Adding a -Wunused-value warning for expressions with side effects used in an unevaluated expression context, such as sizeof(), or decltype(). Also adds a similar warning when the expression passed to typeid() *is* evaluated, since it is equally likely that the user would expect the expression operand to be unevaluated in that case.

llvm-svn: 224465

1 files changed, 1 insertions, 1 deletions

diff --git a/clang/test/CXX/expr/expr.prim/expr.prim.lambda/p2-generic-lambda-1y.cpp b/clang/test/CXX/expr/expr.prim/expr.prim.lambda/p2-generic-lambda-1y.cpp
index 03147a692dd..d791ed60cfc 100644
--- a/clang/test/CXX/expr/expr.prim/expr.prim.lambda/p2-generic-lambda-1y.cpp
+++ b/clang/test/CXX/expr/expr.prim/expr.prim.lambda/p2-generic-lambda-1y.cpp
@@ -18,7 +18,7 @@ void unevaluated_operand(P &p, int i) { //expected-note{{declared here}}
   // FIXME: this should only emit one error.
   int i2 = sizeof([](auto a, auto b)->void{}(3, '4')); // expected-error{{lambda expression in an unevaluated operand}} \
                                                        // expected-error{{invalid application of 'sizeof'}}
-  const std::type_info &ti1 = typeid([](auto &a) -> P& { static P p; return p; }(i));
+  const std::type_info &ti1 = typeid([](auto &a) -> P& { static P p; return p; }(i)); // expected-warning {{expression with side effects will be evaluated despite being used as an operand to 'typeid'}}
   const std::type_info &ti2 = typeid([](auto) -> int { return i; }(i));  // expected-error{{lambda expression in an unevaluated operand}}\
                                                                          // expected-error{{cannot be implicitly captured}}\
                                                                          // expected-note{{begins here}}