Golang types.Package類代碼示例

func declTypeName(pkg *types.Package, name string) *types.TypeName {
	scope := pkg.Scope()
	if obj := scope.Lookup(name); obj != nil {
		return obj.(*types.TypeName)
	}
	obj := types.NewTypeName(token.NoPos, pkg, name, nil)
	// a named type may be referred to before the underlying type
	// is known - set it up
	types.NewNamed(obj, nil, nil)
	scope.Insert(obj)
	return obj
}

// pkgString returns a string representation of a package's exported interface.
func pkgString(pkg *types.Package) string {
	var buf bytes.Buffer

	fmt.Fprintf(&buf, "package %s\n", pkg.Name())

	scope := pkg.Scope()
	for _, name := range scope.Names() {
		if exported(name) {
			obj := scope.Lookup(name)
			buf.WriteString(obj.String())

			switch obj := obj.(type) {
			case *types.Const:
				// For now only print constant values if they are not float
				// or complex. This permits comparing go/types results with
				// gc-generated gcimported package interfaces.
				info := obj.Type().Underlying().(*types.Basic).Info()
				if info&types.IsFloat == 0 && info&types.IsComplex == 0 {
					fmt.Fprintf(&buf, " = %s", obj.Val())
				}

			case *types.TypeName:
				// Print associated methods.
				// Basic types (e.g., unsafe.Pointer) have *types.Basic
				// type rather than *types.Named; so we need to check.
				if typ, _ := obj.Type().(*types.Named); typ != nil {
					if n := typ.NumMethods(); n > 0 {
						// Sort methods by name so that we get the
						// same order independent of whether the
						// methods got imported or coming directly
						// for the source.
						// TODO(gri) This should probably be done
						// in go/types.
						list := make([]*types.Func, n)
						for i := 0; i < n; i++ {
							list[i] = typ.Method(i)
						}
						sort.Sort(byName(list))

						buf.WriteString("\nmethods (\n")
						for _, m := range list {
							fmt.Fprintf(&buf, "\t%s\n", m)
						}
						buf.WriteString(")")
					}
				}
			}
			buf.WriteByte('\n')
		}
	}

	return buf.String()
}

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()))
	}
}

func (p *exporter) pkg(pkg *types.Package) {
	if trace {
		p.tracef("package { ")
		defer p.tracef("} ")
	}

	if pkg == nil {
		panic("unexpected nil pkg")
	}

	// if the package was seen before, write its index (>= 0)
	if i, ok := p.pkgIndex[pkg]; ok {
		p.int(i)
		return
	}
	p.pkgIndex[pkg] = len(p.pkgIndex)

	// otherwise, write the package tag (< 0) and package data
	p.int(packageTag)
	p.string(pkg.Name())
	p.string(pkg.Path())
}

// ExportData serializes the interface (exported package objects)
// of package pkg and returns the corresponding data. The export
// format is described elsewhere (TODO).
func ExportData(pkg *types.Package) []byte {
	p := exporter{
		data:     append([]byte(magic), format()),
		pkgIndex: make(map[*types.Package]int),
		typIndex: make(map[types.Type]int),
	}

	// populate typIndex with predeclared types
	for _, t := range predeclared {
		p.typIndex[t] = len(p.typIndex)
	}

	if trace {
		p.tracef("export %s\n", pkg.Name())
		defer p.tracef("\n")
	}

	p.string(version)

	p.pkg(pkg)

	// collect exported objects from package scope
	var list []types.Object
	scope := pkg.Scope()
	for _, name := range scope.Names() {
		if exported(name) {
			list = append(list, scope.Lookup(name))
		}
	}

	// write objects
	p.int(len(list))
	for _, obj := range list {
		p.obj(obj)
	}

	return p.data
}

// FunctionType = ParamList ResultList .
func (p *parser) parseFunctionType(pkg *types.Package) *types.Signature {
	params, isVariadic := p.parseParamList(pkg)
	results := p.parseResultList(pkg)
	return types.NewSignature(pkg.Scope(), nil, params, results, isVariadic)
}

func (in *interp) augmentPackageScope(pkg *types.Package) {
	for _, obj := range in.scope {
		pkg.Scope().Insert(obj)
	}
}

func testExportImport(t *testing.T, pkg0 *types.Package, path string) (size, gcsize int) {
	data := ExportData(pkg0)
	size = len(data)

	imports := make(map[string]*types.Package)
	n, pkg1, err := ImportData(imports, data)
	if err != nil {
		t.Errorf("package %s: import failed: %s", pkg0.Name(), err)
		return
	}
	if n != size {
		t.Errorf("package %s: not all input data consumed", pkg0.Name())
		return
	}

	s0 := pkgString(pkg0)
	s1 := pkgString(pkg1)
	if s1 != s0 {
		t.Errorf("package %s: \nimport got:\n%s\nwant:\n%s\n", pkg0.Name(), s1, s0)
	}

	// If we have a standard library, compare also against the gcimported package.
	if path == "" {
		return // not std library
	}

	gcdata, err := gcExportData(path)
	if err != nil {
		if pkg0.Name() == "main" {
			return // no export data present for main package
		}
		t.Errorf("package %s: couldn't get export data: %s", pkg0.Name(), err)
	}
	gcsize = len(gcdata)

	imports = make(map[string]*types.Package)
	pkg2, err := gcImportData(imports, gcdata, path)
	if err != nil {
		t.Errorf("package %s: gcimport failed: %s", pkg0.Name(), err)
		return
	}

	s2 := pkgString(pkg2)
	if s2 != s0 {
		t.Errorf("package %s: \ngcimport got:\n%s\nwant:\n%s\n", pkg0.Name(), s2, s0)
	}

	return
}