130 lines
5.5 KiB
Text
130 lines
5.5 KiB
Text
dnl 'extern inline' a la ISO C99.
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dnl Copyright 2012-2023 Free Software Foundation, Inc.
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dnl This file is free software; the Free Software Foundation
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dnl gives unlimited permission to copy and/or distribute it,
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dnl with or without modifications, as long as this notice is preserved.
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AC_DEFUN([gl_EXTERN_INLINE],
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[
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AC_CACHE_CHECK([whether ctype.h defines __header_inline],
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[gl_cv_have___header_inline],
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[AC_PREPROC_IFELSE(
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[AC_LANG_SOURCE([[#include <ctype.h>
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#ifndef __header_inline
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#error "<ctype.h> does not define __header_inline"
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#endif
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]])],
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[gl_cv_have___header_inline=yes],
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[gl_cv_have___header_inline=no])])
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if test "$gl_cv_have___header_inline" = yes; then
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AC_DEFINE([HAVE___HEADER_INLINE], [1],
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[Define to 1 if ctype.h defines __header_inline.])
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fi
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AH_VERBATIM([HAVE___HEADER_INLINE_1],
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[/* Please see the Gnulib manual for how to use these macros.
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Suppress extern inline with HP-UX cc, as it appears to be broken; see
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<https://lists.gnu.org/r/bug-texinfo/2013-02/msg00030.html>.
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Suppress extern inline with Sun C in standards-conformance mode, as it
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mishandles inline functions that call each other. E.g., for 'inline void f
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(void) { } inline void g (void) { f (); }', c99 incorrectly complains
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'reference to static identifier "f" in extern inline function'.
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This bug was observed with Oracle Developer Studio 12.6
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(Sun C 5.15 SunOS_sparc 2017/05/30).
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Suppress extern inline (with or without __attribute__ ((__gnu_inline__)))
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on configurations that mistakenly use 'static inline' to implement
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functions or macros in standard C headers like <ctype.h>. For example,
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if isdigit is mistakenly implemented via a static inline function,
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a program containing an extern inline function that calls isdigit
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may not work since the C standard prohibits extern inline functions
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from calling static functions (ISO C 99 section 6.7.4.(3).
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This bug is known to occur on:
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OS X 10.8 and earlier; see:
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https://lists.gnu.org/r/bug-gnulib/2012-12/msg00023.html
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DragonFly; see
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http://muscles.dragonflybsd.org/bulk/clang-master-potential/20141111_102002/logs/ah-tty-0.3.12.log
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FreeBSD; see:
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https://lists.gnu.org/r/bug-gnulib/2014-07/msg00104.html
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OS X 10.9 has a macro __header_inline indicating the bug is fixed for C and
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for clang but remains for g++; see <https://trac.macports.org/ticket/41033>.
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Assume DragonFly and FreeBSD will be similar.
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GCC 4.3 and above with -std=c99 or -std=gnu99 implements ISO C99
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inline semantics, unless -fgnu89-inline is used. It defines a macro
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__GNUC_STDC_INLINE__ to indicate this situation or a macro
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__GNUC_GNU_INLINE__ to indicate the opposite situation.
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GCC 4.2 with -std=c99 or -std=gnu99 implements the GNU C inline
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semantics but warns, unless -fgnu89-inline is used:
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warning: C99 inline functions are not supported; using GNU89
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warning: to disable this warning use -fgnu89-inline or the gnu_inline function attribute
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It defines a macro __GNUC_GNU_INLINE__ to indicate this situation.
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*/
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#if (((defined __APPLE__ && defined __MACH__) \
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|| defined __DragonFly__ || defined __FreeBSD__) \
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&& (defined HAVE___HEADER_INLINE \
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? (defined __cplusplus && defined __GNUC_STDC_INLINE__ \
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&& ! defined __clang__) \
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: ((! defined _DONT_USE_CTYPE_INLINE_ \
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&& (defined __GNUC__ || defined __cplusplus)) \
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|| (defined _FORTIFY_SOURCE && 0 < _FORTIFY_SOURCE \
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&& defined __GNUC__ && ! defined __cplusplus))))
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# define _GL_EXTERN_INLINE_STDHEADER_BUG
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#endif
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#if ((__GNUC__ \
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? defined __GNUC_STDC_INLINE__ && __GNUC_STDC_INLINE__ \
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: (199901L <= __STDC_VERSION__ \
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&& !defined __HP_cc \
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&& !defined __PGI \
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&& !(defined __SUNPRO_C && __STDC__))) \
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&& !defined _GL_EXTERN_INLINE_STDHEADER_BUG)
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# define _GL_INLINE inline
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# define _GL_EXTERN_INLINE extern inline
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# define _GL_EXTERN_INLINE_IN_USE
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#elif (2 < __GNUC__ + (7 <= __GNUC_MINOR__) && !defined __STRICT_ANSI__ \
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&& !defined _GL_EXTERN_INLINE_STDHEADER_BUG)
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# if defined __GNUC_GNU_INLINE__ && __GNUC_GNU_INLINE__
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/* __gnu_inline__ suppresses a GCC 4.2 diagnostic. */
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# define _GL_INLINE extern inline __attribute__ ((__gnu_inline__))
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# else
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# define _GL_INLINE extern inline
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# endif
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# define _GL_EXTERN_INLINE extern
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# define _GL_EXTERN_INLINE_IN_USE
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#else
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# define _GL_INLINE _GL_UNUSED static
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# define _GL_EXTERN_INLINE _GL_UNUSED static
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#endif
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/* In GCC 4.6 (inclusive) to 5.1 (exclusive),
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suppress bogus "no previous prototype for 'FOO'"
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and "no previous declaration for 'FOO'" diagnostics,
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when FOO is an inline function in the header; see
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<https://gcc.gnu.org/bugzilla/show_bug.cgi?id=54113> and
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<https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63877>. */
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#if __GNUC__ == 4 && 6 <= __GNUC_MINOR__
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# if defined __GNUC_STDC_INLINE__ && __GNUC_STDC_INLINE__
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# define _GL_INLINE_HEADER_CONST_PRAGMA
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# else
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# define _GL_INLINE_HEADER_CONST_PRAGMA \
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_Pragma ("GCC diagnostic ignored \"-Wsuggest-attribute=const\"")
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# endif
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# define _GL_INLINE_HEADER_BEGIN \
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_Pragma ("GCC diagnostic push") \
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_Pragma ("GCC diagnostic ignored \"-Wmissing-prototypes\"") \
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_Pragma ("GCC diagnostic ignored \"-Wmissing-declarations\"") \
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_GL_INLINE_HEADER_CONST_PRAGMA
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# define _GL_INLINE_HEADER_END \
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_Pragma ("GCC diagnostic pop")
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#else
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# define _GL_INLINE_HEADER_BEGIN
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# define _GL_INLINE_HEADER_END
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#endif])
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])
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