extern-inline: make safe for -Wundef usage

[gnulib.git] / m4 / extern-inline.m4

diff --git a/m4/extern-inline.m4 b/m4/extern-inline.m4
index 4e801e3..e4454d8 100644 (file)
--- a/m4/extern-inline.m4
+++ b/m4/extern-inline.m4
@@ -1,3 +1,4 @@
+# extern-inline.m4 serial 2
 dnl 'extern inline' a la ISO C99.
 
 dnl Copyright 2012-2013 Free Software Foundation, Inc.
@@ -19,26 +20,36 @@ AC_DEFUN([gl_EXTERN_INLINE],
    'reference to static identifier "f" in extern inline function'.
    This bug was observed with Sun C 5.12 SunOS_i386 2011/11/16.
 
-   Suppress the use of extern inline on Apple's platforms, as Libc at least
-   through Libc-825.26 (2013-04-09) is incompatible with it; see, e.g.,
+   Suppress the use of extern inline on problematic Apple configurations, as
+   Libc at least through Libc-825.26 (2013-04-09) mishandles it; see, e.g.,
    <http://lists.gnu.org/archive/html/bug-gnulib/2012-12/msg00023.html>.
    Perhaps Apple will fix this some day.  */
+#if (defined __APPLE__ \
+     && ((! defined _DONT_USE_CTYPE_INLINE_ \
+          && (defined __GNUC__ || defined __cplusplus)) \
+         || (defined _FORTIFY_SOURCE && 0 < _FORTIFY_SOURCE \
+             && defined __GNUC__ && ! defined __cplusplus)))
+# define _GL_EXTERN_INLINE_APPLE_BUG
+#endif
 #if ((__GNUC__ \
       ? defined __GNUC_STDC_INLINE__ && __GNUC_STDC_INLINE__ \
       : (199901L <= __STDC_VERSION__ \
          && !defined __HP_cc \
          && !(defined __SUNPRO_C && __STDC__))) \
-     && !defined __APPLE__)
+     && !defined _GL_EXTERN_INLINE_APPLE_BUG)
 # define _GL_INLINE inline
 # define _GL_EXTERN_INLINE extern inline
-#elif 2 < __GNUC__ + (7 <= __GNUC_MINOR__) && !defined __APPLE__
-# if __GNUC_GNU_INLINE__
+# define _GL_EXTERN_INLINE_IN_USE
+#elif (2 < __GNUC__ + (7 <= __GNUC_MINOR__) && !defined __STRICT_ANSI__ \
+       && !defined _GL_EXTERN_INLINE_APPLE_BUG)
+# if defined __GNUC_GNU_INLINE__ && __GNUC_GNU_INLINE__
    /* __gnu_inline__ suppresses a GCC 4.2 diagnostic.  */
 #  define _GL_INLINE extern inline __attribute__ ((__gnu_inline__))
 # else
 #  define _GL_INLINE extern inline
 # endif
 # define _GL_EXTERN_INLINE extern
+# define _GL_EXTERN_INLINE_IN_USE
 #else
 # define _GL_INLINE static _GL_UNUSED
 # define _GL_EXTERN_INLINE static _GL_UNUSED