https://gcc.gnu.org/g:149d87fbe661da29d8a0aa671b42bd532206a8b8
commit r14-10656-g149d87fbe661da29d8a0aa671b42bd532206a8b8
Author: Patrick Palka <ppa...@redhat.com>
Date: Thu Aug 15 10:23:54 2024 -0400
c++: c->B::m access resolved through current inst [PR116320]
Here when checking the access of (the injected-class-name) B in c->B::m
at parse time, we notice its context B (now the type) is a base of the
object type C<T>, so we proceed to use C<T> as the effective qualifying
type. But this C<T> is the dependent specialization not the primary
template type, so it has empty TYPE_BINFO, which leads to a segfault later
from perform_or_defer_access_check.
The reason the DERIVED_FROM_P (B, C<T>) test guarding this code path works
despite C<T> having empty TYPE_BINFO is because of its currently_open_class
logic (added in r9-713-gd9338471b91bbe) which replaces a dependent
specialization with the primary template type if we're inside it. So the
safest fix seems to be to call currently_open_class in the caller as well.
PR c++/116320
gcc/cp/ChangeLog:
* semantics.cc (check_accessibility_of_qualified_id): Try
currently_open_class when using the object type as the
effective qualifying type.
gcc/testsuite/ChangeLog:
* g++.dg/template/access42.C: New test.
Reviewed-by: Jason Merrill <ja...@redhat.com>
(cherry picked from commit 484f139ccd3b631a777802e810a632678b42ffab)
Diff:
---
gcc/cp/semantics.cc | 11 ++++++++---
gcc/testsuite/g++.dg/template/access42.C | 17 +++++++++++++++++
2 files changed, 25 insertions(+), 3 deletions(-)
diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc
index b5569066708e..ceeac82fa081 100644
--- a/gcc/cp/semantics.cc
+++ b/gcc/cp/semantics.cc
@@ -2497,9 +2497,14 @@ check_accessibility_of_qualified_id (tree decl,
OBJECT_TYPE. */
&& CLASS_TYPE_P (object_type)
&& DERIVED_FROM_P (scope, object_type))
- /* If we are processing a `->' or `.' expression, use the type of the
- left-hand side. */
- qualifying_type = object_type;
+ {
+ /* If we are processing a `->' or `.' expression, use the type of the
+ left-hand side. */
+ if (tree open = currently_open_class (object_type))
+ qualifying_type = open;
+ else
+ qualifying_type = object_type;
+ }
else if (nested_name_specifier)
{
/* If the reference is to a non-static member of the
diff --git a/gcc/testsuite/g++.dg/template/access42.C
b/gcc/testsuite/g++.dg/template/access42.C
new file mode 100644
index 000000000000..f1dcbce80c24
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/access42.C
@@ -0,0 +1,17 @@
+// PR c++/116320
+// { dg-do compile { target c++11 } }
+
+template<class T> struct C;
+template<class T> using C_ptr = C<T>*;
+
+struct B { int m; using B_typedef = B; };
+
+template<class T>
+struct C : B {
+ void f(C_ptr<T> c) {
+ c->B::m;
+ c->B_typedef::m;
+ }
+};
+
+template struct C<int>;
