Re: [PATCH] Fix PR middle-end/17703 and the C++ part of 17657

[Andrew Pinski <pinskia at physics dot uc dot edu>]

On Oct 6, 2004, at 2:32 PM, Jason Merrill wrote:

> It would be simpler just to check TREE_SIDE_EFFECTS, though you might 
> as
> well keep the DECL_P check so that we don't build a useless
> CLEANUP_POINT_EXPR for a use of a volatile variable.

Adding back the DECL_P check will be for another patch, this patch was
mainly to fix some regressions.
I did simplify it by adding TREE_SIDE_EFFECTS and added a check for
CLEANUP_POINT_EXPR to just have one next to each other.

OK?

Thanks,
Andrew Pinski

ChangeLog:
	* fold-const.c (fold_build_cleanup_point_expr): New.
	* tree.h (fold_build_cleanup_point_expr): Declare.
	
cp/ChangeLog:
	* semantics.c (maybe_cleanup_point_expr): Use
	fold_build_cleanup_point_expr.
	* typeck.c (condition_conversion): Likewise.

Index: fold-const.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/fold-const.c,v
retrieving revision 1.466
diff -u -p -r1.466 fold-const.c
--- fold-const.c	3 Oct 2004 15:31:50 -0000	1.466
+++ fold-const.c	7 Oct 2004 14:52:21 -0000
@@ -10462,6 +10462,26 @@ fold_relational_const (enum tree_code co
   return constant_boolean_node (result, type);
 }

+/* Build an expression for the a clean point containing EXPR with type 
TYPE.
+   Don't build a cleanup point expression for EXPR which don't have 
side
+   effects.  */
+
+tree
+fold_build_cleanup_point_expr (tree type, tree expr)
+{
+  /* If the expression does not have side effects then the expression 
does not
+     need to be wrapped with a cleanup point expression.  */
+  if (!TREE_SIDE_EFFECTS (expr))
+    return expr;
+
+  /* If we already have a cleanup pont expression build a new one with
+     the inner expression.  */
+  if (TREE_CODE (expr) == CLEANUP_POINT_EXPR)
+    return build1 (CLEANUP_POINT_EXPR, type, TREE_OPERAND (expr, 0));
+
+  return build1 (CLEANUP_POINT_EXPR, type, expr);
+}
+
 /* Build an expression for the address of T.  Folds away INDIRECT_REF 
to
    avoid confusing the gimplify process.  */
Index: tree.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/tree.h,v
retrieving revision 1.635
diff -u -p -r1.635 tree.h
--- tree.h	1 Oct 2004 07:42:49 -0000	1.635
+++ tree.h	6 Oct 2004 13:15:14 -0000
@@ -3539,6 +3539,7 @@ extern tree nondestructive_fold_binary_t
 extern tree fold_read_from_constant_string (tree);
 extern tree int_const_binop (enum tree_code, tree, tree, int);
 extern tree build_fold_addr_expr (tree);
+tree fold_build_cleanup_point_expr (tree type, tree expr);
 extern tree build_fold_addr_expr_with_type (tree, tree);
 extern tree build_fold_indirect_ref (tree);
 extern tree constant_boolean_node (int, tree);
Index: cp/semantics.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cp/semantics.c,v
retrieving revision 1.441
diff -u -p -r1.441 semantics.c
--- cp/semantics.c	1 Oct 2004 15:11:21 -0000	1.441
+++ cp/semantics.c	6 Oct 2004 13:15:14 -0000
@@ -358,7 +358,7 @@ static tree
 maybe_cleanup_point_expr (tree expr)
 {
   if (!processing_template_decl && stmts_are_full_exprs_p ())
-    expr = build1 (CLEANUP_POINT_EXPR, TREE_TYPE (expr), expr);
+    expr = fold_build_cleanup_point_expr (type, expr);
   return expr;
 }

Index: cp/typeck.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cp/typeck.c,v
retrieving revision 1.580
diff -u -p -r1.580 typeck.c
--- cp/typeck.c	3 Oct 2004 18:07:56 -0000	1.580
+++ cp/typeck.c	6 Oct 2004 13:15:14 -0000
@@ -3677,7 +3677,7 @@ condition_conversion (tree expr)
   if (processing_template_decl)
     return expr;
   t = perform_implicit_conversion (boolean_type_node, expr);
-  t = build1 (CLEANUP_POINT_EXPR, boolean_type_node, t);
+  t = fold_build_cleanup_point_expr (boolean_type_node, t);
   return t;
 }