clang-1/test/Sema/predefined-function.c

// RUN: clang -fsyntax-only -verify -pedantic %s
 
int foo();
int foo()
{
	return 0;	
}

int bar();
int bar(int i) // expected-error {{previous definition is here}}
{
	return 0;
}
int bar() // expected-error {{redefinition of 'bar'}}
{
	return 0;
}

int foobar(int); // expected-error {{previous definition is here}}
int foobar() // expected-error {{redefinition of 'foobar'}}
{
	return 0;
}

int wibble(); // expected-error {{previous definition is here}}
float wibble() // expected-error {{redefinition of 'wibble'}}
{
	return 0.0f;
}