1 files changed, 65 insertions, 0 deletions
diff --git a/test/SemaCXX/std-compare-cxx2a.cpp b/test/SemaCXX/std-compare-cxx2a.cpp
new file mode 100644
index 0000000000000..6746fb480e62b
--- /dev/null
+++ b/test/SemaCXX/std-compare-cxx2a.cpp
@@ -0,0 +1,65 @@
+// Test diagnostics for ill-formed STL <compare> headers.
+
+// RUN: %clang_cc1 -triple x86_64-apple-darwin -fcxx-exceptions -fsyntax-only -pedantic -verify -Wsign-compare -std=c++2a %s
+
+void compare_not_found_test() {
+  // expected-error@+1 {{cannot deduce return type of 'operator<=>' because type 'std::partial_ordering' was not found; include <compare>}}
+  (void)(0.0 <=> 42.123);
+}
+
+namespace std {
+inline namespace __1 {
+struct partial_ordering; // expected-note {{forward declaration}}
+}
+} // namespace std
+
+auto compare_incomplete_test() {
+  // expected-error@+1 {{incomplete type 'std::partial_ordering' where a complete type is required}}
+  return (-1.2 <=> 123.0);
+}
+
+namespace std {
+inline namespace __1 {
+struct partial_ordering {
+  unsigned value;
+};
+} // namespace __1
+} // namespace std
+
+auto missing_member_test() {
+  // expected-error@+1 {{standard library implementation of 'std::partial_ordering' is not supported; member 'equivalent' is missing}}
+  return (1.0 <=> 1.0);
+}
+
+namespace std {
+inline namespace __1 {
+struct strong_ordering {
+  long long value;
+  static const strong_ordering equivalent; // expected-note {{declared here}}
+};
+} // namespace __1
+} // namespace std
+
+auto test_non_constexpr_var() {
+  // expected-error@+1 {{standard library implementation of 'std::strong_ordering' is not supported; member 'equivalent' does not have expected form}}
+  return (1 <=> 0);
+}
+
+namespace std {
+inline namespace __1 {
+struct strong_equality {
+  char value = 0;
+  constexpr strong_equality() = default;
+  // non-trivial
+  constexpr strong_equality(strong_equality const &other) : value(other.value) {}
+};
+} // namespace __1
+} // namespace std
+
+struct Class {};
+using MemPtr = void (Class::*)(int);
+
+auto test_non_trivial(MemPtr LHS, MemPtr RHS) {
+  // expected-error@+1 {{standard library implementation of 'std::strong_equality' is not supported; the type is not trivially copyable}}
+  return LHS <=> RHS;
+}