Here we expect the calls to BaseClass::baseDevice resolve to the second,
third and fourth overloads respectively in light of the cv-qualifiers
of 'this' in each case. But ever since r12-6075-g2decd2cabe5a4f, the
calls incorrectly resolve to the first overload at instantiation time.
This happens because the calls to BaseClass::baseDevice are all deemed
non-dependent (ever since r7-755-g23cb72663051cd made us ignore the
dependentness of 'this' when considering the dependence of a non-static
memfn call), hence we end up checking the call ahead of time, using as
the object argument a dummy object of type BaseClass. Since this object
argument is cv-unqualified, the calls incoherently resolve to the first
overload of baseDevice. Before r12-6075, this incorrect result would
just get silently discarded and we'd end up redoing OR at instantiation
time using 'this' as the object argument. But after r12-6075, we now
reuse this incorrect result at instantiation time.
This patch fixes this by making finish_call_expr request from
maybe_dummy_object a cv-qualified object consistent with the cv-quals of
'this'. That way, ahead of time OR using a dummy object will give us
the right answer and we could safely reuse it at instantiation time.
NB: r7-755 is also the cause of the related issue PR105742. Not sure
if there's a fix that could resolve both PRs at once..
Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK
for trunk/12?
PR c++/105637
gcc/cp/ChangeLog:
* semantics.cc (finish_call_expr): Pass a cv-qualified object
type to maybe_dummy_object that is consistent with the
cv-qualifiers of 'this' if available.
gcc/testsuite/ChangeLog:
* g++.dg/template/non-dependent23.C: New test.
---
gcc/cp/semantics.cc | 15 ++++++++---
.../g++.dg/template/non-dependent23.C | 25 +++++++++++++++++++
2 files changed, 37 insertions(+), 3 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/template/non-dependent23.C
diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc
index cd7a2818feb..1d9348c6cf1 100644
--- a/gcc/cp/semantics.cc
+++ b/gcc/cp/semantics.cc
@@ -2802,16 +2802,25 @@ finish_call_expr (tree fn, vec<tree, va_gc> **args,
bool disallow_virtual,
[class.access.base] says that we need to convert 'this' to B* as
part of the access, so we pass 'B' to maybe_dummy_object. */
+ tree object_type = BINFO_TYPE (BASELINK_ACCESS_BINFO (fn));
if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (get_first_fn (fn)))
{
/* A constructor call always uses a dummy object. (This constructor
call which has the form A::A () is actually invalid and we are
going to reject it later in build_new_method_call.) */
- object = build_dummy_object (BINFO_TYPE (BASELINK_ACCESS_BINFO (fn)));
+ object = build_dummy_object (object_type);
}
else
- object = maybe_dummy_object (BINFO_TYPE (BASELINK_ACCESS_BINFO (fn)),
- NULL);
+ {
+ if (current_class_ref)
+ {
+ /* Make sure that if maybe_dummy_object gives us a dummy object,
+ it'll have the same cv-quals as '*this'. */
+ int quals = cp_type_quals (TREE_TYPE (current_class_ref));
+ object_type = cp_build_qualified_type (object_type, quals);
+ }
+ object = maybe_dummy_object (object_type, NULL);
+ }
result = build_new_method_call (object, fn, args, NULL_TREE,
(disallow_virtual
diff --git a/gcc/testsuite/g++.dg/template/non-dependent23.C
b/gcc/testsuite/g++.dg/template/non-dependent23.C
new file mode 100644
index 00000000000..ef95c591b75
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/non-dependent23.C
@@ -0,0 +1,25 @@
+// PR c++/105637
+
+struct BaseClass {
+ void baseDevice(); // #1
+ void baseDevice() const; // #2
+ void baseDevice() volatile; // #3
+ void baseDevice() const volatile; // #4
+};
+
+template<class T>
+struct TopClass : T {
+ void failsToCompile() const {
+ BaseClass::baseDevice(); // should select #2, not #1
+ }
+
+ void failsToCompile() volatile {
+ BaseClass::baseDevice(); // should select #3, not #1
+ }
+
+ void failsToCompile() const volatile {
+ BaseClass::baseDevice(); // should select #4, not #1
+ }
+};
+
+template struct TopClass<BaseClass>;
--
2.36.1.182.g6afdb07b7b
