Golang Type.String方法代碼示例

func zeroFor(targ *cc.Type) *cc.Expr {
	if targ != nil {
		k := targ.Def().Kind
		switch k {
		case String:
			return &cc.Expr{Op: cc.String, Texts: []string{`""`}}

		case Slice, cc.Ptr:
			return &cc.Expr{Op: cc.Name, Text: "nil"}

		case cc.Struct, cc.Array:
			return &cc.Expr{Op: cc.CastInit, Type: targ, Init: &cc.Init{}}

		case Bool:
			return &cc.Expr{Op: cc.Name, Text: "false"}
		}

		if Int8 <= k && k <= Float64 {
			return &cc.Expr{Op: cc.Number, Text: "0"}
		}

		if isEmptyInterface(targ) {
			return &cc.Expr{Op: cc.Name, Text: "nil"}
		}

		return &cc.Expr{Op: cc.Number, Text: "0 /*" + targ.String() + "*/"}
	}

	return &cc.Expr{Op: cc.Number, Text: "0 /*untyped*/"}
}

func fixSpecialCall(fn *cc.Decl, x *cc.Expr, targ *cc.Type) bool {
	if x.Left.Op != cc.Name {
		return false
	}
	switch x.Left.Text {
	case "memmove":
		if len(x.List) != 3 {
			// fprintf(x.Span, "unsupported %v", x)
			return false
		}
		siz := x.List[2]
		if siz.Op == cc.Number && siz.Text == "4" {
			obj1, obj1Type := objIndir(fn, x.List[0])
			obj2, obj2Type := objIndir(fn, x.List[1])
			if obj1Type == nil || obj2Type == nil {
				// fprintf(x.Span, "unsupported %v - missing types", x)
				return true
			}
			if (obj1Type.Kind == Uint32 || obj1Type.Kind == Int32) && obj2Type.Kind == Float32 {
				x.Op = cc.Eq
				x.Left = obj1
				x.Right = &cc.Expr{
					Op: cc.Call,
					Left: &cc.Expr{Op: cc.Name,
						Text: "math.Float32bits",
					},
					List: []*cc.Expr{obj2},
				}
				x.XType = uint32Type
				return true
			}
			// fprintf(x.Span, "unsupported %v - size 4 type %v %v", x, GoString(obj1Type), GoString(obj2Type))
		}
		if siz.Op == cc.Number && siz.Text == "8" {
			obj1, obj1Type := objIndir(fn, x.List[0])
			obj2, obj2Type := objIndir(fn, x.List[1])
			if obj1Type == nil || obj2Type == nil {
				// fprintf(x.Span, "unsupported %v - missing types", x)
				return true
			}
			if (obj1Type.Kind == Uint64 || obj1Type.Kind == Int64) && obj2Type.Kind == Float64 {
				x.Op = cc.Eq
				x.Left = obj1
				x.Right = &cc.Expr{
					Op: cc.Call,
					Left: &cc.Expr{Op: cc.Name,
						Text: "math.Float64bits",
					},
					List: []*cc.Expr{obj2},
				}
				x.XType = uint64Type
				return true
			}
			// fprintf(x.Span, "unsupported %v - size 8 type %v %v", x, GoString(obj1Type), GoString(obj2Type))
		}
		if siz.Op == cc.SizeofExpr {
			obj1Type := fixGoTypesExpr(fn, x.List[0], nil)
			obj2Type := fixGoTypesExpr(fn, x.List[1], nil)
			sizeType := fixGoTypesExpr(fn, siz.Left, nil)
			if obj1Type == nil || obj2Type == nil {
				// fprintf(x.Span, "unsupported %v - bad types", x)
				return true
			}
			if obj2Type.Kind == cc.Array && sameType(obj2Type, sizeType) || obj2Type.Kind == Slice && GoString(x.List[1]) == GoString(siz.Left) {
				x.Left.Text = "copy"
				x.Left.XDecl = nil
				x.List = x.List[:2]
				return true
			}
			// fprintf(x.Span, "unsupported %v - not array %v %v", x, GoString(obj2Type), GoString(sizeType))
			return true
		}
		left := fixGoTypesExpr(fn, x.List[0], nil)
		right := fixGoTypesExpr(fn, x.List[1], nil)
		fixGoTypesExpr(fn, siz, nil)
		if isSliceOrArray(left) && isSliceOrArray(right) && left.Base.Is(Uint8) && right.Base.Is(Uint8) {
			x.Left.Text = "copy"
			x.Left.XDecl = nil
			if x.List[1].Op == ExprSlice && x.List[1].List[1] == nil {
				x.List[1].List[2] = siz
			} else {
				x.List[1] = &cc.Expr{Op: ExprSlice, List: []*cc.Expr{x.List[1], nil, siz}}
			}
			x.List = x.List[:2]
			return true
		}
		// fprintf(x.Span, "unsupported %v (%v %v)", x, GoString(left), GoString(right))
		return true

	case "mal", "malloc", "emallocz", "xmalloc":
		if len(x.List) != 1 {
			fprintf(x.Span, "unsupported %v - too many args", x)
			return false
		}
		siz := x.List[0]
		var count *cc.Expr
		if siz.Op == cc.Mul {
			count = siz.Left
			siz = siz.Right
			if count.Op == cc.SizeofType || count.Op == cc.SizeofExpr {
//.........這裏部分代碼省略.........

func (p *Printer) printType(t *cc.Type) {
	if t == nil {
		p.Print("nil_type")
		return
	}

	// Shouldn't happen but handle in case it does.
	p.Print(t.Comments.Before)
	defer p.Print(t.Comments.Suffix, t.Comments.After)

	if t == cc.BoolType {
		p.Print("bool")
		return
	}
	if typemap[t.Kind] != "" {
		p.Print(typemap[t.Kind])
		return
	}

	switch t.Kind {
	default:
		if t.String() == "" {
			p.Print("C.unknown")
			break
		}
		p.Print("C.", t.String()) // hope for the best

	case Slice:
		p.Print("[]", t.Base)

	case String:
		p.Print("string")

	case cc.Struct:
		if len(t.Decls) == 0 {
			p.Print("struct{}")
			break
		}
		p.Print("struct {", Indent)
		p.printStructBody(t)
		p.Print(Unindent, Newline, "}")

	case cc.Enum:
		if t.Tag != "" {
			p.Print(t.Tag)
		} else {
			p.Print("int")
		}

	case cc.TypedefType:
		if t.Base != nil && typemap[t.Base.Kind] != "" && strings.ToLower(t.Name) == t.Name {
			p.Print(typemap[t.Base.Kind])
			return
		}
		if t.TypeDecl != nil && t.TypeDecl.GoPackage != "" && p.Package != "" && t.TypeDecl.GoPackage != p.Package {
			p.Print(path.Base(t.TypeDecl.GoPackage) + "." + t.Name)
			break
		}
		p.Print(t.Name)

	case cc.Ptr:
		if t.Base.Is(cc.Func) {
			p.Print(t.Base)
			return
		}
		if t.Base.Is(cc.Void) {
			p.Print("*[0]byte")
			return
		}
		p.Print("*", t.Base)

	case cc.Func:
		p.Print("func(")
		for i, arg := range t.Decls {
			if i > 0 {
				p.Print(", ")
			}
			if arg.Name == "..." {
				p.Print("...interface{}")
				continue
			}
			if arg.Name == "" && arg.Type.Is(cc.Void) {
				continue
			}
			p.Print(arg.Type)
		}
		p.Print(")")
		if !t.Base.Is(cc.Void) {
			p.Print(" ", t.Base)
		}

	case cc.Array:
		if t.Width == nil {
			p.Print("[XXX]", t.Base)
			return
		}
		p.Print("[", t.Width, "]", t.Base)
	}
}

func cTypeToMap(typ *cc.Type) *typeMap {
	switch typ.Kind {
	case cc.Ptr:
		str := typ.Base.String()
		switch str {
		case "char":
			return &typeMap{
				goType: "string",
				cToGo: func(in string) string {
					return fmt.Sprintf("C.GoString(%s)", in)
				},
				goToC: func(in string) (string, string) {
					cvar := fmt.Sprintf("c_%s", in)
					return cvar, fmt.Sprintf("%s := C.CString(%s); defer C.free(unsafe.Pointer(%s))", cvar, in, cvar)
				},
			}
		case "uchar", "void":
			log.Printf("TODO %s: in type blacklist (TODO: add reasoning)", str)
			return nil
		}

		if goType, ok := sharedTypes[str]; ok {
			// TODO: it appears *Rectangle might only be used for out params.
			return &typeMap{
				goType: "*" + goType,
				cToGo: func(in string) string {
					return fmt.Sprintf("(*%s)(unsafe.Pointer(%s))", goType, in)
				},
				goToC: func(in string) (string, string) {
					return fmt.Sprintf("(*C.%s)(unsafe.Pointer(%s))", str, in), ""
				},
				method: goType,
			}
		}

		if rawCTypes[str] {
			return &typeMap{
				goType: "unsafe.Pointer",
				cToGo: func(in string) string {
					return fmt.Sprintf("unsafe.Pointer(%s)", in)
				},
				goToC: func(in string) (string, string) {
					return fmt.Sprintf("(*C.%s)(%s)", str, in), ""
				},
			}
		}

		goName := cNameToGoUpper(str)
		if reason, ok := typeTodoList[str]; ok {
			log.Printf("TODO %s: %s", str, reason)
			return nil
		}
		return &typeMap{
			goType: "*" + goName,
			cToGo: func(in string) string {
				return fmt.Sprintf("wrap%s(%s)", goName, in)
			},
			goToC: func(in string) (string, string) {
				return fmt.Sprintf("%s.Ptr", in), ""
			},
			method: goName,
		}
	case cc.Void:
		return &typeMap{
			goType: "",
			cToGo:  nil,
			goToC:  nil,
		}
	}

	// Otherwise, it's a basic non-pointer type.
	cName := typ.String()
	if reason, ok := typeTodoList[cName]; ok {
		log.Printf("TODO %s: %s", cName, reason)
		return nil
	}

	switch cName {
	case "cairo_bool_t":
		return &typeMap{
			goType: "bool",
			cToGo: func(in string) string {
				return fmt.Sprintf("%s != 0", in)
			},
			goToC: func(in string) (string, string) {
				return fmt.Sprintf("C.%s(%s)", cName, in), ""
			},
		}
	case "cairo_status_t":
		return &typeMap{
			goType: "error",
			cToGo: func(in string) string {
				return fmt.Sprintf("Status(%s).toError()", in)
			},
			goToC: nil,
		}
	case "Drawable", "Pixmap":
		return &typeMap{
			goType: "uint64",
			cToGo: func(in string) string {
//.........這裏部分代碼省略.........