func (imp *importer) newPackageInfo(path string) *PackageInfo {
	pkg := types.NewPackage(path, "")
	info := &PackageInfo{
		Pkg: pkg,
		Info: types.Info{
			Types:      make(map[ast.Expr]types.TypeAndValue),
			Defs:       make(map[*ast.Ident]types.Object),
			Uses:       make(map[*ast.Ident]types.Object),
			Implicits:  make(map[ast.Node]types.Object),
			Scopes:     make(map[ast.Node]*types.Scope),
			Selections: make(map[*ast.SelectorExpr]*types.Selection),
		},
		errorFunc: imp.conf.TypeChecker.Error,
	}

	// Copy the types.Config so we can vary it across PackageInfos.
	tc := imp.conf.TypeChecker
	tc.IgnoreFuncBodies = false
	if f := imp.conf.TypeCheckFuncBodies; f != nil {
		tc.IgnoreFuncBodies = !f(path)
	}
	tc.Import = imp.doImport    // doImport wraps the user's importfn, effectively
	tc.Error = info.appendError // appendError wraps the user's Error function

	info.checker = types.NewChecker(&tc, imp.conf.fset(), pkg, &info.Info)
	imp.prog.AllPackages[pkg] = info
	return info
}

// TODO replace with encoding/gob when reflection is ready
func ReadArchive(packages map[string]*types.Package, filename, id string, data io.Reader) ([]byte, *types.Package, error) {
	r := bufio.NewReader(data)

	code, err := readUntilSeparator(r)
	if err != nil {
		return nil, nil, err
	}
	importList, err := readUntilSeparator(r)
	if err != nil {
		return nil, nil, err
	}

	pkg, err := gcimporter.ImportData(packages, filename, id, r)
	if err != nil {
		return nil, nil, err
	}

	var imports []*types.Package
	for _, path := range strings.Split(string(importList), "\n") {
		if path == "" {
			continue
		}
		impPkg, found := packages[path]
		if !found {
			impPkg = types.NewPackage(path, "", types.NewScope(nil))
			packages[path] = impPkg
		}
		imports = append(imports, impPkg)
	}
	pkg.SetImports(imports)

	return code, pkg, nil
}

func (imp *importer) newPackageInfo(path string) *PackageInfo {
	// Use a copy of the types.Config so we can vary IgnoreFuncBodies.
	tc := imp.conf.TypeChecker
	tc.IgnoreFuncBodies = false
	if f := imp.conf.TypeCheckFuncBodies; f != nil {
		tc.IgnoreFuncBodies = !f(path)
	}
	if tc.Error == nil {
		tc.Error = func(e error) { fmt.Fprintln(os.Stderr, e) }
	}
	tc.Import = imp.doImport // doImport wraps the user's importfn, effectively

	pkg := types.NewPackage(path, "")
	info := &PackageInfo{
		Pkg: pkg,
		Info: types.Info{
			Types:      make(map[ast.Expr]types.TypeAndValue),
			Defs:       make(map[*ast.Ident]types.Object),
			Uses:       make(map[*ast.Ident]types.Object),
			Implicits:  make(map[ast.Node]types.Object),
			Scopes:     make(map[ast.Node]*types.Scope),
			Selections: make(map[*ast.SelectorExpr]*types.Selection),
		},
	}
	info.checker = types.NewChecker(&tc, imp.conf.fset(), pkg, &info.Info)
	imp.prog.AllPackages[pkg] = info
	return info
}

func (p *importer) pkg() *types.Package {
	// if the package was seen before, i is its index (>= 0)
	i := p.int()
	if i >= 0 {
		return p.pkgList[i]
	}

	// otherwise, i is the package tag (< 0)
	if i != packageTag {
		panic(fmt.Sprintf("unexpected package tag %d", i))
	}

	// read package data
	name := p.string()
	path := p.string()

	// if the package was imported before, use that one; otherwise create a new one
	pkg := p.imports[path]
	if pkg == nil {
		pkg = types.NewPackage(path, name)
		p.imports[path] = pkg
	}
	p.pkgList = append(p.pkgList, pkg)

	return pkg
}

// Name = identifier | "?" | QualifiedName .
//
// If materializePkg is set, the returned package is guaranteed to be set.
// For fully qualified names, the returned package may be a fake package
// (without name, scope, and not in the p.imports map), created for the
// sole purpose of providing a package path. Fake packages are created
// when the package id is not found in the p.imports map; in that case
// we cannot create a real package because we don't have a package name.
// For non-qualified names, the returned package is the imported package.
//
func (p *parser) parseName(materializePkg bool) (pkg *types.Package, name string) {
	switch p.tok {
	case scanner.Ident:
		pkg = p.imports[p.id]
		name = p.lit
		p.next()
	case '?':
		// anonymous
		pkg = p.imports[p.id]
		p.next()
	case '@':
		// exported name prefixed with package path
		var id string
		id, name = p.parseQualifiedName()
		if materializePkg {
			// we don't have a package name - if the package
			// doesn't exist yet, create a fake package instead
			pkg = p.getPkg(id, "")
			if pkg == nil {
				pkg = types.NewPackage(id, "", nil)
			}
		}
	default:
		p.error("name expected")
	}
	return
}

// getPkg returns the package for a given id. If the package is
// not found but we have a package name, create the package and
// add it to the p.imports map.
//
func (p *parser) getPkg(id, name string) *types.Package {
	// package unsafe is not in the imports map - handle explicitly
	if id == "unsafe" {
		return types.Unsafe
	}
	pkg := p.imports[id]
	if pkg == nil && name != "" {
		pkg = types.NewPackage(id, name, types.NewScope(nil))
		p.imports[id] = pkg
	}
	return pkg
}

// getPkg returns the package for a given path. If the package is
// not found but we have a package name, create the package and
// add it to the p.imports map.
//
func (p *parser) getPkg(pkgpath, name string) *types.Package {
	// package unsafe is not in the imports map - handle explicitly
	if pkgpath == "unsafe" {
		return types.Unsafe
	}
	pkg := p.imports[pkgpath]
	if pkg == nil && name != "" {
		pkg = types.NewPackage(pkgpath, name)
		p.imports[pkgpath] = pkg
	}
	return pkg
}

// Import implements the Importer type from go/types.
func (imp Importer) Import(imports map[string]*types.Package, path string) (pkg *types.Package, err error) {
	// types.Importer does not seem to be designed for recursive
	// parsing like we're doing here. Specifically, each nested import
	// will maintain its own imports map. This will lead to duplicate
	// imports and in turn packages, which will lead to funny errors
	// such as "cannot pass argument ip (variable of type net.IP) to
	// variable of type net.IP"
	//
	// To work around this, we keep a global imports map, allImports,
	// to which we add all nested imports, and which we use as the
	// cache, instead of imports.
	//
	// Since all nested imports will also use this importer, there
	// should be no way to end up with duplicate imports.

	// We first try to use GcImport directly. This has the downside of
	// using possibly out-of-date packages, but it has the upside of
	// not having to parse most of the Go standard library.

	buildPkg, buildErr := build.Import(path, ".", 0)
	// If we found no build dir, assume we're dealing with installed
	// but no source. If we found a build dir, only use GcImport if
	// it's in GOROOT. This way we always use up-to-date code for
	// normal packages but avoid parsing the standard library.
	if (buildErr == nil && buildPkg.Goroot) || buildErr != nil {
		pkg, err = types.GcImport(imp.Imports, path)
		if err == nil {
			// We don't use imports, but per API we have to add the package.
			imports[pkg.Path()] = pkg
			imp.Imports[pkg.Path()] = pkg
			return pkg, nil
		}
	}

	// See if we already imported this package
	if pkg = imp.Imports[path]; pkg != nil && pkg.Complete() {
		return pkg, nil
	}

	// allImports failed, try to use go/build
	if buildErr != nil {
		return nil, fmt.Errorf("build.Import failed: %s", buildErr)
	}

	// TODO check if the .a file is up to date and use it instead
	fileSet := token.NewFileSet()

	isGoFile := func(d os.FileInfo) bool {
		allFiles := make([]string, 0, len(buildPkg.GoFiles)+len(buildPkg.CgoFiles))
		allFiles = append(allFiles, buildPkg.GoFiles...)
		allFiles = append(allFiles, buildPkg.CgoFiles...)

		for _, file := range allFiles {
			if file == d.Name() {
				return true
			}
		}
		return false
	}
	pkgs, err := parser.ParseDir(fileSet, buildPkg.Dir, isGoFile, 0)
	if err != nil {
		return nil, err
	}

	delete(pkgs, "documentation")
	var astPkg *ast.Package
	var name string
	for name, astPkg = range pkgs {
		// Use the first non-main package, or the only package we
		// found.
		//
		// NOTE(dh) I can't think of a reason why there should be
		// multiple packages in a single directory, but ParseDir
		// accommodates for that possibility.
		if len(pkgs) == 1 || name != "main" {
			break
		}
	}

	if astPkg == nil {
		return nil, fmt.Errorf("can't find import: %s", name)
	}

	var ff []*ast.File
	for _, f := range astPkg.Files {
		ff = append(ff, f)
	}

	context := types.Config{
		Import: imp.Import,
	}

	pkg, err = context.Check(name, fileSet, ff, nil)
	if err != nil {
		return pkg, err
	}
	if !pkg.Complete() {
		pkg = types.NewPackage(pkg.Pos(), pkg.Path(), pkg.Name(), pkg.Scope(), pkg.Imports(), true)
	}
//.........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),
		Object:  types.NewPackage("testmain", "testmain"),
	}

	// 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.
	for _, pkg := range pkgs {
		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.Object.MarkComplete()
	testmain.Members[init.name] = init

	main := &Function{
		name:      "main",
		Signature: new(types.Signature),
		Synthetic: "test main function",
		Prog:      prog,
		Pkg:       testmain,
	}

	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,
			testMainSlice(main, tests, testingMainParams.At(1).Type()),
			testMainSlice(main, benchmarks, testingMainParams.At(2).Type()),
			testMainSlice(main, examples, testingMainParams.At(3).Type()),
		}
		emitTailCall(main, &c)
	} else {
		// The program does not import "testing", but FindTests
		// returned non-nil, which must mean there were Examples
//.........这里部分代码省略.........

	"reflect"
	"unsafe"

	"code.google.com/p/go.tools/go/types"
	"code.google.com/p/go.tools/ssa"
)

type opaqueType struct {
	types.Type
	name string
}

func (t *opaqueType) String() string { return t.name }

// A bogus "reflect" type-checker package.  Shared across interpreters.
var reflectTypesPackage = types.NewPackage("reflect", "reflect", nil)

// rtype is the concrete type the interpreter uses to implement the
// reflect.Type interface.  Since its type is opaque to the target
// language, we use a types.Basic.
//
// type rtype <opaque>
var rtypeType = makeNamedType("rtype", &opaqueType{nil, "rtype"})

// error is an (interpreted) named type whose underlying type is string.
// The interpreter uses it for all implementations of the built-in error
// interface that it creates.
// We put it in the "reflect" package for expedience.
//
// type error string
var errorType = makeNamedType("error", &opaqueType{nil, "error"})

//.........这里部分代码省略.........
					if pkg, err = build.ImportDir(currentDirectory, 0); err != nil {
						return err
					}
					pkg.ImportPath = "_" + currentDirectory
				}
				pkgs = []*build.Package{pkg}
			}

			var exitErr error
			for _, buildPkg := range pkgs {
				if len(buildPkg.TestGoFiles) == 0 && len(buildPkg.XTestGoFiles) == 0 {
					fmt.Printf("?   \t%s\t[no test files]\n", buildPkg.ImportPath)
					continue
				}

				buildPkg.PkgObj = ""
				buildPkg.GoFiles = append(buildPkg.GoFiles, buildPkg.TestGoFiles...)
				pkg := &gbuild.PackageData{Package: buildPkg}
				s := gbuild.NewSession(options)
				if err := s.BuildPackage(pkg); err != nil {
					return err
				}

				mainPkg := &gbuild.PackageData{
					Package: &build.Package{
						Name:       "main",
						ImportPath: "main",
					},
					Archive: &compiler.Archive{
						ImportPath: compiler.PkgPath("main"),
					},
				}
				s.Packages["main"] = mainPkg
				s.ImportContext.Packages["main"] = types.NewPackage("main", "main")
				testingOutput, err := s.ImportPackage("testing")
				if err != nil {
					panic(err)
				}
				mainPkg.Archive.AddDependenciesOf(testingOutput)

				var mainFunc compiler.Decl
				var names []string
				var tests []string
				collectTests := func(pkg *gbuild.PackageData) {
					for _, name := range pkg.Archive.Tests {
						names = append(names, name)
						tests = append(tests, fmt.Sprintf(`$packages["%s"].%s`, pkg.ImportPath, name))
						mainFunc.DceDeps = append(mainFunc.DceDeps, compiler.DepId(pkg.ImportPath+":"+name))
					}
					mainPkg.Archive.AddDependenciesOf(pkg.Archive)
				}

				collectTests(pkg)
				if len(pkg.XTestGoFiles) != 0 {
					testPkg := &gbuild.PackageData{Package: &build.Package{
						ImportPath: pkg.ImportPath + "_test",
						Dir:        pkg.Dir,
						GoFiles:    pkg.XTestGoFiles,
					}}
					if err := s.BuildPackage(testPkg); err != nil {
						return err
					}
					collectTests(testPkg)
				}

				mainFunc.DceDeps = append(mainFunc.DceDeps, compiler.DepId("flag:Parse"))

//.........这里部分代码省略.........
			lastSourceArg += 1
		}
		if lastSourceArg == 1 {
			return fmt.Errorf("gopherjs run: no go files listed")
		}

		tempfile, err := ioutil.TempFile("", path.Base(flag.Arg(1))+".")
		if err != nil {
			return err
		}
		defer func() {
			tempfile.Close()
			os.Remove(tempfile.Name())
		}()

		if err := buildFiles(flag.Args()[1:lastSourceArg], tempfile.Name()); err != nil {
			return err
		}
		if err := runNode(tempfile.Name(), flag.Args()[lastSourceArg:], ""); err != nil {
			return err
		}
		return nil

	case "test":
		testFlags := flag.NewFlagSet("test", flag.ContinueOnError)
		short := testFlags.Bool("short", false, "")
		verbose := testFlags.Bool("v", false, "")
		testFlags.Parse(flag.Args()[1:])

		mainPkg := &Package{Package: &build.Package{
			ImportPath: "main",
		}}
		packages["main"] = mainPkg
		mainPkgTypes := types.NewPackage("main", "main", types.NewScope(nil))
		testingPkgTypes, _ := typesConfig.Import(typesConfig.Packages, "testing")
		mainPkgTypes.SetImports([]*types.Package{testingPkgTypes})
		typesConfig.Packages["main"] = mainPkgTypes
		mainPkg.JavaScriptCode = []byte("Go$pkg.main = function() {\nGo$packages[\"flag\"].Parse();\n")

		for _, pkgPath := range testFlags.Args() {
			buildPkg, err := buildImport(pkgPath, 0)
			if err != nil {
				return err
			}

			pkg := &Package{Package: buildPkg}
			pkg.GoFiles = append(pkg.GoFiles, pkg.TestGoFiles...)
			if err := buildPackage(pkg); err != nil {
				return err
			}

			testPkg := &Package{Package: &build.Package{
				ImportPath: pkg.ImportPath + "_test",
				Dir:        pkg.Dir,
				GoFiles:    pkg.XTestGoFiles,
			}}
			if err := buildPackage(testPkg); err != nil {
				return err
			}

			pkgTypes := typesConfig.Packages[pkg.ImportPath]
			testPkgTypes := typesConfig.Packages[testPkg.ImportPath]
			var names []string
			var tests []string
			for _, name := range pkgTypes.Scope().Names() {
				if strings.HasPrefix(name, "Test") {

func NewPackage(path, name string) *Package {
	return &Package{
		types.NewPackage(path, name),
	}
}

// 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 {
	if len(pkgs) == 0 {
		return nil
	}
	testmain := &Package{
		Prog:    prog,
		Members: make(map[string]Member),
		values:  make(map[types.Object]Value),
		Object:  types.NewPackage("testmain", "testmain"),
	}

	// Build package's init function.
	init := &Function{
		name:      "init",
		Signature: new(types.Signature),
		Synthetic: "package initializer",
		Pkg:       testmain,
		Prog:      prog,
	}
	init.startBody()
	// TODO(adonovan): use lexical order.
	var expfuncs []*Function // all exported functions of *_test.go in pkgs, unordered
	for _, pkg := range pkgs {
		if pkg.Prog != prog {
			panic("wrong Program")
		}
		// Initialize package to test.
		var v Call
		v.Call.Value = pkg.init
		v.setType(types.NewTuple())
		init.emit(&v)

		// Enumerate its possible tests/benchmarks.
		for _, mem := range pkg.Members {
			if f, ok := mem.(*Function); ok &&
				ast.IsExported(f.Name()) &&
				strings.HasSuffix(prog.Fset.Position(f.Pos()).Filename, "_test.go") {
				expfuncs = append(expfuncs, f)
			}
		}
	}
	init.emit(new(Return))
	init.finishBody()
	testmain.init = init
	testmain.Object.MarkComplete()
	testmain.Members[init.name] = init

	testingPkg := prog.ImportedPackage("testing")
	if testingPkg == nil {
		// If the program doesn't import "testing", it can't
		// contain any tests.
		// TODO(adonovan): but it might contain Examples.
		// Support them (by just calling them directly).
		return 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)
	// }

	main := &Function{
		name:      "main",
		Signature: new(types.Signature),
		Synthetic: "test main function",
		Prog:      prog,
		Pkg:       testmain,
	}

	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()

	main.startBody()
	var c Call
	c.Call.Value = testingMain

	tests := testMainSlice(main, expfuncs, "Test", testingMainParams.At(1).Type())
//.........这里部分代码省略.........

func (t *Translator) NewEmptyTypesPackage(path string) {
	t.typesPackages[path] = types.NewPackage(path, path)
}