Hi,
an ICE on invalid, regression in 4.7 and 4.8. In 4.7 (vs 4.6) we started
using stabilize_expr in one more place in cp_build_modify_expr without
also adding a preliminary check that the expr isn't of void type, thus
we can easily end up calling build_type_target_expr_with_type on it and
crash.
The fix I tested could be even simpler but I guess we want to also emit
the error line " in evaluation of...", like in 4.6. If you can't imagine
how we could regress with this sort of fix (I can't ;) probably the
issue should be also addressed in 4.7, this kind of invalid code must be
quite common.
Thanks,
Paolo.
/////////////////////////
/cp
2012-05-26 Paolo Carlini <paolo.carl...@oracle.com>
PR c++/53491
* typeck.c (cp_build_modify_expr): Fo binary ops, check that the
right-hand side isn't of void type.
/testsuite
2012-05-26 Paolo Carlini <paolo.carl...@oracle.com>
PR c++/53491
* g++.dg/parse/crash60.C: New.
Index: testsuite/g++.dg/parse/crash60.C
===================================================================
--- testsuite/g++.dg/parse/crash60.C (revision 0)
+++ testsuite/g++.dg/parse/crash60.C (revision 0)
@@ -0,0 +1,14 @@
+// PR c++/53491
+
+struct M
+{
+ void pop();
+};
+
+void foo()
+{
+ int result = 0;
+ M m;
+
+ result += m.pop(); // { dg-error "not ignored|in evaluation" }
+}
Index: cp/typeck.c
===================================================================
--- cp/typeck.c (revision 187901)
+++ cp/typeck.c (working copy)
@@ -6949,10 +6949,20 @@ cp_build_modify_expr (tree lhs, enum tree_code mod
lhs = stabilize_reference (lhs);
if (TREE_SIDE_EFFECTS (rhs))
rhs = mark_rvalue_use (rhs);
- rhs = stabilize_expr (rhs, &init);
- newrhs = cp_build_binary_op (input_location,
- modifycode, lhs, rhs,
- complain);
+
+ if (VOID_TYPE_P (TREE_TYPE (rhs)))
+ {
+ if (complain & tf_error)
+ error ("void value not ignored as it ought to be");
+ newrhs = error_mark_node;
+ }
+ else
+ {
+ rhs = stabilize_expr (rhs, &init);
+ newrhs = cp_build_binary_op (input_location,
+ modifycode, lhs, rhs,
+ complain);
+ }
if (newrhs == error_mark_node)
{
if (complain & tf_error)
