llvm-project/clang/test/SemaCXX/function-extern-c.cpp

54 lines
1.6 KiB
C++

// RUN: %clang_cc1 -Wreturn-type -fsyntax-only -std=c++11 -verify %s
class A {
public:
A(const A&);
};
struct S {
int i;
double d;
virtual void B() {}
};
union U {
struct {
int i;
virtual void B() {} // Can only do this in C++11
} t;
};
struct S2 {
int i;
double d;
};
extern "C" U f3( void ); // expected-warning {{'f3' has C-linkage specified, but returns user-defined type 'U' which is incompatible with C}}
extern "C" S f0(void); // expected-warning {{'f0' has C-linkage specified, but returns user-defined type 'S' which is incompatible with C}}
extern "C" A f4( void ); // expected-warning {{'f4' has C-linkage specified, but returns user-defined type 'A' which is incompatible with C}}
// These should all be fine
extern "C" S2 f5( void );
extern "C" void f2( A x );
extern "C" void f6( S s );
extern "C" void f7( U u );
extern "C" double f8(void);
extern "C" long long f11( void );
extern "C" A *f10( void );
extern "C" struct mypodstruct f12(); // expected-warning {{'f12' has C-linkage specified, but returns incomplete type 'struct mypodstruct' which could be incompatible with C}}
namespace test2 {
// FIXME: we should probably suppress the first warning as the second one
// is more precise.
// For now this tests that a second 'extern "C"' is not necessary to trigger
// the warning.
struct A;
extern "C" A f(void); // expected-warning {{'f' has C-linkage specified, but returns incomplete type 'test2::A' which could be incompatible with C}}
struct A {
A(const A&);
};
A f(void); // expected-warning {{'f' has C-linkage specified, but returns user-defined type 'test2::A' which is incompatible with C}}
}