Today's CVS preprocessor ICE.

[Zack Weinberg]

On Fri, May 19, 2000 at 11:18:15AM +0200, Mathias Froehlich wrote:
> 
> Hi GCC Team,
> 
> I have the today's (19.5.2000) CVS snapshot of gcc installed.
> Usung this Compiler I have got an ICE in the preprocessor compiling
> this short file: 
> 
> ---------------------------------------------------------
> #define foo
> 
> #define __CAT__(a,b,c,d) a##b##c##d
> #define CAT(a,b,c,d) __CAT__(a,b,c,d)
> 
> #define bar CAT(,foo,bar,)
> bar
> ---------------------------------------------------------

This bug has been there since forever.  I am testing the appended
patch.  With it applied I get simply

bar

as the preprocessed version of the file.  Is that what you expected?

zw

	* cpphash.c (funlike_macroexpand): Make sure not to walk p1
	past l1 when deleting whitespace and markers.

===================================================================
Index: cpphash.c
--- cpphash.c	2000/05/18 15:55:45	1.90
+++ cpphash.c	2000/05/19 16:29:06
@@ -1578,7 +1578,7 @@ funlike_macroexpand (pfile, hp, args)
 	    {
 	      /* Arg is concatenated before: delete leading whitespace,
 		 whitespace markers, and no-reexpansion markers.  */
-	      while (p1 != l1)
+	      while (p1 < l1)
 		{
 		  if (is_space(p1[0]))
 		    p1++;
@@ -1592,7 +1592,7 @@ funlike_macroexpand (pfile, hp, args)
 	    {
 	      /* Arg is concatenated after: delete trailing whitespace,
 		 whitespace markers, and no-reexpansion markers.  */
-	      while (p1 != l1)
+	      while (p1 < l1)
 		{
 		  if (is_space(l1[-1]))
 		    l1--;
@@ -1612,7 +1612,7 @@ funlike_macroexpand (pfile, hp, args)
 
 	  /* Delete any no-reexpansion marker that precedes
 	     an identifier at the beginning of the argument. */
-	  if (p1[0] == '\r' && p1[1] == '-')
+	  if (p1 + 2 <= l1 && p1[0] == '\r' && p1[1] == '-')
 	    p1 += 2;
 
 	  memcpy (xbuf + totlen, p1, l1 - p1);