===================================================================
@@ -1,5 +1,11 @@
2011-01-19 Nicola Pero <nicola.pero@meta-innovation.com>
+ PR objc/47784
+ * objc-act.c (objc_maybe_build_modify_expr): If 'rhs' has side
+ effects, do not use a temporary variable.
+
+2011-01-19 Nicola Pero <nicola.pero@meta-innovation.com>
+
* objc-act.c (objc_init, generate_struct_by_value_array): Updated
comments.
===================================================================
@@ -1790,49 +1790,71 @@ objc_maybe_build_modify_expr (tree lhs, tree rhs)
to get these to work with very little effort, we build a
compound statement which does the setter call (to set the
property to 'rhs'), but which can also be evaluated returning
- the 'rhs'. So, we want to create the following:
+ the 'rhs'. If the 'rhs' has no side effects, we can simply
+ evaluate it twice, building
- (temp = rhs; [object setProperty: temp]; temp)
+ ([object setProperty: rhs]; rhs)
+
+ If it has side effects, we put it in a temporary variable first,
+ so we create the following:
+
+ (temp = rhs; [object setProperty: temp]; temp)
+
+ setter_argument is rhs in the first case, and temp in the second
+ case.
*/
- tree temp_variable_decl, bind;
+ tree setter_argument;
+
/* s1, s2 and s3 are the tree statements that we need in the
compound expression. */
tree s1, s2, s3, compound_expr;
+
+ if (TREE_SIDE_EFFECTS (rhs))
+ {
+ tree bind;
- /* TODO: If 'rhs' is a constant, we could maybe do without the
- 'temp' variable ? */
+ /* Declare __objc_property_temp in a local bind. */
+ setter_argument = objc_create_temporary_var (TREE_TYPE (rhs), "__objc_property_temp");
+ DECL_SOURCE_LOCATION (setter_argument) = input_location;
+ bind = build3 (BIND_EXPR, void_type_node, setter_argument, NULL, NULL);
+ SET_EXPR_LOCATION (bind, input_location);
+ TREE_SIDE_EFFECTS (bind) = 1;
+ add_stmt (bind);
- /* Declare __objc_property_temp in a local bind. */
- temp_variable_decl = objc_create_temporary_var (TREE_TYPE (rhs), "__objc_property_temp");
- DECL_SOURCE_LOCATION (temp_variable_decl) = input_location;
- bind = build3 (BIND_EXPR, void_type_node, temp_variable_decl, NULL, NULL);
- SET_EXPR_LOCATION (bind, input_location);
- TREE_SIDE_EFFECTS (bind) = 1;
- add_stmt (bind);
+ /* s1: x = rhs */
+ s1 = build_modify_expr (input_location, setter_argument, NULL_TREE,
+ NOP_EXPR,
+ input_location, rhs, NULL_TREE);
+ SET_EXPR_LOCATION (s1, input_location);
+ }
+ else
+ {
+ /* No s1. */
+ setter_argument = rhs;
+ s1 = NULL_TREE;
+ }
/* Now build the compound statement. */
+
+ /* s2: [object setProperty: x] */
+ s2 = objc_build_setter_call (lhs, setter_argument);
- /* s1: __objc_property_temp = rhs */
- s1 = build_modify_expr (input_location, temp_variable_decl, NULL_TREE,
- NOP_EXPR,
- input_location, rhs, NULL_TREE);
- SET_EXPR_LOCATION (s1, input_location);
-
- /* s2: [object setProperty: __objc_property_temp] */
- s2 = objc_build_setter_call (lhs, temp_variable_decl);
-
- /* This happens if building the setter failed because the property
- is readonly. */
+ /* This happens if building the setter failed because the
+ property is readonly. */
if (s2 == error_mark_node)
return error_mark_node;
SET_EXPR_LOCATION (s2, input_location);
- /* s3: __objc_property_temp */
- s3 = convert (TREE_TYPE (lhs), temp_variable_decl);
+ /* s3: x */
+ s3 = convert (TREE_TYPE (lhs), setter_argument);
- /* Now build the compound statement (s1, s2, s3) */
- compound_expr = build_compound_expr (input_location, build_compound_expr (input_location, s1, s2), s3);
+ /* Now build the compound statement (s1, s2, s3) or (s2, s3) as
+ appropriate. */
+ if (s1)
+ compound_expr = build_compound_expr (input_location, build_compound_expr (input_location, s1, s2), s3);
+ else
+ compound_expr = build_compound_expr (input_location, s2, s3);
/* Without this, with -Wall you get a 'valued computed is not
used' every time there is a "object.property = x" where the
===================================================================
@@ -1,3 +1,9 @@
+2011-02-19 Nicola Pero <nicola.pero@meta-innovation.com>
+
+ PR objc/47784
+ * objc.dg/property/dotsyntax-22.m: New.
+ * obj-c++.dg/property/dotsyntax-22.mm: New.
+
2011-02-18 Iain Sandoe <iains@gcc.gnu.org>
* objc/execute/exceptions/foward-1.x: New.
===================================================================
@@ -0,0 +1,19 @@
+/* PR objc/47784. This testcase used to crash the compiler. */
+
+typedef struct {
+ float x;
+} SomeType;
+
+@interface MyClass
+
+@property(assign,readwrite) SomeType position;
+
+@end
+
+void example (MyClass *x)
+{
+ const SomeType SomeTypeZero = {0.0f};
+
+ x.position= SomeTypeZero;
+}
+
===================================================================
@@ -0,0 +1,19 @@
+/* PR objc/47784. This testcase used to crash the compiler. */
+
+typedef struct {
+ float x;
+} SomeType;
+
+@interface MyClass
+
+@property(assign,readwrite) SomeType position;
+
+@end
+
+void example (MyClass *x)
+{
+ const SomeType SomeTypeZero = {0.0f};
+
+ x.position= SomeTypeZero;
+}
+
This patch fixes objc/47784 ("Internal compiler error in dot notation assignment of const value"). Due to an ingenuity in our implementation of the dot-syntax, x.property = y; would crash the ObjC compiler if the type of 'y' is some sort of 'const' type (the ObjC++ would just refuse to compile it with an error). This patch fixes it. It seems worthwhile to apply it to 4.6 as the bug is pretty bad; perfectly valid (and common) code would otherwise crash GCC 4.6. Ok to commit ? Thanks