1// RUN: %clang_cc1 -Wreturn-type -fsyntax-only -std=c++11 -verify %s 2 3class A { 4public: 5 A(const A&); 6}; 7 8struct S { 9 int i; 10 double d; 11 12 virtual void B() {} 13}; 14 15union U { 16 struct { 17 int i; 18 virtual void B() {} // Can only do this in C++11 19 } t; 20}; 21 22struct S2 { 23 int i; 24 double d; 25}; 26 27extern "C" U f3( void ); // expected-warning {{'f3' has C-linkage specified, but returns user-defined type 'U' which is incompatible with C}} 28extern "C" S f0(void); // expected-warning {{'f0' has C-linkage specified, but returns user-defined type 'S' which is incompatible with C}} 29extern "C" A f4( void ); // expected-warning {{'f4' has C-linkage specified, but returns user-defined type 'A' which is incompatible with C}} 30 31// These should all be fine 32extern "C" S2 f5( void ); 33extern "C" void f2( A x ); 34extern "C" void f6( S s ); 35extern "C" void f7( U u ); 36extern "C" double f8(void); 37extern "C" long long f11( void ); 38extern "C" A *f10( void ); 39 40extern "C" struct mypodstruct f12(); // expected-warning {{'f12' has C-linkage specified, but returns incomplete type 'struct mypodstruct' which could be incompatible with C}} 41 42namespace test2 { 43 // FIXME: we should probably suppress the first warning as the second one 44 // is more precise. 45 // For now this tests that a second 'extern "C"' is not necessary to trigger 46 // the warning. 47 struct A; 48 extern "C" A f(void); // expected-warning {{'f' has C-linkage specified, but returns incomplete type 'test2::A' which could be incompatible with C}} 49 struct A { 50 A(const A&); 51 }; 52 A f(void); // no warning. warning is already issued on first declaration. 53} 54 55namespace test3 { 56 struct A { 57 A(const A&); 58 }; 59 extern "C" { 60 // Don't warn for static functions. 61 static A f(void); 62 } 63} 64 65// rdar://13364028 66namespace rdar13364028 { 67class A { 68public: 69 virtual int x(); 70}; 71 72extern "C" { 73#pragma clang diagnostic push 74#pragma clang diagnostic ignored "-Wreturn-type-c-linkage" 75A xyzzy(); 76#pragma clang diagnostic pop 77A bbb(); // expected-warning {{'bbb' has C-linkage specified, but returns user-defined type 'rdar13364028::A' which is incompatible with C}} 78A ccc() { // expected-warning {{'ccc' has C-linkage specified, but returns user-defined type 'rdar13364028::A' which is incompatible with C}} 79 return A(); 80}; 81} 82 83A xyzzy(); 84 85A xyzzy() 86{ 87 return A(); 88} 89 90A bbb() 91{ 92 return A(); 93} 94 95A bbb(); 96 97A ccc(); 98} 99