X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Fstdbool.m4;h=43fbe281543ab3716adb8c607ac92440e4047533;hb=50129386b48ab0a7d8267ea6a0f5d515a090df6c;hp=3f6b4bfcbf44e62ca8d34aa42aa8c1bf7632679f;hpb=52aceb00a8ce321a73680b2d5890de75be23f29f;p=gnulib.git

diff --git a/m4/stdbool.m4 b/m4/stdbool.m4
index 3f6b4bfcb..43fbe2815 100644
--- a/m4/stdbool.m4
+++ b/m4/stdbool.m4
@@ -1,6 +1,6 @@
 # Check for stdbool.h that conforms to C99.
 
-dnl Copyright (C) 2002-2004 Free Software Foundation, Inc.
+dnl Copyright (C) 2002-2006 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.
@@ -28,6 +28,9 @@ AC_DEFUN([AM_STDBOOL_H],
   AC_SUBST([HAVE__BOOL])
 ])
 
+# AM_STDBOOL_H will be renamed to gl_STDBOOL_H in the future.
+AC_DEFUN([gl_STDBOOL_H], [AM_STDBOOL_H])
+
 # This macro is only needed in autoconf <= 2.59.  Newer versions of autoconf
 # have this macro built-in.
 
@@ -70,10 +73,39 @@ AC_DEFUN([AC_HEADER_STDBOOL],
 	  enum { j = false, k = true, l = false * true, m = true * 256 };
 	  _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__ || 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
+	      This test is not quite right, since xlc is allowed to
+	      reject this program, as the initializer for xlcbug is
+	      not one of the forms that C requires support for.
+	      However, doing the test right would require a run-time
+	      test, and that would make cross-compilation harder.
+	      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.  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
+	  /* Catch a bug in an HP-UX C compiler.  See
+	     http://gcc.gnu.org/ml/gcc-patches/2003-12/msg02303.html
+	     http://lists.gnu.org/archive/html/bug-coreutils/2005-11/msg00161.html
+	   */
+	  _Bool q = true;
+	  _Bool *pq = &q;
 	],
 	[
-	  return (!a + !b + !c + !d + !e + !f + !g + !h + !i + !j + !k + !l
-		  + !m + !n + !o);
+	  *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 + !q + !pq);
 	],
 	[ac_cv_header_stdbool_h=yes],
 	[ac_cv_header_stdbool_h=no])])