CodeGenerator.java revision 1438:d09ca2242f2f
1/* 2 * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26package jdk.nashorn.internal.codegen; 27 28import static jdk.nashorn.internal.codegen.ClassEmitter.Flag.PRIVATE; 29import static jdk.nashorn.internal.codegen.ClassEmitter.Flag.STATIC; 30import static jdk.nashorn.internal.codegen.CompilerConstants.ARGUMENTS; 31import static jdk.nashorn.internal.codegen.CompilerConstants.CALLEE; 32import static jdk.nashorn.internal.codegen.CompilerConstants.CREATE_PROGRAM_FUNCTION; 33import static jdk.nashorn.internal.codegen.CompilerConstants.GET_MAP; 34import static jdk.nashorn.internal.codegen.CompilerConstants.GET_STRING; 35import static jdk.nashorn.internal.codegen.CompilerConstants.QUICK_PREFIX; 36import static jdk.nashorn.internal.codegen.CompilerConstants.REGEX_PREFIX; 37import static jdk.nashorn.internal.codegen.CompilerConstants.SCOPE; 38import static jdk.nashorn.internal.codegen.CompilerConstants.SPLIT_PREFIX; 39import static jdk.nashorn.internal.codegen.CompilerConstants.THIS; 40import static jdk.nashorn.internal.codegen.CompilerConstants.VARARGS; 41import static jdk.nashorn.internal.codegen.CompilerConstants.interfaceCallNoLookup; 42import static jdk.nashorn.internal.codegen.CompilerConstants.methodDescriptor; 43import static jdk.nashorn.internal.codegen.CompilerConstants.staticCallNoLookup; 44import static jdk.nashorn.internal.codegen.CompilerConstants.typeDescriptor; 45import static jdk.nashorn.internal.codegen.CompilerConstants.virtualCallNoLookup; 46import static jdk.nashorn.internal.ir.Symbol.HAS_SLOT; 47import static jdk.nashorn.internal.ir.Symbol.IS_INTERNAL; 48import static jdk.nashorn.internal.runtime.UnwarrantedOptimismException.INVALID_PROGRAM_POINT; 49import static jdk.nashorn.internal.runtime.UnwarrantedOptimismException.isValid; 50import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_APPLY_TO_CALL; 51import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_DECLARE; 52import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_FAST_SCOPE; 53import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_OPTIMISTIC; 54import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_PROGRAM_POINT_SHIFT; 55import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_SCOPE; 56 57import java.io.PrintWriter; 58import java.util.ArrayDeque; 59import java.util.ArrayList; 60import java.util.Arrays; 61import java.util.BitSet; 62import java.util.Collection; 63import java.util.Collections; 64import java.util.Deque; 65import java.util.EnumSet; 66import java.util.HashMap; 67import java.util.HashSet; 68import java.util.Iterator; 69import java.util.LinkedList; 70import java.util.List; 71import java.util.Map; 72import java.util.Set; 73import java.util.TreeMap; 74import java.util.function.Supplier; 75import jdk.nashorn.internal.AssertsEnabled; 76import jdk.nashorn.internal.IntDeque; 77import jdk.nashorn.internal.codegen.ClassEmitter.Flag; 78import jdk.nashorn.internal.codegen.CompilerConstants.Call; 79import jdk.nashorn.internal.codegen.types.ArrayType; 80import jdk.nashorn.internal.codegen.types.Type; 81import jdk.nashorn.internal.ir.AccessNode; 82import jdk.nashorn.internal.ir.BaseNode; 83import jdk.nashorn.internal.ir.BinaryNode; 84import jdk.nashorn.internal.ir.Block; 85import jdk.nashorn.internal.ir.BlockStatement; 86import jdk.nashorn.internal.ir.BreakNode; 87import jdk.nashorn.internal.ir.CallNode; 88import jdk.nashorn.internal.ir.CaseNode; 89import jdk.nashorn.internal.ir.CatchNode; 90import jdk.nashorn.internal.ir.ContinueNode; 91import jdk.nashorn.internal.ir.EmptyNode; 92import jdk.nashorn.internal.ir.Expression; 93import jdk.nashorn.internal.ir.ExpressionStatement; 94import jdk.nashorn.internal.ir.ForNode; 95import jdk.nashorn.internal.ir.FunctionNode; 96import jdk.nashorn.internal.ir.GetSplitState; 97import jdk.nashorn.internal.ir.IdentNode; 98import jdk.nashorn.internal.ir.IfNode; 99import jdk.nashorn.internal.ir.IndexNode; 100import jdk.nashorn.internal.ir.JoinPredecessorExpression; 101import jdk.nashorn.internal.ir.JumpStatement; 102import jdk.nashorn.internal.ir.JumpToInlinedFinally; 103import jdk.nashorn.internal.ir.LabelNode; 104import jdk.nashorn.internal.ir.LexicalContext; 105import jdk.nashorn.internal.ir.LexicalContextNode; 106import jdk.nashorn.internal.ir.LiteralNode; 107import jdk.nashorn.internal.ir.LiteralNode.ArrayLiteralNode; 108import jdk.nashorn.internal.ir.LiteralNode.PrimitiveLiteralNode; 109import jdk.nashorn.internal.ir.LocalVariableConversion; 110import jdk.nashorn.internal.ir.LoopNode; 111import jdk.nashorn.internal.ir.Node; 112import jdk.nashorn.internal.ir.ObjectNode; 113import jdk.nashorn.internal.ir.Optimistic; 114import jdk.nashorn.internal.ir.PropertyNode; 115import jdk.nashorn.internal.ir.ReturnNode; 116import jdk.nashorn.internal.ir.RuntimeNode; 117import jdk.nashorn.internal.ir.RuntimeNode.Request; 118import jdk.nashorn.internal.ir.SetSplitState; 119import jdk.nashorn.internal.ir.SplitReturn; 120import jdk.nashorn.internal.ir.Splittable; 121import jdk.nashorn.internal.ir.Statement; 122import jdk.nashorn.internal.ir.SwitchNode; 123import jdk.nashorn.internal.ir.Symbol; 124import jdk.nashorn.internal.ir.TernaryNode; 125import jdk.nashorn.internal.ir.ThrowNode; 126import jdk.nashorn.internal.ir.TryNode; 127import jdk.nashorn.internal.ir.UnaryNode; 128import jdk.nashorn.internal.ir.VarNode; 129import jdk.nashorn.internal.ir.WhileNode; 130import jdk.nashorn.internal.ir.WithNode; 131import jdk.nashorn.internal.ir.visitor.NodeOperatorVisitor; 132import jdk.nashorn.internal.ir.visitor.NodeVisitor; 133import jdk.nashorn.internal.objects.Global; 134import jdk.nashorn.internal.parser.Lexer.RegexToken; 135import jdk.nashorn.internal.parser.TokenType; 136import jdk.nashorn.internal.runtime.Context; 137import jdk.nashorn.internal.runtime.Debug; 138import jdk.nashorn.internal.runtime.ECMAException; 139import jdk.nashorn.internal.runtime.JSType; 140import jdk.nashorn.internal.runtime.OptimisticReturnFilters; 141import jdk.nashorn.internal.runtime.PropertyMap; 142import jdk.nashorn.internal.runtime.RecompilableScriptFunctionData; 143import jdk.nashorn.internal.runtime.RewriteException; 144import jdk.nashorn.internal.runtime.Scope; 145import jdk.nashorn.internal.runtime.ScriptEnvironment; 146import jdk.nashorn.internal.runtime.ScriptFunction; 147import jdk.nashorn.internal.runtime.ScriptObject; 148import jdk.nashorn.internal.runtime.ScriptRuntime; 149import jdk.nashorn.internal.runtime.Source; 150import jdk.nashorn.internal.runtime.Undefined; 151import jdk.nashorn.internal.runtime.UnwarrantedOptimismException; 152import jdk.nashorn.internal.runtime.arrays.ArrayData; 153import jdk.nashorn.internal.runtime.linker.LinkerCallSite; 154import jdk.nashorn.internal.runtime.logging.DebugLogger; 155import jdk.nashorn.internal.runtime.logging.Loggable; 156import jdk.nashorn.internal.runtime.logging.Logger; 157import 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") 178final 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_LONG = CompilerConstants.staticCallNoLookup(OptimisticReturnFilters.class, 192 "ensureLong", long.class, Object.class, int.class); 193 private static final Call ENSURE_NUMBER = CompilerConstants.staticCallNoLookup(OptimisticReturnFilters.class, 194 "ensureNumber", double.class, Object.class, int.class); 195 196 private static final Call CREATE_FUNCTION_OBJECT = CompilerConstants.staticCallNoLookup(ScriptFunction.class, 197 "create", ScriptFunction.class, Object[].class, int.class, ScriptObject.class); 198 private static final Call CREATE_FUNCTION_OBJECT_NO_SCOPE = CompilerConstants.staticCallNoLookup(ScriptFunction.class, 199 "create", ScriptFunction.class, Object[].class, int.class); 200 201 private static final Call TO_NUMBER_FOR_EQ = CompilerConstants.staticCallNoLookup(JSType.class, 202 "toNumberForEq", double.class, Object.class); 203 private static final Call TO_NUMBER_FOR_STRICT_EQ = CompilerConstants.staticCallNoLookup(JSType.class, 204 "toNumberForStrictEq", double.class, Object.class); 205 206 207 private static final Class<?> ITERATOR_CLASS = Iterator.class; 208 static { 209 assert ITERATOR_CLASS == CompilerConstants.ITERATOR_PREFIX.type(); 210 } 211 private static final Type ITERATOR_TYPE = Type.typeFor(ITERATOR_CLASS); 212 private static final Type EXCEPTION_TYPE = Type.typeFor(CompilerConstants.EXCEPTION_PREFIX.type()); 213 214 private static final Integer INT_ZERO = 0; 215 216 /** Constant data & installation. The only reason the compiler keeps this is because it is assigned 217 * by reflection in class installation */ 218 private final Compiler compiler; 219 220 /** Is the current code submitted by 'eval' call? */ 221 private final boolean evalCode; 222 223 /** Call site flags given to the code generator to be used for all generated call sites */ 224 private final int callSiteFlags; 225 226 /** How many regexp fields have been emitted */ 227 private int regexFieldCount; 228 229 /** Line number for last statement. If we encounter a new line number, line number bytecode information 230 * needs to be generated */ 231 private int lastLineNumber = -1; 232 233 /** When should we stop caching regexp expressions in fields to limit bytecode size? */ 234 private static final int MAX_REGEX_FIELDS = 2 * 1024; 235 236 /** Current method emitter */ 237 private MethodEmitter method; 238 239 /** Current compile unit */ 240 private CompileUnit unit; 241 242 private final DebugLogger log; 243 244 /** From what size should we use spill instead of fields for JavaScript objects? */ 245 static final int OBJECT_SPILL_THRESHOLD = Options.getIntProperty("nashorn.spill.threshold", 256); 246 247 private final Set<String> emittedMethods = new HashSet<>(); 248 249 // Function Id -> ContinuationInfo. Used by compilation of rest-of function only. 250 private ContinuationInfo continuationInfo; 251 252 private final Deque<Label> scopeEntryLabels = new ArrayDeque<>(); 253 254 private static final Label METHOD_BOUNDARY = new Label(""); 255 private final Deque<Label> catchLabels = new ArrayDeque<>(); 256 // Number of live locals on entry to (and thus also break from) labeled blocks. 257 private final IntDeque labeledBlockBreakLiveLocals = new IntDeque(); 258 259 //is this a rest of compilation 260 private final int[] continuationEntryPoints; 261 262 /** 263 * Constructor. 264 * 265 * @param compiler 266 */ 267 CodeGenerator(final Compiler compiler, final int[] continuationEntryPoints) { 268 super(new CodeGeneratorLexicalContext()); 269 this.compiler = compiler; 270 this.evalCode = compiler.getSource().isEvalCode(); 271 this.continuationEntryPoints = continuationEntryPoints; 272 this.callSiteFlags = compiler.getScriptEnvironment()._callsite_flags; 273 this.log = initLogger(compiler.getContext()); 274 } 275 276 @Override 277 public DebugLogger getLogger() { 278 return log; 279 } 280 281 @Override 282 public DebugLogger initLogger(final Context context) { 283 return context.getLogger(this.getClass()); 284 } 285 286 /** 287 * Gets the call site flags, adding the strict flag if the current function 288 * being generated is in strict mode 289 * 290 * @return the correct flags for a call site in the current function 291 */ 292 int getCallSiteFlags() { 293 return lc.getCurrentFunction().getCallSiteFlags() | callSiteFlags; 294 } 295 296 /** 297 * Gets the flags for a scope call site. 298 * @param symbol a scope symbol 299 * @return the correct flags for the scope call site 300 */ 301 private int getScopeCallSiteFlags(final Symbol symbol) { 302 assert symbol.isScope(); 303 final int flags = getCallSiteFlags() | CALLSITE_SCOPE; 304 if (isEvalCode() && symbol.isGlobal()) { 305 return flags; // Don't set fast-scope flag on non-declared globals in eval code - see JDK-8077955. 306 } 307 return isFastScope(symbol) ? flags | CALLSITE_FAST_SCOPE : flags; 308 } 309 310 /** 311 * Are we generating code for 'eval' code? 312 * @return true if currently compiled code is 'eval' code. 313 */ 314 boolean isEvalCode() { 315 return evalCode; 316 } 317 318 /** 319 * Are we using dual primitive/object field representation? 320 * @return true if using dual field representation, false for object-only fields 321 */ 322 boolean useDualFields() { 323 return compiler.getContext().useDualFields(); 324 } 325 326 /** 327 * Load an identity node 328 * 329 * @param identNode an identity node to load 330 * @return the method generator used 331 */ 332 private MethodEmitter loadIdent(final IdentNode identNode, final TypeBounds resultBounds) { 333 checkTemporalDeadZone(identNode); 334 final Symbol symbol = identNode.getSymbol(); 335 336 if (!symbol.isScope()) { 337 final Type type = identNode.getType(); 338 if(type == Type.UNDEFINED) { 339 return method.loadUndefined(resultBounds.widest); 340 } 341 342 assert symbol.hasSlot() || symbol.isParam(); 343 return method.load(identNode); 344 } 345 346 assert identNode.getSymbol().isScope() : identNode + " is not in scope!"; 347 final int flags = getScopeCallSiteFlags(symbol); 348 if (isFastScope(symbol)) { 349 // Only generate shared scope getter for fast-scope symbols so we know we can dial in correct scope. 350 if (symbol.getUseCount() > SharedScopeCall.FAST_SCOPE_GET_THRESHOLD && !identNode.isOptimistic()) { 351 // As shared scope vars are only used with non-optimistic identifiers, we switch from using TypeBounds to 352 // just a single definitive type, resultBounds.widest. 353 new OptimisticOperation(identNode, TypeBounds.OBJECT) { 354 @Override 355 void loadStack() { 356 method.loadCompilerConstant(SCOPE); 357 } 358 359 @Override 360 void consumeStack() { 361 loadSharedScopeVar(resultBounds.widest, symbol, flags); 362 } 363 }.emit(); 364 } else { 365 new LoadFastScopeVar(identNode, resultBounds, flags).emit(); 366 } 367 } else { 368 //slow scope load, we have no proto depth 369 new LoadScopeVar(identNode, resultBounds, flags).emit(); 370 } 371 372 return method; 373 } 374 375 // Any access to LET and CONST variables before their declaration must throw ReferenceError. 376 // This is called the temporal dead zone (TDZ). See https://gist.github.com/rwaldron/f0807a758aa03bcdd58a 377 private void checkTemporalDeadZone(final IdentNode identNode) { 378 if (identNode.isDead()) { 379 method.load(identNode.getSymbol().getName()).invoke(ScriptRuntime.THROW_REFERENCE_ERROR); 380 } 381 } 382 383 // Runtime check for assignment to ES6 const 384 private void checkAssignTarget(final Expression expression) { 385 if (expression instanceof IdentNode && ((IdentNode)expression).getSymbol().isConst()) { 386 method.load(((IdentNode)expression).getSymbol().getName()).invoke(ScriptRuntime.THROW_CONST_TYPE_ERROR); 387 } 388 } 389 390 private boolean isRestOf() { 391 return continuationEntryPoints != null; 392 } 393 394 private boolean isCurrentContinuationEntryPoint(final int programPoint) { 395 return isRestOf() && getCurrentContinuationEntryPoint() == programPoint; 396 } 397 398 private int[] getContinuationEntryPoints() { 399 return isRestOf() ? continuationEntryPoints : null; 400 } 401 402 private int getCurrentContinuationEntryPoint() { 403 return isRestOf() ? continuationEntryPoints[0] : INVALID_PROGRAM_POINT; 404 } 405 406 private boolean isContinuationEntryPoint(final int programPoint) { 407 if (isRestOf()) { 408 assert continuationEntryPoints != null; 409 for (final int cep : continuationEntryPoints) { 410 if (cep == programPoint) { 411 return true; 412 } 413 } 414 } 415 return false; 416 } 417 418 /** 419 * Check if this symbol can be accessed directly with a putfield or getfield or dynamic load 420 * 421 * @param symbol symbol to check for fast scope 422 * @return true if fast scope 423 */ 424 private boolean isFastScope(final Symbol symbol) { 425 if (!symbol.isScope()) { 426 return false; 427 } 428 429 if (!lc.inDynamicScope()) { 430 // If there's no with or eval in context, and the symbol is marked as scoped, it is fast scoped. Such a 431 // symbol must either be global, or its defining block must need scope. 432 assert symbol.isGlobal() || lc.getDefiningBlock(symbol).needsScope() : symbol.getName(); 433 return true; 434 } 435 436 if (symbol.isGlobal()) { 437 // Shortcut: if there's a with or eval in context, globals can't be fast scoped 438 return false; 439 } 440 441 // Otherwise, check if there's a dynamic scope between use of the symbol and its definition 442 final String name = symbol.getName(); 443 boolean previousWasBlock = false; 444 for (final Iterator<LexicalContextNode> it = lc.getAllNodes(); it.hasNext();) { 445 final LexicalContextNode node = it.next(); 446 if (node instanceof Block) { 447 // If this block defines the symbol, then we can fast scope the symbol. 448 final Block block = (Block)node; 449 if (block.getExistingSymbol(name) == symbol) { 450 assert block.needsScope(); 451 return true; 452 } 453 previousWasBlock = true; 454 } else { 455 if (node instanceof WithNode && previousWasBlock || node instanceof FunctionNode && ((FunctionNode)node).needsDynamicScope()) { 456 // If we hit a scope that can have symbols introduced into it at run time before finding the defining 457 // block, the symbol can't be fast scoped. A WithNode only counts if we've immediately seen a block 458 // before - its block. Otherwise, we are currently processing the WithNode's expression, and that's 459 // obviously not subjected to introducing new symbols. 460 return false; 461 } 462 previousWasBlock = false; 463 } 464 } 465 // Should've found the symbol defined in a block 466 throw new AssertionError(); 467 } 468 469 private MethodEmitter loadSharedScopeVar(final Type valueType, final Symbol symbol, final int flags) { 470 assert isFastScope(symbol); 471 method.load(getScopeProtoDepth(lc.getCurrentBlock(), symbol)); 472 return lc.getScopeGet(unit, symbol, valueType, flags).generateInvoke(method); 473 } 474 475 private class LoadScopeVar extends OptimisticOperation { 476 final IdentNode identNode; 477 private final int flags; 478 479 LoadScopeVar(final IdentNode identNode, final TypeBounds resultBounds, final int flags) { 480 super(identNode, resultBounds); 481 this.identNode = identNode; 482 this.flags = flags; 483 } 484 485 @Override 486 void loadStack() { 487 method.loadCompilerConstant(SCOPE); 488 getProto(); 489 } 490 491 void getProto() { 492 //empty 493 } 494 495 @Override 496 void consumeStack() { 497 // If this is either __FILE__, __DIR__, or __LINE__ then load the property initially as Object as we'd convert 498 // it anyway for replaceLocationPropertyPlaceholder. 499 if(identNode.isCompileTimePropertyName()) { 500 method.dynamicGet(Type.OBJECT, identNode.getSymbol().getName(), flags, identNode.isFunction(), false); 501 replaceCompileTimeProperty(); 502 } else { 503 dynamicGet(identNode.getSymbol().getName(), flags, identNode.isFunction(), false); 504 } 505 } 506 } 507 508 private class LoadFastScopeVar extends LoadScopeVar { 509 LoadFastScopeVar(final IdentNode identNode, final TypeBounds resultBounds, final int flags) { 510 super(identNode, resultBounds, flags); 511 } 512 513 @Override 514 void getProto() { 515 loadFastScopeProto(identNode.getSymbol(), false); 516 } 517 } 518 519 private MethodEmitter storeFastScopeVar(final Symbol symbol, final int flags) { 520 loadFastScopeProto(symbol, true); 521 method.dynamicSet(symbol.getName(), flags, false); 522 return method; 523 } 524 525 private int getScopeProtoDepth(final Block startingBlock, final Symbol symbol) { 526 //walk up the chain from starting block and when we bump into the current function boundary, add the external 527 //information. 528 final FunctionNode fn = lc.getCurrentFunction(); 529 final int externalDepth = compiler.getScriptFunctionData(fn.getId()).getExternalSymbolDepth(symbol.getName()); 530 531 //count the number of scopes from this place to the start of the function 532 533 final int internalDepth = FindScopeDepths.findInternalDepth(lc, fn, startingBlock, symbol); 534 final int scopesToStart = FindScopeDepths.findScopesToStart(lc, fn, startingBlock); 535 int depth = 0; 536 if (internalDepth == -1) { 537 depth = scopesToStart + externalDepth; 538 } else { 539 assert internalDepth <= scopesToStart; 540 depth = internalDepth; 541 } 542 543 return depth; 544 } 545 546 private void loadFastScopeProto(final Symbol symbol, final boolean swap) { 547 final int depth = getScopeProtoDepth(lc.getCurrentBlock(), symbol); 548 assert depth != -1 : "Couldn't find scope depth for symbol " + symbol.getName() + " in " + lc.getCurrentFunction(); 549 if (depth > 0) { 550 if (swap) { 551 method.swap(); 552 } 553 for (int i = 0; i < depth; i++) { 554 method.invoke(ScriptObject.GET_PROTO); 555 } 556 if (swap) { 557 method.swap(); 558 } 559 } 560 } 561 562 /** 563 * Generate code that loads this node to the stack, not constraining its type 564 * 565 * @param expr node to load 566 * 567 * @return the method emitter used 568 */ 569 private MethodEmitter loadExpressionUnbounded(final Expression expr) { 570 return loadExpression(expr, TypeBounds.UNBOUNDED); 571 } 572 573 private MethodEmitter loadExpressionAsObject(final Expression expr) { 574 return loadExpression(expr, TypeBounds.OBJECT); 575 } 576 577 MethodEmitter loadExpressionAsBoolean(final Expression expr) { 578 return loadExpression(expr, TypeBounds.BOOLEAN); 579 } 580 581 // Test whether conversion from source to target involves a call of ES 9.1 ToPrimitive 582 // with possible side effects from calling an object's toString or valueOf methods. 583 private static boolean noToPrimitiveConversion(final Type source, final Type target) { 584 // Object to boolean conversion does not cause ToPrimitive call 585 return source.isJSPrimitive() || !target.isJSPrimitive() || target.isBoolean(); 586 } 587 588 MethodEmitter loadBinaryOperands(final BinaryNode binaryNode) { 589 return loadBinaryOperands(binaryNode.lhs(), binaryNode.rhs(), TypeBounds.UNBOUNDED.notWiderThan(binaryNode.getWidestOperandType()), false, false); 590 } 591 592 private MethodEmitter loadBinaryOperands(final Expression lhs, final Expression rhs, final TypeBounds explicitOperandBounds, final boolean baseAlreadyOnStack, final boolean forceConversionSeparation) { 593 // ECMAScript 5.1 specification (sections 11.5-11.11 and 11.13) prescribes that when evaluating a binary 594 // expression "LEFT op RIGHT", the order of operations must be: LOAD LEFT, LOAD RIGHT, CONVERT LEFT, CONVERT 595 // RIGHT, EXECUTE OP. Unfortunately, doing it in this order defeats potential optimizations that arise when we 596 // can combine a LOAD with a CONVERT operation (e.g. use a dynamic getter with the conversion target type as its 597 // return value). What we do here is reorder LOAD RIGHT and CONVERT LEFT when possible; it is possible only when 598 // we can prove that executing CONVERT LEFT can't have a side effect that changes the value of LOAD RIGHT. 599 // Basically, if we know that either LEFT already is a primitive value, or does not have to be converted to 600 // a primitive value, or RIGHT is an expression that loads without side effects, then we can do the 601 // reordering and collapse LOAD/CONVERT into a single operation; otherwise we need to do the more costly 602 // separate operations to preserve specification semantics. 603 604 // Operands' load type should not be narrower than the narrowest of the individual operand types, nor narrower 605 // than the lower explicit bound, but it should also not be wider than 606 final Type lhsType = undefinedToNumber(lhs.getType()); 607 final Type rhsType = undefinedToNumber(rhs.getType()); 608 final Type narrowestOperandType = Type.narrowest(Type.widest(lhsType, rhsType), explicitOperandBounds.widest); 609 final TypeBounds operandBounds = explicitOperandBounds.notNarrowerThan(narrowestOperandType); 610 if (noToPrimitiveConversion(lhsType, explicitOperandBounds.widest) || rhs.isLocal()) { 611 // Can reorder. We might still need to separate conversion, but at least we can do it with reordering 612 if (forceConversionSeparation) { 613 // Can reorder, but can't move conversion into the operand as the operation depends on operands 614 // exact types for its overflow guarantees. E.g. with {L}{%I}expr1 {L}* {L}{%I}expr2 we are not allowed 615 // to merge {L}{%I} into {%L}, as that can cause subsequent overflows; test for JDK-8058610 contains 616 // concrete cases where this could happen. 617 final TypeBounds safeConvertBounds = TypeBounds.UNBOUNDED.notNarrowerThan(narrowestOperandType); 618 loadExpression(lhs, safeConvertBounds, baseAlreadyOnStack); 619 method.convert(operandBounds.within(method.peekType())); 620 loadExpression(rhs, safeConvertBounds, false); 621 method.convert(operandBounds.within(method.peekType())); 622 } else { 623 // Can reorder and move conversion into the operand. Combine load and convert into single operations. 624 loadExpression(lhs, operandBounds, baseAlreadyOnStack); 625 loadExpression(rhs, operandBounds, false); 626 } 627 } else { 628 // Can't reorder. Load and convert separately. 629 final TypeBounds safeConvertBounds = TypeBounds.UNBOUNDED.notNarrowerThan(narrowestOperandType); 630 loadExpression(lhs, safeConvertBounds, baseAlreadyOnStack); 631 final Type lhsLoadedType = method.peekType(); 632 loadExpression(rhs, safeConvertBounds, false); 633 final Type convertedLhsType = operandBounds.within(method.peekType()); 634 if (convertedLhsType != lhsLoadedType) { 635 // Do it conditionally, so that if conversion is a no-op we don't introduce a SWAP, SWAP. 636 method.swap().convert(convertedLhsType).swap(); 637 } 638 method.convert(operandBounds.within(method.peekType())); 639 } 640 assert Type.generic(method.peekType()) == operandBounds.narrowest; 641 assert Type.generic(method.peekType(1)) == operandBounds.narrowest; 642 643 return method; 644 } 645 646 /** 647 * Similar to {@link #loadBinaryOperands(BinaryNode)} but used specifically for loading operands of 648 * relational and equality comparison operators where at least one argument is non-object. (When both 649 * arguments are objects, we use {@link ScriptRuntime#EQ(Object, Object)}, {@link ScriptRuntime#LT(Object, Object)} 650 * etc. methods instead. Additionally, {@code ScriptRuntime} methods are used for strict (in)equality comparison 651 * of a boolean to anything that isn't a boolean.) This method handles the special case where one argument 652 * is an object and another is a primitive. Naively, these could also be delegated to {@code ScriptRuntime} methods 653 * by boxing the primitive. However, in all such cases the comparison is performed on numeric values, so it is 654 * possible to strength-reduce the operation by taking the number value of the object argument instead and 655 * comparing that to the primitive value ("primitive" will always be int, long, double, or boolean, and booleans 656 * compare as ints in these cases, so they're essentially numbers too). This method will emit code for loading 657 * arguments for such strength-reduced comparison. When both arguments are primitives, it just delegates to 658 * {@link #loadBinaryOperands(BinaryNode)}. 659 * 660 * @param cmp the comparison operation for which the operands need to be loaded on stack. 661 * @return the current method emitter. 662 */ 663 MethodEmitter loadComparisonOperands(final BinaryNode cmp) { 664 final Expression lhs = cmp.lhs(); 665 final Expression rhs = cmp.rhs(); 666 final Type lhsType = lhs.getType(); 667 final Type rhsType = rhs.getType(); 668 669 // Only used when not both are object, for that we have ScriptRuntime.LT etc. 670 assert !(lhsType.isObject() && rhsType.isObject()); 671 672 if (lhsType.isObject() || rhsType.isObject()) { 673 // We can reorder CONVERT LEFT and LOAD RIGHT only if either the left is a primitive, or the right 674 // is a local. This is more strict than loadBinaryNode reorder criteria, as it can allow JS primitive 675 // types too (notably: String is a JS primitive, but not a JVM primitive). We disallow String otherwise 676 // we would prematurely convert it to number when comparing to an optimistic expression, e.g. in 677 // "Hello" === String("Hello") the RHS starts out as an optimistic-int function call. If we allowed 678 // reordering, we'd end up with ToNumber("Hello") === {I%}String("Hello") that is obviously incorrect. 679 final boolean canReorder = lhsType.isPrimitive() || rhs.isLocal(); 680 // If reordering is allowed, and we're using a relational operator (that is, <, <=, >, >=) and not an 681 // (in)equality operator, then we encourage combining of LOAD and CONVERT into a single operation. 682 // This is because relational operators' semantics prescribes vanilla ToNumber() conversion, while 683 // (in)equality operators need the specialized JSType.toNumberFor[Strict]Equals. E.g. in the code snippet 684 // "i < obj.size" (where i is primitive and obj.size is statically an object), ".size" will thus be allowed 685 // to compile as: 686 // invokedynamic dyn:getProp|getElem|getMethod:size(Object;)D 687 // instead of the more costly: 688 // invokedynamic dyn:getProp|getElem|getMethod:size(Object;)Object 689 // invokestatic JSType.toNumber(Object)D 690 // Note also that even if this is allowed, we're only using it on operands that are non-optimistic, as 691 // otherwise the logic for determining effective optimistic-ness would turn an optimistic double return 692 // into a freely coercible one, which would be wrong. 693 final boolean canCombineLoadAndConvert = canReorder && cmp.isRelational(); 694 695 // LOAD LEFT 696 loadExpression(lhs, canCombineLoadAndConvert && !lhs.isOptimistic() ? TypeBounds.NUMBER : TypeBounds.UNBOUNDED); 697 698 final Type lhsLoadedType = method.peekType(); 699 final TokenType tt = cmp.tokenType(); 700 if (canReorder) { 701 // Can reorder CONVERT LEFT and LOAD RIGHT 702 emitObjectToNumberComparisonConversion(method, tt); 703 loadExpression(rhs, canCombineLoadAndConvert && !rhs.isOptimistic() ? TypeBounds.NUMBER : TypeBounds.UNBOUNDED); 704 } else { 705 // Can't reorder CONVERT LEFT and LOAD RIGHT 706 loadExpression(rhs, TypeBounds.UNBOUNDED); 707 if (lhsLoadedType != Type.NUMBER) { 708 method.swap(); 709 emitObjectToNumberComparisonConversion(method, tt); 710 method.swap(); 711 } 712 } 713 714 // CONVERT RIGHT 715 emitObjectToNumberComparisonConversion(method, tt); 716 return method; 717 } 718 // For primitive operands, just don't do anything special. 719 return loadBinaryOperands(cmp); 720 } 721 722 private static void emitObjectToNumberComparisonConversion(final MethodEmitter method, final TokenType tt) { 723 switch(tt) { 724 case EQ: 725 case NE: 726 if (method.peekType().isObject()) { 727 TO_NUMBER_FOR_EQ.invoke(method); 728 return; 729 } 730 break; 731 case EQ_STRICT: 732 case NE_STRICT: 733 if (method.peekType().isObject()) { 734 TO_NUMBER_FOR_STRICT_EQ.invoke(method); 735 return; 736 } 737 break; 738 default: 739 break; 740 } 741 method.convert(Type.NUMBER); 742 } 743 744 private static Type undefinedToNumber(final Type type) { 745 return type == Type.UNDEFINED ? Type.NUMBER : type; 746 } 747 748 private static final class TypeBounds { 749 final Type narrowest; 750 final Type widest; 751 752 static final TypeBounds UNBOUNDED = new TypeBounds(Type.UNKNOWN, Type.OBJECT); 753 static final TypeBounds INT = exact(Type.INT); 754 static final TypeBounds NUMBER = exact(Type.NUMBER); 755 static final TypeBounds OBJECT = exact(Type.OBJECT); 756 static final TypeBounds BOOLEAN = exact(Type.BOOLEAN); 757 758 static TypeBounds exact(final Type type) { 759 return new TypeBounds(type, type); 760 } 761 762 TypeBounds(final Type narrowest, final Type widest) { 763 assert widest != null && widest != Type.UNDEFINED && widest != Type.UNKNOWN : widest; 764 assert narrowest != null && narrowest != Type.UNDEFINED : narrowest; 765 assert !narrowest.widerThan(widest) : narrowest + " wider than " + widest; 766 assert !widest.narrowerThan(narrowest); 767 this.narrowest = Type.generic(narrowest); 768 this.widest = Type.generic(widest); 769 } 770 771 TypeBounds notNarrowerThan(final Type type) { 772 return maybeNew(Type.narrowest(Type.widest(narrowest, type), widest), widest); 773 } 774 775 TypeBounds notWiderThan(final Type type) { 776 return maybeNew(Type.narrowest(narrowest, type), Type.narrowest(widest, type)); 777 } 778 779 boolean canBeNarrowerThan(final Type type) { 780 return narrowest.narrowerThan(type); 781 } 782 783 TypeBounds maybeNew(final Type newNarrowest, final Type newWidest) { 784 if(newNarrowest == narrowest && newWidest == widest) { 785 return this; 786 } 787 return new TypeBounds(newNarrowest, newWidest); 788 } 789 790 TypeBounds booleanToInt() { 791 return maybeNew(CodeGenerator.booleanToInt(narrowest), CodeGenerator.booleanToInt(widest)); 792 } 793 794 TypeBounds objectToNumber() { 795 return maybeNew(CodeGenerator.objectToNumber(narrowest), CodeGenerator.objectToNumber(widest)); 796 } 797 798 Type within(final Type type) { 799 if(type.narrowerThan(narrowest)) { 800 return narrowest; 801 } 802 if(type.widerThan(widest)) { 803 return widest; 804 } 805 return type; 806 } 807 808 @Override 809 public String toString() { 810 return "[" + narrowest + ", " + widest + "]"; 811 } 812 } 813 814 private static Type booleanToInt(final Type t) { 815 return t == Type.BOOLEAN ? Type.INT : t; 816 } 817 818 private static Type objectToNumber(final Type t) { 819 return t.isObject() ? Type.NUMBER : t; 820 } 821 822 MethodEmitter loadExpressionAsType(final Expression expr, final Type type) { 823 if(type == Type.BOOLEAN) { 824 return loadExpressionAsBoolean(expr); 825 } else if(type == Type.UNDEFINED) { 826 assert expr.getType() == Type.UNDEFINED; 827 return loadExpressionAsObject(expr); 828 } 829 // having no upper bound preserves semantics of optimistic operations in the expression (by not having them 830 // converted early) and then applies explicit conversion afterwards. 831 return loadExpression(expr, TypeBounds.UNBOUNDED.notNarrowerThan(type)).convert(type); 832 } 833 834 private MethodEmitter loadExpression(final Expression expr, final TypeBounds resultBounds) { 835 return loadExpression(expr, resultBounds, false); 836 } 837 838 /** 839 * Emits code for evaluating an expression and leaving its value on top of the stack, narrowing or widening it if 840 * necessary. 841 * @param expr the expression to load 842 * @param resultBounds the incoming type bounds. The value on the top of the stack is guaranteed to not be of narrower 843 * type than the narrowest bound, or wider type than the widest bound after it is loaded. 844 * @param baseAlreadyOnStack true if the base of an access or index node is already on the stack. Used to avoid 845 * double evaluation of bases in self-assignment expressions to access and index nodes. {@code Type.OBJECT} is used 846 * to indicate the widest possible type. 847 * @return the method emitter 848 */ 849 private MethodEmitter loadExpression(final Expression expr, final TypeBounds resultBounds, final boolean baseAlreadyOnStack) { 850 851 /* 852 * The load may be of type IdentNode, e.g. "x", AccessNode, e.g. "x.y" 853 * or IndexNode e.g. "x[y]". Both AccessNodes and IndexNodes are 854 * BaseNodes and the logic for loading the base object is reused 855 */ 856 final CodeGenerator codegen = this; 857 858 final boolean isCurrentDiscard = codegen.lc.isCurrentDiscard(expr); 859 expr.accept(new NodeOperatorVisitor<LexicalContext>(new LexicalContext()) { 860 @Override 861 public boolean enterIdentNode(final IdentNode identNode) { 862 loadIdent(identNode, resultBounds); 863 return false; 864 } 865 866 @Override 867 public boolean enterAccessNode(final AccessNode accessNode) { 868 new OptimisticOperation(accessNode, resultBounds) { 869 @Override 870 void loadStack() { 871 if (!baseAlreadyOnStack) { 872 loadExpressionAsObject(accessNode.getBase()); 873 } 874 assert method.peekType().isObject(); 875 } 876 @Override 877 void consumeStack() { 878 final int flags = getCallSiteFlags(); 879 dynamicGet(accessNode.getProperty(), flags, accessNode.isFunction(), accessNode.isIndex()); 880 } 881 }.emit(baseAlreadyOnStack ? 1 : 0); 882 return false; 883 } 884 885 @Override 886 public boolean enterIndexNode(final IndexNode indexNode) { 887 new OptimisticOperation(indexNode, resultBounds) { 888 @Override 889 void loadStack() { 890 if (!baseAlreadyOnStack) { 891 loadExpressionAsObject(indexNode.getBase()); 892 loadExpressionUnbounded(indexNode.getIndex()); 893 } 894 } 895 @Override 896 void consumeStack() { 897 final int flags = getCallSiteFlags(); 898 dynamicGetIndex(flags, indexNode.isFunction()); 899 } 900 }.emit(baseAlreadyOnStack ? 2 : 0); 901 return false; 902 } 903 904 @Override 905 public boolean enterFunctionNode(final FunctionNode functionNode) { 906 // function nodes will always leave a constructed function object on stack, no need to load the symbol 907 // separately as in enterDefault() 908 lc.pop(functionNode); 909 functionNode.accept(codegen); 910 // NOTE: functionNode.accept() will produce a different FunctionNode that we discard. This incidentally 911 // doesn't cause problems as we're never touching FunctionNode again after it's visited here - codegen 912 // is the last element in the compilation pipeline, the AST it produces is not used externally. So, we 913 // re-push the original functionNode. 914 lc.push(functionNode); 915 return false; 916 } 917 918 @Override 919 public boolean enterASSIGN(final BinaryNode binaryNode) { 920 checkAssignTarget(binaryNode.lhs()); 921 loadASSIGN(binaryNode); 922 return false; 923 } 924 925 @Override 926 public boolean enterASSIGN_ADD(final BinaryNode binaryNode) { 927 checkAssignTarget(binaryNode.lhs()); 928 loadASSIGN_ADD(binaryNode); 929 return false; 930 } 931 932 @Override 933 public boolean enterASSIGN_BIT_AND(final BinaryNode binaryNode) { 934 checkAssignTarget(binaryNode.lhs()); 935 loadASSIGN_BIT_AND(binaryNode); 936 return false; 937 } 938 939 @Override 940 public boolean enterASSIGN_BIT_OR(final BinaryNode binaryNode) { 941 checkAssignTarget(binaryNode.lhs()); 942 loadASSIGN_BIT_OR(binaryNode); 943 return false; 944 } 945 946 @Override 947 public boolean enterASSIGN_BIT_XOR(final BinaryNode binaryNode) { 948 checkAssignTarget(binaryNode.lhs()); 949 loadASSIGN_BIT_XOR(binaryNode); 950 return false; 951 } 952 953 @Override 954 public boolean enterASSIGN_DIV(final BinaryNode binaryNode) { 955 checkAssignTarget(binaryNode.lhs()); 956 loadASSIGN_DIV(binaryNode); 957 return false; 958 } 959 960 @Override 961 public boolean enterASSIGN_MOD(final BinaryNode binaryNode) { 962 checkAssignTarget(binaryNode.lhs()); 963 loadASSIGN_MOD(binaryNode); 964 return false; 965 } 966 967 @Override 968 public boolean enterASSIGN_MUL(final BinaryNode binaryNode) { 969 checkAssignTarget(binaryNode.lhs()); 970 loadASSIGN_MUL(binaryNode); 971 return false; 972 } 973 974 @Override 975 public boolean enterASSIGN_SAR(final BinaryNode binaryNode) { 976 checkAssignTarget(binaryNode.lhs()); 977 loadASSIGN_SAR(binaryNode); 978 return false; 979 } 980 981 @Override 982 public boolean enterASSIGN_SHL(final BinaryNode binaryNode) { 983 checkAssignTarget(binaryNode.lhs()); 984 loadASSIGN_SHL(binaryNode); 985 return false; 986 } 987 988 @Override 989 public boolean enterASSIGN_SHR(final BinaryNode binaryNode) { 990 checkAssignTarget(binaryNode.lhs()); 991 loadASSIGN_SHR(binaryNode); 992 return false; 993 } 994 995 @Override 996 public boolean enterASSIGN_SUB(final BinaryNode binaryNode) { 997 checkAssignTarget(binaryNode.lhs()); 998 loadASSIGN_SUB(binaryNode); 999 return false; 1000 } 1001 1002 @Override 1003 public boolean enterCallNode(final CallNode callNode) { 1004 return loadCallNode(callNode, resultBounds); 1005 } 1006 1007 @Override 1008 public boolean enterLiteralNode(final LiteralNode<?> literalNode) { 1009 loadLiteral(literalNode, resultBounds); 1010 return false; 1011 } 1012 1013 @Override 1014 public boolean enterTernaryNode(final TernaryNode ternaryNode) { 1015 loadTernaryNode(ternaryNode, resultBounds); 1016 return false; 1017 } 1018 1019 @Override 1020 public boolean enterADD(final BinaryNode binaryNode) { 1021 loadADD(binaryNode, resultBounds); 1022 return false; 1023 } 1024 1025 @Override 1026 public boolean enterSUB(final UnaryNode unaryNode) { 1027 loadSUB(unaryNode, resultBounds); 1028 return false; 1029 } 1030 1031 @Override 1032 public boolean enterSUB(final BinaryNode binaryNode) { 1033 loadSUB(binaryNode, resultBounds); 1034 return false; 1035 } 1036 1037 @Override 1038 public boolean enterMUL(final BinaryNode binaryNode) { 1039 loadMUL(binaryNode, resultBounds); 1040 return false; 1041 } 1042 1043 @Override 1044 public boolean enterDIV(final BinaryNode binaryNode) { 1045 loadDIV(binaryNode, resultBounds); 1046 return false; 1047 } 1048 1049 @Override 1050 public boolean enterMOD(final BinaryNode binaryNode) { 1051 loadMOD(binaryNode, resultBounds); 1052 return false; 1053 } 1054 1055 @Override 1056 public boolean enterSAR(final BinaryNode binaryNode) { 1057 loadSAR(binaryNode); 1058 return false; 1059 } 1060 1061 @Override 1062 public boolean enterSHL(final BinaryNode binaryNode) { 1063 loadSHL(binaryNode); 1064 return false; 1065 } 1066 1067 @Override 1068 public boolean enterSHR(final BinaryNode binaryNode) { 1069 loadSHR(binaryNode); 1070 return false; 1071 } 1072 1073 @Override 1074 public boolean enterCOMMALEFT(final BinaryNode binaryNode) { 1075 loadCOMMALEFT(binaryNode, resultBounds); 1076 return false; 1077 } 1078 1079 @Override 1080 public boolean enterCOMMARIGHT(final BinaryNode binaryNode) { 1081 loadCOMMARIGHT(binaryNode, resultBounds); 1082 return false; 1083 } 1084 1085 @Override 1086 public boolean enterAND(final BinaryNode binaryNode) { 1087 loadAND_OR(binaryNode, resultBounds, true); 1088 return false; 1089 } 1090 1091 @Override 1092 public boolean enterOR(final BinaryNode binaryNode) { 1093 loadAND_OR(binaryNode, resultBounds, false); 1094 return false; 1095 } 1096 1097 @Override 1098 public boolean enterNOT(final UnaryNode unaryNode) { 1099 loadNOT(unaryNode); 1100 return false; 1101 } 1102 1103 @Override 1104 public boolean enterADD(final UnaryNode unaryNode) { 1105 loadADD(unaryNode, resultBounds); 1106 return false; 1107 } 1108 1109 @Override 1110 public boolean enterBIT_NOT(final UnaryNode unaryNode) { 1111 loadBIT_NOT(unaryNode); 1112 return false; 1113 } 1114 1115 @Override 1116 public boolean enterBIT_AND(final BinaryNode binaryNode) { 1117 loadBIT_AND(binaryNode); 1118 return false; 1119 } 1120 1121 @Override 1122 public boolean enterBIT_OR(final BinaryNode binaryNode) { 1123 loadBIT_OR(binaryNode); 1124 return false; 1125 } 1126 1127 @Override 1128 public boolean enterBIT_XOR(final BinaryNode binaryNode) { 1129 loadBIT_XOR(binaryNode); 1130 return false; 1131 } 1132 1133 @Override 1134 public boolean enterVOID(final UnaryNode unaryNode) { 1135 loadVOID(unaryNode, resultBounds); 1136 return false; 1137 } 1138 1139 @Override 1140 public boolean enterEQ(final BinaryNode binaryNode) { 1141 loadCmp(binaryNode, Condition.EQ); 1142 return false; 1143 } 1144 1145 @Override 1146 public boolean enterEQ_STRICT(final BinaryNode binaryNode) { 1147 loadCmp(binaryNode, Condition.EQ); 1148 return false; 1149 } 1150 1151 @Override 1152 public boolean enterGE(final BinaryNode binaryNode) { 1153 loadCmp(binaryNode, Condition.GE); 1154 return false; 1155 } 1156 1157 @Override 1158 public boolean enterGT(final BinaryNode binaryNode) { 1159 loadCmp(binaryNode, Condition.GT); 1160 return false; 1161 } 1162 1163 @Override 1164 public boolean enterLE(final BinaryNode binaryNode) { 1165 loadCmp(binaryNode, Condition.LE); 1166 return false; 1167 } 1168 1169 @Override 1170 public boolean enterLT(final BinaryNode binaryNode) { 1171 loadCmp(binaryNode, Condition.LT); 1172 return false; 1173 } 1174 1175 @Override 1176 public boolean enterNE(final BinaryNode binaryNode) { 1177 loadCmp(binaryNode, Condition.NE); 1178 return false; 1179 } 1180 1181 @Override 1182 public boolean enterNE_STRICT(final BinaryNode binaryNode) { 1183 loadCmp(binaryNode, Condition.NE); 1184 return false; 1185 } 1186 1187 @Override 1188 public boolean enterObjectNode(final ObjectNode objectNode) { 1189 loadObjectNode(objectNode); 1190 return false; 1191 } 1192 1193 @Override 1194 public boolean enterRuntimeNode(final RuntimeNode runtimeNode) { 1195 loadRuntimeNode(runtimeNode); 1196 return false; 1197 } 1198 1199 @Override 1200 public boolean enterNEW(final UnaryNode unaryNode) { 1201 loadNEW(unaryNode); 1202 return false; 1203 } 1204 1205 @Override 1206 public boolean enterDECINC(final UnaryNode unaryNode) { 1207 checkAssignTarget(unaryNode.getExpression()); 1208 loadDECINC(unaryNode); 1209 return false; 1210 } 1211 1212 @Override 1213 public boolean enterJoinPredecessorExpression(final JoinPredecessorExpression joinExpr) { 1214 loadMaybeDiscard(joinExpr, joinExpr.getExpression(), resultBounds); 1215 return false; 1216 } 1217 1218 @Override 1219 public boolean enterGetSplitState(final GetSplitState getSplitState) { 1220 method.loadScope(); 1221 method.invoke(Scope.GET_SPLIT_STATE); 1222 return false; 1223 } 1224 1225 @Override 1226 public boolean enterDefault(final Node otherNode) { 1227 // Must have handled all expressions that can legally be encountered. 1228 throw new AssertionError(otherNode.getClass().getName()); 1229 } 1230 }); 1231 if(!isCurrentDiscard) { 1232 coerceStackTop(resultBounds); 1233 } 1234 return method; 1235 } 1236 1237 private MethodEmitter coerceStackTop(final TypeBounds typeBounds) { 1238 return method.convert(typeBounds.within(method.peekType())); 1239 } 1240 1241 /** 1242 * Closes any still open entries for this block's local variables in the bytecode local variable table. 1243 * 1244 * @param block block containing symbols. 1245 */ 1246 private void closeBlockVariables(final Block block) { 1247 for (final Symbol symbol : block.getSymbols()) { 1248 if (symbol.isBytecodeLocal()) { 1249 method.closeLocalVariable(symbol, block.getBreakLabel()); 1250 } 1251 } 1252 } 1253 1254 @Override 1255 public boolean enterBlock(final Block block) { 1256 final Label entryLabel = block.getEntryLabel(); 1257 if (entryLabel.isBreakTarget()) { 1258 // Entry label is a break target only for an inlined finally block. 1259 assert !method.isReachable(); 1260 method.breakLabel(entryLabel, lc.getUsedSlotCount()); 1261 } else { 1262 method.label(entryLabel); 1263 } 1264 if(!method.isReachable()) { 1265 return false; 1266 } 1267 if(lc.isFunctionBody() && emittedMethods.contains(lc.getCurrentFunction().getName())) { 1268 return false; 1269 } 1270 initLocals(block); 1271 1272 assert lc.getUsedSlotCount() == method.getFirstTemp(); 1273 return true; 1274 } 1275 1276 boolean useOptimisticTypes() { 1277 return !lc.inSplitNode() && compiler.useOptimisticTypes(); 1278 } 1279 1280 @Override 1281 public Node leaveBlock(final Block block) { 1282 popBlockScope(block); 1283 method.beforeJoinPoint(block); 1284 1285 closeBlockVariables(block); 1286 lc.releaseSlots(); 1287 assert !method.isReachable() || (lc.isFunctionBody() ? 0 : lc.getUsedSlotCount()) == method.getFirstTemp() : 1288 "reachable="+method.isReachable() + 1289 " isFunctionBody=" + lc.isFunctionBody() + 1290 " usedSlotCount=" + lc.getUsedSlotCount() + 1291 " firstTemp=" + method.getFirstTemp(); 1292 1293 return block; 1294 } 1295 1296 private void popBlockScope(final Block block) { 1297 final Label breakLabel = block.getBreakLabel(); 1298 1299 if(!block.needsScope() || lc.isFunctionBody()) { 1300 emitBlockBreakLabel(breakLabel); 1301 return; 1302 } 1303 1304 final Label beginTryLabel = scopeEntryLabels.pop(); 1305 final Label recoveryLabel = new Label("block_popscope_catch"); 1306 emitBlockBreakLabel(breakLabel); 1307 final boolean bodyCanThrow = breakLabel.isAfter(beginTryLabel); 1308 if(bodyCanThrow) { 1309 method._try(beginTryLabel, breakLabel, recoveryLabel); 1310 } 1311 1312 Label afterCatchLabel = null; 1313 1314 if(method.isReachable()) { 1315 popScope(); 1316 if(bodyCanThrow) { 1317 afterCatchLabel = new Label("block_after_catch"); 1318 method._goto(afterCatchLabel); 1319 } 1320 } 1321 1322 if(bodyCanThrow) { 1323 assert !method.isReachable(); 1324 method._catch(recoveryLabel); 1325 popScopeException(); 1326 method.athrow(); 1327 } 1328 if(afterCatchLabel != null) { 1329 method.label(afterCatchLabel); 1330 } 1331 } 1332 1333 private void emitBlockBreakLabel(final Label breakLabel) { 1334 // TODO: this is totally backwards. Block should not be breakable, LabelNode should be breakable. 1335 final LabelNode labelNode = lc.getCurrentBlockLabelNode(); 1336 if(labelNode != null) { 1337 // Only have conversions if we're reachable 1338 assert labelNode.getLocalVariableConversion() == null || method.isReachable(); 1339 method.beforeJoinPoint(labelNode); 1340 method.breakLabel(breakLabel, labeledBlockBreakLiveLocals.pop()); 1341 } else { 1342 method.label(breakLabel); 1343 } 1344 } 1345 1346 private void popScope() { 1347 popScopes(1); 1348 } 1349 1350 /** 1351 * Pop scope as part of an exception handler. Similar to {@code popScope()} but also takes care of adjusting the 1352 * number of scopes that needs to be popped in case a rest-of continuation handler encounters an exception while 1353 * performing a ToPrimitive conversion. 1354 */ 1355 private void popScopeException() { 1356 popScope(); 1357 final ContinuationInfo ci = getContinuationInfo(); 1358 if(ci != null) { 1359 final Label catchLabel = ci.catchLabel; 1360 if(catchLabel != METHOD_BOUNDARY && catchLabel == catchLabels.peek()) { 1361 ++ci.exceptionScopePops; 1362 } 1363 } 1364 } 1365 1366 private void popScopesUntil(final LexicalContextNode until) { 1367 popScopes(lc.getScopeNestingLevelTo(until)); 1368 } 1369 1370 private void popScopes(final int count) { 1371 if(count == 0) { 1372 return; 1373 } 1374 assert count > 0; // together with count == 0 check, asserts nonnegative count 1375 if (!method.hasScope()) { 1376 // We can sometimes invoke this method even if the method has no slot for the scope object. Typical example: 1377 // for(;;) { with({}) { break; } }. WithNode normally creates a scope, but if it uses no identifiers and 1378 // nothing else forces creation of a scope in the method, we just won't have the :scope local variable. 1379 return; 1380 } 1381 method.loadCompilerConstant(SCOPE); 1382 for(int i = 0; i < count; ++i) { 1383 method.invoke(ScriptObject.GET_PROTO); 1384 } 1385 method.storeCompilerConstant(SCOPE); 1386 } 1387 1388 @Override 1389 public boolean enterBreakNode(final BreakNode breakNode) { 1390 return enterJumpStatement(breakNode); 1391 } 1392 1393 @Override 1394 public boolean enterJumpToInlinedFinally(final JumpToInlinedFinally jumpToInlinedFinally) { 1395 return enterJumpStatement(jumpToInlinedFinally); 1396 } 1397 1398 private boolean enterJumpStatement(final JumpStatement jump) { 1399 if(!method.isReachable()) { 1400 return false; 1401 } 1402 enterStatement(jump); 1403 1404 method.beforeJoinPoint(jump); 1405 popScopesUntil(jump.getPopScopeLimit(lc)); 1406 final Label targetLabel = jump.getTargetLabel(lc); 1407 targetLabel.markAsBreakTarget(); 1408 method._goto(targetLabel); 1409 1410 return false; 1411 } 1412 1413 private int loadArgs(final List<Expression> args) { 1414 final int argCount = args.size(); 1415 // arg have already been converted to objects here. 1416 if (argCount > LinkerCallSite.ARGLIMIT) { 1417 loadArgsArray(args); 1418 return 1; 1419 } 1420 1421 for (final Expression arg : args) { 1422 assert arg != null; 1423 loadExpressionUnbounded(arg); 1424 } 1425 return argCount; 1426 } 1427 1428 private boolean loadCallNode(final CallNode callNode, final TypeBounds resultBounds) { 1429 lineNumber(callNode.getLineNumber()); 1430 1431 final List<Expression> args = callNode.getArgs(); 1432 final Expression function = callNode.getFunction(); 1433 final Block currentBlock = lc.getCurrentBlock(); 1434 final CodeGeneratorLexicalContext codegenLexicalContext = lc; 1435 1436 function.accept(new NodeVisitor<LexicalContext>(new LexicalContext()) { 1437 1438 private MethodEmitter sharedScopeCall(final IdentNode identNode, final int flags) { 1439 final Symbol symbol = identNode.getSymbol(); 1440 final boolean isFastScope = isFastScope(symbol); 1441 new OptimisticOperation(callNode, resultBounds) { 1442 @Override 1443 void loadStack() { 1444 method.loadCompilerConstant(SCOPE); 1445 if (isFastScope) { 1446 method.load(getScopeProtoDepth(currentBlock, symbol)); 1447 } else { 1448 method.load(-1); // Bypass fast-scope code in shared callsite 1449 } 1450 loadArgs(args); 1451 } 1452 @Override 1453 void consumeStack() { 1454 final Type[] paramTypes = method.getTypesFromStack(args.size()); 1455 // We have trouble finding e.g. in Type.typeFor(asm.Type) because it can't see the Context class 1456 // loader, so we need to weaken reference signatures to Object. 1457 for(int i = 0; i < paramTypes.length; ++i) { 1458 paramTypes[i] = Type.generic(paramTypes[i]); 1459 } 1460 // As shared scope calls are only used in non-optimistic compilation, we switch from using 1461 // TypeBounds to just a single definitive type, resultBounds.widest. 1462 final SharedScopeCall scopeCall = codegenLexicalContext.getScopeCall(unit, symbol, 1463 identNode.getType(), resultBounds.widest, paramTypes, flags); 1464 scopeCall.generateInvoke(method); 1465 } 1466 }.emit(); 1467 return method; 1468 } 1469 1470 private void scopeCall(final IdentNode ident, final int flags) { 1471 new OptimisticOperation(callNode, resultBounds) { 1472 int argsCount; 1473 @Override 1474 void loadStack() { 1475 loadExpressionAsObject(ident); // foo() makes no sense if foo == 3 1476 // ScriptFunction will see CALLSITE_SCOPE and will bind scope accordingly. 1477 method.loadUndefined(Type.OBJECT); //the 'this' 1478 argsCount = loadArgs(args); 1479 } 1480 @Override 1481 void consumeStack() { 1482 dynamicCall(2 + argsCount, flags, ident.getName()); 1483 } 1484 }.emit(); 1485 } 1486 1487 private void evalCall(final IdentNode ident, final int flags) { 1488 final Label invoke_direct_eval = new Label("invoke_direct_eval"); 1489 final Label is_not_eval = new Label("is_not_eval"); 1490 final Label eval_done = new Label("eval_done"); 1491 1492 new OptimisticOperation(callNode, resultBounds) { 1493 int argsCount; 1494 @Override 1495 void loadStack() { 1496 /* 1497 * We want to load 'eval' to check if it is indeed global builtin eval. 1498 * If this eval call is inside a 'with' statement, dyn:getMethod|getProp|getElem 1499 * would be generated if ident is a "isFunction". But, that would result in a 1500 * bound function from WithObject. We don't want that as bound function as that 1501 * won't be detected as builtin eval. So, we make ident as "not a function" which 1502 * results in "dyn:getProp|getElem|getMethod" being generated and so WithObject 1503 * would return unbounded eval function. 1504 * 1505 * Example: 1506 * 1507 * var global = this; 1508 * function func() { 1509 * with({ eval: global.eval) { eval("var x = 10;") } 1510 * } 1511 */ 1512 loadExpressionAsObject(ident.setIsNotFunction()); // Type.OBJECT as foo() makes no sense if foo == 3 1513 globalIsEval(); 1514 method.ifeq(is_not_eval); 1515 1516 // Load up self (scope). 1517 method.loadCompilerConstant(SCOPE); 1518 final List<Expression> evalArgs = callNode.getEvalArgs().getArgs(); 1519 // load evaluated code 1520 loadExpressionAsObject(evalArgs.get(0)); 1521 // load second and subsequent args for side-effect 1522 final int numArgs = evalArgs.size(); 1523 for (int i = 1; i < numArgs; i++) { 1524 loadAndDiscard(evalArgs.get(i)); 1525 } 1526 method._goto(invoke_direct_eval); 1527 1528 method.label(is_not_eval); 1529 // load this time but with dyn:getMethod|getProp|getElem 1530 loadExpressionAsObject(ident); // Type.OBJECT as foo() makes no sense if foo == 3 1531 // This is some scope 'eval' or global eval replaced by user 1532 // but not the built-in ECMAScript 'eval' function call 1533 method.loadNull(); 1534 argsCount = loadArgs(callNode.getArgs()); 1535 } 1536 1537 @Override 1538 void consumeStack() { 1539 // Ordinary call 1540 dynamicCall(2 + argsCount, flags, "eval"); 1541 method._goto(eval_done); 1542 1543 method.label(invoke_direct_eval); 1544 // Special/extra 'eval' arguments. These can be loaded late (in consumeStack) as we know none of 1545 // them can ever be optimistic. 1546 method.loadCompilerConstant(THIS); 1547 method.load(callNode.getEvalArgs().getLocation()); 1548 method.load(CodeGenerator.this.lc.getCurrentFunction().isStrict()); 1549 // direct call to Global.directEval 1550 globalDirectEval(); 1551 convertOptimisticReturnValue(); 1552 coerceStackTop(resultBounds); 1553 } 1554 }.emit(); 1555 1556 method.label(eval_done); 1557 } 1558 1559 @Override 1560 public boolean enterIdentNode(final IdentNode node) { 1561 final Symbol symbol = node.getSymbol(); 1562 1563 if (symbol.isScope()) { 1564 final int flags = getScopeCallSiteFlags(symbol); 1565 final int useCount = symbol.getUseCount(); 1566 1567 // Threshold for generating shared scope callsite is lower for fast scope symbols because we know 1568 // we can dial in the correct scope. However, we also need to enable it for non-fast scopes to 1569 // support huge scripts like mandreel.js. 1570 if (callNode.isEval()) { 1571 evalCall(node, flags); 1572 } else if (useCount <= SharedScopeCall.FAST_SCOPE_CALL_THRESHOLD 1573 || !isFastScope(symbol) && useCount <= SharedScopeCall.SLOW_SCOPE_CALL_THRESHOLD 1574 || CodeGenerator.this.lc.inDynamicScope() 1575 || callNode.isOptimistic()) { 1576 scopeCall(node, flags); 1577 } else { 1578 sharedScopeCall(node, flags); 1579 } 1580 assert method.peekType().equals(resultBounds.within(callNode.getType())) : method.peekType() + " != " + resultBounds + "(" + callNode.getType() + ")"; 1581 } else { 1582 enterDefault(node); 1583 } 1584 1585 return false; 1586 } 1587 1588 @Override 1589 public boolean enterAccessNode(final AccessNode node) { 1590 //check if this is an apply to call node. only real applies, that haven't been 1591 //shadowed from their way to the global scope counts 1592 1593 //call nodes have program points. 1594 1595 final int flags = getCallSiteFlags() | (callNode.isApplyToCall() ? CALLSITE_APPLY_TO_CALL : 0); 1596 1597 new OptimisticOperation(callNode, resultBounds) { 1598 int argCount; 1599 @Override 1600 void loadStack() { 1601 loadExpressionAsObject(node.getBase()); 1602 method.dup(); 1603 // NOTE: not using a nested OptimisticOperation on this dynamicGet, as we expect to get back 1604 // a callable object. Nobody in their right mind would optimistically type this call site. 1605 assert !node.isOptimistic(); 1606 method.dynamicGet(node.getType(), node.getProperty(), flags, true, node.isIndex()); 1607 method.swap(); 1608 argCount = loadArgs(args); 1609 } 1610 @Override 1611 void consumeStack() { 1612 dynamicCall(2 + argCount, flags, node.toString(false)); 1613 } 1614 }.emit(); 1615 1616 return false; 1617 } 1618 1619 @Override 1620 public boolean enterFunctionNode(final FunctionNode origCallee) { 1621 new OptimisticOperation(callNode, resultBounds) { 1622 FunctionNode callee; 1623 int argsCount; 1624 @Override 1625 void loadStack() { 1626 callee = (FunctionNode)origCallee.accept(CodeGenerator.this); 1627 if (callee.isStrict()) { // "this" is undefined 1628 method.loadUndefined(Type.OBJECT); 1629 } else { // get global from scope (which is the self) 1630 globalInstance(); 1631 } 1632 argsCount = loadArgs(args); 1633 } 1634 1635 @Override 1636 void consumeStack() { 1637 dynamicCall(2 + argsCount, getCallSiteFlags(), null); 1638 } 1639 }.emit(); 1640 return false; 1641 } 1642 1643 @Override 1644 public boolean enterIndexNode(final IndexNode node) { 1645 new OptimisticOperation(callNode, resultBounds) { 1646 int argsCount; 1647 @Override 1648 void loadStack() { 1649 loadExpressionAsObject(node.getBase()); 1650 method.dup(); 1651 final Type indexType = node.getIndex().getType(); 1652 if (indexType.isObject() || indexType.isBoolean()) { 1653 loadExpressionAsObject(node.getIndex()); //TODO boolean 1654 } else { 1655 loadExpressionUnbounded(node.getIndex()); 1656 } 1657 // NOTE: not using a nested OptimisticOperation on this dynamicGetIndex, as we expect to get 1658 // back a callable object. Nobody in their right mind would optimistically type this call site. 1659 assert !node.isOptimistic(); 1660 method.dynamicGetIndex(node.getType(), getCallSiteFlags(), true); 1661 method.swap(); 1662 argsCount = loadArgs(args); 1663 } 1664 @Override 1665 void consumeStack() { 1666 dynamicCall(2 + argsCount, getCallSiteFlags(), node.toString(false)); 1667 } 1668 }.emit(); 1669 return false; 1670 } 1671 1672 @Override 1673 protected boolean enterDefault(final Node node) { 1674 new OptimisticOperation(callNode, resultBounds) { 1675 int argsCount; 1676 @Override 1677 void loadStack() { 1678 // Load up function. 1679 loadExpressionAsObject(function); //TODO, e.g. booleans can be used as functions 1680 method.loadUndefined(Type.OBJECT); // ScriptFunction will figure out the correct this when it sees CALLSITE_SCOPE 1681 argsCount = loadArgs(args); 1682 } 1683 @Override 1684 void consumeStack() { 1685 final int flags = getCallSiteFlags() | CALLSITE_SCOPE; 1686 dynamicCall(2 + argsCount, flags, node.toString(false)); 1687 } 1688 }.emit(); 1689 return false; 1690 } 1691 }); 1692 1693 return false; 1694 } 1695 1696 /** 1697 * Returns the flags with optimistic flag and program point removed. 1698 * @param flags the flags that need optimism stripped from them. 1699 * @return flags without optimism 1700 */ 1701 static int nonOptimisticFlags(final int flags) { 1702 return flags & ~(CALLSITE_OPTIMISTIC | -1 << CALLSITE_PROGRAM_POINT_SHIFT); 1703 } 1704 1705 @Override 1706 public boolean enterContinueNode(final ContinueNode continueNode) { 1707 return enterJumpStatement(continueNode); 1708 } 1709 1710 @Override 1711 public boolean enterEmptyNode(final EmptyNode emptyNode) { 1712 // Don't even record the line number, it's irrelevant as there's no code. 1713 return false; 1714 } 1715 1716 @Override 1717 public boolean enterExpressionStatement(final ExpressionStatement expressionStatement) { 1718 if(!method.isReachable()) { 1719 return false; 1720 } 1721 enterStatement(expressionStatement); 1722 1723 loadAndDiscard(expressionStatement.getExpression()); 1724 assert method.getStackSize() == 0; 1725 1726 return false; 1727 } 1728 1729 @Override 1730 public boolean enterBlockStatement(final BlockStatement blockStatement) { 1731 if(!method.isReachable()) { 1732 return false; 1733 } 1734 enterStatement(blockStatement); 1735 1736 blockStatement.getBlock().accept(this); 1737 1738 return false; 1739 } 1740 1741 @Override 1742 public boolean enterForNode(final ForNode forNode) { 1743 if(!method.isReachable()) { 1744 return false; 1745 } 1746 enterStatement(forNode); 1747 if (forNode.isForIn()) { 1748 enterForIn(forNode); 1749 } else { 1750 final Expression init = forNode.getInit(); 1751 if (init != null) { 1752 loadAndDiscard(init); 1753 } 1754 enterForOrWhile(forNode, forNode.getModify()); 1755 } 1756 1757 return false; 1758 } 1759 1760 private void enterForIn(final ForNode forNode) { 1761 loadExpression(forNode.getModify(), TypeBounds.OBJECT); 1762 method.invoke(forNode.isForEach() ? ScriptRuntime.TO_VALUE_ITERATOR : ScriptRuntime.TO_PROPERTY_ITERATOR); 1763 final Symbol iterSymbol = forNode.getIterator(); 1764 final int iterSlot = iterSymbol.getSlot(Type.OBJECT); 1765 method.store(iterSymbol, ITERATOR_TYPE); 1766 1767 method.beforeJoinPoint(forNode); 1768 1769 final Label continueLabel = forNode.getContinueLabel(); 1770 final Label breakLabel = forNode.getBreakLabel(); 1771 1772 method.label(continueLabel); 1773 method.load(ITERATOR_TYPE, iterSlot); 1774 method.invoke(interfaceCallNoLookup(ITERATOR_CLASS, "hasNext", boolean.class)); 1775 final JoinPredecessorExpression test = forNode.getTest(); 1776 final Block body = forNode.getBody(); 1777 if(LocalVariableConversion.hasLiveConversion(test)) { 1778 final Label afterConversion = new Label("for_in_after_test_conv"); 1779 method.ifne(afterConversion); 1780 method.beforeJoinPoint(test); 1781 method._goto(breakLabel); 1782 method.label(afterConversion); 1783 } else { 1784 method.ifeq(breakLabel); 1785 } 1786 1787 new Store<Expression>(forNode.getInit()) { 1788 @Override 1789 protected void storeNonDiscard() { 1790 // This expression is neither part of a discard, nor needs to be left on the stack after it was 1791 // stored, so we override storeNonDiscard to be a no-op. 1792 } 1793 1794 @Override 1795 protected void evaluate() { 1796 new OptimisticOperation((Optimistic)forNode.getInit(), TypeBounds.UNBOUNDED) { 1797 @Override 1798 void loadStack() { 1799 method.load(ITERATOR_TYPE, iterSlot); 1800 } 1801 1802 @Override 1803 void consumeStack() { 1804 method.invoke(interfaceCallNoLookup(ITERATOR_CLASS, "next", Object.class)); 1805 convertOptimisticReturnValue(); 1806 } 1807 }.emit(); 1808 } 1809 }.store(); 1810 body.accept(this); 1811 1812 if(method.isReachable()) { 1813 method._goto(continueLabel); 1814 } 1815 method.label(breakLabel); 1816 } 1817 1818 /** 1819 * Initialize the slots in a frame to undefined. 1820 * 1821 * @param block block with local vars. 1822 */ 1823 private void initLocals(final Block block) { 1824 lc.onEnterBlock(block); 1825 1826 final boolean isFunctionBody = lc.isFunctionBody(); 1827 final FunctionNode function = lc.getCurrentFunction(); 1828 if (isFunctionBody) { 1829 initializeMethodParameters(function); 1830 if(!function.isVarArg()) { 1831 expandParameterSlots(function); 1832 } 1833 if (method.hasScope()) { 1834 if (function.needsParentScope()) { 1835 method.loadCompilerConstant(CALLEE); 1836 method.invoke(ScriptFunction.GET_SCOPE); 1837 } else { 1838 assert function.hasScopeBlock(); 1839 method.loadNull(); 1840 } 1841 method.storeCompilerConstant(SCOPE); 1842 } 1843 if (function.needsArguments()) { 1844 initArguments(function); 1845 } 1846 } 1847 1848 /* 1849 * Determine if block needs scope, if not, just do initSymbols for this block. 1850 */ 1851 if (block.needsScope()) { 1852 /* 1853 * Determine if function is varargs and consequently variables have to 1854 * be in the scope. 1855 */ 1856 final boolean varsInScope = function.allVarsInScope(); 1857 1858 // TODO for LET we can do better: if *block* does not contain any eval/with, we don't need its vars in scope. 1859 1860 final boolean hasArguments = function.needsArguments(); 1861 final List<MapTuple<Symbol>> tuples = new ArrayList<>(); 1862 final Iterator<IdentNode> paramIter = function.getParameters().iterator(); 1863 for (final Symbol symbol : block.getSymbols()) { 1864 if (symbol.isInternal() || symbol.isThis()) { 1865 continue; 1866 } 1867 1868 if (symbol.isVar()) { 1869 assert !varsInScope || symbol.isScope(); 1870 if (varsInScope || symbol.isScope()) { 1871 assert symbol.isScope() : "scope for " + symbol + " should have been set in Lower already " + function.getName(); 1872 assert !symbol.hasSlot() : "slot for " + symbol + " should have been removed in Lower already" + function.getName(); 1873 1874 //this tuple will not be put fielded, as it has no value, just a symbol 1875 tuples.add(new MapTuple<Symbol>(symbol.getName(), symbol, null)); 1876 } else { 1877 assert symbol.hasSlot() || symbol.slotCount() == 0 : symbol + " should have a slot only, no scope"; 1878 } 1879 } else if (symbol.isParam() && (varsInScope || hasArguments || symbol.isScope())) { 1880 assert symbol.isScope() : "scope for " + symbol + " should have been set in AssignSymbols already " + function.getName() + " varsInScope="+varsInScope+" hasArguments="+hasArguments+" symbol.isScope()=" + symbol.isScope(); 1881 assert !(hasArguments && symbol.hasSlot()) : "slot for " + symbol + " should have been removed in Lower already " + function.getName(); 1882 1883 final Type paramType; 1884 final Symbol paramSymbol; 1885 1886 if (hasArguments) { 1887 assert !symbol.hasSlot() : "slot for " + symbol + " should have been removed in Lower already "; 1888 paramSymbol = null; 1889 paramType = null; 1890 } else { 1891 paramSymbol = symbol; 1892 // NOTE: We're relying on the fact here that Block.symbols is a LinkedHashMap, hence it will 1893 // return symbols in the order they were defined, and parameters are defined in the same order 1894 // they appear in the function. That's why we can have a single pass over the parameter list 1895 // with an iterator, always just scanning forward for the next parameter that matches the symbol 1896 // name. 1897 for(;;) { 1898 final IdentNode nextParam = paramIter.next(); 1899 if(nextParam.getName().equals(symbol.getName())) { 1900 paramType = nextParam.getType(); 1901 break; 1902 } 1903 } 1904 } 1905 1906 tuples.add(new MapTuple<Symbol>(symbol.getName(), symbol, paramType, paramSymbol) { 1907 //this symbol will be put fielded, we can't initialize it as undefined with a known type 1908 @Override 1909 public Class<?> getValueType() { 1910 if (!useDualFields() || value == null || paramType == null || paramType.isBoolean()) { 1911 return Object.class; 1912 } 1913 return paramType.getTypeClass(); 1914 } 1915 }); 1916 } 1917 } 1918 1919 /* 1920 * Create a new object based on the symbols and values, generate 1921 * bootstrap code for object 1922 */ 1923 new FieldObjectCreator<Symbol>(this, tuples, true, hasArguments) { 1924 @Override 1925 protected void loadValue(final Symbol value, final Type type) { 1926 method.load(value, type); 1927 } 1928 }.makeObject(method); 1929 // program function: merge scope into global 1930 if (isFunctionBody && function.isProgram()) { 1931 method.invoke(ScriptRuntime.MERGE_SCOPE); 1932 } 1933 1934 method.storeCompilerConstant(SCOPE); 1935 if(!isFunctionBody) { 1936 // Function body doesn't need a try/catch to restore scope, as it'd be a dead store anyway. Allowing it 1937 // actually causes issues with UnwarrantedOptimismException handlers as ASM will sort this handler to 1938 // the top of the exception handler table, so it'll be triggered instead of the UOE handlers. 1939 final Label scopeEntryLabel = new Label("scope_entry"); 1940 scopeEntryLabels.push(scopeEntryLabel); 1941 method.label(scopeEntryLabel); 1942 } 1943 } else if (isFunctionBody && function.isVarArg()) { 1944 // Since we don't have a scope, parameters didn't get assigned array indices by the FieldObjectCreator, so 1945 // we need to assign them separately here. 1946 int nextParam = 0; 1947 for (final IdentNode param : function.getParameters()) { 1948 param.getSymbol().setFieldIndex(nextParam++); 1949 } 1950 } 1951 1952 // Debugging: print symbols? @see --print-symbols flag 1953 printSymbols(block, function, (isFunctionBody ? "Function " : "Block in ") + (function.getIdent() == null ? "<anonymous>" : function.getIdent().getName())); 1954 } 1955 1956 /** 1957 * Incoming method parameters are always declared on method entry; declare them in the local variable table. 1958 * @param function function for which code is being generated. 1959 */ 1960 private void initializeMethodParameters(final FunctionNode function) { 1961 final Label functionStart = new Label("fn_start"); 1962 method.label(functionStart); 1963 int nextSlot = 0; 1964 if(function.needsCallee()) { 1965 initializeInternalFunctionParameter(CALLEE, function, functionStart, nextSlot++); 1966 } 1967 initializeInternalFunctionParameter(THIS, function, functionStart, nextSlot++); 1968 if(function.isVarArg()) { 1969 initializeInternalFunctionParameter(VARARGS, function, functionStart, nextSlot++); 1970 } else { 1971 for(final IdentNode param: function.getParameters()) { 1972 final Symbol symbol = param.getSymbol(); 1973 if(symbol.isBytecodeLocal()) { 1974 method.initializeMethodParameter(symbol, param.getType(), functionStart); 1975 } 1976 } 1977 } 1978 } 1979 1980 private void initializeInternalFunctionParameter(final CompilerConstants cc, final FunctionNode fn, final Label functionStart, final int slot) { 1981 final Symbol symbol = initializeInternalFunctionOrSplitParameter(cc, fn, functionStart, slot); 1982 // Internal function params (:callee, this, and :varargs) are never expanded to multiple slots 1983 assert symbol.getFirstSlot() == slot; 1984 } 1985 1986 private Symbol initializeInternalFunctionOrSplitParameter(final CompilerConstants cc, final FunctionNode fn, final Label functionStart, final int slot) { 1987 final Symbol symbol = fn.getBody().getExistingSymbol(cc.symbolName()); 1988 final Type type = Type.typeFor(cc.type()); 1989 method.initializeMethodParameter(symbol, type, functionStart); 1990 method.onLocalStore(type, slot); 1991 return symbol; 1992 } 1993 1994 /** 1995 * Parameters come into the method packed into local variable slots next to each other. Nashorn on the other hand 1996 * can use 1-6 slots for a local variable depending on all the types it needs to store. When this method is invoked, 1997 * the symbols are already allocated such wider slots, but the values are still in tightly packed incoming slots, 1998 * and we need to spread them into their new locations. 1999 * @param function the function for which parameter-spreading code needs to be emitted 2000 */ 2001 private void expandParameterSlots(final FunctionNode function) { 2002 final List<IdentNode> parameters = function.getParameters(); 2003 // Calculate the total number of incoming parameter slots 2004 int currentIncomingSlot = function.needsCallee() ? 2 : 1; 2005 for(final IdentNode parameter: parameters) { 2006 currentIncomingSlot += parameter.getType().getSlots(); 2007 } 2008 // Starting from last parameter going backwards, move the parameter values into their new slots. 2009 for(int i = parameters.size(); i-- > 0;) { 2010 final IdentNode parameter = parameters.get(i); 2011 final Type parameterType = parameter.getType(); 2012 final int typeWidth = parameterType.getSlots(); 2013 currentIncomingSlot -= typeWidth; 2014 final Symbol symbol = parameter.getSymbol(); 2015 final int slotCount = symbol.slotCount(); 2016 assert slotCount > 0; 2017 // Scoped parameters must not hold more than one value 2018 assert symbol.isBytecodeLocal() || slotCount == typeWidth; 2019 2020 // Mark it as having its value stored into it by the method invocation. 2021 method.onLocalStore(parameterType, currentIncomingSlot); 2022 if(currentIncomingSlot != symbol.getSlot(parameterType)) { 2023 method.load(parameterType, currentIncomingSlot); 2024 method.store(symbol, parameterType); 2025 } 2026 } 2027 } 2028 2029 private void initArguments(final FunctionNode function) { 2030 method.loadCompilerConstant(VARARGS); 2031 if (function.needsCallee()) { 2032 method.loadCompilerConstant(CALLEE); 2033 } else { 2034 // If function is strict mode, "arguments.callee" is not populated, so we don't necessarily need the 2035 // caller. 2036 assert function.isStrict(); 2037 method.loadNull(); 2038 } 2039 method.load(function.getParameters().size()); 2040 globalAllocateArguments(); 2041 method.storeCompilerConstant(ARGUMENTS); 2042 } 2043 2044 private boolean skipFunction(final FunctionNode functionNode) { 2045 final ScriptEnvironment env = compiler.getScriptEnvironment(); 2046 final boolean lazy = env._lazy_compilation; 2047 final boolean onDemand = compiler.isOnDemandCompilation(); 2048 2049 // If this is on-demand or lazy compilation, don't compile a nested (not topmost) function. 2050 if((onDemand || lazy) && lc.getOutermostFunction() != functionNode) { 2051 return true; 2052 } 2053 2054 // If lazy compiling with optimistic types, don't compile the program eagerly either. It will soon be 2055 // invalidated anyway. In presence of a class cache, this further means that an obsoleted program version 2056 // lingers around. Also, currently loading previously persisted optimistic types information only works if 2057 // we're on-demand compiling a function, so with this strategy the :program method can also have the warmup 2058 // benefit of using previously persisted types. 2059 // 2060 // NOTE that this means the first compiled class will effectively just have a :createProgramFunction method, and 2061 // the RecompilableScriptFunctionData (RSFD) object in its constants array. It won't even have the :program 2062 // method. This is by design. It does mean that we're wasting one compiler execution (and we could minimize this 2063 // by just running it up to scope depth calculation, which creates the RSFDs and then this limited codegen). 2064 // We could emit an initial separate compile unit with the initial version of :program in it to better utilize 2065 // the compilation pipeline, but that would need more invasive changes, as currently the assumption that 2066 // :program is emitted into the first compilation unit of the function lives in many places. 2067 return !onDemand && lazy && env._optimistic_types && functionNode.isProgram(); 2068 } 2069 2070 @Override 2071 public boolean enterFunctionNode(final FunctionNode functionNode) { 2072 if (skipFunction(functionNode)) { 2073 // In case we are not generating code for the function, we must create or retrieve the function object and 2074 // load it on the stack here. 2075 newFunctionObject(functionNode, false); 2076 return false; 2077 } 2078 2079 final String fnName = functionNode.getName(); 2080 2081 // NOTE: we only emit the method for a function with the given name once. We can have multiple functions with 2082 // the same name as a result of inlining finally blocks. However, in the future -- with type specialization, 2083 // notably -- we might need to check for both name *and* signature. Of course, even that might not be 2084 // sufficient; the function might have a code dependency on the type of the variables in its enclosing scopes, 2085 // and the type of such a variable can be different in catch and finally blocks. So, in the future we will have 2086 // to decide to either generate a unique method for each inlined copy of the function, maybe figure out its 2087 // exact type closure and deduplicate based on that, or just decide that functions in finally blocks aren't 2088 // worth it, and generate one method with most generic type closure. 2089 if (!emittedMethods.contains(fnName)) { 2090 log.info("=== BEGIN ", fnName); 2091 2092 assert functionNode.getCompileUnit() != null : "no compile unit for " + fnName + " " + Debug.id(functionNode); 2093 unit = lc.pushCompileUnit(functionNode.getCompileUnit()); 2094 assert lc.hasCompileUnits(); 2095 2096 final ClassEmitter classEmitter = unit.getClassEmitter(); 2097 pushMethodEmitter(isRestOf() ? classEmitter.restOfMethod(functionNode) : classEmitter.method(functionNode)); 2098 method.setPreventUndefinedLoad(); 2099 if(useOptimisticTypes()) { 2100 lc.pushUnwarrantedOptimismHandlers(); 2101 } 2102 2103 // new method - reset last line number 2104 lastLineNumber = -1; 2105 2106 method.begin(); 2107 2108 if (isRestOf()) { 2109 assert continuationInfo == null; 2110 continuationInfo = new ContinuationInfo(); 2111 method.gotoLoopStart(continuationInfo.getHandlerLabel()); 2112 } 2113 } 2114 2115 return true; 2116 } 2117 2118 private void pushMethodEmitter(final MethodEmitter newMethod) { 2119 method = lc.pushMethodEmitter(newMethod); 2120 catchLabels.push(METHOD_BOUNDARY); 2121 } 2122 2123 private void popMethodEmitter() { 2124 method = lc.popMethodEmitter(method); 2125 assert catchLabels.peek() == METHOD_BOUNDARY; 2126 catchLabels.pop(); 2127 } 2128 2129 @Override 2130 public Node leaveFunctionNode(final FunctionNode functionNode) { 2131 try { 2132 final boolean markOptimistic; 2133 if (emittedMethods.add(functionNode.getName())) { 2134 markOptimistic = generateUnwarrantedOptimismExceptionHandlers(functionNode); 2135 generateContinuationHandler(); 2136 method.end(); // wrap up this method 2137 unit = lc.popCompileUnit(functionNode.getCompileUnit()); 2138 popMethodEmitter(); 2139 log.info("=== END ", functionNode.getName()); 2140 } else { 2141 markOptimistic = false; 2142 } 2143 2144 FunctionNode newFunctionNode = functionNode; 2145 if (markOptimistic) { 2146 newFunctionNode = newFunctionNode.setFlag(lc, FunctionNode.IS_DEOPTIMIZABLE); 2147 } 2148 2149 newFunctionObject(newFunctionNode, true); 2150 return newFunctionNode; 2151 } catch (final Throwable t) { 2152 Context.printStackTrace(t); 2153 final VerifyError e = new VerifyError("Code generation bug in \"" + functionNode.getName() + "\": likely stack misaligned: " + t + " " + functionNode.getSource().getName()); 2154 e.initCause(t); 2155 throw e; 2156 } 2157 } 2158 2159 @Override 2160 public boolean enterIfNode(final IfNode ifNode) { 2161 if(!method.isReachable()) { 2162 return false; 2163 } 2164 enterStatement(ifNode); 2165 2166 final Expression test = ifNode.getTest(); 2167 final Block pass = ifNode.getPass(); 2168 final Block fail = ifNode.getFail(); 2169 2170 if (Expression.isAlwaysTrue(test)) { 2171 loadAndDiscard(test); 2172 pass.accept(this); 2173 return false; 2174 } else if (Expression.isAlwaysFalse(test)) { 2175 loadAndDiscard(test); 2176 if (fail != null) { 2177 fail.accept(this); 2178 } 2179 return false; 2180 } 2181 2182 final boolean hasFailConversion = LocalVariableConversion.hasLiveConversion(ifNode); 2183 2184 final Label failLabel = new Label("if_fail"); 2185 final Label afterLabel = (fail == null && !hasFailConversion) ? null : new Label("if_done"); 2186 2187 emitBranch(test, failLabel, false); 2188 2189 pass.accept(this); 2190 if(method.isReachable() && afterLabel != null) { 2191 method._goto(afterLabel); //don't fallthru to fail block 2192 } 2193 method.label(failLabel); 2194 2195 if (fail != null) { 2196 fail.accept(this); 2197 } else if(hasFailConversion) { 2198 method.beforeJoinPoint(ifNode); 2199 } 2200 2201 if(afterLabel != null && afterLabel.isReachable()) { 2202 method.label(afterLabel); 2203 } 2204 2205 return false; 2206 } 2207 2208 private void emitBranch(final Expression test, final Label label, final boolean jumpWhenTrue) { 2209 new BranchOptimizer(this, method).execute(test, label, jumpWhenTrue); 2210 } 2211 2212 private void enterStatement(final Statement statement) { 2213 lineNumber(statement); 2214 } 2215 2216 private void lineNumber(final Statement statement) { 2217 lineNumber(statement.getLineNumber()); 2218 } 2219 2220 private void lineNumber(final int lineNumber) { 2221 if (lineNumber != lastLineNumber && lineNumber != Node.NO_LINE_NUMBER) { 2222 method.lineNumber(lineNumber); 2223 lastLineNumber = lineNumber; 2224 } 2225 } 2226 2227 int getLastLineNumber() { 2228 return lastLineNumber; 2229 } 2230 2231 /** 2232 * Load a list of nodes as an array of a specific type 2233 * The array will contain the visited nodes. 2234 * 2235 * @param arrayLiteralNode the array of contents 2236 * @param arrayType the type of the array, e.g. ARRAY_NUMBER or ARRAY_OBJECT 2237 */ 2238 private void loadArray(final ArrayLiteralNode arrayLiteralNode, final ArrayType arrayType) { 2239 assert arrayType == Type.INT_ARRAY || arrayType == Type.LONG_ARRAY || arrayType == Type.NUMBER_ARRAY || arrayType == Type.OBJECT_ARRAY; 2240 2241 final Expression[] nodes = arrayLiteralNode.getValue(); 2242 final Object presets = arrayLiteralNode.getPresets(); 2243 final int[] postsets = arrayLiteralNode.getPostsets(); 2244 final List<Splittable.SplitRange> ranges = arrayLiteralNode.getSplitRanges(); 2245 2246 loadConstant(presets); 2247 2248 final Type elementType = arrayType.getElementType(); 2249 2250 if (ranges != null) { 2251 2252 loadSplitLiteral(new SplitLiteralCreator() { 2253 @Override 2254 public void populateRange(final MethodEmitter method, final Type type, final int slot, final int start, final int end) { 2255 for (int i = start; i < end; i++) { 2256 method.load(type, slot); 2257 storeElement(nodes, elementType, postsets[i]); 2258 } 2259 method.load(type, slot); 2260 } 2261 }, ranges, arrayType); 2262 2263 return; 2264 } 2265 2266 if(postsets.length > 0) { 2267 final int arraySlot = method.getUsedSlotsWithLiveTemporaries(); 2268 method.storeTemp(arrayType, arraySlot); 2269 for (final int postset : postsets) { 2270 method.load(arrayType, arraySlot); 2271 storeElement(nodes, elementType, postset); 2272 } 2273 method.load(arrayType, arraySlot); 2274 } 2275 } 2276 2277 private void storeElement(final Expression[] nodes, final Type elementType, final int index) { 2278 method.load(index); 2279 2280 final Expression element = nodes[index]; 2281 2282 if (element == null) { 2283 method.loadEmpty(elementType); 2284 } else { 2285 loadExpressionAsType(element, elementType); 2286 } 2287 2288 method.arraystore(); 2289 } 2290 2291 private MethodEmitter loadArgsArray(final List<Expression> args) { 2292 final Object[] array = new Object[args.size()]; 2293 loadConstant(array); 2294 2295 for (int i = 0; i < args.size(); i++) { 2296 method.dup(); 2297 method.load(i); 2298 loadExpression(args.get(i), TypeBounds.OBJECT); // variable arity methods always take objects 2299 method.arraystore(); 2300 } 2301 2302 return method; 2303 } 2304 2305 /** 2306 * Load a constant from the constant array. This is only public to be callable from the objects 2307 * subpackage. Do not call directly. 2308 * 2309 * @param string string to load 2310 */ 2311 void loadConstant(final String string) { 2312 final String unitClassName = unit.getUnitClassName(); 2313 final ClassEmitter classEmitter = unit.getClassEmitter(); 2314 final int index = compiler.getConstantData().add(string); 2315 2316 method.load(index); 2317 method.invokestatic(unitClassName, GET_STRING.symbolName(), methodDescriptor(String.class, int.class)); 2318 classEmitter.needGetConstantMethod(String.class); 2319 } 2320 2321 /** 2322 * Load a constant from the constant array. This is only public to be callable from the objects 2323 * subpackage. Do not call directly. 2324 * 2325 * @param object object to load 2326 */ 2327 void loadConstant(final Object object) { 2328 loadConstant(object, unit, method); 2329 } 2330 2331 private void loadConstant(final Object object, final CompileUnit compileUnit, final MethodEmitter methodEmitter) { 2332 final String unitClassName = compileUnit.getUnitClassName(); 2333 final ClassEmitter classEmitter = compileUnit.getClassEmitter(); 2334 final int index = compiler.getConstantData().add(object); 2335 final Class<?> cls = object.getClass(); 2336 2337 if (cls == PropertyMap.class) { 2338 methodEmitter.load(index); 2339 methodEmitter.invokestatic(unitClassName, GET_MAP.symbolName(), methodDescriptor(PropertyMap.class, int.class)); 2340 classEmitter.needGetConstantMethod(PropertyMap.class); 2341 } else if (cls.isArray()) { 2342 methodEmitter.load(index); 2343 final String methodName = ClassEmitter.getArrayMethodName(cls); 2344 methodEmitter.invokestatic(unitClassName, methodName, methodDescriptor(cls, int.class)); 2345 classEmitter.needGetConstantMethod(cls); 2346 } else { 2347 methodEmitter.loadConstants().load(index).arrayload(); 2348 if (object instanceof ArrayData) { 2349 methodEmitter.checkcast(ArrayData.class); 2350 methodEmitter.invoke(virtualCallNoLookup(ArrayData.class, "copy", ArrayData.class)); 2351 } else if (cls != Object.class) { 2352 methodEmitter.checkcast(cls); 2353 } 2354 } 2355 } 2356 2357 private void loadConstantsAndIndex(final Object object, final MethodEmitter methodEmitter) { 2358 methodEmitter.loadConstants().load(compiler.getConstantData().add(object)); 2359 } 2360 2361 // literal values 2362 private void loadLiteral(final LiteralNode<?> node, final TypeBounds resultBounds) { 2363 final Object value = node.getValue(); 2364 2365 if (value == null) { 2366 method.loadNull(); 2367 } else if (value instanceof Undefined) { 2368 method.loadUndefined(resultBounds.within(Type.OBJECT)); 2369 } else if (value instanceof String) { 2370 final String string = (String)value; 2371 2372 if (string.length() > MethodEmitter.LARGE_STRING_THRESHOLD / 3) { // 3 == max bytes per encoded char 2373 loadConstant(string); 2374 } else { 2375 method.load(string); 2376 } 2377 } else if (value instanceof RegexToken) { 2378 loadRegex((RegexToken)value); 2379 } else if (value instanceof Boolean) { 2380 method.load((Boolean)value); 2381 } else if (value instanceof Integer) { 2382 if(!resultBounds.canBeNarrowerThan(Type.OBJECT)) { 2383 method.load((Integer)value); 2384 method.convert(Type.OBJECT); 2385 } else if(!resultBounds.canBeNarrowerThan(Type.NUMBER)) { 2386 method.load(((Integer)value).doubleValue()); 2387 } else if(!resultBounds.canBeNarrowerThan(Type.LONG)) { 2388 method.load(((Integer)value).longValue()); 2389 } else { 2390 method.load((Integer)value); 2391 } 2392 } else if (value instanceof Long) { 2393 if(!resultBounds.canBeNarrowerThan(Type.OBJECT)) { 2394 method.load((Long)value); 2395 method.convert(Type.OBJECT); 2396 } else if(!resultBounds.canBeNarrowerThan(Type.NUMBER)) { 2397 method.load(((Long)value).doubleValue()); 2398 } else { 2399 method.load((Long)value); 2400 } 2401 } else if (value instanceof Double) { 2402 if(!resultBounds.canBeNarrowerThan(Type.OBJECT)) { 2403 method.load((Double)value); 2404 method.convert(Type.OBJECT); 2405 } else { 2406 method.load((Double)value); 2407 } 2408 } else if (node instanceof ArrayLiteralNode) { 2409 final ArrayLiteralNode arrayLiteral = (ArrayLiteralNode)node; 2410 final ArrayType atype = arrayLiteral.getArrayType(); 2411 loadArray(arrayLiteral, atype); 2412 globalAllocateArray(atype); 2413 } else { 2414 throw new UnsupportedOperationException("Unknown literal for " + node.getClass() + " " + value.getClass() + " " + value); 2415 } 2416 } 2417 2418 private MethodEmitter loadRegexToken(final RegexToken value) { 2419 method.load(value.getExpression()); 2420 method.load(value.getOptions()); 2421 return globalNewRegExp(); 2422 } 2423 2424 private MethodEmitter loadRegex(final RegexToken regexToken) { 2425 if (regexFieldCount > MAX_REGEX_FIELDS) { 2426 return loadRegexToken(regexToken); 2427 } 2428 // emit field 2429 final String regexName = lc.getCurrentFunction().uniqueName(REGEX_PREFIX.symbolName()); 2430 final ClassEmitter classEmitter = unit.getClassEmitter(); 2431 2432 classEmitter.field(EnumSet.of(PRIVATE, STATIC), regexName, Object.class); 2433 regexFieldCount++; 2434 2435 // get field, if null create new regex, finally clone regex object 2436 method.getStatic(unit.getUnitClassName(), regexName, typeDescriptor(Object.class)); 2437 method.dup(); 2438 final Label cachedLabel = new Label("cached"); 2439 method.ifnonnull(cachedLabel); 2440 2441 method.pop(); 2442 loadRegexToken(regexToken); 2443 method.dup(); 2444 method.putStatic(unit.getUnitClassName(), regexName, typeDescriptor(Object.class)); 2445 2446 method.label(cachedLabel); 2447 globalRegExpCopy(); 2448 2449 return method; 2450 } 2451 2452 /** 2453 * Check if a property value contains a particular program point 2454 * @param value value 2455 * @param pp program point 2456 * @return true if it's there. 2457 */ 2458 private static boolean propertyValueContains(final Expression value, final int pp) { 2459 return new Supplier<Boolean>() { 2460 boolean contains; 2461 2462 @Override 2463 public Boolean get() { 2464 value.accept(new NodeVisitor<LexicalContext>(new LexicalContext()) { 2465 @Override 2466 public boolean enterFunctionNode(final FunctionNode functionNode) { 2467 return false; 2468 } 2469 2470 @Override 2471 public boolean enterObjectNode(final ObjectNode objectNode) { 2472 return false; 2473 } 2474 2475 @Override 2476 public boolean enterDefault(final Node node) { 2477 if (contains) { 2478 return false; 2479 } 2480 if (node instanceof Optimistic && ((Optimistic)node).getProgramPoint() == pp) { 2481 contains = true; 2482 return false; 2483 } 2484 return true; 2485 } 2486 }); 2487 2488 return contains; 2489 } 2490 }.get(); 2491 } 2492 2493 private void loadObjectNode(final ObjectNode objectNode) { 2494 final List<PropertyNode> elements = objectNode.getElements(); 2495 2496 final List<MapTuple<Expression>> tuples = new ArrayList<>(); 2497 final List<PropertyNode> gettersSetters = new ArrayList<>(); 2498 final int ccp = getCurrentContinuationEntryPoint(); 2499 final List<Splittable.SplitRange> ranges = objectNode.getSplitRanges(); 2500 2501 Expression protoNode = null; 2502 boolean restOfProperty = false; 2503 2504 for (final PropertyNode propertyNode : elements) { 2505 final Expression value = propertyNode.getValue(); 2506 final String key = propertyNode.getKeyName(); 2507 // Just use a pseudo-symbol. We just need something non null; use the name and zero flags. 2508 final Symbol symbol = value == null ? null : new Symbol(key, 0); 2509 2510 if (value == null) { 2511 gettersSetters.add(propertyNode); 2512 } else if (propertyNode.getKey() instanceof IdentNode && 2513 key.equals(ScriptObject.PROTO_PROPERTY_NAME)) { 2514 // ES6 draft compliant __proto__ inside object literal 2515 // Identifier key and name is __proto__ 2516 protoNode = value; 2517 continue; 2518 } 2519 2520 restOfProperty |= 2521 value != null && 2522 isValid(ccp) && 2523 propertyValueContains(value, ccp); 2524 2525 //for literals, a value of null means object type, i.e. the value null or getter setter function 2526 //(I think) 2527 final Class<?> valueType = (!useDualFields() || value == null || value.getType().isBoolean()) ? Object.class : value.getType().getTypeClass(); 2528 tuples.add(new MapTuple<Expression>(key, symbol, Type.typeFor(valueType), value) { 2529 @Override 2530 public Class<?> getValueType() { 2531 return type.getTypeClass(); 2532 } 2533 }); 2534 } 2535 2536 final ObjectCreator<?> oc; 2537 if (elements.size() > OBJECT_SPILL_THRESHOLD) { 2538 oc = new SpillObjectCreator(this, tuples); 2539 } else { 2540 oc = new FieldObjectCreator<Expression>(this, tuples) { 2541 @Override 2542 protected void loadValue(final Expression node, final Type type) { 2543 loadExpressionAsType(node, type); 2544 }}; 2545 } 2546 2547 if (ranges != null) { 2548 oc.createObject(method); 2549 loadSplitLiteral(oc, ranges, Type.typeFor(oc.getAllocatorClass())); 2550 } else { 2551 oc.makeObject(method); 2552 } 2553 2554 //if this is a rest of method and our continuation point was found as one of the values 2555 //in the properties above, we need to reset the map to oc.getMap() in the continuation 2556 //handler 2557 if (restOfProperty) { 2558 final ContinuationInfo ci = getContinuationInfo(); 2559 // Can be set at most once for a single rest-of method 2560 assert ci.getObjectLiteralMap() == null; 2561 ci.setObjectLiteralMap(oc.getMap()); 2562 ci.setObjectLiteralStackDepth(method.getStackSize()); 2563 } 2564 2565 method.dup(); 2566 if (protoNode != null) { 2567 loadExpressionAsObject(protoNode); 2568 // take care of { __proto__: 34 } or some such! 2569 method.convert(Type.OBJECT); 2570 method.invoke(ScriptObject.SET_PROTO_FROM_LITERAL); 2571 } else { 2572 method.invoke(ScriptObject.SET_GLOBAL_OBJECT_PROTO); 2573 } 2574 2575 for (final PropertyNode propertyNode : gettersSetters) { 2576 final FunctionNode getter = propertyNode.getGetter(); 2577 final FunctionNode setter = propertyNode.getSetter(); 2578 2579 assert getter != null || setter != null; 2580 2581 method.dup().loadKey(propertyNode.getKey()); 2582 if (getter == null) { 2583 method.loadNull(); 2584 } else { 2585 getter.accept(this); 2586 } 2587 2588 if (setter == null) { 2589 method.loadNull(); 2590 } else { 2591 setter.accept(this); 2592 } 2593 2594 method.invoke(ScriptObject.SET_USER_ACCESSORS); 2595 } 2596 } 2597 2598 @Override 2599 public boolean enterReturnNode(final ReturnNode returnNode) { 2600 if(!method.isReachable()) { 2601 return false; 2602 } 2603 enterStatement(returnNode); 2604 2605 final Type returnType = lc.getCurrentFunction().getReturnType(); 2606 2607 final Expression expression = returnNode.getExpression(); 2608 if (expression != null) { 2609 loadExpressionUnbounded(expression); 2610 } else { 2611 method.loadUndefined(returnType); 2612 } 2613 2614 method._return(returnType); 2615 2616 return false; 2617 } 2618 2619 private boolean undefinedCheck(final RuntimeNode runtimeNode, final List<Expression> args) { 2620 final Request request = runtimeNode.getRequest(); 2621 2622 if (!Request.isUndefinedCheck(request)) { 2623 return false; 2624 } 2625 2626 final Expression lhs = args.get(0); 2627 final Expression rhs = args.get(1); 2628 2629 final Symbol lhsSymbol = lhs instanceof IdentNode ? ((IdentNode)lhs).getSymbol() : null; 2630 final Symbol rhsSymbol = rhs instanceof IdentNode ? ((IdentNode)rhs).getSymbol() : null; 2631 // One must be a "undefined" identifier, otherwise we can't get here 2632 assert lhsSymbol != null || rhsSymbol != null; 2633 2634 final Symbol undefinedSymbol; 2635 if (isUndefinedSymbol(lhsSymbol)) { 2636 undefinedSymbol = lhsSymbol; 2637 } else { 2638 assert isUndefinedSymbol(rhsSymbol); 2639 undefinedSymbol = rhsSymbol; 2640 } 2641 2642 assert undefinedSymbol != null; //remove warning 2643 if (!undefinedSymbol.isScope()) { 2644 return false; //disallow undefined as local var or parameter 2645 } 2646 2647 if (lhsSymbol == undefinedSymbol && lhs.getType().isPrimitive()) { 2648 //we load the undefined first. never mind, because this will deoptimize anyway 2649 return false; 2650 } 2651 2652 if(isDeoptimizedExpression(lhs)) { 2653 // This is actually related to "lhs.getType().isPrimitive()" above: any expression being deoptimized in 2654 // the current chain of rest-of compilations used to have a type narrower than Object (so it was primitive). 2655 // We must not perform undefined check specialization for them, as then we'd violate the basic rule of 2656 // "Thou shalt not alter the stack shape between a deoptimized method and any of its (transitive) rest-ofs." 2657 return false; 2658 } 2659 2660 //make sure that undefined has not been overridden or scoped as a local var 2661 //between us and global 2662 if (!compiler.isGlobalSymbol(lc.getCurrentFunction(), "undefined")) { 2663 return false; 2664 } 2665 2666 final boolean isUndefinedCheck = request == Request.IS_UNDEFINED; 2667 final Expression expr = undefinedSymbol == lhsSymbol ? rhs : lhs; 2668 if (expr.getType().isPrimitive()) { 2669 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 2670 method.load(!isUndefinedCheck); 2671 } else { 2672 final Label checkTrue = new Label("ud_check_true"); 2673 final Label end = new Label("end"); 2674 loadExpressionAsObject(expr); 2675 method.loadUndefined(Type.OBJECT); 2676 method.if_acmpeq(checkTrue); 2677 method.load(!isUndefinedCheck); 2678 method._goto(end); 2679 method.label(checkTrue); 2680 method.load(isUndefinedCheck); 2681 method.label(end); 2682 } 2683 2684 return true; 2685 } 2686 2687 private static boolean isUndefinedSymbol(final Symbol symbol) { 2688 return symbol != null && "undefined".equals(symbol.getName()); 2689 } 2690 2691 private static boolean isNullLiteral(final Node node) { 2692 return node instanceof LiteralNode<?> && ((LiteralNode<?>) node).isNull(); 2693 } 2694 2695 private boolean nullCheck(final RuntimeNode runtimeNode, final List<Expression> args) { 2696 final Request request = runtimeNode.getRequest(); 2697 2698 if (!Request.isEQ(request) && !Request.isNE(request)) { 2699 return false; 2700 } 2701 2702 assert args.size() == 2 : "EQ or NE or TYPEOF need two args"; 2703 2704 Expression lhs = args.get(0); 2705 Expression rhs = args.get(1); 2706 2707 if (isNullLiteral(lhs)) { 2708 final Expression tmp = lhs; 2709 lhs = rhs; 2710 rhs = tmp; 2711 } 2712 2713 if (!isNullLiteral(rhs)) { 2714 return false; 2715 } 2716 2717 if (!lhs.getType().isObject()) { 2718 return false; 2719 } 2720 2721 if(isDeoptimizedExpression(lhs)) { 2722 // This is actually related to "!lhs.getType().isObject()" above: any expression being deoptimized in 2723 // the current chain of rest-of compilations used to have a type narrower than Object. We must not 2724 // perform null check specialization for them, as then we'd no longer be loading aconst_null on stack 2725 // and thus violate the basic rule of "Thou shalt not alter the stack shape between a deoptimized 2726 // method and any of its (transitive) rest-ofs." 2727 // NOTE also that if we had a representation for well-known constants (e.g. null, 0, 1, -1, etc.) in 2728 // Label$Stack.localLoads then this wouldn't be an issue, as we would never (somewhat ridiculously) 2729 // allocate a temporary local to hold the result of aconst_null before attempting an optimistic 2730 // operation. 2731 return false; 2732 } 2733 2734 // this is a null literal check, so if there is implicit coercion 2735 // involved like {D}x=null, we will fail - this is very rare 2736 final Label trueLabel = new Label("trueLabel"); 2737 final Label falseLabel = new Label("falseLabel"); 2738 final Label endLabel = new Label("end"); 2739 2740 loadExpressionUnbounded(lhs); //lhs 2741 final Label popLabel; 2742 if (!Request.isStrict(request)) { 2743 method.dup(); //lhs lhs 2744 popLabel = new Label("pop"); 2745 } else { 2746 popLabel = null; 2747 } 2748 2749 if (Request.isEQ(request)) { 2750 method.ifnull(!Request.isStrict(request) ? popLabel : trueLabel); 2751 if (!Request.isStrict(request)) { 2752 method.loadUndefined(Type.OBJECT); 2753 method.if_acmpeq(trueLabel); 2754 } 2755 method.label(falseLabel); 2756 method.load(false); 2757 method._goto(endLabel); 2758 if (!Request.isStrict(request)) { 2759 method.label(popLabel); 2760 method.pop(); 2761 } 2762 method.label(trueLabel); 2763 method.load(true); 2764 method.label(endLabel); 2765 } else if (Request.isNE(request)) { 2766 method.ifnull(!Request.isStrict(request) ? popLabel : falseLabel); 2767 if (!Request.isStrict(request)) { 2768 method.loadUndefined(Type.OBJECT); 2769 method.if_acmpeq(falseLabel); 2770 } 2771 method.label(trueLabel); 2772 method.load(true); 2773 method._goto(endLabel); 2774 if (!Request.isStrict(request)) { 2775 method.label(popLabel); 2776 method.pop(); 2777 } 2778 method.label(falseLabel); 2779 method.load(false); 2780 method.label(endLabel); 2781 } 2782 2783 assert runtimeNode.getType().isBoolean(); 2784 method.convert(runtimeNode.getType()); 2785 2786 return true; 2787 } 2788 2789 /** 2790 * Was this expression or any of its subexpressions deoptimized in the current recompilation chain of rest-of methods? 2791 * @param rootExpr the expression being tested 2792 * @return true if the expression or any of its subexpressions was deoptimized in the current recompilation chain. 2793 */ 2794 private boolean isDeoptimizedExpression(final Expression rootExpr) { 2795 if(!isRestOf()) { 2796 return false; 2797 } 2798 return new Supplier<Boolean>() { 2799 boolean contains; 2800 @Override 2801 public Boolean get() { 2802 rootExpr.accept(new NodeVisitor<LexicalContext>(new LexicalContext()) { 2803 @Override 2804 public boolean enterFunctionNode(final FunctionNode functionNode) { 2805 return false; 2806 } 2807 @Override 2808 public boolean enterDefault(final Node node) { 2809 if(!contains && node instanceof Optimistic) { 2810 final int pp = ((Optimistic)node).getProgramPoint(); 2811 contains = isValid(pp) && isContinuationEntryPoint(pp); 2812 } 2813 return !contains; 2814 } 2815 }); 2816 return contains; 2817 } 2818 }.get(); 2819 } 2820 2821 private void loadRuntimeNode(final RuntimeNode runtimeNode) { 2822 final List<Expression> args = new ArrayList<>(runtimeNode.getArgs()); 2823 if (nullCheck(runtimeNode, args)) { 2824 return; 2825 } else if(undefinedCheck(runtimeNode, args)) { 2826 return; 2827 } 2828 // Revert a false undefined check to a strict equality check 2829 final RuntimeNode newRuntimeNode; 2830 final Request request = runtimeNode.getRequest(); 2831 if (Request.isUndefinedCheck(request)) { 2832 newRuntimeNode = runtimeNode.setRequest(request == Request.IS_UNDEFINED ? Request.EQ_STRICT : Request.NE_STRICT); 2833 } else { 2834 newRuntimeNode = runtimeNode; 2835 } 2836 2837 for (final Expression arg : args) { 2838 loadExpression(arg, TypeBounds.OBJECT); 2839 } 2840 2841 method.invokestatic( 2842 CompilerConstants.className(ScriptRuntime.class), 2843 newRuntimeNode.getRequest().toString(), 2844 new FunctionSignature( 2845 false, 2846 false, 2847 newRuntimeNode.getType(), 2848 args.size()).toString()); 2849 2850 method.convert(newRuntimeNode.getType()); 2851 } 2852 2853 private void defineCommonSplitMethodParameters() { 2854 defineSplitMethodParameter(0, CALLEE); 2855 defineSplitMethodParameter(1, THIS); 2856 defineSplitMethodParameter(2, SCOPE); 2857 } 2858 2859 private void defineSplitMethodParameter(final int slot, final CompilerConstants cc) { 2860 defineSplitMethodParameter(slot, Type.typeFor(cc.type())); 2861 } 2862 2863 private void defineSplitMethodParameter(final int slot, final Type type) { 2864 method.defineBlockLocalVariable(slot, slot + type.getSlots()); 2865 method.onLocalStore(type, slot); 2866 } 2867 2868 private void loadSplitLiteral(final SplitLiteralCreator creator, final List<Splittable.SplitRange> ranges, final Type literalType) { 2869 assert ranges != null; 2870 2871 // final Type literalType = Type.typeFor(literalClass); 2872 final MethodEmitter savedMethod = method; 2873 final FunctionNode currentFunction = lc.getCurrentFunction(); 2874 2875 for (final Splittable.SplitRange splitRange : ranges) { 2876 unit = lc.pushCompileUnit(splitRange.getCompileUnit()); 2877 2878 assert unit != null; 2879 final String className = unit.getUnitClassName(); 2880 final String name = currentFunction.uniqueName(SPLIT_PREFIX.symbolName()); 2881 final Class<?> clazz = literalType.getTypeClass(); 2882 final String signature = methodDescriptor(clazz, ScriptFunction.class, Object.class, ScriptObject.class, clazz); 2883 2884 pushMethodEmitter(unit.getClassEmitter().method(EnumSet.of(Flag.PUBLIC, Flag.STATIC), name, signature)); 2885 2886 method.setFunctionNode(currentFunction); 2887 method.begin(); 2888 2889 defineCommonSplitMethodParameters(); 2890 defineSplitMethodParameter(CompilerConstants.SPLIT_ARRAY_ARG.slot(), literalType); 2891 2892 // NOTE: when this is no longer needed, SplitIntoFunctions will no longer have to add IS_SPLIT 2893 // to synthetic functions, and FunctionNode.needsCallee() will no longer need to test for isSplit(). 2894 final int literalSlot = fixScopeSlot(currentFunction, 3); 2895 2896 lc.enterSplitNode(); 2897 2898 creator.populateRange(method, literalType, literalSlot, splitRange.getLow(), splitRange.getHigh()); 2899 2900 method._return(); 2901 lc.exitSplitNode(); 2902 method.end(); 2903 lc.releaseSlots(); 2904 popMethodEmitter(); 2905 2906 assert method == savedMethod; 2907 method.loadCompilerConstant(CALLEE).swap(); 2908 method.loadCompilerConstant(THIS).swap(); 2909 method.loadCompilerConstant(SCOPE).swap(); 2910 method.invokestatic(className, name, signature); 2911 2912 unit = lc.popCompileUnit(unit); 2913 } 2914 } 2915 2916 private int fixScopeSlot(final FunctionNode functionNode, final int extraSlot) { 2917 // TODO hack to move the scope to the expected slot (needed because split methods reuse the same slots as the root method) 2918 final int actualScopeSlot = functionNode.compilerConstant(SCOPE).getSlot(SCOPE_TYPE); 2919 final int defaultScopeSlot = SCOPE.slot(); 2920 int newExtraSlot = extraSlot; 2921 if (actualScopeSlot != defaultScopeSlot) { 2922 if (actualScopeSlot == extraSlot) { 2923 newExtraSlot = extraSlot + 1; 2924 method.defineBlockLocalVariable(newExtraSlot, newExtraSlot + 1); 2925 method.load(Type.OBJECT, extraSlot); 2926 method.storeHidden(Type.OBJECT, newExtraSlot); 2927 } else { 2928 method.defineBlockLocalVariable(actualScopeSlot, actualScopeSlot + 1); 2929 } 2930 method.load(SCOPE_TYPE, defaultScopeSlot); 2931 method.storeCompilerConstant(SCOPE); 2932 } 2933 return newExtraSlot; 2934 } 2935 2936 @Override 2937 public boolean enterSplitReturn(final SplitReturn splitReturn) { 2938 if (method.isReachable()) { 2939 method.loadUndefined(lc.getCurrentFunction().getReturnType())._return(); 2940 } 2941 return false; 2942 } 2943 2944 @Override 2945 public boolean enterSetSplitState(final SetSplitState setSplitState) { 2946 if (method.isReachable()) { 2947 method.setSplitState(setSplitState.getState()); 2948 } 2949 return false; 2950 } 2951 2952 @Override 2953 public boolean enterSwitchNode(final SwitchNode switchNode) { 2954 if(!method.isReachable()) { 2955 return false; 2956 } 2957 enterStatement(switchNode); 2958 2959 final Expression expression = switchNode.getExpression(); 2960 final List<CaseNode> cases = switchNode.getCases(); 2961 2962 if (cases.isEmpty()) { 2963 // still evaluate expression for side-effects. 2964 loadAndDiscard(expression); 2965 return false; 2966 } 2967 2968 final CaseNode defaultCase = switchNode.getDefaultCase(); 2969 final Label breakLabel = switchNode.getBreakLabel(); 2970 final int liveLocalsOnBreak = method.getUsedSlotsWithLiveTemporaries(); 2971 2972 if (defaultCase != null && cases.size() == 1) { 2973 // default case only 2974 assert cases.get(0) == defaultCase; 2975 loadAndDiscard(expression); 2976 defaultCase.getBody().accept(this); 2977 method.breakLabel(breakLabel, liveLocalsOnBreak); 2978 return false; 2979 } 2980 2981 // NOTE: it can still change in the tableswitch/lookupswitch case if there's no default case 2982 // but we need to add a synthetic default case for local variable conversions 2983 Label defaultLabel = defaultCase != null ? defaultCase.getEntry() : breakLabel; 2984 final boolean hasSkipConversion = LocalVariableConversion.hasLiveConversion(switchNode); 2985 2986 if (switchNode.isUniqueInteger()) { 2987 // Tree for sorting values. 2988 final TreeMap<Integer, Label> tree = new TreeMap<>(); 2989 2990 // Build up sorted tree. 2991 for (final CaseNode caseNode : cases) { 2992 final Node test = caseNode.getTest(); 2993 2994 if (test != null) { 2995 final Integer value = (Integer)((LiteralNode<?>)test).getValue(); 2996 final Label entry = caseNode.getEntry(); 2997 2998 // Take first duplicate. 2999 if (!tree.containsKey(value)) { 3000 tree.put(value, entry); 3001 } 3002 } 3003 } 3004 3005 // Copy values and labels to arrays. 3006 final int size = tree.size(); 3007 final Integer[] values = tree.keySet().toArray(new Integer[size]); 3008 final Label[] labels = tree.values().toArray(new Label[size]); 3009 3010 // Discern low, high and range. 3011 final int lo = values[0]; 3012 final int hi = values[size - 1]; 3013 final long range = (long)hi - (long)lo + 1; 3014 3015 // Find an unused value for default. 3016 int deflt = Integer.MIN_VALUE; 3017 for (final int value : values) { 3018 if (deflt == value) { 3019 deflt++; 3020 } else if (deflt < value) { 3021 break; 3022 } 3023 } 3024 3025 // Load switch expression. 3026 loadExpressionUnbounded(expression); 3027 final Type type = expression.getType(); 3028 3029 // If expression not int see if we can convert, if not use deflt to trigger default. 3030 if (!type.isInteger()) { 3031 method.load(deflt); 3032 final Class<?> exprClass = type.getTypeClass(); 3033 method.invoke(staticCallNoLookup(ScriptRuntime.class, "switchTagAsInt", int.class, exprClass.isPrimitive()? exprClass : Object.class, int.class)); 3034 } 3035 3036 if(hasSkipConversion) { 3037 assert defaultLabel == breakLabel; 3038 defaultLabel = new Label("switch_skip"); 3039 } 3040 // TABLESWITCH needs (range + 3) 32-bit values; LOOKUPSWITCH needs ((size * 2) + 2). Choose the one with 3041 // smaller representation, favor TABLESWITCH when they're equal size. 3042 if (range + 1 <= (size * 2) && range <= Integer.MAX_VALUE) { 3043 final Label[] table = new Label[(int)range]; 3044 Arrays.fill(table, defaultLabel); 3045 for (int i = 0; i < size; i++) { 3046 final int value = values[i]; 3047 table[value - lo] = labels[i]; 3048 } 3049 3050 method.tableswitch(lo, hi, defaultLabel, table); 3051 } else { 3052 final int[] ints = new int[size]; 3053 for (int i = 0; i < size; i++) { 3054 ints[i] = values[i]; 3055 } 3056 3057 method.lookupswitch(defaultLabel, ints, labels); 3058 } 3059 // This is a synthetic "default case" used in absence of actual default case, created if we need to apply 3060 // local variable conversions if neither case is taken. 3061 if(hasSkipConversion) { 3062 method.label(defaultLabel); 3063 method.beforeJoinPoint(switchNode); 3064 method._goto(breakLabel); 3065 } 3066 } else { 3067 final Symbol tagSymbol = switchNode.getTag(); 3068 // TODO: we could have non-object tag 3069 final int tagSlot = tagSymbol.getSlot(Type.OBJECT); 3070 loadExpressionAsObject(expression); 3071 method.store(tagSymbol, Type.OBJECT); 3072 3073 for (final CaseNode caseNode : cases) { 3074 final Expression test = caseNode.getTest(); 3075 3076 if (test != null) { 3077 method.load(Type.OBJECT, tagSlot); 3078 loadExpressionAsObject(test); 3079 method.invoke(ScriptRuntime.EQ_STRICT); 3080 method.ifne(caseNode.getEntry()); 3081 } 3082 } 3083 3084 if (defaultCase != null) { 3085 method._goto(defaultLabel); 3086 } else { 3087 method.beforeJoinPoint(switchNode); 3088 method._goto(breakLabel); 3089 } 3090 } 3091 3092 // First case is only reachable through jump 3093 assert !method.isReachable(); 3094 3095 for (final CaseNode caseNode : cases) { 3096 final Label fallThroughLabel; 3097 if(caseNode.getLocalVariableConversion() != null && method.isReachable()) { 3098 fallThroughLabel = new Label("fallthrough"); 3099 method._goto(fallThroughLabel); 3100 } else { 3101 fallThroughLabel = null; 3102 } 3103 method.label(caseNode.getEntry()); 3104 method.beforeJoinPoint(caseNode); 3105 if(fallThroughLabel != null) { 3106 method.label(fallThroughLabel); 3107 } 3108 caseNode.getBody().accept(this); 3109 } 3110 3111 method.breakLabel(breakLabel, liveLocalsOnBreak); 3112 3113 return false; 3114 } 3115 3116 @Override 3117 public boolean enterThrowNode(final ThrowNode throwNode) { 3118 if(!method.isReachable()) { 3119 return false; 3120 } 3121 enterStatement(throwNode); 3122 3123 if (throwNode.isSyntheticRethrow()) { 3124 method.beforeJoinPoint(throwNode); 3125 3126 //do not wrap whatever this is in an ecma exception, just rethrow it 3127 final IdentNode exceptionExpr = (IdentNode)throwNode.getExpression(); 3128 final Symbol exceptionSymbol = exceptionExpr.getSymbol(); 3129 method.load(exceptionSymbol, EXCEPTION_TYPE); 3130 method.checkcast(EXCEPTION_TYPE.getTypeClass()); 3131 method.athrow(); 3132 return false; 3133 } 3134 3135 final Source source = getCurrentSource(); 3136 final Expression expression = throwNode.getExpression(); 3137 final int position = throwNode.position(); 3138 final int line = throwNode.getLineNumber(); 3139 final int column = source.getColumn(position); 3140 3141 // NOTE: we first evaluate the expression, and only after it was evaluated do we create the new ECMAException 3142 // object and then somewhat cumbersomely move it beneath the evaluated expression on the stack. The reason for 3143 // this is that if expression is optimistic (or contains an optimistic subexpression), we'd potentially access 3144 // the not-yet-<init>ialized object on the stack from the UnwarrantedOptimismException handler, and bytecode 3145 // verifier forbids that. 3146 loadExpressionAsObject(expression); 3147 3148 method.load(source.getName()); 3149 method.load(line); 3150 method.load(column); 3151 method.invoke(ECMAException.CREATE); 3152 3153 method.beforeJoinPoint(throwNode); 3154 method.athrow(); 3155 3156 return false; 3157 } 3158 3159 private Source getCurrentSource() { 3160 return lc.getCurrentFunction().getSource(); 3161 } 3162 3163 @Override 3164 public boolean enterTryNode(final TryNode tryNode) { 3165 if(!method.isReachable()) { 3166 return false; 3167 } 3168 enterStatement(tryNode); 3169 3170 final Block body = tryNode.getBody(); 3171 final List<Block> catchBlocks = tryNode.getCatchBlocks(); 3172 final Symbol vmException = tryNode.getException(); 3173 final Label entry = new Label("try"); 3174 final Label recovery = new Label("catch"); 3175 final Label exit = new Label("end_try"); 3176 final Label skip = new Label("skip"); 3177 3178 method.canThrow(recovery); 3179 // Effect any conversions that might be observed at the entry of the catch node before entering the try node. 3180 // This is because even the first instruction in the try block must be presumed to be able to transfer control 3181 // to the catch block. Note that this doesn't kill the original values; in this regard it works a lot like 3182 // conversions of assignments within the try block. 3183 method.beforeTry(tryNode, recovery); 3184 method.label(entry); 3185 catchLabels.push(recovery); 3186 try { 3187 body.accept(this); 3188 } finally { 3189 assert catchLabels.peek() == recovery; 3190 catchLabels.pop(); 3191 } 3192 3193 method.label(exit); 3194 final boolean bodyCanThrow = exit.isAfter(entry); 3195 if(!bodyCanThrow) { 3196 // The body can't throw an exception; don't even bother emitting the catch handlers, they're all dead code. 3197 return false; 3198 } 3199 3200 method._try(entry, exit, recovery, Throwable.class); 3201 3202 if (method.isReachable()) { 3203 method._goto(skip); 3204 } 3205 3206 for (final Block inlinedFinally : tryNode.getInlinedFinallies()) { 3207 TryNode.getLabelledInlinedFinallyBlock(inlinedFinally).accept(this); 3208 // All inlined finallies end with a jump or a return 3209 assert !method.isReachable(); 3210 } 3211 3212 3213 method._catch(recovery); 3214 method.store(vmException, EXCEPTION_TYPE); 3215 3216 final int catchBlockCount = catchBlocks.size(); 3217 final Label afterCatch = new Label("after_catch"); 3218 for (int i = 0; i < catchBlockCount; i++) { 3219 assert method.isReachable(); 3220 final Block catchBlock = catchBlocks.get(i); 3221 3222 // Because of the peculiarities of the flow control, we need to use an explicit push/enterBlock/leaveBlock 3223 // here. 3224 lc.push(catchBlock); 3225 enterBlock(catchBlock); 3226 3227 final CatchNode catchNode = (CatchNode)catchBlocks.get(i).getStatements().get(0); 3228 final IdentNode exception = catchNode.getException(); 3229 final Expression exceptionCondition = catchNode.getExceptionCondition(); 3230 final Block catchBody = catchNode.getBody(); 3231 3232 new Store<IdentNode>(exception) { 3233 @Override 3234 protected void storeNonDiscard() { 3235 // This expression is neither part of a discard, nor needs to be left on the stack after it was 3236 // stored, so we override storeNonDiscard to be a no-op. 3237 } 3238 3239 @Override 3240 protected void evaluate() { 3241 if (catchNode.isSyntheticRethrow()) { 3242 method.load(vmException, EXCEPTION_TYPE); 3243 return; 3244 } 3245 /* 3246 * If caught object is an instance of ECMAException, then 3247 * bind obj.thrown to the script catch var. Or else bind the 3248 * caught object itself to the script catch var. 3249 */ 3250 final Label notEcmaException = new Label("no_ecma_exception"); 3251 method.load(vmException, EXCEPTION_TYPE).dup()._instanceof(ECMAException.class).ifeq(notEcmaException); 3252 method.checkcast(ECMAException.class); //TODO is this necessary? 3253 method.getField(ECMAException.THROWN); 3254 method.label(notEcmaException); 3255 } 3256 }.store(); 3257 3258 final boolean isConditionalCatch = exceptionCondition != null; 3259 final Label nextCatch; 3260 if (isConditionalCatch) { 3261 loadExpressionAsBoolean(exceptionCondition); 3262 nextCatch = new Label("next_catch"); 3263 nextCatch.markAsBreakTarget(); 3264 method.ifeq(nextCatch); 3265 } else { 3266 nextCatch = null; 3267 } 3268 3269 catchBody.accept(this); 3270 leaveBlock(catchBlock); 3271 lc.pop(catchBlock); 3272 if(nextCatch != null) { 3273 if(method.isReachable()) { 3274 method._goto(afterCatch); 3275 } 3276 method.breakLabel(nextCatch, lc.getUsedSlotCount()); 3277 } 3278 } 3279 3280 // afterCatch could be the same as skip, except that we need to establish that the vmException is dead. 3281 method.label(afterCatch); 3282 if(method.isReachable()) { 3283 method.markDeadLocalVariable(vmException); 3284 } 3285 method.label(skip); 3286 3287 // Finally body is always inlined elsewhere so it doesn't need to be emitted 3288 assert tryNode.getFinallyBody() == null; 3289 3290 return false; 3291 } 3292 3293 @Override 3294 public boolean enterVarNode(final VarNode varNode) { 3295 if(!method.isReachable()) { 3296 return false; 3297 } 3298 final Expression init = varNode.getInit(); 3299 final IdentNode identNode = varNode.getName(); 3300 final Symbol identSymbol = identNode.getSymbol(); 3301 assert identSymbol != null : "variable node " + varNode + " requires a name with a symbol"; 3302 final boolean needsScope = identSymbol.isScope(); 3303 3304 if (init == null) { 3305 if (needsScope && varNode.isBlockScoped()) { 3306 // block scoped variables need a DECLARE flag to signal end of temporal dead zone (TDZ) 3307 method.loadCompilerConstant(SCOPE); 3308 method.loadUndefined(Type.OBJECT); 3309 final int flags = getScopeCallSiteFlags(identSymbol) | (varNode.isBlockScoped() ? CALLSITE_DECLARE : 0); 3310 assert isFastScope(identSymbol); 3311 storeFastScopeVar(identSymbol, flags); 3312 } 3313 return false; 3314 } 3315 3316 enterStatement(varNode); 3317 assert method != null; 3318 3319 if (needsScope) { 3320 method.loadCompilerConstant(SCOPE); 3321 } 3322 3323 if (needsScope) { 3324 loadExpressionUnbounded(init); 3325 // block scoped variables need a DECLARE flag to signal end of temporal dead zone (TDZ) 3326 final int flags = getScopeCallSiteFlags(identSymbol) | (varNode.isBlockScoped() ? CALLSITE_DECLARE : 0); 3327 if (isFastScope(identSymbol)) { 3328 storeFastScopeVar(identSymbol, flags); 3329 } else { 3330 method.dynamicSet(identNode.getName(), flags, false); 3331 } 3332 } else { 3333 final Type identType = identNode.getType(); 3334 if(identType == Type.UNDEFINED) { 3335 // The initializer is either itself undefined (explicit assignment of undefined to undefined), 3336 // or the left hand side is a dead variable. 3337 assert init.getType() == Type.UNDEFINED || identNode.getSymbol().slotCount() == 0; 3338 loadAndDiscard(init); 3339 return false; 3340 } 3341 loadExpressionAsType(init, identType); 3342 storeIdentWithCatchConversion(identNode, identType); 3343 } 3344 3345 return false; 3346 } 3347 3348 private void storeIdentWithCatchConversion(final IdentNode identNode, final Type type) { 3349 // Assignments happening in try/catch blocks need to ensure that they also store a possibly wider typed value 3350 // that will be live at the exit from the try block 3351 final LocalVariableConversion conversion = identNode.getLocalVariableConversion(); 3352 final Symbol symbol = identNode.getSymbol(); 3353 if(conversion != null && conversion.isLive()) { 3354 assert symbol == conversion.getSymbol(); 3355 assert symbol.isBytecodeLocal(); 3356 // Only a single conversion from the target type to the join type is expected. 3357 assert conversion.getNext() == null; 3358 assert conversion.getFrom() == type; 3359 // We must propagate potential type change to the catch block 3360 final Label catchLabel = catchLabels.peek(); 3361 assert catchLabel != METHOD_BOUNDARY; // ident conversion only exists in try blocks 3362 assert catchLabel.isReachable(); 3363 final Type joinType = conversion.getTo(); 3364 final Label.Stack catchStack = catchLabel.getStack(); 3365 final int joinSlot = symbol.getSlot(joinType); 3366 // With nested try/catch blocks (incl. synthetic ones for finally), we can have a supposed conversion for 3367 // the exception symbol in the nested catch, but it isn't live in the outer catch block, so prevent doing 3368 // conversions for it. E.g. in "try { try { ... } catch(e) { e = 1; } } catch(e2) { ... }", we must not 3369 // introduce an I->O conversion on "e = 1" assignment as "e" is not live in "catch(e2)". 3370 if(catchStack.getUsedSlotsWithLiveTemporaries() > joinSlot) { 3371 method.dup(); 3372 method.convert(joinType); 3373 method.store(symbol, joinType); 3374 catchLabel.getStack().onLocalStore(joinType, joinSlot, true); 3375 method.canThrow(catchLabel); 3376 // Store but keep the previous store live too. 3377 method.store(symbol, type, false); 3378 return; 3379 } 3380 } 3381 3382 method.store(symbol, type, true); 3383 } 3384 3385 @Override 3386 public boolean enterWhileNode(final WhileNode whileNode) { 3387 if(!method.isReachable()) { 3388 return false; 3389 } 3390 if(whileNode.isDoWhile()) { 3391 enterDoWhile(whileNode); 3392 } else { 3393 enterStatement(whileNode); 3394 enterForOrWhile(whileNode, null); 3395 } 3396 return false; 3397 } 3398 3399 private void enterForOrWhile(final LoopNode loopNode, final JoinPredecessorExpression modify) { 3400 // NOTE: the usual pattern for compiling test-first loops is "GOTO test; body; test; IFNE body". We use the less 3401 // conventional "test; IFEQ break; body; GOTO test; break;". It has one extra unconditional GOTO in each repeat 3402 // of the loop, but it's not a problem for modern JIT compilers. We do this because our local variable type 3403 // tracking is unfortunately not really prepared for out-of-order execution, e.g. compiling the following 3404 // contrived but legal JavaScript code snippet would fail because the test changes the type of "i" from object 3405 // to double: var i = {valueOf: function() { return 1} }; while(--i >= 0) { ... } 3406 // Instead of adding more complexity to the local variable type tracking, we instead choose to emit this 3407 // different code shape. 3408 final int liveLocalsOnBreak = method.getUsedSlotsWithLiveTemporaries(); 3409 final JoinPredecessorExpression test = loopNode.getTest(); 3410 if(Expression.isAlwaysFalse(test)) { 3411 loadAndDiscard(test); 3412 return; 3413 } 3414 3415 method.beforeJoinPoint(loopNode); 3416 3417 final Label continueLabel = loopNode.getContinueLabel(); 3418 final Label repeatLabel = modify != null ? new Label("for_repeat") : continueLabel; 3419 method.label(repeatLabel); 3420 final int liveLocalsOnContinue = method.getUsedSlotsWithLiveTemporaries(); 3421 3422 final Block body = loopNode.getBody(); 3423 final Label breakLabel = loopNode.getBreakLabel(); 3424 final boolean testHasLiveConversion = test != null && LocalVariableConversion.hasLiveConversion(test); 3425 3426 if(Expression.isAlwaysTrue(test)) { 3427 if(test != null) { 3428 loadAndDiscard(test); 3429 if(testHasLiveConversion) { 3430 method.beforeJoinPoint(test); 3431 } 3432 } 3433 } else if (test != null) { 3434 if (testHasLiveConversion) { 3435 emitBranch(test.getExpression(), body.getEntryLabel(), true); 3436 method.beforeJoinPoint(test); 3437 method._goto(breakLabel); 3438 } else { 3439 emitBranch(test.getExpression(), breakLabel, false); 3440 } 3441 } 3442 3443 body.accept(this); 3444 if(repeatLabel != continueLabel) { 3445 emitContinueLabel(continueLabel, liveLocalsOnContinue); 3446 } 3447 3448 if (loopNode.hasPerIterationScope() && lc.getCurrentBlock().needsScope()) { 3449 // ES6 for loops with LET init need a new scope for each iteration. We just create a shallow copy here. 3450 method.loadCompilerConstant(SCOPE); 3451 method.invoke(virtualCallNoLookup(ScriptObject.class, "copy", ScriptObject.class)); 3452 method.storeCompilerConstant(SCOPE); 3453 } 3454 3455 if(method.isReachable()) { 3456 if(modify != null) { 3457 lineNumber(loopNode); 3458 loadAndDiscard(modify); 3459 method.beforeJoinPoint(modify); 3460 } 3461 method._goto(repeatLabel); 3462 } 3463 3464 method.breakLabel(breakLabel, liveLocalsOnBreak); 3465 } 3466 3467 private void emitContinueLabel(final Label continueLabel, final int liveLocals) { 3468 final boolean reachable = method.isReachable(); 3469 method.breakLabel(continueLabel, liveLocals); 3470 // If we reach here only through a continue statement (e.g. body does not exit normally) then the 3471 // continueLabel can have extra non-temp symbols (e.g. exception from a try/catch contained in the body). We 3472 // must make sure those are thrown away. 3473 if(!reachable) { 3474 method.undefineLocalVariables(lc.getUsedSlotCount(), false); 3475 } 3476 } 3477 3478 private void enterDoWhile(final WhileNode whileNode) { 3479 final int liveLocalsOnContinueOrBreak = method.getUsedSlotsWithLiveTemporaries(); 3480 method.beforeJoinPoint(whileNode); 3481 3482 final Block body = whileNode.getBody(); 3483 body.accept(this); 3484 3485 emitContinueLabel(whileNode.getContinueLabel(), liveLocalsOnContinueOrBreak); 3486 if(method.isReachable()) { 3487 lineNumber(whileNode); 3488 final JoinPredecessorExpression test = whileNode.getTest(); 3489 final Label bodyEntryLabel = body.getEntryLabel(); 3490 final boolean testHasLiveConversion = LocalVariableConversion.hasLiveConversion(test); 3491 if(Expression.isAlwaysFalse(test)) { 3492 loadAndDiscard(test); 3493 if(testHasLiveConversion) { 3494 method.beforeJoinPoint(test); 3495 } 3496 } else if(testHasLiveConversion) { 3497 // If we have conversions after the test in do-while, they need to be effected on both branches. 3498 final Label beforeExit = new Label("do_while_preexit"); 3499 emitBranch(test.getExpression(), beforeExit, false); 3500 method.beforeJoinPoint(test); 3501 method._goto(bodyEntryLabel); 3502 method.label(beforeExit); 3503 method.beforeJoinPoint(test); 3504 } else { 3505 emitBranch(test.getExpression(), bodyEntryLabel, true); 3506 } 3507 } 3508 method.breakLabel(whileNode.getBreakLabel(), liveLocalsOnContinueOrBreak); 3509 } 3510 3511 3512 @Override 3513 public boolean enterWithNode(final WithNode withNode) { 3514 if(!method.isReachable()) { 3515 return false; 3516 } 3517 enterStatement(withNode); 3518 final Expression expression = withNode.getExpression(); 3519 final Block body = withNode.getBody(); 3520 3521 // It is possible to have a "pathological" case where the with block does not reference *any* identifiers. It's 3522 // pointless, but legal. In that case, if nothing else in the method forced the assignment of a slot to the 3523 // scope object, its' possible that it won't have a slot assigned. In this case we'll only evaluate expression 3524 // for its side effect and visit the body, and not bother opening and closing a WithObject. 3525 final boolean hasScope = method.hasScope(); 3526 3527 if (hasScope) { 3528 method.loadCompilerConstant(SCOPE); 3529 } 3530 3531 loadExpressionAsObject(expression); 3532 3533 final Label tryLabel; 3534 if (hasScope) { 3535 // Construct a WithObject if we have a scope 3536 method.invoke(ScriptRuntime.OPEN_WITH); 3537 method.storeCompilerConstant(SCOPE); 3538 tryLabel = new Label("with_try"); 3539 method.label(tryLabel); 3540 } else { 3541 // We just loaded the expression for its side effect and to check 3542 // for null or undefined value. 3543 globalCheckObjectCoercible(); 3544 tryLabel = null; 3545 } 3546 3547 // Always process body 3548 body.accept(this); 3549 3550 if (hasScope) { 3551 // Ensure we always close the WithObject 3552 final Label endLabel = new Label("with_end"); 3553 final Label catchLabel = new Label("with_catch"); 3554 final Label exitLabel = new Label("with_exit"); 3555 3556 method.label(endLabel); 3557 // Somewhat conservatively presume that if the body is not empty, it can throw an exception. In any case, 3558 // we must prevent trying to emit a try-catch for empty range, as it causes a verification error. 3559 final boolean bodyCanThrow = endLabel.isAfter(tryLabel); 3560 if(bodyCanThrow) { 3561 method._try(tryLabel, endLabel, catchLabel); 3562 } 3563 3564 final boolean reachable = method.isReachable(); 3565 if(reachable) { 3566 popScope(); 3567 if(bodyCanThrow) { 3568 method._goto(exitLabel); 3569 } 3570 } 3571 3572 if(bodyCanThrow) { 3573 method._catch(catchLabel); 3574 popScopeException(); 3575 method.athrow(); 3576 if(reachable) { 3577 method.label(exitLabel); 3578 } 3579 } 3580 } 3581 return false; 3582 } 3583 3584 private void loadADD(final UnaryNode unaryNode, final TypeBounds resultBounds) { 3585 loadExpression(unaryNode.getExpression(), resultBounds.booleanToInt().notWiderThan(Type.NUMBER)); 3586 if(method.peekType() == Type.BOOLEAN) { 3587 // It's a no-op in bytecode, but we must make sure it is treated as an int for purposes of type signatures 3588 method.convert(Type.INT); 3589 } 3590 } 3591 3592 private void loadBIT_NOT(final UnaryNode unaryNode) { 3593 loadExpression(unaryNode.getExpression(), TypeBounds.INT).load(-1).xor(); 3594 } 3595 3596 private void loadDECINC(final UnaryNode unaryNode) { 3597 final Expression operand = unaryNode.getExpression(); 3598 final Type type = unaryNode.getType(); 3599 final TypeBounds typeBounds = new TypeBounds(type, Type.NUMBER); 3600 final TokenType tokenType = unaryNode.tokenType(); 3601 final boolean isPostfix = tokenType == TokenType.DECPOSTFIX || tokenType == TokenType.INCPOSTFIX; 3602 final boolean isIncrement = tokenType == TokenType.INCPREFIX || tokenType == TokenType.INCPOSTFIX; 3603 3604 assert !type.isObject(); 3605 3606 new SelfModifyingStore<UnaryNode>(unaryNode, operand) { 3607 3608 private void loadRhs() { 3609 loadExpression(operand, typeBounds, true); 3610 } 3611 3612 @Override 3613 protected void evaluate() { 3614 if(isPostfix) { 3615 loadRhs(); 3616 } else { 3617 new OptimisticOperation(unaryNode, typeBounds) { 3618 @Override 3619 void loadStack() { 3620 loadRhs(); 3621 loadMinusOne(); 3622 } 3623 @Override 3624 void consumeStack() { 3625 doDecInc(getProgramPoint()); 3626 } 3627 }.emit(getOptimisticIgnoreCountForSelfModifyingExpression(operand)); 3628 } 3629 } 3630 3631 @Override 3632 protected void storeNonDiscard() { 3633 super.storeNonDiscard(); 3634 if (isPostfix) { 3635 new OptimisticOperation(unaryNode, typeBounds) { 3636 @Override 3637 void loadStack() { 3638 loadMinusOne(); 3639 } 3640 @Override 3641 void consumeStack() { 3642 doDecInc(getProgramPoint()); 3643 } 3644 }.emit(1); // 1 for non-incremented result on the top of the stack pushed in evaluate() 3645 } 3646 } 3647 3648 private void loadMinusOne() { 3649 if (type.isInteger()) { 3650 method.load(isIncrement ? 1 : -1); 3651 } else if (type.isLong()) { 3652 method.load(isIncrement ? 1L : -1L); 3653 } else { 3654 method.load(isIncrement ? 1.0 : -1.0); 3655 } 3656 } 3657 3658 private void doDecInc(final int programPoint) { 3659 method.add(programPoint); 3660 } 3661 }.store(); 3662 } 3663 3664 private static int getOptimisticIgnoreCountForSelfModifyingExpression(final Expression target) { 3665 return target instanceof AccessNode ? 1 : target instanceof IndexNode ? 2 : 0; 3666 } 3667 3668 private void loadAndDiscard(final Expression expr) { 3669 // TODO: move checks for discarding to actual expression load code (e.g. as we do with void). That way we might 3670 // be able to eliminate even more checks. 3671 if(expr instanceof PrimitiveLiteralNode | isLocalVariable(expr)) { 3672 assert !lc.isCurrentDiscard(expr); 3673 // Don't bother evaluating expressions without side effects. Typical usage is "void 0" for reliably generating 3674 // undefined. 3675 return; 3676 } 3677 3678 lc.pushDiscard(expr); 3679 loadExpression(expr, TypeBounds.UNBOUNDED); 3680 if (lc.popDiscardIfCurrent(expr)) { 3681 assert !expr.isAssignment(); 3682 // NOTE: if we had a way to load with type void, we could avoid popping 3683 method.pop(); 3684 } 3685 } 3686 3687 /** 3688 * Loads the expression with the specified type bounds, but if the parent expression is the current discard, 3689 * then instead loads and discards the expression. 3690 * @param parent the parent expression that's tested for being the current discard 3691 * @param expr the expression that's either normally loaded or discard-loaded 3692 * @param resultBounds result bounds for when loading the expression normally 3693 */ 3694 private void loadMaybeDiscard(final Expression parent, final Expression expr, final TypeBounds resultBounds) { 3695 loadMaybeDiscard(lc.popDiscardIfCurrent(parent), expr, resultBounds); 3696 } 3697 3698 /** 3699 * Loads the expression with the specified type bounds, or loads and discards the expression, depending on the 3700 * value of the discard flag. Useful as a helper for expressions with control flow where you often can't combine 3701 * testing for being the current discard and loading the subexpressions. 3702 * @param discard if true, the expression is loaded and discarded 3703 * @param expr the expression that's either normally loaded or discard-loaded 3704 * @param resultBounds result bounds for when loading the expression normally 3705 */ 3706 private void loadMaybeDiscard(final boolean discard, final Expression expr, final TypeBounds resultBounds) { 3707 if (discard) { 3708 loadAndDiscard(expr); 3709 } else { 3710 loadExpression(expr, resultBounds); 3711 } 3712 } 3713 3714 private void loadNEW(final UnaryNode unaryNode) { 3715 final CallNode callNode = (CallNode)unaryNode.getExpression(); 3716 final List<Expression> args = callNode.getArgs(); 3717 3718 final Expression func = callNode.getFunction(); 3719 // Load function reference. 3720 loadExpressionAsObject(func); // must detect type error 3721 3722 method.dynamicNew(1 + loadArgs(args), getCallSiteFlags(), func.toString(false)); 3723 } 3724 3725 private void loadNOT(final UnaryNode unaryNode) { 3726 final Expression expr = unaryNode.getExpression(); 3727 if(expr instanceof UnaryNode && expr.isTokenType(TokenType.NOT)) { 3728 // !!x is idiomatic boolean cast in JavaScript 3729 loadExpressionAsBoolean(((UnaryNode)expr).getExpression()); 3730 } else { 3731 final Label trueLabel = new Label("true"); 3732 final Label afterLabel = new Label("after"); 3733 3734 emitBranch(expr, trueLabel, true); 3735 method.load(true); 3736 method._goto(afterLabel); 3737 method.label(trueLabel); 3738 method.load(false); 3739 method.label(afterLabel); 3740 } 3741 } 3742 3743 private void loadSUB(final UnaryNode unaryNode, final TypeBounds resultBounds) { 3744 final Type type = unaryNode.getType(); 3745 assert type.isNumeric(); 3746 final TypeBounds numericBounds = resultBounds.booleanToInt(); 3747 new OptimisticOperation(unaryNode, numericBounds) { 3748 @Override 3749 void loadStack() { 3750 final Expression expr = unaryNode.getExpression(); 3751 loadExpression(expr, numericBounds.notWiderThan(Type.NUMBER)); 3752 } 3753 @Override 3754 void consumeStack() { 3755 // Must do an explicit conversion to the operation's type when it's double so that we correctly handle 3756 // negation of an int 0 to a double -0. With this, we get the correct negation of a local variable after 3757 // it deoptimized, e.g. "iload_2; i2d; dneg". Without this, we get "iload_2; ineg; i2d". 3758 if(type.isNumber()) { 3759 method.convert(type); 3760 } 3761 method.neg(getProgramPoint()); 3762 } 3763 }.emit(); 3764 } 3765 3766 public void loadVOID(final UnaryNode unaryNode, final TypeBounds resultBounds) { 3767 loadAndDiscard(unaryNode.getExpression()); 3768 if (!lc.popDiscardIfCurrent(unaryNode)) { 3769 method.loadUndefined(resultBounds.widest); 3770 } 3771 } 3772 3773 public void loadADD(final BinaryNode binaryNode, final TypeBounds resultBounds) { 3774 new OptimisticOperation(binaryNode, resultBounds) { 3775 @Override 3776 void loadStack() { 3777 final TypeBounds operandBounds; 3778 final boolean isOptimistic = isValid(getProgramPoint()); 3779 boolean forceConversionSeparation = false; 3780 if(isOptimistic) { 3781 operandBounds = new TypeBounds(binaryNode.getType(), Type.OBJECT); 3782 } else { 3783 // Non-optimistic, non-FP +. Allow it to overflow. 3784 final Type widestOperationType = binaryNode.getWidestOperationType(); 3785 operandBounds = new TypeBounds(Type.narrowest(binaryNode.getWidestOperandType(), resultBounds.widest), widestOperationType); 3786 forceConversionSeparation = widestOperationType.narrowerThan(resultBounds.widest); 3787 } 3788 loadBinaryOperands(binaryNode.lhs(), binaryNode.rhs(), operandBounds, false, forceConversionSeparation); 3789 } 3790 3791 @Override 3792 void consumeStack() { 3793 method.add(getProgramPoint()); 3794 } 3795 }.emit(); 3796 } 3797 3798 private void loadAND_OR(final BinaryNode binaryNode, final TypeBounds resultBounds, final boolean isAnd) { 3799 final Type narrowestOperandType = Type.widestReturnType(binaryNode.lhs().getType(), binaryNode.rhs().getType()); 3800 3801 final boolean isCurrentDiscard = lc.popDiscardIfCurrent(binaryNode); 3802 3803 final Label skip = new Label("skip"); 3804 if(narrowestOperandType == Type.BOOLEAN) { 3805 // optimize all-boolean logical expressions 3806 final Label onTrue = new Label("andor_true"); 3807 emitBranch(binaryNode, onTrue, true); 3808 if (isCurrentDiscard) { 3809 method.label(onTrue); 3810 } else { 3811 method.load(false); 3812 method._goto(skip); 3813 method.label(onTrue); 3814 method.load(true); 3815 method.label(skip); 3816 } 3817 return; 3818 } 3819 3820 final TypeBounds outBounds = resultBounds.notNarrowerThan(narrowestOperandType); 3821 final JoinPredecessorExpression lhs = (JoinPredecessorExpression)binaryNode.lhs(); 3822 final boolean lhsConvert = LocalVariableConversion.hasLiveConversion(lhs); 3823 final Label evalRhs = lhsConvert ? new Label("eval_rhs") : null; 3824 3825 loadExpression(lhs, outBounds); 3826 if (!isCurrentDiscard) { 3827 method.dup(); 3828 } 3829 method.convert(Type.BOOLEAN); 3830 if (isAnd) { 3831 if(lhsConvert) { 3832 method.ifne(evalRhs); 3833 } else { 3834 method.ifeq(skip); 3835 } 3836 } else if(lhsConvert) { 3837 method.ifeq(evalRhs); 3838 } else { 3839 method.ifne(skip); 3840 } 3841 3842 if(lhsConvert) { 3843 method.beforeJoinPoint(lhs); 3844 method._goto(skip); 3845 method.label(evalRhs); 3846 } 3847 3848 if (!isCurrentDiscard) { 3849 method.pop(); 3850 } 3851 final JoinPredecessorExpression rhs = (JoinPredecessorExpression)binaryNode.rhs(); 3852 loadMaybeDiscard(isCurrentDiscard, rhs, outBounds); 3853 method.beforeJoinPoint(rhs); 3854 method.label(skip); 3855 } 3856 3857 private static boolean isLocalVariable(final Expression lhs) { 3858 return lhs instanceof IdentNode && isLocalVariable((IdentNode)lhs); 3859 } 3860 3861 private static boolean isLocalVariable(final IdentNode lhs) { 3862 return lhs.getSymbol().isBytecodeLocal(); 3863 } 3864 3865 // NOTE: does not use resultBounds as the assignment is driven by the type of the RHS 3866 private void loadASSIGN(final BinaryNode binaryNode) { 3867 final Expression lhs = binaryNode.lhs(); 3868 final Expression rhs = binaryNode.rhs(); 3869 3870 final Type rhsType = rhs.getType(); 3871 // Detect dead assignments 3872 if(lhs instanceof IdentNode) { 3873 final Symbol symbol = ((IdentNode)lhs).getSymbol(); 3874 if(!symbol.isScope() && !symbol.hasSlotFor(rhsType) && lc.popDiscardIfCurrent(binaryNode)) { 3875 loadAndDiscard(rhs); 3876 method.markDeadLocalVariable(symbol); 3877 return; 3878 } 3879 } 3880 3881 new Store<BinaryNode>(binaryNode, lhs) { 3882 @Override 3883 protected void evaluate() { 3884 // NOTE: we're loading with "at least as wide as" so optimistic operations on the right hand side 3885 // remain optimistic, and then explicitly convert to the required type if needed. 3886 loadExpressionAsType(rhs, rhsType); 3887 } 3888 }.store(); 3889 } 3890 3891 /** 3892 * Binary self-assignment that can be optimistic: +=, -=, *=, and /=. 3893 */ 3894 private abstract class BinaryOptimisticSelfAssignment extends SelfModifyingStore<BinaryNode> { 3895 3896 /** 3897 * Constructor 3898 * 3899 * @param node the assign op node 3900 */ 3901 BinaryOptimisticSelfAssignment(final BinaryNode node) { 3902 super(node, node.lhs()); 3903 } 3904 3905 protected abstract void op(OptimisticOperation oo); 3906 3907 @Override 3908 protected void evaluate() { 3909 final Expression lhs = assignNode.lhs(); 3910 final Expression rhs = assignNode.rhs(); 3911 final Type widestOperationType = assignNode.getWidestOperationType(); 3912 final TypeBounds bounds = new TypeBounds(assignNode.getType(), widestOperationType); 3913 new OptimisticOperation(assignNode, bounds) { 3914 @Override 3915 void loadStack() { 3916 final boolean forceConversionSeparation; 3917 if (isValid(getProgramPoint()) || widestOperationType == Type.NUMBER) { 3918 forceConversionSeparation = false; 3919 } else { 3920 final Type operandType = Type.widest(booleanToInt(objectToNumber(lhs.getType())), booleanToInt(objectToNumber(rhs.getType()))); 3921 forceConversionSeparation = operandType.narrowerThan(widestOperationType); 3922 } 3923 loadBinaryOperands(lhs, rhs, bounds, true, forceConversionSeparation); 3924 } 3925 @Override 3926 void consumeStack() { 3927 op(this); 3928 } 3929 }.emit(getOptimisticIgnoreCountForSelfModifyingExpression(lhs)); 3930 method.convert(assignNode.getType()); 3931 } 3932 } 3933 3934 /** 3935 * Non-optimistic binary self-assignment operation. Basically, everything except +=, -=, *=, and /=. 3936 */ 3937 private abstract class BinarySelfAssignment extends SelfModifyingStore<BinaryNode> { 3938 BinarySelfAssignment(final BinaryNode node) { 3939 super(node, node.lhs()); 3940 } 3941 3942 protected abstract void op(); 3943 3944 @Override 3945 protected void evaluate() { 3946 loadBinaryOperands(assignNode.lhs(), assignNode.rhs(), TypeBounds.UNBOUNDED.notWiderThan(assignNode.getWidestOperandType()), true, false); 3947 op(); 3948 } 3949 } 3950 3951 private void loadASSIGN_ADD(final BinaryNode binaryNode) { 3952 new BinaryOptimisticSelfAssignment(binaryNode) { 3953 @Override 3954 protected void op(final OptimisticOperation oo) { 3955 assert !(binaryNode.getType().isObject() && oo.isOptimistic); 3956 method.add(oo.getProgramPoint()); 3957 } 3958 }.store(); 3959 } 3960 3961 private void loadASSIGN_BIT_AND(final BinaryNode binaryNode) { 3962 new BinarySelfAssignment(binaryNode) { 3963 @Override 3964 protected void op() { 3965 method.and(); 3966 } 3967 }.store(); 3968 } 3969 3970 private void loadASSIGN_BIT_OR(final BinaryNode binaryNode) { 3971 new BinarySelfAssignment(binaryNode) { 3972 @Override 3973 protected void op() { 3974 method.or(); 3975 } 3976 }.store(); 3977 } 3978 3979 private void loadASSIGN_BIT_XOR(final BinaryNode binaryNode) { 3980 new BinarySelfAssignment(binaryNode) { 3981 @Override 3982 protected void op() { 3983 method.xor(); 3984 } 3985 }.store(); 3986 } 3987 3988 private void loadASSIGN_DIV(final BinaryNode binaryNode) { 3989 new BinaryOptimisticSelfAssignment(binaryNode) { 3990 @Override 3991 protected void op(final OptimisticOperation oo) { 3992 method.div(oo.getProgramPoint()); 3993 } 3994 }.store(); 3995 } 3996 3997 private void loadASSIGN_MOD(final BinaryNode binaryNode) { 3998 new BinaryOptimisticSelfAssignment(binaryNode) { 3999 @Override 4000 protected void op(final OptimisticOperation oo) { 4001 method.rem(oo.getProgramPoint()); 4002 } 4003 }.store(); 4004 } 4005 4006 private void loadASSIGN_MUL(final BinaryNode binaryNode) { 4007 new BinaryOptimisticSelfAssignment(binaryNode) { 4008 @Override 4009 protected void op(final OptimisticOperation oo) { 4010 method.mul(oo.getProgramPoint()); 4011 } 4012 }.store(); 4013 } 4014 4015 private void loadASSIGN_SAR(final BinaryNode binaryNode) { 4016 new BinarySelfAssignment(binaryNode) { 4017 @Override 4018 protected void op() { 4019 method.sar(); 4020 } 4021 }.store(); 4022 } 4023 4024 private void loadASSIGN_SHL(final BinaryNode binaryNode) { 4025 new BinarySelfAssignment(binaryNode) { 4026 @Override 4027 protected void op() { 4028 method.shl(); 4029 } 4030 }.store(); 4031 } 4032 4033 private void loadASSIGN_SHR(final BinaryNode binaryNode) { 4034 new BinarySelfAssignment(binaryNode) { 4035 @Override 4036 protected void op() { 4037 doSHR(); 4038 } 4039 4040 }.store(); 4041 } 4042 4043 private void doSHR() { 4044 // TODO: make SHR optimistic 4045 method.shr(); 4046 toUint(); 4047 } 4048 4049 private void toUint() { 4050 JSType.TO_UINT32_I.invoke(method); 4051 } 4052 4053 private void loadASSIGN_SUB(final BinaryNode binaryNode) { 4054 new BinaryOptimisticSelfAssignment(binaryNode) { 4055 @Override 4056 protected void op(final OptimisticOperation oo) { 4057 method.sub(oo.getProgramPoint()); 4058 } 4059 }.store(); 4060 } 4061 4062 /** 4063 * Helper class for binary arithmetic ops 4064 */ 4065 private abstract class BinaryArith { 4066 protected abstract void op(int programPoint); 4067 4068 protected void evaluate(final BinaryNode node, final TypeBounds resultBounds) { 4069 final TypeBounds numericBounds = resultBounds.booleanToInt().objectToNumber(); 4070 new OptimisticOperation(node, numericBounds) { 4071 @Override 4072 void loadStack() { 4073 final TypeBounds operandBounds; 4074 boolean forceConversionSeparation = false; 4075 if(numericBounds.narrowest == Type.NUMBER) { 4076 // Result should be double always. Propagate it into the operands so we don't have lots of I2D 4077 // and L2D after operand evaluation. 4078 assert numericBounds.widest == Type.NUMBER; 4079 operandBounds = numericBounds; 4080 } else { 4081 final boolean isOptimistic = isValid(getProgramPoint()); 4082 if(isOptimistic || node.isTokenType(TokenType.DIV) || node.isTokenType(TokenType.MOD)) { 4083 operandBounds = new TypeBounds(node.getType(), Type.NUMBER); 4084 } else { 4085 // Non-optimistic, non-FP subtraction or multiplication. Allow them to overflow. 4086 operandBounds = new TypeBounds(Type.narrowest(node.getWidestOperandType(), 4087 numericBounds.widest), Type.NUMBER); 4088 forceConversionSeparation = node.getWidestOperationType().narrowerThan(numericBounds.widest); 4089 } 4090 } 4091 loadBinaryOperands(node.lhs(), node.rhs(), operandBounds, false, forceConversionSeparation); 4092 } 4093 4094 @Override 4095 void consumeStack() { 4096 op(getProgramPoint()); 4097 } 4098 }.emit(); 4099 } 4100 } 4101 4102 private void loadBIT_AND(final BinaryNode binaryNode) { 4103 loadBinaryOperands(binaryNode); 4104 method.and(); 4105 } 4106 4107 private void loadBIT_OR(final BinaryNode binaryNode) { 4108 // Optimize x|0 to (int)x 4109 if (isRhsZero(binaryNode)) { 4110 loadExpressionAsType(binaryNode.lhs(), Type.INT); 4111 } else { 4112 loadBinaryOperands(binaryNode); 4113 method.or(); 4114 } 4115 } 4116 4117 private static boolean isRhsZero(final BinaryNode binaryNode) { 4118 final Expression rhs = binaryNode.rhs(); 4119 return rhs instanceof LiteralNode && INT_ZERO.equals(((LiteralNode<?>)rhs).getValue()); 4120 } 4121 4122 private void loadBIT_XOR(final BinaryNode binaryNode) { 4123 loadBinaryOperands(binaryNode); 4124 method.xor(); 4125 } 4126 4127 private void loadCOMMARIGHT(final BinaryNode binaryNode, final TypeBounds resultBounds) { 4128 loadAndDiscard(binaryNode.lhs()); 4129 loadMaybeDiscard(binaryNode, binaryNode.rhs(), resultBounds); 4130 } 4131 4132 private void loadCOMMALEFT(final BinaryNode binaryNode, final TypeBounds resultBounds) { 4133 loadMaybeDiscard(binaryNode, binaryNode.lhs(), resultBounds); 4134 loadAndDiscard(binaryNode.rhs()); 4135 } 4136 4137 private void loadDIV(final BinaryNode binaryNode, final TypeBounds resultBounds) { 4138 new BinaryArith() { 4139 @Override 4140 protected void op(final int programPoint) { 4141 method.div(programPoint); 4142 } 4143 }.evaluate(binaryNode, resultBounds); 4144 } 4145 4146 private void loadCmp(final BinaryNode binaryNode, final Condition cond) { 4147 loadComparisonOperands(binaryNode); 4148 4149 final Label trueLabel = new Label("trueLabel"); 4150 final Label afterLabel = new Label("skip"); 4151 4152 method.conditionalJump(cond, trueLabel); 4153 4154 method.load(Boolean.FALSE); 4155 method._goto(afterLabel); 4156 method.label(trueLabel); 4157 method.load(Boolean.TRUE); 4158 method.label(afterLabel); 4159 } 4160 4161 private void loadMOD(final BinaryNode binaryNode, final TypeBounds resultBounds) { 4162 new BinaryArith() { 4163 @Override 4164 protected void op(final int programPoint) { 4165 method.rem(programPoint); 4166 } 4167 }.evaluate(binaryNode, resultBounds); 4168 } 4169 4170 private void loadMUL(final BinaryNode binaryNode, final TypeBounds resultBounds) { 4171 new BinaryArith() { 4172 @Override 4173 protected void op(final int programPoint) { 4174 method.mul(programPoint); 4175 } 4176 }.evaluate(binaryNode, resultBounds); 4177 } 4178 4179 private void loadSAR(final BinaryNode binaryNode) { 4180 loadBinaryOperands(binaryNode); 4181 method.sar(); 4182 } 4183 4184 private void loadSHL(final BinaryNode binaryNode) { 4185 loadBinaryOperands(binaryNode); 4186 method.shl(); 4187 } 4188 4189 private void loadSHR(final BinaryNode binaryNode) { 4190 // Optimize x >>> 0 to (uint)x 4191 if (isRhsZero(binaryNode)) { 4192 loadExpressionAsType(binaryNode.lhs(), Type.INT); 4193 toUint(); 4194 } else { 4195 loadBinaryOperands(binaryNode); 4196 doSHR(); 4197 } 4198 } 4199 4200 private void loadSUB(final BinaryNode binaryNode, final TypeBounds resultBounds) { 4201 new BinaryArith() { 4202 @Override 4203 protected void op(final int programPoint) { 4204 method.sub(programPoint); 4205 } 4206 }.evaluate(binaryNode, resultBounds); 4207 } 4208 4209 @Override 4210 public boolean enterLabelNode(final LabelNode labelNode) { 4211 labeledBlockBreakLiveLocals.push(lc.getUsedSlotCount()); 4212 return true; 4213 } 4214 4215 @Override 4216 protected boolean enterDefault(final Node node) { 4217 throw new AssertionError("Code generator entered node of type " + node.getClass().getName()); 4218 } 4219 4220 private void loadTernaryNode(final TernaryNode ternaryNode, final TypeBounds resultBounds) { 4221 final Expression test = ternaryNode.getTest(); 4222 final JoinPredecessorExpression trueExpr = ternaryNode.getTrueExpression(); 4223 final JoinPredecessorExpression falseExpr = ternaryNode.getFalseExpression(); 4224 4225 final Label falseLabel = new Label("ternary_false"); 4226 final Label exitLabel = new Label("ternary_exit"); 4227 4228 final Type outNarrowest = Type.narrowest(resultBounds.widest, Type.generic(Type.widestReturnType(trueExpr.getType(), falseExpr.getType()))); 4229 final TypeBounds outBounds = resultBounds.notNarrowerThan(outNarrowest); 4230 4231 emitBranch(test, falseLabel, false); 4232 4233 final boolean isCurrentDiscard = lc.popDiscardIfCurrent(ternaryNode); 4234 loadMaybeDiscard(isCurrentDiscard, trueExpr.getExpression(), outBounds); 4235 assert isCurrentDiscard || Type.generic(method.peekType()) == outBounds.narrowest; 4236 method.beforeJoinPoint(trueExpr); 4237 method._goto(exitLabel); 4238 method.label(falseLabel); 4239 loadMaybeDiscard(isCurrentDiscard, falseExpr.getExpression(), outBounds); 4240 assert isCurrentDiscard || Type.generic(method.peekType()) == outBounds.narrowest; 4241 method.beforeJoinPoint(falseExpr); 4242 method.label(exitLabel); 4243 } 4244 4245 /** 4246 * Generate all shared scope calls generated during codegen. 4247 */ 4248 void generateScopeCalls() { 4249 for (final SharedScopeCall scopeAccess : lc.getScopeCalls()) { 4250 scopeAccess.generateScopeCall(); 4251 } 4252 } 4253 4254 /** 4255 * Debug code used to print symbols 4256 * 4257 * @param block the block we are in 4258 * @param function the function we are in 4259 * @param ident identifier for block or function where applicable 4260 */ 4261 private void printSymbols(final Block block, final FunctionNode function, final String ident) { 4262 if (compiler.getScriptEnvironment()._print_symbols || function.getFlag(FunctionNode.IS_PRINT_SYMBOLS)) { 4263 final PrintWriter out = compiler.getScriptEnvironment().getErr(); 4264 out.println("[BLOCK in '" + ident + "']"); 4265 if (!block.printSymbols(out)) { 4266 out.println("<no symbols>"); 4267 } 4268 out.println(); 4269 } 4270 } 4271 4272 4273 /** 4274 * The difference between a store and a self modifying store is that 4275 * the latter may load part of the target on the stack, e.g. the base 4276 * of an AccessNode or the base and index of an IndexNode. These are used 4277 * both as target and as an extra source. Previously it was problematic 4278 * for self modifying stores if the target/lhs didn't belong to one 4279 * of three trivial categories: IdentNode, AcessNodes, IndexNodes. In that 4280 * case it was evaluated and tagged as "resolved", which meant at the second 4281 * time the lhs of this store was read (e.g. in a = a (second) + b for a += b, 4282 * it would be evaluated to a nop in the scope and cause stack underflow 4283 * 4284 * see NASHORN-703 4285 * 4286 * @param <T> 4287 */ 4288 private abstract class SelfModifyingStore<T extends Expression> extends Store<T> { 4289 protected SelfModifyingStore(final T assignNode, final Expression target) { 4290 super(assignNode, target); 4291 } 4292 4293 @Override 4294 protected boolean isSelfModifying() { 4295 return true; 4296 } 4297 } 4298 4299 /** 4300 * Helper class to generate stores 4301 */ 4302 private abstract class Store<T extends Expression> { 4303 4304 /** An assignment node, e.g. x += y */ 4305 protected final T assignNode; 4306 4307 /** The target node to store to, e.g. x */ 4308 private final Expression target; 4309 4310 /** How deep on the stack do the arguments go if this generates an indy call */ 4311 private int depth; 4312 4313 /** If we have too many arguments, we need temporary storage, this is stored in 'quick' */ 4314 private IdentNode quick; 4315 4316 /** 4317 * Constructor 4318 * 4319 * @param assignNode the node representing the whole assignment 4320 * @param target the target node of the assignment (destination) 4321 */ 4322 protected Store(final T assignNode, final Expression target) { 4323 this.assignNode = assignNode; 4324 this.target = target; 4325 } 4326 4327 /** 4328 * Constructor 4329 * 4330 * @param assignNode the node representing the whole assignment 4331 */ 4332 protected Store(final T assignNode) { 4333 this(assignNode, assignNode); 4334 } 4335 4336 /** 4337 * Is this a self modifying store operation, e.g. *= or ++ 4338 * @return true if self modifying store 4339 */ 4340 protected boolean isSelfModifying() { 4341 return false; 4342 } 4343 4344 private void prologue() { 4345 /* 4346 * This loads the parts of the target, e.g base and index. they are kept 4347 * on the stack throughout the store and used at the end to execute it 4348 */ 4349 4350 target.accept(new NodeVisitor<LexicalContext>(new LexicalContext()) { 4351 @Override 4352 public boolean enterIdentNode(final IdentNode node) { 4353 if (node.getSymbol().isScope()) { 4354 method.loadCompilerConstant(SCOPE); 4355 depth += Type.SCOPE.getSlots(); 4356 assert depth == 1; 4357 } 4358 return false; 4359 } 4360 4361 private void enterBaseNode() { 4362 assert target instanceof BaseNode : "error - base node " + target + " must be instanceof BaseNode"; 4363 final BaseNode baseNode = (BaseNode)target; 4364 final Expression base = baseNode.getBase(); 4365 4366 loadExpressionAsObject(base); 4367 depth += Type.OBJECT.getSlots(); 4368 assert depth == 1; 4369 4370 if (isSelfModifying()) { 4371 method.dup(); 4372 } 4373 } 4374 4375 @Override 4376 public boolean enterAccessNode(final AccessNode node) { 4377 enterBaseNode(); 4378 return false; 4379 } 4380 4381 @Override 4382 public boolean enterIndexNode(final IndexNode node) { 4383 enterBaseNode(); 4384 4385 final Expression index = node.getIndex(); 4386 if (!index.getType().isNumeric()) { 4387 // could be boolean here as well 4388 loadExpressionAsObject(index); 4389 } else { 4390 loadExpressionUnbounded(index); 4391 } 4392 depth += index.getType().getSlots(); 4393 4394 if (isSelfModifying()) { 4395 //convert "base base index" to "base index base index" 4396 method.dup(1); 4397 } 4398 4399 return false; 4400 } 4401 4402 }); 4403 } 4404 4405 /** 4406 * Generates an extra local variable, always using the same slot, one that is available after the end of the 4407 * frame. 4408 * 4409 * @param type the type of the variable 4410 * 4411 * @return the quick variable 4412 */ 4413 private IdentNode quickLocalVariable(final Type type) { 4414 final String name = lc.getCurrentFunction().uniqueName(QUICK_PREFIX.symbolName()); 4415 final Symbol symbol = new Symbol(name, IS_INTERNAL | HAS_SLOT); 4416 symbol.setHasSlotFor(type); 4417 symbol.setFirstSlot(lc.quickSlot(type)); 4418 4419 final IdentNode quickIdent = IdentNode.createInternalIdentifier(symbol).setType(type); 4420 4421 return quickIdent; 4422 } 4423 4424 // store the result that "lives on" after the op, e.g. "i" in i++ postfix. 4425 protected void storeNonDiscard() { 4426 if (lc.popDiscardIfCurrent(assignNode)) { 4427 assert assignNode.isAssignment(); 4428 return; 4429 } 4430 4431 if (method.dup(depth) == null) { 4432 method.dup(); 4433 final Type quickType = method.peekType(); 4434 this.quick = quickLocalVariable(quickType); 4435 final Symbol quickSymbol = quick.getSymbol(); 4436 method.storeTemp(quickType, quickSymbol.getFirstSlot()); 4437 } 4438 } 4439 4440 private void epilogue() { 4441 /** 4442 * Take the original target args from the stack and use them 4443 * together with the value to be stored to emit the store code 4444 * 4445 * The case that targetSymbol is in scope (!hasSlot) and we actually 4446 * need to do a conversion on non-equivalent types exists, but is 4447 * very rare. See for example test/script/basic/access-specializer.js 4448 */ 4449 target.accept(new NodeVisitor<LexicalContext>(new LexicalContext()) { 4450 @Override 4451 protected boolean enterDefault(final Node node) { 4452 throw new AssertionError("Unexpected node " + node + " in store epilogue"); 4453 } 4454 4455 @Override 4456 public boolean enterIdentNode(final IdentNode node) { 4457 final Symbol symbol = node.getSymbol(); 4458 assert symbol != null; 4459 if (symbol.isScope()) { 4460 final int flags = getScopeCallSiteFlags(symbol); 4461 if (isFastScope(symbol)) { 4462 storeFastScopeVar(symbol, flags); 4463 } else { 4464 method.dynamicSet(node.getName(), flags, false); 4465 } 4466 } else { 4467 final Type storeType = assignNode.getType(); 4468 if (symbol.hasSlotFor(storeType)) { 4469 // Only emit a convert for a store known to be live; converts for dead stores can 4470 // give us an unnecessary ClassCastException. 4471 method.convert(storeType); 4472 } 4473 storeIdentWithCatchConversion(node, storeType); 4474 } 4475 return false; 4476 4477 } 4478 4479 @Override 4480 public boolean enterAccessNode(final AccessNode node) { 4481 method.dynamicSet(node.getProperty(), getCallSiteFlags(), node.isIndex()); 4482 return false; 4483 } 4484 4485 @Override 4486 public boolean enterIndexNode(final IndexNode node) { 4487 method.dynamicSetIndex(getCallSiteFlags()); 4488 return false; 4489 } 4490 }); 4491 4492 4493 // whatever is on the stack now is the final answer 4494 } 4495 4496 protected abstract void evaluate(); 4497 4498 void store() { 4499 if (target instanceof IdentNode) { 4500 checkTemporalDeadZone((IdentNode)target); 4501 } 4502 prologue(); 4503 evaluate(); // leaves an operation of whatever the operationType was on the stack 4504 storeNonDiscard(); 4505 epilogue(); 4506 if (quick != null) { 4507 method.load(quick); 4508 } 4509 } 4510 } 4511 4512 private void newFunctionObject(final FunctionNode functionNode, final boolean addInitializer) { 4513 assert lc.peek() == functionNode; 4514 4515 final RecompilableScriptFunctionData data = compiler.getScriptFunctionData(functionNode.getId()); 4516 4517 if (functionNode.isProgram() && !compiler.isOnDemandCompilation()) { 4518 final MethodEmitter createFunction = functionNode.getCompileUnit().getClassEmitter().method( 4519 EnumSet.of(Flag.PUBLIC, Flag.STATIC), CREATE_PROGRAM_FUNCTION.symbolName(), 4520 ScriptFunction.class, ScriptObject.class); 4521 createFunction.begin(); 4522 loadConstantsAndIndex(data, createFunction); 4523 createFunction.load(SCOPE_TYPE, 0); 4524 createFunction.invoke(CREATE_FUNCTION_OBJECT); 4525 createFunction._return(); 4526 createFunction.end(); 4527 } 4528 4529 if (addInitializer && !compiler.isOnDemandCompilation()) { 4530 functionNode.getCompileUnit().addFunctionInitializer(data, functionNode); 4531 } 4532 4533 // We don't emit a ScriptFunction on stack for the outermost compiled function (as there's no code being 4534 // generated in its outer context that'd need it as a callee). 4535 if (lc.getOutermostFunction() == functionNode) { 4536 return; 4537 } 4538 4539 loadConstantsAndIndex(data, method); 4540 4541 if (functionNode.needsParentScope()) { 4542 method.loadCompilerConstant(SCOPE); 4543 method.invoke(CREATE_FUNCTION_OBJECT); 4544 } else { 4545 method.invoke(CREATE_FUNCTION_OBJECT_NO_SCOPE); 4546 } 4547 } 4548 4549 // calls on Global class. 4550 private MethodEmitter globalInstance() { 4551 return method.invokestatic(GLOBAL_OBJECT, "instance", "()L" + GLOBAL_OBJECT + ';'); 4552 } 4553 4554 private MethodEmitter globalAllocateArguments() { 4555 return method.invokestatic(GLOBAL_OBJECT, "allocateArguments", methodDescriptor(ScriptObject.class, Object[].class, Object.class, int.class)); 4556 } 4557 4558 private MethodEmitter globalNewRegExp() { 4559 return method.invokestatic(GLOBAL_OBJECT, "newRegExp", methodDescriptor(Object.class, String.class, String.class)); 4560 } 4561 4562 private MethodEmitter globalRegExpCopy() { 4563 return method.invokestatic(GLOBAL_OBJECT, "regExpCopy", methodDescriptor(Object.class, Object.class)); 4564 } 4565 4566 private MethodEmitter globalAllocateArray(final ArrayType type) { 4567 //make sure the native array is treated as an array type 4568 return method.invokestatic(GLOBAL_OBJECT, "allocate", "(" + type.getDescriptor() + ")Ljdk/nashorn/internal/objects/NativeArray;"); 4569 } 4570 4571 private MethodEmitter globalIsEval() { 4572 return method.invokestatic(GLOBAL_OBJECT, "isEval", methodDescriptor(boolean.class, Object.class)); 4573 } 4574 4575 private MethodEmitter globalReplaceLocationPropertyPlaceholder() { 4576 return method.invokestatic(GLOBAL_OBJECT, "replaceLocationPropertyPlaceholder", methodDescriptor(Object.class, Object.class, Object.class)); 4577 } 4578 4579 private MethodEmitter globalCheckObjectCoercible() { 4580 return method.invokestatic(GLOBAL_OBJECT, "checkObjectCoercible", methodDescriptor(void.class, Object.class)); 4581 } 4582 4583 private MethodEmitter globalDirectEval() { 4584 return method.invokestatic(GLOBAL_OBJECT, "directEval", 4585 methodDescriptor(Object.class, Object.class, Object.class, Object.class, Object.class, boolean.class)); 4586 } 4587 4588 private abstract class OptimisticOperation { 4589 private final boolean isOptimistic; 4590 // expression and optimistic are the same reference 4591 private final Expression expression; 4592 private final Optimistic optimistic; 4593 private final TypeBounds resultBounds; 4594 4595 OptimisticOperation(final Optimistic optimistic, final TypeBounds resultBounds) { 4596 this.optimistic = optimistic; 4597 this.expression = (Expression)optimistic; 4598 this.resultBounds = resultBounds; 4599 this.isOptimistic = isOptimistic(optimistic) && useOptimisticTypes() && 4600 // Operation is only effectively optimistic if its type, after being coerced into the result bounds 4601 // is narrower than the upper bound. 4602 resultBounds.within(Type.generic(((Expression)optimistic).getType())).narrowerThan(resultBounds.widest); 4603 } 4604 4605 MethodEmitter emit() { 4606 return emit(0); 4607 } 4608 4609 MethodEmitter emit(final int ignoredArgCount) { 4610 final int programPoint = optimistic.getProgramPoint(); 4611 final boolean optimisticOrContinuation = isOptimistic || isContinuationEntryPoint(programPoint); 4612 final boolean currentContinuationEntryPoint = isCurrentContinuationEntryPoint(programPoint); 4613 final int stackSizeOnEntry = method.getStackSize() - ignoredArgCount; 4614 4615 // First store the values on the stack opportunistically into local variables. Doing it before loadStack() 4616 // allows us to not have to pop/load any arguments that are pushed onto it by loadStack() in the second 4617 // storeStack(). 4618 storeStack(ignoredArgCount, optimisticOrContinuation); 4619 4620 // Now, load the stack 4621 loadStack(); 4622 4623 // Now store the values on the stack ultimately into local variables. In vast majority of cases, this is 4624 // (aside from creating the local types map) a no-op, as the first opportunistic stack store will already 4625 // store all variables. However, there can be operations in the loadStack() that invalidate some of the 4626 // stack stores, e.g. in "x[i] = x[++i]", "++i" will invalidate the already stored value for "i". In such 4627 // unfortunate cases this second storeStack() will restore the invariant that everything on the stack is 4628 // stored into a local variable, although at the cost of doing a store/load on the loaded arguments as well. 4629 final int liveLocalsCount = storeStack(method.getStackSize() - stackSizeOnEntry, optimisticOrContinuation); 4630 assert optimisticOrContinuation == (liveLocalsCount != -1); 4631 4632 final Label beginTry; 4633 final Label catchLabel; 4634 final Label afterConsumeStack = isOptimistic || currentContinuationEntryPoint ? new Label("after_consume_stack") : null; 4635 if(isOptimistic) { 4636 beginTry = new Label("try_optimistic"); 4637 final String catchLabelName = (afterConsumeStack == null ? "" : afterConsumeStack.toString()) + "_handler"; 4638 catchLabel = new Label(catchLabelName); 4639 method.label(beginTry); 4640 } else { 4641 beginTry = catchLabel = null; 4642 } 4643 4644 consumeStack(); 4645 4646 if(isOptimistic) { 4647 method._try(beginTry, afterConsumeStack, catchLabel, UnwarrantedOptimismException.class); 4648 } 4649 4650 if(isOptimistic || currentContinuationEntryPoint) { 4651 method.label(afterConsumeStack); 4652 4653 final int[] localLoads = method.getLocalLoadsOnStack(0, stackSizeOnEntry); 4654 assert everyStackValueIsLocalLoad(localLoads) : Arrays.toString(localLoads) + ", " + stackSizeOnEntry + ", " + ignoredArgCount; 4655 final List<Type> localTypesList = method.getLocalVariableTypes(); 4656 final int usedLocals = method.getUsedSlotsWithLiveTemporaries(); 4657 final List<Type> localTypes = method.getWidestLiveLocals(localTypesList.subList(0, usedLocals)); 4658 assert everyLocalLoadIsValid(localLoads, usedLocals) : Arrays.toString(localLoads) + " ~ " + localTypes; 4659 4660 if(isOptimistic) { 4661 addUnwarrantedOptimismHandlerLabel(localTypes, catchLabel); 4662 } 4663 if(currentContinuationEntryPoint) { 4664 final ContinuationInfo ci = getContinuationInfo(); 4665 assert ci != null : "no continuation info found for " + lc.getCurrentFunction(); 4666 assert !ci.hasTargetLabel(); // No duplicate program points 4667 ci.setTargetLabel(afterConsumeStack); 4668 ci.getHandlerLabel().markAsOptimisticContinuationHandlerFor(afterConsumeStack); 4669 // Can't rely on targetLabel.stack.localVariableTypes.length, as it can be higher due to effectively 4670 // dead local variables. 4671 ci.lvarCount = localTypes.size(); 4672 ci.setStackStoreSpec(localLoads); 4673 ci.setStackTypes(Arrays.copyOf(method.getTypesFromStack(method.getStackSize()), stackSizeOnEntry)); 4674 assert ci.getStackStoreSpec().length == ci.getStackTypes().length; 4675 ci.setReturnValueType(method.peekType()); 4676 ci.lineNumber = getLastLineNumber(); 4677 ci.catchLabel = catchLabels.peek(); 4678 } 4679 } 4680 return method; 4681 } 4682 4683 /** 4684 * Stores the current contents of the stack into local variables so they are not lost before invoking something that 4685 * can result in an {@code UnwarantedOptimizationException}. 4686 * @param ignoreArgCount the number of topmost arguments on stack to ignore when deciding on the shape of the catch 4687 * block. Those are used in the situations when we could not place the call to {@code storeStack} early enough 4688 * (before emitting code for pushing the arguments that the optimistic call will pop). This is admittedly a 4689 * deficiency in the design of the code generator when it deals with self-assignments and we should probably look 4690 * into fixing it. 4691 * @return types of the significant local variables after the stack was stored (types for local variables used 4692 * for temporary storage of ignored arguments are not returned). 4693 * @param optimisticOrContinuation if false, this method should not execute 4694 * a label for a catch block for the {@code UnwarantedOptimizationException}, suitable for capturing the 4695 * currently live local variables, tailored to their types. 4696 */ 4697 private int storeStack(final int ignoreArgCount, final boolean optimisticOrContinuation) { 4698 if(!optimisticOrContinuation) { 4699 return -1; // NOTE: correct value to return is lc.getUsedSlotCount(), but it wouldn't be used anyway 4700 } 4701 4702 final int stackSize = method.getStackSize(); 4703 final Type[] stackTypes = method.getTypesFromStack(stackSize); 4704 final int[] localLoadsOnStack = method.getLocalLoadsOnStack(0, stackSize); 4705 final int usedSlots = method.getUsedSlotsWithLiveTemporaries(); 4706 4707 final int firstIgnored = stackSize - ignoreArgCount; 4708 // Find the first value on the stack (from the bottom) that is not a load from a local variable. 4709 int firstNonLoad = 0; 4710 while(firstNonLoad < firstIgnored && localLoadsOnStack[firstNonLoad] != Label.Stack.NON_LOAD) { 4711 firstNonLoad++; 4712 } 4713 4714 // Only do the store/load if first non-load is not an ignored argument. Otherwise, do nothing and return 4715 // the number of used slots as the number of live local variables. 4716 if(firstNonLoad >= firstIgnored) { 4717 return usedSlots; 4718 } 4719 4720 // Find the number of new temporary local variables that we need; it's the number of values on the stack that 4721 // are not direct loads of existing local variables. 4722 int tempSlotsNeeded = 0; 4723 for(int i = firstNonLoad; i < stackSize; ++i) { 4724 if(localLoadsOnStack[i] == Label.Stack.NON_LOAD) { 4725 tempSlotsNeeded += stackTypes[i].getSlots(); 4726 } 4727 } 4728 4729 // Ensure all values on the stack that weren't directly loaded from a local variable are stored in a local 4730 // variable. We're starting from highest local variable index, so that in case ignoreArgCount > 0 the ignored 4731 // ones end up at the end of the local variable table. 4732 int lastTempSlot = usedSlots + tempSlotsNeeded; 4733 int ignoreSlotCount = 0; 4734 for(int i = stackSize; i -- > firstNonLoad;) { 4735 final int loadSlot = localLoadsOnStack[i]; 4736 if(loadSlot == Label.Stack.NON_LOAD) { 4737 final Type type = stackTypes[i]; 4738 final int slots = type.getSlots(); 4739 lastTempSlot -= slots; 4740 if(i >= firstIgnored) { 4741 ignoreSlotCount += slots; 4742 } 4743 method.storeTemp(type, lastTempSlot); 4744 } else { 4745 method.pop(); 4746 } 4747 } 4748 assert lastTempSlot == usedSlots; // used all temporary locals 4749 4750 final List<Type> localTypesList = method.getLocalVariableTypes(); 4751 4752 // Load values back on stack. 4753 for(int i = firstNonLoad; i < stackSize; ++i) { 4754 final int loadSlot = localLoadsOnStack[i]; 4755 final Type stackType = stackTypes[i]; 4756 final boolean isLoad = loadSlot != Label.Stack.NON_LOAD; 4757 final int lvarSlot = isLoad ? loadSlot : lastTempSlot; 4758 final Type lvarType = localTypesList.get(lvarSlot); 4759 method.load(lvarType, lvarSlot); 4760 if(isLoad) { 4761 // Conversion operators (I2L etc.) preserve "load"-ness of the value despite the fact that, in the 4762 // strict sense they are creating a derived value from the loaded value. This special behavior of 4763 // on-stack conversion operators is necessary to accommodate for differences in local variable types 4764 // after deoptimization; having a conversion operator throw away "load"-ness would create different 4765 // local variable table shapes between optimism-failed code and its deoptimized rest-of method). 4766 // After we load the value back, we need to redo the conversion to the stack type if stack type is 4767 // different. 4768 // NOTE: this would only strictly be necessary for widening conversions (I2L, L2D, I2D), and not for 4769 // narrowing ones (L2I, D2L, D2I) as only widening conversions are the ones that can get eliminated 4770 // in a deoptimized method, as their original input argument got widened. Maybe experiment with 4771 // throwing away "load"-ness for narrowing conversions in MethodEmitter.convert()? 4772 method.convert(stackType); 4773 } else { 4774 // temporary stores never needs a convert, as their type is always the same as the stack type. 4775 assert lvarType == stackType; 4776 lastTempSlot += lvarType.getSlots(); 4777 } 4778 } 4779 // used all temporaries 4780 assert lastTempSlot == usedSlots + tempSlotsNeeded; 4781 4782 return lastTempSlot - ignoreSlotCount; 4783 } 4784 4785 private void addUnwarrantedOptimismHandlerLabel(final List<Type> localTypes, final Label label) { 4786 final String lvarTypesDescriptor = getLvarTypesDescriptor(localTypes); 4787 final Map<String, Collection<Label>> unwarrantedOptimismHandlers = lc.getUnwarrantedOptimismHandlers(); 4788 Collection<Label> labels = unwarrantedOptimismHandlers.get(lvarTypesDescriptor); 4789 if(labels == null) { 4790 labels = new LinkedList<>(); 4791 unwarrantedOptimismHandlers.put(lvarTypesDescriptor, labels); 4792 } 4793 method.markLabelAsOptimisticCatchHandler(label, localTypes.size()); 4794 labels.add(label); 4795 } 4796 4797 abstract void loadStack(); 4798 4799 // Make sure that whatever indy call site you emit from this method uses {@code getCallSiteFlagsOptimistic(node)} 4800 // or otherwise ensure optimistic flag is correctly set in the call site, otherwise it doesn't make much sense 4801 // to use OptimisticExpression for emitting it. 4802 abstract void consumeStack(); 4803 4804 /** 4805 * Emits the correct dynamic getter code. Normally just delegates to method emitter, except when the target 4806 * expression is optimistic, and the desired type is narrower than the optimistic type. In that case, it'll emit a 4807 * dynamic getter with its original optimistic type, and explicitly insert a narrowing conversion. This way we can 4808 * preserve the optimism of the values even if they're subsequently immediately coerced into a narrower type. This 4809 * is beneficial because in this case we can still presume that since the original getter was optimistic, the 4810 * conversion has no side effects. 4811 * @param name the name of the property being get 4812 * @param flags call site flags 4813 * @param isMethod whether we're preferably retrieving a function 4814 * @return the current method emitter 4815 */ 4816 MethodEmitter dynamicGet(final String name, final int flags, final boolean isMethod, final boolean isIndex) { 4817 if(isOptimistic) { 4818 return method.dynamicGet(getOptimisticCoercedType(), name, getOptimisticFlags(flags), isMethod, isIndex); 4819 } 4820 return method.dynamicGet(resultBounds.within(expression.getType()), name, nonOptimisticFlags(flags), isMethod, isIndex); 4821 } 4822 4823 MethodEmitter dynamicGetIndex(final int flags, final boolean isMethod) { 4824 if(isOptimistic) { 4825 return method.dynamicGetIndex(getOptimisticCoercedType(), getOptimisticFlags(flags), isMethod); 4826 } 4827 return method.dynamicGetIndex(resultBounds.within(expression.getType()), nonOptimisticFlags(flags), isMethod); 4828 } 4829 4830 MethodEmitter dynamicCall(final int argCount, final int flags, final String msg) { 4831 if (isOptimistic) { 4832 return method.dynamicCall(getOptimisticCoercedType(), argCount, getOptimisticFlags(flags), msg); 4833 } 4834 return method.dynamicCall(resultBounds.within(expression.getType()), argCount, nonOptimisticFlags(flags), msg); 4835 } 4836 4837 int getOptimisticFlags(final int flags) { 4838 return flags | CALLSITE_OPTIMISTIC | (optimistic.getProgramPoint() << CALLSITE_PROGRAM_POINT_SHIFT); //encode program point in high bits 4839 } 4840 4841 int getProgramPoint() { 4842 return isOptimistic ? optimistic.getProgramPoint() : INVALID_PROGRAM_POINT; 4843 } 4844 4845 void convertOptimisticReturnValue() { 4846 if (isOptimistic) { 4847 final Type optimisticType = getOptimisticCoercedType(); 4848 if(!optimisticType.isObject()) { 4849 method.load(optimistic.getProgramPoint()); 4850 if(optimisticType.isInteger()) { 4851 method.invoke(ENSURE_INT); 4852 } else if(optimisticType.isLong()) { 4853 method.invoke(ENSURE_LONG); 4854 } else if(optimisticType.isNumber()) { 4855 method.invoke(ENSURE_NUMBER); 4856 } else { 4857 throw new AssertionError(optimisticType); 4858 } 4859 } 4860 } 4861 } 4862 4863 void replaceCompileTimeProperty() { 4864 final IdentNode identNode = (IdentNode)expression; 4865 final String name = identNode.getSymbol().getName(); 4866 if (CompilerConstants.__FILE__.name().equals(name)) { 4867 replaceCompileTimeProperty(getCurrentSource().getName()); 4868 } else if (CompilerConstants.__DIR__.name().equals(name)) { 4869 replaceCompileTimeProperty(getCurrentSource().getBase()); 4870 } else if (CompilerConstants.__LINE__.name().equals(name)) { 4871 replaceCompileTimeProperty(getCurrentSource().getLine(identNode.position())); 4872 } 4873 } 4874 4875 /** 4876 * When an ident with name __FILE__, __DIR__, or __LINE__ is loaded, we'll try to look it up as any other 4877 * identifier. However, if it gets all the way up to the Global object, it will send back a special value that 4878 * represents a placeholder for these compile-time location properties. This method will generate code that loads 4879 * the value of the compile-time location property and then invokes a method in Global that will replace the 4880 * placeholder with the value. Effectively, if the symbol for these properties is defined anywhere in the lexical 4881 * scope, they take precedence, but if they aren't, then they resolve to the compile-time location property. 4882 * @param propertyValue the actual value of the property 4883 */ 4884 private void replaceCompileTimeProperty(final Object propertyValue) { 4885 assert method.peekType().isObject(); 4886 if(propertyValue instanceof String || propertyValue == null) { 4887 method.load((String)propertyValue); 4888 } else if(propertyValue instanceof Integer) { 4889 method.load(((Integer)propertyValue)); 4890 method.convert(Type.OBJECT); 4891 } else { 4892 throw new AssertionError(); 4893 } 4894 globalReplaceLocationPropertyPlaceholder(); 4895 convertOptimisticReturnValue(); 4896 } 4897 4898 /** 4899 * Returns the type that should be used as the return type of the dynamic invocation that is emitted as the code 4900 * for the current optimistic operation. If the type bounds is exact boolean or narrower than the expression's 4901 * optimistic type, then the optimistic type is returned, otherwise the coercing type. Effectively, this method 4902 * allows for moving the coercion into the optimistic type when it won't adversely affect the optimistic 4903 * evaluation semantics, and for preserving the optimistic type and doing a separate coercion when it would 4904 * affect it. 4905 * @return 4906 */ 4907 private Type getOptimisticCoercedType() { 4908 final Type optimisticType = expression.getType(); 4909 assert resultBounds.widest.widerThan(optimisticType); 4910 final Type narrowest = resultBounds.narrowest; 4911 4912 if(narrowest.isBoolean() || narrowest.narrowerThan(optimisticType)) { 4913 assert !optimisticType.isObject(); 4914 return optimisticType; 4915 } 4916 assert !narrowest.isObject(); 4917 return narrowest; 4918 } 4919 } 4920 4921 private static boolean isOptimistic(final Optimistic optimistic) { 4922 if(!optimistic.canBeOptimistic()) { 4923 return false; 4924 } 4925 final Expression expr = (Expression)optimistic; 4926 return expr.getType().narrowerThan(expr.getWidestOperationType()); 4927 } 4928 4929 private static boolean everyLocalLoadIsValid(final int[] loads, final int localCount) { 4930 for (final int load : loads) { 4931 if(load < 0 || load >= localCount) { 4932 return false; 4933 } 4934 } 4935 return true; 4936 } 4937 4938 private static boolean everyStackValueIsLocalLoad(final int[] loads) { 4939 for (final int load : loads) { 4940 if(load == Label.Stack.NON_LOAD) { 4941 return false; 4942 } 4943 } 4944 return true; 4945 } 4946 4947 private String getLvarTypesDescriptor(final List<Type> localVarTypes) { 4948 final int count = localVarTypes.size(); 4949 final StringBuilder desc = new StringBuilder(count); 4950 for(int i = 0; i < count;) { 4951 i += appendType(desc, localVarTypes.get(i)); 4952 } 4953 return method.markSymbolBoundariesInLvarTypesDescriptor(desc.toString()); 4954 } 4955 4956 private static int appendType(final StringBuilder b, final Type t) { 4957 b.append(t.getBytecodeStackType()); 4958 return t.getSlots(); 4959 } 4960 4961 private static int countSymbolsInLvarTypeDescriptor(final String lvarTypeDescriptor) { 4962 int count = 0; 4963 for(int i = 0; i < lvarTypeDescriptor.length(); ++i) { 4964 if(Character.isUpperCase(lvarTypeDescriptor.charAt(i))) { 4965 ++count; 4966 } 4967 } 4968 return count; 4969 4970 } 4971 /** 4972 * Generates all the required {@code UnwarrantedOptimismException} handlers for the current function. The employed 4973 * strategy strives to maximize code reuse. Every handler constructs an array to hold the local variables, then 4974 * fills in some trailing part of the local variables (those for which it has a unique suffix in the descriptor), 4975 * then jumps to a handler for a prefix that's shared with other handlers. A handler that fills up locals up to 4976 * position 0 will not jump to a prefix handler (as it has no prefix), but instead end with constructing and 4977 * throwing a {@code RewriteException}. Since we lexicographically sort the entries, we only need to check every 4978 * entry to its immediately preceding one for longest matching prefix. 4979 * @return true if there is at least one exception handler 4980 */ 4981 private boolean generateUnwarrantedOptimismExceptionHandlers(final FunctionNode fn) { 4982 if(!useOptimisticTypes()) { 4983 return false; 4984 } 4985 4986 // Take the mapping of lvarSpecs -> labels, and turn them into a descending lexicographically sorted list of 4987 // handler specifications. 4988 final Map<String, Collection<Label>> unwarrantedOptimismHandlers = lc.popUnwarrantedOptimismHandlers(); 4989 if(unwarrantedOptimismHandlers.isEmpty()) { 4990 return false; 4991 } 4992 4993 method.lineNumber(0); 4994 4995 final List<OptimismExceptionHandlerSpec> handlerSpecs = new ArrayList<>(unwarrantedOptimismHandlers.size() * 4/3); 4996 for(final String spec: unwarrantedOptimismHandlers.keySet()) { 4997 handlerSpecs.add(new OptimismExceptionHandlerSpec(spec, true)); 4998 } 4999 Collections.sort(handlerSpecs, Collections.reverseOrder()); 5000 5001 // Map of local variable specifications to labels for populating the array for that local variable spec. 5002 final Map<String, Label> delegationLabels = new HashMap<>(); 5003 5004 // Do everything in a single pass over the handlerSpecs list. Note that the list can actually grow as we're 5005 // passing through it as we might add new prefix handlers into it, so can't hoist size() outside of the loop. 5006 for(int handlerIndex = 0; handlerIndex < handlerSpecs.size(); ++handlerIndex) { 5007 final OptimismExceptionHandlerSpec spec = handlerSpecs.get(handlerIndex); 5008 final String lvarSpec = spec.lvarSpec; 5009 if(spec.catchTarget) { 5010 assert !method.isReachable(); 5011 // Start a catch block and assign the labels for this lvarSpec with it. 5012 method._catch(unwarrantedOptimismHandlers.get(lvarSpec)); 5013 // This spec is a catch target, so emit array creation code. The length of the array is the number of 5014 // symbols - the number of uppercase characters. 5015 method.load(countSymbolsInLvarTypeDescriptor(lvarSpec)); 5016 method.newarray(Type.OBJECT_ARRAY); 5017 } 5018 if(spec.delegationTarget) { 5019 // If another handler can delegate to this handler as its prefix, then put a jump target here for the 5020 // shared code (after the array creation code, which is never shared). 5021 method.label(delegationLabels.get(lvarSpec)); // label must exist 5022 } 5023 5024 final boolean lastHandler = handlerIndex == handlerSpecs.size() - 1; 5025 5026 int lvarIndex; 5027 final int firstArrayIndex; 5028 final int firstLvarIndex; 5029 Label delegationLabel; 5030 final String commonLvarSpec; 5031 if(lastHandler) { 5032 // Last handler block, doesn't delegate to anything. 5033 lvarIndex = 0; 5034 firstLvarIndex = 0; 5035 firstArrayIndex = 0; 5036 delegationLabel = null; 5037 commonLvarSpec = null; 5038 } else { 5039 // Not yet the last handler block, will definitely delegate to another handler; let's figure out which 5040 // one. It can be an already declared handler further down the list, or it might need to declare a new 5041 // prefix handler. 5042 5043 // Since we're lexicographically ordered, the common prefix handler is defined by the common prefix of 5044 // this handler and the next handler on the list. 5045 final int nextHandlerIndex = handlerIndex + 1; 5046 final String nextLvarSpec = handlerSpecs.get(nextHandlerIndex).lvarSpec; 5047 commonLvarSpec = commonPrefix(lvarSpec, nextLvarSpec); 5048 // We don't chop symbols in half 5049 assert Character.isUpperCase(commonLvarSpec.charAt(commonLvarSpec.length() - 1)); 5050 5051 // Let's find if we already have a declaration for such handler, or we need to insert it. 5052 { 5053 boolean addNewHandler = true; 5054 int commonHandlerIndex = nextHandlerIndex; 5055 for(; commonHandlerIndex < handlerSpecs.size(); ++commonHandlerIndex) { 5056 final OptimismExceptionHandlerSpec forwardHandlerSpec = handlerSpecs.get(commonHandlerIndex); 5057 final String forwardLvarSpec = forwardHandlerSpec.lvarSpec; 5058 if(forwardLvarSpec.equals(commonLvarSpec)) { 5059 // We already have a handler for the common prefix. 5060 addNewHandler = false; 5061 // Make sure we mark it as a delegation target. 5062 forwardHandlerSpec.delegationTarget = true; 5063 break; 5064 } else if(!forwardLvarSpec.startsWith(commonLvarSpec)) { 5065 break; 5066 } 5067 } 5068 if(addNewHandler) { 5069 // We need to insert a common prefix handler. Note handlers created with catchTarget == false 5070 // will automatically have delegationTarget == true (because that's the only reason for their 5071 // existence). 5072 handlerSpecs.add(commonHandlerIndex, new OptimismExceptionHandlerSpec(commonLvarSpec, false)); 5073 } 5074 } 5075 5076 firstArrayIndex = countSymbolsInLvarTypeDescriptor(commonLvarSpec); 5077 lvarIndex = 0; 5078 for(int j = 0; j < commonLvarSpec.length(); ++j) { 5079 lvarIndex += CodeGeneratorLexicalContext.getTypeForSlotDescriptor(commonLvarSpec.charAt(j)).getSlots(); 5080 } 5081 firstLvarIndex = lvarIndex; 5082 5083 // Create a delegation label if not already present 5084 delegationLabel = delegationLabels.get(commonLvarSpec); 5085 if(delegationLabel == null) { 5086 // uo_pa == "unwarranted optimism, populate array" 5087 delegationLabel = new Label("uo_pa_" + commonLvarSpec); 5088 delegationLabels.put(commonLvarSpec, delegationLabel); 5089 } 5090 } 5091 5092 // Load local variables handled by this handler on stack 5093 int args = 0; 5094 boolean symbolHadValue = false; 5095 for(int typeIndex = commonLvarSpec == null ? 0 : commonLvarSpec.length(); typeIndex < lvarSpec.length(); ++typeIndex) { 5096 final char typeDesc = lvarSpec.charAt(typeIndex); 5097 final Type lvarType = CodeGeneratorLexicalContext.getTypeForSlotDescriptor(typeDesc); 5098 if (!lvarType.isUnknown()) { 5099 method.load(lvarType, lvarIndex); 5100 symbolHadValue = true; 5101 args++; 5102 } else if(typeDesc == 'U' && !symbolHadValue) { 5103 // Symbol boundary with undefined last value. Check if all previous values for this symbol were also 5104 // undefined; if so, emit one explicit Undefined. This serves to ensure that we're emiting exactly 5105 // one value for every symbol that uses local slots. While we could in theory ignore symbols that 5106 // are undefined (in other words, dead) at the point where this exception was thrown, unfortunately 5107 // we can't do it in practice. The reason for this is that currently our liveness analysis is 5108 // coarse (it can determine whether a symbol has not been read with a particular type anywhere in 5109 // the function being compiled, but that's it), and a symbol being promoted to Object due to a 5110 // deoptimization will suddenly show up as "live for Object type", and previously dead U->O 5111 // conversions on loop entries will suddenly become alive in the deoptimized method which will then 5112 // expect a value for that slot in its continuation handler. If we had precise liveness analysis, we 5113 // could go back to excluding known dead symbols from the payload of the RewriteException. 5114 if(method.peekType() == Type.UNDEFINED) { 5115 method.dup(); 5116 } else { 5117 method.loadUndefined(Type.OBJECT); 5118 } 5119 args++; 5120 } 5121 if(Character.isUpperCase(typeDesc)) { 5122 // Reached symbol boundary; reset flag for the next symbol. 5123 symbolHadValue = false; 5124 } 5125 lvarIndex += lvarType.getSlots(); 5126 } 5127 assert args > 0; 5128 // Delegate actual storing into array to an array populator utility method. 5129 //on the stack: 5130 // object array to be populated 5131 // start index 5132 // a lot of types 5133 method.dynamicArrayPopulatorCall(args + 1, firstArrayIndex); 5134 if(delegationLabel != null) { 5135 // We cascade to a prefix handler to fill out the rest of the local variables and throw the 5136 // RewriteException. 5137 assert !lastHandler; 5138 assert commonLvarSpec != null; 5139 // Must undefine the local variables that we have already processed for the sake of correct join on the 5140 // delegate label 5141 method.undefineLocalVariables(firstLvarIndex, true); 5142 final OptimismExceptionHandlerSpec nextSpec = handlerSpecs.get(handlerIndex + 1); 5143 // If the delegate immediately follows, and it's not a catch target (so it doesn't have array setup 5144 // code) don't bother emitting a jump, as we'd just jump to the next instruction. 5145 if(!nextSpec.lvarSpec.equals(commonLvarSpec) || nextSpec.catchTarget) { 5146 method._goto(delegationLabel); 5147 } 5148 } else { 5149 assert lastHandler; 5150 // Nothing to delegate to, so this handler must create and throw the RewriteException. 5151 // At this point we have the UnwarrantedOptimismException and the Object[] with local variables on 5152 // stack. We need to create a RewriteException, push two references to it below the constructor 5153 // arguments, invoke the constructor, and throw the exception. 5154 loadConstant(getByteCodeSymbolNames(fn)); 5155 if (isRestOf()) { 5156 loadConstant(getContinuationEntryPoints()); 5157 method.invoke(CREATE_REWRITE_EXCEPTION_REST_OF); 5158 } else { 5159 method.invoke(CREATE_REWRITE_EXCEPTION); 5160 } 5161 method.athrow(); 5162 } 5163 } 5164 return true; 5165 } 5166 5167 private static String[] getByteCodeSymbolNames(final FunctionNode fn) { 5168 // Only names of local variables on the function level are captured. This information is used to reduce 5169 // deoptimizations, so as much as we can capture will help. We rely on the fact that function wide variables are 5170 // all live all the time, so the array passed to rewrite exception contains one element for every slotted symbol 5171 // here. 5172 final List<String> names = new ArrayList<>(); 5173 for (final Symbol symbol: fn.getBody().getSymbols()) { 5174 if (symbol.hasSlot()) { 5175 if (symbol.isScope()) { 5176 // slot + scope can only be true for parameters 5177 assert symbol.isParam(); 5178 names.add(null); 5179 } else { 5180 names.add(symbol.getName()); 5181 } 5182 } 5183 } 5184 return names.toArray(new String[names.size()]); 5185 } 5186 5187 private static String commonPrefix(final String s1, final String s2) { 5188 final int l1 = s1.length(); 5189 final int l = Math.min(l1, s2.length()); 5190 int lms = -1; // last matching symbol 5191 for(int i = 0; i < l; ++i) { 5192 final char c1 = s1.charAt(i); 5193 if(c1 != s2.charAt(i)) { 5194 return s1.substring(0, lms + 1); 5195 } else if(Character.isUpperCase(c1)) { 5196 lms = i; 5197 } 5198 } 5199 return l == l1 ? s1 : s2; 5200 } 5201 5202 private static class OptimismExceptionHandlerSpec implements Comparable<OptimismExceptionHandlerSpec> { 5203 private final String lvarSpec; 5204 private final boolean catchTarget; 5205 private boolean delegationTarget; 5206 5207 OptimismExceptionHandlerSpec(final String lvarSpec, final boolean catchTarget) { 5208 this.lvarSpec = lvarSpec; 5209 this.catchTarget = catchTarget; 5210 if(!catchTarget) { 5211 delegationTarget = true; 5212 } 5213 } 5214 5215 @Override 5216 public int compareTo(final OptimismExceptionHandlerSpec o) { 5217 return lvarSpec.compareTo(o.lvarSpec); 5218 } 5219 5220 @Override 5221 public String toString() { 5222 final StringBuilder b = new StringBuilder(64).append("[HandlerSpec ").append(lvarSpec); 5223 if(catchTarget) { 5224 b.append(", catchTarget"); 5225 } 5226 if(delegationTarget) { 5227 b.append(", delegationTarget"); 5228 } 5229 return b.append("]").toString(); 5230 } 5231 } 5232 5233 private static class ContinuationInfo { 5234 private final Label handlerLabel; 5235 private Label targetLabel; // Label for the target instruction. 5236 int lvarCount; 5237 // Indices of local variables that need to be loaded on the stack when this node completes 5238 private int[] stackStoreSpec; 5239 // Types of values loaded on the stack 5240 private Type[] stackTypes; 5241 // If non-null, this node should perform the requisite type conversion 5242 private Type returnValueType; 5243 // If we are in the middle of an object literal initialization, we need to update the map 5244 private PropertyMap objectLiteralMap; 5245 // Object literal stack depth for object literal - not necessarily top if property is a tree 5246 private int objectLiteralStackDepth = -1; 5247 // The line number at the continuation point 5248 private int lineNumber; 5249 // The active catch label, in case the continuation point is in a try/catch block 5250 private Label catchLabel; 5251 // The number of scopes that need to be popped before control is transferred to the catch label. 5252 private int exceptionScopePops; 5253 5254 ContinuationInfo() { 5255 this.handlerLabel = new Label("continuation_handler"); 5256 } 5257 5258 Label getHandlerLabel() { 5259 return handlerLabel; 5260 } 5261 5262 boolean hasTargetLabel() { 5263 return targetLabel != null; 5264 } 5265 5266 Label getTargetLabel() { 5267 return targetLabel; 5268 } 5269 5270 void setTargetLabel(final Label targetLabel) { 5271 this.targetLabel = targetLabel; 5272 } 5273 5274 int[] getStackStoreSpec() { 5275 return stackStoreSpec.clone(); 5276 } 5277 5278 void setStackStoreSpec(final int[] stackStoreSpec) { 5279 this.stackStoreSpec = stackStoreSpec; 5280 } 5281 5282 Type[] getStackTypes() { 5283 return stackTypes.clone(); 5284 } 5285 5286 void setStackTypes(final Type[] stackTypes) { 5287 this.stackTypes = stackTypes; 5288 } 5289 5290 Type getReturnValueType() { 5291 return returnValueType; 5292 } 5293 5294 void setReturnValueType(final Type returnValueType) { 5295 this.returnValueType = returnValueType; 5296 } 5297 5298 int getObjectLiteralStackDepth() { 5299 return objectLiteralStackDepth; 5300 } 5301 5302 void setObjectLiteralStackDepth(final int objectLiteralStackDepth) { 5303 this.objectLiteralStackDepth = objectLiteralStackDepth; 5304 } 5305 5306 PropertyMap getObjectLiteralMap() { 5307 return objectLiteralMap; 5308 } 5309 5310 void setObjectLiteralMap(final PropertyMap objectLiteralMap) { 5311 this.objectLiteralMap = objectLiteralMap; 5312 } 5313 5314 @Override 5315 public String toString() { 5316 return "[localVariableTypes=" + targetLabel.getStack().getLocalVariableTypesCopy() + ", stackStoreSpec=" + 5317 Arrays.toString(stackStoreSpec) + ", returnValueType=" + returnValueType + "]"; 5318 } 5319 } 5320 5321 private ContinuationInfo getContinuationInfo() { 5322 return continuationInfo; 5323 } 5324 5325 private void generateContinuationHandler() { 5326 if (!isRestOf()) { 5327 return; 5328 } 5329 5330 final ContinuationInfo ci = getContinuationInfo(); 5331 method.label(ci.getHandlerLabel()); 5332 5333 // There should never be an exception thrown from the continuation handler, but in case there is (meaning, 5334 // Nashorn has a bug), then line number 0 will be an indication of where it came from (line numbers are Uint16). 5335 method.lineNumber(0); 5336 5337 final Label.Stack stack = ci.getTargetLabel().getStack(); 5338 final List<Type> lvarTypes = stack.getLocalVariableTypesCopy(); 5339 final BitSet symbolBoundary = stack.getSymbolBoundaryCopy(); 5340 final int lvarCount = ci.lvarCount; 5341 5342 final Type rewriteExceptionType = Type.typeFor(RewriteException.class); 5343 // Store the RewriteException into an unused local variable slot. 5344 method.load(rewriteExceptionType, 0); 5345 method.storeTemp(rewriteExceptionType, lvarCount); 5346 // Get local variable array 5347 method.load(rewriteExceptionType, 0); 5348 method.invoke(RewriteException.GET_BYTECODE_SLOTS); 5349 // Store local variables. Note that deoptimization might introduce new value types for existing local variables, 5350 // so we must use both liveLocals and symbolBoundary, as in some cases (when the continuation is inside of a try 5351 // block) we need to store the incoming value into multiple slots. The optimism exception handlers will have 5352 // exactly one array element for every symbol that uses bytecode storage. If in the originating method the value 5353 // was undefined, there will be an explicit Undefined value in the array. 5354 int arrayIndex = 0; 5355 for(int lvarIndex = 0; lvarIndex < lvarCount;) { 5356 final Type lvarType = lvarTypes.get(lvarIndex); 5357 if(!lvarType.isUnknown()) { 5358 method.dup(); 5359 method.load(arrayIndex).arrayload(); 5360 final Class<?> typeClass = lvarType.getTypeClass(); 5361 // Deoptimization in array initializers can cause arrays to undergo component type widening 5362 if(typeClass == long[].class) { 5363 method.load(rewriteExceptionType, lvarCount); 5364 method.invoke(RewriteException.TO_LONG_ARRAY); 5365 } else if(typeClass == double[].class) { 5366 method.load(rewriteExceptionType, lvarCount); 5367 method.invoke(RewriteException.TO_DOUBLE_ARRAY); 5368 } else if(typeClass == Object[].class) { 5369 method.load(rewriteExceptionType, lvarCount); 5370 method.invoke(RewriteException.TO_OBJECT_ARRAY); 5371 } else { 5372 if(!(typeClass.isPrimitive() || typeClass == Object.class)) { 5373 // NOTE: this can only happen with dead stores. E.g. for the program "1; []; f();" in which the 5374 // call to f() will deoptimize the call site, but it'll expect :return to have the type 5375 // NativeArray. However, in the more optimal version, :return's only live type is int, therefore 5376 // "{O}:return = []" is a dead store, and the variable will be sent into the continuation as 5377 // Undefined, however NativeArray can't hold Undefined instance. 5378 method.loadType(Type.getInternalName(typeClass)); 5379 method.invoke(RewriteException.INSTANCE_OR_NULL); 5380 } 5381 method.convert(lvarType); 5382 } 5383 method.storeHidden(lvarType, lvarIndex, false); 5384 } 5385 final int nextLvarIndex = lvarIndex + lvarType.getSlots(); 5386 if(symbolBoundary.get(nextLvarIndex - 1)) { 5387 ++arrayIndex; 5388 } 5389 lvarIndex = nextLvarIndex; 5390 } 5391 if (AssertsEnabled.assertsEnabled()) { 5392 method.load(arrayIndex); 5393 method.invoke(RewriteException.ASSERT_ARRAY_LENGTH); 5394 } else { 5395 method.pop(); 5396 } 5397 5398 final int[] stackStoreSpec = ci.getStackStoreSpec(); 5399 final Type[] stackTypes = ci.getStackTypes(); 5400 final boolean isStackEmpty = stackStoreSpec.length == 0; 5401 boolean replacedObjectLiteralMap = false; 5402 if(!isStackEmpty) { 5403 // Load arguments on the stack 5404 final int objectLiteralStackDepth = ci.getObjectLiteralStackDepth(); 5405 for(int i = 0; i < stackStoreSpec.length; ++i) { 5406 final int slot = stackStoreSpec[i]; 5407 method.load(lvarTypes.get(slot), slot); 5408 method.convert(stackTypes[i]); 5409 // stack: s0=object literal being initialized 5410 // change map of s0 so that the property we are initializing when we failed 5411 // is now ci.returnValueType 5412 if (i == objectLiteralStackDepth) { 5413 method.dup(); 5414 assert ci.getObjectLiteralMap() != null; 5415 assert ScriptObject.class.isAssignableFrom(method.peekType().getTypeClass()) : method.peekType().getTypeClass() + " is not a script object"; 5416 loadConstant(ci.getObjectLiteralMap()); 5417 method.invoke(ScriptObject.SET_MAP); 5418 replacedObjectLiteralMap = true; 5419 } 5420 } 5421 } 5422 // Must have emitted the code for replacing the map of an object literal if we have a set object literal stack depth 5423 assert ci.getObjectLiteralStackDepth() == -1 || replacedObjectLiteralMap; 5424 // Load RewriteException back. 5425 method.load(rewriteExceptionType, lvarCount); 5426 // Get rid of the stored reference 5427 method.loadNull(); 5428 method.storeHidden(Type.OBJECT, lvarCount); 5429 // Mark it dead 5430 method.markDeadSlots(lvarCount, Type.OBJECT.getSlots()); 5431 5432 // Load return value on the stack 5433 method.invoke(RewriteException.GET_RETURN_VALUE); 5434 5435 final Type returnValueType = ci.getReturnValueType(); 5436 5437 // Set up an exception handler for primitive type conversion of return value if needed 5438 boolean needsCatch = false; 5439 final Label targetCatchLabel = ci.catchLabel; 5440 Label _try = null; 5441 if(returnValueType.isPrimitive()) { 5442 // If the conversion throws an exception, we want to report the line number of the continuation point. 5443 method.lineNumber(ci.lineNumber); 5444 5445 if(targetCatchLabel != METHOD_BOUNDARY) { 5446 _try = new Label(""); 5447 method.label(_try); 5448 needsCatch = true; 5449 } 5450 } 5451 5452 // Convert return value 5453 method.convert(returnValueType); 5454 5455 final int scopePopCount = needsCatch ? ci.exceptionScopePops : 0; 5456 5457 // Declare a try/catch for the conversion. If no scopes need to be popped until the target catch block, just 5458 // jump into it. Otherwise, we'll need to create a scope-popping catch block below. 5459 final Label catchLabel = scopePopCount > 0 ? new Label("") : targetCatchLabel; 5460 if(needsCatch) { 5461 final Label _end_try = new Label(""); 5462 method.label(_end_try); 5463 method._try(_try, _end_try, catchLabel); 5464 } 5465 5466 // Jump to continuation point 5467 method._goto(ci.getTargetLabel()); 5468 5469 // Make a scope-popping exception delegate if needed 5470 if(catchLabel != targetCatchLabel) { 5471 method.lineNumber(0); 5472 assert scopePopCount > 0; 5473 method._catch(catchLabel); 5474 popScopes(scopePopCount); 5475 method.uncheckedGoto(targetCatchLabel); 5476 } 5477 } 5478 5479 /** 5480 * Interface implemented by object creators that support splitting over multiple methods. 5481 */ 5482 interface SplitLiteralCreator { 5483 /** 5484 * Generate code to populate a range of the literal object. A reference to the object 5485 * should be left on the stack when the method terminates. 5486 * 5487 * @param method the method emitter 5488 * @param type the type of the literal object 5489 * @param slot the local slot containing the literal object 5490 * @param start the start index (inclusive) 5491 * @param end the end index (exclusive) 5492 */ 5493 void populateRange(MethodEmitter method, Type type, int slot, int start, int end); 5494 } 5495} 5496