Golang types.NewInterface函数代码示例

func initReflect(i *interpreter) {
	i.reflectPackage = &ssa.Package{
		Prog:    i.prog,
		Pkg:     reflectTypesPackage,
		Members: make(map[string]ssa.Member),
	}

	// Clobber the type-checker's notion of reflect.Value's
	// underlying type so that it more closely matches the fake one
	// (at least in the number of fields---we lie about the type of
	// the rtype field).
	//
	// We must ensure that calls to (ssa.Value).Type() return the
	// fake type so that correct "shape" is used when allocating
	// variables, making zero values, loading, and storing.
	//
	// TODO(adonovan): obviously this is a hack.  We need a cleaner
	// way to fake the reflect package (almost---DeepEqual is fine).
	// One approach would be not to even load its source code, but
	// provide fake source files.  This would guarantee that no bad
	// information leaks into other packages.
	if r := i.prog.ImportedPackage("reflect"); r != nil {
		rV := r.Pkg.Scope().Lookup("Value").Type().(*types.Named)

		// delete bodies of the old methods
		mset := i.prog.MethodSets.MethodSet(rV)
		for j := 0; j < mset.Len(); j++ {
			i.prog.MethodValue(mset.At(j)).Blocks = nil
		}

		tEface := types.NewInterface(nil, nil).Complete()
		rV.SetUnderlying(types.NewStruct([]*types.Var{
			types.NewField(token.NoPos, r.Pkg, "t", tEface, false), // a lie
			types.NewField(token.NoPos, r.Pkg, "v", tEface, false),
		}, nil))
	}

	i.rtypeMethods = methodSet{
		"Bits":      newMethod(i.reflectPackage, rtypeType, "Bits"),
		"Elem":      newMethod(i.reflectPackage, rtypeType, "Elem"),
		"Field":     newMethod(i.reflectPackage, rtypeType, "Field"),
		"In":        newMethod(i.reflectPackage, rtypeType, "In"),
		"Kind":      newMethod(i.reflectPackage, rtypeType, "Kind"),
		"NumField":  newMethod(i.reflectPackage, rtypeType, "NumField"),
		"NumIn":     newMethod(i.reflectPackage, rtypeType, "NumIn"),
		"NumMethod": newMethod(i.reflectPackage, rtypeType, "NumMethod"),
		"NumOut":    newMethod(i.reflectPackage, rtypeType, "NumOut"),
		"Out":       newMethod(i.reflectPackage, rtypeType, "Out"),
		"Size":      newMethod(i.reflectPackage, rtypeType, "Size"),
		"String":    newMethod(i.reflectPackage, rtypeType, "String"),
	}
	i.errorMethods = methodSet{
		"Error": newMethod(i.reflectPackage, errorType, "Error"),
	}
}

// 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()
}

// InterfaceType = "interface" "{" { ("?" Type | Func) ";" } "}" .
func (p *parser) parseInterfaceType(pkg *types.Package) types.Type {
	p.expectKeyword("interface")

	var methods []*types.Func
	var typs []*types.Named

	p.expect('{')
	for p.tok != '}' && p.tok != scanner.EOF {
		if p.tok == '?' {
			p.next()
			typs = append(typs, p.parseType(pkg).(*types.Named))
		} else {
			method := p.parseFunc(pkg)
			methods = append(methods, method)
		}
		p.expect(';')
	}
	p.expect('}')

	return types.NewInterface(methods, typs)
}

//.........这里部分代码省略.........
		*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

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

		params, isddd := p.paramList()
		result, _ := p.paramList()
		*t = *types.NewSignature(nil, params, result, isddd)
		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)

		// no embedded interfaces with gc compiler
		if p.int() != 0 {
			panic("unexpected embedded interface")
		}

		// read methods
		methods := make([]*types.Func, p.int())
		for i := range methods {
			pkg, name := p.fieldName(parent)
			params, isddd := p.paramList()
			result, _ := p.paramList()
			sig := types.NewSignature(nil, params, result, isddd)
			methods[i] = types.NewFunc(token.NoPos, pkg, name, sig)
		}

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

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

		key := p.typ(parent)
		val := p.typ(parent)
		*t = *types.NewMap(key, val)
		return t

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

		var dir types.ChanDir
		// tag values must match the constants in cmd/compile/internal/gc/go.go
		switch d := p.int(); d {
		case 1 /* Crecv */ :
			dir = types.RecvOnly
		case 2 /* Csend */ :
			dir = types.SendOnly
		case 3 /* Cboth */ :
			dir = types.SendRecv
		default:
			panic(fmt.Sprintf("unexpected channel dir %d", d))
		}
		val := p.typ(parent)
		*t = *types.NewChan(dir, val)
		return t

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

// TODO(adonovan): move the constraint definitions and the store() etc
// functions which add them (and are also used by the solver) into a
// new file, constraints.go.

import (
	"fmt"
	"go/token"
	"go/types"

	"golang.org/x/tools/go/callgraph"
	"golang.org/x/tools/go/ssa"
)

var (
	tEface     = types.NewInterface(nil, nil).Complete()
	tInvalid   = types.Typ[types.Invalid]
	tUnsafePtr = types.Typ[types.UnsafePointer]
)

// ---------- Node creation ----------

// nextNode returns the index of the next unused node.
func (a *analysis) nextNode() nodeid {
	return nodeid(len(a.nodes))
}

// addNodes creates nodes for all scalar elements in type typ, and
// returns the id of the first one, or zero if the type was
// analytically uninteresting.
//

func (c *funcContext) translateBuiltin(name string, sig *types.Signature, args []ast.Expr, ellipsis bool) *expression {
	switch name {
	case "new":
		t := sig.Results().At(0).Type().(*types.Pointer)
		if c.p.Pkg.Path() == "syscall" && types.Identical(t.Elem().Underlying(), types.Typ[types.Uintptr]) {
			return c.formatExpr("new Uint8Array(8)")
		}
		switch t.Elem().Underlying().(type) {
		case *types.Struct, *types.Array:
			return c.formatExpr("%e", c.zeroValue(t.Elem()))
		default:
			return c.formatExpr("$newDataPointer(%e, %s)", c.zeroValue(t.Elem()), c.typeName(t))
		}
	case "make":
		switch argType := c.p.TypeOf(args[0]).Underlying().(type) {
		case *types.Slice:
			t := c.typeName(c.p.TypeOf(args[0]))
			if len(args) == 3 {
				return c.formatExpr("$makeSlice(%s, %f, %f)", t, args[1], args[2])
			}
			return c.formatExpr("$makeSlice(%s, %f)", t, args[1])
		case *types.Map:
			if len(args) == 2 && c.p.Types[args[1]].Value == nil {
				return c.formatExpr(`((%1f < 0 || %1f > 2147483647) ? $throwRuntimeError("makemap: size out of range") : {})`, args[1])
			}
			return c.formatExpr("{}")
		case *types.Chan:
			length := "0"
			if len(args) == 2 {
				length = c.formatExpr("%f", args[1]).String()
			}
			return c.formatExpr("new $Chan(%s, %s)", c.typeName(c.p.TypeOf(args[0]).Underlying().(*types.Chan).Elem()), length)
		default:
			panic(fmt.Sprintf("Unhandled make type: %T\n", argType))
		}
	case "len":
		switch argType := c.p.TypeOf(args[0]).Underlying().(type) {
		case *types.Basic:
			return c.formatExpr("%e.length", args[0])
		case *types.Slice:
			return c.formatExpr("%e.$length", args[0])
		case *types.Pointer:
			return c.formatExpr("(%e, %d)", args[0], argType.Elem().(*types.Array).Len())
		case *types.Map:
			return c.formatExpr("$keys(%e).length", args[0])
		case *types.Chan:
			return c.formatExpr("%e.$buffer.length", args[0])
		// length of array is constant
		default:
			panic(fmt.Sprintf("Unhandled len type: %T\n", argType))
		}
	case "cap":
		switch argType := c.p.TypeOf(args[0]).Underlying().(type) {
		case *types.Slice, *types.Chan:
			return c.formatExpr("%e.$capacity", args[0])
		case *types.Pointer:
			return c.formatExpr("(%e, %d)", args[0], argType.Elem().(*types.Array).Len())
		// capacity of array is constant
		default:
			panic(fmt.Sprintf("Unhandled cap type: %T\n", argType))
		}
	case "panic":
		return c.formatExpr("$panic(%s)", c.translateImplicitConversion(args[0], types.NewInterface(nil, nil)))
	case "append":
		if ellipsis || len(args) == 1 {
			argStr := c.translateArgs(sig, args, ellipsis, false)
			return c.formatExpr("$appendSlice(%s, %s)", argStr[0], argStr[1])
		}
		sliceType := sig.Results().At(0).Type().Underlying().(*types.Slice)
		return c.formatExpr("$append(%e, %s)", args[0], strings.Join(c.translateExprSlice(args[1:], sliceType.Elem()), ", "))
	case "delete":
		keyType := c.p.TypeOf(args[0]).Underlying().(*types.Map).Key()
		return c.formatExpr(`delete %e[%s.keyFor(%s)]`, args[0], c.typeName(keyType), c.translateImplicitConversion(args[1], keyType))
	case "copy":
		if basic, isBasic := c.p.TypeOf(args[1]).Underlying().(*types.Basic); isBasic && isString(basic) {
			return c.formatExpr("$copyString(%e, %e)", args[0], args[1])
		}
		return c.formatExpr("$copySlice(%e, %e)", args[0], args[1])
	case "print", "println":
		return c.formatExpr("console.log(%s)", strings.Join(c.translateExprSlice(args, nil), ", "))
	case "complex":
		argStr := c.translateArgs(sig, args, ellipsis, false)
		return c.formatExpr("new %s(%s, %s)", c.typeName(sig.Results().At(0).Type()), argStr[0], argStr[1])
	case "real":
		return c.formatExpr("%e.$real", args[0])
	case "imag":
		return c.formatExpr("%e.$imag", args[0])
	case "recover":
		return c.formatExpr("$recover()")
	case "close":
		return c.formatExpr(`$close(%e)`, args[0])
	default:
		panic(fmt.Sprintf("Unhandled builtin: %s\n", name))
	}
}

//.........这里部分代码省略.........
								objVar := c.newVariable("obj")
								return c.formatExpr("(%s = %s, %s.%s.apply(%s, %s))", objVar, recv, objVar, id, objVar, externalizeExpr(e.Args[1]))
							}
							return c.formatExpr("%s(%s)", globalRef(id), externalizeArgs(e.Args[1:]))
						}
						if e.Ellipsis.IsValid() {
							objVar := c.newVariable("obj")
							return c.formatExpr("(%s = %s, %s[$externalize(%e, $String)].apply(%s, %s))", objVar, recv, objVar, e.Args[0], objVar, externalizeExpr(e.Args[1]))
						}
						return c.formatExpr("%s[$externalize(%e, $String)](%s)", recv, e.Args[0], externalizeArgs(e.Args[1:]))
					case "Invoke":
						if e.Ellipsis.IsValid() {
							return c.formatExpr("%s.apply(undefined, %s)", recv, externalizeExpr(e.Args[0]))
						}
						return c.formatExpr("%s(%s)", recv, externalizeArgs(e.Args))
					case "New":
						if e.Ellipsis.IsValid() {
							return c.formatExpr("new ($global.Function.prototype.bind.apply(%s, [undefined].concat(%s)))", recv, externalizeExpr(e.Args[0]))
						}
						return c.formatExpr("new (%s)(%s)", recv, externalizeArgs(e.Args))
					case "Bool":
						return c.internalize(recv, types.Typ[types.Bool])
					case "String":
						return c.internalize(recv, types.Typ[types.String])
					case "Int":
						return c.internalize(recv, types.Typ[types.Int])
					case "Int64":
						return c.internalize(recv, types.Typ[types.Int64])
					case "Uint64":
						return c.internalize(recv, types.Typ[types.Uint64])
					case "Float":
						return c.internalize(recv, types.Typ[types.Float64])
					case "Interface":
						return c.internalize(recv, types.NewInterface(nil, nil))
					case "Unsafe":
						return recv
					default:
						panic("Invalid js package object: " + sel.Obj().Name())
					}
				}

				methodName := sel.Obj().Name()
				if reservedKeywords[methodName] {
					methodName += "$"
				}
				return c.translateCall(e, sig, c.formatExpr("%s.%s", recv, methodName))

			case types.FieldVal:
				fields, jsTag := c.translateSelection(sel, f.Pos())
				if jsTag != "" {
					call := c.formatExpr("%e.%s.%s(%s)", f.X, strings.Join(fields, "."), jsTag, externalizeArgs(e.Args))
					switch sig.Results().Len() {
					case 0:
						return call
					case 1:
						return c.internalize(call, sig.Results().At(0).Type())
					default:
						c.p.errList = append(c.p.errList, types.Error{Fset: c.p.fileSet, Pos: f.Pos(), Msg: "field with js tag can not have func type with multiple results"})
					}
				}
				return c.translateCall(e, sig, c.formatExpr("%e.%s", f.X, strings.Join(fields, ".")))

			case types.MethodExpr:
				return c.translateCall(e, sig, c.translateExpr(f))

			default:

//.........这里部分代码省略.........
				o := c.p.Defs[spec.(*ast.TypeSpec).Name].(*types.TypeName)
				c.p.typeNames = append(c.p.typeNames, o)
				c.p.objectNames[o] = c.newVariableWithLevel(o.Name(), true)
				c.p.dependencies[o] = true
			}
		case token.CONST:
			// skip, constants are inlined
		}

	case *ast.ExprStmt:
		expr := c.translateExpr(s.X)
		if expr != nil && expr.String() != "" {
			c.Printf("%s;", expr)
		}

	case *ast.LabeledStmt:
		label := c.p.Defs[s.Label].(*types.Label)
		if c.GotoLabel[label] {
			c.PrintCond(false, s.Label.Name+":", fmt.Sprintf("case %d:", c.labelCase(label)))
		}
		c.translateStmt(s.Stmt, label)

	case *ast.GoStmt:
		c.Printf("$go(%s, [%s]);", c.translateExpr(s.Call.Fun), strings.Join(c.translateArgs(c.p.TypeOf(s.Call.Fun).Underlying().(*types.Signature), s.Call.Args, s.Call.Ellipsis.IsValid(), true), ", "))

	case *ast.SendStmt:
		chanType := c.p.TypeOf(s.Chan).Underlying().(*types.Chan)
		call := &ast.CallExpr{
			Fun:  c.newIdent("$send", types.NewSignature(nil, types.NewTuple(types.NewVar(0, nil, "", chanType), types.NewVar(0, nil, "", chanType.Elem())), nil, false)),
			Args: []ast.Expr{s.Chan, c.newIdent(c.translateImplicitConversionWithCloning(s.Value, chanType.Elem()).String(), chanType.Elem())},
		}
		c.Blocking[call] = true
		c.translateStmt(&ast.ExprStmt{X: call}, label)

	case *ast.SelectStmt:
		selectionVar := c.newVariable("_selection")
		var channels []string
		var caseClauses []*ast.CaseClause
		flattened := false
		hasDefault := false
		for i, cc := range s.Body.List {
			clause := cc.(*ast.CommClause)
			switch comm := clause.Comm.(type) {
			case nil:
				channels = append(channels, "[]")
				hasDefault = true
			case *ast.ExprStmt:
				channels = append(channels, c.formatExpr("[%e]", astutil.RemoveParens(comm.X).(*ast.UnaryExpr).X).String())
			case *ast.AssignStmt:
				channels = append(channels, c.formatExpr("[%e]", astutil.RemoveParens(comm.Rhs[0]).(*ast.UnaryExpr).X).String())
			case *ast.SendStmt:
				chanType := c.p.TypeOf(comm.Chan).Underlying().(*types.Chan)
				channels = append(channels, c.formatExpr("[%e, %s]", comm.Chan, c.translateImplicitConversionWithCloning(comm.Value, chanType.Elem())).String())
			default:
				panic(fmt.Sprintf("unhandled: %T", comm))
			}

			indexLit := &ast.BasicLit{Kind: token.INT}
			c.p.Types[indexLit] = types.TypeAndValue{Type: types.Typ[types.Int], Value: constant.MakeInt64(int64(i))}

			var bodyPrefix []ast.Stmt
			if assign, ok := clause.Comm.(*ast.AssignStmt); ok {
				switch rhsType := c.p.TypeOf(assign.Rhs[0]).(type) {
				case *types.Tuple:
					bodyPrefix = []ast.Stmt{&ast.AssignStmt{Lhs: assign.Lhs, Rhs: []ast.Expr{c.newIdent(selectionVar+"[1]", rhsType)}, Tok: assign.Tok}}
				default:
					bodyPrefix = []ast.Stmt{&ast.AssignStmt{Lhs: assign.Lhs, Rhs: []ast.Expr{c.newIdent(selectionVar+"[1][0]", rhsType)}, Tok: assign.Tok}}
				}
			}

			caseClauses = append(caseClauses, &ast.CaseClause{
				List: []ast.Expr{indexLit},
				Body: append(bodyPrefix, clause.Body...),
			})

			flattened = flattened || c.Flattened[clause]
		}

		selectCall := c.setType(&ast.CallExpr{
			Fun:  c.newIdent("$select", types.NewSignature(nil, types.NewTuple(types.NewVar(0, nil, "", types.NewInterface(nil, nil))), types.NewTuple(types.NewVar(0, nil, "", types.Typ[types.Int])), false)),
			Args: []ast.Expr{c.newIdent(fmt.Sprintf("[%s]", strings.Join(channels, ", ")), types.NewInterface(nil, nil))},
		}, types.Typ[types.Int])
		c.Blocking[selectCall] = !hasDefault
		c.Printf("%s = %s;", selectionVar, c.translateExpr(selectCall))

		if len(caseClauses) != 0 {
			translateCond := func(cond ast.Expr) *expression {
				return c.formatExpr("%s[0] === %e", selectionVar, cond)
			}
			c.translateBranchingStmt(caseClauses, nil, true, translateCond, label, flattened)
		}

	case *ast.EmptyStmt:
		// skip

	default:
		panic(fmt.Sprintf("Unhandled statement: %T\n", s))

	}
}

//.........这里部分代码省略.........
		*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))
		return t

	case pointerTag:
		t := new(types.Pointer)
		if p.trackAllTypes {
			p.record(t)
		}

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

	case signatureTag:
		t := new(types.Signature)
		if p.trackAllTypes {
			p.record(t)
		}

		params, isddd := p.paramList()
		result, _ := p.paramList()
		*t = *types.NewSignature(nil, params, result, isddd)
		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)
		if p.trackAllTypes {
			p.record(nil)
		}

		// no embedded interfaces with gc compiler
		if p.int() != 0 {
			errorf("unexpected embedded interface")
		}

		t := types.NewInterface(p.methodList(parent), nil)
		if p.trackAllTypes {
			p.typList[n] = t
		}
		return t

	case mapTag:
		t := new(types.Map)
		if p.trackAllTypes {
			p.record(t)
		}

		key := p.typ(parent)
		val := p.typ(parent)
		*t = *types.NewMap(key, val)
		return t

	case chanTag:
		t := new(types.Chan)
		if p.trackAllTypes {
			p.record(t)
		}

		var dir types.ChanDir
		// tag values must match the constants in cmd/compile/internal/gc/go.go
		switch d := p.int(); d {
		case 1 /* Crecv */ :
			dir = types.RecvOnly
		case 2 /* Csend */ :
			dir = types.SendOnly
		case 3 /* Cboth */ :
			dir = types.SendRecv
		default:
			errorf("unexpected channel dir %d", d)
		}
		val := p.typ(parent)
		*t = *types.NewChan(dir, val)
		return t

	default:
		errorf("unexpected type tag %d", i) // panics
		panic("unreachable")
	}
}

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.........