diff options
Diffstat (limited to 'gnulib-m4/gnulib-common.m4')
| -rw-r--r-- | gnulib-m4/gnulib-common.m4 | 213 |
1 files changed, 137 insertions, 76 deletions
diff --git a/gnulib-m4/gnulib-common.m4 b/gnulib-m4/gnulib-common.m4 index 1fec5c5c..26eef771 100644 --- a/gnulib-m4/gnulib-common.m4 +++ b/gnulib-m4/gnulib-common.m4 @@ -1,9 +1,10 @@ # gnulib-common.m4 -# serial 105 -dnl Copyright (C) 2007-2024 Free Software Foundation, Inc. +# serial 115 +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]) @@ -20,6 +21,20 @@ AC_DEFUN([gl_COMMON_BODY], [ [/* 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 @@ -42,33 +57,25 @@ AC_DEFUN([gl_COMMON_BODY], [ #endif ]) AH_VERBATIM([_Noreturn], -[/* The _Noreturn keyword of C11. */ +[/* 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 \ - && ((201103 <= __cplusplus && !(__GNUC__ == 4 && __GNUC_MINOR__ == 7)) \ - || (defined _MSC_VER && 1900 <= _MSC_VER)) \ - && 0) - /* [[noreturn]] is not practically usable, because with it the syntax - extern _Noreturn void func (...); - would not be valid; such a declaration would only be valid 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'. */ -# 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__ \ - && (_GL_GNUC_PREREQ (4, 7) \ - || (defined __apple_build_version__ \ - ? 6000000 <= __apple_build_version__ \ - : 3 < __clang_major__ + (5 <= __clang_minor__)))))) +# 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) @@ -102,6 +109,9 @@ AC_DEFUN([gl_COMMON_BODY], [ # 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) @@ -122,14 +132,15 @@ AC_DEFUN([gl_COMMON_BODY], [ # 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 0 /* not yet supported, as of GCC 14 */ +# 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 0 /* not yet supported, as of GCC 14 */ +# 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 @@ -157,7 +168,7 @@ AC_DEFUN([gl_COMMON_BODY], [ ====================================================================== This gives a syntax error - in C mode with gcc - <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108796>, and + <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>. @@ -403,22 +414,25 @@ AC_DEFUN([gl_COMMON_BODY], [ #endif /* _GL_ATTRIBUTE_CONST declares: - It is OK for a compiler to move calls to the function and to omit - calls to the function if another call has the same arguments or the - result is not used. - This attribute is safe for a function that neither depends on - nor affects state, and always returns exactly once - + 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. It is stricter than - _GL_ATTRIBUTE_UNSEQUENCED because the function must return exactly - once and cannot depend on state addressed by its arguments.) */ + 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 _GL_ATTRIBUTE_UNSEQUENCED +# define _GL_ATTRIBUTE_CONST # endif #endif @@ -440,7 +454,7 @@ AC_DEFUN([gl_COMMON_BODY], [ yet. */ #ifndef _GL_ATTRIBUTE_DEALLOC_FREE # if defined __cplusplus && defined __GNUC__ && !defined __clang__ -/* Work around GCC bug <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108231> */ +/* Work around GCC bug <https://gcc.gnu.org/PR108231> */ # define _GL_ATTRIBUTE_DEALLOC_FREE \ _GL_ATTRIBUTE_DEALLOC ((void (*) (void *)) free, 1) # else @@ -579,7 +593,9 @@ AC_DEFUN([gl_COMMON_BODY], [ /* _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. */ + 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, @@ -666,6 +682,17 @@ AC_DEFUN([gl_COMMON_BODY], [ # 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 @@ -722,35 +749,38 @@ AC_DEFUN([gl_COMMON_BODY], [ #endif /* _GL_ATTRIBUTE_PURE declares: - It is OK for a compiler to move calls to the function and to omit - calls to the function if another call has the same arguments or the - result is not used, and if observable state is the same. - This attribute is safe for a function that does not affect observable state - and always returns exactly once. + 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. It is stricter than - _GL_ATTRIBUTE_REPRODUCIBLE because the function must return exactly - once and cannot affect state addressed by its arguments.) */ + 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 _GL_ATTRIBUTE_REPRODUCIBLE +# define _GL_ATTRIBUTE_PURE # endif #endif /* _GL_ATTRIBUTE_REPRODUCIBLE declares: - It is OK for a compiler to move calls to the function and to omit duplicate - calls to the function with the same arguments, so long as the state - addressed by its arguments is the same and is updated in time for - the rest of the program. - This attribute is safe for a function that is effectless and idempotent; see - ISO C 23 § 6.7.12.7 for a definition of these terms. + 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 and idempotent. It is looser - than _GL_ATTRIBUTE_PURE because the function need not return - exactly once and can affect state addressed by its arguments.) + 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. */ @@ -792,16 +822,20 @@ AC_DEFUN([gl_COMMON_BODY], [ #endif /* _GL_ATTRIBUTE_UNSEQUENCED declares: - It is OK for a compiler to move calls to the function and to omit duplicate - calls to the function with the same arguments, so long as the state - addressed by its arguments is the same. + 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 § 6.7.12.7 for a definition of + 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. It is looser than - _GL_ATTRIBUTE_CONST because the function need not return exactly - once and can depend on state addressed by its arguments.) + 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. */ @@ -843,6 +877,21 @@ AC_DEFUN([gl_COMMON_BODY], [ # 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 multithread-safety problems and resource leaks at compile-time, by clang ≥ 15, when the warning option -Wthread-safety is enabled. For usage, see @@ -851,7 +900,7 @@ AC_DEFUN([gl_COMMON_BODY], [ # if __clang_major__ >= 15 # define _GL_ATTRIBUTE_CAPABILITY_TYPE(concept) \ __attribute__ ((__capability__ (concept))) -#else +# else # define _GL_ATTRIBUTE_CAPABILITY_TYPE(concept) # endif #endif @@ -921,8 +970,8 @@ AC_DEFUN([gl_COMMON_BODY], [ -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 with many - GCC versions up to GCC 9. + 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))) @@ -1299,7 +1348,7 @@ 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 -f conftest* + [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 $CPPFLAGS -Wno-error -c conftest.c 2>conftest2.err]) >/dev/null @@ -1312,7 +1361,7 @@ AC_DEFUN([gl_CC_ALLOW_WARNINGS], else gl_cv_cc_wallow=none fi - rm -f conftest* + rm -fr conftest* ]) case "$gl_cv_cc_wallow" in none) GL_CFLAG_ALLOW_WARNINGS='' ;; @@ -1330,7 +1379,7 @@ AC_DEFUN([gl_CXX_ALLOW_WARNINGS], if test -n "$CXX" && test "$CXX" != no; then AC_CACHE_CHECK([for C++ compiler option to allow warnings], [gl_cv_cxx_wallow], - [rm -f conftest* + [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 $CPPFLAGS -Wno-error -c conftest.cc 2>conftest2.err]) >/dev/null @@ -1343,7 +1392,7 @@ AC_DEFUN([gl_CXX_ALLOW_WARNINGS], else gl_cv_cxx_wallow=none fi - rm -f conftest* + rm -fr conftest* ]) case "$gl_cv_cxx_wallow" in none) GL_CXXFLAG_ALLOW_WARNINGS='' ;; @@ -1380,7 +1429,7 @@ AC_DEFUN([gl_CC_GNULIB_WARNINGS], 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 >= 4.4 >= 3.9 + dnl -Wno-unused-const-variable >= 6.1 >= 3.9 dnl -Wno-unused-function >= 3 >= 3.9 dnl -Wno-unused-parameter >= 3 >= 3.9 dnl @@ -1410,7 +1459,7 @@ AC_DEFUN([gl_CC_GNULIB_WARNINGS], -Wno-sign-conversion -Wno-type-limits #endif - #if (__GNUC__ + (__GNUC_MINOR__ >= 4) > 4 && !defined __clang__) || (__clang_major__ + (__clang_minor__ >= 9) > 3) + #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__) @@ -1537,13 +1586,25 @@ AC_DEFUN([gl_CHECK_FUNCS_CASE_FOR_MACOS], 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]) @@ -1596,7 +1657,7 @@ 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 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 @@ -1649,7 +1710,7 @@ 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 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 |