X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Fstdbool.m4;h=57c804a80ff7da006714ce54b11da37c58557faa;hb=0443c2f39943017f0aaa0afacbf68fb725858963;hp=f37f27b97332e8fe2d5f1d91296639de3410cd8e;hpb=5ddfb9fbf947533efc2bf7ea764c8e9f93348ab3;p=gnulib.git

diff --git a/m4/stdbool.m4 b/m4/stdbool.m4
index f37f27b97..57c804a80 100644
--- a/m4/stdbool.m4
+++ b/m4/stdbool.m4
@@ -1,6 +1,6 @@
 # Check for stdbool.h that conforms to C99.
 
-dnl Copyright (C) 2002-2006 Free Software Foundation, Inc.
+dnl Copyright (C) 2002-2006, 2009 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
@@ -64,9 +64,9 @@ AC_DEFUN([AC_HEADER_STDBOOL],
 	  char a[true == 1 ? 1 : -1];
 	  char b[false == 0 ? 1 : -1];
 	  char c[__bool_true_false_are_defined == 1 ? 1 : -1];
-	  char d[(bool) -0.5 == true ? 1 : -1];
+	  char d[(bool) 0.5 == true ? 1 : -1];
 	  bool e = &s;
-	  char f[(_Bool) -0.0 == false ? 1 : -1];
+	  char f[(_Bool) 0.0 == false ? 1 : -1];
 	  char g[true];
 	  char h[sizeof (_Bool)];
 	  char i[sizeof s.t];
@@ -74,7 +74,7 @@ AC_DEFUN([AC_HEADER_STDBOOL],
 	  _Bool n[m];
 	  char o[sizeof n == m * sizeof n[0] ? 1 : -1];
 	  char p[-1 - (_Bool) 0 < 0 && -1 - (bool) 0 < 0 ? 1 : -1];
-	  #if defined __xlc__
+	  #if defined __xlc__ || defined __GNUC__
 	   /* Catch a bug in IBM AIX xlc compiler version 6.0.0.0
 	      reported by James Lemley on 2005-10-05; see
 	      http://lists.gnu.org/archive/html/bug-coreutils/2005-10/msg00086.html
@@ -86,7 +86,10 @@ AC_DEFUN([AC_HEADER_STDBOOL],
 	      Let us hope that IBM fixes the xlc bug, and also adds
 	      support for this kind of constant expression.  In the
 	      meantime, this test will reject xlc, which is OK, since
-	      our stdbool.h substitute should suffice.  */
+	      our stdbool.h substitute should suffice.  We also test
+	      this with GCC, where it should work, to detect more
+	      quickly whether someone messes up the test in the
+	      future.  */
 	   char digs[] = "0123456789";
 	   int xlcbug = 1 / (&(digs + 5)[-2 + (bool) 1] == &digs[4] ? 1 : -1);
 	  #endif
@@ -98,13 +101,15 @@ AC_DEFUN([AC_HEADER_STDBOOL],
 	  _Bool *pq = &q;
 	],
 	[
+	  *pq |= q;
+	  *pq |= ! q;
 	  /* Refer to every declared value, to avoid compiler optimizations.  */
 	  return (!a + !b + !c + !d + !e + !f + !g + !h + !i + !!j + !k + !!l
-		  + !m + !n + !o + !p);
+		  + !m + !n + !o + !p + !q + !pq);
 	],
 	[ac_cv_header_stdbool_h=yes],
 	[ac_cv_header_stdbool_h=no])])
    AC_CHECK_TYPES([_Bool])
    if test $ac_cv_header_stdbool_h = yes; then
-     AC_DEFINE(HAVE_STDBOOL_H, 1, [Define to 1 if stdbool.h conforms to C99.])
+     AC_DEFINE([HAVE_STDBOOL_H], [1], [Define to 1 if stdbool.h conforms to C99.])
    fi])