m4/extern-inline.m4

   1 dnl 'extern inline' a la ISO C99.
   2
   3 dnl Copyright 2012-2013 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 [/* _GL_INLINE is a portable alternative to ISO C99 plain 'inline'.
  12    _GL_EXTERN_INLINE is a portable alternative to 'extern inline'.
  13    _GL_INLINE_HEADER_BEGIN contains useful stuff to put
  14      in an include file, before uses of _GL_INLINE.
  15      It suppresses GCC's bogus "no previous prototype for 'FOO'" diagnostic,
  16      when FOO is an inline function in the header; see
  17      <http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54113>.
  18    _GL_INLINE_HEADER_END contains useful stuff to put
  19      in the same include file, after uses of _GL_INLINE.
  20
  21    Suppress the use of extern inline on Apple's platforms,
  22    as Libc-825.25 (2012-09-19) is incompatible with it; see
  23    <http://lists.gnu.org/archive/html/bug-gnulib/2012-12/msg00023.html>.
  24    Perhaps Apple will fix this some day.  */
  25 #if ((__GNUC__ \
  26       ? defined __GNUC_STDC_INLINE__ && __GNUC_STDC_INLINE__ \
  27       : 199901L <= __STDC_VERSION__) \
  28      && !defined __APPLE__)
  29 # define _GL_INLINE inline
  30 # define _GL_EXTERN_INLINE extern inline
  31 #elif 2 < __GNUC__ + (7 <= __GNUC_MINOR__) && !defined __APPLE__
  32 # if __GNUC_GNU_INLINE__
  33    /* __gnu_inline__ suppresses a GCC 4.2 diagnostic.  */
  34 #  define _GL_INLINE extern inline __attribute__ ((__gnu_inline__))
  35 # else
  36 #  define _GL_INLINE extern inline
  37 # endif
  38 # define _GL_EXTERN_INLINE extern
  39 #else
  40 # define _GL_INLINE static _GL_UNUSED
  41 # define _GL_EXTERN_INLINE static _GL_UNUSED
  42 #endif
  43
  44 #if 4 < __GNUC__ + (6 <= __GNUC_MINOR__)
  45 # if defined __GNUC_STDC_INLINE__ && __GNUC_STDC_INLINE__
  46 #  define _GL_INLINE_HEADER_CONST_PRAGMA
  47 # else
  48 #  define _GL_INLINE_HEADER_CONST_PRAGMA \
  49      _Pragma ("GCC diagnostic ignored \"-Wsuggest-attribute=const\"")
  50 # endif
  51 # define _GL_INLINE_HEADER_BEGIN \
  52     _Pragma ("GCC diagnostic push") \
  53     _Pragma ("GCC diagnostic ignored \"-Wmissing-prototypes\"") \
  54     _Pragma ("GCC diagnostic ignored \"-Wmissing-declarations\"") \
  55     _GL_INLINE_HEADER_CONST_PRAGMA
  56 # define _GL_INLINE_HEADER_END \
  57     _Pragma ("GCC diagnostic pop")
  58 #else
  59 # define _GL_INLINE_HEADER_BEGIN
  60 # define _GL_INLINE_HEADER_END
  61 #endif])
  62 ])