foo.c:4:5: error: variably modified 'a' at file scope
foo.c:4:13: error: variably modified 'b' at file scope
foo.c:5:1: error: unknown type name 'bool'
foo.c:5:6: error: variably modified 'hash' at file scope
foo.c:6:1: error: unknown type name 'bool'
foo.c: In function 'init':
foo.c:24:36: error: 'false' undeclared (first use in this function)
foo.c:24:36: note: each undeclared identifier is reported only once for each function it appears in
foo.c:25:13: error: 'true' undeclared (first use in this function)
foo.c:26:1: warning: control reaches end of non-void function [-Wreturn-type]