func (m *TypeMap) descriptorInterface(t *types.Interface, name string) TypeDebugDescriptor {
	ifaceStruct := types.NewStruct([]*types.Var{
		types.NewVar(0, nil, "type", types.NewPointer(types.Typ[types.Uint8])),
		types.NewVar(0, nil, "data", types.NewPointer(types.Typ[types.Uint8])),
	}, nil)
	return m.typeDebugDescriptor(ifaceStruct, name)
}

func (m *TypeMap) descriptorSlice(t *types.Slice, name string) TypeDebugDescriptor {
	sliceStruct := types.NewStruct([]*types.Var{
		types.NewVar(0, nil, "ptr", types.NewPointer(t.Elem())),
		types.NewVar(0, nil, "len", types.Typ[types.Int]),
		types.NewVar(0, nil, "cap", types.Typ[types.Int]),
	}, nil)
	return m.typeDebugDescriptor(sliceStruct, name)
}

func (c *PkgContext) loadStruct(array, target string, s *types.Struct) {
	view := c.newVariable("_view")
	c.Printf("%s = new DataView(%s.buffer, %s.byteOffset);", view, array, array)
	var fields []*types.Var
	var collectFields func(s *types.Struct, path string)
	collectFields = func(s *types.Struct, path string) {
		for i := 0; i < s.NumFields(); i++ {
			field := s.Field(i)
			if fs, isStruct := field.Type().Underlying().(*types.Struct); isStruct {
				collectFields(fs, path+"."+field.Name())
				continue
			}
			fields = append(fields, types.NewVar(0, nil, path+"."+field.Name(), field.Type()))
		}
	}
	collectFields(s, target)
	offsets := sizes32.Offsetsof(fields)
	for i, field := range fields {
		switch t := field.Type().Underlying().(type) {
		case *types.Basic:
			if t.Info()&types.IsNumeric != 0 {
				if is64Bit(t) {
					c.Printf("%s = new %s(%s.getUint32(%d, true), %s.getUint32(%d, true));", field.Name(), c.typeName(field.Type()), view, offsets[i]+4, view, offsets[i])
					continue
				}
				c.Printf("%s = %s.get%s(%d, true);", field.Name(), view, toJavaScriptType(t), offsets[i])
			}
			continue
		case *types.Array:
			c.Printf("%s = new %s(%s.buffer, Go$min(%s.byteOffset + %d, %s.buffer.byteLength));", field.Name(), toArrayType(t.Elem()), array, array, offsets[i], array)
			continue
		}
		c.Printf("// skipped: %s %s", field.Name(), field.Type().String())
	}
}

func (c *funcContext) loadStruct(array, target string, s *types.Struct) string {
	view := c.newVariable("_view")
	code := fmt.Sprintf("%s = new DataView(%s.buffer, %s.byteOffset)", view, array, array)
	var fields []*types.Var
	var collectFields func(s *types.Struct, path string)
	collectFields = func(s *types.Struct, path string) {
		for i := 0; i < s.NumFields(); i++ {
			field := s.Field(i)
			if fs, isStruct := field.Type().Underlying().(*types.Struct); isStruct {
				collectFields(fs, path+"."+fieldName(s, i))
				continue
			}
			fields = append(fields, types.NewVar(0, nil, path+"."+fieldName(s, i), field.Type()))
		}
	}
	collectFields(s, target)
	offsets := sizes32.Offsetsof(fields)
	for i, field := range fields {
		switch t := field.Type().Underlying().(type) {
		case *types.Basic:
			if t.Info()&types.IsNumeric != 0 {
				if is64Bit(t) {
					code += fmt.Sprintf(", %s = new %s(%s.getUint32(%d, true), %s.getUint32(%d, true))", field.Name(), c.typeName(field.Type()), view, offsets[i]+4, view, offsets[i])
					break
				}
				code += fmt.Sprintf(", %s = %s.get%s(%d, true)", field.Name(), view, toJavaScriptType(t), offsets[i])
			}
		case *types.Array:
			code += fmt.Sprintf(`, %s = new ($nativeArray("%s"))(%s.buffer, $min(%s.byteOffset + %d, %s.buffer.byteLength))`, field.Name(), typeKind(t.Elem()), array, array, offsets[i], array)
		}
	}
	return code
}

func (c *PkgContext) newIdent(name string, t types.Type) *ast.Ident {
	ident := ast.NewIdent(name)
	c.info.Types[ident] = t
	obj := types.NewVar(0, c.pkg, name, t)
	c.info.Objects[ident] = obj
	c.objectVars[obj] = name
	return ident
}

func (c *funcContext) newIdent(name string, t types.Type) *ast.Ident {
	ident := ast.NewIdent(name)
	c.setType(ident, t)
	obj := types.NewVar(0, c.p.pkg, name, t)
	c.p.info.Uses[ident] = obj
	c.p.objectVars[obj] = name
	return ident
}

// promoteMethod promotes a named type's method to another type
// which has embedded the named type.
func (c *compiler) promoteMethod(m *types.Func, recv types.Type, indices []int) types.Object {
	var pkg *types.Package
	if recv, ok := recv.(*types.Named); ok {
		pkg = c.objectdata[recv.Obj()].Package
	}
	recvvar := types.NewVar(pkg, "", recv)
	sig := m.Type().(*types.Signature)
	sig = types.NewSignature(recvvar, sig.Params(), sig.Results(), sig.IsVariadic())
	f := &synthFunc{pkg: pkg, name: m.Name(), typ: sig}
	ident := ast.NewIdent(f.Name())

	var isptr bool
	if ptr, ok := recv.(*types.Pointer); ok {
		isptr = true
		recv = ptr.Elem()
	}

	c.objects[ident] = f
	c.objectdata[f] = &ObjectData{Ident: ident, Package: pkg}

	if pkg == nil || pkg == c.pkg {
		if currblock := c.builder.GetInsertBlock(); !currblock.IsNil() {
			defer c.builder.SetInsertPointAtEnd(currblock)
		}
		llvmfn := c.Resolve(ident).LLVMValue()
		llvmfn = c.builder.CreateExtractValue(llvmfn, 0, "")
		llvmfn.SetLinkage(llvm.LinkOnceODRLinkage)
		entry := llvm.AddBasicBlock(llvmfn, "entry")
		c.builder.SetInsertPointAtEnd(entry)

		realfn := c.Resolve(c.objectdata[m].Ident).LLVMValue()
		realfn = c.builder.CreateExtractValue(realfn, 0, "")

		args := llvmfn.Params()
		recvarg := args[0]
		if !isptr {
			ptr := c.builder.CreateAlloca(recvarg.Type(), "")
			c.builder.CreateStore(recvarg, ptr)
			recvarg = ptr
		}
		for _, i := range indices {
			if i == -1 {
				recvarg = c.builder.CreateLoad(recvarg, "")
			} else {
				recvarg = c.builder.CreateStructGEP(recvarg, i, "")
			}
		}

		args[0] = recvarg
		result := c.builder.CreateCall(realfn, args, "")
		if sig.Results().Len() == 0 {
			c.builder.CreateRetVoid()
		} else {
			c.builder.CreateRet(result)
		}
	}
	return f
}

func (m *TypeMap) descriptorBasic(t *types.Basic, name string) TypeDebugDescriptor {
	switch t.Kind() {
	case types.String:
		return m.descriptorStruct(types.NewStruct([]*types.Var{
			types.NewVar(0, nil, "ptr", types.NewPointer(types.Typ[types.Uint8])),
			types.NewVar(0, nil, "len", types.Typ[types.Int]),
		}, nil), name)
	case types.UnsafePointer:
		return &BasicTypeDescriptor{
			TypeDescriptorCommon: TypeDescriptorCommon{
				Name:      name,
				Size:      uint64(m.Sizes.Sizeof(t) * 8),
				Alignment: uint64(m.Sizes.Alignof(t) * 8),
			},
			TypeEncoding: DW_ATE_unsigned,
		}
	default:
		bt := &BasicTypeDescriptor{
			TypeDescriptorCommon: TypeDescriptorCommon{
				Name:      t.String(),
				Size:      uint64(m.Sizes.Sizeof(t) * 8),
				Alignment: uint64(m.Sizes.Alignof(t) * 8),
			},
		}
		switch bi := t.Info(); {
		case bi&types.IsBoolean != 0:
			bt.TypeEncoding = DW_ATE_boolean
		case bi&types.IsUnsigned != 0:
			bt.TypeEncoding = DW_ATE_unsigned
		case bi&types.IsInteger != 0:
			bt.TypeEncoding = DW_ATE_signed
		case bi&types.IsFloat != 0:
			bt.TypeEncoding = DW_ATE_float
		case bi&types.IsComplex != 0:
			bt.TypeEncoding = DW_ATE_imaginary_float
		case bi&types.IsUnsigned != 0:
			bt.TypeEncoding = DW_ATE_unsigned
		default:
			panic(fmt.Sprintf("unhandled: %#v", t))
		}
		return bt
	}
}

// newMethod creates a new method of the specified name, package and receiver type.
func newMethod(pkg *ssa.Package, recvType types.Type, name string) *ssa.Function {
	// TODO(adonovan): fix: hack: currently the only part of Signature
	// that is needed is the "pointerness" of Recv.Type, and for
	// now, we'll set it to always be false since we're only
	// concerned with rtype.  Encapsulate this better.
	sig := types.NewSignature(nil, types.NewVar(token.NoPos, nil, "recv", recvType), nil, nil, false)
	fn := pkg.Prog.NewFunction(name, sig, "fake reflect method")
	fn.Pkg = pkg
	return fn
}

// newMethod creates a new method of the specified name, package and receiver type.
func newMethod(pkg *ssa.Package, recvType types.Type, name string) *ssa.Function {
	fn := &ssa.Function{
		Name_: name,
		Pkg:   pkg,
		Prog:  pkg.Prog,
	}
	// TODO(adonovan): fix: hack: currently the only part of Signature
	// that is needed is the "pointerness" of Recv.Type, and for
	// now, we'll set it to always be false since we're only
	// concerned with rtype.  Encapsulate this better.
	fn.Signature = types.NewSignature(types.NewVar(nil, "recv", recvType), nil, nil, false)
	return fn
}

// emitTypeTest emits to f a type test value,ok := x.(t) and returns
// a (value, ok) tuple.  x.Type() must be an interface.
//
func emitTypeTest(f *Function, x Value, t types.Type, pos token.Pos) Value {
	a := &TypeAssert{
		X:            x,
		AssertedType: t,
		CommaOk:      true,
	}
	a.setPos(pos)
	a.setType(types.NewTuple(
		types.NewVar(token.NoPos, nil, "value", t),
		varOk,
	))
	return f.emit(a)
}

// emitTypeTest emits to f a type test value,ok := x.(t) and returns
// a (value, ok) tuple.  x.Type() must be an interface.
//
func emitTypeTest(f *Function, x Value, t types.Type) Value {
	// TODO(adonovan): opt: simplify infallible tests as per
	// emitTypeAssert, and return (x, vTrue).
	// (Requires that exprN returns a slice of extracted values,
	// not a single Value of type *types.Results.)
	a := &TypeAssert{
		X:            x,
		AssertedType: t,
		CommaOk:      true,
	}
	a.setType(types.NewTuple(
		types.NewVar(nil, "value", t),
		varOk,
	))
	return f.emit(a)
}

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()))
	}
}

// Parameter = ( identifier | "?" ) [ "..." ] Type [ string_lit ] .
//
func (p *parser) parseParameter() (par *types.Var, isVariadic bool) {
	_, name := p.parseName(false)
	if name == "" {
		name = "_" // cannot access unnamed identifiers
	}
	if p.tok == '.' {
		p.expectSpecial("...")
		isVariadic = true
	}
	typ := p.parseType()
	if isVariadic {
		typ = types.NewSlice(typ)
	}
	// ignore argument tag (e.g. "noescape")
	if p.tok == scanner.String {
		p.next()
	}
	// TODO(gri) should we provide a package?
	par = types.NewVar(token.NoPos, nil, name, typ)
	return
}

// Parameter = ( identifier | "?" ) [ "..." ] Type [ string_lit ] .
//
func (p *parser) parseParameter() (par *types.Var, isVariadic bool) {
	_, name := p.parseName(false)
	// remove gc-specific parameter numbering
	if i := strings.Index(name, "·"); i >= 0 {
		name = name[:i]
	}
	if p.tok == '.' {
		p.expectSpecial("...")
		isVariadic = true
	}
	typ := p.parseType()
	if isVariadic {
		typ = types.NewSlice(typ)
	}
	// ignore argument tag (e.g. "noescape")
	if p.tok == scanner.String {
		p.next()
	}
	// TODO(gri) should we provide a package?
	par = types.NewVar(token.NoPos, nil, name, typ)
	return
}

func (cdd *CDD) varDecl(w *bytes.Buffer, typ types.Type, global bool, name string, val ast.Expr) (acds []*CDD) {

	dim, acds := cdd.Type(w, typ)
	w.WriteByte(' ')
	w.WriteString(dimFuncPtr(name, dim))

	constInit := true // true if C declaration can init value

	if global {
		cdd.copyDecl(w, ";\n") // Global variables may need declaration
		if val != nil {
			if i, ok := val.(*ast.Ident); !ok || i.Name != "nil" {
				constInit = cdd.exprValue(val) != nil
			}
		}
	}

	if constInit {
		w.WriteString(" = ")
		if val != nil {
			cdd.Expr(w, val, typ)
		} else {
			zeroVal(w, typ)
		}
	}
	w.WriteString(";\n")
	cdd.copyDef(w)

	if !constInit {
		w.Reset()

		// Runtime initialisation
		assign := false

		switch t := underlying(typ).(type) {
		case *types.Slice:
			switch vt := val.(type) {
			case *ast.CompositeLit:
				aname := "array" + cdd.gtc.uniqueId()
				var n int64
				for _, elem := range vt.Elts {
					switch e := elem.(type) {
					case *ast.KeyValueExpr:
						val := cdd.exprValue(e.Key)
						if val == nil {
							panic("slice: composite literal with non-constant key")
						}
						m, ok := exact.Int64Val(val)
						if !ok {
							panic("slice: can't convert " + val.String() + " to int64")
						}
						m++
						if m > n {
							n = m
						}
					default:
						n++
					}
				}

				at := types.NewArray(t.Elem(), n)
				o := types.NewVar(vt.Lbrace, cdd.gtc.pkg, aname, at)
				cdd.gtc.pkg.Scope().Insert(o)
				acd := cdd.gtc.newCDD(o, VarDecl, cdd.il)
				av := *vt
				cdd.gtc.ti.Types[&av] = types.TypeAndValue{Type: at} // BUG: thread-unsafe
				acd.varDecl(new(bytes.Buffer), o.Type(), cdd.gtc.isGlobal(o), aname, &av)
				cdd.InitNext = acd
				acds = append(acds, acd)

				w.WriteByte('\t')
				w.WriteString(name)
				w.WriteString(" = ASLICE(")
				w.WriteString(strconv.FormatInt(at.Len(), 10))
				w.WriteString(", ")
				w.WriteString(aname)
				w.WriteString(");\n")

			default:
				assign = true
			}

		case *types.Array:
			w.WriteByte('\t')
			w.WriteString("ACPY(")
			w.WriteString(name)
			w.WriteString(", ")

			switch val.(type) {
			case *ast.CompositeLit:
				w.WriteString("((")
				dim, _ := cdd.Type(w, t.Elem())
				dim = append([]string{"[]"}, dim...)
				w.WriteString("(" + dimFuncPtr("", dim) + "))")
				cdd.Expr(w, val, typ)

			default:
				cdd.Expr(w, val, typ)
			}

//.........这里部分代码省略.........

// promoteInterfaceMethod promotes an interface method to a type
// which has embedded the interface.
//
// TODO consolidate this and promoteMethod.
func (c *compiler) promoteInterfaceMethod(iface *types.Interface, methodIndex int, recv types.Type, indices []int) types.Object {
	m := iface.Method(methodIndex)
	var pkg *types.Package
	if recv, ok := recv.(*types.Named); ok {
		pkg = c.objectdata[recv.Obj()].Package
	}
	recvvar := types.NewVar(pkg, "", recv)
	sig := m.Type().(*types.Signature)
	sig = types.NewSignature(recvvar, sig.Params(), sig.Results(), sig.IsVariadic())
	f := &synthFunc{pkg: pkg, name: m.Name(), typ: sig}
	ident := ast.NewIdent(f.Name())

	var isptr bool
	if ptr, ok := recv.(*types.Pointer); ok {
		isptr = true
		recv = ptr.Elem()
	}

	c.objects[ident] = f
	c.objectdata[f] = &ObjectData{Ident: ident, Package: pkg}

	if pkg == nil || pkg == c.pkg {
		if currblock := c.builder.GetInsertBlock(); !currblock.IsNil() {
			defer c.builder.SetInsertPointAtEnd(currblock)
		}
		llvmfn := c.Resolve(ident).LLVMValue()
		llvmfn = c.builder.CreateExtractValue(llvmfn, 0, "")
		llvmfn.SetLinkage(llvm.LinkOnceODRLinkage)
		entry := llvm.AddBasicBlock(llvmfn, "entry")
		c.builder.SetInsertPointAtEnd(entry)

		args := llvmfn.Params()
		ifaceval := args[0]
		if !isptr {
			ptr := c.builder.CreateAlloca(ifaceval.Type(), "")
			c.builder.CreateStore(ifaceval, ptr)
			ifaceval = ptr
		}
		for _, i := range indices {
			if i == -1 {
				ifaceval = c.builder.CreateLoad(ifaceval, "")
			} else {
				ifaceval = c.builder.CreateStructGEP(ifaceval, i, "")
			}
		}

		recvarg := c.builder.CreateExtractValue(ifaceval, 0, "")
		ifn := c.builder.CreateExtractValue(ifaceval, methodIndex+2, "")

		// Add the receiver argument type.
		fntyp := ifn.Type().ElementType()
		returnType := fntyp.ReturnType()
		paramTypes := fntyp.ParamTypes()
		paramTypes = append([]llvm.Type{recvarg.Type()}, paramTypes...)
		vararg := fntyp.IsFunctionVarArg()
		fntyp = llvm.FunctionType(returnType, paramTypes, vararg)
		fnptrtyp := llvm.PointerType(fntyp, 0)
		ifn = c.builder.CreateBitCast(ifn, fnptrtyp, "")

		args[0] = recvarg
		result := c.builder.CreateCall(ifn, args, "")
		if sig.Results().Len() == 0 {
			c.builder.CreateRetVoid()
		} else {
			c.builder.CreateRet(result)
		}
	}

	return f
}

//.........这里部分代码省略.........
		}
		return c.formatExpr("(function(%s) {\n%s%s})", strings.Join(params, ", "), string(body), strings.Repeat("\t", c.p.indentation))

	case *ast.UnaryExpr:
		t := c.p.info.Types[e.X].Type
		switch e.Op {
		case token.AND:
			switch t.Underlying().(type) {
			case *types.Struct, *types.Array:
				return c.translateExpr(e.X)
			}

			switch x := removeParens(e.X).(type) {
			case *ast.CompositeLit:
				return c.formatExpr("$newDataPointer(%e, %s)", x, c.typeName(c.p.info.Types[e].Type))
			case *ast.Ident:
				if obj := c.p.info.Uses[x]; c.p.escapingVars[obj] {
					return c.formatExpr("new %s(function() { return this.$target[0]; }, function($v) { this.$target[0] = $v; }, %s)", c.typeName(exprType), c.p.objectVars[obj])
				}
				return c.formatExpr("new %s(function() { return %e; }, function($v) { %s })", c.typeName(exprType), x, c.translateAssign(x, "$v", exprType, false))
			case *ast.SelectorExpr:
				newSel := &ast.SelectorExpr{X: c.newIdent("this.$target", c.p.info.Types[x.X].Type), Sel: x.Sel}
				c.p.info.Selections[newSel] = c.p.info.Selections[x]
				return c.formatExpr("new %s(function() { return %e; }, function($v) { %s }, %e)", c.typeName(exprType), newSel, c.translateAssign(newSel, "$v", exprType, false), x.X)
			case *ast.IndexExpr:
				newIndex := &ast.IndexExpr{X: c.newIdent("this.$target", c.p.info.Types[x.X].Type), Index: x.Index}
				return c.formatExpr("new %s(function() { return %e; }, function($v) { %s }, %e)", c.typeName(exprType), newIndex, c.translateAssign(newIndex, "$v", exprType, false), x.X)
			default:
				panic(fmt.Sprintf("Unhandled: %T\n", x))
			}

		case token.ARROW:
			call := &ast.CallExpr{
				Fun:  c.newIdent("$recv", types.NewSignature(nil, nil, types.NewTuple(types.NewVar(0, nil, "", t)), types.NewTuple(types.NewVar(0, nil, "", exprType), types.NewVar(0, nil, "", types.Typ[types.Bool])), false)),
				Args: []ast.Expr{e.X},
			}
			c.blocking[call] = true
			if _, isTuple := exprType.(*types.Tuple); isTuple {
				return c.formatExpr("%e", call)
			}
			return c.formatExpr("%e[0]", call)
		}

		basic := t.Underlying().(*types.Basic)
		switch e.Op {
		case token.ADD:
			return c.translateExpr(e.X)
		case token.SUB:
			switch {
			case is64Bit(basic):
				return c.formatExpr("new %1s(-%2h, -%2l)", c.typeName(t), e.X)
			case basic.Info()&types.IsComplex != 0:
				return c.formatExpr("new %1s(-%2r, -%2i)", c.typeName(t), e.X)
			case basic.Info()&types.IsUnsigned != 0:
				return c.fixNumber(c.formatExpr("-%e", e.X), basic)
			default:
				return c.formatExpr("-%e", e.X)
			}
		case token.XOR:
			if is64Bit(basic) {
				return c.formatExpr("new %1s(~%2h, ~%2l >>> 0)", c.typeName(t), e.X)
			}
			return c.fixNumber(c.formatExpr("~%e", e.X), basic)
		case token.NOT:
			x := c.translateExpr(e.X)
			if x.String() == "true" {

// makeWrapper returns a synthetic wrapper Function that optionally
// performs receiver indirection, implicit field selections and then a
// tailcall of a "promoted" method.  For example, given these decls:
//
//    type A struct {B}
//    type B struct {*C}
//    type C ...
//    func (*C) f()
//
// then makeWrapper(typ=A, obj={Func:(*C).f, Indices=[B,C,f]})
// synthesize this wrapper method:
//
//    func (a A) f() { return a.B.C->f() }
//
// prog is the program to which the synthesized method will belong.
// typ is the receiver type of the wrapper method.  obj is the
// type-checker's object for the promoted method; its Func may be a
// concrete or an interface method.
//
// EXCLUSIVE_LOCKS_REQUIRED(prog.methodsMu)
//
func makeWrapper(prog *Program, typ types.Type, meth *types.Selection) *Function {
	obj := meth.Obj().(*types.Func)
	oldsig := obj.Type().(*types.Signature)
	recv := types.NewVar(token.NoPos, nil, "recv", typ)

	description := fmt.Sprintf("wrapper for %s", obj)
	if prog.mode&LogSource != 0 {
		defer logStack("make %s to (%s)", description, typ)()
	}
	fn := &Function{
		name:      obj.Name(),
		method:    meth,
		Signature: changeRecv(oldsig, recv),
		Synthetic: description,
		Prog:      prog,
		pos:       obj.Pos(),
	}
	fn.startBody()
	fn.addSpilledParam(recv)
	createParams(fn)

	var v Value = fn.Locals[0] // spilled receiver
	if isPointer(typ) {
		// TODO(adonovan): consider emitting a nil-pointer check here
		// with a nice error message, like gc does.
		v = emitLoad(fn, v)
	}

	// Invariant: v is a pointer, either
	//   value of *A receiver param, or
	// address of  A spilled receiver.

	// We use pointer arithmetic (FieldAddr possibly followed by
	// Load) in preference to value extraction (Field possibly
	// preceded by Load).

	indices := meth.Index()
	v = emitImplicitSelections(fn, v, indices[:len(indices)-1])

	// Invariant: v is a pointer, either
	//   value of implicit *C field, or
	// address of implicit  C field.

	var c Call
	if _, ok := oldsig.Recv().Type().Underlying().(*types.Interface); !ok { // concrete method
		if !isPointer(oldsig.Recv().Type()) {
			v = emitLoad(fn, v)
		}
		c.Call.Value = prog.declaredFunc(obj)
		c.Call.Args = append(c.Call.Args, v)
	} else {
		c.Call.Method = obj
		c.Call.Value = emitLoad(fn, v)
	}
	for _, arg := range fn.Params[1:] {
		c.Call.Args = append(c.Call.Args, arg)
	}
	emitTailCall(fn, &c)
	fn.finishBody()
	return fn
}

// builtinCallSignature returns a new Signature describing the
// effective type of a builtin operator for the particular call e.
//
// This requires ad-hoc typing rules for all variadic (append, print,
// println) and polymorphic (append, copy, delete, close) built-ins.
// This logic could be part of the typechecker, and should arguably
// be moved there and made accessible via an additional types.Context
// callback.
//
// The returned Signature is degenerate and only intended for use by
// emitCallArgs.
//
func builtinCallSignature(info *TypeInfo, e *ast.CallExpr) *types.Signature {
	var params []*types.Var
	var isVariadic bool

	switch builtin := noparens(e.Fun).(*ast.Ident).Name; builtin {
	case "append":
		var t0, t1 types.Type
		t0 = info.TypeOf(e) // infer arg[0] type from result type
		if e.Ellipsis != 0 {
			// append([]T, []T) []T
			// append([]byte, string) []byte
			t1 = info.TypeOf(e.Args[1]) // no conversion
		} else {
			// append([]T, ...T) []T
			t1 = t0.Underlying().(*types.Slice).Elem()
			isVariadic = true
		}
		params = append(params,
			types.NewVar(nil, "", t0),
			types.NewVar(nil, "", t1))

	case "print", "println": // print{,ln}(any, ...interface{})
		isVariadic = true
		// Note, arg0 may have any type, not necessarily tEface.
		params = append(params,
			types.NewVar(nil, "", info.TypeOf(e.Args[0])),
			types.NewVar(nil, "", tEface))

	case "close":
		params = append(params, types.NewVar(nil, "", info.TypeOf(e.Args[0])))

	case "copy":
		// copy([]T, []T) int
		// Infer arg types from each other.  Sleazy.
		var st *types.Slice
		if t, ok := info.TypeOf(e.Args[0]).Underlying().(*types.Slice); ok {
			st = t
		} else if t, ok := info.TypeOf(e.Args[1]).Underlying().(*types.Slice); ok {
			st = t
		} else {
			panic("cannot infer types in call to copy()")
		}
		stvar := types.NewVar(nil, "", st)
		params = append(params, stvar, stvar)

	case "delete":
		// delete(map[K]V, K)
		tmap := info.TypeOf(e.Args[0])
		tkey := tmap.Underlying().(*types.Map).Key()
		params = append(params,
			types.NewVar(nil, "", tmap),
			types.NewVar(nil, "", tkey))

	case "len", "cap":
		params = append(params, types.NewVar(nil, "", info.TypeOf(e.Args[0])))

	case "real", "imag":
		// Reverse conversion to "complex" case below.
		var argType types.Type
		switch info.TypeOf(e).(*types.Basic).Kind() {
		case types.UntypedFloat:
			argType = types.Typ[types.UntypedComplex]
		case types.Float64:
			argType = tComplex128
		case types.Float32:
			argType = tComplex64
		default:
			unreachable()
		}
		params = append(params, types.NewVar(nil, "", argType))

	case "complex":
		var argType types.Type
		switch info.TypeOf(e).(*types.Basic).Kind() {
		case types.UntypedComplex:
			argType = types.Typ[types.UntypedFloat]
		case types.Complex128:
			argType = tFloat64
		case types.Complex64:
			argType = tFloat32
		default:
			unreachable()
		}
		v := types.NewVar(nil, "", argType)
		params = append(params, v, v)

	case "panic":
		params = append(params, types.NewVar(nil, "", tEface))
//.........这里部分代码省略.........