cp-tree.h (TYPE_RAISES_EXCEPTIONS): Improve documentation.

1998-12-22  Mark Mitchell  <mark@markmitchell.com>
	* cp-tree.h (TYPE_RAISES_EXCEPTIONS): Improve documentation.
	* tree.c (build_exception_variant): Don't crash on empty throw
	specs.

From-SVN: r24394

gcc/cp/ChangeLog

+1998-12-22  Mark Mitchell  <mark@markmitchell.com>
+
+	* cp-tree.h (TYPE_RAISES_EXCEPTIONS): Improve documentation.
+	* tree.c (build_exception_variant): Don't crash on empty throw
+	specs. 
+
 1998-12-18  DJ Delorie  <dj@cygnus.com>
 
 	* cvt.c (convert_to_reference): Check for both error_mark_node

gcc/cp/cp-tree.h

@@ -1143,7 +1143,9 @@ struct lang_type
 #define TREE_PARMLIST(NODE) ((NODE)->common.unsigned_flag) /* overloaded! */
 
 /* For FUNCTION_TYPE or METHOD_TYPE, a list of the exceptions that
-   this type can raise.  */
+   this type can raise.  Each TREE_VALUE is a _TYPE.  The TREE_VALUE
+   will be NULL_TREE to indicate a throw specification of `(...)', or,
+   equivalently, no throw specification.  */
 #define TYPE_RAISES_EXCEPTIONS(NODE) TYPE_NONCOPIED_PARTS (NODE)
 
 /* The binding level associated with the namespace.  */

gcc/cp/tree.c

@@ -1476,7 +1476,9 @@ build_exception_variant (type, raises)
       for (t = TYPE_RAISES_EXCEPTIONS (v), u = raises;
 	   t != NULL_TREE && u != NULL_TREE;
 	   t = TREE_CHAIN (t), u = TREE_CHAIN (v))
-	if (!same_type_p (TREE_VALUE (t), TREE_VALUE (u)))
+	if (((TREE_VALUE (t) != NULL_TREE) 
+	     != (TREE_VALUE (u) != NULL_TREE))
+	    || !same_type_p (TREE_VALUE (t), TREE_VALUE (u)))
 	  break;
 
       if (!t && !u)

gcc/testsuite/g++.old-deja/g++.eh/spec5.C

+// Build don't link:
+
+extern void *f(unsigned int k) throw();