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 [/* 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, as
  23    Libc at least through Libc-825.26 (2013-04-09) mishandles it; see, e.g.,
  24    <http://lists.gnu.org/archive/html/bug-gnulib/2012-12/msg00023.html>.
  25    Perhaps Apple will fix this some day.  */
  26 #if (defined __APPLE__ \
  27      && ((! defined _DONT_USE_CTYPE_INLINE_ \
  28           && (defined __GNUC__ || defined __cplusplus)) \
  29          || (defined _FORTIFY_SOURCE && 0 < _FORTIFY_SOURCE \
  30              && defined __GNUC__ && ! defined __cplusplus)))
  31 # define _GL_EXTERN_INLINE_APPLE_BUG
  32 #endif
  33 #if ((__GNUC__ \
  34       ? defined __GNUC_STDC_INLINE__ && __GNUC_STDC_INLINE__ \
  35       : (199901L <= __STDC_VERSION__ \
  36          && !defined __HP_cc \
  37          && !(defined __SUNPRO_C && __STDC__))) \
  38      && !defined _GL_EXTERN_INLINE_APPLE_BUG)
  39 # define _GL_INLINE inline
  40 # define _GL_EXTERN_INLINE extern inline
  41 # define _GL_EXTERN_INLINE_IN_USE
  42 #elif (2 < __GNUC__ + (7 <= __GNUC_MINOR__) && !defined __STRICT_ANSI__ \
  43        && !defined _GL_EXTERN_INLINE_APPLE_BUG)
  44 # if __GNUC_GNU_INLINE__
  45    /* __gnu_inline__ suppresses a GCC 4.2 diagnostic.  */
  46 #  define _GL_INLINE extern inline __attribute__ ((__gnu_inline__))
  47 # else
  48 #  define _GL_INLINE extern inline
  49 # endif
  50 # define _GL_EXTERN_INLINE extern
  51 # define _GL_EXTERN_INLINE_IN_USE
  52 #else
  53 # define _GL_INLINE static _GL_UNUSED
  54 # define _GL_EXTERN_INLINE static _GL_UNUSED
  55 #endif
  56
  57 #if 4 < __GNUC__ + (6 <= __GNUC_MINOR__)
  58 # if defined __GNUC_STDC_INLINE__ && __GNUC_STDC_INLINE__
  59 #  define _GL_INLINE_HEADER_CONST_PRAGMA
  60 # else
  61 #  define _GL_INLINE_HEADER_CONST_PRAGMA \
  62      _Pragma ("GCC diagnostic ignored \"-Wsuggest-attribute=const\"")
  63 # endif
  64   /* Suppress GCC's bogus "no previous prototype for 'FOO'"
  65      and "no previous declaration for 'FOO'"  diagnostics,
  66      when FOO is an inline function in the header; see
  67      <http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54113>.  */
  68 # define _GL_INLINE_HEADER_BEGIN \
  69     _Pragma ("GCC diagnostic push") \
  70     _Pragma ("GCC diagnostic ignored \"-Wmissing-prototypes\"") \
  71     _Pragma ("GCC diagnostic ignored \"-Wmissing-declarations\"") \
  72     _GL_INLINE_HEADER_CONST_PRAGMA
  73 # define _GL_INLINE_HEADER_END \
  74     _Pragma ("GCC diagnostic pop")
  75 #else
  76 # define _GL_INLINE_HEADER_BEGIN
  77 # define _GL_INLINE_HEADER_END
  78 #endif])
  79 ])