void foo() {
// expected-error@+1 2{{use of undeclared identifier 'a'}}
a = 2; a = 2;
// expected-error@+1 2{{use of undeclared identifier 'b'}}
b = 2; b = 2;
// expected-error@+1 2{{use of undeclared identifier 'c'}}
c = 2; c = 2;
}