return
	}

	if string(line) == "!<arch>\n" {
		// Archive file. Scan to __.PKGDEF.
		var name string
		if name, size, err = readGopackHeader(r); err != nil {
			return
		}

		// First entry should be __.PKGDEF.
		if name != "__.PKGDEF" {
			err = fmt.Errorf("go archive is missing __.PKGDEF")
			return
		}

		// Read first line of __.PKGDEF data, so that line
		// is once again the first line of the input.

			goto close
		}

		for _, e := range aro.Entries {
			if e.Type != archive.EntryPkgDef {
				continue
			}
			if verbose {
				fmt.Printf("__.PKGDEF # %s\n", file)
			}
			ar.a.AddEntry(archive.EntryPkgDef, "__.PKGDEF", 0, 0, 0, 0644, e.Size, io.NewSectionReader(f, e.Offset, e.Size))
			done = true
		}
	close:
		f.Close()
		if done {
			break
		}
	}
}

	"fmt"
	"internal/xcoff"
	"io"
	"io/fs"
	"os"
	"strconv"
	"strings"
)

var (
	errBuildIDMalformed = fmt.Errorf("malformed object file")

	bangArch = []byte("!<arch>")
	pkgdef   = []byte("__.PKGDEF")
	goobject = []byte("go object ")
	buildid  = []byte("build id ")
)

// ReadFile reads the build ID from an archive or executable file.
func ReadFile(name string) (id string, err error) {

		}
		if err != nil {
			return errCorruptArchive
		}
		data = data[60:]
		fsize := size + size&1
		if fsize < 0 || fsize < size {
			return errCorruptArchive
		}
		switch name {
		case "__.PKGDEF":
			r.a.Entries = append(r.a.Entries, Entry{
				Name:  name,
				Type:  EntryPkgDef,
				Mtime: mtime,
				Uid:   uid,
				Gid:   gid,
				Mode:  mode,
				Data:  Data{r.offset, size},
			})

	out := run("./a.out")
	if out != "hello world\n" {
		t.Fatalf("incorrect output: %q, want %q", out, "hello world\n")
	}
}

// Test that pack works with very long lines in PKGDEF.
func TestLargeDefs(t *testing.T) {
	if testing.Short() {
		t.Skip("skipping in -short mode")
	}
	testenv.MustHaveGoBuild(t)

	dir := t.TempDir()
	large := filepath.Join(dir, "large.go")

	Segpdata     sym.Segment // windows-only
	Segxdata     sym.Segment // windows-only

	Segments = []*sym.Segment{&Segtext, &Segrodata, &Segrelrodata, &Segdata, &Segdwarf, &Segpdata, &Segxdata}
)

const pkgdef = "__.PKGDEF"

var (
	// externalobj is set to true if we see an object compiled by
	// the host compiler that is not from a package that is known
	// to support internal linking mode.
	externalobj = false

	errorReporter *ErrorReporter

	npkgsyms    int // number of package symbols, for accounting
	nhashedsyms int // number of hashed symbols, for accounting
}

const (
	pkgDef = iota
	hashed64Def
	hashedDef
	nonPkgDef
	nonPkgRef
)

// objidx
const (
	nilObj = iota
	extObj
	goObjStart
)