decl.c (lookup_label): Build labels on the permanent obstack when building statement trees.

	* decl.c (lookup_label): Build labels on the permanent obstack
	when building statement trees.  Don't build RTL for labels when
	building statement trees.
	* semantics.c (finish_goto_stmt): Use LABEL_DECLs even when
	building statement trees.
	(finish_label_stmt): Likewise.
	(expand_stmt): Adjust accordingly.
	* pt.c (tsubst_expr); Likewise.
	(do_decl_instantiation): Robustify.

From-SVN: r28918

gcc/cp/ChangeLog

 1999-08-26  Mark Mitchell  <mark@codesourcery.com>
 
+	* decl.c (lookup_label): Build labels on the permanent obstack
+	when building statement trees.  Don't build RTL for labels when
+	building statement trees.
+	* semantics.c (finish_goto_stmt): Use LABEL_DECLs even when
+	building statement trees.
+	(finish_label_stmt): Likewise.
+	(expand_stmt): Adjust accordingly.
+	* pt.c (tsubst_expr); Likewise.
+	(do_decl_instantiation): Robustify.
+	
 	* cp-tree.h (AGGR_INIT_VIA_CTOR_P): New macro.
 	* tree.c (build_cplus_new): Set it.
 	* expr.c (cplus_expand_expr): Use it.

gcc/cp/decl.c

@@ -4829,10 +4829,14 @@ lookup_label (id)
       return decl;
     }
 
+  if (building_stmt_tree ())
+    push_permanent_obstack ();
   decl = build_decl (LABEL_DECL, id, void_type_node);
-
-  /* Make sure every label has an rtx.  */
-  label_rtx (decl);
+  if (building_stmt_tree ())
+    pop_obstacks ();
+  else
+    /* Make sure every label has an rtx.  */
+    label_rtx (decl);
 
   /* A label not explicitly declared must be local to where it's ref'd.  */
   DECL_CONTEXT (decl) = current_function_decl;

gcc/cp/pt.c

@@ -7401,11 +7401,13 @@ tsubst_expr (t, args, complain, in_decl)
     case GOTO_STMT:
       lineno = STMT_LINENO (t);
       t = GOTO_DESTINATION (t);
-      if (TREE_CODE (t) != IDENTIFIER_NODE)
+      if (TREE_CODE (t) != LABEL_DECL)
 	/* Computed goto's must be tsubst'd into.  On the other hand,
 	   non-computed gotos must not be; the identifier in question
 	   will have no binding.  */
 	t = tsubst_expr (t, args, complain, in_decl);
+      else
+	t = DECL_NAME (t);
       finish_goto_stmt (t);
       break;
 
@@ -9132,7 +9134,11 @@ do_decl_instantiation (declspecs, declarator, storage)
   tree result = NULL_TREE;
   int extern_p = 0;
 
-  if (! DECL_LANG_SPECIFIC (decl))
+  if (!decl)
+    /* An error ocurred, for which grokdeclarator has already issued
+       an appropriate message.  */
+    return;
+  else if (! DECL_LANG_SPECIFIC (decl))
     {
       cp_error ("explicit instantiation of non-template `%#D'", decl);
       return;

gcc/cp/semantics.c

@@ -599,17 +599,19 @@ void
 finish_goto_stmt (destination)
      tree destination;
 {
+  if (TREE_CODE (destination) == IDENTIFIER_NODE)
+    destination = lookup_label (destination);
+
   if (building_stmt_tree ())
     add_tree (build_min_nt (GOTO_STMT, destination));
   else
     {
       emit_line_note (input_filename, lineno);
 
-      if (TREE_CODE (destination) == IDENTIFIER_NODE)
+      if (TREE_CODE (destination) == LABEL_DECL)
 	{
-	  tree decl = lookup_label (destination);
-	  TREE_USED (decl) = 1;
-	  expand_goto (decl); 
+	  TREE_USED (destination) = 1;
+	  expand_goto (destination); 
 	}
       else
 	expand_computed_goto (destination);
@@ -914,23 +916,12 @@ void
 finish_label_stmt (name)
      tree name;
 {
-  tree decl;
+  tree decl = define_label (input_filename, lineno, name);
 
   if (building_stmt_tree ())
-    {
-      push_permanent_obstack ();
-      decl = build_decl (LABEL_DECL, name, void_type_node);
-      pop_obstacks ();
-      DECL_SOURCE_LINE (decl) = lineno;
-      DECL_SOURCE_FILE (decl) = input_filename;
-      add_tree (decl);
-    }
-  else
-    {
-      decl = define_label (input_filename, lineno, name);
-      if (decl)
-	expand_label (decl);
-    }
+    add_tree (decl);
+  else if (decl)
+    expand_label (decl);
 }
 
 /* Create a declaration statement for the declaration given by the
@@ -2129,10 +2120,9 @@ expand_stmt (t)
       break;
 
     case LABEL_DECL:
-      t = define_label (DECL_SOURCE_FILE (t), DECL_SOURCE_LINE (t),
-			DECL_NAME (t));
-      if (t)
-	expand_label (t);
+      input_filename = DECL_SOURCE_FILE (t);
+      lineno = DECL_SOURCE_LINE (t);
+      finish_label_stmt (DECL_NAME (t));
       break;
 
     case GOTO_STMT: