function-extern-c.cpp revision 168c07b93510aabd2a19af323d1132fffe498ee4 
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