/* Symbol concatenation utilities.
- Copyright (C) 1998, Free Software Foundation, Inc.
+ Copyright (C) 1998, 2000 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
#ifndef SYM_CAT_H
#define SYM_CAT_H
-#if defined (__STDC__) || defined (ALMOST_STDC)
+#if defined (__STDC__) || defined (ALMOST_STDC) || defined (HAVE_STRINGIZE)
#define CONCAT2(a,b) a##b
#define CONCAT3(a,b,c) a##b##c
#define CONCAT4(a,b,c,d) a##b##c##d
#define STRINGX(s) #s
#else
+/* Note one should never pass extra whitespace to the CONCATn macros,
+ e.g. CONCAT2(foo, bar) because traditonal C will keep the space between
+ the two labels instead of concatenating them. Instead, make sure to
+ write CONCAT2(foo,bar). */
#define CONCAT2(a,b) a/**/b
#define CONCAT3(a,b,c) a/**/b/**/c
#define CONCAT4(a,b,c,d) a/**/b/**/c/**/d
-#define STRINGX(s) "?"
+#define STRINGX(s) "s"
#endif
#define XCONCAT2(a,b) CONCAT2(a,b)
#define XCONCAT3(a,b,c) CONCAT3(a,b,c)
#define XCONCAT4(a,b,c,d) CONCAT4(a,b,c,d)
+/* Note the layer of indirection here is typically used to allow
+ stringification of the expansion of macros. I.e. "#define foo
+ bar", "XSTRING(foo)", to yield "bar". Be aware that this only
+ works for __STDC__, not for traditional C which will still resolve
+ to "foo". */
#define XSTRING(s) STRINGX(s)
-#endif SYM_CAT_H
+#endif /* SYM_CAT_H */