re PR c/4294 (ICE for bad empty attribute)

	* c-common.c (split_specs_attrs): Allow for empty attributes with
	empty TREE_PURPOSE.  Fixes PR c/4294.

testsuite:
	* gcc.c-torture/compile/20010911-1.c: New test.

From-SVN: r45541

gcc/ChangeLog

+2001-09-11  Joseph S. Myers  <jsm28@cam.ac.uk>
+
+	* c-common.c (split_specs_attrs): Allow for empty attributes with
+	empty TREE_PURPOSE.  Fixes PR c/4294.
+
 Tue Sep 11 11:37:52 CEST 2001  Jan Hubicka  <jh@suse.cz>
 
 	* basic-block.h (cached_make_edge, make_single_succ): New.

gcc/c-common.c

@@ -1204,7 +1204,9 @@ split_specs_attrs (specs_attrs, declspecs, prefix_attributes)
 	      s = t;
 	    }
 	}
-      else
+      /* The TREE_PURPOSE may also be empty in the case of
+	 __attribute__(()).  */
+      else if (TREE_PURPOSE (t) != NULL_TREE)
 	{
 	  if (attrs == NULL_TREE)
 	    attrs = a = TREE_PURPOSE (t);

gcc/testsuite/ChangeLog

+2001-09-11  Joseph S. Myers  <jsm28@cam.ac.uk>
+
+	* gcc.c-torture/compile/20010911-1.c: New test.
+
 2001-09-10  Janis Johnson  <janis187@us.ibm.com>
 
 	* lib/profopt.exp: New, to support profile-directed optimizations.

gcc/testsuite/gcc.c-torture/compile/20010911-1.c

+/* Test for segfault handling an empty attribute.  */
+/* Origin: PR c/4294 from <tori@ringstrom.mine.nu>.  */
+
+void __attribute__(()) foo();