[MSVC2012] Allow 'mutable' references

Some standard header files from MSVC2012 use 'mutable' on references, though it is directly prohibited by the standard.
Fix for http://llvm.org/PR22444
Differential Revision: http://reviews.llvm.org/D7370

llvm-svn: 228113

1 files changed, 13 insertions, 0 deletions

diff --git a/clang/test/SemaCXX/ms_mutable_reference_member.cpp b/clang/test/SemaCXX/ms_mutable_reference_member.cpp
new file mode 100644
index 00000000000..ae1389d3336
--- /dev/null
+++ b/clang/test/SemaCXX/ms_mutable_reference_member.cpp
@@ -0,0 +1,13 @@
+// RUN: %clang_cc1 %s -fsyntax-only -verify -fms-compatibility
+
+struct S {
+  mutable int &a; // expected-warning {{'mutable' on a reference type is a Microsoft extension}}
+  S(int &b) : a(b) {}
+};
+
+int main() {
+  int a = 0;
+  const S s(a);
+  s.a = 10;
+  return s.a + a;
+}