f.Edit.Insert(f.offset(f.AST.Name.End()), "; import _cgo_unsafe \"unsafe\"")
	}
	p.rewriteRef(f)
}

// loadDefines coerces gcc into spitting out the #defines in use
// in the file f and saves relevant renamings in f.Name[name].Define.
// Returns true if env:CC is Clang
func (f *File) loadDefines(gccOptions []string) bool {
	var b bytes.Buffer
	b.WriteString(builtinProlog)
	b.WriteString(f.Preamble)