func (p *importer) obj(tag int) {
	switch tag {
	case constTag:
		pos := p.pos()
		pkg, name := p.qualifiedName()
		typ := p.typ(nil)
		val := p.value()
		p.declare(types.NewConst(pos, pkg, name, typ, val))

	case typeTag:
		_ = p.typ(nil)

	case varTag:
		pos := p.pos()
		pkg, name := p.qualifiedName()
		typ := p.typ(nil)
		p.declare(types.NewVar(pos, pkg, name, typ))

	case funcTag:
		pos := p.pos()
		pkg, name := p.qualifiedName()
		params, isddd := p.paramList()
		result, _ := p.paramList()
		sig := types.NewSignature(nil, params, result, isddd)
		p.declare(types.NewFunc(pos, pkg, name, sig))

	default:
		panic(fmt.Sprintf("unexpected object tag %d", tag))
	}
}

func (p *importer) method(parent *types.Package) *types.Func {
	pos := p.pos()
	pkg, name := p.fieldName(parent)
	params, isddd := p.paramList()
	result, _ := p.paramList()
	sig := types.NewSignature(nil, params, result, isddd)
	return types.NewFunc(pos, pkg, name, sig)
}

// Func = Name FunctionType .
func (p *parser) parseFunc(pkg *types.Package) *types.Func {
	name := p.parseName()
	if strings.ContainsRune(name, '$') {
		// This is a Type$equal or Type$hash function, which we don't want to parse,
		// except for the types.
		p.discardDirectiveWhileParsingTypes(pkg)
		return nil
	}
	return types.NewFunc(token.NoPos, pkg, name, p.parseFunctionType(pkg))
}

func ParseFuncDecl(fnDecl *gst.FuncDecl) (*types.Func, bool) {
	var fn *types.Func
	var pkg *types.Package
	pkg = nil
	name := fnDecl.Name
	var sig *types.Signature
	sig = types.NewSignature(nil, nil, nil, false)
	var pos token.Pos
	fn = types.NewFunc(pos, pkg, name, sig)
	return fn, true
}

// InterfaceType = "interface" "{" [ MethodList ] "}" .
// MethodList    = Method { ";" Method } .
// Method        = Name Signature .
//
// The methods of embedded interfaces are always "inlined"
// by the compiler and thus embedded interfaces are never
// visible in the export data.
//
func (p *parser) parseInterfaceType(parent *types.Package) types.Type {
	var methods []*types.Func

	p.expectKeyword("interface")
	p.expect('{')
	for i := 0; p.tok != '}' && p.tok != scanner.EOF; i++ {
		if i > 0 {
			p.expect(';')
		}
		pkg, name := p.parseName(parent, true)
		sig := p.parseSignature(nil)
		methods = append(methods, types.NewFunc(token.NoPos, pkg, name, sig))
	}
	p.expect('}')

	// Complete requires the type's embedded interfaces to be fully defined,
	// but we do not define any
	return types.NewInterface(methods, nil).Complete()
}

func (p *importer) obj(tag int) {
	switch tag {
	case constTag:
		pos := p.pos()
		pkg, name := p.qualifiedName()
		typ := p.typ(nil)
		val := p.value()
		p.declare(types.NewConst(pos, pkg, name, typ, val))

	case typeTag:
		p.typ(nil)

	case varTag:
		pos := p.pos()
		pkg, name := p.qualifiedName()
		typ := p.typ(nil)
		p.declare(types.NewVar(pos, pkg, name, typ))

	case funcTag:
		pos := p.pos()
		pkg, name := p.qualifiedName()
		params, isddd := p.paramList()
		result, _ := p.paramList()
		sig := types.NewSignature(nil, params, result, isddd)
		p.declare(types.NewFunc(pos, pkg, name, sig))

	case aliasTag:
		pos := p.pos()
		name := p.string()
		var orig types.Object
		if pkg, name := p.qualifiedName(); pkg != nil {
			orig = pkg.Scope().Lookup(name)
		}
		// Alias-related code. Keep for now.
		_ = pos
		_ = name
		_ = orig
		// p.declare(types.NewAlias(pos, p.pkgList[0], name, orig))

	default:
		errorf("unexpected object tag %d", tag)
	}
}

// MethodDecl = "func" Receiver Name Func .
// Receiver   = "(" ( identifier | "?" ) [ "*" ] ExportedName ")" .
//
func (p *parser) parseMethodDecl() {
	// "func" already consumed
	p.expect('(')
	recv, _ := p.parseParameter() // receiver
	p.expect(')')

	// determine receiver base type object
	base := deref(recv.Type()).(*types.Named)

	// parse method name, signature, and possibly inlined body
	_, name := p.parseName(nil, false)
	sig := p.parseFunc(recv)

	// methods always belong to the same package as the base type object
	pkg := base.Obj().Pkg()

	// add method to type unless type was imported before
	// and method exists already
	// TODO(gri) This leads to a quadratic algorithm - ok for now because method counts are small.
	base.AddMethod(types.NewFunc(token.NoPos, pkg, name, sig))
}

func (p *importer) obj(pkg *types.Package) {
	var obj types.Object
	switch tag := p.int(); tag {
	case constTag:
		obj = types.NewConst(token.NoPos, pkg, p.string(), p.typ(), p.value())
	case typeTag:
		// type object is added to scope via respective named type
		_ = p.typ().(*types.Named)
		return
	case varTag:
		obj = types.NewVar(token.NoPos, pkg, p.string(), p.typ())
	case funcTag:
		obj = types.NewFunc(token.NoPos, pkg, p.string(), p.typ().(*types.Signature))
	default:
		panic(fmt.Sprintf("unexpected object tag %d", tag))
	}

	if alt := pkg.Scope().Insert(obj); alt != nil {
		panic(fmt.Sprintf("%s already declared", alt.Name()))
	}
}

// NamedType = TypeName Type { Method } .
// Method    = "func" "(" Param ")" Name ParamList ResultList ";" .
func (p *parser) parseNamedType(n int) types.Type {
	obj := p.parseTypeName()

	pkg := obj.Pkg()
	typ := obj.Type()
	p.typeMap[n] = typ

	nt, ok := typ.(*types.Named)
	if !ok {
		// This can happen for unsafe.Pointer, which is a TypeName holding a Basic type.
		pt := p.parseType(pkg)
		if pt != typ {
			p.error("unexpected underlying type for non-named TypeName")
		}
		return typ
	}

	underlying := p.parseType(pkg)
	if nt.Underlying() == nil {
		nt.SetUnderlying(underlying.Underlying())
	}

	for p.tok == scanner.Ident {
		// collect associated methods
		p.expectKeyword("func")
		p.expect('(')
		receiver, _ := p.parseParam(pkg)
		p.expect(')')
		name := p.parseName()
		params, isVariadic := p.parseParamList(pkg)
		results := p.parseResultList(pkg)
		p.expect(';')

		sig := types.NewSignature(receiver, params, results, isVariadic)
		nt.AddMethod(types.NewFunc(token.NoPos, pkg, name, sig))
	}

	return nt
}

// BImportData imports a package from the serialized package data
// and returns the number of bytes consumed and a reference to the package.
// If data is obviously malformed, an error is returned but in
// general it is not recommended to call BImportData on untrusted data.
func BImportData(imports map[string]*types.Package, data []byte, path string) (int, *types.Package, error) {
	p := importer{
		imports: imports,
		data:    data,
	}
	p.buf = p.bufarray[:]

	// read low-level encoding format
	switch format := p.byte(); format {
	case 'c':
		// compact format - nothing to do
	case 'd':
		p.debugFormat = true
	default:
		return p.read, nil, fmt.Errorf("invalid encoding format in export data: got %q; want 'c' or 'd'", format)
	}

	// --- generic export data ---

	if v := p.string(); v != "v0" {
		return p.read, nil, fmt.Errorf("unknown version: %s", v)
	}

	// populate typList with predeclared "known" types
	p.typList = append(p.typList, predeclared...)

	// read package data
	// TODO(gri) clean this up
	i := p.tagOrIndex()
	if i != packageTag {
		panic(fmt.Sprintf("package tag expected, got %d", i))
	}
	name := p.string()
	if s := p.string(); s != "" {
		panic(fmt.Sprintf("empty path expected, got %s", s))
	}
	pkg := p.imports[path]
	if pkg == nil {
		pkg = types.NewPackage(path, name)
		p.imports[path] = pkg
	}
	p.pkgList = append(p.pkgList, pkg)

	if debug && p.pkgList[0] != pkg {
		panic("imported packaged not found in pkgList[0]")
	}

	// read compiler-specific flags
	p.string() // discard

	// read consts
	for i := p.int(); i > 0; i-- {
		name := p.string()
		typ := p.typ(nil)
		val := p.value()
		p.declare(types.NewConst(token.NoPos, pkg, name, typ, val))
	}

	// read vars
	for i := p.int(); i > 0; i-- {
		name := p.string()
		typ := p.typ(nil)
		p.declare(types.NewVar(token.NoPos, pkg, name, typ))
	}

	// read funcs
	for i := p.int(); i > 0; i-- {
		name := p.string()
		sig := p.typ(nil).(*types.Signature)
		p.int() // read and discard index of inlined function body
		p.declare(types.NewFunc(token.NoPos, pkg, name, sig))
	}

	// read types
	for i := p.int(); i > 0; i-- {
		// name is parsed as part of named type and the
		// type object is added to scope via respective
		// named type
		_ = p.typ(nil).(*types.Named)
	}

	// ignore compiler-specific import data

	// complete interfaces
	for _, typ := range p.typList {
		if it, ok := typ.(*types.Interface); ok {
			it.Complete()
		}
	}

	// record all referenced packages as imports
	list := append(([]*types.Package)(nil), p.pkgList[1:]...)
	sort.Sort(byPath(list))
	pkg.SetImports(list)

	// package was imported completely and without errors
//.........这里部分代码省略.........

// parent is the package which declared the type; parent == nil means
// the package currently imported. The parent package is needed for
// exported struct fields and interface methods which don't contain
// explicit package information in the export data.
func (p *importer) typ(parent *types.Package) types.Type {
	// if the type was seen before, i is its index (>= 0)
	i := p.tagOrIndex()
	if i >= 0 {
		return p.typList[i]
	}

	// otherwise, i is the type tag (< 0)
	switch i {
	case namedTag:
		// read type object
		name := p.string()
		parent = p.pkg()
		scope := parent.Scope()
		obj := scope.Lookup(name)

		// if the object doesn't exist yet, create and insert it
		if obj == nil {
			obj = types.NewTypeName(token.NoPos, parent, name, nil)
			scope.Insert(obj)
		}

		if _, ok := obj.(*types.TypeName); !ok {
			panic(fmt.Sprintf("pkg = %s, name = %s => %s", parent, name, obj))
		}

		// associate new named type with obj if it doesn't exist yet
		t0 := types.NewNamed(obj.(*types.TypeName), nil, nil)

		// but record the existing type, if any
		t := obj.Type().(*types.Named)
		p.record(t)

		// read underlying type
		t0.SetUnderlying(p.typ(parent))

		// interfaces don't have associated methods
		if _, ok := t0.Underlying().(*types.Interface); ok {
			return t
		}

		// read associated methods
		for i := p.int(); i > 0; i-- {
			name := p.string()
			recv, _ := p.paramList() // TODO(gri) do we need a full param list for the receiver?
			params, isddd := p.paramList()
			result, _ := p.paramList()
			p.int() // read and discard index of inlined function body
			sig := types.NewSignature(recv.At(0), params, result, isddd)
			t0.AddMethod(types.NewFunc(token.NoPos, parent, name, sig))
		}

		return t

	case arrayTag:
		t := new(types.Array)
		p.record(t)

		n := p.int64()
		*t = *types.NewArray(p.typ(parent), n)
		return t

	case sliceTag:
		t := new(types.Slice)
		p.record(t)

		*t = *types.NewSlice(p.typ(parent))
		return t

	case dddTag:
		t := new(dddSlice)
		p.record(t)

		t.elem = p.typ(parent)
		return t

	case structTag:
		t := new(types.Struct)
		p.record(t)

		n := p.int()
		fields := make([]*types.Var, n)
		tags := make([]string, n)
		for i := range fields {
			fields[i] = p.field(parent)
			tags[i] = p.string()
		}
		*t = *types.NewStruct(fields, tags)
		return t

	case pointerTag:
		t := new(types.Pointer)
		p.record(t)

		*t = *types.NewPointer(p.typ(parent))
		return t
//.........这里部分代码省略.........

// FuncDecl = "func" ExportedName Func .
//
func (p *parser) parseFuncDecl() {
	// "func" already consumed
	pkg, name := p.parseExportedName()
	typ := p.parseFunc(nil)
	pkg.Scope().Insert(types.NewFunc(token.NoPos, pkg, name, typ))
}

// parent is the package which declared the type; parent == nil means
// the package currently imported. The parent package is needed for
// exported struct fields and interface methods which don't contain
// explicit package information in the export data.
func (p *importer) typ(parent *types.Package) types.Type {
	// if the type was seen before, i is its index (>= 0)
	i := p.tagOrIndex()
	if i >= 0 {
		return p.typList[i]
	}

	// otherwise, i is the type tag (< 0)
	switch i {
	case namedTag:
		// read type object
		pos := p.pos()
		parent, name := p.qualifiedName()
		scope := parent.Scope()
		obj := scope.Lookup(name)

		// if the object doesn't exist yet, create and insert it
		if obj == nil {
			obj = types.NewTypeName(pos, parent, name, nil)
			scope.Insert(obj)
		}

		if _, ok := obj.(*types.TypeName); !ok {
			errorf("pkg = %s, name = %s => %s", parent, name, obj)
		}

		// associate new named type with obj if it doesn't exist yet
		t0 := types.NewNamed(obj.(*types.TypeName), nil, nil)

		// but record the existing type, if any
		t := obj.Type().(*types.Named)
		p.record(t)

		// read underlying type
		t0.SetUnderlying(p.typ(parent))

		// interfaces don't have associated methods
		if types.IsInterface(t0) {
			return t
		}

		// read associated methods
		for i := p.int(); i > 0; i-- {
			// TODO(gri) replace this with something closer to fieldName
			pos := p.pos()
			name := p.string()
			if !exported(name) {
				p.pkg()
			}

			recv, _ := p.paramList() // TODO(gri) do we need a full param list for the receiver?
			params, isddd := p.paramList()
			result, _ := p.paramList()
			p.int() // go:nointerface pragma - discarded

			sig := types.NewSignature(recv.At(0), params, result, isddd)
			t0.AddMethod(types.NewFunc(pos, parent, name, sig))
		}

		return t

	case arrayTag:
		t := new(types.Array)
		if p.trackAllTypes {
			p.record(t)
		}

		n := p.int64()
		*t = *types.NewArray(p.typ(parent), n)
		return t

	case sliceTag:
		t := new(types.Slice)
		if p.trackAllTypes {
			p.record(t)
		}

		*t = *types.NewSlice(p.typ(parent))
		return t

	case dddTag:
		t := new(dddSlice)
		if p.trackAllTypes {
			p.record(t)
		}

		t.elem = p.typ(parent)
		return t

	case structTag:
		t := new(types.Struct)
		if p.trackAllTypes {
			p.record(t)
		}

		*t = *types.NewStruct(p.fieldList(parent))
//.........这里部分代码省略.........

func (p *importer) typ() types.Type {
	// if the type was seen before, i is its index (>= 0)
	i := p.int()
	if i >= 0 {
		return p.typList[i]
	}

	// otherwise, i is the type tag (< 0)
	switch i {
	case arrayTag:
		t := new(types.Array)
		p.record(t)

		n := p.int64()
		*t = *types.NewArray(p.typ(), n)
		return t

	case sliceTag:
		t := new(types.Slice)
		p.record(t)

		*t = *types.NewSlice(p.typ())
		return t

	case structTag:
		t := new(types.Struct)
		p.record(t)

		n := p.int()
		fields := make([]*types.Var, n)
		tags := make([]string, n)
		for i := range fields {
			fields[i] = p.field()
			tags[i] = p.string()
		}
		*t = *types.NewStruct(fields, tags)
		return t

	case pointerTag:
		t := new(types.Pointer)
		p.record(t)

		*t = *types.NewPointer(p.typ())
		return t

	case signatureTag:
		t := new(types.Signature)
		p.record(t)

		*t = *p.signature()
		return t

	case interfaceTag:
		// Create a dummy entry in the type list. This is safe because we
		// cannot expect the interface type to appear in a cycle, as any
		// such cycle must contain a named type which would have been
		// first defined earlier.
		n := len(p.typList)
		p.record(nil)

		// read embedded interfaces
		embeddeds := make([]*types.Named, p.int())
		for i := range embeddeds {
			embeddeds[i] = p.typ().(*types.Named)
		}

		// read methods
		methods := make([]*types.Func, p.int())
		for i := range methods {
			pkg, name := p.qualifiedName()
			methods[i] = types.NewFunc(token.NoPos, pkg, name, p.typ().(*types.Signature))
		}

		t := types.NewInterface(methods, embeddeds)
		p.typList[n] = t
		return t

	case mapTag:
		t := new(types.Map)
		p.record(t)

		*t = *types.NewMap(p.typ(), p.typ())
		return t

	case chanTag:
		t := new(types.Chan)
		p.record(t)

		*t = *types.NewChan(types.ChanDir(p.int()), p.typ())
		return t

	case namedTag:
		// read type object
		name := p.string()
		pkg := p.pkg()
		scope := pkg.Scope()
		obj := scope.Lookup(name)

		// if the object doesn't exist yet, create and insert it
		if obj == nil {
//.........这里部分代码省略.........

// CreateTestMainPackage creates and returns a synthetic "main"
// package that runs all the tests of the supplied packages, similar
// to the one that would be created by the 'go test' tool.
//
// It returns nil if the program contains no tests.
//
func (prog *Program) CreateTestMainPackage(pkgs ...*Package) *Package {
	pkgs, tests, benchmarks, examples := FindTests(pkgs)
	if len(pkgs) == 0 {
		return nil
	}

	testmain := &Package{
		Prog:    prog,
		Members: make(map[string]Member),
		values:  make(map[types.Object]Value),
		Pkg:     types.NewPackage("test$main", "main"),
	}

	// Build package's init function.
	init := &Function{
		name:      "init",
		Signature: new(types.Signature),
		Synthetic: "package initializer",
		Pkg:       testmain,
		Prog:      prog,
	}
	init.startBody()

	if testMainStartBodyHook != nil {
		testMainStartBodyHook(init)
	}

	// Initialize packages to test.
	var pkgpaths []string
	for _, pkg := range pkgs {
		var v Call
		v.Call.Value = pkg.init
		v.setType(types.NewTuple())
		init.emit(&v)

		pkgpaths = append(pkgpaths, pkg.Pkg.Path())
	}
	sort.Strings(pkgpaths)
	init.emit(new(Return))
	init.finishBody()
	testmain.init = init
	testmain.Pkg.MarkComplete()
	testmain.Members[init.name] = init

	// For debugging convenience, define an unexported const
	// that enumerates the packages.
	packagesConst := types.NewConst(token.NoPos, testmain.Pkg, "packages", tString,
		exact.MakeString(strings.Join(pkgpaths, " ")))
	memberFromObject(testmain, packagesConst, nil)

	// Create main *types.Func and *ssa.Function
	mainFunc := types.NewFunc(token.NoPos, testmain.Pkg, "main", new(types.Signature))
	memberFromObject(testmain, mainFunc, nil)
	main := testmain.Func("main")
	main.Synthetic = "test main function"

	main.startBody()

	if testMainStartBodyHook != nil {
		testMainStartBodyHook(main)
	}

	if testingPkg := prog.ImportedPackage("testing"); testingPkg != nil {
		testingMain := testingPkg.Func("Main")
		testingMainParams := testingMain.Signature.Params()

		// The generated code is as if compiled from this:
		//
		// func main() {
		//      match      := func(_, _ string) (bool, error) { return true, nil }
		//      tests      := []testing.InternalTest{{"TestFoo", TestFoo}, ...}
		//      benchmarks := []testing.InternalBenchmark{...}
		//      examples   := []testing.InternalExample{...}
		// 	testing.Main(match, tests, benchmarks, examples)
		// }

		matcher := &Function{
			name:      "matcher",
			Signature: testingMainParams.At(0).Type().(*types.Signature),
			Synthetic: "test matcher predicate",
			parent:    main,
			Pkg:       testmain,
			Prog:      prog,
		}
		main.AnonFuncs = append(main.AnonFuncs, matcher)
		matcher.startBody()
		matcher.emit(&Return{Results: []Value{vTrue, nilConst(types.Universe.Lookup("error").Type())}})
		matcher.finishBody()

		// Emit call: testing.Main(matcher, tests, benchmarks, examples).
		var c Call
		c.Call.Value = testingMain
		c.Call.Args = []Value{
			matcher,
//.........这里部分代码省略.........

// CreateTestMainPackage creates and returns a synthetic "testmain"
// package for the specified package if it defines tests, benchmarks or
// executable examples, or nil otherwise.  The new package is named
// "main" and provides a function named "main" that runs the tests,
// similar to the one that would be created by the 'go test' tool.
//
// Subsequent calls to prog.AllPackages include the new package.
// The package pkg must belong to the program prog.
func (prog *Program) CreateTestMainPackage(pkg *Package) *Package {
	if pkg.Prog != prog {
		log.Fatal("Package does not belong to Program")
	}

	tests, benchmarks, examples, testMainFunc := FindTests(pkg)

	if testMainFunc == nil && tests == nil && benchmarks == nil && examples == nil {
		return nil
	}

	testmain := &Package{
		Prog:    prog,
		Members: make(map[string]Member),
		values:  make(map[types.Object]Value),
		Pkg:     types.NewPackage(pkg.Pkg.Path()+"$testmain", "main"),
	}

	// Build package's init function.
	init := &Function{
		name:      "init",
		Signature: new(types.Signature),
		Synthetic: "package initializer",
		Pkg:       testmain,
		Prog:      prog,
	}
	init.startBody()

	if testMainStartBodyHook != nil {
		testMainStartBodyHook(init)
	}

	// Initialize package under test.
	var v Call
	v.Call.Value = pkg.init
	v.setType(types.NewTuple())
	init.emit(&v)
	init.emit(new(Return))
	init.finishBody()
	testmain.init = init
	testmain.Pkg.MarkComplete()
	testmain.Members[init.name] = init

	// Create main *types.Func and *Function
	mainFunc := types.NewFunc(token.NoPos, testmain.Pkg, "main", new(types.Signature))
	memberFromObject(testmain, mainFunc, nil)
	main := testmain.Func("main")
	main.Synthetic = "test main function"

	main.startBody()

	if testMainStartBodyHook != nil {
		testMainStartBodyHook(main)
	}

	if testingPkg := prog.ImportedPackage("testing"); testingPkg != nil {
		testingMain := testingPkg.Func("Main")
		testingMainParams := testingMain.Signature.Params()

		// The generated code is as if compiled from this:
		//
		// func main() {
		//      match      := func(_, _ string) (bool, error) { return true, nil }
		//      tests      := []testing.InternalTest{{"TestFoo", TestFoo}, ...}
		//      benchmarks := []testing.InternalBenchmark{...}
		//      examples   := []testing.InternalExample{...}
		//	if TestMain is defined {
		// 		m := testing.MainStart(match, tests, benchmarks, examples)
		// 		return TestMain(m)
		// 	} else {
		// 		return testing.Main(match, tests, benchmarks, examples)
		// 	}
		// }

		matcher := &Function{
			name:      "matcher",
			Signature: testingMainParams.At(0).Type().(*types.Signature),
			Synthetic: "test matcher predicate",
			parent:    main,
			Pkg:       testmain,
			Prog:      prog,
		}
		main.AnonFuncs = append(main.AnonFuncs, matcher)
		matcher.startBody()
		matcher.emit(&Return{Results: []Value{vTrue, nilConst(types.Universe.Lookup("error").Type())}})
		matcher.finishBody()

		var c Call
		c.Call.Args = []Value{
			matcher,
			testMainSlice(main, tests, testingMainParams.At(1).Type()),
			testMainSlice(main, benchmarks, testingMainParams.At(2).Type()),
//.........这里部分代码省略.........