[coroutines] Tweak diagnostics to always use fully-qualified name for std::coroutine_traits.

llvm-svn: 253535

1 files changed, 6 insertions, 1 deletions

diff --git a/clang/test/SemaCXX/coroutines.cpp b/clang/test/SemaCXX/coroutines.cpp
index 3e18187295d..c82302c3c07 100644
--- a/clang/test/SemaCXX/coroutines.cpp
+++ b/clang/test/SemaCXX/coroutines.cpp
@@ -21,7 +21,12 @@ void no_specialization() {
 template<typename ...T> struct std::coroutine_traits<int, T...> {};
 
 int no_promise_type() {
-  co_await a; // expected-error {{this function cannot be a coroutine: 'coroutine_traits<int>' has no member named 'promise_type'}}
+  co_await a; // expected-error {{this function cannot be a coroutine: 'std::coroutine_traits<int>' has no member named 'promise_type'}}
+}
+
+template<> struct std::coroutine_traits<double, double> { typedef int promise_type; };
+double bad_promise_type(double) {
+  co_await a; // expected-error {{this function cannot be a coroutine: 'std::coroutine_traits<double, double>::promise_type' (aka 'int') is not a class}}
 }
 
 struct promise; // expected-note {{forward declaration}}