/*
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package jdk.nashorn.internal.ir;
import static jdk.nashorn.internal.runtime.UnwarrantedOptimismException.INVALID_PROGRAM_POINT;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashSet;
import java.util.Set;
import jdk.nashorn.internal.codegen.types.Type;
import jdk.nashorn.internal.ir.annotations.Ignore;
import jdk.nashorn.internal.ir.annotations.Immutable;
import jdk.nashorn.internal.ir.visitor.NodeVisitor;
import jdk.nashorn.internal.parser.TokenType;
/**
* BinaryNode nodes represent two operand operations.
*/
@Immutable
public final class BinaryNode extends Expression implements Assignment<Expression>, Optimistic {
private static final long serialVersionUID = 1L;
// Placeholder for "undecided optimistic ADD type". Unfortunately, we can't decide the type of ADD during optimistic
// type calculation as it can have local variables as its operands that will decide its ultimate type.
private static final Type OPTIMISTIC_UNDECIDED_TYPE = Type.typeFor(new Object(){/*empty*/}.getClass());
/** Left hand side argument. */
private final Expression lhs;
private final Expression rhs;
private final int programPoint;
private final Type type;
private transient Type cachedType;
@Ignore
private static final Set<TokenType> CAN_OVERFLOW =
Collections.unmodifiableSet(new HashSet<>(Arrays.asList(new TokenType[] {
TokenType.ADD,
TokenType.DIV,
TokenType.MOD,
TokenType.MUL,
TokenType.SUB,
TokenType.ASSIGN_ADD,
TokenType.ASSIGN_DIV,
TokenType.ASSIGN_MOD,
TokenType.ASSIGN_MUL,
TokenType.ASSIGN_SUB,
TokenType.SHR,
TokenType.ASSIGN_SHR
})));
/**
* Constructor
*
* @param token token
* @param lhs left hand side
* @param rhs right hand side
*/
public BinaryNode(final long token, final Expression lhs, final Expression rhs) {
super(token, lhs.getStart(), rhs.getFinish());
assert !(isTokenType(TokenType.AND) || isTokenType(TokenType.OR)) || lhs instanceof JoinPredecessorExpression;
this.lhs = lhs;
this.rhs = rhs;
this.programPoint = INVALID_PROGRAM_POINT;
this.type = null;
}
private BinaryNode(final BinaryNode binaryNode, final Expression lhs, final Expression rhs, final Type type, final int programPoint) {
super(binaryNode);
this.lhs = lhs;
this.rhs = rhs;
this.programPoint = programPoint;
this.type = type;
}
/**
* Returns true if the node is a comparison operation (either equality, inequality, or relational).
* @return true if the node is a comparison operation.
*/
public boolean isComparison() {
switch (tokenType()) {
case EQ:
case EQ_STRICT:
case NE:
case NE_STRICT:
case LE:
case LT:
case GE:
case GT:
return true;
default:
return false;
}
}
/**
* Returns true if the node is a relational operation (less than (or equals), greater than (or equals)).
* @return true if the node is a relational operation.
*/
public boolean isRelational() {
switch (tokenType()) {
case LT:
case GT:
case LE:
case GE:
return true;
default:
return false;
}
}
/**
* Returns true if the node is a logical operation.
* @return true if the node is a logical operation.
*/
public boolean isLogical() {
return isLogical(tokenType());
}
/**
* Returns true if the token type represents a logical operation.
* @param tokenType the token type
* @return true if the token type represents a logical operation.
*/
public static boolean isLogical(final TokenType tokenType) {
switch (tokenType) {
case AND:
case OR:
return true;
default:
return false;
}
}
/**
* Return the widest possible operand type for this operation.
*
* @return Type
*/
public Type getWidestOperandType() {
switch (tokenType()) {
case SHR:
case ASSIGN_SHR:
return Type.INT;
case INSTANCEOF:
return Type.OBJECT;
default:
if (isComparison()) {
return Type.OBJECT;
}
return getWidestOperationType();
}
}
@Override
public Type getWidestOperationType() {
switch (tokenType()) {
case ADD:
case ASSIGN_ADD: {
// Compare this logic to decideType(Type, Type); it's similar, but it handles the optimistic type
// calculation case while this handles the conservative case.
final Type lhsType = lhs.getType();
final Type rhsType = rhs.getType();
if(lhsType == Type.BOOLEAN && rhsType == Type.BOOLEAN) {
// Will always fit in an int, as the value range is [0, 1, 2]. If we didn't treat them specially here,
// they'd end up being treated as generic INT operands and their sum would be conservatively considered
// to be a LONG in the generic case below; we can do better here.
return Type.INT;
} else if(isString(lhsType) || isString(rhsType)) {
// We can statically figure out that this is a string if either operand is a string. In this case, use
// CHARSEQUENCE to prevent it from being proactively flattened.
return Type.CHARSEQUENCE;
}
final Type widestOperandType = Type.widest(undefinedToNumber(booleanToInt(lhsType)), undefinedToNumber(booleanToInt(rhsType)));
if (widestOperandType.isNumeric()) {
return Type.NUMBER;
}
// We pretty much can't know what it will be statically. Must presume OBJECT conservatively, as we can end
// up getting either a string or an object when adding something + object, e.g.:
// 1 + {} == "1[object Object]", but
// 1 + {valueOf: function() { return 2 }} == 3. Also:
// 1 + {valueOf: function() { return "2" }} == "12".
return Type.OBJECT;
}
case SHR:
case ASSIGN_SHR:
return Type.NUMBER;
case ASSIGN_SAR:
case ASSIGN_SHL:
case BIT_AND:
case BIT_OR:
case BIT_XOR:
case ASSIGN_BIT_AND:
case ASSIGN_BIT_OR:
case ASSIGN_BIT_XOR:
case SAR:
case SHL:
return Type.INT;
case DIV:
case MOD:
case ASSIGN_DIV:
case ASSIGN_MOD: {
// Naively, one might think MOD has the same type as the widest of its operands, this is unfortunately not
// true when denominator is zero, so even type(int % int) == double.
return Type.NUMBER;
}
case MUL:
case SUB:
case ASSIGN_MUL:
case ASSIGN_SUB: {
final Type lhsType = lhs.getType();
final Type rhsType = rhs.getType();
if(lhsType == Type.BOOLEAN && rhsType == Type.BOOLEAN) {
return Type.INT;
}
return Type.NUMBER;
}
case VOID: {
return Type.UNDEFINED;
}
case ASSIGN: {
return rhs.getType();
}
case INSTANCEOF: {
return Type.BOOLEAN;
}
case COMMALEFT: {
return lhs.getType();
}
case COMMARIGHT: {
return rhs.getType();
}
case AND:
case OR:{
return Type.widestReturnType(lhs.getType(), rhs.getType());
}
default:
if (isComparison()) {
return Type.BOOLEAN;
}
return Type.OBJECT;
}
}
private static boolean isString(final Type type) {
return type == Type.STRING || type == Type.CHARSEQUENCE;
}
private static Type booleanToInt(final Type type) {
return type == Type.BOOLEAN ? Type.INT : type;
}
private static Type undefinedToNumber(final Type type) {
return type == Type.UNDEFINED ? Type.NUMBER : type;
}
/**
* Check if this node is an assignment
*
* @return true if this node assigns a value
*/
@Override
public boolean isAssignment() {
switch (tokenType()) {
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:
return true;
default:
return false;
}
}
@Override
public boolean isSelfModifying() {
return isAssignment() && !isTokenType(TokenType.ASSIGN);
}
@Override
public Expression getAssignmentDest() {
return isAssignment() ? lhs() : null;
}
@Override
public BinaryNode setAssignmentDest(final Expression n) {
return setLHS(n);
}
@Override
public Expression getAssignmentSource() {
return rhs();
}
/**
* Assist in IR navigation.
* @param visitor IR navigating visitor.
*/
@Override
public Node accept(final NodeVisitor<? extends LexicalContext> visitor) {
if (visitor.enterBinaryNode(this)) {
return visitor.leaveBinaryNode(setLHS((Expression)lhs.accept(visitor)).setRHS((Expression)rhs.accept(visitor)));
}
return this;
}
@Override
public boolean isLocal() {
switch (tokenType()) {
case SAR:
case SHL:
case SHR:
case BIT_AND:
case BIT_OR:
case BIT_XOR:
case ADD:
case DIV:
case MOD:
case MUL:
case SUB:
return lhs.isLocal() && lhs.getType().isJSPrimitive()
&& rhs.isLocal() && rhs.getType().isJSPrimitive();
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:
return lhs instanceof IdentNode && lhs.isLocal() && lhs.getType().isJSPrimitive()
&& rhs.isLocal() && rhs.getType().isJSPrimitive();
case ASSIGN:
return lhs instanceof IdentNode && lhs.isLocal() && rhs.isLocal();
default:
return false;
}
}
@Override
public boolean isAlwaysFalse() {
switch (tokenType()) {
case COMMALEFT:
return lhs.isAlwaysFalse();
case COMMARIGHT:
return rhs.isAlwaysFalse();
default:
return false;
}
}
@Override
public boolean isAlwaysTrue() {
switch (tokenType()) {
case COMMALEFT:
return lhs.isAlwaysTrue();
case COMMARIGHT:
return rhs.isAlwaysTrue();
default:
return false;
}
}
@Override
public void toString(final StringBuilder sb, final boolean printType) {
final TokenType tokenType = tokenType();
final boolean lhsParen = tokenType.needsParens(lhs().tokenType(), true);
final boolean rhsParen = tokenType.needsParens(rhs().tokenType(), false);
if (lhsParen) {
sb.append('(');
}
lhs().toString(sb, printType);
if (lhsParen) {
sb.append(')');
}
sb.append(' ');
switch (tokenType) {
case COMMALEFT:
sb.append(",<");
break;
case COMMARIGHT:
sb.append(",>");
break;
case INCPREFIX:
case DECPREFIX:
sb.append("++");
break;
default:
sb.append(tokenType.getName());
break;
}
if (isOptimistic()) {
sb.append(Expression.OPT_IDENTIFIER);
}
sb.append(' ');
if (rhsParen) {
sb.append('(');
}
rhs().toString(sb, printType);
if (rhsParen) {
sb.append(')');
}
}
/**
* Get the left hand side expression for this node
* @return the left hand side expression
*/
public Expression lhs() {
return lhs;
}
/**
* Get the right hand side expression for this node
* @return the left hand side expression
*/
public Expression rhs() {
return rhs;
}
/**
* Set the left hand side expression for this node
* @param lhs new left hand side expression
* @return a node equivalent to this one except for the requested change.
*/
public BinaryNode setLHS(final Expression lhs) {
if (this.lhs == lhs) {
return this;
}
return new BinaryNode(this, lhs, rhs, type, programPoint);
}
/**
* Set the right hand side expression for this node
* @param rhs new right hand side expression
* @return a node equivalent to this one except for the requested change.
*/
public BinaryNode setRHS(final Expression rhs) {
if (this.rhs == rhs) {
return this;
}
return new BinaryNode(this, lhs, rhs, type, programPoint);
}
/**
* Set both the left and the right hand side expression for this node
* @param lhs new left hand side expression
* @param rhs new left hand side expression
* @return a node equivalent to this one except for the requested change.
*/
public BinaryNode setOperands(final Expression lhs, final Expression rhs) {
if (this.lhs == lhs && this.rhs == rhs) {
return this;
}
return new BinaryNode(this, lhs, rhs, type, programPoint);
}
@Override
public int getProgramPoint() {
return programPoint;
}
@Override
public boolean canBeOptimistic() {
return isTokenType(TokenType.ADD) || (getMostOptimisticType() != getMostPessimisticType());
}
@Override
public BinaryNode setProgramPoint(final int programPoint) {
if (this.programPoint == programPoint) {
return this;
}
return new BinaryNode(this, lhs, rhs, type, programPoint);
}
@Override
public Type getMostOptimisticType() {
final TokenType tokenType = tokenType();
if(tokenType == TokenType.ADD || tokenType == TokenType.ASSIGN_ADD) {
return OPTIMISTIC_UNDECIDED_TYPE;
} else if (CAN_OVERFLOW.contains(tokenType)) {
return Type.INT;
}
return getMostPessimisticType();
}
@Override
public Type getMostPessimisticType() {
return getWidestOperationType();
}
/**
* Returns true if the node has the optimistic type of the node is not yet decided. Optimistic ADD nodes start out
* as undecided until we can figure out if they're numeric or not.
* @return true if the node has the optimistic type of the node is not yet decided.
*/
public boolean isOptimisticUndecidedType() {
return type == OPTIMISTIC_UNDECIDED_TYPE;
}
@Override
public Type getType() {
if (cachedType == null) {
cachedType = getTypeUncached();
}
return cachedType;
}
private Type getTypeUncached() {
if(type == OPTIMISTIC_UNDECIDED_TYPE) {
return decideType(lhs.getType(), rhs.getType());
}
final Type widest = getWidestOperationType();
if(type == null) {
return widest;
}
if (tokenType() == TokenType.ASSIGN_SHR || tokenType() == TokenType.SHR) {
return type;
}
return Type.narrowest(widest, Type.widest(type, Type.widest(lhs.getType(), rhs.getType())));
}
private static Type decideType(final Type lhsType, final Type rhsType) {
// Compare this to getWidestOperationType() for ADD and ASSIGN_ADD cases. There's some similar logic, but these
// are optimistic decisions, meaning that we don't have to treat boolean addition separately (as it'll become
// int addition in the general case anyway), and that we also don't conservatively widen sums of ints to
// longs, or sums of longs to doubles.
if(isString(lhsType) || isString(rhsType)) {
return Type.CHARSEQUENCE;
}
// NOTE: We don't have optimistic object-to-(int, long) conversions. Therefore, if any operand is an Object, we
// bail out of optimism here and presume a conservative Object return value, as the object's ToPrimitive() can
// end up returning either a number or a string, and their common supertype is Object, for better or worse.
final Type widest = Type.widest(undefinedToNumber(booleanToInt(lhsType)), undefinedToNumber(booleanToInt(rhsType)));
return widest.isObject() ? Type.OBJECT : widest;
}
/**
* If the node is a node representing an add operation and has {@link #isOptimisticUndecidedType() optimistic
* undecided type}, decides its type. Should be invoked after its operands types have been finalized.
* @return returns a new node similar to this node, but with its type set to the type decided from the type of its
* operands.
*/
public BinaryNode decideType() {
assert type == OPTIMISTIC_UNDECIDED_TYPE;
return setType(decideType(lhs.getType(), rhs.getType()));
}
@Override
public BinaryNode setType(final Type type) {
if (this.type == type) {
return this;
}
return new BinaryNode(this, lhs, rhs, type, programPoint);
}
}