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
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 03147a6..d791ed6 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 @@
// 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}}