On 12/28/21 10:08, Patrick Palka wrote:
Here during satisfaction of B's associated constraints we're failing to
reject the object-less call to the non-static member function A::size
ultimately because satisfaction is performed in the (access) context of
the class template B, which has a dependent bases, and so the
any_dependent_bases_p check within build_new_method_call causes us to
avoid rejecting the call.
This patch fixes this by refining the any_dependent_bases_p check within
build_new_method_call: dependent bases can't make a difference for
resolving the implicit object parameter if we're in a conext where
'this' is unavailable, so let's check current_class_ptr too.
Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for
trunk and perhaps 11? The first testcase exhibits a regression
introduced by r12-1937.
OK for both.
PR c++/103831
gcc/cp/ChangeLog:
* call.c (build_new_method_call): Consider dependent bases only
if 'this' is available.
gcc/testsuite/ChangeLog:
* g++.dg/cpp2a/concepts-class3.C: New test.
* g++.dg/template/non-dependent18.C: New test.
---
gcc/cp/call.c | 2 +-
gcc/testsuite/g++.dg/cpp2a/concepts-class3.C | 12 ++++++++++++
.../g++.dg/template/non-dependent18.C | 19 +++++++++++++++++++
3 files changed, 32 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/g++.dg/cpp2a/concepts-class3.C
create mode 100644 gcc/testsuite/g++.dg/template/non-dependent18.C
diff --git a/gcc/cp/call.c b/gcc/cp/call.c
index bee367f57d7..3da9e7a6284 100644
--- a/gcc/cp/call.c
+++ b/gcc/cp/call.c
@@ -11098,7 +11098,7 @@ build_new_method_call (tree instance, tree fns, vec<tree,
va_gc> **args,
we know we really need it. */
cand->first_arg = instance;
}
- else if (any_dependent_bases_p ())
+ else if (current_class_ptr && any_dependent_bases_p ())
/* We can't tell until instantiation time whether we can use
*this as the implicit object argument. */;
else
diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-class3.C
b/gcc/testsuite/g++.dg/cpp2a/concepts-class3.C
new file mode 100644
index 00000000000..68b50b71278
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/concepts-class3.C
@@ -0,0 +1,12 @@
+// PR c++/103831
+// { dg-do compile { target c++20 } }
+
+struct A {
+ constexpr int size() { return 42; } // non-static
+};
+
+template<class T>
+ requires (T::size() == 42) // { dg-error "without object" }
+struct B : T { };
+
+template struct B<A>; // { dg-error "constraint" }
diff --git a/gcc/testsuite/g++.dg/template/non-dependent18.C
b/gcc/testsuite/g++.dg/template/non-dependent18.C
new file mode 100644
index 00000000000..7fe623d497f
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/non-dependent18.C
@@ -0,0 +1,19 @@
+// PR c++/103831
+// { dg-do compile { target c++11 } }
+
+struct A {
+ constexpr int size() { return 42; } // non-static
+};
+
+template<class T>
+struct B : T {
+ static_assert(A::size() == 42); // { dg-error "without object" }
+
+ static int f() {
+ static_assert(A::size() == 42, ""); // { dg-error "without object" }
+ return A::size(); // { dg-error "without object" }
+ }
+
+ int n = A::size();
+ static const int m = A::size(); // { dg-error "without object" }
+};
