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author | Paul Eggert <eggert@cs.ucla.edu> | 2020-05-01 18:12:12 -0700 |
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committer | Paul Eggert <eggert@cs.ucla.edu> | 2020-05-03 13:49:20 -0700 |
commit | c08f85d74f2964c00613930342bfa27f971fc2be (patch) | |
tree | 23fcb7481abab5e59a9d62e7aae2d73a7d2f0b8f /m4 | |
parent | 2ac33b29fc09f72a18eb08829eb142eb86428747 (diff) | |
download | gnulib-c08f85d74f2964c00613930342bfa27f971fc2be.tar.gz |
attribute: new module
This simplifies use of GCC and C2X attributes like ‘deprecated’.
* MODULES.html.sh: Add attribute.
* doc/attribute.texi, lib/attribute.h, modules/attribute: New files.
* doc/gnulib.texi (Particular Modules): Add Attributes.
* lib/backupfile.c, lib/fnmatch.c, lib/freopen-safer.c:
* lib/mbrtoc32.c, lib/mbrtowc.c, lib/nstrftime.c, lib/quotearg.c:
* lib/savewd.c, lib/unistr/u8-uctomb-aux.c, lib/unistr/u8-uctomb.c:
* lib/vasnprintf.c:
Include attribute.h, and let it define FALLTHROUGH.
* lib/bitset/base.h, lib/c-stack.c (__attribute__): Remove macro.
* lib/bitset/base.h (ATTRIBUTE_UNUSED): Define in terms of
_GL_ATTRIBUTE_MAYBE_UNUSED, for forwards compatibility to C2X.
* lib/dfa.c (FALLTHROUGH): Define consistently with gl_COMMON_BODY.
This is a copy since Gawk doesn’t use Gnulib.
* lib/di-set.h (_GL_ATTRIBUTE_NONNULL): Remove definition that
is incompatible with gl_COMMON_BODY’s. All uses changed.
* lib/fts.c: Include attribte.h, for FALLTHROUGH.
Keep the existing FALLTHROUGH definition since Glibc might use it,
and it does no harm to Gnulib’s FALLTHROUGH.
* lib/fts_.h, lib/inttostr.h:
(__GNUC_PREREQ): Remove; no longer needed.
(__attribute_warn_unused_result__): Remove. All uses
replaced by _GL_ATTRIBUTE_NODISCARD.
* lib/gl_list.h, lib/gl_map.h, lib/gl_omap.h, lib/gl_oset.h:
* lib/gl_set.h: Prefer _GL_ATTRIBUTE_NODISCARD to an ifdeffed
__attribute__ ((__warn_unused_result__)), for forward
compatibility to C2X.
* lib/hash.h (_GL_ATTRIBUTE_WUR): Remove. All uses replaced by
_GL_ATTRIBUTE_NODISCARD.
(_GL_ATTRIBUTE_DEPRECATED): Remove, since gl_COMMON_BODY defines it.
* lib/ino-map.h (_GL_ATTRIBUTE_NONNULL): Remove. All uses
replaced by gl_COMMON_BODY’s implementation, which has a
slightly different signature.
* lib/safe-alloc.h (_GL_ATTRIBUTE_RETURN_CHECK):
Remove. All uses replaced by _GL_ATTRIBUTE_NODISCARD.
* lib/unused-parameter.h (_GL_UNUSED_PARAMETER):
Define in terms of _GL_ATTRIBUTE_MAYBE_UNUSED.
No doubt all uses should be replaced, at some point.
* m4/gnulib-common.m4 (_GL_GNUC_PREREQ): New macro.
(_Noreturn): Use it.
(_GL_HAS_ATTRIBUTE, _GL_ATTRIBUTE_ALLOC_SIZE)
(_GL_ATTRIBUTE_ALWAYS_INLINE, _GL_ATTRIBUTE_ARTIFICIAL)
(_GL_ATTRIBUTE_COLD)
(_GL_ATTRIBUTE_DEPRECATED, _GL_ATTRIBUTE_ERROR)
(_GL_ATTRIBUTE_WARNING, _GL_ATTRIBUTE_EXTERNALLY_VISIBLE)
(_GL_ATTRIBUTE_FALLTHROUGH, _GL_ATTRIBUTE_FORMAT)
(_GL_ATTRIBUTE_LEAF, _GL_ATTRIBUTE_MAY_ALIAS)
(_GL_ATTRIBUTE_MAYBE_UNUSED)
(_GL_ATTRIBUTE_NODISCARD, _GL_ATTRIBUTE_NOINLINE)
(_GL_ATTRIBUTE_NONNULL, _GL_ATTRIBUTE_NONSTRING)
(_GL_ATTRIBUTE_NOTHROW, _GL_ATTRIBUTE_PACKED, _GL_ATTRIBUTE_PURE)
(_GL_ATTRIBUTE_SENTINEL): New macros.
* modules/backup-rename, modules/backupfile, modules/c-vasnprintf:
* modules/fnmatch, modules/freopen-safer, modules/fts:
* modules/mbrtoc32, modules/mbrtowc, modules/nstrftime:
* modules/quotearg, modules/savewd:
* modules/unistdio/u16-u16-vasnprintf:
* modules/unistdio/u16-vasnprintf:
* modules/unistdio/u32-u32-vasnprintf:
* modules/unistdio/u32-vasnprintf:
* modules/unistdio/u8-u8-vasnprintf:
* modules/unistdio/u8-vasnprintf:
* modules/unistdio/ulc-vasnprintf:
* modules/unistr/u8-uctomb, modules/vasnprintf:
(Depends-on:): Add attribute module.
Diffstat (limited to 'm4')
-rw-r--r-- | m4/gnulib-common.m4 | 223 |
1 files changed, 192 insertions, 31 deletions
diff --git a/m4/gnulib-common.m4 b/m4/gnulib-common.m4 index b4795c18ae..1a817662c2 100644 --- a/m4/gnulib-common.m4 +++ b/m4/gnulib-common.m4 @@ -1,4 +1,4 @@ -# gnulib-common.m4 serial 48 +# gnulib-common.m4 serial 49 dnl Copyright (C) 2007-2020 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, @@ -15,6 +15,15 @@ AC_DEFUN([gl_COMMON], [ AC_REQUIRE([gl_ZZGNULIB]) ]) AC_DEFUN([gl_COMMON_BODY], [ + AH_VERBATIM([_GL_GNUC_PREREQ], +[/* True if the compiler says it groks GNU C version MAJOR.MINOR. */ +#if defined __GNUC__ && defined __GNUC_MINOR__ +# define _GL_GNUC_PREREQ(major, minor) \ + ((major) < __GNUC__ + ((minor) <= __GNUC_MINOR__)) +#else +# define _GL_GNUC_PREREQ(major, minor) 0 +#endif +]) AH_VERBATIM([_Noreturn], [/* The _Noreturn keyword of C11. */ #ifndef _Noreturn @@ -31,12 +40,12 @@ AC_DEFUN([gl_COMMON_BODY], [ # define _Noreturn [[noreturn]] # elif ((!defined __cplusplus || defined __clang__) \ && (201112 <= (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) \ - || 4 < __GNUC__ + (7 <= __GNUC_MINOR__) \ + || _GL_GNUC_PREREQ (4, 7) \ || (defined __apple_build_version__ \ ? 6000000 <= __apple_build_version__ \ : 3 < __clang_major__ + (5 <= __clang_minor__)))) /* _Noreturn works as-is. */ -# elif 2 < __GNUC__ + (8 <= __GNUC_MINOR__) || 0x5110 <= __SUNPRO_C +# elif _GL_GNUC_PREREQ (2, 8) || 0x5110 <= __SUNPRO_C # define _Noreturn __attribute__ ((__noreturn__)) # elif 1200 <= (defined _MSC_VER ? _MSC_VER : 0) # define _Noreturn __declspec (noreturn) @@ -55,48 +64,200 @@ AC_DEFUN([gl_COMMON_BODY], [ #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([unused_parameter], -[/* Define as a marker that can be attached to declarations that might not - be used. This helps to reduce warnings, such as from - GCC -Wunused-parameter. */ -#if __GNUC__ >= 3 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 7) -# define _GL_UNUSED __attribute__ ((__unused__)) + AH_VERBATIM([attribute], +[/* Attributes. */ +#ifdef __has_attribute +# define _GL_HAS_ATTRIBUTE(attr) __has_attribute (__##attr##__) #else -# define _GL_UNUSED +# 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_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) +# ifdef _ICC +# define _GL_ATTR_may_alias 0 +# else +# define _GL_ATTR_may_alias _GL_GNUC_PREREQ (3, 3) +# endif +# define _GL_ATTR_malloc _GL_GNUC_PREREQ (3, 0) +# 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 -/* The name _UNUSED_PARAMETER_ is an earlier spelling, although the name - is a misnomer outside of parameter lists. */ -#define _UNUSED_PARAMETER_ _GL_UNUSED - -/* gcc supports the "unused" attribute on possibly unused labels, and - g++ has since version 4.5. Note to support C++ as well as C, - _GL_UNUSED_LABEL should be used with a trailing ; */ -#if !defined __cplusplus || __GNUC__ > 4 \ - || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5) -# define _GL_UNUSED_LABEL _GL_UNUSED + +]dnl There is no _GL_ATTRIBUTE_ALIGNED; use stdalign's _Alignas instead. +[ +#if _GL_HAS_ATTRIBUTE (alloc_size) +# define _GL_ATTRIBUTE_ALLOC_SIZE(args) __attribute__ ((__alloc_size__ args)) #else -# define _GL_UNUSED_LABEL +# define _GL_ATTRIBUTE_ALLOC_SIZE(args) #endif -/* The __pure__ attribute was added in gcc 2.96. */ -#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 96) -# define _GL_ATTRIBUTE_PURE __attribute__ ((__pure__)) +#if _GL_HAS_ATTRIBUTE (always_inline) +# define _GL_ATTRIBUTE_ALWAYS_INLINE __attribute__ ((__always_inline__)) #else -# define _GL_ATTRIBUTE_PURE /* empty */ +# define _GL_ATTRIBUTE_ALWAYS_INLINE #endif -/* The __const__ attribute was added in gcc 2.95. */ -#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 95) +#if _GL_HAS_ATTRIBUTE (artificial) +# define _GL_ATTRIBUTE_ARTIFICIAL __attribute__ ((__artificial__)) +#else +# define _GL_ATTRIBUTE_ARTIFICIAL +#endif + +/* Avoid __attribute__ ((cold)) on MinGW; see thread starting at + <https://lists.gnu.org/r/emacs-devel/2019-04/msg01152.html>. */ +#if _GL_HAS_ATTRIBUTE (cold) && !defined __MINGW32__ +# define _GL_ATTRIBUTE_COLD __attribute__ ((cold)) +#else +# define _GL_ATTRIBUTE_COLD +#endif + +#if _GL_HAS_ATTRIBUTE (const) # define _GL_ATTRIBUTE_CONST __attribute__ ((__const__)) #else -# define _GL_ATTRIBUTE_CONST /* empty */ +# define _GL_ATTRIBUTE_CONST +#endif + +#if 201710L < __STDC_VERSION__ +# define _GL_ATTRIBUTE_DEPRECATED [[__deprecated__]] +#elif _GL_HAS_ATTRIBUTE (deprecated) +# define _GL_ATTRIBUTE_DEPRECATED __attribute__ ((__deprecated__)) +#else +# define _GL_ATTRIBUTE_DEPRECATED +#endif + +#if _GL_HAS_ATTRIBUTE (error) +# define _GL_ATTRIBUTE_ERROR(msg) __attribute__((__error__ (msg))) +# define _GL_ATTRIBUTE_WARNING(msg) __attribute__((__warning__ (msg))) +#else +# define _GL_ATTRIBUTE_ERROR(msg) +# define _GL_ATTRIBUTE_WARNING(msg) +#endif + +#if _GL_HAS_ATTRIBUTE (externally_visible) +# define _GL_ATTRIBUTE_EXTERNALLY_VISIBLE __attribute__ ((externally_visible)) +#else +# define _GL_ATTRIBUTE_EXTERNALLY_VISIBLE +#endif + +/* FALLTHROUGH is special, because it always expands to something. */ +#if 201710L < __STDC_VERSION__ +# define _GL_ATTRIBUTE_FALLTHROUGH [[__fallthrough__]] +#elif _GL_HAS_ATTRIBUTE (fallthrough) +# define _GL_ATTRIBUTE_FALLTHROUGH __attribute__ ((__fallthrough__)) +#else +# define _GL_ATTRIBUTE_FALLTHROUGH ((void) 0) +#endif + +#if _GL_HAS_ATTRIBUTE (format) +# define _GL_ATTRIBUTE_FORMAT(spec) __attribute__ ((__format__ spec)) +#else +# define _GL_ATTRIBUTE_FORMAT(spec) +#endif + +#if _GL_HAS_ATTRIBUTE (leaf) +# define _GL_ATTRIBUTE_LEAF __attribute__ ((__leaf__)) +#else +# define _GL_ATTRIBUTE_LEAF +#endif + +#if _GL_HAS_ATTRIBUTE (may_alias) +# define _GL_ATTRIBUTE_MAY_ALIAS __attribute__ ((__may_alias__)) +#else +# define _GL_ATTRIBUTE_MAY_ALIAS #endif -/* The __malloc__ attribute was added in gcc 3. */ -#if 3 <= __GNUC__ +#if 201710L < __STDC_VERSION__ +# define _GL_ATTRIBUTE_MAYBE_UNUSED [[__maybe_unused__]] +#elif _GL_HAS_ATTRIBUTE (unused) +# define _GL_ATTRIBUTE_MAYBE_UNUSED __attribute__ ((__unused__)) +#else +# define _GL_ATTRIBUTE_MAYBE_UNUSED +#endif +/* Earlier spellings of this macro. */ +#define _GL_UNUSED _GL_ATTRIBUTE_MAYBE_UNUSED +#define _UNUSED_PARAMETER_ _GL_ATTRIBUTE_MAYBE_UNUSED + +#if _GL_HAS_ATTRIBUTE (malloc) # define _GL_ATTRIBUTE_MALLOC __attribute__ ((__malloc__)) #else -# define _GL_ATTRIBUTE_MALLOC /* empty */ +# define _GL_ATTRIBUTE_MALLOC +#endif + +#if 201710L < __STDC_VERSION__ +# 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 +#endif + +#if _GL_HAS_ATTRIBUTE (noinline) +# define _GL_ATTRIBUTE_NOINLINE __attribute__ ((__noinline__)) +#else +# define _GL_ATTRIBUTE_NOINLINE +#endif + +#if _GL_HAS_ATTRIBUTE (nonnull) +# define _GL_ATTRIBUTE_NONNULL(args) __attribute__ ((__nonnull__ args)) +#else +# define _GL_ATTRIBUTE_NONNULL(args) +#endif + +#if _GL_HAS_ATTRIBUTE (nonstring) +# define _GL_ATTRIBUTE_NONSTRING __attribute__ ((__nonstring__)) +#else +# define _GL_ATTRIBUTE_NONSTRING +#endif + +/* There is no _GL_ATTRIBUTE_NORETURN; use _Noreturn instead. */ + +#if _GL_HAS_ATTRIBUTE (nothrow) && !defined __cplusplus +# define _GL_ATTRIBUTE_NOTHROW __attribute__ ((__nothrow__)) +#else +# define _GL_ATTRIBUTE_NOTHROW +#endif + +#if _GL_HAS_ATTRIBUTE (packed) +# define _GL_ATTRIBUTE_PACKED __attribute__ ((__packed__)) +#else +# define _GL_ATTRIBUTE_PACKED +#endif + +#if _GL_HAS_ATTRIBUTE (pure) +# define _GL_ATTRIBUTE_PURE __attribute__ ((__pure__)) +#else +# define _GL_ATTRIBUTE_PURE +#endif + +#if _GL_HAS_ATTRIBUTE (sentinel) +# define _GL_ATTRIBUTE_SENTINEL(pos) __attribute__ ((__sentinel__ pos)) +#else +# define _GL_ATTRIBUTE_SENTINEL(pos) +#endif + +]dnl There is no _GL_ATTRIBUTE_VISIBILITY; see m4/visibility.m4 instead. +[ +/* To support C++ as well as C, use _GL_UNUSED_LABEL with trailing ';'. */ +#if !defined __cplusplus || _GL_GNUC_PREREQ (4, 5) +# define _GL_UNUSED_LABEL _GL_ATTRIBUTE_MAYBE_UNUSED +#else +# define _GL_UNUSED_LABEL #endif ]) AH_VERBATIM([async_safe], |