// The Go build system's swarming user is known not to be root.
		// Unfortunately, it sometimes appears as root due the current
		// implementation of a no-network check using 'unshare -n -r'.
		// Since this test does need root to work, we need to skip it.
		t.Skip("skipping root only test on a non-root builder")
	}
	if runtime.GOOS == "linux" {
		if _, err := os.Stat("/etc/alpine-release"); err == nil {

// operations do not read across the boundary and cause a page
// fault where they shouldn't.

// These tests run only on linux. The code being tested is
// not OS-specific, so it does not need to be tested on all
// operating systems.

// dangerousSlice returns a slice which is immediately
// preceded and followed by a faulting page.
func dangerousSlice(t *testing.T) []byte {
	pagesize := syscall.Getpagesize()

	var s scanner.Scanner
	s.Init(r)
	// Newline is like a semicolon; other space characters are fine.
	s.Whitespace = 1<<'\t' | 1<<'\r' | 1<<' '
	// Don't skip comments: we need to count newlines.
	s.Mode = scanner.ScanChars |
		scanner.ScanFloats |
		scanner.ScanIdents |
		scanner.ScanInts |
		scanner.ScanStrings |
		scanner.ScanComments
	s.Position.Filename = name

// The difference between MRC and MCR is represented by a bit high in the word, not
// in the usual way by the opcode itself. Asm must use AMRC for both instructions, so
// we return the opcode for MRC so that asm doesn't need to import obj/arm.
func ARMMRCOffset(op obj.As, cond string, x0, x1, x2, x3, x4, x5 int64) (offset int64, op0 obj.As, ok bool) {
	op1 := int64(0)
	if op == arm.AMRC {
		op1 = 1
	}
	bits, ok := ParseARMCondition(cond)

		return
	}

	f.formatOctal(b, 0) // Last resort, just write zero
	f.err = ErrFieldTooLong
}

func (p *parser) parseOctal(b []byte) int64 {
	// Because unused fields are filled with NULs, we need
	// to skip leading NULs. Fields may also be padded with
	// spaces or NULs.
	// So we remove leading and trailing NULs and spaces to
	// be sure.
	b = bytes.Trim(b, " \x00")

	if len(b) == 0 {
		return 0

//export Gosched
func Gosched() {
	runtime.Gosched()
}

func init() {
	testThreadLockFunc = testThreadLock
}

func testThreadLock(t *testing.T) {
	stop := make(chan int)
	go func() {
		// We need the G continue running,
		// so the M has a chance to run this G.
		for {
			select {
			case <-stop:
				return
			case <-time.After(time.Millisecond * 100):
			}
		}
	}()
	defer close(stop)

// the text of the most recently returned token is, and where it was found.
// The underlying scanner elides all spaces except newline, so the input looks like a stream of
// Tokens; original spacing is lost but we don't need it.
type TokenReader interface {
	// Next returns the next token.
	Next() ScanToken
	// The following methods all refer to the most recent token returned by Next.