golang buildtag 代码
文件路径：/src/cmd/vet/testdata/buildtag/buildtag.go
/ Copyright 2013 The Go Authors. All rights reserved.
/ Use of this source code is governed by a BSD-style
/ license that can be found in the LICENSE file.
/ This file contains tests for the buildtag checker.
/ ERRORNEXT "possible malformed [+]build comment"
/ +builder
/ +build !ignore
package testdata
/ ERRORNEXT "misplaced \+build comment"
/ +build toolate
var _ = 3
var _ = `
/ +build notacomment
`