Java Code Examples for jdk.nashorn.internal.ir.BinaryNode#isLogical()

The following examples show how to use jdk.nashorn.internal.ir.BinaryNode#isLogical() . You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. You may check out the related API usage on the sidebar.
Example 1
Source File: JSONWriter.java    From openjdk-jdk8u-backup with GNU General Public License v2.0 5 votes vote down vote up
@Override
public boolean enterBinaryNode(final BinaryNode binaryNode) {
    enterDefault(binaryNode);

    final String name;
    if (binaryNode.isAssignment()) {
        name = "AssignmentExpression";
    } else if (binaryNode.isLogical()) {
        name = "LogicalExpression";
    } else {
        name = "BinaryExpression";
    }

    type(name);
    comma();

    property("operator", binaryNode.tokenType().getName());
    comma();

    property("left");
    binaryNode.lhs().accept(this);
    comma();

    property("right");
    binaryNode.rhs().accept(this);

    return leave();
}
 
Example 2
Source File: LocalVariableTypesCalculator.java    From jdk8u_nashorn with GNU General Public License v2.0 5 votes vote down vote up
@Override
public boolean enterBinaryNode(final BinaryNode binaryNode) {
    // NOTE: regardless of operator's lexical associativity, lhs is always evaluated first.
    final Expression lhs = binaryNode.lhs();
    final LvarType lhsType;
    if (!(lhs instanceof IdentNode && binaryNode.isTokenType(TokenType.ASSIGN))) {
        lhsType = visitExpression(lhs);
    } else {
        // Can't visit IdentNode on LHS of a simple assignment, as visits imply use, and this is def.
        // The type is irrelevant, as only RHS is used to determine the type anyway.
        lhsType = LvarType.UNDEFINED;
    }

    final boolean isLogical = binaryNode.isLogical();
    final Label joinLabel = isLogical ? new Label("") : null;
    if(isLogical) {
        jumpToLabel((JoinPredecessor)lhs, joinLabel);
    }

    final Expression rhs = binaryNode.rhs();
    final LvarType rhsType = visitExpression(rhs);
    if(isLogical) {
        jumpToLabel((JoinPredecessor)rhs, joinLabel);
    }
    joinOnLabel(joinLabel);

    final LvarType type = toLvarType(binaryNode.setOperands(lhsType.typeExpression, rhsType.typeExpression).getType());

    if(binaryNode.isAssignment() && lhs instanceof IdentNode) {
        if(binaryNode.isSelfModifying()) {
            onSelfAssignment((IdentNode)lhs, type);
        } else {
            onAssignment((IdentNode)lhs, type);
        }
    }
    typeStack.push(type);
    return false;
}
 
Example 3
Source File: JSONWriter.java    From jdk8u_nashorn with GNU General Public License v2.0 5 votes vote down vote up
@Override
public boolean enterBinaryNode(final BinaryNode binaryNode) {
    enterDefault(binaryNode);

    final String name;
    if (binaryNode.isAssignment()) {
        name = "AssignmentExpression";
    } else if (binaryNode.isLogical()) {
        name = "LogicalExpression";
    } else {
        name = "BinaryExpression";
    }

    type(name);
    comma();

    property("operator", binaryNode.tokenType().getName());
    comma();

    property("left");
    binaryNode.lhs().accept(this);
    comma();

    property("right");
    binaryNode.rhs().accept(this);

    return leave();
}
 
Example 4
Source File: LocalVariableTypesCalculator.java    From hottub with GNU General Public License v2.0 5 votes vote down vote up
@Override
public boolean enterBinaryNode(final BinaryNode binaryNode) {
    // NOTE: regardless of operator's lexical associativity, lhs is always evaluated first.
    final Expression lhs = binaryNode.lhs();
    final LvarType lhsType;
    if (!(lhs instanceof IdentNode && binaryNode.isTokenType(TokenType.ASSIGN))) {
        lhsType = visitExpression(lhs);
    } else {
        // Can't visit IdentNode on LHS of a simple assignment, as visits imply use, and this is def.
        // The type is irrelevant, as only RHS is used to determine the type anyway.
        lhsType = LvarType.UNDEFINED;
    }

    final boolean isLogical = binaryNode.isLogical();
    final Label joinLabel = isLogical ? new Label("") : null;
    if(isLogical) {
        jumpToLabel((JoinPredecessor)lhs, joinLabel);
    }

    final Expression rhs = binaryNode.rhs();
    final LvarType rhsType = visitExpression(rhs);
    if(isLogical) {
        jumpToLabel((JoinPredecessor)rhs, joinLabel);
    }
    joinOnLabel(joinLabel);

    final LvarType type = toLvarType(binaryNode.setOperands(lhsType.typeExpression, rhsType.typeExpression).getType());

    if(binaryNode.isAssignment() && lhs instanceof IdentNode) {
        if(binaryNode.isSelfModifying()) {
            onSelfAssignment((IdentNode)lhs, type);
        } else {
            onAssignment((IdentNode)lhs, type);
        }
    }
    typeStack.push(type);
    return false;
}
 
Example 5
Source File: JSONWriter.java    From hottub with GNU General Public License v2.0 5 votes vote down vote up
@Override
public boolean enterBinaryNode(final BinaryNode binaryNode) {
    enterDefault(binaryNode);

    final String name;
    if (binaryNode.isAssignment()) {
        name = "AssignmentExpression";
    } else if (binaryNode.isLogical()) {
        name = "LogicalExpression";
    } else {
        name = "BinaryExpression";
    }

    type(name);
    comma();

    property("operator", binaryNode.tokenType().getName());
    comma();

    property("left");
    binaryNode.lhs().accept(this);
    comma();

    property("right");
    binaryNode.rhs().accept(this);

    return leave();
}
 
Example 6
Source File: LocalVariableTypesCalculator.java    From openjdk-jdk9 with GNU General Public License v2.0 5 votes vote down vote up
@Override
public boolean enterBinaryNode(final BinaryNode binaryNode) {
    // NOTE: regardless of operator's lexical associativity, lhs is always evaluated first.
    final Expression lhs = binaryNode.lhs();
    final LvarType lhsType;
    if (!(lhs instanceof IdentNode && binaryNode.isTokenType(TokenType.ASSIGN))) {
        lhsType = visitExpression(lhs);
    } else {
        // Can't visit IdentNode on LHS of a simple assignment, as visits imply use, and this is def.
        // The type is irrelevant, as only RHS is used to determine the type anyway.
        lhsType = LvarType.UNDEFINED;
    }

    final boolean isLogical = binaryNode.isLogical();
    final Label joinLabel = isLogical ? new Label("") : null;
    if(isLogical) {
        jumpToLabel((JoinPredecessor)lhs, joinLabel);
    }

    final Expression rhs = binaryNode.rhs();
    final LvarType rhsType = visitExpression(rhs);
    if(isLogical) {
        jumpToLabel((JoinPredecessor)rhs, joinLabel);
    }
    joinOnLabel(joinLabel);

    final LvarType type = toLvarType(binaryNode.setOperands(lhsType.typeExpression, rhsType.typeExpression).getType());

    if(binaryNode.isAssignment() && lhs instanceof IdentNode) {
        if(binaryNode.isSelfModifying()) {
            onSelfAssignment((IdentNode)lhs, type);
        } else {
            onAssignment((IdentNode)lhs, type);
        }
    }
    typeStack.push(type);
    return false;
}
 
Example 7
Source File: JSONWriter.java    From openjdk-jdk9 with GNU General Public License v2.0 5 votes vote down vote up
@Override
public boolean enterBinaryNode(final BinaryNode binaryNode) {
    enterDefault(binaryNode);

    final String name;
    if (binaryNode.isAssignment()) {
        name = "AssignmentExpression";
    } else if (binaryNode.isLogical()) {
        name = "LogicalExpression";
    } else {
        name = "BinaryExpression";
    }

    type(name);
    comma();

    property("operator", binaryNode.tokenType().getName());
    comma();

    property("left");
    binaryNode.lhs().accept(this);
    comma();

    property("right");
    binaryNode.rhs().accept(this);

    return leave();
}
 
Example 8
Source File: LocalVariableTypesCalculator.java    From openjdk-jdk8u-backup with GNU General Public License v2.0 5 votes vote down vote up
@Override
public boolean enterBinaryNode(final BinaryNode binaryNode) {
    // NOTE: regardless of operator's lexical associativity, lhs is always evaluated first.
    final Expression lhs = binaryNode.lhs();
    final LvarType lhsType;
    if (!(lhs instanceof IdentNode && binaryNode.isTokenType(TokenType.ASSIGN))) {
        lhsType = visitExpression(lhs);
    } else {
        // Can't visit IdentNode on LHS of a simple assignment, as visits imply use, and this is def.
        // The type is irrelevant, as only RHS is used to determine the type anyway.
        lhsType = LvarType.UNDEFINED;
    }

    final boolean isLogical = binaryNode.isLogical();
    final Label joinLabel = isLogical ? new Label("") : null;
    if(isLogical) {
        jumpToLabel((JoinPredecessor)lhs, joinLabel);
    }

    final Expression rhs = binaryNode.rhs();
    final LvarType rhsType = visitExpression(rhs);
    if(isLogical) {
        jumpToLabel((JoinPredecessor)rhs, joinLabel);
    }
    joinOnLabel(joinLabel);

    final LvarType type = toLvarType(binaryNode.setOperands(lhsType.typeExpression, rhsType.typeExpression).getType());

    if(binaryNode.isAssignment() && lhs instanceof IdentNode) {
        if(binaryNode.isSelfModifying()) {
            onSelfAssignment((IdentNode)lhs, type);
        } else {
            onAssignment((IdentNode)lhs, type);
        }
    }
    typeStack.push(type);
    return false;
}
 
Example 9
Source File: LocalVariableTypesCalculator.java    From openjdk-jdk8u with GNU General Public License v2.0 5 votes vote down vote up
@Override
public boolean enterBinaryNode(final BinaryNode binaryNode) {
    // NOTE: regardless of operator's lexical associativity, lhs is always evaluated first.
    final Expression lhs = binaryNode.lhs();
    final LvarType lhsType;
    if (!(lhs instanceof IdentNode && binaryNode.isTokenType(TokenType.ASSIGN))) {
        lhsType = visitExpression(lhs);
    } else {
        // Can't visit IdentNode on LHS of a simple assignment, as visits imply use, and this is def.
        // The type is irrelevant, as only RHS is used to determine the type anyway.
        lhsType = LvarType.UNDEFINED;
    }

    final boolean isLogical = binaryNode.isLogical();
    final Label joinLabel = isLogical ? new Label("") : null;
    if(isLogical) {
        jumpToLabel((JoinPredecessor)lhs, joinLabel);
    }

    final Expression rhs = binaryNode.rhs();
    final LvarType rhsType = visitExpression(rhs);
    if(isLogical) {
        jumpToLabel((JoinPredecessor)rhs, joinLabel);
    }
    joinOnLabel(joinLabel);

    final LvarType type = toLvarType(binaryNode.setOperands(lhsType.typeExpression, rhsType.typeExpression).getType());

    if(binaryNode.isAssignment() && lhs instanceof IdentNode) {
        if(binaryNode.isSelfModifying()) {
            onSelfAssignment((IdentNode)lhs, type);
        } else {
            onAssignment((IdentNode)lhs, type);
        }
    }
    typeStack.push(type);
    return false;
}
 
Example 10
Source File: JSONWriter.java    From openjdk-jdk8u with GNU General Public License v2.0 5 votes vote down vote up
@Override
public boolean enterBinaryNode(final BinaryNode binaryNode) {
    enterDefault(binaryNode);

    final String name;
    if (binaryNode.isAssignment()) {
        name = "AssignmentExpression";
    } else if (binaryNode.isLogical()) {
        name = "LogicalExpression";
    } else {
        name = "BinaryExpression";
    }

    type(name);
    comma();

    property("operator", binaryNode.tokenType().getName());
    comma();

    property("left");
    binaryNode.lhs().accept(this);
    comma();

    property("right");
    binaryNode.rhs().accept(this);

    return leave();
}
 
Example 11
Source File: LocalVariableTypesCalculator.java    From jdk8u60 with GNU General Public License v2.0 5 votes vote down vote up
@Override
public boolean enterBinaryNode(final BinaryNode binaryNode) {
    // NOTE: regardless of operator's lexical associativity, lhs is always evaluated first.
    final Expression lhs = binaryNode.lhs();
    final LvarType lhsType;
    if (!(lhs instanceof IdentNode && binaryNode.isTokenType(TokenType.ASSIGN))) {
        lhsType = visitExpression(lhs);
    } else {
        // Can't visit IdentNode on LHS of a simple assignment, as visits imply use, and this is def.
        // The type is irrelevant, as only RHS is used to determine the type anyway.
        lhsType = LvarType.UNDEFINED;
    }

    final boolean isLogical = binaryNode.isLogical();
    final Label joinLabel = isLogical ? new Label("") : null;
    if(isLogical) {
        jumpToLabel((JoinPredecessor)lhs, joinLabel);
    }

    final Expression rhs = binaryNode.rhs();
    final LvarType rhsType = visitExpression(rhs);
    if(isLogical) {
        jumpToLabel((JoinPredecessor)rhs, joinLabel);
    }
    joinOnLabel(joinLabel);

    final LvarType type = toLvarType(binaryNode.setOperands(lhsType.typeExpression, rhsType.typeExpression).getType());

    if(binaryNode.isAssignment() && lhs instanceof IdentNode) {
        if(binaryNode.isSelfModifying()) {
            onSelfAssignment((IdentNode)lhs, type);
        } else {
            onAssignment((IdentNode)lhs, type);
        }
    }
    typeStack.push(type);
    return false;
}
 
Example 12
Source File: JSONWriter.java    From jdk8u60 with GNU General Public License v2.0 5 votes vote down vote up
@Override
public boolean enterBinaryNode(final BinaryNode binaryNode) {
    enterDefault(binaryNode);

    final String name;
    if (binaryNode.isAssignment()) {
        name = "AssignmentExpression";
    } else if (binaryNode.isLogical()) {
        name = "LogicalExpression";
    } else {
        name = "BinaryExpression";
    }

    type(name);
    comma();

    property("operator", binaryNode.tokenType().getName());
    comma();

    property("left");
    binaryNode.lhs().accept(this);
    comma();

    property("right");
    binaryNode.rhs().accept(this);

    return leave();
}
 
Example 13
Source File: LocalVariableTypesCalculator.java    From TencentKona-8 with GNU General Public License v2.0 5 votes vote down vote up
@Override
public boolean enterBinaryNode(final BinaryNode binaryNode) {
    // NOTE: regardless of operator's lexical associativity, lhs is always evaluated first.
    final Expression lhs = binaryNode.lhs();
    final LvarType lhsType;
    if (!(lhs instanceof IdentNode && binaryNode.isTokenType(TokenType.ASSIGN))) {
        lhsType = visitExpression(lhs);
    } else {
        // Can't visit IdentNode on LHS of a simple assignment, as visits imply use, and this is def.
        // The type is irrelevant, as only RHS is used to determine the type anyway.
        lhsType = LvarType.UNDEFINED;
    }

    final boolean isLogical = binaryNode.isLogical();
    final Label joinLabel = isLogical ? new Label("") : null;
    if(isLogical) {
        jumpToLabel((JoinPredecessor)lhs, joinLabel);
    }

    final Expression rhs = binaryNode.rhs();
    final LvarType rhsType = visitExpression(rhs);
    if(isLogical) {
        jumpToLabel((JoinPredecessor)rhs, joinLabel);
    }
    joinOnLabel(joinLabel);

    final LvarType type = toLvarType(binaryNode.setOperands(lhsType.typeExpression, rhsType.typeExpression).getType());

    if(binaryNode.isAssignment() && lhs instanceof IdentNode) {
        if(binaryNode.isSelfModifying()) {
            onSelfAssignment((IdentNode)lhs, type);
        } else {
            onAssignment((IdentNode)lhs, type);
        }
    }
    typeStack.push(type);
    return false;
}
 
Example 14
Source File: JSONWriter.java    From TencentKona-8 with GNU General Public License v2.0 5 votes vote down vote up
@Override
public boolean enterBinaryNode(final BinaryNode binaryNode) {
    enterDefault(binaryNode);

    final String name;
    if (binaryNode.isAssignment()) {
        name = "AssignmentExpression";
    } else if (binaryNode.isLogical()) {
        name = "LogicalExpression";
    } else {
        name = "BinaryExpression";
    }

    type(name);
    comma();

    property("operator", binaryNode.tokenType().getName());
    comma();

    property("left");
    binaryNode.lhs().accept(this);
    comma();

    property("right");
    binaryNode.rhs().accept(this);

    return leave();
}
 
Example 15
Source File: Parser.java    From openjdk-jdk8u-backup with GNU General Public License v2.0 4 votes vote down vote up
/**
 * Verify an assignment expression.
 * @param op  Operation token.
 * @param lhs Left hand side expression.
 * @param rhs Right hand side expression.
 * @return Verified expression.
 */
private Expression verifyAssignment(final long op, final Expression lhs, final Expression rhs) {
    final TokenType opType = Token.descType(op);

    switch (opType) {
    case ASSIGN:
    case ASSIGN_ADD:
    case ASSIGN_BIT_AND:
    case ASSIGN_BIT_OR:
    case ASSIGN_BIT_XOR:
    case ASSIGN_DIV:
    case ASSIGN_MOD:
    case ASSIGN_MUL:
    case ASSIGN_SAR:
    case ASSIGN_SHL:
    case ASSIGN_SHR:
    case ASSIGN_SUB:
        if (!(lhs instanceof AccessNode ||
              lhs instanceof IndexNode ||
              lhs instanceof IdentNode)) {
            return referenceError(lhs, rhs, env._early_lvalue_error);
        }

        if (lhs instanceof IdentNode) {
            if (!checkIdentLValue((IdentNode)lhs)) {
                return referenceError(lhs, rhs, false);
            }
            verifyStrictIdent((IdentNode)lhs, "assignment");
        }
        break;

    default:
        break;
    }

    // Build up node.
    if(BinaryNode.isLogical(opType)) {
        return new BinaryNode(op, new JoinPredecessorExpression(lhs), new JoinPredecessorExpression(rhs));
    }
    return new BinaryNode(op, lhs, rhs);
}
 
Example 16
Source File: Parser.java    From TencentKona-8 with GNU General Public License v2.0 4 votes vote down vote up
/**
 * Verify an assignment expression.
 * @param op  Operation token.
 * @param lhs Left hand side expression.
 * @param rhs Right hand side expression.
 * @return Verified expression.
 */
private Expression verifyAssignment(final long op, final Expression lhs, final Expression rhs) {
    final TokenType opType = Token.descType(op);

    switch (opType) {
    case ASSIGN:
    case ASSIGN_ADD:
    case ASSIGN_BIT_AND:
    case ASSIGN_BIT_OR:
    case ASSIGN_BIT_XOR:
    case ASSIGN_DIV:
    case ASSIGN_MOD:
    case ASSIGN_MUL:
    case ASSIGN_SAR:
    case ASSIGN_SHL:
    case ASSIGN_SHR:
    case ASSIGN_SUB:
        if (!(lhs instanceof AccessNode ||
              lhs instanceof IndexNode ||
              lhs instanceof IdentNode)) {
            return referenceError(lhs, rhs, env._early_lvalue_error);
        }

        if (lhs instanceof IdentNode) {
            if (!checkIdentLValue((IdentNode)lhs)) {
                return referenceError(lhs, rhs, false);
            }
            verifyStrictIdent((IdentNode)lhs, "assignment");
        }
        break;

    default:
        break;
    }

    // Build up node.
    if(BinaryNode.isLogical(opType)) {
        return new BinaryNode(op, new JoinPredecessorExpression(lhs), new JoinPredecessorExpression(rhs));
    }
    return new BinaryNode(op, lhs, rhs);
}
 
Example 17
Source File: Parser.java    From openjdk-jdk8u with GNU General Public License v2.0 4 votes vote down vote up
/**
 * Verify an assignment expression.
 * @param op  Operation token.
 * @param lhs Left hand side expression.
 * @param rhs Right hand side expression.
 * @return Verified expression.
 */
private Expression verifyAssignment(final long op, final Expression lhs, final Expression rhs) {
    final TokenType opType = Token.descType(op);

    switch (opType) {
    case ASSIGN:
    case ASSIGN_ADD:
    case ASSIGN_BIT_AND:
    case ASSIGN_BIT_OR:
    case ASSIGN_BIT_XOR:
    case ASSIGN_DIV:
    case ASSIGN_MOD:
    case ASSIGN_MUL:
    case ASSIGN_SAR:
    case ASSIGN_SHL:
    case ASSIGN_SHR:
    case ASSIGN_SUB:
        if (!(lhs instanceof AccessNode ||
              lhs instanceof IndexNode ||
              lhs instanceof IdentNode)) {
            return referenceError(lhs, rhs, env._early_lvalue_error);
        }

        if (lhs instanceof IdentNode) {
            if (!checkIdentLValue((IdentNode)lhs)) {
                return referenceError(lhs, rhs, false);
            }
            verifyStrictIdent((IdentNode)lhs, "assignment");
        }
        break;

    default:
        break;
    }

    // Build up node.
    if(BinaryNode.isLogical(opType)) {
        return new BinaryNode(op, new JoinPredecessorExpression(lhs), new JoinPredecessorExpression(rhs));
    }
    return new BinaryNode(op, lhs, rhs);
}
 
Example 18
Source File: Parser.java    From hottub with GNU General Public License v2.0 4 votes vote down vote up
/**
 * Verify an assignment expression.
 * @param op  Operation token.
 * @param lhs Left hand side expression.
 * @param rhs Right hand side expression.
 * @return Verified expression.
 */
private Expression verifyAssignment(final long op, final Expression lhs, final Expression rhs) {
    final TokenType opType = Token.descType(op);

    switch (opType) {
    case ASSIGN:
    case ASSIGN_ADD:
    case ASSIGN_BIT_AND:
    case ASSIGN_BIT_OR:
    case ASSIGN_BIT_XOR:
    case ASSIGN_DIV:
    case ASSIGN_MOD:
    case ASSIGN_MUL:
    case ASSIGN_SAR:
    case ASSIGN_SHL:
    case ASSIGN_SHR:
    case ASSIGN_SUB:
        if (!(lhs instanceof AccessNode ||
              lhs instanceof IndexNode ||
              lhs instanceof IdentNode)) {
            return referenceError(lhs, rhs, env._early_lvalue_error);
        }

        if (lhs instanceof IdentNode) {
            if (!checkIdentLValue((IdentNode)lhs)) {
                return referenceError(lhs, rhs, false);
            }
            verifyStrictIdent((IdentNode)lhs, "assignment");
        }
        break;

    default:
        break;
    }

    // Build up node.
    if(BinaryNode.isLogical(opType)) {
        return new BinaryNode(op, new JoinPredecessorExpression(lhs), new JoinPredecessorExpression(rhs));
    }
    return new BinaryNode(op, lhs, rhs);
}
 
Example 19
Source File: Parser.java    From jdk8u60 with GNU General Public License v2.0 4 votes vote down vote up
/**
 * Verify an assignment expression.
 * @param op  Operation token.
 * @param lhs Left hand side expression.
 * @param rhs Right hand side expression.
 * @return Verified expression.
 */
private Expression verifyAssignment(final long op, final Expression lhs, final Expression rhs) {
    final TokenType opType = Token.descType(op);

    switch (opType) {
    case ASSIGN:
    case ASSIGN_ADD:
    case ASSIGN_BIT_AND:
    case ASSIGN_BIT_OR:
    case ASSIGN_BIT_XOR:
    case ASSIGN_DIV:
    case ASSIGN_MOD:
    case ASSIGN_MUL:
    case ASSIGN_SAR:
    case ASSIGN_SHL:
    case ASSIGN_SHR:
    case ASSIGN_SUB:
        if (!(lhs instanceof AccessNode ||
              lhs instanceof IndexNode ||
              lhs instanceof IdentNode)) {
            return referenceError(lhs, rhs, env._early_lvalue_error);
        }

        if (lhs instanceof IdentNode) {
            if (!checkIdentLValue((IdentNode)lhs)) {
                return referenceError(lhs, rhs, false);
            }
            verifyStrictIdent((IdentNode)lhs, "assignment");
        }
        break;

    default:
        break;
    }

    // Build up node.
    if(BinaryNode.isLogical(opType)) {
        return new BinaryNode(op, new JoinPredecessorExpression(lhs), new JoinPredecessorExpression(rhs));
    }
    return new BinaryNode(op, lhs, rhs);
}
 
Example 20
Source File: Parser.java    From jdk8u_nashorn with GNU General Public License v2.0 4 votes vote down vote up
/**
 * Verify an assignment expression.
 * @param op  Operation token.
 * @param lhs Left hand side expression.
 * @param rhs Right hand side expression.
 * @return Verified expression.
 */
private Expression verifyAssignment(final long op, final Expression lhs, final Expression rhs) {
    final TokenType opType = Token.descType(op);

    switch (opType) {
    case ASSIGN:
    case ASSIGN_ADD:
    case ASSIGN_BIT_AND:
    case ASSIGN_BIT_OR:
    case ASSIGN_BIT_XOR:
    case ASSIGN_DIV:
    case ASSIGN_MOD:
    case ASSIGN_MUL:
    case ASSIGN_SAR:
    case ASSIGN_SHL:
    case ASSIGN_SHR:
    case ASSIGN_SUB:
        if (!(lhs instanceof AccessNode ||
              lhs instanceof IndexNode ||
              lhs instanceof IdentNode)) {
            return referenceError(lhs, rhs, env._early_lvalue_error);
        }

        if (lhs instanceof IdentNode) {
            if (!checkIdentLValue((IdentNode)lhs)) {
                return referenceError(lhs, rhs, false);
            }
            verifyStrictIdent((IdentNode)lhs, "assignment");
        }
        break;

    default:
        break;
    }

    // Build up node.
    if(BinaryNode.isLogical(opType)) {
        return new BinaryNode(op, new JoinPredecessorExpression(lhs), new JoinPredecessorExpression(rhs));
    }
    return new BinaryNode(op, lhs, rhs);
}