Compiling the following program:

#define STDCALL __attribute__((stdcall))

struct  B1 {
	int x;
	virtual int STDCALL bar(int x) = 0;
};

struct  B2 {
	int x;
	virtual int STDCALL foo(int x) = 0;
};

struct D: B1, B2 {
	int a;
	int STDCALL bar(int n);
	int STDCALL foo(int n);
};

int STDCALL
D::bar(int n) {
	return a + n;
}

int STDCALL
D::foo(int n) {
	return a + n;
}

with "gcc -x c++ gccbug5.c" on MinGW results in the following error message:

gccbug5.c:26: error: 'int *LTHUNK0(int)' aliased to undefined symbol '_ZN1D3fooEi'