Golang Type.Obj方法代码示例

func (g *goGen) genWrite(valName, seqName string, T types.Type) {
	if isErrorType(T) {
		g.Printf("if %s == nil {\n", valName)
		g.Printf("    %s.WriteString(\"\");\n", seqName)
		g.Printf("} else {\n")
		g.Printf("    %s.WriteString(%s.Error());\n", seqName, valName)
		g.Printf("}\n")
		return
	}
	switch T := T.(type) {
	case *types.Pointer:
		// TODO(crawshaw): test *int
		// TODO(crawshaw): test **Generator
		switch T := T.Elem().(type) {
		case *types.Named:
			obj := T.Obj()
			if obj.Pkg() != g.pkg {
				g.errorf("type %s not defined in package %s", T, g.pkg)
				return
			}
			g.Printf("%s.WriteGoRef(%s)\n", seqName, valName)
		default:
			g.errorf("unsupported type %s", T)
		}
	case *types.Named:
		switch u := T.Underlying().(type) {
		case *types.Interface, *types.Pointer:
			g.Printf("%s.WriteGoRef(%s)\n", seqName, valName)
		default:
			g.errorf("unsupported, direct named type %s: %s", T, u)
		}
	default:
		g.Printf("%s.Write%s(%s);\n", seqName, seqType(T), valName)
	}
}

func (g *javaGen) genRead(resName, seqName string, T types.Type) {
	switch T := T.(type) {
	case *types.Pointer:
		// TODO(crawshaw): test *int
		// TODO(crawshaw): test **Generator
		switch T := T.Elem().(type) {
		case *types.Named:
			o := T.Obj()
			if o.Pkg() != g.pkg {
				g.errorf("type %s not defined in %s", T, g.pkg)
				return
			}
			g.Printf("%s = new %s(%s.readRef());\n", resName, o.Name(), seqName)
		default:
			g.errorf("unsupported type %s", T)
		}
	case *types.Named:
		switch T.Underlying().(type) {
		case *types.Interface, *types.Pointer:
			o := T.Obj()
			if o.Pkg() != g.pkg {
				g.errorf("type %s not defined in %s", T, g.pkg)
				return
			}
			g.Printf("%s = new %s.Proxy(%s.readRef());\n", resName, o.Name(), seqName)
		default:
			g.errorf("unsupported, direct named type %s", T)
		}
	default:
		g.Printf("%s = %s.read%s();\n", resName, seqName, seqType(T))
	}
}

// isSupported returns whether the generators can handle the type.
func (g *generator) isSupported(t types.Type) bool {
	if isErrorType(t) {
		return true
	}
	switch t := t.(type) {
	case *types.Basic:
		return true
	case *types.Slice:
		switch e := t.Elem().(type) {
		case *types.Basic:
			return e.Kind() == types.Uint8
		}
	case *types.Pointer:
		switch t := t.Elem().(type) {
		case *types.Named:
			return g.validPkg(t.Obj().Pkg())
		}
	case *types.Named:
		switch t.Underlying().(type) {
		case *types.Interface, *types.Pointer:
			return g.validPkg(t.Obj().Pkg())
		}
	}
	return false
}

// CanHaveDynamicTypes reports whether the type T can "hold" dynamic types,
// i.e. is an interface (incl. reflect.Type) or a reflect.Value.
//
func CanHaveDynamicTypes(T types.Type) bool {
	switch T := T.(type) {
	case *types.Named:
		if obj := T.Obj(); obj.Name() == "Value" && obj.Pkg().Path() == "reflect" {
			return true // reflect.Value
		}
		return CanHaveDynamicTypes(T.Underlying())
	case *types.Interface:
		return true
	}
	return false
}

// 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"
	}
}

// CanPoint reports whether the type T is pointerlike,
// for the purposes of this analysis.
func CanPoint(T types.Type) bool {
	switch T := T.(type) {
	case *types.Named:
		if obj := T.Obj(); obj.Name() == "Value" && obj.Pkg().Path() == "reflect" {
			return true // treat reflect.Value like interface{}
		}
		return CanPoint(T.Underlying())

	case *types.Pointer, *types.Interface, *types.Map, *types.Chan, *types.Signature, *types.Slice:
		return true
	}

	return false // array struct tuple builtin basic
}

func isExported(t types.Type) bool {
	if isErrorType(t) {
		return true
	}
	switch t := t.(type) {
	case *types.Basic:
		return true
	case *types.Named:
		return t.Obj().Exported()
	case *types.Pointer:
		return isExported(t.Elem())
	default:
		return true
	}
}

func describeType(qpos *queryPos, path []ast.Node) (*describeTypeResult, error) {
	var description string
	var t types.Type
	switch n := path[0].(type) {
	case *ast.Ident:
		t = qpos.info.TypeOf(n)
		switch t := t.(type) {
		case *types.Basic:
			description = "reference to built-in "

		case *types.Named:
			isDef := t.Obj().Pos() == n.Pos() // see caveats at isDef above
			if isDef {
				description = "definition of "
			} else if _, ok := qpos.info.ObjectOf(n).(*types.Alias); ok {
				description = "alias of "
			} else {
				description = "reference to "
			}
		}

	case ast.Expr:
		t = qpos.info.TypeOf(n)

	default:
		// Unreachable?
		return nil, fmt.Errorf("unexpected AST for type: %T", n)
	}

	description = description + "type " + qpos.typeString(t)

	// Show sizes for structs and named types (it's fairly obvious for others).
	switch t.(type) {
	case *types.Named, *types.Struct:
		szs := types.StdSizes{WordSize: 8, MaxAlign: 8} // assume amd64
		description = fmt.Sprintf("%s (size %d, align %d)", description,
			szs.Sizeof(t), szs.Alignof(t))
	}

	return &describeTypeResult{
		qpos:        qpos,
		node:        path[0],
		description: description,
		typ:         t,
		methods:     accessibleMethods(t, qpos.info.Pkg),
		fields:      accessibleFields(t, qpos.info.Pkg),
	}, nil
}

func (g *javaGen) genCToJava(toName, fromName string, t types.Type, mode varMode) {
	if isErrorType(t) {
		g.genCToJava(toName, fromName, types.Typ[types.String], mode)
		return
	}
	switch t := t.(type) {
	case *types.Basic:
		switch t.Kind() {
		case types.String:
			g.Printf("jstring %s = go_seq_to_java_string(env, %s);\n", toName, fromName)
		case types.Bool:
			g.Printf("jboolean %s = %s ? JNI_TRUE : JNI_FALSE;\n", toName, fromName)
		default:
			g.Printf("%s %s = (%s)%s;\n", g.jniType(t), toName, g.jniType(t), fromName)
		}
	case *types.Slice:
		switch e := t.Elem().(type) {
		case *types.Basic:
			switch e.Kind() {
			case types.Uint8: // Byte.
				g.Printf("jbyteArray %s = go_seq_to_java_bytearray(env, %s, %d);\n", toName, fromName, g.toCFlag(mode == modeRetained))
			default:
				g.errorf("unsupported type: %s", t)
			}
		default:
			g.errorf("unsupported type: %s", t)
		}
	case *types.Pointer:
		// TODO(crawshaw): test *int
		// TODO(crawshaw): test **Generator
		switch t := t.Elem().(type) {
		case *types.Named:
			g.genFromRefnum(toName, fromName, t, t.Obj())
		default:
			g.errorf("unsupported type %s", t)
		}
	case *types.Named:
		switch t.Underlying().(type) {
		case *types.Interface, *types.Pointer:
			g.genFromRefnum(toName, fromName, t, t.Obj())
		default:
			g.errorf("unsupported, direct named type %s", t)
		}
	default:
		g.Printf("%s %s = (%s)%s;\n", g.jniType(t), toName, g.jniType(t), fromName)
	}
}

func (g *javaGen) jniSigType(T types.Type) string {
	if isErrorType(T) {
		return g.jniSigType(types.Typ[types.String])
	}
	switch T := T.(type) {
	case *types.Basic:
		switch T.Kind() {
		case types.Bool, types.UntypedBool:
			return "Z"
		case types.Int:
			return "J"
		case types.Int8:
			return "B"
		case types.Int16:
			return "S"
		case types.Int32, types.UntypedRune: // types.Rune
			return "I"
		case types.Int64, types.UntypedInt:
			return "J"
		case types.Uint8: // types.Byte
			return "B"
		case types.Float32:
			return "F"
		case types.Float64, types.UntypedFloat:
			return "D"
		case types.String, types.UntypedString:
			return "Ljava/lang/String;"
		default:
			g.errorf("unsupported basic type: %s", T)
			return "TODO"
		}
	case *types.Slice:
		return "[" + g.jniSigType(T.Elem())
	case *types.Pointer:
		if _, ok := T.Elem().(*types.Named); ok {
			return g.jniSigType(T.Elem())
		}
		g.errorf("unsupported pointer to type: %s", T)
	case *types.Named:
		return "L" + g.jniClassSigPrefix(T.Obj().Pkg()) + T.Obj().Name() + ";"
	default:
		g.errorf("unsupported jniType: %#+v, %s\n", T, T)
	}
	return "TODO"
}

func (g *objcGen) refTypeBase(typ types.Type) string {
	switch typ := typ.(type) {
	case *types.Pointer:
		if _, ok := typ.Elem().(*types.Named); ok {
			return g.objcType(typ.Elem())
		}
	case *types.Named:
		n := typ.Obj()
		if n.Pkg() == g.pkg {
			switch typ.Underlying().(type) {
			case *types.Interface, *types.Struct:
				return g.namePrefix + n.Name()
			}
		}
	}

	// fallback to whatever objcType returns. This must not happen.
	return g.objcType(typ)
}

func (g *ObjcGen) refTypeBase(typ types.Type) string {
	switch typ := typ.(type) {
	case *types.Pointer:
		if _, ok := typ.Elem().(*types.Named); ok {
			return g.objcType(typ.Elem())
		}
	case *types.Named:
		n := typ.Obj()
		if isObjcType(typ) {
			return g.wrapMap[n.Name()].Name
		}
		if isErrorType(typ) || g.validPkg(n.Pkg()) {
			switch typ.Underlying().(type) {
			case *types.Interface, *types.Struct:
				return g.namePrefixOf(n.Pkg()) + n.Name()
			}
		}
	}

	// fallback to whatever objcType returns. This must not happen.
	return g.objcType(typ)
}

// javaType returns a string that can be used as a Java type.
func (g *JavaGen) javaType(T types.Type) string {
	if isErrorType(T) {
		// The error type is usually translated into an exception in
		// Java, however the type can be exposed in other ways, such
		// as an exported field.
		return "java.lang.Exception"
	} else if isJavaType(T) {
		return classNameFor(T)
	}
	switch T := T.(type) {
	case *types.Basic:
		return g.javaBasicType(T)
	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())
		}
		g.errorf("unsupported pointer to type: %s", T)
	case *types.Named:
		n := T.Obj()
		nPkg := n.Pkg()
		if !isErrorType(T) && !g.validPkg(nPkg) {
			g.errorf("type %s is in %s, which is not bound", n.Name(), nPkg)
			break
		}
		// TODO(crawshaw): more checking here
		if nPkg != g.Pkg {
			return fmt.Sprintf("%s.%s", g.javaPkgName(nPkg), n.Name())
		} else {
			return n.Name()
		}
	default:
		g.errorf("unsupported javaType: %#+v, %s\n", T, T)
	}
	return "TODO"
}

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 "id<" + 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 (p *exporter) typ(t types.Type) {
	if t == nil {
		log.Fatalf("gcimporter: nil type")
	}

	// Possible optimization: Anonymous pointer types *T where
	// T is a named type are common. We could canonicalize all
	// such types *T to a single type PT = *T. This would lead
	// to at most one *T entry in typIndex, and all future *T's
	// would be encoded as the respective index directly. Would
	// save 1 byte (pointerTag) per *T and reduce the typIndex
	// size (at the cost of a canonicalization map). We can do
	// this later, without encoding format change.

	// if we saw the type before, write its index (>= 0)
	if i, ok := p.typIndex[t]; ok {
		p.index('T', i)
		return
	}

	// otherwise, remember the type, write the type tag (< 0) and type data
	if trackAllTypes {
		if trace {
			p.tracef("T%d = {>\n", len(p.typIndex))
			defer p.tracef("<\n} ")
		}
		p.typIndex[t] = len(p.typIndex)
	}

	switch t := t.(type) {
	case *types.Named:
		if !trackAllTypes {
			// if we don't track all types, track named types now
			p.typIndex[t] = len(p.typIndex)
		}

		p.tag(namedTag)
		p.pos(t.Obj())
		p.qualifiedName(t.Obj())
		p.typ(t.Underlying())
		if !types.IsInterface(t) {
			p.assocMethods(t)
		}

	case *types.Array:
		p.tag(arrayTag)
		p.int64(t.Len())
		p.typ(t.Elem())

	case *types.Slice:
		p.tag(sliceTag)
		p.typ(t.Elem())

	case *dddSlice:
		p.tag(dddTag)
		p.typ(t.elem)

	case *types.Struct:
		p.tag(structTag)
		p.fieldList(t)

	case *types.Pointer:
		p.tag(pointerTag)
		p.typ(t.Elem())

	case *types.Signature:
		p.tag(signatureTag)
		p.paramList(t.Params(), t.Variadic())
		p.paramList(t.Results(), false)

	case *types.Interface:
		p.tag(interfaceTag)
		p.iface(t)

	case *types.Map:
		p.tag(mapTag)
		p.typ(t.Key())
		p.typ(t.Elem())

	case *types.Chan:
		p.tag(chanTag)
		p.int(int(3 - t.Dir())) // hack
		p.typ(t.Elem())

	default:
		log.Fatalf("gcimporter: unexpected type %T: %s", t, t)
	}
}