"slices"
	"strings"
	"time"
)

// Writer provides sequential writing of a tar archive.
// [Writer.WriteHeader] begins a new file with the provided [Header],
// and then Writer can be treated as an io.Writer to supply that file's data.
type Writer struct {
	w    io.Writer
	pad  int64      // Amount of padding to write after current file entry
	curr fileWriter // Writer for current file entry

	return tags, nil
}

// repoSum returns a checksum of the entire repo state,
// which can be checked (as Origin.RepoSum) to cache
// the absence of a specific module version.
// The caller must supply refs, the result of a successful r.loadRefs.
func (r *gitRepo) repoSum(refs map[string]string) string {
	var list []string
	for ref := range refs {
		list = append(list, ref)
	}
	sort.Strings(list)

	actionID cache.ActionID // cache ID of action input
	buildID  string         // build ID of action output

	VetxOnly  bool       // Mode=="vet": only being called to supply info about dependencies
	needVet   bool       // Mode=="build": need to fill in vet config
	needBuild bool       // Mode=="build": need to do actual build (can be false if needVet is true)
	vetCfg    *vetConfig // vet config

	c.Cancel = func() error { return c.Process.Signal(os.Interrupt) }
	c.Dir = dir
	c.Stdin = stdin
	c.Stderr = &stderr
	c.Stdout = &stdout
	// For Git commands, manually supply GIT_DIR so Git works with safe.bareRepository=explicit set. Noop for other commands.
	c.Env = append(c.Environ(), "GIT_DIR="+dir)
	err := c.Run()
	if err != nil {

		testenv.MustHaveGoBuild(t) // Really just 'go tool cgo', but close enough.

		// The reportCgoError hook is global, so we can't set it per-test
		// if we want to be able to run those tests in parallel.
		// Instead, simply set it to panic on error: the goroutine dump
		// from the panic should help us determine which test failed.
		prevReportCgoError := reportCgoError
		reportCgoError = func(err error) {

			if p.ImportPath == "runtime/cgo" && strings.HasPrefix(sfile, "gcc_") {
				continue
			}
			op, _ := fsys.OverlayPath(mkAbs(p.Dir, sfile))
			args = append(args, op)
		}

		// Supply an empty go_asm.h as if the compiler had been run.
		// -gensymabis parsing is lax enough that we don't need the
		// actual definitions that would appear in go_asm.h.

See also: go build, go vet.
`,
}

var HelpTestflag = &base.Command{
	UsageLine: "testflag",
	Short:     "testing flags",
	Long: `
The 'go test' command takes both flags that apply to 'go test' itself
and flags that apply to the resulting test binary.

Several of the flags control profiling and write an execution profile
suitable for "go tool pprof"; run "go tool pprof -h" for more

}

func (pos Pos) RelCol() uint {
	b := pos.base
	if b.Col() == 0 {
		// base column is unknown => relative column is unknown
		// (the current specification for line directives requires
		// this to apply until the next PosBase/line directive,
		// not just until the new newline)
		return 0
	}
	if pos.Line() == b.Pos().Line() {
		// pos on same line as pos base => column is relative to pos base

		A regular expression specifying additional flags to allow
		to appear in #cgo CFLAGS source code directives.
		Does not apply to the CGO_CFLAGS environment variable.
	CGO_CFLAGS_DISALLOW
		A regular expression specifying flags that must be disallowed
		from appearing in #cgo CFLAGS source code directives.
		Does not apply to the CGO_CFLAGS environment variable.
	CGO_CPPFLAGS, CGO_CPPFLAGS_ALLOW, CGO_CPPFLAGS_DISALLOW

//			significantly more expensive.
//		Sets -cover.
//	-coverpkg pattern1,pattern2,pattern3
//		For a build that targets package 'main' (e.g. building a Go
//		executable), apply coverage analysis to each package matching
//		the patterns. The default is to apply coverage analysis to
//		packages in the main Go module. See 'go help packages' for a
//		description of package patterns.  Sets -cover.
//	-v