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 }