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      1 /* Symbol concatenation utilities.
      2 
      3    Copyright (C) 1998, 2000 Free Software Foundation, Inc.
      4 
      5    This program is free software; you can redistribute it and/or modify
      6    it under the terms of the GNU General Public License as published by
      7    the Free Software Foundation; either version 2 of the License, or
      8    (at your option) any later version.
      9 
     10    This program is distributed in the hope that it will be useful,
     11    but WITHOUT ANY WARRANTY; without even the implied warranty of
     12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     13    GNU General Public License for more details.
     14 
     15    You should have received a copy of the GNU General Public License along
     16    with this program; if not, write to the Free Software Foundation, Inc.,
     17    51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.  */
     18 
     19 #ifndef SYM_CAT_H
     20 #define SYM_CAT_H
     21 
     22 #if defined (__STDC__) || defined (ALMOST_STDC) || defined (HAVE_STRINGIZE)
     23 #define CONCAT2(a,b)	 a##b
     24 #define CONCAT3(a,b,c)	 a##b##c
     25 #define CONCAT4(a,b,c,d) a##b##c##d
     26 #define STRINGX(s) #s
     27 #else
     28 /* Note one should never pass extra whitespace to the CONCATn macros,
     29    e.g. CONCAT2(foo, bar) because traditonal C will keep the space between
     30    the two labels instead of concatenating them.  Instead, make sure to
     31    write CONCAT2(foo,bar).  */
     32 #define CONCAT2(a,b)	 a/**/b
     33 #define CONCAT3(a,b,c)	 a/**/b/**/c
     34 #define CONCAT4(a,b,c,d) a/**/b/**/c/**/d
     35 #define STRINGX(s) "s"
     36 #endif
     37 
     38 #define XCONCAT2(a,b)     CONCAT2(a,b)
     39 #define XCONCAT3(a,b,c)   CONCAT3(a,b,c)
     40 #define XCONCAT4(a,b,c,d) CONCAT4(a,b,c,d)
     41 
     42 /* Note the layer of indirection here is typically used to allow
     43    stringification of the expansion of macros.  I.e. "#define foo
     44    bar", "XSTRING(foo)", to yield "bar".  Be aware that this only
     45    works for __STDC__, not for traditional C which will still resolve
     46    to "foo".  */
     47 #define XSTRING(s) STRINGX(s)
     48 
     49 #endif /* SYM_CAT_H */
     50