freebsd-dev/contrib/gcclibs/include/symcat.h
2007-05-19 01:27:20 +00:00

50 lines
1.9 KiB
C

/* Symbol concatenation utilities.
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
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */
#ifndef SYM_CAT_H
#define SYM_CAT_H
#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) "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 */