Hi,
Manuel did most of the work on this [5 Regression], caused by my fix for
c++/43906, which extended a lot the functionality of -Waddress: a
spurious warning is emitted with -Waddress for an expression internally
generated in cp_build_binary_op. Manuel suggested that when safe we
could completely avoid generating the relevant recursive calls to
cp_build_binary_op. Alternately, for these internally generated
expressions we could probably use tf_none instead of passing down
complain. Note: I'm not 100% sure the ptrmemfunc_vbit_in_delta bits are
correct, for sure avoid the spurious warning for those targets too.
Thanks,
Paolo.
///////////////////////////
Index: cp/typeck.c
===================================================================
--- cp/typeck.c (revision 220366)
+++ cp/typeck.c (working copy)
@@ -4552,35 +4552,44 @@ cp_build_binary_op (location_t location,
The reason for the `!op0.pfn' bit is that a NULL
pointer-to-member is any member with a zero PFN and
- LSB of the DELTA field is 0. */
+ LSB of the DELTA field is 0. Note: avoid generating the
+ '|| (!op0.pfn && ...)' if !op0.pfn is known to be false. */
- e1 = cp_build_binary_op (location, BIT_AND_EXPR,
- delta0,
- integer_one_node,
- complain);
- e1 = cp_build_binary_op (location,
- EQ_EXPR, e1, integer_zero_node,
- complain);
- e2 = cp_build_binary_op (location, BIT_AND_EXPR,
- delta1,
- integer_one_node,
- complain);
- e2 = cp_build_binary_op (location,
- EQ_EXPR, e2, integer_zero_node,
- complain);
- e1 = cp_build_binary_op (location,
- TRUTH_ANDIF_EXPR, e2, e1,
- complain);
- e2 = cp_build_binary_op (location, EQ_EXPR,
- pfn0,
- build_zero_cst (TREE_TYPE (pfn0)),
- complain);
- e2 = cp_build_binary_op (location,
- TRUTH_ANDIF_EXPR, e2, e1, complain);
- e1 = cp_build_binary_op (location,
- EQ_EXPR, delta0, delta1, complain);
- e1 = cp_build_binary_op (location,
- TRUTH_ORIF_EXPR, e1, e2, complain);
+ if (TREE_CODE (pfn0) != ADDR_EXPR
+ || !decl_with_nonnull_addr_p (TREE_OPERAND (pfn0, 0)))
+ {
+ e1 = cp_build_binary_op (location, BIT_AND_EXPR,
+ delta0,
+ integer_one_node,
+ complain);
+ e1 = cp_build_binary_op (location,
+ EQ_EXPR, e1, integer_zero_node,
+ complain);
+ e2 = cp_build_binary_op (location, BIT_AND_EXPR,
+ delta1,
+ integer_one_node,
+ complain);
+ e2 = cp_build_binary_op (location,
+ EQ_EXPR, e2, integer_zero_node,
+ complain);
+ e1 = cp_build_binary_op (location,
+ TRUTH_ANDIF_EXPR, e2, e1,
+ complain);
+ e2 = cp_build_binary_op (location, EQ_EXPR,
+ pfn0,
+ build_zero_cst (TREE_TYPE (pfn0)),
+ complain);
+ e2 = cp_build_binary_op (location,
+ TRUTH_ANDIF_EXPR, e2, e1, complain);
+ e1 = cp_build_binary_op (location,
+ EQ_EXPR, delta0, delta1, complain);
+ e1 = cp_build_binary_op (location,
+ TRUTH_ORIF_EXPR, e1, e2, complain);
+
+ }
+ else
+ e1 = cp_build_binary_op (location,
+ EQ_EXPR, delta0, delta1, complain);
}
else
{
@@ -4591,17 +4600,22 @@ cp_build_binary_op (location_t location,
The reason for the `!op0.pfn' bit is that a NULL
pointer-to-member is any member with a zero PFN; the
- DELTA field is unspecified. */
+ DELTA field is unspecified. Note: avoid generating the
+ '!op0.pfn ||' if !op0.pfn is known to be false. */
e1 = cp_build_binary_op (location,
EQ_EXPR, delta0, delta1, complain);
- e2 = cp_build_binary_op (location,
- EQ_EXPR,
- pfn0,
- build_zero_cst (TREE_TYPE (pfn0)),
- complain);
- e1 = cp_build_binary_op (location,
- TRUTH_ORIF_EXPR, e1, e2, complain);
+ if (TREE_CODE (pfn0) != ADDR_EXPR
+ || !decl_with_nonnull_addr_p (TREE_OPERAND (pfn0, 0)))
+ {
+ e2 = cp_build_binary_op (location,
+ EQ_EXPR,
+ pfn0,
+ build_zero_cst (TREE_TYPE (pfn0)),
+ complain);
+ e1 = cp_build_binary_op (location,
+ TRUTH_ORIF_EXPR, e1, e2, complain);
+ }
}
e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
e = cp_build_binary_op (location,
Index: testsuite/g++.dg/warn/Waddress-2.C
===================================================================
--- testsuite/g++.dg/warn/Waddress-2.C (revision 0)
+++ testsuite/g++.dg/warn/Waddress-2.C (working copy)
@@ -0,0 +1,24 @@
+// PR c++/64877
+// { dg-options "-Waddress" }
+
+template<class Derived>
+struct S
+{
+ void m() {
+ }
+
+ S()
+ {
+ if (&S<Derived>::Unwrap != &Derived::Unwrap)
+ m();
+ }
+
+ void Unwrap() {
+ }
+};
+
+struct T : public S<T>
+{
+};
+
+T t;
