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// RUN: %clang_cc1 -fsyntax-only -verify -Wunused %s
// RUN: %clang_cc1 -fsyntax-only -verify -std=c++98 -Wunused %s
// RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 -Wunused %s
// RUN: %clang_cc1 -fsyntax-only -verify -std=c++17 -Wunused %s
// PR4103 : Make sure we don't get a bogus unused expression warning
namespace PR4103 {
class APInt {
char foo; // expected-warning {{private field 'foo' is not used}}
};
class APSInt : public APInt {
char bar; // expected-warning {{private field 'bar' is not used}}
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;
#if __cplusplus <= 199711L
// expected-warning@-2 {{expression result unused; assign into a variable to force a volatile load}}
#endif
(void)*x;
#if __cplusplus <= 199711L
// expected-warning@-2 {{expression result unused; assign into a variable to force a volatile load}}
#endif
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
}
};
}
#if __cplusplus >= 201703L
namespace PR33839 {
void a() {
struct X { int a, b; } x;
auto [a, b] = x; // expected-warning {{unused variable '[a, b]'}}
auto [c, d] = x;
(void)d;
}
template<typename T> void f() {
struct A { int n; } a[1];
for (auto [x] : a) {
(void)x;
}
auto [y] = a[0]; // expected-warning {{unused}}
}
template<bool b> void g() {
struct A { int n; } a[1];
for (auto [x] : a) {
if constexpr (b)
(void)x;
}
auto [y] = a[0];
if constexpr (b)
(void)y; // ok, even when b == false
}
template<typename T> void h() {
struct A { int n; } a[1];
for (auto [x] : a) { // expected-warning {{unused variable '[x]'}}
}
}
void use() {
f<int>(); // expected-note {{instantiation of}}
g<true>();
g<false>();
h<int>(); // expected-note {{instantiation of}}
}
}
#endif
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