Doc fix.

[gnulib.git] / lib / stdbool_.h

diff --git a/lib/stdbool_.h b/lib/stdbool_.h
index 3177ae0..efa80ba 100644 (file)
--- a/lib/stdbool_.h
+++ b/lib/stdbool_.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2001, 2002, 2003 Free Software Foundation, Inc.
+/* Copyright (C) 2001, 2002, 2003, 2006 Free Software Foundation, Inc.
    Written by Bruno Haible <haible@clisp.cons.org>, 2001.
 
    This program is free software; you can redistribute it and/or modify
@@ -70,18 +70,40 @@
    (see ISO C 99 6.7.2.2.(4)); however, '_Bool' must promote to 'int'
    (see ISO C 99 6.3.1.1.(2)).  So we add a negative value to the
    enum; this ensures that '_Bool' promotes to 'int'.  */
-#if !(defined __cplusplus || defined __BEOS__)
+#if defined __cplusplus || defined __BEOS__
+  /* A compiler known to have 'bool'.  */
+  /* If the compiler already has both 'bool' and '_Bool', we can assume they
+     are the same types.  */
 # if !@HAVE__BOOL@
-#  if defined __SUNPRO_C && (__SUNPRO_C < 0x550 || __STDC__ == 1)
-    /* Avoid stupid "warning: _Bool is a keyword in ISO C99".  */
-#   define _Bool signed char
+typedef bool _Bool;
+# endif
+#else
+# if !defined __GNUC__
+   /* If @HAVE__BOOL@:
+        Some HP-UX cc and AIX IBM C compiler versions have compiler bugs when
+        the built-in _Bool type is used.  See
+          http://gcc.gnu.org/ml/gcc-patches/2003-12/msg02303.html
+          http://lists.gnu.org/archive/html/bug-coreutils/2005-11/msg00161.html
+          http://lists.gnu.org/archive/html/bug-coreutils/2005-10/msg00086.html
+        Similar bugs are likely with other compilers as well; this file
+        wouldn't be used if <stdbool.h> was working.
+        So we override the _Bool type.
+      If !@HAVE__BOOL@:
+        Need to define _Bool ourselves. As 'signed char' or as an enum type?
+        Use of a typedef, with SunPRO C, leads to a stupid
+          "warning: _Bool is a keyword in ISO C99".
+        Use of an enum type, with IRIX cc, leads to a stupid
+          "warning(1185): enumerated type mixed with another type".
+        The only benefit of the enum type, debuggability, is not important
+        with these compilers.  So use 'signed char' and no typedef.  */
+#  define _Bool signed char
 enum { false = 0, true = 1 };
-#  else
+# else
+   /* With this compiler, trust the _Bool type if the compiler has it.  */
+#  if !@HAVE__BOOL@
 typedef enum { _Bool_must_promote_to_int = -1, false = 0, true = 1 } _Bool;
 #  endif
 # endif
-#else
-typedef bool _Bool;
 #endif
 #define bool _Bool