BuiltinOperatorOverloadBuilder: Don't consider types that are unavailable on the target (PR35174)

In the PR, Clang ended up in a situation where it tried to mangle the
__float128 type, which isn't supported when targetingt MSVC, because
Clang instantiated a variable template with that type when searching for
a conversion to use in an arithmetic expression.

Differential revision: https://reviews.llvm.org/D39579

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@318309 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 34 insertions, 0 deletions

diff --git a/test/SemaCXX/microsoft-vs-float128.cpp b/test/SemaCXX/microsoft-vs-float128.cpp
new file mode 100644
index 0000000000..d271e47003
--- /dev/null
+++ b/test/SemaCXX/microsoft-vs-float128.cpp
@@ -0,0 +1,34 @@
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -fms-compatibility -fms-extensions -fsyntax-only -verify -std=c++11 %s
+// RUN: %clang_cc1 -triple i686-pc-win32 -fms-compatibility -fms-extensions -fsyntax-only -verify -std=c++11 -DMS %s
+
+template <bool> struct enable_if {};
+template<> struct enable_if<true> { typedef void type; };
+
+template <typename, typename> struct is_same { static constexpr bool value = false; };
+template <typename T> struct is_same<T, T> { static constexpr bool value = true; };
+
+
+
+
+struct S {
+  // The only numeric types S can be converted to is __int128 and __float128.
+  template <typename T, typename = typename enable_if<
+                            !((__is_integral(T) && sizeof(T) != 16) ||
+                              is_same<T, float>::value ||
+                              is_same<T, double>::value ||
+                              is_same<T, long double>::value)>::type>
+  operator T() { return T(); }
+};
+
+void f() {
+#ifdef MS
+  // When targeting Win32, __float128 and __int128 do not exist, so the S
+  // object cannot be converted to anything usable in the expression.
+  // expected-error@+2{{invalid operands to binary expression ('S' and 'double')}}
+#endif
+  double d = S() + 1.0;
+#ifndef MS
+  // expected-error@-2{{use of overloaded operator '+' is ambiguous}}
+  // expected-note@-3 36{{built-in candidate operator+}}
+#endif
+}