Update the address and phone number of the FSF organization.

[pf3gnuchains/gcc-fork.git] / include / symcat.h

diff --git a/include/symcat.h b/include/symcat.h
index 3e27162..03a1292 100644 (file)
--- a/include/symcat.h
+++ b/include/symcat.h
@@ -14,17 +14,21 @@
  
    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.,
-   59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+   51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.  */
 
 #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
@@ -35,6 +39,11 @@
 #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 */