llvm-project/clang/test/SemaCXX/unused.cpp

64 lines
1.4 KiB
C++

// RUN: %clang_cc1 -fsyntax-only -verify %s
// PR4103 : Make sure we don't get a bogus unused expression warning
namespace PR4103 {
class APInt {
char foo;
};
class APSInt : public APInt {
char bar;
public:
APSInt &operator=(const APSInt &RHS);
};
APSInt& APSInt::operator=(const APSInt &RHS) {
APInt::operator=(RHS);
return *this;
}
template<typename T>
struct X {
X();
};
void test() {
X<int>();
}
}
namespace derefvolatile {
void f(volatile char* x) {
*x; // expected-warning {{expression result unused; assign into a variable to force a volatile load}}
(void)*x; // expected-warning {{expression result unused; assign into a variable to force a volatile load}}
volatile char y = 10;
(void)y; // don't warn here, because it's a common pattern.
}
}
// <rdar://problem/12359208>
namespace AnonObject {
struct Foo {
Foo(const char* const message);
~Foo();
};
void f() {
Foo("Hello World!"); // don't warn
int(1); // expected-warning {{expression result unused}}
}
}
// Test that constructing an object (which may have side effects) with
// constructor arguments which are dependent doesn't produce an unused value
// warning.
namespace UnresolvedLookup {
struct Foo {
Foo(int i, int j);
};
template <typename T>
struct Bar {
void f(T t) {
Foo(t, 0); // no warning
}
};
}