Golang Type.Kind方法代码示例

// zeroConst returns a new "zero" constant of the specified type,
// which must not be an array or struct type: the zero values of
// aggregates are well-defined but cannot be represented by Const.
//
func zeroConst(t types.Type) *Const {
	switch t := t.(type) {
	case *types.Basic:
		switch {
		case t.Info()&types.IsBoolean != 0:
			return NewConst(exact.MakeBool(false), t)
		case t.Info()&types.IsNumeric != 0:
			return NewConst(exact.MakeInt64(0), t)
		case t.Info()&types.IsString != 0:
			return NewConst(exact.MakeString(""), t)
		case t.Kind() == types.UnsafePointer:
			fallthrough
		case t.Kind() == types.UntypedNil:
			return nilConst(t)
		default:
			panic(fmt.Sprint("zeroConst for unexpected type:", t))
		}
	case *types.Pointer, *types.Slice, *types.Interface, *types.Chan, *types.Map, *types.Signature:
		return nilConst(t)
	case *types.Named:
		return NewConst(zeroConst(t.Underlying()).Value, t)
	case *types.Array, *types.Struct, *types.Tuple:
		panic(fmt.Sprint("zeroConst applied to aggregate:", t))
	}
	panic(fmt.Sprint("zeroConst: unexpected ", t))
}

func sizeof(t types.Type) uint {

	switch t := t.(type) {
	case *types.Tuple:
		// TODO: usage of reflect most likely wrong!
		// uint(reflect.TypeOf(t).Elem().Size())
		panic("Tuples are unsupported")
	case *types.Basic:
		return sizeBasic(t.Kind())
	case *types.Pointer:
		return sizePtr()
	case *types.Slice:
		return sizeSlice(t)
	case *types.Array:
		return sizeArray(t)
	case *types.Named:
		if sse2, ok := sse2Info(t); ok {
			return sse2.size
		} else if info, ok := simdInfo(t); ok {
			return info.size
		} else {
			panic(ice(fmt.Sprintf("unknown named type \"%v\"", t.String())))
		}
	}
	panic(ice(fmt.Sprintf("unknown type: %v", t)))
}

func signed(t types.Type) bool {

	switch t := t.(type) {
	case *types.Basic:
		return signedBasic(t.Kind())
	}
	panic(ice(fmt.Sprintf("unknown type: %v", t)))
}

func isInt(t types.Type) bool {
	if t, ok := t.(*types.Basic); ok {
		switch t.Kind() {
		case types.Int, types.Int8, types.Int16, types.Int32, types.Int64:
			return true
		}
	}
	return false
}

func cgoTypeName(typ types.Type) string {
	switch typ := typ.(type) {
	case *types.Basic:
		kind := typ.Kind()
		o, ok := typedescr[kind]
		if ok {
			return o.cgotype
		}
	}
	return typ.String()
}

// javaType returns a string that can be used as a Java type.
func (g *javaGen) javaType(T types.Type) string {
	switch T := T.(type) {
	case *types.Basic:
		switch T.Kind() {
		case types.Bool:
			return "boolean"
		case types.Int:
			return "long"
		case types.Int8:
			return "byte"
		case types.Int16:
			return "short"
		case types.Int32:
			return "int"
		case types.Int64:
			return "long"
		case types.Uint8:
			// TODO(crawshaw): Java bytes are signed, so this is
			// questionable, but vital.
			return "byte"
		// TODO(crawshaw): case types.Uint, types.Uint16, types.Uint32, types.Uint64:
		case types.Float32:
			return "float"
		case types.Float64:
			return "double"
		case types.String:
			return "String"
		default:
			g.errorf("unsupported return type: %s", T)
			return "TODO"
		}
	case *types.Slice:
		elem := g.javaType(T.Elem())
		return elem + "[]"

	case *types.Pointer:
		if _, ok := T.Elem().(*types.Named); ok {
			return g.javaType(T.Elem())
		}
		panic(fmt.Sprintf("unsupporter pointer to type: %s", T))
	case *types.Named:
		n := T.Obj()
		if n.Pkg() != g.pkg {
			panic(fmt.Sprintf("type %s is in package %s, must be defined in package %s", n.Name(), n.Pkg().Name(), g.pkg.Name()))
		}
		// TODO(crawshaw): more checking here
		return n.Name()
	default:
		g.errorf("unsupported javaType: %#+v, %s\n", T, T)
		return "TODO"
	}
}

// seqType returns a string that can be used for reading and writing a
// type using the seq library.
func seqType(t types.Type) string {
	if isErrorType(t) {
		return "UTF16"
	}
	switch t := t.(type) {
	case *types.Basic:
		switch t.Kind() {
		case types.Int:
			return "Int"
		case types.Int8:
			return "Int8"
		case types.Int16:
			return "Int16"
		case types.Int32:
			return "Int32"
		case types.Int64:
			return "Int64"
		case types.Uint8:
			// TODO(crawshaw): questionable, but vital?
			return "Byte"
		// TODO(crawshaw): case types.Uint, types.Uint16, types.Uint32, types.Uint64:
		case types.Float32:
			return "Float32"
		case types.Float64:
			return "Float64"
		case types.String:
			return "UTF16"
		default:
			// Should be caught earlier in processing.
			panic(fmt.Sprintf("unsupported return type: %s", t))
		}
	case *types.Named:
		switch u := t.Underlying().(type) {
		case *types.Interface:
			return "Ref"
		default:
			panic(fmt.Sprintf("unsupported named seqType: %s / %T", u, u))
		}
	default:
		panic(fmt.Sprintf("unsupported seqType: %s / %T", t, t))
	}
}

// javaTypeDefault returns a string that represents the default value of the mapped java type.
// TODO(hyangah): Combine javaType and javaTypeDefault?
func (g *javaGen) javaTypeDefault(T types.Type) string {
	switch T := T.(type) {
	case *types.Basic:
		switch T.Kind() {
		case types.Bool:
			return "false"
		case types.Int, types.Int8, types.Int16, types.Int32,
			types.Int64, types.Uint8, types.Float32, types.Float64:
			return "0"
		case types.String:
			return "null"
		default:
			g.errorf("unsupported return type: %s", T)
			return "TODO"
		}
	case *types.Slice, *types.Pointer, *types.Named:
		return "null"

	default:
		g.errorf("unsupported javaType: %#+v, %s\n", T, T)
		return "TODO"
	}
}

func reflectType(t types.Type) reflect.Type {
	switch t := t.(type) {
	case *types.Tuple:
		// TODO
	case *types.Basic:
		return reflectBasic(t.Kind())
	case *types.Pointer:
		return reflect.PtrTo(reflectType(t.Elem()))
	case *types.Slice:
		return reflect.SliceOf(reflectType(t.Elem()))
	case *types.Array:
		return reflect.ArrayOf(int(t.Len()), reflectType(t.Elem()))
	case *types.Named:
		if st, ok := simdInfo(t); ok {
			return st.t
		}
		if sse2, ok := sse2Info(t); ok {
			return sse2.t
		}
	}
	ice(fmt.Sprintf("error unknown type:\"%v\"", t))
	panic("")
}

func (tm *llvmTypeMap) getBackendType(t types.Type) backendType {
	switch t := t.(type) {
	case *types.Named:
		return tm.getBackendType(t.Underlying())

	case *types.Basic:
		switch t.Kind() {
		case types.Bool, types.Uint8:
			return &intBType{1, false}
		case types.Int8:
			return &intBType{1, true}
		case types.Uint16:
			return &intBType{2, false}
		case types.Int16:
			return &intBType{2, true}
		case types.Uint32:
			return &intBType{4, false}
		case types.Int32:
			return &intBType{4, true}
		case types.Uint64:
			return &intBType{8, false}
		case types.Int64:
			return &intBType{8, true}
		case types.Uint, types.Uintptr:
			return &intBType{tm.target.PointerSize(), false}
		case types.Int:
			return &intBType{tm.target.PointerSize(), true}
		case types.Float32:
			return &floatBType{false}
		case types.Float64:
			return &floatBType{true}
		case types.UnsafePointer:
			return &ptrBType{}
		case types.Complex64:
			f32 := &floatBType{false}
			return &structBType{[]backendType{f32, f32}}
		case types.Complex128:
			f64 := &floatBType{true}
			return &structBType{[]backendType{f64, f64}}
		case types.String:
			return &structBType{[]backendType{&ptrBType{}, &intBType{tm.target.PointerSize(), false}}}
		}

	case *types.Struct:
		var fields []backendType
		for i := 0; i != t.NumFields(); i++ {
			f := t.Field(i)
			fields = append(fields, tm.getBackendType(f.Type()))
		}
		return &structBType{fields}

	case *types.Pointer, *types.Signature, *types.Map, *types.Chan:
		return &ptrBType{}

	case *types.Interface:
		i8ptr := &ptrBType{}
		return &structBType{[]backendType{i8ptr, i8ptr}}

	case *types.Slice:
		return tm.sliceBackendType()

	case *types.Array:
		return &arrayBType{uint64(t.Len()), tm.getBackendType(t.Elem())}
	}

	panic("unhandled type: " + t.String())
}

func (g *objcGen) objcType(typ types.Type) string {
	if isErrorType(typ) {
		return "NSError*"
	}

	switch typ := typ.(type) {
	case *types.Basic:
		switch typ.Kind() {
		case types.Bool:
			return "BOOL"
		case types.Int:
			return "int"
		case types.Int8:
			return "int8_t"
		case types.Int16:
			return "int16_t"
		case types.Int32:
			return "int32_t"
		case types.Int64:
			return "int64_t"
		case types.Uint8:
			// byte is an alias of uint8, and the alias is lost.
			return "byte"
		case types.Uint16:
			return "uint16_t"
		case types.Uint32:
			return "uint32_t"
		case types.Uint64:
			return "uint64_t"
		case types.Float32:
			return "float"
		case types.Float64:
			return "double"
		case types.String:
			return "NSString*"
		default:
			g.errorf("unsupported type: %s", typ)
			return "TODO"
		}
	case *types.Slice:
		elem := g.objcType(typ.Elem())
		// Special case: NSData seems to be a better option for byte slice.
		if elem == "byte" {
			return "NSData*"
		}
		// TODO(hyangah): support other slice types: NSArray or CFArrayRef.
		// Investigate the performance implication.
		g.errorf("unsupported type: %s", typ)
		return "TODO"
	case *types.Pointer:
		if _, ok := typ.Elem().(*types.Named); ok {
			return g.objcType(typ.Elem()) + "*"
		}
		g.errorf("unsupported pointer to type: %s", typ)
		return "TODO"
	case *types.Named:
		n := typ.Obj()
		if n.Pkg() != g.pkg {
			g.errorf("type %s is in package %s; only types defined in package %s is supported", n.Name(), n.Pkg().Name(), g.pkg.Name())
			return "TODO"
		}
		switch typ.Underlying().(type) {
		case *types.Interface:
			return g.namePrefix + n.Name() + "*"
		case *types.Struct:
			return g.namePrefix + n.Name()
		}
		g.errorf("unsupported, named type %s", typ)
		return "TODO"
	default:
		g.errorf("unsupported type: %#+v, %s", typ, typ)
		return "TODO"
	}
}

func reflectKind(t types.Type) reflect.Kind {
	switch t := t.(type) {
	case *types.Named:
		return reflectKind(t.Underlying())
	case *types.Basic:
		switch t.Kind() {
		case types.Bool:
			return reflect.Bool
		case types.Int:
			return reflect.Int
		case types.Int8:
			return reflect.Int8
		case types.Int16:
			return reflect.Int16
		case types.Int32:
			return reflect.Int32
		case types.Int64:
			return reflect.Int64
		case types.Uint:
			return reflect.Uint
		case types.Uint8:
			return reflect.Uint8
		case types.Uint16:
			return reflect.Uint16
		case types.Uint32:
			return reflect.Uint32
		case types.Uint64:
			return reflect.Uint64
		case types.Uintptr:
			return reflect.Uintptr
		case types.Float32:
			return reflect.Float32
		case types.Float64:
			return reflect.Float64
		case types.Complex64:
			return reflect.Complex64
		case types.Complex128:
			return reflect.Complex128
		case types.String:
			return reflect.String
		case types.UnsafePointer:
			return reflect.UnsafePointer
		}
	case *types.Array:
		return reflect.Array
	case *types.Chan:
		return reflect.Chan
	case *types.Signature:
		return reflect.Func
	case *types.Interface:
		return reflect.Interface
	case *types.Map:
		return reflect.Map
	case *types.Pointer:
		return reflect.Ptr
	case *types.Slice:
		return reflect.Slice
	case *types.Struct:
		return reflect.Struct
	}
	panic(fmt.Sprint("unexpected type: ", t))
}

//.........这里部分代码省略.........
		}
		// Recur: []int matches %d.
		return t&argPointer != 0 || f.matchArgTypeInternal(t, typ.Elem().Underlying(), arg, inProgress)

	case *types.Slice:
		// Same as array.
		if types.Identical(typ.Elem().Underlying(), types.Typ[types.Byte]) && t&argString != 0 {
			return true // %s matches []byte
		}
		// Recur: []int matches %d. But watch out for
		//	type T []T
		// If the element is a pointer type (type T[]*T), it's handled fine by the Pointer case below.
		return t&argPointer != 0 || f.matchArgTypeInternal(t, typ.Elem(), arg, inProgress)

	case *types.Pointer:
		// Ugly, but dealing with an edge case: a known pointer to an invalid type,
		// probably something from a failed import.
		if typ.Elem().String() == "invalid type" {
			if *verbose {
				f.Warnf(arg.Pos(), "printf argument %v is pointer to invalid or unknown type", f.gofmt(arg))
			}
			return true // special case
		}
		// If it's actually a pointer with %p, it prints as one.
		if t == argPointer {
			return true
		}
		// If it's pointer to struct, that's equivalent in our analysis to whether we can print the struct.
		if str, ok := typ.Elem().Underlying().(*types.Struct); ok {
			return f.matchStructArgType(t, str, arg, inProgress)
		}
		// The rest can print with %p as pointers, or as integers with %x etc.
		return t&(argInt|argPointer) != 0

	case *types.Struct:
		return f.matchStructArgType(t, typ, arg, inProgress)

	case *types.Interface:
		// If the static type of the argument is empty interface, there's little we can do.
		// Example:
		//	func f(x interface{}) { fmt.Printf("%s", x) }
		// Whether x is valid for %s depends on the type of the argument to f. One day
		// we will be able to do better. For now, we assume that empty interface is OK
		// but non-empty interfaces, with Stringer and Error handled above, are errors.
		return typ.NumMethods() == 0

	case *types.Basic:
		switch typ.Kind() {
		case types.UntypedBool,
			types.Bool:
			return t&argBool != 0

		case types.UntypedInt,
			types.Int,
			types.Int8,
			types.Int16,
			types.Int32,
			types.Int64,
			types.Uint,
			types.Uint8,
			types.Uint16,
			types.Uint32,
			types.Uint64,
			types.Uintptr:
			return t&argInt != 0

		case types.UntypedFloat,
			types.Float32,
			types.Float64:
			return t&argFloat != 0

		case types.UntypedComplex,
			types.Complex64,
			types.Complex128:
			return t&argComplex != 0

		case types.UntypedString,
			types.String:
			return t&argString != 0

		case types.UnsafePointer:
			return t&(argPointer|argInt) != 0

		case types.UntypedRune:
			return t&(argInt|argRune) != 0

		case types.UntypedNil:
			return t&argPointer != 0 // TODO?

		case types.Invalid:
			if *verbose {
				f.Warnf(arg.Pos(), "printf argument %v has invalid or unknown type", f.gofmt(arg))
			}
			return true // Probably a type check problem.
		}
		panic("unreachable")
	}

	return false
}

func isBasicKind(t types.Type, basickind types.BasicKind) bool {
	if t, ok := t.(*types.Basic); ok {
		return t.Kind() == basickind
	}
	return false
}

// seqType returns a string that can be used for reading and writing a
// type using the seq library.
// TODO(hyangah): avoid panic; gobind needs to output the problematic code location.
func seqType(t types.Type) string {
	if isErrorType(t) {
		return "UTF16"
	}
	switch t := t.(type) {
	case *types.Basic:
		switch t.Kind() {
		case types.Int:
			return "Int"
		case types.Int8:
			return "Int8"
		case types.Int16:
			return "Int16"
		case types.Int32:
			return "Int32"
		case types.Int64:
			return "Int64"
		case types.Uint8: // Byte.
			// TODO(crawshaw): questionable, but vital?
			return "Byte"
		// TODO(crawshaw): case types.Uint, types.Uint16, types.Uint32, types.Uint64:
		case types.Float32:
			return "Float32"
		case types.Float64:
			return "Float64"
		case types.String:
			return "UTF16"
		default:
			// Should be caught earlier in processing.
			panic(fmt.Sprintf("unsupported basic seqType: %s", t))
		}
	case *types.Named:
		switch u := t.Underlying().(type) {
		case *types.Interface:
			return "Ref"
		default:
			panic(fmt.Sprintf("unsupported named seqType: %s / %T", u, u))
		}
	case *types.Slice:
		switch e := t.Elem().(type) {
		case *types.Basic:
			switch e.Kind() {
			case types.Uint8: // Byte.
				return "ByteArray"
			default:
				panic(fmt.Sprintf("unsupported seqType: %s(%s) / %T(%T)", t, e, t, e))
			}
		default:
			panic(fmt.Sprintf("unsupported seqType: %s(%s) / %T(%T)", t, e, t, e))
		}
	// TODO: let the types.Array case handled like types.Slice?
	case *types.Pointer:
		if _, ok := t.Elem().(*types.Named); ok {
			return "Ref"
		}
		panic(fmt.Sprintf("not supported yet, pointer type: %s / %T", t, t))

	default:
		panic(fmt.Sprintf("unsupported seqType: %s / %T", t, t))
	}
}