| dnl 'extern inline' a la ISO C99. |
| |
| dnl Copyright 2012-2021 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. |
| |
| AC_DEFUN([gl_EXTERN_INLINE], |
| [ |
| AH_VERBATIM([extern_inline], |
| [/* Please see the Gnulib manual for how to use these macros. |
| |
| Suppress extern inline with HP-UX cc, as it appears to be broken; see |
| <https://lists.gnu.org/r/bug-texinfo/2013-02/msg00030.html>. |
| |
| Suppress extern inline with Sun C in standards-conformance mode, as it |
| mishandles inline functions that call each other. E.g., for 'inline void f |
| (void) { } inline void g (void) { f (); }', c99 incorrectly complains |
| 'reference to static identifier "f" in extern inline function'. |
| This bug was observed with Sun C 5.12 SunOS_i386 2011/11/16. |
| |
| Suppress extern inline (with or without __attribute__ ((__gnu_inline__))) |
| on configurations that mistakenly use 'static inline' to implement |
| functions or macros in standard C headers like <ctype.h>. For example, |
| if isdigit is mistakenly implemented via a static inline function, |
| a program containing an extern inline function that calls isdigit |
| may not work since the C standard prohibits extern inline functions |
| from calling static functions (ISO C 99 section 6.7.4.(3). |
| This bug is known to occur on: |
| |
| OS X 10.8 and earlier; see: |
| https://lists.gnu.org/r/bug-gnulib/2012-12/msg00023.html |
| |
| DragonFly; see |
| http://muscles.dragonflybsd.org/bulk/clang-master-potential/20141111_102002/logs/ah-tty-0.3.12.log |
| |
| FreeBSD; see: |
| https://lists.gnu.org/r/bug-gnulib/2014-07/msg00104.html |
| |
| OS X 10.9 has a macro __header_inline indicating the bug is fixed for C and |
| for clang but remains for g++; see <https://trac.macports.org/ticket/41033>. |
| Assume DragonFly and FreeBSD will be similar. |
| |
| GCC 4.3 and above with -std=c99 or -std=gnu99 implements ISO C99 |
| inline semantics, unless -fgnu89-inline is used. It defines a macro |
| __GNUC_STDC_INLINE__ to indicate this situation or a macro |
| __GNUC_GNU_INLINE__ to indicate the opposite situation. |
| GCC 4.2 with -std=c99 or -std=gnu99 implements the GNU C inline |
| semantics but warns, unless -fgnu89-inline is used: |
| warning: C99 inline functions are not supported; using GNU89 |
| warning: to disable this warning use -fgnu89-inline or the gnu_inline function attribute |
| It defines a macro __GNUC_GNU_INLINE__ to indicate this situation. |
| */ |
| #if (((defined __APPLE__ && defined __MACH__) \ |
| || defined __DragonFly__ || defined __FreeBSD__) \ |
| && (defined __header_inline \ |
| ? (defined __cplusplus && defined __GNUC_STDC_INLINE__ \ |
| && ! defined __clang__) \ |
| : ((! defined _DONT_USE_CTYPE_INLINE_ \ |
| && (defined __GNUC__ || defined __cplusplus)) \ |
| || (defined _FORTIFY_SOURCE && 0 < _FORTIFY_SOURCE \ |
| && defined __GNUC__ && ! defined __cplusplus)))) |
| # define _GL_EXTERN_INLINE_STDHEADER_BUG |
| #endif |
| #if ((__GNUC__ \ |
| ? defined __GNUC_STDC_INLINE__ && __GNUC_STDC_INLINE__ \ |
| : (199901L <= __STDC_VERSION__ \ |
| && !defined __HP_cc \ |
| && !defined __PGI \ |
| && !(defined __SUNPRO_C && __STDC__))) \ |
| && !defined _GL_EXTERN_INLINE_STDHEADER_BUG) |
| # define _GL_INLINE inline |
| # define _GL_EXTERN_INLINE extern inline |
| # define _GL_EXTERN_INLINE_IN_USE |
| #elif (2 < __GNUC__ + (7 <= __GNUC_MINOR__) && !defined __STRICT_ANSI__ \ |
| && !defined _GL_EXTERN_INLINE_STDHEADER_BUG) |
| # if defined __GNUC_GNU_INLINE__ && __GNUC_GNU_INLINE__ |
| /* __gnu_inline__ suppresses a GCC 4.2 diagnostic. */ |
| # define _GL_INLINE extern inline __attribute__ ((__gnu_inline__)) |
| # else |
| # define _GL_INLINE extern inline |
| # endif |
| # define _GL_EXTERN_INLINE extern |
| # define _GL_EXTERN_INLINE_IN_USE |
| #else |
| # define _GL_INLINE static _GL_UNUSED |
| # define _GL_EXTERN_INLINE static _GL_UNUSED |
| #endif |
| |
| /* In GCC 4.6 (inclusive) to 5.1 (exclusive), |
| suppress bogus "no previous prototype for 'FOO'" |
| and "no previous declaration for 'FOO'" diagnostics, |
| when FOO is an inline function in the header; see |
| <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=54113> and |
| <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63877>. */ |
| #if __GNUC__ == 4 && 6 <= __GNUC_MINOR__ |
| # if defined __GNUC_STDC_INLINE__ && __GNUC_STDC_INLINE__ |
| # define _GL_INLINE_HEADER_CONST_PRAGMA |
| # else |
| # define _GL_INLINE_HEADER_CONST_PRAGMA \ |
| _Pragma ("GCC diagnostic ignored \"-Wsuggest-attribute=const\"") |
| # endif |
| # define _GL_INLINE_HEADER_BEGIN \ |
| _Pragma ("GCC diagnostic push") \ |
| _Pragma ("GCC diagnostic ignored \"-Wmissing-prototypes\"") \ |
| _Pragma ("GCC diagnostic ignored \"-Wmissing-declarations\"") \ |
| _GL_INLINE_HEADER_CONST_PRAGMA |
| # define _GL_INLINE_HEADER_END \ |
| _Pragma ("GCC diagnostic pop") |
| #else |
| # define _GL_INLINE_HEADER_BEGIN |
| # define _GL_INLINE_HEADER_END |
| #endif]) |
| ]) |