defer wg.Done()

	req, err := http.NewRequest("GET", url, nil)
	if err != nil {
		return err
	}
	res, err := http.DefaultTransport.RoundTrip(req)
	if err != nil {
		return err
	}
	// Handle redirects.
	if res.StatusCode/100 == 3 {
		newURL, err := res.Location()
		if err != nil {
			return fmt.Errorf("resolving redirect: %v", err)
		}
		if !strings.HasPrefix(newURL.String(), *root) {

		if s := override[n.Go]; s != "" {
			override[n.Mangle] = s
		}
	}

	// Otherwise, if the source file says type T C.whatever,
	// use "T" as the mangling of C.whatever,
	// 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 {

	for i := riscv.REG_X0; i <= riscv.REG_X31; i++ {
		// Disallow X3 in shared mode, as this will likely be used as the
		// GP register, which could result in problems in non-Go code,
		// including signal handlers.
		if shared && i == riscv.REG_GP {
			continue
		}
		if i == riscv.REG_TP || i == riscv.REG_G {
			continue
		}
		name := fmt.Sprintf("X%d", i-riscv.REG_X0)
		register[name] = int16(i)
	}

	"strconv"
	"strings"
	"text/scanner"

	"cmd/asm/internal/flags"
	"cmd/internal/objabi"
	"cmd/internal/src"
)

// Input is the main input: a stack of readers and some macro definitions.
// It also handles #include processing (by pushing onto the input stack)
// and parses and instantiates macro definitions.
type Input struct {
	Stack
	includes        []string
	beginningOfLine bool
	ifdefStack      []bool

	realName, realSize := hdr.Name, hdr.Size

	// TODO(dsnet): Re-enable this when adding sparse support.
	// See https://golang.org/issue/22735
	/*
		// Handle sparse files.
		var spd sparseDatas
		var spb []byte
		if len(hdr.SparseHoles) > 0 {
			sph := append([]sparseEntry{}, hdr.SparseHoles...) // Copy sparse map
			sph = alignSparseEntries(sph, hdr.Size)

		}
		if asciiSpace[c] == 0 {
			break
		}
	}

	// At this point s[start:stop] starts and ends with an ASCII
	// non-space bytes, so we're done. Non-ASCII cases have already
	// been handled above.
	if start == stop {
		// Special case to preserve previous TrimLeftFunc behavior,
		// returning nil instead of empty slice if all spaces.
		return nil
	}
	return s[start:stop]
}

	// ARM only.
	if !p.arch.InFamily(sys.ARM, sys.ARM64) {
		return false
	}
	// R1<<...
	if lex.IsRegisterShift(p.peek()) {
		return true
	}
	// R(1)<<...   Ugly check. TODO: Rethink how we handle ARM register shifts to be
	// less special.
	if p.peek() != '(' || len(p.input)-p.inputPos < 4 {
		return false
	}
	return p.at('(', scanner.Int, ')') && lex.IsRegisterShift(p.input[p.inputPos+3].ScanToken)
}

	"cmd/asm/internal/arch"
	"cmd/asm/internal/lex"
	"cmd/internal/obj"
)

// A simple in-out test: Do we print what we parse?

func setArch(goarch string) (*arch.Arch, *obj.Link) {
	buildcfg.GOOS = "linux" // obj can handle this OS for all architectures.
	buildcfg.GOARCH = goarch
	architecture := arch.Set(goarch, false)
	if architecture == nil {
		panic("asm: unrecognized architecture " + goarch)
	}

and of course there is nothing stopping the C code from doing anything
it likes. However, programs that break these rules are likely to fail
in unexpected and unpredictable ways.

The runtime/cgo.Handle type can be used to safely pass Go values
between Go and C. See the runtime/cgo package documentation for details.

Note: the current implementation has a bug. While Go code is permitted

		},
		// ReadLine doesn't fit the data/pattern easily
		// so we leave it out. It should be covered via
		// the ReadSlice test since ReadLine simply calls
		// ReadSlice, and it's that function that handles
		// the last byte.
	}

	// Try all readers with UnreadByte.
	for rno, read := range readers {
		// Some input data that is longer than the minimum reader buffer size.
		const n = 10
		var buf bytes.Buffer