init.c (construct_virtual_bases): Don't look up the addresses of virtual bases at...

	* init.c (construct_virtual_bases): Don't look up the addresses of
	virtual bases at run-time.

From-SVN: r31447

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 99147e2..a8d7922 100644 (file)
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,8 @@
 2000-01-16  Mark Mitchell  <mark@codesourcery.com>
 
+       * init.c (construct_virtual_bases): Don't look up the addresses of
+       virtual bases at run-time.
+
        * class.c (build_vbase_pointer): Relocate.
        (build_vbase_pointer_fields): Likewise.
        (dfs_build_vbase_offset_vtbl_entries): Likewise.

diff --git a/gcc/cp/init.c b/gcc/cp/init.c
index 12815e4..3828ddf 100644 (file)
--- a/gcc/cp/init.c
+++ b/gcc/cp/init.c
@@ -751,9 +751,9 @@ construct_virtual_bases (type, this_ref, this_ptr, init_list, flag)
   for (vbases = CLASSTYPE_VBASECLASSES (type); vbases;
        vbases = TREE_CHAIN (vbases))
     {
-      tree tmp = purpose_member (vbases, result);
       tree inner_if_stmt;
       tree compound_stmt;
+      tree exp;
 
       /* If there are virtual base classes with destructors, we need to
         emit cleanups to destroy them if an exception is thrown during
@@ -772,9 +772,20 @@ construct_virtual_bases (type, this_ref, this_ptr, init_list, flag)
       inner_if_stmt = begin_if_stmt ();
       finish_if_stmt_cond (flag, inner_if_stmt);
       compound_stmt = begin_compound_stmt (/*has_no_scope=*/1);
-      expand_aggr_vbase_init_1 (vbases, this_ref,
-                               TREE_OPERAND (TREE_VALUE (tmp), 0),
-                               init_list);
+
+      /* Compute the location of the virtual base.  If we're
+        constructing virtual bases, then we must be the most derived
+        class.  Therefore, we don't have to look up the virtual base;
+        we already know where it is.  */
+      exp = build (PLUS_EXPR,
+                  TREE_TYPE (this_ptr),
+                  this_ptr,
+                  BINFO_OFFSET (vbases));
+      exp = build1 (NOP_EXPR, 
+                   build_pointer_type (BINFO_TYPE (vbases)), 
+                   exp);
+
+      expand_aggr_vbase_init_1 (vbases, this_ref, exp, init_list);
       finish_compound_stmt (/*has_no_scope=*/1, compound_stmt);
       finish_then_clause (inner_if_stmt);
       finish_if_stmt ();