diff options
Diffstat (limited to 'gnulib-m4/gnulib-common.m4')
| -rw-r--r-- | gnulib-m4/gnulib-common.m4 | 712 |
1 files changed, 549 insertions, 163 deletions
diff --git a/gnulib-m4/gnulib-common.m4 b/gnulib-m4/gnulib-common.m4 index d17cbec5..d8d0904f 100644 --- a/gnulib-m4/gnulib-common.m4 +++ b/gnulib-m4/gnulib-common.m4 @@ -1,5 +1,5 @@ -# gnulib-common.m4 serial 74 -dnl Copyright (C) 2007-2022 Free Software Foundation, Inc. +# gnulib-common.m4 serial 92 +dnl Copyright (C) 2007-2024 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. @@ -15,6 +15,10 @@ AC_DEFUN([gl_COMMON], [ 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 +]) AH_VERBATIM([_GL_GNUC_PREREQ], [/* True if the compiler says it groks GNU C version MAJOR.MINOR. */ #if defined __GNUC__ && defined __GNUC_MINOR__ @@ -38,6 +42,11 @@ AC_DEFUN([gl_COMMON_BODY], [ AIX system header files and several gnulib header files use precisely this syntax with 'extern'. */ # define _Noreturn [[noreturn]] +# elif (defined __clang__ && __clang_major__ < 16 \ + && defined _GL_WORK_AROUND_LLVM_BUG_59792) + /* Compile with -D_GL_WORK_AROUND_LLVM_BUG_59792 to work around + that rare LLVM bug, though you may get many false-alarm warnings. */ +# define _Noreturn # elif ((!defined __cplusplus || defined __clang__) \ && (201112 <= (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) \ || (!defined __STRICT_ANSI__ \ @@ -67,54 +76,74 @@ AC_DEFUN([gl_COMMON_BODY], [ #endif]) AH_VERBATIM([attribute], [/* Attributes. */ -#if (defined __has_attribute \ - && (!defined __clang_minor__ \ - || (defined __apple_build_version__ \ - ? 6000000 <= __apple_build_version__ \ - : 3 < __clang_major__ + (5 <= __clang_minor__)))) -# define _GL_HAS_ATTRIBUTE(attr) __has_attribute (__##attr##__) -#else -# define _GL_HAS_ATTRIBUTE(attr) _GL_ATTR_##attr -# 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 +/* 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_ATTR_may_alias _GL_GNUC_PREREQ (3, 3) +# define _GL_HAS_ATTRIBUTE(attr) _GL_ATTR_##attr +# 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_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_returns_nonnull _GL_GNUC_PREREQ (4, 9) +# define _GL_ATTR_sentinel _GL_GNUC_PREREQ (4, 0) +# define _GL_ATTR_unused _GL_GNUC_PREREQ (2, 7) +# define _GL_ATTR_warn_unused_result _GL_GNUC_PREREQ (3, 4) # endif -# define _GL_ATTR_noinline _GL_GNUC_PREREQ (3, 1) -# define _GL_ATTR_nonnull _GL_GNUC_PREREQ (3, 3) -# 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_returns_nonnull _GL_GNUC_PREREQ (4, 9) -# define _GL_ATTR_sentinel _GL_GNUC_PREREQ (4, 0) -# define _GL_ATTR_unused _GL_GNUC_PREREQ (2, 7) -# define _GL_ATTR_warn_unused_result _GL_GNUC_PREREQ (3, 4) #endif -#ifdef __has_c_attribute -# if ((defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) <= 201710 \ - && _GL_GNUC_PREREQ (4, 6)) -# pragma GCC diagnostic ignored "-Wpedantic" -# endif -# define _GL_HAS_C_ATTRIBUTE(attr) __has_c_attribute (__##attr##__) +/* 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_HAS_C_ATTRIBUTE(attr) 0 +# define _GL_HAVE___HAS_C_ATTRIBUTE 0 #endif +/* 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 ]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 @@ -123,29 +152,35 @@ AC_DEFUN([gl_COMMON_BODY], [ by the Nth argument of the function is the size of the returned memory block. */ /* Applies to: function, pointer to function, function types. */ -#if _GL_HAS_ATTRIBUTE (alloc_size) -# define _GL_ATTRIBUTE_ALLOC_SIZE(args) __attribute__ ((__alloc_size__ args)) -#else -# define _GL_ATTRIBUTE_ALLOC_SIZE(args) +#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: function. */ -#if _GL_HAS_ATTRIBUTE (always_inline) -# define _GL_ATTRIBUTE_ALWAYS_INLINE __attribute__ ((__always_inline__)) -#else -# define _GL_ATTRIBUTE_ALWAYS_INLINE +#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: function. */ -#if _GL_HAS_ATTRIBUTE (artificial) -# define _GL_ATTRIBUTE_ARTIFICIAL __attribute__ ((__artificial__)) -#else -# define _GL_ATTRIBUTE_ARTIFICIAL +#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. */ @@ -153,14 +188,16 @@ AC_DEFUN([gl_COMMON_BODY], [ /* 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__'. */ -#if _GL_HAS_ATTRIBUTE (cold) && !defined __MINGW32__ -# ifndef __SUNPRO_C -# define _GL_ATTRIBUTE_COLD __attribute__ ((__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 __attribute__ ((cold)) +# define _GL_ATTRIBUTE_COLD # endif -#else -# define _GL_ATTRIBUTE_COLD #endif /* _GL_ATTRIBUTE_CONST declares that it is OK for a compiler to omit duplicate @@ -170,10 +207,12 @@ AC_DEFUN([gl_COMMON_BODY], [ forever, and does not call longjmp. (This attribute is stricter than _GL_ATTRIBUTE_PURE.) */ /* Applies to: functions. */ -#if _GL_HAS_ATTRIBUTE (const) -# define _GL_ATTRIBUTE_CONST __attribute__ ((__const__)) -#else -# define _GL_ATTRIBUTE_CONST +#ifndef _GL_ATTRIBUTE_CONST +# if _GL_HAS_ATTRIBUTE (const) +# define _GL_ATTRIBUTE_CONST __attribute__ ((__const__)) +# else +# define _GL_ATTRIBUTE_CONST +# endif #endif /* _GL_ATTRIBUTE_DEALLOC (F, I) declares that the function returns pointers @@ -182,16 +221,25 @@ AC_DEFUN([gl_COMMON_BODY], [ _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. */ -#if _GL_GNUC_PREREQ (11, 0) -# define _GL_ATTRIBUTE_DEALLOC(f, i) __attribute__ ((__malloc__ (f, i))) -#else -# define _GL_ATTRIBUTE_DEALLOC(f, i) +#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 -# define _GL_ATTRIBUTE_DEALLOC_FREE _GL_ATTRIBUTE_DEALLOC (free, 1) +# if defined __cplusplus && defined __GNUC__ && !defined __clang__ +/* Work around GCC bug <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108231> */ +# 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. @@ -202,12 +250,20 @@ AC_DEFUN([gl_COMMON_BODY], [ - enumeration, enumeration item, - typedef, in C++ also: namespace, class, template specialization. */ -#if _GL_HAS_C_ATTRIBUTE (deprecated) -# define _GL_ATTRIBUTE_DEPRECATED [[__deprecated__]] -#elif _GL_HAS_ATTRIBUTE (deprecated) -# define _GL_ATTRIBUTE_DEPRECATED __attribute__ ((__deprecated__)) -#else -# define _GL_ATTRIBUTE_DEPRECATED +#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 @@ -215,24 +271,28 @@ AC_DEFUN([gl_COMMON_BODY], [ _GL_ATTRIBUTE_WARNING(msg) requests a warning if a function is called and the function call is not optimized away. */ /* Applies to: functions. */ -#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) +#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. */ -#if _GL_HAS_ATTRIBUTE (externally_visible) -# define _GL_ATTRIBUTE_EXTERNALLY_VISIBLE __attribute__ ((externally_visible)) -#else -# define _GL_ATTRIBUTE_EXTERNALLY_VISIBLE +#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 @@ -240,12 +300,18 @@ AC_DEFUN([gl_COMMON_BODY], [ 'default' label. The compiler should not warn in this case. */ /* Applies to: Empty statement (;), inside a 'switch' statement. */ /* Always expands to something. */ -#if _GL_HAS_C_ATTRIBUTE (fallthrough) -# define _GL_ATTRIBUTE_FALLTHROUGH [[__fallthrough__]] -#elif _GL_HAS_ATTRIBUTE (fallthrough) -# define _GL_ATTRIBUTE_FALLTHROUGH __attribute__ ((__fallthrough__)) -#else -# define _GL_ATTRIBUTE_FALLTHROUGH ((void) 0) +#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)) @@ -259,10 +325,12 @@ AC_DEFUN([gl_COMMON_BODY], [ If FIRST-TO-CHECK is not 0, arguments starting at FIRST-TO_CHECK are suitable for the format string. */ /* Applies to: functions. */ -#if _GL_HAS_ATTRIBUTE (format) -# define _GL_ATTRIBUTE_FORMAT(spec) __attribute__ ((__format__ spec)) -#else -# define _GL_ATTRIBUTE_FORMAT(spec) +#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 @@ -270,19 +338,23 @@ AC_DEFUN([gl_COMMON_BODY], [ exception handling. This declaration lets the compiler optimize that unit more aggressively. */ /* Applies to: functions. */ -#if _GL_HAS_ATTRIBUTE (leaf) -# define _GL_ATTRIBUTE_LEAF __attribute__ ((__leaf__)) -#else -# define _GL_ATTRIBUTE_LEAF +#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. */ -#if _GL_HAS_ATTRIBUTE (malloc) -# define _GL_ATTRIBUTE_MALLOC __attribute__ ((__malloc__)) -#else -# define _GL_ATTRIBUTE_MALLOC +#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 @@ -290,10 +362,12 @@ AC_DEFUN([gl_COMMON_BODY], [ strict aliasing optimization. */ /* Applies to: types. */ /* Oracle Studio 12.6 mishandles may_alias despite __has_attribute OK. */ -#if _GL_HAS_ATTRIBUTE (may_alias) && !defined __SUNPRO_C -# define _GL_ATTRIBUTE_MAY_ALIAS __attribute__ ((__may_alias__)) -#else -# define _GL_ATTRIBUTE_MAY_ALIAS +#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 @@ -305,13 +379,26 @@ AC_DEFUN([gl_COMMON_BODY], [ - enumeration, enumeration item, - typedef, in C++ also: class. */ -/* In C++ and C2x, this is spelled [[__maybe_unused__]]. +/* In C++ and C23, this is spelled [[__maybe_unused__]]. GCC's syntax is __attribute__ ((__unused__)). - clang supports both syntaxes. */ -#if _GL_HAS_C_ATTRIBUTE (maybe_unused) -# define _GL_ATTRIBUTE_MAYBE_UNUSED [[__maybe_unused__]] -#else -# define _GL_ATTRIBUTE_MAYBE_UNUSED _GL_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. */ @@ -323,21 +410,40 @@ AC_DEFUN([gl_COMMON_BODY], [ 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. */ -#if _GL_HAS_C_ATTRIBUTE (nodiscard) -# define _GL_ATTRIBUTE_NODISCARD [[__nodiscard__]] -#elif _GL_HAS_ATTRIBUTE (warn_unused_result) -# define _GL_ATTRIBUTE_NODISCARD __attribute__ ((__warn_unused_result__)) -#else -# define _GL_ATTRIBUTE_NODISCARD +#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. */ -#if _GL_HAS_ATTRIBUTE (noinline) -# define _GL_ATTRIBUTE_NOINLINE __attribute__ ((__noinline__)) -#else -# define _GL_ATTRIBUTE_NOINLINE +#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,... @@ -345,20 +451,24 @@ AC_DEFUN([gl_COMMON_BODY], [ _GL_ATTRIBUTE_NONNULL () declares that all pointer arguments must not be null. */ /* Applies to: functions. */ -#if _GL_HAS_ATTRIBUTE (nonnull) -# define _GL_ATTRIBUTE_NONNULL(args) __attribute__ ((__nonnull__ args)) -#else -# define _GL_ATTRIBUTE_NONNULL(args) +#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_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'. */ -#if _GL_HAS_ATTRIBUTE (nonstring) -# define _GL_ATTRIBUTE_NONSTRING __attribute__ ((__nonstring__)) -#else -# define _GL_ATTRIBUTE_NONSTRING +#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. */ @@ -366,10 +476,26 @@ AC_DEFUN([gl_COMMON_BODY], [ /* _GL_ATTRIBUTE_NOTHROW declares that the function does not throw exceptions. */ /* Applies to: functions. */ -#if _GL_HAS_ATTRIBUTE (nothrow) && !defined __cplusplus -# define _GL_ATTRIBUTE_NOTHROW __attribute__ ((__nothrow__)) -#else -# define _GL_ATTRIBUTE_NOTHROW +/* 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: @@ -378,10 +504,12 @@ AC_DEFUN([gl_COMMON_BODY], [ minimizing the memory required. */ /* Applies to: struct members, struct, union, in C++ also: class. */ -#if _GL_HAS_ATTRIBUTE (packed) -# define _GL_ATTRIBUTE_PACKED __attribute__ ((__packed__)) -#else -# define _GL_ATTRIBUTE_PACKED +#ifndef _GL_ATTRIBUTE_PACKED +# if _GL_HAS_ATTRIBUTE (packed) +# define _GL_ATTRIBUTE_PACKED __attribute__ ((__packed__)) +# else +# define _GL_ATTRIBUTE_PACKED +# endif #endif /* _GL_ATTRIBUTE_PURE declares that It is OK for a compiler to omit duplicate @@ -391,19 +519,23 @@ AC_DEFUN([gl_COMMON_BODY], [ observable state, and always returns exactly once. (This attribute is looser than _GL_ATTRIBUTE_CONST.) */ /* Applies to: functions. */ -#if _GL_HAS_ATTRIBUTE (pure) -# define _GL_ATTRIBUTE_PURE __attribute__ ((__pure__)) -#else -# define _GL_ATTRIBUTE_PURE +#ifndef _GL_ATTRIBUTE_PURE +# if _GL_HAS_ATTRIBUTE (pure) +# define _GL_ATTRIBUTE_PURE __attribute__ ((__pure__)) +# else +# define _GL_ATTRIBUTE_PURE +# endif #endif /* _GL_ATTRIBUTE_RETURNS_NONNULL declares that the function's return value is a non-NULL pointer. */ /* Applies to: functions. */ -#if _GL_HAS_ATTRIBUTE (returns_nonnull) -# define _GL_ATTRIBUTE_RETURNS_NONNULL __attribute__ ((__returns_nonnull__)) -#else -# define _GL_ATTRIBUTE_RETURNS_NONNULL +#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 @@ -411,17 +543,21 @@ AC_DEFUN([gl_COMMON_BODY], [ _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. */ -#if _GL_HAS_ATTRIBUTE (sentinel) -# define _GL_ATTRIBUTE_SENTINEL(pos) __attribute__ ((__sentinel__ pos)) -#else -# define _GL_ATTRIBUTE_SENTINEL(pos) +#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 /* A helper macro. Don't use it directly. */ -#if _GL_HAS_ATTRIBUTE (unused) -# define _GL_ATTRIBUTE_UNUSED __attribute__ ((__unused__)) -#else -# define _GL_ATTRIBUTE_UNUSED +#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. @@ -432,10 +568,24 @@ AC_DEFUN([gl_COMMON_BODY], [ /* Applies to: label (both in C and C++). */ /* Note that g++ < 4.5 does not support the '__attribute__ ((__unused__)) ;' syntax. But clang does. */ -#if !(defined __cplusplus && !_GL_GNUC_PREREQ (4, 5)) || defined __clang__ -# define _GL_UNUSED_LABEL _GL_ATTRIBUTE_UNUSED +#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 +]) + 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_UNUSED_LABEL +# define _GL_BEGIN_C_LINKAGE +# define _GL_END_C_LINKAGE #endif ]) AH_VERBATIM([async_safe], @@ -493,7 +643,7 @@ AC_DEFUN([gl_COMMON_BODY], [ 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}], + [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]) @@ -930,6 +1080,7 @@ AC_DEFUN([gl_CC_GNULIB_WARNINGS], dnl -Wno-pedantic >= 4.8 >= 3.9 dnl -Wno-sign-compare >= 3 >= 3.9 dnl -Wno-sign-conversion >= 4.3 >= 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 @@ -955,6 +1106,9 @@ AC_DEFUN([gl_CC_GNULIB_WARNINGS], #if __GNUC__ + (__GNUC_MINOR__ >= 8) > 4 || (__clang_major__ + (__clang_minor__ >= 9) > 3) -Wno-pedantic #endif + #if 3 < __clang_major__ + (9 <= __clang_minor__) + -Wno-tautological-constant-out-of-range-compare + #endif #if __GNUC__ + (__GNUC_MINOR__ >= 3) > 4 || (__clang_major__ + (__clang_minor__ >= 9) > 3) -Wno-sign-conversion -Wno-type-limits @@ -1005,6 +1159,238 @@ AC_DEFUN([gl_CONDITIONAL_HEADER], 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 + unset [ac_cv_have_decl_][$1] + AC_CHECK_DECL([$1], , , [$2]) + 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 + 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 to distinguish 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 to distinguish 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 |