Golang Func.Type方法代码示例

func (g *goGen) genFunc(o *types.Func) {
	sig := o.Type().(*types.Signature)

	params := "(" + g.tupleString(sig.Params()) + ")"
	ret := g.tupleString(sig.Results())
	if sig.Results().Len() > 1 {
		ret = "(" + ret + ") "
	} else {
		ret += " "
	}

	//funcName := o.Name()
	g.Printf(`
//export GoPy_%[1]s
// GoPy_%[1]s wraps %[2]s
func GoPy_%[1]s%[3]v%[4]v{
`,
		o.Name(), o.FullName(),
		params,
		ret,
	)

	g.Indent()
	g.genFuncBody(o)
	g.Outdent()
	g.Printf("}\n\n")
}

// interfaceMethod returns a function and receiver pointer for the specified
// interface and method pair.
func (fr *frame) interfaceMethod(lliface llvm.Value, ifacety types.Type, method *types.Func) (fn, recv *govalue) {
	llitab := fr.builder.CreateExtractValue(lliface, 0, "")
	recv = newValue(fr.builder.CreateExtractValue(lliface, 1, ""), types.Typ[types.UnsafePointer])
	methodset := fr.types.MethodSet(ifacety)
	// TODO(axw) cache ordered method index
	index := -1
	for i, m := range orderedMethodSet(methodset) {
		if m.Obj() == method {
			index = i
			break
		}
	}
	if index == -1 {
		panic("could not find method index")
	}
	llitab = fr.builder.CreateBitCast(llitab, llvm.PointerType(llvm.PointerType(llvm.Int8Type(), 0), 0), "")
	// Skip runtime type pointer.
	llifnptr := fr.builder.CreateGEP(llitab, []llvm.Value{
		llvm.ConstInt(llvm.Int32Type(), uint64(index+1), false),
	}, "")

	llifn := fr.builder.CreateLoad(llifnptr, "")
	// Replace receiver type with unsafe.Pointer.
	recvparam := types.NewParam(0, nil, "", types.Typ[types.UnsafePointer])
	sig := method.Type().(*types.Signature)
	sig = types.NewSignature(nil, recvparam, sig.Params(), sig.Results(), sig.Variadic())
	fn = newValue(llifn, sig)
	return
}

func (g *goGen) genFuncBody(o *types.Func, selectorLHS string) {
	sig := o.Type().(*types.Signature)
	params := sig.Params()
	for i := 0; i < params.Len(); i++ {
		p := params.At(i)
		t := seqType(p.Type())
		if t == "Ref" {
			name := p.Type().(*types.Named).Obj().Name()
			g.Printf("var param_%s %s.%s\n", p.Name(), g.pkg.Name(), name)
			g.Printf("param_%s_ref := in.ReadRef()\n", p.Name())
			g.Printf("if param_%s_ref.Num < 0 {\n", p.Name())
			g.Printf("    param_%s = param_%s_ref.Get().(%s.%s)\n", p.Name(), p.Name(), g.pkg.Name(), name)
			g.Printf("} else {\n")
			g.Printf("    param_%s = (*proxy%s)(param_%s_ref)\n", p.Name(), name, p.Name())
			g.Printf("}\n")
		} else {
			g.Printf("param_%s := in.Read%s()\n", p.Name(), t)
		}
	}

	res := sig.Results()
	if res.Len() > 2 || res.Len() == 2 && !isErrorType(res.At(1).Type()) {
		g.errorf("functions and methods must return either zero or one values, and optionally an error")
		return
	}
	returnsValue := false
	returnsError := false
	if res.Len() == 1 {
		if isErrorType(res.At(0).Type()) {
			returnsError = true
			g.Printf("err := ")
		} else {
			returnsValue = true
			g.Printf("res := ")
		}
	} else if res.Len() == 2 {
		returnsValue = true
		returnsError = true
		g.Printf("res, err := ")
	}

	g.Printf("%s.%s(", selectorLHS, o.Name())
	for i := 0; i < params.Len(); i++ {
		if i > 0 {
			g.Printf(", ")
		}
		g.Printf("param_%s", params.At(i).Name())
	}
	g.Printf(")\n")

	if returnsValue {
		g.genWrite("res", "out", res.At(0).Type())
	}
	if returnsError {
		g.genWrite("err", "out", res.At(res.Len()-1).Type())
	}
}

func (p *printer) printFunc(recvType types.Type, obj *types.Func) {
	p.print("func ")
	sig := obj.Type().(*types.Signature)
	if recvType != nil {
		p.print("(")
		p.writeType(p.pkg, recvType)
		p.print(") ")
	}
	p.print(obj.Name())
	p.writeSignature(p.pkg, sig)
}

func (g *javaGen) genFunc(o *types.Func, method bool) {
	if err := g.funcSignature(o, !method); err != nil {
		g.errorf("%v", err)
		return
	}
	sig := o.Type().(*types.Signature)
	res := sig.Results()

	g.Printf(" {\n")
	g.Indent()
	g.Printf("go.Seq _in = new go.Seq();\n")
	g.Printf("go.Seq _out = new go.Seq();\n")

	returnsError := false
	var resultType types.Type
	if res.Len() > 0 {
		if !isErrorType(res.At(0).Type()) {
			resultType = res.At(0).Type()
		}
		if res.Len() > 1 || isErrorType(res.At(0).Type()) {
			returnsError = true
		}
	}
	if resultType != nil {
		t := g.javaType(resultType)
		g.Printf("%s _result;\n", t)
	}

	if method {
		g.Printf("_in.writeRef(ref);\n")
	}
	params := sig.Params()
	for i := 0; i < params.Len(); i++ {
		p := params.At(i)
		g.Printf("_in.write%s;\n", seqWrite(p.Type(), paramName(params, i)))
	}
	g.Printf("Seq.send(DESCRIPTOR, CALL_%s, _in, _out);\n", o.Name())
	if resultType != nil {
		g.genRead("_result", "_out", resultType)
	}
	if returnsError {
		g.Printf(`String _err = _out.readString();
if (_err != null) {
    throw new Exception(_err);
}
`)
	}
	if resultType != nil {
		g.Printf("return _result;\n")
	}
	g.Outdent()
	g.Printf("}\n\n")
}

// check if function is a test function for the testing package
// we don't unexport those
func (e *Export) checkFunction(from *types.Func, to string) {
	if !strings.HasPrefix(from.Name(), "Test") {
		return
	}
	sig := from.Type().(*types.Signature)
	if sig.Params().Len() != 1 {
		return
	}
	if sig.Params().At(0).Type().String() == "*testing.T" {
		e.Conflicting = true
		return
	}
}

func (g *goGen) genFuncBody(o *types.Func) {

	sig := o.Type().(*types.Signature)
	results := newVars(sig.Results())
	for i := range results {
		if i > 0 {
			g.Printf(", ")
		}
		g.Printf("_gopy_%03d", i)
	}
	if len(results) > 0 {
		g.Printf(" := ")
	}

	g.Printf("%s.%s(", g.pkg.Name(), o.Name())

	args := sig.Params()
	for i := 0; i < args.Len(); i++ {
		arg := args.At(i)
		tail := ""
		if i+1 < args.Len() {
			tail = ", "
		}
		g.Printf("%s%s", arg.Name(), tail)
	}
	g.Printf(")\n")

	if len(results) <= 0 {
		return
	}

	g.Printf("return ")
	for i, res := range results {
		if i > 0 {
			g.Printf(", ")
		}
		// if needWrap(res.GoType()) {
		// 	g.Printf("")
		// }
		if res.needWrap() {
			g.Printf("%s(unsafe.Pointer(&", res.dtype.cgotype)
		}
		g.Printf("_gopy_%03d /* %#v %v */", i, res, res.GoType().Underlying())
		if res.needWrap() {
			g.Printf("))")
		}
	}
	g.Printf("\n")
}

func (g *javaGen) funcSignature(o *types.Func, static bool) error {
	sig := o.Type().(*types.Signature)
	res := sig.Results()

	var returnsError bool
	var ret string
	switch res.Len() {
	case 2:
		if !isErrorType(res.At(1).Type()) {
			return fmt.Errorf("second result value must be of type error: %s", o)
		}
		returnsError = true
		ret = g.javaType(res.At(0).Type())
	case 1:
		if isErrorType(res.At(0).Type()) {
			returnsError = true
			ret = "void"
		} else {
			ret = g.javaType(res.At(0).Type())
		}
	case 0:
		ret = "void"
	default:
		return fmt.Errorf("too many result values: %s", o)
	}

	g.Printf("public ")
	if static {
		g.Printf("static ")
	}
	g.Printf("%s %s(", ret, o.Name())
	params := sig.Params()
	for i := 0; i < params.Len(); i++ {
		if i > 0 {
			g.Printf(", ")
		}
		v := sig.Params().At(i)
		name := paramName(params, i)
		jt := g.javaType(v.Type())
		g.Printf("%s %s", jt, name)
	}
	g.Printf(")")
	if returnsError {
		g.Printf(" throws Exception")
	}
	return nil
}

func (g *goGen) genFuncBody(o *types.Func, selectorLHS string) {
	sig := o.Type().(*types.Signature)
	params := sig.Params()
	for i := 0; i < params.Len(); i++ {
		p := params.At(i)
		g.genRead("param_"+paramName(params, i), "in", p.Type())
	}

	res := sig.Results()
	if res.Len() > 2 || res.Len() == 2 && !isErrorType(res.At(1).Type()) {
		g.errorf("functions and methods must return either zero or one values, and optionally an error")
		return
	}
	returnsValue := false
	returnsError := false
	if res.Len() == 1 {
		if isErrorType(res.At(0).Type()) {
			returnsError = true
			g.Printf("err := ")
		} else {
			returnsValue = true
			g.Printf("res := ")
		}
	} else if res.Len() == 2 {
		returnsValue = true
		returnsError = true
		g.Printf("res, err := ")
	}

	g.Printf("%s.%s(", selectorLHS, o.Name())
	for i := 0; i < params.Len(); i++ {
		if i > 0 {
			g.Printf(", ")
		}
		g.Printf("param_%s", paramName(params, i))
	}
	g.Printf(")\n")

	if returnsValue {
		g.genWrite("res", "out", res.At(0).Type())
	}
	if returnsError {
		g.genWrite("err", "out", res.At(res.Len()-1).Type())
	}
}

func checkFuncValue(t *testing.T, prog *ssa.Program, obj *types.Func) {
	fn := prog.FuncValue(obj)
	// fmt.Printf("FuncValue(%s) = %s\n", obj, fn) // debugging
	if fn == nil {
		if obj.Name() != "interfaceMethod" {
			t.Errorf("FuncValue(%s) == nil", obj)
		}
		return
	}
	if fnobj := fn.Object(); fnobj != obj {
		t.Errorf("FuncValue(%s).Object() == %s; value was %s",
			obj, fnobj, fn.Name())
		return
	}
	if !types.Identical(fn.Type(), obj.Type()) {
		t.Errorf("FuncValue(%s).Type() == %s", obj, fn.Type())
		return
	}
}

// makeBound returns a bound method wrapper (or "bound"), a synthetic
// function that delegates to a concrete or interface method denoted
// by obj.  The resulting function has no receiver, but has one free
// variable which will be used as the method's receiver in the
// tail-call.
//
// Use MakeClosure with such a wrapper to construct a bound method
// closure.  e.g.:
//
//   type T int          or:  type T interface { meth() }
//   func (t T) meth()
//   var t T
//   f := t.meth
//   f() // calls t.meth()
//
// f is a closure of a synthetic wrapper defined as if by:
//
//   f := func() { return t.meth() }
//
// Unlike makeWrapper, makeBound need perform no indirection or field
// selections because that can be done before the closure is
// constructed.
//
// EXCLUSIVE_LOCKS_ACQUIRED(meth.Prog.methodsMu)
//
func makeBound(prog *Program, obj *types.Func) *Function {
	prog.methodsMu.Lock()
	defer prog.methodsMu.Unlock()
	fn, ok := prog.bounds[obj]
	if !ok {
		description := fmt.Sprintf("bound method wrapper for %s", obj)
		if prog.mode&LogSource != 0 {
			defer logStack("%s", description)()
		}
		fn = &Function{
			name:      obj.Name() + "$bound",
			object:    obj,
			Signature: changeRecv(obj.Type().(*types.Signature), nil), // drop receiver
			Synthetic: description,
			Prog:      prog,
			pos:       obj.Pos(),
		}

		fv := &FreeVar{name: "recv", typ: recvType(obj), parent: fn}
		fn.FreeVars = []*FreeVar{fv}
		fn.startBody()
		createParams(fn, 0)
		var c Call

		if !isInterface(recvType(obj)) { // concrete
			c.Call.Value = prog.declaredFunc(obj)
			c.Call.Args = []Value{fv}
		} else {
			c.Call.Value = fv
			c.Call.Method = obj
		}
		for _, arg := range fn.Params {
			c.Call.Args = append(c.Call.Args, arg)
		}
		emitTailCall(fn, &c)
		fn.finishBody()

		prog.bounds[obj] = fn
	}
	return fn
}

func (p *Processor) tryMatchNewFunc(models []*Model, fun *types.Func) {
	modelName := fun.Name()[len("new"):]

	for _, m := range models {
		if m.Name != modelName {
			continue
		}

		sig := fun.Type().(*types.Signature)

		if sig.Recv() != nil {
			continue
		}

		res := sig.Results()
		for i := 0; i < res.Len(); i++ {
			if isTypeOrPtrTo(res.At(i).Type(), m.CheckedNode) {
				m.NewFunc = fun
				return
			}
		}
	}
}

// recv returns the method's receiver.
func recv(meth *types.Func) *types.Var {
	return meth.Type().(*types.Signature).Recv()
}

func (g *objcGen) funcSummary(obj *types.Func) *funcSummary {
	s := &funcSummary{name: obj.Name()}

	sig := obj.Type().(*types.Signature)
	params := sig.Params()
	for i := 0; i < params.Len(); i++ {
		p := params.At(i)
		v := paramInfo{
			typ:  p.Type(),
			name: paramName(params, i),
		}
		s.params = append(s.params, v)
	}

	res := sig.Results()
	switch res.Len() {
	case 0:
		s.ret = "void"
	case 1:
		p := res.At(0)
		if isErrorType(p.Type()) {
			s.retParams = append(s.retParams, paramInfo{
				typ:  p.Type(),
				name: "error",
			})
			s.ret = "BOOL"
		} else {
			name := p.Name()
			if name == "" || paramRE.MatchString(name) {
				name = "ret0_"
			}
			typ := p.Type()
			s.retParams = append(s.retParams, paramInfo{typ: typ, name: name})
			s.ret = g.objcType(typ)
		}
	case 2:
		name := res.At(0).Name()
		if name == "" || paramRE.MatchString(name) {
			name = "ret0_"
		}
		s.retParams = append(s.retParams, paramInfo{
			typ:  res.At(0).Type(),
			name: name,
		})

		if !isErrorType(res.At(1).Type()) {
			g.errorf("second result value must be of type error: %s", obj)
			return nil
		}
		s.retParams = append(s.retParams, paramInfo{
			typ:  res.At(1).Type(),
			name: "error", // TODO(hyangah): name collision check.
		})
		s.ret = "BOOL"
	default:
		// TODO(hyangah): relax the constraint on multiple return params.
		g.errorf("too many result values: %s", obj)
		return nil
	}

	return s
}

// recvType returns the receiver type of method obj.
func recvType(obj *types.Func) types.Type {
	return obj.Type().(*types.Signature).Recv().Type()
}