CodeGenerator.java revision 1245:c55ce3738888
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.FunctionNode.CompilationState; 97import jdk.nashorn.internal.ir.GetSplitState; 98import jdk.nashorn.internal.ir.IdentNode; 99import jdk.nashorn.internal.ir.IfNode; 100import jdk.nashorn.internal.ir.IndexNode; 101import jdk.nashorn.internal.ir.JoinPredecessorExpression; 102import jdk.nashorn.internal.ir.JumpStatement; 103import jdk.nashorn.internal.ir.JumpToInlinedFinally; 104import jdk.nashorn.internal.ir.LabelNode; 105import jdk.nashorn.internal.ir.LexicalContext; 106import jdk.nashorn.internal.ir.LexicalContextNode; 107import jdk.nashorn.internal.ir.LiteralNode; 108import jdk.nashorn.internal.ir.LiteralNode.ArrayLiteralNode; 109import jdk.nashorn.internal.ir.LiteralNode.ArrayLiteralNode.ArrayUnit; 110import jdk.nashorn.internal.ir.LiteralNode.PrimitiveLiteralNode; 111import jdk.nashorn.internal.ir.LocalVariableConversion; 112import jdk.nashorn.internal.ir.LoopNode; 113import jdk.nashorn.internal.ir.Node; 114import jdk.nashorn.internal.ir.ObjectNode; 115import jdk.nashorn.internal.ir.Optimistic; 116import jdk.nashorn.internal.ir.PropertyNode; 117import jdk.nashorn.internal.ir.ReturnNode; 118import jdk.nashorn.internal.ir.RuntimeNode; 119import jdk.nashorn.internal.ir.RuntimeNode.Request; 120import jdk.nashorn.internal.ir.SetSplitState; 121import jdk.nashorn.internal.ir.SplitReturn; 122import jdk.nashorn.internal.ir.Statement; 123import jdk.nashorn.internal.ir.SwitchNode; 124import jdk.nashorn.internal.ir.Symbol; 125import jdk.nashorn.internal.ir.TernaryNode; 126import jdk.nashorn.internal.ir.ThrowNode; 127import jdk.nashorn.internal.ir.TryNode; 128import jdk.nashorn.internal.ir.UnaryNode; 129import jdk.nashorn.internal.ir.VarNode; 130import jdk.nashorn.internal.ir.WhileNode; 131import jdk.nashorn.internal.ir.WithNode; 132import jdk.nashorn.internal.ir.visitor.NodeOperatorVisitor; 133import jdk.nashorn.internal.ir.visitor.NodeVisitor; 134import jdk.nashorn.internal.objects.Global; 135import jdk.nashorn.internal.objects.ScriptFunctionImpl; 136import jdk.nashorn.internal.parser.Lexer.RegexToken; 137import jdk.nashorn.internal.parser.TokenType; 138import jdk.nashorn.internal.runtime.Context; 139import jdk.nashorn.internal.runtime.Debug; 140import jdk.nashorn.internal.runtime.ECMAException; 141import jdk.nashorn.internal.runtime.JSType; 142import jdk.nashorn.internal.runtime.OptimisticReturnFilters; 143import jdk.nashorn.internal.runtime.PropertyMap; 144import jdk.nashorn.internal.runtime.RecompilableScriptFunctionData; 145import jdk.nashorn.internal.runtime.RewriteException; 146import jdk.nashorn.internal.runtime.Scope; 147import jdk.nashorn.internal.runtime.ScriptEnvironment; 148import jdk.nashorn.internal.runtime.ScriptFunction; 149import jdk.nashorn.internal.runtime.ScriptObject; 150import jdk.nashorn.internal.runtime.ScriptRuntime; 151import jdk.nashorn.internal.runtime.Source; 152import jdk.nashorn.internal.runtime.Undefined; 153import jdk.nashorn.internal.runtime.UnwarrantedOptimismException; 154import jdk.nashorn.internal.runtime.arrays.ArrayData; 155import jdk.nashorn.internal.runtime.linker.LinkerCallSite; 156import jdk.nashorn.internal.runtime.logging.DebugLogger; 157import jdk.nashorn.internal.runtime.logging.Loggable; 158import jdk.nashorn.internal.runtime.logging.Logger; 159import jdk.nashorn.internal.runtime.options.Options; 160 161/** 162 * This is the lowest tier of the code generator. It takes lowered ASTs emitted 163 * from Lower and emits Java byte code. The byte code emission logic is broken 164 * out into MethodEmitter. MethodEmitter works internally with a type stack, and 165 * keeps track of the contents of the byte code stack. This way we avoid a large 166 * number of special cases on the form 167 * <pre> 168 * if (type == INT) { 169 * visitInsn(ILOAD, slot); 170 * } else if (type == DOUBLE) { 171 * visitInsn(DOUBLE, slot); 172 * } 173 * </pre> 174 * This quickly became apparent when the code generator was generalized to work 175 * with all types, and not just numbers or objects. 176 * <p> 177 * The CodeGenerator visits nodes only once, tags them as resolved and emits 178 * bytecode for them. 179 */ 180@Logger(name="codegen") 181final class CodeGenerator extends NodeOperatorVisitor<CodeGeneratorLexicalContext> implements Loggable { 182 183 private static final Type SCOPE_TYPE = Type.typeFor(ScriptObject.class); 184 185 private static final String GLOBAL_OBJECT = Type.getInternalName(Global.class); 186 187 private static final Call CREATE_REWRITE_EXCEPTION = CompilerConstants.staticCallNoLookup(RewriteException.class, 188 "create", RewriteException.class, UnwarrantedOptimismException.class, Object[].class, String[].class); 189 private static final Call CREATE_REWRITE_EXCEPTION_REST_OF = CompilerConstants.staticCallNoLookup(RewriteException.class, 190 "create", RewriteException.class, UnwarrantedOptimismException.class, Object[].class, String[].class, int[].class); 191 192 private static final Call ENSURE_INT = CompilerConstants.staticCallNoLookup(OptimisticReturnFilters.class, 193 "ensureInt", int.class, Object.class, int.class); 194 private static final Call ENSURE_LONG = CompilerConstants.staticCallNoLookup(OptimisticReturnFilters.class, 195 "ensureLong", long.class, Object.class, int.class); 196 private static final Call ENSURE_NUMBER = CompilerConstants.staticCallNoLookup(OptimisticReturnFilters.class, 197 "ensureNumber", double.class, Object.class, int.class); 198 199 private static final Call CREATE_FUNCTION_OBJECT = CompilerConstants.staticCallNoLookup(ScriptFunctionImpl.class, 200 "create", ScriptFunction.class, Object[].class, int.class, ScriptObject.class); 201 private static final Call CREATE_FUNCTION_OBJECT_NO_SCOPE = CompilerConstants.staticCallNoLookup(ScriptFunctionImpl.class, 202 "create", ScriptFunction.class, Object[].class, int.class); 203 204 private static final Call TO_NUMBER_FOR_EQ = CompilerConstants.staticCallNoLookup(JSType.class, 205 "toNumberForEq", double.class, Object.class); 206 private static final Call TO_NUMBER_FOR_STRICT_EQ = CompilerConstants.staticCallNoLookup(JSType.class, 207 "toNumberForStrictEq", double.class, Object.class); 208 209 210 private static final Class<?> ITERATOR_CLASS = Iterator.class; 211 static { 212 assert ITERATOR_CLASS == CompilerConstants.ITERATOR_PREFIX.type(); 213 } 214 private static final Type ITERATOR_TYPE = Type.typeFor(ITERATOR_CLASS); 215 private static final Type EXCEPTION_TYPE = Type.typeFor(CompilerConstants.EXCEPTION_PREFIX.type()); 216 217 private static final Integer INT_ZERO = Integer.valueOf(0); 218 219 /** Constant data & installation. The only reason the compiler keeps this is because it is assigned 220 * by reflection in class installation */ 221 private final Compiler compiler; 222 223 /** Is the current code submitted by 'eval' call? */ 224 private final boolean evalCode; 225 226 /** Call site flags given to the code generator to be used for all generated call sites */ 227 private final int callSiteFlags; 228 229 /** How many regexp fields have been emitted */ 230 private int regexFieldCount; 231 232 /** Line number for last statement. If we encounter a new line number, line number bytecode information 233 * needs to be generated */ 234 private int lastLineNumber = -1; 235 236 /** When should we stop caching regexp expressions in fields to limit bytecode size? */ 237 private static final int MAX_REGEX_FIELDS = 2 * 1024; 238 239 /** Current method emitter */ 240 private MethodEmitter method; 241 242 /** Current compile unit */ 243 private CompileUnit unit; 244 245 private final DebugLogger log; 246 247 /** From what size should we use spill instead of fields for JavaScript objects? */ 248 private static final int OBJECT_SPILL_THRESHOLD = Options.getIntProperty("nashorn.spill.threshold", 256); 249 250 private final Set<String> emittedMethods = new HashSet<>(); 251 252 // Function Id -> ContinuationInfo. Used by compilation of rest-of function only. 253 private final Map<Integer, ContinuationInfo> fnIdToContinuationInfo = new HashMap<>(); 254 255 private final Deque<Label> scopeEntryLabels = new ArrayDeque<>(); 256 257 private static final Label METHOD_BOUNDARY = new Label(""); 258 private final Deque<Label> catchLabels = new ArrayDeque<>(); 259 // Number of live locals on entry to (and thus also break from) labeled blocks. 260 private final IntDeque labeledBlockBreakLiveLocals = new IntDeque(); 261 262 //is this a rest of compilation 263 private final int[] continuationEntryPoints; 264 265 /** 266 * Constructor. 267 * 268 * @param compiler 269 */ 270 CodeGenerator(final Compiler compiler, final int[] continuationEntryPoints) { 271 super(new CodeGeneratorLexicalContext()); 272 this.compiler = compiler; 273 this.evalCode = compiler.getSource().isEvalCode(); 274 this.continuationEntryPoints = continuationEntryPoints; 275 this.callSiteFlags = compiler.getScriptEnvironment()._callsite_flags; 276 this.log = initLogger(compiler.getContext()); 277 } 278 279 @Override 280 public DebugLogger getLogger() { 281 return log; 282 } 283 284 @Override 285 public DebugLogger initLogger(final Context context) { 286 return context.getLogger(this.getClass()); 287 } 288 289 /** 290 * Gets the call site flags, adding the strict flag if the current function 291 * being generated is in strict mode 292 * 293 * @return the correct flags for a call site in the current function 294 */ 295 int getCallSiteFlags() { 296 return lc.getCurrentFunction().getCallSiteFlags() | callSiteFlags; 297 } 298 299 /** 300 * Are we generating code for 'eval' code? 301 * @return true if currently compiled code is 'eval' code. 302 */ 303 boolean isEvalCode() { 304 return evalCode; 305 } 306 307 /** 308 * Are we using dual primitive/object field representation? 309 * @return true if using dual field representation, false for object-only fields 310 */ 311 boolean useDualFields() { 312 return compiler.getContext().useDualFields(); 313 } 314 315 /** 316 * Load an identity node 317 * 318 * @param identNode an identity node to load 319 * @return the method generator used 320 */ 321 private MethodEmitter loadIdent(final IdentNode identNode, final TypeBounds resultBounds) { 322 checkTemporalDeadZone(identNode); 323 final Symbol symbol = identNode.getSymbol(); 324 325 if (!symbol.isScope()) { 326 final Type type = identNode.getType(); 327 if(type == Type.UNDEFINED) { 328 return method.loadUndefined(resultBounds.widest); 329 } 330 331 assert symbol.hasSlot() || symbol.isParam(); 332 return method.load(identNode); 333 } 334 335 assert identNode.getSymbol().isScope() : identNode + " is not in scope!"; 336 final int flags = CALLSITE_SCOPE | getCallSiteFlags(); 337 if (isFastScope(symbol)) { 338 // Only generate shared scope getter for fast-scope symbols so we know we can dial in correct scope. 339 if (symbol.getUseCount() > SharedScopeCall.FAST_SCOPE_GET_THRESHOLD && !isOptimisticOrRestOf()) { 340 method.loadCompilerConstant(SCOPE); 341 // As shared scope vars are only used in non-optimistic compilation, we switch from using TypeBounds to 342 // just a single definitive type, resultBounds.widest. 343 loadSharedScopeVar(resultBounds.widest, symbol, flags); 344 } else { 345 new LoadFastScopeVar(identNode, resultBounds, flags).emit(); 346 } 347 } else { 348 //slow scope load, we have no proto depth 349 new LoadScopeVar(identNode, resultBounds, flags).emit(); 350 } 351 352 return method; 353 } 354 355 // Any access to LET and CONST variables before their declaration must throw ReferenceError. 356 // This is called the temporal dead zone (TDZ). See https://gist.github.com/rwaldron/f0807a758aa03bcdd58a 357 private void checkTemporalDeadZone(final IdentNode identNode) { 358 if (identNode.isDead()) { 359 method.load(identNode.getSymbol().getName()).invoke(ScriptRuntime.THROW_REFERENCE_ERROR); 360 } 361 } 362 363 // Runtime check for assignment to ES6 const 364 private void checkAssignTarget(final Expression expression) { 365 if (expression instanceof IdentNode && ((IdentNode)expression).getSymbol().isConst()) { 366 method.load(((IdentNode)expression).getSymbol().getName()).invoke(ScriptRuntime.THROW_CONST_TYPE_ERROR); 367 } 368 } 369 370 private boolean isRestOf() { 371 return continuationEntryPoints != null; 372 } 373 374 private boolean isOptimisticOrRestOf() { 375 return useOptimisticTypes() || isRestOf(); 376 } 377 378 private boolean isCurrentContinuationEntryPoint(final int programPoint) { 379 return isRestOf() && getCurrentContinuationEntryPoint() == programPoint; 380 } 381 382 private int[] getContinuationEntryPoints() { 383 return isRestOf() ? continuationEntryPoints : null; 384 } 385 386 private int getCurrentContinuationEntryPoint() { 387 return isRestOf() ? continuationEntryPoints[0] : INVALID_PROGRAM_POINT; 388 } 389 390 private boolean isContinuationEntryPoint(final int programPoint) { 391 if (isRestOf()) { 392 assert continuationEntryPoints != null; 393 for (final int cep : continuationEntryPoints) { 394 if (cep == programPoint) { 395 return true; 396 } 397 } 398 } 399 return false; 400 } 401 402 /** 403 * Check if this symbol can be accessed directly with a putfield or getfield or dynamic load 404 * 405 * @param symbol symbol to check for fast scope 406 * @return true if fast scope 407 */ 408 private boolean isFastScope(final Symbol symbol) { 409 if (!symbol.isScope()) { 410 return false; 411 } 412 413 if (!lc.inDynamicScope()) { 414 // If there's no with or eval in context, and the symbol is marked as scoped, it is fast scoped. Such a 415 // symbol must either be global, or its defining block must need scope. 416 assert symbol.isGlobal() || lc.getDefiningBlock(symbol).needsScope() : symbol.getName(); 417 return true; 418 } 419 420 if (symbol.isGlobal()) { 421 // Shortcut: if there's a with or eval in context, globals can't be fast scoped 422 return false; 423 } 424 425 // Otherwise, check if there's a dynamic scope between use of the symbol and its definition 426 final String name = symbol.getName(); 427 boolean previousWasBlock = false; 428 for (final Iterator<LexicalContextNode> it = lc.getAllNodes(); it.hasNext();) { 429 final LexicalContextNode node = it.next(); 430 if (node instanceof Block) { 431 // If this block defines the symbol, then we can fast scope the symbol. 432 final Block block = (Block)node; 433 if (block.getExistingSymbol(name) == symbol) { 434 assert block.needsScope(); 435 return true; 436 } 437 previousWasBlock = true; 438 } else { 439 if (node instanceof WithNode && previousWasBlock || node instanceof FunctionNode && ((FunctionNode)node).needsDynamicScope()) { 440 // If we hit a scope that can have symbols introduced into it at run time before finding the defining 441 // block, the symbol can't be fast scoped. A WithNode only counts if we've immediately seen a block 442 // before - its block. Otherwise, we are currently processing the WithNode's expression, and that's 443 // obviously not subjected to introducing new symbols. 444 return false; 445 } 446 previousWasBlock = false; 447 } 448 } 449 // Should've found the symbol defined in a block 450 throw new AssertionError(); 451 } 452 453 private MethodEmitter loadSharedScopeVar(final Type valueType, final Symbol symbol, final int flags) { 454 assert !isOptimisticOrRestOf(); 455 if (isFastScope(symbol)) { 456 method.load(getScopeProtoDepth(lc.getCurrentBlock(), symbol)); 457 } else { 458 method.load(-1); 459 } 460 return lc.getScopeGet(unit, symbol, valueType, flags | CALLSITE_FAST_SCOPE).generateInvoke(method); 461 } 462 463 private class LoadScopeVar extends OptimisticOperation { 464 final IdentNode identNode; 465 private final int flags; 466 467 LoadScopeVar(final IdentNode identNode, final TypeBounds resultBounds, final int flags) { 468 super(identNode, resultBounds); 469 this.identNode = identNode; 470 this.flags = flags; 471 } 472 473 @Override 474 void loadStack() { 475 method.loadCompilerConstant(SCOPE); 476 getProto(); 477 } 478 479 void getProto() { 480 //empty 481 } 482 483 @Override 484 void consumeStack() { 485 // If this is either __FILE__, __DIR__, or __LINE__ then load the property initially as Object as we'd convert 486 // it anyway for replaceLocationPropertyPlaceholder. 487 if(identNode.isCompileTimePropertyName()) { 488 method.dynamicGet(Type.OBJECT, identNode.getSymbol().getName(), flags, identNode.isFunction(), false); 489 replaceCompileTimeProperty(); 490 } else { 491 dynamicGet(identNode.getSymbol().getName(), flags, identNode.isFunction(), false); 492 } 493 } 494 } 495 496 private class LoadFastScopeVar extends LoadScopeVar { 497 LoadFastScopeVar(final IdentNode identNode, final TypeBounds resultBounds, final int flags) { 498 super(identNode, resultBounds, flags | CALLSITE_FAST_SCOPE); 499 } 500 501 @Override 502 void getProto() { 503 loadFastScopeProto(identNode.getSymbol(), false); 504 } 505 } 506 507 private MethodEmitter storeFastScopeVar(final Symbol symbol, final int flags) { 508 loadFastScopeProto(symbol, true); 509 method.dynamicSet(symbol.getName(), flags | CALLSITE_FAST_SCOPE, false); 510 return method; 511 } 512 513 private int getScopeProtoDepth(final Block startingBlock, final Symbol symbol) { 514 //walk up the chain from starting block and when we bump into the current function boundary, add the external 515 //information. 516 final FunctionNode fn = lc.getCurrentFunction(); 517 final int externalDepth = compiler.getScriptFunctionData(fn.getId()).getExternalSymbolDepth(symbol.getName()); 518 519 //count the number of scopes from this place to the start of the function 520 521 final int internalDepth = FindScopeDepths.findInternalDepth(lc, fn, startingBlock, symbol); 522 final int scopesToStart = FindScopeDepths.findScopesToStart(lc, fn, startingBlock); 523 int depth = 0; 524 if (internalDepth == -1) { 525 depth = scopesToStart + externalDepth; 526 } else { 527 assert internalDepth <= scopesToStart; 528 depth = internalDepth; 529 } 530 531 return depth; 532 } 533 534 private void loadFastScopeProto(final Symbol symbol, final boolean swap) { 535 final int depth = getScopeProtoDepth(lc.getCurrentBlock(), symbol); 536 assert depth != -1 : "Couldn't find scope depth for symbol " + symbol.getName() + " in " + lc.getCurrentFunction(); 537 if (depth > 0) { 538 if (swap) { 539 method.swap(); 540 } 541 for (int i = 0; i < depth; i++) { 542 method.invoke(ScriptObject.GET_PROTO); 543 } 544 if (swap) { 545 method.swap(); 546 } 547 } 548 } 549 550 /** 551 * Generate code that loads this node to the stack, not constraining its type 552 * 553 * @param expr node to load 554 * 555 * @return the method emitter used 556 */ 557 private MethodEmitter loadExpressionUnbounded(final Expression expr) { 558 return loadExpression(expr, TypeBounds.UNBOUNDED); 559 } 560 561 private MethodEmitter loadExpressionAsObject(final Expression expr) { 562 return loadExpression(expr, TypeBounds.OBJECT); 563 } 564 565 MethodEmitter loadExpressionAsBoolean(final Expression expr) { 566 return loadExpression(expr, TypeBounds.BOOLEAN); 567 } 568 569 // Test whether conversion from source to target involves a call of ES 9.1 ToPrimitive 570 // with possible side effects from calling an object's toString or valueOf methods. 571 private static boolean noToPrimitiveConversion(final Type source, final Type target) { 572 // Object to boolean conversion does not cause ToPrimitive call 573 return source.isJSPrimitive() || !target.isJSPrimitive() || target.isBoolean(); 574 } 575 576 MethodEmitter loadBinaryOperands(final BinaryNode binaryNode) { 577 return loadBinaryOperands(binaryNode.lhs(), binaryNode.rhs(), TypeBounds.UNBOUNDED.notWiderThan(binaryNode.getWidestOperandType()), false, false); 578 } 579 580 private MethodEmitter loadBinaryOperands(final Expression lhs, final Expression rhs, final TypeBounds explicitOperandBounds, final boolean baseAlreadyOnStack, final boolean forceConversionSeparation) { 581 // ECMAScript 5.1 specification (sections 11.5-11.11 and 11.13) prescribes that when evaluating a binary 582 // expression "LEFT op RIGHT", the order of operations must be: LOAD LEFT, LOAD RIGHT, CONVERT LEFT, CONVERT 583 // RIGHT, EXECUTE OP. Unfortunately, doing it in this order defeats potential optimizations that arise when we 584 // can combine a LOAD with a CONVERT operation (e.g. use a dynamic getter with the conversion target type as its 585 // return value). What we do here is reorder LOAD RIGHT and CONVERT LEFT when possible; it is possible only when 586 // we can prove that executing CONVERT LEFT can't have a side effect that changes the value of LOAD RIGHT. 587 // Basically, if we know that either LEFT already is a primitive value, or does not have to be converted to 588 // a primitive value, or RIGHT is an expression that loads without side effects, then we can do the 589 // reordering and collapse LOAD/CONVERT into a single operation; otherwise we need to do the more costly 590 // separate operations to preserve specification semantics. 591 592 // Operands' load type should not be narrower than the narrowest of the individual operand types, nor narrower 593 // than the lower explicit bound, but it should also not be wider than 594 final Type lhsType = undefinedToNumber(lhs.getType()); 595 final Type rhsType = undefinedToNumber(rhs.getType()); 596 final Type narrowestOperandType = Type.narrowest(Type.widest(lhsType, rhsType), explicitOperandBounds.widest); 597 final TypeBounds operandBounds = explicitOperandBounds.notNarrowerThan(narrowestOperandType); 598 if (noToPrimitiveConversion(lhsType, explicitOperandBounds.widest) || rhs.isLocal()) { 599 // Can reorder. We might still need to separate conversion, but at least we can do it with reordering 600 if (forceConversionSeparation) { 601 // Can reorder, but can't move conversion into the operand as the operation depends on operands 602 // exact types for its overflow guarantees. E.g. with {L}{%I}expr1 {L}* {L}{%I}expr2 we are not allowed 603 // to merge {L}{%I} into {%L}, as that can cause subsequent overflows; test for JDK-8058610 contains 604 // concrete cases where this could happen. 605 final TypeBounds safeConvertBounds = TypeBounds.UNBOUNDED.notNarrowerThan(narrowestOperandType); 606 loadExpression(lhs, safeConvertBounds, baseAlreadyOnStack); 607 method.convert(operandBounds.within(method.peekType())); 608 loadExpression(rhs, safeConvertBounds, false); 609 method.convert(operandBounds.within(method.peekType())); 610 } else { 611 // Can reorder and move conversion into the operand. Combine load and convert into single operations. 612 loadExpression(lhs, operandBounds, baseAlreadyOnStack); 613 loadExpression(rhs, operandBounds, false); 614 } 615 } else { 616 // Can't reorder. Load and convert separately. 617 final TypeBounds safeConvertBounds = TypeBounds.UNBOUNDED.notNarrowerThan(narrowestOperandType); 618 loadExpression(lhs, safeConvertBounds, baseAlreadyOnStack); 619 final Type lhsLoadedType = method.peekType(); 620 loadExpression(rhs, safeConvertBounds, false); 621 final Type convertedLhsType = operandBounds.within(method.peekType()); 622 if (convertedLhsType != lhsLoadedType) { 623 // Do it conditionally, so that if conversion is a no-op we don't introduce a SWAP, SWAP. 624 method.swap().convert(convertedLhsType).swap(); 625 } 626 method.convert(operandBounds.within(method.peekType())); 627 } 628 assert Type.generic(method.peekType()) == operandBounds.narrowest; 629 assert Type.generic(method.peekType(1)) == operandBounds.narrowest; 630 631 return method; 632 } 633 634 /** 635 * Similar to {@link #loadBinaryOperands(BinaryNode)} but used specifically for loading operands of 636 * relational and equality comparison operators where at least one argument is non-object. (When both 637 * arguments are objects, we use {@link ScriptRuntime#EQ(Object, Object)}, {@link ScriptRuntime#LT(Object, Object)} 638 * etc. methods instead. Additionally, {@code ScriptRuntime} methods are used for strict (in)equality comparison 639 * of a boolean to anything that isn't a boolean.) This method handles the special case where one argument 640 * is an object and another is a primitive. Naively, these could also be delegated to {@code ScriptRuntime} methods 641 * by boxing the primitive. However, in all such cases the comparison is performed on numeric values, so it is 642 * possible to strength-reduce the operation by taking the number value of the object argument instead and 643 * comparing that to the primitive value ("primitive" will always be int, long, double, or boolean, and booleans 644 * compare as ints in these cases, so they're essentially numbers too). This method will emit code for loading 645 * arguments for such strength-reduced comparison. When both arguments are primitives, it just delegates to 646 * {@link #loadBinaryOperands(BinaryNode)}. 647 * 648 * @param cmp the comparison operation for which the operands need to be loaded on stack. 649 * @return the current method emitter. 650 */ 651 MethodEmitter loadComparisonOperands(final BinaryNode cmp) { 652 final Expression lhs = cmp.lhs(); 653 final Expression rhs = cmp.rhs(); 654 final Type lhsType = lhs.getType(); 655 final Type rhsType = rhs.getType(); 656 657 // Only used when not both are object, for that we have ScriptRuntime.LT etc. 658 assert !(lhsType.isObject() && rhsType.isObject()); 659 660 if (lhsType.isObject() || rhsType.isObject()) { 661 // We can reorder CONVERT LEFT and LOAD RIGHT only if either the left is a primitive, or the right 662 // is a local. This is more strict than loadBinaryNode reorder criteria, as it can allow JS primitive 663 // types too (notably: String is a JS primitive, but not a JVM primitive). We disallow String otherwise 664 // we would prematurely convert it to number when comparing to an optimistic expression, e.g. in 665 // "Hello" === String("Hello") the RHS starts out as an optimistic-int function call. If we allowed 666 // reordering, we'd end up with ToNumber("Hello") === {I%}String("Hello") that is obviously incorrect. 667 final boolean canReorder = lhsType.isPrimitive() || rhs.isLocal(); 668 // If reordering is allowed, and we're using a relational operator (that is, <, <=, >, >=) and not an 669 // (in)equality operator, then we encourage combining of LOAD and CONVERT into a single operation. 670 // This is because relational operators' semantics prescribes vanilla ToNumber() conversion, while 671 // (in)equality operators need the specialized JSType.toNumberFor[Strict]Equals. E.g. in the code snippet 672 // "i < obj.size" (where i is primitive and obj.size is statically an object), ".size" will thus be allowed 673 // to compile as: 674 // invokedynamic dyn:getProp|getElem|getMethod:size(Object;)D 675 // instead of the more costly: 676 // invokedynamic dyn:getProp|getElem|getMethod:size(Object;)Object 677 // invokestatic JSType.toNumber(Object)D 678 // Note also that even if this is allowed, we're only using it on operands that are non-optimistic, as 679 // otherwise the logic for determining effective optimistic-ness would turn an optimistic double return 680 // into a freely coercible one, which would be wrong. 681 final boolean canCombineLoadAndConvert = canReorder && cmp.isRelational(); 682 683 // LOAD LEFT 684 loadExpression(lhs, canCombineLoadAndConvert && !lhs.isOptimistic() ? TypeBounds.NUMBER : TypeBounds.UNBOUNDED); 685 686 final Type lhsLoadedType = method.peekType(); 687 final TokenType tt = cmp.tokenType(); 688 if (canReorder) { 689 // Can reorder CONVERT LEFT and LOAD RIGHT 690 emitObjectToNumberComparisonConversion(method, tt); 691 loadExpression(rhs, canCombineLoadAndConvert && !rhs.isOptimistic() ? TypeBounds.NUMBER : TypeBounds.UNBOUNDED); 692 } else { 693 // Can't reorder CONVERT LEFT and LOAD RIGHT 694 loadExpression(rhs, TypeBounds.UNBOUNDED); 695 if (lhsLoadedType != Type.NUMBER) { 696 method.swap(); 697 emitObjectToNumberComparisonConversion(method, tt); 698 method.swap(); 699 } 700 } 701 702 // CONVERT RIGHT 703 emitObjectToNumberComparisonConversion(method, tt); 704 return method; 705 } 706 // For primitive operands, just don't do anything special. 707 return loadBinaryOperands(cmp); 708 } 709 710 private static void emitObjectToNumberComparisonConversion(final MethodEmitter method, final TokenType tt) { 711 switch(tt) { 712 case EQ: 713 case NE: 714 if (method.peekType().isObject()) { 715 TO_NUMBER_FOR_EQ.invoke(method); 716 return; 717 } 718 break; 719 case EQ_STRICT: 720 case NE_STRICT: 721 if (method.peekType().isObject()) { 722 TO_NUMBER_FOR_STRICT_EQ.invoke(method); 723 return; 724 } 725 break; 726 default: 727 break; 728 } 729 method.convert(Type.NUMBER); 730 } 731 732 private static final Type undefinedToNumber(final Type type) { 733 return type == Type.UNDEFINED ? Type.NUMBER : type; 734 } 735 736 private static final class TypeBounds { 737 final Type narrowest; 738 final Type widest; 739 740 static final TypeBounds UNBOUNDED = new TypeBounds(Type.UNKNOWN, Type.OBJECT); 741 static final TypeBounds INT = exact(Type.INT); 742 static final TypeBounds NUMBER = exact(Type.NUMBER); 743 static final TypeBounds OBJECT = exact(Type.OBJECT); 744 static final TypeBounds BOOLEAN = exact(Type.BOOLEAN); 745 746 static TypeBounds exact(final Type type) { 747 return new TypeBounds(type, type); 748 } 749 750 TypeBounds(final Type narrowest, final Type widest) { 751 assert widest != null && widest != Type.UNDEFINED && widest != Type.UNKNOWN : widest; 752 assert narrowest != null && narrowest != Type.UNDEFINED : narrowest; 753 assert !narrowest.widerThan(widest) : narrowest + " wider than " + widest; 754 assert !widest.narrowerThan(narrowest); 755 this.narrowest = Type.generic(narrowest); 756 this.widest = Type.generic(widest); 757 } 758 759 TypeBounds notNarrowerThan(final Type type) { 760 return maybeNew(Type.narrowest(Type.widest(narrowest, type), widest), widest); 761 } 762 763 TypeBounds notWiderThan(final Type type) { 764 return maybeNew(Type.narrowest(narrowest, type), Type.narrowest(widest, type)); 765 } 766 767 boolean canBeNarrowerThan(final Type type) { 768 return narrowest.narrowerThan(type); 769 } 770 771 TypeBounds maybeNew(final Type newNarrowest, final Type newWidest) { 772 if(newNarrowest == narrowest && newWidest == widest) { 773 return this; 774 } 775 return new TypeBounds(newNarrowest, newWidest); 776 } 777 778 TypeBounds booleanToInt() { 779 return maybeNew(CodeGenerator.booleanToInt(narrowest), CodeGenerator.booleanToInt(widest)); 780 } 781 782 TypeBounds objectToNumber() { 783 return maybeNew(CodeGenerator.objectToNumber(narrowest), CodeGenerator.objectToNumber(widest)); 784 } 785 786 Type within(final Type type) { 787 if(type.narrowerThan(narrowest)) { 788 return narrowest; 789 } 790 if(type.widerThan(widest)) { 791 return widest; 792 } 793 return type; 794 } 795 796 @Override 797 public String toString() { 798 return "[" + narrowest + ", " + widest + "]"; 799 } 800 } 801 802 private static Type booleanToInt(final Type t) { 803 return t == Type.BOOLEAN ? Type.INT : t; 804 } 805 806 private static Type objectToNumber(final Type t) { 807 return t.isObject() ? Type.NUMBER : t; 808 } 809 810 MethodEmitter loadExpressionAsType(final Expression expr, final Type type) { 811 if(type == Type.BOOLEAN) { 812 return loadExpressionAsBoolean(expr); 813 } else if(type == Type.UNDEFINED) { 814 assert expr.getType() == Type.UNDEFINED; 815 return loadExpressionAsObject(expr); 816 } 817 // having no upper bound preserves semantics of optimistic operations in the expression (by not having them 818 // converted early) and then applies explicit conversion afterwards. 819 return loadExpression(expr, TypeBounds.UNBOUNDED.notNarrowerThan(type)).convert(type); 820 } 821 822 private MethodEmitter loadExpression(final Expression expr, final TypeBounds resultBounds) { 823 return loadExpression(expr, resultBounds, false); 824 } 825 826 /** 827 * Emits code for evaluating an expression and leaving its value on top of the stack, narrowing or widening it if 828 * necessary. 829 * @param expr the expression to load 830 * @param resultBounds the incoming type bounds. The value on the top of the stack is guaranteed to not be of narrower 831 * type than the narrowest bound, or wider type than the widest bound after it is loaded. 832 * @param baseAlreadyOnStack true if the base of an access or index node is already on the stack. Used to avoid 833 * double evaluation of bases in self-assignment expressions to access and index nodes. {@code Type.OBJECT} is used 834 * to indicate the widest possible type. 835 * @return the method emitter 836 */ 837 private MethodEmitter loadExpression(final Expression expr, final TypeBounds resultBounds, final boolean baseAlreadyOnStack) { 838 839 /* 840 * The load may be of type IdentNode, e.g. "x", AccessNode, e.g. "x.y" 841 * or IndexNode e.g. "x[y]". Both AccessNodes and IndexNodes are 842 * BaseNodes and the logic for loading the base object is reused 843 */ 844 final CodeGenerator codegen = this; 845 846 final boolean isCurrentDiscard = codegen.lc.isCurrentDiscard(expr); 847 expr.accept(new NodeOperatorVisitor<LexicalContext>(new LexicalContext()) { 848 @Override 849 public boolean enterIdentNode(final IdentNode identNode) { 850 loadIdent(identNode, resultBounds); 851 return false; 852 } 853 854 @Override 855 public boolean enterAccessNode(final AccessNode accessNode) { 856 new OptimisticOperation(accessNode, resultBounds) { 857 @Override 858 void loadStack() { 859 if (!baseAlreadyOnStack) { 860 loadExpressionAsObject(accessNode.getBase()); 861 } 862 assert method.peekType().isObject(); 863 } 864 @Override 865 void consumeStack() { 866 final int flags = getCallSiteFlags(); 867 dynamicGet(accessNode.getProperty(), flags, accessNode.isFunction(), accessNode.isIndex()); 868 } 869 }.emit(baseAlreadyOnStack ? 1 : 0); 870 return false; 871 } 872 873 @Override 874 public boolean enterIndexNode(final IndexNode indexNode) { 875 new OptimisticOperation(indexNode, resultBounds) { 876 @Override 877 void loadStack() { 878 if (!baseAlreadyOnStack) { 879 loadExpressionAsObject(indexNode.getBase()); 880 loadExpressionUnbounded(indexNode.getIndex()); 881 } 882 } 883 @Override 884 void consumeStack() { 885 final int flags = getCallSiteFlags(); 886 dynamicGetIndex(flags, indexNode.isFunction()); 887 } 888 }.emit(baseAlreadyOnStack ? 2 : 0); 889 return false; 890 } 891 892 @Override 893 public boolean enterFunctionNode(final FunctionNode functionNode) { 894 // function nodes will always leave a constructed function object on stack, no need to load the symbol 895 // separately as in enterDefault() 896 lc.pop(functionNode); 897 functionNode.accept(codegen); 898 // NOTE: functionNode.accept() will produce a different FunctionNode that we discard. This incidentally 899 // doesn't cause problems as we're never touching FunctionNode again after it's visited here - codegen 900 // is the last element in the compilation pipeline, the AST it produces is not used externally. So, we 901 // re-push the original functionNode. 902 lc.push(functionNode); 903 return false; 904 } 905 906 @Override 907 public boolean enterASSIGN(final BinaryNode binaryNode) { 908 checkAssignTarget(binaryNode.lhs()); 909 loadASSIGN(binaryNode); 910 return false; 911 } 912 913 @Override 914 public boolean enterASSIGN_ADD(final BinaryNode binaryNode) { 915 checkAssignTarget(binaryNode.lhs()); 916 loadASSIGN_ADD(binaryNode); 917 return false; 918 } 919 920 @Override 921 public boolean enterASSIGN_BIT_AND(final BinaryNode binaryNode) { 922 checkAssignTarget(binaryNode.lhs()); 923 loadASSIGN_BIT_AND(binaryNode); 924 return false; 925 } 926 927 @Override 928 public boolean enterASSIGN_BIT_OR(final BinaryNode binaryNode) { 929 checkAssignTarget(binaryNode.lhs()); 930 loadASSIGN_BIT_OR(binaryNode); 931 return false; 932 } 933 934 @Override 935 public boolean enterASSIGN_BIT_XOR(final BinaryNode binaryNode) { 936 checkAssignTarget(binaryNode.lhs()); 937 loadASSIGN_BIT_XOR(binaryNode); 938 return false; 939 } 940 941 @Override 942 public boolean enterASSIGN_DIV(final BinaryNode binaryNode) { 943 checkAssignTarget(binaryNode.lhs()); 944 loadASSIGN_DIV(binaryNode); 945 return false; 946 } 947 948 @Override 949 public boolean enterASSIGN_MOD(final BinaryNode binaryNode) { 950 checkAssignTarget(binaryNode.lhs()); 951 loadASSIGN_MOD(binaryNode); 952 return false; 953 } 954 955 @Override 956 public boolean enterASSIGN_MUL(final BinaryNode binaryNode) { 957 checkAssignTarget(binaryNode.lhs()); 958 loadASSIGN_MUL(binaryNode); 959 return false; 960 } 961 962 @Override 963 public boolean enterASSIGN_SAR(final BinaryNode binaryNode) { 964 checkAssignTarget(binaryNode.lhs()); 965 loadASSIGN_SAR(binaryNode); 966 return false; 967 } 968 969 @Override 970 public boolean enterASSIGN_SHL(final BinaryNode binaryNode) { 971 checkAssignTarget(binaryNode.lhs()); 972 loadASSIGN_SHL(binaryNode); 973 return false; 974 } 975 976 @Override 977 public boolean enterASSIGN_SHR(final BinaryNode binaryNode) { 978 checkAssignTarget(binaryNode.lhs()); 979 loadASSIGN_SHR(binaryNode); 980 return false; 981 } 982 983 @Override 984 public boolean enterASSIGN_SUB(final BinaryNode binaryNode) { 985 checkAssignTarget(binaryNode.lhs()); 986 loadASSIGN_SUB(binaryNode); 987 return false; 988 } 989 990 @Override 991 public boolean enterCallNode(final CallNode callNode) { 992 return loadCallNode(callNode, resultBounds); 993 } 994 995 @Override 996 public boolean enterLiteralNode(final LiteralNode<?> literalNode) { 997 loadLiteral(literalNode, resultBounds); 998 return false; 999 } 1000 1001 @Override 1002 public boolean enterTernaryNode(final TernaryNode ternaryNode) { 1003 loadTernaryNode(ternaryNode, resultBounds); 1004 return false; 1005 } 1006 1007 @Override 1008 public boolean enterADD(final BinaryNode binaryNode) { 1009 loadADD(binaryNode, resultBounds); 1010 return false; 1011 } 1012 1013 @Override 1014 public boolean enterSUB(final UnaryNode unaryNode) { 1015 loadSUB(unaryNode, resultBounds); 1016 return false; 1017 } 1018 1019 @Override 1020 public boolean enterSUB(final BinaryNode binaryNode) { 1021 loadSUB(binaryNode, resultBounds); 1022 return false; 1023 } 1024 1025 @Override 1026 public boolean enterMUL(final BinaryNode binaryNode) { 1027 loadMUL(binaryNode, resultBounds); 1028 return false; 1029 } 1030 1031 @Override 1032 public boolean enterDIV(final BinaryNode binaryNode) { 1033 loadDIV(binaryNode, resultBounds); 1034 return false; 1035 } 1036 1037 @Override 1038 public boolean enterMOD(final BinaryNode binaryNode) { 1039 loadMOD(binaryNode, resultBounds); 1040 return false; 1041 } 1042 1043 @Override 1044 public boolean enterSAR(final BinaryNode binaryNode) { 1045 loadSAR(binaryNode); 1046 return false; 1047 } 1048 1049 @Override 1050 public boolean enterSHL(final BinaryNode binaryNode) { 1051 loadSHL(binaryNode); 1052 return false; 1053 } 1054 1055 @Override 1056 public boolean enterSHR(final BinaryNode binaryNode) { 1057 loadSHR(binaryNode); 1058 return false; 1059 } 1060 1061 @Override 1062 public boolean enterCOMMALEFT(final BinaryNode binaryNode) { 1063 loadCOMMALEFT(binaryNode, resultBounds); 1064 return false; 1065 } 1066 1067 @Override 1068 public boolean enterCOMMARIGHT(final BinaryNode binaryNode) { 1069 loadCOMMARIGHT(binaryNode, resultBounds); 1070 return false; 1071 } 1072 1073 @Override 1074 public boolean enterAND(final BinaryNode binaryNode) { 1075 loadAND_OR(binaryNode, resultBounds, true); 1076 return false; 1077 } 1078 1079 @Override 1080 public boolean enterOR(final BinaryNode binaryNode) { 1081 loadAND_OR(binaryNode, resultBounds, false); 1082 return false; 1083 } 1084 1085 @Override 1086 public boolean enterNOT(final UnaryNode unaryNode) { 1087 loadNOT(unaryNode); 1088 return false; 1089 } 1090 1091 @Override 1092 public boolean enterADD(final UnaryNode unaryNode) { 1093 loadADD(unaryNode, resultBounds); 1094 return false; 1095 } 1096 1097 @Override 1098 public boolean enterBIT_NOT(final UnaryNode unaryNode) { 1099 loadBIT_NOT(unaryNode); 1100 return false; 1101 } 1102 1103 @Override 1104 public boolean enterBIT_AND(final BinaryNode binaryNode) { 1105 loadBIT_AND(binaryNode); 1106 return false; 1107 } 1108 1109 @Override 1110 public boolean enterBIT_OR(final BinaryNode binaryNode) { 1111 loadBIT_OR(binaryNode); 1112 return false; 1113 } 1114 1115 @Override 1116 public boolean enterBIT_XOR(final BinaryNode binaryNode) { 1117 loadBIT_XOR(binaryNode); 1118 return false; 1119 } 1120 1121 @Override 1122 public boolean enterVOID(final UnaryNode unaryNode) { 1123 loadVOID(unaryNode, resultBounds); 1124 return false; 1125 } 1126 1127 @Override 1128 public boolean enterEQ(final BinaryNode binaryNode) { 1129 loadCmp(binaryNode, Condition.EQ); 1130 return false; 1131 } 1132 1133 @Override 1134 public boolean enterEQ_STRICT(final BinaryNode binaryNode) { 1135 loadCmp(binaryNode, Condition.EQ); 1136 return false; 1137 } 1138 1139 @Override 1140 public boolean enterGE(final BinaryNode binaryNode) { 1141 loadCmp(binaryNode, Condition.GE); 1142 return false; 1143 } 1144 1145 @Override 1146 public boolean enterGT(final BinaryNode binaryNode) { 1147 loadCmp(binaryNode, Condition.GT); 1148 return false; 1149 } 1150 1151 @Override 1152 public boolean enterLE(final BinaryNode binaryNode) { 1153 loadCmp(binaryNode, Condition.LE); 1154 return false; 1155 } 1156 1157 @Override 1158 public boolean enterLT(final BinaryNode binaryNode) { 1159 loadCmp(binaryNode, Condition.LT); 1160 return false; 1161 } 1162 1163 @Override 1164 public boolean enterNE(final BinaryNode binaryNode) { 1165 loadCmp(binaryNode, Condition.NE); 1166 return false; 1167 } 1168 1169 @Override 1170 public boolean enterNE_STRICT(final BinaryNode binaryNode) { 1171 loadCmp(binaryNode, Condition.NE); 1172 return false; 1173 } 1174 1175 @Override 1176 public boolean enterObjectNode(final ObjectNode objectNode) { 1177 loadObjectNode(objectNode); 1178 return false; 1179 } 1180 1181 @Override 1182 public boolean enterRuntimeNode(final RuntimeNode runtimeNode) { 1183 loadRuntimeNode(runtimeNode); 1184 return false; 1185 } 1186 1187 @Override 1188 public boolean enterNEW(final UnaryNode unaryNode) { 1189 loadNEW(unaryNode); 1190 return false; 1191 } 1192 1193 @Override 1194 public boolean enterDECINC(final UnaryNode unaryNode) { 1195 checkAssignTarget(unaryNode.getExpression()); 1196 loadDECINC(unaryNode); 1197 return false; 1198 } 1199 1200 @Override 1201 public boolean enterJoinPredecessorExpression(final JoinPredecessorExpression joinExpr) { 1202 loadMaybeDiscard(joinExpr, joinExpr.getExpression(), resultBounds); 1203 return false; 1204 } 1205 1206 @Override 1207 public boolean enterGetSplitState(final GetSplitState getSplitState) { 1208 method.loadScope(); 1209 method.invoke(Scope.GET_SPLIT_STATE); 1210 return false; 1211 } 1212 1213 @Override 1214 public boolean enterDefault(final Node otherNode) { 1215 // Must have handled all expressions that can legally be encountered. 1216 throw new AssertionError(otherNode.getClass().getName()); 1217 } 1218 }); 1219 if(!isCurrentDiscard) { 1220 coerceStackTop(resultBounds); 1221 } 1222 return method; 1223 } 1224 1225 private MethodEmitter coerceStackTop(final TypeBounds typeBounds) { 1226 return method.convert(typeBounds.within(method.peekType())); 1227 } 1228 1229 /** 1230 * Closes any still open entries for this block's local variables in the bytecode local variable table. 1231 * 1232 * @param block block containing symbols. 1233 */ 1234 private void closeBlockVariables(final Block block) { 1235 for (final Symbol symbol : block.getSymbols()) { 1236 if (symbol.isBytecodeLocal()) { 1237 method.closeLocalVariable(symbol, block.getBreakLabel()); 1238 } 1239 } 1240 } 1241 1242 @Override 1243 public boolean enterBlock(final Block block) { 1244 final Label entryLabel = block.getEntryLabel(); 1245 if (entryLabel.isBreakTarget()) { 1246 // Entry label is a break target only for an inlined finally block. 1247 assert !method.isReachable(); 1248 method.breakLabel(entryLabel, lc.getUsedSlotCount()); 1249 } else { 1250 method.label(entryLabel); 1251 } 1252 if(!method.isReachable()) { 1253 return false; 1254 } 1255 if(lc.isFunctionBody() && emittedMethods.contains(lc.getCurrentFunction().getName())) { 1256 return false; 1257 } 1258 initLocals(block); 1259 1260 assert lc.getUsedSlotCount() == method.getFirstTemp(); 1261 return true; 1262 } 1263 1264 private boolean useOptimisticTypes() { 1265 return !lc.inSplitNode() && compiler.useOptimisticTypes(); 1266 } 1267 1268 @Override 1269 public Node leaveBlock(final Block block) { 1270 popBlockScope(block); 1271 method.beforeJoinPoint(block); 1272 1273 closeBlockVariables(block); 1274 lc.releaseSlots(); 1275 assert !method.isReachable() || (lc.isFunctionBody() ? 0 : lc.getUsedSlotCount()) == method.getFirstTemp() : 1276 "reachable="+method.isReachable() + 1277 " isFunctionBody=" + lc.isFunctionBody() + 1278 " usedSlotCount=" + lc.getUsedSlotCount() + 1279 " firstTemp=" + method.getFirstTemp(); 1280 1281 return block; 1282 } 1283 1284 private void popBlockScope(final Block block) { 1285 final Label breakLabel = block.getBreakLabel(); 1286 1287 if(!block.needsScope() || lc.isFunctionBody()) { 1288 emitBlockBreakLabel(breakLabel); 1289 return; 1290 } 1291 1292 final Label beginTryLabel = scopeEntryLabels.pop(); 1293 final Label recoveryLabel = new Label("block_popscope_catch"); 1294 emitBlockBreakLabel(breakLabel); 1295 final boolean bodyCanThrow = breakLabel.isAfter(beginTryLabel); 1296 if(bodyCanThrow) { 1297 method._try(beginTryLabel, breakLabel, recoveryLabel); 1298 } 1299 1300 Label afterCatchLabel = null; 1301 1302 if(method.isReachable()) { 1303 popScope(); 1304 if(bodyCanThrow) { 1305 afterCatchLabel = new Label("block_after_catch"); 1306 method._goto(afterCatchLabel); 1307 } 1308 } 1309 1310 if(bodyCanThrow) { 1311 assert !method.isReachable(); 1312 method._catch(recoveryLabel); 1313 popScopeException(); 1314 method.athrow(); 1315 } 1316 if(afterCatchLabel != null) { 1317 method.label(afterCatchLabel); 1318 } 1319 } 1320 1321 private void emitBlockBreakLabel(final Label breakLabel) { 1322 // TODO: this is totally backwards. Block should not be breakable, LabelNode should be breakable. 1323 final LabelNode labelNode = lc.getCurrentBlockLabelNode(); 1324 if(labelNode != null) { 1325 // Only have conversions if we're reachable 1326 assert labelNode.getLocalVariableConversion() == null || method.isReachable(); 1327 method.beforeJoinPoint(labelNode); 1328 method.breakLabel(breakLabel, labeledBlockBreakLiveLocals.pop()); 1329 } else { 1330 method.label(breakLabel); 1331 } 1332 } 1333 1334 private void popScope() { 1335 popScopes(1); 1336 } 1337 1338 /** 1339 * Pop scope as part of an exception handler. Similar to {@code popScope()} but also takes care of adjusting the 1340 * number of scopes that needs to be popped in case a rest-of continuation handler encounters an exception while 1341 * performing a ToPrimitive conversion. 1342 */ 1343 private void popScopeException() { 1344 popScope(); 1345 final ContinuationInfo ci = getContinuationInfo(); 1346 if(ci != null) { 1347 final Label catchLabel = ci.catchLabel; 1348 if(catchLabel != METHOD_BOUNDARY && catchLabel == catchLabels.peek()) { 1349 ++ci.exceptionScopePops; 1350 } 1351 } 1352 } 1353 1354 private void popScopesUntil(final LexicalContextNode until) { 1355 popScopes(lc.getScopeNestingLevelTo(until)); 1356 } 1357 1358 private void popScopes(final int count) { 1359 if(count == 0) { 1360 return; 1361 } 1362 assert count > 0; // together with count == 0 check, asserts nonnegative count 1363 if (!method.hasScope()) { 1364 // We can sometimes invoke this method even if the method has no slot for the scope object. Typical example: 1365 // for(;;) { with({}) { break; } }. WithNode normally creates a scope, but if it uses no identifiers and 1366 // nothing else forces creation of a scope in the method, we just won't have the :scope local variable. 1367 return; 1368 } 1369 method.loadCompilerConstant(SCOPE); 1370 for(int i = 0; i < count; ++i) { 1371 method.invoke(ScriptObject.GET_PROTO); 1372 } 1373 method.storeCompilerConstant(SCOPE); 1374 } 1375 1376 @Override 1377 public boolean enterBreakNode(final BreakNode breakNode) { 1378 return enterJumpStatement(breakNode); 1379 } 1380 1381 @Override 1382 public boolean enterJumpToInlinedFinally(final JumpToInlinedFinally jumpToInlinedFinally) { 1383 return enterJumpStatement(jumpToInlinedFinally); 1384 } 1385 1386 private boolean enterJumpStatement(final JumpStatement jump) { 1387 if(!method.isReachable()) { 1388 return false; 1389 } 1390 enterStatement(jump); 1391 1392 method.beforeJoinPoint(jump); 1393 popScopesUntil(jump.getPopScopeLimit(lc)); 1394 final Label targetLabel = jump.getTargetLabel(lc); 1395 targetLabel.markAsBreakTarget(); 1396 method._goto(targetLabel); 1397 1398 return false; 1399 } 1400 1401 private int loadArgs(final List<Expression> args) { 1402 final int argCount = args.size(); 1403 // arg have already been converted to objects here. 1404 if (argCount > LinkerCallSite.ARGLIMIT) { 1405 loadArgsArray(args); 1406 return 1; 1407 } 1408 1409 for (final Expression arg : args) { 1410 assert arg != null; 1411 loadExpressionUnbounded(arg); 1412 } 1413 return argCount; 1414 } 1415 1416 private boolean loadCallNode(final CallNode callNode, final TypeBounds resultBounds) { 1417 lineNumber(callNode.getLineNumber()); 1418 1419 final List<Expression> args = callNode.getArgs(); 1420 final Expression function = callNode.getFunction(); 1421 final Block currentBlock = lc.getCurrentBlock(); 1422 final CodeGeneratorLexicalContext codegenLexicalContext = lc; 1423 1424 function.accept(new NodeVisitor<LexicalContext>(new LexicalContext()) { 1425 1426 private MethodEmitter sharedScopeCall(final IdentNode identNode, final int flags) { 1427 final Symbol symbol = identNode.getSymbol(); 1428 final boolean isFastScope = isFastScope(symbol); 1429 final int scopeCallFlags = flags | (isFastScope ? CALLSITE_FAST_SCOPE : 0); 1430 new OptimisticOperation(callNode, resultBounds) { 1431 @Override 1432 void loadStack() { 1433 method.loadCompilerConstant(SCOPE); 1434 if (isFastScope) { 1435 method.load(getScopeProtoDepth(currentBlock, symbol)); 1436 } else { 1437 method.load(-1); // Bypass fast-scope code in shared callsite 1438 } 1439 loadArgs(args); 1440 } 1441 @Override 1442 void consumeStack() { 1443 final Type[] paramTypes = method.getTypesFromStack(args.size()); 1444 // We have trouble finding e.g. in Type.typeFor(asm.Type) because it can't see the Context class 1445 // loader, so we need to weaken reference signatures to Object. 1446 for(int i = 0; i < paramTypes.length; ++i) { 1447 paramTypes[i] = Type.generic(paramTypes[i]); 1448 } 1449 // As shared scope calls are only used in non-optimistic compilation, we switch from using 1450 // TypeBounds to just a single definitive type, resultBounds.widest. 1451 final SharedScopeCall scopeCall = codegenLexicalContext.getScopeCall(unit, symbol, 1452 identNode.getType(), resultBounds.widest, paramTypes, scopeCallFlags); 1453 scopeCall.generateInvoke(method); 1454 } 1455 }.emit(); 1456 return method; 1457 } 1458 1459 private void scopeCall(final IdentNode ident, final int flags) { 1460 new OptimisticOperation(callNode, resultBounds) { 1461 int argsCount; 1462 @Override 1463 void loadStack() { 1464 loadExpressionAsObject(ident); // foo() makes no sense if foo == 3 1465 // ScriptFunction will see CALLSITE_SCOPE and will bind scope accordingly. 1466 method.loadUndefined(Type.OBJECT); //the 'this' 1467 argsCount = loadArgs(args); 1468 } 1469 @Override 1470 void consumeStack() { 1471 dynamicCall(2 + argsCount, flags); 1472 } 1473 }.emit(); 1474 } 1475 1476 private void evalCall(final IdentNode ident, final int flags) { 1477 final Label invoke_direct_eval = new Label("invoke_direct_eval"); 1478 final Label is_not_eval = new Label("is_not_eval"); 1479 final Label eval_done = new Label("eval_done"); 1480 1481 new OptimisticOperation(callNode, resultBounds) { 1482 int argsCount; 1483 @Override 1484 void loadStack() { 1485 /** 1486 * We want to load 'eval' to check if it is indeed global builtin eval. 1487 * If this eval call is inside a 'with' statement, dyn:getMethod|getProp|getElem 1488 * would be generated if ident is a "isFunction". But, that would result in a 1489 * bound function from WithObject. We don't want that as bound function as that 1490 * won't be detected as builtin eval. So, we make ident as "not a function" which 1491 * results in "dyn:getProp|getElem|getMethod" being generated and so WithObject 1492 * would return unbounded eval function. 1493 * 1494 * Example: 1495 * 1496 * var global = this; 1497 * function func() { 1498 * with({ eval: global.eval) { eval("var x = 10;") } 1499 * } 1500 */ 1501 loadExpressionAsObject(ident.setIsNotFunction()); // Type.OBJECT as foo() makes no sense if foo == 3 1502 globalIsEval(); 1503 method.ifeq(is_not_eval); 1504 1505 // Load up self (scope). 1506 method.loadCompilerConstant(SCOPE); 1507 final List<Expression> evalArgs = callNode.getEvalArgs().getArgs(); 1508 // load evaluated code 1509 loadExpressionAsObject(evalArgs.get(0)); 1510 // load second and subsequent args for side-effect 1511 final int numArgs = evalArgs.size(); 1512 for (int i = 1; i < numArgs; i++) { 1513 loadAndDiscard(evalArgs.get(i)); 1514 } 1515 method._goto(invoke_direct_eval); 1516 1517 method.label(is_not_eval); 1518 // load this time but with dyn:getMethod|getProp|getElem 1519 loadExpressionAsObject(ident); // Type.OBJECT as foo() makes no sense if foo == 3 1520 // This is some scope 'eval' or global eval replaced by user 1521 // but not the built-in ECMAScript 'eval' function call 1522 method.loadNull(); 1523 argsCount = loadArgs(callNode.getArgs()); 1524 } 1525 1526 @Override 1527 void consumeStack() { 1528 // Ordinary call 1529 dynamicCall(2 + argsCount, flags); 1530 method._goto(eval_done); 1531 1532 method.label(invoke_direct_eval); 1533 // Special/extra 'eval' arguments. These can be loaded late (in consumeStack) as we know none of 1534 // them can ever be optimistic. 1535 method.loadCompilerConstant(THIS); 1536 method.load(callNode.getEvalArgs().getLocation()); 1537 method.load(CodeGenerator.this.lc.getCurrentFunction().isStrict()); 1538 // direct call to Global.directEval 1539 globalDirectEval(); 1540 convertOptimisticReturnValue(); 1541 coerceStackTop(resultBounds); 1542 } 1543 }.emit(); 1544 1545 method.label(eval_done); 1546 } 1547 1548 @Override 1549 public boolean enterIdentNode(final IdentNode node) { 1550 final Symbol symbol = node.getSymbol(); 1551 1552 if (symbol.isScope()) { 1553 final int flags = getCallSiteFlags() | CALLSITE_SCOPE; 1554 final int useCount = symbol.getUseCount(); 1555 1556 // Threshold for generating shared scope callsite is lower for fast scope symbols because we know 1557 // we can dial in the correct scope. However, we also need to enable it for non-fast scopes to 1558 // support huge scripts like mandreel.js. 1559 if (callNode.isEval()) { 1560 evalCall(node, flags); 1561 } else if (useCount <= SharedScopeCall.FAST_SCOPE_CALL_THRESHOLD 1562 || !isFastScope(symbol) && useCount <= SharedScopeCall.SLOW_SCOPE_CALL_THRESHOLD 1563 || CodeGenerator.this.lc.inDynamicScope() 1564 || isOptimisticOrRestOf()) { 1565 scopeCall(node, flags); 1566 } else { 1567 sharedScopeCall(node, flags); 1568 } 1569 assert method.peekType().equals(resultBounds.within(callNode.getType())) : method.peekType() + " != " + resultBounds + "(" + callNode.getType() + ")"; 1570 } else { 1571 enterDefault(node); 1572 } 1573 1574 return false; 1575 } 1576 1577 @Override 1578 public boolean enterAccessNode(final AccessNode node) { 1579 //check if this is an apply to call node. only real applies, that haven't been 1580 //shadowed from their way to the global scope counts 1581 1582 //call nodes have program points. 1583 1584 final int flags = getCallSiteFlags() | (callNode.isApplyToCall() ? CALLSITE_APPLY_TO_CALL : 0); 1585 1586 new OptimisticOperation(callNode, resultBounds) { 1587 int argCount; 1588 @Override 1589 void loadStack() { 1590 loadExpressionAsObject(node.getBase()); 1591 method.dup(); 1592 // NOTE: not using a nested OptimisticOperation on this dynamicGet, as we expect to get back 1593 // a callable object. Nobody in their right mind would optimistically type this call site. 1594 assert !node.isOptimistic(); 1595 method.dynamicGet(node.getType(), node.getProperty(), flags, true, node.isIndex()); 1596 method.swap(); 1597 argCount = loadArgs(args); 1598 } 1599 @Override 1600 void consumeStack() { 1601 dynamicCall(2 + argCount, flags); 1602 } 1603 }.emit(); 1604 1605 return false; 1606 } 1607 1608 @Override 1609 public boolean enterFunctionNode(final FunctionNode origCallee) { 1610 new OptimisticOperation(callNode, resultBounds) { 1611 FunctionNode callee; 1612 int argsCount; 1613 @Override 1614 void loadStack() { 1615 callee = (FunctionNode)origCallee.accept(CodeGenerator.this); 1616 if (callee.isStrict()) { // "this" is undefined 1617 method.loadUndefined(Type.OBJECT); 1618 } else { // get global from scope (which is the self) 1619 globalInstance(); 1620 } 1621 argsCount = loadArgs(args); 1622 } 1623 1624 @Override 1625 void consumeStack() { 1626 final int flags = getCallSiteFlags(); 1627 //assert callNodeType.equals(callee.getReturnType()) : callNodeType + " != " + callee.getReturnType(); 1628 dynamicCall(2 + argsCount, flags); 1629 } 1630 }.emit(); 1631 return false; 1632 } 1633 1634 @Override 1635 public boolean enterIndexNode(final IndexNode node) { 1636 new OptimisticOperation(callNode, resultBounds) { 1637 int argsCount; 1638 @Override 1639 void loadStack() { 1640 loadExpressionAsObject(node.getBase()); 1641 method.dup(); 1642 final Type indexType = node.getIndex().getType(); 1643 if (indexType.isObject() || indexType.isBoolean()) { 1644 loadExpressionAsObject(node.getIndex()); //TODO boolean 1645 } else { 1646 loadExpressionUnbounded(node.getIndex()); 1647 } 1648 // NOTE: not using a nested OptimisticOperation on this dynamicGetIndex, as we expect to get 1649 // back a callable object. Nobody in their right mind would optimistically type this call site. 1650 assert !node.isOptimistic(); 1651 method.dynamicGetIndex(node.getType(), getCallSiteFlags(), true); 1652 method.swap(); 1653 argsCount = loadArgs(args); 1654 } 1655 @Override 1656 void consumeStack() { 1657 final int flags = getCallSiteFlags(); 1658 dynamicCall(2 + argsCount, flags); 1659 } 1660 }.emit(); 1661 return false; 1662 } 1663 1664 @Override 1665 protected boolean enterDefault(final Node node) { 1666 new OptimisticOperation(callNode, resultBounds) { 1667 int argsCount; 1668 @Override 1669 void loadStack() { 1670 // Load up function. 1671 loadExpressionAsObject(function); //TODO, e.g. booleans can be used as functions 1672 method.loadUndefined(Type.OBJECT); // ScriptFunction will figure out the correct this when it sees CALLSITE_SCOPE 1673 argsCount = loadArgs(args); 1674 } 1675 @Override 1676 void consumeStack() { 1677 final int flags = getCallSiteFlags() | CALLSITE_SCOPE; 1678 dynamicCall(2 + argsCount, flags); 1679 } 1680 }.emit(); 1681 return false; 1682 } 1683 }); 1684 1685 return false; 1686 } 1687 1688 /** 1689 * Returns the flags with optimistic flag and program point removed. 1690 * @param flags the flags that need optimism stripped from them. 1691 * @return flags without optimism 1692 */ 1693 static int nonOptimisticFlags(final int flags) { 1694 return flags & ~(CALLSITE_OPTIMISTIC | -1 << CALLSITE_PROGRAM_POINT_SHIFT); 1695 } 1696 1697 @Override 1698 public boolean enterContinueNode(final ContinueNode continueNode) { 1699 return enterJumpStatement(continueNode); 1700 } 1701 1702 @Override 1703 public boolean enterEmptyNode(final EmptyNode emptyNode) { 1704 if(!method.isReachable()) { 1705 return false; 1706 } 1707 enterStatement(emptyNode); 1708 1709 return false; 1710 } 1711 1712 @Override 1713 public boolean enterExpressionStatement(final ExpressionStatement expressionStatement) { 1714 if(!method.isReachable()) { 1715 return false; 1716 } 1717 enterStatement(expressionStatement); 1718 1719 loadAndDiscard(expressionStatement.getExpression()); 1720 assert method.getStackSize() == 0; 1721 1722 return false; 1723 } 1724 1725 @Override 1726 public boolean enterBlockStatement(final BlockStatement blockStatement) { 1727 if(!method.isReachable()) { 1728 return false; 1729 } 1730 enterStatement(blockStatement); 1731 1732 blockStatement.getBlock().accept(this); 1733 1734 return false; 1735 } 1736 1737 @Override 1738 public boolean enterForNode(final ForNode forNode) { 1739 if(!method.isReachable()) { 1740 return false; 1741 } 1742 enterStatement(forNode); 1743 if (forNode.isForIn()) { 1744 enterForIn(forNode); 1745 } else { 1746 final Expression init = forNode.getInit(); 1747 if (init != null) { 1748 loadAndDiscard(init); 1749 } 1750 enterForOrWhile(forNode, forNode.getModify()); 1751 } 1752 1753 return false; 1754 } 1755 1756 private void enterForIn(final ForNode forNode) { 1757 loadExpression(forNode.getModify(), TypeBounds.OBJECT); 1758 method.invoke(forNode.isForEach() ? ScriptRuntime.TO_VALUE_ITERATOR : ScriptRuntime.TO_PROPERTY_ITERATOR); 1759 final Symbol iterSymbol = forNode.getIterator(); 1760 final int iterSlot = iterSymbol.getSlot(Type.OBJECT); 1761 method.store(iterSymbol, ITERATOR_TYPE); 1762 1763 method.beforeJoinPoint(forNode); 1764 1765 final Label continueLabel = forNode.getContinueLabel(); 1766 final Label breakLabel = forNode.getBreakLabel(); 1767 1768 method.label(continueLabel); 1769 method.load(ITERATOR_TYPE, iterSlot); 1770 method.invoke(interfaceCallNoLookup(ITERATOR_CLASS, "hasNext", boolean.class)); 1771 final JoinPredecessorExpression test = forNode.getTest(); 1772 final Block body = forNode.getBody(); 1773 if(LocalVariableConversion.hasLiveConversion(test)) { 1774 final Label afterConversion = new Label("for_in_after_test_conv"); 1775 method.ifne(afterConversion); 1776 method.beforeJoinPoint(test); 1777 method._goto(breakLabel); 1778 method.label(afterConversion); 1779 } else { 1780 method.ifeq(breakLabel); 1781 } 1782 1783 new Store<Expression>(forNode.getInit()) { 1784 @Override 1785 protected void storeNonDiscard() { 1786 // This expression is neither part of a discard, nor needs to be left on the stack after it was 1787 // stored, so we override storeNonDiscard to be a no-op. 1788 } 1789 1790 @Override 1791 protected void evaluate() { 1792 new OptimisticOperation((Optimistic)forNode.getInit(), TypeBounds.UNBOUNDED) { 1793 @Override 1794 void loadStack() { 1795 method.load(ITERATOR_TYPE, iterSlot); 1796 } 1797 1798 @Override 1799 void consumeStack() { 1800 method.invoke(interfaceCallNoLookup(ITERATOR_CLASS, "next", Object.class)); 1801 convertOptimisticReturnValue(); 1802 } 1803 }.emit(); 1804 } 1805 }.store(); 1806 body.accept(this); 1807 1808 if(method.isReachable()) { 1809 method._goto(continueLabel); 1810 } 1811 method.label(breakLabel); 1812 } 1813 1814 /** 1815 * Initialize the slots in a frame to undefined. 1816 * 1817 * @param block block with local vars. 1818 */ 1819 private void initLocals(final Block block) { 1820 lc.onEnterBlock(block); 1821 1822 final boolean isFunctionBody = lc.isFunctionBody(); 1823 final FunctionNode function = lc.getCurrentFunction(); 1824 if (isFunctionBody) { 1825 initializeMethodParameters(function); 1826 if(!function.isVarArg()) { 1827 expandParameterSlots(function); 1828 } 1829 if (method.hasScope()) { 1830 if (function.needsParentScope()) { 1831 method.loadCompilerConstant(CALLEE); 1832 method.invoke(ScriptFunction.GET_SCOPE); 1833 } else { 1834 assert function.hasScopeBlock(); 1835 method.loadNull(); 1836 } 1837 method.storeCompilerConstant(SCOPE); 1838 } 1839 if (function.needsArguments()) { 1840 initArguments(function); 1841 } 1842 } 1843 1844 /* 1845 * Determine if block needs scope, if not, just do initSymbols for this block. 1846 */ 1847 if (block.needsScope()) { 1848 /* 1849 * Determine if function is varargs and consequently variables have to 1850 * be in the scope. 1851 */ 1852 final boolean varsInScope = function.allVarsInScope(); 1853 1854 // TODO for LET we can do better: if *block* does not contain any eval/with, we don't need its vars in scope. 1855 1856 final boolean hasArguments = function.needsArguments(); 1857 final List<MapTuple<Symbol>> tuples = new ArrayList<>(); 1858 final Iterator<IdentNode> paramIter = function.getParameters().iterator(); 1859 for (final Symbol symbol : block.getSymbols()) { 1860 if (symbol.isInternal() || symbol.isThis()) { 1861 continue; 1862 } 1863 1864 if (symbol.isVar()) { 1865 assert !varsInScope || symbol.isScope(); 1866 if (varsInScope || symbol.isScope()) { 1867 assert symbol.isScope() : "scope for " + symbol + " should have been set in Lower already " + function.getName(); 1868 assert !symbol.hasSlot() : "slot for " + symbol + " should have been removed in Lower already" + function.getName(); 1869 1870 //this tuple will not be put fielded, as it has no value, just a symbol 1871 tuples.add(new MapTuple<Symbol>(symbol.getName(), symbol, null)); 1872 } else { 1873 assert symbol.hasSlot() || symbol.slotCount() == 0 : symbol + " should have a slot only, no scope"; 1874 } 1875 } else if (symbol.isParam() && (varsInScope || hasArguments || symbol.isScope())) { 1876 assert symbol.isScope() : "scope for " + symbol + " should have been set in AssignSymbols already " + function.getName() + " varsInScope="+varsInScope+" hasArguments="+hasArguments+" symbol.isScope()=" + symbol.isScope(); 1877 assert !(hasArguments && symbol.hasSlot()) : "slot for " + symbol + " should have been removed in Lower already " + function.getName(); 1878 1879 final Type paramType; 1880 final Symbol paramSymbol; 1881 1882 if (hasArguments) { 1883 assert !symbol.hasSlot() : "slot for " + symbol + " should have been removed in Lower already "; 1884 paramSymbol = null; 1885 paramType = null; 1886 } else { 1887 paramSymbol = symbol; 1888 // NOTE: We're relying on the fact here that Block.symbols is a LinkedHashMap, hence it will 1889 // return symbols in the order they were defined, and parameters are defined in the same order 1890 // they appear in the function. That's why we can have a single pass over the parameter list 1891 // with an iterator, always just scanning forward for the next parameter that matches the symbol 1892 // name. 1893 for(;;) { 1894 final IdentNode nextParam = paramIter.next(); 1895 if(nextParam.getName().equals(symbol.getName())) { 1896 paramType = nextParam.getType(); 1897 break; 1898 } 1899 } 1900 } 1901 1902 tuples.add(new MapTuple<Symbol>(symbol.getName(), symbol, paramType, paramSymbol) { 1903 //this symbol will be put fielded, we can't initialize it as undefined with a known type 1904 @Override 1905 public Class<?> getValueType() { 1906 if (!useDualFields() || value == null || paramType == null || paramType.isBoolean()) { 1907 return Object.class; 1908 } 1909 return paramType.getTypeClass(); 1910 } 1911 }); 1912 } 1913 } 1914 1915 /* 1916 * Create a new object based on the symbols and values, generate 1917 * bootstrap code for object 1918 */ 1919 new FieldObjectCreator<Symbol>(this, tuples, true, hasArguments) { 1920 @Override 1921 protected void loadValue(final Symbol value, final Type type) { 1922 method.load(value, type); 1923 } 1924 }.makeObject(method); 1925 // program function: merge scope into global 1926 if (isFunctionBody && function.isProgram()) { 1927 method.invoke(ScriptRuntime.MERGE_SCOPE); 1928 } 1929 1930 method.storeCompilerConstant(SCOPE); 1931 if(!isFunctionBody) { 1932 // Function body doesn't need a try/catch to restore scope, as it'd be a dead store anyway. Allowing it 1933 // actually causes issues with UnwarrantedOptimismException handlers as ASM will sort this handler to 1934 // the top of the exception handler table, so it'll be triggered instead of the UOE handlers. 1935 final Label scopeEntryLabel = new Label("scope_entry"); 1936 scopeEntryLabels.push(scopeEntryLabel); 1937 method.label(scopeEntryLabel); 1938 } 1939 } else if (isFunctionBody && function.isVarArg()) { 1940 // Since we don't have a scope, parameters didn't get assigned array indices by the FieldObjectCreator, so 1941 // we need to assign them separately here. 1942 int nextParam = 0; 1943 for (final IdentNode param : function.getParameters()) { 1944 param.getSymbol().setFieldIndex(nextParam++); 1945 } 1946 } 1947 1948 // Debugging: print symbols? @see --print-symbols flag 1949 printSymbols(block, function, (isFunctionBody ? "Function " : "Block in ") + (function.getIdent() == null ? "<anonymous>" : function.getIdent().getName())); 1950 } 1951 1952 /** 1953 * Incoming method parameters are always declared on method entry; declare them in the local variable table. 1954 * @param function function for which code is being generated. 1955 */ 1956 private void initializeMethodParameters(final FunctionNode function) { 1957 final Label functionStart = new Label("fn_start"); 1958 method.label(functionStart); 1959 int nextSlot = 0; 1960 if(function.needsCallee()) { 1961 initializeInternalFunctionParameter(CALLEE, function, functionStart, nextSlot++); 1962 } 1963 initializeInternalFunctionParameter(THIS, function, functionStart, nextSlot++); 1964 if(function.isVarArg()) { 1965 initializeInternalFunctionParameter(VARARGS, function, functionStart, nextSlot++); 1966 } else { 1967 for(final IdentNode param: function.getParameters()) { 1968 final Symbol symbol = param.getSymbol(); 1969 if(symbol.isBytecodeLocal()) { 1970 method.initializeMethodParameter(symbol, param.getType(), functionStart); 1971 } 1972 } 1973 } 1974 } 1975 1976 private void initializeInternalFunctionParameter(final CompilerConstants cc, final FunctionNode fn, final Label functionStart, final int slot) { 1977 final Symbol symbol = initializeInternalFunctionOrSplitParameter(cc, fn, functionStart, slot); 1978 // Internal function params (:callee, this, and :varargs) are never expanded to multiple slots 1979 assert symbol.getFirstSlot() == slot; 1980 } 1981 1982 private Symbol initializeInternalFunctionOrSplitParameter(final CompilerConstants cc, final FunctionNode fn, final Label functionStart, final int slot) { 1983 final Symbol symbol = fn.getBody().getExistingSymbol(cc.symbolName()); 1984 final Type type = Type.typeFor(cc.type()); 1985 method.initializeMethodParameter(symbol, type, functionStart); 1986 method.onLocalStore(type, slot); 1987 return symbol; 1988 } 1989 1990 /** 1991 * Parameters come into the method packed into local variable slots next to each other. Nashorn on the other hand 1992 * can use 1-6 slots for a local variable depending on all the types it needs to store. When this method is invoked, 1993 * the symbols are already allocated such wider slots, but the values are still in tightly packed incoming slots, 1994 * and we need to spread them into their new locations. 1995 * @param function the function for which parameter-spreading code needs to be emitted 1996 */ 1997 private void expandParameterSlots(final FunctionNode function) { 1998 final List<IdentNode> parameters = function.getParameters(); 1999 // Calculate the total number of incoming parameter slots 2000 int currentIncomingSlot = function.needsCallee() ? 2 : 1; 2001 for(final IdentNode parameter: parameters) { 2002 currentIncomingSlot += parameter.getType().getSlots(); 2003 } 2004 // Starting from last parameter going backwards, move the parameter values into their new slots. 2005 for(int i = parameters.size(); i-- > 0;) { 2006 final IdentNode parameter = parameters.get(i); 2007 final Type parameterType = parameter.getType(); 2008 final int typeWidth = parameterType.getSlots(); 2009 currentIncomingSlot -= typeWidth; 2010 final Symbol symbol = parameter.getSymbol(); 2011 final int slotCount = symbol.slotCount(); 2012 assert slotCount > 0; 2013 // Scoped parameters must not hold more than one value 2014 assert symbol.isBytecodeLocal() || slotCount == typeWidth; 2015 2016 // Mark it as having its value stored into it by the method invocation. 2017 method.onLocalStore(parameterType, currentIncomingSlot); 2018 if(currentIncomingSlot != symbol.getSlot(parameterType)) { 2019 method.load(parameterType, currentIncomingSlot); 2020 method.store(symbol, parameterType); 2021 } 2022 } 2023 } 2024 2025 private void initArguments(final FunctionNode function) { 2026 method.loadCompilerConstant(VARARGS); 2027 if (function.needsCallee()) { 2028 method.loadCompilerConstant(CALLEE); 2029 } else { 2030 // If function is strict mode, "arguments.callee" is not populated, so we don't necessarily need the 2031 // caller. 2032 assert function.isStrict(); 2033 method.loadNull(); 2034 } 2035 method.load(function.getParameters().size()); 2036 globalAllocateArguments(); 2037 method.storeCompilerConstant(ARGUMENTS); 2038 } 2039 2040 private boolean skipFunction(final FunctionNode functionNode) { 2041 final ScriptEnvironment env = compiler.getScriptEnvironment(); 2042 final boolean lazy = env._lazy_compilation; 2043 final boolean onDemand = compiler.isOnDemandCompilation(); 2044 2045 // If this is on-demand or lazy compilation, don't compile a nested (not topmost) function. 2046 if((onDemand || lazy) && lc.getOutermostFunction() != functionNode) { 2047 return true; 2048 } 2049 2050 // If lazy compiling with optimistic types, don't compile the program eagerly either. It will soon be 2051 // invalidated anyway. In presence of a class cache, this further means that an obsoleted program version 2052 // lingers around. Also, currently loading previously persisted optimistic types information only works if 2053 // we're on-demand compiling a function, so with this strategy the :program method can also have the warmup 2054 // benefit of using previously persisted types. 2055 // 2056 // NOTE that this means the first compiled class will effectively just have a :createProgramFunction method, and 2057 // the RecompilableScriptFunctionData (RSFD) object in its constants array. It won't even have the :program 2058 // method. This is by design. It does mean that we're wasting one compiler execution (and we could minimize this 2059 // by just running it up to scope depth calculation, which creates the RSFDs and then this limited codegen). 2060 // We could emit an initial separate compile unit with the initial version of :program in it to better utilize 2061 // the compilation pipeline, but that would need more invasive changes, as currently the assumption that 2062 // :program is emitted into the first compilation unit of the function lives in many places. 2063 return !onDemand && lazy && env._optimistic_types && functionNode.isProgram(); 2064 } 2065 2066 @Override 2067 public boolean enterFunctionNode(final FunctionNode functionNode) { 2068 final int fnId = functionNode.getId(); 2069 2070 if (skipFunction(functionNode)) { 2071 // In case we are not generating code for the function, we must create or retrieve the function object and 2072 // load it on the stack here. 2073 newFunctionObject(functionNode, false); 2074 return false; 2075 } 2076 2077 final String fnName = functionNode.getName(); 2078 2079 // NOTE: we only emit the method for a function with the given name once. We can have multiple functions with 2080 // the same name as a result of inlining finally blocks. However, in the future -- with type specialization, 2081 // notably -- we might need to check for both name *and* signature. Of course, even that might not be 2082 // sufficient; the function might have a code dependency on the type of the variables in its enclosing scopes, 2083 // and the type of such a variable can be different in catch and finally blocks. So, in the future we will have 2084 // to decide to either generate a unique method for each inlined copy of the function, maybe figure out its 2085 // exact type closure and deduplicate based on that, or just decide that functions in finally blocks aren't 2086 // worth it, and generate one method with most generic type closure. 2087 if (!emittedMethods.contains(fnName)) { 2088 log.info("=== BEGIN ", fnName); 2089 2090 assert functionNode.getCompileUnit() != null : "no compile unit for " + fnName + " " + Debug.id(functionNode); 2091 unit = lc.pushCompileUnit(functionNode.getCompileUnit()); 2092 assert lc.hasCompileUnits(); 2093 2094 final ClassEmitter classEmitter = unit.getClassEmitter(); 2095 pushMethodEmitter(isRestOf() ? classEmitter.restOfMethod(functionNode) : classEmitter.method(functionNode)); 2096 method.setPreventUndefinedLoad(); 2097 if(useOptimisticTypes()) { 2098 lc.pushUnwarrantedOptimismHandlers(); 2099 } 2100 2101 // new method - reset last line number 2102 lastLineNumber = -1; 2103 2104 method.begin(); 2105 2106 if (isRestOf()) { 2107 final ContinuationInfo ci = new ContinuationInfo(); 2108 fnIdToContinuationInfo.put(fnId, ci); 2109 method.gotoLoopStart(ci.getHandlerLabel()); 2110 } 2111 } 2112 2113 return true; 2114 } 2115 2116 private void pushMethodEmitter(final MethodEmitter newMethod) { 2117 method = lc.pushMethodEmitter(newMethod); 2118 catchLabels.push(METHOD_BOUNDARY); 2119 } 2120 2121 private void popMethodEmitter() { 2122 method = lc.popMethodEmitter(method); 2123 assert catchLabels.peek() == METHOD_BOUNDARY; 2124 catchLabels.pop(); 2125 } 2126 2127 @Override 2128 public Node leaveFunctionNode(final FunctionNode functionNode) { 2129 try { 2130 final boolean markOptimistic; 2131 if (emittedMethods.add(functionNode.getName())) { 2132 markOptimistic = generateUnwarrantedOptimismExceptionHandlers(functionNode); 2133 generateContinuationHandler(); 2134 method.end(); // wrap up this method 2135 unit = lc.popCompileUnit(functionNode.getCompileUnit()); 2136 popMethodEmitter(); 2137 log.info("=== END ", functionNode.getName()); 2138 } else { 2139 markOptimistic = false; 2140 } 2141 2142 FunctionNode newFunctionNode = functionNode.setState(lc, CompilationState.BYTECODE_GENERATED); 2143 if (markOptimistic) { 2144 newFunctionNode = newFunctionNode.setFlag(lc, FunctionNode.IS_DEOPTIMIZABLE); 2145 } 2146 2147 newFunctionObject(newFunctionNode, true); 2148 return newFunctionNode; 2149 } catch (final Throwable t) { 2150 Context.printStackTrace(t); 2151 final VerifyError e = new VerifyError("Code generation bug in \"" + functionNode.getName() + "\": likely stack misaligned: " + t + " " + functionNode.getSource().getName()); 2152 e.initCause(t); 2153 throw e; 2154 } 2155 } 2156 2157 @Override 2158 public boolean enterIfNode(final IfNode ifNode) { 2159 if(!method.isReachable()) { 2160 return false; 2161 } 2162 enterStatement(ifNode); 2163 2164 final Expression test = ifNode.getTest(); 2165 final Block pass = ifNode.getPass(); 2166 final Block fail = ifNode.getFail(); 2167 2168 if (Expression.isAlwaysTrue(test)) { 2169 loadAndDiscard(test); 2170 pass.accept(this); 2171 return false; 2172 } else if (Expression.isAlwaysFalse(test)) { 2173 loadAndDiscard(test); 2174 if (fail != null) { 2175 fail.accept(this); 2176 } 2177 return false; 2178 } 2179 2180 final boolean hasFailConversion = LocalVariableConversion.hasLiveConversion(ifNode); 2181 2182 final Label failLabel = new Label("if_fail"); 2183 final Label afterLabel = (fail == null && !hasFailConversion) ? null : new Label("if_done"); 2184 2185 emitBranch(test, failLabel, false); 2186 2187 pass.accept(this); 2188 if(method.isReachable() && afterLabel != null) { 2189 method._goto(afterLabel); //don't fallthru to fail block 2190 } 2191 method.label(failLabel); 2192 2193 if (fail != null) { 2194 fail.accept(this); 2195 } else if(hasFailConversion) { 2196 method.beforeJoinPoint(ifNode); 2197 } 2198 2199 if(afterLabel != null && afterLabel.isReachable()) { 2200 method.label(afterLabel); 2201 } 2202 2203 return false; 2204 } 2205 2206 private void emitBranch(final Expression test, final Label label, final boolean jumpWhenTrue) { 2207 new BranchOptimizer(this, method).execute(test, label, jumpWhenTrue); 2208 } 2209 2210 private void enterStatement(final Statement statement) { 2211 lineNumber(statement); 2212 } 2213 2214 private void lineNumber(final Statement statement) { 2215 lineNumber(statement.getLineNumber()); 2216 } 2217 2218 private void lineNumber(final int lineNumber) { 2219 if (lineNumber != lastLineNumber && lineNumber != Node.NO_LINE_NUMBER) { 2220 method.lineNumber(lineNumber); 2221 lastLineNumber = lineNumber; 2222 } 2223 } 2224 2225 int getLastLineNumber() { 2226 return lastLineNumber; 2227 } 2228 2229 /** 2230 * Load a list of nodes as an array of a specific type 2231 * The array will contain the visited nodes. 2232 * 2233 * @param arrayLiteralNode the array of contents 2234 * @param arrayType the type of the array, e.g. ARRAY_NUMBER or ARRAY_OBJECT 2235 * 2236 * @return the method generator that was used 2237 */ 2238 private MethodEmitter 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 Class<?> type = arrayType.getTypeClass(); 2245 final List<ArrayUnit> units = arrayLiteralNode.getUnits(); 2246 2247 loadConstant(presets); 2248 2249 final Type elementType = arrayType.getElementType(); 2250 2251 if (units != null) { 2252 final MethodEmitter savedMethod = method; 2253 final FunctionNode currentFunction = lc.getCurrentFunction(); 2254 2255 for (final ArrayUnit arrayUnit : units) { 2256 unit = lc.pushCompileUnit(arrayUnit.getCompileUnit()); 2257 2258 final String className = unit.getUnitClassName(); 2259 assert unit != null; 2260 final String name = currentFunction.uniqueName(SPLIT_PREFIX.symbolName()); 2261 final String signature = methodDescriptor(type, ScriptFunction.class, Object.class, ScriptObject.class, type); 2262 2263 pushMethodEmitter(unit.getClassEmitter().method(EnumSet.of(Flag.PUBLIC, Flag.STATIC), name, signature)); 2264 2265 method.setFunctionNode(currentFunction); 2266 method.begin(); 2267 2268 defineCommonSplitMethodParameters(); 2269 defineSplitMethodParameter(CompilerConstants.SPLIT_ARRAY_ARG.slot(), arrayType); 2270 2271 // NOTE: when this is no longer needed, SplitIntoFunctions will no longer have to add IS_SPLIT 2272 // to synthetic functions, and FunctionNode.needsCallee() will no longer need to test for isSplit(). 2273 final int arraySlot = fixScopeSlot(currentFunction, 3); 2274 2275 lc.enterSplitNode(); 2276 2277 for (int i = arrayUnit.getLo(); i < arrayUnit.getHi(); i++) { 2278 method.load(arrayType, arraySlot); 2279 storeElement(nodes, elementType, postsets[i]); 2280 } 2281 2282 method.load(arrayType, arraySlot); 2283 method._return(); 2284 lc.exitSplitNode(); 2285 method.end(); 2286 lc.releaseSlots(); 2287 popMethodEmitter(); 2288 2289 assert method == savedMethod; 2290 method.loadCompilerConstant(CALLEE); 2291 method.swap(); 2292 method.loadCompilerConstant(THIS); 2293 method.swap(); 2294 method.loadCompilerConstant(SCOPE); 2295 method.swap(); 2296 method.invokestatic(className, name, signature); 2297 2298 unit = lc.popCompileUnit(unit); 2299 } 2300 2301 return method; 2302 } 2303 2304 if(postsets.length > 0) { 2305 final int arraySlot = method.getUsedSlotsWithLiveTemporaries(); 2306 method.storeTemp(arrayType, arraySlot); 2307 for (final int postset : postsets) { 2308 method.load(arrayType, arraySlot); 2309 storeElement(nodes, elementType, postset); 2310 } 2311 method.load(arrayType, arraySlot); 2312 } 2313 return method; 2314 } 2315 2316 private void storeElement(final Expression[] nodes, final Type elementType, final int index) { 2317 method.load(index); 2318 2319 final Expression element = nodes[index]; 2320 2321 if (element == null) { 2322 method.loadEmpty(elementType); 2323 } else { 2324 loadExpressionAsType(element, elementType); 2325 } 2326 2327 method.arraystore(); 2328 } 2329 2330 private MethodEmitter loadArgsArray(final List<Expression> args) { 2331 final Object[] array = new Object[args.size()]; 2332 loadConstant(array); 2333 2334 for (int i = 0; i < args.size(); i++) { 2335 method.dup(); 2336 method.load(i); 2337 loadExpression(args.get(i), TypeBounds.OBJECT); // variable arity methods always take objects 2338 method.arraystore(); 2339 } 2340 2341 return method; 2342 } 2343 2344 /** 2345 * Load a constant from the constant array. This is only public to be callable from the objects 2346 * subpackage. Do not call directly. 2347 * 2348 * @param string string to load 2349 */ 2350 void loadConstant(final String string) { 2351 final String unitClassName = unit.getUnitClassName(); 2352 final ClassEmitter classEmitter = unit.getClassEmitter(); 2353 final int index = compiler.getConstantData().add(string); 2354 2355 method.load(index); 2356 method.invokestatic(unitClassName, GET_STRING.symbolName(), methodDescriptor(String.class, int.class)); 2357 classEmitter.needGetConstantMethod(String.class); 2358 } 2359 2360 /** 2361 * Load a constant from the constant array. This is only public to be callable from the objects 2362 * subpackage. Do not call directly. 2363 * 2364 * @param object object to load 2365 */ 2366 void loadConstant(final Object object) { 2367 loadConstant(object, unit, method); 2368 } 2369 2370 private void loadConstant(final Object object, final CompileUnit compileUnit, final MethodEmitter methodEmitter) { 2371 final String unitClassName = compileUnit.getUnitClassName(); 2372 final ClassEmitter classEmitter = compileUnit.getClassEmitter(); 2373 final int index = compiler.getConstantData().add(object); 2374 final Class<?> cls = object.getClass(); 2375 2376 if (cls == PropertyMap.class) { 2377 methodEmitter.load(index); 2378 methodEmitter.invokestatic(unitClassName, GET_MAP.symbolName(), methodDescriptor(PropertyMap.class, int.class)); 2379 classEmitter.needGetConstantMethod(PropertyMap.class); 2380 } else if (cls.isArray()) { 2381 methodEmitter.load(index); 2382 final String methodName = ClassEmitter.getArrayMethodName(cls); 2383 methodEmitter.invokestatic(unitClassName, methodName, methodDescriptor(cls, int.class)); 2384 classEmitter.needGetConstantMethod(cls); 2385 } else { 2386 methodEmitter.loadConstants().load(index).arrayload(); 2387 if (object instanceof ArrayData) { 2388 methodEmitter.checkcast(ArrayData.class); 2389 methodEmitter.invoke(virtualCallNoLookup(ArrayData.class, "copy", ArrayData.class)); 2390 } else if (cls != Object.class) { 2391 methodEmitter.checkcast(cls); 2392 } 2393 } 2394 } 2395 2396 private void loadConstantsAndIndex(final Object object, final MethodEmitter methodEmitter) { 2397 methodEmitter.loadConstants().load(compiler.getConstantData().add(object)); 2398 } 2399 2400 // literal values 2401 private void loadLiteral(final LiteralNode<?> node, final TypeBounds resultBounds) { 2402 final Object value = node.getValue(); 2403 2404 if (value == null) { 2405 method.loadNull(); 2406 } else if (value instanceof Undefined) { 2407 method.loadUndefined(resultBounds.within(Type.OBJECT)); 2408 } else if (value instanceof String) { 2409 final String string = (String)value; 2410 2411 if (string.length() > MethodEmitter.LARGE_STRING_THRESHOLD / 3) { // 3 == max bytes per encoded char 2412 loadConstant(string); 2413 } else { 2414 method.load(string); 2415 } 2416 } else if (value instanceof RegexToken) { 2417 loadRegex((RegexToken)value); 2418 } else if (value instanceof Boolean) { 2419 method.load((Boolean)value); 2420 } else if (value instanceof Integer) { 2421 if(!resultBounds.canBeNarrowerThan(Type.OBJECT)) { 2422 method.load((Integer)value); 2423 method.convert(Type.OBJECT); 2424 } else if(!resultBounds.canBeNarrowerThan(Type.NUMBER)) { 2425 method.load(((Integer)value).doubleValue()); 2426 } else if(!resultBounds.canBeNarrowerThan(Type.LONG)) { 2427 method.load(((Integer)value).longValue()); 2428 } else { 2429 method.load((Integer)value); 2430 } 2431 } else if (value instanceof Long) { 2432 if(!resultBounds.canBeNarrowerThan(Type.OBJECT)) { 2433 method.load((Long)value); 2434 method.convert(Type.OBJECT); 2435 } else if(!resultBounds.canBeNarrowerThan(Type.NUMBER)) { 2436 method.load(((Long)value).doubleValue()); 2437 } else { 2438 method.load((Long)value); 2439 } 2440 } else if (value instanceof Double) { 2441 if(!resultBounds.canBeNarrowerThan(Type.OBJECT)) { 2442 method.load((Double)value); 2443 method.convert(Type.OBJECT); 2444 } else { 2445 method.load((Double)value); 2446 } 2447 } else if (node instanceof ArrayLiteralNode) { 2448 final ArrayLiteralNode arrayLiteral = (ArrayLiteralNode)node; 2449 final ArrayType atype = arrayLiteral.getArrayType(); 2450 loadArray(arrayLiteral, atype); 2451 globalAllocateArray(atype); 2452 } else { 2453 throw new UnsupportedOperationException("Unknown literal for " + node.getClass() + " " + value.getClass() + " " + value); 2454 } 2455 } 2456 2457 private MethodEmitter loadRegexToken(final RegexToken value) { 2458 method.load(value.getExpression()); 2459 method.load(value.getOptions()); 2460 return globalNewRegExp(); 2461 } 2462 2463 private MethodEmitter loadRegex(final RegexToken regexToken) { 2464 if (regexFieldCount > MAX_REGEX_FIELDS) { 2465 return loadRegexToken(regexToken); 2466 } 2467 // emit field 2468 final String regexName = lc.getCurrentFunction().uniqueName(REGEX_PREFIX.symbolName()); 2469 final ClassEmitter classEmitter = unit.getClassEmitter(); 2470 2471 classEmitter.field(EnumSet.of(PRIVATE, STATIC), regexName, Object.class); 2472 regexFieldCount++; 2473 2474 // get field, if null create new regex, finally clone regex object 2475 method.getStatic(unit.getUnitClassName(), regexName, typeDescriptor(Object.class)); 2476 method.dup(); 2477 final Label cachedLabel = new Label("cached"); 2478 method.ifnonnull(cachedLabel); 2479 2480 method.pop(); 2481 loadRegexToken(regexToken); 2482 method.dup(); 2483 method.putStatic(unit.getUnitClassName(), regexName, typeDescriptor(Object.class)); 2484 2485 method.label(cachedLabel); 2486 globalRegExpCopy(); 2487 2488 return method; 2489 } 2490 2491 /** 2492 * Check if a property value contains a particular program point 2493 * @param value value 2494 * @param pp program point 2495 * @return true if it's there. 2496 */ 2497 private static boolean propertyValueContains(final Expression value, final int pp) { 2498 return new Supplier<Boolean>() { 2499 boolean contains; 2500 2501 @Override 2502 public Boolean get() { 2503 value.accept(new NodeVisitor<LexicalContext>(new LexicalContext()) { 2504 @Override 2505 public boolean enterFunctionNode(final FunctionNode functionNode) { 2506 return false; 2507 } 2508 2509 @Override 2510 public boolean enterObjectNode(final ObjectNode objectNode) { 2511 return false; 2512 } 2513 2514 @Override 2515 public boolean enterDefault(final Node node) { 2516 if (contains) { 2517 return false; 2518 } 2519 if (node instanceof Optimistic && ((Optimistic)node).getProgramPoint() == pp) { 2520 contains = true; 2521 return false; 2522 } 2523 return true; 2524 } 2525 }); 2526 2527 return contains; 2528 } 2529 }.get(); 2530 } 2531 2532 private void loadObjectNode(final ObjectNode objectNode) { 2533 final List<PropertyNode> elements = objectNode.getElements(); 2534 2535 final List<MapTuple<Expression>> tuples = new ArrayList<>(); 2536 final List<PropertyNode> gettersSetters = new ArrayList<>(); 2537 final int ccp = getCurrentContinuationEntryPoint(); 2538 2539 Expression protoNode = null; 2540 boolean restOfProperty = false; 2541 2542 for (final PropertyNode propertyNode : elements) { 2543 final Expression value = propertyNode.getValue(); 2544 final String key = propertyNode.getKeyName(); 2545 // Just use a pseudo-symbol. We just need something non null; use the name and zero flags. 2546 final Symbol symbol = value == null ? null : new Symbol(key, 0); 2547 2548 if (value == null) { 2549 gettersSetters.add(propertyNode); 2550 } else if (propertyNode.getKey() instanceof IdentNode && 2551 key.equals(ScriptObject.PROTO_PROPERTY_NAME)) { 2552 // ES6 draft compliant __proto__ inside object literal 2553 // Identifier key and name is __proto__ 2554 protoNode = value; 2555 continue; 2556 } 2557 2558 restOfProperty |= 2559 value != null && 2560 isValid(ccp) && 2561 propertyValueContains(value, ccp); 2562 2563 //for literals, a value of null means object type, i.e. the value null or getter setter function 2564 //(I think) 2565 final Class<?> valueType = (!useDualFields() || value == null || value.getType().isBoolean()) ? Object.class : value.getType().getTypeClass(); 2566 tuples.add(new MapTuple<Expression>(key, symbol, Type.typeFor(valueType), value) { 2567 @Override 2568 public Class<?> getValueType() { 2569 return type.getTypeClass(); 2570 } 2571 }); 2572 } 2573 2574 final ObjectCreator<?> oc; 2575 if (elements.size() > OBJECT_SPILL_THRESHOLD) { 2576 oc = new SpillObjectCreator(this, tuples); 2577 } else { 2578 oc = new FieldObjectCreator<Expression>(this, tuples) { 2579 @Override 2580 protected void loadValue(final Expression node, final Type type) { 2581 loadExpressionAsType(node, type); 2582 }}; 2583 } 2584 oc.makeObject(method); 2585 2586 //if this is a rest of method and our continuation point was found as one of the values 2587 //in the properties above, we need to reset the map to oc.getMap() in the continuation 2588 //handler 2589 if (restOfProperty) { 2590 final ContinuationInfo ci = getContinuationInfo(); 2591 // Can be set at most once for a single rest-of method 2592 assert ci.getObjectLiteralMap() == null; 2593 ci.setObjectLiteralMap(oc.getMap()); 2594 ci.setObjectLiteralStackDepth(method.getStackSize()); 2595 } 2596 2597 method.dup(); 2598 if (protoNode != null) { 2599 loadExpressionAsObject(protoNode); 2600 // take care of { __proto__: 34 } or some such! 2601 method.convert(Type.OBJECT); 2602 method.invoke(ScriptObject.SET_PROTO_FROM_LITERAL); 2603 } else { 2604 method.invoke(ScriptObject.SET_GLOBAL_OBJECT_PROTO); 2605 } 2606 2607 for (final PropertyNode propertyNode : gettersSetters) { 2608 final FunctionNode getter = propertyNode.getGetter(); 2609 final FunctionNode setter = propertyNode.getSetter(); 2610 2611 assert getter != null || setter != null; 2612 2613 method.dup().loadKey(propertyNode.getKey()); 2614 if (getter == null) { 2615 method.loadNull(); 2616 } else { 2617 getter.accept(this); 2618 } 2619 2620 if (setter == null) { 2621 method.loadNull(); 2622 } else { 2623 setter.accept(this); 2624 } 2625 2626 method.invoke(ScriptObject.SET_USER_ACCESSORS); 2627 } 2628 } 2629 2630 @Override 2631 public boolean enterReturnNode(final ReturnNode returnNode) { 2632 if(!method.isReachable()) { 2633 return false; 2634 } 2635 enterStatement(returnNode); 2636 2637 method.registerReturn(); 2638 2639 final Type returnType = lc.getCurrentFunction().getReturnType(); 2640 2641 final Expression expression = returnNode.getExpression(); 2642 if (expression != null) { 2643 loadExpressionUnbounded(expression); 2644 } else { 2645 method.loadUndefined(returnType); 2646 } 2647 2648 method._return(returnType); 2649 2650 return false; 2651 } 2652 2653 private boolean undefinedCheck(final RuntimeNode runtimeNode, final List<Expression> args) { 2654 final Request request = runtimeNode.getRequest(); 2655 2656 if (!Request.isUndefinedCheck(request)) { 2657 return false; 2658 } 2659 2660 final Expression lhs = args.get(0); 2661 final Expression rhs = args.get(1); 2662 2663 final Symbol lhsSymbol = lhs instanceof IdentNode ? ((IdentNode)lhs).getSymbol() : null; 2664 final Symbol rhsSymbol = rhs instanceof IdentNode ? ((IdentNode)rhs).getSymbol() : null; 2665 // One must be a "undefined" identifier, otherwise we can't get here 2666 assert lhsSymbol != null || rhsSymbol != null; 2667 2668 final Symbol undefinedSymbol; 2669 if (isUndefinedSymbol(lhsSymbol)) { 2670 undefinedSymbol = lhsSymbol; 2671 } else { 2672 assert isUndefinedSymbol(rhsSymbol); 2673 undefinedSymbol = rhsSymbol; 2674 } 2675 2676 assert undefinedSymbol != null; //remove warning 2677 if (!undefinedSymbol.isScope()) { 2678 return false; //disallow undefined as local var or parameter 2679 } 2680 2681 if (lhsSymbol == undefinedSymbol && lhs.getType().isPrimitive()) { 2682 //we load the undefined first. never mind, because this will deoptimize anyway 2683 return false; 2684 } 2685 2686 if(isDeoptimizedExpression(lhs)) { 2687 // This is actually related to "lhs.getType().isPrimitive()" above: any expression being deoptimized in 2688 // the current chain of rest-of compilations used to have a type narrower than Object (so it was primitive). 2689 // We must not perform undefined check specialization for them, as then we'd violate the basic rule of 2690 // "Thou shalt not alter the stack shape between a deoptimized method and any of its (transitive) rest-ofs." 2691 return false; 2692 } 2693 2694 //make sure that undefined has not been overridden or scoped as a local var 2695 //between us and global 2696 if (!compiler.isGlobalSymbol(lc.getCurrentFunction(), "undefined")) { 2697 return false; 2698 } 2699 2700 final boolean isUndefinedCheck = request == Request.IS_UNDEFINED; 2701 final Expression expr = undefinedSymbol == lhsSymbol ? rhs : lhs; 2702 if (expr.getType().isPrimitive()) { 2703 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 2704 method.load(!isUndefinedCheck); 2705 } else { 2706 final Label checkTrue = new Label("ud_check_true"); 2707 final Label end = new Label("end"); 2708 loadExpressionAsObject(expr); 2709 method.loadUndefined(Type.OBJECT); 2710 method.if_acmpeq(checkTrue); 2711 method.load(!isUndefinedCheck); 2712 method._goto(end); 2713 method.label(checkTrue); 2714 method.load(isUndefinedCheck); 2715 method.label(end); 2716 } 2717 2718 return true; 2719 } 2720 2721 private static boolean isUndefinedSymbol(final Symbol symbol) { 2722 return symbol != null && "undefined".equals(symbol.getName()); 2723 } 2724 2725 private static boolean isNullLiteral(final Node node) { 2726 return node instanceof LiteralNode<?> && ((LiteralNode<?>) node).isNull(); 2727 } 2728 2729 private boolean nullCheck(final RuntimeNode runtimeNode, final List<Expression> args) { 2730 final Request request = runtimeNode.getRequest(); 2731 2732 if (!Request.isEQ(request) && !Request.isNE(request)) { 2733 return false; 2734 } 2735 2736 assert args.size() == 2 : "EQ or NE or TYPEOF need two args"; 2737 2738 Expression lhs = args.get(0); 2739 Expression rhs = args.get(1); 2740 2741 if (isNullLiteral(lhs)) { 2742 final Expression tmp = lhs; 2743 lhs = rhs; 2744 rhs = tmp; 2745 } 2746 2747 if (!isNullLiteral(rhs)) { 2748 return false; 2749 } 2750 2751 if (!lhs.getType().isObject()) { 2752 return false; 2753 } 2754 2755 if(isDeoptimizedExpression(lhs)) { 2756 // This is actually related to "!lhs.getType().isObject()" above: any expression being deoptimized in 2757 // the current chain of rest-of compilations used to have a type narrower than Object. We must not 2758 // perform null check specialization for them, as then we'd no longer be loading aconst_null on stack 2759 // and thus violate the basic rule of "Thou shalt not alter the stack shape between a deoptimized 2760 // method and any of its (transitive) rest-ofs." 2761 // NOTE also that if we had a representation for well-known constants (e.g. null, 0, 1, -1, etc.) in 2762 // Label$Stack.localLoads then this wouldn't be an issue, as we would never (somewhat ridiculously) 2763 // allocate a temporary local to hold the result of aconst_null before attempting an optimistic 2764 // operation. 2765 return false; 2766 } 2767 2768 // this is a null literal check, so if there is implicit coercion 2769 // involved like {D}x=null, we will fail - this is very rare 2770 final Label trueLabel = new Label("trueLabel"); 2771 final Label falseLabel = new Label("falseLabel"); 2772 final Label endLabel = new Label("end"); 2773 2774 loadExpressionUnbounded(lhs); //lhs 2775 final Label popLabel; 2776 if (!Request.isStrict(request)) { 2777 method.dup(); //lhs lhs 2778 popLabel = new Label("pop"); 2779 } else { 2780 popLabel = null; 2781 } 2782 2783 if (Request.isEQ(request)) { 2784 method.ifnull(!Request.isStrict(request) ? popLabel : trueLabel); 2785 if (!Request.isStrict(request)) { 2786 method.loadUndefined(Type.OBJECT); 2787 method.if_acmpeq(trueLabel); 2788 } 2789 method.label(falseLabel); 2790 method.load(false); 2791 method._goto(endLabel); 2792 if (!Request.isStrict(request)) { 2793 method.label(popLabel); 2794 method.pop(); 2795 } 2796 method.label(trueLabel); 2797 method.load(true); 2798 method.label(endLabel); 2799 } else if (Request.isNE(request)) { 2800 method.ifnull(!Request.isStrict(request) ? popLabel : falseLabel); 2801 if (!Request.isStrict(request)) { 2802 method.loadUndefined(Type.OBJECT); 2803 method.if_acmpeq(falseLabel); 2804 } 2805 method.label(trueLabel); 2806 method.load(true); 2807 method._goto(endLabel); 2808 if (!Request.isStrict(request)) { 2809 method.label(popLabel); 2810 method.pop(); 2811 } 2812 method.label(falseLabel); 2813 method.load(false); 2814 method.label(endLabel); 2815 } 2816 2817 assert runtimeNode.getType().isBoolean(); 2818 method.convert(runtimeNode.getType()); 2819 2820 return true; 2821 } 2822 2823 /** 2824 * Was this expression or any of its subexpressions deoptimized in the current recompilation chain of rest-of methods? 2825 * @param rootExpr the expression being tested 2826 * @return true if the expression or any of its subexpressions was deoptimized in the current recompilation chain. 2827 */ 2828 private boolean isDeoptimizedExpression(final Expression rootExpr) { 2829 if(!isRestOf()) { 2830 return false; 2831 } 2832 return new Supplier<Boolean>() { 2833 boolean contains; 2834 @Override 2835 public Boolean get() { 2836 rootExpr.accept(new NodeVisitor<LexicalContext>(new LexicalContext()) { 2837 @Override 2838 public boolean enterFunctionNode(final FunctionNode functionNode) { 2839 return false; 2840 } 2841 @Override 2842 public boolean enterDefault(final Node node) { 2843 if(!contains && node instanceof Optimistic) { 2844 final int pp = ((Optimistic)node).getProgramPoint(); 2845 contains = isValid(pp) && isContinuationEntryPoint(pp); 2846 } 2847 return !contains; 2848 } 2849 }); 2850 return contains; 2851 } 2852 }.get(); 2853 } 2854 2855 private void loadRuntimeNode(final RuntimeNode runtimeNode) { 2856 final List<Expression> args = new ArrayList<>(runtimeNode.getArgs()); 2857 if (nullCheck(runtimeNode, args)) { 2858 return; 2859 } else if(undefinedCheck(runtimeNode, args)) { 2860 return; 2861 } 2862 // Revert a false undefined check to a strict equality check 2863 final RuntimeNode newRuntimeNode; 2864 final Request request = runtimeNode.getRequest(); 2865 if (Request.isUndefinedCheck(request)) { 2866 newRuntimeNode = runtimeNode.setRequest(request == Request.IS_UNDEFINED ? Request.EQ_STRICT : Request.NE_STRICT); 2867 } else { 2868 newRuntimeNode = runtimeNode; 2869 } 2870 2871 for (final Expression arg : args) { 2872 loadExpression(arg, TypeBounds.OBJECT); 2873 } 2874 2875 method.invokestatic( 2876 CompilerConstants.className(ScriptRuntime.class), 2877 newRuntimeNode.getRequest().toString(), 2878 new FunctionSignature( 2879 false, 2880 false, 2881 newRuntimeNode.getType(), 2882 args.size()).toString()); 2883 2884 method.convert(newRuntimeNode.getType()); 2885 } 2886 2887 private void defineCommonSplitMethodParameters() { 2888 defineSplitMethodParameter(0, CALLEE); 2889 defineSplitMethodParameter(1, THIS); 2890 defineSplitMethodParameter(2, SCOPE); 2891 } 2892 2893 private void defineSplitMethodParameter(final int slot, final CompilerConstants cc) { 2894 defineSplitMethodParameter(slot, Type.typeFor(cc.type())); 2895 } 2896 2897 private void defineSplitMethodParameter(final int slot, final Type type) { 2898 method.defineBlockLocalVariable(slot, slot + type.getSlots()); 2899 method.onLocalStore(type, slot); 2900 } 2901 2902 private int fixScopeSlot(final FunctionNode functionNode, final int extraSlot) { 2903 // TODO hack to move the scope to the expected slot (needed because split methods reuse the same slots as the root method) 2904 final int actualScopeSlot = functionNode.compilerConstant(SCOPE).getSlot(SCOPE_TYPE); 2905 final int defaultScopeSlot = SCOPE.slot(); 2906 int newExtraSlot = extraSlot; 2907 if (actualScopeSlot != defaultScopeSlot) { 2908 if (actualScopeSlot == extraSlot) { 2909 newExtraSlot = extraSlot + 1; 2910 method.defineBlockLocalVariable(newExtraSlot, newExtraSlot + 1); 2911 method.load(Type.OBJECT, extraSlot); 2912 method.storeHidden(Type.OBJECT, newExtraSlot); 2913 } else { 2914 method.defineBlockLocalVariable(actualScopeSlot, actualScopeSlot + 1); 2915 } 2916 method.load(SCOPE_TYPE, defaultScopeSlot); 2917 method.storeCompilerConstant(SCOPE); 2918 } 2919 return newExtraSlot; 2920 } 2921 2922 @Override 2923 public boolean enterSplitReturn(final SplitReturn splitReturn) { 2924 if (method.isReachable()) { 2925 method.loadUndefined(lc.getCurrentFunction().getReturnType())._return(); 2926 } 2927 return false; 2928 } 2929 2930 @Override 2931 public boolean enterSetSplitState(final SetSplitState setSplitState) { 2932 if (method.isReachable()) { 2933 method.setSplitState(setSplitState.getState()); 2934 } 2935 return false; 2936 } 2937 2938 @Override 2939 public boolean enterSwitchNode(final SwitchNode switchNode) { 2940 if(!method.isReachable()) { 2941 return false; 2942 } 2943 enterStatement(switchNode); 2944 2945 final Expression expression = switchNode.getExpression(); 2946 final List<CaseNode> cases = switchNode.getCases(); 2947 2948 if (cases.isEmpty()) { 2949 // still evaluate expression for side-effects. 2950 loadAndDiscard(expression); 2951 return false; 2952 } 2953 2954 final CaseNode defaultCase = switchNode.getDefaultCase(); 2955 final Label breakLabel = switchNode.getBreakLabel(); 2956 final int liveLocalsOnBreak = method.getUsedSlotsWithLiveTemporaries(); 2957 2958 if (defaultCase != null && cases.size() == 1) { 2959 // default case only 2960 assert cases.get(0) == defaultCase; 2961 loadAndDiscard(expression); 2962 defaultCase.getBody().accept(this); 2963 method.breakLabel(breakLabel, liveLocalsOnBreak); 2964 return false; 2965 } 2966 2967 // NOTE: it can still change in the tableswitch/lookupswitch case if there's no default case 2968 // but we need to add a synthetic default case for local variable conversions 2969 Label defaultLabel = defaultCase != null ? defaultCase.getEntry() : breakLabel; 2970 final boolean hasSkipConversion = LocalVariableConversion.hasLiveConversion(switchNode); 2971 2972 if (switchNode.isUniqueInteger()) { 2973 // Tree for sorting values. 2974 final TreeMap<Integer, Label> tree = new TreeMap<>(); 2975 2976 // Build up sorted tree. 2977 for (final CaseNode caseNode : cases) { 2978 final Node test = caseNode.getTest(); 2979 2980 if (test != null) { 2981 final Integer value = (Integer)((LiteralNode<?>)test).getValue(); 2982 final Label entry = caseNode.getEntry(); 2983 2984 // Take first duplicate. 2985 if (!tree.containsKey(value)) { 2986 tree.put(value, entry); 2987 } 2988 } 2989 } 2990 2991 // Copy values and labels to arrays. 2992 final int size = tree.size(); 2993 final Integer[] values = tree.keySet().toArray(new Integer[size]); 2994 final Label[] labels = tree.values().toArray(new Label[size]); 2995 2996 // Discern low, high and range. 2997 final int lo = values[0]; 2998 final int hi = values[size - 1]; 2999 final long range = (long)hi - (long)lo + 1; 3000 3001 // Find an unused value for default. 3002 int deflt = Integer.MIN_VALUE; 3003 for (final int value : values) { 3004 if (deflt == value) { 3005 deflt++; 3006 } else if (deflt < value) { 3007 break; 3008 } 3009 } 3010 3011 // Load switch expression. 3012 loadExpressionUnbounded(expression); 3013 final Type type = expression.getType(); 3014 3015 // If expression not int see if we can convert, if not use deflt to trigger default. 3016 if (!type.isInteger()) { 3017 method.load(deflt); 3018 final Class<?> exprClass = type.getTypeClass(); 3019 method.invoke(staticCallNoLookup(ScriptRuntime.class, "switchTagAsInt", int.class, exprClass.isPrimitive()? exprClass : Object.class, int.class)); 3020 } 3021 3022 if(hasSkipConversion) { 3023 assert defaultLabel == breakLabel; 3024 defaultLabel = new Label("switch_skip"); 3025 } 3026 // TABLESWITCH needs (range + 3) 32-bit values; LOOKUPSWITCH needs ((size * 2) + 2). Choose the one with 3027 // smaller representation, favor TABLESWITCH when they're equal size. 3028 if (range + 1 <= (size * 2) && range <= Integer.MAX_VALUE) { 3029 final Label[] table = new Label[(int)range]; 3030 Arrays.fill(table, defaultLabel); 3031 for (int i = 0; i < size; i++) { 3032 final int value = values[i]; 3033 table[value - lo] = labels[i]; 3034 } 3035 3036 method.tableswitch(lo, hi, defaultLabel, table); 3037 } else { 3038 final int[] ints = new int[size]; 3039 for (int i = 0; i < size; i++) { 3040 ints[i] = values[i]; 3041 } 3042 3043 method.lookupswitch(defaultLabel, ints, labels); 3044 } 3045 // This is a synthetic "default case" used in absence of actual default case, created if we need to apply 3046 // local variable conversions if neither case is taken. 3047 if(hasSkipConversion) { 3048 method.label(defaultLabel); 3049 method.beforeJoinPoint(switchNode); 3050 method._goto(breakLabel); 3051 } 3052 } else { 3053 final Symbol tagSymbol = switchNode.getTag(); 3054 // TODO: we could have non-object tag 3055 final int tagSlot = tagSymbol.getSlot(Type.OBJECT); 3056 loadExpressionAsObject(expression); 3057 method.store(tagSymbol, Type.OBJECT); 3058 3059 for (final CaseNode caseNode : cases) { 3060 final Expression test = caseNode.getTest(); 3061 3062 if (test != null) { 3063 method.load(Type.OBJECT, tagSlot); 3064 loadExpressionAsObject(test); 3065 method.invoke(ScriptRuntime.EQ_STRICT); 3066 method.ifne(caseNode.getEntry()); 3067 } 3068 } 3069 3070 if (defaultCase != null) { 3071 method._goto(defaultLabel); 3072 } else { 3073 method.beforeJoinPoint(switchNode); 3074 method._goto(breakLabel); 3075 } 3076 } 3077 3078 // First case is only reachable through jump 3079 assert !method.isReachable(); 3080 3081 for (final CaseNode caseNode : cases) { 3082 final Label fallThroughLabel; 3083 if(caseNode.getLocalVariableConversion() != null && method.isReachable()) { 3084 fallThroughLabel = new Label("fallthrough"); 3085 method._goto(fallThroughLabel); 3086 } else { 3087 fallThroughLabel = null; 3088 } 3089 method.label(caseNode.getEntry()); 3090 method.beforeJoinPoint(caseNode); 3091 if(fallThroughLabel != null) { 3092 method.label(fallThroughLabel); 3093 } 3094 caseNode.getBody().accept(this); 3095 } 3096 3097 method.breakLabel(breakLabel, liveLocalsOnBreak); 3098 3099 return false; 3100 } 3101 3102 @Override 3103 public boolean enterThrowNode(final ThrowNode throwNode) { 3104 if(!method.isReachable()) { 3105 return false; 3106 } 3107 enterStatement(throwNode); 3108 3109 if (throwNode.isSyntheticRethrow()) { 3110 method.beforeJoinPoint(throwNode); 3111 3112 //do not wrap whatever this is in an ecma exception, just rethrow it 3113 final IdentNode exceptionExpr = (IdentNode)throwNode.getExpression(); 3114 final Symbol exceptionSymbol = exceptionExpr.getSymbol(); 3115 method.load(exceptionSymbol, EXCEPTION_TYPE); 3116 method.checkcast(EXCEPTION_TYPE.getTypeClass()); 3117 method.athrow(); 3118 return false; 3119 } 3120 3121 final Source source = getCurrentSource(); 3122 final Expression expression = throwNode.getExpression(); 3123 final int position = throwNode.position(); 3124 final int line = throwNode.getLineNumber(); 3125 final int column = source.getColumn(position); 3126 3127 // NOTE: we first evaluate the expression, and only after it was evaluated do we create the new ECMAException 3128 // object and then somewhat cumbersomely move it beneath the evaluated expression on the stack. The reason for 3129 // this is that if expression is optimistic (or contains an optimistic subexpression), we'd potentially access 3130 // the not-yet-<init>ialized object on the stack from the UnwarrantedOptimismException handler, and bytecode 3131 // verifier forbids that. 3132 loadExpressionAsObject(expression); 3133 3134 method.load(source.getName()); 3135 method.load(line); 3136 method.load(column); 3137 method.invoke(ECMAException.CREATE); 3138 3139 method.beforeJoinPoint(throwNode); 3140 method.athrow(); 3141 3142 return false; 3143 } 3144 3145 private Source getCurrentSource() { 3146 return lc.getCurrentFunction().getSource(); 3147 } 3148 3149 @Override 3150 public boolean enterTryNode(final TryNode tryNode) { 3151 if(!method.isReachable()) { 3152 return false; 3153 } 3154 enterStatement(tryNode); 3155 3156 final Block body = tryNode.getBody(); 3157 final List<Block> catchBlocks = tryNode.getCatchBlocks(); 3158 final Symbol vmException = tryNode.getException(); 3159 final Label entry = new Label("try"); 3160 final Label recovery = new Label("catch"); 3161 final Label exit = new Label("end_try"); 3162 final Label skip = new Label("skip"); 3163 3164 method.canThrow(recovery); 3165 // Effect any conversions that might be observed at the entry of the catch node before entering the try node. 3166 // This is because even the first instruction in the try block must be presumed to be able to transfer control 3167 // to the catch block. Note that this doesn't kill the original values; in this regard it works a lot like 3168 // conversions of assignments within the try block. 3169 method.beforeTry(tryNode, recovery); 3170 method.label(entry); 3171 catchLabels.push(recovery); 3172 try { 3173 body.accept(this); 3174 } finally { 3175 assert catchLabels.peek() == recovery; 3176 catchLabels.pop(); 3177 } 3178 3179 method.label(exit); 3180 final boolean bodyCanThrow = exit.isAfter(entry); 3181 if(!bodyCanThrow) { 3182 // The body can't throw an exception; don't even bother emitting the catch handlers, they're all dead code. 3183 return false; 3184 } 3185 3186 method._try(entry, exit, recovery, Throwable.class); 3187 3188 if (method.isReachable()) { 3189 method._goto(skip); 3190 } 3191 3192 for (final Block inlinedFinally : tryNode.getInlinedFinallies()) { 3193 TryNode.getLabelledInlinedFinallyBlock(inlinedFinally).accept(this); 3194 // All inlined finallies end with a jump or a return 3195 assert !method.isReachable(); 3196 } 3197 3198 3199 method._catch(recovery); 3200 method.store(vmException, EXCEPTION_TYPE); 3201 3202 final int catchBlockCount = catchBlocks.size(); 3203 final Label afterCatch = new Label("after_catch"); 3204 for (int i = 0; i < catchBlockCount; i++) { 3205 assert method.isReachable(); 3206 final Block catchBlock = catchBlocks.get(i); 3207 3208 // Because of the peculiarities of the flow control, we need to use an explicit push/enterBlock/leaveBlock 3209 // here. 3210 lc.push(catchBlock); 3211 enterBlock(catchBlock); 3212 3213 final CatchNode catchNode = (CatchNode)catchBlocks.get(i).getStatements().get(0); 3214 final IdentNode exception = catchNode.getException(); 3215 final Expression exceptionCondition = catchNode.getExceptionCondition(); 3216 final Block catchBody = catchNode.getBody(); 3217 3218 new Store<IdentNode>(exception) { 3219 @Override 3220 protected void storeNonDiscard() { 3221 // This expression is neither part of a discard, nor needs to be left on the stack after it was 3222 // stored, so we override storeNonDiscard to be a no-op. 3223 } 3224 3225 @Override 3226 protected void evaluate() { 3227 if (catchNode.isSyntheticRethrow()) { 3228 method.load(vmException, EXCEPTION_TYPE); 3229 return; 3230 } 3231 /* 3232 * If caught object is an instance of ECMAException, then 3233 * bind obj.thrown to the script catch var. Or else bind the 3234 * caught object itself to the script catch var. 3235 */ 3236 final Label notEcmaException = new Label("no_ecma_exception"); 3237 method.load(vmException, EXCEPTION_TYPE).dup()._instanceof(ECMAException.class).ifeq(notEcmaException); 3238 method.checkcast(ECMAException.class); //TODO is this necessary? 3239 method.getField(ECMAException.THROWN); 3240 method.label(notEcmaException); 3241 } 3242 }.store(); 3243 3244 final boolean isConditionalCatch = exceptionCondition != null; 3245 final Label nextCatch; 3246 if (isConditionalCatch) { 3247 loadExpressionAsBoolean(exceptionCondition); 3248 nextCatch = new Label("next_catch"); 3249 nextCatch.markAsBreakTarget(); 3250 method.ifeq(nextCatch); 3251 } else { 3252 nextCatch = null; 3253 } 3254 3255 catchBody.accept(this); 3256 leaveBlock(catchBlock); 3257 lc.pop(catchBlock); 3258 if(nextCatch != null) { 3259 if(method.isReachable()) { 3260 method._goto(afterCatch); 3261 } 3262 method.breakLabel(nextCatch, lc.getUsedSlotCount()); 3263 } 3264 } 3265 3266 // afterCatch could be the same as skip, except that we need to establish that the vmException is dead. 3267 method.label(afterCatch); 3268 if(method.isReachable()) { 3269 method.markDeadLocalVariable(vmException); 3270 } 3271 method.label(skip); 3272 3273 // Finally body is always inlined elsewhere so it doesn't need to be emitted 3274 assert tryNode.getFinallyBody() == null; 3275 3276 return false; 3277 } 3278 3279 @Override 3280 public boolean enterVarNode(final VarNode varNode) { 3281 if(!method.isReachable()) { 3282 return false; 3283 } 3284 final Expression init = varNode.getInit(); 3285 final IdentNode identNode = varNode.getName(); 3286 final Symbol identSymbol = identNode.getSymbol(); 3287 assert identSymbol != null : "variable node " + varNode + " requires a name with a symbol"; 3288 final boolean needsScope = identSymbol.isScope(); 3289 3290 if (init == null) { 3291 if (needsScope && varNode.isBlockScoped()) { 3292 // block scoped variables need a DECLARE flag to signal end of temporal dead zone (TDZ) 3293 method.loadCompilerConstant(SCOPE); 3294 method.loadUndefined(Type.OBJECT); 3295 final int flags = CALLSITE_SCOPE | getCallSiteFlags() | (varNode.isBlockScoped() ? CALLSITE_DECLARE : 0); 3296 assert isFastScope(identSymbol); 3297 storeFastScopeVar(identSymbol, flags); 3298 } 3299 return false; 3300 } 3301 3302 enterStatement(varNode); 3303 assert method != null; 3304 3305 if (needsScope) { 3306 method.loadCompilerConstant(SCOPE); 3307 } 3308 3309 if (needsScope) { 3310 loadExpressionUnbounded(init); 3311 // block scoped variables need a DECLARE flag to signal end of temporal dead zone (TDZ) 3312 final int flags = CALLSITE_SCOPE | getCallSiteFlags() | (varNode.isBlockScoped() ? CALLSITE_DECLARE : 0); 3313 if (isFastScope(identSymbol)) { 3314 storeFastScopeVar(identSymbol, flags); 3315 } else { 3316 method.dynamicSet(identNode.getName(), flags, false); 3317 } 3318 } else { 3319 final Type identType = identNode.getType(); 3320 if(identType == Type.UNDEFINED) { 3321 // The initializer is either itself undefined (explicit assignment of undefined to undefined), 3322 // or the left hand side is a dead variable. 3323 assert init.getType() == Type.UNDEFINED || identNode.getSymbol().slotCount() == 0; 3324 loadAndDiscard(init); 3325 return false; 3326 } 3327 loadExpressionAsType(init, identType); 3328 storeIdentWithCatchConversion(identNode, identType); 3329 } 3330 3331 return false; 3332 } 3333 3334 private void storeIdentWithCatchConversion(final IdentNode identNode, final Type type) { 3335 // Assignments happening in try/catch blocks need to ensure that they also store a possibly wider typed value 3336 // that will be live at the exit from the try block 3337 final LocalVariableConversion conversion = identNode.getLocalVariableConversion(); 3338 final Symbol symbol = identNode.getSymbol(); 3339 if(conversion != null && conversion.isLive()) { 3340 assert symbol == conversion.getSymbol(); 3341 assert symbol.isBytecodeLocal(); 3342 // Only a single conversion from the target type to the join type is expected. 3343 assert conversion.getNext() == null; 3344 assert conversion.getFrom() == type; 3345 // We must propagate potential type change to the catch block 3346 final Label catchLabel = catchLabels.peek(); 3347 assert catchLabel != METHOD_BOUNDARY; // ident conversion only exists in try blocks 3348 assert catchLabel.isReachable(); 3349 final Type joinType = conversion.getTo(); 3350 final Label.Stack catchStack = catchLabel.getStack(); 3351 final int joinSlot = symbol.getSlot(joinType); 3352 // With nested try/catch blocks (incl. synthetic ones for finally), we can have a supposed conversion for 3353 // the exception symbol in the nested catch, but it isn't live in the outer catch block, so prevent doing 3354 // conversions for it. E.g. in "try { try { ... } catch(e) { e = 1; } } catch(e2) { ... }", we must not 3355 // introduce an I->O conversion on "e = 1" assignment as "e" is not live in "catch(e2)". 3356 if(catchStack.getUsedSlotsWithLiveTemporaries() > joinSlot) { 3357 method.dup(); 3358 method.convert(joinType); 3359 method.store(symbol, joinType); 3360 catchLabel.getStack().onLocalStore(joinType, joinSlot, true); 3361 method.canThrow(catchLabel); 3362 // Store but keep the previous store live too. 3363 method.store(symbol, type, false); 3364 return; 3365 } 3366 } 3367 3368 method.store(symbol, type, true); 3369 } 3370 3371 @Override 3372 public boolean enterWhileNode(final WhileNode whileNode) { 3373 if(!method.isReachable()) { 3374 return false; 3375 } 3376 if(whileNode.isDoWhile()) { 3377 enterDoWhile(whileNode); 3378 } else { 3379 enterStatement(whileNode); 3380 enterForOrWhile(whileNode, null); 3381 } 3382 return false; 3383 } 3384 3385 private void enterForOrWhile(final LoopNode loopNode, final JoinPredecessorExpression modify) { 3386 // NOTE: the usual pattern for compiling test-first loops is "GOTO test; body; test; IFNE body". We use the less 3387 // conventional "test; IFEQ break; body; GOTO test; break;". It has one extra unconditional GOTO in each repeat 3388 // of the loop, but it's not a problem for modern JIT compilers. We do this because our local variable type 3389 // tracking is unfortunately not really prepared for out-of-order execution, e.g. compiling the following 3390 // contrived but legal JavaScript code snippet would fail because the test changes the type of "i" from object 3391 // to double: var i = {valueOf: function() { return 1} }; while(--i >= 0) { ... } 3392 // Instead of adding more complexity to the local variable type tracking, we instead choose to emit this 3393 // different code shape. 3394 final int liveLocalsOnBreak = method.getUsedSlotsWithLiveTemporaries(); 3395 final JoinPredecessorExpression test = loopNode.getTest(); 3396 if(Expression.isAlwaysFalse(test)) { 3397 loadAndDiscard(test); 3398 return; 3399 } 3400 3401 method.beforeJoinPoint(loopNode); 3402 3403 final Label continueLabel = loopNode.getContinueLabel(); 3404 final Label repeatLabel = modify != null ? new Label("for_repeat") : continueLabel; 3405 method.label(repeatLabel); 3406 final int liveLocalsOnContinue = method.getUsedSlotsWithLiveTemporaries(); 3407 3408 final Block body = loopNode.getBody(); 3409 final Label breakLabel = loopNode.getBreakLabel(); 3410 final boolean testHasLiveConversion = test != null && LocalVariableConversion.hasLiveConversion(test); 3411 3412 if(Expression.isAlwaysTrue(test)) { 3413 if(test != null) { 3414 loadAndDiscard(test); 3415 if(testHasLiveConversion) { 3416 method.beforeJoinPoint(test); 3417 } 3418 } 3419 } else if (test != null) { 3420 if (testHasLiveConversion) { 3421 emitBranch(test.getExpression(), body.getEntryLabel(), true); 3422 method.beforeJoinPoint(test); 3423 method._goto(breakLabel); 3424 } else { 3425 emitBranch(test.getExpression(), breakLabel, false); 3426 } 3427 } 3428 3429 body.accept(this); 3430 if(repeatLabel != continueLabel) { 3431 emitContinueLabel(continueLabel, liveLocalsOnContinue); 3432 } 3433 3434 if (loopNode.hasPerIterationScope() && lc.getCurrentBlock().needsScope()) { 3435 // ES6 for loops with LET init need a new scope for each iteration. We just create a shallow copy here. 3436 method.loadCompilerConstant(SCOPE); 3437 method.invoke(virtualCallNoLookup(ScriptObject.class, "copy", ScriptObject.class)); 3438 method.storeCompilerConstant(SCOPE); 3439 } 3440 3441 if(method.isReachable()) { 3442 if(modify != null) { 3443 lineNumber(loopNode); 3444 loadAndDiscard(modify); 3445 method.beforeJoinPoint(modify); 3446 } 3447 method._goto(repeatLabel); 3448 } 3449 3450 method.breakLabel(breakLabel, liveLocalsOnBreak); 3451 } 3452 3453 private void emitContinueLabel(final Label continueLabel, final int liveLocals) { 3454 final boolean reachable = method.isReachable(); 3455 method.breakLabel(continueLabel, liveLocals); 3456 // If we reach here only through a continue statement (e.g. body does not exit normally) then the 3457 // continueLabel can have extra non-temp symbols (e.g. exception from a try/catch contained in the body). We 3458 // must make sure those are thrown away. 3459 if(!reachable) { 3460 method.undefineLocalVariables(lc.getUsedSlotCount(), false); 3461 } 3462 } 3463 3464 private void enterDoWhile(final WhileNode whileNode) { 3465 final int liveLocalsOnContinueOrBreak = method.getUsedSlotsWithLiveTemporaries(); 3466 method.beforeJoinPoint(whileNode); 3467 3468 final Block body = whileNode.getBody(); 3469 body.accept(this); 3470 3471 emitContinueLabel(whileNode.getContinueLabel(), liveLocalsOnContinueOrBreak); 3472 if(method.isReachable()) { 3473 lineNumber(whileNode); 3474 final JoinPredecessorExpression test = whileNode.getTest(); 3475 final Label bodyEntryLabel = body.getEntryLabel(); 3476 final boolean testHasLiveConversion = LocalVariableConversion.hasLiveConversion(test); 3477 if(Expression.isAlwaysFalse(test)) { 3478 loadAndDiscard(test); 3479 if(testHasLiveConversion) { 3480 method.beforeJoinPoint(test); 3481 } 3482 } else if(testHasLiveConversion) { 3483 // If we have conversions after the test in do-while, they need to be effected on both branches. 3484 final Label beforeExit = new Label("do_while_preexit"); 3485 emitBranch(test.getExpression(), beforeExit, false); 3486 method.beforeJoinPoint(test); 3487 method._goto(bodyEntryLabel); 3488 method.label(beforeExit); 3489 method.beforeJoinPoint(test); 3490 } else { 3491 emitBranch(test.getExpression(), bodyEntryLabel, true); 3492 } 3493 } 3494 method.breakLabel(whileNode.getBreakLabel(), liveLocalsOnContinueOrBreak); 3495 } 3496 3497 3498 @Override 3499 public boolean enterWithNode(final WithNode withNode) { 3500 if(!method.isReachable()) { 3501 return false; 3502 } 3503 enterStatement(withNode); 3504 final Expression expression = withNode.getExpression(); 3505 final Block body = withNode.getBody(); 3506 3507 // It is possible to have a "pathological" case where the with block does not reference *any* identifiers. It's 3508 // pointless, but legal. In that case, if nothing else in the method forced the assignment of a slot to the 3509 // scope object, its' possible that it won't have a slot assigned. In this case we'll only evaluate expression 3510 // for its side effect and visit the body, and not bother opening and closing a WithObject. 3511 final boolean hasScope = method.hasScope(); 3512 3513 if (hasScope) { 3514 method.loadCompilerConstant(SCOPE); 3515 } 3516 3517 loadExpressionAsObject(expression); 3518 3519 final Label tryLabel; 3520 if (hasScope) { 3521 // Construct a WithObject if we have a scope 3522 method.invoke(ScriptRuntime.OPEN_WITH); 3523 method.storeCompilerConstant(SCOPE); 3524 tryLabel = new Label("with_try"); 3525 method.label(tryLabel); 3526 } else { 3527 // We just loaded the expression for its side effect and to check 3528 // for null or undefined value. 3529 globalCheckObjectCoercible(); 3530 tryLabel = null; 3531 } 3532 3533 // Always process body 3534 body.accept(this); 3535 3536 if (hasScope) { 3537 // Ensure we always close the WithObject 3538 final Label endLabel = new Label("with_end"); 3539 final Label catchLabel = new Label("with_catch"); 3540 final Label exitLabel = new Label("with_exit"); 3541 3542 method.label(endLabel); 3543 // Somewhat conservatively presume that if the body is not empty, it can throw an exception. In any case, 3544 // we must prevent trying to emit a try-catch for empty range, as it causes a verification error. 3545 final boolean bodyCanThrow = endLabel.isAfter(tryLabel); 3546 if(bodyCanThrow) { 3547 method._try(tryLabel, endLabel, catchLabel); 3548 } 3549 3550 final boolean reachable = method.isReachable(); 3551 if(reachable) { 3552 popScope(); 3553 if(bodyCanThrow) { 3554 method._goto(exitLabel); 3555 } 3556 } 3557 3558 if(bodyCanThrow) { 3559 method._catch(catchLabel); 3560 popScopeException(); 3561 method.athrow(); 3562 if(reachable) { 3563 method.label(exitLabel); 3564 } 3565 } 3566 } 3567 return false; 3568 } 3569 3570 private void loadADD(final UnaryNode unaryNode, final TypeBounds resultBounds) { 3571 loadExpression(unaryNode.getExpression(), resultBounds.booleanToInt().notWiderThan(Type.NUMBER)); 3572 if(method.peekType() == Type.BOOLEAN) { 3573 // It's a no-op in bytecode, but we must make sure it is treated as an int for purposes of type signatures 3574 method.convert(Type.INT); 3575 } 3576 } 3577 3578 private void loadBIT_NOT(final UnaryNode unaryNode) { 3579 loadExpression(unaryNode.getExpression(), TypeBounds.INT).load(-1).xor(); 3580 } 3581 3582 private void loadDECINC(final UnaryNode unaryNode) { 3583 final Expression operand = unaryNode.getExpression(); 3584 final Type type = unaryNode.getType(); 3585 final TypeBounds typeBounds = new TypeBounds(type, Type.NUMBER); 3586 final TokenType tokenType = unaryNode.tokenType(); 3587 final boolean isPostfix = tokenType == TokenType.DECPOSTFIX || tokenType == TokenType.INCPOSTFIX; 3588 final boolean isIncrement = tokenType == TokenType.INCPREFIX || tokenType == TokenType.INCPOSTFIX; 3589 3590 assert !type.isObject(); 3591 3592 new SelfModifyingStore<UnaryNode>(unaryNode, operand) { 3593 3594 private void loadRhs() { 3595 loadExpression(operand, typeBounds, true); 3596 } 3597 3598 @Override 3599 protected void evaluate() { 3600 if(isPostfix) { 3601 loadRhs(); 3602 } else { 3603 new OptimisticOperation(unaryNode, typeBounds) { 3604 @Override 3605 void loadStack() { 3606 loadRhs(); 3607 loadMinusOne(); 3608 } 3609 @Override 3610 void consumeStack() { 3611 doDecInc(getProgramPoint()); 3612 } 3613 }.emit(getOptimisticIgnoreCountForSelfModifyingExpression(operand)); 3614 } 3615 } 3616 3617 @Override 3618 protected void storeNonDiscard() { 3619 super.storeNonDiscard(); 3620 if (isPostfix) { 3621 new OptimisticOperation(unaryNode, typeBounds) { 3622 @Override 3623 void loadStack() { 3624 loadMinusOne(); 3625 } 3626 @Override 3627 void consumeStack() { 3628 doDecInc(getProgramPoint()); 3629 } 3630 }.emit(1); // 1 for non-incremented result on the top of the stack pushed in evaluate() 3631 } 3632 } 3633 3634 private void loadMinusOne() { 3635 if (type.isInteger()) { 3636 method.load(isIncrement ? 1 : -1); 3637 } else if (type.isLong()) { 3638 method.load(isIncrement ? 1L : -1L); 3639 } else { 3640 method.load(isIncrement ? 1.0 : -1.0); 3641 } 3642 } 3643 3644 private void doDecInc(final int programPoint) { 3645 method.add(programPoint); 3646 } 3647 }.store(); 3648 } 3649 3650 private static int getOptimisticIgnoreCountForSelfModifyingExpression(final Expression target) { 3651 return target instanceof AccessNode ? 1 : target instanceof IndexNode ? 2 : 0; 3652 } 3653 3654 private void loadAndDiscard(final Expression expr) { 3655 // TODO: move checks for discarding to actual expression load code (e.g. as we do with void). That way we might 3656 // be able to eliminate even more checks. 3657 if(expr instanceof PrimitiveLiteralNode | isLocalVariable(expr)) { 3658 assert !lc.isCurrentDiscard(expr); 3659 // Don't bother evaluating expressions without side effects. Typical usage is "void 0" for reliably generating 3660 // undefined. 3661 return; 3662 } 3663 3664 lc.pushDiscard(expr); 3665 loadExpression(expr, TypeBounds.UNBOUNDED); 3666 if (lc.popDiscardIfCurrent(expr)) { 3667 assert !expr.isAssignment(); 3668 // NOTE: if we had a way to load with type void, we could avoid popping 3669 method.pop(); 3670 } 3671 } 3672 3673 /** 3674 * Loads the expression with the specified type bounds, but if the parent expression is the current discard, 3675 * then instead loads and discards the expression. 3676 * @param parent the parent expression that's tested for being the current discard 3677 * @param expr the expression that's either normally loaded or discard-loaded 3678 * @param resultBounds result bounds for when loading the expression normally 3679 */ 3680 private void loadMaybeDiscard(final Expression parent, final Expression expr, final TypeBounds resultBounds) { 3681 loadMaybeDiscard(lc.popDiscardIfCurrent(parent), expr, resultBounds); 3682 } 3683 3684 /** 3685 * Loads the expression with the specified type bounds, or loads and discards the expression, depending on the 3686 * value of the discard flag. Useful as a helper for expressions with control flow where you often can't combine 3687 * testing for being the current discard and loading the subexpressions. 3688 * @param discard if true, the expression is loaded and discarded 3689 * @param expr the expression that's either normally loaded or discard-loaded 3690 * @param resultBounds result bounds for when loading the expression normally 3691 */ 3692 private void loadMaybeDiscard(final boolean discard, final Expression expr, final TypeBounds resultBounds) { 3693 if (discard) { 3694 loadAndDiscard(expr); 3695 } else { 3696 loadExpression(expr, resultBounds); 3697 } 3698 } 3699 3700 private void loadNEW(final UnaryNode unaryNode) { 3701 final CallNode callNode = (CallNode)unaryNode.getExpression(); 3702 final List<Expression> args = callNode.getArgs(); 3703 3704 // Load function reference. 3705 loadExpressionAsObject(callNode.getFunction()); // must detect type error 3706 3707 method.dynamicNew(1 + loadArgs(args), getCallSiteFlags()); 3708 } 3709 3710 private void loadNOT(final UnaryNode unaryNode) { 3711 final Expression expr = unaryNode.getExpression(); 3712 if(expr instanceof UnaryNode && expr.isTokenType(TokenType.NOT)) { 3713 // !!x is idiomatic boolean cast in JavaScript 3714 loadExpressionAsBoolean(((UnaryNode)expr).getExpression()); 3715 } else { 3716 final Label trueLabel = new Label("true"); 3717 final Label afterLabel = new Label("after"); 3718 3719 emitBranch(expr, trueLabel, true); 3720 method.load(true); 3721 method._goto(afterLabel); 3722 method.label(trueLabel); 3723 method.load(false); 3724 method.label(afterLabel); 3725 } 3726 } 3727 3728 private void loadSUB(final UnaryNode unaryNode, final TypeBounds resultBounds) { 3729 final Type type = unaryNode.getType(); 3730 assert type.isNumeric(); 3731 final TypeBounds numericBounds = resultBounds.booleanToInt(); 3732 new OptimisticOperation(unaryNode, numericBounds) { 3733 @Override 3734 void loadStack() { 3735 final Expression expr = unaryNode.getExpression(); 3736 loadExpression(expr, numericBounds.notWiderThan(Type.NUMBER)); 3737 } 3738 @Override 3739 void consumeStack() { 3740 // Must do an explicit conversion to the operation's type when it's double so that we correctly handle 3741 // negation of an int 0 to a double -0. With this, we get the correct negation of a local variable after 3742 // it deoptimized, e.g. "iload_2; i2d; dneg". Without this, we get "iload_2; ineg; i2d". 3743 if(type.isNumber()) { 3744 method.convert(type); 3745 } 3746 method.neg(getProgramPoint()); 3747 } 3748 }.emit(); 3749 } 3750 3751 public void loadVOID(final UnaryNode unaryNode, final TypeBounds resultBounds) { 3752 loadAndDiscard(unaryNode.getExpression()); 3753 if (!lc.popDiscardIfCurrent(unaryNode)) { 3754 method.loadUndefined(resultBounds.widest); 3755 } 3756 } 3757 3758 public void loadADD(final BinaryNode binaryNode, final TypeBounds resultBounds) { 3759 new OptimisticOperation(binaryNode, resultBounds) { 3760 @Override 3761 void loadStack() { 3762 final TypeBounds operandBounds; 3763 final boolean isOptimistic = isValid(getProgramPoint()); 3764 boolean forceConversionSeparation = false; 3765 if(isOptimistic) { 3766 operandBounds = new TypeBounds(binaryNode.getType(), Type.OBJECT); 3767 } else { 3768 // Non-optimistic, non-FP +. Allow it to overflow. 3769 final Type widestOperationType = binaryNode.getWidestOperationType(); 3770 operandBounds = new TypeBounds(Type.narrowest(binaryNode.getWidestOperandType(), resultBounds.widest), widestOperationType); 3771 forceConversionSeparation = widestOperationType.narrowerThan(resultBounds.widest); 3772 } 3773 loadBinaryOperands(binaryNode.lhs(), binaryNode.rhs(), operandBounds, false, forceConversionSeparation); 3774 } 3775 3776 @Override 3777 void consumeStack() { 3778 method.add(getProgramPoint()); 3779 } 3780 }.emit(); 3781 } 3782 3783 private void loadAND_OR(final BinaryNode binaryNode, final TypeBounds resultBounds, final boolean isAnd) { 3784 final Type narrowestOperandType = Type.widestReturnType(binaryNode.lhs().getType(), binaryNode.rhs().getType()); 3785 3786 final boolean isCurrentDiscard = lc.popDiscardIfCurrent(binaryNode); 3787 3788 final Label skip = new Label("skip"); 3789 if(narrowestOperandType == Type.BOOLEAN) { 3790 // optimize all-boolean logical expressions 3791 final Label onTrue = new Label("andor_true"); 3792 emitBranch(binaryNode, onTrue, true); 3793 if (isCurrentDiscard) { 3794 method.label(onTrue); 3795 method.pop(); 3796 } else { 3797 method.load(false); 3798 method._goto(skip); 3799 method.label(onTrue); 3800 method.load(true); 3801 method.label(skip); 3802 } 3803 return; 3804 } 3805 3806 final TypeBounds outBounds = resultBounds.notNarrowerThan(narrowestOperandType); 3807 final JoinPredecessorExpression lhs = (JoinPredecessorExpression)binaryNode.lhs(); 3808 final boolean lhsConvert = LocalVariableConversion.hasLiveConversion(lhs); 3809 final Label evalRhs = lhsConvert ? new Label("eval_rhs") : null; 3810 3811 loadExpression(lhs, outBounds); 3812 if (!isCurrentDiscard) { 3813 method.dup(); 3814 } 3815 method.convert(Type.BOOLEAN); 3816 if (isAnd) { 3817 if(lhsConvert) { 3818 method.ifne(evalRhs); 3819 } else { 3820 method.ifeq(skip); 3821 } 3822 } else if(lhsConvert) { 3823 method.ifeq(evalRhs); 3824 } else { 3825 method.ifne(skip); 3826 } 3827 3828 if(lhsConvert) { 3829 method.beforeJoinPoint(lhs); 3830 method._goto(skip); 3831 method.label(evalRhs); 3832 } 3833 3834 if (!isCurrentDiscard) { 3835 method.pop(); 3836 } 3837 final JoinPredecessorExpression rhs = (JoinPredecessorExpression)binaryNode.rhs(); 3838 loadMaybeDiscard(isCurrentDiscard, rhs, outBounds); 3839 method.beforeJoinPoint(rhs); 3840 method.label(skip); 3841 } 3842 3843 private static boolean isLocalVariable(final Expression lhs) { 3844 return lhs instanceof IdentNode && isLocalVariable((IdentNode)lhs); 3845 } 3846 3847 private static boolean isLocalVariable(final IdentNode lhs) { 3848 return lhs.getSymbol().isBytecodeLocal(); 3849 } 3850 3851 // NOTE: does not use resultBounds as the assignment is driven by the type of the RHS 3852 private void loadASSIGN(final BinaryNode binaryNode) { 3853 final Expression lhs = binaryNode.lhs(); 3854 final Expression rhs = binaryNode.rhs(); 3855 3856 final Type rhsType = rhs.getType(); 3857 // Detect dead assignments 3858 if(lhs instanceof IdentNode) { 3859 final Symbol symbol = ((IdentNode)lhs).getSymbol(); 3860 if(!symbol.isScope() && !symbol.hasSlotFor(rhsType) && lc.popDiscardIfCurrent(binaryNode)) { 3861 loadAndDiscard(rhs); 3862 method.markDeadLocalVariable(symbol); 3863 return; 3864 } 3865 } 3866 3867 new Store<BinaryNode>(binaryNode, lhs) { 3868 @Override 3869 protected void evaluate() { 3870 // NOTE: we're loading with "at least as wide as" so optimistic operations on the right hand side 3871 // remain optimistic, and then explicitly convert to the required type if needed. 3872 loadExpressionAsType(rhs, rhsType); 3873 } 3874 }.store(); 3875 } 3876 3877 /** 3878 * Binary self-assignment that can be optimistic: +=, -=, *=, and /=. 3879 */ 3880 private abstract class BinaryOptimisticSelfAssignment extends SelfModifyingStore<BinaryNode> { 3881 3882 /** 3883 * Constructor 3884 * 3885 * @param node the assign op node 3886 */ 3887 BinaryOptimisticSelfAssignment(final BinaryNode node) { 3888 super(node, node.lhs()); 3889 } 3890 3891 protected abstract void op(OptimisticOperation oo); 3892 3893 @Override 3894 protected void evaluate() { 3895 final Expression lhs = assignNode.lhs(); 3896 final Expression rhs = assignNode.rhs(); 3897 final Type widestOperationType = assignNode.getWidestOperationType(); 3898 final TypeBounds bounds = new TypeBounds(assignNode.getType(), widestOperationType); 3899 new OptimisticOperation(assignNode, bounds) { 3900 @Override 3901 void loadStack() { 3902 final boolean forceConversionSeparation; 3903 if (isValid(getProgramPoint()) || widestOperationType == Type.NUMBER) { 3904 forceConversionSeparation = false; 3905 } else { 3906 final Type operandType = Type.widest(booleanToInt(objectToNumber(lhs.getType())), booleanToInt(objectToNumber(rhs.getType()))); 3907 forceConversionSeparation = operandType.narrowerThan(widestOperationType); 3908 } 3909 loadBinaryOperands(lhs, rhs, bounds, true, forceConversionSeparation); 3910 } 3911 @Override 3912 void consumeStack() { 3913 op(this); 3914 } 3915 }.emit(getOptimisticIgnoreCountForSelfModifyingExpression(lhs)); 3916 method.convert(assignNode.getType()); 3917 } 3918 } 3919 3920 /** 3921 * Non-optimistic binary self-assignment operation. Basically, everything except +=, -=, *=, and /=. 3922 */ 3923 private abstract class BinarySelfAssignment extends SelfModifyingStore<BinaryNode> { 3924 BinarySelfAssignment(final BinaryNode node) { 3925 super(node, node.lhs()); 3926 } 3927 3928 protected abstract void op(); 3929 3930 @Override 3931 protected void evaluate() { 3932 loadBinaryOperands(assignNode.lhs(), assignNode.rhs(), TypeBounds.UNBOUNDED.notWiderThan(assignNode.getWidestOperandType()), true, false); 3933 op(); 3934 } 3935 } 3936 3937 private void loadASSIGN_ADD(final BinaryNode binaryNode) { 3938 new BinaryOptimisticSelfAssignment(binaryNode) { 3939 @Override 3940 protected void op(final OptimisticOperation oo) { 3941 assert !(binaryNode.getType().isObject() && oo.isOptimistic); 3942 method.add(oo.getProgramPoint()); 3943 } 3944 }.store(); 3945 } 3946 3947 private void loadASSIGN_BIT_AND(final BinaryNode binaryNode) { 3948 new BinarySelfAssignment(binaryNode) { 3949 @Override 3950 protected void op() { 3951 method.and(); 3952 } 3953 }.store(); 3954 } 3955 3956 private void loadASSIGN_BIT_OR(final BinaryNode binaryNode) { 3957 new BinarySelfAssignment(binaryNode) { 3958 @Override 3959 protected void op() { 3960 method.or(); 3961 } 3962 }.store(); 3963 } 3964 3965 private void loadASSIGN_BIT_XOR(final BinaryNode binaryNode) { 3966 new BinarySelfAssignment(binaryNode) { 3967 @Override 3968 protected void op() { 3969 method.xor(); 3970 } 3971 }.store(); 3972 } 3973 3974 private void loadASSIGN_DIV(final BinaryNode binaryNode) { 3975 new BinaryOptimisticSelfAssignment(binaryNode) { 3976 @Override 3977 protected void op(final OptimisticOperation oo) { 3978 method.div(oo.getProgramPoint()); 3979 } 3980 }.store(); 3981 } 3982 3983 private void loadASSIGN_MOD(final BinaryNode binaryNode) { 3984 new BinaryOptimisticSelfAssignment(binaryNode) { 3985 @Override 3986 protected void op(final OptimisticOperation oo) { 3987 method.rem(oo.getProgramPoint()); 3988 } 3989 }.store(); 3990 } 3991 3992 private void loadASSIGN_MUL(final BinaryNode binaryNode) { 3993 new BinaryOptimisticSelfAssignment(binaryNode) { 3994 @Override 3995 protected void op(final OptimisticOperation oo) { 3996 method.mul(oo.getProgramPoint()); 3997 } 3998 }.store(); 3999 } 4000 4001 private void loadASSIGN_SAR(final BinaryNode binaryNode) { 4002 new BinarySelfAssignment(binaryNode) { 4003 @Override 4004 protected void op() { 4005 method.sar(); 4006 } 4007 }.store(); 4008 } 4009 4010 private void loadASSIGN_SHL(final BinaryNode binaryNode) { 4011 new BinarySelfAssignment(binaryNode) { 4012 @Override 4013 protected void op() { 4014 method.shl(); 4015 } 4016 }.store(); 4017 } 4018 4019 private void loadASSIGN_SHR(final BinaryNode binaryNode) { 4020 new BinarySelfAssignment(binaryNode) { 4021 @Override 4022 protected void op() { 4023 doSHR(); 4024 } 4025 4026 }.store(); 4027 } 4028 4029 private void doSHR() { 4030 // TODO: make SHR optimistic 4031 method.shr(); 4032 toUint(); 4033 } 4034 4035 private void toUint() { 4036 JSType.TO_UINT32_I.invoke(method); 4037 } 4038 4039 private void loadASSIGN_SUB(final BinaryNode binaryNode) { 4040 new BinaryOptimisticSelfAssignment(binaryNode) { 4041 @Override 4042 protected void op(final OptimisticOperation oo) { 4043 method.sub(oo.getProgramPoint()); 4044 } 4045 }.store(); 4046 } 4047 4048 /** 4049 * Helper class for binary arithmetic ops 4050 */ 4051 private abstract class BinaryArith { 4052 protected abstract void op(int programPoint); 4053 4054 protected void evaluate(final BinaryNode node, final TypeBounds resultBounds) { 4055 final TypeBounds numericBounds = resultBounds.booleanToInt().objectToNumber(); 4056 new OptimisticOperation(node, numericBounds) { 4057 @Override 4058 void loadStack() { 4059 final TypeBounds operandBounds; 4060 boolean forceConversionSeparation = false; 4061 if(numericBounds.narrowest == Type.NUMBER) { 4062 // Result should be double always. Propagate it into the operands so we don't have lots of I2D 4063 // and L2D after operand evaluation. 4064 assert numericBounds.widest == Type.NUMBER; 4065 operandBounds = numericBounds; 4066 } else { 4067 final boolean isOptimistic = isValid(getProgramPoint()); 4068 if(isOptimistic || node.isTokenType(TokenType.DIV) || node.isTokenType(TokenType.MOD)) { 4069 operandBounds = new TypeBounds(node.getType(), Type.NUMBER); 4070 } else { 4071 // Non-optimistic, non-FP subtraction or multiplication. Allow them to overflow. 4072 operandBounds = new TypeBounds(Type.narrowest(node.getWidestOperandType(), 4073 numericBounds.widest), Type.NUMBER); 4074 forceConversionSeparation = node.getWidestOperationType().narrowerThan(numericBounds.widest); 4075 } 4076 } 4077 loadBinaryOperands(node.lhs(), node.rhs(), operandBounds, false, forceConversionSeparation); 4078 } 4079 4080 @Override 4081 void consumeStack() { 4082 op(getProgramPoint()); 4083 } 4084 }.emit(); 4085 } 4086 } 4087 4088 private void loadBIT_AND(final BinaryNode binaryNode) { 4089 loadBinaryOperands(binaryNode); 4090 method.and(); 4091 } 4092 4093 private void loadBIT_OR(final BinaryNode binaryNode) { 4094 // Optimize x|0 to (int)x 4095 if (isRhsZero(binaryNode)) { 4096 loadExpressionAsType(binaryNode.lhs(), Type.INT); 4097 } else { 4098 loadBinaryOperands(binaryNode); 4099 method.or(); 4100 } 4101 } 4102 4103 private static boolean isRhsZero(final BinaryNode binaryNode) { 4104 final Expression rhs = binaryNode.rhs(); 4105 return rhs instanceof LiteralNode && INT_ZERO.equals(((LiteralNode<?>)rhs).getValue()); 4106 } 4107 4108 private void loadBIT_XOR(final BinaryNode binaryNode) { 4109 loadBinaryOperands(binaryNode); 4110 method.xor(); 4111 } 4112 4113 private void loadCOMMARIGHT(final BinaryNode binaryNode, final TypeBounds resultBounds) { 4114 loadAndDiscard(binaryNode.lhs()); 4115 loadMaybeDiscard(binaryNode, binaryNode.rhs(), resultBounds); 4116 } 4117 4118 private void loadCOMMALEFT(final BinaryNode binaryNode, final TypeBounds resultBounds) { 4119 loadMaybeDiscard(binaryNode, binaryNode.lhs(), resultBounds); 4120 loadAndDiscard(binaryNode.rhs()); 4121 } 4122 4123 private void loadDIV(final BinaryNode binaryNode, final TypeBounds resultBounds) { 4124 new BinaryArith() { 4125 @Override 4126 protected void op(final int programPoint) { 4127 method.div(programPoint); 4128 } 4129 }.evaluate(binaryNode, resultBounds); 4130 } 4131 4132 private void loadCmp(final BinaryNode binaryNode, final Condition cond) { 4133 loadComparisonOperands(binaryNode); 4134 4135 final Label trueLabel = new Label("trueLabel"); 4136 final Label afterLabel = new Label("skip"); 4137 4138 method.conditionalJump(cond, trueLabel); 4139 4140 method.load(Boolean.FALSE); 4141 method._goto(afterLabel); 4142 method.label(trueLabel); 4143 method.load(Boolean.TRUE); 4144 method.label(afterLabel); 4145 } 4146 4147 private void loadMOD(final BinaryNode binaryNode, final TypeBounds resultBounds) { 4148 new BinaryArith() { 4149 @Override 4150 protected void op(final int programPoint) { 4151 method.rem(programPoint); 4152 } 4153 }.evaluate(binaryNode, resultBounds); 4154 } 4155 4156 private void loadMUL(final BinaryNode binaryNode, final TypeBounds resultBounds) { 4157 new BinaryArith() { 4158 @Override 4159 protected void op(final int programPoint) { 4160 method.mul(programPoint); 4161 } 4162 }.evaluate(binaryNode, resultBounds); 4163 } 4164 4165 private void loadSAR(final BinaryNode binaryNode) { 4166 loadBinaryOperands(binaryNode); 4167 method.sar(); 4168 } 4169 4170 private void loadSHL(final BinaryNode binaryNode) { 4171 loadBinaryOperands(binaryNode); 4172 method.shl(); 4173 } 4174 4175 private void loadSHR(final BinaryNode binaryNode) { 4176 // Optimize x >>> 0 to (uint)x 4177 if (isRhsZero(binaryNode)) { 4178 loadExpressionAsType(binaryNode.lhs(), Type.INT); 4179 toUint(); 4180 } else { 4181 loadBinaryOperands(binaryNode); 4182 doSHR(); 4183 } 4184 } 4185 4186 private void loadSUB(final BinaryNode binaryNode, final TypeBounds resultBounds) { 4187 new BinaryArith() { 4188 @Override 4189 protected void op(final int programPoint) { 4190 method.sub(programPoint); 4191 } 4192 }.evaluate(binaryNode, resultBounds); 4193 } 4194 4195 @Override 4196 public boolean enterLabelNode(final LabelNode labelNode) { 4197 labeledBlockBreakLiveLocals.push(lc.getUsedSlotCount()); 4198 return true; 4199 } 4200 4201 @Override 4202 protected boolean enterDefault(final Node node) { 4203 throw new AssertionError("Code generator entered node of type " + node.getClass().getName()); 4204 } 4205 4206 private void loadTernaryNode(final TernaryNode ternaryNode, final TypeBounds resultBounds) { 4207 final Expression test = ternaryNode.getTest(); 4208 final JoinPredecessorExpression trueExpr = ternaryNode.getTrueExpression(); 4209 final JoinPredecessorExpression falseExpr = ternaryNode.getFalseExpression(); 4210 4211 final Label falseLabel = new Label("ternary_false"); 4212 final Label exitLabel = new Label("ternary_exit"); 4213 4214 final Type outNarrowest = Type.narrowest(resultBounds.widest, Type.generic(Type.widestReturnType(trueExpr.getType(), falseExpr.getType()))); 4215 final TypeBounds outBounds = resultBounds.notNarrowerThan(outNarrowest); 4216 4217 emitBranch(test, falseLabel, false); 4218 4219 final boolean isCurrentDiscard = lc.popDiscardIfCurrent(ternaryNode); 4220 loadMaybeDiscard(isCurrentDiscard, trueExpr.getExpression(), outBounds); 4221 assert isCurrentDiscard || Type.generic(method.peekType()) == outBounds.narrowest; 4222 method.beforeJoinPoint(trueExpr); 4223 method._goto(exitLabel); 4224 method.label(falseLabel); 4225 loadMaybeDiscard(isCurrentDiscard, falseExpr.getExpression(), outBounds); 4226 assert isCurrentDiscard || Type.generic(method.peekType()) == outBounds.narrowest; 4227 method.beforeJoinPoint(falseExpr); 4228 method.label(exitLabel); 4229 } 4230 4231 /** 4232 * Generate all shared scope calls generated during codegen. 4233 */ 4234 void generateScopeCalls() { 4235 for (final SharedScopeCall scopeAccess : lc.getScopeCalls()) { 4236 scopeAccess.generateScopeCall(); 4237 } 4238 } 4239 4240 /** 4241 * Debug code used to print symbols 4242 * 4243 * @param block the block we are in 4244 * @param function the function we are in 4245 * @param ident identifier for block or function where applicable 4246 */ 4247 private void printSymbols(final Block block, final FunctionNode function, final String ident) { 4248 if (compiler.getScriptEnvironment()._print_symbols || function.getFlag(FunctionNode.IS_PRINT_SYMBOLS)) { 4249 final PrintWriter out = compiler.getScriptEnvironment().getErr(); 4250 out.println("[BLOCK in '" + ident + "']"); 4251 if (!block.printSymbols(out)) { 4252 out.println("<no symbols>"); 4253 } 4254 out.println(); 4255 } 4256 } 4257 4258 4259 /** 4260 * The difference between a store and a self modifying store is that 4261 * the latter may load part of the target on the stack, e.g. the base 4262 * of an AccessNode or the base and index of an IndexNode. These are used 4263 * both as target and as an extra source. Previously it was problematic 4264 * for self modifying stores if the target/lhs didn't belong to one 4265 * of three trivial categories: IdentNode, AcessNodes, IndexNodes. In that 4266 * case it was evaluated and tagged as "resolved", which meant at the second 4267 * time the lhs of this store was read (e.g. in a = a (second) + b for a += b, 4268 * it would be evaluated to a nop in the scope and cause stack underflow 4269 * 4270 * see NASHORN-703 4271 * 4272 * @param <T> 4273 */ 4274 private abstract class SelfModifyingStore<T extends Expression> extends Store<T> { 4275 protected SelfModifyingStore(final T assignNode, final Expression target) { 4276 super(assignNode, target); 4277 } 4278 4279 @Override 4280 protected boolean isSelfModifying() { 4281 return true; 4282 } 4283 } 4284 4285 /** 4286 * Helper class to generate stores 4287 */ 4288 private abstract class Store<T extends Expression> { 4289 4290 /** An assignment node, e.g. x += y */ 4291 protected final T assignNode; 4292 4293 /** The target node to store to, e.g. x */ 4294 private final Expression target; 4295 4296 /** How deep on the stack do the arguments go if this generates an indy call */ 4297 private int depth; 4298 4299 /** If we have too many arguments, we need temporary storage, this is stored in 'quick' */ 4300 private IdentNode quick; 4301 4302 /** 4303 * Constructor 4304 * 4305 * @param assignNode the node representing the whole assignment 4306 * @param target the target node of the assignment (destination) 4307 */ 4308 protected Store(final T assignNode, final Expression target) { 4309 this.assignNode = assignNode; 4310 this.target = target; 4311 } 4312 4313 /** 4314 * Constructor 4315 * 4316 * @param assignNode the node representing the whole assignment 4317 */ 4318 protected Store(final T assignNode) { 4319 this(assignNode, assignNode); 4320 } 4321 4322 /** 4323 * Is this a self modifying store operation, e.g. *= or ++ 4324 * @return true if self modifying store 4325 */ 4326 protected boolean isSelfModifying() { 4327 return false; 4328 } 4329 4330 private void prologue() { 4331 /** 4332 * This loads the parts of the target, e.g base and index. they are kept 4333 * on the stack throughout the store and used at the end to execute it 4334 */ 4335 4336 target.accept(new NodeVisitor<LexicalContext>(new LexicalContext()) { 4337 @Override 4338 public boolean enterIdentNode(final IdentNode node) { 4339 if (node.getSymbol().isScope()) { 4340 method.loadCompilerConstant(SCOPE); 4341 depth += Type.SCOPE.getSlots(); 4342 assert depth == 1; 4343 } 4344 return false; 4345 } 4346 4347 private void enterBaseNode() { 4348 assert target instanceof BaseNode : "error - base node " + target + " must be instanceof BaseNode"; 4349 final BaseNode baseNode = (BaseNode)target; 4350 final Expression base = baseNode.getBase(); 4351 4352 loadExpressionAsObject(base); 4353 depth += Type.OBJECT.getSlots(); 4354 assert depth == 1; 4355 4356 if (isSelfModifying()) { 4357 method.dup(); 4358 } 4359 } 4360 4361 @Override 4362 public boolean enterAccessNode(final AccessNode node) { 4363 enterBaseNode(); 4364 return false; 4365 } 4366 4367 @Override 4368 public boolean enterIndexNode(final IndexNode node) { 4369 enterBaseNode(); 4370 4371 final Expression index = node.getIndex(); 4372 if (!index.getType().isNumeric()) { 4373 // could be boolean here as well 4374 loadExpressionAsObject(index); 4375 } else { 4376 loadExpressionUnbounded(index); 4377 } 4378 depth += index.getType().getSlots(); 4379 4380 if (isSelfModifying()) { 4381 //convert "base base index" to "base index base index" 4382 method.dup(1); 4383 } 4384 4385 return false; 4386 } 4387 4388 }); 4389 } 4390 4391 /** 4392 * Generates an extra local variable, always using the same slot, one that is available after the end of the 4393 * frame. 4394 * 4395 * @param type the type of the variable 4396 * 4397 * @return the quick variable 4398 */ 4399 private IdentNode quickLocalVariable(final Type type) { 4400 final String name = lc.getCurrentFunction().uniqueName(QUICK_PREFIX.symbolName()); 4401 final Symbol symbol = new Symbol(name, IS_INTERNAL | HAS_SLOT); 4402 symbol.setHasSlotFor(type); 4403 symbol.setFirstSlot(lc.quickSlot(type)); 4404 4405 final IdentNode quickIdent = IdentNode.createInternalIdentifier(symbol).setType(type); 4406 4407 return quickIdent; 4408 } 4409 4410 // store the result that "lives on" after the op, e.g. "i" in i++ postfix. 4411 protected void storeNonDiscard() { 4412 if (lc.popDiscardIfCurrent(assignNode)) { 4413 assert assignNode.isAssignment(); 4414 return; 4415 } 4416 4417 if (method.dup(depth) == null) { 4418 method.dup(); 4419 final Type quickType = method.peekType(); 4420 this.quick = quickLocalVariable(quickType); 4421 final Symbol quickSymbol = quick.getSymbol(); 4422 method.storeTemp(quickType, quickSymbol.getFirstSlot()); 4423 } 4424 } 4425 4426 private void epilogue() { 4427 /** 4428 * Take the original target args from the stack and use them 4429 * together with the value to be stored to emit the store code 4430 * 4431 * The case that targetSymbol is in scope (!hasSlot) and we actually 4432 * need to do a conversion on non-equivalent types exists, but is 4433 * very rare. See for example test/script/basic/access-specializer.js 4434 */ 4435 target.accept(new NodeVisitor<LexicalContext>(new LexicalContext()) { 4436 @Override 4437 protected boolean enterDefault(final Node node) { 4438 throw new AssertionError("Unexpected node " + node + " in store epilogue"); 4439 } 4440 4441 @Override 4442 public boolean enterIdentNode(final IdentNode node) { 4443 final Symbol symbol = node.getSymbol(); 4444 assert symbol != null; 4445 if (symbol.isScope()) { 4446 final int flags = CALLSITE_SCOPE | getCallSiteFlags(); 4447 if (isFastScope(symbol)) { 4448 storeFastScopeVar(symbol, flags); 4449 } else { 4450 method.dynamicSet(node.getName(), flags, false); 4451 } 4452 } else { 4453 final Type storeType = assignNode.getType(); 4454 if (symbol.hasSlotFor(storeType)) { 4455 // Only emit a convert for a store known to be live; converts for dead stores can 4456 // give us an unnecessary ClassCastException. 4457 method.convert(storeType); 4458 } 4459 storeIdentWithCatchConversion(node, storeType); 4460 } 4461 return false; 4462 4463 } 4464 4465 @Override 4466 public boolean enterAccessNode(final AccessNode node) { 4467 method.dynamicSet(node.getProperty(), getCallSiteFlags(), node.isIndex()); 4468 return false; 4469 } 4470 4471 @Override 4472 public boolean enterIndexNode(final IndexNode node) { 4473 method.dynamicSetIndex(getCallSiteFlags()); 4474 return false; 4475 } 4476 }); 4477 4478 4479 // whatever is on the stack now is the final answer 4480 } 4481 4482 protected abstract void evaluate(); 4483 4484 void store() { 4485 if (target instanceof IdentNode) { 4486 checkTemporalDeadZone((IdentNode)target); 4487 } 4488 prologue(); 4489 evaluate(); // leaves an operation of whatever the operationType was on the stack 4490 storeNonDiscard(); 4491 epilogue(); 4492 if (quick != null) { 4493 method.load(quick); 4494 } 4495 } 4496 } 4497 4498 private void newFunctionObject(final FunctionNode functionNode, final boolean addInitializer) { 4499 assert lc.peek() == functionNode; 4500 4501 final RecompilableScriptFunctionData data = compiler.getScriptFunctionData(functionNode.getId()); 4502 4503 if (functionNode.isProgram() && !compiler.isOnDemandCompilation()) { 4504 final MethodEmitter createFunction = functionNode.getCompileUnit().getClassEmitter().method( 4505 EnumSet.of(Flag.PUBLIC, Flag.STATIC), CREATE_PROGRAM_FUNCTION.symbolName(), 4506 ScriptFunction.class, ScriptObject.class); 4507 createFunction.begin(); 4508 loadConstantsAndIndex(data, createFunction); 4509 createFunction.load(SCOPE_TYPE, 0); 4510 createFunction.invoke(CREATE_FUNCTION_OBJECT); 4511 createFunction._return(); 4512 createFunction.end(); 4513 } 4514 4515 if (addInitializer && !compiler.isOnDemandCompilation()) { 4516 compiler.addFunctionInitializer(data, functionNode); 4517 } 4518 4519 // We don't emit a ScriptFunction on stack for the outermost compiled function (as there's no code being 4520 // generated in its outer context that'd need it as a callee). 4521 if (lc.getOutermostFunction() == functionNode) { 4522 return; 4523 } 4524 4525 loadConstantsAndIndex(data, method); 4526 4527 if (functionNode.needsParentScope()) { 4528 method.loadCompilerConstant(SCOPE); 4529 method.invoke(CREATE_FUNCTION_OBJECT); 4530 } else { 4531 method.invoke(CREATE_FUNCTION_OBJECT_NO_SCOPE); 4532 } 4533 } 4534 4535 // calls on Global class. 4536 private MethodEmitter globalInstance() { 4537 return method.invokestatic(GLOBAL_OBJECT, "instance", "()L" + GLOBAL_OBJECT + ';'); 4538 } 4539 4540 private MethodEmitter globalAllocateArguments() { 4541 return method.invokestatic(GLOBAL_OBJECT, "allocateArguments", methodDescriptor(ScriptObject.class, Object[].class, Object.class, int.class)); 4542 } 4543 4544 private MethodEmitter globalNewRegExp() { 4545 return method.invokestatic(GLOBAL_OBJECT, "newRegExp", methodDescriptor(Object.class, String.class, String.class)); 4546 } 4547 4548 private MethodEmitter globalRegExpCopy() { 4549 return method.invokestatic(GLOBAL_OBJECT, "regExpCopy", methodDescriptor(Object.class, Object.class)); 4550 } 4551 4552 private MethodEmitter globalAllocateArray(final ArrayType type) { 4553 //make sure the native array is treated as an array type 4554 return method.invokestatic(GLOBAL_OBJECT, "allocate", "(" + type.getDescriptor() + ")Ljdk/nashorn/internal/objects/NativeArray;"); 4555 } 4556 4557 private MethodEmitter globalIsEval() { 4558 return method.invokestatic(GLOBAL_OBJECT, "isEval", methodDescriptor(boolean.class, Object.class)); 4559 } 4560 4561 private MethodEmitter globalReplaceLocationPropertyPlaceholder() { 4562 return method.invokestatic(GLOBAL_OBJECT, "replaceLocationPropertyPlaceholder", methodDescriptor(Object.class, Object.class, Object.class)); 4563 } 4564 4565 private MethodEmitter globalCheckObjectCoercible() { 4566 return method.invokestatic(GLOBAL_OBJECT, "checkObjectCoercible", methodDescriptor(void.class, Object.class)); 4567 } 4568 4569 private MethodEmitter globalDirectEval() { 4570 return method.invokestatic(GLOBAL_OBJECT, "directEval", 4571 methodDescriptor(Object.class, Object.class, Object.class, Object.class, Object.class, boolean.class)); 4572 } 4573 4574 private abstract class OptimisticOperation { 4575 private final boolean isOptimistic; 4576 // expression and optimistic are the same reference 4577 private final Expression expression; 4578 private final Optimistic optimistic; 4579 private final TypeBounds resultBounds; 4580 4581 OptimisticOperation(final Optimistic optimistic, final TypeBounds resultBounds) { 4582 this.optimistic = optimistic; 4583 this.expression = (Expression)optimistic; 4584 this.resultBounds = resultBounds; 4585 this.isOptimistic = isOptimistic(optimistic) && useOptimisticTypes() && 4586 // Operation is only effectively optimistic if its type, after being coerced into the result bounds 4587 // is narrower than the upper bound. 4588 resultBounds.within(Type.generic(((Expression)optimistic).getType())).narrowerThan(resultBounds.widest); 4589 } 4590 4591 MethodEmitter emit() { 4592 return emit(0); 4593 } 4594 4595 MethodEmitter emit(final int ignoredArgCount) { 4596 final int programPoint = optimistic.getProgramPoint(); 4597 final boolean optimisticOrContinuation = isOptimistic || isContinuationEntryPoint(programPoint); 4598 final boolean currentContinuationEntryPoint = isCurrentContinuationEntryPoint(programPoint); 4599 final int stackSizeOnEntry = method.getStackSize() - ignoredArgCount; 4600 4601 // First store the values on the stack opportunistically into local variables. Doing it before loadStack() 4602 // allows us to not have to pop/load any arguments that are pushed onto it by loadStack() in the second 4603 // storeStack(). 4604 storeStack(ignoredArgCount, optimisticOrContinuation); 4605 4606 // Now, load the stack 4607 loadStack(); 4608 4609 // Now store the values on the stack ultimately into local variables. In vast majority of cases, this is 4610 // (aside from creating the local types map) a no-op, as the first opportunistic stack store will already 4611 // store all variables. However, there can be operations in the loadStack() that invalidate some of the 4612 // stack stores, e.g. in "x[i] = x[++i]", "++i" will invalidate the already stored value for "i". In such 4613 // unfortunate cases this second storeStack() will restore the invariant that everything on the stack is 4614 // stored into a local variable, although at the cost of doing a store/load on the loaded arguments as well. 4615 final int liveLocalsCount = storeStack(method.getStackSize() - stackSizeOnEntry, optimisticOrContinuation); 4616 assert optimisticOrContinuation == (liveLocalsCount != -1); 4617 4618 final Label beginTry; 4619 final Label catchLabel; 4620 final Label afterConsumeStack = isOptimistic || currentContinuationEntryPoint ? new Label("after_consume_stack") : null; 4621 if(isOptimistic) { 4622 beginTry = new Label("try_optimistic"); 4623 final String catchLabelName = (afterConsumeStack == null ? "" : afterConsumeStack.toString()) + "_handler"; 4624 catchLabel = new Label(catchLabelName); 4625 method.label(beginTry); 4626 } else { 4627 beginTry = catchLabel = null; 4628 } 4629 4630 consumeStack(); 4631 4632 if(isOptimistic) { 4633 method._try(beginTry, afterConsumeStack, catchLabel, UnwarrantedOptimismException.class); 4634 } 4635 4636 if(isOptimistic || currentContinuationEntryPoint) { 4637 method.label(afterConsumeStack); 4638 4639 final int[] localLoads = method.getLocalLoadsOnStack(0, stackSizeOnEntry); 4640 assert everyStackValueIsLocalLoad(localLoads) : Arrays.toString(localLoads) + ", " + stackSizeOnEntry + ", " + ignoredArgCount; 4641 final List<Type> localTypesList = method.getLocalVariableTypes(); 4642 final int usedLocals = method.getUsedSlotsWithLiveTemporaries(); 4643 final List<Type> localTypes = method.getWidestLiveLocals(localTypesList.subList(0, usedLocals)); 4644 assert everyLocalLoadIsValid(localLoads, usedLocals) : Arrays.toString(localLoads) + " ~ " + localTypes; 4645 4646 if(isOptimistic) { 4647 addUnwarrantedOptimismHandlerLabel(localTypes, catchLabel); 4648 } 4649 if(currentContinuationEntryPoint) { 4650 final ContinuationInfo ci = getContinuationInfo(); 4651 assert ci != null : "no continuation info found for " + lc.getCurrentFunction(); 4652 assert !ci.hasTargetLabel(); // No duplicate program points 4653 ci.setTargetLabel(afterConsumeStack); 4654 ci.getHandlerLabel().markAsOptimisticContinuationHandlerFor(afterConsumeStack); 4655 // Can't rely on targetLabel.stack.localVariableTypes.length, as it can be higher due to effectively 4656 // dead local variables. 4657 ci.lvarCount = localTypes.size(); 4658 ci.setStackStoreSpec(localLoads); 4659 ci.setStackTypes(Arrays.copyOf(method.getTypesFromStack(method.getStackSize()), stackSizeOnEntry)); 4660 assert ci.getStackStoreSpec().length == ci.getStackTypes().length; 4661 ci.setReturnValueType(method.peekType()); 4662 ci.lineNumber = getLastLineNumber(); 4663 ci.catchLabel = catchLabels.peek(); 4664 } 4665 } 4666 return method; 4667 } 4668 4669 /** 4670 * Stores the current contents of the stack into local variables so they are not lost before invoking something that 4671 * can result in an {@code UnwarantedOptimizationException}. 4672 * @param ignoreArgCount the number of topmost arguments on stack to ignore when deciding on the shape of the catch 4673 * block. Those are used in the situations when we could not place the call to {@code storeStack} early enough 4674 * (before emitting code for pushing the arguments that the optimistic call will pop). This is admittedly a 4675 * deficiency in the design of the code generator when it deals with self-assignments and we should probably look 4676 * into fixing it. 4677 * @return types of the significant local variables after the stack was stored (types for local variables used 4678 * for temporary storage of ignored arguments are not returned). 4679 * @param optimisticOrContinuation if false, this method should not execute 4680 * a label for a catch block for the {@code UnwarantedOptimizationException}, suitable for capturing the 4681 * currently live local variables, tailored to their types. 4682 */ 4683 private int storeStack(final int ignoreArgCount, final boolean optimisticOrContinuation) { 4684 if(!optimisticOrContinuation) { 4685 return -1; // NOTE: correct value to return is lc.getUsedSlotCount(), but it wouldn't be used anyway 4686 } 4687 4688 final int stackSize = method.getStackSize(); 4689 final Type[] stackTypes = method.getTypesFromStack(stackSize); 4690 final int[] localLoadsOnStack = method.getLocalLoadsOnStack(0, stackSize); 4691 final int usedSlots = method.getUsedSlotsWithLiveTemporaries(); 4692 4693 final int firstIgnored = stackSize - ignoreArgCount; 4694 // Find the first value on the stack (from the bottom) that is not a load from a local variable. 4695 int firstNonLoad = 0; 4696 while(firstNonLoad < firstIgnored && localLoadsOnStack[firstNonLoad] != Label.Stack.NON_LOAD) { 4697 firstNonLoad++; 4698 } 4699 4700 // Only do the store/load if first non-load is not an ignored argument. Otherwise, do nothing and return 4701 // the number of used slots as the number of live local variables. 4702 if(firstNonLoad >= firstIgnored) { 4703 return usedSlots; 4704 } 4705 4706 // Find the number of new temporary local variables that we need; it's the number of values on the stack that 4707 // are not direct loads of existing local variables. 4708 int tempSlotsNeeded = 0; 4709 for(int i = firstNonLoad; i < stackSize; ++i) { 4710 if(localLoadsOnStack[i] == Label.Stack.NON_LOAD) { 4711 tempSlotsNeeded += stackTypes[i].getSlots(); 4712 } 4713 } 4714 4715 // Ensure all values on the stack that weren't directly loaded from a local variable are stored in a local 4716 // variable. We're starting from highest local variable index, so that in case ignoreArgCount > 0 the ignored 4717 // ones end up at the end of the local variable table. 4718 int lastTempSlot = usedSlots + tempSlotsNeeded; 4719 int ignoreSlotCount = 0; 4720 for(int i = stackSize; i -- > firstNonLoad;) { 4721 final int loadSlot = localLoadsOnStack[i]; 4722 if(loadSlot == Label.Stack.NON_LOAD) { 4723 final Type type = stackTypes[i]; 4724 final int slots = type.getSlots(); 4725 lastTempSlot -= slots; 4726 if(i >= firstIgnored) { 4727 ignoreSlotCount += slots; 4728 } 4729 method.storeTemp(type, lastTempSlot); 4730 } else { 4731 method.pop(); 4732 } 4733 } 4734 assert lastTempSlot == usedSlots; // used all temporary locals 4735 4736 final List<Type> localTypesList = method.getLocalVariableTypes(); 4737 4738 // Load values back on stack. 4739 for(int i = firstNonLoad; i < stackSize; ++i) { 4740 final int loadSlot = localLoadsOnStack[i]; 4741 final Type stackType = stackTypes[i]; 4742 final boolean isLoad = loadSlot != Label.Stack.NON_LOAD; 4743 final int lvarSlot = isLoad ? loadSlot : lastTempSlot; 4744 final Type lvarType = localTypesList.get(lvarSlot); 4745 method.load(lvarType, lvarSlot); 4746 if(isLoad) { 4747 // Conversion operators (I2L etc.) preserve "load"-ness of the value despite the fact that, in the 4748 // strict sense they are creating a derived value from the loaded value. This special behavior of 4749 // on-stack conversion operators is necessary to accommodate for differences in local variable types 4750 // after deoptimization; having a conversion operator throw away "load"-ness would create different 4751 // local variable table shapes between optimism-failed code and its deoptimized rest-of method). 4752 // After we load the value back, we need to redo the conversion to the stack type if stack type is 4753 // different. 4754 // NOTE: this would only strictly be necessary for widening conversions (I2L, L2D, I2D), and not for 4755 // narrowing ones (L2I, D2L, D2I) as only widening conversions are the ones that can get eliminated 4756 // in a deoptimized method, as their original input argument got widened. Maybe experiment with 4757 // throwing away "load"-ness for narrowing conversions in MethodEmitter.convert()? 4758 method.convert(stackType); 4759 } else { 4760 // temporary stores never needs a convert, as their type is always the same as the stack type. 4761 assert lvarType == stackType; 4762 lastTempSlot += lvarType.getSlots(); 4763 } 4764 } 4765 // used all temporaries 4766 assert lastTempSlot == usedSlots + tempSlotsNeeded; 4767 4768 return lastTempSlot - ignoreSlotCount; 4769 } 4770 4771 private void addUnwarrantedOptimismHandlerLabel(final List<Type> localTypes, final Label label) { 4772 final String lvarTypesDescriptor = getLvarTypesDescriptor(localTypes); 4773 final Map<String, Collection<Label>> unwarrantedOptimismHandlers = lc.getUnwarrantedOptimismHandlers(); 4774 Collection<Label> labels = unwarrantedOptimismHandlers.get(lvarTypesDescriptor); 4775 if(labels == null) { 4776 labels = new LinkedList<>(); 4777 unwarrantedOptimismHandlers.put(lvarTypesDescriptor, labels); 4778 } 4779 method.markLabelAsOptimisticCatchHandler(label, localTypes.size()); 4780 labels.add(label); 4781 } 4782 4783 abstract void loadStack(); 4784 4785 // Make sure that whatever indy call site you emit from this method uses {@code getCallSiteFlagsOptimistic(node)} 4786 // or otherwise ensure optimistic flag is correctly set in the call site, otherwise it doesn't make much sense 4787 // to use OptimisticExpression for emitting it. 4788 abstract void consumeStack(); 4789 4790 /** 4791 * Emits the correct dynamic getter code. Normally just delegates to method emitter, except when the target 4792 * expression is optimistic, and the desired type is narrower than the optimistic type. In that case, it'll emit a 4793 * dynamic getter with its original optimistic type, and explicitly insert a narrowing conversion. This way we can 4794 * preserve the optimism of the values even if they're subsequently immediately coerced into a narrower type. This 4795 * is beneficial because in this case we can still presume that since the original getter was optimistic, the 4796 * conversion has no side effects. 4797 * @param name the name of the property being get 4798 * @param flags call site flags 4799 * @param isMethod whether we're preferrably retrieving a function 4800 * @return the current method emitter 4801 */ 4802 MethodEmitter dynamicGet(final String name, final int flags, final boolean isMethod, final boolean isIndex) { 4803 if(isOptimistic) { 4804 return method.dynamicGet(getOptimisticCoercedType(), name, getOptimisticFlags(flags), isMethod, isIndex); 4805 } 4806 return method.dynamicGet(resultBounds.within(expression.getType()), name, nonOptimisticFlags(flags), isMethod, isIndex); 4807 } 4808 4809 MethodEmitter dynamicGetIndex(final int flags, final boolean isMethod) { 4810 if(isOptimistic) { 4811 return method.dynamicGetIndex(getOptimisticCoercedType(), getOptimisticFlags(flags), isMethod); 4812 } 4813 return method.dynamicGetIndex(resultBounds.within(expression.getType()), nonOptimisticFlags(flags), isMethod); 4814 } 4815 4816 MethodEmitter dynamicCall(final int argCount, final int flags) { 4817 if (isOptimistic) { 4818 return method.dynamicCall(getOptimisticCoercedType(), argCount, getOptimisticFlags(flags)); 4819 } 4820 return method.dynamicCall(resultBounds.within(expression.getType()), argCount, nonOptimisticFlags(flags)); 4821 } 4822 4823 int getOptimisticFlags(final int flags) { 4824 return flags | CALLSITE_OPTIMISTIC | (optimistic.getProgramPoint() << CALLSITE_PROGRAM_POINT_SHIFT); //encode program point in high bits 4825 } 4826 4827 int getProgramPoint() { 4828 return isOptimistic ? optimistic.getProgramPoint() : INVALID_PROGRAM_POINT; 4829 } 4830 4831 void convertOptimisticReturnValue() { 4832 if (isOptimistic) { 4833 final Type optimisticType = getOptimisticCoercedType(); 4834 if(!optimisticType.isObject()) { 4835 method.load(optimistic.getProgramPoint()); 4836 if(optimisticType.isInteger()) { 4837 method.invoke(ENSURE_INT); 4838 } else if(optimisticType.isLong()) { 4839 method.invoke(ENSURE_LONG); 4840 } else if(optimisticType.isNumber()) { 4841 method.invoke(ENSURE_NUMBER); 4842 } else { 4843 throw new AssertionError(optimisticType); 4844 } 4845 } 4846 } 4847 } 4848 4849 void replaceCompileTimeProperty() { 4850 final IdentNode identNode = (IdentNode)expression; 4851 final String name = identNode.getSymbol().getName(); 4852 if (CompilerConstants.__FILE__.name().equals(name)) { 4853 replaceCompileTimeProperty(getCurrentSource().getName()); 4854 } else if (CompilerConstants.__DIR__.name().equals(name)) { 4855 replaceCompileTimeProperty(getCurrentSource().getBase()); 4856 } else if (CompilerConstants.__LINE__.name().equals(name)) { 4857 replaceCompileTimeProperty(getCurrentSource().getLine(identNode.position())); 4858 } 4859 } 4860 4861 /** 4862 * When an ident with name __FILE__, __DIR__, or __LINE__ is loaded, we'll try to look it up as any other 4863 * identifier. However, if it gets all the way up to the Global object, it will send back a special value that 4864 * represents a placeholder for these compile-time location properties. This method will generate code that loads 4865 * the value of the compile-time location property and then invokes a method in Global that will replace the 4866 * placeholder with the value. Effectively, if the symbol for these properties is defined anywhere in the lexical 4867 * scope, they take precedence, but if they aren't, then they resolve to the compile-time location property. 4868 * @param propertyValue the actual value of the property 4869 */ 4870 private void replaceCompileTimeProperty(final Object propertyValue) { 4871 assert method.peekType().isObject(); 4872 if(propertyValue instanceof String || propertyValue == null) { 4873 method.load((String)propertyValue); 4874 } else if(propertyValue instanceof Integer) { 4875 method.load(((Integer)propertyValue).intValue()); 4876 method.convert(Type.OBJECT); 4877 } else { 4878 throw new AssertionError(); 4879 } 4880 globalReplaceLocationPropertyPlaceholder(); 4881 convertOptimisticReturnValue(); 4882 } 4883 4884 /** 4885 * Returns the type that should be used as the return type of the dynamic invocation that is emitted as the code 4886 * for the current optimistic operation. If the type bounds is exact boolean or narrower than the expression's 4887 * optimistic type, then the optimistic type is returned, otherwise the coercing type. Effectively, this method 4888 * allows for moving the coercion into the optimistic type when it won't adversely affect the optimistic 4889 * evaluation semantics, and for preserving the optimistic type and doing a separate coercion when it would 4890 * affect it. 4891 * @return 4892 */ 4893 private Type getOptimisticCoercedType() { 4894 final Type optimisticType = expression.getType(); 4895 assert resultBounds.widest.widerThan(optimisticType); 4896 final Type narrowest = resultBounds.narrowest; 4897 4898 if(narrowest.isBoolean() || narrowest.narrowerThan(optimisticType)) { 4899 assert !optimisticType.isObject(); 4900 return optimisticType; 4901 } 4902 assert !narrowest.isObject(); 4903 return narrowest; 4904 } 4905 } 4906 4907 private static boolean isOptimistic(final Optimistic optimistic) { 4908 if(!optimistic.canBeOptimistic()) { 4909 return false; 4910 } 4911 final Expression expr = (Expression)optimistic; 4912 return expr.getType().narrowerThan(expr.getWidestOperationType()); 4913 } 4914 4915 private static boolean everyLocalLoadIsValid(final int[] loads, final int localCount) { 4916 for (final int load : loads) { 4917 if(load < 0 || load >= localCount) { 4918 return false; 4919 } 4920 } 4921 return true; 4922 } 4923 4924 private static boolean everyStackValueIsLocalLoad(final int[] loads) { 4925 for (final int load : loads) { 4926 if(load == Label.Stack.NON_LOAD) { 4927 return false; 4928 } 4929 } 4930 return true; 4931 } 4932 4933 private String getLvarTypesDescriptor(final List<Type> localVarTypes) { 4934 final int count = localVarTypes.size(); 4935 final StringBuilder desc = new StringBuilder(count); 4936 for(int i = 0; i < count;) { 4937 i += appendType(desc, localVarTypes.get(i)); 4938 } 4939 return method.markSymbolBoundariesInLvarTypesDescriptor(desc.toString()); 4940 } 4941 4942 private static int appendType(final StringBuilder b, final Type t) { 4943 b.append(t.getBytecodeStackType()); 4944 return t.getSlots(); 4945 } 4946 4947 private static int countSymbolsInLvarTypeDescriptor(final String lvarTypeDescriptor) { 4948 int count = 0; 4949 for(int i = 0; i < lvarTypeDescriptor.length(); ++i) { 4950 if(Character.isUpperCase(lvarTypeDescriptor.charAt(i))) { 4951 ++count; 4952 } 4953 } 4954 return count; 4955 4956 } 4957 /** 4958 * Generates all the required {@code UnwarrantedOptimismException} handlers for the current function. The employed 4959 * strategy strives to maximize code reuse. Every handler constructs an array to hold the local variables, then 4960 * fills in some trailing part of the local variables (those for which it has a unique suffix in the descriptor), 4961 * then jumps to a handler for a prefix that's shared with other handlers. A handler that fills up locals up to 4962 * position 0 will not jump to a prefix handler (as it has no prefix), but instead end with constructing and 4963 * throwing a {@code RewriteException}. Since we lexicographically sort the entries, we only need to check every 4964 * entry to its immediately preceding one for longest matching prefix. 4965 * @return true if there is at least one exception handler 4966 */ 4967 private boolean generateUnwarrantedOptimismExceptionHandlers(final FunctionNode fn) { 4968 if(!useOptimisticTypes()) { 4969 return false; 4970 } 4971 4972 // Take the mapping of lvarSpecs -> labels, and turn them into a descending lexicographically sorted list of 4973 // handler specifications. 4974 final Map<String, Collection<Label>> unwarrantedOptimismHandlers = lc.popUnwarrantedOptimismHandlers(); 4975 if(unwarrantedOptimismHandlers.isEmpty()) { 4976 return false; 4977 } 4978 4979 method.lineNumber(0); 4980 4981 final List<OptimismExceptionHandlerSpec> handlerSpecs = new ArrayList<>(unwarrantedOptimismHandlers.size() * 4/3); 4982 for(final String spec: unwarrantedOptimismHandlers.keySet()) { 4983 handlerSpecs.add(new OptimismExceptionHandlerSpec(spec, true)); 4984 } 4985 Collections.sort(handlerSpecs, Collections.reverseOrder()); 4986 4987 // Map of local variable specifications to labels for populating the array for that local variable spec. 4988 final Map<String, Label> delegationLabels = new HashMap<>(); 4989 4990 // Do everything in a single pass over the handlerSpecs list. Note that the list can actually grow as we're 4991 // passing through it as we might add new prefix handlers into it, so can't hoist size() outside of the loop. 4992 for(int handlerIndex = 0; handlerIndex < handlerSpecs.size(); ++handlerIndex) { 4993 final OptimismExceptionHandlerSpec spec = handlerSpecs.get(handlerIndex); 4994 final String lvarSpec = spec.lvarSpec; 4995 if(spec.catchTarget) { 4996 assert !method.isReachable(); 4997 // Start a catch block and assign the labels for this lvarSpec with it. 4998 method._catch(unwarrantedOptimismHandlers.get(lvarSpec)); 4999 // This spec is a catch target, so emit array creation code. The length of the array is the number of 5000 // symbols - the number of uppercase characters. 5001 method.load(countSymbolsInLvarTypeDescriptor(lvarSpec)); 5002 method.newarray(Type.OBJECT_ARRAY); 5003 } 5004 if(spec.delegationTarget) { 5005 // If another handler can delegate to this handler as its prefix, then put a jump target here for the 5006 // shared code (after the array creation code, which is never shared). 5007 method.label(delegationLabels.get(lvarSpec)); // label must exist 5008 } 5009 5010 final boolean lastHandler = handlerIndex == handlerSpecs.size() - 1; 5011 5012 int lvarIndex; 5013 final int firstArrayIndex; 5014 final int firstLvarIndex; 5015 Label delegationLabel; 5016 final String commonLvarSpec; 5017 if(lastHandler) { 5018 // Last handler block, doesn't delegate to anything. 5019 lvarIndex = 0; 5020 firstLvarIndex = 0; 5021 firstArrayIndex = 0; 5022 delegationLabel = null; 5023 commonLvarSpec = null; 5024 } else { 5025 // Not yet the last handler block, will definitely delegate to another handler; let's figure out which 5026 // one. It can be an already declared handler further down the list, or it might need to declare a new 5027 // prefix handler. 5028 5029 // Since we're lexicographically ordered, the common prefix handler is defined by the common prefix of 5030 // this handler and the next handler on the list. 5031 final int nextHandlerIndex = handlerIndex + 1; 5032 final String nextLvarSpec = handlerSpecs.get(nextHandlerIndex).lvarSpec; 5033 commonLvarSpec = commonPrefix(lvarSpec, nextLvarSpec); 5034 // We don't chop symbols in half 5035 assert Character.isUpperCase(commonLvarSpec.charAt(commonLvarSpec.length() - 1)); 5036 5037 // Let's find if we already have a declaration for such handler, or we need to insert it. 5038 { 5039 boolean addNewHandler = true; 5040 int commonHandlerIndex = nextHandlerIndex; 5041 for(; commonHandlerIndex < handlerSpecs.size(); ++commonHandlerIndex) { 5042 final OptimismExceptionHandlerSpec forwardHandlerSpec = handlerSpecs.get(commonHandlerIndex); 5043 final String forwardLvarSpec = forwardHandlerSpec.lvarSpec; 5044 if(forwardLvarSpec.equals(commonLvarSpec)) { 5045 // We already have a handler for the common prefix. 5046 addNewHandler = false; 5047 // Make sure we mark it as a delegation target. 5048 forwardHandlerSpec.delegationTarget = true; 5049 break; 5050 } else if(!forwardLvarSpec.startsWith(commonLvarSpec)) { 5051 break; 5052 } 5053 } 5054 if(addNewHandler) { 5055 // We need to insert a common prefix handler. Note handlers created with catchTarget == false 5056 // will automatically have delegationTarget == true (because that's the only reason for their 5057 // existence). 5058 handlerSpecs.add(commonHandlerIndex, new OptimismExceptionHandlerSpec(commonLvarSpec, false)); 5059 } 5060 } 5061 5062 firstArrayIndex = countSymbolsInLvarTypeDescriptor(commonLvarSpec); 5063 lvarIndex = 0; 5064 for(int j = 0; j < commonLvarSpec.length(); ++j) { 5065 lvarIndex += CodeGeneratorLexicalContext.getTypeForSlotDescriptor(commonLvarSpec.charAt(j)).getSlots(); 5066 } 5067 firstLvarIndex = lvarIndex; 5068 5069 // Create a delegation label if not already present 5070 delegationLabel = delegationLabels.get(commonLvarSpec); 5071 if(delegationLabel == null) { 5072 // uo_pa == "unwarranted optimism, populate array" 5073 delegationLabel = new Label("uo_pa_" + commonLvarSpec); 5074 delegationLabels.put(commonLvarSpec, delegationLabel); 5075 } 5076 } 5077 5078 // Load local variables handled by this handler on stack 5079 int args = 0; 5080 boolean symbolHadValue = false; 5081 for(int typeIndex = commonLvarSpec == null ? 0 : commonLvarSpec.length(); typeIndex < lvarSpec.length(); ++typeIndex) { 5082 final char typeDesc = lvarSpec.charAt(typeIndex); 5083 final Type lvarType = CodeGeneratorLexicalContext.getTypeForSlotDescriptor(typeDesc); 5084 if (!lvarType.isUnknown()) { 5085 method.load(lvarType, lvarIndex); 5086 symbolHadValue = true; 5087 args++; 5088 } else if(typeDesc == 'U' && !symbolHadValue) { 5089 // Symbol boundary with undefined last value. Check if all previous values for this symbol were also 5090 // undefined; if so, emit one explicit Undefined. This serves to ensure that we're emiting exactly 5091 // one value for every symbol that uses local slots. While we could in theory ignore symbols that 5092 // are undefined (in other words, dead) at the point where this exception was thrown, unfortunately 5093 // we can't do it in practice. The reason for this is that currently our liveness analysis is 5094 // coarse (it can determine whether a symbol has not been read with a particular type anywhere in 5095 // the function being compiled, but that's it), and a symbol being promoted to Object due to a 5096 // deoptimization will suddenly show up as "live for Object type", and previously dead U->O 5097 // conversions on loop entries will suddenly become alive in the deoptimized method which will then 5098 // expect a value for that slot in its continuation handler. If we had precise liveness analysis, we 5099 // could go back to excluding known dead symbols from the payload of the RewriteException. 5100 if(method.peekType() == Type.UNDEFINED) { 5101 method.dup(); 5102 } else { 5103 method.loadUndefined(Type.OBJECT); 5104 } 5105 args++; 5106 } 5107 if(Character.isUpperCase(typeDesc)) { 5108 // Reached symbol boundary; reset flag for the next symbol. 5109 symbolHadValue = false; 5110 } 5111 lvarIndex += lvarType.getSlots(); 5112 } 5113 assert args > 0; 5114 // Delegate actual storing into array to an array populator utility method. 5115 //on the stack: 5116 // object array to be populated 5117 // start index 5118 // a lot of types 5119 method.dynamicArrayPopulatorCall(args + 1, firstArrayIndex); 5120 if(delegationLabel != null) { 5121 // We cascade to a prefix handler to fill out the rest of the local variables and throw the 5122 // RewriteException. 5123 assert !lastHandler; 5124 assert commonLvarSpec != null; 5125 // Must undefine the local variables that we have already processed for the sake of correct join on the 5126 // delegate label 5127 method.undefineLocalVariables(firstLvarIndex, true); 5128 final OptimismExceptionHandlerSpec nextSpec = handlerSpecs.get(handlerIndex + 1); 5129 // If the delegate immediately follows, and it's not a catch target (so it doesn't have array setup 5130 // code) don't bother emitting a jump, as we'd just jump to the next instruction. 5131 if(!nextSpec.lvarSpec.equals(commonLvarSpec) || nextSpec.catchTarget) { 5132 method._goto(delegationLabel); 5133 } 5134 } else { 5135 assert lastHandler; 5136 // Nothing to delegate to, so this handler must create and throw the RewriteException. 5137 // At this point we have the UnwarrantedOptimismException and the Object[] with local variables on 5138 // stack. We need to create a RewriteException, push two references to it below the constructor 5139 // arguments, invoke the constructor, and throw the exception. 5140 loadConstant(getByteCodeSymbolNames(fn)); 5141 if (isRestOf()) { 5142 loadConstant(getContinuationEntryPoints()); 5143 method.invoke(CREATE_REWRITE_EXCEPTION_REST_OF); 5144 } else { 5145 method.invoke(CREATE_REWRITE_EXCEPTION); 5146 } 5147 method.athrow(); 5148 } 5149 } 5150 return true; 5151 } 5152 5153 private static String[] getByteCodeSymbolNames(final FunctionNode fn) { 5154 // Only names of local variables on the function level are captured. This information is used to reduce 5155 // deoptimizations, so as much as we can capture will help. We rely on the fact that function wide variables are 5156 // all live all the time, so the array passed to rewrite exception contains one element for every slotted symbol 5157 // here. 5158 final List<String> names = new ArrayList<>(); 5159 for (final Symbol symbol: fn.getBody().getSymbols()) { 5160 if (symbol.hasSlot()) { 5161 if (symbol.isScope()) { 5162 // slot + scope can only be true for parameters 5163 assert symbol.isParam(); 5164 names.add(null); 5165 } else { 5166 names.add(symbol.getName()); 5167 } 5168 } 5169 } 5170 return names.toArray(new String[names.size()]); 5171 } 5172 5173 private static String commonPrefix(final String s1, final String s2) { 5174 final int l1 = s1.length(); 5175 final int l = Math.min(l1, s2.length()); 5176 int lms = -1; // last matching symbol 5177 for(int i = 0; i < l; ++i) { 5178 final char c1 = s1.charAt(i); 5179 if(c1 != s2.charAt(i)) { 5180 return s1.substring(0, lms + 1); 5181 } else if(Character.isUpperCase(c1)) { 5182 lms = i; 5183 } 5184 } 5185 return l == l1 ? s1 : s2; 5186 } 5187 5188 private static class OptimismExceptionHandlerSpec implements Comparable<OptimismExceptionHandlerSpec> { 5189 private final String lvarSpec; 5190 private final boolean catchTarget; 5191 private boolean delegationTarget; 5192 5193 OptimismExceptionHandlerSpec(final String lvarSpec, final boolean catchTarget) { 5194 this.lvarSpec = lvarSpec; 5195 this.catchTarget = catchTarget; 5196 if(!catchTarget) { 5197 delegationTarget = true; 5198 } 5199 } 5200 5201 @Override 5202 public int compareTo(final OptimismExceptionHandlerSpec o) { 5203 return lvarSpec.compareTo(o.lvarSpec); 5204 } 5205 5206 @Override 5207 public String toString() { 5208 final StringBuilder b = new StringBuilder(64).append("[HandlerSpec ").append(lvarSpec); 5209 if(catchTarget) { 5210 b.append(", catchTarget"); 5211 } 5212 if(delegationTarget) { 5213 b.append(", delegationTarget"); 5214 } 5215 return b.append("]").toString(); 5216 } 5217 } 5218 5219 private static class ContinuationInfo { 5220 private final Label handlerLabel; 5221 private Label targetLabel; // Label for the target instruction. 5222 int lvarCount; 5223 // Indices of local variables that need to be loaded on the stack when this node completes 5224 private int[] stackStoreSpec; 5225 // Types of values loaded on the stack 5226 private Type[] stackTypes; 5227 // If non-null, this node should perform the requisite type conversion 5228 private Type returnValueType; 5229 // If we are in the middle of an object literal initialization, we need to update the map 5230 private PropertyMap objectLiteralMap; 5231 // Object literal stack depth for object literal - not necessarly top if property is a tree 5232 private int objectLiteralStackDepth = -1; 5233 // The line number at the continuation point 5234 private int lineNumber; 5235 // The active catch label, in case the continuation point is in a try/catch block 5236 private Label catchLabel; 5237 // The number of scopes that need to be popped before control is transferred to the catch label. 5238 private int exceptionScopePops; 5239 5240 ContinuationInfo() { 5241 this.handlerLabel = new Label("continuation_handler"); 5242 } 5243 5244 Label getHandlerLabel() { 5245 return handlerLabel; 5246 } 5247 5248 boolean hasTargetLabel() { 5249 return targetLabel != null; 5250 } 5251 5252 Label getTargetLabel() { 5253 return targetLabel; 5254 } 5255 5256 void setTargetLabel(final Label targetLabel) { 5257 this.targetLabel = targetLabel; 5258 } 5259 5260 int[] getStackStoreSpec() { 5261 return stackStoreSpec.clone(); 5262 } 5263 5264 void setStackStoreSpec(final int[] stackStoreSpec) { 5265 this.stackStoreSpec = stackStoreSpec; 5266 } 5267 5268 Type[] getStackTypes() { 5269 return stackTypes.clone(); 5270 } 5271 5272 void setStackTypes(final Type[] stackTypes) { 5273 this.stackTypes = stackTypes; 5274 } 5275 5276 Type getReturnValueType() { 5277 return returnValueType; 5278 } 5279 5280 void setReturnValueType(final Type returnValueType) { 5281 this.returnValueType = returnValueType; 5282 } 5283 5284 int getObjectLiteralStackDepth() { 5285 return objectLiteralStackDepth; 5286 } 5287 5288 void setObjectLiteralStackDepth(final int objectLiteralStackDepth) { 5289 this.objectLiteralStackDepth = objectLiteralStackDepth; 5290 } 5291 5292 PropertyMap getObjectLiteralMap() { 5293 return objectLiteralMap; 5294 } 5295 5296 void setObjectLiteralMap(final PropertyMap objectLiteralMap) { 5297 this.objectLiteralMap = objectLiteralMap; 5298 } 5299 5300 @Override 5301 public String toString() { 5302 return "[localVariableTypes=" + targetLabel.getStack().getLocalVariableTypesCopy() + ", stackStoreSpec=" + 5303 Arrays.toString(stackStoreSpec) + ", returnValueType=" + returnValueType + "]"; 5304 } 5305 } 5306 5307 private ContinuationInfo getContinuationInfo() { 5308 return fnIdToContinuationInfo.get(lc.getCurrentFunction().getId()); 5309 } 5310 5311 private void generateContinuationHandler() { 5312 if (!isRestOf()) { 5313 return; 5314 } 5315 5316 final ContinuationInfo ci = getContinuationInfo(); 5317 method.label(ci.getHandlerLabel()); 5318 5319 // There should never be an exception thrown from the continuation handler, but in case there is (meaning, 5320 // Nashorn has a bug), then line number 0 will be an indication of where it came from (line numbers are Uint16). 5321 method.lineNumber(0); 5322 5323 final Label.Stack stack = ci.getTargetLabel().getStack(); 5324 final List<Type> lvarTypes = stack.getLocalVariableTypesCopy(); 5325 final BitSet symbolBoundary = stack.getSymbolBoundaryCopy(); 5326 final int lvarCount = ci.lvarCount; 5327 5328 final Type rewriteExceptionType = Type.typeFor(RewriteException.class); 5329 // Store the RewriteException into an unused local variable slot. 5330 method.load(rewriteExceptionType, 0); 5331 method.storeTemp(rewriteExceptionType, lvarCount); 5332 // Get local variable array 5333 method.load(rewriteExceptionType, 0); 5334 method.invoke(RewriteException.GET_BYTECODE_SLOTS); 5335 // Store local variables. Note that deoptimization might introduce new value types for existing local variables, 5336 // so we must use both liveLocals and symbolBoundary, as in some cases (when the continuation is inside of a try 5337 // block) we need to store the incoming value into multiple slots. The optimism exception handlers will have 5338 // exactly one array element for every symbol that uses bytecode storage. If in the originating method the value 5339 // was undefined, there will be an explicit Undefined value in the array. 5340 int arrayIndex = 0; 5341 for(int lvarIndex = 0; lvarIndex < lvarCount;) { 5342 final Type lvarType = lvarTypes.get(lvarIndex); 5343 if(!lvarType.isUnknown()) { 5344 method.dup(); 5345 method.load(arrayIndex).arrayload(); 5346 final Class<?> typeClass = lvarType.getTypeClass(); 5347 // Deoptimization in array initializers can cause arrays to undergo component type widening 5348 if(typeClass == long[].class) { 5349 method.load(rewriteExceptionType, lvarCount); 5350 method.invoke(RewriteException.TO_LONG_ARRAY); 5351 } else if(typeClass == double[].class) { 5352 method.load(rewriteExceptionType, lvarCount); 5353 method.invoke(RewriteException.TO_DOUBLE_ARRAY); 5354 } else if(typeClass == Object[].class) { 5355 method.load(rewriteExceptionType, lvarCount); 5356 method.invoke(RewriteException.TO_OBJECT_ARRAY); 5357 } else { 5358 if(!(typeClass.isPrimitive() || typeClass == Object.class)) { 5359 // NOTE: this can only happen with dead stores. E.g. for the program "1; []; f();" in which the 5360 // call to f() will deoptimize the call site, but it'll expect :return to have the type 5361 // NativeArray. However, in the more optimal version, :return's only live type is int, therefore 5362 // "{O}:return = []" is a dead store, and the variable will be sent into the continuation as 5363 // Undefined, however NativeArray can't hold Undefined instance. 5364 method.loadType(Type.getInternalName(typeClass)); 5365 method.invoke(RewriteException.INSTANCE_OR_NULL); 5366 } 5367 method.convert(lvarType); 5368 } 5369 method.storeHidden(lvarType, lvarIndex, false); 5370 } 5371 final int nextLvarIndex = lvarIndex + lvarType.getSlots(); 5372 if(symbolBoundary.get(nextLvarIndex - 1)) { 5373 ++arrayIndex; 5374 } 5375 lvarIndex = nextLvarIndex; 5376 } 5377 if (AssertsEnabled.assertsEnabled()) { 5378 method.load(arrayIndex); 5379 method.invoke(RewriteException.ASSERT_ARRAY_LENGTH); 5380 } else { 5381 method.pop(); 5382 } 5383 5384 final int[] stackStoreSpec = ci.getStackStoreSpec(); 5385 final Type[] stackTypes = ci.getStackTypes(); 5386 final boolean isStackEmpty = stackStoreSpec.length == 0; 5387 boolean replacedObjectLiteralMap = false; 5388 if(!isStackEmpty) { 5389 // Load arguments on the stack 5390 final int objectLiteralStackDepth = ci.getObjectLiteralStackDepth(); 5391 for(int i = 0; i < stackStoreSpec.length; ++i) { 5392 final int slot = stackStoreSpec[i]; 5393 method.load(lvarTypes.get(slot), slot); 5394 method.convert(stackTypes[i]); 5395 // stack: s0=object literal being initialized 5396 // change map of s0 so that the property we are initilizing when we failed 5397 // is now ci.returnValueType 5398 if (i == objectLiteralStackDepth) { 5399 method.dup(); 5400 assert ci.getObjectLiteralMap() != null; 5401 assert ScriptObject.class.isAssignableFrom(method.peekType().getTypeClass()) : method.peekType().getTypeClass() + " is not a script object"; 5402 loadConstant(ci.getObjectLiteralMap()); 5403 method.invoke(ScriptObject.SET_MAP); 5404 replacedObjectLiteralMap = true; 5405 } 5406 } 5407 } 5408 // Must have emitted the code for replacing the map of an object literal if we have a set object literal stack depth 5409 assert ci.getObjectLiteralStackDepth() == -1 || replacedObjectLiteralMap; 5410 // Load RewriteException back. 5411 method.load(rewriteExceptionType, lvarCount); 5412 // Get rid of the stored reference 5413 method.loadNull(); 5414 method.storeHidden(Type.OBJECT, lvarCount); 5415 // Mark it dead 5416 method.markDeadSlots(lvarCount, Type.OBJECT.getSlots()); 5417 5418 // Load return value on the stack 5419 method.invoke(RewriteException.GET_RETURN_VALUE); 5420 5421 final Type returnValueType = ci.getReturnValueType(); 5422 5423 // Set up an exception handler for primitive type conversion of return value if needed 5424 boolean needsCatch = false; 5425 final Label targetCatchLabel = ci.catchLabel; 5426 Label _try = null; 5427 if(returnValueType.isPrimitive()) { 5428 // If the conversion throws an exception, we want to report the line number of the continuation point. 5429 method.lineNumber(ci.lineNumber); 5430 5431 if(targetCatchLabel != METHOD_BOUNDARY) { 5432 _try = new Label(""); 5433 method.label(_try); 5434 needsCatch = true; 5435 } 5436 } 5437 5438 // Convert return value 5439 method.convert(returnValueType); 5440 5441 final int scopePopCount = needsCatch ? ci.exceptionScopePops : 0; 5442 5443 // Declare a try/catch for the conversion. If no scopes need to be popped until the target catch block, just 5444 // jump into it. Otherwise, we'll need to create a scope-popping catch block below. 5445 final Label catchLabel = scopePopCount > 0 ? new Label("") : targetCatchLabel; 5446 if(needsCatch) { 5447 final Label _end_try = new Label(""); 5448 method.label(_end_try); 5449 method._try(_try, _end_try, catchLabel); 5450 } 5451 5452 // Jump to continuation point 5453 method._goto(ci.getTargetLabel()); 5454 5455 // Make a scope-popping exception delegate if needed 5456 if(catchLabel != targetCatchLabel) { 5457 method.lineNumber(0); 5458 assert scopePopCount > 0; 5459 method._catch(catchLabel); 5460 popScopes(scopePopCount); 5461 method.uncheckedGoto(targetCatchLabel); 5462 } 5463 } 5464} 5465