Beispiel #1
0
func buildBinaryOpExpr(b *builder, expr *tast.OpExpr) *ref {
	op := expr.Op.Lit
	A := b.buildExpr(expr.A)
	atyp := A.Type()
	if types.IsBasic(atyp, types.Bool) && (op == "&&" || op == "||") {
		switch op {
		case "&&":
			return buildLogicAnd(b, A, expr.B)
		case "||":
			return buildLogicOr(b, A, expr.B)
		}
		panic("unreachable")
	}

	B := b.buildExpr(expr.B)
	btyp := B.Type()
	if types.IsConst(atyp) && types.IsConst(btyp) {
		return binaryOpConst(b, op, A, B)
	}

	if op == ">>" || op == "<<" {
		ret := b.newTemp(atyp)
		buildShift(b, ret, A, B, op)
		return ret
	}

	if ok, t := types.SameBasic(atyp, btyp); ok {
		switch t {
		case types.Int, types.Int8:
			return binaryOpInt(b, op, A, B, t)
		case types.Uint, types.Uint8:
			return binaryOpUint(b, op, A, B, t)
		case types.Bool:
			return binaryOpBool(b, op, A, B)
		}
		panic("bug")
	}

	if types.IsNil(atyp) && types.IsNil(btyp) {
		return binaryOpNil(b, op, A, B)
	} else if types.BothPointer(atyp, btyp) {
		return binaryOpPtr(b, op, A, B)
	} else if types.BothFuncPointer(atyp, btyp) {
		return binaryOpPtr(b, op, A, B)
	} else if types.BothSlice(atyp, btyp) {
		return binaryOpSlice(b, op, A, B)
	}
	panic("bug")
}
Beispiel #2
0
// allocPrepare checks if the provided types are all allocable, and insert
// implicit type casts if needed. Only literay expression list needs alloc
// prepare.
func allocPrepare(
	b *builder, toks []*lex8.Token, lst *tast.ExprList,
) *tast.ExprList {
	ret := tast.NewExprList()
	for i, tok := range toks {
		e := lst.Exprs[i]
		t := e.Type()
		if types.IsNil(t) {
			b.Errorf(tok.Pos, "cannot infer type from nil for %q", tok.Lit)
			return nil
		}
		if v, ok := types.NumConst(t); ok {
			e = constCastInt(b, tok.Pos, v, e)
			if e == nil {
				return nil
			}
		}
		if !types.IsAllocable(t) {
			b.Errorf(tok.Pos, "cannot allocate for %s", t)
			return nil
		}
		ret.Append(e)
	}
	return ret
}
Beispiel #3
0
func binaryOpPtr(b *builder, op string, A, B *ref) *ref {
	atyp := A.Type()
	btyp := B.Type()

	switch op {
	case "==", "!=":
		// replace nil with a typed zero
		if types.IsNil(atyp) {
			A = newRef(btyp, ir.Num(0))
		} else if types.IsNil(btyp) {
			B = newRef(atyp, ir.Num(0))
		}

		ret := b.newTemp(types.Bool)
		b.b.Arith(ret.IR(), A.IR(), op, B.IR())
		return ret
	}
	panic("bug")
}
Beispiel #4
0
func binaryOpPtr(b *builder, opTok *lex8.Token, A, B tast.Expr) tast.Expr {
	op := opTok.Lit
	atyp := A.R().T
	btyp := B.R().T

	switch op {
	case "==", "!=":
		if types.IsNil(atyp) {
			A = tast.NewCast(A, btyp)
		} else if types.IsNil(btyp) {
			B = tast.NewCast(B, atyp)
		}

		return &tast.OpExpr{A, opTok, B, tast.NewRef(types.Bool)}
	}

	b.Errorf(opTok.Pos, "%q on pointers", op)
	return nil
}
Beispiel #5
0
func binaryOpSlice(b *builder, op string, A, B *ref) *ref {
	atyp := A.Type()
	btyp := B.Type()

	switch op {
	case "==", "!=":
		if types.IsNil(atyp) {
			return testNilSlice(b, B, op == "==")
		} else if types.IsNil(btyp) {
			return testNilSlice(b, A, op == "==")
		}

		addrA := b.newPtr()
		addrB := b.newPtr()
		b.b.Arith(addrA, nil, "&", A.IR())
		b.b.Arith(addrB, nil, "&", B.IR())
		baseA := ir.NewAddrRef(addrA, 4, 0, false, true)
		sizeA := ir.NewAddrRef(addrA, 4, 4, false, true)
		baseB := ir.NewAddrRef(addrB, 4, 0, false, true)
		sizeB := ir.NewAddrRef(addrB, 4, 4, false, true)

		ptrEq := b.newCond()
		sizeEq := b.newCond()

		b.b.Arith(ptrEq, baseA, "==", baseB)
		b.b.Arith(sizeEq, sizeA, "==", sizeB)

		ret := b.newCond()
		b.b.Arith(ret, ptrEq, "&", sizeEq)
		if op == "!=" {
			b.b.Arith(ret, nil, "!", ret)
		}
		return newRef(types.Bool, ret)
	}
	panic("bug")
}
Beispiel #6
0
func assign(b *builder, dest, src tast.Expr, op *lex8.Token) tast.Stmt {
	destRef := dest.R()
	srcRef := src.R()

	ndest := destRef.Len()
	nsrc := srcRef.Len()
	if ndest != nsrc {
		b.Errorf(op.Pos, "cannot assign %s to %s", nsrc, ndest)
		return nil
	}

	for i := 0; i < ndest; i++ {
		r := destRef.At(i)
		if !r.Addressable {
			b.Errorf(op.Pos, "assigning to non-addressable")
			return nil
		}

		destType := r.Type()
		srcType := srcRef.At(i).Type()
		if !types.CanAssign(destType, srcType) {
			b.Errorf(op.Pos, "cannot assign %s to %s", srcType, destType)
			return nil
		}
	}

	// insert casting if needed
	if srcList, ok := tast.MakeExprList(src); ok {
		newList := tast.NewExprList()
		for i, e := range srcList.Exprs {
			t := e.Type()
			if types.IsNil(t) {
				e = tast.NewCast(e, destRef.At(i).Type())
			} else if v, ok := types.NumConst(t); ok {
				e = constCast(b, nil, v, e, destRef.At(i).Type())
				if e == nil {
					panic("bug")
				}
			}
			newList.Append(e)
		}
		src = newList
	}

	return &tast.AssignStmt{dest, op, src}
}
Beispiel #7
0
func varDeclPrepare(
	b *builder, toks []*lex8.Token, lst *tast.ExprList, t types.T,
) *tast.ExprList {
	ret := tast.NewExprList()
	for i, tok := range toks {
		e := lst.Exprs[i]
		etype := e.Type()
		if types.IsNil(etype) {
			e = tast.NewCast(e, t)
		} else if v, ok := types.NumConst(etype); ok {
			e = constCast(b, tok.Pos, v, e, t)
			if e == nil {
				return nil
			}
		}
		ret.Append(e)
	}
	return ret
}
Beispiel #8
0
func buildCast(b *builder, from *ref, t types.T) *ref {
	srcType := from.Type()
	ret := b.newTemp(t)

	if types.IsNil(srcType) {
		size := t.Size()
		if size == arch8.RegSize {
			return newRef(t, ir.Num(0))
		}
		if _, ok := t.(*types.Slice); !ok {
			panic("bug")
		}
		ret := b.newTemp(t)
		b.b.Zero(ret.IR())
		return ret
	}

	if c, ok := srcType.(*types.Const); ok {
		if v, ok := types.NumConst(srcType); ok && types.IsInteger(t) {
			return newRef(t, constNumIr(v, t))
		}
		// TODO: we do not support typed const right?
		// so why need this line?
		srcType = c.Type // using the underlying type
	}

	if types.IsInteger(t) && types.IsInteger(srcType) {
		b.b.Arith(ret.IR(), nil, "cast", from.IR())
		return ret
	}
	if regSizeCastable(t, srcType) {
		b.b.Arith(ret.IR(), nil, "", from.IR())
		return ret
	}
	panic("bug")
}
Beispiel #9
0
func buildReturnStmt(b *builder, stmt *ast.ReturnStmt) tast.Stmt {
	pos := stmt.Kw.Pos
	if stmt.Exprs == nil {
		if b.retType == nil || b.retNamed {
			return &tast.ReturnStmt{}
		}
		b.Errorf(pos, "expects return %s", fmt8.Join(b.retType, ","))
		return nil
	}

	if b.retType == nil {
		b.Errorf(pos, "function expects no return value")
		return nil
	}

	src := b.buildExpr(stmt.Exprs)
	if src == nil {
		return nil
	}

	srcRef := src.R()
	nret := len(b.retType)
	nsrc := srcRef.Len()
	if nret != nsrc {
		b.Errorf(pos, "expect (%s), returning (%s)",
			fmt8.Join(b.retType, ","), srcRef,
		)
		return nil
	}

	for i := 0; i < nret; i++ {
		t := b.retType[i]
		srcType := srcRef.At(i).Type()
		if !types.CanAssign(t, srcType) {
			b.Errorf(pos, "expect (%s), returning (%s)",
				fmt8.Join(b.retType, ","), srcRef,
			)
			return nil
		}
	}

	// insert implicit type casts
	if srcList, ok := tast.MakeExprList(src); ok {
		newList := tast.NewExprList()
		for i, e := range srcList.Exprs {
			t := e.Type()
			if types.IsNil(t) {
				e = tast.NewCast(e, b.retType[i])
			} else if v, ok := types.NumConst(t); ok {
				e = constCast(b, nil, v, e, b.retType[i])
				if e == nil {
					panic("bug")
				}
			}
			newList.Append(e)
		}
		src = newList
	}

	return &tast.ReturnStmt{src}
}
Beispiel #10
0
func buildBinaryOpExpr(b *builder, expr *ast.OpExpr) tast.Expr {
	opTok := expr.Op
	op := opTok.Lit
	opPos := opTok.Pos

	A := b.buildExpr(expr.A)
	if A == nil {
		return nil
	}
	aref := A.R()
	if !aref.IsSingle() {
		b.Errorf(opPos, "%q on %s", op, aref)
		return nil
	}
	atyp := aref.T

	B := b.buildExpr(expr.B)
	if B == nil {
		return nil
	}
	bref := B.R()
	if !bref.IsSingle() {
		b.Errorf(opPos, "%q on %s", op, bref)
		return nil
	}
	btyp := bref.T

	if types.IsConst(atyp) && types.IsConst(btyp) {
		return binaryOpConst(b, opTok, A, B)
	}

	if op == ">>" || op == "<<" {
		if v, ok := types.NumConst(btyp); ok {
			B = constCast(b, opPos, v, B, types.Uint)
			if B == nil {
				return nil
			}
			btyp = types.Uint
		}

		if v, ok := types.NumConst(atyp); ok {
			A = constCast(b, opPos, v, A, types.Int)
			if A == nil {
				return nil
			}
			atyp = types.Int
		}

		if !canShift(b, atyp, btyp, opPos, op) {
			return nil
		}

		r := tast.NewRef(atyp)
		return &tast.OpExpr{A, opTok, B, r}
	}

	if v, ok := types.NumConst(atyp); ok {
		A = constCast(b, opPos, v, A, btyp)
		if A == nil {
			return nil
		}
		atyp = btyp
	} else if c, ok := atyp.(*types.Const); ok {
		atyp = c.Type
	}

	if v, ok := types.NumConst(btyp); ok {
		B = constCast(b, opPos, v, B, atyp)
		if B == nil {
			return nil
		}
		btyp = atyp
	} else if c, ok := btyp.(*types.Const); ok {
		btyp = c.Type
	}

	if ok, t := types.SameBasic(atyp, btyp); ok {
		switch t {
		case types.Int, types.Int8, types.Uint, types.Uint8:
			return binaryOpInt(b, opTok, A, B, t)
		case types.Bool:
			return binaryOpBool(b, opTok, A, B)
		case types.Float32:
			b.Errorf(opPos, "floating point operations not implemented")
			return nil
		}
	}

	if types.IsNil(atyp) && types.IsNil(btyp) {
		return binaryOpNil(b, opTok, A, B)
	} else if types.BothPointer(atyp, btyp) {
		return binaryOpPtr(b, opTok, A, B)
	} else if types.BothFuncPointer(atyp, btyp) {
		return binaryOpPtr(b, opTok, A, B)
	} else if types.BothSlice(atyp, btyp) {
		return binaryOpSlice(b, opTok, A, B)
	}

	b.Errorf(opPos, "invalid operation of %s %s %s", atyp, op, btyp)
	if types.IsInteger(atyp) && types.IsInteger(btyp) {
		switch op {
		case "+", "-", "*", "&", "|", "^", "%", "/",
			"==", "!=", ">", "<", ">=", "<=":
			b.Errorf(
				opPos,
				"operation %s needs the same type on both sides",
				op,
			)
		}
	}
	return nil
}
Beispiel #11
0
func (r *ref) IsNil() bool {
	if !r.IsSingle() {
		return false
	}
	return types.IsNil(r.Type())
}
Beispiel #12
0
func buildCallExpr(b *builder, expr *ast.CallExpr) tast.Expr {
	f := b.buildExpr(expr.Func)
	if f == nil {
		return nil
	}

	pos := ast.ExprPos(expr.Func)
	fref := f.R()
	if !fref.IsSingle() {
		b.Errorf(pos, "%s is not callable", fref)
		return nil
	}
	if t, ok := fref.T.(*types.Type); ok {
		return buildCast(b, expr, t.T)
	}

	builtin, ok := fref.T.(*types.BuiltInFunc)
	if ok {
		switch builtin.Name {
		case "len":
			return buildCallLen(b, expr, f)
		case "make":
			return buildCallMake(b, expr, f)
		}
		b.Errorf(pos, "builtin %s() not implemented", builtin.Name)
		return nil
	}

	funcType, ok := fref.T.(*types.Func)
	if !ok {
		b.Errorf(pos, "function call on non-callable: %s", fref)
		return nil
	}

	args := buildExprList(b, expr.Args)
	if args == nil {
		return nil
	}

	argsRef := args.R()
	nargs := argsRef.Len()
	if nargs != len(funcType.Args) {
		b.Errorf(ast.ExprPos(expr), "argument expects (%s), got (%s)",
			fmt8.Join(funcType.Args, ","), args,
		)
		return nil
	}

	// type check on each argument
	for i := 0; i < nargs; i++ {
		argType := argsRef.At(i).Type()
		expect := funcType.Args[i].T
		if !types.CanAssign(expect, argType) {
			pos := ast.ExprPos(expr.Args.Exprs[i])
			b.Errorf(pos, "argument %d expects %s, got %s",
				i+1, expect, argType,
			)
			return nil
		}
	}

	// insert casting when it is a literal expression list.
	callArgs, ok := tast.MakeExprList(args)
	if ok {
		castedArgs := tast.NewExprList()
		for i := 0; i < nargs; i++ {
			argExpr := callArgs.Exprs[i]
			argType := argExpr.Type()
			expect := funcType.Args[i].T

			// insert auto casts for consts
			if types.IsNil(argType) {
				castedArgs.Append(tast.NewCast(argExpr, expect))
			} else if _, ok := types.NumConst(argType); ok {
				castedArgs.Append(tast.NewCast(argExpr, expect))
			} else {
				castedArgs.Append(argExpr)
			}
		}
		args = castedArgs
	}

	retRef := tast.Void
	for _, t := range funcType.RetTypes {
		retRef = tast.AppendRef(retRef, tast.NewRef(t))
	}

	return &tast.CallExpr{f, args, retRef}
}