Beispiel #1
0
func forceConvert(fn *cc.Decl, x *cc.Expr, actual, targ *cc.Type) {
	if isEmptyInterface(targ) {
		return
	}
	if isEmptyInterface(actual) {
		old := copyExpr(x)
		x.Op = TypeAssert
		x.Left = old
		x.Right = nil
		x.List = nil
		x.Type = targ
		x.XType = targ
		return
	}

	if isNumericConst(x) && targ != nil {
		switch targ.Kind {
		case cc.Ptr, Slice:
			if x.Op == cc.Number && x.Text == "0" {
				x.Op = cc.Name
				x.Text = "nil"
				x.XType = targ
			}
		case String:
			if x.Op == cc.Number && x.Text == "0" {
				x.Op = cc.Name
				x.Text = `""`
				x.XType = targ
			}
		}
		return
	}

	if x.Op == cc.Name && x.Text == "nil" && targ != nil {
		switch targ.Kind {
		case cc.Func, cc.Ptr, Slice:
			return
		case String:
			x.Text = `""`
			x.XType = targ
			x.XDecl = nil
			return
		}
	}

	if actual == nil || targ == nil {
		return
	}

	if actual.Kind == Ideal && Int8 <= targ.Kind && targ.Kind <= Float64 {
		return
	}

	if x != nil && x.Op == cc.Name && x.Text == "nil" {
		if targ.Kind == cc.Func || targ.Kind == cc.Ptr || targ.Kind == Slice {
			return
		}
	}

	// Func conversions are never useful.
	// If the func types are different, the conversion will fail;
	// if not, the conversion is unnecessary.
	// Either way the conversion is an eyesore.
	if targ.Kind == cc.Func || targ.Kind == cc.Ptr && targ.Base.Kind == cc.Func {
		return
	}

	if actual.Kind == Bool && Int8 <= targ.Kind && targ.Kind <= Float64 {
		old := copyExpr(x)
		if targ.Kind == Int {
			x.Op = cc.Call
			x.Left = &cc.Expr{Op: cc.Name, Text: "bool2int"}
			x.List = []*cc.Expr{old}
			x.Right = nil
		} else {
			x.Op = cc.Cast
			x.Left = &cc.Expr{Op: cc.Call, Left: &cc.Expr{Op: cc.Name, Text: "bool2int"}, List: []*cc.Expr{old}}
			x.Type = targ
		}
		return
	}

	if actual.Kind == cc.Array && targ.Kind == Slice && sameType(actual.Base, targ.Base) {
		old := copyExpr(x)
		x.Op = ExprSlice
		x.List = []*cc.Expr{old, nil, nil}
		x.Left = nil
		x.Right = nil
		return
	}

	if actual.Kind == Slice && targ.Kind == cc.Ptr && sameType(actual.Base, targ.Base) {
		if isCall(x, "make") {
			return
		}
		old := copyExpr(x)
		x.Op = cc.Addr
		x.Left = &cc.Expr{Op: cc.Index, Left: old, Right: &cc.Expr{Op: cc.Number, Text: "0"}}
		return
	}

	if !sameType(actual, targ) {
		if x.Op == cc.Twid {
			forceConvert(fn, x.Left, actual, targ)
			x.XType = targ
			return
		}
		old := copyExpr(x)
		// for debugging:
		// old = &cc.Expr{Op: cc.Cast, Left: old, Type: actual, XType: actual}
		x.Op = cc.Cast
		x.Left = old
		x.Right = nil
		x.List = nil
		x.Type = targ
		x.XType = targ
		if actual.Kind == cc.Array && targ.Kind == Slice {
			x.Op = ExprSlice
			x.List = []*cc.Expr{old, nil, nil}
			x.Left = nil
			x.Type = nil
		}
	}
}
Beispiel #2
0
func fixGoTypesExpr(fn *cc.Decl, x *cc.Expr, targ *cc.Type) (ret *cc.Type) {
	if x == nil {
		return nil
	}

	defer func() {
		x.XType = ret
	}()

	if x.Op == cc.Paren {
		return fixGoTypesExpr(fn, x.Left, targ)
	}

	// Make explicit C's implicit conversions from boolean to non-boolean and vice versa.
	switch x.Op {
	case cc.AndAnd, cc.OrOr, cc.Not, cc.EqEq, cc.Lt, cc.LtEq, cc.Gt, cc.GtEq, cc.NotEq:
		if targ != nil && targ.Kind != Bool {
			old := copyExpr(x)
			if targ.Kind == Int {
				x.Op = cc.Call
				x.Left = &cc.Expr{Op: cc.Name, Text: "bool2int"}
				x.List = []*cc.Expr{old}
				x.Right = nil
			} else {
				x.Op = cc.Cast
				x.Left = &cc.Expr{Op: cc.Call, Left: &cc.Expr{Op: cc.Name, Text: "bool2int"}, List: []*cc.Expr{old}}
				x.Type = targ
			}
			fixGoTypesExpr(fn, old, boolType)
			return targ
		}
	default:
		if targ != nil && targ.Kind == Bool {
			old := copyExpr(x)
			left := fixGoTypesExpr(fn, old, nil)
			if left != nil && left.Kind == Bool {
				return targ
			}
			if old.Op == cc.Number {
				switch old.Text {
				case "1":
					x.Op = cc.Name
					x.Text = "true"
					return targ
				case "0":
					x.Op = cc.Name
					x.Text = "false"
					return targ
				}
			}
			x.Op = cc.NotEq
			x.Left = old
			x.Right = zeroFor(left)
			fixSpecialCompare(fn, x)
			return targ
		}
	}

	fixArray(fn, x)

	switch x.Op {
	default:
		panic(fmt.Sprintf("unexpected construct %v in fixGoTypesExpr - %v - %v", GoString(x), x.Op, x.Span))

	case ExprType:
		// inserted by a rewrite
		return nil

	case ExprSlice:
		// inserted by rewriteLen
		left := fixGoTypesExpr(fn, x.List[0], targ)
		fixGoTypesExpr(fn, x.List[1], nil)
		fixGoTypesExpr(fn, x.List[2], nil)
		return left

	case cc.Comma:
		for i, y := range x.List {
			t := targ
			if i+1 < len(x.List) {
				t = nil
			}
			fixGoTypesExpr(fn, y, t)
		}
		return nil

	case ExprBlock:
		for _, stmt := range x.Block {
			fixGoTypesStmt(nil, fn, stmt)
		}
		return nil

	case cc.Add, cc.And, cc.Div, cc.Mod, cc.Mul, cc.Or, cc.Sub, cc.Xor:
		if x.Op == cc.Sub && isPtrSliceOrArray(x.Left.XType) && isPtrSliceOrArray(x.Right.XType) {
			left := fixGoTypesExpr(fn, x.Left, nil)
			right := fixGoTypesExpr(fn, x.Right, nil)
			if left != nil && right != nil && left.Kind != right.Kind {
				if left.Kind == Slice {
					forceConvert(fn, x.Right, right, left)
				} else {
					forceConvert(fn, x.Left, left, right)
				}
			}
			x.Left = &cc.Expr{Op: cc.Minus, Left: &cc.Expr{Op: cc.Call, Left: &cc.Expr{Op: cc.Name, Text: "cap"}, List: []*cc.Expr{x.Left}}}
			x.Right = &cc.Expr{Op: cc.Call, Left: &cc.Expr{Op: cc.Name, Text: "cap"}, List: []*cc.Expr{x.Right}}
			x.Op = cc.Add
			return intType
		}

		left := fixGoTypesExpr(fn, x.Left, targ)

		if x.Op == cc.And && x.Right.Op == cc.Twid {
			x.Op = AndNot
			x.Right = x.Right.Left
		}

		if x.Op == cc.Add && isSliceStringOrArray(left) {
			fixGoTypesExpr(fn, x.Right, nil)
			x.Op = ExprSlice
			x.List = []*cc.Expr{x.Left, x.Right, nil}
			x.Left = nil
			x.Right = nil
			if left.Kind == cc.Array {
				left = &cc.Type{Kind: Slice, Base: left.Base}
			}
			return left
		}

		right := fixGoTypesExpr(fn, x.Right, targ)
		return fixBinary(fn, x, left, right, targ)

	case cc.AddEq, cc.AndEq, cc.DivEq, cc.Eq, cc.ModEq, cc.MulEq, cc.OrEq, cc.SubEq, cc.XorEq:
		left := fixGoTypesExpr(fn, x.Left, nil)

		if x.Op == cc.AndEq && x.Right.Op == cc.Twid {
			x.Op = AndNotEq
			x.Right = x.Right.Left
		}

		if x.Op == cc.AddEq && isSliceOrString(left) {
			fixGoTypesExpr(fn, x.Right, nil)
			old := copyExpr(x.Left)
			x.Op = cc.Eq
			x.Right = &cc.Expr{Op: ExprSlice, List: []*cc.Expr{old, x.Right, nil}}
			return left
		}

		if x.Op == cc.Eq && x.Left.Op == cc.Index && sameType(x.Left.Left.XType, stringType) && GoString(x.Left.Right) == "0" && GoString(x.Right) == "0" {
			x.Left = x.Left.Left
			x.Right = &cc.Expr{Op: cc.Name, Text: `""`}
			return x.Left.XType
		}

		forceGoType(fn, x.Right, left)

		if x.Op == cc.Eq && x.Left != nil && x.Right != nil && x.Right.XType != nil && isCall(x.Right, "make") && x.Left.XDecl != nil && x.Left.XDecl.Type != nil && x.Left.XDecl.Type.Kind == cc.Ptr && sameType(x.Left.XDecl.Type.Base, x.Right.XType.Base) {
			x.Left.XDecl.Type = x.Right.XType
			x.Left.XType = x.Right.XType
			left = x.Right.XType
		}

		return left

	case ColonEq:
		left := fixGoTypesExpr(fn, x.Right, nil)
		x.Left.XType = left
		x.Left.XDecl.Type = left
		return left

	case cc.Addr:
		left := fixGoTypesExpr(fn, x.Left, nil)
		if left == nil {
			return nil
		}

		if targ != nil && targ.Kind == Slice && sameType(targ.Base, left) {
			l := x.Left
			l.Op = ExprSlice
			l.List = []*cc.Expr{l.Left, l.Right, nil}
			l.Left = nil
			l.Right = nil
			fixMerge(x, l)
			return targ
		}

		return &cc.Type{Kind: cc.Ptr, Base: left}

	case cc.AndAnd, cc.OrOr, cc.Not:
		fixGoTypesExpr(fn, x.Left, boolType)
		if x.Right != nil {
			fixGoTypesExpr(fn, x.Right, boolType)
		}
		return boolType

	case cc.Arrow, cc.Dot:
		left := fixGoTypesExpr(fn, x.Left, nil)

		if x.Op == cc.Arrow && isSliceOrString(left) {
			x.Left = &cc.Expr{Op: cc.Index, Left: x.Left, Right: &cc.Expr{Op: cc.Number, Text: "0"}}
		}

		return x.XDecl.Type

	case cc.Call:
		if fixPrintf(fn, x) {
			return x.XType
		}
		if fixSpecialCall(fn, x, targ) {
			return x.XType
		}
		left := fixGoTypesExpr(fn, x.Left, nil)
		if left != nil && left.Kind == cc.Ptr && left.Base.Kind == cc.Func {
			left = left.Base
		}
		for i, y := range x.List {
			if left != nil && left.Kind == cc.Func && i < len(left.Decls) {
				forceGoType(fn, y, left.Decls[i].Type)
			} else {
				fixGoTypesExpr(fn, y, nil)
			}
		}
		if left != nil && left.Kind == cc.Func {
			return left.Base
		}
		return nil

	case cc.Cast:
		fixGoTypesExpr(fn, x.Left, nil)
		if isEmptyInterface(x.Left.XType) {
			x.Op = TypeAssert
		}
		return x.Type

	case cc.CastInit:
		fixGoTypesInit(nil, x.Init)
		return x.Type

	case cc.EqEq, cc.Gt, cc.GtEq, cc.Lt, cc.LtEq, cc.NotEq:
		if fixSpecialCompare(fn, x) {
			return boolType
		}
		left := fixGoTypesExpr(fn, x.Left, nil)
		if x.Right.Op == cc.Number && x.Right.Text == "0" || x.Right.Op == cc.Name && x.Right.Text == "nil" {
			if isSliceOrPtr(left) {
				x.Right.Op = cc.Name
				x.Right.Text = "nil"
				return boolType
			}
			if left != nil && left.Kind == String {
				x.Right.Op = cc.String
				x.Right.Texts = []string{`""`}
				return boolType
			}
		}
		right := fixGoTypesExpr(fn, x.Right, nil)

		if isSliceOrArray(x.Left.XType) && isSliceOrArray(x.Right.XType) {
			x.Left = &cc.Expr{Op: cc.Minus, Left: &cc.Expr{Op: cc.Call, Left: &cc.Expr{Op: cc.Name, Text: "cap"}, List: []*cc.Expr{x.Left}}}
			x.Right = &cc.Expr{Op: cc.Minus, Left: &cc.Expr{Op: cc.Call, Left: &cc.Expr{Op: cc.Name, Text: "cap"}, List: []*cc.Expr{x.Right}}}
			return boolType
		}

		fixBinary(fn, x, left, right, nil)
		return boolType

	case cc.Index, cc.Indir:
		left := fixGoTypesExpr(fn, x.Left, nil)
		if x.Right != nil {
			fixGoTypesExpr(fn, x.Right, nil)
		}
		if left == nil {
			return nil
		}

		if isSliceOrString(left) && x.Op == cc.Indir {
			x.Op = cc.Index
			x.Right = &cc.Expr{Op: cc.Number, Text: "0"}
		}

		switch left.Kind {
		case cc.Ptr, Slice, cc.Array:
			if x.Op == cc.Indir && left.Kind == cc.Ptr && left.Base.Kind == cc.Func {
				*x = *x.Left
			}
			return left.Base

		case String:
			return byteType
		}
		return nil

	case cc.Lsh, cc.Rsh:
		left := fixGoTypesExpr(fn, x.Left, targ)
		if left != nil && targ != nil && Int8 <= left.Kind && left.Kind <= Float64 && targ.Kind > left.Kind {
			forceConvert(fn, x.Left, left, targ)
			left = targ
		}
		fixShiftCount(fn, x.Right)
		return left

	case cc.LshEq, cc.RshEq:
		left := fixGoTypesExpr(fn, x.Left, nil)
		fixShiftCount(fn, x.Right)
		return left

	case cc.Name:
		if x.Text == "nelem" {
		}
		switch x.Text {
		case "T", "S", "N", "L", "P", "C":
			x.Text = "nil"
			x.XDecl = nil
			return nil
		case "nelem":
			x.Text = "len"
			x.XDecl = nil
			fallthrough
		case "len":
			return &cc.Type{Kind: cc.Func, Base: intType}
		}
		if x.XDecl == nil {
			if x.Text == "true" || x.Text == "false" {
				return x.XType
			}
			return nil
		}
		return x.XDecl.Type

	case cc.Number:
		return idealType

	case cc.Minus, cc.Plus, cc.Twid:
		return fixGoTypesExpr(fn, x.Left, targ)

	case cc.Offsetof:
		// TODO
		return nil

	case cc.Paren:
		return fixGoTypesExpr(fn, x.Left, targ)

	case cc.PostDec, cc.PostInc:
		left := fixGoTypesExpr(fn, x.Left, nil)

		if x.Op == cc.PostInc && isSliceOrString(left) {
			old := copyExpr(x.Left)
			x.Op = cc.Eq
			x.Right = &cc.Expr{Op: ExprSlice, List: []*cc.Expr{old, &cc.Expr{Op: cc.Number, Text: "1"}, nil}}
		}

		return nil

	case cc.SizeofExpr:
		left := fixGoTypesExpr(fn, x.Left, nil)
		if left != nil && (left.Kind == cc.Array || left.Kind == Slice) && left.Base.Def().Is(Uint8) {
			x.Op = cc.Call
			x.List = []*cc.Expr{x.Left}
			x.Left = &cc.Expr{Op: cc.Name, Text: "len"}
			return intType
		}
		return nil

	case cc.SizeofType:
		return nil

	case cc.String:
		return &cc.Type{Kind: String}

	case cc.VaArg:
		// TODO
		return nil
	}
}