1 /* 2 * Copyright (c) 2010, 2016, 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.codegen; 27 28 import static jdk.nashorn.internal.codegen.ClassEmitter.Flag.PRIVATE; 29 import static jdk.nashorn.internal.codegen.ClassEmitter.Flag.STATIC; 30 import static jdk.nashorn.internal.codegen.CompilerConstants.ARGUMENTS; 31 import static jdk.nashorn.internal.codegen.CompilerConstants.CALLEE; 32 import static jdk.nashorn.internal.codegen.CompilerConstants.CREATE_PROGRAM_FUNCTION; 33 import static jdk.nashorn.internal.codegen.CompilerConstants.GET_MAP; 34 import static jdk.nashorn.internal.codegen.CompilerConstants.GET_STRING; 35 import static jdk.nashorn.internal.codegen.CompilerConstants.QUICK_PREFIX; 36 import static jdk.nashorn.internal.codegen.CompilerConstants.REGEX_PREFIX; 37 import static jdk.nashorn.internal.codegen.CompilerConstants.SCOPE; 38 import static jdk.nashorn.internal.codegen.CompilerConstants.SPLIT_PREFIX; 39 import static jdk.nashorn.internal.codegen.CompilerConstants.THIS; 40 import static jdk.nashorn.internal.codegen.CompilerConstants.VARARGS; 41 import static jdk.nashorn.internal.codegen.CompilerConstants.interfaceCallNoLookup; 42 import static jdk.nashorn.internal.codegen.CompilerConstants.methodDescriptor; 43 import static jdk.nashorn.internal.codegen.CompilerConstants.staticCallNoLookup; 44 import static jdk.nashorn.internal.codegen.CompilerConstants.typeDescriptor; 45 import static jdk.nashorn.internal.codegen.CompilerConstants.virtualCallNoLookup; 46 import static jdk.nashorn.internal.ir.Symbol.HAS_SLOT; 47 import static jdk.nashorn.internal.ir.Symbol.IS_INTERNAL; 48 import static jdk.nashorn.internal.runtime.UnwarrantedOptimismException.INVALID_PROGRAM_POINT; 49 import static jdk.nashorn.internal.runtime.UnwarrantedOptimismException.isValid; 50 import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_APPLY_TO_CALL; 51 import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_DECLARE; 52 import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_FAST_SCOPE; 53 import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_OPTIMISTIC; 54 import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_PROGRAM_POINT_SHIFT; 55 import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_SCOPE; 56 57 import java.io.PrintWriter; 58 import java.util.ArrayDeque; 59 import java.util.ArrayList; 60 import java.util.Arrays; 61 import java.util.BitSet; 62 import java.util.Collection; 63 import java.util.Collections; 64 import java.util.Deque; 65 import java.util.EnumSet; 66 import java.util.HashMap; 67 import java.util.HashSet; 68 import java.util.Iterator; 69 import java.util.LinkedList; 70 import java.util.List; 71 import java.util.Map; 72 import java.util.Set; 73 import java.util.TreeMap; 74 import java.util.function.Supplier; 75 import jdk.nashorn.internal.AssertsEnabled; 76 import jdk.nashorn.internal.IntDeque; 77 import jdk.nashorn.internal.codegen.ClassEmitter.Flag; 78 import jdk.nashorn.internal.codegen.CompilerConstants.Call; 79 import jdk.nashorn.internal.codegen.types.ArrayType; 80 import jdk.nashorn.internal.codegen.types.Type; 81 import jdk.nashorn.internal.ir.AccessNode; 82 import jdk.nashorn.internal.ir.BaseNode; 83 import jdk.nashorn.internal.ir.BinaryNode; 84 import jdk.nashorn.internal.ir.Block; 85 import jdk.nashorn.internal.ir.BlockStatement; 86 import jdk.nashorn.internal.ir.BreakNode; 87 import jdk.nashorn.internal.ir.CallNode; 88 import jdk.nashorn.internal.ir.CaseNode; 89 import jdk.nashorn.internal.ir.CatchNode; 90 import jdk.nashorn.internal.ir.ContinueNode; 91 import jdk.nashorn.internal.ir.EmptyNode; 92 import jdk.nashorn.internal.ir.Expression; 93 import jdk.nashorn.internal.ir.ExpressionStatement; 94 import jdk.nashorn.internal.ir.ForNode; 95 import jdk.nashorn.internal.ir.FunctionNode; 96 import jdk.nashorn.internal.ir.GetSplitState; 97 import jdk.nashorn.internal.ir.IdentNode; 98 import jdk.nashorn.internal.ir.IfNode; 99 import jdk.nashorn.internal.ir.IndexNode; 100 import jdk.nashorn.internal.ir.JoinPredecessorExpression; 101 import jdk.nashorn.internal.ir.JumpStatement; 102 import jdk.nashorn.internal.ir.JumpToInlinedFinally; 103 import jdk.nashorn.internal.ir.LabelNode; 104 import jdk.nashorn.internal.ir.LexicalContext; 105 import jdk.nashorn.internal.ir.LexicalContextNode; 106 import jdk.nashorn.internal.ir.LiteralNode; 107 import jdk.nashorn.internal.ir.LiteralNode.ArrayLiteralNode; 108 import jdk.nashorn.internal.ir.LiteralNode.PrimitiveLiteralNode; 109 import jdk.nashorn.internal.ir.LocalVariableConversion; 110 import jdk.nashorn.internal.ir.LoopNode; 111 import jdk.nashorn.internal.ir.Node; 112 import jdk.nashorn.internal.ir.ObjectNode; 113 import jdk.nashorn.internal.ir.Optimistic; 114 import jdk.nashorn.internal.ir.PropertyNode; 115 import jdk.nashorn.internal.ir.ReturnNode; 116 import jdk.nashorn.internal.ir.RuntimeNode; 117 import jdk.nashorn.internal.ir.RuntimeNode.Request; 118 import jdk.nashorn.internal.ir.SetSplitState; 119 import jdk.nashorn.internal.ir.SplitReturn; 120 import jdk.nashorn.internal.ir.Splittable; 121 import jdk.nashorn.internal.ir.Statement; 122 import jdk.nashorn.internal.ir.SwitchNode; 123 import jdk.nashorn.internal.ir.Symbol; 124 import jdk.nashorn.internal.ir.TernaryNode; 125 import jdk.nashorn.internal.ir.ThrowNode; 126 import jdk.nashorn.internal.ir.TryNode; 127 import jdk.nashorn.internal.ir.UnaryNode; 128 import jdk.nashorn.internal.ir.VarNode; 129 import jdk.nashorn.internal.ir.WhileNode; 130 import jdk.nashorn.internal.ir.WithNode; 131 import jdk.nashorn.internal.ir.visitor.NodeOperatorVisitor; 132 import jdk.nashorn.internal.ir.visitor.SimpleNodeVisitor; 133 import jdk.nashorn.internal.objects.Global; 134 import jdk.nashorn.internal.parser.Lexer.RegexToken; 135 import jdk.nashorn.internal.parser.TokenType; 136 import jdk.nashorn.internal.runtime.Context; 137 import jdk.nashorn.internal.runtime.Debug; 138 import jdk.nashorn.internal.runtime.ECMAException; 139 import jdk.nashorn.internal.runtime.JSType; 140 import jdk.nashorn.internal.runtime.OptimisticReturnFilters; 141 import jdk.nashorn.internal.runtime.PropertyMap; 142 import jdk.nashorn.internal.runtime.RecompilableScriptFunctionData; 143 import jdk.nashorn.internal.runtime.RewriteException; 144 import jdk.nashorn.internal.runtime.Scope; 145 import jdk.nashorn.internal.runtime.ScriptEnvironment; 146 import jdk.nashorn.internal.runtime.ScriptFunction; 147 import jdk.nashorn.internal.runtime.ScriptObject; 148 import jdk.nashorn.internal.runtime.ScriptRuntime; 149 import jdk.nashorn.internal.runtime.Source; 150 import jdk.nashorn.internal.runtime.Undefined; 151 import jdk.nashorn.internal.runtime.UnwarrantedOptimismException; 152 import jdk.nashorn.internal.runtime.arrays.ArrayData; 153 import jdk.nashorn.internal.runtime.linker.LinkerCallSite; 154 import jdk.nashorn.internal.runtime.logging.DebugLogger; 155 import jdk.nashorn.internal.runtime.logging.Loggable; 156 import jdk.nashorn.internal.runtime.logging.Logger; 157 import jdk.nashorn.internal.runtime.options.Options; 158 159 /** 160 * This is the lowest tier of the code generator. It takes lowered ASTs emitted 161 * from Lower and emits Java byte code. The byte code emission logic is broken 162 * out into MethodEmitter. MethodEmitter works internally with a type stack, and 163 * keeps track of the contents of the byte code stack. This way we avoid a large 164 * number of special cases on the form 165 * <pre> 166 * if (type == INT) { 167 * visitInsn(ILOAD, slot); 168 * } else if (type == DOUBLE) { 169 * visitInsn(DOUBLE, slot); 170 * } 171 * </pre> 172 * This quickly became apparent when the code generator was generalized to work 173 * with all types, and not just numbers or objects. 174 * <p> 175 * The CodeGenerator visits nodes only once and emits bytecode for them. 176 */ 177 @Logger(name="codegen") 178 final class CodeGenerator extends NodeOperatorVisitor<CodeGeneratorLexicalContext> implements Loggable { 179 180 private static final Type SCOPE_TYPE = Type.typeFor(ScriptObject.class); 181 182 private static final String GLOBAL_OBJECT = Type.getInternalName(Global.class); 183 184 private static final Call CREATE_REWRITE_EXCEPTION = CompilerConstants.staticCallNoLookup(RewriteException.class, 185 "create", RewriteException.class, UnwarrantedOptimismException.class, Object[].class, String[].class); 186 private static final Call CREATE_REWRITE_EXCEPTION_REST_OF = CompilerConstants.staticCallNoLookup(RewriteException.class, 187 "create", RewriteException.class, UnwarrantedOptimismException.class, Object[].class, String[].class, int[].class); 188 189 private static final Call ENSURE_INT = CompilerConstants.staticCallNoLookup(OptimisticReturnFilters.class, 190 "ensureInt", int.class, Object.class, int.class); 191 private static final Call ENSURE_NUMBER = CompilerConstants.staticCallNoLookup(OptimisticReturnFilters.class, 192 "ensureNumber", double.class, Object.class, int.class); 193 194 private static final Call CREATE_FUNCTION_OBJECT = CompilerConstants.staticCallNoLookup(ScriptFunction.class, 195 "create", ScriptFunction.class, Object[].class, int.class, ScriptObject.class); 196 private static final Call CREATE_FUNCTION_OBJECT_NO_SCOPE = CompilerConstants.staticCallNoLookup(ScriptFunction.class, 197 "create", ScriptFunction.class, Object[].class, int.class); 198 199 private static final Call TO_NUMBER_FOR_EQ = CompilerConstants.staticCallNoLookup(JSType.class, 200 "toNumberForEq", double.class, Object.class); 201 private static final Call TO_NUMBER_FOR_STRICT_EQ = CompilerConstants.staticCallNoLookup(JSType.class, 202 "toNumberForStrictEq", double.class, Object.class); 203 204 205 private static final Class<?> ITERATOR_CLASS = Iterator.class; 206 static { 207 assert ITERATOR_CLASS == CompilerConstants.ITERATOR_PREFIX.type(); 208 } 209 private static final Type ITERATOR_TYPE = Type.typeFor(ITERATOR_CLASS); 210 private static final Type EXCEPTION_TYPE = Type.typeFor(CompilerConstants.EXCEPTION_PREFIX.type()); 211 212 private static final Integer INT_ZERO = 0; 213 214 /** Constant data & installation. The only reason the compiler keeps this is because it is assigned 215 * by reflection in class installation */ 216 private final Compiler compiler; 217 218 /** Is the current code submitted by 'eval' call? */ 219 private final boolean evalCode; 220 221 /** Call site flags given to the code generator to be used for all generated call sites */ 222 private final int callSiteFlags; 223 224 /** How many regexp fields have been emitted */ 225 private int regexFieldCount; 226 227 /** Line number for last statement. If we encounter a new line number, line number bytecode information 228 * needs to be generated */ 229 private int lastLineNumber = -1; 230 231 /** When should we stop caching regexp expressions in fields to limit bytecode size? */ 232 private static final int MAX_REGEX_FIELDS = 2 * 1024; 233 234 /** Current method emitter */ 235 private MethodEmitter method; 236 237 /** Current compile unit */ 238 private CompileUnit unit; 239 240 private final DebugLogger log; 241 242 /** From what size should we use spill instead of fields for JavaScript objects? */ 243 static final int OBJECT_SPILL_THRESHOLD = Options.getIntProperty("nashorn.spill.threshold", 256); 244 245 private final Set<String> emittedMethods = new HashSet<>(); 246 247 // Function Id -> ContinuationInfo. Used by compilation of rest-of function only. 248 private ContinuationInfo continuationInfo; 249 250 private final Deque<Label> scopeEntryLabels = new ArrayDeque<>(); 251 252 private static final Label METHOD_BOUNDARY = new Label(""); 253 private final Deque<Label> catchLabels = new ArrayDeque<>(); 254 // Number of live locals on entry to (and thus also break from) labeled blocks. 255 private final IntDeque labeledBlockBreakLiveLocals = new IntDeque(); 256 257 //is this a rest of compilation 258 private final int[] continuationEntryPoints; 259 260 // Scope object creators needed for for-of and for-in loops 261 private Deque<FieldObjectCreator<?>> scopeObjectCreators = new ArrayDeque<>(); 262 263 /** 264 * Constructor. 265 * 266 * @param compiler 267 */ 268 CodeGenerator(final Compiler compiler, final int[] continuationEntryPoints) { 269 super(new CodeGeneratorLexicalContext()); 270 this.compiler = compiler; 271 this.evalCode = compiler.getSource().isEvalCode(); 272 this.continuationEntryPoints = continuationEntryPoints; 273 this.callSiteFlags = compiler.getScriptEnvironment()._callsite_flags; 274 this.log = initLogger(compiler.getContext()); 275 } 276 277 @Override 278 public DebugLogger getLogger() { 279 return log; 280 } 281 282 @Override 283 public DebugLogger initLogger(final Context context) { 284 return context.getLogger(this.getClass()); 285 } 286 287 /** 288 * Gets the call site flags, adding the strict flag if the current function 289 * being generated is in strict mode 290 * 291 * @return the correct flags for a call site in the current function 292 */ 293 int getCallSiteFlags() { 294 return lc.getCurrentFunction().getCallSiteFlags() | callSiteFlags; 295 } 296 297 /** 298 * Gets the flags for a scope call site. 299 * @param symbol a scope symbol 300 * @return the correct flags for the scope call site 301 */ 302 private int getScopeCallSiteFlags(final Symbol symbol) { 303 assert symbol.isScope(); 304 final int flags = getCallSiteFlags() | CALLSITE_SCOPE; 305 if (isEvalCode() && symbol.isGlobal()) { 306 return flags; // Don't set fast-scope flag on non-declared globals in eval code - see JDK-8077955. 307 } 308 return isFastScope(symbol) ? flags | CALLSITE_FAST_SCOPE : flags; 309 } 310 311 /** 312 * Are we generating code for 'eval' code? 313 * @return true if currently compiled code is 'eval' code. 314 */ 315 boolean isEvalCode() { 316 return evalCode; 317 } 318 319 /** 320 * Are we using dual primitive/object field representation? 321 * @return true if using dual field representation, false for object-only fields 322 */ 323 boolean useDualFields() { 324 return compiler.getContext().useDualFields(); 325 } 326 327 /** 328 * Load an identity node 329 * 330 * @param identNode an identity node to load 331 * @return the method generator used 332 */ 333 private MethodEmitter loadIdent(final IdentNode identNode, final TypeBounds resultBounds) { 334 checkTemporalDeadZone(identNode); 335 final Symbol symbol = identNode.getSymbol(); 336 337 if (!symbol.isScope()) { 338 final Type type = identNode.getType(); 339 if(type == Type.UNDEFINED) { 340 return method.loadUndefined(resultBounds.widest); 341 } 342 343 assert symbol.hasSlot() || symbol.isParam(); 344 return method.load(identNode); 345 } 346 347 assert identNode.getSymbol().isScope() : identNode + " is not in scope!"; 348 final int flags = getScopeCallSiteFlags(symbol); 349 if (isFastScope(symbol)) { 350 // Only generate shared scope getter for fast-scope symbols so we know we can dial in correct scope. 351 if (symbol.getUseCount() > SharedScopeCall.FAST_SCOPE_GET_THRESHOLD && !identNode.isOptimistic()) { 352 // As shared scope vars are only used with non-optimistic identifiers, we switch from using TypeBounds to 353 // just a single definitive type, resultBounds.widest. 354 new OptimisticOperation(identNode, TypeBounds.OBJECT) { 355 @Override 356 void loadStack() { 357 method.loadCompilerConstant(SCOPE); 358 } 359 360 @Override 361 void consumeStack() { 362 loadSharedScopeVar(resultBounds.widest, symbol, flags); 363 } 364 }.emit(); 365 } else { 366 new LoadFastScopeVar(identNode, resultBounds, flags).emit(); 367 } 368 } else { 369 //slow scope load, we have no proto depth 370 new LoadScopeVar(identNode, resultBounds, flags).emit(); 371 } 372 373 return method; 374 } 375 376 // Any access to LET and CONST variables before their declaration must throw ReferenceError. 377 // This is called the temporal dead zone (TDZ). See https://gist.github.com/rwaldron/f0807a758aa03bcdd58a 378 private void checkTemporalDeadZone(final IdentNode identNode) { 379 if (identNode.isDead()) { 380 method.load(identNode.getSymbol().getName()).invoke(ScriptRuntime.THROW_REFERENCE_ERROR); 381 } 382 } 383 384 // Runtime check for assignment to ES6 const 385 private void checkAssignTarget(final Expression expression) { 386 if (expression instanceof IdentNode && ((IdentNode)expression).getSymbol().isConst()) { 387 method.load(((IdentNode)expression).getSymbol().getName()).invoke(ScriptRuntime.THROW_CONST_TYPE_ERROR); 388 } 389 } 390 391 private boolean isRestOf() { 392 return continuationEntryPoints != null; 393 } 394 395 private boolean isCurrentContinuationEntryPoint(final int programPoint) { 396 return isRestOf() && getCurrentContinuationEntryPoint() == programPoint; 397 } 398 399 private int[] getContinuationEntryPoints() { 400 return isRestOf() ? continuationEntryPoints : null; 401 } 402 403 private int getCurrentContinuationEntryPoint() { 404 return isRestOf() ? continuationEntryPoints[0] : INVALID_PROGRAM_POINT; 405 } 406 407 private boolean isContinuationEntryPoint(final int programPoint) { 408 if (isRestOf()) { 409 assert continuationEntryPoints != null; 410 for (final int cep : continuationEntryPoints) { 411 if (cep == programPoint) { 412 return true; 413 } 414 } 415 } 416 return false; 417 } 418 419 /** 420 * Check if this symbol can be accessed directly with a putfield or getfield or dynamic load 421 * 422 * @param symbol symbol to check for fast scope 423 * @return true if fast scope 424 */ 425 private boolean isFastScope(final Symbol symbol) { 426 if (!symbol.isScope()) { 427 return false; 428 } 429 430 if (!lc.inDynamicScope()) { 431 // If there's no with or eval in context, and the symbol is marked as scoped, it is fast scoped. Such a 432 // symbol must either be global, or its defining block must need scope. 433 assert symbol.isGlobal() || lc.getDefiningBlock(symbol).needsScope() : symbol.getName(); 434 return true; 435 } 436 437 if (symbol.isGlobal()) { 438 // Shortcut: if there's a with or eval in context, globals can't be fast scoped 439 return false; 440 } 441 442 // Otherwise, check if there's a dynamic scope between use of the symbol and its definition 443 final String name = symbol.getName(); 444 boolean previousWasBlock = false; 445 for (final Iterator<LexicalContextNode> it = lc.getAllNodes(); it.hasNext();) { 446 final LexicalContextNode node = it.next(); 447 if (node instanceof Block) { 448 // If this block defines the symbol, then we can fast scope the symbol. 449 final Block block = (Block)node; 450 if (block.getExistingSymbol(name) == symbol) { 451 assert block.needsScope(); 452 return true; 453 } 454 previousWasBlock = true; 455 } else { 456 if (node instanceof WithNode && previousWasBlock || node instanceof FunctionNode && ((FunctionNode)node).needsDynamicScope()) { 457 // If we hit a scope that can have symbols introduced into it at run time before finding the defining 458 // block, the symbol can't be fast scoped. A WithNode only counts if we've immediately seen a block 459 // before - its block. Otherwise, we are currently processing the WithNode's expression, and that's 460 // obviously not subjected to introducing new symbols. 461 return false; 462 } 463 previousWasBlock = false; 464 } 465 } 466 // Should've found the symbol defined in a block 467 throw new AssertionError(); 468 } 469 470 private MethodEmitter loadSharedScopeVar(final Type valueType, final Symbol symbol, final int flags) { 471 assert isFastScope(symbol); 472 method.load(getScopeProtoDepth(lc.getCurrentBlock(), symbol)); 473 return lc.getScopeGet(unit, symbol, valueType, flags).generateInvoke(method); 474 } 475 476 private class LoadScopeVar extends OptimisticOperation { 477 final IdentNode identNode; 478 private final int flags; 479 480 LoadScopeVar(final IdentNode identNode, final TypeBounds resultBounds, final int flags) { 481 super(identNode, resultBounds); 482 this.identNode = identNode; 483 this.flags = flags; 484 } 485 486 @Override 487 void loadStack() { 488 method.loadCompilerConstant(SCOPE); 489 getProto(); 490 } 491 492 void getProto() { 493 //empty 494 } 495 496 @Override 497 void consumeStack() { 498 // If this is either __FILE__, __DIR__, or __LINE__ then load the property initially as Object as we'd convert 499 // it anyway for replaceLocationPropertyPlaceholder. 500 if(identNode.isCompileTimePropertyName()) { 501 method.dynamicGet(Type.OBJECT, identNode.getSymbol().getName(), flags, identNode.isFunction(), false); 502 replaceCompileTimeProperty(); 503 } else { 504 dynamicGet(identNode.getSymbol().getName(), flags, identNode.isFunction(), false); 505 } 506 } 507 } 508 509 private class LoadFastScopeVar extends LoadScopeVar { 510 LoadFastScopeVar(final IdentNode identNode, final TypeBounds resultBounds, final int flags) { 511 super(identNode, resultBounds, flags); 512 } 513 514 @Override 515 void getProto() { 516 loadFastScopeProto(identNode.getSymbol(), false); 517 } 518 } 519 520 private MethodEmitter storeFastScopeVar(final Symbol symbol, final int flags) { 521 loadFastScopeProto(symbol, true); 522 method.dynamicSet(symbol.getName(), flags, false); 523 return method; 524 } 525 526 private int getScopeProtoDepth(final Block startingBlock, final Symbol symbol) { 527 //walk up the chain from starting block and when we bump into the current function boundary, add the external 528 //information. 529 final FunctionNode fn = lc.getCurrentFunction(); 530 final int externalDepth = compiler.getScriptFunctionData(fn.getId()).getExternalSymbolDepth(symbol.getName()); 531 532 //count the number of scopes from this place to the start of the function 533 534 final int internalDepth = FindScopeDepths.findInternalDepth(lc, fn, startingBlock, symbol); 535 final int scopesToStart = FindScopeDepths.findScopesToStart(lc, fn, startingBlock); 536 int depth = 0; 537 if (internalDepth == -1) { 538 depth = scopesToStart + externalDepth; 539 } else { 540 assert internalDepth <= scopesToStart; 541 depth = internalDepth; 542 } 543 544 return depth; 545 } 546 547 private void loadFastScopeProto(final Symbol symbol, final boolean swap) { 548 final int depth = getScopeProtoDepth(lc.getCurrentBlock(), symbol); 549 assert depth != -1 : "Couldn't find scope depth for symbol " + symbol.getName() + " in " + lc.getCurrentFunction(); 550 if (depth > 0) { 551 if (swap) { 552 method.swap(); 553 } 554 if (depth > 1) { 555 method.load(depth); 556 method.invoke(ScriptObject.GET_PROTO_DEPTH); 557 } else { 558 method.invoke(ScriptObject.GET_PROTO); 559 } 560 if (swap) { 561 method.swap(); 562 } 563 } 564 } 565 566 /** 567 * Generate code that loads this node to the stack, not constraining its type 568 * 569 * @param expr node to load 570 * 571 * @return the method emitter used 572 */ 573 private MethodEmitter loadExpressionUnbounded(final Expression expr) { 574 return loadExpression(expr, TypeBounds.UNBOUNDED); 575 } 576 577 private MethodEmitter loadExpressionAsObject(final Expression expr) { 578 return loadExpression(expr, TypeBounds.OBJECT); 579 } 580 581 MethodEmitter loadExpressionAsBoolean(final Expression expr) { 582 return loadExpression(expr, TypeBounds.BOOLEAN); 583 } 584 585 // Test whether conversion from source to target involves a call of ES 9.1 ToPrimitive 586 // with possible side effects from calling an object's toString or valueOf methods. 587 private static boolean noToPrimitiveConversion(final Type source, final Type target) { 588 // Object to boolean conversion does not cause ToPrimitive call 589 return source.isJSPrimitive() || !target.isJSPrimitive() || target.isBoolean(); 590 } 591 592 MethodEmitter loadBinaryOperands(final BinaryNode binaryNode) { 593 return loadBinaryOperands(binaryNode.lhs(), binaryNode.rhs(), TypeBounds.UNBOUNDED.notWiderThan(binaryNode.getWidestOperandType()), false, false); 594 } 595 596 private MethodEmitter loadBinaryOperands(final Expression lhs, final Expression rhs, final TypeBounds explicitOperandBounds, final boolean baseAlreadyOnStack, final boolean forceConversionSeparation) { 597 // ECMAScript 5.1 specification (sections 11.5-11.11 and 11.13) prescribes that when evaluating a binary 598 // expression "LEFT op RIGHT", the order of operations must be: LOAD LEFT, LOAD RIGHT, CONVERT LEFT, CONVERT 599 // RIGHT, EXECUTE OP. Unfortunately, doing it in this order defeats potential optimizations that arise when we 600 // can combine a LOAD with a CONVERT operation (e.g. use a dynamic getter with the conversion target type as its 601 // return value). What we do here is reorder LOAD RIGHT and CONVERT LEFT when possible; it is possible only when 602 // we can prove that executing CONVERT LEFT can't have a side effect that changes the value of LOAD RIGHT. 603 // Basically, if we know that either LEFT already is a primitive value, or does not have to be converted to 604 // a primitive value, or RIGHT is an expression that loads without side effects, then we can do the 605 // reordering and collapse LOAD/CONVERT into a single operation; otherwise we need to do the more costly 606 // separate operations to preserve specification semantics. 607 608 // Operands' load type should not be narrower than the narrowest of the individual operand types, nor narrower 609 // than the lower explicit bound, but it should also not be wider than 610 final Type lhsType = undefinedToNumber(lhs.getType()); 611 final Type rhsType = undefinedToNumber(rhs.getType()); 612 final Type narrowestOperandType = Type.narrowest(Type.widest(lhsType, rhsType), explicitOperandBounds.widest); 613 final TypeBounds operandBounds = explicitOperandBounds.notNarrowerThan(narrowestOperandType); 614 if (noToPrimitiveConversion(lhsType, explicitOperandBounds.widest) || rhs.isLocal()) { 615 // Can reorder. We might still need to separate conversion, but at least we can do it with reordering 616 if (forceConversionSeparation) { 617 // Can reorder, but can't move conversion into the operand as the operation depends on operands 618 // exact types for its overflow guarantees. E.g. with {L}{%I}expr1 {L}* {L}{%I}expr2 we are not allowed 619 // to merge {L}{%I} into {%L}, as that can cause subsequent overflows; test for JDK-8058610 contains 620 // concrete cases where this could happen. 621 final TypeBounds safeConvertBounds = TypeBounds.UNBOUNDED.notNarrowerThan(narrowestOperandType); 622 loadExpression(lhs, safeConvertBounds, baseAlreadyOnStack); 623 method.convert(operandBounds.within(method.peekType())); 624 loadExpression(rhs, safeConvertBounds, false); 625 method.convert(operandBounds.within(method.peekType())); 626 } else { 627 // Can reorder and move conversion into the operand. Combine load and convert into single operations. 628 loadExpression(lhs, operandBounds, baseAlreadyOnStack); 629 loadExpression(rhs, operandBounds, false); 630 } 631 } else { 632 // Can't reorder. Load and convert separately. 633 final TypeBounds safeConvertBounds = TypeBounds.UNBOUNDED.notNarrowerThan(narrowestOperandType); 634 loadExpression(lhs, safeConvertBounds, baseAlreadyOnStack); 635 final Type lhsLoadedType = method.peekType(); 636 loadExpression(rhs, safeConvertBounds, false); 637 final Type convertedLhsType = operandBounds.within(method.peekType()); 638 if (convertedLhsType != lhsLoadedType) { 639 // Do it conditionally, so that if conversion is a no-op we don't introduce a SWAP, SWAP. 640 method.swap().convert(convertedLhsType).swap(); 641 } 642 method.convert(operandBounds.within(method.peekType())); 643 } 644 assert Type.generic(method.peekType()) == operandBounds.narrowest; 645 assert Type.generic(method.peekType(1)) == operandBounds.narrowest; 646 647 return method; 648 } 649 650 /** 651 * Similar to {@link #loadBinaryOperands(BinaryNode)} but used specifically for loading operands of 652 * relational and equality comparison operators where at least one argument is non-object. (When both 653 * arguments are objects, we use {@link ScriptRuntime#EQ(Object, Object)}, {@link ScriptRuntime#LT(Object, Object)} 654 * etc. methods instead. Additionally, {@code ScriptRuntime} methods are used for strict (in)equality comparison 655 * of a boolean to anything that isn't a boolean.) This method handles the special case where one argument 656 * is an object and another is a primitive. Naively, these could also be delegated to {@code ScriptRuntime} methods 657 * by boxing the primitive. However, in all such cases the comparison is performed on numeric values, so it is 658 * possible to strength-reduce the operation by taking the number value of the object argument instead and 659 * comparing that to the primitive value ("primitive" will always be int, long, double, or boolean, and booleans 660 * compare as ints in these cases, so they're essentially numbers too). This method will emit code for loading 661 * arguments for such strength-reduced comparison. When both arguments are primitives, it just delegates to 662 * {@link #loadBinaryOperands(BinaryNode)}. 663 * 664 * @param cmp the comparison operation for which the operands need to be loaded on stack. 665 * @return the current method emitter. 666 */ 667 MethodEmitter loadComparisonOperands(final BinaryNode cmp) { 668 final Expression lhs = cmp.lhs(); 669 final Expression rhs = cmp.rhs(); 670 final Type lhsType = lhs.getType(); 671 final Type rhsType = rhs.getType(); 672 673 // Only used when not both are object, for that we have ScriptRuntime.LT etc. 674 assert !(lhsType.isObject() && rhsType.isObject()); 675 676 if (lhsType.isObject() || rhsType.isObject()) { 677 // We can reorder CONVERT LEFT and LOAD RIGHT only if either the left is a primitive, or the right 678 // is a local. This is more strict than loadBinaryNode reorder criteria, as it can allow JS primitive 679 // types too (notably: String is a JS primitive, but not a JVM primitive). We disallow String otherwise 680 // we would prematurely convert it to number when comparing to an optimistic expression, e.g. in 681 // "Hello" === String("Hello") the RHS starts out as an optimistic-int function call. If we allowed 682 // reordering, we'd end up with ToNumber("Hello") === {I%}String("Hello") that is obviously incorrect. 683 final boolean canReorder = lhsType.isPrimitive() || rhs.isLocal(); 684 // If reordering is allowed, and we're using a relational operator (that is, <, <=, >, >=) and not an 685 // (in)equality operator, then we encourage combining of LOAD and CONVERT into a single operation. 686 // This is because relational operators' semantics prescribes vanilla ToNumber() conversion, while 687 // (in)equality operators need the specialized JSType.toNumberFor[Strict]Equals. E.g. in the code snippet 688 // "i < obj.size" (where i is primitive and obj.size is statically an object), ".size" will thus be allowed 689 // to compile as: 690 // invokedynamic GET_PROPERTY:size(Object;)D 691 // instead of the more costly: 692 // invokedynamic GET_PROPERTY:size(Object;)Object 693 // invokestatic JSType.toNumber(Object)D 694 // Note also that even if this is allowed, we're only using it on operands that are non-optimistic, as 695 // otherwise the logic for determining effective optimistic-ness would turn an optimistic double return 696 // into a freely coercible one, which would be wrong. 697 final boolean canCombineLoadAndConvert = canReorder && cmp.isRelational(); 698 699 // LOAD LEFT 700 loadExpression(lhs, canCombineLoadAndConvert && !lhs.isOptimistic() ? TypeBounds.NUMBER : TypeBounds.UNBOUNDED); 701 702 final Type lhsLoadedType = method.peekType(); 703 final TokenType tt = cmp.tokenType(); 704 if (canReorder) { 705 // Can reorder CONVERT LEFT and LOAD RIGHT 706 emitObjectToNumberComparisonConversion(method, tt); 707 loadExpression(rhs, canCombineLoadAndConvert && !rhs.isOptimistic() ? TypeBounds.NUMBER : TypeBounds.UNBOUNDED); 708 } else { 709 // Can't reorder CONVERT LEFT and LOAD RIGHT 710 loadExpression(rhs, TypeBounds.UNBOUNDED); 711 if (lhsLoadedType != Type.NUMBER) { 712 method.swap(); 713 emitObjectToNumberComparisonConversion(method, tt); 714 method.swap(); 715 } 716 } 717 718 // CONVERT RIGHT 719 emitObjectToNumberComparisonConversion(method, tt); 720 return method; 721 } 722 // For primitive operands, just don't do anything special. 723 return loadBinaryOperands(cmp); 724 } 725 726 private static void emitObjectToNumberComparisonConversion(final MethodEmitter method, final TokenType tt) { 727 switch(tt) { 728 case EQ: 729 case NE: 730 if (method.peekType().isObject()) { 731 TO_NUMBER_FOR_EQ.invoke(method); 732 return; 733 } 734 break; 735 case EQ_STRICT: 736 case NE_STRICT: 737 if (method.peekType().isObject()) { 738 TO_NUMBER_FOR_STRICT_EQ.invoke(method); 739 return; 740 } 741 break; 742 default: 743 break; 744 } 745 method.convert(Type.NUMBER); 746 } 747 748 private static Type undefinedToNumber(final Type type) { 749 return type == Type.UNDEFINED ? Type.NUMBER : type; 750 } 751 752 private static final class TypeBounds { 753 final Type narrowest; 754 final Type widest; 755 756 static final TypeBounds UNBOUNDED = new TypeBounds(Type.UNKNOWN, Type.OBJECT); 757 static final TypeBounds INT = exact(Type.INT); 758 static final TypeBounds NUMBER = exact(Type.NUMBER); 759 static final TypeBounds OBJECT = exact(Type.OBJECT); 760 static final TypeBounds BOOLEAN = exact(Type.BOOLEAN); 761 762 static TypeBounds exact(final Type type) { 763 return new TypeBounds(type, type); 764 } 765 766 TypeBounds(final Type narrowest, final Type widest) { 767 assert widest != null && widest != Type.UNDEFINED && widest != Type.UNKNOWN : widest; 768 assert narrowest != null && narrowest != Type.UNDEFINED : narrowest; 769 assert !narrowest.widerThan(widest) : narrowest + " wider than " + widest; 770 assert !widest.narrowerThan(narrowest); 771 this.narrowest = Type.generic(narrowest); 772 this.widest = Type.generic(widest); 773 } 774 775 TypeBounds notNarrowerThan(final Type type) { 776 return maybeNew(Type.narrowest(Type.widest(narrowest, type), widest), widest); 777 } 778 779 TypeBounds notWiderThan(final Type type) { 780 return maybeNew(Type.narrowest(narrowest, type), Type.narrowest(widest, type)); 781 } 782 783 boolean canBeNarrowerThan(final Type type) { 784 return narrowest.narrowerThan(type); 785 } 786 787 TypeBounds maybeNew(final Type newNarrowest, final Type newWidest) { 788 if(newNarrowest == narrowest && newWidest == widest) { 789 return this; 790 } 791 return new TypeBounds(newNarrowest, newWidest); 792 } 793 794 TypeBounds booleanToInt() { 795 return maybeNew(CodeGenerator.booleanToInt(narrowest), CodeGenerator.booleanToInt(widest)); 796 } 797 798 TypeBounds objectToNumber() { 799 return maybeNew(CodeGenerator.objectToNumber(narrowest), CodeGenerator.objectToNumber(widest)); 800 } 801 802 Type within(final Type type) { 803 if(type.narrowerThan(narrowest)) { 804 return narrowest; 805 } 806 if(type.widerThan(widest)) { 807 return widest; 808 } 809 return type; 810 } 811 812 @Override 813 public String toString() { 814 return "[" + narrowest + ", " + widest + "]"; 815 } 816 } 817 818 private static Type booleanToInt(final Type t) { 819 return t == Type.BOOLEAN ? Type.INT : t; 820 } 821 822 private static Type objectToNumber(final Type t) { 823 return t.isObject() ? Type.NUMBER : t; 824 } 825 826 MethodEmitter loadExpressionAsType(final Expression expr, final Type type) { 827 if(type == Type.BOOLEAN) { 828 return loadExpressionAsBoolean(expr); 829 } else if(type == Type.UNDEFINED) { 830 assert expr.getType() == Type.UNDEFINED; 831 return loadExpressionAsObject(expr); 832 } 833 // having no upper bound preserves semantics of optimistic operations in the expression (by not having them 834 // converted early) and then applies explicit conversion afterwards. 835 return loadExpression(expr, TypeBounds.UNBOUNDED.notNarrowerThan(type)).convert(type); 836 } 837 838 private MethodEmitter loadExpression(final Expression expr, final TypeBounds resultBounds) { 839 return loadExpression(expr, resultBounds, false); 840 } 841 842 /** 843 * Emits code for evaluating an expression and leaving its value on top of the stack, narrowing or widening it if 844 * necessary. 845 * @param expr the expression to load 846 * @param resultBounds the incoming type bounds. The value on the top of the stack is guaranteed to not be of narrower 847 * type than the narrowest bound, or wider type than the widest bound after it is loaded. 848 * @param baseAlreadyOnStack true if the base of an access or index node is already on the stack. Used to avoid 849 * double evaluation of bases in self-assignment expressions to access and index nodes. {@code Type.OBJECT} is used 850 * to indicate the widest possible type. 851 * @return the method emitter 852 */ 853 private MethodEmitter loadExpression(final Expression expr, final TypeBounds resultBounds, final boolean baseAlreadyOnStack) { 854 855 /* 856 * The load may be of type IdentNode, e.g. "x", AccessNode, e.g. "x.y" 857 * or IndexNode e.g. "x[y]". Both AccessNodes and IndexNodes are 858 * BaseNodes and the logic for loading the base object is reused 859 */ 860 final CodeGenerator codegen = this; 861 862 final boolean isCurrentDiscard = codegen.lc.isCurrentDiscard(expr); 863 expr.accept(new NodeOperatorVisitor<LexicalContext>(new LexicalContext()) { 864 @Override 865 public boolean enterIdentNode(final IdentNode identNode) { 866 loadIdent(identNode, resultBounds); 867 return false; 868 } 869 870 @Override 871 public boolean enterAccessNode(final AccessNode accessNode) { 872 new OptimisticOperation(accessNode, resultBounds) { 873 @Override 874 void loadStack() { 875 if (!baseAlreadyOnStack) { 876 loadExpressionAsObject(accessNode.getBase()); 877 } 878 assert method.peekType().isObject(); 879 } 880 @Override 881 void consumeStack() { 882 final int flags = getCallSiteFlags(); 883 dynamicGet(accessNode.getProperty(), flags, accessNode.isFunction(), accessNode.isIndex()); 884 } 885 }.emit(baseAlreadyOnStack ? 1 : 0); 886 return false; 887 } 888 889 @Override 890 public boolean enterIndexNode(final IndexNode indexNode) { 891 new OptimisticOperation(indexNode, resultBounds) { 892 @Override 893 void loadStack() { 894 if (!baseAlreadyOnStack) { 895 loadExpressionAsObject(indexNode.getBase()); 896 loadExpressionUnbounded(indexNode.getIndex()); 897 } 898 } 899 @Override 900 void consumeStack() { 901 final int flags = getCallSiteFlags(); 902 dynamicGetIndex(flags, indexNode.isFunction()); 903 } 904 }.emit(baseAlreadyOnStack ? 2 : 0); 905 return false; 906 } 907 908 @Override 909 public boolean enterFunctionNode(final FunctionNode functionNode) { 910 // function nodes will always leave a constructed function object on stack, no need to load the symbol 911 // separately as in enterDefault() 912 lc.pop(functionNode); 913 functionNode.accept(codegen); 914 // NOTE: functionNode.accept() will produce a different FunctionNode that we discard. This incidentally 915 // doesn't cause problems as we're never touching FunctionNode again after it's visited here - codegen 916 // is the last element in the compilation pipeline, the AST it produces is not used externally. So, we 917 // re-push the original functionNode. 918 lc.push(functionNode); 919 return false; 920 } 921 922 @Override 923 public boolean enterASSIGN(final BinaryNode binaryNode) { 924 checkAssignTarget(binaryNode.lhs()); 925 loadASSIGN(binaryNode); 926 return false; 927 } 928 929 @Override 930 public boolean enterASSIGN_ADD(final BinaryNode binaryNode) { 931 checkAssignTarget(binaryNode.lhs()); 932 loadASSIGN_ADD(binaryNode); 933 return false; 934 } 935 936 @Override 937 public boolean enterASSIGN_BIT_AND(final BinaryNode binaryNode) { 938 checkAssignTarget(binaryNode.lhs()); 939 loadASSIGN_BIT_AND(binaryNode); 940 return false; 941 } 942 943 @Override 944 public boolean enterASSIGN_BIT_OR(final BinaryNode binaryNode) { 945 checkAssignTarget(binaryNode.lhs()); 946 loadASSIGN_BIT_OR(binaryNode); 947 return false; 948 } 949 950 @Override 951 public boolean enterASSIGN_BIT_XOR(final BinaryNode binaryNode) { 952 checkAssignTarget(binaryNode.lhs()); 953 loadASSIGN_BIT_XOR(binaryNode); 954 return false; 955 } 956 957 @Override 958 public boolean enterASSIGN_DIV(final BinaryNode binaryNode) { 959 checkAssignTarget(binaryNode.lhs()); 960 loadASSIGN_DIV(binaryNode); 961 return false; 962 } 963 964 @Override 965 public boolean enterASSIGN_MOD(final BinaryNode binaryNode) { 966 checkAssignTarget(binaryNode.lhs()); 967 loadASSIGN_MOD(binaryNode); 968 return false; 969 } 970 971 @Override 972 public boolean enterASSIGN_MUL(final BinaryNode binaryNode) { 973 checkAssignTarget(binaryNode.lhs()); 974 loadASSIGN_MUL(binaryNode); 975 return false; 976 } 977 978 @Override 979 public boolean enterASSIGN_SAR(final BinaryNode binaryNode) { 980 checkAssignTarget(binaryNode.lhs()); 981 loadASSIGN_SAR(binaryNode); 982 return false; 983 } 984 985 @Override 986 public boolean enterASSIGN_SHL(final BinaryNode binaryNode) { 987 checkAssignTarget(binaryNode.lhs()); 988 loadASSIGN_SHL(binaryNode); 989 return false; 990 } 991 992 @Override 993 public boolean enterASSIGN_SHR(final BinaryNode binaryNode) { 994 checkAssignTarget(binaryNode.lhs()); 995 loadASSIGN_SHR(binaryNode); 996 return false; 997 } 998 999 @Override 1000 public boolean enterASSIGN_SUB(final BinaryNode binaryNode) { 1001 checkAssignTarget(binaryNode.lhs()); 1002 loadASSIGN_SUB(binaryNode); 1003 return false; 1004 } 1005 1006 @Override 1007 public boolean enterCallNode(final CallNode callNode) { 1008 return loadCallNode(callNode, resultBounds); 1009 } 1010 1011 @Override 1012 public boolean enterLiteralNode(final LiteralNode<?> literalNode) { 1013 loadLiteral(literalNode, resultBounds); 1014 return false; 1015 } 1016 1017 @Override 1018 public boolean enterTernaryNode(final TernaryNode ternaryNode) { 1019 loadTernaryNode(ternaryNode, resultBounds); 1020 return false; 1021 } 1022 1023 @Override 1024 public boolean enterADD(final BinaryNode binaryNode) { 1025 loadADD(binaryNode, resultBounds); 1026 return false; 1027 } 1028 1029 @Override 1030 public boolean enterSUB(final UnaryNode unaryNode) { 1031 loadSUB(unaryNode, resultBounds); 1032 return false; 1033 } 1034 1035 @Override 1036 public boolean enterSUB(final BinaryNode binaryNode) { 1037 loadSUB(binaryNode, resultBounds); 1038 return false; 1039 } 1040 1041 @Override 1042 public boolean enterMUL(final BinaryNode binaryNode) { 1043 loadMUL(binaryNode, resultBounds); 1044 return false; 1045 } 1046 1047 @Override 1048 public boolean enterDIV(final BinaryNode binaryNode) { 1049 loadDIV(binaryNode, resultBounds); 1050 return false; 1051 } 1052 1053 @Override 1054 public boolean enterMOD(final BinaryNode binaryNode) { 1055 loadMOD(binaryNode, resultBounds); 1056 return false; 1057 } 1058 1059 @Override 1060 public boolean enterSAR(final BinaryNode binaryNode) { 1061 loadSAR(binaryNode); 1062 return false; 1063 } 1064 1065 @Override 1066 public boolean enterSHL(final BinaryNode binaryNode) { 1067 loadSHL(binaryNode); 1068 return false; 1069 } 1070 1071 @Override 1072 public boolean enterSHR(final BinaryNode binaryNode) { 1073 loadSHR(binaryNode); 1074 return false; 1075 } 1076 1077 @Override 1078 public boolean enterCOMMALEFT(final BinaryNode binaryNode) { 1079 loadCOMMALEFT(binaryNode, resultBounds); 1080 return false; 1081 } 1082 1083 @Override 1084 public boolean enterCOMMARIGHT(final BinaryNode binaryNode) { 1085 loadCOMMARIGHT(binaryNode, resultBounds); 1086 return false; 1087 } 1088 1089 @Override 1090 public boolean enterAND(final BinaryNode binaryNode) { 1091 loadAND_OR(binaryNode, resultBounds, true); 1092 return false; 1093 } 1094 1095 @Override 1096 public boolean enterOR(final BinaryNode binaryNode) { 1097 loadAND_OR(binaryNode, resultBounds, false); 1098 return false; 1099 } 1100 1101 @Override 1102 public boolean enterNOT(final UnaryNode unaryNode) { 1103 loadNOT(unaryNode); 1104 return false; 1105 } 1106 1107 @Override 1108 public boolean enterADD(final UnaryNode unaryNode) { 1109 loadADD(unaryNode, resultBounds); 1110 return false; 1111 } 1112 1113 @Override 1114 public boolean enterBIT_NOT(final UnaryNode unaryNode) { 1115 loadBIT_NOT(unaryNode); 1116 return false; 1117 } 1118 1119 @Override 1120 public boolean enterBIT_AND(final BinaryNode binaryNode) { 1121 loadBIT_AND(binaryNode); 1122 return false; 1123 } 1124 1125 @Override 1126 public boolean enterBIT_OR(final BinaryNode binaryNode) { 1127 loadBIT_OR(binaryNode); 1128 return false; 1129 } 1130 1131 @Override 1132 public boolean enterBIT_XOR(final BinaryNode binaryNode) { 1133 loadBIT_XOR(binaryNode); 1134 return false; 1135 } 1136 1137 @Override 1138 public boolean enterVOID(final UnaryNode unaryNode) { 1139 loadVOID(unaryNode, resultBounds); 1140 return false; 1141 } 1142 1143 @Override 1144 public boolean enterEQ(final BinaryNode binaryNode) { 1145 loadCmp(binaryNode, Condition.EQ); 1146 return false; 1147 } 1148 1149 @Override 1150 public boolean enterEQ_STRICT(final BinaryNode binaryNode) { 1151 loadCmp(binaryNode, Condition.EQ); 1152 return false; 1153 } 1154 1155 @Override 1156 public boolean enterGE(final BinaryNode binaryNode) { 1157 loadCmp(binaryNode, Condition.GE); 1158 return false; 1159 } 1160 1161 @Override 1162 public boolean enterGT(final BinaryNode binaryNode) { 1163 loadCmp(binaryNode, Condition.GT); 1164 return false; 1165 } 1166 1167 @Override 1168 public boolean enterLE(final BinaryNode binaryNode) { 1169 loadCmp(binaryNode, Condition.LE); 1170 return false; 1171 } 1172 1173 @Override 1174 public boolean enterLT(final BinaryNode binaryNode) { 1175 loadCmp(binaryNode, Condition.LT); 1176 return false; 1177 } 1178 1179 @Override 1180 public boolean enterNE(final BinaryNode binaryNode) { 1181 loadCmp(binaryNode, Condition.NE); 1182 return false; 1183 } 1184 1185 @Override 1186 public boolean enterNE_STRICT(final BinaryNode binaryNode) { 1187 loadCmp(binaryNode, Condition.NE); 1188 return false; 1189 } 1190 1191 @Override 1192 public boolean enterObjectNode(final ObjectNode objectNode) { 1193 loadObjectNode(objectNode); 1194 return false; 1195 } 1196 1197 @Override 1198 public boolean enterRuntimeNode(final RuntimeNode runtimeNode) { 1199 loadRuntimeNode(runtimeNode); 1200 return false; 1201 } 1202 1203 @Override 1204 public boolean enterNEW(final UnaryNode unaryNode) { 1205 loadNEW(unaryNode); 1206 return false; 1207 } 1208 1209 @Override 1210 public boolean enterDECINC(final UnaryNode unaryNode) { 1211 checkAssignTarget(unaryNode.getExpression()); 1212 loadDECINC(unaryNode); 1213 return false; 1214 } 1215 1216 @Override 1217 public boolean enterJoinPredecessorExpression(final JoinPredecessorExpression joinExpr) { 1218 loadMaybeDiscard(joinExpr, joinExpr.getExpression(), resultBounds); 1219 return false; 1220 } 1221 1222 @Override 1223 public boolean enterGetSplitState(final GetSplitState getSplitState) { 1224 method.loadScope(); 1225 method.invoke(Scope.GET_SPLIT_STATE); 1226 return false; 1227 } 1228 1229 @Override 1230 public boolean enterDefault(final Node otherNode) { 1231 // Must have handled all expressions that can legally be encountered. 1232 throw new AssertionError(otherNode.getClass().getName()); 1233 } 1234 }); 1235 if(!isCurrentDiscard) { 1236 coerceStackTop(resultBounds); 1237 } 1238 return method; 1239 } 1240 1241 private MethodEmitter coerceStackTop(final TypeBounds typeBounds) { 1242 return method.convert(typeBounds.within(method.peekType())); 1243 } 1244 1245 /** 1246 * Closes any still open entries for this block's local variables in the bytecode local variable table. 1247 * 1248 * @param block block containing symbols. 1249 */ 1250 private void closeBlockVariables(final Block block) { 1251 for (final Symbol symbol : block.getSymbols()) { 1252 if (symbol.isBytecodeLocal()) { 1253 method.closeLocalVariable(symbol, block.getBreakLabel()); 1254 } 1255 } 1256 } 1257 1258 @Override 1259 public boolean enterBlock(final Block block) { 1260 final Label entryLabel = block.getEntryLabel(); 1261 if (entryLabel.isBreakTarget()) { 1262 // Entry label is a break target only for an inlined finally block. 1263 assert !method.isReachable(); 1264 method.breakLabel(entryLabel, lc.getUsedSlotCount()); 1265 } else { 1266 method.label(entryLabel); 1267 } 1268 if(!method.isReachable()) { 1269 return false; 1270 } 1271 if(lc.isFunctionBody() && emittedMethods.contains(lc.getCurrentFunction().getName())) { 1272 return false; 1273 } 1274 initLocals(block); 1275 1276 assert lc.getUsedSlotCount() == method.getFirstTemp(); 1277 return true; 1278 } 1279 1280 boolean useOptimisticTypes() { 1281 return !lc.inSplitNode() && compiler.useOptimisticTypes(); 1282 } 1283 1284 @Override 1285 public Node leaveBlock(final Block block) { 1286 popBlockScope(block); 1287 method.beforeJoinPoint(block); 1288 1289 closeBlockVariables(block); 1290 lc.releaseSlots(); 1291 assert !method.isReachable() || (lc.isFunctionBody() ? 0 : lc.getUsedSlotCount()) == method.getFirstTemp() : 1292 "reachable="+method.isReachable() + 1293 " isFunctionBody=" + lc.isFunctionBody() + 1294 " usedSlotCount=" + lc.getUsedSlotCount() + 1295 " firstTemp=" + method.getFirstTemp(); 1296 1297 return block; 1298 } 1299 1300 private void popBlockScope(final Block block) { 1301 final Label breakLabel = block.getBreakLabel(); 1302 1303 if (block.providesScopeCreator()) { 1304 scopeObjectCreators.pop(); 1305 } 1306 if(!block.needsScope() || lc.isFunctionBody()) { 1307 emitBlockBreakLabel(breakLabel); 1308 return; 1309 } 1310 1311 final Label beginTryLabel = scopeEntryLabels.pop(); 1312 final Label recoveryLabel = new Label("block_popscope_catch"); 1313 emitBlockBreakLabel(breakLabel); 1314 final boolean bodyCanThrow = breakLabel.isAfter(beginTryLabel); 1315 if(bodyCanThrow) { 1316 method._try(beginTryLabel, breakLabel, recoveryLabel); 1317 } 1318 1319 Label afterCatchLabel = null; 1320 1321 if(method.isReachable()) { 1322 popScope(); 1323 if(bodyCanThrow) { 1324 afterCatchLabel = new Label("block_after_catch"); 1325 method._goto(afterCatchLabel); 1326 } 1327 } 1328 1329 if(bodyCanThrow) { 1330 assert !method.isReachable(); 1331 method._catch(recoveryLabel); 1332 popScopeException(); 1333 method.athrow(); 1334 } 1335 if(afterCatchLabel != null) { 1336 method.label(afterCatchLabel); 1337 } 1338 } 1339 1340 private void emitBlockBreakLabel(final Label breakLabel) { 1341 // TODO: this is totally backwards. Block should not be breakable, LabelNode should be breakable. 1342 final LabelNode labelNode = lc.getCurrentBlockLabelNode(); 1343 if(labelNode != null) { 1344 // Only have conversions if we're reachable 1345 assert labelNode.getLocalVariableConversion() == null || method.isReachable(); 1346 method.beforeJoinPoint(labelNode); 1347 method.breakLabel(breakLabel, labeledBlockBreakLiveLocals.pop()); 1348 } else { 1349 method.label(breakLabel); 1350 } 1351 } 1352 1353 private void popScope() { 1354 popScopes(1); 1355 } 1356 1357 /** 1358 * Pop scope as part of an exception handler. Similar to {@code popScope()} but also takes care of adjusting the 1359 * number of scopes that needs to be popped in case a rest-of continuation handler encounters an exception while 1360 * performing a ToPrimitive conversion. 1361 */ 1362 private void popScopeException() { 1363 popScope(); 1364 final ContinuationInfo ci = getContinuationInfo(); 1365 if(ci != null) { 1366 final Label catchLabel = ci.catchLabel; 1367 if(catchLabel != METHOD_BOUNDARY && catchLabel == catchLabels.peek()) { 1368 ++ci.exceptionScopePops; 1369 } 1370 } 1371 } 1372 1373 private void popScopesUntil(final LexicalContextNode until) { 1374 popScopes(lc.getScopeNestingLevelTo(until)); 1375 } 1376 1377 private void popScopes(final int count) { 1378 if(count == 0) { 1379 return; 1380 } 1381 assert count > 0; // together with count == 0 check, asserts nonnegative count 1382 if (!method.hasScope()) { 1383 // We can sometimes invoke this method even if the method has no slot for the scope object. Typical example: 1384 // for(;;) { with({}) { break; } }. WithNode normally creates a scope, but if it uses no identifiers and 1385 // nothing else forces creation of a scope in the method, we just won't have the :scope local variable. 1386 return; 1387 } 1388 method.loadCompilerConstant(SCOPE); 1389 if (count > 1) { 1390 method.load(count); 1391 method.invoke(ScriptObject.GET_PROTO_DEPTH); 1392 } else { 1393 method.invoke(ScriptObject.GET_PROTO); 1394 } 1395 method.storeCompilerConstant(SCOPE); 1396 } 1397 1398 @Override 1399 public boolean enterBreakNode(final BreakNode breakNode) { 1400 return enterJumpStatement(breakNode); 1401 } 1402 1403 @Override 1404 public boolean enterJumpToInlinedFinally(final JumpToInlinedFinally jumpToInlinedFinally) { 1405 return enterJumpStatement(jumpToInlinedFinally); 1406 } 1407 1408 private boolean enterJumpStatement(final JumpStatement jump) { 1409 if(!method.isReachable()) { 1410 return false; 1411 } 1412 enterStatement(jump); 1413 1414 method.beforeJoinPoint(jump); 1415 popScopesUntil(jump.getPopScopeLimit(lc)); 1416 final Label targetLabel = jump.getTargetLabel(lc); 1417 targetLabel.markAsBreakTarget(); 1418 method._goto(targetLabel); 1419 1420 return false; 1421 } 1422 1423 private int loadArgs(final List<Expression> args) { 1424 final int argCount = args.size(); 1425 // arg have already been converted to objects here. 1426 if (argCount > LinkerCallSite.ARGLIMIT) { 1427 loadArgsArray(args); 1428 return 1; 1429 } 1430 1431 for (final Expression arg : args) { 1432 assert arg != null; 1433 loadExpressionUnbounded(arg); 1434 } 1435 return argCount; 1436 } 1437 1438 private boolean loadCallNode(final CallNode callNode, final TypeBounds resultBounds) { 1439 lineNumber(callNode.getLineNumber()); 1440 1441 final List<Expression> args = callNode.getArgs(); 1442 final Expression function = callNode.getFunction(); 1443 final Block currentBlock = lc.getCurrentBlock(); 1444 final CodeGeneratorLexicalContext codegenLexicalContext = lc; 1445 1446 function.accept(new SimpleNodeVisitor() { 1447 private MethodEmitter sharedScopeCall(final IdentNode identNode, final int flags) { 1448 final Symbol symbol = identNode.getSymbol(); 1449 final boolean isFastScope = isFastScope(symbol); 1450 new OptimisticOperation(callNode, resultBounds) { 1451 @Override 1452 void loadStack() { 1453 method.loadCompilerConstant(SCOPE); 1454 if (isFastScope) { 1455 method.load(getScopeProtoDepth(currentBlock, symbol)); 1456 } else { 1457 method.load(-1); // Bypass fast-scope code in shared callsite 1458 } 1459 loadArgs(args); 1460 } 1461 @Override 1462 void consumeStack() { 1463 final Type[] paramTypes = method.getTypesFromStack(args.size()); 1464 // We have trouble finding e.g. in Type.typeFor(asm.Type) because it can't see the Context class 1465 // loader, so we need to weaken reference signatures to Object. 1466 for(int i = 0; i < paramTypes.length; ++i) { 1467 paramTypes[i] = Type.generic(paramTypes[i]); 1468 } 1469 // As shared scope calls are only used in non-optimistic compilation, we switch from using 1470 // TypeBounds to just a single definitive type, resultBounds.widest. 1471 final SharedScopeCall scopeCall = codegenLexicalContext.getScopeCall(unit, symbol, 1472 identNode.getType(), resultBounds.widest, paramTypes, flags); 1473 scopeCall.generateInvoke(method); 1474 } 1475 }.emit(); 1476 return method; 1477 } 1478 1479 private void scopeCall(final IdentNode ident, final int flags) { 1480 new OptimisticOperation(callNode, resultBounds) { 1481 int argsCount; 1482 @Override 1483 void loadStack() { 1484 loadExpressionAsObject(ident); // foo() makes no sense if foo == 3 1485 // ScriptFunction will see CALLSITE_SCOPE and will bind scope accordingly. 1486 method.loadUndefined(Type.OBJECT); //the 'this' 1487 argsCount = loadArgs(args); 1488 } 1489 @Override 1490 void consumeStack() { 1491 dynamicCall(2 + argsCount, flags, ident.getName()); 1492 } 1493 }.emit(); 1494 } 1495 1496 private void evalCall(final IdentNode ident, final int flags) { 1497 final Label invoke_direct_eval = new Label("invoke_direct_eval"); 1498 final Label is_not_eval = new Label("is_not_eval"); 1499 final Label eval_done = new Label("eval_done"); 1500 1501 new OptimisticOperation(callNode, resultBounds) { 1502 int argsCount; 1503 @Override 1504 void loadStack() { 1505 /* 1506 * We want to load 'eval' to check if it is indeed global builtin eval. 1507 * If this eval call is inside a 'with' statement, GET_METHOD_PROPERTY 1508 * would be generated if ident is a "isFunction". But, that would result in a 1509 * bound function from WithObject. We don't want that as bound function as that 1510 * won't be detected as builtin eval. So, we make ident as "not a function" which 1511 * results in GET_PROPERTY being generated and so WithObject 1512 * would return unbounded eval function. 1513 * 1514 * Example: 1515 * 1516 * var global = this; 1517 * function func() { 1518 * with({ eval: global.eval) { eval("var x = 10;") } 1519 * } 1520 */ 1521 loadExpressionAsObject(ident.setIsNotFunction()); // Type.OBJECT as foo() makes no sense if foo == 3 1522 globalIsEval(); 1523 method.ifeq(is_not_eval); 1524 1525 // Load up self (scope). 1526 method.loadCompilerConstant(SCOPE); 1527 final List<Expression> evalArgs = callNode.getEvalArgs().getArgs(); 1528 // load evaluated code 1529 loadExpressionAsObject(evalArgs.get(0)); 1530 // load second and subsequent args for side-effect 1531 final int numArgs = evalArgs.size(); 1532 for (int i = 1; i < numArgs; i++) { 1533 loadAndDiscard(evalArgs.get(i)); 1534 } 1535 method._goto(invoke_direct_eval); 1536 1537 method.label(is_not_eval); 1538 // load this time but with GET_METHOD_PROPERTY 1539 loadExpressionAsObject(ident); // Type.OBJECT as foo() makes no sense if foo == 3 1540 // This is some scope 'eval' or global eval replaced by user 1541 // but not the built-in ECMAScript 'eval' function call 1542 method.loadNull(); 1543 argsCount = loadArgs(callNode.getArgs()); 1544 } 1545 1546 @Override 1547 void consumeStack() { 1548 // Ordinary call 1549 dynamicCall(2 + argsCount, flags, "eval"); 1550 method._goto(eval_done); 1551 1552 method.label(invoke_direct_eval); 1553 // Special/extra 'eval' arguments. These can be loaded late (in consumeStack) as we know none of 1554 // them can ever be optimistic. 1555 method.loadCompilerConstant(THIS); 1556 method.load(callNode.getEvalArgs().getLocation()); 1557 method.load(CodeGenerator.this.lc.getCurrentFunction().isStrict()); 1558 // direct call to Global.directEval 1559 globalDirectEval(); 1560 convertOptimisticReturnValue(); 1561 coerceStackTop(resultBounds); 1562 } 1563 }.emit(); 1564 1565 method.label(eval_done); 1566 } 1567 1568 @Override 1569 public boolean enterIdentNode(final IdentNode node) { 1570 final Symbol symbol = node.getSymbol(); 1571 1572 if (symbol.isScope()) { 1573 final int flags = getScopeCallSiteFlags(symbol); 1574 final int useCount = symbol.getUseCount(); 1575 1576 // Threshold for generating shared scope callsite is lower for fast scope symbols because we know 1577 // we can dial in the correct scope. However, we also need to enable it for non-fast scopes to 1578 // support huge scripts like mandreel.js. 1579 if (callNode.isEval()) { 1580 evalCall(node, flags); 1581 } else if (useCount <= SharedScopeCall.FAST_SCOPE_CALL_THRESHOLD 1582 || !isFastScope(symbol) && useCount <= SharedScopeCall.SLOW_SCOPE_CALL_THRESHOLD 1583 || CodeGenerator.this.lc.inDynamicScope() 1584 || callNode.isOptimistic()) { 1585 scopeCall(node, flags); 1586 } else { 1587 sharedScopeCall(node, flags); 1588 } 1589 assert method.peekType().equals(resultBounds.within(callNode.getType())) : method.peekType() + " != " + resultBounds + "(" + callNode.getType() + ")"; 1590 } else { 1591 enterDefault(node); 1592 } 1593 1594 return false; 1595 } 1596 1597 @Override 1598 public boolean enterAccessNode(final AccessNode node) { 1599 //check if this is an apply to call node. only real applies, that haven't been 1600 //shadowed from their way to the global scope counts 1601 1602 //call nodes have program points. 1603 1604 final int flags = getCallSiteFlags() | (callNode.isApplyToCall() ? CALLSITE_APPLY_TO_CALL : 0); 1605 1606 new OptimisticOperation(callNode, resultBounds) { 1607 int argCount; 1608 @Override 1609 void loadStack() { 1610 loadExpressionAsObject(node.getBase()); 1611 method.dup(); 1612 // NOTE: not using a nested OptimisticOperation on this dynamicGet, as we expect to get back 1613 // a callable object. Nobody in their right mind would optimistically type this call site. 1614 assert !node.isOptimistic(); 1615 method.dynamicGet(node.getType(), node.getProperty(), flags, true, node.isIndex()); 1616 method.swap(); 1617 argCount = loadArgs(args); 1618 } 1619 @Override 1620 void consumeStack() { 1621 dynamicCall(2 + argCount, flags, node.toString(false)); 1622 } 1623 }.emit(); 1624 1625 return false; 1626 } 1627 1628 @Override 1629 public boolean enterFunctionNode(final FunctionNode origCallee) { 1630 new OptimisticOperation(callNode, resultBounds) { 1631 FunctionNode callee; 1632 int argsCount; 1633 @Override 1634 void loadStack() { 1635 callee = (FunctionNode)origCallee.accept(CodeGenerator.this); 1636 if (callee.isStrict()) { // "this" is undefined 1637 method.loadUndefined(Type.OBJECT); 1638 } else { // get global from scope (which is the self) 1639 globalInstance(); 1640 } 1641 argsCount = loadArgs(args); 1642 } 1643 1644 @Override 1645 void consumeStack() { 1646 dynamicCall(2 + argsCount, getCallSiteFlags(), null); 1647 } 1648 }.emit(); 1649 return false; 1650 } 1651 1652 @Override 1653 public boolean enterIndexNode(final IndexNode node) { 1654 new OptimisticOperation(callNode, resultBounds) { 1655 int argsCount; 1656 @Override 1657 void loadStack() { 1658 loadExpressionAsObject(node.getBase()); 1659 method.dup(); 1660 final Type indexType = node.getIndex().getType(); 1661 if (indexType.isObject() || indexType.isBoolean()) { 1662 loadExpressionAsObject(node.getIndex()); //TODO boolean 1663 } else { 1664 loadExpressionUnbounded(node.getIndex()); 1665 } 1666 // NOTE: not using a nested OptimisticOperation on this dynamicGetIndex, as we expect to get 1667 // back a callable object. Nobody in their right mind would optimistically type this call site. 1668 assert !node.isOptimistic(); 1669 method.dynamicGetIndex(node.getType(), getCallSiteFlags(), true); 1670 method.swap(); 1671 argsCount = loadArgs(args); 1672 } 1673 @Override 1674 void consumeStack() { 1675 dynamicCall(2 + argsCount, getCallSiteFlags(), node.toString(false)); 1676 } 1677 }.emit(); 1678 return false; 1679 } 1680 1681 @Override 1682 protected boolean enterDefault(final Node node) { 1683 new OptimisticOperation(callNode, resultBounds) { 1684 int argsCount; 1685 @Override 1686 void loadStack() { 1687 // Load up function. 1688 loadExpressionAsObject(function); //TODO, e.g. booleans can be used as functions 1689 method.loadUndefined(Type.OBJECT); // ScriptFunction will figure out the correct this when it sees CALLSITE_SCOPE 1690 argsCount = loadArgs(args); 1691 } 1692 @Override 1693 void consumeStack() { 1694 final int flags = getCallSiteFlags() | CALLSITE_SCOPE; 1695 dynamicCall(2 + argsCount, flags, node.toString(false)); 1696 } 1697 }.emit(); 1698 return false; 1699 } 1700 }); 1701 1702 return false; 1703 } 1704 1705 /** 1706 * Returns the flags with optimistic flag and program point removed. 1707 * @param flags the flags that need optimism stripped from them. 1708 * @return flags without optimism 1709 */ 1710 static int nonOptimisticFlags(final int flags) { 1711 return flags & ~(CALLSITE_OPTIMISTIC | -1 << CALLSITE_PROGRAM_POINT_SHIFT); 1712 } 1713 1714 @Override 1715 public boolean enterContinueNode(final ContinueNode continueNode) { 1716 return enterJumpStatement(continueNode); 1717 } 1718 1719 @Override 1720 public boolean enterEmptyNode(final EmptyNode emptyNode) { 1721 // Don't even record the line number, it's irrelevant as there's no code. 1722 return false; 1723 } 1724 1725 @Override 1726 public boolean enterExpressionStatement(final ExpressionStatement expressionStatement) { 1727 if(!method.isReachable()) { 1728 return false; 1729 } 1730 enterStatement(expressionStatement); 1731 1732 loadAndDiscard(expressionStatement.getExpression()); 1733 assert method.getStackSize() == 0 : "stack not empty in " + expressionStatement; 1734 1735 return false; 1736 } 1737 1738 @Override 1739 public boolean enterBlockStatement(final BlockStatement blockStatement) { 1740 if(!method.isReachable()) { 1741 return false; 1742 } 1743 enterStatement(blockStatement); 1744 1745 blockStatement.getBlock().accept(this); 1746 1747 return false; 1748 } 1749 1750 @Override 1751 public boolean enterForNode(final ForNode forNode) { 1752 if(!method.isReachable()) { 1753 return false; 1754 } 1755 enterStatement(forNode); 1756 if (forNode.isForIn()) { 1757 enterForIn(forNode); 1758 } else { 1759 final Expression init = forNode.getInit(); 1760 if (init != null) { 1761 loadAndDiscard(init); 1762 } 1763 enterForOrWhile(forNode, forNode.getModify()); 1764 } 1765 1766 return false; 1767 } 1768 1769 private void enterForIn(final ForNode forNode) { 1770 loadExpression(forNode.getModify(), TypeBounds.OBJECT); 1771 method.invoke(forNode.isForEach() ? ScriptRuntime.TO_VALUE_ITERATOR : ScriptRuntime.TO_PROPERTY_ITERATOR); 1772 final Symbol iterSymbol = forNode.getIterator(); 1773 final int iterSlot = iterSymbol.getSlot(Type.OBJECT); 1774 method.store(iterSymbol, ITERATOR_TYPE); 1775 1776 method.beforeJoinPoint(forNode); 1777 1778 final Label continueLabel = forNode.getContinueLabel(); 1779 final Label breakLabel = forNode.getBreakLabel(); 1780 1781 method.label(continueLabel); 1782 method.load(ITERATOR_TYPE, iterSlot); 1783 method.invoke(interfaceCallNoLookup(ITERATOR_CLASS, "hasNext", boolean.class)); 1784 final JoinPredecessorExpression test = forNode.getTest(); 1785 final Block body = forNode.getBody(); 1786 if(LocalVariableConversion.hasLiveConversion(test)) { 1787 final Label afterConversion = new Label("for_in_after_test_conv"); 1788 method.ifne(afterConversion); 1789 method.beforeJoinPoint(test); 1790 method._goto(breakLabel); 1791 method.label(afterConversion); 1792 } else { 1793 method.ifeq(breakLabel); 1794 } 1795 1796 new Store<Expression>(forNode.getInit()) { 1797 @Override 1798 protected void storeNonDiscard() { 1799 // This expression is neither part of a discard, nor needs to be left on the stack after it was 1800 // stored, so we override storeNonDiscard to be a no-op. 1801 } 1802 1803 @Override 1804 protected void evaluate() { 1805 new OptimisticOperation((Optimistic)forNode.getInit(), TypeBounds.UNBOUNDED) { 1806 @Override 1807 void loadStack() { 1808 method.load(ITERATOR_TYPE, iterSlot); 1809 } 1810 1811 @Override 1812 void consumeStack() { 1813 method.invoke(interfaceCallNoLookup(ITERATOR_CLASS, "next", Object.class)); 1814 convertOptimisticReturnValue(); 1815 } 1816 }.emit(); 1817 } 1818 }.store(); 1819 body.accept(this); 1820 1821 if (forNode.needsScopeCreator() && lc.getCurrentBlock().providesScopeCreator()) { 1822 // for-in loops with lexical declaration need a new scope for each iteration. 1823 final FieldObjectCreator<?> creator = scopeObjectCreators.peek(); 1824 assert creator != null; 1825 creator.createForInIterationScope(method); 1826 method.storeCompilerConstant(SCOPE); 1827 } 1828 1829 if(method.isReachable()) { 1830 method._goto(continueLabel); 1831 } 1832 method.label(breakLabel); 1833 } 1834 1835 /** 1836 * Initialize the slots in a frame to undefined. 1837 * 1838 * @param block block with local vars. 1839 */ 1840 private void initLocals(final Block block) { 1841 lc.onEnterBlock(block); 1842 1843 final boolean isFunctionBody = lc.isFunctionBody(); 1844 final FunctionNode function = lc.getCurrentFunction(); 1845 if (isFunctionBody) { 1846 initializeMethodParameters(function); 1847 if(!function.isVarArg()) { 1848 expandParameterSlots(function); 1849 } 1850 if (method.hasScope()) { 1851 if (function.needsParentScope()) { 1852 method.loadCompilerConstant(CALLEE); 1853 method.invoke(ScriptFunction.GET_SCOPE); 1854 } else { 1855 assert function.hasScopeBlock(); 1856 method.loadNull(); 1857 } 1858 method.storeCompilerConstant(SCOPE); 1859 } 1860 if (function.needsArguments()) { 1861 initArguments(function); 1862 } 1863 } 1864 1865 /* 1866 * Determine if block needs scope, if not, just do initSymbols for this block. 1867 */ 1868 if (block.needsScope()) { 1869 /* 1870 * Determine if function is varargs and consequently variables have to 1871 * be in the scope. 1872 */ 1873 final boolean varsInScope = function.allVarsInScope(); 1874 1875 // TODO for LET we can do better: if *block* does not contain any eval/with, we don't need its vars in scope. 1876 1877 final boolean hasArguments = function.needsArguments(); 1878 final List<MapTuple<Symbol>> tuples = new ArrayList<>(); 1879 final Iterator<IdentNode> paramIter = function.getParameters().iterator(); 1880 for (final Symbol symbol : block.getSymbols()) { 1881 if (symbol.isInternal() || symbol.isThis()) { 1882 continue; 1883 } 1884 1885 if (symbol.isVar()) { 1886 assert !varsInScope || symbol.isScope(); 1887 if (varsInScope || symbol.isScope()) { 1888 assert symbol.isScope() : "scope for " + symbol + " should have been set in Lower already " + function.getName(); 1889 assert !symbol.hasSlot() : "slot for " + symbol + " should have been removed in Lower already" + function.getName(); 1890 1891 //this tuple will not be put fielded, as it has no value, just a symbol 1892 tuples.add(new MapTuple<Symbol>(symbol.getName(), symbol, null)); 1893 } else { 1894 assert symbol.hasSlot() || symbol.slotCount() == 0 : symbol + " should have a slot only, no scope"; 1895 } 1896 } else if (symbol.isParam() && (varsInScope || hasArguments || symbol.isScope())) { 1897 assert symbol.isScope() : "scope for " + symbol + " should have been set in AssignSymbols already " + function.getName() + " varsInScope="+varsInScope+" hasArguments="+hasArguments+" symbol.isScope()=" + symbol.isScope(); 1898 assert !(hasArguments && symbol.hasSlot()) : "slot for " + symbol + " should have been removed in Lower already " + function.getName(); 1899 1900 final Type paramType; 1901 final Symbol paramSymbol; 1902 1903 if (hasArguments) { 1904 assert !symbol.hasSlot() : "slot for " + symbol + " should have been removed in Lower already "; 1905 paramSymbol = null; 1906 paramType = null; 1907 } else { 1908 paramSymbol = symbol; 1909 // NOTE: We're relying on the fact here that Block.symbols is a LinkedHashMap, hence it will 1910 // return symbols in the order they were defined, and parameters are defined in the same order 1911 // they appear in the function. That's why we can have a single pass over the parameter list 1912 // with an iterator, always just scanning forward for the next parameter that matches the symbol 1913 // name. 1914 for(;;) { 1915 final IdentNode nextParam = paramIter.next(); 1916 if(nextParam.getName().equals(symbol.getName())) { 1917 paramType = nextParam.getType(); 1918 break; 1919 } 1920 } 1921 } 1922 1923 tuples.add(new MapTuple<Symbol>(symbol.getName(), symbol, paramType, paramSymbol) { 1924 //this symbol will be put fielded, we can't initialize it as undefined with a known type 1925 @Override 1926 public Class<?> getValueType() { 1927 if (!useDualFields() || value == null || paramType == null || paramType.isBoolean()) { 1928 return Object.class; 1929 } 1930 return paramType.getTypeClass(); 1931 } 1932 }); 1933 } 1934 } 1935 1936 /* 1937 * Create a new object based on the symbols and values, generate 1938 * bootstrap code for object 1939 */ 1940 final FieldObjectCreator<Symbol> creator = new FieldObjectCreator<Symbol>(this, tuples, true, hasArguments) { 1941 @Override 1942 protected void loadValue(final Symbol value, final Type type) { 1943 method.load(value, type); 1944 } 1945 }; 1946 creator.makeObject(method); 1947 if (block.providesScopeCreator()) { 1948 scopeObjectCreators.push(creator); 1949 } 1950 // program function: merge scope into global 1951 if (isFunctionBody && function.isProgram()) { 1952 method.invoke(ScriptRuntime.MERGE_SCOPE); 1953 } 1954 1955 method.storeCompilerConstant(SCOPE); 1956 if(!isFunctionBody) { 1957 // Function body doesn't need a try/catch to restore scope, as it'd be a dead store anyway. Allowing it 1958 // actually causes issues with UnwarrantedOptimismException handlers as ASM will sort this handler to 1959 // the top of the exception handler table, so it'll be triggered instead of the UOE handlers. 1960 final Label scopeEntryLabel = new Label("scope_entry"); 1961 scopeEntryLabels.push(scopeEntryLabel); 1962 method.label(scopeEntryLabel); 1963 } 1964 } else if (isFunctionBody && function.isVarArg()) { 1965 // Since we don't have a scope, parameters didn't get assigned array indices by the FieldObjectCreator, so 1966 // we need to assign them separately here. 1967 int nextParam = 0; 1968 for (final IdentNode param : function.getParameters()) { 1969 param.getSymbol().setFieldIndex(nextParam++); 1970 } 1971 } 1972 1973 // Debugging: print symbols? @see --print-symbols flag 1974 printSymbols(block, function, (isFunctionBody ? "Function " : "Block in ") + (function.getIdent() == null ? "<anonymous>" : function.getIdent().getName())); 1975 } 1976 1977 /** 1978 * Incoming method parameters are always declared on method entry; declare them in the local variable table. 1979 * @param function function for which code is being generated. 1980 */ 1981 private void initializeMethodParameters(final FunctionNode function) { 1982 final Label functionStart = new Label("fn_start"); 1983 method.label(functionStart); 1984 int nextSlot = 0; 1985 if(function.needsCallee()) { 1986 initializeInternalFunctionParameter(CALLEE, function, functionStart, nextSlot++); 1987 } 1988 initializeInternalFunctionParameter(THIS, function, functionStart, nextSlot++); 1989 if(function.isVarArg()) { 1990 initializeInternalFunctionParameter(VARARGS, function, functionStart, nextSlot++); 1991 } else { 1992 for(final IdentNode param: function.getParameters()) { 1993 final Symbol symbol = param.getSymbol(); 1994 if(symbol.isBytecodeLocal()) { 1995 method.initializeMethodParameter(symbol, param.getType(), functionStart); 1996 } 1997 } 1998 } 1999 } 2000 2001 private void initializeInternalFunctionParameter(final CompilerConstants cc, final FunctionNode fn, final Label functionStart, final int slot) { 2002 final Symbol symbol = initializeInternalFunctionOrSplitParameter(cc, fn, functionStart, slot); 2003 // Internal function params (:callee, this, and :varargs) are never expanded to multiple slots 2004 assert symbol.getFirstSlot() == slot; 2005 } 2006 2007 private Symbol initializeInternalFunctionOrSplitParameter(final CompilerConstants cc, final FunctionNode fn, final Label functionStart, final int slot) { 2008 final Symbol symbol = fn.getBody().getExistingSymbol(cc.symbolName()); 2009 final Type type = Type.typeFor(cc.type()); 2010 method.initializeMethodParameter(symbol, type, functionStart); 2011 method.onLocalStore(type, slot); 2012 return symbol; 2013 } 2014 2015 /** 2016 * Parameters come into the method packed into local variable slots next to each other. Nashorn on the other hand 2017 * can use 1-6 slots for a local variable depending on all the types it needs to store. When this method is invoked, 2018 * the symbols are already allocated such wider slots, but the values are still in tightly packed incoming slots, 2019 * and we need to spread them into their new locations. 2020 * @param function the function for which parameter-spreading code needs to be emitted 2021 */ 2022 private void expandParameterSlots(final FunctionNode function) { 2023 final List<IdentNode> parameters = function.getParameters(); 2024 // Calculate the total number of incoming parameter slots 2025 int currentIncomingSlot = function.needsCallee() ? 2 : 1; 2026 for(final IdentNode parameter: parameters) { 2027 currentIncomingSlot += parameter.getType().getSlots(); 2028 } 2029 // Starting from last parameter going backwards, move the parameter values into their new slots. 2030 for(int i = parameters.size(); i-- > 0;) { 2031 final IdentNode parameter = parameters.get(i); 2032 final Type parameterType = parameter.getType(); 2033 final int typeWidth = parameterType.getSlots(); 2034 currentIncomingSlot -= typeWidth; 2035 final Symbol symbol = parameter.getSymbol(); 2036 final int slotCount = symbol.slotCount(); 2037 assert slotCount > 0; 2038 // Scoped parameters must not hold more than one value 2039 assert symbol.isBytecodeLocal() || slotCount == typeWidth; 2040 2041 // Mark it as having its value stored into it by the method invocation. 2042 method.onLocalStore(parameterType, currentIncomingSlot); 2043 if(currentIncomingSlot != symbol.getSlot(parameterType)) { 2044 method.load(parameterType, currentIncomingSlot); 2045 method.store(symbol, parameterType); 2046 } 2047 } 2048 } 2049 2050 private void initArguments(final FunctionNode function) { 2051 method.loadCompilerConstant(VARARGS); 2052 if (function.needsCallee()) { 2053 method.loadCompilerConstant(CALLEE); 2054 } else { 2055 // If function is strict mode, "arguments.callee" is not populated, so we don't necessarily need the 2056 // caller. 2057 assert function.isStrict(); 2058 method.loadNull(); 2059 } 2060 method.load(function.getParameters().size()); 2061 globalAllocateArguments(); 2062 method.storeCompilerConstant(ARGUMENTS); 2063 } 2064 2065 private boolean skipFunction(final FunctionNode functionNode) { 2066 final ScriptEnvironment env = compiler.getScriptEnvironment(); 2067 final boolean lazy = env._lazy_compilation; 2068 final boolean onDemand = compiler.isOnDemandCompilation(); 2069 2070 // If this is on-demand or lazy compilation, don't compile a nested (not topmost) function. 2071 if((onDemand || lazy) && lc.getOutermostFunction() != functionNode) { 2072 return true; 2073 } 2074 2075 // If lazy compiling with optimistic types, don't compile the program eagerly either. It will soon be 2076 // invalidated anyway. In presence of a class cache, this further means that an obsoleted program version 2077 // lingers around. Also, currently loading previously persisted optimistic types information only works if 2078 // we're on-demand compiling a function, so with this strategy the :program method can also have the warmup 2079 // benefit of using previously persisted types. 2080 // 2081 // NOTE that this means the first compiled class will effectively just have a :createProgramFunction method, and 2082 // the RecompilableScriptFunctionData (RSFD) object in its constants array. It won't even have the :program 2083 // method. This is by design. It does mean that we're wasting one compiler execution (and we could minimize this 2084 // by just running it up to scope depth calculation, which creates the RSFDs and then this limited codegen). 2085 // We could emit an initial separate compile unit with the initial version of :program in it to better utilize 2086 // the compilation pipeline, but that would need more invasive changes, as currently the assumption that 2087 // :program is emitted into the first compilation unit of the function lives in many places. 2088 return !onDemand && lazy && env._optimistic_types && functionNode.isProgram(); 2089 } 2090 2091 @Override 2092 public boolean enterFunctionNode(final FunctionNode functionNode) { 2093 if (skipFunction(functionNode)) { 2094 // In case we are not generating code for the function, we must create or retrieve the function object and 2095 // load it on the stack here. 2096 newFunctionObject(functionNode, false); 2097 return false; 2098 } 2099 2100 final String fnName = functionNode.getName(); 2101 2102 // NOTE: we only emit the method for a function with the given name once. We can have multiple functions with 2103 // the same name as a result of inlining finally blocks. However, in the future -- with type specialization, 2104 // notably -- we might need to check for both name *and* signature. Of course, even that might not be 2105 // sufficient; the function might have a code dependency on the type of the variables in its enclosing scopes, 2106 // and the type of such a variable can be different in catch and finally blocks. So, in the future we will have 2107 // to decide to either generate a unique method for each inlined copy of the function, maybe figure out its 2108 // exact type closure and deduplicate based on that, or just decide that functions in finally blocks aren't 2109 // worth it, and generate one method with most generic type closure. 2110 if (!emittedMethods.contains(fnName)) { 2111 log.info("=== BEGIN ", fnName); 2112 2113 assert functionNode.getCompileUnit() != null : "no compile unit for " + fnName + " " + Debug.id(functionNode); 2114 unit = lc.pushCompileUnit(functionNode.getCompileUnit()); 2115 assert lc.hasCompileUnits(); 2116 2117 final ClassEmitter classEmitter = unit.getClassEmitter(); 2118 pushMethodEmitter(isRestOf() ? classEmitter.restOfMethod(functionNode) : classEmitter.method(functionNode)); 2119 method.setPreventUndefinedLoad(); 2120 if(useOptimisticTypes()) { 2121 lc.pushUnwarrantedOptimismHandlers(); 2122 } 2123 2124 // new method - reset last line number 2125 lastLineNumber = -1; 2126 2127 method.begin(); 2128 2129 if (isRestOf()) { 2130 assert continuationInfo == null; 2131 continuationInfo = new ContinuationInfo(); 2132 method.gotoLoopStart(continuationInfo.getHandlerLabel()); 2133 } 2134 } 2135 2136 return true; 2137 } 2138 2139 private void pushMethodEmitter(final MethodEmitter newMethod) { 2140 method = lc.pushMethodEmitter(newMethod); 2141 catchLabels.push(METHOD_BOUNDARY); 2142 } 2143 2144 private void popMethodEmitter() { 2145 method = lc.popMethodEmitter(method); 2146 assert catchLabels.peek() == METHOD_BOUNDARY; 2147 catchLabels.pop(); 2148 } 2149 2150 @Override 2151 public Node leaveFunctionNode(final FunctionNode functionNode) { 2152 try { 2153 final boolean markOptimistic; 2154 if (emittedMethods.add(functionNode.getName())) { 2155 markOptimistic = generateUnwarrantedOptimismExceptionHandlers(functionNode); 2156 generateContinuationHandler(); 2157 method.end(); // wrap up this method 2158 unit = lc.popCompileUnit(functionNode.getCompileUnit()); 2159 popMethodEmitter(); 2160 log.info("=== END ", functionNode.getName()); 2161 } else { 2162 markOptimistic = false; 2163 } 2164 2165 FunctionNode newFunctionNode = functionNode; 2166 if (markOptimistic) { 2167 newFunctionNode = newFunctionNode.setFlag(lc, FunctionNode.IS_DEOPTIMIZABLE); 2168 } 2169 2170 newFunctionObject(newFunctionNode, true); 2171 return newFunctionNode; 2172 } catch (final Throwable t) { 2173 Context.printStackTrace(t); 2174 final VerifyError e = new VerifyError("Code generation bug in \"" + functionNode.getName() + "\": likely stack misaligned: " + t + " " + functionNode.getSource().getName()); 2175 e.initCause(t); 2176 throw e; 2177 } 2178 } 2179 2180 @Override 2181 public boolean enterIfNode(final IfNode ifNode) { 2182 if(!method.isReachable()) { 2183 return false; 2184 } 2185 enterStatement(ifNode); 2186 2187 final Expression test = ifNode.getTest(); 2188 final Block pass = ifNode.getPass(); 2189 final Block fail = ifNode.getFail(); 2190 2191 if (Expression.isAlwaysTrue(test)) { 2192 loadAndDiscard(test); 2193 pass.accept(this); 2194 return false; 2195 } else if (Expression.isAlwaysFalse(test)) { 2196 loadAndDiscard(test); 2197 if (fail != null) { 2198 fail.accept(this); 2199 } 2200 return false; 2201 } 2202 2203 final boolean hasFailConversion = LocalVariableConversion.hasLiveConversion(ifNode); 2204 2205 final Label failLabel = new Label("if_fail"); 2206 final Label afterLabel = (fail == null && !hasFailConversion) ? null : new Label("if_done"); 2207 2208 emitBranch(test, failLabel, false); 2209 2210 pass.accept(this); 2211 if(method.isReachable() && afterLabel != null) { 2212 method._goto(afterLabel); //don't fallthru to fail block 2213 } 2214 method.label(failLabel); 2215 2216 if (fail != null) { 2217 fail.accept(this); 2218 } else if(hasFailConversion) { 2219 method.beforeJoinPoint(ifNode); 2220 } 2221 2222 if(afterLabel != null && afterLabel.isReachable()) { 2223 method.label(afterLabel); 2224 } 2225 2226 return false; 2227 } 2228 2229 private void emitBranch(final Expression test, final Label label, final boolean jumpWhenTrue) { 2230 new BranchOptimizer(this, method).execute(test, label, jumpWhenTrue); 2231 } 2232 2233 private void enterStatement(final Statement statement) { 2234 lineNumber(statement); 2235 } 2236 2237 private void lineNumber(final Statement statement) { 2238 lineNumber(statement.getLineNumber()); 2239 } 2240 2241 private void lineNumber(final int lineNumber) { 2242 if (lineNumber != lastLineNumber && lineNumber != Node.NO_LINE_NUMBER) { 2243 method.lineNumber(lineNumber); 2244 lastLineNumber = lineNumber; 2245 } 2246 } 2247 2248 int getLastLineNumber() { 2249 return lastLineNumber; 2250 } 2251 2252 /** 2253 * Load a list of nodes as an array of a specific type 2254 * The array will contain the visited nodes. 2255 * 2256 * @param arrayLiteralNode the array of contents 2257 * @param arrayType the type of the array, e.g. ARRAY_NUMBER or ARRAY_OBJECT 2258 */ 2259 private void loadArray(final ArrayLiteralNode arrayLiteralNode, final ArrayType arrayType) { 2260 assert arrayType == Type.INT_ARRAY || arrayType == Type.NUMBER_ARRAY || arrayType == Type.OBJECT_ARRAY; 2261 2262 final Expression[] nodes = arrayLiteralNode.getValue(); 2263 final Object presets = arrayLiteralNode.getPresets(); 2264 final int[] postsets = arrayLiteralNode.getPostsets(); 2265 final List<Splittable.SplitRange> ranges = arrayLiteralNode.getSplitRanges(); 2266 2267 loadConstant(presets); 2268 2269 final Type elementType = arrayType.getElementType(); 2270 2271 if (ranges != null) { 2272 2273 loadSplitLiteral(new SplitLiteralCreator() { 2274 @Override 2275 public void populateRange(final MethodEmitter method, final Type type, final int slot, final int start, final int end) { 2276 for (int i = start; i < end; i++) { 2277 method.load(type, slot); 2278 storeElement(nodes, elementType, postsets[i]); 2279 } 2280 method.load(type, slot); 2281 } 2282 }, ranges, arrayType); 2283 2284 return; 2285 } 2286 2287 if(postsets.length > 0) { 2288 final int arraySlot = method.getUsedSlotsWithLiveTemporaries(); 2289 method.storeTemp(arrayType, arraySlot); 2290 for (final int postset : postsets) { 2291 method.load(arrayType, arraySlot); 2292 storeElement(nodes, elementType, postset); 2293 } 2294 method.load(arrayType, arraySlot); 2295 } 2296 } 2297 2298 private void storeElement(final Expression[] nodes, final Type elementType, final int index) { 2299 method.load(index); 2300 2301 final Expression element = nodes[index]; 2302 2303 if (element == null) { 2304 method.loadEmpty(elementType); 2305 } else { 2306 loadExpressionAsType(element, elementType); 2307 } 2308 2309 method.arraystore(); 2310 } 2311 2312 private MethodEmitter loadArgsArray(final List<Expression> args) { 2313 final Object[] array = new Object[args.size()]; 2314 loadConstant(array); 2315 2316 for (int i = 0; i < args.size(); i++) { 2317 method.dup(); 2318 method.load(i); 2319 loadExpression(args.get(i), TypeBounds.OBJECT); // variable arity methods always take objects 2320 method.arraystore(); 2321 } 2322 2323 return method; 2324 } 2325 2326 /** 2327 * Load a constant from the constant array. This is only public to be callable from the objects 2328 * subpackage. Do not call directly. 2329 * 2330 * @param string string to load 2331 */ 2332 void loadConstant(final String string) { 2333 final String unitClassName = unit.getUnitClassName(); 2334 final ClassEmitter classEmitter = unit.getClassEmitter(); 2335 final int index = compiler.getConstantData().add(string); 2336 2337 method.load(index); 2338 method.invokestatic(unitClassName, GET_STRING.symbolName(), methodDescriptor(String.class, int.class)); 2339 classEmitter.needGetConstantMethod(String.class); 2340 } 2341 2342 /** 2343 * Load a constant from the constant array. This is only public to be callable from the objects 2344 * subpackage. Do not call directly. 2345 * 2346 * @param object object to load 2347 */ 2348 void loadConstant(final Object object) { 2349 loadConstant(object, unit, method); 2350 } 2351 2352 private void loadConstant(final Object object, final CompileUnit compileUnit, final MethodEmitter methodEmitter) { 2353 final String unitClassName = compileUnit.getUnitClassName(); 2354 final ClassEmitter classEmitter = compileUnit.getClassEmitter(); 2355 final int index = compiler.getConstantData().add(object); 2356 final Class<?> cls = object.getClass(); 2357 2358 if (cls == PropertyMap.class) { 2359 methodEmitter.load(index); 2360 methodEmitter.invokestatic(unitClassName, GET_MAP.symbolName(), methodDescriptor(PropertyMap.class, int.class)); 2361 classEmitter.needGetConstantMethod(PropertyMap.class); 2362 } else if (cls.isArray()) { 2363 methodEmitter.load(index); 2364 final String methodName = ClassEmitter.getArrayMethodName(cls); 2365 methodEmitter.invokestatic(unitClassName, methodName, methodDescriptor(cls, int.class)); 2366 classEmitter.needGetConstantMethod(cls); 2367 } else { 2368 methodEmitter.loadConstants().load(index).arrayload(); 2369 if (object instanceof ArrayData) { 2370 methodEmitter.checkcast(ArrayData.class); 2371 methodEmitter.invoke(virtualCallNoLookup(ArrayData.class, "copy", ArrayData.class)); 2372 } else if (cls != Object.class) { 2373 methodEmitter.checkcast(cls); 2374 } 2375 } 2376 } 2377 2378 private void loadConstantsAndIndex(final Object object, final MethodEmitter methodEmitter) { 2379 methodEmitter.loadConstants().load(compiler.getConstantData().add(object)); 2380 } 2381 2382 // literal values 2383 private void loadLiteral(final LiteralNode<?> node, final TypeBounds resultBounds) { 2384 final Object value = node.getValue(); 2385 2386 if (value == null) { 2387 method.loadNull(); 2388 } else if (value instanceof Undefined) { 2389 method.loadUndefined(resultBounds.within(Type.OBJECT)); 2390 } else if (value instanceof String) { 2391 final String string = (String)value; 2392 2393 if (string.length() > MethodEmitter.LARGE_STRING_THRESHOLD / 3) { // 3 == max bytes per encoded char 2394 loadConstant(string); 2395 } else { 2396 method.load(string); 2397 } 2398 } else if (value instanceof RegexToken) { 2399 loadRegex((RegexToken)value); 2400 } else if (value instanceof Boolean) { 2401 method.load((Boolean)value); 2402 } else if (value instanceof Integer) { 2403 if(!resultBounds.canBeNarrowerThan(Type.OBJECT)) { 2404 method.load((Integer)value); 2405 method.convert(Type.OBJECT); 2406 } else if(!resultBounds.canBeNarrowerThan(Type.NUMBER)) { 2407 method.load(((Integer)value).doubleValue()); 2408 } else { 2409 method.load((Integer)value); 2410 } 2411 } else if (value instanceof Double) { 2412 if(!resultBounds.canBeNarrowerThan(Type.OBJECT)) { 2413 method.load((Double)value); 2414 method.convert(Type.OBJECT); 2415 } else { 2416 method.load((Double)value); 2417 } 2418 } else if (node instanceof ArrayLiteralNode) { 2419 final ArrayLiteralNode arrayLiteral = (ArrayLiteralNode)node; 2420 final ArrayType atype = arrayLiteral.getArrayType(); 2421 loadArray(arrayLiteral, atype); 2422 globalAllocateArray(atype); 2423 } else { 2424 throw new UnsupportedOperationException("Unknown literal for " + node.getClass() + " " + value.getClass() + " " + value); 2425 } 2426 } 2427 2428 private MethodEmitter loadRegexToken(final RegexToken value) { 2429 method.load(value.getExpression()); 2430 method.load(value.getOptions()); 2431 return globalNewRegExp(); 2432 } 2433 2434 private MethodEmitter loadRegex(final RegexToken regexToken) { 2435 if (regexFieldCount > MAX_REGEX_FIELDS) { 2436 return loadRegexToken(regexToken); 2437 } 2438 // emit field 2439 final String regexName = lc.getCurrentFunction().uniqueName(REGEX_PREFIX.symbolName()); 2440 final ClassEmitter classEmitter = unit.getClassEmitter(); 2441 2442 classEmitter.field(EnumSet.of(PRIVATE, STATIC), regexName, Object.class); 2443 regexFieldCount++; 2444 2445 // get field, if null create new regex, finally clone regex object 2446 method.getStatic(unit.getUnitClassName(), regexName, typeDescriptor(Object.class)); 2447 method.dup(); 2448 final Label cachedLabel = new Label("cached"); 2449 method.ifnonnull(cachedLabel); 2450 2451 method.pop(); 2452 loadRegexToken(regexToken); 2453 method.dup(); 2454 method.putStatic(unit.getUnitClassName(), regexName, typeDescriptor(Object.class)); 2455 2456 method.label(cachedLabel); 2457 globalRegExpCopy(); 2458 2459 return method; 2460 } 2461 2462 /** 2463 * Check if a property value contains a particular program point 2464 * @param value value 2465 * @param pp program point 2466 * @return true if it's there. 2467 */ 2468 private static boolean propertyValueContains(final Expression value, final int pp) { 2469 return new Supplier<Boolean>() { 2470 boolean contains; 2471 2472 @Override 2473 public Boolean get() { 2474 value.accept(new SimpleNodeVisitor() { 2475 @Override 2476 public boolean enterFunctionNode(final FunctionNode functionNode) { 2477 return false; 2478 } 2479 2480 @Override 2481 public boolean enterObjectNode(final ObjectNode objectNode) { 2482 return false; 2483 } 2484 2485 @Override 2486 public boolean enterDefault(final Node node) { 2487 if (contains) { 2488 return false; 2489 } 2490 if (node instanceof Optimistic && ((Optimistic)node).getProgramPoint() == pp) { 2491 contains = true; 2492 return false; 2493 } 2494 return true; 2495 } 2496 }); 2497 2498 return contains; 2499 } 2500 }.get(); 2501 } 2502 2503 private void loadObjectNode(final ObjectNode objectNode) { 2504 final List<PropertyNode> elements = objectNode.getElements(); 2505 2506 final List<MapTuple<Expression>> tuples = new ArrayList<>(); 2507 final List<PropertyNode> gettersSetters = new ArrayList<>(); 2508 final int ccp = getCurrentContinuationEntryPoint(); 2509 final List<Splittable.SplitRange> ranges = objectNode.getSplitRanges(); 2510 2511 Expression protoNode = null; 2512 boolean restOfProperty = false; 2513 2514 for (final PropertyNode propertyNode : elements) { 2515 final Expression value = propertyNode.getValue(); 2516 final String key = propertyNode.getKeyName(); 2517 // Just use a pseudo-symbol. We just need something non null; use the name and zero flags. 2518 final Symbol symbol = value == null ? null : new Symbol(key, 0); 2519 2520 if (value == null) { 2521 gettersSetters.add(propertyNode); 2522 } else if (propertyNode.getKey() instanceof IdentNode && 2523 key.equals(ScriptObject.PROTO_PROPERTY_NAME)) { 2524 // ES6 draft compliant __proto__ inside object literal 2525 // Identifier key and name is __proto__ 2526 protoNode = value; 2527 continue; 2528 } 2529 2530 restOfProperty |= 2531 value != null && 2532 isValid(ccp) && 2533 propertyValueContains(value, ccp); 2534 2535 //for literals, a value of null means object type, i.e. the value null or getter setter function 2536 //(I think) 2537 final Class<?> valueType = (!useDualFields() || value == null || value.getType().isBoolean()) ? Object.class : value.getType().getTypeClass(); 2538 tuples.add(new MapTuple<Expression>(key, symbol, Type.typeFor(valueType), value) { 2539 @Override 2540 public Class<?> getValueType() { 2541 return type.getTypeClass(); 2542 } 2543 }); 2544 } 2545 2546 final ObjectCreator<?> oc; 2547 if (elements.size() > OBJECT_SPILL_THRESHOLD) { 2548 oc = new SpillObjectCreator(this, tuples); 2549 } else { 2550 oc = new FieldObjectCreator<Expression>(this, tuples) { 2551 @Override 2552 protected void loadValue(final Expression node, final Type type) { 2553 loadExpressionAsType(node, type); 2554 }}; 2555 } 2556 2557 if (ranges != null) { 2558 oc.createObject(method); 2559 loadSplitLiteral(oc, ranges, Type.typeFor(oc.getAllocatorClass())); 2560 } else { 2561 oc.makeObject(method); 2562 } 2563 2564 //if this is a rest of method and our continuation point was found as one of the values 2565 //in the properties above, we need to reset the map to oc.getMap() in the continuation 2566 //handler 2567 if (restOfProperty) { 2568 final ContinuationInfo ci = getContinuationInfo(); 2569 // Can be set at most once for a single rest-of method 2570 assert ci.getObjectLiteralMap() == null; 2571 ci.setObjectLiteralMap(oc.getMap()); 2572 ci.setObjectLiteralStackDepth(method.getStackSize()); 2573 } 2574 2575 method.dup(); 2576 if (protoNode != null) { 2577 loadExpressionAsObject(protoNode); 2578 // take care of { __proto__: 34 } or some such! 2579 method.convert(Type.OBJECT); 2580 method.invoke(ScriptObject.SET_PROTO_FROM_LITERAL); 2581 } else { 2582 method.invoke(ScriptObject.SET_GLOBAL_OBJECT_PROTO); 2583 } 2584 2585 for (final PropertyNode propertyNode : gettersSetters) { 2586 final FunctionNode getter = propertyNode.getGetter(); 2587 final FunctionNode setter = propertyNode.getSetter(); 2588 2589 assert getter != null || setter != null; 2590 2591 method.dup().loadKey(propertyNode.getKey()); 2592 if (getter == null) { 2593 method.loadNull(); 2594 } else { 2595 getter.accept(this); 2596 } 2597 2598 if (setter == null) { 2599 method.loadNull(); 2600 } else { 2601 setter.accept(this); 2602 } 2603 2604 method.invoke(ScriptObject.SET_USER_ACCESSORS); 2605 } 2606 } 2607 2608 @Override 2609 public boolean enterReturnNode(final ReturnNode returnNode) { 2610 if(!method.isReachable()) { 2611 return false; 2612 } 2613 enterStatement(returnNode); 2614 2615 final Type returnType = lc.getCurrentFunction().getReturnType(); 2616 2617 final Expression expression = returnNode.getExpression(); 2618 if (expression != null) { 2619 loadExpressionUnbounded(expression); 2620 } else { 2621 method.loadUndefined(returnType); 2622 } 2623 2624 method._return(returnType); 2625 2626 return false; 2627 } 2628 2629 private boolean undefinedCheck(final RuntimeNode runtimeNode, final List<Expression> args) { 2630 final Request request = runtimeNode.getRequest(); 2631 2632 if (!Request.isUndefinedCheck(request)) { 2633 return false; 2634 } 2635 2636 final Expression lhs = args.get(0); 2637 final Expression rhs = args.get(1); 2638 2639 final Symbol lhsSymbol = lhs instanceof IdentNode ? ((IdentNode)lhs).getSymbol() : null; 2640 final Symbol rhsSymbol = rhs instanceof IdentNode ? ((IdentNode)rhs).getSymbol() : null; 2641 // One must be a "undefined" identifier, otherwise we can't get here 2642 assert lhsSymbol != null || rhsSymbol != null; 2643 2644 final Symbol undefinedSymbol; 2645 if (isUndefinedSymbol(lhsSymbol)) { 2646 undefinedSymbol = lhsSymbol; 2647 } else { 2648 assert isUndefinedSymbol(rhsSymbol); 2649 undefinedSymbol = rhsSymbol; 2650 } 2651 2652 assert undefinedSymbol != null; //remove warning 2653 if (!undefinedSymbol.isScope()) { 2654 return false; //disallow undefined as local var or parameter 2655 } 2656 2657 if (lhsSymbol == undefinedSymbol && lhs.getType().isPrimitive()) { 2658 //we load the undefined first. never mind, because this will deoptimize anyway 2659 return false; 2660 } 2661 2662 if(isDeoptimizedExpression(lhs)) { 2663 // This is actually related to "lhs.getType().isPrimitive()" above: any expression being deoptimized in 2664 // the current chain of rest-of compilations used to have a type narrower than Object (so it was primitive). 2665 // We must not perform undefined check specialization for them, as then we'd violate the basic rule of 2666 // "Thou shalt not alter the stack shape between a deoptimized method and any of its (transitive) rest-ofs." 2667 return false; 2668 } 2669 2670 //make sure that undefined has not been overridden or scoped as a local var 2671 //between us and global 2672 if (!compiler.isGlobalSymbol(lc.getCurrentFunction(), "undefined")) { 2673 return false; 2674 } 2675 2676 final boolean isUndefinedCheck = request == Request.IS_UNDEFINED; 2677 final Expression expr = undefinedSymbol == lhsSymbol ? rhs : lhs; 2678 if (expr.getType().isPrimitive()) { 2679 loadAndDiscard(expr); //throw away lhs, but it still needs to be evaluated for side effects, even if not in scope, as it can be optimistic 2680 method.load(!isUndefinedCheck); 2681 } else { 2682 final Label checkTrue = new Label("ud_check_true"); 2683 final Label end = new Label("end"); 2684 loadExpressionAsObject(expr); 2685 method.loadUndefined(Type.OBJECT); 2686 method.if_acmpeq(checkTrue); 2687 method.load(!isUndefinedCheck); 2688 method._goto(end); 2689 method.label(checkTrue); 2690 method.load(isUndefinedCheck); 2691 method.label(end); 2692 } 2693 2694 return true; 2695 } 2696 2697 private static boolean isUndefinedSymbol(final Symbol symbol) { 2698 return symbol != null && "undefined".equals(symbol.getName()); 2699 } 2700 2701 private static boolean isNullLiteral(final Node node) { 2702 return node instanceof LiteralNode<?> && ((LiteralNode<?>) node).isNull(); 2703 } 2704 2705 private boolean nullCheck(final RuntimeNode runtimeNode, final List<Expression> args) { 2706 final Request request = runtimeNode.getRequest(); 2707 2708 if (!Request.isEQ(request) && !Request.isNE(request)) { 2709 return false; 2710 } 2711 2712 assert args.size() == 2 : "EQ or NE or TYPEOF need two args"; 2713 2714 Expression lhs = args.get(0); 2715 Expression rhs = args.get(1); 2716 2717 if (isNullLiteral(lhs)) { 2718 final Expression tmp = lhs; 2719 lhs = rhs; 2720 rhs = tmp; 2721 } 2722 2723 if (!isNullLiteral(rhs)) { 2724 return false; 2725 } 2726 2727 if (!lhs.getType().isObject()) { 2728 return false; 2729 } 2730 2731 if(isDeoptimizedExpression(lhs)) { 2732 // This is actually related to "!lhs.getType().isObject()" above: any expression being deoptimized in 2733 // the current chain of rest-of compilations used to have a type narrower than Object. We must not 2734 // perform null check specialization for them, as then we'd no longer be loading aconst_null on stack 2735 // and thus violate the basic rule of "Thou shalt not alter the stack shape between a deoptimized 2736 // method and any of its (transitive) rest-ofs." 2737 // NOTE also that if we had a representation for well-known constants (e.g. null, 0, 1, -1, etc.) in 2738 // Label$Stack.localLoads then this wouldn't be an issue, as we would never (somewhat ridiculously) 2739 // allocate a temporary local to hold the result of aconst_null before attempting an optimistic 2740 // operation. 2741 return false; 2742 } 2743 2744 // this is a null literal check, so if there is implicit coercion 2745 // involved like {D}x=null, we will fail - this is very rare 2746 final Label trueLabel = new Label("trueLabel"); 2747 final Label falseLabel = new Label("falseLabel"); 2748 final Label endLabel = new Label("end"); 2749 2750 loadExpressionUnbounded(lhs); //lhs 2751 final Label popLabel; 2752 if (!Request.isStrict(request)) { 2753 method.dup(); //lhs lhs 2754 popLabel = new Label("pop"); 2755 } else { 2756 popLabel = null; 2757 } 2758 2759 if (Request.isEQ(request)) { 2760 method.ifnull(!Request.isStrict(request) ? popLabel : trueLabel); 2761 if (!Request.isStrict(request)) { 2762 method.loadUndefined(Type.OBJECT); 2763 method.if_acmpeq(trueLabel); 2764 } 2765 method.label(falseLabel); 2766 method.load(false); 2767 method._goto(endLabel); 2768 if (!Request.isStrict(request)) { 2769 method.label(popLabel); 2770 method.pop(); 2771 } 2772 method.label(trueLabel); 2773 method.load(true); 2774 method.label(endLabel); 2775 } else if (Request.isNE(request)) { 2776 method.ifnull(!Request.isStrict(request) ? popLabel : falseLabel); 2777 if (!Request.isStrict(request)) { 2778 method.loadUndefined(Type.OBJECT); 2779 method.if_acmpeq(falseLabel); 2780 } 2781 method.label(trueLabel); 2782 method.load(true); 2783 method._goto(endLabel); 2784 if (!Request.isStrict(request)) { 2785 method.label(popLabel); 2786 method.pop(); 2787 } 2788 method.label(falseLabel); 2789 method.load(false); 2790 method.label(endLabel); 2791 } 2792 2793 assert runtimeNode.getType().isBoolean(); 2794 method.convert(runtimeNode.getType()); 2795 2796 return true; 2797 } 2798 2799 /** 2800 * Was this expression or any of its subexpressions deoptimized in the current recompilation chain of rest-of methods? 2801 * @param rootExpr the expression being tested 2802 * @return true if the expression or any of its subexpressions was deoptimized in the current recompilation chain. 2803 */ 2804 private boolean isDeoptimizedExpression(final Expression rootExpr) { 2805 if(!isRestOf()) { 2806 return false; 2807 } 2808 return new Supplier<Boolean>() { 2809 boolean contains; 2810 @Override 2811 public Boolean get() { 2812 rootExpr.accept(new SimpleNodeVisitor() { 2813 @Override 2814 public boolean enterFunctionNode(final FunctionNode functionNode) { 2815 return false; 2816 } 2817 @Override 2818 public boolean enterDefault(final Node node) { 2819 if(!contains && node instanceof Optimistic) { 2820 final int pp = ((Optimistic)node).getProgramPoint(); 2821 contains = isValid(pp) && isContinuationEntryPoint(pp); 2822 } 2823 return !contains; 2824 } 2825 }); 2826 return contains; 2827 } 2828 }.get(); 2829 } 2830 2831 private void loadRuntimeNode(final RuntimeNode runtimeNode) { 2832 final List<Expression> args = new ArrayList<>(runtimeNode.getArgs()); 2833 if (nullCheck(runtimeNode, args)) { 2834 return; 2835 } else if(undefinedCheck(runtimeNode, args)) { 2836 return; 2837 } 2838 // Revert a false undefined check to a strict equality check 2839 final RuntimeNode newRuntimeNode; 2840 final Request request = runtimeNode.getRequest(); 2841 if (Request.isUndefinedCheck(request)) { 2842 newRuntimeNode = runtimeNode.setRequest(request == Request.IS_UNDEFINED ? Request.EQ_STRICT : Request.NE_STRICT); 2843 } else { 2844 newRuntimeNode = runtimeNode; 2845 } 2846 2847 for (final Expression arg : args) { 2848 loadExpression(arg, TypeBounds.OBJECT); 2849 } 2850 2851 method.invokestatic( 2852 CompilerConstants.className(ScriptRuntime.class), 2853 newRuntimeNode.getRequest().toString(), 2854 new FunctionSignature( 2855 false, 2856 false, 2857 newRuntimeNode.getType(), 2858 args.size()).toString()); 2859 2860 method.convert(newRuntimeNode.getType()); 2861 } 2862 2863 private void defineCommonSplitMethodParameters() { 2864 defineSplitMethodParameter(0, CALLEE); 2865 defineSplitMethodParameter(1, THIS); 2866 defineSplitMethodParameter(2, SCOPE); 2867 } 2868 2869 private void defineSplitMethodParameter(final int slot, final CompilerConstants cc) { 2870 defineSplitMethodParameter(slot, Type.typeFor(cc.type())); 2871 } 2872 2873 private void defineSplitMethodParameter(final int slot, final Type type) { 2874 method.defineBlockLocalVariable(slot, slot + type.getSlots()); 2875 method.onLocalStore(type, slot); 2876 } 2877 2878 private void loadSplitLiteral(final SplitLiteralCreator creator, final List<Splittable.SplitRange> ranges, final Type literalType) { 2879 assert ranges != null; 2880 2881 // final Type literalType = Type.typeFor(literalClass); 2882 final MethodEmitter savedMethod = method; 2883 final FunctionNode currentFunction = lc.getCurrentFunction(); 2884 2885 for (final Splittable.SplitRange splitRange : ranges) { 2886 unit = lc.pushCompileUnit(splitRange.getCompileUnit()); 2887 2888 assert unit != null; 2889 final String className = unit.getUnitClassName(); 2890 final String name = currentFunction.uniqueName(SPLIT_PREFIX.symbolName()); 2891 final Class<?> clazz = literalType.getTypeClass(); 2892 final String signature = methodDescriptor(clazz, ScriptFunction.class, Object.class, ScriptObject.class, clazz); 2893 2894 pushMethodEmitter(unit.getClassEmitter().method(EnumSet.of(Flag.PUBLIC, Flag.STATIC), name, signature)); 2895 2896 method.setFunctionNode(currentFunction); 2897 method.begin(); 2898 2899 defineCommonSplitMethodParameters(); 2900 defineSplitMethodParameter(CompilerConstants.SPLIT_ARRAY_ARG.slot(), literalType); 2901 2902 // NOTE: when this is no longer needed, SplitIntoFunctions will no longer have to add IS_SPLIT 2903 // to synthetic functions, and FunctionNode.needsCallee() will no longer need to test for isSplit(). 2904 final int literalSlot = fixScopeSlot(currentFunction, 3); 2905 2906 lc.enterSplitNode(); 2907 2908 creator.populateRange(method, literalType, literalSlot, splitRange.getLow(), splitRange.getHigh()); 2909 2910 method._return(); 2911 lc.exitSplitNode(); 2912 method.end(); 2913 lc.releaseSlots(); 2914 popMethodEmitter(); 2915 2916 assert method == savedMethod; 2917 method.loadCompilerConstant(CALLEE).swap(); 2918 method.loadCompilerConstant(THIS).swap(); 2919 method.loadCompilerConstant(SCOPE).swap(); 2920 method.invokestatic(className, name, signature); 2921 2922 unit = lc.popCompileUnit(unit); 2923 } 2924 } 2925 2926 private int fixScopeSlot(final FunctionNode functionNode, final int extraSlot) { 2927 // TODO hack to move the scope to the expected slot (needed because split methods reuse the same slots as the root method) 2928 final int actualScopeSlot = functionNode.compilerConstant(SCOPE).getSlot(SCOPE_TYPE); 2929 final int defaultScopeSlot = SCOPE.slot(); 2930 int newExtraSlot = extraSlot; 2931 if (actualScopeSlot != defaultScopeSlot) { 2932 if (actualScopeSlot == extraSlot) { 2933 newExtraSlot = extraSlot + 1; 2934 method.defineBlockLocalVariable(newExtraSlot, newExtraSlot + 1); 2935 method.load(Type.OBJECT, extraSlot); 2936 method.storeHidden(Type.OBJECT, newExtraSlot); 2937 } else { 2938 method.defineBlockLocalVariable(actualScopeSlot, actualScopeSlot + 1); 2939 } 2940 method.load(SCOPE_TYPE, defaultScopeSlot); 2941 method.storeCompilerConstant(SCOPE); 2942 } 2943 return newExtraSlot; 2944 } 2945 2946 @Override 2947 public boolean enterSplitReturn(final SplitReturn splitReturn) { 2948 if (method.isReachable()) { 2949 method.loadUndefined(lc.getCurrentFunction().getReturnType())._return(); 2950 } 2951 return false; 2952 } 2953 2954 @Override 2955 public boolean enterSetSplitState(final SetSplitState setSplitState) { 2956 if (method.isReachable()) { 2957 method.setSplitState(setSplitState.getState()); 2958 } 2959 return false; 2960 } 2961 2962 @Override 2963 public boolean enterSwitchNode(final SwitchNode switchNode) { 2964 if(!method.isReachable()) { 2965 return false; 2966 } 2967 enterStatement(switchNode); 2968 2969 final Expression expression = switchNode.getExpression(); 2970 final List<CaseNode> cases = switchNode.getCases(); 2971 2972 if (cases.isEmpty()) { 2973 // still evaluate expression for side-effects. 2974 loadAndDiscard(expression); 2975 return false; 2976 } 2977 2978 final CaseNode defaultCase = switchNode.getDefaultCase(); 2979 final Label breakLabel = switchNode.getBreakLabel(); 2980 final int liveLocalsOnBreak = method.getUsedSlotsWithLiveTemporaries(); 2981 2982 if (defaultCase != null && cases.size() == 1) { 2983 // default case only 2984 assert cases.get(0) == defaultCase; 2985 loadAndDiscard(expression); 2986 defaultCase.getBody().accept(this); 2987 method.breakLabel(breakLabel, liveLocalsOnBreak); 2988 return false; 2989 } 2990 2991 // NOTE: it can still change in the tableswitch/lookupswitch case if there's no default case 2992 // but we need to add a synthetic default case for local variable conversions 2993 Label defaultLabel = defaultCase != null ? defaultCase.getEntry() : breakLabel; 2994 final boolean hasSkipConversion = LocalVariableConversion.hasLiveConversion(switchNode); 2995 2996 if (switchNode.isUniqueInteger()) { 2997 // Tree for sorting values. 2998 final TreeMap<Integer, Label> tree = new TreeMap<>(); 2999 3000 // Build up sorted tree. 3001 for (final CaseNode caseNode : cases) { 3002 final Node test = caseNode.getTest(); 3003 3004 if (test != null) { 3005 final Integer value = (Integer)((LiteralNode<?>)test).getValue(); 3006 final Label entry = caseNode.getEntry(); 3007 3008 // Take first duplicate. 3009 if (!tree.containsKey(value)) { 3010 tree.put(value, entry); 3011 } 3012 } 3013 } 3014 3015 // Copy values and labels to arrays. 3016 final int size = tree.size(); 3017 final Integer[] values = tree.keySet().toArray(new Integer[0]); 3018 final Label[] labels = tree.values().toArray(new Label[0]); 3019 3020 // Discern low, high and range. 3021 final int lo = values[0]; 3022 final int hi = values[size - 1]; 3023 final long range = (long)hi - (long)lo + 1; 3024 3025 // Find an unused value for default. 3026 int deflt = Integer.MIN_VALUE; 3027 for (final int value : values) { 3028 if (deflt == value) { 3029 deflt++; 3030 } else if (deflt < value) { 3031 break; 3032 } 3033 } 3034 3035 // Load switch expression. 3036 loadExpressionUnbounded(expression); 3037 final Type type = expression.getType(); 3038 3039 // If expression not int see if we can convert, if not use deflt to trigger default. 3040 if (!type.isInteger()) { 3041 method.load(deflt); 3042 final Class<?> exprClass = type.getTypeClass(); 3043 method.invoke(staticCallNoLookup(ScriptRuntime.class, "switchTagAsInt", int.class, exprClass.isPrimitive()? exprClass : Object.class, int.class)); 3044 } 3045 3046 if(hasSkipConversion) { 3047 assert defaultLabel == breakLabel; 3048 defaultLabel = new Label("switch_skip"); 3049 } 3050 // TABLESWITCH needs (range + 3) 32-bit values; LOOKUPSWITCH needs ((size * 2) + 2). Choose the one with 3051 // smaller representation, favor TABLESWITCH when they're equal size. 3052 if (range + 1 <= (size * 2) && range <= Integer.MAX_VALUE) { 3053 final Label[] table = new Label[(int)range]; 3054 Arrays.fill(table, defaultLabel); 3055 for (int i = 0; i < size; i++) { 3056 final int value = values[i]; 3057 table[value - lo] = labels[i]; 3058 } 3059 3060 method.tableswitch(lo, hi, defaultLabel, table); 3061 } else { 3062 final int[] ints = new int[size]; 3063 for (int i = 0; i < size; i++) { 3064 ints[i] = values[i]; 3065 } 3066 3067 method.lookupswitch(defaultLabel, ints, labels); 3068 } 3069 // This is a synthetic "default case" used in absence of actual default case, created if we need to apply 3070 // local variable conversions if neither case is taken. 3071 if(hasSkipConversion) { 3072 method.label(defaultLabel); 3073 method.beforeJoinPoint(switchNode); 3074 method._goto(breakLabel); 3075 } 3076 } else { 3077 final Symbol tagSymbol = switchNode.getTag(); 3078 // TODO: we could have non-object tag 3079 final int tagSlot = tagSymbol.getSlot(Type.OBJECT); 3080 loadExpressionAsObject(expression); 3081 method.store(tagSymbol, Type.OBJECT); 3082 3083 for (final CaseNode caseNode : cases) { 3084 final Expression test = caseNode.getTest(); 3085 3086 if (test != null) { 3087 method.load(Type.OBJECT, tagSlot); 3088 loadExpressionAsObject(test); 3089 method.invoke(ScriptRuntime.EQ_STRICT); 3090 method.ifne(caseNode.getEntry()); 3091 } 3092 } 3093 3094 if (defaultCase != null) { 3095 method._goto(defaultLabel); 3096 } else { 3097 method.beforeJoinPoint(switchNode); 3098 method._goto(breakLabel); 3099 } 3100 } 3101 3102 // First case is only reachable through jump 3103 assert !method.isReachable(); 3104 3105 for (final CaseNode caseNode : cases) { 3106 final Label fallThroughLabel; 3107 if(caseNode.getLocalVariableConversion() != null && method.isReachable()) { 3108 fallThroughLabel = new Label("fallthrough"); 3109 method._goto(fallThroughLabel); 3110 } else { 3111 fallThroughLabel = null; 3112 } 3113 method.label(caseNode.getEntry()); 3114 method.beforeJoinPoint(caseNode); 3115 if(fallThroughLabel != null) { 3116 method.label(fallThroughLabel); 3117 } 3118 caseNode.getBody().accept(this); 3119 } 3120 3121 method.breakLabel(breakLabel, liveLocalsOnBreak); 3122 3123 return false; 3124 } 3125 3126 @Override 3127 public boolean enterThrowNode(final ThrowNode throwNode) { 3128 if(!method.isReachable()) { 3129 return false; 3130 } 3131 enterStatement(throwNode); 3132 3133 if (throwNode.isSyntheticRethrow()) { 3134 method.beforeJoinPoint(throwNode); 3135 3136 //do not wrap whatever this is in an ecma exception, just rethrow it 3137 final IdentNode exceptionExpr = (IdentNode)throwNode.getExpression(); 3138 final Symbol exceptionSymbol = exceptionExpr.getSymbol(); 3139 method.load(exceptionSymbol, EXCEPTION_TYPE); 3140 method.checkcast(EXCEPTION_TYPE.getTypeClass()); 3141 method.athrow(); 3142 return false; 3143 } 3144 3145 final Source source = getCurrentSource(); 3146 final Expression expression = throwNode.getExpression(); 3147 final int position = throwNode.position(); 3148 final int line = throwNode.getLineNumber(); 3149 final int column = source.getColumn(position); 3150 3151 // NOTE: we first evaluate the expression, and only after it was evaluated do we create the new ECMAException 3152 // object and then somewhat cumbersomely move it beneath the evaluated expression on the stack. The reason for 3153 // this is that if expression is optimistic (or contains an optimistic subexpression), we'd potentially access 3154 // the not-yet-<init>ialized object on the stack from the UnwarrantedOptimismException handler, and bytecode 3155 // verifier forbids that. 3156 loadExpressionAsObject(expression); 3157 3158 method.load(source.getName()); 3159 method.load(line); 3160 method.load(column); 3161 method.invoke(ECMAException.CREATE); 3162 3163 method.beforeJoinPoint(throwNode); 3164 method.athrow(); 3165 3166 return false; 3167 } 3168 3169 private Source getCurrentSource() { 3170 return lc.getCurrentFunction().getSource(); 3171 } 3172 3173 @Override 3174 public boolean enterTryNode(final TryNode tryNode) { 3175 if(!method.isReachable()) { 3176 return false; 3177 } 3178 enterStatement(tryNode); 3179 3180 final Block body = tryNode.getBody(); 3181 final List<Block> catchBlocks = tryNode.getCatchBlocks(); 3182 final Symbol vmException = tryNode.getException(); 3183 final Label entry = new Label("try"); 3184 final Label recovery = new Label("catch"); 3185 final Label exit = new Label("end_try"); 3186 final Label skip = new Label("skip"); 3187 3188 method.canThrow(recovery); 3189 // Effect any conversions that might be observed at the entry of the catch node before entering the try node. 3190 // This is because even the first instruction in the try block must be presumed to be able to transfer control 3191 // to the catch block. Note that this doesn't kill the original values; in this regard it works a lot like 3192 // conversions of assignments within the try block. 3193 method.beforeTry(tryNode, recovery); 3194 method.label(entry); 3195 catchLabels.push(recovery); 3196 try { 3197 body.accept(this); 3198 } finally { 3199 assert catchLabels.peek() == recovery; 3200 catchLabels.pop(); 3201 } 3202 3203 method.label(exit); 3204 final boolean bodyCanThrow = exit.isAfter(entry); 3205 if(!bodyCanThrow) { 3206 // The body can't throw an exception; don't even bother emitting the catch handlers, they're all dead code. 3207 return false; 3208 } 3209 3210 method._try(entry, exit, recovery, Throwable.class); 3211 3212 if (method.isReachable()) { 3213 method._goto(skip); 3214 } 3215 3216 for (final Block inlinedFinally : tryNode.getInlinedFinallies()) { 3217 TryNode.getLabelledInlinedFinallyBlock(inlinedFinally).accept(this); 3218 // All inlined finallies end with a jump or a return 3219 assert !method.isReachable(); 3220 } 3221 3222 3223 method._catch(recovery); 3224 method.store(vmException, EXCEPTION_TYPE); 3225 3226 final int catchBlockCount = catchBlocks.size(); 3227 final Label afterCatch = new Label("after_catch"); 3228 for (int i = 0; i < catchBlockCount; i++) { 3229 assert method.isReachable(); 3230 final Block catchBlock = catchBlocks.get(i); 3231 3232 // Because of the peculiarities of the flow control, we need to use an explicit push/enterBlock/leaveBlock 3233 // here. 3234 lc.push(catchBlock); 3235 enterBlock(catchBlock); 3236 3237 final CatchNode catchNode = (CatchNode)catchBlocks.get(i).getStatements().get(0); 3238 final IdentNode exception = catchNode.getException(); 3239 final Expression exceptionCondition = catchNode.getExceptionCondition(); 3240 final Block catchBody = catchNode.getBody(); 3241 3242 new Store<IdentNode>(exception) { 3243 @Override 3244 protected void storeNonDiscard() { 3245 // This expression is neither part of a discard, nor needs to be left on the stack after it was 3246 // stored, so we override storeNonDiscard to be a no-op. 3247 } 3248 3249 @Override 3250 protected void evaluate() { 3251 if (catchNode.isSyntheticRethrow()) { 3252 method.load(vmException, EXCEPTION_TYPE); 3253 return; 3254 } 3255 /* 3256 * If caught object is an instance of ECMAException, then 3257 * bind obj.thrown to the script catch var. Or else bind the 3258 * caught object itself to the script catch var. 3259 */ 3260 final Label notEcmaException = new Label("no_ecma_exception"); 3261 method.load(vmException, EXCEPTION_TYPE).dup()._instanceof(ECMAException.class).ifeq(notEcmaException); 3262 method.checkcast(ECMAException.class); //TODO is this necessary? 3263 method.getField(ECMAException.THROWN); 3264 method.label(notEcmaException); 3265 } 3266 }.store(); 3267 3268 final boolean isConditionalCatch = exceptionCondition != null; 3269 final Label nextCatch; 3270 if (isConditionalCatch) { 3271 loadExpressionAsBoolean(exceptionCondition); 3272 nextCatch = new Label("next_catch"); 3273 nextCatch.markAsBreakTarget(); 3274 method.ifeq(nextCatch); 3275 } else { 3276 nextCatch = null; 3277 } 3278 3279 catchBody.accept(this); 3280 leaveBlock(catchBlock); 3281 lc.pop(catchBlock); 3282 if(nextCatch != null) { 3283 if(method.isReachable()) { 3284 method._goto(afterCatch); 3285 } 3286 method.breakLabel(nextCatch, lc.getUsedSlotCount()); 3287 } 3288 } 3289 3290 // afterCatch could be the same as skip, except that we need to establish that the vmException is dead. 3291 method.label(afterCatch); 3292 if(method.isReachable()) { 3293 method.markDeadLocalVariable(vmException); 3294 } 3295 method.label(skip); 3296 3297 // Finally body is always inlined elsewhere so it doesn't need to be emitted 3298 assert tryNode.getFinallyBody() == null; 3299 3300 return false; 3301 } 3302 3303 @Override 3304 public boolean enterVarNode(final VarNode varNode) { 3305 if(!method.isReachable()) { 3306 return false; 3307 } 3308 final Expression init = varNode.getInit(); 3309 final IdentNode identNode = varNode.getName(); 3310 final Symbol identSymbol = identNode.getSymbol(); 3311 assert identSymbol != null : "variable node " + varNode + " requires a name with a symbol"; 3312 final boolean needsScope = identSymbol.isScope(); 3313 3314 if (init == null) { 3315 // Block-scoped variables need a DECLARE flag to signal end of temporal dead zone (TDZ). 3316 // However, don't do this for CONST which always has an initializer except in the special case of 3317 // for-in/of loops, in which it is initialized in the loop header and should be left untouched here. 3318 if (needsScope && varNode.isLet()) { 3319 method.loadCompilerConstant(SCOPE); 3320 method.loadUndefined(Type.OBJECT); 3321 final int flags = getScopeCallSiteFlags(identSymbol) | (varNode.isBlockScoped() ? CALLSITE_DECLARE : 0); 3322 assert isFastScope(identSymbol); 3323 storeFastScopeVar(identSymbol, flags); 3324 } 3325 return false; 3326 } 3327 3328 enterStatement(varNode); 3329 assert method != null; 3330 3331 if (needsScope) { 3332 method.loadCompilerConstant(SCOPE); 3333 loadExpressionUnbounded(init); 3334 // block scoped variables need a DECLARE flag to signal end of temporal dead zone (TDZ) 3335 final int flags = getScopeCallSiteFlags(identSymbol) | (varNode.isBlockScoped() ? CALLSITE_DECLARE : 0); 3336 if (isFastScope(identSymbol)) { 3337 storeFastScopeVar(identSymbol, flags); 3338 } else { 3339 method.dynamicSet(identNode.getName(), flags, false); 3340 } 3341 } else { 3342 final Type identType = identNode.getType(); 3343 if(identType == Type.UNDEFINED) { 3344 // The initializer is either itself undefined (explicit assignment of undefined to undefined), 3345 // or the left hand side is a dead variable. 3346 assert init.getType() == Type.UNDEFINED || identNode.getSymbol().slotCount() == 0; 3347 loadAndDiscard(init); 3348 return false; 3349 } 3350 loadExpressionAsType(init, identType); 3351 storeIdentWithCatchConversion(identNode, identType); 3352 } 3353 3354 return false; 3355 } 3356 3357 private void storeIdentWithCatchConversion(final IdentNode identNode, final Type type) { 3358 // Assignments happening in try/catch blocks need to ensure that they also store a possibly wider typed value 3359 // that will be live at the exit from the try block 3360 final LocalVariableConversion conversion = identNode.getLocalVariableConversion(); 3361 final Symbol symbol = identNode.getSymbol(); 3362 if(conversion != null && conversion.isLive()) { 3363 assert symbol == conversion.getSymbol(); 3364 assert symbol.isBytecodeLocal(); 3365 // Only a single conversion from the target type to the join type is expected. 3366 assert conversion.getNext() == null; 3367 assert conversion.getFrom() == type; 3368 // We must propagate potential type change to the catch block 3369 final Label catchLabel = catchLabels.peek(); 3370 assert catchLabel != METHOD_BOUNDARY; // ident conversion only exists in try blocks 3371 assert catchLabel.isReachable(); 3372 final Type joinType = conversion.getTo(); 3373 final Label.Stack catchStack = catchLabel.getStack(); 3374 final int joinSlot = symbol.getSlot(joinType); 3375 // With nested try/catch blocks (incl. synthetic ones for finally), we can have a supposed conversion for 3376 // the exception symbol in the nested catch, but it isn't live in the outer catch block, so prevent doing 3377 // conversions for it. E.g. in "try { try { ... } catch(e) { e = 1; } } catch(e2) { ... }", we must not 3378 // introduce an I->O conversion on "e = 1" assignment as "e" is not live in "catch(e2)". 3379 if(catchStack.getUsedSlotsWithLiveTemporaries() > joinSlot) { 3380 method.dup(); 3381 method.convert(joinType); 3382 method.store(symbol, joinType); 3383 catchLabel.getStack().onLocalStore(joinType, joinSlot, true); 3384 method.canThrow(catchLabel); 3385 // Store but keep the previous store live too. 3386 method.store(symbol, type, false); 3387 return; 3388 } 3389 } 3390 3391 method.store(symbol, type, true); 3392 } 3393 3394 @Override 3395 public boolean enterWhileNode(final WhileNode whileNode) { 3396 if(!method.isReachable()) { 3397 return false; 3398 } 3399 if(whileNode.isDoWhile()) { 3400 enterDoWhile(whileNode); 3401 } else { 3402 enterStatement(whileNode); 3403 enterForOrWhile(whileNode, null); 3404 } 3405 return false; 3406 } 3407 3408 private void enterForOrWhile(final LoopNode loopNode, final JoinPredecessorExpression modify) { 3409 // NOTE: the usual pattern for compiling test-first loops is "GOTO test; body; test; IFNE body". We use the less 3410 // conventional "test; IFEQ break; body; GOTO test; break;". It has one extra unconditional GOTO in each repeat 3411 // of the loop, but it's not a problem for modern JIT compilers. We do this because our local variable type 3412 // tracking is unfortunately not really prepared for out-of-order execution, e.g. compiling the following 3413 // contrived but legal JavaScript code snippet would fail because the test changes the type of "i" from object 3414 // to double: var i = {valueOf: function() { return 1} }; while(--i >= 0) { ... } 3415 // Instead of adding more complexity to the local variable type tracking, we instead choose to emit this 3416 // different code shape. 3417 final int liveLocalsOnBreak = method.getUsedSlotsWithLiveTemporaries(); 3418 final JoinPredecessorExpression test = loopNode.getTest(); 3419 if(Expression.isAlwaysFalse(test)) { 3420 loadAndDiscard(test); 3421 return; 3422 } 3423 3424 method.beforeJoinPoint(loopNode); 3425 3426 final Label continueLabel = loopNode.getContinueLabel(); 3427 final Label repeatLabel = modify != null ? new Label("for_repeat") : continueLabel; 3428 method.label(repeatLabel); 3429 final int liveLocalsOnContinue = method.getUsedSlotsWithLiveTemporaries(); 3430 3431 final Block body = loopNode.getBody(); 3432 final Label breakLabel = loopNode.getBreakLabel(); 3433 final boolean testHasLiveConversion = test != null && LocalVariableConversion.hasLiveConversion(test); 3434 3435 if(Expression.isAlwaysTrue(test)) { 3436 if(test != null) { 3437 loadAndDiscard(test); 3438 if(testHasLiveConversion) { 3439 method.beforeJoinPoint(test); 3440 } 3441 } 3442 } else if (test != null) { 3443 if (testHasLiveConversion) { 3444 emitBranch(test.getExpression(), body.getEntryLabel(), true); 3445 method.beforeJoinPoint(test); 3446 method._goto(breakLabel); 3447 } else { 3448 emitBranch(test.getExpression(), breakLabel, false); 3449 } 3450 } 3451 3452 body.accept(this); 3453 if(repeatLabel != continueLabel) { 3454 emitContinueLabel(continueLabel, liveLocalsOnContinue); 3455 } 3456 3457 if (loopNode.hasPerIterationScope() && lc.getCurrentBlock().needsScope()) { 3458 // ES6 for loops with LET init need a new scope for each iteration. We just create a shallow copy here. 3459 method.loadCompilerConstant(SCOPE); 3460 method.invoke(virtualCallNoLookup(ScriptObject.class, "copy", ScriptObject.class)); 3461 method.storeCompilerConstant(SCOPE); 3462 } 3463 3464 if(method.isReachable()) { 3465 if(modify != null) { 3466 lineNumber(loopNode); 3467 loadAndDiscard(modify); 3468 method.beforeJoinPoint(modify); 3469 } 3470 method._goto(repeatLabel); 3471 } 3472 3473 method.breakLabel(breakLabel, liveLocalsOnBreak); 3474 } 3475 3476 private void emitContinueLabel(final Label continueLabel, final int liveLocals) { 3477 final boolean reachable = method.isReachable(); 3478 method.breakLabel(continueLabel, liveLocals); 3479 // If we reach here only through a continue statement (e.g. body does not exit normally) then the 3480 // continueLabel can have extra non-temp symbols (e.g. exception from a try/catch contained in the body). We 3481 // must make sure those are thrown away. 3482 if(!reachable) { 3483 method.undefineLocalVariables(lc.getUsedSlotCount(), false); 3484 } 3485 } 3486 3487 private void enterDoWhile(final WhileNode whileNode) { 3488 final int liveLocalsOnContinueOrBreak = method.getUsedSlotsWithLiveTemporaries(); 3489 method.beforeJoinPoint(whileNode); 3490 3491 final Block body = whileNode.getBody(); 3492 body.accept(this); 3493 3494 emitContinueLabel(whileNode.getContinueLabel(), liveLocalsOnContinueOrBreak); 3495 if(method.isReachable()) { 3496 lineNumber(whileNode); 3497 final JoinPredecessorExpression test = whileNode.getTest(); 3498 final Label bodyEntryLabel = body.getEntryLabel(); 3499 final boolean testHasLiveConversion = LocalVariableConversion.hasLiveConversion(test); 3500 if(Expression.isAlwaysFalse(test)) { 3501 loadAndDiscard(test); 3502 if(testHasLiveConversion) { 3503 method.beforeJoinPoint(test); 3504 } 3505 } else if(testHasLiveConversion) { 3506 // If we have conversions after the test in do-while, they need to be effected on both branches. 3507 final Label beforeExit = new Label("do_while_preexit"); 3508 emitBranch(test.getExpression(), beforeExit, false); 3509 method.beforeJoinPoint(test); 3510 method._goto(bodyEntryLabel); 3511 method.label(beforeExit); 3512 method.beforeJoinPoint(test); 3513 } else { 3514 emitBranch(test.getExpression(), bodyEntryLabel, true); 3515 } 3516 } 3517 method.breakLabel(whileNode.getBreakLabel(), liveLocalsOnContinueOrBreak); 3518 } 3519 3520 3521 @Override 3522 public boolean enterWithNode(final WithNode withNode) { 3523 if(!method.isReachable()) { 3524 return false; 3525 } 3526 enterStatement(withNode); 3527 final Expression expression = withNode.getExpression(); 3528 final Block body = withNode.getBody(); 3529 3530 // It is possible to have a "pathological" case where the with block does not reference *any* identifiers. It's 3531 // pointless, but legal. In that case, if nothing else in the method forced the assignment of a slot to the 3532 // scope object, its' possible that it won't have a slot assigned. In this case we'll only evaluate expression 3533 // for its side effect and visit the body, and not bother opening and closing a WithObject. 3534 final boolean hasScope = method.hasScope(); 3535 3536 if (hasScope) { 3537 method.loadCompilerConstant(SCOPE); 3538 } 3539 3540 loadExpressionAsObject(expression); 3541 3542 final Label tryLabel; 3543 if (hasScope) { 3544 // Construct a WithObject if we have a scope 3545 method.invoke(ScriptRuntime.OPEN_WITH); 3546 method.storeCompilerConstant(SCOPE); 3547 tryLabel = new Label("with_try"); 3548 method.label(tryLabel); 3549 } else { 3550 // We just loaded the expression for its side effect and to check 3551 // for null or undefined value. 3552 globalCheckObjectCoercible(); 3553 tryLabel = null; 3554 } 3555 3556 // Always process body 3557 body.accept(this); 3558 3559 if (hasScope) { 3560 // Ensure we always close the WithObject 3561 final Label endLabel = new Label("with_end"); 3562 final Label catchLabel = new Label("with_catch"); 3563 final Label exitLabel = new Label("with_exit"); 3564 3565 method.label(endLabel); 3566 // Somewhat conservatively presume that if the body is not empty, it can throw an exception. In any case, 3567 // we must prevent trying to emit a try-catch for empty range, as it causes a verification error. 3568 final boolean bodyCanThrow = endLabel.isAfter(tryLabel); 3569 if(bodyCanThrow) { 3570 method._try(tryLabel, endLabel, catchLabel); 3571 } 3572 3573 final boolean reachable = method.isReachable(); 3574 if(reachable) { 3575 popScope(); 3576 if(bodyCanThrow) { 3577 method._goto(exitLabel); 3578 } 3579 } 3580 3581 if(bodyCanThrow) { 3582 method._catch(catchLabel); 3583 popScopeException(); 3584 method.athrow(); 3585 if(reachable) { 3586 method.label(exitLabel); 3587 } 3588 } 3589 } 3590 return false; 3591 } 3592 3593 private void loadADD(final UnaryNode unaryNode, final TypeBounds resultBounds) { 3594 loadExpression(unaryNode.getExpression(), resultBounds.booleanToInt().notWiderThan(Type.NUMBER)); 3595 if(method.peekType() == Type.BOOLEAN) { 3596 // It's a no-op in bytecode, but we must make sure it is treated as an int for purposes of type signatures 3597 method.convert(Type.INT); 3598 } 3599 } 3600 3601 private void loadBIT_NOT(final UnaryNode unaryNode) { 3602 loadExpression(unaryNode.getExpression(), TypeBounds.INT).load(-1).xor(); 3603 } 3604 3605 private void loadDECINC(final UnaryNode unaryNode) { 3606 final Expression operand = unaryNode.getExpression(); 3607 final Type type = unaryNode.getType(); 3608 final TypeBounds typeBounds = new TypeBounds(type, Type.NUMBER); 3609 final TokenType tokenType = unaryNode.tokenType(); 3610 final boolean isPostfix = tokenType == TokenType.DECPOSTFIX || tokenType == TokenType.INCPOSTFIX; 3611 final boolean isIncrement = tokenType == TokenType.INCPREFIX || tokenType == TokenType.INCPOSTFIX; 3612 3613 assert !type.isObject(); 3614 3615 new SelfModifyingStore<UnaryNode>(unaryNode, operand) { 3616 3617 private void loadRhs() { 3618 loadExpression(operand, typeBounds, true); 3619 } 3620 3621 @Override 3622 protected void evaluate() { 3623 if(isPostfix) { 3624 loadRhs(); 3625 } else { 3626 new OptimisticOperation(unaryNode, typeBounds) { 3627 @Override 3628 void loadStack() { 3629 loadRhs(); 3630 loadMinusOne(); 3631 } 3632 @Override 3633 void consumeStack() { 3634 doDecInc(getProgramPoint()); 3635 } 3636 }.emit(getOptimisticIgnoreCountForSelfModifyingExpression(operand)); 3637 } 3638 } 3639 3640 @Override 3641 protected void storeNonDiscard() { 3642 super.storeNonDiscard(); 3643 if (isPostfix) { 3644 new OptimisticOperation(unaryNode, typeBounds) { 3645 @Override 3646 void loadStack() { 3647 loadMinusOne(); 3648 } 3649 @Override 3650 void consumeStack() { 3651 doDecInc(getProgramPoint()); 3652 } 3653 }.emit(1); // 1 for non-incremented result on the top of the stack pushed in evaluate() 3654 } 3655 } 3656 3657 private void loadMinusOne() { 3658 if (type.isInteger()) { 3659 method.load(isIncrement ? 1 : -1); 3660 } else { 3661 method.load(isIncrement ? 1.0 : -1.0); 3662 } 3663 } 3664 3665 private void doDecInc(final int programPoint) { 3666 method.add(programPoint); 3667 } 3668 }.store(); 3669 } 3670 3671 private static int getOptimisticIgnoreCountForSelfModifyingExpression(final Expression target) { 3672 return target instanceof AccessNode ? 1 : target instanceof IndexNode ? 2 : 0; 3673 } 3674 3675 private void loadAndDiscard(final Expression expr) { 3676 // TODO: move checks for discarding to actual expression load code (e.g. as we do with void). That way we might 3677 // be able to eliminate even more checks. 3678 if(expr instanceof PrimitiveLiteralNode | isLocalVariable(expr)) { 3679 assert !lc.isCurrentDiscard(expr); 3680 // Don't bother evaluating expressions without side effects. Typical usage is "void 0" for reliably generating 3681 // undefined. 3682 return; 3683 } 3684 3685 lc.pushDiscard(expr); 3686 loadExpression(expr, TypeBounds.UNBOUNDED); 3687 if (lc.popDiscardIfCurrent(expr)) { 3688 assert !expr.isAssignment(); 3689 // NOTE: if we had a way to load with type void, we could avoid popping 3690 method.pop(); 3691 } 3692 } 3693 3694 /** 3695 * Loads the expression with the specified type bounds, but if the parent expression is the current discard, 3696 * then instead loads and discards the expression. 3697 * @param parent the parent expression that's tested for being the current discard 3698 * @param expr the expression that's either normally loaded or discard-loaded 3699 * @param resultBounds result bounds for when loading the expression normally 3700 */ 3701 private void loadMaybeDiscard(final Expression parent, final Expression expr, final TypeBounds resultBounds) { 3702 loadMaybeDiscard(lc.popDiscardIfCurrent(parent), expr, resultBounds); 3703 } 3704 3705 /** 3706 * Loads the expression with the specified type bounds, or loads and discards the expression, depending on the 3707 * value of the discard flag. Useful as a helper for expressions with control flow where you often can't combine 3708 * testing for being the current discard and loading the subexpressions. 3709 * @param discard if true, the expression is loaded and discarded 3710 * @param expr the expression that's either normally loaded or discard-loaded 3711 * @param resultBounds result bounds for when loading the expression normally 3712 */ 3713 private void loadMaybeDiscard(final boolean discard, final Expression expr, final TypeBounds resultBounds) { 3714 if (discard) { 3715 loadAndDiscard(expr); 3716 } else { 3717 loadExpression(expr, resultBounds); 3718 } 3719 } 3720 3721 private void loadNEW(final UnaryNode unaryNode) { 3722 final CallNode callNode = (CallNode)unaryNode.getExpression(); 3723 final List<Expression> args = callNode.getArgs(); 3724 3725 final Expression func = callNode.getFunction(); 3726 // Load function reference. 3727 loadExpressionAsObject(func); // must detect type error 3728 3729 method.dynamicNew(1 + loadArgs(args), getCallSiteFlags(), func.toString(false)); 3730 } 3731 3732 private void loadNOT(final UnaryNode unaryNode) { 3733 final Expression expr = unaryNode.getExpression(); 3734 if(expr instanceof UnaryNode && expr.isTokenType(TokenType.NOT)) { 3735 // !!x is idiomatic boolean cast in JavaScript 3736 loadExpressionAsBoolean(((UnaryNode)expr).getExpression()); 3737 } else { 3738 final Label trueLabel = new Label("true"); 3739 final Label afterLabel = new Label("after"); 3740 3741 emitBranch(expr, trueLabel, true); 3742 method.load(true); 3743 method._goto(afterLabel); 3744 method.label(trueLabel); 3745 method.load(false); 3746 method.label(afterLabel); 3747 } 3748 } 3749 3750 private void loadSUB(final UnaryNode unaryNode, final TypeBounds resultBounds) { 3751 final Type type = unaryNode.getType(); 3752 assert type.isNumeric(); 3753 final TypeBounds numericBounds = resultBounds.booleanToInt(); 3754 new OptimisticOperation(unaryNode, numericBounds) { 3755 @Override 3756 void loadStack() { 3757 final Expression expr = unaryNode.getExpression(); 3758 loadExpression(expr, numericBounds.notWiderThan(Type.NUMBER)); 3759 } 3760 @Override 3761 void consumeStack() { 3762 // Must do an explicit conversion to the operation's type when it's double so that we correctly handle 3763 // negation of an int 0 to a double -0. With this, we get the correct negation of a local variable after 3764 // it deoptimized, e.g. "iload_2; i2d; dneg". Without this, we get "iload_2; ineg; i2d". 3765 if(type.isNumber()) { 3766 method.convert(type); 3767 } 3768 method.neg(getProgramPoint()); 3769 } 3770 }.emit(); 3771 } 3772 3773 public void loadVOID(final UnaryNode unaryNode, final TypeBounds resultBounds) { 3774 loadAndDiscard(unaryNode.getExpression()); 3775 if (!lc.popDiscardIfCurrent(unaryNode)) { 3776 method.loadUndefined(resultBounds.widest); 3777 } 3778 } 3779 3780 public void loadADD(final BinaryNode binaryNode, final TypeBounds resultBounds) { 3781 new OptimisticOperation(binaryNode, resultBounds) { 3782 @Override 3783 void loadStack() { 3784 final TypeBounds operandBounds; 3785 final boolean isOptimistic = isValid(getProgramPoint()); 3786 boolean forceConversionSeparation = false; 3787 if(isOptimistic) { 3788 operandBounds = new TypeBounds(binaryNode.getType(), Type.OBJECT); 3789 } else { 3790 // Non-optimistic, non-FP +. Allow it to overflow. 3791 final Type widestOperationType = binaryNode.getWidestOperationType(); 3792 operandBounds = new TypeBounds(Type.narrowest(binaryNode.getWidestOperandType(), resultBounds.widest), widestOperationType); 3793 forceConversionSeparation = widestOperationType.narrowerThan(resultBounds.widest); 3794 } 3795 loadBinaryOperands(binaryNode.lhs(), binaryNode.rhs(), operandBounds, false, forceConversionSeparation); 3796 } 3797 3798 @Override 3799 void consumeStack() { 3800 method.add(getProgramPoint()); 3801 } 3802 }.emit(); 3803 } 3804 3805 private void loadAND_OR(final BinaryNode binaryNode, final TypeBounds resultBounds, final boolean isAnd) { 3806 final Type narrowestOperandType = Type.widestReturnType(binaryNode.lhs().getType(), binaryNode.rhs().getType()); 3807 3808 final boolean isCurrentDiscard = lc.popDiscardIfCurrent(binaryNode); 3809 3810 final Label skip = new Label("skip"); 3811 if(narrowestOperandType == Type.BOOLEAN) { 3812 // optimize all-boolean logical expressions 3813 final Label onTrue = new Label("andor_true"); 3814 emitBranch(binaryNode, onTrue, true); 3815 if (isCurrentDiscard) { 3816 method.label(onTrue); 3817 } else { 3818 method.load(false); 3819 method._goto(skip); 3820 method.label(onTrue); 3821 method.load(true); 3822 method.label(skip); 3823 } 3824 return; 3825 } 3826 3827 final TypeBounds outBounds = resultBounds.notNarrowerThan(narrowestOperandType); 3828 final JoinPredecessorExpression lhs = (JoinPredecessorExpression)binaryNode.lhs(); 3829 final boolean lhsConvert = LocalVariableConversion.hasLiveConversion(lhs); 3830 final Label evalRhs = lhsConvert ? new Label("eval_rhs") : null; 3831 3832 loadExpression(lhs, outBounds); 3833 if (!isCurrentDiscard) { 3834 method.dup(); 3835 } 3836 method.convert(Type.BOOLEAN); 3837 if (isAnd) { 3838 if(lhsConvert) { 3839 method.ifne(evalRhs); 3840 } else { 3841 method.ifeq(skip); 3842 } 3843 } else if(lhsConvert) { 3844 method.ifeq(evalRhs); 3845 } else { 3846 method.ifne(skip); 3847 } 3848 3849 if(lhsConvert) { 3850 method.beforeJoinPoint(lhs); 3851 method._goto(skip); 3852 method.label(evalRhs); 3853 } 3854 3855 if (!isCurrentDiscard) { 3856 method.pop(); 3857 } 3858 final JoinPredecessorExpression rhs = (JoinPredecessorExpression)binaryNode.rhs(); 3859 loadMaybeDiscard(isCurrentDiscard, rhs, outBounds); 3860 method.beforeJoinPoint(rhs); 3861 method.label(skip); 3862 } 3863 3864 private static boolean isLocalVariable(final Expression lhs) { 3865 return lhs instanceof IdentNode && isLocalVariable((IdentNode)lhs); 3866 } 3867 3868 private static boolean isLocalVariable(final IdentNode lhs) { 3869 return lhs.getSymbol().isBytecodeLocal(); 3870 } 3871 3872 // NOTE: does not use resultBounds as the assignment is driven by the type of the RHS 3873 private void loadASSIGN(final BinaryNode binaryNode) { 3874 final Expression lhs = binaryNode.lhs(); 3875 final Expression rhs = binaryNode.rhs(); 3876 3877 final Type rhsType = rhs.getType(); 3878 // Detect dead assignments 3879 if(lhs instanceof IdentNode) { 3880 final Symbol symbol = ((IdentNode)lhs).getSymbol(); 3881 if(!symbol.isScope() && !symbol.hasSlotFor(rhsType) && lc.popDiscardIfCurrent(binaryNode)) { 3882 loadAndDiscard(rhs); 3883 method.markDeadLocalVariable(symbol); 3884 return; 3885 } 3886 } 3887 3888 new Store<BinaryNode>(binaryNode, lhs) { 3889 @Override 3890 protected void evaluate() { 3891 // NOTE: we're loading with "at least as wide as" so optimistic operations on the right hand side 3892 // remain optimistic, and then explicitly convert to the required type if needed. 3893 loadExpressionAsType(rhs, rhsType); 3894 } 3895 }.store(); 3896 } 3897 3898 /** 3899 * Binary self-assignment that can be optimistic: +=, -=, *=, and /=. 3900 */ 3901 private abstract class BinaryOptimisticSelfAssignment extends SelfModifyingStore<BinaryNode> { 3902 3903 /** 3904 * Constructor 3905 * 3906 * @param node the assign op node 3907 */ 3908 BinaryOptimisticSelfAssignment(final BinaryNode node) { 3909 super(node, node.lhs()); 3910 } 3911 3912 protected abstract void op(OptimisticOperation oo); 3913 3914 @Override 3915 protected void evaluate() { 3916 final Expression lhs = assignNode.lhs(); 3917 final Expression rhs = assignNode.rhs(); 3918 final Type widestOperationType = assignNode.getWidestOperationType(); 3919 final TypeBounds bounds = new TypeBounds(assignNode.getType(), widestOperationType); 3920 new OptimisticOperation(assignNode, bounds) { 3921 @Override 3922 void loadStack() { 3923 final boolean forceConversionSeparation; 3924 if (isValid(getProgramPoint()) || widestOperationType == Type.NUMBER) { 3925 forceConversionSeparation = false; 3926 } else { 3927 final Type operandType = Type.widest(booleanToInt(objectToNumber(lhs.getType())), booleanToInt(objectToNumber(rhs.getType()))); 3928 forceConversionSeparation = operandType.narrowerThan(widestOperationType); 3929 } 3930 loadBinaryOperands(lhs, rhs, bounds, true, forceConversionSeparation); 3931 } 3932 @Override 3933 void consumeStack() { 3934 op(this); 3935 } 3936 }.emit(getOptimisticIgnoreCountForSelfModifyingExpression(lhs)); 3937 method.convert(assignNode.getType()); 3938 } 3939 } 3940 3941 /** 3942 * Non-optimistic binary self-assignment operation. Basically, everything except +=, -=, *=, and /=. 3943 */ 3944 private abstract class BinarySelfAssignment extends SelfModifyingStore<BinaryNode> { 3945 BinarySelfAssignment(final BinaryNode node) { 3946 super(node, node.lhs()); 3947 } 3948 3949 protected abstract void op(); 3950 3951 @Override 3952 protected void evaluate() { 3953 loadBinaryOperands(assignNode.lhs(), assignNode.rhs(), TypeBounds.UNBOUNDED.notWiderThan(assignNode.getWidestOperandType()), true, false); 3954 op(); 3955 } 3956 } 3957 3958 private void loadASSIGN_ADD(final BinaryNode binaryNode) { 3959 new BinaryOptimisticSelfAssignment(binaryNode) { 3960 @Override 3961 protected void op(final OptimisticOperation oo) { 3962 assert !(binaryNode.getType().isObject() && oo.isOptimistic); 3963 method.add(oo.getProgramPoint()); 3964 } 3965 }.store(); 3966 } 3967 3968 private void loadASSIGN_BIT_AND(final BinaryNode binaryNode) { 3969 new BinarySelfAssignment(binaryNode) { 3970 @Override 3971 protected void op() { 3972 method.and(); 3973 } 3974 }.store(); 3975 } 3976 3977 private void loadASSIGN_BIT_OR(final BinaryNode binaryNode) { 3978 new BinarySelfAssignment(binaryNode) { 3979 @Override 3980 protected void op() { 3981 method.or(); 3982 } 3983 }.store(); 3984 } 3985 3986 private void loadASSIGN_BIT_XOR(final BinaryNode binaryNode) { 3987 new BinarySelfAssignment(binaryNode) { 3988 @Override 3989 protected void op() { 3990 method.xor(); 3991 } 3992 }.store(); 3993 } 3994 3995 private void loadASSIGN_DIV(final BinaryNode binaryNode) { 3996 new BinaryOptimisticSelfAssignment(binaryNode) { 3997 @Override 3998 protected void op(final OptimisticOperation oo) { 3999 method.div(oo.getProgramPoint()); 4000 } 4001 }.store(); 4002 } 4003 4004 private void loadASSIGN_MOD(final BinaryNode binaryNode) { 4005 new BinaryOptimisticSelfAssignment(binaryNode) { 4006 @Override 4007 protected void op(final OptimisticOperation oo) { 4008 method.rem(oo.getProgramPoint()); 4009 } 4010 }.store(); 4011 } 4012 4013 private void loadASSIGN_MUL(final BinaryNode binaryNode) { 4014 new BinaryOptimisticSelfAssignment(binaryNode) { 4015 @Override 4016 protected void op(final OptimisticOperation oo) { 4017 method.mul(oo.getProgramPoint()); 4018 } 4019 }.store(); 4020 } 4021 4022 private void loadASSIGN_SAR(final BinaryNode binaryNode) { 4023 new BinarySelfAssignment(binaryNode) { 4024 @Override 4025 protected void op() { 4026 method.sar(); 4027 } 4028 }.store(); 4029 } 4030 4031 private void loadASSIGN_SHL(final BinaryNode binaryNode) { 4032 new BinarySelfAssignment(binaryNode) { 4033 @Override 4034 protected void op() { 4035 method.shl(); 4036 } 4037 }.store(); 4038 } 4039 4040 private void loadASSIGN_SHR(final BinaryNode binaryNode) { 4041 new SelfModifyingStore<BinaryNode>(binaryNode, binaryNode.lhs()) { 4042 @Override 4043 protected void evaluate() { 4044 new OptimisticOperation(assignNode, new TypeBounds(Type.INT, Type.NUMBER)) { 4045 @Override 4046 void loadStack() { 4047 assert assignNode.getWidestOperandType() == Type.INT; 4048 if (isRhsZero(binaryNode)) { 4049 loadExpressionAsType(binaryNode.lhs(), Type.INT); 4050 } else { 4051 loadBinaryOperands(binaryNode.lhs(), binaryNode.rhs(), TypeBounds.INT, true, false); 4052 method.shr(); 4053 } 4054 } 4055 4056 @Override 4057 void consumeStack() { 4058 if (isOptimistic(binaryNode)) { 4059 toUint32Optimistic(binaryNode.getProgramPoint()); 4060 } else { 4061 toUint32Double(); 4062 } 4063 } 4064 }.emit(getOptimisticIgnoreCountForSelfModifyingExpression(binaryNode.lhs())); 4065 method.convert(assignNode.getType()); 4066 } 4067 }.store(); 4068 } 4069 4070 private void doSHR(final BinaryNode binaryNode) { 4071 new OptimisticOperation(binaryNode, new TypeBounds(Type.INT, Type.NUMBER)) { 4072 @Override 4073 void loadStack() { 4074 if (isRhsZero(binaryNode)) { 4075 loadExpressionAsType(binaryNode.lhs(), Type.INT); 4076 } else { 4077 loadBinaryOperands(binaryNode); 4078 method.shr(); 4079 } 4080 } 4081 4082 @Override 4083 void consumeStack() { 4084 if (isOptimistic(binaryNode)) { 4085 toUint32Optimistic(binaryNode.getProgramPoint()); 4086 } else { 4087 toUint32Double(); 4088 } 4089 } 4090 }.emit(); 4091 4092 } 4093 4094 private void toUint32Optimistic(final int programPoint) { 4095 method.load(programPoint); 4096 JSType.TO_UINT32_OPTIMISTIC.invoke(method); 4097 } 4098 4099 private void toUint32Double() { 4100 JSType.TO_UINT32_DOUBLE.invoke(method); 4101 } 4102 4103 private void loadASSIGN_SUB(final BinaryNode binaryNode) { 4104 new BinaryOptimisticSelfAssignment(binaryNode) { 4105 @Override 4106 protected void op(final OptimisticOperation oo) { 4107 method.sub(oo.getProgramPoint()); 4108 } 4109 }.store(); 4110 } 4111 4112 /** 4113 * Helper class for binary arithmetic ops 4114 */ 4115 private abstract class BinaryArith { 4116 protected abstract void op(int programPoint); 4117 4118 protected void evaluate(final BinaryNode node, final TypeBounds resultBounds) { 4119 final TypeBounds numericBounds = resultBounds.booleanToInt().objectToNumber(); 4120 new OptimisticOperation(node, numericBounds) { 4121 @Override 4122 void loadStack() { 4123 final TypeBounds operandBounds; 4124 boolean forceConversionSeparation = false; 4125 if(numericBounds.narrowest == Type.NUMBER) { 4126 // Result should be double always. Propagate it into the operands so we don't have lots of I2D 4127 // and L2D after operand evaluation. 4128 assert numericBounds.widest == Type.NUMBER; 4129 operandBounds = numericBounds; 4130 } else { 4131 final boolean isOptimistic = isValid(getProgramPoint()); 4132 if(isOptimistic || node.isTokenType(TokenType.DIV) || node.isTokenType(TokenType.MOD)) { 4133 operandBounds = new TypeBounds(node.getType(), Type.NUMBER); 4134 } else { 4135 // Non-optimistic, non-FP subtraction or multiplication. Allow them to overflow. 4136 operandBounds = new TypeBounds(Type.narrowest(node.getWidestOperandType(), 4137 numericBounds.widest), Type.NUMBER); 4138 forceConversionSeparation = true; 4139 } 4140 } 4141 loadBinaryOperands(node.lhs(), node.rhs(), operandBounds, false, forceConversionSeparation); 4142 } 4143 4144 @Override 4145 void consumeStack() { 4146 op(getProgramPoint()); 4147 } 4148 }.emit(); 4149 } 4150 } 4151 4152 private void loadBIT_AND(final BinaryNode binaryNode) { 4153 loadBinaryOperands(binaryNode); 4154 method.and(); 4155 } 4156 4157 private void loadBIT_OR(final BinaryNode binaryNode) { 4158 // Optimize x|0 to (int)x 4159 if (isRhsZero(binaryNode)) { 4160 loadExpressionAsType(binaryNode.lhs(), Type.INT); 4161 } else { 4162 loadBinaryOperands(binaryNode); 4163 method.or(); 4164 } 4165 } 4166 4167 private static boolean isRhsZero(final BinaryNode binaryNode) { 4168 final Expression rhs = binaryNode.rhs(); 4169 return rhs instanceof LiteralNode && INT_ZERO.equals(((LiteralNode<?>)rhs).getValue()); 4170 } 4171 4172 private void loadBIT_XOR(final BinaryNode binaryNode) { 4173 loadBinaryOperands(binaryNode); 4174 method.xor(); 4175 } 4176 4177 private void loadCOMMARIGHT(final BinaryNode binaryNode, final TypeBounds resultBounds) { 4178 loadAndDiscard(binaryNode.lhs()); 4179 loadMaybeDiscard(binaryNode, binaryNode.rhs(), resultBounds); 4180 } 4181 4182 private void loadCOMMALEFT(final BinaryNode binaryNode, final TypeBounds resultBounds) { 4183 loadMaybeDiscard(binaryNode, binaryNode.lhs(), resultBounds); 4184 loadAndDiscard(binaryNode.rhs()); 4185 } 4186 4187 private void loadDIV(final BinaryNode binaryNode, final TypeBounds resultBounds) { 4188 new BinaryArith() { 4189 @Override 4190 protected void op(final int programPoint) { 4191 method.div(programPoint); 4192 } 4193 }.evaluate(binaryNode, resultBounds); 4194 } 4195 4196 private void loadCmp(final BinaryNode binaryNode, final Condition cond) { 4197 loadComparisonOperands(binaryNode); 4198 4199 final Label trueLabel = new Label("trueLabel"); 4200 final Label afterLabel = new Label("skip"); 4201 4202 method.conditionalJump(cond, trueLabel); 4203 4204 method.load(Boolean.FALSE); 4205 method._goto(afterLabel); 4206 method.label(trueLabel); 4207 method.load(Boolean.TRUE); 4208 method.label(afterLabel); 4209 } 4210 4211 private void loadMOD(final BinaryNode binaryNode, final TypeBounds resultBounds) { 4212 new BinaryArith() { 4213 @Override 4214 protected void op(final int programPoint) { 4215 method.rem(programPoint); 4216 } 4217 }.evaluate(binaryNode, resultBounds); 4218 } 4219 4220 private void loadMUL(final BinaryNode binaryNode, final TypeBounds resultBounds) { 4221 new BinaryArith() { 4222 @Override 4223 protected void op(final int programPoint) { 4224 method.mul(programPoint); 4225 } 4226 }.evaluate(binaryNode, resultBounds); 4227 } 4228 4229 private void loadSAR(final BinaryNode binaryNode) { 4230 loadBinaryOperands(binaryNode); 4231 method.sar(); 4232 } 4233 4234 private void loadSHL(final BinaryNode binaryNode) { 4235 loadBinaryOperands(binaryNode); 4236 method.shl(); 4237 } 4238 4239 private void loadSHR(final BinaryNode binaryNode) { 4240 doSHR(binaryNode); 4241 } 4242 4243 private void loadSUB(final BinaryNode binaryNode, final TypeBounds resultBounds) { 4244 new BinaryArith() { 4245 @Override 4246 protected void op(final int programPoint) { 4247 method.sub(programPoint); 4248 } 4249 }.evaluate(binaryNode, resultBounds); 4250 } 4251 4252 @Override 4253 public boolean enterLabelNode(final LabelNode labelNode) { 4254 labeledBlockBreakLiveLocals.push(lc.getUsedSlotCount()); 4255 return true; 4256 } 4257 4258 @Override 4259 protected boolean enterDefault(final Node node) { 4260 throw new AssertionError("Code generator entered node of type " + node.getClass().getName()); 4261 } 4262 4263 private void loadTernaryNode(final TernaryNode ternaryNode, final TypeBounds resultBounds) { 4264 final Expression test = ternaryNode.getTest(); 4265 final JoinPredecessorExpression trueExpr = ternaryNode.getTrueExpression(); 4266 final JoinPredecessorExpression falseExpr = ternaryNode.getFalseExpression(); 4267 4268 final Label falseLabel = new Label("ternary_false"); 4269 final Label exitLabel = new Label("ternary_exit"); 4270 4271 final Type outNarrowest = Type.narrowest(resultBounds.widest, Type.generic(Type.widestReturnType(trueExpr.getType(), falseExpr.getType()))); 4272 final TypeBounds outBounds = resultBounds.notNarrowerThan(outNarrowest); 4273 4274 emitBranch(test, falseLabel, false); 4275 4276 final boolean isCurrentDiscard = lc.popDiscardIfCurrent(ternaryNode); 4277 loadMaybeDiscard(isCurrentDiscard, trueExpr.getExpression(), outBounds); 4278 assert isCurrentDiscard || Type.generic(method.peekType()) == outBounds.narrowest; 4279 method.beforeJoinPoint(trueExpr); 4280 method._goto(exitLabel); 4281 method.label(falseLabel); 4282 loadMaybeDiscard(isCurrentDiscard, falseExpr.getExpression(), outBounds); 4283 assert isCurrentDiscard || Type.generic(method.peekType()) == outBounds.narrowest; 4284 method.beforeJoinPoint(falseExpr); 4285 method.label(exitLabel); 4286 } 4287 4288 /** 4289 * Generate all shared scope calls generated during codegen. 4290 */ 4291 void generateScopeCalls() { 4292 for (final SharedScopeCall scopeAccess : lc.getScopeCalls()) { 4293 scopeAccess.generateScopeCall(); 4294 } 4295 } 4296 4297 /** 4298 * Debug code used to print symbols 4299 * 4300 * @param block the block we are in 4301 * @param function the function we are in 4302 * @param ident identifier for block or function where applicable 4303 */ 4304 private void printSymbols(final Block block, final FunctionNode function, final String ident) { 4305 if (compiler.getScriptEnvironment()._print_symbols || function.getFlag(FunctionNode.IS_PRINT_SYMBOLS)) { 4306 final PrintWriter out = compiler.getScriptEnvironment().getErr(); 4307 out.println("[BLOCK in '" + ident + "']"); 4308 if (!block.printSymbols(out)) { 4309 out.println("<no symbols>"); 4310 } 4311 out.println(); 4312 } 4313 } 4314 4315 4316 /** 4317 * The difference between a store and a self modifying store is that 4318 * the latter may load part of the target on the stack, e.g. the base 4319 * of an AccessNode or the base and index of an IndexNode. These are used 4320 * both as target and as an extra source. Previously it was problematic 4321 * for self modifying stores if the target/lhs didn't belong to one 4322 * of three trivial categories: IdentNode, AcessNodes, IndexNodes. In that 4323 * case it was evaluated and tagged as "resolved", which meant at the second 4324 * time the lhs of this store was read (e.g. in a = a (second) + b for a += b, 4325 * it would be evaluated to a nop in the scope and cause stack underflow 4326 * 4327 * see NASHORN-703 4328 * 4329 * @param <T> 4330 */ 4331 private abstract class SelfModifyingStore<T extends Expression> extends Store<T> { 4332 protected SelfModifyingStore(final T assignNode, final Expression target) { 4333 super(assignNode, target); 4334 } 4335 4336 @Override 4337 protected boolean isSelfModifying() { 4338 return true; 4339 } 4340 } 4341 4342 /** 4343 * Helper class to generate stores 4344 */ 4345 private abstract class Store<T extends Expression> { 4346 4347 /** An assignment node, e.g. x += y */ 4348 protected final T assignNode; 4349 4350 /** The target node to store to, e.g. x */ 4351 private final Expression target; 4352 4353 /** How deep on the stack do the arguments go if this generates an indy call */ 4354 private int depth; 4355 4356 /** If we have too many arguments, we need temporary storage, this is stored in 'quick' */ 4357 private IdentNode quick; 4358 4359 /** 4360 * Constructor 4361 * 4362 * @param assignNode the node representing the whole assignment 4363 * @param target the target node of the assignment (destination) 4364 */ 4365 protected Store(final T assignNode, final Expression target) { 4366 this.assignNode = assignNode; 4367 this.target = target; 4368 } 4369 4370 /** 4371 * Constructor 4372 * 4373 * @param assignNode the node representing the whole assignment 4374 */ 4375 protected Store(final T assignNode) { 4376 this(assignNode, assignNode); 4377 } 4378 4379 /** 4380 * Is this a self modifying store operation, e.g. *= or ++ 4381 * @return true if self modifying store 4382 */ 4383 protected boolean isSelfModifying() { 4384 return false; 4385 } 4386 4387 private void prologue() { 4388 /* 4389 * This loads the parts of the target, e.g base and index. they are kept 4390 * on the stack throughout the store and used at the end to execute it 4391 */ 4392 4393 target.accept(new SimpleNodeVisitor() { 4394 @Override 4395 public boolean enterIdentNode(final IdentNode node) { 4396 if (node.getSymbol().isScope()) { 4397 method.loadCompilerConstant(SCOPE); 4398 depth += Type.SCOPE.getSlots(); 4399 assert depth == 1; 4400 } 4401 return false; 4402 } 4403 4404 private void enterBaseNode() { 4405 assert target instanceof BaseNode : "error - base node " + target + " must be instanceof BaseNode"; 4406 final BaseNode baseNode = (BaseNode)target; 4407 final Expression base = baseNode.getBase(); 4408 4409 loadExpressionAsObject(base); 4410 depth += Type.OBJECT.getSlots(); 4411 assert depth == 1; 4412 4413 if (isSelfModifying()) { 4414 method.dup(); 4415 } 4416 } 4417 4418 @Override 4419 public boolean enterAccessNode(final AccessNode node) { 4420 enterBaseNode(); 4421 return false; 4422 } 4423 4424 @Override 4425 public boolean enterIndexNode(final IndexNode node) { 4426 enterBaseNode(); 4427 4428 final Expression index = node.getIndex(); 4429 if (!index.getType().isNumeric()) { 4430 // could be boolean here as well 4431 loadExpressionAsObject(index); 4432 } else { 4433 loadExpressionUnbounded(index); 4434 } 4435 depth += index.getType().getSlots(); 4436 4437 if (isSelfModifying()) { 4438 //convert "base base index" to "base index base index" 4439 method.dup(1); 4440 } 4441 4442 return false; 4443 } 4444 4445 }); 4446 } 4447 4448 /** 4449 * Generates an extra local variable, always using the same slot, one that is available after the end of the 4450 * frame. 4451 * 4452 * @param type the type of the variable 4453 * 4454 * @return the quick variable 4455 */ 4456 private IdentNode quickLocalVariable(final Type type) { 4457 final String name = lc.getCurrentFunction().uniqueName(QUICK_PREFIX.symbolName()); 4458 final Symbol symbol = new Symbol(name, IS_INTERNAL | HAS_SLOT); 4459 symbol.setHasSlotFor(type); 4460 symbol.setFirstSlot(lc.quickSlot(type)); 4461 4462 final IdentNode quickIdent = IdentNode.createInternalIdentifier(symbol).setType(type); 4463 4464 return quickIdent; 4465 } 4466 4467 // store the result that "lives on" after the op, e.g. "i" in i++ postfix. 4468 protected void storeNonDiscard() { 4469 if (lc.popDiscardIfCurrent(assignNode)) { 4470 assert assignNode.isAssignment(); 4471 return; 4472 } 4473 4474 if (method.dup(depth) == null) { 4475 method.dup(); 4476 final Type quickType = method.peekType(); 4477 this.quick = quickLocalVariable(quickType); 4478 final Symbol quickSymbol = quick.getSymbol(); 4479 method.storeTemp(quickType, quickSymbol.getFirstSlot()); 4480 } 4481 } 4482 4483 private void epilogue() { 4484 /** 4485 * Take the original target args from the stack and use them 4486 * together with the value to be stored to emit the store code 4487 * 4488 * The case that targetSymbol is in scope (!hasSlot) and we actually 4489 * need to do a conversion on non-equivalent types exists, but is 4490 * very rare. See for example test/script/basic/access-specializer.js 4491 */ 4492 target.accept(new SimpleNodeVisitor() { 4493 @Override 4494 protected boolean enterDefault(final Node node) { 4495 throw new AssertionError("Unexpected node " + node + " in store epilogue"); 4496 } 4497 4498 @Override 4499 public boolean enterIdentNode(final IdentNode node) { 4500 final Symbol symbol = node.getSymbol(); 4501 assert symbol != null; 4502 if (symbol.isScope()) { 4503 final int flags = getScopeCallSiteFlags(symbol) | (node.isDeclaredHere() ? CALLSITE_DECLARE : 0); 4504 if (isFastScope(symbol)) { 4505 storeFastScopeVar(symbol, flags); 4506 } else { 4507 method.dynamicSet(node.getName(), flags, false); 4508 } 4509 } else { 4510 final Type storeType = assignNode.getType(); 4511 assert storeType != Type.LONG; 4512 if (symbol.hasSlotFor(storeType)) { 4513 // Only emit a convert for a store known to be live; converts for dead stores can 4514 // give us an unnecessary ClassCastException. 4515 method.convert(storeType); 4516 } 4517 storeIdentWithCatchConversion(node, storeType); 4518 } 4519 return false; 4520 4521 } 4522 4523 @Override 4524 public boolean enterAccessNode(final AccessNode node) { 4525 method.dynamicSet(node.getProperty(), getCallSiteFlags(), node.isIndex()); 4526 return false; 4527 } 4528 4529 @Override 4530 public boolean enterIndexNode(final IndexNode node) { 4531 method.dynamicSetIndex(getCallSiteFlags()); 4532 return false; 4533 } 4534 }); 4535 4536 4537 // whatever is on the stack now is the final answer 4538 } 4539 4540 protected abstract void evaluate(); 4541 4542 void store() { 4543 if (target instanceof IdentNode) { 4544 checkTemporalDeadZone((IdentNode)target); 4545 } 4546 prologue(); 4547 evaluate(); // leaves an operation of whatever the operationType was on the stack 4548 storeNonDiscard(); 4549 epilogue(); 4550 if (quick != null) { 4551 method.load(quick); 4552 } 4553 } 4554 } 4555 4556 private void newFunctionObject(final FunctionNode functionNode, final boolean addInitializer) { 4557 assert lc.peek() == functionNode; 4558 4559 final RecompilableScriptFunctionData data = compiler.getScriptFunctionData(functionNode.getId()); 4560 4561 if (functionNode.isProgram() && !compiler.isOnDemandCompilation()) { 4562 final MethodEmitter createFunction = functionNode.getCompileUnit().getClassEmitter().method( 4563 EnumSet.of(Flag.PUBLIC, Flag.STATIC), CREATE_PROGRAM_FUNCTION.symbolName(), 4564 ScriptFunction.class, ScriptObject.class); 4565 createFunction.begin(); 4566 loadConstantsAndIndex(data, createFunction); 4567 createFunction.load(SCOPE_TYPE, 0); 4568 createFunction.invoke(CREATE_FUNCTION_OBJECT); 4569 createFunction._return(); 4570 createFunction.end(); 4571 } 4572 4573 if (addInitializer && !compiler.isOnDemandCompilation()) { 4574 functionNode.getCompileUnit().addFunctionInitializer(data, functionNode); 4575 } 4576 4577 // We don't emit a ScriptFunction on stack for the outermost compiled function (as there's no code being 4578 // generated in its outer context that'd need it as a callee). 4579 if (lc.getOutermostFunction() == functionNode) { 4580 return; 4581 } 4582 4583 loadConstantsAndIndex(data, method); 4584 4585 if (functionNode.needsParentScope()) { 4586 method.loadCompilerConstant(SCOPE); 4587 method.invoke(CREATE_FUNCTION_OBJECT); 4588 } else { 4589 method.invoke(CREATE_FUNCTION_OBJECT_NO_SCOPE); 4590 } 4591 } 4592 4593 // calls on Global class. 4594 private MethodEmitter globalInstance() { 4595 return method.invokestatic(GLOBAL_OBJECT, "instance", "()L" + GLOBAL_OBJECT + ';'); 4596 } 4597 4598 private MethodEmitter globalAllocateArguments() { 4599 return method.invokestatic(GLOBAL_OBJECT, "allocateArguments", methodDescriptor(ScriptObject.class, Object[].class, Object.class, int.class)); 4600 } 4601 4602 private MethodEmitter globalNewRegExp() { 4603 return method.invokestatic(GLOBAL_OBJECT, "newRegExp", methodDescriptor(Object.class, String.class, String.class)); 4604 } 4605 4606 private MethodEmitter globalRegExpCopy() { 4607 return method.invokestatic(GLOBAL_OBJECT, "regExpCopy", methodDescriptor(Object.class, Object.class)); 4608 } 4609 4610 private MethodEmitter globalAllocateArray(final ArrayType type) { 4611 //make sure the native array is treated as an array type 4612 return method.invokestatic(GLOBAL_OBJECT, "allocate", "(" + type.getDescriptor() + ")Ljdk/nashorn/internal/objects/NativeArray;"); 4613 } 4614 4615 private MethodEmitter globalIsEval() { 4616 return method.invokestatic(GLOBAL_OBJECT, "isEval", methodDescriptor(boolean.class, Object.class)); 4617 } 4618 4619 private MethodEmitter globalReplaceLocationPropertyPlaceholder() { 4620 return method.invokestatic(GLOBAL_OBJECT, "replaceLocationPropertyPlaceholder", methodDescriptor(Object.class, Object.class, Object.class)); 4621 } 4622 4623 private MethodEmitter globalCheckObjectCoercible() { 4624 return method.invokestatic(GLOBAL_OBJECT, "checkObjectCoercible", methodDescriptor(void.class, Object.class)); 4625 } 4626 4627 private MethodEmitter globalDirectEval() { 4628 return method.invokestatic(GLOBAL_OBJECT, "directEval", 4629 methodDescriptor(Object.class, Object.class, Object.class, Object.class, Object.class, boolean.class)); 4630 } 4631 4632 private abstract class OptimisticOperation { 4633 private final boolean isOptimistic; 4634 // expression and optimistic are the same reference 4635 private final Expression expression; 4636 private final Optimistic optimistic; 4637 private final TypeBounds resultBounds; 4638 4639 OptimisticOperation(final Optimistic optimistic, final TypeBounds resultBounds) { 4640 this.optimistic = optimistic; 4641 this.expression = (Expression)optimistic; 4642 this.resultBounds = resultBounds; 4643 this.isOptimistic = isOptimistic(optimistic) && useOptimisticTypes() && 4644 // Operation is only effectively optimistic if its type, after being coerced into the result bounds 4645 // is narrower than the upper bound. 4646 resultBounds.within(Type.generic(((Expression)optimistic).getType())).narrowerThan(resultBounds.widest); 4647 } 4648 4649 MethodEmitter emit() { 4650 return emit(0); 4651 } 4652 4653 MethodEmitter emit(final int ignoredArgCount) { 4654 final int programPoint = optimistic.getProgramPoint(); 4655 final boolean optimisticOrContinuation = isOptimistic || isContinuationEntryPoint(programPoint); 4656 final boolean currentContinuationEntryPoint = isCurrentContinuationEntryPoint(programPoint); 4657 final int stackSizeOnEntry = method.getStackSize() - ignoredArgCount; 4658 4659 // First store the values on the stack opportunistically into local variables. Doing it before loadStack() 4660 // allows us to not have to pop/load any arguments that are pushed onto it by loadStack() in the second 4661 // storeStack(). 4662 storeStack(ignoredArgCount, optimisticOrContinuation); 4663 4664 // Now, load the stack 4665 loadStack(); 4666 4667 // Now store the values on the stack ultimately into local variables. In vast majority of cases, this is 4668 // (aside from creating the local types map) a no-op, as the first opportunistic stack store will already 4669 // store all variables. However, there can be operations in the loadStack() that invalidate some of the 4670 // stack stores, e.g. in "x[i] = x[++i]", "++i" will invalidate the already stored value for "i". In such 4671 // unfortunate cases this second storeStack() will restore the invariant that everything on the stack is 4672 // stored into a local variable, although at the cost of doing a store/load on the loaded arguments as well. 4673 final int liveLocalsCount = storeStack(method.getStackSize() - stackSizeOnEntry, optimisticOrContinuation); 4674 assert optimisticOrContinuation == (liveLocalsCount != -1); 4675 4676 final Label beginTry; 4677 final Label catchLabel; 4678 final Label afterConsumeStack = isOptimistic || currentContinuationEntryPoint ? new Label("after_consume_stack") : null; 4679 if(isOptimistic) { 4680 beginTry = new Label("try_optimistic"); 4681 final String catchLabelName = (afterConsumeStack == null ? "" : afterConsumeStack.toString()) + "_handler"; 4682 catchLabel = new Label(catchLabelName); 4683 method.label(beginTry); 4684 } else { 4685 beginTry = catchLabel = null; 4686 } 4687 4688 consumeStack(); 4689 4690 if(isOptimistic) { 4691 method._try(beginTry, afterConsumeStack, catchLabel, UnwarrantedOptimismException.class); 4692 } 4693 4694 if(isOptimistic || currentContinuationEntryPoint) { 4695 method.label(afterConsumeStack); 4696 4697 final int[] localLoads = method.getLocalLoadsOnStack(0, stackSizeOnEntry); 4698 assert everyStackValueIsLocalLoad(localLoads) : Arrays.toString(localLoads) + ", " + stackSizeOnEntry + ", " + ignoredArgCount; 4699 final List<Type> localTypesList = method.getLocalVariableTypes(); 4700 final int usedLocals = method.getUsedSlotsWithLiveTemporaries(); 4701 final List<Type> localTypes = method.getWidestLiveLocals(localTypesList.subList(0, usedLocals)); 4702 assert everyLocalLoadIsValid(localLoads, usedLocals) : Arrays.toString(localLoads) + " ~ " + localTypes; 4703 4704 if(isOptimistic) { 4705 addUnwarrantedOptimismHandlerLabel(localTypes, catchLabel); 4706 } 4707 if(currentContinuationEntryPoint) { 4708 final ContinuationInfo ci = getContinuationInfo(); 4709 assert ci != null : "no continuation info found for " + lc.getCurrentFunction(); 4710 assert !ci.hasTargetLabel(); // No duplicate program points 4711 ci.setTargetLabel(afterConsumeStack); 4712 ci.getHandlerLabel().markAsOptimisticContinuationHandlerFor(afterConsumeStack); 4713 // Can't rely on targetLabel.stack.localVariableTypes.length, as it can be higher due to effectively 4714 // dead local variables. 4715 ci.lvarCount = localTypes.size(); 4716 ci.setStackStoreSpec(localLoads); 4717 ci.setStackTypes(Arrays.copyOf(method.getTypesFromStack(method.getStackSize()), stackSizeOnEntry)); 4718 assert ci.getStackStoreSpec().length == ci.getStackTypes().length; 4719 ci.setReturnValueType(method.peekType()); 4720 ci.lineNumber = getLastLineNumber(); 4721 ci.catchLabel = catchLabels.peek(); 4722 } 4723 } 4724 return method; 4725 } 4726 4727 /** 4728 * Stores the current contents of the stack into local variables so they are not lost before invoking something that 4729 * can result in an {@code UnwarantedOptimizationException}. 4730 * @param ignoreArgCount the number of topmost arguments on stack to ignore when deciding on the shape of the catch 4731 * block. Those are used in the situations when we could not place the call to {@code storeStack} early enough 4732 * (before emitting code for pushing the arguments that the optimistic call will pop). This is admittedly a 4733 * deficiency in the design of the code generator when it deals with self-assignments and we should probably look 4734 * into fixing it. 4735 * @return types of the significant local variables after the stack was stored (types for local variables used 4736 * for temporary storage of ignored arguments are not returned). 4737 * @param optimisticOrContinuation if false, this method should not execute 4738 * a label for a catch block for the {@code UnwarantedOptimizationException}, suitable for capturing the 4739 * currently live local variables, tailored to their types. 4740 */ 4741 private int storeStack(final int ignoreArgCount, final boolean optimisticOrContinuation) { 4742 if(!optimisticOrContinuation) { 4743 return -1; // NOTE: correct value to return is lc.getUsedSlotCount(), but it wouldn't be used anyway 4744 } 4745 4746 final int stackSize = method.getStackSize(); 4747 final Type[] stackTypes = method.getTypesFromStack(stackSize); 4748 final int[] localLoadsOnStack = method.getLocalLoadsOnStack(0, stackSize); 4749 final int usedSlots = method.getUsedSlotsWithLiveTemporaries(); 4750 4751 final int firstIgnored = stackSize - ignoreArgCount; 4752 // Find the first value on the stack (from the bottom) that is not a load from a local variable. 4753 int firstNonLoad = 0; 4754 while(firstNonLoad < firstIgnored && localLoadsOnStack[firstNonLoad] != Label.Stack.NON_LOAD) { 4755 firstNonLoad++; 4756 } 4757 4758 // Only do the store/load if first non-load is not an ignored argument. Otherwise, do nothing and return 4759 // the number of used slots as the number of live local variables. 4760 if(firstNonLoad >= firstIgnored) { 4761 return usedSlots; 4762 } 4763 4764 // Find the number of new temporary local variables that we need; it's the number of values on the stack that 4765 // are not direct loads of existing local variables. 4766 int tempSlotsNeeded = 0; 4767 for(int i = firstNonLoad; i < stackSize; ++i) { 4768 if(localLoadsOnStack[i] == Label.Stack.NON_LOAD) { 4769 tempSlotsNeeded += stackTypes[i].getSlots(); 4770 } 4771 } 4772 4773 // Ensure all values on the stack that weren't directly loaded from a local variable are stored in a local 4774 // variable. We're starting from highest local variable index, so that in case ignoreArgCount > 0 the ignored 4775 // ones end up at the end of the local variable table. 4776 int lastTempSlot = usedSlots + tempSlotsNeeded; 4777 int ignoreSlotCount = 0; 4778 for(int i = stackSize; i -- > firstNonLoad;) { 4779 final int loadSlot = localLoadsOnStack[i]; 4780 if(loadSlot == Label.Stack.NON_LOAD) { 4781 final Type type = stackTypes[i]; 4782 final int slots = type.getSlots(); 4783 lastTempSlot -= slots; 4784 if(i >= firstIgnored) { 4785 ignoreSlotCount += slots; 4786 } 4787 method.storeTemp(type, lastTempSlot); 4788 } else { 4789 method.pop(); 4790 } 4791 } 4792 assert lastTempSlot == usedSlots; // used all temporary locals 4793 4794 final List<Type> localTypesList = method.getLocalVariableTypes(); 4795 4796 // Load values back on stack. 4797 for(int i = firstNonLoad; i < stackSize; ++i) { 4798 final int loadSlot = localLoadsOnStack[i]; 4799 final Type stackType = stackTypes[i]; 4800 final boolean isLoad = loadSlot != Label.Stack.NON_LOAD; 4801 final int lvarSlot = isLoad ? loadSlot : lastTempSlot; 4802 final Type lvarType = localTypesList.get(lvarSlot); 4803 method.load(lvarType, lvarSlot); 4804 if(isLoad) { 4805 // Conversion operators (I2L etc.) preserve "load"-ness of the value despite the fact that, in the 4806 // strict sense they are creating a derived value from the loaded value. This special behavior of 4807 // on-stack conversion operators is necessary to accommodate for differences in local variable types 4808 // after deoptimization; having a conversion operator throw away "load"-ness would create different 4809 // local variable table shapes between optimism-failed code and its deoptimized rest-of method). 4810 // After we load the value back, we need to redo the conversion to the stack type if stack type is 4811 // different. 4812 // NOTE: this would only strictly be necessary for widening conversions (I2L, L2D, I2D), and not for 4813 // narrowing ones (L2I, D2L, D2I) as only widening conversions are the ones that can get eliminated 4814 // in a deoptimized method, as their original input argument got widened. Maybe experiment with 4815 // throwing away "load"-ness for narrowing conversions in MethodEmitter.convert()? 4816 method.convert(stackType); 4817 } else { 4818 // temporary stores never needs a convert, as their type is always the same as the stack type. 4819 assert lvarType == stackType; 4820 lastTempSlot += lvarType.getSlots(); 4821 } 4822 } 4823 // used all temporaries 4824 assert lastTempSlot == usedSlots + tempSlotsNeeded; 4825 4826 return lastTempSlot - ignoreSlotCount; 4827 } 4828 4829 private void addUnwarrantedOptimismHandlerLabel(final List<Type> localTypes, final Label label) { 4830 final String lvarTypesDescriptor = getLvarTypesDescriptor(localTypes); 4831 final Map<String, Collection<Label>> unwarrantedOptimismHandlers = lc.getUnwarrantedOptimismHandlers(); 4832 Collection<Label> labels = unwarrantedOptimismHandlers.get(lvarTypesDescriptor); 4833 if(labels == null) { 4834 labels = new LinkedList<>(); 4835 unwarrantedOptimismHandlers.put(lvarTypesDescriptor, labels); 4836 } 4837 method.markLabelAsOptimisticCatchHandler(label, localTypes.size()); 4838 labels.add(label); 4839 } 4840 4841 abstract void loadStack(); 4842 4843 // Make sure that whatever indy call site you emit from this method uses {@code getCallSiteFlagsOptimistic(node)} 4844 // or otherwise ensure optimistic flag is correctly set in the call site, otherwise it doesn't make much sense 4845 // to use OptimisticExpression for emitting it. 4846 abstract void consumeStack(); 4847 4848 /** 4849 * Emits the correct dynamic getter code. Normally just delegates to method emitter, except when the target 4850 * expression is optimistic, and the desired type is narrower than the optimistic type. In that case, it'll emit a 4851 * dynamic getter with its original optimistic type, and explicitly insert a narrowing conversion. This way we can 4852 * preserve the optimism of the values even if they're subsequently immediately coerced into a narrower type. This 4853 * is beneficial because in this case we can still presume that since the original getter was optimistic, the 4854 * conversion has no side effects. 4855 * @param name the name of the property being get 4856 * @param flags call site flags 4857 * @param isMethod whether we're preferably retrieving a function 4858 * @return the current method emitter 4859 */ 4860 MethodEmitter dynamicGet(final String name, final int flags, final boolean isMethod, final boolean isIndex) { 4861 if(isOptimistic) { 4862 return method.dynamicGet(getOptimisticCoercedType(), name, getOptimisticFlags(flags), isMethod, isIndex); 4863 } 4864 return method.dynamicGet(resultBounds.within(expression.getType()), name, nonOptimisticFlags(flags), isMethod, isIndex); 4865 } 4866 4867 MethodEmitter dynamicGetIndex(final int flags, final boolean isMethod) { 4868 if(isOptimistic) { 4869 return method.dynamicGetIndex(getOptimisticCoercedType(), getOptimisticFlags(flags), isMethod); 4870 } 4871 return method.dynamicGetIndex(resultBounds.within(expression.getType()), nonOptimisticFlags(flags), isMethod); 4872 } 4873 4874 MethodEmitter dynamicCall(final int argCount, final int flags, final String msg) { 4875 if (isOptimistic) { 4876 return method.dynamicCall(getOptimisticCoercedType(), argCount, getOptimisticFlags(flags), msg); 4877 } 4878 return method.dynamicCall(resultBounds.within(expression.getType()), argCount, nonOptimisticFlags(flags), msg); 4879 } 4880 4881 int getOptimisticFlags(final int flags) { 4882 return flags | CALLSITE_OPTIMISTIC | (optimistic.getProgramPoint() << CALLSITE_PROGRAM_POINT_SHIFT); //encode program point in high bits 4883 } 4884 4885 int getProgramPoint() { 4886 return isOptimistic ? optimistic.getProgramPoint() : INVALID_PROGRAM_POINT; 4887 } 4888 4889 void convertOptimisticReturnValue() { 4890 if (isOptimistic) { 4891 final Type optimisticType = getOptimisticCoercedType(); 4892 if(!optimisticType.isObject()) { 4893 method.load(optimistic.getProgramPoint()); 4894 if(optimisticType.isInteger()) { 4895 method.invoke(ENSURE_INT); 4896 } else if(optimisticType.isNumber()) { 4897 method.invoke(ENSURE_NUMBER); 4898 } else { 4899 throw new AssertionError(optimisticType); 4900 } 4901 } 4902 } 4903 } 4904 4905 void replaceCompileTimeProperty() { 4906 final IdentNode identNode = (IdentNode)expression; 4907 final String name = identNode.getSymbol().getName(); 4908 if (CompilerConstants.__FILE__.name().equals(name)) { 4909 replaceCompileTimeProperty(getCurrentSource().getName()); 4910 } else if (CompilerConstants.__DIR__.name().equals(name)) { 4911 replaceCompileTimeProperty(getCurrentSource().getBase()); 4912 } else if (CompilerConstants.__LINE__.name().equals(name)) { 4913 replaceCompileTimeProperty(getCurrentSource().getLine(identNode.position())); 4914 } 4915 } 4916 4917 /** 4918 * When an ident with name __FILE__, __DIR__, or __LINE__ is loaded, we'll try to look it up as any other 4919 * identifier. However, if it gets all the way up to the Global object, it will send back a special value that 4920 * represents a placeholder for these compile-time location properties. This method will generate code that loads 4921 * the value of the compile-time location property and then invokes a method in Global that will replace the 4922 * placeholder with the value. Effectively, if the symbol for these properties is defined anywhere in the lexical 4923 * scope, they take precedence, but if they aren't, then they resolve to the compile-time location property. 4924 * @param propertyValue the actual value of the property 4925 */ 4926 private void replaceCompileTimeProperty(final Object propertyValue) { 4927 assert method.peekType().isObject(); 4928 if(propertyValue instanceof String || propertyValue == null) { 4929 method.load((String)propertyValue); 4930 } else if(propertyValue instanceof Integer) { 4931 method.load(((Integer)propertyValue)); 4932 method.convert(Type.OBJECT); 4933 } else { 4934 throw new AssertionError(); 4935 } 4936 globalReplaceLocationPropertyPlaceholder(); 4937 convertOptimisticReturnValue(); 4938 } 4939 4940 /** 4941 * Returns the type that should be used as the return type of the dynamic invocation that is emitted as the code 4942 * for the current optimistic operation. If the type bounds is exact boolean or narrower than the expression's 4943 * optimistic type, then the optimistic type is returned, otherwise the coercing type. Effectively, this method 4944 * allows for moving the coercion into the optimistic type when it won't adversely affect the optimistic 4945 * evaluation semantics, and for preserving the optimistic type and doing a separate coercion when it would 4946 * affect it. 4947 * @return 4948 */ 4949 private Type getOptimisticCoercedType() { 4950 final Type optimisticType = expression.getType(); 4951 assert resultBounds.widest.widerThan(optimisticType); 4952 final Type narrowest = resultBounds.narrowest; 4953 4954 if(narrowest.isBoolean() || narrowest.narrowerThan(optimisticType)) { 4955 assert !optimisticType.isObject(); 4956 return optimisticType; 4957 } 4958 assert !narrowest.isObject(); 4959 return narrowest; 4960 } 4961 } 4962 4963 private static boolean isOptimistic(final Optimistic optimistic) { 4964 if(!optimistic.canBeOptimistic()) { 4965 return false; 4966 } 4967 final Expression expr = (Expression)optimistic; 4968 return expr.getType().narrowerThan(expr.getWidestOperationType()); 4969 } 4970 4971 private static boolean everyLocalLoadIsValid(final int[] loads, final int localCount) { 4972 for (final int load : loads) { 4973 if(load < 0 || load >= localCount) { 4974 return false; 4975 } 4976 } 4977 return true; 4978 } 4979 4980 private static boolean everyStackValueIsLocalLoad(final int[] loads) { 4981 for (final int load : loads) { 4982 if(load == Label.Stack.NON_LOAD) { 4983 return false; 4984 } 4985 } 4986 return true; 4987 } 4988 4989 private String getLvarTypesDescriptor(final List<Type> localVarTypes) { 4990 final int count = localVarTypes.size(); 4991 final StringBuilder desc = new StringBuilder(count); 4992 for(int i = 0; i < count;) { 4993 i += appendType(desc, localVarTypes.get(i)); 4994 } 4995 return method.markSymbolBoundariesInLvarTypesDescriptor(desc.toString()); 4996 } 4997 4998 private static int appendType(final StringBuilder b, final Type t) { 4999 b.append(t.getBytecodeStackType()); 5000 return t.getSlots(); 5001 } 5002 5003 private static int countSymbolsInLvarTypeDescriptor(final String lvarTypeDescriptor) { 5004 int count = 0; 5005 for(int i = 0; i < lvarTypeDescriptor.length(); ++i) { 5006 if(Character.isUpperCase(lvarTypeDescriptor.charAt(i))) { 5007 ++count; 5008 } 5009 } 5010 return count; 5011 5012 } 5013 /** 5014 * Generates all the required {@code UnwarrantedOptimismException} handlers for the current function. The employed 5015 * strategy strives to maximize code reuse. Every handler constructs an array to hold the local variables, then 5016 * fills in some trailing part of the local variables (those for which it has a unique suffix in the descriptor), 5017 * then jumps to a handler for a prefix that's shared with other handlers. A handler that fills up locals up to 5018 * position 0 will not jump to a prefix handler (as it has no prefix), but instead end with constructing and 5019 * throwing a {@code RewriteException}. Since we lexicographically sort the entries, we only need to check every 5020 * entry to its immediately preceding one for longest matching prefix. 5021 * @return true if there is at least one exception handler 5022 */ 5023 private boolean generateUnwarrantedOptimismExceptionHandlers(final FunctionNode fn) { 5024 if(!useOptimisticTypes()) { 5025 return false; 5026 } 5027 5028 // Take the mapping of lvarSpecs -> labels, and turn them into a descending lexicographically sorted list of 5029 // handler specifications. 5030 final Map<String, Collection<Label>> unwarrantedOptimismHandlers = lc.popUnwarrantedOptimismHandlers(); 5031 if(unwarrantedOptimismHandlers.isEmpty()) { 5032 return false; 5033 } 5034 5035 method.lineNumber(0); 5036 5037 final List<OptimismExceptionHandlerSpec> handlerSpecs = new ArrayList<>(unwarrantedOptimismHandlers.size() * 4/3); 5038 for(final String spec: unwarrantedOptimismHandlers.keySet()) { 5039 handlerSpecs.add(new OptimismExceptionHandlerSpec(spec, true)); 5040 } 5041 Collections.sort(handlerSpecs, Collections.reverseOrder()); 5042 5043 // Map of local variable specifications to labels for populating the array for that local variable spec. 5044 final Map<String, Label> delegationLabels = new HashMap<>(); 5045 5046 // Do everything in a single pass over the handlerSpecs list. Note that the list can actually grow as we're 5047 // passing through it as we might add new prefix handlers into it, so can't hoist size() outside of the loop. 5048 for(int handlerIndex = 0; handlerIndex < handlerSpecs.size(); ++handlerIndex) { 5049 final OptimismExceptionHandlerSpec spec = handlerSpecs.get(handlerIndex); 5050 final String lvarSpec = spec.lvarSpec; 5051 if(spec.catchTarget) { 5052 assert !method.isReachable(); 5053 // Start a catch block and assign the labels for this lvarSpec with it. 5054 method._catch(unwarrantedOptimismHandlers.get(lvarSpec)); 5055 // This spec is a catch target, so emit array creation code. The length of the array is the number of 5056 // symbols - the number of uppercase characters. 5057 method.load(countSymbolsInLvarTypeDescriptor(lvarSpec)); 5058 method.newarray(Type.OBJECT_ARRAY); 5059 } 5060 if(spec.delegationTarget) { 5061 // If another handler can delegate to this handler as its prefix, then put a jump target here for the 5062 // shared code (after the array creation code, which is never shared). 5063 method.label(delegationLabels.get(lvarSpec)); // label must exist 5064 } 5065 5066 final boolean lastHandler = handlerIndex == handlerSpecs.size() - 1; 5067 5068 int lvarIndex; 5069 final int firstArrayIndex; 5070 final int firstLvarIndex; 5071 Label delegationLabel; 5072 final String commonLvarSpec; 5073 if(lastHandler) { 5074 // Last handler block, doesn't delegate to anything. 5075 lvarIndex = 0; 5076 firstLvarIndex = 0; 5077 firstArrayIndex = 0; 5078 delegationLabel = null; 5079 commonLvarSpec = null; 5080 } else { 5081 // Not yet the last handler block, will definitely delegate to another handler; let's figure out which 5082 // one. It can be an already declared handler further down the list, or it might need to declare a new 5083 // prefix handler. 5084 5085 // Since we're lexicographically ordered, the common prefix handler is defined by the common prefix of 5086 // this handler and the next handler on the list. 5087 final int nextHandlerIndex = handlerIndex + 1; 5088 final String nextLvarSpec = handlerSpecs.get(nextHandlerIndex).lvarSpec; 5089 commonLvarSpec = commonPrefix(lvarSpec, nextLvarSpec); 5090 // We don't chop symbols in half 5091 assert Character.isUpperCase(commonLvarSpec.charAt(commonLvarSpec.length() - 1)); 5092 5093 // Let's find if we already have a declaration for such handler, or we need to insert it. 5094 { 5095 boolean addNewHandler = true; 5096 int commonHandlerIndex = nextHandlerIndex; 5097 for(; commonHandlerIndex < handlerSpecs.size(); ++commonHandlerIndex) { 5098 final OptimismExceptionHandlerSpec forwardHandlerSpec = handlerSpecs.get(commonHandlerIndex); 5099 final String forwardLvarSpec = forwardHandlerSpec.lvarSpec; 5100 if(forwardLvarSpec.equals(commonLvarSpec)) { 5101 // We already have a handler for the common prefix. 5102 addNewHandler = false; 5103 // Make sure we mark it as a delegation target. 5104 forwardHandlerSpec.delegationTarget = true; 5105 break; 5106 } else if(!forwardLvarSpec.startsWith(commonLvarSpec)) { 5107 break; 5108 } 5109 } 5110 if(addNewHandler) { 5111 // We need to insert a common prefix handler. Note handlers created with catchTarget == false 5112 // will automatically have delegationTarget == true (because that's the only reason for their 5113 // existence). 5114 handlerSpecs.add(commonHandlerIndex, new OptimismExceptionHandlerSpec(commonLvarSpec, false)); 5115 } 5116 } 5117 5118 firstArrayIndex = countSymbolsInLvarTypeDescriptor(commonLvarSpec); 5119 lvarIndex = 0; 5120 for(int j = 0; j < commonLvarSpec.length(); ++j) { 5121 lvarIndex += CodeGeneratorLexicalContext.getTypeForSlotDescriptor(commonLvarSpec.charAt(j)).getSlots(); 5122 } 5123 firstLvarIndex = lvarIndex; 5124 5125 // Create a delegation label if not already present 5126 delegationLabel = delegationLabels.get(commonLvarSpec); 5127 if(delegationLabel == null) { 5128 // uo_pa == "unwarranted optimism, populate array" 5129 delegationLabel = new Label("uo_pa_" + commonLvarSpec); 5130 delegationLabels.put(commonLvarSpec, delegationLabel); 5131 } 5132 } 5133 5134 // Load local variables handled by this handler on stack 5135 int args = 0; 5136 boolean symbolHadValue = false; 5137 for(int typeIndex = commonLvarSpec == null ? 0 : commonLvarSpec.length(); typeIndex < lvarSpec.length(); ++typeIndex) { 5138 final char typeDesc = lvarSpec.charAt(typeIndex); 5139 final Type lvarType = CodeGeneratorLexicalContext.getTypeForSlotDescriptor(typeDesc); 5140 if (!lvarType.isUnknown()) { 5141 method.load(lvarType, lvarIndex); 5142 symbolHadValue = true; 5143 args++; 5144 } else if(typeDesc == 'U' && !symbolHadValue) { 5145 // Symbol boundary with undefined last value. Check if all previous values for this symbol were also 5146 // undefined; if so, emit one explicit Undefined. This serves to ensure that we're emiting exactly 5147 // one value for every symbol that uses local slots. While we could in theory ignore symbols that 5148 // are undefined (in other words, dead) at the point where this exception was thrown, unfortunately 5149 // we can't do it in practice. The reason for this is that currently our liveness analysis is 5150 // coarse (it can determine whether a symbol has not been read with a particular type anywhere in 5151 // the function being compiled, but that's it), and a symbol being promoted to Object due to a 5152 // deoptimization will suddenly show up as "live for Object type", and previously dead U->O 5153 // conversions on loop entries will suddenly become alive in the deoptimized method which will then 5154 // expect a value for that slot in its continuation handler. If we had precise liveness analysis, we 5155 // could go back to excluding known dead symbols from the payload of the RewriteException. 5156 if(method.peekType() == Type.UNDEFINED) { 5157 method.dup(); 5158 } else { 5159 method.loadUndefined(Type.OBJECT); 5160 } 5161 args++; 5162 } 5163 if(Character.isUpperCase(typeDesc)) { 5164 // Reached symbol boundary; reset flag for the next symbol. 5165 symbolHadValue = false; 5166 } 5167 lvarIndex += lvarType.getSlots(); 5168 } 5169 assert args > 0; 5170 // Delegate actual storing into array to an array populator utility method. 5171 //on the stack: 5172 // object array to be populated 5173 // start index 5174 // a lot of types 5175 method.dynamicArrayPopulatorCall(args + 1, firstArrayIndex); 5176 if(delegationLabel != null) { 5177 // We cascade to a prefix handler to fill out the rest of the local variables and throw the 5178 // RewriteException. 5179 assert !lastHandler; 5180 assert commonLvarSpec != null; 5181 // Must undefine the local variables that we have already processed for the sake of correct join on the 5182 // delegate label 5183 method.undefineLocalVariables(firstLvarIndex, true); 5184 final OptimismExceptionHandlerSpec nextSpec = handlerSpecs.get(handlerIndex + 1); 5185 // If the delegate immediately follows, and it's not a catch target (so it doesn't have array setup 5186 // code) don't bother emitting a jump, as we'd just jump to the next instruction. 5187 if(!nextSpec.lvarSpec.equals(commonLvarSpec) || nextSpec.catchTarget) { 5188 method._goto(delegationLabel); 5189 } 5190 } else { 5191 assert lastHandler; 5192 // Nothing to delegate to, so this handler must create and throw the RewriteException. 5193 // At this point we have the UnwarrantedOptimismException and the Object[] with local variables on 5194 // stack. We need to create a RewriteException, push two references to it below the constructor 5195 // arguments, invoke the constructor, and throw the exception. 5196 loadConstant(getByteCodeSymbolNames(fn)); 5197 if (isRestOf()) { 5198 loadConstant(getContinuationEntryPoints()); 5199 method.invoke(CREATE_REWRITE_EXCEPTION_REST_OF); 5200 } else { 5201 method.invoke(CREATE_REWRITE_EXCEPTION); 5202 } 5203 method.athrow(); 5204 } 5205 } 5206 return true; 5207 } 5208 5209 private static String[] getByteCodeSymbolNames(final FunctionNode fn) { 5210 // Only names of local variables on the function level are captured. This information is used to reduce 5211 // deoptimizations, so as much as we can capture will help. We rely on the fact that function wide variables are 5212 // all live all the time, so the array passed to rewrite exception contains one element for every slotted symbol 5213 // here. 5214 final List<String> names = new ArrayList<>(); 5215 for (final Symbol symbol: fn.getBody().getSymbols()) { 5216 if (symbol.hasSlot()) { 5217 if (symbol.isScope()) { 5218 // slot + scope can only be true for parameters 5219 assert symbol.isParam(); 5220 names.add(null); 5221 } else { 5222 names.add(symbol.getName()); 5223 } 5224 } 5225 } 5226 return names.toArray(new String[0]); 5227 } 5228 5229 private static String commonPrefix(final String s1, final String s2) { 5230 final int l1 = s1.length(); 5231 final int l = Math.min(l1, s2.length()); 5232 int lms = -1; // last matching symbol 5233 for(int i = 0; i < l; ++i) { 5234 final char c1 = s1.charAt(i); 5235 if(c1 != s2.charAt(i)) { 5236 return s1.substring(0, lms + 1); 5237 } else if(Character.isUpperCase(c1)) { 5238 lms = i; 5239 } 5240 } 5241 return l == l1 ? s1 : s2; 5242 } 5243 5244 private static class OptimismExceptionHandlerSpec implements Comparable<OptimismExceptionHandlerSpec> { 5245 private final String lvarSpec; 5246 private final boolean catchTarget; 5247 private boolean delegationTarget; 5248 5249 OptimismExceptionHandlerSpec(final String lvarSpec, final boolean catchTarget) { 5250 this.lvarSpec = lvarSpec; 5251 this.catchTarget = catchTarget; 5252 if(!catchTarget) { 5253 delegationTarget = true; 5254 } 5255 } 5256 5257 @Override 5258 public int compareTo(final OptimismExceptionHandlerSpec o) { 5259 return lvarSpec.compareTo(o.lvarSpec); 5260 } 5261 5262 @Override 5263 public String toString() { 5264 final StringBuilder b = new StringBuilder(64).append("[HandlerSpec ").append(lvarSpec); 5265 if(catchTarget) { 5266 b.append(", catchTarget"); 5267 } 5268 if(delegationTarget) { 5269 b.append(", delegationTarget"); 5270 } 5271 return b.append("]").toString(); 5272 } 5273 } 5274 5275 private static class ContinuationInfo { 5276 private final Label handlerLabel; 5277 private Label targetLabel; // Label for the target instruction. 5278 int lvarCount; 5279 // Indices of local variables that need to be loaded on the stack when this node completes 5280 private int[] stackStoreSpec; 5281 // Types of values loaded on the stack 5282 private Type[] stackTypes; 5283 // If non-null, this node should perform the requisite type conversion 5284 private Type returnValueType; 5285 // If we are in the middle of an object literal initialization, we need to update the map 5286 private PropertyMap objectLiteralMap; 5287 // Object literal stack depth for object literal - not necessarily top if property is a tree 5288 private int objectLiteralStackDepth = -1; 5289 // The line number at the continuation point 5290 private int lineNumber; 5291 // The active catch label, in case the continuation point is in a try/catch block 5292 private Label catchLabel; 5293 // The number of scopes that need to be popped before control is transferred to the catch label. 5294 private int exceptionScopePops; 5295 5296 ContinuationInfo() { 5297 this.handlerLabel = new Label("continuation_handler"); 5298 } 5299 5300 Label getHandlerLabel() { 5301 return handlerLabel; 5302 } 5303 5304 boolean hasTargetLabel() { 5305 return targetLabel != null; 5306 } 5307 5308 Label getTargetLabel() { 5309 return targetLabel; 5310 } 5311 5312 void setTargetLabel(final Label targetLabel) { 5313 this.targetLabel = targetLabel; 5314 } 5315 5316 int[] getStackStoreSpec() { 5317 return stackStoreSpec.clone(); 5318 } 5319 5320 void setStackStoreSpec(final int[] stackStoreSpec) { 5321 this.stackStoreSpec = stackStoreSpec; 5322 } 5323 5324 Type[] getStackTypes() { 5325 return stackTypes.clone(); 5326 } 5327 5328 void setStackTypes(final Type[] stackTypes) { 5329 this.stackTypes = stackTypes; 5330 } 5331 5332 Type getReturnValueType() { 5333 return returnValueType; 5334 } 5335 5336 void setReturnValueType(final Type returnValueType) { 5337 this.returnValueType = returnValueType; 5338 } 5339 5340 int getObjectLiteralStackDepth() { 5341 return objectLiteralStackDepth; 5342 } 5343 5344 void setObjectLiteralStackDepth(final int objectLiteralStackDepth) { 5345 this.objectLiteralStackDepth = objectLiteralStackDepth; 5346 } 5347 5348 PropertyMap getObjectLiteralMap() { 5349 return objectLiteralMap; 5350 } 5351 5352 void setObjectLiteralMap(final PropertyMap objectLiteralMap) { 5353 this.objectLiteralMap = objectLiteralMap; 5354 } 5355 5356 @Override 5357 public String toString() { 5358 return "[localVariableTypes=" + targetLabel.getStack().getLocalVariableTypesCopy() + ", stackStoreSpec=" + 5359 Arrays.toString(stackStoreSpec) + ", returnValueType=" + returnValueType + "]"; 5360 } 5361 } 5362 5363 private ContinuationInfo getContinuationInfo() { 5364 return continuationInfo; 5365 } 5366 5367 private void generateContinuationHandler() { 5368 if (!isRestOf()) { 5369 return; 5370 } 5371 5372 final ContinuationInfo ci = getContinuationInfo(); 5373 method.label(ci.getHandlerLabel()); 5374 5375 // There should never be an exception thrown from the continuation handler, but in case there is (meaning, 5376 // Nashorn has a bug), then line number 0 will be an indication of where it came from (line numbers are Uint16). 5377 method.lineNumber(0); 5378 5379 final Label.Stack stack = ci.getTargetLabel().getStack(); 5380 final List<Type> lvarTypes = stack.getLocalVariableTypesCopy(); 5381 final BitSet symbolBoundary = stack.getSymbolBoundaryCopy(); 5382 final int lvarCount = ci.lvarCount; 5383 5384 final Type rewriteExceptionType = Type.typeFor(RewriteException.class); 5385 // Store the RewriteException into an unused local variable slot. 5386 method.load(rewriteExceptionType, 0); 5387 method.storeTemp(rewriteExceptionType, lvarCount); 5388 // Get local variable array 5389 method.load(rewriteExceptionType, 0); 5390 method.invoke(RewriteException.GET_BYTECODE_SLOTS); 5391 // Store local variables. Note that deoptimization might introduce new value types for existing local variables, 5392 // so we must use both liveLocals and symbolBoundary, as in some cases (when the continuation is inside of a try 5393 // block) we need to store the incoming value into multiple slots. The optimism exception handlers will have 5394 // exactly one array element for every symbol that uses bytecode storage. If in the originating method the value 5395 // was undefined, there will be an explicit Undefined value in the array. 5396 int arrayIndex = 0; 5397 for(int lvarIndex = 0; lvarIndex < lvarCount;) { 5398 final Type lvarType = lvarTypes.get(lvarIndex); 5399 if(!lvarType.isUnknown()) { 5400 method.dup(); 5401 method.load(arrayIndex).arrayload(); 5402 final Class<?> typeClass = lvarType.getTypeClass(); 5403 // Deoptimization in array initializers can cause arrays to undergo component type widening 5404 if(typeClass == long[].class) { 5405 method.load(rewriteExceptionType, lvarCount); 5406 method.invoke(RewriteException.TO_LONG_ARRAY); 5407 } else if(typeClass == double[].class) { 5408 method.load(rewriteExceptionType, lvarCount); 5409 method.invoke(RewriteException.TO_DOUBLE_ARRAY); 5410 } else if(typeClass == Object[].class) { 5411 method.load(rewriteExceptionType, lvarCount); 5412 method.invoke(RewriteException.TO_OBJECT_ARRAY); 5413 } else { 5414 if(!(typeClass.isPrimitive() || typeClass == Object.class)) { 5415 // NOTE: this can only happen with dead stores. E.g. for the program "1; []; f();" in which the 5416 // call to f() will deoptimize the call site, but it'll expect :return to have the type 5417 // NativeArray. However, in the more optimal version, :return's only live type is int, therefore 5418 // "{O}:return = []" is a dead store, and the variable will be sent into the continuation as 5419 // Undefined, however NativeArray can't hold Undefined instance. 5420 method.loadType(Type.getInternalName(typeClass)); 5421 method.invoke(RewriteException.INSTANCE_OR_NULL); 5422 } 5423 method.convert(lvarType); 5424 } 5425 method.storeHidden(lvarType, lvarIndex, false); 5426 } 5427 final int nextLvarIndex = lvarIndex + lvarType.getSlots(); 5428 if(symbolBoundary.get(nextLvarIndex - 1)) { 5429 ++arrayIndex; 5430 } 5431 lvarIndex = nextLvarIndex; 5432 } 5433 if (AssertsEnabled.assertsEnabled()) { 5434 method.load(arrayIndex); 5435 method.invoke(RewriteException.ASSERT_ARRAY_LENGTH); 5436 } else { 5437 method.pop(); 5438 } 5439 5440 final int[] stackStoreSpec = ci.getStackStoreSpec(); 5441 final Type[] stackTypes = ci.getStackTypes(); 5442 final boolean isStackEmpty = stackStoreSpec.length == 0; 5443 boolean replacedObjectLiteralMap = false; 5444 if(!isStackEmpty) { 5445 // Load arguments on the stack 5446 final int objectLiteralStackDepth = ci.getObjectLiteralStackDepth(); 5447 for(int i = 0; i < stackStoreSpec.length; ++i) { 5448 final int slot = stackStoreSpec[i]; 5449 method.load(lvarTypes.get(slot), slot); 5450 method.convert(stackTypes[i]); 5451 // stack: s0=object literal being initialized 5452 // change map of s0 so that the property we are initializing when we failed 5453 // is now ci.returnValueType 5454 if (i == objectLiteralStackDepth) { 5455 method.dup(); 5456 assert ci.getObjectLiteralMap() != null; 5457 assert ScriptObject.class.isAssignableFrom(method.peekType().getTypeClass()) : method.peekType().getTypeClass() + " is not a script object"; 5458 loadConstant(ci.getObjectLiteralMap()); 5459 method.invoke(ScriptObject.SET_MAP); 5460 replacedObjectLiteralMap = true; 5461 } 5462 } 5463 } 5464 // Must have emitted the code for replacing the map of an object literal if we have a set object literal stack depth 5465 assert ci.getObjectLiteralStackDepth() == -1 || replacedObjectLiteralMap; 5466 // Load RewriteException back. 5467 method.load(rewriteExceptionType, lvarCount); 5468 // Get rid of the stored reference 5469 method.loadNull(); 5470 method.storeHidden(Type.OBJECT, lvarCount); 5471 // Mark it dead 5472 method.markDeadSlots(lvarCount, Type.OBJECT.getSlots()); 5473 5474 // Load return value on the stack 5475 method.invoke(RewriteException.GET_RETURN_VALUE); 5476 5477 final Type returnValueType = ci.getReturnValueType(); 5478 5479 // Set up an exception handler for primitive type conversion of return value if needed 5480 boolean needsCatch = false; 5481 final Label targetCatchLabel = ci.catchLabel; 5482 Label _try = null; 5483 if(returnValueType.isPrimitive()) { 5484 // If the conversion throws an exception, we want to report the line number of the continuation point. 5485 method.lineNumber(ci.lineNumber); 5486 5487 if(targetCatchLabel != METHOD_BOUNDARY) { 5488 _try = new Label(""); 5489 method.label(_try); 5490 needsCatch = true; 5491 } 5492 } 5493 5494 // Convert return value 5495 method.convert(returnValueType); 5496 5497 final int scopePopCount = needsCatch ? ci.exceptionScopePops : 0; 5498 5499 // Declare a try/catch for the conversion. If no scopes need to be popped until the target catch block, just 5500 // jump into it. Otherwise, we'll need to create a scope-popping catch block below. 5501 final Label catchLabel = scopePopCount > 0 ? new Label("") : targetCatchLabel; 5502 if(needsCatch) { 5503 final Label _end_try = new Label(""); 5504 method.label(_end_try); 5505 method._try(_try, _end_try, catchLabel); 5506 } 5507 5508 // Jump to continuation point 5509 method._goto(ci.getTargetLabel()); 5510 5511 // Make a scope-popping exception delegate if needed 5512 if(catchLabel != targetCatchLabel) { 5513 method.lineNumber(0); 5514 assert scopePopCount > 0; 5515 method._catch(catchLabel); 5516 popScopes(scopePopCount); 5517 method.uncheckedGoto(targetCatchLabel); 5518 } 5519 } 5520 5521 /** 5522 * Interface implemented by object creators that support splitting over multiple methods. 5523 */ 5524 interface SplitLiteralCreator { 5525 /** 5526 * Generate code to populate a range of the literal object. A reference to the object 5527 * should be left on the stack when the method terminates. 5528 * 5529 * @param method the method emitter 5530 * @param type the type of the literal object 5531 * @param slot the local slot containing the literal object 5532 * @param start the start index (inclusive) 5533 * @param end the end index (exclusive) 5534 */ 5535 void populateRange(MethodEmitter method, Type type, int slot, int start, int end); 5536 } 5537 }