var buildtagFix = fix{
	name: "buildtag",
	date: "2021-08-25",
	f:    buildtag,
	desc: `Remove +build comments from modules using Go 1.18 or later`,
}

func buildtag(f *ast.File) bool {
	if version.Compare(*goVersion, buildtagGoVersionCutoff) < 0 {
		return false
	}

	// File is already gofmt-ed, so we know that if there are +build lines,
	// they are in a comment group that starts with a //go:build line followed

	// since at that time the go directive wasn't clearly
	// specified as a toolchain requirement.
	//
	// TODO(adonovan): after go1.21, call GoVersion directly.
	pkgVersion := any(pass.Pkg).(interface{ GoVersion() string }).GoVersion()
	if !versions.AtLeast(pkgVersion, "go1.21") {
		return nil, nil
	}

	// disallowedSymbols returns the set of standard library symbols

	example.com/testdep v0.1.0 => ./testdep
)
-- go.mod.untidy --
module example.com/m

go $goversion

require example.com/dep v0.1.0

require example.com/testdep v0.1.0 // indirect

replace (
	example.com/dep v0.1.0 => ./dep
	example.com/testdep v0.1.0 => ./testdep
)
-- go.mod.tidy --
module example.com/m

go $goversion

require example.com/dep v0.1.0

replace (
	example.com/dep v0.1.0 => ./dep

env GOWORK=$GOPATH/src/unformatted
go work edit -print -fmt
cmp stdout $GOPATH/src/formatted

-- m/go.mod --
module m

go 1.18
-- go.work.want_initial --
go $goversion

use ./m
-- go.work.want_use_n --
go $goversion

use (
	./m
	./n
)
-- go.work.want_go_118 --
go 1.18

use (
	./m
	./n
)
-- go.work.want_dropuse_m --
go 1.18

use ./n

// version of the form "v1.2.3". Go versions may also include spaces and
// special characters.
func ProgramInfo(info *debug.BuildInfo) (goVers, progPath, progVers string) {
	goVers = info.GoVersion
	if strings.Contains(goVers, "devel") || strings.Contains(goVers, "-") {
		goVers = "devel"
	}

	progPath = info.Path
	if progPath == "" {
		progPath = strings.TrimSuffix(filepath.Base(os.Args[0]), ".exe")
	}

				if isGoBinaryCandidate(file, info) {
					fmt.Fprintf(os.Stderr, "%s: %v\n", file, err)
				}
			}
		}
		return
	}

	fmt.Printf("%s: %s\n", file, bi.GoVersion)
	bi.GoVersion = "" // suppress printing go version again
	mod := bi.String()
	if *versionM && len(mod) > 0 {
		fmt.Printf("\t%s\n", strings.ReplaceAll(mod[:len(mod)-1], "\n", "\n\t"))
	}

)

var (
	VersionInfo = []string{"major", "minor", "gitVersion", "gitCommit", "gitTreeState", "buildDate", "goVersion", "compiler", "platform"}
)

func TestCmdVersion(t *testing.T) {
	var versionTest = []struct {
		name     string
		args     string

! stderr .+

# go env -w rejects unknown or bad variables
! go env -w GOGC=off
stderr 'unknown go command variable GOGC'
! go env -w GOEXE=.bat
stderr 'GOEXE cannot be modified'
! go env -w GOVERSION=customversion
stderr 'GOVERSION cannot be modified'
! go env -w GOENV=/env
stderr 'GOENV can only be set using the OS environment'
! go env -w GODEBUG=gctrace=1
stderr 'GODEBUG can only be set using the OS environment'

// then a 5-byte indicator sequence unlikely to occur in real x86 instructions,
// then a randomly-chosen 24-byte sequence, and finally a return instruction
// (the target of the jump).
//
// These sequences are known to rsc.io/goversion.

#define START \
	BYTE $0xEB; BYTE $0x1D; BYTE $0xF4; BYTE $0x48; BYTE $0xF4; BYTE $0x4B; BYTE $0xF4

#define END \
	BYTE $0xC3

	Dir        string           `json:",omitempty"` // directory holding local copy of files, if any
	GoMod      string           `json:",omitempty"` // path to go.mod file describing module, if any
	GoVersion  string           `json:",omitempty"` // go version used in module
	Retracted  []string         `json:",omitempty"` // retraction information, if any (with -retracted or -u)