1 // RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 %s 2 3 int f() __attribute__((warn_unused_result)); 4 5 struct S { 6 void t() const; 7 }; 8 S g1() __attribute__((warn_unused_result)); 9 S *g2() __attribute__((warn_unused_result)); 10 S &g3() __attribute__((warn_unused_result)); 11 12 void test() { 13 f(); // expected-warning {{ignoring return value}} 14 g1(); // expected-warning {{ignoring return value}} 15 g2(); // expected-warning {{ignoring return value}} 16 g3(); // expected-warning {{ignoring return value}} 17 18 (void)f(); 19 (void)g1(); 20 (void)g2(); 21 (void)g3(); 22 23 if (f() == 0) return; 24 25 g1().t(); 26 g2()->t(); 27 g3().t(); 28 29 int i = f(); 30 S s1 = g1(); 31 S *s2 = g2(); 32 S &s3 = g3(); 33 const S &s4 = g1(); 34 } 35 36 struct X { 37 int foo() __attribute__((warn_unused_result)); 38 }; 39 40 void bah() { 41 X x, *x2; 42 x.foo(); // expected-warning {{ignoring return value}} 43 x2->foo(); // expected-warning {{ignoring return value}} 44 } 45 46 namespace warn_unused_CXX11 { 47 struct [[clang::warn_unused_result]] Status { 48 bool ok() const; 49 Status& operator=(const Status& x); 50 inline void Update(const Status& new_status) { 51 if (ok()) { 52 *this = new_status; //no-warning 53 } 54 } 55 }; 56 Status DoSomething(); 57 Status& DoSomethingElse(); 58 Status* DoAnotherThing(); 59 Status** DoYetAnotherThing(); 60 void lazy() { 61 Status s = DoSomething(); 62 if (!s.ok()) return; 63 Status &rs = DoSomethingElse(); 64 if (!rs.ok()) return; 65 Status *ps = DoAnotherThing(); 66 if (!ps->ok()) return; 67 Status **pps = DoYetAnotherThing(); 68 if (!(*pps)->ok()) return; 69 70 (void)DoSomething(); 71 (void)DoSomethingElse(); 72 (void)DoAnotherThing(); 73 (void)DoYetAnotherThing(); 74 75 DoSomething(); // expected-warning {{ignoring return value}} 76 DoSomethingElse(); // expected-warning {{ignoring return value}} 77 DoAnotherThing(); // expected-warning {{ignoring return value}} 78 DoYetAnotherThing(); 79 } 80 } 81 82 namespace PR17587 { 83 struct [[clang::warn_unused_result]] Status; 84 85 struct Foo { 86 Status Bar(); 87 }; 88 89 struct Status {}; 90 91 void Bar() { 92 Foo f; 93 f.Bar(); // expected-warning {{ignoring return value}} 94 }; 95 96 } 97
