cvt.c (convert_lvalue): New fn.

        * cvt.c (convert_lvalue): New fn.
        * cp-tree.h: Declare it.
        * method.c (do_build_assign_ref): Use it.
        (do_build_copy_constructor): Convert parm to base types
        before calling base constructors.

        * typeck.c (check_return_expr): Check DECL_ALIGN instead of
        DECL_USER_ALIGN.  Check flag_elide_constructors instead of
        optimize.
        * semantics.c (cp_expand_stmt): Don't destroy the named return value.

From-SVN: r43780

gcc/cp/ChangeLog

+2001-07-05  Jason Merrill  <jason_merrill@redhat.com>
+
+	* cvt.c (convert_lvalue): New fn.
+	* cp-tree.h: Declare it.
+	* method.c (do_build_assign_ref): Use it.
+	(do_build_copy_constructor): Convert parm to base types
+	before calling base constructors.
+
+	* typeck.c (check_return_expr): Check DECL_ALIGN instead of
+	DECL_USER_ALIGN.  Check flag_elide_constructors instead of
+	optimize.
+	* semantics.c (cp_expand_stmt): Don't destroy the named return value.
+
 2001-07-02  Nathan Sidwell  <nathan@codesourcery.com>
 
 	* optimize.c (optimize_inline_calls): New function, broken out

gcc/cp/cp-tree.h

@@ -3735,6 +3735,7 @@ extern tree get_primary_binfo                   PARAMS ((tree));
 /* in cvt.c */
 extern tree convert_to_reference		PARAMS ((tree, tree, int, int, tree));
 extern tree convert_from_reference		PARAMS ((tree));
+extern tree convert_lvalue			PARAMS ((tree, tree));
 extern tree convert_pointer_to_real		PARAMS ((tree, tree));
 extern tree convert_pointer_to			PARAMS ((tree, tree));
 extern tree ocp_convert				PARAMS ((tree, tree, int, int));

gcc/cp/cvt.c

@@ -597,6 +597,20 @@ convert_from_reference (val)
     return build_indirect_ref (val, NULL);
   return val;
 }
+
+/* Implicitly convert the lvalue EXPR to another lvalue of type TOTYPE,
+   preserving cv-qualification.  */
+
+tree
+convert_lvalue (totype, expr)
+     tree totype, expr;
+{
+  totype = cp_build_qualified_type (totype, TYPE_QUALS (TREE_TYPE (expr)));
+  totype = build_reference_type (totype);
+  expr = convert_to_reference (totype, expr, CONV_IMPLICIT, LOOKUP_NORMAL,
+			       NULL_TREE);
+  return convert_from_reference (expr);
+}
 
 /* Call this when we know (for any reason) that expr is not, in fact,
    zero.  This routine is like convert_pointer_to, but it pays

gcc/cp/method.c

@@ -557,25 +557,31 @@ do_build_copy_constructor (fndecl)
       int cvquals = CP_TYPE_QUALS (TREE_TYPE (parm));
       int i;
 
-      /* Initialize all the base-classes.  */
+      /* Initialize all the base-classes with the parameter converted to
+         their type so that we get their copy constructor and not another
+         constructor that takes current_class_type.  */
       for (t = CLASSTYPE_VBASECLASSES (current_class_type); t;
 	   t = TREE_CHAIN (t))
-	base_init_list 
-	  = tree_cons (BINFO_TYPE (TREE_VALUE (t)), parm, 
-		       base_init_list);
+	{
+	  tree type = BINFO_TYPE (TREE_VALUE (t));
+	  base_init_list = tree_cons (type, convert_lvalue (type, parm),
+				      base_init_list);
+	}
+
       for (i = 0; i < n_bases; ++i)
 	{
 	  t = TREE_VEC_ELT (binfos, i);
 	  if (TREE_VIA_VIRTUAL (t))
 	    continue; 
 
-	  base_init_list 
-	    = tree_cons (BINFO_TYPE (t), parm, base_init_list);
+	  t = BINFO_TYPE (t);
+	  base_init_list = tree_cons (t, convert_lvalue (t, parm),
+				      base_init_list);
 	}
 
       for (; fields; fields = TREE_CHAIN (fields))
 	{
-	  tree init, t;
+	  tree init;
 	  tree field = fields;
 
 	  if (TREE_CODE (field) != FIELD_DECL)
@@ -645,12 +651,7 @@ do_build_assign_ref (fndecl)
       for (i = 0; i < n_bases; ++i)
 	{
 	  tree basetype = BINFO_TYPE (TREE_VEC_ELT (binfos, i));
-	  tree p = build_qualified_type (basetype, cvquals);
-
-	  p = convert_to_reference
-	    (build_reference_type (p), parm,
-	     CONV_IMPLICIT, LOOKUP_COMPLAIN, NULL_TREE);
-	  p = convert_from_reference (p);
+	  tree p = convert_lvalue (basetype, parm);
 	  p = build_member_call (basetype, ansi_assopname (NOP_EXPR),
 				 build_tree_list (NULL_TREE, p));
 	  finish_expr_stmt (p);

gcc/cp/semantics.c

@@ -2156,7 +2156,9 @@ cp_expand_stmt (t)
   switch (TREE_CODE (t))
     {
     case CLEANUP_STMT:
-      genrtl_decl_cleanup (CLEANUP_DECL (t), CLEANUP_EXPR (t));
+      /* Don't destroy the chosen named return value.  */
+      if (CLEANUP_DECL (t) != current_function_return_value)
+	genrtl_decl_cleanup (CLEANUP_DECL (t), CLEANUP_EXPR (t));
       break;
 
     case CTOR_STMT:

gcc/cp/typeck.c

@@ -6684,7 +6684,7 @@ check_return_expr (retval)
      returned expression uses the chosen variable somehow.  And people expect
      this restriction, anyway.  (jason 2000-11-19) */
 
-  if (fn_returns_value_p && optimize)
+  if (fn_returns_value_p && flag_elide_constructors)
     {
       if (retval != NULL_TREE
 	  && (current_function_return_value == NULL_TREE
@@ -6692,7 +6692,8 @@ check_return_expr (retval)
 	  && TREE_CODE (retval) == VAR_DECL
 	  && DECL_CONTEXT (retval) == current_function_decl
 	  && ! TREE_STATIC (retval)
-	  && ! DECL_USER_ALIGN (retval)
+	  && (DECL_ALIGN (retval)
+	      == DECL_ALIGN (DECL_RESULT (current_function_decl)))
 	  && same_type_p (TREE_TYPE (retval),
 			  TREE_TYPE (TREE_TYPE (current_function_decl))))
 	current_function_return_value = retval;