needsUnsafe := false
	f.walk(arg, ctxExpr, func(f *File, arg interface{}, context astContext) {
		px, ok := arg.(*ast.Expr)
		if !ok {
			return
		}
		sel, ok := (*px).(*ast.SelectorExpr)
		if ok {
			if l, ok := sel.X.(*ast.Ident); !ok || l.Name != "C" {
				return
			}

			for _, r := range f.Ref {
				if r.Expr == px {

	// except in the definition (handled at end of function).
	refName := make(map[*ast.Expr]*Name)
	for _, r := range f.Ref {
		refName[r.Expr] = r.Name
	}
	for _, d := range f.AST.Decls {
		d, ok := d.(*ast.GenDecl)
		if !ok || d.Tok != token.TYPE {
			continue
		}
		for _, s := range d.Specs {
			s := s.(*ast.TypeSpec)
			n := refName[&s.Type]
			if n != nil && n.Mangle != "" {
				override[n.Mangle] = s.Name.Name
			}

// including forms involving multiple registers such as R1:R2.
func (p *Parser) register(name string, prefix rune) (r1, r2 int16, scale int8, ok bool) {
	// R1 or R(1) R1:R2 R1,R2 R1+R2, or R1*scale.
	r1, ok = p.registerReference(name)
	if !ok {
		return
	}
	if prefix != 0 && prefix != '*' { // *AX is OK.
		p.errorf("prefix %c not allowed for register: %c%s", prefix, prefix, name)
	}
	c := p.peek()

func (b *Buffer) grow(n int) int {
	m := b.Len()
	// If buffer is empty, reset to recover space.
	if m == 0 && b.off != 0 {
		b.Reset()
	}
	// Try to grow by means of a reslice.
	if i, ok := b.tryGrowByReslice(n); ok {
		return i
	}
	if b.buf == nil && n <= smallBufferSize {
		b.buf = make([]byte, n, smallBufferSize)
		return 0
	}
	c := cap(b.buf)
	if n <= c/2-m {

// 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)
	if !ok {
		return
	}
	offset = (0xe << 24) | // opcode
		(op1 << 20) | // MCR/MRC
		((int64(bits) ^ arm.C_SCOND_XOR) << 28) | // scond

			canSplitUSTAR := paxKey == paxPath
			if _, _, ok := splitUSTARPath(s); !canSplitUSTAR || !ok {
				whyNoUSTAR = fmt.Sprintf("USTAR cannot encode %s=%q", name, s)
				format.mustNotBe(FormatUSTAR)
			}
			if paxKey == paxNone {
				whyNoPAX = fmt.Sprintf("PAX cannot encode %s=%q", name, s)
				format.mustNotBe(FormatPAX)
			} else {
				paxHdrs[paxKey] = s
			}
		}
		if v, ok := h.PAXRecords[paxKey]; ok && v == s {

			}
			continue
		} else {
			if !test.ok {
				t.Fatalf("SetComment: unexpected success, want error")
			}
		}

		if err := w.Close(); test.ok == (err != nil) {
			t.Fatal(err)
		}

		if w.closed != test.ok {
			t.Fatalf("Writer.closed: got %v, want %v", w.closed, test.ok)
		}

		// skip read test in failure cases
		if !test.ok {
			continue
		}

		// read it back

				"SCHILY.xattr.key": "value",
			},
		},
		ok: true,
	}}

	for i, v := range vectors {
		got := new(Header)
		err := mergePAX(got, v.in)
		if v.ok && !reflect.DeepEqual(*got, *v.want) {
			t.Errorf("test %d, mergePAX(...):\ngot  %+v\nwant %+v", i, *got, *v.want)
		}
		if ok := err == nil; ok != v.ok {
			t.Errorf("test %d, mergePAX(...): got %v, want %v", i, ok, v.ok)
		}
	}
}

			isDir := len(file.Name) > 0 && file.Name[len(file.Name)-1] == '/'
			name := toValidName(file.Name)
			if name == "" {
				continue
			}

			if idx, ok := files[name]; ok {
				r.fileList[idx].isDup = true
				continue
			}
			if idx, ok := knownDirs[name]; ok {
				r.fileList[idx].isDup = true
				continue
			}

			for dir := path.Dir(name); dir != "."; dir = path.Dir(dir) {
				dirs[dir] = true
			}

func crawl(url string, sourceURL string) {
	if strings.Contains(url, "/devel/release") {
		return
	}
	mu.Lock()
	defer mu.Unlock()
	if u, frag, ok := strings.Cut(url, "#"); ok {
		url = u
		if frag != "" {
			uf := urlFrag{url, frag}
			neededFrags[uf] = append(neededFrags[uf], sourceURL)
		}
	}
	if crawled[url] {
		return
	}
	crawled[url] = true

	wg.Add(1)