X-Git-Url: https://git.gag.com/?a=blobdiff_plain;f=m4%2Fextensions.m4;h=7d9458a8d65a0b085d93b695beaaa6685b824c18;hb=22f1eb8bc17e5be72dd23d42d6aaa60196ac22e6;hp=bcbb3ceee2c30bd23176dcd1e55af74185b7ec1b;hpb=138fc7e67e3d9845cd7d81aad0e9c7724784f9b9;p=debian%2Ftar

diff --git a/m4/extensions.m4 b/m4/extensions.m4
index bcbb3cee..7d9458a8 100644
--- a/m4/extensions.m4
+++ b/m4/extensions.m4
@@ -1,7 +1,7 @@
-# serial 5  -*- Autoconf -*-
+# serial 9  -*- Autoconf -*-
 # Enable extensions on systems that normally disable them.
 
-# Copyright (C) 2003, 2006, 2007 Free Software Foundation, Inc.
+# Copyright (C) 2003, 2006-2010 Free Software Foundation, Inc.
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
 # with or without modifications, as long as this notice is preserved.
@@ -12,6 +12,20 @@
 # enough in this area it's likely we'll need to redefine
 # AC_USE_SYSTEM_EXTENSIONS for quite some time.
 
+# If autoconf reports a warning
+#     warning: AC_COMPILE_IFELSE was called before AC_USE_SYSTEM_EXTENSIONS
+# or  warning: AC_RUN_IFELSE was called before AC_USE_SYSTEM_EXTENSIONS
+# the fix is
+#   1) to ensure that AC_USE_SYSTEM_EXTENSIONS is never directly invoked
+#      but always AC_REQUIREd,
+#   2) to ensure that for each occurrence of
+#        AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
+#      or
+#        AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+#      the corresponding gnulib module description has 'extensions' among
+#      its dependencies. This will ensure that the gl_USE_SYSTEM_EXTENSIONS
+#      invocation occurs in gl_EARLY, not in gl_INIT.
+
 # AC_USE_SYSTEM_EXTENSIONS
 # ------------------------
 # Enable extensions on systems that normally disable them,
@@ -20,10 +34,12 @@
 # AC_DEFINE.  The goal here is to define all known feature-enabling
 # macros, then, if reports of conflicts are made, disable macros that
 # cause problems on some platforms (such as __EXTENSIONS__).
-AC_DEFUN([AC_USE_SYSTEM_EXTENSIONS],
+AC_DEFUN_ONCE([AC_USE_SYSTEM_EXTENSIONS],
 [AC_BEFORE([$0], [AC_COMPILE_IFELSE])dnl
 AC_BEFORE([$0], [AC_RUN_IFELSE])dnl
 
+  AC_REQUIRE([AC_CANONICAL_HOST])
+
   AC_CHECK_HEADER([minix/config.h], [MINIX=yes], [MINIX=])
   if test "$MINIX" = yes; then
     AC_DEFINE([_POSIX_SOURCE], [1],
@@ -36,6 +52,16 @@ AC_BEFORE([$0], [AC_RUN_IFELSE])dnl
       [Define to 1 if on MINIX.])
   fi
 
+  dnl HP-UX 11.11 defines mbstate_t only if _XOPEN_SOURCE is defined to 500,
+  dnl regardless of whether the flags -Ae or _D_HPUX_SOURCE=1 are already
+  dnl provided.
+  case "$host_os" in
+    hpux*)
+      AC_DEFINE([_XOPEN_SOURCE], [500],
+        [Define to 500 only on HP-UX.])
+      ;;
+  esac
+
   AH_VERBATIM([__EXTENSIONS__],
 [/* Enable extensions on AIX 3, Interix.  */
 #ifndef _ALL_SOURCE
@@ -61,9 +87,9 @@ AC_BEFORE([$0], [AC_RUN_IFELSE])dnl
   AC_CACHE_CHECK([whether it is safe to define __EXTENSIONS__],
     [ac_cv_safe_to_define___extensions__],
     [AC_COMPILE_IFELSE(
-       [AC_LANG_PROGRAM([
-#	  define __EXTENSIONS__ 1
-	  AC_INCLUDES_DEFAULT])],
+       [AC_LANG_PROGRAM([[
+#         define __EXTENSIONS__ 1
+          ]AC_INCLUDES_DEFAULT])],
        [ac_cv_safe_to_define___extensions__=yes],
        [ac_cv_safe_to_define___extensions__=no])])
   test $ac_cv_safe_to_define___extensions__ = yes &&
@@ -78,5 +104,15 @@ AC_BEFORE([$0], [AC_RUN_IFELSE])dnl
 # ------------------------
 # Enable extensions on systems that normally disable them,
 # typically due to standards-conformance issues.
-AC_DEFUN([gl_USE_SYSTEM_EXTENSIONS],
-  [AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])])
+AC_DEFUN_ONCE([gl_USE_SYSTEM_EXTENSIONS],
+[
+  dnl Require this macro before AC_USE_SYSTEM_EXTENSIONS.
+  dnl gnulib does not need it. But if it gets required by third-party macros
+  dnl after AC_USE_SYSTEM_EXTENSIONS is required, autoconf 2.62..2.63 emit a
+  dnl warning: "AC_COMPILE_IFELSE was called before AC_USE_SYSTEM_EXTENSIONS".
+  dnl Note: We can do this only for one of the macros AC_AIX, AC_GNU_SOURCE,
+  dnl AC_MINIX. If people still use AC_AIX or AC_MINIX, they are out of luck.
+  AC_REQUIRE([AC_GNU_SOURCE])
+
+  AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
+])