1 /*
2 * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package jdk.nashorn.internal.ir;
27
28 import static jdk.nashorn.internal.runtime.UnwarrantedOptimismException.INVALID_PROGRAM_POINT;
29
30 import java.util.Arrays;
31 import java.util.Collections;
32 import java.util.HashSet;
33 import java.util.Set;
34 import jdk.nashorn.internal.codegen.types.Type;
35 import jdk.nashorn.internal.ir.annotations.Ignore;
36 import jdk.nashorn.internal.ir.annotations.Immutable;
37 import jdk.nashorn.internal.ir.visitor.NodeVisitor;
38 import jdk.nashorn.internal.parser.TokenType;
39
40 /**
41 * BinaryNode nodes represent two operand operations.
42 */
43 @Immutable
44 public final class BinaryNode extends Expression implements Assignment<Expression>, Optimistic {
45 private static final long serialVersionUID = 1L;
46
47 // Placeholder for "undecided optimistic ADD type". Unfortunately, we can't decide the type of ADD during optimistic
48 // type calculation as it can have local variables as its operands that will decide its ultimate type.
49 private static final Type OPTIMISTIC_UNDECIDED_TYPE = Type.typeFor(new Object(){/*empty*/}.getClass());
50
51 /** Left hand side argument. */
52 private final Expression lhs;
53
54 private final Expression rhs;
55
56 private final int programPoint;
57
58 private final Type type;
59 private transient Type cachedType;
60
61 @Ignore
62 private static final Set<TokenType> CAN_OVERFLOW =
63 Collections.unmodifiableSet(new HashSet<>(Arrays.asList(new TokenType[] {
64 TokenType.ADD,
65 TokenType.DIV,
66 TokenType.MOD,
67 TokenType.MUL,
68 TokenType.SUB,
69 TokenType.ASSIGN_ADD,
70 TokenType.ASSIGN_DIV,
71 TokenType.ASSIGN_MOD,
72 TokenType.ASSIGN_MUL,
73 TokenType.ASSIGN_SUB
74 })));
75
76 /**
77 * Constructor
78 *
79 * @param token token
80 * @param lhs left hand side
81 * @param rhs right hand side
82 */
83 public BinaryNode(final long token, final Expression lhs, final Expression rhs) {
84 super(token, lhs.getStart(), rhs.getFinish());
85 assert !(isTokenType(TokenType.AND) || isTokenType(TokenType.OR)) || lhs instanceof JoinPredecessorExpression;
86 this.lhs = lhs;
87 this.rhs = rhs;
88 this.programPoint = INVALID_PROGRAM_POINT;
89 this.type = null;
90 }
91
92 private BinaryNode(final BinaryNode binaryNode, final Expression lhs, final Expression rhs, final Type type, final int programPoint) {
93 super(binaryNode);
94 this.lhs = lhs;
95 this.rhs = rhs;
96 this.programPoint = programPoint;
97 this.type = type;
98 }
99
100 /**
101 * Returns true if the node is a comparison operation (either equality, inequality, or relational).
102 * @return true if the node is a comparison operation.
103 */
104 public boolean isComparison() {
105 switch (tokenType()) {
106 case EQ:
107 case EQ_STRICT:
108 case NE:
109 case NE_STRICT:
110 case LE:
111 case LT:
112 case GE:
113 case GT:
114 return true;
115 default:
116 return false;
117 }
118 }
119
120 /**
121 * Returns true if the node is a relational operation (less than (or equals), greater than (or equals)).
122 * @return true if the node is a relational operation.
123 */
124 public boolean isRelational() {
125 switch (tokenType()) {
126 case LT:
127 case GT:
128 case LE:
129 case GE:
130 return true;
131 default:
132 return false;
133 }
134 }
135
136 /**
137 * Returns true if the node is a logical operation.
138 * @return true if the node is a logical operation.
139 */
140 public boolean isLogical() {
141 return isLogical(tokenType());
142 }
143
144 /**
145 * Returns true if the token type represents a logical operation.
146 * @param tokenType the token type
147 * @return true if the token type represents a logical operation.
148 */
149 public static boolean isLogical(final TokenType tokenType) {
150 switch (tokenType) {
151 case AND:
152 case OR:
153 return true;
154 default:
155 return false;
156 }
157 }
158
159 /**
160 * Return the widest possible operand type for this operation.
161 *
162 * @return Type
163 */
164 public Type getWidestOperandType() {
165 switch (tokenType()) {
166 case SHR:
167 case ASSIGN_SHR:
168 return Type.INT;
169 case INSTANCEOF:
170 return Type.OBJECT;
171 default:
172 if (isComparison()) {
173 return Type.OBJECT;
174 }
175 return getWidestOperationType();
176 }
177 }
178
179 @Override
180 public Type getWidestOperationType() {
181 switch (tokenType()) {
182 case ADD:
183 case ASSIGN_ADD: {
184 // Compare this logic to decideType(Type, Type); it's similar, but it handles the optimistic type
185 // calculation case while this handles the conservative case.
186 final Type lhsType = lhs.getType();
187 final Type rhsType = rhs.getType();
188 if(lhsType == Type.BOOLEAN && rhsType == Type.BOOLEAN) {
189 // Will always fit in an int, as the value range is [0, 1, 2]. If we didn't treat them specially here,
190 // they'd end up being treated as generic INT operands and their sum would be conservatively considered
191 // to be a LONG in the generic case below; we can do better here.
192 return Type.INT;
193 } else if(isString(lhsType) || isString(rhsType)) {
194 // We can statically figure out that this is a string if either operand is a string. In this case, use
195 // CHARSEQUENCE to prevent it from being proactively flattened.
196 return Type.CHARSEQUENCE;
197 }
198 final Type widestOperandType = Type.widest(undefinedToNumber(booleanToInt(lhsType)), undefinedToNumber(booleanToInt(rhsType)));
199 if(widestOperandType == Type.INT) {
200 return Type.LONG;
201 } else if (widestOperandType.isNumeric()) {
202 return Type.NUMBER;
203 }
204 // We pretty much can't know what it will be statically. Must presume OBJECT conservatively, as we can end
205 // up getting either a string or an object when adding something + object, e.g.:
206 // 1 + {} == "1[object Object]", but
207 // 1 + {valueOf: function() { return 2 }} == 3. Also:
208 // 1 + {valueOf: function() { return "2" }} == "12".
209 return Type.OBJECT;
210 }
211 case SHR:
212 case ASSIGN_SHR:
213 return Type.LONG;
214 case ASSIGN_SAR:
215 case ASSIGN_SHL:
216 case BIT_AND:
217 case BIT_OR:
218 case BIT_XOR:
219 case ASSIGN_BIT_AND:
220 case ASSIGN_BIT_OR:
221 case ASSIGN_BIT_XOR:
222 case SAR:
223 case SHL:
224 return Type.INT;
225 case DIV:
226 case MOD:
227 case ASSIGN_DIV:
228 case ASSIGN_MOD: {
229 // Naively, one might think MOD has the same type as the widest of its operands, this is unfortunately not
230 // true when denominator is zero, so even type(int % int) == double.
231 return Type.NUMBER;
232 }
233 case MUL:
234 case SUB:
235 case ASSIGN_MUL:
236 case ASSIGN_SUB: {
237 final Type lhsType = lhs.getType();
238 final Type rhsType = rhs.getType();
239 if(lhsType == Type.BOOLEAN && rhsType == Type.BOOLEAN) {
240 return Type.INT;
241 }
242 final Type widestOperandType = Type.widest(booleanToInt(lhsType), booleanToInt(rhsType));
243 if(widestOperandType == Type.INT) {
244 return Type.LONG;
245 }
246 return Type.NUMBER;
247 }
248 case VOID: {
249 return Type.UNDEFINED;
250 }
251 case ASSIGN: {
252 return rhs.getType();
253 }
254 case INSTANCEOF: {
255 return Type.BOOLEAN;
256 }
257 case COMMALEFT: {
258 return lhs.getType();
259 }
260 case COMMARIGHT: {
261 return rhs.getType();
262 }
263 case AND:
264 case OR:{
265 return Type.widestReturnType(lhs.getType(), rhs.getType());
266 }
267 default:
268 if (isComparison()) {
269 return Type.BOOLEAN;
270 }
271 return Type.OBJECT;
272 }
273 }
274
275 private static boolean isString(final Type type) {
276 return type == Type.STRING || type == Type.CHARSEQUENCE;
277 }
278
279 private static Type booleanToInt(final Type type) {
280 return type == Type.BOOLEAN ? Type.INT : type;
281 }
282
283 private static Type undefinedToNumber(final Type type) {
284 return type == Type.UNDEFINED ? Type.NUMBER : type;
285 }
286
287 /**
288 * Check if this node is an assignment
289 *
290 * @return true if this node assigns a value
291 */
292 @Override
293 public boolean isAssignment() {
294 switch (tokenType()) {
295 case ASSIGN:
296 case ASSIGN_ADD:
297 case ASSIGN_BIT_AND:
298 case ASSIGN_BIT_OR:
299 case ASSIGN_BIT_XOR:
300 case ASSIGN_DIV:
301 case ASSIGN_MOD:
302 case ASSIGN_MUL:
303 case ASSIGN_SAR:
304 case ASSIGN_SHL:
305 case ASSIGN_SHR:
306 case ASSIGN_SUB:
307 return true;
308 default:
309 return false;
310 }
311 }
312
313 @Override
314 public boolean isSelfModifying() {
315 return isAssignment() && !isTokenType(TokenType.ASSIGN);
316 }
317
318 @Override
319 public Expression getAssignmentDest() {
320 return isAssignment() ? lhs() : null;
321 }
322
323 @Override
324 public BinaryNode setAssignmentDest(final Expression n) {
325 return setLHS(n);
326 }
327
328 @Override
329 public Expression getAssignmentSource() {
330 return rhs();
331 }
332
333 /**
334 * Assist in IR navigation.
335 * @param visitor IR navigating visitor.
336 */
337 @Override
338 public Node accept(final NodeVisitor<? extends LexicalContext> visitor) {
339 if (visitor.enterBinaryNode(this)) {
340 return visitor.leaveBinaryNode(setLHS((Expression)lhs.accept(visitor)).setRHS((Expression)rhs.accept(visitor)));
341 }
342
343 return this;
344 }
345
346 @Override
347 public boolean isLocal() {
348 switch (tokenType()) {
349 case SAR:
350 case SHL:
351 case SHR:
352 case BIT_AND:
353 case BIT_OR:
354 case BIT_XOR:
355 case ADD:
356 case DIV:
357 case MOD:
358 case MUL:
359 case SUB:
360 return lhs.isLocal() && lhs.getType().isJSPrimitive()
361 && rhs.isLocal() && rhs.getType().isJSPrimitive();
362 case ASSIGN_ADD:
363 case ASSIGN_BIT_AND:
364 case ASSIGN_BIT_OR:
365 case ASSIGN_BIT_XOR:
366 case ASSIGN_DIV:
367 case ASSIGN_MOD:
368 case ASSIGN_MUL:
369 case ASSIGN_SAR:
370 case ASSIGN_SHL:
371 case ASSIGN_SHR:
372 case ASSIGN_SUB:
373 return lhs instanceof IdentNode && lhs.isLocal() && lhs.getType().isJSPrimitive()
374 && rhs.isLocal() && rhs.getType().isJSPrimitive();
375 case ASSIGN:
376 return lhs instanceof IdentNode && lhs.isLocal() && rhs.isLocal();
377 default:
378 return false;
379 }
380 }
381
382 @Override
383 public boolean isAlwaysFalse() {
384 switch (tokenType()) {
385 case COMMALEFT:
386 return lhs.isAlwaysFalse();
387 case COMMARIGHT:
388 return rhs.isAlwaysFalse();
389 default:
390 return false;
391 }
392 }
393
394 @Override
395 public boolean isAlwaysTrue() {
396 switch (tokenType()) {
397 case COMMALEFT:
398 return lhs.isAlwaysTrue();
399 case COMMARIGHT:
400 return rhs.isAlwaysTrue();
401 default:
402 return false;
403 }
404 }
405
406 @Override
407 public void toString(final StringBuilder sb, final boolean printType) {
408 final TokenType tokenType = tokenType();
409
410 final boolean lhsParen = tokenType.needsParens(lhs().tokenType(), true);
411 final boolean rhsParen = tokenType.needsParens(rhs().tokenType(), false);
412
413 if (lhsParen) {
414 sb.append('(');
415 }
416
417 lhs().toString(sb, printType);
418
419 if (lhsParen) {
420 sb.append(')');
421 }
422
423 sb.append(' ');
424
425 switch (tokenType) {
426 case COMMALEFT:
427 sb.append(",<");
428 break;
429 case COMMARIGHT:
430 sb.append(",>");
431 break;
432 case INCPREFIX:
433 case DECPREFIX:
434 sb.append("++");
435 break;
436 default:
437 sb.append(tokenType.getName());
438 break;
439 }
440
441 if (isOptimistic()) {
442 sb.append(Expression.OPT_IDENTIFIER);
443 }
444
445 sb.append(' ');
446
447 if (rhsParen) {
448 sb.append('(');
449 }
450 rhs().toString(sb, printType);
451 if (rhsParen) {
452 sb.append(')');
453 }
454 }
455
456 /**
457 * Get the left hand side expression for this node
458 * @return the left hand side expression
459 */
460 public Expression lhs() {
461 return lhs;
462 }
463
464 /**
465 * Get the right hand side expression for this node
466 * @return the left hand side expression
467 */
468 public Expression rhs() {
469 return rhs;
470 }
471
472 /**
473 * Set the left hand side expression for this node
474 * @param lhs new left hand side expression
475 * @return a node equivalent to this one except for the requested change.
476 */
477 public BinaryNode setLHS(final Expression lhs) {
478 if (this.lhs == lhs) {
479 return this;
480 }
481 return new BinaryNode(this, lhs, rhs, type, programPoint);
482 }
483
484 /**
485 * Set the right hand side expression for this node
486 * @param rhs new right hand side expression
487 * @return a node equivalent to this one except for the requested change.
488 */
489 public BinaryNode setRHS(final Expression rhs) {
490 if (this.rhs == rhs) {
491 return this;
492 }
493 return new BinaryNode(this, lhs, rhs, type, programPoint);
494 }
495
496 /**
497 * Set both the left and the right hand side expression for this node
498 * @param lhs new left hand side expression
499 * @param rhs new left hand side expression
500 * @return a node equivalent to this one except for the requested change.
501 */
502 public BinaryNode setOperands(final Expression lhs, final Expression rhs) {
503 if (this.lhs == lhs && this.rhs == rhs) {
504 return this;
505 }
506 return new BinaryNode(this, lhs, rhs, type, programPoint);
507 }
508
509 @Override
510 public int getProgramPoint() {
511 return programPoint;
512 }
513
514 @Override
515 public boolean canBeOptimistic() {
516 return isTokenType(TokenType.ADD) || (getMostOptimisticType() != getMostPessimisticType());
517 }
518
519 @Override
520 public BinaryNode setProgramPoint(final int programPoint) {
521 if (this.programPoint == programPoint) {
522 return this;
523 }
524 return new BinaryNode(this, lhs, rhs, type, programPoint);
525 }
526
527 @Override
528 public Type getMostOptimisticType() {
529 final TokenType tokenType = tokenType();
530 if(tokenType == TokenType.ADD || tokenType == TokenType.ASSIGN_ADD) {
531 return OPTIMISTIC_UNDECIDED_TYPE;
532 } else if (CAN_OVERFLOW.contains(tokenType)) {
533 return Type.INT;
534 }
535 return getMostPessimisticType();
536 }
537
538 @Override
539 public Type getMostPessimisticType() {
540 return getWidestOperationType();
541 }
542
543 /**
544 * Returns true if the node has the optimistic type of the node is not yet decided. Optimistic ADD nodes start out
545 * as undecided until we can figure out if they're numeric or not.
546 * @return true if the node has the optimistic type of the node is not yet decided.
547 */
548 public boolean isOptimisticUndecidedType() {
549 return type == OPTIMISTIC_UNDECIDED_TYPE;
550 }
551
552 @Override
553 public Type getType() {
554 if (cachedType == null) {
555 cachedType = getTypeUncached();
556 }
557 return cachedType;
558 }
559
560 private Type getTypeUncached() {
561 if(type == OPTIMISTIC_UNDECIDED_TYPE) {
562 return decideType(lhs.getType(), rhs.getType());
563 }
564 final Type widest = getWidestOperationType();
565 if(type == null) {
566 return widest;
567 }
568 return Type.narrowest(widest, Type.widest(type, Type.widest(lhs.getType(), rhs.getType())));
569 }
570
571 private static Type decideType(final Type lhsType, final Type rhsType) {
572 // Compare this to getWidestOperationType() for ADD and ASSIGN_ADD cases. There's some similar logic, but these
573 // are optimistic decisions, meaning that we don't have to treat boolean addition separately (as it'll become
574 // int addition in the general case anyway), and that we also don't conservatively widen sums of ints to
575 // longs, or sums of longs to doubles.
576 if(isString(lhsType) || isString(rhsType)) {
577 return Type.CHARSEQUENCE;
578 }
579 // NOTE: We don't have optimistic object-to-(int, long) conversions. Therefore, if any operand is an Object, we
580 // bail out of optimism here and presume a conservative Object return value, as the object's ToPrimitive() can
581 // end up returning either a number or a string, and their common supertype is Object, for better or worse.
582 final Type widest = Type.widest(undefinedToNumber(booleanToInt(lhsType)), undefinedToNumber(booleanToInt(rhsType)));
583 return widest.isObject() ? Type.OBJECT : widest;
584 }
585
586 /**
587 * If the node is a node representing an add operation and has {@link #isOptimisticUndecidedType() optimistic
588 * undecided type}, decides its type. Should be invoked after its operands types have been finalized.
589 * @return returns a new node similar to this node, but with its type set to the type decided from the type of its
590 * operands.
591 */
592 public BinaryNode decideType() {
593 assert type == OPTIMISTIC_UNDECIDED_TYPE;
594 return setType(decideType(lhs.getType(), rhs.getType()));
595 }
596
597 @Override
598 public BinaryNode setType(final Type type) {
599 if (this.type == type) {
600 return this;
601 }
602 return new BinaryNode(this, lhs, rhs, type, programPoint);
603 }
604 }