class.c (get_enclosing_class): New function.

* class.c (get_enclosing_class): New function.
	(is_base_of_enclosing_class): Likewise.
	* cp-tree.h (get_enclosing_class): Declare.
	(is_base_of_enclosing_class): Likewise.
	* pt.c (coerce_template_parms): Use them.
	* g++spec.c (lang_specific_driver): Check whether MATH_LIBRARY is
	null to decide whether to use it.

From-SVN: r22343

gcc/cp/ChangeLog

@@ -1,5 +1,16 @@
+1998-09-09  Kriang Lerdsuwanakij <lerdsuwa@scf-fs.usc.edu>
+
+	* class.c (get_enclosing_class): New function.
+	(is_base_of_enclosing_class): Likewise.
+	* cp-tree.h (get_enclosing_class): Declare.
+	(is_base_of_enclosing_class): Likewise.
+	* pt.c (coerce_template_parms): Use them.
+
 1998-09-09  Jason Merrill  <jason@yorick.cygnus.com>
 
+	* g++spec.c (lang_specific_driver): Check whether MATH_LIBRARY is
+	null to decide whether to use it.
+
 	* error.c (dump_type_real): Handle NAMESPACE_DECL.
 	* parse.y (base_class.1): Avoid crash on error.
 

gcc/cp/class.c

@@ -5449,3 +5449,49 @@ is_empty_class (type)
     t = TREE_CHAIN (t);
   return (t == NULL_TREE);
 }
+
+/* Find the enclosing class of the given NODE.  NODE can be a *_DECL or
+   a *_TYPE node.  NODE can also be a local class.  */
+
+tree
+get_enclosing_class (type)
+     tree type;
+{
+  tree node = type;
+
+  while (node && TREE_CODE (node) != NAMESPACE_DECL)
+    {
+      switch (TREE_CODE_CLASS (TREE_CODE (node)))
+	{
+	case 'd':
+	  node = DECL_CONTEXT (node);
+	  break;
+
+	case 't':
+	  if (node != type)
+	    return node;
+	  node = TYPE_CONTEXT (node);
+	  break;
+
+	default:
+	  my_friendly_abort (0);
+	}
+    }
+  return NULL_TREE;
+}
+
+/* Return 1 if TYPE or one of its enclosing classes is derived from BASE.  */
+
+int
+is_base_of_enclosing_class (base, type)
+     tree base, type;
+{
+  while (type)
+    {
+      if (get_binfo (base, type, 0))
+	return 1;
+
+      type = get_enclosing_class (type);
+    }
+  return 0;
+}

gcc/cp/cp-tree.h

@@ -2425,6 +2425,8 @@ extern void maybe_push_cache_obstack		PROTO((void));
 extern unsigned HOST_WIDE_INT skip_rtti_stuff	PROTO((tree *));
 extern tree build_self_reference		PROTO((void));
 extern void warn_hidden				PROTO((tree));
+extern tree get_enclosing_class			PROTO((tree));
+int is_base_of_enclosing_class			PROTO((tree, tree));
 
 /* in cvt.c */
 extern tree convert_to_reference		PROTO((tree, tree, int, int, tree));

gcc/cp/g++spec.c

@@ -34,9 +34,6 @@ Boston, MA 02111-1307, USA.  */
 #ifndef MATH_LIBRARY
 #define MATH_LIBRARY "-lm"
 #endif
-#ifndef NEED_MATH_LIBRARY
-#define NEED_MATH_LIBRARY 1	/* Default is pass MATH_LIBRARY to linker */
-#endif
 
 extern char *xmalloc PROTO((size_t));
 
@@ -83,8 +80,8 @@ lang_specific_driver (fn, in_argc, in_argv, in_added_libraries)
      LANGSPEC, MATHLIB, or WITHLIBC.  */
   int *args;
 
-  /* By default, we throw on the math library.  */
-  int need_math = NEED_MATH_LIBRARY;
+  /* By default, we throw on the math library if we have one.  */
+  int need_math = (MATH_LIBRARY[0] != '\0');
 
   /* The total number of arguments with the new stuff.  */
   int argc;
@@ -128,6 +125,7 @@ lang_specific_driver (fn, in_argc, in_argv, in_added_libraries)
 	    }
 	  else if (strcmp (argv[i], "-lm") == 0
 		   || strcmp (argv[i], "-lmath") == 0
+		   || strcmp (argv[i], MATH_LIBRARY) == 0
 #ifdef ALT_LIBM
 		   || strcmp (argv[i], ALT_LIBM) == 0
 #endif

gcc/cp/pt.c

@@ -2806,9 +2806,7 @@ convert_template_argument (parm, arg, args, complain, i, in_decl)
 	   && TREE_CODE (TYPE_NAME (arg)) == TYPE_DECL
 	   && DECL_ARTIFICIAL (TYPE_NAME (arg))
 	   && requires_tmpl_type
-	   && current_class_type
-	   /* FIXME what about nested types?  */
-	   && get_binfo (arg, current_class_type, 0)));
+	   && is_base_of_enclosing_class (arg, current_class_type)));
   if (is_tmpl_type && TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
     arg = TYPE_STUB_DECL (arg);
   else if (is_tmpl_type && TREE_CODE (arg) == RECORD_TYPE)