patch for overzealous standard conformance / mangling .S files

[Zack Weinberg <zack at wolery dot cumb dot org>]

cpp would issue a hard error for # not followed by a macro argument
name in function-like macros.  That caused problems with preprocessing
assembly language on some platforms; e.g. on MIPS, # may be needed to
introduce an integer literal.

This patch downgrades the error to a pedwarn, shuts it off entirely
when we're preprocessing assembly, and preserves the # in the output.
You'll need a patch to the testsuite drivers for 20000510-1.S to be
recognized - see "RFA: testsuite change" which appeared earlier today
(um, yesterday now).  The patch is in CVS.

Bootstrapped on i386-linux, as usual.

zw

	* cpphash.c (collect_funlike_expansion): Make "# is not
	followed by a macro argument name" a pedwarn, not an error.
	Preserve the # in the output.  Suppress the warning if lang_asm.

===================================================================
Index: cpphash.c
--- cpphash.c	2000/05/10 19:11:02	1.87
+++ cpphash.c	2000/05/11 08:41:28
@@ -639,7 +639,22 @@ collect_funlike_expansion (pfile, list, 
 	default:
 	norm:
 	  if (last_token == STRIZE)
-	    cpp_error (pfile, "# is not followed by a macro argument name");
+	    {
+	      /* This is a mandatory diagnostic (6.10.3.2 para 1), but
+		 in assembly language # may have some other
+		 significance we don't know about, so suppress the
+		 warning. */
+	      if (! CPP_OPTION (pfile, lang_asm))
+		cpp_pedwarn (pfile,
+			     "# is not followed by a macro argument name");
+	      if (TOK_PREV_WHITE (list, i))
+		CPP_ADJUST_WRITTEN (pfile, -1);
+	      if (TOK_PREV_WHITE (list, i-1))
+		CPP_PUTC (pfile, ' ');
+	      CPP_PUTC (pfile, '#');
+	      if (TOK_PREV_WHITE (list, i))
+		CPP_PUTC (pfile, ' ');
+	    }
 	  CPP_PUTS (pfile, tok, len);
 	  last_token = NORM;
 	}
===================================================================
Index: testsuite/gcc.dg/20000510-1.S
--- testsuite/gcc.dg/20000510-1.S	Tue May  5 13:32:27 1998
+++ testsuite/gcc.dg/20000510-1.S	Thu May 11 01:41:28 2000
@@ -0,0 +1,20 @@
+/* Regression test - in assembly language, # may have some significance
+   other than 'stringize macro argument' and therefore must be preserved
+   in the output, and should not be warned about.  */
+/* { dg-do preprocess } */
+
+#define foo() mov r0, #5  /* { dg-bogus "not followed" "spurious warning" } */
+
+entry:
+	foo()
+
+/*
+   { dg-final { if ![file exists 20000510-1.i] { return }	} }
+   { dg-final { set tmp [grep 20000510-1.i # line]		} }
+   { dg-final { if {[string length $tmp] > 0} \{		} }
+   { dg-final {     pass "20000510-1.S: # preservation"		} }
+   { dg-final { \} else \{					} }
+   { dg-final {     fail "20000510-1.S: # preservation"		} }
+   { dg-final { \}						} }
+*/
+