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Re: egcs-20000403 Build Failure on SunOS 4.1.5
- To: zack at wolery dot cumb dot org
- Subject: Re: egcs-20000403 Build Failure on SunOS 4.1.5
- From: "Kaveh R. Ghazi" <ghazi at caip dot rutgers dot edu>
- Date: Tue, 4 Apr 2000 17:50:26 -0400 (EDT)
- Cc: egcs-patches at egcs dot cygnus dot com, schuld at btv dot ibm dot com
> From: Zack Weinberg <zack@wolery.cumb.org>
>
> Could you please add a comment to symcat.h explaining that CONCATn
> must not have spaces around its arguments?
> zw
How's this wording? (Also, by adding the check on the autoconf macro
HAVE_STRINGIZE, we can eliminate some of the redundant code in
system.h.)
--Kaveh
2000-04-04 Kaveh R. Ghazi <ghazi@caip.rutgers.edu>
* symcat.h: Honor HAVE_STRINGIZE. Add comments/caveats with
regard to traditional C behavior.
diff -rup ../egcs-CVS20000404/include/symcat.h egcs-CVS20000404/include/symcat.h
--- ../egcs-CVS20000404/include/symcat.h Tue Apr 4 11:26:11 2000
+++ egcs-CVS20000404/include/symcat.h Tue Apr 4 12:04:26 2000
@@ -19,12 +19,16 @@
#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 +39,10 @@
#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)". Be aware that this only works for __STDC__, not for
+ traditional C compilers. */
#define XSTRING(s) STRINGX(s)
#endif SYM_CAT_H