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      1 # serial 4  -*- Autoconf -*-
      2 # Enable extensions on systems that normally disable them.
      3 
      4 # Copyright (C) 2003, 2006 Free Software Foundation, Inc.
      5 # This file is free software; the Free Software Foundation
      6 # gives unlimited permission to copy and/or distribute it,
      7 # with or without modifications, as long as this notice is preserved.
      8 
      9 # This definition of AC_USE_SYSTEM_EXTENSIONS is stolen from CVS
     10 # Autoconf.  Perhaps we can remove this once we can assume Autoconf
     11 # 2.61 or later everywhere, but since CVS Autoconf mutates rapidly
     12 # enough in this area it's likely we'll need to redefine
     13 # AC_USE_SYSTEM_EXTENSIONS for quite some time.
     14 
     15 # AC_USE_SYSTEM_EXTENSIONS
     16 # ------------------------
     17 # Enable extensions on systems that normally disable them,
     18 # typically due to standards-conformance issues.
     19 AC_DEFUN([AC_USE_SYSTEM_EXTENSIONS],
     20 [
     21   AC_BEFORE([$0], [AC_COMPILE_IFELSE])
     22   AC_BEFORE([$0], [AC_RUN_IFELSE])
     23 
     24   AC_REQUIRE([AC_GNU_SOURCE])
     25   AC_REQUIRE([AC_AIX])
     26   AC_REQUIRE([AC_MINIX])
     27 
     28   AH_VERBATIM([__EXTENSIONS__],
     29 [/* Enable extensions on Solaris.  */
     30 #ifndef __EXTENSIONS__
     31 # undef __EXTENSIONS__
     32 #endif
     33 #ifndef _POSIX_PTHREAD_SEMANTICS
     34 # undef _POSIX_PTHREAD_SEMANTICS
     35 #endif
     36 #ifndef _TANDEM_SOURCE
     37 # undef _TANDEM_SOURCE
     38 #endif])
     39   AC_CACHE_CHECK([whether it is safe to define __EXTENSIONS__],
     40     [ac_cv_safe_to_define___extensions__],
     41     [AC_COMPILE_IFELSE(
     42        [AC_LANG_PROGRAM([
     43 #	  define __EXTENSIONS__ 1
     44 	  AC_INCLUDES_DEFAULT])],
     45        [ac_cv_safe_to_define___extensions__=yes],
     46        [ac_cv_safe_to_define___extensions__=no])])
     47   test $ac_cv_safe_to_define___extensions__ = yes &&
     48     AC_DEFINE([__EXTENSIONS__])
     49   AC_DEFINE([_POSIX_PTHREAD_SEMANTICS])
     50   AC_DEFINE([_TANDEM_SOURCE])
     51 ])
     52 
     53 # gl_USE_SYSTEM_EXTENSIONS
     54 # ------------------------
     55 # Enable extensions on systems that normally disable them,
     56 # typically due to standards-conformance issues.
     57 AC_DEFUN([gl_USE_SYSTEM_EXTENSIONS],
     58   [AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])])
     59