + to what the _GL_ATTRIBUTE_* macros expand. + */ + +/* Attributes in bracket syntax [[...]] vs. attributes in __attribute__((...)) + syntax, in static/inline function definitions. + + There are similar constraints as for function declarations. However, here, + we cannot omit the storage-class specifier. Therefore, the following rule + applies: + * The macros + _GL_ATTRIBUTE_DEPRECATED + _GL_ATTRIBUTE_MAYBE_UNUSED + _GL_ATTRIBUTE_NODISCARD + _GL_ATTRIBUTE_REPRODUCIBLE + _GL_ATTRIBUTE_UNSEQUENCED + which may expand to bracket syntax [[...]], must come first, before the + storage-class specifier. + * Other _GL_ATTRIBUTE_* macros, that expand to __attribute__((...)) syntax, + are better placed between the storage-class specifier and the return + type. + */ + +/* Attributes in bracket syntax [[...]] vs. attributes in __attribute__((...)) + syntax, in variable declarations. + + At which position can they be placed? + (Last tested with gcc/g++ 14 and clang/clang++ 18.) + + =========================== foo.c = foo.cc =========================== + #ifdef __cplusplus + # define CC "C" + #else + # define CC + #endif + + #define BD [[__deprecated__]] + #define AD __attribute__ ((__deprecated__)) + + // gcc clang g++ clang++ + + BD extern CC int var; // error error + extern CC BD int var; // error error + extern CC int BD var; // warn error warn error + extern CC int var BD; + + AD extern CC int var; // warn + extern CC AD int var; + extern CC int AD var; + extern CC int var AD; + + BD extern CC int z[]; // error error + extern CC BD int z[]; // error error + extern CC int BD z[]; // warn error warn error + extern CC int z1 BD []; + extern CC int z[] BD; // warn error error + + AD extern CC int z[]; // warn + extern CC AD int z[]; + extern CC int AD z[]; + extern CC int z2 AD []; // error error error error + extern CC int z[] AD; + ====================================================================== + + * For non-array variables, the only good position is after the variable name, + that is, at the end of the declaration. + * For array variables, you will need to distinguish C and C++: + - In C, before the 'extern' keyword. + - In C++, between the 'extern "C"' and the variable's type. + */ +]dnl There is no _GL_ATTRIBUTE_ALIGNED; use stdalign's alignas instead. +[ +/* _GL_ATTRIBUTE_ALLOC_SIZE ((N)) declares that the Nth argument of the function + is the size of the returned memory block. + _GL_ATTRIBUTE_ALLOC_SIZE ((M, N)) declares that the Mth argument multiplied + by the Nth argument of the function is the size of the returned memory block. + */ +/* Applies to: functions, pointer to functions, function types. */ +#ifndef _GL_ATTRIBUTE_ALLOC_SIZE +# if _GL_HAS_ATTRIBUTE (alloc_size) +# define _GL_ATTRIBUTE_ALLOC_SIZE(args) __attribute__ ((__alloc_size__ args)) +# else +# define _GL_ATTRIBUTE_ALLOC_SIZE(args) +# endif +#endif + +/* _GL_ATTRIBUTE_ALWAYS_INLINE tells that the compiler should always inline the + function and report an error if it cannot do so. */ +/* Applies to: functions. */ +#ifndef _GL_ATTRIBUTE_ALWAYS_INLINE +# if _GL_HAS_ATTRIBUTE (always_inline) +# define _GL_ATTRIBUTE_ALWAYS_INLINE __attribute__ ((__always_inline__)) +# else +# define _GL_ATTRIBUTE_ALWAYS_INLINE +# endif +#endif + +/* _GL_ATTRIBUTE_ARTIFICIAL declares that the function is not important to show + in stack traces when debugging. The compiler should omit the function from + stack traces. */ +/* Applies to: functions. */ +#ifndef _GL_ATTRIBUTE_ARTIFICIAL +# if _GL_HAS_ATTRIBUTE (artificial) +# define _GL_ATTRIBUTE_ARTIFICIAL __attribute__ ((__artificial__)) +# else +# define _GL_ATTRIBUTE_ARTIFICIAL +# endif +#endif + +/* _GL_ATTRIBUTE_COLD declares that the function is rarely executed. */ +/* Applies to: functions. */ +/* Avoid __attribute__ ((cold)) on MinGW; see thread starting at + <https://lists.gnu.org/r/emacs-devel/2019-04/msg01152.html>. + Also, Oracle Studio 12.6 requires 'cold' not '__cold__'. */ +#ifndef _GL_ATTRIBUTE_COLD +# if _GL_HAS_ATTRIBUTE (cold) && !defined __MINGW32__ +# ifndef __SUNPRO_C +# define _GL_ATTRIBUTE_COLD __attribute__ ((__cold__)) +# else +# define _GL_ATTRIBUTE_COLD __attribute__ ((cold)) +# endif +# else +# define _GL_ATTRIBUTE_COLD +# endif +#endif + +/* _GL_ATTRIBUTE_CONST declares: + It is OK for a compiler to move a call, or omit a duplicate call + and reuse a cached return value, even if the state changes between calls. + It is also OK to omit a call if the result is not used. + This attribute is safe if the function does not change observable state, + returns a value determined solely by its arguments' values + without examining state, and always returns exactly once - + e.g., does not raise an exception, call longjmp, or loop forever. + (This attribute is stricter than _GL_ATTRIBUTE_PURE because the + function cannot observe state. Unlike _GL_ATTRIBUTE_UNSEQUENCED + the function must return exactly once and cannot access state + addressed by its pointer arguments or that happens to have the same + value for all calls to the function, but the function is allowed to + return a pointer to storage that can be modified later. */ +/* Applies to: functions. */ +#ifndef _GL_ATTRIBUTE_CONST +# if _GL_HAS_ATTRIBUTE (const) +# define _GL_ATTRIBUTE_CONST __attribute__ ((__const__)) +# else +# define _GL_ATTRIBUTE_CONST +# endif +#endif + +/* _GL_ATTRIBUTE_COUNTED_BY (C) declares that the number of elements of + the field is given by C, which must be another field in the same struct. + The programmer is responsible for guaranteeing some invariants; see + <https://gcc.gnu.org/onlinedocs/gcc/Common-Attributes.html> for details. */ +/* Applies to struct fields of type array or pointer (to data). */ +#ifndef _GL_ATTRIBUTE_COUNTED_BY +/* This attributes is supported + - for fields of array type: by gcc >= 16, clang >= 18, + - for fields of pointer type: by gcc when <https://gcc.gnu.org/PR125072> + will be fixed, clang >= 19. */ +# if defined __clang__ && __clang_major__ >= 19 +# define _GL_ATTRIBUTE_COUNTED_BY(c) __attribute__ ((__counted_by__ (c))) +# else +# define _GL_ATTRIBUTE_COUNTED_BY(c) +# endif +#endif + +/* _GL_ATTRIBUTE_DEALLOC (F, I) declares that the function returns pointers + that can be freed by passing them as the Ith argument to the + function F. + _GL_ATTRIBUTE_DEALLOC_FREE declares that the function returns pointers that + can be freed via 'free'; it can be used only after declaring 'free'. */ +/* Applies to: functions. Cannot be used on inline functions. */ +#ifndef _GL_ATTRIBUTE_DEALLOC +# if _GL_GNUC_PREREQ (11, 0) +# define _GL_ATTRIBUTE_DEALLOC(f, i) __attribute__ ((__malloc__ (f, i))) +# else +# define _GL_ATTRIBUTE_DEALLOC(f, i) +# endif +#endif +/* If gnulib's <string.h> or <wchar.h> has already defined this macro, continue + to use this earlier definition, since <stdlib.h> may not have been included + yet. */ +#ifndef _GL_ATTRIBUTE_DEALLOC_FREE +# if defined __cplusplus && defined __GNUC__ && !defined __clang__ +/* Work around GCC bug <https://gcc.gnu.org/PR108231> */ +# define _GL_ATTRIBUTE_DEALLOC_FREE \ + _GL_ATTRIBUTE_DEALLOC ((void (*) (void *)) free, 1) +# else +# define _GL_ATTRIBUTE_DEALLOC_FREE \ + _GL_ATTRIBUTE_DEALLOC (free, 1) +# endif +#endif + +/* _GL_ATTRIBUTE_DEPRECATED: Declares that an entity is deprecated. + The compiler may warn if the entity is used. */ +/* Applies to: + - function, variable, + - struct, union, struct/union member, + - enumeration, enumeration item, + - typedef, + in C++ also: namespace, class, template specialization. */ +#ifndef _GL_ATTRIBUTE_DEPRECATED +# ifndef _GL_BRACKET_BEFORE_ATTRIBUTE +# if _GL_HAVE___HAS_C_ATTRIBUTE +# if __has_c_attribute (__deprecated__) +# define _GL_ATTRIBUTE_DEPRECATED [[__deprecated__]] +# endif +# endif +# endif +# if !defined _GL_ATTRIBUTE_DEPRECATED && _GL_HAS_ATTRIBUTE (deprecated) +# define _GL_ATTRIBUTE_DEPRECATED __attribute__ ((__deprecated__)) +# endif +# ifndef _GL_ATTRIBUTE_DEPRECATED +# define _GL_ATTRIBUTE_DEPRECATED +# endif +#endif + +/* _GL_ATTRIBUTE_ERROR(msg) requests an error if a function is called and + the function call is not optimized away. + _GL_ATTRIBUTE_WARNING(msg) requests a warning if a function is called and + the function call is not optimized away. */ +/* Applies to: functions. */ +#if !(defined _GL_ATTRIBUTE_ERROR && defined _GL_ATTRIBUTE_WARNING) +# if _GL_HAS_ATTRIBUTE (error) +# define _GL_ATTRIBUTE_ERROR(msg) __attribute__ ((__error__ (msg))) +# define _GL_ATTRIBUTE_WARNING(msg) __attribute__ ((__warning__ (msg))) +# elif _GL_HAS_ATTRIBUTE (diagnose_if) +# define _GL_ATTRIBUTE_ERROR(msg) __attribute__ ((__diagnose_if__ (1, msg, "error"))) +# define _GL_ATTRIBUTE_WARNING(msg) __attribute__ ((__diagnose_if__ (1, msg, "warning"))) +# else +# define _GL_ATTRIBUTE_ERROR(msg) +# define _GL_ATTRIBUTE_WARNING(msg) +# endif +#endif + +/* _GL_ATTRIBUTE_EXTERNALLY_VISIBLE declares that the entity should remain + visible to debuggers etc., even with '-fwhole-program'. */ +/* Applies to: functions, variables. */ +#ifndef _GL_ATTRIBUTE_EXTERNALLY_VISIBLE +# if _GL_HAS_ATTRIBUTE (externally_visible) +# define _GL_ATTRIBUTE_EXTERNALLY_VISIBLE __attribute__ ((externally_visible)) +# else +# define _GL_ATTRIBUTE_EXTERNALLY_VISIBLE +# endif +#endif + +/* _GL_ATTRIBUTE_FALLTHROUGH declares that it is not a programming mistake if + the control flow falls through to the immediately following 'case' or + 'default' label. The compiler should not warn in this case. */ +/* Applies to: Empty statement (;), inside a 'switch' statement. */ +/* Always expands to something. */ +#ifndef _GL_ATTRIBUTE_FALLTHROUGH +# if _GL_HAVE___HAS_C_ATTRIBUTE +# if __has_c_attribute (__fallthrough__) +# define _GL_ATTRIBUTE_FALLTHROUGH [[__fallthrough__]] +# endif +# endif +# if !defined _GL_ATTRIBUTE_FALLTHROUGH && _GL_HAS_ATTRIBUTE (fallthrough) +# define _GL_ATTRIBUTE_FALLTHROUGH __attribute__ ((__fallthrough__)) +# endif +# ifndef _GL_ATTRIBUTE_FALLTHROUGH +# define _GL_ATTRIBUTE_FALLTHROUGH ((void) 0) +# endif +#endif + +/* _GL_ATTRIBUTE_FORMAT ((ARCHETYPE, STRING-INDEX, FIRST-TO-CHECK)) + declares that the STRING-INDEXth function argument is a format string of + style ARCHETYPE, which is one of: + printf, gnu_printf + scanf, gnu_scanf, + strftime, gnu_strftime, + strfmon, + or the same thing prefixed and suffixed with '__'. + If FIRST-TO-CHECK is not 0, arguments starting at FIRST-TO_CHECK + are suitable for the format string. */ +/* Applies to: functions. */ +#ifndef _GL_ATTRIBUTE_FORMAT +# if _GL_HAS_ATTRIBUTE (format) +# define _GL_ATTRIBUTE_FORMAT(spec) __attribute__ ((__format__ spec)) +# else +# define _GL_ATTRIBUTE_FORMAT(spec) +# endif +#endif + +/* _GL_ATTRIBUTE_LEAF declares that if the function is called from some other + compilation unit, it executes code from that unit only by return or by + exception handling. This declaration lets the compiler optimize that unit + more aggressively. */ +/* Applies to: functions. */ +#ifndef _GL_ATTRIBUTE_LEAF +# if _GL_HAS_ATTRIBUTE (leaf) +# define _GL_ATTRIBUTE_LEAF __attribute__ ((__leaf__)) +# else +# define _GL_ATTRIBUTE_LEAF +# endif +#endif + +/* _GL_ATTRIBUTE_MALLOC declares that the function returns a pointer to freshly + allocated memory. */ +/* Applies to: functions. */ +#ifndef _GL_ATTRIBUTE_MALLOC +# if _GL_HAS_ATTRIBUTE (malloc) +# define _GL_ATTRIBUTE_MALLOC __attribute__ ((__malloc__)) +# else +# define _GL_ATTRIBUTE_MALLOC +# endif +#endif + +/* _GL_ATTRIBUTE_MAY_ALIAS declares that pointers to the type may point to the + same storage as pointers to other types. Thus this declaration disables + strict aliasing optimization. */ +/* Applies to: types. */ +/* Oracle Studio 12.6 mishandles may_alias despite __has_attribute OK. */ +#ifndef _GL_ATTRIBUTE_MAY_ALIAS +# if _GL_HAS_ATTRIBUTE (may_alias) && !defined __SUNPRO_C +# define _GL_ATTRIBUTE_MAY_ALIAS __attribute__ ((__may_alias__)) +# else +# define _GL_ATTRIBUTE_MAY_ALIAS +# endif +#endif + +/* _GL_ATTRIBUTE_MAYBE_UNUSED declares that it is not a programming mistake if + the entity is not used. The compiler should not warn if the entity is not + used. However, 'int _GL_UNNAMED (i)' is preferable to + '_GL_ATTRIBUTE_MAYBE_UNUSED int i' when parameter I is unused + regardless of preprocessor macro settings. */ +/* Applies to: + - function, variable, + - struct, union, struct/union member, + - enumeration, enumeration item, + - typedef, + in C++ also: class. */ +/* In C++ and C23, this is spelled [[__maybe_unused__]]. + GCC's syntax is __attribute__ ((__unused__)). + clang supports both syntaxes. Except that with clang ≥ 6, < 10, in C++ mode, + __has_c_attribute (__maybe_unused__) yields true but the use of + [[__maybe_unused__]] nevertheless produces a warning. */ +#ifndef _GL_ATTRIBUTE_MAYBE_UNUSED +# ifndef _GL_BRACKET_BEFORE_ATTRIBUTE +# if defined __clang__ && defined __cplusplus +# if !defined __apple_build_version__ && __clang_major__ >= 10 +# define _GL_ATTRIBUTE_MAYBE_UNUSED [[__maybe_unused__]] +# endif +# elif _GL_HAVE___HAS_C_ATTRIBUTE +# if __has_c_attribute (__maybe_unused__) +# define _GL_ATTRIBUTE_MAYBE_UNUSED [[__maybe_unused__]] +# endif +# endif +# endif +# ifndef _GL_ATTRIBUTE_MAYBE_UNUSED +# define _GL_ATTRIBUTE_MAYBE_UNUSED _GL_ATTRIBUTE_UNUSED +# endif +#endif +/* Alternative spelling of this macro, for convenience and for + compatibility with glibc/include/libc-symbols.h. */ +#define _GL_UNUSED _GL_ATTRIBUTE_MAYBE_UNUSED +/* Earlier spellings of this macro. */ +#define _UNUSED_PARAMETER_ _GL_ATTRIBUTE_MAYBE_UNUSED + +/* _GL_ATTRIBUTE_NODISCARD declares that the caller of the function should not + discard the return value. The compiler may warn if the caller does not use + the return value, unless the caller uses something like ignore_value. */ +/* Applies to: function, enumeration, class. */ +#ifndef _GL_ATTRIBUTE_NODISCARD +# ifndef _GL_BRACKET_BEFORE_ATTRIBUTE +# if defined __clang__ && defined __cplusplus + /* With clang up to 15.0.6 (at least), in C++ mode, [[__nodiscard__]] produces + a warning. + The 1000 below means a yet unknown threshold. When clang++ version X + starts supporting [[__nodiscard__]] without warning about it, you can + replace the 1000 with X. */ +# if __clang_major__ >= 1000 +# define _GL_ATTRIBUTE_NODISCARD [[__nodiscard__]] +# endif +# elif _GL_HAVE___HAS_C_ATTRIBUTE +# if __has_c_attribute (__nodiscard__) +# define _GL_ATTRIBUTE_NODISCARD [[__nodiscard__]] +# endif +# endif +# endif +# if !defined _GL_ATTRIBUTE_NODISCARD && _GL_HAS_ATTRIBUTE (warn_unused_result) +# define _GL_ATTRIBUTE_NODISCARD __attribute__ ((__warn_unused_result__)) +# endif +# ifndef _GL_ATTRIBUTE_NODISCARD +# define _GL_ATTRIBUTE_NODISCARD +# endif +#endif + +/* _GL_ATTRIBUTE_NOINLINE tells that the compiler should not inline the + function. */ +/* Applies to: functions. */ +#ifndef _GL_ATTRIBUTE_NOINLINE +# if _GL_HAS_ATTRIBUTE (noinline) +# define _GL_ATTRIBUTE_NOINLINE __attribute__ ((__noinline__)) +# else +# define _GL_ATTRIBUTE_NOINLINE +# endif +#endif + +/* _GL_ATTRIBUTE_NONNULL ((N1, N2,...)) declares that the arguments N1, N2,... + must not be NULL. + _GL_ATTRIBUTE_NONNULL () declares that all pointer arguments must not be + null. */ +/* Applies to: functions. */ +#ifndef _GL_ATTRIBUTE_NONNULL +# if _GL_HAS_ATTRIBUTE (nonnull) +# define _GL_ATTRIBUTE_NONNULL(args) __attribute__ ((__nonnull__ args)) +# else +# define _GL_ATTRIBUTE_NONNULL(args) +# endif +#endif + +/* _GL_ATTRIBUTE_NONNULL_IF_NONZERO (NP, NI) declares that the argument NP + (a pointer) must not be NULL if the argument NI (an integer) is != 0. */ +/* Applies to: functions. */ +#ifndef _GL_ATTRIBUTE_NONNULL_IF_NONZERO +# if _GL_HAS_ATTRIBUTE (nonnull_if_nonzero) +# define _GL_ATTRIBUTE_NONNULL_IF_NONZERO(np, ni) __attribute__ ((__nonnull_if_nonzero__ (np, ni))) +# else +# define _GL_ATTRIBUTE_NONNULL_IF_NONZERO(np, ni) +# endif +#endif + +/* _GL_ATTRIBUTE_NONSTRING declares that the contents of a character array is + not meant to be NUL-terminated. */ +/* Applies to: struct/union members and variables that are arrays of element + type '[[un]signed] char'. */ +#ifndef _GL_ATTRIBUTE_NONSTRING +# if _GL_HAS_ATTRIBUTE (nonstring) +# define _GL_ATTRIBUTE_NONSTRING __attribute__ ((__nonstring__)) +# else +# define _GL_ATTRIBUTE_NONSTRING +# endif +#endif + +/* There is no _GL_ATTRIBUTE_NORETURN; use _Noreturn instead. */ + +/* _GL_ATTRIBUTE_NOTHROW declares that the function does not throw exceptions. + */ +/* Applies to: functions. */ +/* After a function's parameter list, this attribute must come first, before + other attributes. */ +#ifndef _GL_ATTRIBUTE_NOTHROW +# if defined __cplusplus +# if _GL_GNUC_PREREQ (2, 8) || __clang_major__ >= 4 +# if __cplusplus >= 201103L +# define _GL_ATTRIBUTE_NOTHROW noexcept (true) +# else +# define _GL_ATTRIBUTE_NOTHROW throw () +# endif +# else +# define _GL_ATTRIBUTE_NOTHROW +# endif +# else +# if _GL_HAS_ATTRIBUTE (nothrow) +# define _GL_ATTRIBUTE_NOTHROW __attribute__ ((__nothrow__)) +# else +# define _GL_ATTRIBUTE_NOTHROW +# endif +# endif +#endif + +/* _GL_ATTRIBUTE_PACKED declares: + For struct members: The member has the smallest possible alignment. + For struct, union, class: All members have the smallest possible alignment, + minimizing the memory required. */ +/* Applies to: struct members, struct, union, + in C++ also: class. */ +#ifndef _GL_ATTRIBUTE_PACKED +/* Oracle Studio 12.6 miscompiles code with __attribute__ ((__packed__)) despite + __has_attribute OK. */ +# if _GL_HAS_ATTRIBUTE (packed) && !defined __SUNPRO_C +# define _GL_ATTRIBUTE_PACKED __attribute__ ((__packed__)) +# else +# define _GL_ATTRIBUTE_PACKED +# endif +#endif + +/* _GL_ATTRIBUTE_PURE declares: + It is OK for a compiler to move a call, or omit a duplicate call + and reuse a cached return value, if observable state is the same. + It is also OK to omit a call if the return value is not used. + This attribute is safe if the function does not change observable state, + returns a value determined solely by its arguments's values + together with observable state, and always returns exactly once. + (This attribute is looser than _GL_ATTRIBUTE_CONST because the function + can depend on observable state. + Unlike _GL_ATTRIBUTE_REPRODUCIBLE the function must return exactly + once and cannot change state addressed by its arguments, but the + function can return a pointer to storage whose contents change later.) */ +/* Applies to: functions. */ +#ifndef _GL_ATTRIBUTE_PURE +# if _GL_HAS_ATTRIBUTE (pure) +# define _GL_ATTRIBUTE_PURE __attribute__ ((__pure__)) +# else +# define _GL_ATTRIBUTE_PURE +# endif +#endif + +/* _GL_ATTRIBUTE_REPRODUCIBLE declares: + It is OK for a compiler to move a call, or omit a duplicate call + and reuse a cached value returned either directly or indirectly via + a pointer, if other observable state is the same; + however, pointer arguments cannot alias. + This attribute is safe for a function that is effectless and idempotent; + see ISO C 23 § 6.7.13.8 for a definition of these terms. + (This attribute is looser than _GL_ATTRIBUTE_UNSEQUENCED because + the function need not be stateless or independent. + Unlike _GL_ATTRIBUTE_PURE the function need not return exactly once + and can change state addressed by its pointer arguments, but the + function cannot return a pointer to storage whose contents change later.) + See also <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2956.htm> and + <https://stackoverflow.com/questions/76847905/>. */ +/* Applies to: functions, pointer to functions, function types. */ +#ifndef _GL_ATTRIBUTE_REPRODUCIBLE +/* This may be revisited when gcc and clang support [[reproducible]] or possibly + __attribute__ ((__reproducible__)). */ +# ifndef _GL_BRACKET_BEFORE_ATTRIBUTE +# if _GL_HAS_ATTRIBUTE (reproducible) +# define _GL_ATTRIBUTE_REPRODUCIBLE [[reproducible]] +# endif +# endif +# ifndef _GL_ATTRIBUTE_REPRODUCIBLE +# define _GL_ATTRIBUTE_REPRODUCIBLE +# endif +#endif + +/* _GL_ATTRIBUTE_RETURNS_NONNULL declares that the function's return value is + a non-NULL pointer. */ +/* Applies to: functions. */ +#ifndef _GL_ATTRIBUTE_RETURNS_NONNULL +# if _GL_HAS_ATTRIBUTE (returns_nonnull) +# define _GL_ATTRIBUTE_RETURNS_NONNULL __attribute__ ((__returns_nonnull__)) +# else +# define _GL_ATTRIBUTE_RETURNS_NONNULL +# endif +#endif + +/* _GL_ATTRIBUTE_SENTINEL(pos) declares that the variadic function expects a + trailing NULL argument. + _GL_ATTRIBUTE_SENTINEL () - The last argument is NULL (requires C99). + _GL_ATTRIBUTE_SENTINEL ((N)) - The (N+1)st argument from the end is NULL. */ +/* Applies to: functions. */ +#ifndef _GL_ATTRIBUTE_SENTINEL +# if _GL_HAS_ATTRIBUTE (sentinel) +# define _GL_ATTRIBUTE_SENTINEL(pos) __attribute__ ((__sentinel__ pos)) +# else +# define _GL_ATTRIBUTE_SENTINEL(pos) +# endif +#endif + +/* _GL_ATTRIBUTE_UNSEQUENCED declares: + It is OK for a compiler to move a call, or omit a duplicate call + and reuse a cached value returned either directly or indirectly via + a pointer, if the state addressed by its pointer arguments is the same; + however, pointer arguments cannot alias. + This attribute is safe for a function that is effectless, idempotent, + stateless, and independent; see ISO C 23 § 6.7.13.8 for a definition of + these terms. + (This attribute is stricter than _GL_ATTRIBUTE_REPRODUCIBLE because + the function must be stateless and independent. Unlike + _GL_ATTRIBUTE_CONST the function need not return exactly once, and + can depend on state accessed via its pointer arguments or that + happens to have the same value for all calls to the function, but + the function cannot return a pointer to storage whose contents + change later.) + See also <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2956.htm> and + <https://stackoverflow.com/questions/76847905/>. */ +/* Applies to: functions, pointer to functions, function types. */ +#ifndef _GL_ATTRIBUTE_UNSEQUENCED +/* This may be revisited when gcc and clang support [[unsequenced]] or possibly + __attribute__ ((__unsequenced__)). */ +# ifndef _GL_BRACKET_BEFORE_ATTRIBUTE +# if _GL_HAS_ATTRIBUTE (unsequenced) +# define _GL_ATTRIBUTE_UNSEQUENCED [[unsequenced]] +# endif +# endif +# ifndef _GL_ATTRIBUTE_UNSEQUENCED +# define _GL_ATTRIBUTE_UNSEQUENCED +# endif +#endif + +/* A helper macro. Don't use it directly. */ +#ifndef _GL_ATTRIBUTE_UNUSED +# if _GL_HAS_ATTRIBUTE (unused) +# define _GL_ATTRIBUTE_UNUSED __attribute__ ((__unused__)) +# else +# define _GL_ATTRIBUTE_UNUSED +# endif +#endif + +]dnl There is no _GL_ATTRIBUTE_VISIBILITY; see m4/visibility.m4 instead. +[ +/* _GL_UNUSED_LABEL; declares that it is not a programming mistake if the + immediately preceding label is not used. The compiler should not warn + if the label is not used. */ +/* Applies to: label (both in C and C++). */ +/* Note that g++ < 4.5 does not support the '__attribute__ ((__unused__)) ;' + syntax. But clang does. */ +#ifndef _GL_UNUSED_LABEL +# if !(defined __cplusplus && !_GL_GNUC_PREREQ (4, 5)) || defined __clang__ +# define _GL_UNUSED_LABEL _GL_ATTRIBUTE_UNUSED +# else +# define _GL_UNUSED_LABEL +# endif +#endif + +/* _GL_UNNAMED (ID) is the "name" of an unnamed function parameter. + Each of the function's unnamed parameters should have a unique "name". + The "name" cannot be used. This ports both to C17 and earlier, which + lack unnamed parameters, and to C++ and later C, which have them. */ +/* Applies to: + - function parameters. */ +#ifndef _GL_UNNAMED +# if ((defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 202311 \ + && !defined __cplusplus) +# define _GL_UNNAMED(id) unnamed_##id _GL_ATTRIBUTE_UNUSED +# else +# define _GL_UNNAMED(id) +# endif +#endif + +/* The following attributes enable detection of thread safety problems + and resource leaks at compile-time, by clang ≥ 15, when the warning option + -Wthread-safety is enabled. For usage, see + <https://clang.llvm.org/docs/ThreadSafetyAnalysis.html>. */ +#ifndef _GL_ATTRIBUTE_CAPABILITY_TYPE +# if __clang_major__ >= 15 +# define _GL_ATTRIBUTE_CAPABILITY_TYPE(concept) \ + __attribute__ ((__capability__ (concept))) +# else +# define _GL_ATTRIBUTE_CAPABILITY_TYPE(concept) +# endif +#endif +#ifndef _GL_ATTRIBUTE_ACQUIRE_CAPABILITY +# if __clang_major__ >= 15 +# define _GL_ATTRIBUTE_ACQUIRE_CAPABILITY(resource) \ + __attribute__ ((__acquire_capability__ (resource))) +# else +# define _GL_ATTRIBUTE_ACQUIRE_CAPABILITY(resource) +# endif +#endif +#ifndef _GL_ATTRIBUTE_RELEASE_CAPABILITY +# if __clang_major__ >= 15 +# define _GL_ATTRIBUTE_RELEASE_CAPABILITY(resource) \ + __attribute__ ((__release_capability__ (resource))) +# else +# define _GL_ATTRIBUTE_RELEASE_CAPABILITY(resource) +# endif +#endif +]) + AH_VERBATIM([c_linkage], +[/* In C++, there is the concept of "language linkage", that encompasses + name mangling and function calling conventions. + The following macros start and end a block of "C" linkage. */ +#ifdef __cplusplus +# define _GL_BEGIN_C_LINKAGE extern "C" { +# define _GL_END_C_LINKAGE } +#else +# define _GL_BEGIN_C_LINKAGE +# define _GL_END_C_LINKAGE +#endif +]) + AH_VERBATIM([async_safe], +[/* The _GL_ASYNC_SAFE marker should be attached to functions that are + signal handlers (for signals other than SIGABRT, SIGPIPE) or can be + invoked from such signal handlers. Such functions have some restrictions: + * All functions that it calls should be marked _GL_ASYNC_SAFE as well, + or should be listed as async-signal-safe in POSIX + <https://pubs.opengroup.org/onlinepubs/9699919799/functions/V2_chap02.html#tag_15_04> + section 2.4.3. Note that malloc(), sprintf(), and fwrite(), in + particular, are NOT async-signal-safe. + * All memory locations (variables and struct fields) that these functions + access must be marked 'volatile'. This holds for both read and write + accesses. Otherwise the compiler might optimize away stores to and + reads from such locations that occur in the program, depending on its + data flow analysis. For example, when the program contains a loop + that is intended to inspect a variable set from within a signal handler + while (!signal_occurred) + ; + the compiler is allowed to transform this into an endless loop if the + variable 'signal_occurred' is not declared 'volatile'. + Additionally, recall that: + * A signal handler should not modify errno (except if it is a handler + for a fatal signal and ends by raising the same signal again, thus + provoking the termination of the process). If it invokes a function + that may clobber errno, it needs to save and restore the value of + errno. */ +#define _GL_ASYNC_SAFE +]) + AH_VERBATIM([micro_optimizations], +[/* _GL_CMP (n1, n2) performs a three-valued comparison on n1 vs. n2, where + n1 and n2 are expressions without side effects, that evaluate to real + numbers (excluding NaN). + It returns + 1 if n1 > n2 + 0 if n1 == n2 + -1 if n1 < n2 + The naïve code (n1 > n2 ? 1 : n1 < n2 ? -1 : 0) produces a conditional + jump with nearly all GCC versions up to GCC 10. + This variant (n1 < n2 ? -1 : n1 > n2) produces a conditional jump with + many GCC versions up to GCC 9. + The better code (n1 > n2) - (n1 < n2) from Hacker's Delight § 2-9 + avoids conditional jumps in all GCC versions >= 3.4. */ +#define _GL_CMP(n1, n2) (((n1) > (n2)) - ((n1) < (n2))) +]) + dnl Hint which direction to take regarding cross-compilation guesses: + dnl When a user installs a program on a platform they are not intimately + dnl familiar with, --enable-cross-guesses=conservative is the appropriate + dnl choice. It implements the "If we don't know, assume the worst" principle. + dnl However, when an operating system developer (on a platform which is not + dnl yet known to gnulib) builds packages for their platform, they want to + dnl expose, not hide, possible platform bugs; in this case, + dnl --enable-cross-guesses=risky is the appropriate choice. + dnl Sets the variables + dnl gl_cross_guess_normal (to be used when 'yes' is good and 'no' is bad), + dnl gl_cross_guess_inverted (to be used when 'no' is good and 'yes' is bad). + AC_ARG_ENABLE([cross-guesses], + [AS_HELP_STRING([[--enable-cross-guesses={conservative|risky}]], + [specify policy for cross-compilation guesses])], + [if test "x$enableval" != xconservative && test "x$enableval" != xrisky; then + AC_MSG_WARN([invalid argument supplied to --enable-cross-guesses]) + enableval=conservative + fi + gl_cross_guesses="$enableval"], + [gl_cross_guesses=conservative]) + if test $gl_cross_guesses = risky; then + gl_cross_guess_normal="guessing yes" + gl_cross_guess_inverted="guessing no" + else + gl_cross_guess_normal="guessing no" + gl_cross_guess_inverted="guessing yes" + fi + dnl Preparation for running test programs: + dnl Tell glibc to write diagnostics from -D_FORTIFY_SOURCE=2 to stderr, not + dnl to /dev/tty, so they can be redirected to log files. Such diagnostics + dnl arise e.g., in the macros gl_PRINTF_DIRECTIVE_N, gl_SNPRINTF_DIRECTIVE_N. + LIBC_FATAL_STDERR_=1 + export LIBC_FATAL_STDERR_ +]) + +# gl_MODULE_INDICATOR_INIT_VARIABLE([variablename]) +# gl_MODULE_INDICATOR_INIT_VARIABLE([variablename], [initialvalue]) +# initializes the shell variable that indicates the presence of the given module +# as a C preprocessor expression. +AC_DEFUN([gl_MODULE_INDICATOR_INIT_VARIABLE], +[ + GL_MODULE_INDICATOR_PREFIX[]_[$1]=m4_if([$2], , [0], [$2]) + AC_SUBST(GL_MODULE_INDICATOR_PREFIX[]_[$1]) +]) + +# gl_MODULE_INDICATOR_CONDITION +# expands to a C preprocessor expression that evaluates to 1 or 0, depending +# whether a gnulib module that has been requested shall be considered present +# or not. +m4_define([gl_MODULE_INDICATOR_CONDITION], [1]) + +# gl_MODULE_INDICATOR_SET_VARIABLE([modulename]) +# sets the shell variable that indicates the presence of the given module to +# a C preprocessor expression that will evaluate to 1. +AC_DEFUN([gl_MODULE_INDICATOR_SET_VARIABLE], +[ + gl_MODULE_INDICATOR_SET_VARIABLE_AUX( + [GL_MODULE_INDICATOR_PREFIX[]_GNULIB_[]m4_translit([[$1]], + [abcdefghijklmnopqrstuvwxyz./-], + [ABCDEFGHIJKLMNOPQRSTUVWXYZ___])], + [gl_MODULE_INDICATOR_CONDITION]) +]) + +# gl_MODULE_INDICATOR_SET_VARIABLE_AUX([variable]) +# modifies the shell variable to include the gl_MODULE_INDICATOR_CONDITION. +# The shell variable's value is a C preprocessor expression that evaluates +# to 0 or 1. +AC_DEFUN([gl_MODULE_INDICATOR_SET_VARIABLE_AUX], +[ + m4_if(m4_defn([gl_MODULE_INDICATOR_CONDITION]), [1], + [ + dnl Simplify the expression VALUE || 1 to 1. + $1=1 + ], + [gl_MODULE_INDICATOR_SET_VARIABLE_AUX_OR([$1], + [gl_MODULE_INDICATOR_CONDITION])]) +]) + +# gl_MODULE_INDICATOR_SET_VARIABLE_AUX_OR([variable], [condition]) +# modifies the shell variable to include the given condition. The shell +# variable's value is a C preprocessor expression that evaluates to 0 or 1. +AC_DEFUN([gl_MODULE_INDICATOR_SET_VARIABLE_AUX_OR], +[ + dnl Simplify the expression 1 || CONDITION to 1. + if test "$[]$1" != 1; then + dnl Simplify the expression 0 || CONDITION to CONDITION. + if test "$[]$1" = 0; then + $1=$2 + else + $1="($[]$1 || $2)" + fi + fi +]) + +# gl_MODULE_INDICATOR([modulename]) +# defines a C macro indicating the presence of the given module +# in a location where it can be used. +# | Value | Value | +# | in lib/ | in tests/ | +# --------------------------------------------+---------+-----------+ +# Module present among main modules: | 1 | 1 | +# --------------------------------------------+---------+-----------+ +# Module present among tests-related modules: | 0 | 1 | +# --------------------------------------------+---------+-----------+ +# Module not present at all: | 0 | 0 | +# --------------------------------------------+---------+-----------+ +AC_DEFUN([gl_MODULE_INDICATOR], +[ + AC_DEFINE_UNQUOTED([GNULIB_]m4_translit([[$1]], + [abcdefghijklmnopqrstuvwxyz./-], + [ABCDEFGHIJKLMNOPQRSTUVWXYZ___]), + [gl_MODULE_INDICATOR_CONDITION], + [Define to a C preprocessor expression that evaluates to 1 or 0, + depending whether the gnulib module $1 shall be considered present.]) +]) + +# gl_MODULE_INDICATOR_FOR_TESTS([modulename]) +# defines a C macro indicating the presence of the given module +# in lib or tests. This is useful to determine whether the module +# should be tested. +# | Value | Value | +# | in lib/ | in tests/ | +# --------------------------------------------+---------+-----------+ +# Module present among main modules: | 1 | 1 | +# --------------------------------------------+---------+-----------+ +# Module present among tests-related modules: | 1 | 1 | +# --------------------------------------------+---------+-----------+ +# Module not present at all: | 0 | 0 | +# --------------------------------------------+---------+-----------+ +AC_DEFUN([gl_MODULE_INDICATOR_FOR_TESTS], +[ + AC_DEFINE([GNULIB_TEST_]m4_translit([[$1]], + [abcdefghijklmnopqrstuvwxyz./-], + [ABCDEFGHIJKLMNOPQRSTUVWXYZ___]), [1], + [Define to 1 when the gnulib module $1 should be tested.]) +]) + +# gl_ASSERT_NO_GNULIB_POSIXCHECK +# asserts that there will never be a need to #define GNULIB_POSIXCHECK. +# and thereby enables an optimization of configure and config.h. +# Used by Emacs. +AC_DEFUN([gl_ASSERT_NO_GNULIB_POSIXCHECK], +[ + dnl Override gl_WARN_ON_USE_PREPARE. + dnl But hide this definition from 'aclocal'. + AC_DEFUN([gl_W][ARN_ON_USE_PREPARE], []) +]) + +# gl_ASSERT_NO_GNULIB_TESTS +# asserts that there will be no gnulib tests in the scope of the configure.ac +# and thereby enables an optimization of config.h. +# Used by Emacs. +AC_DEFUN([gl_ASSERT_NO_GNULIB_TESTS], +[ + dnl Override gl_MODULE_INDICATOR_FOR_TESTS. + AC_DEFUN([gl_MODULE_INDICATOR_FOR_TESTS], []) +]) + +# Test whether <features.h> exists. +# Set HAVE_FEATURES_H. +AC_DEFUN([gl_FEATURES_H], +[ + AC_CHECK_HEADERS_ONCE([features.h]) + if test $ac_cv_header_features_h = yes; then + HAVE_FEATURES_H=1 + else + HAVE_FEATURES_H=0 + fi + AC_SUBST([HAVE_FEATURES_H]) +]) + +# gl_PROG_CC_C99 +# Modifies the value of the shell variable CC in an attempt to make $CC +# understand ISO C99 source code. +AC_DEFUN([gl_PROG_CC_C99], +[ + dnl Just use AC_PROG_CC_C99. + dnl When AC_PROG_CC_C99 and AC_PROG_CC_STDC are used together, the substituted + dnl value of CC will contain the C99 enabling options twice. But this is only + dnl a cosmetic problem. + dnl With Autoconf >= 2.70, use AC_PROG_CC since it implies AC_PROG_CC_C99; + dnl this avoids a "warning: The macro `AC_PROG_CC_C99' is obsolete." + m4_version_prereq([2.70], + [AC_REQUIRE([AC_PROG_CC])], + [AC_REQUIRE([AC_PROG_CC_C99])]) +]) + +# gl_PROG_AR_RANLIB +# Determines the values for AR, ARFLAGS, RANLIB that fit with the compiler. +# The user can set the variables AR, ARFLAGS, RANLIB if he wants to override +# the values. +AC_DEFUN([gl_PROG_AR_RANLIB], +[ + dnl Minix 3 comes with two toolchains: The Amsterdam Compiler Kit compiler + dnl as "cc", and GCC as "gcc". They have different object file formats and + dnl library formats. In particular, the GNU binutils programs ar and ranlib + dnl produce libraries that work only with gcc, not with cc. + AC_REQUIRE([AC_PROG_CC]) + dnl The '][' hides this use from 'aclocal'. + AC_BEFORE([$0], [A][M_PROG_AR]) + AC_CACHE_CHECK([for Minix Amsterdam compiler], [gl_cv_c_amsterdam_compiler], + [ + AC_EGREP_CPP([Amsterdam], + [ +#ifdef __ACK__ +Amsterdam +#endif + ], + [gl_cv_c_amsterdam_compiler=yes], + [gl_cv_c_amsterdam_compiler=no]) + ]) + + dnl Don't compete with AM_PROG_AR's decision about AR/ARFLAGS if we are not + dnl building with __ACK__. + if test $gl_cv_c_amsterdam_compiler = yes; then + if test -z "$AR"; then + AR='cc -c.a' + fi + if test -z "$ARFLAGS"; then + ARFLAGS='-o' + fi + else + dnl AM_PROG_AR was added in automake v1.11.2. AM_PROG_AR does not AC_SUBST + dnl ARFLAGS variable (it is filed into Makefile.in directly by automake + dnl script on-demand, if not specified by ./configure of course). + dnl Don't AC_REQUIRE the AM_PROG_AR otherwise the code for __ACK__ above + dnl will be ignored. Also, pay attention to call AM_PROG_AR in else block + dnl because AM_PROG_AR is written so it could re-set AR variable even for + dnl __ACK__. It may seem like its easier to avoid calling the macro here, + dnl but we need to AC_SUBST both AR/ARFLAGS (thus those must have some good + dnl default value and automake should usually know them). + dnl + dnl The '][' hides this use from 'aclocal'. + m4_ifdef([A][M_PROG_AR], [A][M_PROG_AR], [:]) + fi + + dnl In case the code above has not helped with setting AR/ARFLAGS, use + dnl Automake-documented default values for AR and ARFLAGS, but prefer + dnl ${host}-ar over ar (useful for cross-compiling). + AC_CHECK_TOOL([AR], [ar], [ar]) + if test -z "$ARFLAGS"; then + ARFLAGS='cr' + fi + + AC_SUBST([AR]) + AC_SUBST([ARFLAGS]) + if test -z "$RANLIB"; then + if test $gl_cv_c_amsterdam_compiler = yes; then + RANLIB=':' + else + dnl Use the ranlib program if it is available. + AC_PROG_RANLIB + fi + fi + AC_SUBST([RANLIB]) +]) + +# AC_C_RESTRICT +# This definition is copied from post-2.73 Autoconf and overrides the +# AC_C_RESTRICT macro from autoconf 2.60..2.73. +m4_version_prereq([2.73.1], [], [ +AC_DEFUN([AC_C_RESTRICT], +[AC_CACHE_CHECK([for C/C++ restrict keyword], [ac_cv_c_restrict], + [ac_cv_c_restrict=no + # Put '__restrict__' first, to avoid problems with glibc and non-GCC; see: + # https://lists.gnu.org/archive/html/bug-autoconf/2016-02/msg00006.html + # Put 'restrict' last, because C++ lacks it. + for ac_kw in __restrict__ __restrict _Restrict restrict; do + AC_COMPILE_IFELSE( + [AC_LANG_PROGRAM( + [[typedef int *int_ptr; + int foo (int_ptr $ac_kw ip) { return ip[0]; } + int bar (int [$ac_kw]); /* Catch GCC bug 14050. */ + int bar (int ip[$ac_kw]) { return ip[0]; } + ]], + [[int s[1]; + int *$ac_kw t = s; + t[0] = 0; + return foo (t) + bar (t); + ]])], + [ac_cv_c_restrict=$ac_kw]) + test "$ac_cv_c_restrict" != no && break + done + ]) + AH_VERBATIM([restrict], +[/* Define to the equivalent of the C99 'restrict' keyword, or to + nothing if this is not supported. In particular it is not supported + in MSVC 14.44 and in g++ 7 on Solaris 11, although these compilers + define __STDC_VERSION__ to 199901L. + Do not define if restrict is supported directly. */ +#if ! (defined __STDC_VERSION__ && 199901L <= __STDC_VERSION__ \ + && !defined _MSC_VER && !defined __cplusplus) +#undef restrict +#endif +/* Work around a bug in older versions of Sun C++, which did not + #define __restrict__ or support _Restrict or __restrict__ + even though the corresponding Sun C compiler ended up with + "#define restrict _Restrict" or "#define restrict __restrict__" + in the previous line. This workaround can be removed once + we assume Oracle Developer Studio 12.5 (2016) or later. */ +#if defined __SUNPRO_CC && !defined __RESTRICT && !defined __restrict__ +# define _Restrict +# define __restrict__ +#endif]) + case $ac_cv_c_restrict in + restrict) ;; + no) AC_DEFINE([restrict], []) ;; + *) AC_DEFINE_UNQUOTED([restrict], [$ac_cv_c_restrict]) ;; + esac +])# AC_C_RESTRICT +]) + +# gl_BIGENDIAN +# is like AC_C_BIGENDIAN, except that it can be AC_REQUIREd. +# Note that AC_REQUIRE([AC_C_BIGENDIAN]) does not work reliably because some +# macros invoke AC_C_BIGENDIAN with arguments. +AC_DEFUN([gl_BIGENDIAN], +[ + AC_C_BIGENDIAN +]) + +# A temporary file descriptor. +# Must be less than 10, because dash 0.5.8 does not support redirections +# with multi-digit file descriptors. +m4_define([GL_TMP_FD], 9) + +# gl_SILENT(command) +# executes command, but without the normal configure output. +# This is useful when you want to invoke AC_CACHE_CHECK (or AC_CHECK_FUNC etc.) +# inside another AC_CACHE_CHECK. +AC_DEFUN([gl_SILENT], +[ + exec GL_TMP_FD>&AS_MESSAGE_FD AS_MESSAGE_FD>/dev/null + $1 + exec AS_MESSAGE_FD>&GL_TMP_FD GL_TMP_FD>&- +]) + +# gl_CACHE_VAL_SILENT(cache-id, command-to-set-it) +# is like AC_CACHE_VAL(cache-id, command-to-set-it), except that it does not +# output a spurious "(cached)" mark in the midst of other configure output. +# This macro should be used instead of AC_CACHE_VAL when it is not surrounded +# by an AC_MSG_CHECKING/AC_MSG_RESULT pair. +AC_DEFUN([gl_CACHE_VAL_SILENT], +[ + gl_SILENT([ + AC_CACHE_VAL([$1], [$2]) + ]) +]) + +# gl_CONDITIONAL(conditional, condition) +# is like AM_CONDITIONAL(conditional, condition), except that it does not +# produce an error +# configure: error: conditional "..." was never defined. +# Usually this means the macro was only invoked conditionally. +# when only invoked conditionally. Instead, in that case, both the _TRUE +# and the _FALSE case are disabled. +AC_DEFUN([gl_CONDITIONAL], +[ + pushdef([AC_CONFIG_COMMANDS_PRE], [:])dnl + AM_CONDITIONAL([$1], [$2]) + popdef([AC_CONFIG_COMMANDS_PRE])dnl + if test -z "${[$1]_TRUE}" && test -z "${[$1]_FALSE}"; then + [$1]_TRUE='#' + [$1]_FALSE='#' + fi +]) + +# gl_CC_ALLOW_WARNINGS +# sets and substitutes a variable GL_CFLAG_ALLOW_WARNINGS, to a $(CC) option +# that reverts a preceding '-Werror' option, if available. +# This is expected to be '-Wno-error' on gcc, clang (except clang/MSVC), xlclang +# and empty otherwise. +AC_DEFUN([gl_CC_ALLOW_WARNINGS], +[ + AC_REQUIRE([AC_PROG_CC]) + AC_CACHE_CHECK([for C compiler option to allow warnings], + [gl_cv_cc_wallow], + [rm -fr conftest* + echo 'int dummy;' > conftest.c + AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS -c conftest.c 2>conftest1.err]) >/dev/null + AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS -Wno-error -c conftest.c 2>conftest2.err]) >/dev/null + dnl Test the number of error output lines, because AIX xlc accepts the + dnl option '-Wno-error', just to produce a warning + dnl "Option -Wno-error was incorrectly specified. The option will be ignored." + dnl afterwards. + if test $? = 0 && test `wc -l < conftest1.err` = `wc -l < conftest2.err`; then + gl_cv_cc_wallow='-Wno-error' + else + gl_cv_cc_wallow=none + fi + rm -fr conftest* + ]) + case "$gl_cv_cc_wallow" in + none) GL_CFLAG_ALLOW_WARNINGS='' ;; + *) GL_CFLAG_ALLOW_WARNINGS="$gl_cv_cc_wallow" ;; + esac + AC_SUBST([GL_CFLAG_ALLOW_WARNINGS]) +]) + +# gl_CXX_ALLOW_WARNINGS +# sets and substitutes a variable GL_CXXFLAG_ALLOW_WARNINGS, to a $(CC) option +# that reverts a preceding '-Werror' option, if available. +AC_DEFUN([gl_CXX_ALLOW_WARNINGS], +[ + dnl Requires AC_PROG_CXX or gl_PROG_ANSI_CXX. + if test -n "$CXX" && test "$CXX" != no; then + AC_CACHE_CHECK([for C++ compiler option to allow warnings], + [gl_cv_cxx_wallow], + [rm -fr conftest* + echo 'int dummy;' > conftest.cc + AC_TRY_COMMAND([${CXX-c++} $CXXFLAGS $CPPFLAGS -c conftest.cc 2>conftest1.err]) >/dev/null + AC_TRY_COMMAND([${CXX-c++} $CXXFLAGS $CPPFLAGS -Wno-error -c conftest.cc 2>conftest2.err]) >/dev/null + dnl Test the number of error output lines, because AIX xlC accepts the + dnl option '-Wno-error', just to produce a warning + dnl "Option -Wno-error was incorrectly specified. The option will be ignored." + dnl afterwards. + if test $? = 0 && test `wc -l < conftest1.err` = `wc -l < conftest2.err`; then + gl_cv_cxx_wallow='-Wno-error' + else + gl_cv_cxx_wallow=none + fi + rm -fr conftest* + ]) + case "$gl_cv_cxx_wallow" in + none) GL_CXXFLAG_ALLOW_WARNINGS='' ;; + *) GL_CXXFLAG_ALLOW_WARNINGS="$gl_cv_cxx_wallow" ;; + esac + else + GL_CXXFLAG_ALLOW_WARNINGS='' + fi + AC_SUBST([GL_CXXFLAG_ALLOW_WARNINGS]) +]) + +# gl_CC_GNULIB_WARNINGS +# sets and substitutes a variable GL_CFLAG_GNULIB_WARNINGS, to a $(CC) option +# set that enables or disables warnings as suitable for the Gnulib coding style. +AC_DEFUN([gl_CC_GNULIB_WARNINGS], +[ + AC_REQUIRE([gl_CC_ALLOW_WARNINGS]) + dnl Assume that the compiler supports -Wno-* options only if it also supports + dnl -Wno-error. + GL_CFLAG_GNULIB_WARNINGS='' + if test -n "$GL_CFLAG_ALLOW_WARNINGS"; then + dnl Enable these warning options: + dnl + dnl GCC clang + dnl -Wno-cast-qual >= 3 >= 3.9 + dnl -Wno-conversion >= 3 >= 3.9 + dnl -Wno-float-conversion >= 4.9 >= 3.9 + dnl -Wno-float-equal >= 3 >= 3.9 + dnl -Wimplicit-fallthrough >= 7 >= 3.9 + dnl -Wno-pedantic >= 4.8 >= 3.9 + dnl -Wno-sign-compare >= 3 >= 3.9 + dnl -Wno-sign-conversion >= 4.3 >= 3.9 + dnl -Wno-string-plus-int - >= 3.9 + dnl -Wno-tautological-out-of-range-compare - >= 3.9 + dnl -Wno-type-limits >= 4.3 >= 3.9 + dnl -Wno-undef >= 3 >= 3.9 + dnl -Wno-unsuffixed-float-constants >= 4.5 + dnl -Wno-unused-const-variable >= 6.1 >= 3.9 + dnl -Wno-unused-function >= 3 >= 3.9 + dnl -Wno-unused-parameter >= 3 >= 3.9 + dnl + cat > conftest.c <<\EOF + #if (__GNUC__ >= 3 && !defined __clang__) || (__clang_major__ + (__clang_minor__ >= 9) > 3) + -Wno-cast-qual + -Wno-conversion + -Wno-float-equal + -Wno-sign-compare + -Wno-undef + -Wno-unused-function + -Wno-unused-parameter + #endif + #if (__GNUC__ + (__GNUC_MINOR__ >= 9) > 4 && !defined __clang__) || (__clang_major__ + (__clang_minor__ >= 9) > 3) + -Wno-float-conversion + #endif + #if (__GNUC__ >= 7 && !defined __clang__) || (__clang_major__ + (__clang_minor__ >= 9) > 3) + -Wimplicit-fallthrough + #endif + #if (__GNUC__ + (__GNUC_MINOR__ >= 8) > 4 && !defined __clang__) || (__clang_major__ + (__clang_minor__ >= 9) > 3) + -Wno-pedantic + #endif + #if 3 < __clang_major__ + (9 <= __clang_minor__) + -Wno-string-plus-int + -Wno-tautological-constant-out-of-range-compare + #endif + #if (__GNUC__ + (__GNUC_MINOR__ >= 3) > 4 && !defined __clang__) || (__clang_major__ + (__clang_minor__ >= 9) > 3) + -Wno-sign-conversion + -Wno-type-limits + #endif + #if (__GNUC__ + (__GNUC_MINOR__ >= 1) > 6 && !defined __clang__) || (__clang_major__ + (__clang_minor__ >= 9) > 3) + -Wno-unused-const-variable + #endif + #if (__GNUC__ + (__GNUC_MINOR__ >= 5) > 4 && !defined __clang__) + -Wno-unsuffixed-float-constants + #endif +EOF + gl_command="$CC $CFLAGS $CPPFLAGS -E conftest.c > conftest.out" + if AC_TRY_EVAL([gl_command]); then + gl_options=`grep -v '#' conftest.out` + for word in $gl_options; do + GL_CFLAG_GNULIB_WARNINGS="$GL_CFLAG_GNULIB_WARNINGS $word" + done + fi + rm -f conftest.c conftest.out + fi + AC_SUBST([GL_CFLAG_GNULIB_WARNINGS]) +]) + +dnl gl_CONDITIONAL_HEADER([foo.h]) +dnl takes a shell variable GL_GENERATE_FOO_H (with value true or false) as input +dnl and produces +dnl - an AC_SUBSTed variable FOO_H that is either a file name or empty, based +dnl on whether GL_GENERATE_FOO_H is true or false, +dnl - an Automake conditional GL_GENERATE_FOO_H that evaluates to the value of +dnl the shell variable GL_GENERATE_FOO_H. +AC_DEFUN([gl_CONDITIONAL_HEADER], +[ + m4_pushdef([gl_header_name], AS_TR_SH(m4_toupper($1))) + m4_pushdef([gl_generate_var], [GL_GENERATE_]AS_TR_SH(m4_toupper($1))) + m4_pushdef([gl_generate_cond], [GL_GENERATE_]AS_TR_SH(m4_toupper($1))) + case "$gl_generate_var" in + false) gl_header_name='' ;; + true) + dnl It is OK to use a .h file in lib/ from within tests/, but not vice + dnl versa. + if test -z "$gl_header_name"; then + gl_header_name="${gl_source_base_prefix}$1" + fi + ;; + *) echo "*** gl_generate_var is not set correctly" 1>&2; exit 1 ;; + esac + AC_SUBST(gl_header_name) + gl_CONDITIONAL(gl_generate_cond, [$gl_generate_var]) + m4_popdef([gl_generate_cond]) + m4_popdef([gl_generate_var]) + m4_popdef([gl_header_name]) +]) + +dnl Preparations for gl_CHECK_FUNCS_MACOS. +AC_DEFUN([gl_PREPARE_CHECK_FUNCS_MACOS], +[ + AC_REQUIRE([AC_CANONICAL_HOST]) + AC_REQUIRE([gl_COMPILER_CLANG]) + AC_CACHE_CHECK([for compiler option needed when checking for future declarations], + [gl_cv_compiler_check_future_option], + [case "$host_os" in + dnl This is only needed on macOS. + darwin*) + if test $gl_cv_compiler_clang = yes; then + dnl Test whether the compiler supports the option + dnl '-Werror=unguarded-availability-new'. + saved_ac_compile="$ac_compile" + ac_compile="$ac_compile -Werror=unguarded-availability-new" + AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]],[[]])], + [gl_cv_compiler_check_future_option='-Werror=unguarded-availability-new'], + [gl_cv_compiler_check_future_option=none]) + ac_compile="$saved_ac_compile" + else + gl_cv_compiler_check_future_option=none + fi + ;; + *) gl_cv_compiler_check_future_option=none ;; + esac + ]) +]) + +dnl Pieces of the expansion of +dnl gl_CHECK_FUNCS_ANDROID +dnl gl_CHECK_FUNCS_MACOS +dnl gl_CHECK_FUNCS_ANDROID_MACOS + +AC_DEFUN([gl_CHECK_FUNCS_DEFAULT_CASE], +[ + *) + AC_CHECK_FUNC([$1]) + [gl_cv_onwards_func_][$1]=$[ac_cv_func_][$1] + ;; +]) + +AC_DEFUN([gl_CHECK_FUNCS_CASE_FOR_ANDROID], +[ + linux*-android*) + AC_CHECK_DECL([$1], , , [$2]) + if test $[ac_cv_have_decl_][$1] = yes; then + AC_CHECK_FUNC([[$1]]) + if test $[ac_cv_func_][$1] = yes; then + [gl_cv_onwards_func_][$1]=yes + else + dnl The function is declared but does not exist. This should not + dnl happen normally. But anyway, we know that a future version + dnl of Android will have the function. + [gl_cv_onwards_func_][$1]='future OS version' + fi + else + [gl_cv_onwards_func_][$1]='future OS version' + fi + ;; +]) + +AC_DEFUN([gl_CHECK_FUNCS_CASE_FOR_MACOS], +[ + darwin*) + if test "x$gl_cv_compiler_check_future_option" != "xnone"; then + dnl Use a compile test, not a link test. + saved_ac_compile="$ac_compile" + ac_compile="$ac_compile $gl_cv_compiler_check_future_option" + saved_ac_compile_for_check_decl="$ac_compile_for_check_decl" + ac_compile_for_check_decl="$ac_compile_for_check_decl $gl_cv_compiler_check_future_option" + unset [ac_cv_have_decl_][$1] + AC_CHECK_DECL([$1], , , [$2]) + ac_compile="$saved_ac_compile" + ac_compile_for_check_decl="$saved_ac_compile_for_check_decl" + [ac_cv_func_][$1]="$[ac_cv_have_decl_][$1]" + if test $[ac_cv_func_][$1] = yes; then + [gl_cv_onwards_func_][$1]=yes + else + dnl This is a bit complicated, because here we need the behaviour + dnl of AC_CHECK_DECL before the + dnl commit e1bbc9b93cdff61d70719c224b37970e065008bb (2025-05-26). + [ac_cv_have_decl_][$1][_saved]="$[ac_cv_have_decl_][$1]" + unset [ac_cv_have_decl_][$1] + ac_c_future_darwin_options_saved="$ac_c_future_darwin_options" + ac_cxx_future_darwin_options_saved="$ac_cxx_future_darwin_options" + ac_c_future_darwin_options= + ac_cxx_future_darwin_options= + AC_CHECK_DECL([$1], , , [$2]) + ac_c_future_darwin_options="$ac_c_future_darwin_options_saved" + ac_cxx_future_darwin_options="$ac_cxx_future_darwin_options_saved" + if test $[ac_cv_have_decl_][$1] = yes; then + [gl_cv_onwards_func_][$1]='future OS version' + else + [gl_cv_onwards_func_][$1]=no + fi + [ac_cv_have_decl_][$1]="$[ac_cv_have_decl_][$1][_saved]" + unset [ac_cv_have_decl_][$1][_saved] + fi + else + AC_CHECK_FUNC([$1]) + [gl_cv_onwards_func_][$1]=$[ac_cv_func_][$1] + fi + ;; +]) + +AC_DEFUN([gl_CHECK_FUNCS_SET_RESULTS], +[ + case "$[gl_cv_onwards_func_][$1]" in + future*) [ac_cv_func_][$1]=no ;; + *) [ac_cv_func_][$1]=$[gl_cv_onwards_func_][$1] ;; + esac + if test $[ac_cv_func_][$1] = yes; then + AC_DEFINE([HAVE_]m4_translit([[$1]], + [abcdefghijklmnopqrstuvwxyz], + [ABCDEFGHIJKLMNOPQRSTUVWXYZ]), + [1], [Define to 1 if you have the `$1' function.]) + fi +]) + +dnl gl_CHECK_FUNCS_ANDROID([func], [[#include <foo.h>]]) +dnl is like AC_CHECK_FUNCS([func]), taking into account a portability problem +dnl on Android. +dnl +dnl When code is compiled on Android, it is in the context of a certain +dnl "Android API level", which indicates the minimum version of Android on +dnl which the app can be installed. In other words, you don't compile for a +dnl specific version of Android. You compile for all versions of Android, +dnl onwards from the given API level. +dnl Thus, the question "does the OS have the function func" has three possible +dnl answers: +dnl - yes, in all versions starting from the given API level, +dnl - no, in no version, +dnl - not in the given API level, but in a later version of Android. +dnl +dnl In detail, this works as follows: +dnl If func was added to Android API level, say, 28, then the libc.so has the +dnl symbol func always, whereas the header file <foo.h> declares func +dnl conditionally: +dnl #if __ANDROID_API__ >= 28 +dnl ... func (...) __INTRODUCED_IN(28); +dnl #endif +dnl Thus, when compiling with "clang -target armv7a-unknown-linux-android28", +dnl the function func is declared and exists in libc. +dnl Whereas when compiling with "clang -target armv7a-unknown-linux-android27", +dnl the function func is not declared but exists in libc. +dnl +dnl This macro sets two variables: +dnl - gl_cv_onwards_func_<func> to yes / no / "future OS version" +dnl - ac_cv_func_<func> to yes / no / no +dnl The first variable allows distinguishing all three cases. +dnl The second variable is set, so that an invocation +dnl gl_CHECK_FUNCS_ANDROID([func], [[#include <foo.h>]]) +dnl can be used as a drop-in replacement for +dnl AC_CHECK_FUNCS([func]). +AC_DEFUN([gl_CHECK_FUNCS_ANDROID], +[ + AC_REQUIRE([AC_CANONICAL_HOST]) + AC_CACHE_CHECK([for [$1]], + [[gl_cv_onwards_func_][$1]], + [gl_SILENT([ + case "$host_os" in + gl_CHECK_FUNCS_CASE_FOR_ANDROID([$1], [$2]) + gl_CHECK_FUNCS_DEFAULT_CASE([$1]) + esac + ]) + ]) + gl_CHECK_FUNCS_SET_RESULTS([$1]) +]) + +dnl gl_CHECK_FUNCS_MACOS([func], [[#include <foo.h>]]) +dnl is like AC_CHECK_FUNCS([func]), taking into account a portability problem +dnl on macOS. +dnl +dnl When code is compiled on macOS, it is in the context of a certain minimum +dnl macOS version, that can be set through the option '-mmacosx-version-min='. +dnl In other words, you don't compile for a specific version of macOS. You +dnl compile for all versions of macOS, onwards from the given version. +dnl Thus, the question "does the OS have the function func" has three possible +dnl answers: +dnl - yes, in all versions starting from the given version, +dnl - no, in no version, +dnl - not in the given version, but in a later version of macOS. +dnl +dnl In detail, this works as follows: +dnl If func was added to, say, macOS version 13, then the libc has the +dnl symbol func always, whereas the header file <foo.h> declares func +dnl conditionally with a special availability attribute: +dnl ... func (...) __attribute__((availability(macos,introduced=13.0))); +dnl Thus, when compiling with "clang mmacosx-version-min=13", there is no +dnl warning about the use of func, and the resulting binary +dnl - runs fine on macOS 13, +dnl - aborts with a dyld "Symbol not found" message on macOS 12. +dnl Whereas, when compiling with "clang mmacosx-version-min=12", there is a +dnl warning: 'func' is only available on macOS 13.0 or newer +dnl [-Wunguarded-availability-new], +dnl and the resulting binary +dnl - runs fine on macOS 13, +dnl - crashes with a SIGSEGV (signal 11) on macOS 12. +dnl +dnl This macro sets two variables: +dnl - gl_cv_onwards_func_<func> to yes / no / "future OS version" +dnl - ac_cv_func_<func> to yes / no / no +dnl The first variable allows distinguishing all three cases. +dnl The second variable is set, so that an invocation +dnl gl_CHECK_FUNCS_MACOS([func], [[#include <foo.h>]]) +dnl can be used as a drop-in replacement for +dnl AC_CHECK_FUNCS([func]). +AC_DEFUN([gl_CHECK_FUNCS_MACOS], +[ + AC_REQUIRE([AC_CANONICAL_HOST]) + AC_REQUIRE([gl_PREPARE_CHECK_FUNCS_MACOS]) + AC_CACHE_CHECK([for [$1]], + [[gl_cv_onwards_func_][$1]], + [gl_SILENT([ + case "$host_os" in + gl_CHECK_FUNCS_CASE_FOR_MACOS([$1], [$2]) + gl_CHECK_FUNCS_DEFAULT_CASE([$1]) + esac + ]) + ]) + gl_CHECK_FUNCS_SET_RESULTS([$1]) +]) + +dnl gl_CHECK_FUNCS_ANDROID_MACOS([func], [[#include <foo.h>]]) +dnl is like AC_CHECK_FUNCS([func]), taking into account a portability problem +dnl on Android and on macOS. +dnl It is the combination of gl_CHECK_FUNCS_ANDROID and gl_CHECK_FUNCS_MACOS. +AC_DEFUN([gl_CHECK_FUNCS_ANDROID_MACOS], +[ + AC_REQUIRE([AC_CANONICAL_HOST]) + AC_REQUIRE([gl_PREPARE_CHECK_FUNCS_MACOS]) + AC_CACHE_CHECK([for [$1]], + [[gl_cv_onwards_func_][$1]], + [gl_SILENT([ + case "$host_os" in + gl_CHECK_FUNCS_CASE_FOR_ANDROID([$1], [$2]) + gl_CHECK_FUNCS_CASE_FOR_MACOS([$1], [$2]) + gl_CHECK_FUNCS_DEFAULT_CASE([$1]) + esac + ]) + ]) + gl_CHECK_FUNCS_SET_RESULTS([$1]) +]) + +dnl Expands to some code for use in .c programs that, on native Windows, defines +dnl the Microsoft deprecated alias function names to the underscore-prefixed +dnl actual function names. With this macro, these function names are available +dnl without linking with '-loldnames' and without generating warnings. +dnl Usage: Use it after all system header files are included. +dnl #include <...> +dnl #include <...> +dnl ]GL_MDA_DEFINES[ +dnl ... +AC_DEFUN([GL_MDA_DEFINES],[ +AC_REQUIRE([_GL_MDA_DEFINES]) +[$gl_mda_defines] +]) +AC_DEFUN([_GL_MDA_DEFINES], +[gl_mda_defines=' +#if defined _WIN32 && !defined __CYGWIN__ +#define access _access +#define chdir _chdir +#define chmod _chmod +#define close _close +#define creat _creat +#define dup _dup +#define dup2 _dup2 +#define ecvt _ecvt +#define execl _execl +#define execle _execle +#define execlp _execlp +#define execv _execv +#define execve _execve +#define execvp _execvp +#define execvpe _execvpe +#define fcloseall _fcloseall +#define fcvt _fcvt +#define fdopen _fdopen +#define fileno _fileno +#define gcvt _gcvt +#define getcwd _getcwd +#define getpid _getpid +#define getw _getw +#define isatty _isatty +#define j0 _j0 +#define j1 _j1 +#define jn _jn +#define lfind _lfind +#define lsearch _lsearch +#define lseek _lseek +#define memccpy _memccpy +#define mkdir _mkdir +#define mktemp _mktemp +#define open _open +#define putenv _putenv +#define putw _putw +#define read _read +#define rmdir _rmdir +#define strdup _strdup +#define swab _swab +#define tempnam _tempnam +#define tzset _tzset +#define umask _umask +#define unlink _unlink +#define utime _utime +#define wcsdup _wcsdup +#define write _write +#define y0 _y0 +#define y1 _y1 +#define yn _yn +#endif +' +]) diff --git a/m4/threadlib.m4 b/m4/threadlib.m4 index 6a24e49..a16d626 100644 --- a/m4/threadlib.m4 +++ b/m4/threadlib.m4 @@ -1,8 +1,10 @@ -# threadlib.m4 serial 31 -dnl Copyright (C) 2005-2021 Free Software Foundation, Inc. +# threadlib.m4 +# serial 49 +dnl Copyright (C) 2005-2026 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, dnl with or without modifications, as long as this notice is preserved. +dnl This file is offered as-is, without any warranty. dnl From Bruno Haible. @@ -55,29 +57,14 @@ AC_DEFUN([gl_ANYTHREADLIB_EARLY], [ AC_REQUIRE([AC_CANONICAL_HOST]) if test -z "$gl_anythreadlib_early_done"; then - case "$host_os" in - osf*) - # On OSF/1, the compiler needs the flag -D_REENTRANT so that it - # groks <pthread.h>. cc also understands the flag -pthread, but - # we don't use it because 1. gcc-2.95 doesn't understand -pthread, - # 2. putting a flag into CPPFLAGS that has an effect on the linker - # causes the AC_LINK_IFELSE test below to succeed unexpectedly, - # leading to wrong values of LIBTHREAD and LTLIBTHREAD. - THREADLIB_CPPFLAGS="$THREADLIB_CPPFLAGS -D_REENTRANT" - ;; - esac # Some systems optimize for single-threaded programs by default, and # need special flags to disable these optimizations. For example, the - # definition of 'errno' in <errno.h>. - case "$host_os" in - aix* | freebsd*) THREADLIB_CPPFLAGS="$THREADLIB_CPPFLAGS -D_THREAD_SAFE" ;; - solaris*) THREADLIB_CPPFLAGS="$THREADLIB_CPPFLAGS -D_REENTRANT" ;; - esac + # definition of errno in <errno.h>. + AS_CASE([$host_os], + [aix* | freebsd*], [CPPFLAGS="$CPPFLAGS -D_THREAD_SAFE"], + [hpux* | solaris*], [CPPFLAGS="$CPPFLAGS -D_REENTRANT"]) gl_anythreadlib_early_done=done fi - if test x"$THREADLIB_CPPFLAGS" != x ; then - CPPFLAGS="$CPPFLAGS $THREADLIB_CPPFLAGS" - fi ]) dnl Checks whether the compiler and linker support weak declarations of symbols. @@ -87,49 +74,61 @@ AC_DEFUN([gl_WEAK_SYMBOLS], AC_REQUIRE([AC_CANONICAL_HOST]) AC_CACHE_CHECK([whether imported symbols can be declared weak], [gl_cv_have_weak], - [gl_cv_have_weak=no - dnl First, test whether the compiler accepts it syntactically. - AC_LINK_IFELSE( - [AC_LANG_PROGRAM( - [[extern void xyzzy (); -#pragma weak xyzzy]], - [[xyzzy();]])], - [gl_cv_have_weak=maybe]) - if test $gl_cv_have_weak = maybe; then - dnl Second, test whether it actually works. On Cygwin 1.7.2, with - dnl gcc 4.3, symbols declared weak always evaluate to the address 0. - AC_RUN_IFELSE( - [AC_LANG_SOURCE([[ + [AS_CASE([$host_os], + [cygwin* | mingw* | windows*], + [ + dnl On Cygwin 3.2.0 with gcc 10.2, and likewise on mingw 10.0.0 with + dnl gcc 11.3, the test below would succeed, but programs that use + dnl pthread_in_use() with weak symbol references crash miserably at + dnl runtime. + gl_cv_have_weak="guessing no" + ], + [ + gl_cv_have_weak=no + dnl First, test whether the compiler accepts it syntactically. + AC_LINK_IFELSE( + [AC_LANG_PROGRAM( + [[extern void xyzzy (); +#pragma weak xyzzy + ]], + [[xyzzy();]])], + [gl_cv_have_weak=maybe]) + AS_IF([test $gl_cv_have_weak = maybe], [ + dnl Second, test whether it actually works. On Cygwin 1.7.2, with + dnl gcc 4.3, symbols declared weak always evaluate to the address 0. + AC_RUN_IFELSE( + [AC_LANG_SOURCE([[ #include <stdio.h> #pragma weak fputs int main () { return (fputs == NULL); }]])], - [gl_cv_have_weak=yes], - [gl_cv_have_weak=no], - [dnl When cross-compiling, assume that only ELF platforms support - dnl weak symbols. - AC_EGREP_CPP([Extensible Linking Format], - [#ifdef __ELF__ - Extensible Linking Format - #endif - ], - [gl_cv_have_weak="guessing yes"], - [gl_cv_have_weak="guessing no"]) + [gl_cv_have_weak=yes], + [gl_cv_have_weak=no], + [dnl When cross-compiling, assume that only ELF platforms support + dnl weak symbols. + AC_EGREP_CPP([Extensible Linking Format], + [#ifdef __ELF__ + Extensible Linking Format + #endif + ], + [gl_cv_have_weak="guessing yes"], + [gl_cv_have_weak="guessing no"]) + ]) ]) - fi - dnl But when linking statically, weak symbols don't work. - case " $LDFLAGS " in - *" -static "*) gl_cv_have_weak=no ;; - esac + ]) + dnl But when linking statically, weak symbols do not work. + AS_CASE([" $LDFLAGS "], + [*" -static "*], [gl_cv_have_weak=no]) dnl Test for a bug in FreeBSD 11: A link error occurs when using a weak dnl symbol and linking against a shared library that has a dependency on dnl the shared library that defines the symbol. - case "$gl_cv_have_weak" in - *yes) - case "$host_os" in - freebsd* | dragonfly* | midnightbsd*) + AS_CASE([$gl_cv_have_weak], + [*yes], + [AS_CASE([$host_os], + [freebsd* | dragonfly* | midnightbsd*], + [ : > conftest1.c $CC $CPPFLAGS $CFLAGS $LDFLAGS -fPIC -shared -o libempty.so conftest1.c -lpthread >&AS_MESSAGE_LOG_FD 2>&1 cat <<EOF > conftest2.c @@ -143,17 +142,15 @@ EOF $CC $CPPFLAGS $CFLAGS $LDFLAGS -o conftest conftest2.c libempty.so >&AS_MESSAGE_LOG_FD 2>&1 \ || gl_cv_have_weak=no rm -f conftest1.c libempty.so conftest2.c conftest - ;; - esac - ;; - esac + ]) + ]) ]) - case "$gl_cv_have_weak" in - *yes) + AS_CASE([$gl_cv_have_weak], + [*yes], + [ AC_DEFINE([HAVE_WEAK_SYMBOLS], [1], [Define to 1 if the compiler and linker support weak declarations of symbols.]) - ;; - esac + ]) ]) dnl ============================================================================ @@ -164,14 +161,13 @@ dnl ------------- dnl Tests for the libraries needs for using the POSIX threads API. dnl Sets the variable LIBPTHREAD to the linker options for use in a Makefile. dnl Sets the variable LIBPMULTITHREAD, for programs that really need -dnl multithread functionality. The difference between LIBPTHREAD and +dnl multithreading. The difference between LIBPTHREAD and dnl LIBPMULTITHREAD is that on platforms supporting weak symbols, typically dnl LIBPTHREAD is empty whereas LIBPMULTITHREAD is not. -dnl Sets the variable LIB_SCHED_YIELD to the linker options needed to use the +dnl Sets the variable SCHED_YIELD_LIB to the linker options needed to use the dnl sched_yield() function. -dnl Sets the variable THREADLIB_CPPFLAGS the flag -D_REENTRANT or -dnl -D_THREAD_SAFE if needed for multithread-safe programs and adds -dnl THREADLIB_CPPFLAGS to CPPFLAGS. +dnl Adds to CPPFLAGS the flag -D_REENTRANT or -D_THREAD_SAFE if needed for +dnl thread-safe programs. dnl Defines the C macro HAVE_PTHREAD_API if (at least parts of) the POSIX dnl threads API is available. @@ -180,40 +176,34 @@ dnl The guts of gl_PTHREADLIB. Needs to be expanded only once. AC_DEFUN([gl_PTHREADLIB_BODY], [ AC_REQUIRE([gl_ANYTHREADLIB_EARLY]) - if test -z "$gl_pthreadlib_body_done"; then + AS_IF([test -z "$gl_pthreadlib_body_done"], [ gl_pthread_api=no LIBPTHREAD= LIBPMULTITHREAD= - # On OSF/1, the compiler needs the flag -pthread or -D_REENTRANT so that - # it groks <pthread.h>. It's added above, in gl_ANYTHREADLIB_EARLY. AC_CHECK_HEADER([pthread.h], [gl_have_pthread_h=yes], [gl_have_pthread_h=no]) - if test "$gl_have_pthread_h" = yes; then + AS_IF([test "$gl_have_pthread_h" = yes], [ # Other possible tests: # -lpthreads (FSU threads, PCthreads) # -lgthreads - # Test whether both pthread_mutex_lock and pthread_mutexattr_init exist - # in libc. IRIX 6.5 has the first one in both libc and libpthread, but - # the second one only in libpthread, and lock.c needs it. + # Test whether both pthread_mutex_lock exists in libc. # # If -pthread works, prefer it to -lpthread, since Ubuntu 14.04 # needs -pthread for some reason. See: # https://lists.gnu.org/r/bug-gnulib/2014-09/msg00023.html - save_LIBS=$LIBS - for gl_pthread in '' '-pthread'; do + saved_LIBS="$LIBS" + for gl_pthread in "" "-pthread"; do LIBS="$LIBS $gl_pthread" AC_LINK_IFELSE( [AC_LANG_PROGRAM( [[#include <pthread.h> pthread_mutex_t m; - pthread_mutexattr_t ma; ]], - [[pthread_mutex_lock (&m); - pthread_mutexattr_init (&ma);]])], + [[pthread_mutex_lock (&m);]])], [gl_pthread_api=yes LIBPTHREAD=$gl_pthread LIBPMULTITHREAD=$gl_pthread]) - LIBS=$save_LIBS + LIBS="$saved_LIBS" test $gl_pthread_api = yes && break done echo "$as_me:__oline__: gl_pthread_api=$gl_pthread_api" >&AS_MESSAGE_LOG_FD @@ -222,8 +212,9 @@ AC_DEFUN([gl_PTHREADLIB_BODY], gl_pthread_in_glibc=no # On Linux with glibc >= 2.34, libc contains the fully functional # pthread functions. - case "$host_os" in - linux*) + AS_CASE([$host_os], + [linux*], + [ AC_EGREP_CPP([Lucky user], [#include <features.h> #ifdef __GNU_LIBRARY__ @@ -234,19 +225,17 @@ AC_DEFUN([gl_PTHREADLIB_BODY], ], [gl_pthread_in_glibc=yes], []) - ;; - esac + ]) echo "$as_me:__oline__: gl_pthread_in_glibc=$gl_pthread_in_glibc" >&AS_MESSAGE_LOG_FD - # Test for libpthread by looking for pthread_kill. (Not pthread_self, - # since it is defined as a macro on OSF/1.) - if test $gl_pthread_api = yes && test -z "$LIBPTHREAD"; then + # Test for libpthread by looking for pthread_kill. + AS_IF([test $gl_pthread_api = yes && test -z "$LIBPTHREAD"], [ # The program links fine without libpthread. But it may actually # need to link with libpthread in order to create multiple threads. AC_CHECK_LIB([pthread], [pthread_kill], - [if test $gl_pthread_in_glibc = yes; then + [AS_IF([test $gl_pthread_in_glibc = yes], [ LIBPMULTITHREAD= - else + ], [ LIBPMULTITHREAD=-lpthread # On Solaris and HP-UX, most pthread functions exist also in libc. # Therefore pthread_in_use() needs to actually try to create a @@ -254,54 +243,68 @@ AC_DEFUN([gl_PTHREADLIB_BODY], # pthread_create will actually create a thread. # On Solaris 10 or newer, this test is no longer needed, because # libc contains the fully functional pthread functions. - case "$host_os" in - solaris | solaris2.[1-9] | solaris2.[1-9].* | hpux*) - AC_DEFINE([PTHREAD_IN_USE_DETECTION_HARD], [1], - [Define if the pthread_in_use() detection is hard.]) - esac - fi + AS_CASE([$host_os], + [[solaris | solaris2.[1-9] | solaris2.[1-9].* | hpux*]], + [ + AC_DEFINE([PTHREAD_IN_USE_DETECTION_HARD], [1], + [Define if the pthread_in_use() detection is hard.]) + ]) + ]) + ], + [dnl This is needed on FreeBSD 5.2.1. + AC_CHECK_LIB([thr], [pthread_kill], + [if test $gl_pthread_in_glibc = yes; then + LIBPMULTITHREAD= + else + LIBPMULTITHREAD=-lthr + fi + ]) ]) - elif test $gl_pthread_api != yes; then + ], [test $gl_pthread_api != yes], [ # Some library is needed. Try libpthread and libc_r. AC_CHECK_LIB([pthread], [pthread_kill], [gl_pthread_api=yes LIBPTHREAD=-lpthread LIBPMULTITHREAD=-lpthread]) - if test $gl_pthread_api != yes; then + AS_IF([test $gl_pthread_api != yes], [ # For FreeBSD 4. AC_CHECK_LIB([c_r], [pthread_kill], [gl_pthread_api=yes LIBPTHREAD=-lc_r LIBPMULTITHREAD=-lc_r]) - fi - fi + ]) + ]) echo "$as_me:__oline__: LIBPMULTITHREAD=$LIBPMULTITHREAD" >&AS_MESSAGE_LOG_FD - fi + ]) AC_MSG_CHECKING([whether POSIX threads API is available]) AC_MSG_RESULT([$gl_pthread_api]) AC_SUBST([LIBPTHREAD]) AC_SUBST([LIBPMULTITHREAD]) - if test $gl_pthread_api = yes; then + AS_IF([test $gl_pthread_api = yes], [ AC_DEFINE([HAVE_PTHREAD_API], [1], [Define if you have the <pthread.h> header and the POSIX threads API.]) - fi + ]) dnl On some systems, sched_yield is in librt, rather than in libpthread. AC_LINK_IFELSE( [AC_LANG_PROGRAM( - [[#include <sched.h>]], + [[#include <sched.h> + ]], [[sched_yield ();]])], - [LIB_SCHED_YIELD= + [SCHED_YIELD_LIB= ], [dnl Solaris 7...10 has sched_yield in librt, not in libpthread or libc. - AC_CHECK_LIB([rt], [sched_yield], [LIB_SCHED_YIELD=-lrt], + AC_CHECK_LIB([rt], [sched_yield], [SCHED_YIELD_LIB=-lrt], [dnl Solaris 2.5.1, 2.6 has sched_yield in libposix4, not librt. - AC_CHECK_LIB([posix4], [sched_yield], [LIB_SCHED_YIELD=-lposix4])]) + AC_CHECK_LIB([posix4], [sched_yield], [SCHED_YIELD_LIB=-lposix4])]) ]) + AC_SUBST([SCHED_YIELD_LIB]) + dnl For backward compatibility. + LIB_SCHED_YIELD="$SCHED_YIELD_LIB" AC_SUBST([LIB_SCHED_YIELD]) gl_pthreadlib_body_done=done - fi + ]) ]) AC_DEFUN([gl_PTHREADLIB], @@ -317,9 +320,8 @@ dnl gl_STDTHREADLIB dnl --------------- dnl Tests for the libraries needs for using the ISO C threads API. dnl Sets the variable LIBSTDTHREAD to the linker options for use in a Makefile. -dnl Sets the variable THREADLIB_CPPFLAGS the flag -D_REENTRANT or -dnl -D_THREAD_SAFE if needed for multithread-safe programs and adds -dnl THREADLIB_CPPFLAGS to CPPFLAGS. +dnl Adds to CPPFLAGS the flag -D_REENTRANT or -D_THREAD_SAFE if needed for +dnl thread-safe programs. dnl Defines the C macro HAVE_THREADS_H if (at least parts of) the ISO C threads dnl API is available. @@ -329,44 +331,45 @@ AC_DEFUN([gl_STDTHREADLIB_BODY], [ AC_REQUIRE([gl_ANYTHREADLIB_EARLY]) AC_REQUIRE([AC_CANONICAL_HOST]) - if test -z "$gl_stdthreadlib_body_done"; then + AS_IF([test -z "$gl_stdthreadlib_body_done"], [ AC_CHECK_HEADERS_ONCE([threads.h]) - case "$host_os" in - mingw*) + AS_CASE([$host_os], + [mingw* | windows*], + [ LIBSTDTHREAD= - ;; - *) + ], + [ gl_PTHREADLIB_BODY - if test $ac_cv_header_threads_h = yes; then + AS_IF([test $ac_cv_header_threads_h = yes], [ dnl glibc >= 2.29 has thrd_create in libpthread. dnl FreeBSD >= 10 has thrd_create in libstdthreads; this library depends - dnl on libpthread (for the symbol 'pthread_mutexattr_gettype'). + dnl on libpthread (for the symbol pthread_mutexattr_gettype). dnl glibc >= 2.34, AIX >= 7.1, and Solaris >= 11.4 have thrd_create in dnl libc. - AC_CHECK_FUNCS([thrd_create]) - if test $ac_cv_func_thrd_create = yes; then + gl_CHECK_FUNCS_ANDROID([thrd_create], [[#include <threads.h> + ]]) + AS_IF([test $ac_cv_func_thrd_create = yes], [ LIBSTDTHREAD= - else + ], [ AC_CHECK_LIB([stdthreads], [thrd_create], [ - LIBSTDTHREAD='-lstdthreads -lpthread' + LIBSTDTHREAD="-lstdthreads -lpthread" ], [ dnl Guess that thrd_create is in libpthread. LIBSTDTHREAD="$LIBPMULTITHREAD" ]) - fi - else + ]) + ], [ dnl Libraries needed by thrd.c, mtx.c, cnd.c, tss.c. - LIBSTDTHREAD="$LIBPMULTITHREAD $LIB_SCHED_YIELD" - fi - ;; - esac + LIBSTDTHREAD="$LIBPMULTITHREAD $SCHED_YIELD_LIB" + ]) + ]) AC_SUBST([LIBSTDTHREAD]) AC_MSG_CHECKING([whether ISO C threads API is available]) AC_MSG_RESULT([$ac_cv_header_threads_h]) gl_stdthreadlib_body_done=done - fi + ]) ]) AC_DEFUN([gl_STDTHREADLIB], @@ -383,7 +386,7 @@ dnl ------------ dnl Tests for a multithreading library to be used. dnl If the configure.ac contains a definition of the gl_THREADLIB_DEFAULT_NO dnl (it must be placed before the invocation of gl_THREADLIB_EARLY!), then the -dnl default is 'no', otherwise it is system dependent. In both cases, the user +dnl default is "no", otherwise it is system dependent. In both cases, the user dnl can change the choice through the options --enable-threads=choice or dnl --disable-threads. dnl Defines at most one of the macros USE_ISOC_THREADS, USE_POSIX_THREADS, @@ -397,12 +400,11 @@ dnl Sets the variables LIBTHREAD and LTLIBTHREAD to the linker options for use dnl in a Makefile (LIBTHREAD for use without libtool, LTLIBTHREAD for use with dnl libtool). dnl Sets the variables LIBMULTITHREAD and LTLIBMULTITHREAD similarly, for -dnl programs that really need multithread functionality. The difference +dnl programs that really need multithreading. The difference dnl between LIBTHREAD and LIBMULTITHREAD is that on platforms supporting weak dnl symbols, typically LIBTHREAD is empty whereas LIBMULTITHREAD is not. -dnl Sets the variable THREADLIB_CPPFLAGS the flag -D_REENTRANT or -dnl -D_THREAD_SAFE if needed for multithread-safe programs and adds -dnl THREADLIB_CPPFLAGS to CPPFLAGS. +dnl Adds to CPPFLAGS the flag -D_REENTRANT or -D_THREAD_SAFE if needed for +dnl thread-safe programs. dnl Since support for GNU pth was removed, $LTLIBTHREAD and $LIBTHREAD have the dnl same value, and similarly $LTLIBMULTITHREAD and $LIBMULTITHREAD have the dnl same value. Only system libraries are needed. @@ -426,53 +428,49 @@ AC_DEFUN([gl_THREADLIB_EARLY_BODY], dnl _GNU_SOURCE is needed for pthread_rwlock_t on glibc systems. AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS]) dnl Check for multithreading. - THREADLIB_CPPFLAGS="" m4_ifdef([gl_THREADLIB_DEFAULT_NO], [m4_divert_text([DEFAULTS], [gl_use_threads_default=no])], [m4_divert_text([DEFAULTS], [gl_use_threads_default=])]) - m4_divert_text([DEFAULTS], [gl_use_winpthreads_default=]) + dnl gl_use_winpthreads_default defaults to "no", because in mingw 10, like + dnl in mingw 5, the use of libwinpthread still makes test-pthread-tss crash. + m4_divert_text([DEFAULTS], [gl_use_winpthreads_default=no]) + dnl Don't display the --disable-threads option + dnl - if the package builds one or more libraries, because libraries must + dnl always be thread-safe (as far as possible), + dnl - if the package defines gl_THREADLIB_DEFAULT_NO, because the option + dnl would then be a no-op. AC_ARG_ENABLE([threads], -AS_HELP_STRING([--enable-threads={isoc|posix|isoc+posix|windows}], [specify multithreading API])m4_ifdef([gl_THREADLIB_DEFAULT_NO], [], [ -AS_HELP_STRING([--disable-threads], [build without multithread safety])]), +AS_HELP_STRING([[--enable-threads={isoc|posix|isoc+posix|windows}]], [specify multithreading API])m4_ifdef([LT_INIT], [], [m4_ifdef([gl_THREADLIB_DEFAULT_NO], [], [ +AS_HELP_STRING([[--disable-threads]], [build without thread safety])])]), [gl_use_threads=$enableval], [if test -n "$gl_use_threads_default"; then gl_use_threads="$gl_use_threads_default" else -changequote(,)dnl - case "$host_os" in - dnl Disable multithreading by default on OSF/1, because it interferes - dnl with fork()/exec(): When msgexec is linked with -lpthread, its - dnl child process gets an endless segmentation fault inside execvp(). - osf*) gl_use_threads=no ;; + AS_CASE([$host_os], dnl Disable multithreading by default on Cygwin 1.5.x, because it has dnl bugs that lead to endless loops or crashes. See dnl <https://cygwin.com/ml/cygwin/2009-08/msg00283.html>. - cygwin*) - case `uname -r` in - 1.[0-5].*) gl_use_threads=no ;; - *) gl_use_threads=yes ;; - esac - ;; + [cygwin*], + [AS_CASE([$(uname -r)], + [[1.[0-5].*]], [gl_use_threads=no], + [gl_use_threads=yes]) + ], dnl Obey gl_AVOID_WINPTHREAD on mingw. - mingw*) - case "$gl_use_winpthreads_default" in - yes) gl_use_threads=posix ;; - no) gl_use_threads=windows ;; - *) gl_use_threads=yes ;; - esac - ;; - *) gl_use_threads=yes ;; - esac -changequote([,])dnl + [mingw* | windows*], + [AS_CASE([$gl_use_winpthreads_default], + [yes], [gl_use_threads=posix], + [no], [gl_use_threads=windows], + [gl_use_threads=yes]) + ], + [gl_use_threads=yes]) fi ]) - if test "$gl_use_threads" = yes \ - || test "$gl_use_threads" = isoc \ - || test "$gl_use_threads" = posix \ - || test "$gl_use_threads" = isoc+posix; then - # For using <threads.h> or <pthread.h>: - gl_ANYTHREADLIB_EARLY - fi + AS_CASE([$gl_use_threads], + [yes | isoc | posix | isoc+posix], + [ + # For using <threads.h> or <pthread.h>: + gl_ANYTHREADLIB_EARLY + ]) ]) dnl The guts of gl_THREADLIB. Needs to be expanded only once. @@ -485,87 +483,96 @@ AC_DEFUN([gl_THREADLIB_BODY], LTLIBTHREAD= LIBMULTITHREAD= LTLIBMULTITHREAD= - if test "$gl_use_threads" != no; then + AS_IF([test "$gl_use_threads" = no], + [AC_DEFINE([AVOID_ANY_THREADS], [1], + [Define if neither thread safety nor multithreading is desired.])], + [ dnl Check whether the compiler and linker support weak declarations. gl_WEAK_SYMBOLS - if case "$gl_cv_have_weak" in *yes) true;; *) false;; esac; then - dnl If we use weak symbols to implement pthread_in_use / pth_in_use / - dnl thread_in_use, we also need to test whether the ISO C 11 thrd_create - dnl facility is in use. - AC_CHECK_HEADERS_ONCE([threads.h]) - : - fi - if test "$gl_use_threads" = isoc || test "$gl_use_threads" = isoc+posix; then - AC_CHECK_HEADERS_ONCE([threads.h]) - gl_have_isoc_threads="$ac_cv_header_threads_h" - fi - if test "$gl_use_threads" = yes \ - || test "$gl_use_threads" = posix \ - || test "$gl_use_threads" = isoc+posix; then - gl_PTHREADLIB_BODY - LIBTHREAD=$LIBPTHREAD LTLIBTHREAD=$LIBPTHREAD - LIBMULTITHREAD=$LIBPMULTITHREAD LTLIBMULTITHREAD=$LIBPMULTITHREAD - if test $gl_pthread_api = yes; then - if test "$gl_use_threads" = isoc+posix && test "$gl_have_isoc_threads" = yes; then - gl_threads_api='isoc+posix' - AC_DEFINE([USE_ISOC_AND_POSIX_THREADS], [1], - [Define if the combination of the ISO C and POSIX multithreading APIs can be used.]) - LIBTHREAD= LTLIBTHREAD= - else - gl_threads_api=posix - AC_DEFINE([USE_POSIX_THREADS], [1], - [Define if the POSIX multithreading library can be used.]) - if test -z "$LIBMULTITHREAD" && test -z "$LTLIBMULTITHREAD"; then - AC_DEFINE([USE_POSIX_THREADS_FROM_LIBC], [1], - [Define if references to the POSIX multithreading library are satisfied by libc.]) - else - if case "$gl_cv_have_weak" in *yes) true;; *) false;; esac; then - AC_DEFINE([USE_POSIX_THREADS_WEAK], [1], - [Define if references to the POSIX multithreading library should be made weak.]) - LIBTHREAD= LTLIBTHREAD= - else - case "$host_os" in - freebsd* | dragonfly* | midnightbsd*) - if test "x$LIBTHREAD" != "x$LIBMULTITHREAD"; then - dnl If weak symbols can't tell whether pthread_create(), pthread_key_create() - dnl etc. will succeed, we need a runtime test. - AC_DEFINE([PTHREAD_IN_USE_DETECTION_HARD], [1], - [Define if the pthread_in_use() detection is hard.]) - fi - ;; - esac - fi - fi - fi - fi - fi - if test $gl_threads_api = none; then - if test "$gl_use_threads" = isoc && test "$gl_have_isoc_threads" = yes; then + AS_CASE([$gl_cv_have_weak], + [*yes], + [ + dnl If we use weak symbols to implement pthread_in_use / pth_in_use / + dnl thread_in_use, we also need to test whether the ISO C 11 thrd_create + dnl facility is in use. + AC_CHECK_HEADERS_ONCE([threads.h]) + : + ]) + AS_CASE([$gl_use_threads], + [isoc | isoc+posix], + [ + AC_CHECK_HEADERS_ONCE([threads.h]) + gl_have_isoc_threads="$ac_cv_header_threads_h" + ]) + AS_CASE([$gl_use_threads], + [yes | posix | isoc+posix], + [ + gl_PTHREADLIB_BODY + LIBTHREAD=$LIBPTHREAD LTLIBTHREAD=$LIBPTHREAD + LIBMULTITHREAD=$LIBPMULTITHREAD LTLIBMULTITHREAD=$LIBPMULTITHREAD + AS_IF([test $gl_pthread_api = yes], [ + AS_IF([test "$gl_use_threads" = isoc+posix && + test "$gl_have_isoc_threads" = yes], [ + gl_threads_api="isoc+posix" + AC_DEFINE([USE_ISOC_AND_POSIX_THREADS], [1], + [Define if the combination of the ISO C and POSIX multithreading APIs can be used.]) + LIBTHREAD= LTLIBTHREAD= + ], [ + gl_threads_api=posix + AC_DEFINE([USE_POSIX_THREADS], [1], + [Define if the POSIX multithreading library can be used.]) + AS_IF([test -z "$LIBMULTITHREAD" && test -z "$LTLIBMULTITHREAD"], [ + AC_DEFINE([USE_POSIX_THREADS_FROM_LIBC], [1], + [Define if references to the POSIX multithreading library are satisfied by libc.]) + ], [ + AS_CASE([$gl_cv_have_weak], + [*yes], + [ + AC_DEFINE([USE_POSIX_THREADS_WEAK], [1], + [Define if references to the POSIX multithreading library should be made weak.]) + LIBTHREAD= LTLIBTHREAD= + ], + [AS_CASE([$host_os], + [freebsd* | dragonfly* | midnightbsd*], + [ + AS_IF([test "x$LIBTHREAD" != "x$LIBMULTITHREAD"], [ + dnl If weak symbols cannot tell whether + dnl pthread_create(), dnl pthread_key_create() + dnl etc. will succeed, we need a runtime test. + AC_DEFINE([PTHREAD_IN_USE_DETECTION_HARD], [1], + [Define if the pthread_in_use() detection is hard.]) + ]) + ]) + ]) + ]) + ]) + ]) + ]) + AS_IF([test $gl_threads_api = none], [ + AS_IF([test "$gl_use_threads" = isoc && test "$gl_have_isoc_threads" = yes], [ gl_STDTHREADLIB_BODY LIBTHREAD=$LIBSTDTHREAD LTLIBTHREAD=$LIBSTDTHREAD LIBMULTITHREAD=$LIBSTDTHREAD LTLIBMULTITHREAD=$LIBSTDTHREAD gl_threads_api=isoc AC_DEFINE([USE_ISOC_THREADS], [1], [Define if the ISO C multithreading library can be used.]) - fi - fi - if test $gl_threads_api = none; then - case "$gl_use_threads" in - yes | windows | win32) # The 'win32' is for backward compatibility. - if { case "$host_os" in - mingw*) true;; - *) false;; - esac - }; then - gl_threads_api=windows - AC_DEFINE([USE_WINDOWS_THREADS], [1], - [Define if the native Windows multithreading API can be used.]) - fi - ;; - esac - fi - fi - AC_MSG_CHECKING([for multithread API to use]) + ]) + ]) + AS_IF([test $gl_threads_api = none], [ + # The "win32" is for backward compatibility. + AS_CASE([$gl_use_threads], + [yes | windows | win32], + [AS_CASE([$host_os], + [mingw* | windows*], + [ + gl_threads_api=windows + AC_DEFINE([USE_WINDOWS_THREADS], [1], + [Define if the native Windows multithreading API can be used.]) + ]) + ]) + ]) + ]) + AC_MSG_CHECKING([for multithreading API to use]) AC_MSG_RESULT([$gl_threads_api]) AC_SUBST([LIBTHREAD]) AC_SUBST([LTLIBTHREAD]) @@ -584,7 +591,7 @@ dnl gl_DISABLE_THREADS dnl ------------------ dnl Sets the gl_THREADLIB default so that threads are not used by default. dnl The user can still override it at installation time, by using the -dnl configure option '--enable-threads'. +dnl configure option "--enable-threads". AC_DEFUN([gl_DISABLE_THREADS], [ m4_divert_text([INIT_PREPARE], [gl_use_threads_default=no]) @@ -596,7 +603,8 @@ dnl ------------------- dnl Sets the gl_THREADLIB default so that on mingw, a dependency to the dnl libwinpthread DLL (mingw-w64 winpthreads library) is avoided. dnl The user can still override it at installation time, by using the -dnl configure option '--enable-threads'. +dnl configure option "--enable-threads=posix". +dnl As of 2023, this is now the default. AC_DEFUN([gl_AVOID_WINPTHREAD], [ m4_divert_text([INIT_PREPARE], [gl_use_winpthreads_default=no]) @@ -641,13 +649,8 @@ dnl dnl HP-UX 11 posix -lpthread N (cc) OK dnl Y (gcc) dnl -dnl IRIX 6.5 posix -lpthread Y 0.5 -dnl dnl AIX 4.3,5.1 posix -lpthread N AIX 4: 0.5; AIX 5: OK dnl -dnl OSF/1 4.0,5.1 posix -pthread (cc) N OK -dnl -lpthread (gcc) Y -dnl dnl Cygwin posix -lpthread Y OK dnl dnl Mingw windows N OK |