1dnl 'extern inline' a la ISO C99.
2
3dnl Copyright 2012-2014 Free Software Foundation, Inc.
4dnl This file is free software; the Free Software Foundation
5dnl gives unlimited permission to copy and/or distribute it,
6dnl with or without modifications, as long as this notice is preserved.
7
8AC_DEFUN([gl_EXTERN_INLINE],
9[
10  AH_VERBATIM([extern_inline],
11[/* Please see the Gnulib manual for how to use these macros.
12
13   Suppress extern inline with HP-UX cc, as it appears to be broken; see
14   <http://lists.gnu.org/archive/html/bug-texinfo/2013-02/msg00030.html>.
15
16   Suppress extern inline with Sun C in standards-conformance mode, as it
17   mishandles inline functions that call each other.  E.g., for 'inline void f
18   (void) { } inline void g (void) { f (); }', c99 incorrectly complains
19   'reference to static identifier "f" in extern inline function'.
20   This bug was observed with Sun C 5.12 SunOS_i386 2011/11/16.
21
22   Suppress the use of extern inline on problematic Apple configurations.
23   OS X 10.8 and earlier mishandle it; see, e.g.,
24   <http://lists.gnu.org/archive/html/bug-gnulib/2012-12/msg00023.html>.
25   OS X 10.9 has a macro __header_inline indicating the bug is fixed for C and
26   for clang but remains for g++; see <http://trac.macports.org/ticket/41033>.
27   Perhaps Apple will fix this some day.  */
28#if (defined __APPLE__ \
29     && (defined __header_inline \
30         ? (defined __cplusplus && defined __GNUC_STDC_INLINE__ \
31            && ! defined __clang__) \
32         : ((! defined _DONT_USE_CTYPE_INLINE_ \
33             && (defined __GNUC__ || defined __cplusplus)) \
34            || (defined _FORTIFY_SOURCE && 0 < _FORTIFY_SOURCE \
35                && defined __GNUC__ && ! defined __cplusplus))))
36# define _GL_EXTERN_INLINE_APPLE_BUG
37#endif
38#if ((__GNUC__ \
39      ? defined __GNUC_STDC_INLINE__ && __GNUC_STDC_INLINE__ \
40      : (199901L <= __STDC_VERSION__ \
41         && !defined __HP_cc \
42         && !(defined __SUNPRO_C && __STDC__))) \
43     && !defined _GL_EXTERN_INLINE_APPLE_BUG)
44# define _GL_INLINE inline
45# define _GL_EXTERN_INLINE extern inline
46# define _GL_EXTERN_INLINE_IN_USE
47#elif (2 < __GNUC__ + (7 <= __GNUC_MINOR__) && !defined __STRICT_ANSI__ \
48       && !defined _GL_EXTERN_INLINE_APPLE_BUG)
49# if defined __GNUC_GNU_INLINE__ && __GNUC_GNU_INLINE__
50   /* __gnu_inline__ suppresses a GCC 4.2 diagnostic.  */
51#  define _GL_INLINE extern inline __attribute__ ((__gnu_inline__))
52# else
53#  define _GL_INLINE extern inline
54# endif
55# define _GL_EXTERN_INLINE extern
56# define _GL_EXTERN_INLINE_IN_USE
57#else
58# define _GL_INLINE static _GL_UNUSED
59# define _GL_EXTERN_INLINE static _GL_UNUSED
60#endif
61
62#if 4 < __GNUC__ + (6 <= __GNUC_MINOR__)
63# if defined __GNUC_STDC_INLINE__ && __GNUC_STDC_INLINE__
64#  define _GL_INLINE_HEADER_CONST_PRAGMA
65# else
66#  define _GL_INLINE_HEADER_CONST_PRAGMA \
67     _Pragma ("GCC diagnostic ignored \"-Wsuggest-attribute=const\"")
68# endif
69  /* Suppress GCC's bogus "no previous prototype for 'FOO'"
70     and "no previous declaration for 'FOO'"  diagnostics,
71     when FOO is an inline function in the header; see
72     <http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54113>.  */
73# define _GL_INLINE_HEADER_BEGIN \
74    _Pragma ("GCC diagnostic push") \
75    _Pragma ("GCC diagnostic ignored \"-Wmissing-prototypes\"") \
76    _Pragma ("GCC diagnostic ignored \"-Wmissing-declarations\"") \
77    _GL_INLINE_HEADER_CONST_PRAGMA
78# define _GL_INLINE_HEADER_END \
79    _Pragma ("GCC diagnostic pop")
80#else
81# define _GL_INLINE_HEADER_BEGIN
82# define _GL_INLINE_HEADER_END
83#endif])
84])
85