/in/foo.c:1:1: warning: data definition has no type or storage class
    1 | pi = 0
      | ^~
/in/foo.c:1:1: warning: type defaults to 'int' in declaration of 'pi' [-Wimplicit-int]
/in/foo.c:2:1: error: expected ',' or ';' before 'sign'
    2 | sign = 1
      | ^~~~