*this is const in a trailing-return-type for a constexpr member function.

llvm-svn: 172375

clang/lib/Parse/ParseDecl.cpp

@@ -4761,7 +4761,9 @@ void Parser::ParseFunctionDeclarator(Declarator &D,
           Actions.CurContext->isRecord()));
       Sema::CXXThisScopeRAII ThisScope(Actions,
                                dyn_cast<CXXRecordDecl>(Actions.CurContext),
-                               DS.getTypeQualifiers(),
+                               DS.getTypeQualifiers() |
+                               (D.getDeclSpec().isConstexprSpecified()
+                                  ? Qualifiers::Const : 0),
                                IsCXX11MemberFunction);
 
       // Parse exception-specification[opt].

clang/test/Parser/cxx0x-decl.cpp

@@ -41,3 +41,11 @@ struct SS {
 };
 
 using PR14855 = int S::; // expected-error {{expected ';' after alias declaration}}
+
+// Ensure that 'this' has a const-qualified type in a trailing return type for
+// a constexpr function.
+struct ConstexprTrailingReturn {
+  int n;
+  constexpr auto f() -> decltype((n));
+};
+constexpr const int &ConstexprTrailingReturn::f() const { return n; }