helper<token>::c isn't dependent just because we haven't deduced its return
type yet. type_dependent_expression_p already knows how to deal with that
for bare FUNCTION_DECL, but needs to learn to look through a BASELINK.
Tested x86_64-pc-linux-gnu, applying to trunk.
PR c++/105964
gcc/cp/ChangeLog:
* pt.cc (type_dependent_expression_p): Look through BASELINK.
gcc/testsuite/ChangeLog:
* g++.dg/cpp1z/nontype-auto21.C: New test.
---
gcc/cp/pt.cc | 9 +++++++++
gcc/testsuite/g++.dg/cpp1z/nontype-auto21.C | 20 ++++++++++++++++++++
2 files changed, 29 insertions(+)
create mode 100644 gcc/testsuite/g++.dg/cpp1z/nontype-auto21.C
diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index 28edc6ae988..4d1c325432d 100644
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -27960,6 +27960,15 @@ type_dependent_expression_p (tree expression)
&& DECL_INITIAL (expression))
return true;
+ /* Pull a FUNCTION_DECL out of a BASELINK if we can. */
+ if (BASELINK_P (expression))
+ {
+ if (BASELINK_OPTYPE (expression)
+ && dependent_type_p (BASELINK_OPTYPE (expression)))
+ return true;
+ expression = BASELINK_FUNCTIONS (expression);
+ }
+
/* A function or variable template-id is type-dependent if it has any
dependent template arguments. */
if (VAR_OR_FUNCTION_DECL_P (expression)
diff --git a/gcc/testsuite/g++.dg/cpp1z/nontype-auto21.C
b/gcc/testsuite/g++.dg/cpp1z/nontype-auto21.C
new file mode 100644
index 00000000000..376d63269cb
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1z/nontype-auto21.C
@@ -0,0 +1,20 @@
+// PR c++/105964
+// { dg-do compile { target c++17 } }
+
+struct token {};
+
+struct example {};
+
+template< typename >
+struct helper
+{
+ static constexpr auto c() { return 42; }
+};
+
+struct impostor_c
+{
+ template< typename T, auto= helper< T >::c >
+ static example func();
+};
+
+example c= impostor_c::func< token >();
base-commit: 349a39f061407ce2339d2ba25da97005f2030c88
--
2.27.0
