1 /* 2 * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package jdk.nashorn.internal.codegen; 27 28 import static jdk.nashorn.internal.codegen.ClassEmitter.Flag.PRIVATE; 29 import static jdk.nashorn.internal.codegen.ClassEmitter.Flag.STATIC; 30 import static jdk.nashorn.internal.codegen.CompilerConstants.ARGUMENTS; 31 import static jdk.nashorn.internal.codegen.CompilerConstants.CALLEE; 32 import static jdk.nashorn.internal.codegen.CompilerConstants.CREATE_PROGRAM_FUNCTION; 33 import static jdk.nashorn.internal.codegen.CompilerConstants.GET_MAP; 34 import static jdk.nashorn.internal.codegen.CompilerConstants.GET_STRING; 35 import static jdk.nashorn.internal.codegen.CompilerConstants.QUICK_PREFIX; 36 import static jdk.nashorn.internal.codegen.CompilerConstants.REGEX_PREFIX; 37 import static jdk.nashorn.internal.codegen.CompilerConstants.SCOPE; 38 import static jdk.nashorn.internal.codegen.CompilerConstants.SPLIT_PREFIX; 39 import static jdk.nashorn.internal.codegen.CompilerConstants.THIS; 40 import static jdk.nashorn.internal.codegen.CompilerConstants.VARARGS; 41 import static jdk.nashorn.internal.codegen.CompilerConstants.interfaceCallNoLookup; 42 import static jdk.nashorn.internal.codegen.CompilerConstants.methodDescriptor; 43 import static jdk.nashorn.internal.codegen.CompilerConstants.staticCallNoLookup; 44 import static jdk.nashorn.internal.codegen.CompilerConstants.typeDescriptor; 45 import static jdk.nashorn.internal.codegen.CompilerConstants.virtualCallNoLookup; 46 import static jdk.nashorn.internal.codegen.ObjectClassGenerator.OBJECT_FIELDS_ONLY; 47 import static jdk.nashorn.internal.ir.Symbol.HAS_SLOT; 48 import static jdk.nashorn.internal.ir.Symbol.IS_INTERNAL; 49 import static jdk.nashorn.internal.runtime.UnwarrantedOptimismException.INVALID_PROGRAM_POINT; 50 import static jdk.nashorn.internal.runtime.UnwarrantedOptimismException.isValid; 51 import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_APPLY_TO_CALL; 52 import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_DECLARE; 53 import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_FAST_SCOPE; 54 import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_OPTIMISTIC; 55 import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_PROGRAM_POINT_SHIFT; 56 import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_SCOPE; 57 58 import java.io.PrintWriter; 59 import java.util.ArrayDeque; 60 import java.util.ArrayList; 61 import java.util.Arrays; 62 import java.util.BitSet; 63 import java.util.Collection; 64 import java.util.Collections; 65 import java.util.Deque; 66 import java.util.EnumSet; 67 import java.util.HashMap; 68 import java.util.HashSet; 69 import java.util.Iterator; 70 import java.util.LinkedList; 71 import java.util.List; 72 import java.util.Map; 73 import java.util.Set; 74 import java.util.TreeMap; 75 import java.util.function.Supplier; 76 import jdk.nashorn.internal.AssertsEnabled; 77 import jdk.nashorn.internal.IntDeque; 78 import jdk.nashorn.internal.codegen.ClassEmitter.Flag; 79 import jdk.nashorn.internal.codegen.CompilerConstants.Call; 80 import jdk.nashorn.internal.codegen.types.ArrayType; 81 import jdk.nashorn.internal.codegen.types.Type; 82 import jdk.nashorn.internal.ir.AccessNode; 83 import jdk.nashorn.internal.ir.BaseNode; 84 import jdk.nashorn.internal.ir.BinaryNode; 85 import jdk.nashorn.internal.ir.Block; 86 import jdk.nashorn.internal.ir.BlockStatement; 87 import jdk.nashorn.internal.ir.BreakNode; 88 import jdk.nashorn.internal.ir.CallNode; 89 import jdk.nashorn.internal.ir.CaseNode; 90 import jdk.nashorn.internal.ir.CatchNode; 91 import jdk.nashorn.internal.ir.ContinueNode; 92 import jdk.nashorn.internal.ir.EmptyNode; 93 import jdk.nashorn.internal.ir.Expression; 94 import jdk.nashorn.internal.ir.ExpressionStatement; 95 import jdk.nashorn.internal.ir.ForNode; 96 import jdk.nashorn.internal.ir.FunctionNode; 97 import jdk.nashorn.internal.ir.FunctionNode.CompilationState; 98 import jdk.nashorn.internal.ir.GetSplitState; 99 import jdk.nashorn.internal.ir.IdentNode; 100 import jdk.nashorn.internal.ir.IfNode; 101 import jdk.nashorn.internal.ir.IndexNode; 102 import jdk.nashorn.internal.ir.JoinPredecessorExpression; 103 import jdk.nashorn.internal.ir.JumpStatement; 104 import jdk.nashorn.internal.ir.JumpToInlinedFinally; 105 import jdk.nashorn.internal.ir.LabelNode; 106 import jdk.nashorn.internal.ir.LexicalContext; 107 import jdk.nashorn.internal.ir.LexicalContextNode; 108 import jdk.nashorn.internal.ir.LiteralNode; 109 import jdk.nashorn.internal.ir.LiteralNode.ArrayLiteralNode; 110 import jdk.nashorn.internal.ir.LiteralNode.ArrayLiteralNode.ArrayUnit; 111 import jdk.nashorn.internal.ir.LiteralNode.PrimitiveLiteralNode; 112 import jdk.nashorn.internal.ir.LocalVariableConversion; 113 import jdk.nashorn.internal.ir.LoopNode; 114 import jdk.nashorn.internal.ir.Node; 115 import jdk.nashorn.internal.ir.ObjectNode; 116 import jdk.nashorn.internal.ir.Optimistic; 117 import jdk.nashorn.internal.ir.PropertyNode; 118 import jdk.nashorn.internal.ir.ReturnNode; 119 import jdk.nashorn.internal.ir.RuntimeNode; 120 import jdk.nashorn.internal.ir.RuntimeNode.Request; 121 import jdk.nashorn.internal.ir.SetSplitState; 122 import jdk.nashorn.internal.ir.SplitReturn; 123 import jdk.nashorn.internal.ir.Statement; 124 import jdk.nashorn.internal.ir.SwitchNode; 125 import jdk.nashorn.internal.ir.Symbol; 126 import jdk.nashorn.internal.ir.TernaryNode; 127 import jdk.nashorn.internal.ir.ThrowNode; 128 import jdk.nashorn.internal.ir.TryNode; 129 import jdk.nashorn.internal.ir.UnaryNode; 130 import jdk.nashorn.internal.ir.VarNode; 131 import jdk.nashorn.internal.ir.WhileNode; 132 import jdk.nashorn.internal.ir.WithNode; 133 import jdk.nashorn.internal.ir.visitor.NodeOperatorVisitor; 134 import jdk.nashorn.internal.ir.visitor.NodeVisitor; 135 import jdk.nashorn.internal.objects.Global; 136 import jdk.nashorn.internal.objects.ScriptFunctionImpl; 137 import jdk.nashorn.internal.parser.Lexer.RegexToken; 138 import jdk.nashorn.internal.parser.TokenType; 139 import jdk.nashorn.internal.runtime.Context; 140 import jdk.nashorn.internal.runtime.Debug; 141 import jdk.nashorn.internal.runtime.ECMAException; 142 import jdk.nashorn.internal.runtime.JSType; 143 import jdk.nashorn.internal.runtime.OptimisticReturnFilters; 144 import jdk.nashorn.internal.runtime.PropertyMap; 145 import jdk.nashorn.internal.runtime.RecompilableScriptFunctionData; 146 import jdk.nashorn.internal.runtime.RewriteException; 147 import jdk.nashorn.internal.runtime.Scope; 148 import jdk.nashorn.internal.runtime.ScriptEnvironment; 149 import jdk.nashorn.internal.runtime.ScriptFunction; 150 import jdk.nashorn.internal.runtime.ScriptObject; 151 import jdk.nashorn.internal.runtime.ScriptRuntime; 152 import jdk.nashorn.internal.runtime.Source; 153 import jdk.nashorn.internal.runtime.Undefined; 154 import jdk.nashorn.internal.runtime.UnwarrantedOptimismException; 155 import jdk.nashorn.internal.runtime.arrays.ArrayData; 156 import jdk.nashorn.internal.runtime.linker.LinkerCallSite; 157 import jdk.nashorn.internal.runtime.logging.DebugLogger; 158 import jdk.nashorn.internal.runtime.logging.Loggable; 159 import jdk.nashorn.internal.runtime.logging.Logger; 160 import jdk.nashorn.internal.runtime.options.Options; 161 162 /** 163 * This is the lowest tier of the code generator. It takes lowered ASTs emitted 164 * from Lower and emits Java byte code. The byte code emission logic is broken 165 * out into MethodEmitter. MethodEmitter works internally with a type stack, and 166 * keeps track of the contents of the byte code stack. This way we avoid a large 167 * number of special cases on the form 168 * <pre> 169 * if (type == INT) { 170 * visitInsn(ILOAD, slot); 171 * } else if (type == DOUBLE) { 172 * visitInsn(DOUBLE, slot); 173 * } 174 * </pre> 175 * This quickly became apparent when the code generator was generalized to work 176 * with all types, and not just numbers or objects. 177 * <p> 178 * The CodeGenerator visits nodes only once, tags them as resolved and emits 179 * bytecode for them. 180 */ 181 @Logger(name="codegen") 182 final class CodeGenerator extends NodeOperatorVisitor<CodeGeneratorLexicalContext> implements Loggable { 183 184 private static final Type SCOPE_TYPE = Type.typeFor(ScriptObject.class); 185 186 private static final String GLOBAL_OBJECT = Type.getInternalName(Global.class); 187 188 private static final Call CREATE_REWRITE_EXCEPTION = CompilerConstants.staticCallNoLookup(RewriteException.class, 189 "create", RewriteException.class, UnwarrantedOptimismException.class, Object[].class, String[].class); 190 private static final Call CREATE_REWRITE_EXCEPTION_REST_OF = CompilerConstants.staticCallNoLookup(RewriteException.class, 191 "create", RewriteException.class, UnwarrantedOptimismException.class, Object[].class, String[].class, int[].class); 192 193 private static final Call ENSURE_INT = CompilerConstants.staticCallNoLookup(OptimisticReturnFilters.class, 194 "ensureInt", int.class, Object.class, int.class); 195 private static final Call ENSURE_LONG = CompilerConstants.staticCallNoLookup(OptimisticReturnFilters.class, 196 "ensureLong", long.class, Object.class, int.class); 197 private static final Call ENSURE_NUMBER = CompilerConstants.staticCallNoLookup(OptimisticReturnFilters.class, 198 "ensureNumber", double.class, Object.class, int.class); 199 200 private static final Call CREATE_FUNCTION_OBJECT = CompilerConstants.staticCallNoLookup(ScriptFunctionImpl.class, 201 "create", ScriptFunction.class, Object[].class, int.class, ScriptObject.class); 202 private static final Call CREATE_FUNCTION_OBJECT_NO_SCOPE = CompilerConstants.staticCallNoLookup(ScriptFunctionImpl.class, 203 "create", ScriptFunction.class, Object[].class, int.class); 204 205 private static final Class<?> ITERATOR_CLASS = Iterator.class; 206 static { 207 assert ITERATOR_CLASS == CompilerConstants.ITERATOR_PREFIX.type(); 208 } 209 private static final Type ITERATOR_TYPE = Type.typeFor(ITERATOR_CLASS); 210 private static final Type EXCEPTION_TYPE = Type.typeFor(CompilerConstants.EXCEPTION_PREFIX.type()); 211 212 private static final Integer INT_ZERO = Integer.valueOf(0); 213 214 /** Constant data & installation. The only reason the compiler keeps this is because it is assigned 215 * by reflection in class installation */ 216 private final Compiler compiler; 217 218 /** Is the current code submitted by 'eval' call? */ 219 private final boolean evalCode; 220 221 /** Call site flags given to the code generator to be used for all generated call sites */ 222 private final int callSiteFlags; 223 224 /** How many regexp fields have been emitted */ 225 private int regexFieldCount; 226 227 /** Line number for last statement. If we encounter a new line number, line number bytecode information 228 * needs to be generated */ 229 private int lastLineNumber = -1; 230 231 /** When should we stop caching regexp expressions in fields to limit bytecode size? */ 232 private static final int MAX_REGEX_FIELDS = 2 * 1024; 233 234 /** Current method emitter */ 235 private MethodEmitter method; 236 237 /** Current compile unit */ 238 private CompileUnit unit; 239 240 private final DebugLogger log; 241 242 /** From what size should we use spill instead of fields for JavaScript objects? */ 243 private static final int OBJECT_SPILL_THRESHOLD = Options.getIntProperty("nashorn.spill.threshold", 256); 244 245 private final Set<String> emittedMethods = new HashSet<>(); 246 247 // Function Id -> ContinuationInfo. Used by compilation of rest-of function only. 248 private final Map<Integer, ContinuationInfo> fnIdToContinuationInfo = new HashMap<>(); 249 250 private final Deque<Label> scopeEntryLabels = new ArrayDeque<>(); 251 252 private static final Label METHOD_BOUNDARY = new Label(""); 253 private final Deque<Label> catchLabels = new ArrayDeque<>(); 254 // Number of live locals on entry to (and thus also break from) labeled blocks. 255 private final IntDeque labeledBlockBreakLiveLocals = new IntDeque(); 256 257 //is this a rest of compilation 258 private final int[] continuationEntryPoints; 259 260 /** 261 * Constructor. 262 * 263 * @param compiler 264 */ 265 CodeGenerator(final Compiler compiler, final int[] continuationEntryPoints) { 266 super(new CodeGeneratorLexicalContext()); 267 this.compiler = compiler; 268 this.evalCode = compiler.getSource().isEvalCode(); 269 this.continuationEntryPoints = continuationEntryPoints; 270 this.callSiteFlags = compiler.getScriptEnvironment()._callsite_flags; 271 this.log = initLogger(compiler.getContext()); 272 } 273 274 @Override 275 public DebugLogger getLogger() { 276 return log; 277 } 278 279 @Override 280 public DebugLogger initLogger(final Context context) { 281 return context.getLogger(this.getClass()); 282 } 283 284 /** 285 * Gets the call site flags, adding the strict flag if the current function 286 * being generated is in strict mode 287 * 288 * @return the correct flags for a call site in the current function 289 */ 290 int getCallSiteFlags() { 291 return lc.getCurrentFunction().getCallSiteFlags() | callSiteFlags; 292 } 293 294 /** 295 * Are we generating code for 'eval' code? 296 * @return true if currently compiled code is 'eval' code. 297 */ 298 boolean isEvalCode() { 299 return evalCode; 300 } 301 302 /** 303 * Load an identity node 304 * 305 * @param identNode an identity node to load 306 * @return the method generator used 307 */ 308 private MethodEmitter loadIdent(final IdentNode identNode, final TypeBounds resultBounds) { 309 checkTemporalDeadZone(identNode); 310 final Symbol symbol = identNode.getSymbol(); 311 312 if (!symbol.isScope()) { 313 final Type type = identNode.getType(); 314 if(type == Type.UNDEFINED) { 315 return method.loadUndefined(resultBounds.widest); 316 } 317 318 assert symbol.hasSlot() || symbol.isParam(); 319 return method.load(identNode); 320 } 321 322 assert identNode.getSymbol().isScope() : identNode + " is not in scope!"; 323 final int flags = CALLSITE_SCOPE | getCallSiteFlags(); 324 if (isFastScope(symbol)) { 325 // Only generate shared scope getter for fast-scope symbols so we know we can dial in correct scope. 326 if (symbol.getUseCount() > SharedScopeCall.FAST_SCOPE_GET_THRESHOLD && !isOptimisticOrRestOf()) { 327 method.loadCompilerConstant(SCOPE); 328 // As shared scope vars are only used in non-optimistic compilation, we switch from using TypeBounds to 329 // just a single definitive type, resultBounds.widest. 330 loadSharedScopeVar(resultBounds.widest, symbol, flags); 331 } else { 332 new LoadFastScopeVar(identNode, resultBounds, flags).emit(); 333 } 334 } else { 335 //slow scope load, we have no proto depth 336 new LoadScopeVar(identNode, resultBounds, flags).emit(); 337 } 338 339 return method; 340 } 341 342 // Any access to LET and CONST variables before their declaration must throw ReferenceError. 343 // This is called the temporal dead zone (TDZ). See https://gist.github.com/rwaldron/f0807a758aa03bcdd58a 344 private void checkTemporalDeadZone(final IdentNode identNode) { 345 if (identNode.isDead()) { 346 method.load(identNode.getSymbol().getName()); 347 method.invoke(ScriptRuntime.THROW_REFERENCE_ERROR); 348 } 349 } 350 351 private boolean isRestOf() { 352 return continuationEntryPoints != null; 353 } 354 355 private boolean isOptimisticOrRestOf() { 356 return useOptimisticTypes() || isRestOf(); 357 } 358 359 private boolean isCurrentContinuationEntryPoint(final int programPoint) { 360 return isRestOf() && getCurrentContinuationEntryPoint() == programPoint; 361 } 362 363 private int[] getContinuationEntryPoints() { 364 return isRestOf() ? continuationEntryPoints : null; 365 } 366 367 private int getCurrentContinuationEntryPoint() { 368 return isRestOf() ? continuationEntryPoints[0] : INVALID_PROGRAM_POINT; 369 } 370 371 private boolean isContinuationEntryPoint(final int programPoint) { 372 if (isRestOf()) { 373 assert continuationEntryPoints != null; 374 for (final int cep : continuationEntryPoints) { 375 if (cep == programPoint) { 376 return true; 377 } 378 } 379 } 380 return false; 381 } 382 383 /** 384 * Check if this symbol can be accessed directly with a putfield or getfield or dynamic load 385 * 386 * @param symbol symbol to check for fast scope 387 * @return true if fast scope 388 */ 389 private boolean isFastScope(final Symbol symbol) { 390 if (!symbol.isScope()) { 391 return false; 392 } 393 394 if (!lc.inDynamicScope()) { 395 // If there's no with or eval in context, and the symbol is marked as scoped, it is fast scoped. Such a 396 // symbol must either be global, or its defining block must need scope. 397 assert symbol.isGlobal() || lc.getDefiningBlock(symbol).needsScope() : symbol.getName(); 398 return true; 399 } 400 401 if (symbol.isGlobal()) { 402 // Shortcut: if there's a with or eval in context, globals can't be fast scoped 403 return false; 404 } 405 406 // Otherwise, check if there's a dynamic scope between use of the symbol and its definition 407 final String name = symbol.getName(); 408 boolean previousWasBlock = false; 409 for (final Iterator<LexicalContextNode> it = lc.getAllNodes(); it.hasNext();) { 410 final LexicalContextNode node = it.next(); 411 if (node instanceof Block) { 412 // If this block defines the symbol, then we can fast scope the symbol. 413 final Block block = (Block)node; 414 if (block.getExistingSymbol(name) == symbol) { 415 assert block.needsScope(); 416 return true; 417 } 418 previousWasBlock = true; 419 } else { 420 if (node instanceof WithNode && previousWasBlock || node instanceof FunctionNode && ((FunctionNode)node).needsDynamicScope()) { 421 // If we hit a scope that can have symbols introduced into it at run time before finding the defining 422 // block, the symbol can't be fast scoped. A WithNode only counts if we've immediately seen a block 423 // before - its block. Otherwise, we are currently processing the WithNode's expression, and that's 424 // obviously not subjected to introducing new symbols. 425 return false; 426 } 427 previousWasBlock = false; 428 } 429 } 430 // Should've found the symbol defined in a block 431 throw new AssertionError(); 432 } 433 434 private MethodEmitter loadSharedScopeVar(final Type valueType, final Symbol symbol, final int flags) { 435 assert !isOptimisticOrRestOf(); 436 if (isFastScope(symbol)) { 437 method.load(getScopeProtoDepth(lc.getCurrentBlock(), symbol)); 438 } else { 439 method.load(-1); 440 } 441 return lc.getScopeGet(unit, symbol, valueType, flags | CALLSITE_FAST_SCOPE).generateInvoke(method); 442 } 443 444 private class LoadScopeVar extends OptimisticOperation { 445 final IdentNode identNode; 446 private final int flags; 447 448 LoadScopeVar(final IdentNode identNode, final TypeBounds resultBounds, final int flags) { 449 super(identNode, resultBounds); 450 this.identNode = identNode; 451 this.flags = flags; 452 } 453 454 @Override 455 void loadStack() { 456 method.loadCompilerConstant(SCOPE); 457 getProto(); 458 } 459 460 void getProto() { 461 //empty 462 } 463 464 @Override 465 void consumeStack() { 466 // If this is either __FILE__, __DIR__, or __LINE__ then load the property initially as Object as we'd convert 467 // it anyway for replaceLocationPropertyPlaceholder. 468 if(identNode.isCompileTimePropertyName()) { 469 method.dynamicGet(Type.OBJECT, identNode.getSymbol().getName(), flags, identNode.isFunction(), false); 470 replaceCompileTimeProperty(); 471 } else { 472 dynamicGet(identNode.getSymbol().getName(), flags, identNode.isFunction(), false); 473 } 474 } 475 } 476 477 private class LoadFastScopeVar extends LoadScopeVar { 478 LoadFastScopeVar(final IdentNode identNode, final TypeBounds resultBounds, final int flags) { 479 super(identNode, resultBounds, flags | CALLSITE_FAST_SCOPE); 480 } 481 482 @Override 483 void getProto() { 484 loadFastScopeProto(identNode.getSymbol(), false); 485 } 486 } 487 488 private MethodEmitter storeFastScopeVar(final Symbol symbol, final int flags) { 489 loadFastScopeProto(symbol, true); 490 method.dynamicSet(symbol.getName(), flags | CALLSITE_FAST_SCOPE, false); 491 return method; 492 } 493 494 private int getScopeProtoDepth(final Block startingBlock, final Symbol symbol) { 495 //walk up the chain from starting block and when we bump into the current function boundary, add the external 496 //information. 497 final FunctionNode fn = lc.getCurrentFunction(); 498 final int externalDepth = compiler.getScriptFunctionData(fn.getId()).getExternalSymbolDepth(symbol.getName()); 499 500 //count the number of scopes from this place to the start of the function 501 502 final int internalDepth = FindScopeDepths.findInternalDepth(lc, fn, startingBlock, symbol); 503 final int scopesToStart = FindScopeDepths.findScopesToStart(lc, fn, startingBlock); 504 int depth = 0; 505 if (internalDepth == -1) { 506 depth = scopesToStart + externalDepth; 507 } else { 508 assert internalDepth <= scopesToStart; 509 depth = internalDepth; 510 } 511 512 return depth; 513 } 514 515 private void loadFastScopeProto(final Symbol symbol, final boolean swap) { 516 final int depth = getScopeProtoDepth(lc.getCurrentBlock(), symbol); 517 assert depth != -1 : "Couldn't find scope depth for symbol " + symbol.getName() + " in " + lc.getCurrentFunction(); 518 if (depth > 0) { 519 if (swap) { 520 method.swap(); 521 } 522 for (int i = 0; i < depth; i++) { 523 method.invoke(ScriptObject.GET_PROTO); 524 } 525 if (swap) { 526 method.swap(); 527 } 528 } 529 } 530 531 /** 532 * Generate code that loads this node to the stack, not constraining its type 533 * 534 * @param expr node to load 535 * 536 * @return the method emitter used 537 */ 538 private MethodEmitter loadExpressionUnbounded(final Expression expr) { 539 return loadExpression(expr, TypeBounds.UNBOUNDED); 540 } 541 542 private MethodEmitter loadExpressionAsObject(final Expression expr) { 543 return loadExpression(expr, TypeBounds.OBJECT); 544 } 545 546 MethodEmitter loadExpressionAsBoolean(final Expression expr) { 547 return loadExpression(expr, TypeBounds.BOOLEAN); 548 } 549 550 // Test whether conversion from source to target involves a call of ES 9.1 ToPrimitive 551 // with possible side effects from calling an object's toString or valueOf methods. 552 private static boolean noToPrimitiveConversion(final Type source, final Type target) { 553 // Object to boolean conversion does not cause ToPrimitive call 554 return source.isJSPrimitive() || !target.isJSPrimitive() || target.isBoolean(); 555 } 556 557 MethodEmitter loadBinaryOperands(final BinaryNode binaryNode) { 558 return loadBinaryOperands(binaryNode.lhs(), binaryNode.rhs(), TypeBounds.UNBOUNDED.notWiderThan(binaryNode.getWidestOperandType()), false, false); 559 } 560 561 private MethodEmitter loadBinaryOperands(final Expression lhs, final Expression rhs, final TypeBounds explicitOperandBounds, final boolean baseAlreadyOnStack, final boolean forceConversionSeparation) { 562 // ECMAScript 5.1 specification (sections 11.5-11.11 and 11.13) prescribes that when evaluating a binary 563 // expression "LEFT op RIGHT", the order of operations must be: LOAD LEFT, LOAD RIGHT, CONVERT LEFT, CONVERT 564 // RIGHT, EXECUTE OP. Unfortunately, doing it in this order defeats potential optimizations that arise when we 565 // can combine a LOAD with a CONVERT operation (e.g. use a dynamic getter with the conversion target type as its 566 // return value). What we do here is reorder LOAD RIGHT and CONVERT LEFT when possible; it is possible only when 567 // we can prove that executing CONVERT LEFT can't have a side effect that changes the value of LOAD RIGHT. 568 // Basically, if we know that either LEFT already is a primitive value, or does not have to be converted to 569 // a primitive value, or RIGHT is an expression that loads without side effects, then we can do the 570 // reordering and collapse LOAD/CONVERT into a single operation; otherwise we need to do the more costly 571 // separate operations to preserve specification semantics. 572 573 // Operands' load type should not be narrower than the narrowest of the individual operand types, nor narrower 574 // than the lower explicit bound, but it should also not be wider than 575 final Type lhsType = undefinedToNumber(lhs.getType()); 576 final Type rhsType = undefinedToNumber(rhs.getType()); 577 final Type narrowestOperandType = Type.narrowest(Type.widest(lhsType, rhsType), explicitOperandBounds.widest); 578 final TypeBounds operandBounds = explicitOperandBounds.notNarrowerThan(narrowestOperandType); 579 if (noToPrimitiveConversion(lhsType, explicitOperandBounds.widest) || rhs.isLocal()) { 580 // Can reorder. We might still need to separate conversion, but at least we can do it with reordering 581 if (forceConversionSeparation) { 582 // Can reorder, but can't move conversion into the operand as the operation depends on operands 583 // exact types for its overflow guarantees. E.g. with {L}{%I}expr1 {L}* {L}{%I}expr2 we are not allowed 584 // to merge {L}{%I} into {%L}, as that can cause subsequent overflows; test for JDK-8058610 contains 585 // concrete cases where this could happen. 586 final TypeBounds safeConvertBounds = TypeBounds.UNBOUNDED.notNarrowerThan(narrowestOperandType); 587 loadExpression(lhs, safeConvertBounds, baseAlreadyOnStack); 588 method.convert(operandBounds.within(method.peekType())); 589 loadExpression(rhs, safeConvertBounds, false); 590 method.convert(operandBounds.within(method.peekType())); 591 } else { 592 // Can reorder and move conversion into the operand. Combine load and convert into single operations. 593 loadExpression(lhs, operandBounds, baseAlreadyOnStack); 594 loadExpression(rhs, operandBounds, false); 595 } 596 } else { 597 // Can't reorder. Load and convert separately. 598 final TypeBounds safeConvertBounds = TypeBounds.UNBOUNDED.notNarrowerThan(narrowestOperandType); 599 loadExpression(lhs, safeConvertBounds, baseAlreadyOnStack); 600 final Type lhsLoadedType = method.peekType(); 601 loadExpression(rhs, safeConvertBounds, false); 602 final Type convertedLhsType = operandBounds.within(method.peekType()); 603 if (convertedLhsType != lhsLoadedType) { 604 // Do it conditionally, so that if conversion is a no-op we don't introduce a SWAP, SWAP. 605 method.swap().convert(convertedLhsType).swap(); 606 } 607 method.convert(operandBounds.within(method.peekType())); 608 } 609 assert Type.generic(method.peekType()) == operandBounds.narrowest; 610 assert Type.generic(method.peekType(1)) == operandBounds.narrowest; 611 612 return method; 613 } 614 615 private static final Type undefinedToNumber(final Type type) { 616 return type == Type.UNDEFINED ? Type.NUMBER : type; 617 } 618 619 private static final class TypeBounds { 620 final Type narrowest; 621 final Type widest; 622 623 static final TypeBounds UNBOUNDED = new TypeBounds(Type.UNKNOWN, Type.OBJECT); 624 static final TypeBounds INT = exact(Type.INT); 625 static final TypeBounds OBJECT = exact(Type.OBJECT); 626 static final TypeBounds BOOLEAN = exact(Type.BOOLEAN); 627 628 static TypeBounds exact(final Type type) { 629 return new TypeBounds(type, type); 630 } 631 632 TypeBounds(final Type narrowest, final Type widest) { 633 assert widest != null && widest != Type.UNDEFINED && widest != Type.UNKNOWN : widest; 634 assert narrowest != null && narrowest != Type.UNDEFINED : narrowest; 635 assert !narrowest.widerThan(widest) : narrowest + " wider than " + widest; 636 assert !widest.narrowerThan(narrowest); 637 this.narrowest = Type.generic(narrowest); 638 this.widest = Type.generic(widest); 639 } 640 641 TypeBounds notNarrowerThan(final Type type) { 642 return maybeNew(Type.narrowest(Type.widest(narrowest, type), widest), widest); 643 } 644 645 TypeBounds notWiderThan(final Type type) { 646 return maybeNew(Type.narrowest(narrowest, type), Type.narrowest(widest, type)); 647 } 648 649 boolean canBeNarrowerThan(final Type type) { 650 return narrowest.narrowerThan(type); 651 } 652 653 TypeBounds maybeNew(final Type newNarrowest, final Type newWidest) { 654 if(newNarrowest == narrowest && newWidest == widest) { 655 return this; 656 } 657 return new TypeBounds(newNarrowest, newWidest); 658 } 659 660 TypeBounds booleanToInt() { 661 return maybeNew(CodeGenerator.booleanToInt(narrowest), CodeGenerator.booleanToInt(widest)); 662 } 663 664 TypeBounds objectToNumber() { 665 return maybeNew(CodeGenerator.objectToNumber(narrowest), CodeGenerator.objectToNumber(widest)); 666 } 667 668 Type within(final Type type) { 669 if(type.narrowerThan(narrowest)) { 670 return narrowest; 671 } 672 if(type.widerThan(widest)) { 673 return widest; 674 } 675 return type; 676 } 677 678 @Override 679 public String toString() { 680 return "[" + narrowest + ", " + widest + "]"; 681 } 682 } 683 684 private static Type booleanToInt(final Type t) { 685 return t == Type.BOOLEAN ? Type.INT : t; 686 } 687 688 private static Type objectToNumber(final Type t) { 689 return t.isObject() ? Type.NUMBER : t; 690 } 691 692 MethodEmitter loadExpressionAsType(final Expression expr, final Type type) { 693 if(type == Type.BOOLEAN) { 694 return loadExpressionAsBoolean(expr); 695 } else if(type == Type.UNDEFINED) { 696 assert expr.getType() == Type.UNDEFINED; 697 return loadExpressionAsObject(expr); 698 } 699 // having no upper bound preserves semantics of optimistic operations in the expression (by not having them 700 // converted early) and then applies explicit conversion afterwards. 701 return loadExpression(expr, TypeBounds.UNBOUNDED.notNarrowerThan(type)).convert(type); 702 } 703 704 private MethodEmitter loadExpression(final Expression expr, final TypeBounds resultBounds) { 705 return loadExpression(expr, resultBounds, false); 706 } 707 708 /** 709 * Emits code for evaluating an expression and leaving its value on top of the stack, narrowing or widening it if 710 * necessary. 711 * @param expr the expression to load 712 * @param resultBounds the incoming type bounds. The value on the top of the stack is guaranteed to not be of narrower 713 * type than the narrowest bound, or wider type than the widest bound after it is loaded. 714 * @param baseAlreadyOnStack true if the base of an access or index node is already on the stack. Used to avoid 715 * double evaluation of bases in self-assignment expressions to access and index nodes. {@code Type.OBJECT} is used 716 * to indicate the widest possible type. 717 * @return the method emitter 718 */ 719 private MethodEmitter loadExpression(final Expression expr, final TypeBounds resultBounds, final boolean baseAlreadyOnStack) { 720 721 /* 722 * The load may be of type IdentNode, e.g. "x", AccessNode, e.g. "x.y" 723 * or IndexNode e.g. "x[y]". Both AccessNodes and IndexNodes are 724 * BaseNodes and the logic for loading the base object is reused 725 */ 726 final CodeGenerator codegen = this; 727 728 final Node currentDiscard = codegen.lc.getCurrentDiscard(); 729 expr.accept(new NodeOperatorVisitor<LexicalContext>(new LexicalContext()) { 730 @Override 731 public boolean enterIdentNode(final IdentNode identNode) { 732 loadIdent(identNode, resultBounds); 733 return false; 734 } 735 736 @Override 737 public boolean enterAccessNode(final AccessNode accessNode) { 738 new OptimisticOperation(accessNode, resultBounds) { 739 @Override 740 void loadStack() { 741 if (!baseAlreadyOnStack) { 742 loadExpressionAsObject(accessNode.getBase()); 743 } 744 assert method.peekType().isObject(); 745 } 746 @Override 747 void consumeStack() { 748 final int flags = getCallSiteFlags(); 749 dynamicGet(accessNode.getProperty(), flags, accessNode.isFunction(), accessNode.isIndex()); 750 } 751 }.emit(baseAlreadyOnStack ? 1 : 0); 752 return false; 753 } 754 755 @Override 756 public boolean enterIndexNode(final IndexNode indexNode) { 757 new OptimisticOperation(indexNode, resultBounds) { 758 @Override 759 void loadStack() { 760 if (!baseAlreadyOnStack) { 761 loadExpressionAsObject(indexNode.getBase()); 762 loadExpressionUnbounded(indexNode.getIndex()); 763 } 764 } 765 @Override 766 void consumeStack() { 767 final int flags = getCallSiteFlags(); 768 dynamicGetIndex(flags, indexNode.isFunction()); 769 } 770 }.emit(baseAlreadyOnStack ? 2 : 0); 771 return false; 772 } 773 774 @Override 775 public boolean enterFunctionNode(final FunctionNode functionNode) { 776 // function nodes will always leave a constructed function object on stack, no need to load the symbol 777 // separately as in enterDefault() 778 lc.pop(functionNode); 779 functionNode.accept(codegen); 780 // NOTE: functionNode.accept() will produce a different FunctionNode that we discard. This incidentally 781 // doesn't cause problems as we're never touching FunctionNode again after it's visited here - codegen 782 // is the last element in the compilation pipeline, the AST it produces is not used externally. So, we 783 // re-push the original functionNode. 784 lc.push(functionNode); 785 return false; 786 } 787 788 @Override 789 public boolean enterASSIGN(final BinaryNode binaryNode) { 790 loadASSIGN(binaryNode); 791 return false; 792 } 793 794 @Override 795 public boolean enterASSIGN_ADD(final BinaryNode binaryNode) { 796 loadASSIGN_ADD(binaryNode); 797 return false; 798 } 799 800 @Override 801 public boolean enterASSIGN_BIT_AND(final BinaryNode binaryNode) { 802 loadASSIGN_BIT_AND(binaryNode); 803 return false; 804 } 805 806 @Override 807 public boolean enterASSIGN_BIT_OR(final BinaryNode binaryNode) { 808 loadASSIGN_BIT_OR(binaryNode); 809 return false; 810 } 811 812 @Override 813 public boolean enterASSIGN_BIT_XOR(final BinaryNode binaryNode) { 814 loadASSIGN_BIT_XOR(binaryNode); 815 return false; 816 } 817 818 @Override 819 public boolean enterASSIGN_DIV(final BinaryNode binaryNode) { 820 loadASSIGN_DIV(binaryNode); 821 return false; 822 } 823 824 @Override 825 public boolean enterASSIGN_MOD(final BinaryNode binaryNode) { 826 loadASSIGN_MOD(binaryNode); 827 return false; 828 } 829 830 @Override 831 public boolean enterASSIGN_MUL(final BinaryNode binaryNode) { 832 loadASSIGN_MUL(binaryNode); 833 return false; 834 } 835 836 @Override 837 public boolean enterASSIGN_SAR(final BinaryNode binaryNode) { 838 loadASSIGN_SAR(binaryNode); 839 return false; 840 } 841 842 @Override 843 public boolean enterASSIGN_SHL(final BinaryNode binaryNode) { 844 loadASSIGN_SHL(binaryNode); 845 return false; 846 } 847 848 @Override 849 public boolean enterASSIGN_SHR(final BinaryNode binaryNode) { 850 loadASSIGN_SHR(binaryNode); 851 return false; 852 } 853 854 @Override 855 public boolean enterASSIGN_SUB(final BinaryNode binaryNode) { 856 loadASSIGN_SUB(binaryNode); 857 return false; 858 } 859 860 @Override 861 public boolean enterCallNode(final CallNode callNode) { 862 return loadCallNode(callNode, resultBounds); 863 } 864 865 @Override 866 public boolean enterLiteralNode(final LiteralNode<?> literalNode) { 867 loadLiteral(literalNode, resultBounds); 868 return false; 869 } 870 871 @Override 872 public boolean enterTernaryNode(final TernaryNode ternaryNode) { 873 loadTernaryNode(ternaryNode, resultBounds); 874 return false; 875 } 876 877 @Override 878 public boolean enterADD(final BinaryNode binaryNode) { 879 loadADD(binaryNode, resultBounds); 880 return false; 881 } 882 883 @Override 884 public boolean enterSUB(final UnaryNode unaryNode) { 885 loadSUB(unaryNode, resultBounds); 886 return false; 887 } 888 889 @Override 890 public boolean enterSUB(final BinaryNode binaryNode) { 891 loadSUB(binaryNode, resultBounds); 892 return false; 893 } 894 895 @Override 896 public boolean enterMUL(final BinaryNode binaryNode) { 897 loadMUL(binaryNode, resultBounds); 898 return false; 899 } 900 901 @Override 902 public boolean enterDIV(final BinaryNode binaryNode) { 903 loadDIV(binaryNode, resultBounds); 904 return false; 905 } 906 907 @Override 908 public boolean enterMOD(final BinaryNode binaryNode) { 909 loadMOD(binaryNode, resultBounds); 910 return false; 911 } 912 913 @Override 914 public boolean enterSAR(final BinaryNode binaryNode) { 915 loadSAR(binaryNode); 916 return false; 917 } 918 919 @Override 920 public boolean enterSHL(final BinaryNode binaryNode) { 921 loadSHL(binaryNode); 922 return false; 923 } 924 925 @Override 926 public boolean enterSHR(final BinaryNode binaryNode) { 927 loadSHR(binaryNode); 928 return false; 929 } 930 931 @Override 932 public boolean enterCOMMALEFT(final BinaryNode binaryNode) { 933 loadCOMMALEFT(binaryNode, resultBounds); 934 return false; 935 } 936 937 @Override 938 public boolean enterCOMMARIGHT(final BinaryNode binaryNode) { 939 loadCOMMARIGHT(binaryNode, resultBounds); 940 return false; 941 } 942 943 @Override 944 public boolean enterAND(final BinaryNode binaryNode) { 945 loadAND_OR(binaryNode, resultBounds, true); 946 return false; 947 } 948 949 @Override 950 public boolean enterOR(final BinaryNode binaryNode) { 951 loadAND_OR(binaryNode, resultBounds, false); 952 return false; 953 } 954 955 @Override 956 public boolean enterNOT(final UnaryNode unaryNode) { 957 loadNOT(unaryNode); 958 return false; 959 } 960 961 @Override 962 public boolean enterADD(final UnaryNode unaryNode) { 963 loadADD(unaryNode, resultBounds); 964 return false; 965 } 966 967 @Override 968 public boolean enterBIT_NOT(final UnaryNode unaryNode) { 969 loadBIT_NOT(unaryNode); 970 return false; 971 } 972 973 @Override 974 public boolean enterBIT_AND(final BinaryNode binaryNode) { 975 loadBIT_AND(binaryNode); 976 return false; 977 } 978 979 @Override 980 public boolean enterBIT_OR(final BinaryNode binaryNode) { 981 loadBIT_OR(binaryNode); 982 return false; 983 } 984 985 @Override 986 public boolean enterBIT_XOR(final BinaryNode binaryNode) { 987 loadBIT_XOR(binaryNode); 988 return false; 989 } 990 991 @Override 992 public boolean enterVOID(final UnaryNode unaryNode) { 993 loadVOID(unaryNode, resultBounds); 994 return false; 995 } 996 997 @Override 998 public boolean enterEQ(final BinaryNode binaryNode) { 999 loadCmp(binaryNode, Condition.EQ); 1000 return false; 1001 } 1002 1003 @Override 1004 public boolean enterEQ_STRICT(final BinaryNode binaryNode) { 1005 loadCmp(binaryNode, Condition.EQ); 1006 return false; 1007 } 1008 1009 @Override 1010 public boolean enterGE(final BinaryNode binaryNode) { 1011 loadCmp(binaryNode, Condition.GE); 1012 return false; 1013 } 1014 1015 @Override 1016 public boolean enterGT(final BinaryNode binaryNode) { 1017 loadCmp(binaryNode, Condition.GT); 1018 return false; 1019 } 1020 1021 @Override 1022 public boolean enterLE(final BinaryNode binaryNode) { 1023 loadCmp(binaryNode, Condition.LE); 1024 return false; 1025 } 1026 1027 @Override 1028 public boolean enterLT(final BinaryNode binaryNode) { 1029 loadCmp(binaryNode, Condition.LT); 1030 return false; 1031 } 1032 1033 @Override 1034 public boolean enterNE(final BinaryNode binaryNode) { 1035 loadCmp(binaryNode, Condition.NE); 1036 return false; 1037 } 1038 1039 @Override 1040 public boolean enterNE_STRICT(final BinaryNode binaryNode) { 1041 loadCmp(binaryNode, Condition.NE); 1042 return false; 1043 } 1044 1045 @Override 1046 public boolean enterObjectNode(final ObjectNode objectNode) { 1047 loadObjectNode(objectNode); 1048 return false; 1049 } 1050 1051 @Override 1052 public boolean enterRuntimeNode(final RuntimeNode runtimeNode) { 1053 loadRuntimeNode(runtimeNode); 1054 return false; 1055 } 1056 1057 @Override 1058 public boolean enterNEW(final UnaryNode unaryNode) { 1059 loadNEW(unaryNode); 1060 return false; 1061 } 1062 1063 @Override 1064 public boolean enterDECINC(final UnaryNode unaryNode) { 1065 loadDECINC(unaryNode); 1066 return false; 1067 } 1068 1069 @Override 1070 public boolean enterJoinPredecessorExpression(final JoinPredecessorExpression joinExpr) { 1071 loadExpression(joinExpr.getExpression(), resultBounds); 1072 return false; 1073 } 1074 1075 @Override 1076 public boolean enterGetSplitState(final GetSplitState getSplitState) { 1077 method.loadScope(); 1078 method.invoke(Scope.GET_SPLIT_STATE); 1079 return false; 1080 } 1081 1082 @Override 1083 public boolean enterDefault(final Node otherNode) { 1084 // Must have handled all expressions that can legally be encountered. 1085 throw new AssertionError(otherNode.getClass().getName()); 1086 } 1087 }); 1088 if(currentDiscard != expr) { 1089 coerceStackTop(resultBounds); 1090 } 1091 return method; 1092 } 1093 1094 private MethodEmitter coerceStackTop(final TypeBounds typeBounds) { 1095 return method.convert(typeBounds.within(method.peekType())); 1096 } 1097 1098 /** 1099 * Closes any still open entries for this block's local variables in the bytecode local variable table. 1100 * 1101 * @param block block containing symbols. 1102 */ 1103 private void closeBlockVariables(final Block block) { 1104 for (final Symbol symbol : block.getSymbols()) { 1105 if (symbol.isBytecodeLocal()) { 1106 method.closeLocalVariable(symbol, block.getBreakLabel()); 1107 } 1108 } 1109 } 1110 1111 @Override 1112 public boolean enterBlock(final Block block) { 1113 final Label entryLabel = block.getEntryLabel(); 1114 if (entryLabel.isBreakTarget()) { 1115 // Entry label is a break target only for an inlined finally block. 1116 assert !method.isReachable(); 1117 method.breakLabel(entryLabel, lc.getUsedSlotCount()); 1118 } else { 1119 method.label(entryLabel); 1120 } 1121 if(!method.isReachable()) { 1122 return false; 1123 } 1124 if(lc.isFunctionBody() && emittedMethods.contains(lc.getCurrentFunction().getName())) { 1125 return false; 1126 } 1127 initLocals(block); 1128 1129 assert lc.getUsedSlotCount() == method.getFirstTemp(); 1130 return true; 1131 } 1132 1133 private boolean useOptimisticTypes() { 1134 return !lc.inSplitNode() && compiler.useOptimisticTypes(); 1135 } 1136 1137 @Override 1138 public Node leaveBlock(final Block block) { 1139 popBlockScope(block); 1140 method.beforeJoinPoint(block); 1141 1142 closeBlockVariables(block); 1143 lc.releaseSlots(); 1144 assert !method.isReachable() || (lc.isFunctionBody() ? 0 : lc.getUsedSlotCount()) == method.getFirstTemp() : 1145 "reachable="+method.isReachable() + 1146 " isFunctionBody=" + lc.isFunctionBody() + 1147 " usedSlotCount=" + lc.getUsedSlotCount() + 1148 " firstTemp=" + method.getFirstTemp(); 1149 1150 return block; 1151 } 1152 1153 private void popBlockScope(final Block block) { 1154 final Label breakLabel = block.getBreakLabel(); 1155 1156 if(!block.needsScope() || lc.isFunctionBody()) { 1157 emitBlockBreakLabel(breakLabel); 1158 return; 1159 } 1160 1161 final Label beginTryLabel = scopeEntryLabels.pop(); 1162 final Label recoveryLabel = new Label("block_popscope_catch"); 1163 emitBlockBreakLabel(breakLabel); 1164 final boolean bodyCanThrow = breakLabel.isAfter(beginTryLabel); 1165 if(bodyCanThrow) { 1166 method._try(beginTryLabel, breakLabel, recoveryLabel); 1167 } 1168 1169 Label afterCatchLabel = null; 1170 1171 if(method.isReachable()) { 1172 popScope(); 1173 if(bodyCanThrow) { 1174 afterCatchLabel = new Label("block_after_catch"); 1175 method._goto(afterCatchLabel); 1176 } 1177 } 1178 1179 if(bodyCanThrow) { 1180 assert !method.isReachable(); 1181 method._catch(recoveryLabel); 1182 popScopeException(); 1183 method.athrow(); 1184 } 1185 if(afterCatchLabel != null) { 1186 method.label(afterCatchLabel); 1187 } 1188 } 1189 1190 private void emitBlockBreakLabel(final Label breakLabel) { 1191 // TODO: this is totally backwards. Block should not be breakable, LabelNode should be breakable. 1192 final LabelNode labelNode = lc.getCurrentBlockLabelNode(); 1193 if(labelNode != null) { 1194 // Only have conversions if we're reachable 1195 assert labelNode.getLocalVariableConversion() == null || method.isReachable(); 1196 method.beforeJoinPoint(labelNode); 1197 method.breakLabel(breakLabel, labeledBlockBreakLiveLocals.pop()); 1198 } else { 1199 method.label(breakLabel); 1200 } 1201 } 1202 1203 private void popScope() { 1204 popScopes(1); 1205 } 1206 1207 /** 1208 * Pop scope as part of an exception handler. Similar to {@code popScope()} but also takes care of adjusting the 1209 * number of scopes that needs to be popped in case a rest-of continuation handler encounters an exception while 1210 * performing a ToPrimitive conversion. 1211 */ 1212 private void popScopeException() { 1213 popScope(); 1214 final ContinuationInfo ci = getContinuationInfo(); 1215 if(ci != null) { 1216 final Label catchLabel = ci.catchLabel; 1217 if(catchLabel != METHOD_BOUNDARY && catchLabel == catchLabels.peek()) { 1218 ++ci.exceptionScopePops; 1219 } 1220 } 1221 } 1222 1223 private void popScopesUntil(final LexicalContextNode until) { 1224 popScopes(lc.getScopeNestingLevelTo(until)); 1225 } 1226 1227 private void popScopes(final int count) { 1228 if(count == 0) { 1229 return; 1230 } 1231 assert count > 0; // together with count == 0 check, asserts nonnegative count 1232 if (!method.hasScope()) { 1233 // We can sometimes invoke this method even if the method has no slot for the scope object. Typical example: 1234 // for(;;) { with({}) { break; } }. WithNode normally creates a scope, but if it uses no identifiers and 1235 // nothing else forces creation of a scope in the method, we just won't have the :scope local variable. 1236 return; 1237 } 1238 method.loadCompilerConstant(SCOPE); 1239 for(int i = 0; i < count; ++i) { 1240 method.invoke(ScriptObject.GET_PROTO); 1241 } 1242 method.storeCompilerConstant(SCOPE); 1243 } 1244 1245 @Override 1246 public boolean enterBreakNode(final BreakNode breakNode) { 1247 return enterJumpStatement(breakNode); 1248 } 1249 1250 @Override 1251 public boolean enterJumpToInlinedFinally(final JumpToInlinedFinally jumpToInlinedFinally) { 1252 return enterJumpStatement(jumpToInlinedFinally); 1253 } 1254 1255 private boolean enterJumpStatement(final JumpStatement jump) { 1256 if(!method.isReachable()) { 1257 return false; 1258 } 1259 enterStatement(jump); 1260 1261 method.beforeJoinPoint(jump); 1262 popScopesUntil(jump.getPopScopeLimit(lc)); 1263 final Label targetLabel = jump.getTargetLabel(lc); 1264 targetLabel.markAsBreakTarget(); 1265 method._goto(targetLabel); 1266 1267 return false; 1268 } 1269 1270 private int loadArgs(final List<Expression> args) { 1271 final int argCount = args.size(); 1272 // arg have already been converted to objects here. 1273 if (argCount > LinkerCallSite.ARGLIMIT) { 1274 loadArgsArray(args); 1275 return 1; 1276 } 1277 1278 for (final Expression arg : args) { 1279 assert arg != null; 1280 loadExpressionUnbounded(arg); 1281 } 1282 return argCount; 1283 } 1284 1285 private boolean loadCallNode(final CallNode callNode, final TypeBounds resultBounds) { 1286 lineNumber(callNode.getLineNumber()); 1287 1288 final List<Expression> args = callNode.getArgs(); 1289 final Expression function = callNode.getFunction(); 1290 final Block currentBlock = lc.getCurrentBlock(); 1291 final CodeGeneratorLexicalContext codegenLexicalContext = lc; 1292 1293 function.accept(new NodeVisitor<LexicalContext>(new LexicalContext()) { 1294 1295 private MethodEmitter sharedScopeCall(final IdentNode identNode, final int flags) { 1296 final Symbol symbol = identNode.getSymbol(); 1297 final boolean isFastScope = isFastScope(symbol); 1298 final int scopeCallFlags = flags | (isFastScope ? CALLSITE_FAST_SCOPE : 0); 1299 new OptimisticOperation(callNode, resultBounds) { 1300 @Override 1301 void loadStack() { 1302 method.loadCompilerConstant(SCOPE); 1303 if (isFastScope) { 1304 method.load(getScopeProtoDepth(currentBlock, symbol)); 1305 } else { 1306 method.load(-1); // Bypass fast-scope code in shared callsite 1307 } 1308 loadArgs(args); 1309 } 1310 @Override 1311 void consumeStack() { 1312 final Type[] paramTypes = method.getTypesFromStack(args.size()); 1313 // We have trouble finding e.g. in Type.typeFor(asm.Type) because it can't see the Context class 1314 // loader, so we need to weaken reference signatures to Object. 1315 for(int i = 0; i < paramTypes.length; ++i) { 1316 paramTypes[i] = Type.generic(paramTypes[i]); 1317 } 1318 // As shared scope calls are only used in non-optimistic compilation, we switch from using 1319 // TypeBounds to just a single definitive type, resultBounds.widest. 1320 final SharedScopeCall scopeCall = codegenLexicalContext.getScopeCall(unit, symbol, 1321 identNode.getType(), resultBounds.widest, paramTypes, scopeCallFlags); 1322 scopeCall.generateInvoke(method); 1323 } 1324 }.emit(); 1325 return method; 1326 } 1327 1328 private void scopeCall(final IdentNode ident, final int flags) { 1329 new OptimisticOperation(callNode, resultBounds) { 1330 int argsCount; 1331 @Override 1332 void loadStack() { 1333 loadExpressionAsObject(ident); // foo() makes no sense if foo == 3 1334 // ScriptFunction will see CALLSITE_SCOPE and will bind scope accordingly. 1335 method.loadUndefined(Type.OBJECT); //the 'this' 1336 argsCount = loadArgs(args); 1337 } 1338 @Override 1339 void consumeStack() { 1340 dynamicCall(2 + argsCount, flags); 1341 } 1342 }.emit(); 1343 } 1344 1345 private void evalCall(final IdentNode ident, final int flags) { 1346 final Label invoke_direct_eval = new Label("invoke_direct_eval"); 1347 final Label is_not_eval = new Label("is_not_eval"); 1348 final Label eval_done = new Label("eval_done"); 1349 1350 new OptimisticOperation(callNode, resultBounds) { 1351 int argsCount; 1352 @Override 1353 void loadStack() { 1354 /** 1355 * We want to load 'eval' to check if it is indeed global builtin eval. 1356 * If this eval call is inside a 'with' statement, dyn:getMethod|getProp|getElem 1357 * would be generated if ident is a "isFunction". But, that would result in a 1358 * bound function from WithObject. We don't want that as bound function as that 1359 * won't be detected as builtin eval. So, we make ident as "not a function" which 1360 * results in "dyn:getProp|getElem|getMethod" being generated and so WithObject 1361 * would return unbounded eval function. 1362 * 1363 * Example: 1364 * 1365 * var global = this; 1366 * function func() { 1367 * with({ eval: global.eval) { eval("var x = 10;") } 1368 * } 1369 */ 1370 loadExpressionAsObject(ident.setIsNotFunction()); // Type.OBJECT as foo() makes no sense if foo == 3 1371 globalIsEval(); 1372 method.ifeq(is_not_eval); 1373 1374 // Load up self (scope). 1375 method.loadCompilerConstant(SCOPE); 1376 final List<Expression> evalArgs = callNode.getEvalArgs().getArgs(); 1377 // load evaluated code 1378 loadExpressionAsObject(evalArgs.get(0)); 1379 // load second and subsequent args for side-effect 1380 final int numArgs = evalArgs.size(); 1381 for (int i = 1; i < numArgs; i++) { 1382 loadAndDiscard(evalArgs.get(i)); 1383 } 1384 method._goto(invoke_direct_eval); 1385 1386 method.label(is_not_eval); 1387 // load this time but with dyn:getMethod|getProp|getElem 1388 loadExpressionAsObject(ident); // Type.OBJECT as foo() makes no sense if foo == 3 1389 // This is some scope 'eval' or global eval replaced by user 1390 // but not the built-in ECMAScript 'eval' function call 1391 method.loadNull(); 1392 argsCount = loadArgs(callNode.getArgs()); 1393 } 1394 1395 @Override 1396 void consumeStack() { 1397 // Ordinary call 1398 dynamicCall(2 + argsCount, flags); 1399 method._goto(eval_done); 1400 1401 method.label(invoke_direct_eval); 1402 // Special/extra 'eval' arguments. These can be loaded late (in consumeStack) as we know none of 1403 // them can ever be optimistic. 1404 method.loadCompilerConstant(THIS); 1405 method.load(callNode.getEvalArgs().getLocation()); 1406 method.load(CodeGenerator.this.lc.getCurrentFunction().isStrict()); 1407 // direct call to Global.directEval 1408 globalDirectEval(); 1409 convertOptimisticReturnValue(); 1410 coerceStackTop(resultBounds); 1411 } 1412 }.emit(); 1413 1414 method.label(eval_done); 1415 } 1416 1417 @Override 1418 public boolean enterIdentNode(final IdentNode node) { 1419 final Symbol symbol = node.getSymbol(); 1420 1421 if (symbol.isScope()) { 1422 final int flags = getCallSiteFlags() | CALLSITE_SCOPE; 1423 final int useCount = symbol.getUseCount(); 1424 1425 // Threshold for generating shared scope callsite is lower for fast scope symbols because we know 1426 // we can dial in the correct scope. However, we also need to enable it for non-fast scopes to 1427 // support huge scripts like mandreel.js. 1428 if (callNode.isEval()) { 1429 evalCall(node, flags); 1430 } else if (useCount <= SharedScopeCall.FAST_SCOPE_CALL_THRESHOLD 1431 || !isFastScope(symbol) && useCount <= SharedScopeCall.SLOW_SCOPE_CALL_THRESHOLD 1432 || CodeGenerator.this.lc.inDynamicScope() 1433 || isOptimisticOrRestOf()) { 1434 scopeCall(node, flags); 1435 } else { 1436 sharedScopeCall(node, flags); 1437 } 1438 assert method.peekType().equals(resultBounds.within(callNode.getType())) : method.peekType() + " != " + resultBounds + "(" + callNode.getType() + ")"; 1439 } else { 1440 enterDefault(node); 1441 } 1442 1443 return false; 1444 } 1445 1446 @Override 1447 public boolean enterAccessNode(final AccessNode node) { 1448 //check if this is an apply to call node. only real applies, that haven't been 1449 //shadowed from their way to the global scope counts 1450 1451 //call nodes have program points. 1452 1453 final int flags = getCallSiteFlags() | (callNode.isApplyToCall() ? CALLSITE_APPLY_TO_CALL : 0); 1454 1455 new OptimisticOperation(callNode, resultBounds) { 1456 int argCount; 1457 @Override 1458 void loadStack() { 1459 loadExpressionAsObject(node.getBase()); 1460 method.dup(); 1461 // NOTE: not using a nested OptimisticOperation on this dynamicGet, as we expect to get back 1462 // a callable object. Nobody in their right mind would optimistically type this call site. 1463 assert !node.isOptimistic(); 1464 method.dynamicGet(node.getType(), node.getProperty(), flags, true, node.isIndex()); 1465 method.swap(); 1466 argCount = loadArgs(args); 1467 } 1468 @Override 1469 void consumeStack() { 1470 dynamicCall(2 + argCount, flags); 1471 } 1472 }.emit(); 1473 1474 return false; 1475 } 1476 1477 @Override 1478 public boolean enterFunctionNode(final FunctionNode origCallee) { 1479 new OptimisticOperation(callNode, resultBounds) { 1480 FunctionNode callee; 1481 int argsCount; 1482 @Override 1483 void loadStack() { 1484 callee = (FunctionNode)origCallee.accept(CodeGenerator.this); 1485 if (callee.isStrict()) { // "this" is undefined 1486 method.loadUndefined(Type.OBJECT); 1487 } else { // get global from scope (which is the self) 1488 globalInstance(); 1489 } 1490 argsCount = loadArgs(args); 1491 } 1492 1493 @Override 1494 void consumeStack() { 1495 final int flags = getCallSiteFlags(); 1496 //assert callNodeType.equals(callee.getReturnType()) : callNodeType + " != " + callee.getReturnType(); 1497 dynamicCall(2 + argsCount, flags); 1498 } 1499 }.emit(); 1500 return false; 1501 } 1502 1503 @Override 1504 public boolean enterIndexNode(final IndexNode node) { 1505 new OptimisticOperation(callNode, resultBounds) { 1506 int argsCount; 1507 @Override 1508 void loadStack() { 1509 loadExpressionAsObject(node.getBase()); 1510 method.dup(); 1511 final Type indexType = node.getIndex().getType(); 1512 if (indexType.isObject() || indexType.isBoolean()) { 1513 loadExpressionAsObject(node.getIndex()); //TODO boolean 1514 } else { 1515 loadExpressionUnbounded(node.getIndex()); 1516 } 1517 // NOTE: not using a nested OptimisticOperation on this dynamicGetIndex, as we expect to get 1518 // back a callable object. Nobody in their right mind would optimistically type this call site. 1519 assert !node.isOptimistic(); 1520 method.dynamicGetIndex(node.getType(), getCallSiteFlags(), true); 1521 method.swap(); 1522 argsCount = loadArgs(args); 1523 } 1524 @Override 1525 void consumeStack() { 1526 final int flags = getCallSiteFlags(); 1527 dynamicCall(2 + argsCount, flags); 1528 } 1529 }.emit(); 1530 return false; 1531 } 1532 1533 @Override 1534 protected boolean enterDefault(final Node node) { 1535 new OptimisticOperation(callNode, resultBounds) { 1536 int argsCount; 1537 @Override 1538 void loadStack() { 1539 // Load up function. 1540 loadExpressionAsObject(function); //TODO, e.g. booleans can be used as functions 1541 method.loadUndefined(Type.OBJECT); // ScriptFunction will figure out the correct this when it sees CALLSITE_SCOPE 1542 argsCount = loadArgs(args); 1543 } 1544 @Override 1545 void consumeStack() { 1546 final int flags = getCallSiteFlags() | CALLSITE_SCOPE; 1547 dynamicCall(2 + argsCount, flags); 1548 } 1549 }.emit(); 1550 return false; 1551 } 1552 }); 1553 1554 return false; 1555 } 1556 1557 /** 1558 * Returns the flags with optimistic flag and program point removed. 1559 * @param flags the flags that need optimism stripped from them. 1560 * @return flags without optimism 1561 */ 1562 static int nonOptimisticFlags(final int flags) { 1563 return flags & ~(CALLSITE_OPTIMISTIC | -1 << CALLSITE_PROGRAM_POINT_SHIFT); 1564 } 1565 1566 @Override 1567 public boolean enterContinueNode(final ContinueNode continueNode) { 1568 return enterJumpStatement(continueNode); 1569 } 1570 1571 @Override 1572 public boolean enterEmptyNode(final EmptyNode emptyNode) { 1573 if(!method.isReachable()) { 1574 return false; 1575 } 1576 enterStatement(emptyNode); 1577 1578 return false; 1579 } 1580 1581 @Override 1582 public boolean enterExpressionStatement(final ExpressionStatement expressionStatement) { 1583 if(!method.isReachable()) { 1584 return false; 1585 } 1586 enterStatement(expressionStatement); 1587 1588 loadAndDiscard(expressionStatement.getExpression()); 1589 assert method.getStackSize() == 0; 1590 1591 return false; 1592 } 1593 1594 @Override 1595 public boolean enterBlockStatement(final BlockStatement blockStatement) { 1596 if(!method.isReachable()) { 1597 return false; 1598 } 1599 enterStatement(blockStatement); 1600 1601 blockStatement.getBlock().accept(this); 1602 1603 return false; 1604 } 1605 1606 @Override 1607 public boolean enterForNode(final ForNode forNode) { 1608 if(!method.isReachable()) { 1609 return false; 1610 } 1611 enterStatement(forNode); 1612 if (forNode.isForIn()) { 1613 enterForIn(forNode); 1614 } else { 1615 final Expression init = forNode.getInit(); 1616 if (init != null) { 1617 loadAndDiscard(init); 1618 } 1619 enterForOrWhile(forNode, forNode.getModify()); 1620 } 1621 1622 return false; 1623 } 1624 1625 private void enterForIn(final ForNode forNode) { 1626 loadExpression(forNode.getModify(), TypeBounds.OBJECT); 1627 method.invoke(forNode.isForEach() ? ScriptRuntime.TO_VALUE_ITERATOR : ScriptRuntime.TO_PROPERTY_ITERATOR); 1628 final Symbol iterSymbol = forNode.getIterator(); 1629 final int iterSlot = iterSymbol.getSlot(Type.OBJECT); 1630 method.store(iterSymbol, ITERATOR_TYPE); 1631 1632 method.beforeJoinPoint(forNode); 1633 1634 final Label continueLabel = forNode.getContinueLabel(); 1635 final Label breakLabel = forNode.getBreakLabel(); 1636 1637 method.label(continueLabel); 1638 method.load(ITERATOR_TYPE, iterSlot); 1639 method.invoke(interfaceCallNoLookup(ITERATOR_CLASS, "hasNext", boolean.class)); 1640 final JoinPredecessorExpression test = forNode.getTest(); 1641 final Block body = forNode.getBody(); 1642 if(LocalVariableConversion.hasLiveConversion(test)) { 1643 final Label afterConversion = new Label("for_in_after_test_conv"); 1644 method.ifne(afterConversion); 1645 method.beforeJoinPoint(test); 1646 method._goto(breakLabel); 1647 method.label(afterConversion); 1648 } else { 1649 method.ifeq(breakLabel); 1650 } 1651 1652 new Store<Expression>(forNode.getInit()) { 1653 @Override 1654 protected void storeNonDiscard() { 1655 // This expression is neither part of a discard, nor needs to be left on the stack after it was 1656 // stored, so we override storeNonDiscard to be a no-op. 1657 } 1658 1659 @Override 1660 protected void evaluate() { 1661 new OptimisticOperation((Optimistic)forNode.getInit(), TypeBounds.UNBOUNDED) { 1662 @Override 1663 void loadStack() { 1664 method.load(ITERATOR_TYPE, iterSlot); 1665 } 1666 1667 @Override 1668 void consumeStack() { 1669 method.invoke(interfaceCallNoLookup(ITERATOR_CLASS, "next", Object.class)); 1670 convertOptimisticReturnValue(); 1671 } 1672 }.emit(); 1673 } 1674 }.store(); 1675 body.accept(this); 1676 1677 if(method.isReachable()) { 1678 method._goto(continueLabel); 1679 } 1680 method.label(breakLabel); 1681 } 1682 1683 /** 1684 * Initialize the slots in a frame to undefined. 1685 * 1686 * @param block block with local vars. 1687 */ 1688 private void initLocals(final Block block) { 1689 lc.onEnterBlock(block); 1690 1691 final boolean isFunctionBody = lc.isFunctionBody(); 1692 final FunctionNode function = lc.getCurrentFunction(); 1693 if (isFunctionBody) { 1694 initializeMethodParameters(function); 1695 if(!function.isVarArg()) { 1696 expandParameterSlots(function); 1697 } 1698 if (method.hasScope()) { 1699 if (function.needsParentScope()) { 1700 method.loadCompilerConstant(CALLEE); 1701 method.invoke(ScriptFunction.GET_SCOPE); 1702 } else { 1703 assert function.hasScopeBlock(); 1704 method.loadNull(); 1705 } 1706 method.storeCompilerConstant(SCOPE); 1707 } 1708 if (function.needsArguments()) { 1709 initArguments(function); 1710 } 1711 } 1712 1713 /* 1714 * Determine if block needs scope, if not, just do initSymbols for this block. 1715 */ 1716 if (block.needsScope()) { 1717 /* 1718 * Determine if function is varargs and consequently variables have to 1719 * be in the scope. 1720 */ 1721 final boolean varsInScope = function.allVarsInScope(); 1722 1723 // TODO for LET we can do better: if *block* does not contain any eval/with, we don't need its vars in scope. 1724 1725 final boolean hasArguments = function.needsArguments(); 1726 final List<MapTuple<Symbol>> tuples = new ArrayList<>(); 1727 final Iterator<IdentNode> paramIter = function.getParameters().iterator(); 1728 for (final Symbol symbol : block.getSymbols()) { 1729 if (symbol.isInternal() || symbol.isThis()) { 1730 continue; 1731 } 1732 1733 if (symbol.isVar()) { 1734 assert !varsInScope || symbol.isScope(); 1735 if (varsInScope || symbol.isScope()) { 1736 assert symbol.isScope() : "scope for " + symbol + " should have been set in Lower already " + function.getName(); 1737 assert !symbol.hasSlot() : "slot for " + symbol + " should have been removed in Lower already" + function.getName(); 1738 1739 //this tuple will not be put fielded, as it has no value, just a symbol 1740 tuples.add(new MapTuple<Symbol>(symbol.getName(), symbol, null)); 1741 } else { 1742 assert symbol.hasSlot() || symbol.slotCount() == 0 : symbol + " should have a slot only, no scope"; 1743 } 1744 } else if (symbol.isParam() && (varsInScope || hasArguments || symbol.isScope())) { 1745 assert symbol.isScope() : "scope for " + symbol + " should have been set in AssignSymbols already " + function.getName() + " varsInScope="+varsInScope+" hasArguments="+hasArguments+" symbol.isScope()=" + symbol.isScope(); 1746 assert !(hasArguments && symbol.hasSlot()) : "slot for " + symbol + " should have been removed in Lower already " + function.getName(); 1747 1748 final Type paramType; 1749 final Symbol paramSymbol; 1750 1751 if (hasArguments) { 1752 assert !symbol.hasSlot() : "slot for " + symbol + " should have been removed in Lower already "; 1753 paramSymbol = null; 1754 paramType = null; 1755 } else { 1756 paramSymbol = symbol; 1757 // NOTE: We're relying on the fact here that Block.symbols is a LinkedHashMap, hence it will 1758 // return symbols in the order they were defined, and parameters are defined in the same order 1759 // they appear in the function. That's why we can have a single pass over the parameter list 1760 // with an iterator, always just scanning forward for the next parameter that matches the symbol 1761 // name. 1762 for(;;) { 1763 final IdentNode nextParam = paramIter.next(); 1764 if(nextParam.getName().equals(symbol.getName())) { 1765 paramType = nextParam.getType(); 1766 break; 1767 } 1768 } 1769 } 1770 1771 tuples.add(new MapTuple<Symbol>(symbol.getName(), symbol, paramType, paramSymbol) { 1772 //this symbol will be put fielded, we can't initialize it as undefined with a known type 1773 @Override 1774 public Class<?> getValueType() { 1775 if (OBJECT_FIELDS_ONLY || value == null || paramType == null) { 1776 return Object.class; 1777 } 1778 return paramType.isBoolean() ? Object.class : paramType.getTypeClass(); 1779 } 1780 }); 1781 } 1782 } 1783 1784 /* 1785 * Create a new object based on the symbols and values, generate 1786 * bootstrap code for object 1787 */ 1788 new FieldObjectCreator<Symbol>(this, tuples, true, hasArguments) { 1789 @Override 1790 protected void loadValue(final Symbol value, final Type type) { 1791 method.load(value, type); 1792 } 1793 }.makeObject(method); 1794 // program function: merge scope into global 1795 if (isFunctionBody && function.isProgram()) { 1796 method.invoke(ScriptRuntime.MERGE_SCOPE); 1797 } 1798 1799 method.storeCompilerConstant(SCOPE); 1800 if(!isFunctionBody) { 1801 // Function body doesn't need a try/catch to restore scope, as it'd be a dead store anyway. Allowing it 1802 // actually causes issues with UnwarrantedOptimismException handlers as ASM will sort this handler to 1803 // the top of the exception handler table, so it'll be triggered instead of the UOE handlers. 1804 final Label scopeEntryLabel = new Label("scope_entry"); 1805 scopeEntryLabels.push(scopeEntryLabel); 1806 method.label(scopeEntryLabel); 1807 } 1808 } else if (isFunctionBody && function.isVarArg()) { 1809 // Since we don't have a scope, parameters didn't get assigned array indices by the FieldObjectCreator, so 1810 // we need to assign them separately here. 1811 int nextParam = 0; 1812 for (final IdentNode param : function.getParameters()) { 1813 param.getSymbol().setFieldIndex(nextParam++); 1814 } 1815 } 1816 1817 // Debugging: print symbols? @see --print-symbols flag 1818 printSymbols(block, function, (isFunctionBody ? "Function " : "Block in ") + (function.getIdent() == null ? "<anonymous>" : function.getIdent().getName())); 1819 } 1820 1821 /** 1822 * Incoming method parameters are always declared on method entry; declare them in the local variable table. 1823 * @param function function for which code is being generated. 1824 */ 1825 private void initializeMethodParameters(final FunctionNode function) { 1826 final Label functionStart = new Label("fn_start"); 1827 method.label(functionStart); 1828 int nextSlot = 0; 1829 if(function.needsCallee()) { 1830 initializeInternalFunctionParameter(CALLEE, function, functionStart, nextSlot++); 1831 } 1832 initializeInternalFunctionParameter(THIS, function, functionStart, nextSlot++); 1833 if(function.isVarArg()) { 1834 initializeInternalFunctionParameter(VARARGS, function, functionStart, nextSlot++); 1835 } else { 1836 for(final IdentNode param: function.getParameters()) { 1837 final Symbol symbol = param.getSymbol(); 1838 if(symbol.isBytecodeLocal()) { 1839 method.initializeMethodParameter(symbol, param.getType(), functionStart); 1840 } 1841 } 1842 } 1843 } 1844 1845 private void initializeInternalFunctionParameter(final CompilerConstants cc, final FunctionNode fn, final Label functionStart, final int slot) { 1846 final Symbol symbol = initializeInternalFunctionOrSplitParameter(cc, fn, functionStart, slot); 1847 // Internal function params (:callee, this, and :varargs) are never expanded to multiple slots 1848 assert symbol.getFirstSlot() == slot; 1849 } 1850 1851 private Symbol initializeInternalFunctionOrSplitParameter(final CompilerConstants cc, final FunctionNode fn, final Label functionStart, final int slot) { 1852 final Symbol symbol = fn.getBody().getExistingSymbol(cc.symbolName()); 1853 final Type type = Type.typeFor(cc.type()); 1854 method.initializeMethodParameter(symbol, type, functionStart); 1855 method.onLocalStore(type, slot); 1856 return symbol; 1857 } 1858 1859 /** 1860 * Parameters come into the method packed into local variable slots next to each other. Nashorn on the other hand 1861 * can use 1-6 slots for a local variable depending on all the types it needs to store. When this method is invoked, 1862 * the symbols are already allocated such wider slots, but the values are still in tightly packed incoming slots, 1863 * and we need to spread them into their new locations. 1864 * @param function the function for which parameter-spreading code needs to be emitted 1865 */ 1866 private void expandParameterSlots(final FunctionNode function) { 1867 final List<IdentNode> parameters = function.getParameters(); 1868 // Calculate the total number of incoming parameter slots 1869 int currentIncomingSlot = function.needsCallee() ? 2 : 1; 1870 for(final IdentNode parameter: parameters) { 1871 currentIncomingSlot += parameter.getType().getSlots(); 1872 } 1873 // Starting from last parameter going backwards, move the parameter values into their new slots. 1874 for(int i = parameters.size(); i-- > 0;) { 1875 final IdentNode parameter = parameters.get(i); 1876 final Type parameterType = parameter.getType(); 1877 final int typeWidth = parameterType.getSlots(); 1878 currentIncomingSlot -= typeWidth; 1879 final Symbol symbol = parameter.getSymbol(); 1880 final int slotCount = symbol.slotCount(); 1881 assert slotCount > 0; 1882 // Scoped parameters must not hold more than one value 1883 assert symbol.isBytecodeLocal() || slotCount == typeWidth; 1884 1885 // Mark it as having its value stored into it by the method invocation. 1886 method.onLocalStore(parameterType, currentIncomingSlot); 1887 if(currentIncomingSlot != symbol.getSlot(parameterType)) { 1888 method.load(parameterType, currentIncomingSlot); 1889 method.store(symbol, parameterType); 1890 } 1891 } 1892 } 1893 1894 private void initArguments(final FunctionNode function) { 1895 method.loadCompilerConstant(VARARGS); 1896 if (function.needsCallee()) { 1897 method.loadCompilerConstant(CALLEE); 1898 } else { 1899 // If function is strict mode, "arguments.callee" is not populated, so we don't necessarily need the 1900 // caller. 1901 assert function.isStrict(); 1902 method.loadNull(); 1903 } 1904 method.load(function.getParameters().size()); 1905 globalAllocateArguments(); 1906 method.storeCompilerConstant(ARGUMENTS); 1907 } 1908 1909 private boolean skipFunction(final FunctionNode functionNode) { 1910 final ScriptEnvironment env = compiler.getScriptEnvironment(); 1911 final boolean lazy = env._lazy_compilation; 1912 final boolean onDemand = compiler.isOnDemandCompilation(); 1913 1914 // If this is on-demand or lazy compilation, don't compile a nested (not topmost) function. 1915 if((onDemand || lazy) && lc.getOutermostFunction() != functionNode) { 1916 return true; 1917 } 1918 1919 // If lazy compiling with optimistic types, don't compile the program eagerly either. It will soon be 1920 // invalidated anyway. In presence of a class cache, this further means that an obsoleted program version 1921 // lingers around. Also, currently loading previously persisted optimistic types information only works if 1922 // we're on-demand compiling a function, so with this strategy the :program method can also have the warmup 1923 // benefit of using previously persisted types. 1924 // 1925 // NOTE that this means the first compiled class will effectively just have a :createProgramFunction method, and 1926 // the RecompilableScriptFunctionData (RSFD) object in its constants array. It won't even have the :program 1927 // method. This is by design. It does mean that we're wasting one compiler execution (and we could minimize this 1928 // by just running it up to scope depth calculation, which creates the RSFDs and then this limited codegen). 1929 // We could emit an initial separate compile unit with the initial version of :program in it to better utilize 1930 // the compilation pipeline, but that would need more invasive changes, as currently the assumption that 1931 // :program is emitted into the first compilation unit of the function lives in many places. 1932 return !onDemand && lazy && env._optimistic_types && functionNode.isProgram(); 1933 } 1934 1935 @Override 1936 public boolean enterFunctionNode(final FunctionNode functionNode) { 1937 final int fnId = functionNode.getId(); 1938 1939 if (skipFunction(functionNode)) { 1940 // In case we are not generating code for the function, we must create or retrieve the function object and 1941 // load it on the stack here. 1942 newFunctionObject(functionNode, false); 1943 return false; 1944 } 1945 1946 final String fnName = functionNode.getName(); 1947 1948 // NOTE: we only emit the method for a function with the given name once. We can have multiple functions with 1949 // the same name as a result of inlining finally blocks. However, in the future -- with type specialization, 1950 // notably -- we might need to check for both name *and* signature. Of course, even that might not be 1951 // sufficient; the function might have a code dependency on the type of the variables in its enclosing scopes, 1952 // and the type of such a variable can be different in catch and finally blocks. So, in the future we will have 1953 // to decide to either generate a unique method for each inlined copy of the function, maybe figure out its 1954 // exact type closure and deduplicate based on that, or just decide that functions in finally blocks aren't 1955 // worth it, and generate one method with most generic type closure. 1956 if (!emittedMethods.contains(fnName)) { 1957 log.info("=== BEGIN ", fnName); 1958 1959 assert functionNode.getCompileUnit() != null : "no compile unit for " + fnName + " " + Debug.id(functionNode); 1960 unit = lc.pushCompileUnit(functionNode.getCompileUnit()); 1961 assert lc.hasCompileUnits(); 1962 1963 final ClassEmitter classEmitter = unit.getClassEmitter(); 1964 pushMethodEmitter(isRestOf() ? classEmitter.restOfMethod(functionNode) : classEmitter.method(functionNode)); 1965 method.setPreventUndefinedLoad(); 1966 if(useOptimisticTypes()) { 1967 lc.pushUnwarrantedOptimismHandlers(); 1968 } 1969 1970 // new method - reset last line number 1971 lastLineNumber = -1; 1972 1973 method.begin(); 1974 1975 if (isRestOf()) { 1976 final ContinuationInfo ci = new ContinuationInfo(); 1977 fnIdToContinuationInfo.put(fnId, ci); 1978 method.gotoLoopStart(ci.getHandlerLabel()); 1979 } 1980 } 1981 1982 return true; 1983 } 1984 1985 private void pushMethodEmitter(final MethodEmitter newMethod) { 1986 method = lc.pushMethodEmitter(newMethod); 1987 catchLabels.push(METHOD_BOUNDARY); 1988 } 1989 1990 private void popMethodEmitter() { 1991 method = lc.popMethodEmitter(method); 1992 assert catchLabels.peek() == METHOD_BOUNDARY; 1993 catchLabels.pop(); 1994 } 1995 1996 @Override 1997 public Node leaveFunctionNode(final FunctionNode functionNode) { 1998 try { 1999 final boolean markOptimistic; 2000 if (emittedMethods.add(functionNode.getName())) { 2001 markOptimistic = generateUnwarrantedOptimismExceptionHandlers(functionNode); 2002 generateContinuationHandler(); 2003 method.end(); // wrap up this method 2004 unit = lc.popCompileUnit(functionNode.getCompileUnit()); 2005 popMethodEmitter(); 2006 log.info("=== END ", functionNode.getName()); 2007 } else { 2008 markOptimistic = false; 2009 } 2010 2011 FunctionNode newFunctionNode = functionNode.setState(lc, CompilationState.BYTECODE_GENERATED); 2012 if (markOptimistic) { 2013 newFunctionNode = newFunctionNode.setFlag(lc, FunctionNode.IS_DEOPTIMIZABLE); 2014 } 2015 2016 newFunctionObject(newFunctionNode, true); 2017 return newFunctionNode; 2018 } catch (final Throwable t) { 2019 Context.printStackTrace(t); 2020 final VerifyError e = new VerifyError("Code generation bug in \"" + functionNode.getName() + "\": likely stack misaligned: " + t + " " + functionNode.getSource().getName()); 2021 e.initCause(t); 2022 throw e; 2023 } 2024 } 2025 2026 @Override 2027 public boolean enterIfNode(final IfNode ifNode) { 2028 if(!method.isReachable()) { 2029 return false; 2030 } 2031 enterStatement(ifNode); 2032 2033 final Expression test = ifNode.getTest(); 2034 final Block pass = ifNode.getPass(); 2035 final Block fail = ifNode.getFail(); 2036 2037 if (Expression.isAlwaysTrue(test)) { 2038 loadAndDiscard(test); 2039 pass.accept(this); 2040 return false; 2041 } else if (Expression.isAlwaysFalse(test)) { 2042 loadAndDiscard(test); 2043 if (fail != null) { 2044 fail.accept(this); 2045 } 2046 return false; 2047 } 2048 2049 final boolean hasFailConversion = LocalVariableConversion.hasLiveConversion(ifNode); 2050 2051 final Label failLabel = new Label("if_fail"); 2052 final Label afterLabel = (fail == null && !hasFailConversion) ? null : new Label("if_done"); 2053 2054 emitBranch(test, failLabel, false); 2055 2056 pass.accept(this); 2057 if(method.isReachable() && afterLabel != null) { 2058 method._goto(afterLabel); //don't fallthru to fail block 2059 } 2060 method.label(failLabel); 2061 2062 if (fail != null) { 2063 fail.accept(this); 2064 } else if(hasFailConversion) { 2065 method.beforeJoinPoint(ifNode); 2066 } 2067 2068 if(afterLabel != null && afterLabel.isReachable()) { 2069 method.label(afterLabel); 2070 } 2071 2072 return false; 2073 } 2074 2075 private void emitBranch(final Expression test, final Label label, final boolean jumpWhenTrue) { 2076 new BranchOptimizer(this, method).execute(test, label, jumpWhenTrue); 2077 } 2078 2079 private void enterStatement(final Statement statement) { 2080 lineNumber(statement); 2081 } 2082 2083 private void lineNumber(final Statement statement) { 2084 lineNumber(statement.getLineNumber()); 2085 } 2086 2087 private void lineNumber(final int lineNumber) { 2088 if (lineNumber != lastLineNumber && lineNumber != Node.NO_LINE_NUMBER) { 2089 method.lineNumber(lineNumber); 2090 lastLineNumber = lineNumber; 2091 } 2092 } 2093 2094 int getLastLineNumber() { 2095 return lastLineNumber; 2096 } 2097 2098 /** 2099 * Load a list of nodes as an array of a specific type 2100 * The array will contain the visited nodes. 2101 * 2102 * @param arrayLiteralNode the array of contents 2103 * @param arrayType the type of the array, e.g. ARRAY_NUMBER or ARRAY_OBJECT 2104 * 2105 * @return the method generator that was used 2106 */ 2107 private MethodEmitter loadArray(final ArrayLiteralNode arrayLiteralNode, final ArrayType arrayType) { 2108 assert arrayType == Type.INT_ARRAY || arrayType == Type.LONG_ARRAY || arrayType == Type.NUMBER_ARRAY || arrayType == Type.OBJECT_ARRAY; 2109 2110 final Expression[] nodes = arrayLiteralNode.getValue(); 2111 final Object presets = arrayLiteralNode.getPresets(); 2112 final int[] postsets = arrayLiteralNode.getPostsets(); 2113 final Class<?> type = arrayType.getTypeClass(); 2114 final List<ArrayUnit> units = arrayLiteralNode.getUnits(); 2115 2116 loadConstant(presets); 2117 2118 final Type elementType = arrayType.getElementType(); 2119 2120 if (units != null) { 2121 final MethodEmitter savedMethod = method; 2122 final FunctionNode currentFunction = lc.getCurrentFunction(); 2123 2124 for (final ArrayUnit arrayUnit : units) { 2125 unit = lc.pushCompileUnit(arrayUnit.getCompileUnit()); 2126 2127 final String className = unit.getUnitClassName(); 2128 assert unit != null; 2129 final String name = currentFunction.uniqueName(SPLIT_PREFIX.symbolName()); 2130 final String signature = methodDescriptor(type, ScriptFunction.class, Object.class, ScriptObject.class, type); 2131 2132 pushMethodEmitter(unit.getClassEmitter().method(EnumSet.of(Flag.PUBLIC, Flag.STATIC), name, signature)); 2133 2134 method.setFunctionNode(currentFunction); 2135 method.begin(); 2136 2137 defineCommonSplitMethodParameters(); 2138 defineSplitMethodParameter(CompilerConstants.SPLIT_ARRAY_ARG.slot(), arrayType); 2139 2140 // NOTE: when this is no longer needed, SplitIntoFunctions will no longer have to add IS_SPLIT 2141 // to synthetic functions, and FunctionNode.needsCallee() will no longer need to test for isSplit(). 2142 final int arraySlot = fixScopeSlot(currentFunction, 3); 2143 2144 lc.enterSplitNode(); 2145 2146 for (int i = arrayUnit.getLo(); i < arrayUnit.getHi(); i++) { 2147 method.load(arrayType, arraySlot); 2148 storeElement(nodes, elementType, postsets[i]); 2149 } 2150 2151 method.load(arrayType, arraySlot); 2152 method._return(); 2153 lc.exitSplitNode(); 2154 method.end(); 2155 lc.releaseSlots(); 2156 popMethodEmitter(); 2157 2158 assert method == savedMethod; 2159 method.loadCompilerConstant(CALLEE); 2160 method.swap(); 2161 method.loadCompilerConstant(THIS); 2162 method.swap(); 2163 method.loadCompilerConstant(SCOPE); 2164 method.swap(); 2165 method.invokestatic(className, name, signature); 2166 2167 unit = lc.popCompileUnit(unit); 2168 } 2169 2170 return method; 2171 } 2172 2173 if(postsets.length > 0) { 2174 final int arraySlot = method.getUsedSlotsWithLiveTemporaries(); 2175 method.storeTemp(arrayType, arraySlot); 2176 for (final int postset : postsets) { 2177 method.load(arrayType, arraySlot); 2178 storeElement(nodes, elementType, postset); 2179 } 2180 method.load(arrayType, arraySlot); 2181 } 2182 return method; 2183 } 2184 2185 private void storeElement(final Expression[] nodes, final Type elementType, final int index) { 2186 method.load(index); 2187 2188 final Expression element = nodes[index]; 2189 2190 if (element == null) { 2191 method.loadEmpty(elementType); 2192 } else { 2193 loadExpressionAsType(element, elementType); 2194 } 2195 2196 method.arraystore(); 2197 } 2198 2199 private MethodEmitter loadArgsArray(final List<Expression> args) { 2200 final Object[] array = new Object[args.size()]; 2201 loadConstant(array); 2202 2203 for (int i = 0; i < args.size(); i++) { 2204 method.dup(); 2205 method.load(i); 2206 loadExpression(args.get(i), TypeBounds.OBJECT); // variable arity methods always take objects 2207 method.arraystore(); 2208 } 2209 2210 return method; 2211 } 2212 2213 /** 2214 * Load a constant from the constant array. This is only public to be callable from the objects 2215 * subpackage. Do not call directly. 2216 * 2217 * @param string string to load 2218 */ 2219 void loadConstant(final String string) { 2220 final String unitClassName = unit.getUnitClassName(); 2221 final ClassEmitter classEmitter = unit.getClassEmitter(); 2222 final int index = compiler.getConstantData().add(string); 2223 2224 method.load(index); 2225 method.invokestatic(unitClassName, GET_STRING.symbolName(), methodDescriptor(String.class, int.class)); 2226 classEmitter.needGetConstantMethod(String.class); 2227 } 2228 2229 /** 2230 * Load a constant from the constant array. This is only public to be callable from the objects 2231 * subpackage. Do not call directly. 2232 * 2233 * @param object object to load 2234 */ 2235 void loadConstant(final Object object) { 2236 loadConstant(object, unit, method); 2237 } 2238 2239 private void loadConstant(final Object object, final CompileUnit compileUnit, final MethodEmitter methodEmitter) { 2240 final String unitClassName = compileUnit.getUnitClassName(); 2241 final ClassEmitter classEmitter = compileUnit.getClassEmitter(); 2242 final int index = compiler.getConstantData().add(object); 2243 final Class<?> cls = object.getClass(); 2244 2245 if (cls == PropertyMap.class) { 2246 methodEmitter.load(index); 2247 methodEmitter.invokestatic(unitClassName, GET_MAP.symbolName(), methodDescriptor(PropertyMap.class, int.class)); 2248 classEmitter.needGetConstantMethod(PropertyMap.class); 2249 } else if (cls.isArray()) { 2250 methodEmitter.load(index); 2251 final String methodName = ClassEmitter.getArrayMethodName(cls); 2252 methodEmitter.invokestatic(unitClassName, methodName, methodDescriptor(cls, int.class)); 2253 classEmitter.needGetConstantMethod(cls); 2254 } else { 2255 methodEmitter.loadConstants().load(index).arrayload(); 2256 if (object instanceof ArrayData) { 2257 methodEmitter.checkcast(ArrayData.class); 2258 methodEmitter.invoke(virtualCallNoLookup(ArrayData.class, "copy", ArrayData.class)); 2259 } else if (cls != Object.class) { 2260 methodEmitter.checkcast(cls); 2261 } 2262 } 2263 } 2264 2265 private void loadConstantsAndIndex(final Object object, final MethodEmitter methodEmitter) { 2266 methodEmitter.loadConstants().load(compiler.getConstantData().add(object)); 2267 } 2268 2269 // literal values 2270 private void loadLiteral(final LiteralNode<?> node, final TypeBounds resultBounds) { 2271 final Object value = node.getValue(); 2272 2273 if (value == null) { 2274 method.loadNull(); 2275 } else if (value instanceof Undefined) { 2276 method.loadUndefined(resultBounds.within(Type.OBJECT)); 2277 } else if (value instanceof String) { 2278 final String string = (String)value; 2279 2280 if (string.length() > MethodEmitter.LARGE_STRING_THRESHOLD / 3) { // 3 == max bytes per encoded char 2281 loadConstant(string); 2282 } else { 2283 method.load(string); 2284 } 2285 } else if (value instanceof RegexToken) { 2286 loadRegex((RegexToken)value); 2287 } else if (value instanceof Boolean) { 2288 method.load((Boolean)value); 2289 } else if (value instanceof Integer) { 2290 if(!resultBounds.canBeNarrowerThan(Type.OBJECT)) { 2291 method.load((Integer)value); 2292 method.convert(Type.OBJECT); 2293 } else if(!resultBounds.canBeNarrowerThan(Type.NUMBER)) { 2294 method.load(((Integer)value).doubleValue()); 2295 } else if(!resultBounds.canBeNarrowerThan(Type.LONG)) { 2296 method.load(((Integer)value).longValue()); 2297 } else { 2298 method.load((Integer)value); 2299 } 2300 } else if (value instanceof Long) { 2301 if(!resultBounds.canBeNarrowerThan(Type.OBJECT)) { 2302 method.load((Long)value); 2303 method.convert(Type.OBJECT); 2304 } else if(!resultBounds.canBeNarrowerThan(Type.NUMBER)) { 2305 method.load(((Long)value).doubleValue()); 2306 } else { 2307 method.load((Long)value); 2308 } 2309 } else if (value instanceof Double) { 2310 if(!resultBounds.canBeNarrowerThan(Type.OBJECT)) { 2311 method.load((Double)value); 2312 method.convert(Type.OBJECT); 2313 } else { 2314 method.load((Double)value); 2315 } 2316 } else if (node instanceof ArrayLiteralNode) { 2317 final ArrayLiteralNode arrayLiteral = (ArrayLiteralNode)node; 2318 final ArrayType atype = arrayLiteral.getArrayType(); 2319 loadArray(arrayLiteral, atype); 2320 globalAllocateArray(atype); 2321 } else { 2322 throw new UnsupportedOperationException("Unknown literal for " + node.getClass() + " " + value.getClass() + " " + value); 2323 } 2324 } 2325 2326 private MethodEmitter loadRegexToken(final RegexToken value) { 2327 method.load(value.getExpression()); 2328 method.load(value.getOptions()); 2329 return globalNewRegExp(); 2330 } 2331 2332 private MethodEmitter loadRegex(final RegexToken regexToken) { 2333 if (regexFieldCount > MAX_REGEX_FIELDS) { 2334 return loadRegexToken(regexToken); 2335 } 2336 // emit field 2337 final String regexName = lc.getCurrentFunction().uniqueName(REGEX_PREFIX.symbolName()); 2338 final ClassEmitter classEmitter = unit.getClassEmitter(); 2339 2340 classEmitter.field(EnumSet.of(PRIVATE, STATIC), regexName, Object.class); 2341 regexFieldCount++; 2342 2343 // get field, if null create new regex, finally clone regex object 2344 method.getStatic(unit.getUnitClassName(), regexName, typeDescriptor(Object.class)); 2345 method.dup(); 2346 final Label cachedLabel = new Label("cached"); 2347 method.ifnonnull(cachedLabel); 2348 2349 method.pop(); 2350 loadRegexToken(regexToken); 2351 method.dup(); 2352 method.putStatic(unit.getUnitClassName(), regexName, typeDescriptor(Object.class)); 2353 2354 method.label(cachedLabel); 2355 globalRegExpCopy(); 2356 2357 return method; 2358 } 2359 2360 /** 2361 * Check if a property value contains a particular program point 2362 * @param value value 2363 * @param pp program point 2364 * @return true if it's there. 2365 */ 2366 private static boolean propertyValueContains(final Expression value, final int pp) { 2367 return new Supplier<Boolean>() { 2368 boolean contains; 2369 2370 @Override 2371 public Boolean get() { 2372 value.accept(new NodeVisitor<LexicalContext>(new LexicalContext()) { 2373 @Override 2374 public boolean enterFunctionNode(final FunctionNode functionNode) { 2375 return false; 2376 } 2377 2378 @Override 2379 public boolean enterObjectNode(final ObjectNode objectNode) { 2380 return false; 2381 } 2382 2383 @Override 2384 public boolean enterDefault(final Node node) { 2385 if (contains) { 2386 return false; 2387 } 2388 if (node instanceof Optimistic && ((Optimistic)node).getProgramPoint() == pp) { 2389 contains = true; 2390 return false; 2391 } 2392 return true; 2393 } 2394 }); 2395 2396 return contains; 2397 } 2398 }.get(); 2399 } 2400 2401 private void loadObjectNode(final ObjectNode objectNode) { 2402 final List<PropertyNode> elements = objectNode.getElements(); 2403 2404 final List<MapTuple<Expression>> tuples = new ArrayList<>(); 2405 final List<PropertyNode> gettersSetters = new ArrayList<>(); 2406 final int ccp = getCurrentContinuationEntryPoint(); 2407 2408 Expression protoNode = null; 2409 boolean restOfProperty = false; 2410 2411 for (final PropertyNode propertyNode : elements) { 2412 final Expression value = propertyNode.getValue(); 2413 final String key = propertyNode.getKeyName(); 2414 // Just use a pseudo-symbol. We just need something non null; use the name and zero flags. 2415 final Symbol symbol = value == null ? null : new Symbol(key, 0); 2416 2417 if (value == null) { 2418 gettersSetters.add(propertyNode); 2419 } else if (propertyNode.getKey() instanceof IdentNode && 2420 key.equals(ScriptObject.PROTO_PROPERTY_NAME)) { 2421 // ES6 draft compliant __proto__ inside object literal 2422 // Identifier key and name is __proto__ 2423 protoNode = value; 2424 continue; 2425 } 2426 2427 restOfProperty |= 2428 value != null && 2429 isValid(ccp) && 2430 propertyValueContains(value, ccp); 2431 2432 //for literals, a value of null means object type, i.e. the value null or getter setter function 2433 //(I think) 2434 final Class<?> valueType = (OBJECT_FIELDS_ONLY || value == null || value.getType().isBoolean()) ? Object.class : value.getType().getTypeClass(); 2435 tuples.add(new MapTuple<Expression>(key, symbol, Type.typeFor(valueType), value) { 2436 @Override 2437 public Class<?> getValueType() { 2438 return type.getTypeClass(); 2439 } 2440 }); 2441 } 2442 2443 final ObjectCreator<?> oc; 2444 if (elements.size() > OBJECT_SPILL_THRESHOLD) { 2445 oc = new SpillObjectCreator(this, tuples); 2446 } else { 2447 oc = new FieldObjectCreator<Expression>(this, tuples) { 2448 @Override 2449 protected void loadValue(final Expression node, final Type type) { 2450 loadExpressionAsType(node, type); 2451 }}; 2452 } 2453 oc.makeObject(method); 2454 2455 //if this is a rest of method and our continuation point was found as one of the values 2456 //in the properties above, we need to reset the map to oc.getMap() in the continuation 2457 //handler 2458 if (restOfProperty) { 2459 final ContinuationInfo ci = getContinuationInfo(); 2460 // Can be set at most once for a single rest-of method 2461 assert ci.getObjectLiteralMap() == null; 2462 ci.setObjectLiteralMap(oc.getMap()); 2463 ci.setObjectLiteralStackDepth(method.getStackSize()); 2464 } 2465 2466 method.dup(); 2467 if (protoNode != null) { 2468 loadExpressionAsObject(protoNode); 2469 // take care of { __proto__: 34 } or some such! 2470 method.convert(Type.OBJECT); 2471 method.invoke(ScriptObject.SET_PROTO_FROM_LITERAL); 2472 } else { 2473 method.invoke(ScriptObject.SET_GLOBAL_OBJECT_PROTO); 2474 } 2475 2476 for (final PropertyNode propertyNode : gettersSetters) { 2477 final FunctionNode getter = propertyNode.getGetter(); 2478 final FunctionNode setter = propertyNode.getSetter(); 2479 2480 assert getter != null || setter != null; 2481 2482 method.dup().loadKey(propertyNode.getKey()); 2483 if (getter == null) { 2484 method.loadNull(); 2485 } else { 2486 getter.accept(this); 2487 } 2488 2489 if (setter == null) { 2490 method.loadNull(); 2491 } else { 2492 setter.accept(this); 2493 } 2494 2495 method.invoke(ScriptObject.SET_USER_ACCESSORS); 2496 } 2497 } 2498 2499 @Override 2500 public boolean enterReturnNode(final ReturnNode returnNode) { 2501 if(!method.isReachable()) { 2502 return false; 2503 } 2504 enterStatement(returnNode); 2505 2506 method.registerReturn(); 2507 2508 final Type returnType = lc.getCurrentFunction().getReturnType(); 2509 2510 final Expression expression = returnNode.getExpression(); 2511 if (expression != null) { 2512 loadExpressionUnbounded(expression); 2513 } else { 2514 method.loadUndefined(returnType); 2515 } 2516 2517 method._return(returnType); 2518 2519 return false; 2520 } 2521 2522 private boolean undefinedCheck(final RuntimeNode runtimeNode, final List<Expression> args) { 2523 final Request request = runtimeNode.getRequest(); 2524 2525 if (!Request.isUndefinedCheck(request)) { 2526 return false; 2527 } 2528 2529 final Expression lhs = args.get(0); 2530 final Expression rhs = args.get(1); 2531 2532 final Symbol lhsSymbol = lhs instanceof IdentNode ? ((IdentNode)lhs).getSymbol() : null; 2533 final Symbol rhsSymbol = rhs instanceof IdentNode ? ((IdentNode)rhs).getSymbol() : null; 2534 // One must be a "undefined" identifier, otherwise we can't get here 2535 assert lhsSymbol != null || rhsSymbol != null; 2536 2537 final Symbol undefinedSymbol; 2538 if (isUndefinedSymbol(lhsSymbol)) { 2539 undefinedSymbol = lhsSymbol; 2540 } else { 2541 assert isUndefinedSymbol(rhsSymbol); 2542 undefinedSymbol = rhsSymbol; 2543 } 2544 2545 assert undefinedSymbol != null; //remove warning 2546 if (!undefinedSymbol.isScope()) { 2547 return false; //disallow undefined as local var or parameter 2548 } 2549 2550 if (lhsSymbol == undefinedSymbol && lhs.getType().isPrimitive()) { 2551 //we load the undefined first. never mind, because this will deoptimize anyway 2552 return false; 2553 } 2554 2555 if(isDeoptimizedExpression(lhs)) { 2556 // This is actually related to "lhs.getType().isPrimitive()" above: any expression being deoptimized in 2557 // the current chain of rest-of compilations used to have a type narrower than Object (so it was primitive). 2558 // We must not perform undefined check specialization for them, as then we'd violate the basic rule of 2559 // "Thou shalt not alter the stack shape between a deoptimized method and any of its (transitive) rest-ofs." 2560 return false; 2561 } 2562 2563 //make sure that undefined has not been overridden or scoped as a local var 2564 //between us and global 2565 if (!compiler.isGlobalSymbol(lc.getCurrentFunction(), "undefined")) { 2566 return false; 2567 } 2568 2569 final boolean isUndefinedCheck = request == Request.IS_UNDEFINED; 2570 final Expression expr = undefinedSymbol == lhsSymbol ? rhs : lhs; 2571 if (expr.getType().isPrimitive()) { 2572 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 2573 method.load(!isUndefinedCheck); 2574 } else { 2575 final Label checkTrue = new Label("ud_check_true"); 2576 final Label end = new Label("end"); 2577 loadExpressionAsObject(expr); 2578 method.loadUndefined(Type.OBJECT); 2579 method.if_acmpeq(checkTrue); 2580 method.load(!isUndefinedCheck); 2581 method._goto(end); 2582 method.label(checkTrue); 2583 method.load(isUndefinedCheck); 2584 method.label(end); 2585 } 2586 2587 return true; 2588 } 2589 2590 private static boolean isUndefinedSymbol(final Symbol symbol) { 2591 return symbol != null && "undefined".equals(symbol.getName()); 2592 } 2593 2594 private static boolean isNullLiteral(final Node node) { 2595 return node instanceof LiteralNode<?> && ((LiteralNode<?>) node).isNull(); 2596 } 2597 2598 private boolean nullCheck(final RuntimeNode runtimeNode, final List<Expression> args) { 2599 final Request request = runtimeNode.getRequest(); 2600 2601 if (!Request.isEQ(request) && !Request.isNE(request)) { 2602 return false; 2603 } 2604 2605 assert args.size() == 2 : "EQ or NE or TYPEOF need two args"; 2606 2607 Expression lhs = args.get(0); 2608 Expression rhs = args.get(1); 2609 2610 if (isNullLiteral(lhs)) { 2611 final Expression tmp = lhs; 2612 lhs = rhs; 2613 rhs = tmp; 2614 } 2615 2616 if (!isNullLiteral(rhs)) { 2617 return false; 2618 } 2619 2620 if (!lhs.getType().isObject()) { 2621 return false; 2622 } 2623 2624 if(isDeoptimizedExpression(lhs)) { 2625 // This is actually related to "!lhs.getType().isObject()" above: any expression being deoptimized in 2626 // the current chain of rest-of compilations used to have a type narrower than Object. We must not 2627 // perform null check specialization for them, as then we'd no longer be loading aconst_null on stack 2628 // and thus violate the basic rule of "Thou shalt not alter the stack shape between a deoptimized 2629 // method and any of its (transitive) rest-ofs." 2630 // NOTE also that if we had a representation for well-known constants (e.g. null, 0, 1, -1, etc.) in 2631 // Label$Stack.localLoads then this wouldn't be an issue, as we would never (somewhat ridiculously) 2632 // allocate a temporary local to hold the result of aconst_null before attempting an optimistic 2633 // operation. 2634 return false; 2635 } 2636 2637 // this is a null literal check, so if there is implicit coercion 2638 // involved like {D}x=null, we will fail - this is very rare 2639 final Label trueLabel = new Label("trueLabel"); 2640 final Label falseLabel = new Label("falseLabel"); 2641 final Label endLabel = new Label("end"); 2642 2643 loadExpressionUnbounded(lhs); //lhs 2644 final Label popLabel; 2645 if (!Request.isStrict(request)) { 2646 method.dup(); //lhs lhs 2647 popLabel = new Label("pop"); 2648 } else { 2649 popLabel = null; 2650 } 2651 2652 if (Request.isEQ(request)) { 2653 method.ifnull(!Request.isStrict(request) ? popLabel : trueLabel); 2654 if (!Request.isStrict(request)) { 2655 method.loadUndefined(Type.OBJECT); 2656 method.if_acmpeq(trueLabel); 2657 } 2658 method.label(falseLabel); 2659 method.load(false); 2660 method._goto(endLabel); 2661 if (!Request.isStrict(request)) { 2662 method.label(popLabel); 2663 method.pop(); 2664 } 2665 method.label(trueLabel); 2666 method.load(true); 2667 method.label(endLabel); 2668 } else if (Request.isNE(request)) { 2669 method.ifnull(!Request.isStrict(request) ? popLabel : falseLabel); 2670 if (!Request.isStrict(request)) { 2671 method.loadUndefined(Type.OBJECT); 2672 method.if_acmpeq(falseLabel); 2673 } 2674 method.label(trueLabel); 2675 method.load(true); 2676 method._goto(endLabel); 2677 if (!Request.isStrict(request)) { 2678 method.label(popLabel); 2679 method.pop(); 2680 } 2681 method.label(falseLabel); 2682 method.load(false); 2683 method.label(endLabel); 2684 } 2685 2686 assert runtimeNode.getType().isBoolean(); 2687 method.convert(runtimeNode.getType()); 2688 2689 return true; 2690 } 2691 2692 /** 2693 * Was this expression or any of its subexpressions deoptimized in the current recompilation chain of rest-of methods? 2694 * @param rootExpr the expression being tested 2695 * @return true if the expression or any of its subexpressions was deoptimized in the current recompilation chain. 2696 */ 2697 private boolean isDeoptimizedExpression(final Expression rootExpr) { 2698 if(!isRestOf()) { 2699 return false; 2700 } 2701 return new Supplier<Boolean>() { 2702 boolean contains; 2703 @Override 2704 public Boolean get() { 2705 rootExpr.accept(new NodeVisitor<LexicalContext>(new LexicalContext()) { 2706 @Override 2707 public boolean enterFunctionNode(final FunctionNode functionNode) { 2708 return false; 2709 } 2710 @Override 2711 public boolean enterDefault(final Node node) { 2712 if(!contains && node instanceof Optimistic) { 2713 final int pp = ((Optimistic)node).getProgramPoint(); 2714 contains = isValid(pp) && isContinuationEntryPoint(pp); 2715 } 2716 return !contains; 2717 } 2718 }); 2719 return contains; 2720 } 2721 }.get(); 2722 } 2723 2724 private void loadRuntimeNode(final RuntimeNode runtimeNode) { 2725 final List<Expression> args = new ArrayList<>(runtimeNode.getArgs()); 2726 if (nullCheck(runtimeNode, args)) { 2727 return; 2728 } else if(undefinedCheck(runtimeNode, args)) { 2729 return; 2730 } 2731 // Revert a false undefined check to a strict equality check 2732 final RuntimeNode newRuntimeNode; 2733 final Request request = runtimeNode.getRequest(); 2734 if (Request.isUndefinedCheck(request)) { 2735 newRuntimeNode = runtimeNode.setRequest(request == Request.IS_UNDEFINED ? Request.EQ_STRICT : Request.NE_STRICT); 2736 } else { 2737 newRuntimeNode = runtimeNode; 2738 } 2739 2740 new OptimisticOperation(newRuntimeNode, TypeBounds.UNBOUNDED) { 2741 @Override 2742 void loadStack() { 2743 for (final Expression arg : args) { 2744 loadExpression(arg, TypeBounds.OBJECT); 2745 } 2746 } 2747 @Override 2748 void consumeStack() { 2749 method.invokestatic( 2750 CompilerConstants.className(ScriptRuntime.class), 2751 newRuntimeNode.getRequest().toString(), 2752 new FunctionSignature( 2753 false, 2754 false, 2755 newRuntimeNode.getType(), 2756 args.size()).toString()); 2757 } 2758 }.emit(); 2759 2760 method.convert(newRuntimeNode.getType()); 2761 } 2762 2763 private void defineCommonSplitMethodParameters() { 2764 defineSplitMethodParameter(0, CALLEE); 2765 defineSplitMethodParameter(1, THIS); 2766 defineSplitMethodParameter(2, SCOPE); 2767 } 2768 2769 private void defineSplitMethodParameter(final int slot, final CompilerConstants cc) { 2770 defineSplitMethodParameter(slot, Type.typeFor(cc.type())); 2771 } 2772 2773 private void defineSplitMethodParameter(final int slot, final Type type) { 2774 method.defineBlockLocalVariable(slot, slot + type.getSlots()); 2775 method.onLocalStore(type, slot); 2776 } 2777 2778 private int fixScopeSlot(final FunctionNode functionNode, final int extraSlot) { 2779 // TODO hack to move the scope to the expected slot (needed because split methods reuse the same slots as the root method) 2780 final int actualScopeSlot = functionNode.compilerConstant(SCOPE).getSlot(SCOPE_TYPE); 2781 final int defaultScopeSlot = SCOPE.slot(); 2782 int newExtraSlot = extraSlot; 2783 if (actualScopeSlot != defaultScopeSlot) { 2784 if (actualScopeSlot == extraSlot) { 2785 newExtraSlot = extraSlot + 1; 2786 method.defineBlockLocalVariable(newExtraSlot, newExtraSlot + 1); 2787 method.load(Type.OBJECT, extraSlot); 2788 method.storeHidden(Type.OBJECT, newExtraSlot); 2789 } else { 2790 method.defineBlockLocalVariable(actualScopeSlot, actualScopeSlot + 1); 2791 } 2792 method.load(SCOPE_TYPE, defaultScopeSlot); 2793 method.storeCompilerConstant(SCOPE); 2794 } 2795 return newExtraSlot; 2796 } 2797 2798 @Override 2799 public boolean enterSplitReturn(final SplitReturn splitReturn) { 2800 if (method.isReachable()) { 2801 method.loadUndefined(lc.getCurrentFunction().getReturnType())._return(); 2802 } 2803 return false; 2804 } 2805 2806 @Override 2807 public boolean enterSetSplitState(final SetSplitState setSplitState) { 2808 if (method.isReachable()) { 2809 method.setSplitState(setSplitState.getState()); 2810 } 2811 return false; 2812 } 2813 2814 @Override 2815 public boolean enterSwitchNode(final SwitchNode switchNode) { 2816 if(!method.isReachable()) { 2817 return false; 2818 } 2819 enterStatement(switchNode); 2820 2821 final Expression expression = switchNode.getExpression(); 2822 final List<CaseNode> cases = switchNode.getCases(); 2823 2824 if (cases.isEmpty()) { 2825 // still evaluate expression for side-effects. 2826 loadAndDiscard(expression); 2827 return false; 2828 } 2829 2830 final CaseNode defaultCase = switchNode.getDefaultCase(); 2831 final Label breakLabel = switchNode.getBreakLabel(); 2832 final int liveLocalsOnBreak = method.getUsedSlotsWithLiveTemporaries(); 2833 2834 if (defaultCase != null && cases.size() == 1) { 2835 // default case only 2836 assert cases.get(0) == defaultCase; 2837 loadAndDiscard(expression); 2838 defaultCase.getBody().accept(this); 2839 method.breakLabel(breakLabel, liveLocalsOnBreak); 2840 return false; 2841 } 2842 2843 // NOTE: it can still change in the tableswitch/lookupswitch case if there's no default case 2844 // but we need to add a synthetic default case for local variable conversions 2845 Label defaultLabel = defaultCase != null ? defaultCase.getEntry() : breakLabel; 2846 final boolean hasSkipConversion = LocalVariableConversion.hasLiveConversion(switchNode); 2847 2848 if (switchNode.isUniqueInteger()) { 2849 // Tree for sorting values. 2850 final TreeMap<Integer, Label> tree = new TreeMap<>(); 2851 2852 // Build up sorted tree. 2853 for (final CaseNode caseNode : cases) { 2854 final Node test = caseNode.getTest(); 2855 2856 if (test != null) { 2857 final Integer value = (Integer)((LiteralNode<?>)test).getValue(); 2858 final Label entry = caseNode.getEntry(); 2859 2860 // Take first duplicate. 2861 if (!tree.containsKey(value)) { 2862 tree.put(value, entry); 2863 } 2864 } 2865 } 2866 2867 // Copy values and labels to arrays. 2868 final int size = tree.size(); 2869 final Integer[] values = tree.keySet().toArray(new Integer[size]); 2870 final Label[] labels = tree.values().toArray(new Label[size]); 2871 2872 // Discern low, high and range. 2873 final int lo = values[0]; 2874 final int hi = values[size - 1]; 2875 final long range = (long)hi - (long)lo + 1; 2876 2877 // Find an unused value for default. 2878 int deflt = Integer.MIN_VALUE; 2879 for (final int value : values) { 2880 if (deflt == value) { 2881 deflt++; 2882 } else if (deflt < value) { 2883 break; 2884 } 2885 } 2886 2887 // Load switch expression. 2888 loadExpressionUnbounded(expression); 2889 final Type type = expression.getType(); 2890 2891 // If expression not int see if we can convert, if not use deflt to trigger default. 2892 if (!type.isInteger()) { 2893 method.load(deflt); 2894 final Class<?> exprClass = type.getTypeClass(); 2895 method.invoke(staticCallNoLookup(ScriptRuntime.class, "switchTagAsInt", int.class, exprClass.isPrimitive()? exprClass : Object.class, int.class)); 2896 } 2897 2898 if(hasSkipConversion) { 2899 assert defaultLabel == breakLabel; 2900 defaultLabel = new Label("switch_skip"); 2901 } 2902 // TABLESWITCH needs (range + 3) 32-bit values; LOOKUPSWITCH needs ((size * 2) + 2). Choose the one with 2903 // smaller representation, favor TABLESWITCH when they're equal size. 2904 if (range + 1 <= (size * 2) && range <= Integer.MAX_VALUE) { 2905 final Label[] table = new Label[(int)range]; 2906 Arrays.fill(table, defaultLabel); 2907 for (int i = 0; i < size; i++) { 2908 final int value = values[i]; 2909 table[value - lo] = labels[i]; 2910 } 2911 2912 method.tableswitch(lo, hi, defaultLabel, table); 2913 } else { 2914 final int[] ints = new int[size]; 2915 for (int i = 0; i < size; i++) { 2916 ints[i] = values[i]; 2917 } 2918 2919 method.lookupswitch(defaultLabel, ints, labels); 2920 } 2921 // This is a synthetic "default case" used in absence of actual default case, created if we need to apply 2922 // local variable conversions if neither case is taken. 2923 if(hasSkipConversion) { 2924 method.label(defaultLabel); 2925 method.beforeJoinPoint(switchNode); 2926 method._goto(breakLabel); 2927 } 2928 } else { 2929 final Symbol tagSymbol = switchNode.getTag(); 2930 // TODO: we could have non-object tag 2931 final int tagSlot = tagSymbol.getSlot(Type.OBJECT); 2932 loadExpressionAsObject(expression); 2933 method.store(tagSymbol, Type.OBJECT); 2934 2935 for (final CaseNode caseNode : cases) { 2936 final Expression test = caseNode.getTest(); 2937 2938 if (test != null) { 2939 method.load(Type.OBJECT, tagSlot); 2940 loadExpressionAsObject(test); 2941 method.invoke(ScriptRuntime.EQ_STRICT); 2942 method.ifne(caseNode.getEntry()); 2943 } 2944 } 2945 2946 if (defaultCase != null) { 2947 method._goto(defaultLabel); 2948 } else { 2949 method.beforeJoinPoint(switchNode); 2950 method._goto(breakLabel); 2951 } 2952 } 2953 2954 // First case is only reachable through jump 2955 assert !method.isReachable(); 2956 2957 for (final CaseNode caseNode : cases) { 2958 final Label fallThroughLabel; 2959 if(caseNode.getLocalVariableConversion() != null && method.isReachable()) { 2960 fallThroughLabel = new Label("fallthrough"); 2961 method._goto(fallThroughLabel); 2962 } else { 2963 fallThroughLabel = null; 2964 } 2965 method.label(caseNode.getEntry()); 2966 method.beforeJoinPoint(caseNode); 2967 if(fallThroughLabel != null) { 2968 method.label(fallThroughLabel); 2969 } 2970 caseNode.getBody().accept(this); 2971 } 2972 2973 method.breakLabel(breakLabel, liveLocalsOnBreak); 2974 2975 return false; 2976 } 2977 2978 @Override 2979 public boolean enterThrowNode(final ThrowNode throwNode) { 2980 if(!method.isReachable()) { 2981 return false; 2982 } 2983 enterStatement(throwNode); 2984 2985 if (throwNode.isSyntheticRethrow()) { 2986 method.beforeJoinPoint(throwNode); 2987 2988 //do not wrap whatever this is in an ecma exception, just rethrow it 2989 final IdentNode exceptionExpr = (IdentNode)throwNode.getExpression(); 2990 final Symbol exceptionSymbol = exceptionExpr.getSymbol(); 2991 method.load(exceptionSymbol, EXCEPTION_TYPE); 2992 method.checkcast(EXCEPTION_TYPE.getTypeClass()); 2993 method.athrow(); 2994 return false; 2995 } 2996 2997 final Source source = getCurrentSource(); 2998 final Expression expression = throwNode.getExpression(); 2999 final int position = throwNode.position(); 3000 final int line = throwNode.getLineNumber(); 3001 final int column = source.getColumn(position); 3002 3003 // NOTE: we first evaluate the expression, and only after it was evaluated do we create the new ECMAException 3004 // object and then somewhat cumbersomely move it beneath the evaluated expression on the stack. The reason for 3005 // this is that if expression is optimistic (or contains an optimistic subexpression), we'd potentially access 3006 // the not-yet-<init>ialized object on the stack from the UnwarrantedOptimismException handler, and bytecode 3007 // verifier forbids that. 3008 loadExpressionAsObject(expression); 3009 3010 method.load(source.getName()); 3011 method.load(line); 3012 method.load(column); 3013 method.invoke(ECMAException.CREATE); 3014 3015 method.beforeJoinPoint(throwNode); 3016 method.athrow(); 3017 3018 return false; 3019 } 3020 3021 private Source getCurrentSource() { 3022 return lc.getCurrentFunction().getSource(); 3023 } 3024 3025 @Override 3026 public boolean enterTryNode(final TryNode tryNode) { 3027 if(!method.isReachable()) { 3028 return false; 3029 } 3030 enterStatement(tryNode); 3031 3032 final Block body = tryNode.getBody(); 3033 final List<Block> catchBlocks = tryNode.getCatchBlocks(); 3034 final Symbol vmException = tryNode.getException(); 3035 final Label entry = new Label("try"); 3036 final Label recovery = new Label("catch"); 3037 final Label exit = new Label("end_try"); 3038 final Label skip = new Label("skip"); 3039 3040 method.canThrow(recovery); 3041 // Effect any conversions that might be observed at the entry of the catch node before entering the try node. 3042 // This is because even the first instruction in the try block must be presumed to be able to transfer control 3043 // to the catch block. Note that this doesn't kill the original values; in this regard it works a lot like 3044 // conversions of assignments within the try block. 3045 method.beforeTry(tryNode, recovery); 3046 method.label(entry); 3047 catchLabels.push(recovery); 3048 try { 3049 body.accept(this); 3050 } finally { 3051 assert catchLabels.peek() == recovery; 3052 catchLabels.pop(); 3053 } 3054 3055 method.label(exit); 3056 final boolean bodyCanThrow = exit.isAfter(entry); 3057 if(!bodyCanThrow) { 3058 // The body can't throw an exception; don't even bother emitting the catch handlers, they're all dead code. 3059 return false; 3060 } 3061 3062 method._try(entry, exit, recovery, Throwable.class); 3063 3064 if (method.isReachable()) { 3065 method._goto(skip); 3066 } 3067 3068 for (final Block inlinedFinally : tryNode.getInlinedFinallies()) { 3069 TryNode.getLabelledInlinedFinallyBlock(inlinedFinally).accept(this); 3070 // All inlined finallies end with a jump or a return 3071 assert !method.isReachable(); 3072 } 3073 3074 3075 method._catch(recovery); 3076 method.store(vmException, EXCEPTION_TYPE); 3077 3078 final int catchBlockCount = catchBlocks.size(); 3079 final Label afterCatch = new Label("after_catch"); 3080 for (int i = 0; i < catchBlockCount; i++) { 3081 assert method.isReachable(); 3082 final Block catchBlock = catchBlocks.get(i); 3083 3084 // Because of the peculiarities of the flow control, we need to use an explicit push/enterBlock/leaveBlock 3085 // here. 3086 lc.push(catchBlock); 3087 enterBlock(catchBlock); 3088 3089 final CatchNode catchNode = (CatchNode)catchBlocks.get(i).getStatements().get(0); 3090 final IdentNode exception = catchNode.getException(); 3091 final Expression exceptionCondition = catchNode.getExceptionCondition(); 3092 final Block catchBody = catchNode.getBody(); 3093 3094 new Store<IdentNode>(exception) { 3095 @Override 3096 protected void storeNonDiscard() { 3097 // This expression is neither part of a discard, nor needs to be left on the stack after it was 3098 // stored, so we override storeNonDiscard to be a no-op. 3099 } 3100 3101 @Override 3102 protected void evaluate() { 3103 if (catchNode.isSyntheticRethrow()) { 3104 method.load(vmException, EXCEPTION_TYPE); 3105 return; 3106 } 3107 /* 3108 * If caught object is an instance of ECMAException, then 3109 * bind obj.thrown to the script catch var. Or else bind the 3110 * caught object itself to the script catch var. 3111 */ 3112 final Label notEcmaException = new Label("no_ecma_exception"); 3113 method.load(vmException, EXCEPTION_TYPE).dup()._instanceof(ECMAException.class).ifeq(notEcmaException); 3114 method.checkcast(ECMAException.class); //TODO is this necessary? 3115 method.getField(ECMAException.THROWN); 3116 method.label(notEcmaException); 3117 } 3118 }.store(); 3119 3120 final boolean isConditionalCatch = exceptionCondition != null; 3121 final Label nextCatch; 3122 if (isConditionalCatch) { 3123 loadExpressionAsBoolean(exceptionCondition); 3124 nextCatch = new Label("next_catch"); 3125 nextCatch.markAsBreakTarget(); 3126 method.ifeq(nextCatch); 3127 } else { 3128 nextCatch = null; 3129 } 3130 3131 catchBody.accept(this); 3132 leaveBlock(catchBlock); 3133 lc.pop(catchBlock); 3134 if(nextCatch != null) { 3135 if(method.isReachable()) { 3136 method._goto(afterCatch); 3137 } 3138 method.breakLabel(nextCatch, lc.getUsedSlotCount()); 3139 } 3140 } 3141 3142 // afterCatch could be the same as skip, except that we need to establish that the vmException is dead. 3143 method.label(afterCatch); 3144 if(method.isReachable()) { 3145 method.markDeadLocalVariable(vmException); 3146 } 3147 method.label(skip); 3148 3149 // Finally body is always inlined elsewhere so it doesn't need to be emitted 3150 assert tryNode.getFinallyBody() == null; 3151 3152 return false; 3153 } 3154 3155 @Override 3156 public boolean enterVarNode(final VarNode varNode) { 3157 if(!method.isReachable()) { 3158 return false; 3159 } 3160 final Expression init = varNode.getInit(); 3161 final IdentNode identNode = varNode.getName(); 3162 final Symbol identSymbol = identNode.getSymbol(); 3163 assert identSymbol != null : "variable node " + varNode + " requires a name with a symbol"; 3164 final boolean needsScope = identSymbol.isScope(); 3165 3166 if (init == null) { 3167 if (needsScope && varNode.isBlockScoped()) { 3168 // block scoped variables need a DECLARE flag to signal end of temporal dead zone (TDZ) 3169 method.loadCompilerConstant(SCOPE); 3170 method.loadUndefined(Type.OBJECT); 3171 final int flags = CALLSITE_SCOPE | getCallSiteFlags() | (varNode.isBlockScoped() ? CALLSITE_DECLARE : 0); 3172 assert isFastScope(identSymbol); 3173 storeFastScopeVar(identSymbol, flags); 3174 } 3175 return false; 3176 } 3177 3178 enterStatement(varNode); 3179 assert method != null; 3180 3181 if (needsScope) { 3182 method.loadCompilerConstant(SCOPE); 3183 } 3184 3185 if (needsScope) { 3186 loadExpressionUnbounded(init); 3187 // block scoped variables need a DECLARE flag to signal end of temporal dead zone (TDZ) 3188 final int flags = CALLSITE_SCOPE | getCallSiteFlags() | (varNode.isBlockScoped() ? CALLSITE_DECLARE : 0); 3189 if (isFastScope(identSymbol)) { 3190 storeFastScopeVar(identSymbol, flags); 3191 } else { 3192 method.dynamicSet(identNode.getName(), flags, false); 3193 } 3194 } else { 3195 final Type identType = identNode.getType(); 3196 if(identType == Type.UNDEFINED) { 3197 // The initializer is either itself undefined (explicit assignment of undefined to undefined), 3198 // or the left hand side is a dead variable. 3199 assert init.getType() == Type.UNDEFINED || identNode.getSymbol().slotCount() == 0; 3200 loadAndDiscard(init); 3201 return false; 3202 } 3203 loadExpressionAsType(init, identType); 3204 storeIdentWithCatchConversion(identNode, identType); 3205 } 3206 3207 return false; 3208 } 3209 3210 private void storeIdentWithCatchConversion(final IdentNode identNode, final Type type) { 3211 // Assignments happening in try/catch blocks need to ensure that they also store a possibly wider typed value 3212 // that will be live at the exit from the try block 3213 final LocalVariableConversion conversion = identNode.getLocalVariableConversion(); 3214 final Symbol symbol = identNode.getSymbol(); 3215 if(conversion != null && conversion.isLive()) { 3216 assert symbol == conversion.getSymbol(); 3217 assert symbol.isBytecodeLocal(); 3218 // Only a single conversion from the target type to the join type is expected. 3219 assert conversion.getNext() == null; 3220 assert conversion.getFrom() == type; 3221 // We must propagate potential type change to the catch block 3222 final Label catchLabel = catchLabels.peek(); 3223 assert catchLabel != METHOD_BOUNDARY; // ident conversion only exists in try blocks 3224 assert catchLabel.isReachable(); 3225 final Type joinType = conversion.getTo(); 3226 final Label.Stack catchStack = catchLabel.getStack(); 3227 final int joinSlot = symbol.getSlot(joinType); 3228 // With nested try/catch blocks (incl. synthetic ones for finally), we can have a supposed conversion for 3229 // the exception symbol in the nested catch, but it isn't live in the outer catch block, so prevent doing 3230 // conversions for it. E.g. in "try { try { ... } catch(e) { e = 1; } } catch(e2) { ... }", we must not 3231 // introduce an I->O conversion on "e = 1" assignment as "e" is not live in "catch(e2)". 3232 if(catchStack.getUsedSlotsWithLiveTemporaries() > joinSlot) { 3233 method.dup(); 3234 method.convert(joinType); 3235 method.store(symbol, joinType); 3236 catchLabel.getStack().onLocalStore(joinType, joinSlot, true); 3237 method.canThrow(catchLabel); 3238 // Store but keep the previous store live too. 3239 method.store(symbol, type, false); 3240 return; 3241 } 3242 } 3243 3244 method.store(symbol, type, true); 3245 } 3246 3247 @Override 3248 public boolean enterWhileNode(final WhileNode whileNode) { 3249 if(!method.isReachable()) { 3250 return false; 3251 } 3252 if(whileNode.isDoWhile()) { 3253 enterDoWhile(whileNode); 3254 } else { 3255 enterStatement(whileNode); 3256 enterForOrWhile(whileNode, null); 3257 } 3258 return false; 3259 } 3260 3261 private void enterForOrWhile(final LoopNode loopNode, final JoinPredecessorExpression modify) { 3262 // NOTE: the usual pattern for compiling test-first loops is "GOTO test; body; test; IFNE body". We use the less 3263 // conventional "test; IFEQ break; body; GOTO test; break;". It has one extra unconditional GOTO in each repeat 3264 // of the loop, but it's not a problem for modern JIT compilers. We do this because our local variable type 3265 // tracking is unfortunately not really prepared for out-of-order execution, e.g. compiling the following 3266 // contrived but legal JavaScript code snippet would fail because the test changes the type of "i" from object 3267 // to double: var i = {valueOf: function() { return 1} }; while(--i >= 0) { ... } 3268 // Instead of adding more complexity to the local variable type tracking, we instead choose to emit this 3269 // different code shape. 3270 final int liveLocalsOnBreak = method.getUsedSlotsWithLiveTemporaries(); 3271 final JoinPredecessorExpression test = loopNode.getTest(); 3272 if(Expression.isAlwaysFalse(test)) { 3273 loadAndDiscard(test); 3274 return; 3275 } 3276 3277 method.beforeJoinPoint(loopNode); 3278 3279 final Label continueLabel = loopNode.getContinueLabel(); 3280 final Label repeatLabel = modify != null ? new Label("for_repeat") : continueLabel; 3281 method.label(repeatLabel); 3282 final int liveLocalsOnContinue = method.getUsedSlotsWithLiveTemporaries(); 3283 3284 final Block body = loopNode.getBody(); 3285 final Label breakLabel = loopNode.getBreakLabel(); 3286 final boolean testHasLiveConversion = test != null && LocalVariableConversion.hasLiveConversion(test); 3287 3288 if(Expression.isAlwaysTrue(test)) { 3289 if(test != null) { 3290 loadAndDiscard(test); 3291 if(testHasLiveConversion) { 3292 method.beforeJoinPoint(test); 3293 } 3294 } 3295 } else if (test != null) { 3296 if (testHasLiveConversion) { 3297 emitBranch(test.getExpression(), body.getEntryLabel(), true); 3298 method.beforeJoinPoint(test); 3299 method._goto(breakLabel); 3300 } else { 3301 emitBranch(test.getExpression(), breakLabel, false); 3302 } 3303 } 3304 3305 body.accept(this); 3306 if(repeatLabel != continueLabel) { 3307 emitContinueLabel(continueLabel, liveLocalsOnContinue); 3308 } 3309 3310 if (loopNode.hasPerIterationScope() && lc.getCurrentBlock().needsScope()) { 3311 // ES6 for loops with LET init need a new scope for each iteration. We just create a shallow copy here. 3312 method.loadCompilerConstant(SCOPE); 3313 method.invoke(virtualCallNoLookup(ScriptObject.class, "copy", ScriptObject.class)); 3314 method.storeCompilerConstant(SCOPE); 3315 } 3316 3317 if(method.isReachable()) { 3318 if(modify != null) { 3319 lineNumber(loopNode); 3320 loadAndDiscard(modify); 3321 method.beforeJoinPoint(modify); 3322 } 3323 method._goto(repeatLabel); 3324 } 3325 3326 method.breakLabel(breakLabel, liveLocalsOnBreak); 3327 } 3328 3329 private void emitContinueLabel(final Label continueLabel, final int liveLocals) { 3330 final boolean reachable = method.isReachable(); 3331 method.breakLabel(continueLabel, liveLocals); 3332 // If we reach here only through a continue statement (e.g. body does not exit normally) then the 3333 // continueLabel can have extra non-temp symbols (e.g. exception from a try/catch contained in the body). We 3334 // must make sure those are thrown away. 3335 if(!reachable) { 3336 method.undefineLocalVariables(lc.getUsedSlotCount(), false); 3337 } 3338 } 3339 3340 private void enterDoWhile(final WhileNode whileNode) { 3341 final int liveLocalsOnContinueOrBreak = method.getUsedSlotsWithLiveTemporaries(); 3342 method.beforeJoinPoint(whileNode); 3343 3344 final Block body = whileNode.getBody(); 3345 body.accept(this); 3346 3347 emitContinueLabel(whileNode.getContinueLabel(), liveLocalsOnContinueOrBreak); 3348 if(method.isReachable()) { 3349 lineNumber(whileNode); 3350 final JoinPredecessorExpression test = whileNode.getTest(); 3351 final Label bodyEntryLabel = body.getEntryLabel(); 3352 final boolean testHasLiveConversion = LocalVariableConversion.hasLiveConversion(test); 3353 if(Expression.isAlwaysFalse(test)) { 3354 loadAndDiscard(test); 3355 if(testHasLiveConversion) { 3356 method.beforeJoinPoint(test); 3357 } 3358 } else if(testHasLiveConversion) { 3359 // If we have conversions after the test in do-while, they need to be effected on both branches. 3360 final Label beforeExit = new Label("do_while_preexit"); 3361 emitBranch(test.getExpression(), beforeExit, false); 3362 method.beforeJoinPoint(test); 3363 method._goto(bodyEntryLabel); 3364 method.label(beforeExit); 3365 method.beforeJoinPoint(test); 3366 } else { 3367 emitBranch(test.getExpression(), bodyEntryLabel, true); 3368 } 3369 } 3370 method.breakLabel(whileNode.getBreakLabel(), liveLocalsOnContinueOrBreak); 3371 } 3372 3373 3374 @Override 3375 public boolean enterWithNode(final WithNode withNode) { 3376 if(!method.isReachable()) { 3377 return false; 3378 } 3379 enterStatement(withNode); 3380 final Expression expression = withNode.getExpression(); 3381 final Block body = withNode.getBody(); 3382 3383 // It is possible to have a "pathological" case where the with block does not reference *any* identifiers. It's 3384 // pointless, but legal. In that case, if nothing else in the method forced the assignment of a slot to the 3385 // scope object, its' possible that it won't have a slot assigned. In this case we'll only evaluate expression 3386 // for its side effect and visit the body, and not bother opening and closing a WithObject. 3387 final boolean hasScope = method.hasScope(); 3388 3389 if (hasScope) { 3390 method.loadCompilerConstant(SCOPE); 3391 } 3392 3393 loadExpressionAsObject(expression); 3394 3395 final Label tryLabel; 3396 if (hasScope) { 3397 // Construct a WithObject if we have a scope 3398 method.invoke(ScriptRuntime.OPEN_WITH); 3399 method.storeCompilerConstant(SCOPE); 3400 tryLabel = new Label("with_try"); 3401 method.label(tryLabel); 3402 } else { 3403 // We just loaded the expression for its side effect and to check 3404 // for null or undefined value. 3405 globalCheckObjectCoercible(); 3406 tryLabel = null; 3407 } 3408 3409 // Always process body 3410 body.accept(this); 3411 3412 if (hasScope) { 3413 // Ensure we always close the WithObject 3414 final Label endLabel = new Label("with_end"); 3415 final Label catchLabel = new Label("with_catch"); 3416 final Label exitLabel = new Label("with_exit"); 3417 3418 method.label(endLabel); 3419 // Somewhat conservatively presume that if the body is not empty, it can throw an exception. In any case, 3420 // we must prevent trying to emit a try-catch for empty range, as it causes a verification error. 3421 final boolean bodyCanThrow = endLabel.isAfter(tryLabel); 3422 if(bodyCanThrow) { 3423 method._try(tryLabel, endLabel, catchLabel); 3424 } 3425 3426 final boolean reachable = method.isReachable(); 3427 if(reachable) { 3428 popScope(); 3429 if(bodyCanThrow) { 3430 method._goto(exitLabel); 3431 } 3432 } 3433 3434 if(bodyCanThrow) { 3435 method._catch(catchLabel); 3436 popScopeException(); 3437 method.athrow(); 3438 if(reachable) { 3439 method.label(exitLabel); 3440 } 3441 } 3442 } 3443 return false; 3444 } 3445 3446 private void loadADD(final UnaryNode unaryNode, final TypeBounds resultBounds) { 3447 loadExpression(unaryNode.getExpression(), resultBounds.booleanToInt().notWiderThan(Type.NUMBER)); 3448 if(method.peekType() == Type.BOOLEAN) { 3449 // It's a no-op in bytecode, but we must make sure it is treated as an int for purposes of type signatures 3450 method.convert(Type.INT); 3451 } 3452 } 3453 3454 private void loadBIT_NOT(final UnaryNode unaryNode) { 3455 loadExpression(unaryNode.getExpression(), TypeBounds.INT).load(-1).xor(); 3456 } 3457 3458 private void loadDECINC(final UnaryNode unaryNode) { 3459 final Expression operand = unaryNode.getExpression(); 3460 final Type type = unaryNode.getType(); 3461 final TypeBounds typeBounds = new TypeBounds(type, Type.NUMBER); 3462 final TokenType tokenType = unaryNode.tokenType(); 3463 final boolean isPostfix = tokenType == TokenType.DECPOSTFIX || tokenType == TokenType.INCPOSTFIX; 3464 final boolean isIncrement = tokenType == TokenType.INCPREFIX || tokenType == TokenType.INCPOSTFIX; 3465 3466 assert !type.isObject(); 3467 3468 new SelfModifyingStore<UnaryNode>(unaryNode, operand) { 3469 3470 private void loadRhs() { 3471 loadExpression(operand, typeBounds, true); 3472 } 3473 3474 @Override 3475 protected void evaluate() { 3476 if(isPostfix) { 3477 loadRhs(); 3478 } else { 3479 new OptimisticOperation(unaryNode, typeBounds) { 3480 @Override 3481 void loadStack() { 3482 loadRhs(); 3483 loadMinusOne(); 3484 } 3485 @Override 3486 void consumeStack() { 3487 doDecInc(getProgramPoint()); 3488 } 3489 }.emit(getOptimisticIgnoreCountForSelfModifyingExpression(operand)); 3490 } 3491 } 3492 3493 @Override 3494 protected void storeNonDiscard() { 3495 super.storeNonDiscard(); 3496 if (isPostfix) { 3497 new OptimisticOperation(unaryNode, typeBounds) { 3498 @Override 3499 void loadStack() { 3500 loadMinusOne(); 3501 } 3502 @Override 3503 void consumeStack() { 3504 doDecInc(getProgramPoint()); 3505 } 3506 }.emit(1); // 1 for non-incremented result on the top of the stack pushed in evaluate() 3507 } 3508 } 3509 3510 private void loadMinusOne() { 3511 if (type.isInteger()) { 3512 method.load(isIncrement ? 1 : -1); 3513 } else if (type.isLong()) { 3514 method.load(isIncrement ? 1L : -1L); 3515 } else { 3516 method.load(isIncrement ? 1.0 : -1.0); 3517 } 3518 } 3519 3520 private void doDecInc(final int programPoint) { 3521 method.add(programPoint); 3522 } 3523 }.store(); 3524 } 3525 3526 private static int getOptimisticIgnoreCountForSelfModifyingExpression(final Expression target) { 3527 return target instanceof AccessNode ? 1 : target instanceof IndexNode ? 2 : 0; 3528 } 3529 3530 private void loadAndDiscard(final Expression expr) { 3531 // TODO: move checks for discarding to actual expression load code (e.g. as we do with void). That way we might 3532 // be able to eliminate even more checks. 3533 if(expr instanceof PrimitiveLiteralNode | isLocalVariable(expr)) { 3534 assert lc.getCurrentDiscard() != expr; 3535 // Don't bother evaluating expressions without side effects. Typical usage is "void 0" for reliably generating 3536 // undefined. 3537 return; 3538 } 3539 3540 lc.pushDiscard(expr); 3541 loadExpression(expr, TypeBounds.UNBOUNDED); 3542 if (lc.getCurrentDiscard() == expr) { 3543 assert !expr.isAssignment(); 3544 // NOTE: if we had a way to load with type void, we could avoid popping 3545 method.pop(); 3546 lc.popDiscard(); 3547 } 3548 } 3549 3550 private void loadNEW(final UnaryNode unaryNode) { 3551 final CallNode callNode = (CallNode)unaryNode.getExpression(); 3552 final List<Expression> args = callNode.getArgs(); 3553 3554 // Load function reference. 3555 loadExpressionAsObject(callNode.getFunction()); // must detect type error 3556 3557 method.dynamicNew(1 + loadArgs(args), getCallSiteFlags()); 3558 } 3559 3560 private void loadNOT(final UnaryNode unaryNode) { 3561 final Expression expr = unaryNode.getExpression(); 3562 if(expr instanceof UnaryNode && expr.isTokenType(TokenType.NOT)) { 3563 // !!x is idiomatic boolean cast in JavaScript 3564 loadExpressionAsBoolean(((UnaryNode)expr).getExpression()); 3565 } else { 3566 final Label trueLabel = new Label("true"); 3567 final Label afterLabel = new Label("after"); 3568 3569 emitBranch(expr, trueLabel, true); 3570 method.load(true); 3571 method._goto(afterLabel); 3572 method.label(trueLabel); 3573 method.load(false); 3574 method.label(afterLabel); 3575 } 3576 } 3577 3578 private void loadSUB(final UnaryNode unaryNode, final TypeBounds resultBounds) { 3579 final Type type = unaryNode.getType(); 3580 assert type.isNumeric(); 3581 final TypeBounds numericBounds = resultBounds.booleanToInt(); 3582 new OptimisticOperation(unaryNode, numericBounds) { 3583 @Override 3584 void loadStack() { 3585 final Expression expr = unaryNode.getExpression(); 3586 loadExpression(expr, numericBounds.notWiderThan(Type.NUMBER)); 3587 } 3588 @Override 3589 void consumeStack() { 3590 // Must do an explicit conversion to the operation's type when it's double so that we correctly handle 3591 // negation of an int 0 to a double -0. With this, we get the correct negation of a local variable after 3592 // it deoptimized, e.g. "iload_2; i2d; dneg". Without this, we get "iload_2; ineg; i2d". 3593 if(type.isNumber()) { 3594 method.convert(type); 3595 } 3596 method.neg(getProgramPoint()); 3597 } 3598 }.emit(); 3599 } 3600 3601 public void loadVOID(final UnaryNode unaryNode, final TypeBounds resultBounds) { 3602 loadAndDiscard(unaryNode.getExpression()); 3603 if(lc.getCurrentDiscard() == unaryNode) { 3604 lc.popDiscard(); 3605 } else { 3606 method.loadUndefined(resultBounds.widest); 3607 } 3608 } 3609 3610 public void loadADD(final BinaryNode binaryNode, final TypeBounds resultBounds) { 3611 new OptimisticOperation(binaryNode, resultBounds) { 3612 @Override 3613 void loadStack() { 3614 final TypeBounds operandBounds; 3615 final boolean isOptimistic = isValid(getProgramPoint()); 3616 boolean forceConversionSeparation = false; 3617 if(isOptimistic) { 3618 operandBounds = new TypeBounds(binaryNode.getType(), Type.OBJECT); 3619 } else { 3620 // Non-optimistic, non-FP +. Allow it to overflow. 3621 final Type widestOperationType = binaryNode.getWidestOperationType(); 3622 operandBounds = new TypeBounds(Type.narrowest(binaryNode.getWidestOperandType(), resultBounds.widest), widestOperationType); 3623 forceConversionSeparation = widestOperationType.narrowerThan(resultBounds.widest); 3624 } 3625 loadBinaryOperands(binaryNode.lhs(), binaryNode.rhs(), operandBounds, false, forceConversionSeparation); 3626 } 3627 3628 @Override 3629 void consumeStack() { 3630 method.add(getProgramPoint()); 3631 } 3632 }.emit(); 3633 } 3634 3635 private void loadAND_OR(final BinaryNode binaryNode, final TypeBounds resultBounds, final boolean isAnd) { 3636 final Type narrowestOperandType = Type.widestReturnType(binaryNode.lhs().getType(), binaryNode.rhs().getType()); 3637 3638 final Label skip = new Label("skip"); 3639 if(narrowestOperandType == Type.BOOLEAN) { 3640 // optimize all-boolean logical expressions 3641 final Label onTrue = new Label("andor_true"); 3642 emitBranch(binaryNode, onTrue, true); 3643 method.load(false); 3644 method._goto(skip); 3645 method.label(onTrue); 3646 method.load(true); 3647 method.label(skip); 3648 return; 3649 } 3650 3651 final TypeBounds outBounds = resultBounds.notNarrowerThan(narrowestOperandType); 3652 final JoinPredecessorExpression lhs = (JoinPredecessorExpression)binaryNode.lhs(); 3653 final boolean lhsConvert = LocalVariableConversion.hasLiveConversion(lhs); 3654 final Label evalRhs = lhsConvert ? new Label("eval_rhs") : null; 3655 3656 loadExpression(lhs, outBounds).dup().convert(Type.BOOLEAN); 3657 if (isAnd) { 3658 if(lhsConvert) { 3659 method.ifne(evalRhs); 3660 } else { 3661 method.ifeq(skip); 3662 } 3663 } else if(lhsConvert) { 3664 method.ifeq(evalRhs); 3665 } else { 3666 method.ifne(skip); 3667 } 3668 3669 if(lhsConvert) { 3670 method.beforeJoinPoint(lhs); 3671 method._goto(skip); 3672 method.label(evalRhs); 3673 } 3674 3675 method.pop(); 3676 final JoinPredecessorExpression rhs = (JoinPredecessorExpression)binaryNode.rhs(); 3677 loadExpression(rhs, outBounds); 3678 method.beforeJoinPoint(rhs); 3679 method.label(skip); 3680 } 3681 3682 private static boolean isLocalVariable(final Expression lhs) { 3683 return lhs instanceof IdentNode && isLocalVariable((IdentNode)lhs); 3684 } 3685 3686 private static boolean isLocalVariable(final IdentNode lhs) { 3687 return lhs.getSymbol().isBytecodeLocal(); 3688 } 3689 3690 // NOTE: does not use resultBounds as the assignment is driven by the type of the RHS 3691 private void loadASSIGN(final BinaryNode binaryNode) { 3692 final Expression lhs = binaryNode.lhs(); 3693 final Expression rhs = binaryNode.rhs(); 3694 3695 final Type rhsType = rhs.getType(); 3696 // Detect dead assignments 3697 if(lhs instanceof IdentNode) { 3698 final Symbol symbol = ((IdentNode)lhs).getSymbol(); 3699 if(!symbol.isScope() && !symbol.hasSlotFor(rhsType) && lc.getCurrentDiscard() == binaryNode) { 3700 loadAndDiscard(rhs); 3701 lc.popDiscard(); 3702 method.markDeadLocalVariable(symbol); 3703 return; 3704 } 3705 } 3706 3707 new Store<BinaryNode>(binaryNode, lhs) { 3708 @Override 3709 protected void evaluate() { 3710 // NOTE: we're loading with "at least as wide as" so optimistic operations on the right hand side 3711 // remain optimistic, and then explicitly convert to the required type if needed. 3712 loadExpressionAsType(rhs, rhsType); 3713 } 3714 }.store(); 3715 } 3716 3717 /** 3718 * Binary self-assignment that can be optimistic: +=, -=, *=, and /=. 3719 */ 3720 private abstract class BinaryOptimisticSelfAssignment extends SelfModifyingStore<BinaryNode> { 3721 3722 /** 3723 * Constructor 3724 * 3725 * @param node the assign op node 3726 */ 3727 BinaryOptimisticSelfAssignment(final BinaryNode node) { 3728 super(node, node.lhs()); 3729 } 3730 3731 protected abstract void op(OptimisticOperation oo); 3732 3733 @Override 3734 protected void evaluate() { 3735 final Expression lhs = assignNode.lhs(); 3736 final Expression rhs = assignNode.rhs(); 3737 final Type widestOperationType = assignNode.getWidestOperationType(); 3738 final TypeBounds bounds = new TypeBounds(assignNode.getType(), widestOperationType); 3739 new OptimisticOperation(assignNode, bounds) { 3740 @Override 3741 void loadStack() { 3742 final boolean forceConversionSeparation; 3743 if (isValid(getProgramPoint()) || widestOperationType == Type.NUMBER) { 3744 forceConversionSeparation = false; 3745 } else { 3746 final Type operandType = Type.widest(booleanToInt(objectToNumber(lhs.getType())), booleanToInt(objectToNumber(rhs.getType()))); 3747 forceConversionSeparation = operandType.narrowerThan(widestOperationType); 3748 } 3749 loadBinaryOperands(lhs, rhs, bounds, true, forceConversionSeparation); 3750 } 3751 @Override 3752 void consumeStack() { 3753 op(this); 3754 } 3755 }.emit(getOptimisticIgnoreCountForSelfModifyingExpression(lhs)); 3756 method.convert(assignNode.getType()); 3757 } 3758 } 3759 3760 /** 3761 * Non-optimistic binary self-assignment operation. Basically, everything except +=, -=, *=, and /=. 3762 */ 3763 private abstract class BinarySelfAssignment extends SelfModifyingStore<BinaryNode> { 3764 BinarySelfAssignment(final BinaryNode node) { 3765 super(node, node.lhs()); 3766 } 3767 3768 protected abstract void op(); 3769 3770 @Override 3771 protected void evaluate() { 3772 loadBinaryOperands(assignNode.lhs(), assignNode.rhs(), TypeBounds.UNBOUNDED.notWiderThan(assignNode.getWidestOperandType()), true, false); 3773 op(); 3774 } 3775 } 3776 3777 private void loadASSIGN_ADD(final BinaryNode binaryNode) { 3778 new BinaryOptimisticSelfAssignment(binaryNode) { 3779 @Override 3780 protected void op(final OptimisticOperation oo) { 3781 assert !(binaryNode.getType().isObject() && oo.isOptimistic); 3782 method.add(oo.getProgramPoint()); 3783 } 3784 }.store(); 3785 } 3786 3787 private void loadASSIGN_BIT_AND(final BinaryNode binaryNode) { 3788 new BinarySelfAssignment(binaryNode) { 3789 @Override 3790 protected void op() { 3791 method.and(); 3792 } 3793 }.store(); 3794 } 3795 3796 private void loadASSIGN_BIT_OR(final BinaryNode binaryNode) { 3797 new BinarySelfAssignment(binaryNode) { 3798 @Override 3799 protected void op() { 3800 method.or(); 3801 } 3802 }.store(); 3803 } 3804 3805 private void loadASSIGN_BIT_XOR(final BinaryNode binaryNode) { 3806 new BinarySelfAssignment(binaryNode) { 3807 @Override 3808 protected void op() { 3809 method.xor(); 3810 } 3811 }.store(); 3812 } 3813 3814 private void loadASSIGN_DIV(final BinaryNode binaryNode) { 3815 new BinaryOptimisticSelfAssignment(binaryNode) { 3816 @Override 3817 protected void op(final OptimisticOperation oo) { 3818 method.div(oo.getProgramPoint()); 3819 } 3820 }.store(); 3821 } 3822 3823 private void loadASSIGN_MOD(final BinaryNode binaryNode) { 3824 new BinaryOptimisticSelfAssignment(binaryNode) { 3825 @Override 3826 protected void op(final OptimisticOperation oo) { 3827 method.rem(oo.getProgramPoint()); 3828 } 3829 }.store(); 3830 } 3831 3832 private void loadASSIGN_MUL(final BinaryNode binaryNode) { 3833 new BinaryOptimisticSelfAssignment(binaryNode) { 3834 @Override 3835 protected void op(final OptimisticOperation oo) { 3836 method.mul(oo.getProgramPoint()); 3837 } 3838 }.store(); 3839 } 3840 3841 private void loadASSIGN_SAR(final BinaryNode binaryNode) { 3842 new BinarySelfAssignment(binaryNode) { 3843 @Override 3844 protected void op() { 3845 method.sar(); 3846 } 3847 }.store(); 3848 } 3849 3850 private void loadASSIGN_SHL(final BinaryNode binaryNode) { 3851 new BinarySelfAssignment(binaryNode) { 3852 @Override 3853 protected void op() { 3854 method.shl(); 3855 } 3856 }.store(); 3857 } 3858 3859 private void loadASSIGN_SHR(final BinaryNode binaryNode) { 3860 new BinarySelfAssignment(binaryNode) { 3861 @Override 3862 protected void op() { 3863 doSHR(); 3864 } 3865 3866 }.store(); 3867 } 3868 3869 private void doSHR() { 3870 // TODO: make SHR optimistic 3871 method.shr(); 3872 toUint(); 3873 } 3874 3875 private void toUint() { 3876 JSType.TO_UINT32_I.invoke(method); 3877 } 3878 3879 private void loadASSIGN_SUB(final BinaryNode binaryNode) { 3880 new BinaryOptimisticSelfAssignment(binaryNode) { 3881 @Override 3882 protected void op(final OptimisticOperation oo) { 3883 method.sub(oo.getProgramPoint()); 3884 } 3885 }.store(); 3886 } 3887 3888 /** 3889 * Helper class for binary arithmetic ops 3890 */ 3891 private abstract class BinaryArith { 3892 protected abstract void op(int programPoint); 3893 3894 protected void evaluate(final BinaryNode node, final TypeBounds resultBounds) { 3895 final TypeBounds numericBounds = resultBounds.booleanToInt().objectToNumber(); 3896 new OptimisticOperation(node, numericBounds) { 3897 @Override 3898 void loadStack() { 3899 final TypeBounds operandBounds; 3900 boolean forceConversionSeparation = false; 3901 if(numericBounds.narrowest == Type.NUMBER) { 3902 // Result should be double always. Propagate it into the operands so we don't have lots of I2D 3903 // and L2D after operand evaluation. 3904 assert numericBounds.widest == Type.NUMBER; 3905 operandBounds = numericBounds; 3906 } else { 3907 final boolean isOptimistic = isValid(getProgramPoint()); 3908 if(isOptimistic || node.isTokenType(TokenType.DIV) || node.isTokenType(TokenType.MOD)) { 3909 operandBounds = new TypeBounds(node.getType(), Type.NUMBER); 3910 } else { 3911 // Non-optimistic, non-FP subtraction or multiplication. Allow them to overflow. 3912 operandBounds = new TypeBounds(Type.narrowest(node.getWidestOperandType(), 3913 numericBounds.widest), Type.NUMBER); 3914 forceConversionSeparation = node.getWidestOperationType().narrowerThan(numericBounds.widest); 3915 } 3916 } 3917 loadBinaryOperands(node.lhs(), node.rhs(), operandBounds, false, forceConversionSeparation); 3918 } 3919 3920 @Override 3921 void consumeStack() { 3922 op(getProgramPoint()); 3923 } 3924 }.emit(); 3925 } 3926 } 3927 3928 private void loadBIT_AND(final BinaryNode binaryNode) { 3929 loadBinaryOperands(binaryNode); 3930 method.and(); 3931 } 3932 3933 private void loadBIT_OR(final BinaryNode binaryNode) { 3934 // Optimize x|0 to (int)x 3935 if (isRhsZero(binaryNode)) { 3936 loadExpressionAsType(binaryNode.lhs(), Type.INT); 3937 } else { 3938 loadBinaryOperands(binaryNode); 3939 method.or(); 3940 } 3941 } 3942 3943 private static boolean isRhsZero(final BinaryNode binaryNode) { 3944 final Expression rhs = binaryNode.rhs(); 3945 return rhs instanceof LiteralNode && INT_ZERO.equals(((LiteralNode<?>)rhs).getValue()); 3946 } 3947 3948 private void loadBIT_XOR(final BinaryNode binaryNode) { 3949 loadBinaryOperands(binaryNode); 3950 method.xor(); 3951 } 3952 3953 private void loadCOMMARIGHT(final BinaryNode binaryNode, final TypeBounds resultBounds) { 3954 loadAndDiscard(binaryNode.lhs()); 3955 loadExpression(binaryNode.rhs(), resultBounds); 3956 } 3957 3958 private void loadCOMMALEFT(final BinaryNode binaryNode, final TypeBounds resultBounds) { 3959 loadExpression(binaryNode.lhs(), resultBounds); 3960 loadAndDiscard(binaryNode.rhs()); 3961 } 3962 3963 private void loadDIV(final BinaryNode binaryNode, final TypeBounds resultBounds) { 3964 new BinaryArith() { 3965 @Override 3966 protected void op(final int programPoint) { 3967 method.div(programPoint); 3968 } 3969 }.evaluate(binaryNode, resultBounds); 3970 } 3971 3972 private void loadCmp(final BinaryNode binaryNode, final Condition cond) { 3973 assert comparisonOperandsArePrimitive(binaryNode) : binaryNode; 3974 loadBinaryOperands(binaryNode); 3975 3976 final Label trueLabel = new Label("trueLabel"); 3977 final Label afterLabel = new Label("skip"); 3978 3979 method.conditionalJump(cond, trueLabel); 3980 3981 method.load(Boolean.FALSE); 3982 method._goto(afterLabel); 3983 method.label(trueLabel); 3984 method.load(Boolean.TRUE); 3985 method.label(afterLabel); 3986 } 3987 3988 private static boolean comparisonOperandsArePrimitive(final BinaryNode binaryNode) { 3989 final Type widest = Type.widest(binaryNode.lhs().getType(), binaryNode.rhs().getType()); 3990 return widest.isNumeric() || widest.isBoolean(); 3991 } 3992 3993 private void loadMOD(final BinaryNode binaryNode, final TypeBounds resultBounds) { 3994 new BinaryArith() { 3995 @Override 3996 protected void op(final int programPoint) { 3997 method.rem(programPoint); 3998 } 3999 }.evaluate(binaryNode, resultBounds); 4000 } 4001 4002 private void loadMUL(final BinaryNode binaryNode, final TypeBounds resultBounds) { 4003 new BinaryArith() { 4004 @Override 4005 protected void op(final int programPoint) { 4006 method.mul(programPoint); 4007 } 4008 }.evaluate(binaryNode, resultBounds); 4009 } 4010 4011 private void loadSAR(final BinaryNode binaryNode) { 4012 loadBinaryOperands(binaryNode); 4013 method.sar(); 4014 } 4015 4016 private void loadSHL(final BinaryNode binaryNode) { 4017 loadBinaryOperands(binaryNode); 4018 method.shl(); 4019 } 4020 4021 private void loadSHR(final BinaryNode binaryNode) { 4022 // Optimize x >>> 0 to (uint)x 4023 if (isRhsZero(binaryNode)) { 4024 loadExpressionAsType(binaryNode.lhs(), Type.INT); 4025 toUint(); 4026 } else { 4027 loadBinaryOperands(binaryNode); 4028 doSHR(); 4029 } 4030 } 4031 4032 private void loadSUB(final BinaryNode binaryNode, final TypeBounds resultBounds) { 4033 new BinaryArith() { 4034 @Override 4035 protected void op(final int programPoint) { 4036 method.sub(programPoint); 4037 } 4038 }.evaluate(binaryNode, resultBounds); 4039 } 4040 4041 @Override 4042 public boolean enterLabelNode(final LabelNode labelNode) { 4043 labeledBlockBreakLiveLocals.push(lc.getUsedSlotCount()); 4044 return true; 4045 } 4046 4047 @Override 4048 protected boolean enterDefault(final Node node) { 4049 throw new AssertionError("Code generator entered node of type " + node.getClass().getName()); 4050 } 4051 4052 private void loadTernaryNode(final TernaryNode ternaryNode, final TypeBounds resultBounds) { 4053 final Expression test = ternaryNode.getTest(); 4054 final JoinPredecessorExpression trueExpr = ternaryNode.getTrueExpression(); 4055 final JoinPredecessorExpression falseExpr = ternaryNode.getFalseExpression(); 4056 4057 final Label falseLabel = new Label("ternary_false"); 4058 final Label exitLabel = new Label("ternary_exit"); 4059 4060 final Type outNarrowest = Type.narrowest(resultBounds.widest, Type.generic(Type.widestReturnType(trueExpr.getType(), falseExpr.getType()))); 4061 final TypeBounds outBounds = resultBounds.notNarrowerThan(outNarrowest); 4062 4063 emitBranch(test, falseLabel, false); 4064 4065 loadExpression(trueExpr.getExpression(), outBounds); 4066 assert Type.generic(method.peekType()) == outBounds.narrowest; 4067 method.beforeJoinPoint(trueExpr); 4068 method._goto(exitLabel); 4069 method.label(falseLabel); 4070 loadExpression(falseExpr.getExpression(), outBounds); 4071 assert Type.generic(method.peekType()) == outBounds.narrowest; 4072 method.beforeJoinPoint(falseExpr); 4073 method.label(exitLabel); 4074 } 4075 4076 /** 4077 * Generate all shared scope calls generated during codegen. 4078 */ 4079 void generateScopeCalls() { 4080 for (final SharedScopeCall scopeAccess : lc.getScopeCalls()) { 4081 scopeAccess.generateScopeCall(); 4082 } 4083 } 4084 4085 /** 4086 * Debug code used to print symbols 4087 * 4088 * @param block the block we are in 4089 * @param function the function we are in 4090 * @param ident identifier for block or function where applicable 4091 */ 4092 private void printSymbols(final Block block, final FunctionNode function, final String ident) { 4093 if (compiler.getScriptEnvironment()._print_symbols || function.getFlag(FunctionNode.IS_PRINT_SYMBOLS)) { 4094 final PrintWriter out = compiler.getScriptEnvironment().getErr(); 4095 out.println("[BLOCK in '" + ident + "']"); 4096 if (!block.printSymbols(out)) { 4097 out.println("<no symbols>"); 4098 } 4099 out.println(); 4100 } 4101 } 4102 4103 4104 /** 4105 * The difference between a store and a self modifying store is that 4106 * the latter may load part of the target on the stack, e.g. the base 4107 * of an AccessNode or the base and index of an IndexNode. These are used 4108 * both as target and as an extra source. Previously it was problematic 4109 * for self modifying stores if the target/lhs didn't belong to one 4110 * of three trivial categories: IdentNode, AcessNodes, IndexNodes. In that 4111 * case it was evaluated and tagged as "resolved", which meant at the second 4112 * time the lhs of this store was read (e.g. in a = a (second) + b for a += b, 4113 * it would be evaluated to a nop in the scope and cause stack underflow 4114 * 4115 * see NASHORN-703 4116 * 4117 * @param <T> 4118 */ 4119 private abstract class SelfModifyingStore<T extends Expression> extends Store<T> { 4120 protected SelfModifyingStore(final T assignNode, final Expression target) { 4121 super(assignNode, target); 4122 } 4123 4124 @Override 4125 protected boolean isSelfModifying() { 4126 return true; 4127 } 4128 } 4129 4130 /** 4131 * Helper class to generate stores 4132 */ 4133 private abstract class Store<T extends Expression> { 4134 4135 /** An assignment node, e.g. x += y */ 4136 protected final T assignNode; 4137 4138 /** The target node to store to, e.g. x */ 4139 private final Expression target; 4140 4141 /** How deep on the stack do the arguments go if this generates an indy call */ 4142 private int depth; 4143 4144 /** If we have too many arguments, we need temporary storage, this is stored in 'quick' */ 4145 private IdentNode quick; 4146 4147 /** 4148 * Constructor 4149 * 4150 * @param assignNode the node representing the whole assignment 4151 * @param target the target node of the assignment (destination) 4152 */ 4153 protected Store(final T assignNode, final Expression target) { 4154 this.assignNode = assignNode; 4155 this.target = target; 4156 } 4157 4158 /** 4159 * Constructor 4160 * 4161 * @param assignNode the node representing the whole assignment 4162 */ 4163 protected Store(final T assignNode) { 4164 this(assignNode, assignNode); 4165 } 4166 4167 /** 4168 * Is this a self modifying store operation, e.g. *= or ++ 4169 * @return true if self modifying store 4170 */ 4171 protected boolean isSelfModifying() { 4172 return false; 4173 } 4174 4175 private void prologue() { 4176 /** 4177 * This loads the parts of the target, e.g base and index. they are kept 4178 * on the stack throughout the store and used at the end to execute it 4179 */ 4180 4181 target.accept(new NodeVisitor<LexicalContext>(new LexicalContext()) { 4182 @Override 4183 public boolean enterIdentNode(final IdentNode node) { 4184 if (node.getSymbol().isScope()) { 4185 method.loadCompilerConstant(SCOPE); 4186 depth += Type.SCOPE.getSlots(); 4187 assert depth == 1; 4188 } 4189 return false; 4190 } 4191 4192 private void enterBaseNode() { 4193 assert target instanceof BaseNode : "error - base node " + target + " must be instanceof BaseNode"; 4194 final BaseNode baseNode = (BaseNode)target; 4195 final Expression base = baseNode.getBase(); 4196 4197 loadExpressionAsObject(base); 4198 depth += Type.OBJECT.getSlots(); 4199 assert depth == 1; 4200 4201 if (isSelfModifying()) { 4202 method.dup(); 4203 } 4204 } 4205 4206 @Override 4207 public boolean enterAccessNode(final AccessNode node) { 4208 enterBaseNode(); 4209 return false; 4210 } 4211 4212 @Override 4213 public boolean enterIndexNode(final IndexNode node) { 4214 enterBaseNode(); 4215 4216 final Expression index = node.getIndex(); 4217 if (!index.getType().isNumeric()) { 4218 // could be boolean here as well 4219 loadExpressionAsObject(index); 4220 } else { 4221 loadExpressionUnbounded(index); 4222 } 4223 depth += index.getType().getSlots(); 4224 4225 if (isSelfModifying()) { 4226 //convert "base base index" to "base index base index" 4227 method.dup(1); 4228 } 4229 4230 return false; 4231 } 4232 4233 }); 4234 } 4235 4236 /** 4237 * Generates an extra local variable, always using the same slot, one that is available after the end of the 4238 * frame. 4239 * 4240 * @param type the type of the variable 4241 * 4242 * @return the quick variable 4243 */ 4244 private IdentNode quickLocalVariable(final Type type) { 4245 final String name = lc.getCurrentFunction().uniqueName(QUICK_PREFIX.symbolName()); 4246 final Symbol symbol = new Symbol(name, IS_INTERNAL | HAS_SLOT); 4247 symbol.setHasSlotFor(type); 4248 symbol.setFirstSlot(lc.quickSlot(type)); 4249 4250 final IdentNode quickIdent = IdentNode.createInternalIdentifier(symbol).setType(type); 4251 4252 return quickIdent; 4253 } 4254 4255 // store the result that "lives on" after the op, e.g. "i" in i++ postfix. 4256 protected void storeNonDiscard() { 4257 if (lc.getCurrentDiscard() == assignNode) { 4258 assert assignNode.isAssignment(); 4259 lc.popDiscard(); 4260 return; 4261 } 4262 4263 if (method.dup(depth) == null) { 4264 method.dup(); 4265 final Type quickType = method.peekType(); 4266 this.quick = quickLocalVariable(quickType); 4267 final Symbol quickSymbol = quick.getSymbol(); 4268 method.storeTemp(quickType, quickSymbol.getFirstSlot()); 4269 } 4270 } 4271 4272 private void epilogue() { 4273 /** 4274 * Take the original target args from the stack and use them 4275 * together with the value to be stored to emit the store code 4276 * 4277 * The case that targetSymbol is in scope (!hasSlot) and we actually 4278 * need to do a conversion on non-equivalent types exists, but is 4279 * very rare. See for example test/script/basic/access-specializer.js 4280 */ 4281 target.accept(new NodeVisitor<LexicalContext>(new LexicalContext()) { 4282 @Override 4283 protected boolean enterDefault(final Node node) { 4284 throw new AssertionError("Unexpected node " + node + " in store epilogue"); 4285 } 4286 4287 @Override 4288 public boolean enterIdentNode(final IdentNode node) { 4289 final Symbol symbol = node.getSymbol(); 4290 assert symbol != null; 4291 if (symbol.isScope()) { 4292 final int flags = CALLSITE_SCOPE | getCallSiteFlags(); 4293 if (isFastScope(symbol)) { 4294 storeFastScopeVar(symbol, flags); 4295 } else { 4296 method.dynamicSet(node.getName(), flags, false); 4297 } 4298 } else { 4299 final Type storeType = assignNode.getType(); 4300 if (symbol.hasSlotFor(storeType)) { 4301 // Only emit a convert for a store known to be live; converts for dead stores can 4302 // give us an unnecessary ClassCastException. 4303 method.convert(storeType); 4304 } 4305 storeIdentWithCatchConversion(node, storeType); 4306 } 4307 return false; 4308 4309 } 4310 4311 @Override 4312 public boolean enterAccessNode(final AccessNode node) { 4313 method.dynamicSet(node.getProperty(), getCallSiteFlags(), node.isIndex()); 4314 return false; 4315 } 4316 4317 @Override 4318 public boolean enterIndexNode(final IndexNode node) { 4319 method.dynamicSetIndex(getCallSiteFlags()); 4320 return false; 4321 } 4322 }); 4323 4324 4325 // whatever is on the stack now is the final answer 4326 } 4327 4328 protected abstract void evaluate(); 4329 4330 void store() { 4331 if (target instanceof IdentNode) { 4332 checkTemporalDeadZone((IdentNode)target); 4333 } 4334 prologue(); 4335 evaluate(); // leaves an operation of whatever the operationType was on the stack 4336 storeNonDiscard(); 4337 epilogue(); 4338 if (quick != null) { 4339 method.load(quick); 4340 } 4341 } 4342 } 4343 4344 private void newFunctionObject(final FunctionNode functionNode, final boolean addInitializer) { 4345 assert lc.peek() == functionNode; 4346 4347 final RecompilableScriptFunctionData data = compiler.getScriptFunctionData(functionNode.getId()); 4348 4349 if (functionNode.isProgram() && !compiler.isOnDemandCompilation()) { 4350 final MethodEmitter createFunction = functionNode.getCompileUnit().getClassEmitter().method( 4351 EnumSet.of(Flag.PUBLIC, Flag.STATIC), CREATE_PROGRAM_FUNCTION.symbolName(), 4352 ScriptFunction.class, ScriptObject.class); 4353 createFunction.begin(); 4354 loadConstantsAndIndex(data, createFunction); 4355 createFunction.load(SCOPE_TYPE, 0); 4356 createFunction.invoke(CREATE_FUNCTION_OBJECT); 4357 createFunction._return(); 4358 createFunction.end(); 4359 } 4360 4361 if (addInitializer && !compiler.isOnDemandCompilation()) { 4362 compiler.addFunctionInitializer(data, functionNode); 4363 } 4364 4365 // We don't emit a ScriptFunction on stack for the outermost compiled function (as there's no code being 4366 // generated in its outer context that'd need it as a callee). 4367 if (lc.getOutermostFunction() == functionNode) { 4368 return; 4369 } 4370 4371 loadConstantsAndIndex(data, method); 4372 4373 if (functionNode.needsParentScope()) { 4374 method.loadCompilerConstant(SCOPE); 4375 method.invoke(CREATE_FUNCTION_OBJECT); 4376 } else { 4377 method.invoke(CREATE_FUNCTION_OBJECT_NO_SCOPE); 4378 } 4379 } 4380 4381 // calls on Global class. 4382 private MethodEmitter globalInstance() { 4383 return method.invokestatic(GLOBAL_OBJECT, "instance", "()L" + GLOBAL_OBJECT + ';'); 4384 } 4385 4386 private MethodEmitter globalAllocateArguments() { 4387 return method.invokestatic(GLOBAL_OBJECT, "allocateArguments", methodDescriptor(ScriptObject.class, Object[].class, Object.class, int.class)); 4388 } 4389 4390 private MethodEmitter globalNewRegExp() { 4391 return method.invokestatic(GLOBAL_OBJECT, "newRegExp", methodDescriptor(Object.class, String.class, String.class)); 4392 } 4393 4394 private MethodEmitter globalRegExpCopy() { 4395 return method.invokestatic(GLOBAL_OBJECT, "regExpCopy", methodDescriptor(Object.class, Object.class)); 4396 } 4397 4398 private MethodEmitter globalAllocateArray(final ArrayType type) { 4399 //make sure the native array is treated as an array type 4400 return method.invokestatic(GLOBAL_OBJECT, "allocate", "(" + type.getDescriptor() + ")Ljdk/nashorn/internal/objects/NativeArray;"); 4401 } 4402 4403 private MethodEmitter globalIsEval() { 4404 return method.invokestatic(GLOBAL_OBJECT, "isEval", methodDescriptor(boolean.class, Object.class)); 4405 } 4406 4407 private MethodEmitter globalReplaceLocationPropertyPlaceholder() { 4408 return method.invokestatic(GLOBAL_OBJECT, "replaceLocationPropertyPlaceholder", methodDescriptor(Object.class, Object.class, Object.class)); 4409 } 4410 4411 private MethodEmitter globalCheckObjectCoercible() { 4412 return method.invokestatic(GLOBAL_OBJECT, "checkObjectCoercible", methodDescriptor(void.class, Object.class)); 4413 } 4414 4415 private MethodEmitter globalDirectEval() { 4416 return method.invokestatic(GLOBAL_OBJECT, "directEval", 4417 methodDescriptor(Object.class, Object.class, Object.class, Object.class, Object.class, boolean.class)); 4418 } 4419 4420 private abstract class OptimisticOperation { 4421 private final boolean isOptimistic; 4422 // expression and optimistic are the same reference 4423 private final Expression expression; 4424 private final Optimistic optimistic; 4425 private final TypeBounds resultBounds; 4426 4427 OptimisticOperation(final Optimistic optimistic, final TypeBounds resultBounds) { 4428 this.optimistic = optimistic; 4429 this.expression = (Expression)optimistic; 4430 this.resultBounds = resultBounds; 4431 this.isOptimistic = isOptimistic(optimistic) && useOptimisticTypes() && 4432 // Operation is only effectively optimistic if its type, after being coerced into the result bounds 4433 // is narrower than the upper bound. 4434 resultBounds.within(Type.generic(((Expression)optimistic).getType())).narrowerThan(resultBounds.widest); 4435 } 4436 4437 MethodEmitter emit() { 4438 return emit(0); 4439 } 4440 4441 MethodEmitter emit(final int ignoredArgCount) { 4442 final int programPoint = optimistic.getProgramPoint(); 4443 final boolean optimisticOrContinuation = isOptimistic || isContinuationEntryPoint(programPoint); 4444 final boolean currentContinuationEntryPoint = isCurrentContinuationEntryPoint(programPoint); 4445 final int stackSizeOnEntry = method.getStackSize() - ignoredArgCount; 4446 4447 // First store the values on the stack opportunistically into local variables. Doing it before loadStack() 4448 // allows us to not have to pop/load any arguments that are pushed onto it by loadStack() in the second 4449 // storeStack(). 4450 storeStack(ignoredArgCount, optimisticOrContinuation); 4451 4452 // Now, load the stack 4453 loadStack(); 4454 4455 // Now store the values on the stack ultimately into local variables. In vast majority of cases, this is 4456 // (aside from creating the local types map) a no-op, as the first opportunistic stack store will already 4457 // store all variables. However, there can be operations in the loadStack() that invalidate some of the 4458 // stack stores, e.g. in "x[i] = x[++i]", "++i" will invalidate the already stored value for "i". In such 4459 // unfortunate cases this second storeStack() will restore the invariant that everything on the stack is 4460 // stored into a local variable, although at the cost of doing a store/load on the loaded arguments as well. 4461 final int liveLocalsCount = storeStack(method.getStackSize() - stackSizeOnEntry, optimisticOrContinuation); 4462 assert optimisticOrContinuation == (liveLocalsCount != -1); 4463 4464 final Label beginTry; 4465 final Label catchLabel; 4466 final Label afterConsumeStack = isOptimistic || currentContinuationEntryPoint ? new Label("after_consume_stack") : null; 4467 if(isOptimistic) { 4468 beginTry = new Label("try_optimistic"); 4469 final String catchLabelName = (afterConsumeStack == null ? "" : afterConsumeStack.toString()) + "_handler"; 4470 catchLabel = new Label(catchLabelName); 4471 method.label(beginTry); 4472 } else { 4473 beginTry = catchLabel = null; 4474 } 4475 4476 consumeStack(); 4477 4478 if(isOptimistic) { 4479 method._try(beginTry, afterConsumeStack, catchLabel, UnwarrantedOptimismException.class); 4480 } 4481 4482 if(isOptimistic || currentContinuationEntryPoint) { 4483 method.label(afterConsumeStack); 4484 4485 final int[] localLoads = method.getLocalLoadsOnStack(0, stackSizeOnEntry); 4486 assert everyStackValueIsLocalLoad(localLoads) : Arrays.toString(localLoads) + ", " + stackSizeOnEntry + ", " + ignoredArgCount; 4487 final List<Type> localTypesList = method.getLocalVariableTypes(); 4488 final int usedLocals = method.getUsedSlotsWithLiveTemporaries(); 4489 final List<Type> localTypes = method.getWidestLiveLocals(localTypesList.subList(0, usedLocals)); 4490 assert everyLocalLoadIsValid(localLoads, usedLocals) : Arrays.toString(localLoads) + " ~ " + localTypes; 4491 4492 if(isOptimistic) { 4493 addUnwarrantedOptimismHandlerLabel(localTypes, catchLabel); 4494 } 4495 if(currentContinuationEntryPoint) { 4496 final ContinuationInfo ci = getContinuationInfo(); 4497 assert ci != null : "no continuation info found for " + lc.getCurrentFunction(); 4498 assert !ci.hasTargetLabel(); // No duplicate program points 4499 ci.setTargetLabel(afterConsumeStack); 4500 ci.getHandlerLabel().markAsOptimisticContinuationHandlerFor(afterConsumeStack); 4501 // Can't rely on targetLabel.stack.localVariableTypes.length, as it can be higher due to effectively 4502 // dead local variables. 4503 ci.lvarCount = localTypes.size(); 4504 ci.setStackStoreSpec(localLoads); 4505 ci.setStackTypes(Arrays.copyOf(method.getTypesFromStack(method.getStackSize()), stackSizeOnEntry)); 4506 assert ci.getStackStoreSpec().length == ci.getStackTypes().length; 4507 ci.setReturnValueType(method.peekType()); 4508 ci.lineNumber = getLastLineNumber(); 4509 ci.catchLabel = catchLabels.peek(); 4510 } 4511 } 4512 return method; 4513 } 4514 4515 /** 4516 * Stores the current contents of the stack into local variables so they are not lost before invoking something that 4517 * can result in an {@code UnwarantedOptimizationException}. 4518 * @param ignoreArgCount the number of topmost arguments on stack to ignore when deciding on the shape of the catch 4519 * block. Those are used in the situations when we could not place the call to {@code storeStack} early enough 4520 * (before emitting code for pushing the arguments that the optimistic call will pop). This is admittedly a 4521 * deficiency in the design of the code generator when it deals with self-assignments and we should probably look 4522 * into fixing it. 4523 * @return types of the significant local variables after the stack was stored (types for local variables used 4524 * for temporary storage of ignored arguments are not returned). 4525 * @param optimisticOrContinuation if false, this method should not execute 4526 * a label for a catch block for the {@code UnwarantedOptimizationException}, suitable for capturing the 4527 * currently live local variables, tailored to their types. 4528 */ 4529 private int storeStack(final int ignoreArgCount, final boolean optimisticOrContinuation) { 4530 if(!optimisticOrContinuation) { 4531 return -1; // NOTE: correct value to return is lc.getUsedSlotCount(), but it wouldn't be used anyway 4532 } 4533 4534 final int stackSize = method.getStackSize(); 4535 final Type[] stackTypes = method.getTypesFromStack(stackSize); 4536 final int[] localLoadsOnStack = method.getLocalLoadsOnStack(0, stackSize); 4537 final int usedSlots = method.getUsedSlotsWithLiveTemporaries(); 4538 4539 final int firstIgnored = stackSize - ignoreArgCount; 4540 // Find the first value on the stack (from the bottom) that is not a load from a local variable. 4541 int firstNonLoad = 0; 4542 while(firstNonLoad < firstIgnored && localLoadsOnStack[firstNonLoad] != Label.Stack.NON_LOAD) { 4543 firstNonLoad++; 4544 } 4545 4546 // Only do the store/load if first non-load is not an ignored argument. Otherwise, do nothing and return 4547 // the number of used slots as the number of live local variables. 4548 if(firstNonLoad >= firstIgnored) { 4549 return usedSlots; 4550 } 4551 4552 // Find the number of new temporary local variables that we need; it's the number of values on the stack that 4553 // are not direct loads of existing local variables. 4554 int tempSlotsNeeded = 0; 4555 for(int i = firstNonLoad; i < stackSize; ++i) { 4556 if(localLoadsOnStack[i] == Label.Stack.NON_LOAD) { 4557 tempSlotsNeeded += stackTypes[i].getSlots(); 4558 } 4559 } 4560 4561 // Ensure all values on the stack that weren't directly loaded from a local variable are stored in a local 4562 // variable. We're starting from highest local variable index, so that in case ignoreArgCount > 0 the ignored 4563 // ones end up at the end of the local variable table. 4564 int lastTempSlot = usedSlots + tempSlotsNeeded; 4565 int ignoreSlotCount = 0; 4566 for(int i = stackSize; i -- > firstNonLoad;) { 4567 final int loadSlot = localLoadsOnStack[i]; 4568 if(loadSlot == Label.Stack.NON_LOAD) { 4569 final Type type = stackTypes[i]; 4570 final int slots = type.getSlots(); 4571 lastTempSlot -= slots; 4572 if(i >= firstIgnored) { 4573 ignoreSlotCount += slots; 4574 } 4575 method.storeTemp(type, lastTempSlot); 4576 } else { 4577 method.pop(); 4578 } 4579 } 4580 assert lastTempSlot == usedSlots; // used all temporary locals 4581 4582 final List<Type> localTypesList = method.getLocalVariableTypes(); 4583 4584 // Load values back on stack. 4585 for(int i = firstNonLoad; i < stackSize; ++i) { 4586 final int loadSlot = localLoadsOnStack[i]; 4587 final Type stackType = stackTypes[i]; 4588 final boolean isLoad = loadSlot != Label.Stack.NON_LOAD; 4589 final int lvarSlot = isLoad ? loadSlot : lastTempSlot; 4590 final Type lvarType = localTypesList.get(lvarSlot); 4591 method.load(lvarType, lvarSlot); 4592 if(isLoad) { 4593 // Conversion operators (I2L etc.) preserve "load"-ness of the value despite the fact that, in the 4594 // strict sense they are creating a derived value from the loaded value. This special behavior of 4595 // on-stack conversion operators is necessary to accommodate for differences in local variable types 4596 // after deoptimization; having a conversion operator throw away "load"-ness would create different 4597 // local variable table shapes between optimism-failed code and its deoptimized rest-of method). 4598 // After we load the value back, we need to redo the conversion to the stack type if stack type is 4599 // different. 4600 // NOTE: this would only strictly be necessary for widening conversions (I2L, L2D, I2D), and not for 4601 // narrowing ones (L2I, D2L, D2I) as only widening conversions are the ones that can get eliminated 4602 // in a deoptimized method, as their original input argument got widened. Maybe experiment with 4603 // throwing away "load"-ness for narrowing conversions in MethodEmitter.convert()? 4604 method.convert(stackType); 4605 } else { 4606 // temporary stores never needs a convert, as their type is always the same as the stack type. 4607 assert lvarType == stackType; 4608 lastTempSlot += lvarType.getSlots(); 4609 } 4610 } 4611 // used all temporaries 4612 assert lastTempSlot == usedSlots + tempSlotsNeeded; 4613 4614 return lastTempSlot - ignoreSlotCount; 4615 } 4616 4617 private void addUnwarrantedOptimismHandlerLabel(final List<Type> localTypes, final Label label) { 4618 final String lvarTypesDescriptor = getLvarTypesDescriptor(localTypes); 4619 final Map<String, Collection<Label>> unwarrantedOptimismHandlers = lc.getUnwarrantedOptimismHandlers(); 4620 Collection<Label> labels = unwarrantedOptimismHandlers.get(lvarTypesDescriptor); 4621 if(labels == null) { 4622 labels = new LinkedList<>(); 4623 unwarrantedOptimismHandlers.put(lvarTypesDescriptor, labels); 4624 } 4625 method.markLabelAsOptimisticCatchHandler(label, localTypes.size()); 4626 labels.add(label); 4627 } 4628 4629 abstract void loadStack(); 4630 4631 // Make sure that whatever indy call site you emit from this method uses {@code getCallSiteFlagsOptimistic(node)} 4632 // or otherwise ensure optimistic flag is correctly set in the call site, otherwise it doesn't make much sense 4633 // to use OptimisticExpression for emitting it. 4634 abstract void consumeStack(); 4635 4636 /** 4637 * Emits the correct dynamic getter code. Normally just delegates to method emitter, except when the target 4638 * expression is optimistic, and the desired type is narrower than the optimistic type. In that case, it'll emit a 4639 * dynamic getter with its original optimistic type, and explicitly insert a narrowing conversion. This way we can 4640 * preserve the optimism of the values even if they're subsequently immediately coerced into a narrower type. This 4641 * is beneficial because in this case we can still presume that since the original getter was optimistic, the 4642 * conversion has no side effects. 4643 * @param name the name of the property being get 4644 * @param flags call site flags 4645 * @param isMethod whether we're preferrably retrieving a function 4646 * @return the current method emitter 4647 */ 4648 MethodEmitter dynamicGet(final String name, final int flags, final boolean isMethod, final boolean isIndex) { 4649 if(isOptimistic) { 4650 return method.dynamicGet(getOptimisticCoercedType(), name, getOptimisticFlags(flags), isMethod, isIndex); 4651 } 4652 return method.dynamicGet(resultBounds.within(expression.getType()), name, nonOptimisticFlags(flags), isMethod, isIndex); 4653 } 4654 4655 MethodEmitter dynamicGetIndex(final int flags, final boolean isMethod) { 4656 if(isOptimistic) { 4657 return method.dynamicGetIndex(getOptimisticCoercedType(), getOptimisticFlags(flags), isMethod); 4658 } 4659 return method.dynamicGetIndex(resultBounds.within(expression.getType()), nonOptimisticFlags(flags), isMethod); 4660 } 4661 4662 MethodEmitter dynamicCall(final int argCount, final int flags) { 4663 if (isOptimistic) { 4664 return method.dynamicCall(getOptimisticCoercedType(), argCount, getOptimisticFlags(flags)); 4665 } 4666 return method.dynamicCall(resultBounds.within(expression.getType()), argCount, nonOptimisticFlags(flags)); 4667 } 4668 4669 int getOptimisticFlags(final int flags) { 4670 return flags | CALLSITE_OPTIMISTIC | (optimistic.getProgramPoint() << CALLSITE_PROGRAM_POINT_SHIFT); //encode program point in high bits 4671 } 4672 4673 int getProgramPoint() { 4674 return isOptimistic ? optimistic.getProgramPoint() : INVALID_PROGRAM_POINT; 4675 } 4676 4677 void convertOptimisticReturnValue() { 4678 if (isOptimistic) { 4679 final Type optimisticType = getOptimisticCoercedType(); 4680 if(!optimisticType.isObject()) { 4681 method.load(optimistic.getProgramPoint()); 4682 if(optimisticType.isInteger()) { 4683 method.invoke(ENSURE_INT); 4684 } else if(optimisticType.isLong()) { 4685 method.invoke(ENSURE_LONG); 4686 } else if(optimisticType.isNumber()) { 4687 method.invoke(ENSURE_NUMBER); 4688 } else { 4689 throw new AssertionError(optimisticType); 4690 } 4691 } 4692 } 4693 } 4694 4695 void replaceCompileTimeProperty() { 4696 final IdentNode identNode = (IdentNode)expression; 4697 final String name = identNode.getSymbol().getName(); 4698 if (CompilerConstants.__FILE__.name().equals(name)) { 4699 replaceCompileTimeProperty(getCurrentSource().getName()); 4700 } else if (CompilerConstants.__DIR__.name().equals(name)) { 4701 replaceCompileTimeProperty(getCurrentSource().getBase()); 4702 } else if (CompilerConstants.__LINE__.name().equals(name)) { 4703 replaceCompileTimeProperty(getCurrentSource().getLine(identNode.position())); 4704 } 4705 } 4706 4707 /** 4708 * When an ident with name __FILE__, __DIR__, or __LINE__ is loaded, we'll try to look it up as any other 4709 * identifier. However, if it gets all the way up to the Global object, it will send back a special value that 4710 * represents a placeholder for these compile-time location properties. This method will generate code that loads 4711 * the value of the compile-time location property and then invokes a method in Global that will replace the 4712 * placeholder with the value. Effectively, if the symbol for these properties is defined anywhere in the lexical 4713 * scope, they take precedence, but if they aren't, then they resolve to the compile-time location property. 4714 * @param propertyValue the actual value of the property 4715 */ 4716 private void replaceCompileTimeProperty(final Object propertyValue) { 4717 assert method.peekType().isObject(); 4718 if(propertyValue instanceof String || propertyValue == null) { 4719 method.load((String)propertyValue); 4720 } else if(propertyValue instanceof Integer) { 4721 method.load(((Integer)propertyValue).intValue()); 4722 method.convert(Type.OBJECT); 4723 } else { 4724 throw new AssertionError(); 4725 } 4726 globalReplaceLocationPropertyPlaceholder(); 4727 convertOptimisticReturnValue(); 4728 } 4729 4730 /** 4731 * Returns the type that should be used as the return type of the dynamic invocation that is emitted as the code 4732 * for the current optimistic operation. If the type bounds is exact boolean or narrower than the expression's 4733 * optimistic type, then the optimistic type is returned, otherwise the coercing type. Effectively, this method 4734 * allows for moving the coercion into the optimistic type when it won't adversely affect the optimistic 4735 * evaluation semantics, and for preserving the optimistic type and doing a separate coercion when it would 4736 * affect it. 4737 * @return 4738 */ 4739 private Type getOptimisticCoercedType() { 4740 final Type optimisticType = expression.getType(); 4741 assert resultBounds.widest.widerThan(optimisticType); 4742 final Type narrowest = resultBounds.narrowest; 4743 4744 if(narrowest.isBoolean() || narrowest.narrowerThan(optimisticType)) { 4745 assert !optimisticType.isObject(); 4746 return optimisticType; 4747 } 4748 assert !narrowest.isObject(); 4749 return narrowest; 4750 } 4751 } 4752 4753 private static boolean isOptimistic(final Optimistic optimistic) { 4754 if(!optimistic.canBeOptimistic()) { 4755 return false; 4756 } 4757 final Expression expr = (Expression)optimistic; 4758 return expr.getType().narrowerThan(expr.getWidestOperationType()); 4759 } 4760 4761 private static boolean everyLocalLoadIsValid(final int[] loads, final int localCount) { 4762 for (final int load : loads) { 4763 if(load < 0 || load >= localCount) { 4764 return false; 4765 } 4766 } 4767 return true; 4768 } 4769 4770 private static boolean everyStackValueIsLocalLoad(final int[] loads) { 4771 for (final int load : loads) { 4772 if(load == Label.Stack.NON_LOAD) { 4773 return false; 4774 } 4775 } 4776 return true; 4777 } 4778 4779 private String getLvarTypesDescriptor(final List<Type> localVarTypes) { 4780 final int count = localVarTypes.size(); 4781 final StringBuilder desc = new StringBuilder(count); 4782 for(int i = 0; i < count;) { 4783 i += appendType(desc, localVarTypes.get(i)); 4784 } 4785 return method.markSymbolBoundariesInLvarTypesDescriptor(desc.toString()); 4786 } 4787 4788 private static int appendType(final StringBuilder b, final Type t) { 4789 b.append(t.getBytecodeStackType()); 4790 return t.getSlots(); 4791 } 4792 4793 private static int countSymbolsInLvarTypeDescriptor(final String lvarTypeDescriptor) { 4794 int count = 0; 4795 for(int i = 0; i < lvarTypeDescriptor.length(); ++i) { 4796 if(Character.isUpperCase(lvarTypeDescriptor.charAt(i))) { 4797 ++count; 4798 } 4799 } 4800 return count; 4801 4802 } 4803 /** 4804 * Generates all the required {@code UnwarrantedOptimismException} handlers for the current function. The employed 4805 * strategy strives to maximize code reuse. Every handler constructs an array to hold the local variables, then 4806 * fills in some trailing part of the local variables (those for which it has a unique suffix in the descriptor), 4807 * then jumps to a handler for a prefix that's shared with other handlers. A handler that fills up locals up to 4808 * position 0 will not jump to a prefix handler (as it has no prefix), but instead end with constructing and 4809 * throwing a {@code RewriteException}. Since we lexicographically sort the entries, we only need to check every 4810 * entry to its immediately preceding one for longest matching prefix. 4811 * @return true if there is at least one exception handler 4812 */ 4813 private boolean generateUnwarrantedOptimismExceptionHandlers(final FunctionNode fn) { 4814 if(!useOptimisticTypes()) { 4815 return false; 4816 } 4817 4818 // Take the mapping of lvarSpecs -> labels, and turn them into a descending lexicographically sorted list of 4819 // handler specifications. 4820 final Map<String, Collection<Label>> unwarrantedOptimismHandlers = lc.popUnwarrantedOptimismHandlers(); 4821 if(unwarrantedOptimismHandlers.isEmpty()) { 4822 return false; 4823 } 4824 4825 method.lineNumber(0); 4826 4827 final List<OptimismExceptionHandlerSpec> handlerSpecs = new ArrayList<>(unwarrantedOptimismHandlers.size() * 4/3); 4828 for(final String spec: unwarrantedOptimismHandlers.keySet()) { 4829 handlerSpecs.add(new OptimismExceptionHandlerSpec(spec, true)); 4830 } 4831 Collections.sort(handlerSpecs, Collections.reverseOrder()); 4832 4833 // Map of local variable specifications to labels for populating the array for that local variable spec. 4834 final Map<String, Label> delegationLabels = new HashMap<>(); 4835 4836 // Do everything in a single pass over the handlerSpecs list. Note that the list can actually grow as we're 4837 // passing through it as we might add new prefix handlers into it, so can't hoist size() outside of the loop. 4838 for(int handlerIndex = 0; handlerIndex < handlerSpecs.size(); ++handlerIndex) { 4839 final OptimismExceptionHandlerSpec spec = handlerSpecs.get(handlerIndex); 4840 final String lvarSpec = spec.lvarSpec; 4841 if(spec.catchTarget) { 4842 assert !method.isReachable(); 4843 // Start a catch block and assign the labels for this lvarSpec with it. 4844 method._catch(unwarrantedOptimismHandlers.get(lvarSpec)); 4845 // This spec is a catch target, so emit array creation code. The length of the array is the number of 4846 // symbols - the number of uppercase characters. 4847 method.load(countSymbolsInLvarTypeDescriptor(lvarSpec)); 4848 method.newarray(Type.OBJECT_ARRAY); 4849 } 4850 if(spec.delegationTarget) { 4851 // If another handler can delegate to this handler as its prefix, then put a jump target here for the 4852 // shared code (after the array creation code, which is never shared). 4853 method.label(delegationLabels.get(lvarSpec)); // label must exist 4854 } 4855 4856 final boolean lastHandler = handlerIndex == handlerSpecs.size() - 1; 4857 4858 int lvarIndex; 4859 final int firstArrayIndex; 4860 final int firstLvarIndex; 4861 Label delegationLabel; 4862 final String commonLvarSpec; 4863 if(lastHandler) { 4864 // Last handler block, doesn't delegate to anything. 4865 lvarIndex = 0; 4866 firstLvarIndex = 0; 4867 firstArrayIndex = 0; 4868 delegationLabel = null; 4869 commonLvarSpec = null; 4870 } else { 4871 // Not yet the last handler block, will definitely delegate to another handler; let's figure out which 4872 // one. It can be an already declared handler further down the list, or it might need to declare a new 4873 // prefix handler. 4874 4875 // Since we're lexicographically ordered, the common prefix handler is defined by the common prefix of 4876 // this handler and the next handler on the list. 4877 final int nextHandlerIndex = handlerIndex + 1; 4878 final String nextLvarSpec = handlerSpecs.get(nextHandlerIndex).lvarSpec; 4879 commonLvarSpec = commonPrefix(lvarSpec, nextLvarSpec); 4880 // We don't chop symbols in half 4881 assert Character.isUpperCase(commonLvarSpec.charAt(commonLvarSpec.length() - 1)); 4882 4883 // Let's find if we already have a declaration for such handler, or we need to insert it. 4884 { 4885 boolean addNewHandler = true; 4886 int commonHandlerIndex = nextHandlerIndex; 4887 for(; commonHandlerIndex < handlerSpecs.size(); ++commonHandlerIndex) { 4888 final OptimismExceptionHandlerSpec forwardHandlerSpec = handlerSpecs.get(commonHandlerIndex); 4889 final String forwardLvarSpec = forwardHandlerSpec.lvarSpec; 4890 if(forwardLvarSpec.equals(commonLvarSpec)) { 4891 // We already have a handler for the common prefix. 4892 addNewHandler = false; 4893 // Make sure we mark it as a delegation target. 4894 forwardHandlerSpec.delegationTarget = true; 4895 break; 4896 } else if(!forwardLvarSpec.startsWith(commonLvarSpec)) { 4897 break; 4898 } 4899 } 4900 if(addNewHandler) { 4901 // We need to insert a common prefix handler. Note handlers created with catchTarget == false 4902 // will automatically have delegationTarget == true (because that's the only reason for their 4903 // existence). 4904 handlerSpecs.add(commonHandlerIndex, new OptimismExceptionHandlerSpec(commonLvarSpec, false)); 4905 } 4906 } 4907 4908 firstArrayIndex = countSymbolsInLvarTypeDescriptor(commonLvarSpec); 4909 lvarIndex = 0; 4910 for(int j = 0; j < commonLvarSpec.length(); ++j) { 4911 lvarIndex += CodeGeneratorLexicalContext.getTypeForSlotDescriptor(commonLvarSpec.charAt(j)).getSlots(); 4912 } 4913 firstLvarIndex = lvarIndex; 4914 4915 // Create a delegation label if not already present 4916 delegationLabel = delegationLabels.get(commonLvarSpec); 4917 if(delegationLabel == null) { 4918 // uo_pa == "unwarranted optimism, populate array" 4919 delegationLabel = new Label("uo_pa_" + commonLvarSpec); 4920 delegationLabels.put(commonLvarSpec, delegationLabel); 4921 } 4922 } 4923 4924 // Load local variables handled by this handler on stack 4925 int args = 0; 4926 boolean symbolHadValue = false; 4927 for(int typeIndex = commonLvarSpec == null ? 0 : commonLvarSpec.length(); typeIndex < lvarSpec.length(); ++typeIndex) { 4928 final char typeDesc = lvarSpec.charAt(typeIndex); 4929 final Type lvarType = CodeGeneratorLexicalContext.getTypeForSlotDescriptor(typeDesc); 4930 if (!lvarType.isUnknown()) { 4931 method.load(lvarType, lvarIndex); 4932 symbolHadValue = true; 4933 args++; 4934 } else if(typeDesc == 'U' && !symbolHadValue) { 4935 // Symbol boundary with undefined last value. Check if all previous values for this symbol were also 4936 // undefined; if so, emit one explicit Undefined. This serves to ensure that we're emiting exactly 4937 // one value for every symbol that uses local slots. While we could in theory ignore symbols that 4938 // are undefined (in other words, dead) at the point where this exception was thrown, unfortunately 4939 // we can't do it in practice. The reason for this is that currently our liveness analysis is 4940 // coarse (it can determine whether a symbol has not been read with a particular type anywhere in 4941 // the function being compiled, but that's it), and a symbol being promoted to Object due to a 4942 // deoptimization will suddenly show up as "live for Object type", and previously dead U->O 4943 // conversions on loop entries will suddenly become alive in the deoptimized method which will then 4944 // expect a value for that slot in its continuation handler. If we had precise liveness analysis, we 4945 // could go back to excluding known dead symbols from the payload of the RewriteException. 4946 if(method.peekType() == Type.UNDEFINED) { 4947 method.dup(); 4948 } else { 4949 method.loadUndefined(Type.OBJECT); 4950 } 4951 args++; 4952 } 4953 if(Character.isUpperCase(typeDesc)) { 4954 // Reached symbol boundary; reset flag for the next symbol. 4955 symbolHadValue = false; 4956 } 4957 lvarIndex += lvarType.getSlots(); 4958 } 4959 assert args > 0; 4960 // Delegate actual storing into array to an array populator utility method. 4961 //on the stack: 4962 // object array to be populated 4963 // start index 4964 // a lot of types 4965 method.dynamicArrayPopulatorCall(args + 1, firstArrayIndex); 4966 if(delegationLabel != null) { 4967 // We cascade to a prefix handler to fill out the rest of the local variables and throw the 4968 // RewriteException. 4969 assert !lastHandler; 4970 assert commonLvarSpec != null; 4971 // Must undefine the local variables that we have already processed for the sake of correct join on the 4972 // delegate label 4973 method.undefineLocalVariables(firstLvarIndex, true); 4974 final OptimismExceptionHandlerSpec nextSpec = handlerSpecs.get(handlerIndex + 1); 4975 // If the delegate immediately follows, and it's not a catch target (so it doesn't have array setup 4976 // code) don't bother emitting a jump, as we'd just jump to the next instruction. 4977 if(!nextSpec.lvarSpec.equals(commonLvarSpec) || nextSpec.catchTarget) { 4978 method._goto(delegationLabel); 4979 } 4980 } else { 4981 assert lastHandler; 4982 // Nothing to delegate to, so this handler must create and throw the RewriteException. 4983 // At this point we have the UnwarrantedOptimismException and the Object[] with local variables on 4984 // stack. We need to create a RewriteException, push two references to it below the constructor 4985 // arguments, invoke the constructor, and throw the exception. 4986 loadConstant(getByteCodeSymbolNames(fn)); 4987 if (isRestOf()) { 4988 loadConstant(getContinuationEntryPoints()); 4989 method.invoke(CREATE_REWRITE_EXCEPTION_REST_OF); 4990 } else { 4991 method.invoke(CREATE_REWRITE_EXCEPTION); 4992 } 4993 method.athrow(); 4994 } 4995 } 4996 return true; 4997 } 4998 4999 private static String[] getByteCodeSymbolNames(final FunctionNode fn) { 5000 // Only names of local variables on the function level are captured. This information is used to reduce 5001 // deoptimizations, so as much as we can capture will help. We rely on the fact that function wide variables are 5002 // all live all the time, so the array passed to rewrite exception contains one element for every slotted symbol 5003 // here. 5004 final List<String> names = new ArrayList<>(); 5005 for (final Symbol symbol: fn.getBody().getSymbols()) { 5006 if (symbol.hasSlot()) { 5007 if (symbol.isScope()) { 5008 // slot + scope can only be true for parameters 5009 assert symbol.isParam(); 5010 names.add(null); 5011 } else { 5012 names.add(symbol.getName()); 5013 } 5014 } 5015 } 5016 return names.toArray(new String[names.size()]); 5017 } 5018 5019 private static String commonPrefix(final String s1, final String s2) { 5020 final int l1 = s1.length(); 5021 final int l = Math.min(l1, s2.length()); 5022 int lms = -1; // last matching symbol 5023 for(int i = 0; i < l; ++i) { 5024 final char c1 = s1.charAt(i); 5025 if(c1 != s2.charAt(i)) { 5026 return s1.substring(0, lms + 1); 5027 } else if(Character.isUpperCase(c1)) { 5028 lms = i; 5029 } 5030 } 5031 return l == l1 ? s1 : s2; 5032 } 5033 5034 private static class OptimismExceptionHandlerSpec implements Comparable<OptimismExceptionHandlerSpec> { 5035 private final String lvarSpec; 5036 private final boolean catchTarget; 5037 private boolean delegationTarget; 5038 5039 OptimismExceptionHandlerSpec(final String lvarSpec, final boolean catchTarget) { 5040 this.lvarSpec = lvarSpec; 5041 this.catchTarget = catchTarget; 5042 if(!catchTarget) { 5043 delegationTarget = true; 5044 } 5045 } 5046 5047 @Override 5048 public int compareTo(final OptimismExceptionHandlerSpec o) { 5049 return lvarSpec.compareTo(o.lvarSpec); 5050 } 5051 5052 @Override 5053 public String toString() { 5054 final StringBuilder b = new StringBuilder(64).append("[HandlerSpec ").append(lvarSpec); 5055 if(catchTarget) { 5056 b.append(", catchTarget"); 5057 } 5058 if(delegationTarget) { 5059 b.append(", delegationTarget"); 5060 } 5061 return b.append("]").toString(); 5062 } 5063 } 5064 5065 private static class ContinuationInfo { 5066 private final Label handlerLabel; 5067 private Label targetLabel; // Label for the target instruction. 5068 int lvarCount; 5069 // Indices of local variables that need to be loaded on the stack when this node completes 5070 private int[] stackStoreSpec; 5071 // Types of values loaded on the stack 5072 private Type[] stackTypes; 5073 // If non-null, this node should perform the requisite type conversion 5074 private Type returnValueType; 5075 // If we are in the middle of an object literal initialization, we need to update the map 5076 private PropertyMap objectLiteralMap; 5077 // Object literal stack depth for object literal - not necessarly top if property is a tree 5078 private int objectLiteralStackDepth = -1; 5079 // The line number at the continuation point 5080 private int lineNumber; 5081 // The active catch label, in case the continuation point is in a try/catch block 5082 private Label catchLabel; 5083 // The number of scopes that need to be popped before control is transferred to the catch label. 5084 private int exceptionScopePops; 5085 5086 ContinuationInfo() { 5087 this.handlerLabel = new Label("continuation_handler"); 5088 } 5089 5090 Label getHandlerLabel() { 5091 return handlerLabel; 5092 } 5093 5094 boolean hasTargetLabel() { 5095 return targetLabel != null; 5096 } 5097 5098 Label getTargetLabel() { 5099 return targetLabel; 5100 } 5101 5102 void setTargetLabel(final Label targetLabel) { 5103 this.targetLabel = targetLabel; 5104 } 5105 5106 int[] getStackStoreSpec() { 5107 return stackStoreSpec.clone(); 5108 } 5109 5110 void setStackStoreSpec(final int[] stackStoreSpec) { 5111 this.stackStoreSpec = stackStoreSpec; 5112 } 5113 5114 Type[] getStackTypes() { 5115 return stackTypes.clone(); 5116 } 5117 5118 void setStackTypes(final Type[] stackTypes) { 5119 this.stackTypes = stackTypes; 5120 } 5121 5122 Type getReturnValueType() { 5123 return returnValueType; 5124 } 5125 5126 void setReturnValueType(final Type returnValueType) { 5127 this.returnValueType = returnValueType; 5128 } 5129 5130 int getObjectLiteralStackDepth() { 5131 return objectLiteralStackDepth; 5132 } 5133 5134 void setObjectLiteralStackDepth(final int objectLiteralStackDepth) { 5135 this.objectLiteralStackDepth = objectLiteralStackDepth; 5136 } 5137 5138 PropertyMap getObjectLiteralMap() { 5139 return objectLiteralMap; 5140 } 5141 5142 void setObjectLiteralMap(final PropertyMap objectLiteralMap) { 5143 this.objectLiteralMap = objectLiteralMap; 5144 } 5145 5146 @Override 5147 public String toString() { 5148 return "[localVariableTypes=" + targetLabel.getStack().getLocalVariableTypesCopy() + ", stackStoreSpec=" + 5149 Arrays.toString(stackStoreSpec) + ", returnValueType=" + returnValueType + "]"; 5150 } 5151 } 5152 5153 private ContinuationInfo getContinuationInfo() { 5154 return fnIdToContinuationInfo.get(lc.getCurrentFunction().getId()); 5155 } 5156 5157 private void generateContinuationHandler() { 5158 if (!isRestOf()) { 5159 return; 5160 } 5161 5162 final ContinuationInfo ci = getContinuationInfo(); 5163 method.label(ci.getHandlerLabel()); 5164 5165 // There should never be an exception thrown from the continuation handler, but in case there is (meaning, 5166 // Nashorn has a bug), then line number 0 will be an indication of where it came from (line numbers are Uint16). 5167 method.lineNumber(0); 5168 5169 final Label.Stack stack = ci.getTargetLabel().getStack(); 5170 final List<Type> lvarTypes = stack.getLocalVariableTypesCopy(); 5171 final BitSet symbolBoundary = stack.getSymbolBoundaryCopy(); 5172 final int lvarCount = ci.lvarCount; 5173 5174 final Type rewriteExceptionType = Type.typeFor(RewriteException.class); 5175 // Store the RewriteException into an unused local variable slot. 5176 method.load(rewriteExceptionType, 0); 5177 method.storeTemp(rewriteExceptionType, lvarCount); 5178 // Get local variable array 5179 method.load(rewriteExceptionType, 0); 5180 method.invoke(RewriteException.GET_BYTECODE_SLOTS); 5181 // Store local variables. Note that deoptimization might introduce new value types for existing local variables, 5182 // so we must use both liveLocals and symbolBoundary, as in some cases (when the continuation is inside of a try 5183 // block) we need to store the incoming value into multiple slots. The optimism exception handlers will have 5184 // exactly one array element for every symbol that uses bytecode storage. If in the originating method the value 5185 // was undefined, there will be an explicit Undefined value in the array. 5186 int arrayIndex = 0; 5187 for(int lvarIndex = 0; lvarIndex < lvarCount;) { 5188 final Type lvarType = lvarTypes.get(lvarIndex); 5189 if(!lvarType.isUnknown()) { 5190 method.dup(); 5191 method.load(arrayIndex).arrayload(); 5192 final Class<?> typeClass = lvarType.getTypeClass(); 5193 // Deoptimization in array initializers can cause arrays to undergo component type widening 5194 if(typeClass == long[].class) { 5195 method.load(rewriteExceptionType, lvarCount); 5196 method.invoke(RewriteException.TO_LONG_ARRAY); 5197 } else if(typeClass == double[].class) { 5198 method.load(rewriteExceptionType, lvarCount); 5199 method.invoke(RewriteException.TO_DOUBLE_ARRAY); 5200 } else if(typeClass == Object[].class) { 5201 method.load(rewriteExceptionType, lvarCount); 5202 method.invoke(RewriteException.TO_OBJECT_ARRAY); 5203 } else { 5204 if(!(typeClass.isPrimitive() || typeClass == Object.class)) { 5205 // NOTE: this can only happen with dead stores. E.g. for the program "1; []; f();" in which the 5206 // call to f() will deoptimize the call site, but it'll expect :return to have the type 5207 // NativeArray. However, in the more optimal version, :return's only live type is int, therefore 5208 // "{O}:return = []" is a dead store, and the variable will be sent into the continuation as 5209 // Undefined, however NativeArray can't hold Undefined instance. 5210 method.loadType(Type.getInternalName(typeClass)); 5211 method.invoke(RewriteException.INSTANCE_OR_NULL); 5212 } 5213 method.convert(lvarType); 5214 } 5215 method.storeHidden(lvarType, lvarIndex, false); 5216 } 5217 final int nextLvarIndex = lvarIndex + lvarType.getSlots(); 5218 if(symbolBoundary.get(nextLvarIndex - 1)) { 5219 ++arrayIndex; 5220 } 5221 lvarIndex = nextLvarIndex; 5222 } 5223 if (AssertsEnabled.assertsEnabled()) { 5224 method.load(arrayIndex); 5225 method.invoke(RewriteException.ASSERT_ARRAY_LENGTH); 5226 } else { 5227 method.pop(); 5228 } 5229 5230 final int[] stackStoreSpec = ci.getStackStoreSpec(); 5231 final Type[] stackTypes = ci.getStackTypes(); 5232 final boolean isStackEmpty = stackStoreSpec.length == 0; 5233 boolean replacedObjectLiteralMap = false; 5234 if(!isStackEmpty) { 5235 // Load arguments on the stack 5236 final int objectLiteralStackDepth = ci.getObjectLiteralStackDepth(); 5237 for(int i = 0; i < stackStoreSpec.length; ++i) { 5238 final int slot = stackStoreSpec[i]; 5239 method.load(lvarTypes.get(slot), slot); 5240 method.convert(stackTypes[i]); 5241 // stack: s0=object literal being initialized 5242 // change map of s0 so that the property we are initilizing when we failed 5243 // is now ci.returnValueType 5244 if (i == objectLiteralStackDepth) { 5245 method.dup(); 5246 assert ci.getObjectLiteralMap() != null; 5247 assert ScriptObject.class.isAssignableFrom(method.peekType().getTypeClass()) : method.peekType().getTypeClass() + " is not a script object"; 5248 loadConstant(ci.getObjectLiteralMap()); 5249 method.invoke(ScriptObject.SET_MAP); 5250 replacedObjectLiteralMap = true; 5251 } 5252 } 5253 } 5254 // Must have emitted the code for replacing the map of an object literal if we have a set object literal stack depth 5255 assert ci.getObjectLiteralStackDepth() == -1 || replacedObjectLiteralMap; 5256 // Load RewriteException back. 5257 method.load(rewriteExceptionType, lvarCount); 5258 // Get rid of the stored reference 5259 method.loadNull(); 5260 method.storeHidden(Type.OBJECT, lvarCount); 5261 // Mark it dead 5262 method.markDeadSlots(lvarCount, Type.OBJECT.getSlots()); 5263 5264 // Load return value on the stack 5265 method.invoke(RewriteException.GET_RETURN_VALUE); 5266 5267 final Type returnValueType = ci.getReturnValueType(); 5268 5269 // Set up an exception handler for primitive type conversion of return value if needed 5270 boolean needsCatch = false; 5271 final Label targetCatchLabel = ci.catchLabel; 5272 Label _try = null; 5273 if(returnValueType.isPrimitive()) { 5274 // If the conversion throws an exception, we want to report the line number of the continuation point. 5275 method.lineNumber(ci.lineNumber); 5276 5277 if(targetCatchLabel != METHOD_BOUNDARY) { 5278 _try = new Label(""); 5279 method.label(_try); 5280 needsCatch = true; 5281 } 5282 } 5283 5284 // Convert return value 5285 method.convert(returnValueType); 5286 5287 final int scopePopCount = needsCatch ? ci.exceptionScopePops : 0; 5288 5289 // Declare a try/catch for the conversion. If no scopes need to be popped until the target catch block, just 5290 // jump into it. Otherwise, we'll need to create a scope-popping catch block below. 5291 final Label catchLabel = scopePopCount > 0 ? new Label("") : targetCatchLabel; 5292 if(needsCatch) { 5293 final Label _end_try = new Label(""); 5294 method.label(_end_try); 5295 method._try(_try, _end_try, catchLabel); 5296 } 5297 5298 // Jump to continuation point 5299 method._goto(ci.getTargetLabel()); 5300 5301 // Make a scope-popping exception delegate if needed 5302 if(catchLabel != targetCatchLabel) { 5303 method.lineNumber(0); 5304 assert scopePopCount > 0; 5305 method._catch(catchLabel); 5306 popScopes(scopePopCount); 5307 method.uncheckedGoto(targetCatchLabel); 5308 } 5309 } 5310 } --- EOF ---