if err != nil {
			log.Fatal(err)
		}
		if strings.HasSuffix(path, ".zip") {
			log.Fatalf("unexpected file during walk: %s", path)
		}
		name := filepath.ToSlash(path)
		w, err := zw.CreateRaw(&zip.FileHeader{
			Name:               name,
			Method:             zip.Store,
			CompressedSize64:   uint64(len(data)),
			UncompressedSize64: uint64(len(data)),
			CRC32:              crc32.ChecksumIEEE(data),
		})

	}
	if e.isDir {
		return &openDir{e, r.openReadDir(name), 0}, nil
	}
	rc, err := e.file.Open()
	if err != nil {
		return nil, err
	}
	return rc.(fs.File), nil
}

func split(name string) (dir, elem string, isDir bool) {
	if len(name) > 0 && name[len(name)-1] == '/' {
		isDir = true
		name = name[:len(name)-1]
	}
	i := len(name) - 1
	for i >= 0 && name[i] != '/' {
		i--

// into Go.
func testCallbackCallersSEH(t *testing.T) {
	testenv.SkipIfOptimizationOff(t) // This test requires inlining.
	if runtime.Compiler != "gc" {
		// The exact function names are not going to be the same.
		t.Skip("skipping for non-gc toolchain")
	}
	if runtime.GOARCH != "amd64" {
		// TODO: support SEH on other architectures.
		t.Skip("skipping on non-amd64")
	}

			}
			// Invent new Name for the two-result function.
			n := f.Name["2"+r.Name.Go]
			if n == nil {
				n = new(Name)
				*n = *r.Name
				n.AddError = true
				n.Mangle = "_C2func_" + n.Go
				f.Name["2"+r.Name.Go] = n
			}
			expr = getNewIdent(n.Mangle)
			r.Name = n
			break
		}
	case ctxExpr:
		switch r.Name.Kind {
		case "func":
			if builtinDefs[r.Name.C] != "" {

environment variables work in a similar way for C++ code.

# Go references to C

Within the Go file, C's struct field names that are keywords in Go
can be accessed by prefixing them with an underscore: if x points at a C
struct with a field named "type", x._type accesses the field.
C struct fields that cannot be expressed in Go, such as bit fields
or misaligned data, are omitted in the Go struct, replaced by

func (in *Input) define() {
	name := in.macroName()
	args, tokens := in.macroDefinition(name)
	in.defineMacro(name, args, tokens)
}

// defineMacro stores the macro definition in the Input.
func (in *Input) defineMacro(name string, args []string, tokens []Token) {
	if in.macros[name] != nil {
		in.Error("redefinition of macro:", name)
	}
	in.macros[name] = &Macro{
		name:   name,
		args:   args,
		tokens: tokens,

	entryNames := []string{`/`, `//`, `\`, `/test.txt`}
	var names []string
	for _, f := range r.File {
		names = append(names, f.Name)
		if _, err := f.Open(); err != nil {
			t.Errorf("Error opening %q: %v", f.Name, err)
		}
		if _, err := r.Open(f.Name); err == nil {
			t.Errorf("Opening %q with fs.FS API succeeded", f.Name)
		}
	}
	if !reflect.DeepEqual(names, entryNames) {

		return
	}
	if goname == "malloc" {
		goname = "_CMalloc"
	}
	name := f.Name[goname]
	if name == nil {
		name = &Name{
			Go: goname,
		}
		f.Name[goname] = name
		f.NamePos[name] = sel.Pos()
	}
	f.Ref = append(f.Ref, &Ref{
		Name:    name,
		Expr:    n,
		Context: context,
	})
}

// Save calls to C.xxx for later processing.

		w.emitf("type %s = %s", name, w.typeString(typ))
		return
	}
	if tparams := obj.Type().(*types.Named).TypeParams(); tparams != nil {
		var buf bytes.Buffer
		buf.WriteString(name)
		w.writeTypeParams(&buf, tparams, true)
		name = buf.String()
	}
	switch typ := typ.Underlying().(type) {
	case *types.Struct:
		w.emitStructType(name, typ)
	case *types.Interface:
		w.emitIfaceType(name, typ)

	Spectre    = flag.String("spectre", "", "enable spectre mitigations in `list` (all, ret)")
)

var DebugFlags struct {
	MayMoreStack string `help:"call named function before all stack growth checks"`
	PCTab        string `help:"print named pc-value table\nOne of: pctospadj, pctofile, pctoline, pctoinline, pctopcdata"`
}

var (
	D        MultiFlag
	I        MultiFlag
	PrintOut int
	DebugV   bool
)