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 extern inline (with or without __attribute__ ((__gnu_inline__)))
23   on configurations that mistakenly use 'static inline' to implement
24   functions or macros in standard C headers like <ctype.h>.  For example,
25   if isdigit is mistakenly implemented via a static inline function,
26   a program containing an extern inline function that calls isdigit
27   may not work since the C standard prohibits extern inline functions
28   from calling static functions.  This bug is known to occur on:
29
30     OS X 10.8 and earlier; see:
31     http://lists.gnu.org/archive/html/bug-gnulib/2012-12/msg00023.html
32
33     DragonFly; see
34     http://muscles.dragonflybsd.org/bulk/bleeding-edge-potential/latest-per-pkg/ah-tty-0.3.12.log
35
36     FreeBSD; see:
37     http://lists.gnu.org/archive/html/bug-gnulib/2014-07/msg00104.html
38
39   OS X 10.9 has a macro __header_inline indicating the bug is fixed for C and
40   for clang but remains for g++; see <http://trac.macports.org/ticket/41033>.
41   Assume DragonFly and FreeBSD will be similar.  */
42#if (((defined __APPLE__ && defined __MACH__) \
43      || defined __DragonFly__ || defined __FreeBSD__) \
44     && (defined __header_inline \
45         ? (defined __cplusplus && defined __GNUC_STDC_INLINE__ \
46            && ! defined __clang__) \
47         : ((! defined _DONT_USE_CTYPE_INLINE_ \
48             && (defined __GNUC__ || defined __cplusplus)) \
49            || (defined _FORTIFY_SOURCE && 0 < _FORTIFY_SOURCE \
50                && defined __GNUC__ && ! defined __cplusplus))))
51# define _GL_EXTERN_INLINE_STDHEADER_BUG
52#endif
53#if ((__GNUC__ \
54      ? defined __GNUC_STDC_INLINE__ && __GNUC_STDC_INLINE__ \
55      : (199901L <= __STDC_VERSION__ \
56         && !defined __HP_cc \
57         && !(defined __SUNPRO_C && __STDC__))) \
58     && !defined _GL_EXTERN_INLINE_STDHEADER_BUG)
59# define _GL_INLINE inline
60# define _GL_EXTERN_INLINE extern inline
61# define _GL_EXTERN_INLINE_IN_USE
62#elif (2 < __GNUC__ + (7 <= __GNUC_MINOR__) && !defined __STRICT_ANSI__ \
63       && !defined _GL_EXTERN_INLINE_STDHEADER_BUG)
64# if defined __GNUC_GNU_INLINE__ && __GNUC_GNU_INLINE__
65   /* __gnu_inline__ suppresses a GCC 4.2 diagnostic.  */
66#  define _GL_INLINE extern inline __attribute__ ((__gnu_inline__))
67# else
68#  define _GL_INLINE extern inline
69# endif
70# define _GL_EXTERN_INLINE extern
71# define _GL_EXTERN_INLINE_IN_USE
72#else
73# define _GL_INLINE static _GL_UNUSED
74# define _GL_EXTERN_INLINE static _GL_UNUSED
75#endif
76
77#if 4 < __GNUC__ + (6 <= __GNUC_MINOR__)
78# if defined __GNUC_STDC_INLINE__ && __GNUC_STDC_INLINE__
79#  define _GL_INLINE_HEADER_CONST_PRAGMA
80# else
81#  define _GL_INLINE_HEADER_CONST_PRAGMA \
82     _Pragma ("GCC diagnostic ignored \"-Wsuggest-attribute=const\"")
83# endif
84  /* Suppress GCC's bogus "no previous prototype for 'FOO'"
85     and "no previous declaration for 'FOO'"  diagnostics,
86     when FOO is an inline function in the header; see
87     <http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54113>.  */
88# define _GL_INLINE_HEADER_BEGIN \
89    _Pragma ("GCC diagnostic push") \
90    _Pragma ("GCC diagnostic ignored \"-Wmissing-prototypes\"") \
91    _Pragma ("GCC diagnostic ignored \"-Wmissing-declarations\"") \
92    _GL_INLINE_HEADER_CONST_PRAGMA
93# define _GL_INLINE_HEADER_END \
94    _Pragma ("GCC diagnostic pop")
95#else
96# define _GL_INLINE_HEADER_BEGIN
97# define _GL_INLINE_HEADER_END
98#endif])
99])
100