On 2/17/22 09:26, Patrick Palka wrote:
Here when instantiating the noexcept-spec we fail to resolve the
implicit object parameter for the call A<T>::f() ultimately because
maybe_instantiate_noexcept sets current_class_ptr/ref to the dependent
'this' (of type B<T>) rather than the specialized 'this' (of type B<int>).
This ends up causing maybe_dummy_object (called from
finish_qualified_id_expr) to return a dummy object instead of 'this'.
This patch corrects this by making maybe_instantiate_noexcept always set
current_class_ptr/ref to the specialized 'this', consistent with what
tsubst_function_type does when substituting into a trailing return type.
Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for
trunk perhaps?
OK.
PR c++/94944
gcc/cp/ChangeLog:
* pt.cc (maybe_instantiate_noexcept): For non-static member
functions, set current_class_ptr/ref to the specialized 'this'
instead.
gcc/testsuite/ChangeLog:
* g++.dg/cpp0x/noexcept34.C: Adjusted expected diagnostics.
* g++.dg/cpp0x/noexcept75.C: New test.
---
gcc/cp/pt.cc | 19 +++++++------------
gcc/testsuite/g++.dg/cpp0x/noexcept34.C | 8 ++++----
gcc/testsuite/g++.dg/cpp0x/noexcept75.C | 17 +++++++++++++++++
3 files changed, 28 insertions(+), 16 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/cpp0x/noexcept75.C
diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index 6dda66081bd..a7a524fe9fc 100644
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -26139,20 +26139,15 @@ maybe_instantiate_noexcept (tree fn, tsubst_flags_t
complain)
push_deferring_access_checks (dk_no_deferred);
input_location = DECL_SOURCE_LOCATION (fn);
- if (!DECL_LOCAL_DECL_P (fn))
+ if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
+ && !DECL_LOCAL_DECL_P (fn))
{
/* If needed, set current_class_ptr for the benefit of
- tsubst_copy/PARM_DECL. The exception pattern will
- refer to the parm of the template, not the
- instantiation. */
- tree tdecl = DECL_TEMPLATE_RESULT (DECL_TI_TEMPLATE (fn));
- if (DECL_NONSTATIC_MEMBER_FUNCTION_P (tdecl))
- {
- tree this_parm = DECL_ARGUMENTS (tdecl);
- current_class_ptr = NULL_TREE;
- current_class_ref = cp_build_fold_indirect_ref (this_parm);
- current_class_ptr = this_parm;
- }
+ tsubst_copy/PARM_DECL. */
+ tree this_parm = DECL_ARGUMENTS (fn);
+ current_class_ptr = NULL_TREE;
+ current_class_ref = cp_build_fold_indirect_ref (this_parm);
+ current_class_ptr = this_parm;
}
/* If this function is represented by a TEMPLATE_DECL, then
diff --git a/gcc/testsuite/g++.dg/cpp0x/noexcept34.C
b/gcc/testsuite/g++.dg/cpp0x/noexcept34.C
index dce35652ef5..86129e7a520 100644
--- a/gcc/testsuite/g++.dg/cpp0x/noexcept34.C
+++ b/gcc/testsuite/g++.dg/cpp0x/noexcept34.C
@@ -7,13 +7,13 @@ template<typename> struct A
{
constexpr int f () { return 0; }
bool b = true;
- void g () noexcept (f()) { } // { dg-error "use of parameter" }
- void g2 () noexcept (this->f()) { } // { dg-error "use of parameter" }
+ void g () noexcept (f()) { } // { dg-error ".this. is not a constant" }
+ void g2 () noexcept (this->f()) { } // { dg-error ".this. is not a constant"
}
void g3 () noexcept (b) { } // { dg-error "use of .this. in a constant
expression|use of parameter" }
void g4 (int i) noexcept (i) { } // { dg-error "use of parameter" }
- void g5 () noexcept (A::f()) { } // { dg-error "use of parameter" }
+ void g5 () noexcept (A::f()) { } // { dg-error ".this. is not a constant" }
void g6 () noexcept (foo(b)) { } // { dg-error "use of .this. in a constant
expression|use of parameter" }
- void g7 () noexcept (int{f()}) { } // { dg-error "use of parameter" }
+ void g7 () noexcept (int{f()}) { } // { dg-error ".this. is not a constant" }
};
int main ()
diff --git a/gcc/testsuite/g++.dg/cpp0x/noexcept75.C
b/gcc/testsuite/g++.dg/cpp0x/noexcept75.C
new file mode 100644
index 00000000000..d746f4768d0
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/noexcept75.C
@@ -0,0 +1,17 @@
+// PR c++/94944
+// { dg-do compile { target c++11 } }
+
+template<class T>
+struct A {
+ void f();
+};
+
+template<class T>
+struct B : A<T> {
+ void g() noexcept(noexcept(A<T>::f()));
+};
+
+int main() {
+ B<int> b;
+ b.g();
+}
