ast1 := parse(abspath, src, parser.SkipObjectResolution|parser.ParseComments)
	ast2 := parse(abspath, src, parser.SkipObjectResolution)

	f.Package = ast1.Name.Name
	f.Name = make(map[string]*Name)
	f.NamePos = make(map[*Name]token.Pos)

	// In ast1, find the import "C" line and get any extra C preamble.
	sawC := false
	for _, decl := range ast1.Decls {
		switch decl := decl.(type) {
		case *ast.GenDecl: