m4/extern-inline.m4

   1 dnl 'extern inline' a la ISO C99.
   2
   3 dnl Copyright 2012-2014 Free Software Foundation, Inc.
   4 dnl This file is free software; the Free Software Foundation
   5 dnl gives unlimited permission to copy and/or distribute it,
   6 dnl with or without modifications, as long as this notice is preserved.
   7
   8 AC_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 ])