1 /*
2 * Copyright (c) 2010, 2016, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package jdk.nashorn.internal.codegen;
27
28 import static jdk.nashorn.internal.codegen.ClassEmitter.Flag.PRIVATE;
29 import static jdk.nashorn.internal.codegen.ClassEmitter.Flag.STATIC;
30 import static jdk.nashorn.internal.codegen.CompilerConstants.ARGUMENTS;
31 import static jdk.nashorn.internal.codegen.CompilerConstants.CALLEE;
32 import static jdk.nashorn.internal.codegen.CompilerConstants.CREATE_PROGRAM_FUNCTION;
33 import static jdk.nashorn.internal.codegen.CompilerConstants.GET_MAP;
34 import static jdk.nashorn.internal.codegen.CompilerConstants.GET_STRING;
35 import static jdk.nashorn.internal.codegen.CompilerConstants.QUICK_PREFIX;
36 import static jdk.nashorn.internal.codegen.CompilerConstants.REGEX_PREFIX;
37 import static jdk.nashorn.internal.codegen.CompilerConstants.SCOPE;
38 import static jdk.nashorn.internal.codegen.CompilerConstants.SPLIT_PREFIX;
39 import static jdk.nashorn.internal.codegen.CompilerConstants.THIS;
40 import static jdk.nashorn.internal.codegen.CompilerConstants.VARARGS;
41 import static jdk.nashorn.internal.codegen.CompilerConstants.interfaceCallNoLookup;
42 import static jdk.nashorn.internal.codegen.CompilerConstants.methodDescriptor;
43 import static jdk.nashorn.internal.codegen.CompilerConstants.staticCallNoLookup;
44 import static jdk.nashorn.internal.codegen.CompilerConstants.typeDescriptor;
45 import static jdk.nashorn.internal.codegen.CompilerConstants.virtualCallNoLookup;
46 import static jdk.nashorn.internal.ir.Symbol.HAS_SLOT;
47 import static jdk.nashorn.internal.ir.Symbol.IS_INTERNAL;
48 import static jdk.nashorn.internal.runtime.UnwarrantedOptimismException.INVALID_PROGRAM_POINT;
49 import static jdk.nashorn.internal.runtime.UnwarrantedOptimismException.isValid;
50 import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_APPLY_TO_CALL;
51 import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_DECLARE;
52 import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_FAST_SCOPE;
53 import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_OPTIMISTIC;
54 import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_PROGRAM_POINT_SHIFT;
55 import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_SCOPE;
56
57 import java.io.PrintWriter;
58 import java.util.ArrayDeque;
59 import java.util.ArrayList;
60 import java.util.Arrays;
61 import java.util.BitSet;
62 import java.util.Collection;
63 import java.util.Collections;
64 import java.util.Deque;
65 import java.util.EnumSet;
66 import java.util.HashMap;
67 import java.util.HashSet;
68 import java.util.Iterator;
69 import java.util.LinkedList;
70 import java.util.List;
71 import java.util.Map;
72 import java.util.Set;
73 import java.util.TreeMap;
74 import java.util.function.Supplier;
75 import jdk.nashorn.internal.AssertsEnabled;
76 import jdk.nashorn.internal.IntDeque;
77 import jdk.nashorn.internal.codegen.ClassEmitter.Flag;
78 import jdk.nashorn.internal.codegen.CompilerConstants.Call;
79 import jdk.nashorn.internal.codegen.types.ArrayType;
80 import jdk.nashorn.internal.codegen.types.Type;
81 import jdk.nashorn.internal.ir.AccessNode;
82 import jdk.nashorn.internal.ir.BaseNode;
83 import jdk.nashorn.internal.ir.BinaryNode;
84 import jdk.nashorn.internal.ir.Block;
85 import jdk.nashorn.internal.ir.BlockStatement;
86 import jdk.nashorn.internal.ir.BreakNode;
87 import jdk.nashorn.internal.ir.CallNode;
88 import jdk.nashorn.internal.ir.CaseNode;
89 import jdk.nashorn.internal.ir.CatchNode;
90 import jdk.nashorn.internal.ir.ContinueNode;
91 import jdk.nashorn.internal.ir.EmptyNode;
92 import jdk.nashorn.internal.ir.Expression;
93 import jdk.nashorn.internal.ir.ExpressionStatement;
94 import jdk.nashorn.internal.ir.ForNode;
95 import jdk.nashorn.internal.ir.FunctionNode;
96 import jdk.nashorn.internal.ir.GetSplitState;
97 import jdk.nashorn.internal.ir.IdentNode;
98 import jdk.nashorn.internal.ir.IfNode;
99 import jdk.nashorn.internal.ir.IndexNode;
100 import jdk.nashorn.internal.ir.JoinPredecessorExpression;
101 import jdk.nashorn.internal.ir.JumpStatement;
102 import jdk.nashorn.internal.ir.JumpToInlinedFinally;
103 import jdk.nashorn.internal.ir.LabelNode;
104 import jdk.nashorn.internal.ir.LexicalContext;
105 import jdk.nashorn.internal.ir.LexicalContextNode;
106 import jdk.nashorn.internal.ir.LiteralNode;
107 import jdk.nashorn.internal.ir.LiteralNode.ArrayLiteralNode;
108 import jdk.nashorn.internal.ir.LiteralNode.PrimitiveLiteralNode;
109 import jdk.nashorn.internal.ir.LocalVariableConversion;
110 import jdk.nashorn.internal.ir.LoopNode;
111 import jdk.nashorn.internal.ir.Node;
112 import jdk.nashorn.internal.ir.ObjectNode;
113 import jdk.nashorn.internal.ir.Optimistic;
114 import jdk.nashorn.internal.ir.PropertyNode;
115 import jdk.nashorn.internal.ir.ReturnNode;
116 import jdk.nashorn.internal.ir.RuntimeNode;
117 import jdk.nashorn.internal.ir.RuntimeNode.Request;
118 import jdk.nashorn.internal.ir.SetSplitState;
119 import jdk.nashorn.internal.ir.SplitReturn;
120 import jdk.nashorn.internal.ir.Splittable;
121 import jdk.nashorn.internal.ir.Statement;
122 import jdk.nashorn.internal.ir.SwitchNode;
123 import jdk.nashorn.internal.ir.Symbol;
124 import jdk.nashorn.internal.ir.TernaryNode;
125 import jdk.nashorn.internal.ir.ThrowNode;
126 import jdk.nashorn.internal.ir.TryNode;
127 import jdk.nashorn.internal.ir.UnaryNode;
128 import jdk.nashorn.internal.ir.VarNode;
129 import jdk.nashorn.internal.ir.WhileNode;
130 import jdk.nashorn.internal.ir.WithNode;
131 import jdk.nashorn.internal.ir.visitor.NodeOperatorVisitor;
132 import jdk.nashorn.internal.ir.visitor.SimpleNodeVisitor;
133 import jdk.nashorn.internal.objects.Global;
134 import jdk.nashorn.internal.parser.Lexer.RegexToken;
135 import jdk.nashorn.internal.parser.TokenType;
136 import jdk.nashorn.internal.runtime.Context;
137 import jdk.nashorn.internal.runtime.Debug;
138 import jdk.nashorn.internal.runtime.ECMAException;
139 import jdk.nashorn.internal.runtime.JSType;
140 import jdk.nashorn.internal.runtime.OptimisticReturnFilters;
141 import jdk.nashorn.internal.runtime.PropertyMap;
142 import jdk.nashorn.internal.runtime.RecompilableScriptFunctionData;
143 import jdk.nashorn.internal.runtime.RewriteException;
144 import jdk.nashorn.internal.runtime.Scope;
145 import jdk.nashorn.internal.runtime.ScriptEnvironment;
146 import jdk.nashorn.internal.runtime.ScriptFunction;
147 import jdk.nashorn.internal.runtime.ScriptObject;
148 import jdk.nashorn.internal.runtime.ScriptRuntime;
149 import jdk.nashorn.internal.runtime.Source;
150 import jdk.nashorn.internal.runtime.Undefined;
151 import jdk.nashorn.internal.runtime.UnwarrantedOptimismException;
152 import jdk.nashorn.internal.runtime.arrays.ArrayData;
153 import jdk.nashorn.internal.runtime.linker.LinkerCallSite;
154 import jdk.nashorn.internal.runtime.logging.DebugLogger;
155 import jdk.nashorn.internal.runtime.logging.Loggable;
156 import jdk.nashorn.internal.runtime.logging.Logger;
157 import jdk.nashorn.internal.runtime.options.Options;
158
159 /**
160 * This is the lowest tier of the code generator. It takes lowered ASTs emitted
161 * from Lower and emits Java byte code. The byte code emission logic is broken
162 * out into MethodEmitter. MethodEmitter works internally with a type stack, and
163 * keeps track of the contents of the byte code stack. This way we avoid a large
164 * number of special cases on the form
165 * <pre>
166 * if (type == INT) {
167 * visitInsn(ILOAD, slot);
168 * } else if (type == DOUBLE) {
169 * visitInsn(DOUBLE, slot);
170 * }
171 * </pre>
172 * This quickly became apparent when the code generator was generalized to work
173 * with all types, and not just numbers or objects.
174 * <p>
175 * The CodeGenerator visits nodes only once and emits bytecode for them.
176 */
177 @Logger(name="codegen")
178 final class CodeGenerator extends NodeOperatorVisitor<CodeGeneratorLexicalContext> implements Loggable {
179
180 private static final Type SCOPE_TYPE = Type.typeFor(ScriptObject.class);
181
182 private static final String GLOBAL_OBJECT = Type.getInternalName(Global.class);
183
184 private static final Call CREATE_REWRITE_EXCEPTION = CompilerConstants.staticCallNoLookup(RewriteException.class,
185 "create", RewriteException.class, UnwarrantedOptimismException.class, Object[].class, String[].class);
186 private static final Call CREATE_REWRITE_EXCEPTION_REST_OF = CompilerConstants.staticCallNoLookup(RewriteException.class,
187 "create", RewriteException.class, UnwarrantedOptimismException.class, Object[].class, String[].class, int[].class);
188
189 private static final Call ENSURE_INT = CompilerConstants.staticCallNoLookup(OptimisticReturnFilters.class,
190 "ensureInt", int.class, Object.class, int.class);
191 private static final Call ENSURE_NUMBER = CompilerConstants.staticCallNoLookup(OptimisticReturnFilters.class,
192 "ensureNumber", double.class, Object.class, int.class);
193
194 private static final Call CREATE_FUNCTION_OBJECT = CompilerConstants.staticCallNoLookup(ScriptFunction.class,
195 "create", ScriptFunction.class, Object[].class, int.class, ScriptObject.class);
196 private static final Call CREATE_FUNCTION_OBJECT_NO_SCOPE = CompilerConstants.staticCallNoLookup(ScriptFunction.class,
197 "create", ScriptFunction.class, Object[].class, int.class);
198
199 private static final Call TO_NUMBER_FOR_EQ = CompilerConstants.staticCallNoLookup(JSType.class,
200 "toNumberForEq", double.class, Object.class);
201 private static final Call TO_NUMBER_FOR_STRICT_EQ = CompilerConstants.staticCallNoLookup(JSType.class,
202 "toNumberForStrictEq", double.class, Object.class);
203
204
205 private static final Class<?> ITERATOR_CLASS = Iterator.class;
206 static {
207 assert ITERATOR_CLASS == CompilerConstants.ITERATOR_PREFIX.type();
208 }
209 private static final Type ITERATOR_TYPE = Type.typeFor(ITERATOR_CLASS);
210 private static final Type EXCEPTION_TYPE = Type.typeFor(CompilerConstants.EXCEPTION_PREFIX.type());
211
212 private static final Integer INT_ZERO = 0;
213
214 /** Constant data & installation. The only reason the compiler keeps this is because it is assigned
215 * by reflection in class installation */
216 private final Compiler compiler;
217
218 /** Is the current code submitted by 'eval' call? */
219 private final boolean evalCode;
220
221 /** Call site flags given to the code generator to be used for all generated call sites */
222 private final int callSiteFlags;
223
224 /** How many regexp fields have been emitted */
225 private int regexFieldCount;
226
227 /** Line number for last statement. If we encounter a new line number, line number bytecode information
228 * needs to be generated */
229 private int lastLineNumber = -1;
230
231 /** When should we stop caching regexp expressions in fields to limit bytecode size? */
232 private static final int MAX_REGEX_FIELDS = 2 * 1024;
233
234 /** Current method emitter */
235 private MethodEmitter method;
236
237 /** Current compile unit */
238 private CompileUnit unit;
239
240 private final DebugLogger log;
241
242 /** From what size should we use spill instead of fields for JavaScript objects? */
243 static final int OBJECT_SPILL_THRESHOLD = Options.getIntProperty("nashorn.spill.threshold", 256);
244
245 private final Set<String> emittedMethods = new HashSet<>();
246
247 // Function Id -> ContinuationInfo. Used by compilation of rest-of function only.
248 private ContinuationInfo continuationInfo;
249
250 private final Deque<Label> scopeEntryLabels = new ArrayDeque<>();
251
252 private static final Label METHOD_BOUNDARY = new Label("");
253 private final Deque<Label> catchLabels = new ArrayDeque<>();
254 // Number of live locals on entry to (and thus also break from) labeled blocks.
255 private final IntDeque labeledBlockBreakLiveLocals = new IntDeque();
256
257 //is this a rest of compilation
258 private final int[] continuationEntryPoints;
259
260 // Scope object creators needed for for-of and for-in loops
261 private Deque<FieldObjectCreator<?>> scopeObjectCreators = new ArrayDeque<>();
262
263 /**
264 * Constructor.
265 *
266 * @param compiler
267 */
268 CodeGenerator(final Compiler compiler, final int[] continuationEntryPoints) {
269 super(new CodeGeneratorLexicalContext());
270 this.compiler = compiler;
271 this.evalCode = compiler.getSource().isEvalCode();
272 this.continuationEntryPoints = continuationEntryPoints;
273 this.callSiteFlags = compiler.getScriptEnvironment()._callsite_flags;
274 this.log = initLogger(compiler.getContext());
275 }
276
277 @Override
278 public DebugLogger getLogger() {
279 return log;
280 }
281
282 @Override
283 public DebugLogger initLogger(final Context context) {
284 return context.getLogger(this.getClass());
285 }
286
287 /**
288 * Gets the call site flags, adding the strict flag if the current function
289 * being generated is in strict mode
290 *
291 * @return the correct flags for a call site in the current function
292 */
293 int getCallSiteFlags() {
294 return lc.getCurrentFunction().getCallSiteFlags() | callSiteFlags;
295 }
296
297 /**
298 * Gets the flags for a scope call site.
299 * @param symbol a scope symbol
300 * @return the correct flags for the scope call site
301 */
302 private int getScopeCallSiteFlags(final Symbol symbol) {
303 assert symbol.isScope();
304 final int flags = getCallSiteFlags() | CALLSITE_SCOPE;
305 if (isEvalCode() && symbol.isGlobal()) {
306 return flags; // Don't set fast-scope flag on non-declared globals in eval code - see JDK-8077955.
307 }
308 return isFastScope(symbol) ? flags | CALLSITE_FAST_SCOPE : flags;
309 }
310
311 /**
312 * Are we generating code for 'eval' code?
313 * @return true if currently compiled code is 'eval' code.
314 */
315 boolean isEvalCode() {
316 return evalCode;
317 }
318
319 /**
320 * Are we using dual primitive/object field representation?
321 * @return true if using dual field representation, false for object-only fields
322 */
323 boolean useDualFields() {
324 return compiler.getContext().useDualFields();
325 }
326
327 /**
328 * Load an identity node
329 *
330 * @param identNode an identity node to load
331 * @return the method generator used
332 */
333 private MethodEmitter loadIdent(final IdentNode identNode, final TypeBounds resultBounds) {
334 checkTemporalDeadZone(identNode);
335 final Symbol symbol = identNode.getSymbol();
336
337 if (!symbol.isScope()) {
338 final Type type = identNode.getType();
339 if(type == Type.UNDEFINED) {
340 return method.loadUndefined(resultBounds.widest);
341 }
342
343 assert symbol.hasSlot() || symbol.isParam();
344 return method.load(identNode);
345 }
346
347 assert identNode.getSymbol().isScope() : identNode + " is not in scope!";
348 final int flags = getScopeCallSiteFlags(symbol);
349 if (isFastScope(symbol)) {
350 // Only generate shared scope getter for fast-scope symbols so we know we can dial in correct scope.
351 if (symbol.getUseCount() > SharedScopeCall.FAST_SCOPE_GET_THRESHOLD && !identNode.isOptimistic()) {
352 // As shared scope vars are only used with non-optimistic identifiers, we switch from using TypeBounds to
353 // just a single definitive type, resultBounds.widest.
354 new OptimisticOperation(identNode, TypeBounds.OBJECT) {
355 @Override
356 void loadStack() {
357 method.loadCompilerConstant(SCOPE);
358 }
359
360 @Override
361 void consumeStack() {
362 loadSharedScopeVar(resultBounds.widest, symbol, flags);
363 }
364 }.emit();
365 } else {
366 new LoadFastScopeVar(identNode, resultBounds, flags).emit();
367 }
368 } else {
369 //slow scope load, we have no proto depth
370 new LoadScopeVar(identNode, resultBounds, flags).emit();
371 }
372
373 return method;
374 }
375
376 // Any access to LET and CONST variables before their declaration must throw ReferenceError.
377 // This is called the temporal dead zone (TDZ). See https://gist.github.com/rwaldron/f0807a758aa03bcdd58a
378 private void checkTemporalDeadZone(final IdentNode identNode) {
379 if (identNode.isDead()) {
380 method.load(identNode.getSymbol().getName()).invoke(ScriptRuntime.THROW_REFERENCE_ERROR);
381 }
382 }
383
384 // Runtime check for assignment to ES6 const
385 private void checkAssignTarget(final Expression expression) {
386 if (expression instanceof IdentNode && ((IdentNode)expression).getSymbol().isConst()) {
387 method.load(((IdentNode)expression).getSymbol().getName()).invoke(ScriptRuntime.THROW_CONST_TYPE_ERROR);
388 }
389 }
390
391 private boolean isRestOf() {
392 return continuationEntryPoints != null;
393 }
394
395 private boolean isCurrentContinuationEntryPoint(final int programPoint) {
396 return isRestOf() && getCurrentContinuationEntryPoint() == programPoint;
397 }
398
399 private int[] getContinuationEntryPoints() {
400 return isRestOf() ? continuationEntryPoints : null;
401 }
402
403 private int getCurrentContinuationEntryPoint() {
404 return isRestOf() ? continuationEntryPoints[0] : INVALID_PROGRAM_POINT;
405 }
406
407 private boolean isContinuationEntryPoint(final int programPoint) {
408 if (isRestOf()) {
409 assert continuationEntryPoints != null;
410 for (final int cep : continuationEntryPoints) {
411 if (cep == programPoint) {
412 return true;
413 }
414 }
415 }
416 return false;
417 }
418
419 /**
420 * Check if this symbol can be accessed directly with a putfield or getfield or dynamic load
421 *
422 * @param symbol symbol to check for fast scope
423 * @return true if fast scope
424 */
425 private boolean isFastScope(final Symbol symbol) {
426 if (!symbol.isScope()) {
427 return false;
428 }
429
430 if (!lc.inDynamicScope()) {
431 // If there's no with or eval in context, and the symbol is marked as scoped, it is fast scoped. Such a
432 // symbol must either be global, or its defining block must need scope.
433 assert symbol.isGlobal() || lc.getDefiningBlock(symbol).needsScope() : symbol.getName();
434 return true;
435 }
436
437 if (symbol.isGlobal()) {
438 // Shortcut: if there's a with or eval in context, globals can't be fast scoped
439 return false;
440 }
441
442 // Otherwise, check if there's a dynamic scope between use of the symbol and its definition
443 final String name = symbol.getName();
444 boolean previousWasBlock = false;
445 for (final Iterator<LexicalContextNode> it = lc.getAllNodes(); it.hasNext();) {
446 final LexicalContextNode node = it.next();
447 if (node instanceof Block) {
448 // If this block defines the symbol, then we can fast scope the symbol.
449 final Block block = (Block)node;
450 if (block.getExistingSymbol(name) == symbol) {
451 assert block.needsScope();
452 return true;
453 }
454 previousWasBlock = true;
455 } else {
456 if (node instanceof WithNode && previousWasBlock || node instanceof FunctionNode && ((FunctionNode)node).needsDynamicScope()) {
457 // If we hit a scope that can have symbols introduced into it at run time before finding the defining
458 // block, the symbol can't be fast scoped. A WithNode only counts if we've immediately seen a block
459 // before - its block. Otherwise, we are currently processing the WithNode's expression, and that's
460 // obviously not subjected to introducing new symbols.
461 return false;
462 }
463 previousWasBlock = false;
464 }
465 }
466 // Should've found the symbol defined in a block
467 throw new AssertionError();
468 }
469
470 private MethodEmitter loadSharedScopeVar(final Type valueType, final Symbol symbol, final int flags) {
471 assert isFastScope(symbol);
472 method.load(getScopeProtoDepth(lc.getCurrentBlock(), symbol));
473 return lc.getScopeGet(unit, symbol, valueType, flags).generateInvoke(method);
474 }
475
476 private class LoadScopeVar extends OptimisticOperation {
477 final IdentNode identNode;
478 private final int flags;
479
480 LoadScopeVar(final IdentNode identNode, final TypeBounds resultBounds, final int flags) {
481 super(identNode, resultBounds);
482 this.identNode = identNode;
483 this.flags = flags;
484 }
485
486 @Override
487 void loadStack() {
488 method.loadCompilerConstant(SCOPE);
489 getProto();
490 }
491
492 void getProto() {
493 //empty
494 }
495
496 @Override
497 void consumeStack() {
498 // If this is either __FILE__, __DIR__, or __LINE__ then load the property initially as Object as we'd convert
499 // it anyway for replaceLocationPropertyPlaceholder.
500 if(identNode.isCompileTimePropertyName()) {
501 method.dynamicGet(Type.OBJECT, identNode.getSymbol().getName(), flags, identNode.isFunction(), false);
502 replaceCompileTimeProperty();
503 } else {
504 dynamicGet(identNode.getSymbol().getName(), flags, identNode.isFunction(), false);
505 }
506 }
507 }
508
509 private class LoadFastScopeVar extends LoadScopeVar {
510 LoadFastScopeVar(final IdentNode identNode, final TypeBounds resultBounds, final int flags) {
511 super(identNode, resultBounds, flags);
512 }
513
514 @Override
515 void getProto() {
516 loadFastScopeProto(identNode.getSymbol(), false);
517 }
518 }
519
520 private MethodEmitter storeFastScopeVar(final Symbol symbol, final int flags) {
521 loadFastScopeProto(symbol, true);
522 method.dynamicSet(symbol.getName(), flags, false);
523 return method;
524 }
525
526 private int getScopeProtoDepth(final Block startingBlock, final Symbol symbol) {
527 //walk up the chain from starting block and when we bump into the current function boundary, add the external
528 //information.
529 final FunctionNode fn = lc.getCurrentFunction();
530 final int externalDepth = compiler.getScriptFunctionData(fn.getId()).getExternalSymbolDepth(symbol.getName());
531
532 //count the number of scopes from this place to the start of the function
533
534 final int internalDepth = FindScopeDepths.findInternalDepth(lc, fn, startingBlock, symbol);
535 final int scopesToStart = FindScopeDepths.findScopesToStart(lc, fn, startingBlock);
536 int depth = 0;
537 if (internalDepth == -1) {
538 depth = scopesToStart + externalDepth;
539 } else {
540 assert internalDepth <= scopesToStart;
541 depth = internalDepth;
542 }
543
544 return depth;
545 }
546
547 private void loadFastScopeProto(final Symbol symbol, final boolean swap) {
548 final int depth = getScopeProtoDepth(lc.getCurrentBlock(), symbol);
549 assert depth != -1 : "Couldn't find scope depth for symbol " + symbol.getName() + " in " + lc.getCurrentFunction();
550 if (depth > 0) {
551 if (swap) {
552 method.swap();
553 }
554 if (depth > 1) {
555 method.load(depth);
556 method.invoke(ScriptObject.GET_PROTO_DEPTH);
557 } else {
558 method.invoke(ScriptObject.GET_PROTO);
559 }
560 if (swap) {
561 method.swap();
562 }
563 }
564 }
565
566 /**
567 * Generate code that loads this node to the stack, not constraining its type
568 *
569 * @param expr node to load
570 *
571 * @return the method emitter used
572 */
573 private MethodEmitter loadExpressionUnbounded(final Expression expr) {
574 return loadExpression(expr, TypeBounds.UNBOUNDED);
575 }
576
577 private MethodEmitter loadExpressionAsObject(final Expression expr) {
578 return loadExpression(expr, TypeBounds.OBJECT);
579 }
580
581 MethodEmitter loadExpressionAsBoolean(final Expression expr) {
582 return loadExpression(expr, TypeBounds.BOOLEAN);
583 }
584
585 // Test whether conversion from source to target involves a call of ES 9.1 ToPrimitive
586 // with possible side effects from calling an object's toString or valueOf methods.
587 private static boolean noToPrimitiveConversion(final Type source, final Type target) {
588 // Object to boolean conversion does not cause ToPrimitive call
589 return source.isJSPrimitive() || !target.isJSPrimitive() || target.isBoolean();
590 }
591
592 MethodEmitter loadBinaryOperands(final BinaryNode binaryNode) {
593 return loadBinaryOperands(binaryNode.lhs(), binaryNode.rhs(), TypeBounds.UNBOUNDED.notWiderThan(binaryNode.getWidestOperandType()), false, false);
594 }
595
596 private MethodEmitter loadBinaryOperands(final Expression lhs, final Expression rhs, final TypeBounds explicitOperandBounds, final boolean baseAlreadyOnStack, final boolean forceConversionSeparation) {
597 // ECMAScript 5.1 specification (sections 11.5-11.11 and 11.13) prescribes that when evaluating a binary
598 // expression "LEFT op RIGHT", the order of operations must be: LOAD LEFT, LOAD RIGHT, CONVERT LEFT, CONVERT
599 // RIGHT, EXECUTE OP. Unfortunately, doing it in this order defeats potential optimizations that arise when we
600 // can combine a LOAD with a CONVERT operation (e.g. use a dynamic getter with the conversion target type as its
601 // return value). What we do here is reorder LOAD RIGHT and CONVERT LEFT when possible; it is possible only when
602 // we can prove that executing CONVERT LEFT can't have a side effect that changes the value of LOAD RIGHT.
603 // Basically, if we know that either LEFT already is a primitive value, or does not have to be converted to
604 // a primitive value, or RIGHT is an expression that loads without side effects, then we can do the
605 // reordering and collapse LOAD/CONVERT into a single operation; otherwise we need to do the more costly
606 // separate operations to preserve specification semantics.
607
608 // Operands' load type should not be narrower than the narrowest of the individual operand types, nor narrower
609 // than the lower explicit bound, but it should also not be wider than
610 final Type lhsType = undefinedToNumber(lhs.getType());
611 final Type rhsType = undefinedToNumber(rhs.getType());
612 final Type narrowestOperandType = Type.narrowest(Type.widest(lhsType, rhsType), explicitOperandBounds.widest);
613 final TypeBounds operandBounds = explicitOperandBounds.notNarrowerThan(narrowestOperandType);
614 if (noToPrimitiveConversion(lhsType, explicitOperandBounds.widest) || rhs.isLocal()) {
615 // Can reorder. We might still need to separate conversion, but at least we can do it with reordering
616 if (forceConversionSeparation) {
617 // Can reorder, but can't move conversion into the operand as the operation depends on operands
618 // exact types for its overflow guarantees. E.g. with {L}{%I}expr1 {L}* {L}{%I}expr2 we are not allowed
619 // to merge {L}{%I} into {%L}, as that can cause subsequent overflows; test for JDK-8058610 contains
620 // concrete cases where this could happen.
621 final TypeBounds safeConvertBounds = TypeBounds.UNBOUNDED.notNarrowerThan(narrowestOperandType);
622 loadExpression(lhs, safeConvertBounds, baseAlreadyOnStack);
623 method.convert(operandBounds.within(method.peekType()));
624 loadExpression(rhs, safeConvertBounds, false);
625 method.convert(operandBounds.within(method.peekType()));
626 } else {
627 // Can reorder and move conversion into the operand. Combine load and convert into single operations.
628 loadExpression(lhs, operandBounds, baseAlreadyOnStack);
629 loadExpression(rhs, operandBounds, false);
630 }
631 } else {
632 // Can't reorder. Load and convert separately.
633 final TypeBounds safeConvertBounds = TypeBounds.UNBOUNDED.notNarrowerThan(narrowestOperandType);
634 loadExpression(lhs, safeConvertBounds, baseAlreadyOnStack);
635 final Type lhsLoadedType = method.peekType();
636 loadExpression(rhs, safeConvertBounds, false);
637 final Type convertedLhsType = operandBounds.within(method.peekType());
638 if (convertedLhsType != lhsLoadedType) {
639 // Do it conditionally, so that if conversion is a no-op we don't introduce a SWAP, SWAP.
640 method.swap().convert(convertedLhsType).swap();
641 }
642 method.convert(operandBounds.within(method.peekType()));
643 }
644 assert Type.generic(method.peekType()) == operandBounds.narrowest;
645 assert Type.generic(method.peekType(1)) == operandBounds.narrowest;
646
647 return method;
648 }
649
650 /**
651 * Similar to {@link #loadBinaryOperands(BinaryNode)} but used specifically for loading operands of
652 * relational and equality comparison operators where at least one argument is non-object. (When both
653 * arguments are objects, we use {@link ScriptRuntime#EQ(Object, Object)}, {@link ScriptRuntime#LT(Object, Object)}
654 * etc. methods instead. Additionally, {@code ScriptRuntime} methods are used for strict (in)equality comparison
655 * of a boolean to anything that isn't a boolean.) This method handles the special case where one argument
656 * is an object and another is a primitive. Naively, these could also be delegated to {@code ScriptRuntime} methods
657 * by boxing the primitive. However, in all such cases the comparison is performed on numeric values, so it is
658 * possible to strength-reduce the operation by taking the number value of the object argument instead and
659 * comparing that to the primitive value ("primitive" will always be int, long, double, or boolean, and booleans
660 * compare as ints in these cases, so they're essentially numbers too). This method will emit code for loading
661 * arguments for such strength-reduced comparison. When both arguments are primitives, it just delegates to
662 * {@link #loadBinaryOperands(BinaryNode)}.
663 *
664 * @param cmp the comparison operation for which the operands need to be loaded on stack.
665 * @return the current method emitter.
666 */
667 MethodEmitter loadComparisonOperands(final BinaryNode cmp) {
668 final Expression lhs = cmp.lhs();
669 final Expression rhs = cmp.rhs();
670 final Type lhsType = lhs.getType();
671 final Type rhsType = rhs.getType();
672
673 // Only used when not both are object, for that we have ScriptRuntime.LT etc.
674 assert !(lhsType.isObject() && rhsType.isObject());
675
676 if (lhsType.isObject() || rhsType.isObject()) {
677 // We can reorder CONVERT LEFT and LOAD RIGHT only if either the left is a primitive, or the right
678 // is a local. This is more strict than loadBinaryNode reorder criteria, as it can allow JS primitive
679 // types too (notably: String is a JS primitive, but not a JVM primitive). We disallow String otherwise
680 // we would prematurely convert it to number when comparing to an optimistic expression, e.g. in
681 // "Hello" === String("Hello") the RHS starts out as an optimistic-int function call. If we allowed
682 // reordering, we'd end up with ToNumber("Hello") === {I%}String("Hello") that is obviously incorrect.
683 final boolean canReorder = lhsType.isPrimitive() || rhs.isLocal();
684 // If reordering is allowed, and we're using a relational operator (that is, <, <=, >, >=) and not an
685 // (in)equality operator, then we encourage combining of LOAD and CONVERT into a single operation.
686 // This is because relational operators' semantics prescribes vanilla ToNumber() conversion, while
687 // (in)equality operators need the specialized JSType.toNumberFor[Strict]Equals. E.g. in the code snippet
688 // "i < obj.size" (where i is primitive and obj.size is statically an object), ".size" will thus be allowed
689 // to compile as:
690 // invokedynamic GET_PROPERTY:size(Object;)D
691 // instead of the more costly:
692 // invokedynamic GET_PROPERTY:size(Object;)Object
693 // invokestatic JSType.toNumber(Object)D
694 // Note also that even if this is allowed, we're only using it on operands that are non-optimistic, as
695 // otherwise the logic for determining effective optimistic-ness would turn an optimistic double return
696 // into a freely coercible one, which would be wrong.
697 final boolean canCombineLoadAndConvert = canReorder && cmp.isRelational();
698
699 // LOAD LEFT
700 loadExpression(lhs, canCombineLoadAndConvert && !lhs.isOptimistic() ? TypeBounds.NUMBER : TypeBounds.UNBOUNDED);
701
702 final Type lhsLoadedType = method.peekType();
703 final TokenType tt = cmp.tokenType();
704 if (canReorder) {
705 // Can reorder CONVERT LEFT and LOAD RIGHT
706 emitObjectToNumberComparisonConversion(method, tt);
707 loadExpression(rhs, canCombineLoadAndConvert && !rhs.isOptimistic() ? TypeBounds.NUMBER : TypeBounds.UNBOUNDED);
708 } else {
709 // Can't reorder CONVERT LEFT and LOAD RIGHT
710 loadExpression(rhs, TypeBounds.UNBOUNDED);
711 if (lhsLoadedType != Type.NUMBER) {
712 method.swap();
713 emitObjectToNumberComparisonConversion(method, tt);
714 method.swap();
715 }
716 }
717
718 // CONVERT RIGHT
719 emitObjectToNumberComparisonConversion(method, tt);
720 return method;
721 }
722 // For primitive operands, just don't do anything special.
723 return loadBinaryOperands(cmp);
724 }
725
726 private static void emitObjectToNumberComparisonConversion(final MethodEmitter method, final TokenType tt) {
727 switch(tt) {
728 case EQ:
729 case NE:
730 if (method.peekType().isObject()) {
731 TO_NUMBER_FOR_EQ.invoke(method);
732 return;
733 }
734 break;
735 case EQ_STRICT:
736 case NE_STRICT:
737 if (method.peekType().isObject()) {
738 TO_NUMBER_FOR_STRICT_EQ.invoke(method);
739 return;
740 }
741 break;
742 default:
743 break;
744 }
745 method.convert(Type.NUMBER);
746 }
747
748 private static Type undefinedToNumber(final Type type) {
749 return type == Type.UNDEFINED ? Type.NUMBER : type;
750 }
751
752 private static final class TypeBounds {
753 final Type narrowest;
754 final Type widest;
755
756 static final TypeBounds UNBOUNDED = new TypeBounds(Type.UNKNOWN, Type.OBJECT);
757 static final TypeBounds INT = exact(Type.INT);
758 static final TypeBounds NUMBER = exact(Type.NUMBER);
759 static final TypeBounds OBJECT = exact(Type.OBJECT);
760 static final TypeBounds BOOLEAN = exact(Type.BOOLEAN);
761
762 static TypeBounds exact(final Type type) {
763 return new TypeBounds(type, type);
764 }
765
766 TypeBounds(final Type narrowest, final Type widest) {
767 assert widest != null && widest != Type.UNDEFINED && widest != Type.UNKNOWN : widest;
768 assert narrowest != null && narrowest != Type.UNDEFINED : narrowest;
769 assert !narrowest.widerThan(widest) : narrowest + " wider than " + widest;
770 assert !widest.narrowerThan(narrowest);
771 this.narrowest = Type.generic(narrowest);
772 this.widest = Type.generic(widest);
773 }
774
775 TypeBounds notNarrowerThan(final Type type) {
776 return maybeNew(Type.narrowest(Type.widest(narrowest, type), widest), widest);
777 }
778
779 TypeBounds notWiderThan(final Type type) {
780 return maybeNew(Type.narrowest(narrowest, type), Type.narrowest(widest, type));
781 }
782
783 boolean canBeNarrowerThan(final Type type) {
784 return narrowest.narrowerThan(type);
785 }
786
787 TypeBounds maybeNew(final Type newNarrowest, final Type newWidest) {
788 if(newNarrowest == narrowest && newWidest == widest) {
789 return this;
790 }
791 return new TypeBounds(newNarrowest, newWidest);
792 }
793
794 TypeBounds booleanToInt() {
795 return maybeNew(CodeGenerator.booleanToInt(narrowest), CodeGenerator.booleanToInt(widest));
796 }
797
798 TypeBounds objectToNumber() {
799 return maybeNew(CodeGenerator.objectToNumber(narrowest), CodeGenerator.objectToNumber(widest));
800 }
801
802 Type within(final Type type) {
803 if(type.narrowerThan(narrowest)) {
804 return narrowest;
805 }
806 if(type.widerThan(widest)) {
807 return widest;
808 }
809 return type;
810 }
811
812 @Override
813 public String toString() {
814 return "[" + narrowest + ", " + widest + "]";
815 }
816 }
817
818 private static Type booleanToInt(final Type t) {
819 return t == Type.BOOLEAN ? Type.INT : t;
820 }
821
822 private static Type objectToNumber(final Type t) {
823 return t.isObject() ? Type.NUMBER : t;
824 }
825
826 MethodEmitter loadExpressionAsType(final Expression expr, final Type type) {
827 if(type == Type.BOOLEAN) {
828 return loadExpressionAsBoolean(expr);
829 } else if(type == Type.UNDEFINED) {
830 assert expr.getType() == Type.UNDEFINED;
831 return loadExpressionAsObject(expr);
832 }
833 // having no upper bound preserves semantics of optimistic operations in the expression (by not having them
834 // converted early) and then applies explicit conversion afterwards.
835 return loadExpression(expr, TypeBounds.UNBOUNDED.notNarrowerThan(type)).convert(type);
836 }
837
838 private MethodEmitter loadExpression(final Expression expr, final TypeBounds resultBounds) {
839 return loadExpression(expr, resultBounds, false);
840 }
841
842 /**
843 * Emits code for evaluating an expression and leaving its value on top of the stack, narrowing or widening it if
844 * necessary.
845 * @param expr the expression to load
846 * @param resultBounds the incoming type bounds. The value on the top of the stack is guaranteed to not be of narrower
847 * type than the narrowest bound, or wider type than the widest bound after it is loaded.
848 * @param baseAlreadyOnStack true if the base of an access or index node is already on the stack. Used to avoid
849 * double evaluation of bases in self-assignment expressions to access and index nodes. {@code Type.OBJECT} is used
850 * to indicate the widest possible type.
851 * @return the method emitter
852 */
853 private MethodEmitter loadExpression(final Expression expr, final TypeBounds resultBounds, final boolean baseAlreadyOnStack) {
854
855 /*
856 * The load may be of type IdentNode, e.g. "x", AccessNode, e.g. "x.y"
857 * or IndexNode e.g. "x[y]". Both AccessNodes and IndexNodes are
858 * BaseNodes and the logic for loading the base object is reused
859 */
860 final CodeGenerator codegen = this;
861
862 final boolean isCurrentDiscard = codegen.lc.isCurrentDiscard(expr);
863 expr.accept(new NodeOperatorVisitor<LexicalContext>(new LexicalContext()) {
864 @Override
865 public boolean enterIdentNode(final IdentNode identNode) {
866 loadIdent(identNode, resultBounds);
867 return false;
868 }
869
870 @Override
871 public boolean enterAccessNode(final AccessNode accessNode) {
872 new OptimisticOperation(accessNode, resultBounds) {
873 @Override
874 void loadStack() {
875 if (!baseAlreadyOnStack) {
876 loadExpressionAsObject(accessNode.getBase());
877 }
878 assert method.peekType().isObject();
879 }
880 @Override
881 void consumeStack() {
882 final int flags = getCallSiteFlags();
883 dynamicGet(accessNode.getProperty(), flags, accessNode.isFunction(), accessNode.isIndex());
884 }
885 }.emit(baseAlreadyOnStack ? 1 : 0);
886 return false;
887 }
888
889 @Override
890 public boolean enterIndexNode(final IndexNode indexNode) {
891 new OptimisticOperation(indexNode, resultBounds) {
892 @Override
893 void loadStack() {
894 if (!baseAlreadyOnStack) {
895 loadExpressionAsObject(indexNode.getBase());
896 loadExpressionUnbounded(indexNode.getIndex());
897 }
898 }
899 @Override
900 void consumeStack() {
901 final int flags = getCallSiteFlags();
902 dynamicGetIndex(flags, indexNode.isFunction());
903 }
904 }.emit(baseAlreadyOnStack ? 2 : 0);
905 return false;
906 }
907
908 @Override
909 public boolean enterFunctionNode(final FunctionNode functionNode) {
910 // function nodes will always leave a constructed function object on stack, no need to load the symbol
911 // separately as in enterDefault()
912 lc.pop(functionNode);
913 functionNode.accept(codegen);
914 // NOTE: functionNode.accept() will produce a different FunctionNode that we discard. This incidentally
915 // doesn't cause problems as we're never touching FunctionNode again after it's visited here - codegen
916 // is the last element in the compilation pipeline, the AST it produces is not used externally. So, we
917 // re-push the original functionNode.
918 lc.push(functionNode);
919 return false;
920 }
921
922 @Override
923 public boolean enterASSIGN(final BinaryNode binaryNode) {
924 checkAssignTarget(binaryNode.lhs());
925 loadASSIGN(binaryNode);
926 return false;
927 }
928
929 @Override
930 public boolean enterASSIGN_ADD(final BinaryNode binaryNode) {
931 checkAssignTarget(binaryNode.lhs());
932 loadASSIGN_ADD(binaryNode);
933 return false;
934 }
935
936 @Override
937 public boolean enterASSIGN_BIT_AND(final BinaryNode binaryNode) {
938 checkAssignTarget(binaryNode.lhs());
939 loadASSIGN_BIT_AND(binaryNode);
940 return false;
941 }
942
943 @Override
944 public boolean enterASSIGN_BIT_OR(final BinaryNode binaryNode) {
945 checkAssignTarget(binaryNode.lhs());
946 loadASSIGN_BIT_OR(binaryNode);
947 return false;
948 }
949
950 @Override
951 public boolean enterASSIGN_BIT_XOR(final BinaryNode binaryNode) {
952 checkAssignTarget(binaryNode.lhs());
953 loadASSIGN_BIT_XOR(binaryNode);
954 return false;
955 }
956
957 @Override
958 public boolean enterASSIGN_DIV(final BinaryNode binaryNode) {
959 checkAssignTarget(binaryNode.lhs());
960 loadASSIGN_DIV(binaryNode);
961 return false;
962 }
963
964 @Override
965 public boolean enterASSIGN_MOD(final BinaryNode binaryNode) {
966 checkAssignTarget(binaryNode.lhs());
967 loadASSIGN_MOD(binaryNode);
968 return false;
969 }
970
971 @Override
972 public boolean enterASSIGN_MUL(final BinaryNode binaryNode) {
973 checkAssignTarget(binaryNode.lhs());
974 loadASSIGN_MUL(binaryNode);
975 return false;
976 }
977
978 @Override
979 public boolean enterASSIGN_SAR(final BinaryNode binaryNode) {
980 checkAssignTarget(binaryNode.lhs());
981 loadASSIGN_SAR(binaryNode);
982 return false;
983 }
984
985 @Override
986 public boolean enterASSIGN_SHL(final BinaryNode binaryNode) {
987 checkAssignTarget(binaryNode.lhs());
988 loadASSIGN_SHL(binaryNode);
989 return false;
990 }
991
992 @Override
993 public boolean enterASSIGN_SHR(final BinaryNode binaryNode) {
994 checkAssignTarget(binaryNode.lhs());
995 loadASSIGN_SHR(binaryNode);
996 return false;
997 }
998
999 @Override
1000 public boolean enterASSIGN_SUB(final BinaryNode binaryNode) {
1001 checkAssignTarget(binaryNode.lhs());
1002 loadASSIGN_SUB(binaryNode);
1003 return false;
1004 }
1005
1006 @Override
1007 public boolean enterCallNode(final CallNode callNode) {
1008 return loadCallNode(callNode, resultBounds);
1009 }
1010
1011 @Override
1012 public boolean enterLiteralNode(final LiteralNode<?> literalNode) {
1013 loadLiteral(literalNode, resultBounds);
1014 return false;
1015 }
1016
1017 @Override
1018 public boolean enterTernaryNode(final TernaryNode ternaryNode) {
1019 loadTernaryNode(ternaryNode, resultBounds);
1020 return false;
1021 }
1022
1023 @Override
1024 public boolean enterADD(final BinaryNode binaryNode) {
1025 loadADD(binaryNode, resultBounds);
1026 return false;
1027 }
1028
1029 @Override
1030 public boolean enterSUB(final UnaryNode unaryNode) {
1031 loadSUB(unaryNode, resultBounds);
1032 return false;
1033 }
1034
1035 @Override
1036 public boolean enterSUB(final BinaryNode binaryNode) {
1037 loadSUB(binaryNode, resultBounds);
1038 return false;
1039 }
1040
1041 @Override
1042 public boolean enterMUL(final BinaryNode binaryNode) {
1043 loadMUL(binaryNode, resultBounds);
1044 return false;
1045 }
1046
1047 @Override
1048 public boolean enterDIV(final BinaryNode binaryNode) {
1049 loadDIV(binaryNode, resultBounds);
1050 return false;
1051 }
1052
1053 @Override
1054 public boolean enterMOD(final BinaryNode binaryNode) {
1055 loadMOD(binaryNode, resultBounds);
1056 return false;
1057 }
1058
1059 @Override
1060 public boolean enterSAR(final BinaryNode binaryNode) {
1061 loadSAR(binaryNode);
1062 return false;
1063 }
1064
1065 @Override
1066 public boolean enterSHL(final BinaryNode binaryNode) {
1067 loadSHL(binaryNode);
1068 return false;
1069 }
1070
1071 @Override
1072 public boolean enterSHR(final BinaryNode binaryNode) {
1073 loadSHR(binaryNode);
1074 return false;
1075 }
1076
1077 @Override
1078 public boolean enterCOMMALEFT(final BinaryNode binaryNode) {
1079 loadCOMMALEFT(binaryNode, resultBounds);
1080 return false;
1081 }
1082
1083 @Override
1084 public boolean enterCOMMARIGHT(final BinaryNode binaryNode) {
1085 loadCOMMARIGHT(binaryNode, resultBounds);
1086 return false;
1087 }
1088
1089 @Override
1090 public boolean enterAND(final BinaryNode binaryNode) {
1091 loadAND_OR(binaryNode, resultBounds, true);
1092 return false;
1093 }
1094
1095 @Override
1096 public boolean enterOR(final BinaryNode binaryNode) {
1097 loadAND_OR(binaryNode, resultBounds, false);
1098 return false;
1099 }
1100
1101 @Override
1102 public boolean enterNOT(final UnaryNode unaryNode) {
1103 loadNOT(unaryNode);
1104 return false;
1105 }
1106
1107 @Override
1108 public boolean enterADD(final UnaryNode unaryNode) {
1109 loadADD(unaryNode, resultBounds);
1110 return false;
1111 }
1112
1113 @Override
1114 public boolean enterBIT_NOT(final UnaryNode unaryNode) {
1115 loadBIT_NOT(unaryNode);
1116 return false;
1117 }
1118
1119 @Override
1120 public boolean enterBIT_AND(final BinaryNode binaryNode) {
1121 loadBIT_AND(binaryNode);
1122 return false;
1123 }
1124
1125 @Override
1126 public boolean enterBIT_OR(final BinaryNode binaryNode) {
1127 loadBIT_OR(binaryNode);
1128 return false;
1129 }
1130
1131 @Override
1132 public boolean enterBIT_XOR(final BinaryNode binaryNode) {
1133 loadBIT_XOR(binaryNode);
1134 return false;
1135 }
1136
1137 @Override
1138 public boolean enterVOID(final UnaryNode unaryNode) {
1139 loadVOID(unaryNode, resultBounds);
1140 return false;
1141 }
1142
1143 @Override
1144 public boolean enterEQ(final BinaryNode binaryNode) {
1145 loadCmp(binaryNode, Condition.EQ);
1146 return false;
1147 }
1148
1149 @Override
1150 public boolean enterEQ_STRICT(final BinaryNode binaryNode) {
1151 loadCmp(binaryNode, Condition.EQ);
1152 return false;
1153 }
1154
1155 @Override
1156 public boolean enterGE(final BinaryNode binaryNode) {
1157 loadCmp(binaryNode, Condition.GE);
1158 return false;
1159 }
1160
1161 @Override
1162 public boolean enterGT(final BinaryNode binaryNode) {
1163 loadCmp(binaryNode, Condition.GT);
1164 return false;
1165 }
1166
1167 @Override
1168 public boolean enterLE(final BinaryNode binaryNode) {
1169 loadCmp(binaryNode, Condition.LE);
1170 return false;
1171 }
1172
1173 @Override
1174 public boolean enterLT(final BinaryNode binaryNode) {
1175 loadCmp(binaryNode, Condition.LT);
1176 return false;
1177 }
1178
1179 @Override
1180 public boolean enterNE(final BinaryNode binaryNode) {
1181 loadCmp(binaryNode, Condition.NE);
1182 return false;
1183 }
1184
1185 @Override
1186 public boolean enterNE_STRICT(final BinaryNode binaryNode) {
1187 loadCmp(binaryNode, Condition.NE);
1188 return false;
1189 }
1190
1191 @Override
1192 public boolean enterObjectNode(final ObjectNode objectNode) {
1193 loadObjectNode(objectNode);
1194 return false;
1195 }
1196
1197 @Override
1198 public boolean enterRuntimeNode(final RuntimeNode runtimeNode) {
1199 loadRuntimeNode(runtimeNode);
1200 return false;
1201 }
1202
1203 @Override
1204 public boolean enterNEW(final UnaryNode unaryNode) {
1205 loadNEW(unaryNode);
1206 return false;
1207 }
1208
1209 @Override
1210 public boolean enterDECINC(final UnaryNode unaryNode) {
1211 checkAssignTarget(unaryNode.getExpression());
1212 loadDECINC(unaryNode);
1213 return false;
1214 }
1215
1216 @Override
1217 public boolean enterJoinPredecessorExpression(final JoinPredecessorExpression joinExpr) {
1218 loadMaybeDiscard(joinExpr, joinExpr.getExpression(), resultBounds);
1219 return false;
1220 }
1221
1222 @Override
1223 public boolean enterGetSplitState(final GetSplitState getSplitState) {
1224 method.loadScope();
1225 method.invoke(Scope.GET_SPLIT_STATE);
1226 return false;
1227 }
1228
1229 @Override
1230 public boolean enterDefault(final Node otherNode) {
1231 // Must have handled all expressions that can legally be encountered.
1232 throw new AssertionError(otherNode.getClass().getName());
1233 }
1234 });
1235 if(!isCurrentDiscard) {
1236 coerceStackTop(resultBounds);
1237 }
1238 return method;
1239 }
1240
1241 private MethodEmitter coerceStackTop(final TypeBounds typeBounds) {
1242 return method.convert(typeBounds.within(method.peekType()));
1243 }
1244
1245 /**
1246 * Closes any still open entries for this block's local variables in the bytecode local variable table.
1247 *
1248 * @param block block containing symbols.
1249 */
1250 private void closeBlockVariables(final Block block) {
1251 for (final Symbol symbol : block.getSymbols()) {
1252 if (symbol.isBytecodeLocal()) {
1253 method.closeLocalVariable(symbol, block.getBreakLabel());
1254 }
1255 }
1256 }
1257
1258 @Override
1259 public boolean enterBlock(final Block block) {
1260 final Label entryLabel = block.getEntryLabel();
1261 if (entryLabel.isBreakTarget()) {
1262 // Entry label is a break target only for an inlined finally block.
1263 assert !method.isReachable();
1264 method.breakLabel(entryLabel, lc.getUsedSlotCount());
1265 } else {
1266 method.label(entryLabel);
1267 }
1268 if(!method.isReachable()) {
1269 return false;
1270 }
1271 if(lc.isFunctionBody() && emittedMethods.contains(lc.getCurrentFunction().getName())) {
1272 return false;
1273 }
1274 initLocals(block);
1275
1276 assert lc.getUsedSlotCount() == method.getFirstTemp();
1277 return true;
1278 }
1279
1280 boolean useOptimisticTypes() {
1281 return !lc.inSplitNode() && compiler.useOptimisticTypes();
1282 }
1283
1284 // Determine whether a block needs to provide its scope object creator for use by its child nodes.
1285 // This is only necessary for synthetic parent blocks of for-in loops with lexical declarations.
1286 boolean providesScopeCreator(final Block block) {
1287 return block.needsScope() && compiler.getScriptEnvironment()._es6
1288 && block.isSynthetic() && (block.getLastStatement() instanceof ForNode)
1289 && ((ForNode) block.getLastStatement()).needsScopeCreator();
1290 }
1291
1292 @Override
1293 public Node leaveBlock(final Block block) {
1294 popBlockScope(block);
1295 method.beforeJoinPoint(block);
1296
1297 closeBlockVariables(block);
1298 lc.releaseSlots();
1299 assert !method.isReachable() || (lc.isFunctionBody() ? 0 : lc.getUsedSlotCount()) == method.getFirstTemp() :
1300 "reachable="+method.isReachable() +
1301 " isFunctionBody=" + lc.isFunctionBody() +
1302 " usedSlotCount=" + lc.getUsedSlotCount() +
1303 " firstTemp=" + method.getFirstTemp();
1304
1305 return block;
1306 }
1307
1308 private void popBlockScope(final Block block) {
1309 final Label breakLabel = block.getBreakLabel();
1310
1311 if (providesScopeCreator(block)) {
1312 scopeObjectCreators.pop();
1313 }
1314 if(!block.needsScope() || lc.isFunctionBody()) {
1315 emitBlockBreakLabel(breakLabel);
1316 return;
1317 }
1318
1319 final Label beginTryLabel = scopeEntryLabels.pop();
1320 final Label recoveryLabel = new Label("block_popscope_catch");
1321 emitBlockBreakLabel(breakLabel);
1322 final boolean bodyCanThrow = breakLabel.isAfter(beginTryLabel);
1323 if(bodyCanThrow) {
1324 method._try(beginTryLabel, breakLabel, recoveryLabel);
1325 }
1326
1327 Label afterCatchLabel = null;
1328
1329 if(method.isReachable()) {
1330 popScope();
1331 if(bodyCanThrow) {
1332 afterCatchLabel = new Label("block_after_catch");
1333 method._goto(afterCatchLabel);
1334 }
1335 }
1336
1337 if(bodyCanThrow) {
1338 assert !method.isReachable();
1339 method._catch(recoveryLabel);
1340 popScopeException();
1341 method.athrow();
1342 }
1343 if(afterCatchLabel != null) {
1344 method.label(afterCatchLabel);
1345 }
1346 }
1347
1348 private void emitBlockBreakLabel(final Label breakLabel) {
1349 // TODO: this is totally backwards. Block should not be breakable, LabelNode should be breakable.
1350 final LabelNode labelNode = lc.getCurrentBlockLabelNode();
1351 if(labelNode != null) {
1352 // Only have conversions if we're reachable
1353 assert labelNode.getLocalVariableConversion() == null || method.isReachable();
1354 method.beforeJoinPoint(labelNode);
1355 method.breakLabel(breakLabel, labeledBlockBreakLiveLocals.pop());
1356 } else {
1357 method.label(breakLabel);
1358 }
1359 }
1360
1361 private void popScope() {
1362 popScopes(1);
1363 }
1364
1365 /**
1366 * Pop scope as part of an exception handler. Similar to {@code popScope()} but also takes care of adjusting the
1367 * number of scopes that needs to be popped in case a rest-of continuation handler encounters an exception while
1368 * performing a ToPrimitive conversion.
1369 */
1370 private void popScopeException() {
1371 popScope();
1372 final ContinuationInfo ci = getContinuationInfo();
1373 if(ci != null) {
1374 final Label catchLabel = ci.catchLabel;
1375 if(catchLabel != METHOD_BOUNDARY && catchLabel == catchLabels.peek()) {
1376 ++ci.exceptionScopePops;
1377 }
1378 }
1379 }
1380
1381 private void popScopesUntil(final LexicalContextNode until) {
1382 popScopes(lc.getScopeNestingLevelTo(until));
1383 }
1384
1385 private void popScopes(final int count) {
1386 if(count == 0) {
1387 return;
1388 }
1389 assert count > 0; // together with count == 0 check, asserts nonnegative count
1390 if (!method.hasScope()) {
1391 // We can sometimes invoke this method even if the method has no slot for the scope object. Typical example:
1392 // for(;;) { with({}) { break; } }. WithNode normally creates a scope, but if it uses no identifiers and
1393 // nothing else forces creation of a scope in the method, we just won't have the :scope local variable.
1394 return;
1395 }
1396 method.loadCompilerConstant(SCOPE);
1397 if (count > 1) {
1398 method.load(count);
1399 method.invoke(ScriptObject.GET_PROTO_DEPTH);
1400 } else {
1401 method.invoke(ScriptObject.GET_PROTO);
1402 }
1403 method.storeCompilerConstant(SCOPE);
1404 }
1405
1406 @Override
1407 public boolean enterBreakNode(final BreakNode breakNode) {
1408 return enterJumpStatement(breakNode);
1409 }
1410
1411 @Override
1412 public boolean enterJumpToInlinedFinally(final JumpToInlinedFinally jumpToInlinedFinally) {
1413 return enterJumpStatement(jumpToInlinedFinally);
1414 }
1415
1416 private boolean enterJumpStatement(final JumpStatement jump) {
1417 if(!method.isReachable()) {
1418 return false;
1419 }
1420 enterStatement(jump);
1421
1422 method.beforeJoinPoint(jump);
1423 popScopesUntil(jump.getPopScopeLimit(lc));
1424 final Label targetLabel = jump.getTargetLabel(lc);
1425 targetLabel.markAsBreakTarget();
1426 method._goto(targetLabel);
1427
1428 return false;
1429 }
1430
1431 private int loadArgs(final List<Expression> args) {
1432 final int argCount = args.size();
1433 // arg have already been converted to objects here.
1434 if (argCount > LinkerCallSite.ARGLIMIT) {
1435 loadArgsArray(args);
1436 return 1;
1437 }
1438
1439 for (final Expression arg : args) {
1440 assert arg != null;
1441 loadExpressionUnbounded(arg);
1442 }
1443 return argCount;
1444 }
1445
1446 private boolean loadCallNode(final CallNode callNode, final TypeBounds resultBounds) {
1447 lineNumber(callNode.getLineNumber());
1448
1449 final List<Expression> args = callNode.getArgs();
1450 final Expression function = callNode.getFunction();
1451 final Block currentBlock = lc.getCurrentBlock();
1452 final CodeGeneratorLexicalContext codegenLexicalContext = lc;
1453
1454 function.accept(new SimpleNodeVisitor() {
1455 private MethodEmitter sharedScopeCall(final IdentNode identNode, final int flags) {
1456 final Symbol symbol = identNode.getSymbol();
1457 final boolean isFastScope = isFastScope(symbol);
1458 new OptimisticOperation(callNode, resultBounds) {
1459 @Override
1460 void loadStack() {
1461 method.loadCompilerConstant(SCOPE);
1462 if (isFastScope) {
1463 method.load(getScopeProtoDepth(currentBlock, symbol));
1464 } else {
1465 method.load(-1); // Bypass fast-scope code in shared callsite
1466 }
1467 loadArgs(args);
1468 }
1469 @Override
1470 void consumeStack() {
1471 final Type[] paramTypes = method.getTypesFromStack(args.size());
1472 // We have trouble finding e.g. in Type.typeFor(asm.Type) because it can't see the Context class
1473 // loader, so we need to weaken reference signatures to Object.
1474 for(int i = 0; i < paramTypes.length; ++i) {
1475 paramTypes[i] = Type.generic(paramTypes[i]);
1476 }
1477 // As shared scope calls are only used in non-optimistic compilation, we switch from using
1478 // TypeBounds to just a single definitive type, resultBounds.widest.
1479 final SharedScopeCall scopeCall = codegenLexicalContext.getScopeCall(unit, symbol,
1480 identNode.getType(), resultBounds.widest, paramTypes, flags);
1481 scopeCall.generateInvoke(method);
1482 }
1483 }.emit();
1484 return method;
1485 }
1486
1487 private void scopeCall(final IdentNode ident, final int flags) {
1488 new OptimisticOperation(callNode, resultBounds) {
1489 int argsCount;
1490 @Override
1491 void loadStack() {
1492 loadExpressionAsObject(ident); // foo() makes no sense if foo == 3
1493 // ScriptFunction will see CALLSITE_SCOPE and will bind scope accordingly.
1494 method.loadUndefined(Type.OBJECT); //the 'this'
1495 argsCount = loadArgs(args);
1496 }
1497 @Override
1498 void consumeStack() {
1499 dynamicCall(2 + argsCount, flags, ident.getName());
1500 }
1501 }.emit();
1502 }
1503
1504 private void evalCall(final IdentNode ident, final int flags) {
1505 final Label invoke_direct_eval = new Label("invoke_direct_eval");
1506 final Label is_not_eval = new Label("is_not_eval");
1507 final Label eval_done = new Label("eval_done");
1508
1509 new OptimisticOperation(callNode, resultBounds) {
1510 int argsCount;
1511 @Override
1512 void loadStack() {
1513 /*
1514 * We want to load 'eval' to check if it is indeed global builtin eval.
1515 * If this eval call is inside a 'with' statement, GET_METHOD_PROPERTY
1516 * would be generated if ident is a "isFunction". But, that would result in a
1517 * bound function from WithObject. We don't want that as bound function as that
1518 * won't be detected as builtin eval. So, we make ident as "not a function" which
1519 * results in GET_PROPERTY being generated and so WithObject
1520 * would return unbounded eval function.
1521 *
1522 * Example:
1523 *
1524 * var global = this;
1525 * function func() {
1526 * with({ eval: global.eval) { eval("var x = 10;") }
1527 * }
1528 */
1529 loadExpressionAsObject(ident.setIsNotFunction()); // Type.OBJECT as foo() makes no sense if foo == 3
1530 globalIsEval();
1531 method.ifeq(is_not_eval);
1532
1533 // Load up self (scope).
1534 method.loadCompilerConstant(SCOPE);
1535 final List<Expression> evalArgs = callNode.getEvalArgs().getArgs();
1536 // load evaluated code
1537 loadExpressionAsObject(evalArgs.get(0));
1538 // load second and subsequent args for side-effect
1539 final int numArgs = evalArgs.size();
1540 for (int i = 1; i < numArgs; i++) {
1541 loadAndDiscard(evalArgs.get(i));
1542 }
1543 method._goto(invoke_direct_eval);
1544
1545 method.label(is_not_eval);
1546 // load this time but with GET_METHOD_PROPERTY
1547 loadExpressionAsObject(ident); // Type.OBJECT as foo() makes no sense if foo == 3
1548 // This is some scope 'eval' or global eval replaced by user
1549 // but not the built-in ECMAScript 'eval' function call
1550 method.loadNull();
1551 argsCount = loadArgs(callNode.getArgs());
1552 }
1553
1554 @Override
1555 void consumeStack() {
1556 // Ordinary call
1557 dynamicCall(2 + argsCount, flags, "eval");
1558 method._goto(eval_done);
1559
1560 method.label(invoke_direct_eval);
1561 // Special/extra 'eval' arguments. These can be loaded late (in consumeStack) as we know none of
1562 // them can ever be optimistic.
1563 method.loadCompilerConstant(THIS);
1564 method.load(callNode.getEvalArgs().getLocation());
1565 method.load(CodeGenerator.this.lc.getCurrentFunction().isStrict());
1566 // direct call to Global.directEval
1567 globalDirectEval();
1568 convertOptimisticReturnValue();
1569 coerceStackTop(resultBounds);
1570 }
1571 }.emit();
1572
1573 method.label(eval_done);
1574 }
1575
1576 @Override
1577 public boolean enterIdentNode(final IdentNode node) {
1578 final Symbol symbol = node.getSymbol();
1579
1580 if (symbol.isScope()) {
1581 final int flags = getScopeCallSiteFlags(symbol);
1582 final int useCount = symbol.getUseCount();
1583
1584 // Threshold for generating shared scope callsite is lower for fast scope symbols because we know
1585 // we can dial in the correct scope. However, we also need to enable it for non-fast scopes to
1586 // support huge scripts like mandreel.js.
1587 if (callNode.isEval()) {
1588 evalCall(node, flags);
1589 } else if (useCount <= SharedScopeCall.FAST_SCOPE_CALL_THRESHOLD
1590 || !isFastScope(symbol) && useCount <= SharedScopeCall.SLOW_SCOPE_CALL_THRESHOLD
1591 || CodeGenerator.this.lc.inDynamicScope()
1592 || callNode.isOptimistic()) {
1593 scopeCall(node, flags);
1594 } else {
1595 sharedScopeCall(node, flags);
1596 }
1597 assert method.peekType().equals(resultBounds.within(callNode.getType())) : method.peekType() + " != " + resultBounds + "(" + callNode.getType() + ")";
1598 } else {
1599 enterDefault(node);
1600 }
1601
1602 return false;
1603 }
1604
1605 @Override
1606 public boolean enterAccessNode(final AccessNode node) {
1607 //check if this is an apply to call node. only real applies, that haven't been
1608 //shadowed from their way to the global scope counts
1609
1610 //call nodes have program points.
1611
1612 final int flags = getCallSiteFlags() | (callNode.isApplyToCall() ? CALLSITE_APPLY_TO_CALL : 0);
1613
1614 new OptimisticOperation(callNode, resultBounds) {
1615 int argCount;
1616 @Override
1617 void loadStack() {
1618 loadExpressionAsObject(node.getBase());
1619 method.dup();
1620 // NOTE: not using a nested OptimisticOperation on this dynamicGet, as we expect to get back
1621 // a callable object. Nobody in their right mind would optimistically type this call site.
1622 assert !node.isOptimistic();
1623 method.dynamicGet(node.getType(), node.getProperty(), flags, true, node.isIndex());
1624 method.swap();
1625 argCount = loadArgs(args);
1626 }
1627 @Override
1628 void consumeStack() {
1629 dynamicCall(2 + argCount, flags, node.toString(false));
1630 }
1631 }.emit();
1632
1633 return false;
1634 }
1635
1636 @Override
1637 public boolean enterFunctionNode(final FunctionNode origCallee) {
1638 new OptimisticOperation(callNode, resultBounds) {
1639 FunctionNode callee;
1640 int argsCount;
1641 @Override
1642 void loadStack() {
1643 callee = (FunctionNode)origCallee.accept(CodeGenerator.this);
1644 if (callee.isStrict()) { // "this" is undefined
1645 method.loadUndefined(Type.OBJECT);
1646 } else { // get global from scope (which is the self)
1647 globalInstance();
1648 }
1649 argsCount = loadArgs(args);
1650 }
1651
1652 @Override
1653 void consumeStack() {
1654 dynamicCall(2 + argsCount, getCallSiteFlags(), null);
1655 }
1656 }.emit();
1657 return false;
1658 }
1659
1660 @Override
1661 public boolean enterIndexNode(final IndexNode node) {
1662 new OptimisticOperation(callNode, resultBounds) {
1663 int argsCount;
1664 @Override
1665 void loadStack() {
1666 loadExpressionAsObject(node.getBase());
1667 method.dup();
1668 final Type indexType = node.getIndex().getType();
1669 if (indexType.isObject() || indexType.isBoolean()) {
1670 loadExpressionAsObject(node.getIndex()); //TODO boolean
1671 } else {
1672 loadExpressionUnbounded(node.getIndex());
1673 }
1674 // NOTE: not using a nested OptimisticOperation on this dynamicGetIndex, as we expect to get
1675 // back a callable object. Nobody in their right mind would optimistically type this call site.
1676 assert !node.isOptimistic();
1677 method.dynamicGetIndex(node.getType(), getCallSiteFlags(), true);
1678 method.swap();
1679 argsCount = loadArgs(args);
1680 }
1681 @Override
1682 void consumeStack() {
1683 dynamicCall(2 + argsCount, getCallSiteFlags(), node.toString(false));
1684 }
1685 }.emit();
1686 return false;
1687 }
1688
1689 @Override
1690 protected boolean enterDefault(final Node node) {
1691 new OptimisticOperation(callNode, resultBounds) {
1692 int argsCount;
1693 @Override
1694 void loadStack() {
1695 // Load up function.
1696 loadExpressionAsObject(function); //TODO, e.g. booleans can be used as functions
1697 method.loadUndefined(Type.OBJECT); // ScriptFunction will figure out the correct this when it sees CALLSITE_SCOPE
1698 argsCount = loadArgs(args);
1699 }
1700 @Override
1701 void consumeStack() {
1702 final int flags = getCallSiteFlags() | CALLSITE_SCOPE;
1703 dynamicCall(2 + argsCount, flags, node.toString(false));
1704 }
1705 }.emit();
1706 return false;
1707 }
1708 });
1709
1710 return false;
1711 }
1712
1713 /**
1714 * Returns the flags with optimistic flag and program point removed.
1715 * @param flags the flags that need optimism stripped from them.
1716 * @return flags without optimism
1717 */
1718 static int nonOptimisticFlags(final int flags) {
1719 return flags & ~(CALLSITE_OPTIMISTIC | -1 << CALLSITE_PROGRAM_POINT_SHIFT);
1720 }
1721
1722 @Override
1723 public boolean enterContinueNode(final ContinueNode continueNode) {
1724 return enterJumpStatement(continueNode);
1725 }
1726
1727 @Override
1728 public boolean enterEmptyNode(final EmptyNode emptyNode) {
1729 // Don't even record the line number, it's irrelevant as there's no code.
1730 return false;
1731 }
1732
1733 @Override
1734 public boolean enterExpressionStatement(final ExpressionStatement expressionStatement) {
1735 if(!method.isReachable()) {
1736 return false;
1737 }
1738 enterStatement(expressionStatement);
1739
1740 loadAndDiscard(expressionStatement.getExpression());
1741 assert method.getStackSize() == 0 : "stack not empty in " + expressionStatement;
1742
1743 return false;
1744 }
1745
1746 @Override
1747 public boolean enterBlockStatement(final BlockStatement blockStatement) {
1748 if(!method.isReachable()) {
1749 return false;
1750 }
1751 enterStatement(blockStatement);
1752
1753 blockStatement.getBlock().accept(this);
1754
1755 return false;
1756 }
1757
1758 @Override
1759 public boolean enterForNode(final ForNode forNode) {
1760 if(!method.isReachable()) {
1761 return false;
1762 }
1763 enterStatement(forNode);
1764 if (forNode.isForIn() || forNode.isForOf()) {
1765 enterForIn(forNode);
1766 } else {
1767 final Expression init = forNode.getInit();
1768 if (init != null) {
1769 loadAndDiscard(init);
1770 }
1771 enterForOrWhile(forNode, forNode.getModify());
1772 }
1773
1774 return false;
1775 }
1776
1777 private void enterForIn(final ForNode forNode) {
1778 loadExpression(forNode.getModify(), TypeBounds.OBJECT);
1779 if (forNode.isForEach()) {
1780 method.invoke(ScriptRuntime.TO_VALUE_ITERATOR);
1781 } else if (forNode.isForIn()) {
1782 method.invoke(ScriptRuntime.TO_PROPERTY_ITERATOR);
1783 } else if (forNode.isForOf()) {
1784 method.invoke(ScriptRuntime.TO_ES6_ITERATOR);
1785 } else {
1786 throw new IllegalArgumentException("Unexpected for node");
1787 }
1788 final Symbol iterSymbol = forNode.getIterator();
1789 final int iterSlot = iterSymbol.getSlot(Type.OBJECT);
1790 method.store(iterSymbol, ITERATOR_TYPE);
1791
1792 method.beforeJoinPoint(forNode);
1793
1794 final Label continueLabel = forNode.getContinueLabel();
1795 final Label breakLabel = forNode.getBreakLabel();
1796
1797 method.label(continueLabel);
1798 method.load(ITERATOR_TYPE, iterSlot);
1799 method.invoke(interfaceCallNoLookup(ITERATOR_CLASS, "hasNext", boolean.class));
1800 final JoinPredecessorExpression test = forNode.getTest();
1801 final Block body = forNode.getBody();
1802 if(LocalVariableConversion.hasLiveConversion(test)) {
1803 final Label afterConversion = new Label("for_in_after_test_conv");
1804 method.ifne(afterConversion);
1805 method.beforeJoinPoint(test);
1806 method._goto(breakLabel);
1807 method.label(afterConversion);
1808 } else {
1809 method.ifeq(breakLabel);
1810 }
1811
1812 new Store<Expression>(forNode.getInit()) {
1813 @Override
1814 protected void storeNonDiscard() {
1815 // This expression is neither part of a discard, nor needs to be left on the stack after it was
1816 // stored, so we override storeNonDiscard to be a no-op.
1817 }
1818
1819 @Override
1820 protected void evaluate() {
1821 new OptimisticOperation((Optimistic)forNode.getInit(), TypeBounds.UNBOUNDED) {
1822 @Override
1823 void loadStack() {
1824 method.load(ITERATOR_TYPE, iterSlot);
1825 }
1826
1827 @Override
1828 void consumeStack() {
1829 method.invoke(interfaceCallNoLookup(ITERATOR_CLASS, "next", Object.class));
1830 convertOptimisticReturnValue();
1831 }
1832 }.emit();
1833 }
1834 }.store();
1835 body.accept(this);
1836
1837 if (forNode.needsScopeCreator() && providesScopeCreator(lc.getCurrentBlock())) {
1838 // for-in loops with lexical declaration need a new scope for each iteration.
1839 final FieldObjectCreator<?> creator = scopeObjectCreators.peek();
1840 assert creator != null;
1841 creator.createForInIterationScope(method);
1842 method.storeCompilerConstant(SCOPE);
1843 }
1844
1845 if(method.isReachable()) {
1846 method._goto(continueLabel);
1847 }
1848 method.label(breakLabel);
1849 }
1850
1851 /**
1852 * Initialize the slots in a frame to undefined.
1853 *
1854 * @param block block with local vars.
1855 */
1856 private void initLocals(final Block block) {
1857 lc.onEnterBlock(block);
1858
1859 final boolean isFunctionBody = lc.isFunctionBody();
1860 final FunctionNode function = lc.getCurrentFunction();
1861 if (isFunctionBody) {
1862 initializeMethodParameters(function);
1863 if(!function.isVarArg()) {
1864 expandParameterSlots(function);
1865 }
1866 if (method.hasScope()) {
1867 if (function.needsParentScope()) {
1868 method.loadCompilerConstant(CALLEE);
1869 method.invoke(ScriptFunction.GET_SCOPE);
1870 } else {
1871 assert function.hasScopeBlock();
1872 method.loadNull();
1873 }
1874 method.storeCompilerConstant(SCOPE);
1875 }
1876 if (function.needsArguments()) {
1877 initArguments(function);
1878 }
1879 }
1880
1881 /*
1882 * Determine if block needs scope, if not, just do initSymbols for this block.
1883 */
1884 if (block.needsScope()) {
1885 /*
1886 * Determine if function is varargs and consequently variables have to
1887 * be in the scope.
1888 */
1889 final boolean varsInScope = function.allVarsInScope();
1890
1891 // TODO for LET we can do better: if *block* does not contain any eval/with, we don't need its vars in scope.
1892
1893 final boolean hasArguments = function.needsArguments();
1894 final List<MapTuple<Symbol>> tuples = new ArrayList<>();
1895 final Iterator<IdentNode> paramIter = function.getParameters().iterator();
1896 for (final Symbol symbol : block.getSymbols()) {
1897 if (symbol.isInternal() || symbol.isThis()) {
1898 continue;
1899 }
1900
1901 if (symbol.isVar()) {
1902 assert !varsInScope || symbol.isScope();
1903 if (varsInScope || symbol.isScope()) {
1904 assert symbol.isScope() : "scope for " + symbol + " should have been set in Lower already " + function.getName();
1905 assert !symbol.hasSlot() : "slot for " + symbol + " should have been removed in Lower already" + function.getName();
1906
1907 //this tuple will not be put fielded, as it has no value, just a symbol
1908 tuples.add(new MapTuple<Symbol>(symbol.getName(), symbol, null));
1909 } else {
1910 assert symbol.hasSlot() || symbol.slotCount() == 0 : symbol + " should have a slot only, no scope";
1911 }
1912 } else if (symbol.isParam() && (varsInScope || hasArguments || symbol.isScope())) {
1913 assert symbol.isScope() : "scope for " + symbol + " should have been set in AssignSymbols already " + function.getName() + " varsInScope="+varsInScope+" hasArguments="+hasArguments+" symbol.isScope()=" + symbol.isScope();
1914 assert !(hasArguments && symbol.hasSlot()) : "slot for " + symbol + " should have been removed in Lower already " + function.getName();
1915
1916 final Type paramType;
1917 final Symbol paramSymbol;
1918
1919 if (hasArguments) {
1920 assert !symbol.hasSlot() : "slot for " + symbol + " should have been removed in Lower already ";
1921 paramSymbol = null;
1922 paramType = null;
1923 } else {
1924 paramSymbol = symbol;
1925 // NOTE: We're relying on the fact here that Block.symbols is a LinkedHashMap, hence it will
1926 // return symbols in the order they were defined, and parameters are defined in the same order
1927 // they appear in the function. That's why we can have a single pass over the parameter list
1928 // with an iterator, always just scanning forward for the next parameter that matches the symbol
1929 // name.
1930 for(;;) {
1931 final IdentNode nextParam = paramIter.next();
1932 if(nextParam.getName().equals(symbol.getName())) {
1933 paramType = nextParam.getType();
1934 break;
1935 }
1936 }
1937 }
1938
1939 tuples.add(new MapTuple<Symbol>(symbol.getName(), symbol, paramType, paramSymbol) {
1940 //this symbol will be put fielded, we can't initialize it as undefined with a known type
1941 @Override
1942 public Class<?> getValueType() {
1943 if (!useDualFields() || value == null || paramType == null || paramType.isBoolean()) {
1944 return Object.class;
1945 }
1946 return paramType.getTypeClass();
1947 }
1948 });
1949 }
1950 }
1951
1952 /*
1953 * Create a new object based on the symbols and values, generate
1954 * bootstrap code for object
1955 */
1956 final FieldObjectCreator<Symbol> creator = new FieldObjectCreator<Symbol>(this, tuples, true, hasArguments) {
1957 @Override
1958 protected void loadValue(final Symbol value, final Type type) {
1959 method.load(value, type);
1960 }
1961 };
1962 creator.makeObject(method);
1963 if (providesScopeCreator(block)) {
1964 scopeObjectCreators.push(creator);
1965 }
1966 // program function: merge scope into global
1967 if (isFunctionBody && function.isProgram()) {
1968 method.invoke(ScriptRuntime.MERGE_SCOPE);
1969 }
1970
1971 method.storeCompilerConstant(SCOPE);
1972 if(!isFunctionBody) {
1973 // Function body doesn't need a try/catch to restore scope, as it'd be a dead store anyway. Allowing it
1974 // actually causes issues with UnwarrantedOptimismException handlers as ASM will sort this handler to
1975 // the top of the exception handler table, so it'll be triggered instead of the UOE handlers.
1976 final Label scopeEntryLabel = new Label("scope_entry");
1977 scopeEntryLabels.push(scopeEntryLabel);
1978 method.label(scopeEntryLabel);
1979 }
1980 } else if (isFunctionBody && function.isVarArg()) {
1981 // Since we don't have a scope, parameters didn't get assigned array indices by the FieldObjectCreator, so
1982 // we need to assign them separately here.
1983 int nextParam = 0;
1984 for (final IdentNode param : function.getParameters()) {
1985 param.getSymbol().setFieldIndex(nextParam++);
1986 }
1987 }
1988
1989 // Debugging: print symbols? @see --print-symbols flag
1990 printSymbols(block, function, (isFunctionBody ? "Function " : "Block in ") + (function.getIdent() == null ? "<anonymous>" : function.getIdent().getName()));
1991 }
1992
1993 /**
1994 * Incoming method parameters are always declared on method entry; declare them in the local variable table.
1995 * @param function function for which code is being generated.
1996 */
1997 private void initializeMethodParameters(final FunctionNode function) {
1998 final Label functionStart = new Label("fn_start");
1999 method.label(functionStart);
2000 int nextSlot = 0;
2001 if(function.needsCallee()) {
2002 initializeInternalFunctionParameter(CALLEE, function, functionStart, nextSlot++);
2003 }
2004 initializeInternalFunctionParameter(THIS, function, functionStart, nextSlot++);
2005 if(function.isVarArg()) {
2006 initializeInternalFunctionParameter(VARARGS, function, functionStart, nextSlot++);
2007 } else {
2008 for(final IdentNode param: function.getParameters()) {
2009 final Symbol symbol = param.getSymbol();
2010 if(symbol.isBytecodeLocal()) {
2011 method.initializeMethodParameter(symbol, param.getType(), functionStart);
2012 }
2013 }
2014 }
2015 }
2016
2017 private void initializeInternalFunctionParameter(final CompilerConstants cc, final FunctionNode fn, final Label functionStart, final int slot) {
2018 final Symbol symbol = initializeInternalFunctionOrSplitParameter(cc, fn, functionStart, slot);
2019 // Internal function params (:callee, this, and :varargs) are never expanded to multiple slots
2020 assert symbol.getFirstSlot() == slot;
2021 }
2022
2023 private Symbol initializeInternalFunctionOrSplitParameter(final CompilerConstants cc, final FunctionNode fn, final Label functionStart, final int slot) {
2024 final Symbol symbol = fn.getBody().getExistingSymbol(cc.symbolName());
2025 final Type type = Type.typeFor(cc.type());
2026 method.initializeMethodParameter(symbol, type, functionStart);
2027 method.onLocalStore(type, slot);
2028 return symbol;
2029 }
2030
2031 /**
2032 * Parameters come into the method packed into local variable slots next to each other. Nashorn on the other hand
2033 * can use 1-6 slots for a local variable depending on all the types it needs to store. When this method is invoked,
2034 * the symbols are already allocated such wider slots, but the values are still in tightly packed incoming slots,
2035 * and we need to spread them into their new locations.
2036 * @param function the function for which parameter-spreading code needs to be emitted
2037 */
2038 private void expandParameterSlots(final FunctionNode function) {
2039 final List<IdentNode> parameters = function.getParameters();
2040 // Calculate the total number of incoming parameter slots
2041 int currentIncomingSlot = function.needsCallee() ? 2 : 1;
2042 for(final IdentNode parameter: parameters) {
2043 currentIncomingSlot += parameter.getType().getSlots();
2044 }
2045 // Starting from last parameter going backwards, move the parameter values into their new slots.
2046 for(int i = parameters.size(); i-- > 0;) {
2047 final IdentNode parameter = parameters.get(i);
2048 final Type parameterType = parameter.getType();
2049 final int typeWidth = parameterType.getSlots();
2050 currentIncomingSlot -= typeWidth;
2051 final Symbol symbol = parameter.getSymbol();
2052 final int slotCount = symbol.slotCount();
2053 assert slotCount > 0;
2054 // Scoped parameters must not hold more than one value
2055 assert symbol.isBytecodeLocal() || slotCount == typeWidth;
2056
2057 // Mark it as having its value stored into it by the method invocation.
2058 method.onLocalStore(parameterType, currentIncomingSlot);
2059 if(currentIncomingSlot != symbol.getSlot(parameterType)) {
2060 method.load(parameterType, currentIncomingSlot);
2061 method.store(symbol, parameterType);
2062 }
2063 }
2064 }
2065
2066 private void initArguments(final FunctionNode function) {
2067 method.loadCompilerConstant(VARARGS);
2068 if (function.needsCallee()) {
2069 method.loadCompilerConstant(CALLEE);
2070 } else {
2071 // If function is strict mode, "arguments.callee" is not populated, so we don't necessarily need the
2072 // caller.
2073 assert function.isStrict();
2074 method.loadNull();
2075 }
2076 method.load(function.getParameters().size());
2077 globalAllocateArguments();
2078 method.storeCompilerConstant(ARGUMENTS);
2079 }
2080
2081 private boolean skipFunction(final FunctionNode functionNode) {
2082 final ScriptEnvironment env = compiler.getScriptEnvironment();
2083 final boolean lazy = env._lazy_compilation;
2084 final boolean onDemand = compiler.isOnDemandCompilation();
2085
2086 // If this is on-demand or lazy compilation, don't compile a nested (not topmost) function.
2087 if((onDemand || lazy) && lc.getOutermostFunction() != functionNode) {
2088 return true;
2089 }
2090
2091 // If lazy compiling with optimistic types, don't compile the program eagerly either. It will soon be
2092 // invalidated anyway. In presence of a class cache, this further means that an obsoleted program version
2093 // lingers around. Also, currently loading previously persisted optimistic types information only works if
2094 // we're on-demand compiling a function, so with this strategy the :program method can also have the warmup
2095 // benefit of using previously persisted types.
2096 //
2097 // NOTE that this means the first compiled class will effectively just have a :createProgramFunction method, and
2098 // the RecompilableScriptFunctionData (RSFD) object in its constants array. It won't even have the :program
2099 // method. This is by design. It does mean that we're wasting one compiler execution (and we could minimize this
2100 // by just running it up to scope depth calculation, which creates the RSFDs and then this limited codegen).
2101 // We could emit an initial separate compile unit with the initial version of :program in it to better utilize
2102 // the compilation pipeline, but that would need more invasive changes, as currently the assumption that
2103 // :program is emitted into the first compilation unit of the function lives in many places.
2104 return !onDemand && lazy && env._optimistic_types && functionNode.isProgram();
2105 }
2106
2107 @Override
2108 public boolean enterFunctionNode(final FunctionNode functionNode) {
2109 if (skipFunction(functionNode)) {
2110 // In case we are not generating code for the function, we must create or retrieve the function object and
2111 // load it on the stack here.
2112 newFunctionObject(functionNode, false);
2113 return false;
2114 }
2115
2116 final String fnName = functionNode.getName();
2117
2118 // NOTE: we only emit the method for a function with the given name once. We can have multiple functions with
2119 // the same name as a result of inlining finally blocks. However, in the future -- with type specialization,
2120 // notably -- we might need to check for both name *and* signature. Of course, even that might not be
2121 // sufficient; the function might have a code dependency on the type of the variables in its enclosing scopes,
2122 // and the type of such a variable can be different in catch and finally blocks. So, in the future we will have
2123 // to decide to either generate a unique method for each inlined copy of the function, maybe figure out its
2124 // exact type closure and deduplicate based on that, or just decide that functions in finally blocks aren't
2125 // worth it, and generate one method with most generic type closure.
2126 if (!emittedMethods.contains(fnName)) {
2127 log.info("=== BEGIN ", fnName);
2128
2129 assert functionNode.getCompileUnit() != null : "no compile unit for " + fnName + " " + Debug.id(functionNode);
2130 unit = lc.pushCompileUnit(functionNode.getCompileUnit());
2131 assert lc.hasCompileUnits();
2132
2133 final ClassEmitter classEmitter = unit.getClassEmitter();
2134 pushMethodEmitter(isRestOf() ? classEmitter.restOfMethod(functionNode) : classEmitter.method(functionNode));
2135 method.setPreventUndefinedLoad();
2136 if(useOptimisticTypes()) {
2137 lc.pushUnwarrantedOptimismHandlers();
2138 }
2139
2140 // new method - reset last line number
2141 lastLineNumber = -1;
2142
2143 method.begin();
2144
2145 if (isRestOf()) {
2146 assert continuationInfo == null;
2147 continuationInfo = new ContinuationInfo();
2148 method.gotoLoopStart(continuationInfo.getHandlerLabel());
2149 }
2150 }
2151
2152 return true;
2153 }
2154
2155 private void pushMethodEmitter(final MethodEmitter newMethod) {
2156 method = lc.pushMethodEmitter(newMethod);
2157 catchLabels.push(METHOD_BOUNDARY);
2158 }
2159
2160 private void popMethodEmitter() {
2161 method = lc.popMethodEmitter(method);
2162 assert catchLabels.peek() == METHOD_BOUNDARY;
2163 catchLabels.pop();
2164 }
2165
2166 @Override
2167 public Node leaveFunctionNode(final FunctionNode functionNode) {
2168 try {
2169 final boolean markOptimistic;
2170 if (emittedMethods.add(functionNode.getName())) {
2171 markOptimistic = generateUnwarrantedOptimismExceptionHandlers(functionNode);
2172 generateContinuationHandler();
2173 method.end(); // wrap up this method
2174 unit = lc.popCompileUnit(functionNode.getCompileUnit());
2175 popMethodEmitter();
2176 log.info("=== END ", functionNode.getName());
2177 } else {
2178 markOptimistic = false;
2179 }
2180
2181 FunctionNode newFunctionNode = functionNode;
2182 if (markOptimistic) {
2183 newFunctionNode = newFunctionNode.setFlag(lc, FunctionNode.IS_DEOPTIMIZABLE);
2184 }
2185
2186 newFunctionObject(newFunctionNode, true);
2187 return newFunctionNode;
2188 } catch (final Throwable t) {
2189 Context.printStackTrace(t);
2190 final VerifyError e = new VerifyError("Code generation bug in \"" + functionNode.getName() + "\": likely stack misaligned: " + t + " " + functionNode.getSource().getName());
2191 e.initCause(t);
2192 throw e;
2193 }
2194 }
2195
2196 @Override
2197 public boolean enterIfNode(final IfNode ifNode) {
2198 if(!method.isReachable()) {
2199 return false;
2200 }
2201 enterStatement(ifNode);
2202
2203 final Expression test = ifNode.getTest();
2204 final Block pass = ifNode.getPass();
2205 final Block fail = ifNode.getFail();
2206
2207 if (Expression.isAlwaysTrue(test)) {
2208 loadAndDiscard(test);
2209 pass.accept(this);
2210 return false;
2211 } else if (Expression.isAlwaysFalse(test)) {
2212 loadAndDiscard(test);
2213 if (fail != null) {
2214 fail.accept(this);
2215 }
2216 return false;
2217 }
2218
2219 final boolean hasFailConversion = LocalVariableConversion.hasLiveConversion(ifNode);
2220
2221 final Label failLabel = new Label("if_fail");
2222 final Label afterLabel = (fail == null && !hasFailConversion) ? null : new Label("if_done");
2223
2224 emitBranch(test, failLabel, false);
2225
2226 pass.accept(this);
2227 if(method.isReachable() && afterLabel != null) {
2228 method._goto(afterLabel); //don't fallthru to fail block
2229 }
2230 method.label(failLabel);
2231
2232 if (fail != null) {
2233 fail.accept(this);
2234 } else if(hasFailConversion) {
2235 method.beforeJoinPoint(ifNode);
2236 }
2237
2238 if(afterLabel != null && afterLabel.isReachable()) {
2239 method.label(afterLabel);
2240 }
2241
2242 return false;
2243 }
2244
2245 private void emitBranch(final Expression test, final Label label, final boolean jumpWhenTrue) {
2246 new BranchOptimizer(this, method).execute(test, label, jumpWhenTrue);
2247 }
2248
2249 private void enterStatement(final Statement statement) {
2250 lineNumber(statement);
2251 }
2252
2253 private void lineNumber(final Statement statement) {
2254 lineNumber(statement.getLineNumber());
2255 }
2256
2257 private void lineNumber(final int lineNumber) {
2258 if (lineNumber != lastLineNumber && lineNumber != Node.NO_LINE_NUMBER) {
2259 method.lineNumber(lineNumber);
2260 lastLineNumber = lineNumber;
2261 }
2262 }
2263
2264 int getLastLineNumber() {
2265 return lastLineNumber;
2266 }
2267
2268 /**
2269 * Load a list of nodes as an array of a specific type
2270 * The array will contain the visited nodes.
2271 *
2272 * @param arrayLiteralNode the array of contents
2273 * @param arrayType the type of the array, e.g. ARRAY_NUMBER or ARRAY_OBJECT
2274 */
2275 private void loadArray(final ArrayLiteralNode arrayLiteralNode, final ArrayType arrayType) {
2276 assert arrayType == Type.INT_ARRAY || arrayType == Type.NUMBER_ARRAY || arrayType == Type.OBJECT_ARRAY;
2277
2278 final Expression[] nodes = arrayLiteralNode.getValue();
2279 final Object presets = arrayLiteralNode.getPresets();
2280 final int[] postsets = arrayLiteralNode.getPostsets();
2281 final List<Splittable.SplitRange> ranges = arrayLiteralNode.getSplitRanges();
2282
2283 loadConstant(presets);
2284
2285 final Type elementType = arrayType.getElementType();
2286
2287 if (ranges != null) {
2288
2289 loadSplitLiteral(new SplitLiteralCreator() {
2290 @Override
2291 public void populateRange(final MethodEmitter method, final Type type, final int slot, final int start, final int end) {
2292 for (int i = start; i < end; i++) {
2293 method.load(type, slot);
2294 storeElement(nodes, elementType, postsets[i]);
2295 }
2296 method.load(type, slot);
2297 }
2298 }, ranges, arrayType);
2299
2300 return;
2301 }
2302
2303 if(postsets.length > 0) {
2304 final int arraySlot = method.getUsedSlotsWithLiveTemporaries();
2305 method.storeTemp(arrayType, arraySlot);
2306 for (final int postset : postsets) {
2307 method.load(arrayType, arraySlot);
2308 storeElement(nodes, elementType, postset);
2309 }
2310 method.load(arrayType, arraySlot);
2311 }
2312 }
2313
2314 private void storeElement(final Expression[] nodes, final Type elementType, final int index) {
2315 method.load(index);
2316
2317 final Expression element = nodes[index];
2318
2319 if (element == null) {
2320 method.loadEmpty(elementType);
2321 } else {
2322 loadExpressionAsType(element, elementType);
2323 }
2324
2325 method.arraystore();
2326 }
2327
2328 private MethodEmitter loadArgsArray(final List<Expression> args) {
2329 final Object[] array = new Object[args.size()];
2330 loadConstant(array);
2331
2332 for (int i = 0; i < args.size(); i++) {
2333 method.dup();
2334 method.load(i);
2335 loadExpression(args.get(i), TypeBounds.OBJECT); // variable arity methods always take objects
2336 method.arraystore();
2337 }
2338
2339 return method;
2340 }
2341
2342 /**
2343 * Load a constant from the constant array. This is only public to be callable from the objects
2344 * subpackage. Do not call directly.
2345 *
2346 * @param string string to load
2347 */
2348 void loadConstant(final String string) {
2349 final String unitClassName = unit.getUnitClassName();
2350 final ClassEmitter classEmitter = unit.getClassEmitter();
2351 final int index = compiler.getConstantData().add(string);
2352
2353 method.load(index);
2354 method.invokestatic(unitClassName, GET_STRING.symbolName(), methodDescriptor(String.class, int.class));
2355 classEmitter.needGetConstantMethod(String.class);
2356 }
2357
2358 /**
2359 * Load a constant from the constant array. This is only public to be callable from the objects
2360 * subpackage. Do not call directly.
2361 *
2362 * @param object object to load
2363 */
2364 void loadConstant(final Object object) {
2365 loadConstant(object, unit, method);
2366 }
2367
2368 private void loadConstant(final Object object, final CompileUnit compileUnit, final MethodEmitter methodEmitter) {
2369 final String unitClassName = compileUnit.getUnitClassName();
2370 final ClassEmitter classEmitter = compileUnit.getClassEmitter();
2371 final int index = compiler.getConstantData().add(object);
2372 final Class<?> cls = object.getClass();
2373
2374 if (cls == PropertyMap.class) {
2375 methodEmitter.load(index);
2376 methodEmitter.invokestatic(unitClassName, GET_MAP.symbolName(), methodDescriptor(PropertyMap.class, int.class));
2377 classEmitter.needGetConstantMethod(PropertyMap.class);
2378 } else if (cls.isArray()) {
2379 methodEmitter.load(index);
2380 final String methodName = ClassEmitter.getArrayMethodName(cls);
2381 methodEmitter.invokestatic(unitClassName, methodName, methodDescriptor(cls, int.class));
2382 classEmitter.needGetConstantMethod(cls);
2383 } else {
2384 methodEmitter.loadConstants().load(index).arrayload();
2385 if (object instanceof ArrayData) {
2386 methodEmitter.checkcast(ArrayData.class);
2387 methodEmitter.invoke(virtualCallNoLookup(ArrayData.class, "copy", ArrayData.class));
2388 } else if (cls != Object.class) {
2389 methodEmitter.checkcast(cls);
2390 }
2391 }
2392 }
2393
2394 private void loadConstantsAndIndex(final Object object, final MethodEmitter methodEmitter) {
2395 methodEmitter.loadConstants().load(compiler.getConstantData().add(object));
2396 }
2397
2398 // literal values
2399 private void loadLiteral(final LiteralNode<?> node, final TypeBounds resultBounds) {
2400 final Object value = node.getValue();
2401
2402 if (value == null) {
2403 method.loadNull();
2404 } else if (value instanceof Undefined) {
2405 method.loadUndefined(resultBounds.within(Type.OBJECT));
2406 } else if (value instanceof String) {
2407 final String string = (String)value;
2408
2409 if (string.length() > MethodEmitter.LARGE_STRING_THRESHOLD / 3) { // 3 == max bytes per encoded char
2410 loadConstant(string);
2411 } else {
2412 method.load(string);
2413 }
2414 } else if (value instanceof RegexToken) {
2415 loadRegex((RegexToken)value);
2416 } else if (value instanceof Boolean) {
2417 method.load((Boolean)value);
2418 } else if (value instanceof Integer) {
2419 if(!resultBounds.canBeNarrowerThan(Type.OBJECT)) {
2420 method.load((Integer)value);
2421 method.convert(Type.OBJECT);
2422 } else if(!resultBounds.canBeNarrowerThan(Type.NUMBER)) {
2423 method.load(((Integer)value).doubleValue());
2424 } else {
2425 method.load((Integer)value);
2426 }
2427 } else if (value instanceof Double) {
2428 if(!resultBounds.canBeNarrowerThan(Type.OBJECT)) {
2429 method.load((Double)value);
2430 method.convert(Type.OBJECT);
2431 } else {
2432 method.load((Double)value);
2433 }
2434 } else if (node instanceof ArrayLiteralNode) {
2435 final ArrayLiteralNode arrayLiteral = (ArrayLiteralNode)node;
2436 final ArrayType atype = arrayLiteral.getArrayType();
2437 loadArray(arrayLiteral, atype);
2438 globalAllocateArray(atype);
2439 } else {
2440 throw new UnsupportedOperationException("Unknown literal for " + node.getClass() + " " + value.getClass() + " " + value);
2441 }
2442 }
2443
2444 private MethodEmitter loadRegexToken(final RegexToken value) {
2445 method.load(value.getExpression());
2446 method.load(value.getOptions());
2447 return globalNewRegExp();
2448 }
2449
2450 private MethodEmitter loadRegex(final RegexToken regexToken) {
2451 if (regexFieldCount > MAX_REGEX_FIELDS) {
2452 return loadRegexToken(regexToken);
2453 }
2454 // emit field
2455 final String regexName = lc.getCurrentFunction().uniqueName(REGEX_PREFIX.symbolName());
2456 final ClassEmitter classEmitter = unit.getClassEmitter();
2457
2458 classEmitter.field(EnumSet.of(PRIVATE, STATIC), regexName, Object.class);
2459 regexFieldCount++;
2460
2461 // get field, if null create new regex, finally clone regex object
2462 method.getStatic(unit.getUnitClassName(), regexName, typeDescriptor(Object.class));
2463 method.dup();
2464 final Label cachedLabel = new Label("cached");
2465 method.ifnonnull(cachedLabel);
2466
2467 method.pop();
2468 loadRegexToken(regexToken);
2469 method.dup();
2470 method.putStatic(unit.getUnitClassName(), regexName, typeDescriptor(Object.class));
2471
2472 method.label(cachedLabel);
2473 globalRegExpCopy();
2474
2475 return method;
2476 }
2477
2478 /**
2479 * Check if a property value contains a particular program point
2480 * @param value value
2481 * @param pp program point
2482 * @return true if it's there.
2483 */
2484 private static boolean propertyValueContains(final Expression value, final int pp) {
2485 return new Supplier<Boolean>() {
2486 boolean contains;
2487
2488 @Override
2489 public Boolean get() {
2490 value.accept(new SimpleNodeVisitor() {
2491 @Override
2492 public boolean enterFunctionNode(final FunctionNode functionNode) {
2493 return false;
2494 }
2495
2496 @Override
2497 public boolean enterObjectNode(final ObjectNode objectNode) {
2498 return false;
2499 }
2500
2501 @Override
2502 public boolean enterDefault(final Node node) {
2503 if (contains) {
2504 return false;
2505 }
2506 if (node instanceof Optimistic && ((Optimistic)node).getProgramPoint() == pp) {
2507 contains = true;
2508 return false;
2509 }
2510 return true;
2511 }
2512 });
2513
2514 return contains;
2515 }
2516 }.get();
2517 }
2518
2519 private void loadObjectNode(final ObjectNode objectNode) {
2520 final List<PropertyNode> elements = objectNode.getElements();
2521
2522 final List<MapTuple<Expression>> tuples = new ArrayList<>();
2523 final List<PropertyNode> gettersSetters = new ArrayList<>();
2524 final int ccp = getCurrentContinuationEntryPoint();
2525 final List<Splittable.SplitRange> ranges = objectNode.getSplitRanges();
2526
2527 Expression protoNode = null;
2528 boolean restOfProperty = false;
2529
2530 for (final PropertyNode propertyNode : elements) {
2531 final Expression value = propertyNode.getValue();
2532 final String key = propertyNode.getKeyName();
2533 // Just use a pseudo-symbol. We just need something non null; use the name and zero flags.
2534 final Symbol symbol = value == null ? null : new Symbol(key, 0);
2535
2536 if (value == null) {
2537 gettersSetters.add(propertyNode);
2538 } else if (propertyNode.getKey() instanceof IdentNode &&
2539 key.equals(ScriptObject.PROTO_PROPERTY_NAME)) {
2540 // ES6 draft compliant __proto__ inside object literal
2541 // Identifier key and name is __proto__
2542 protoNode = value;
2543 continue;
2544 }
2545
2546 restOfProperty |=
2547 value != null &&
2548 isValid(ccp) &&
2549 propertyValueContains(value, ccp);
2550
2551 //for literals, a value of null means object type, i.e. the value null or getter setter function
2552 //(I think)
2553 final Class<?> valueType = (!useDualFields() || value == null || value.getType().isBoolean()) ? Object.class : value.getType().getTypeClass();
2554 tuples.add(new MapTuple<Expression>(key, symbol, Type.typeFor(valueType), value) {
2555 @Override
2556 public Class<?> getValueType() {
2557 return type.getTypeClass();
2558 }
2559 });
2560 }
2561
2562 final ObjectCreator<?> oc;
2563 if (elements.size() > OBJECT_SPILL_THRESHOLD) {
2564 oc = new SpillObjectCreator(this, tuples);
2565 } else {
2566 oc = new FieldObjectCreator<Expression>(this, tuples) {
2567 @Override
2568 protected void loadValue(final Expression node, final Type type) {
2569 loadExpressionAsType(node, type);
2570 }};
2571 }
2572
2573 if (ranges != null) {
2574 oc.createObject(method);
2575 loadSplitLiteral(oc, ranges, Type.typeFor(oc.getAllocatorClass()));
2576 } else {
2577 oc.makeObject(method);
2578 }
2579
2580 //if this is a rest of method and our continuation point was found as one of the values
2581 //in the properties above, we need to reset the map to oc.getMap() in the continuation
2582 //handler
2583 if (restOfProperty) {
2584 final ContinuationInfo ci = getContinuationInfo();
2585 // Can be set at most once for a single rest-of method
2586 assert ci.getObjectLiteralMap() == null;
2587 ci.setObjectLiteralMap(oc.getMap());
2588 ci.setObjectLiteralStackDepth(method.getStackSize());
2589 }
2590
2591 method.dup();
2592 if (protoNode != null) {
2593 loadExpressionAsObject(protoNode);
2594 // take care of { __proto__: 34 } or some such!
2595 method.convert(Type.OBJECT);
2596 method.invoke(ScriptObject.SET_PROTO_FROM_LITERAL);
2597 } else {
2598 method.invoke(ScriptObject.SET_GLOBAL_OBJECT_PROTO);
2599 }
2600
2601 for (final PropertyNode propertyNode : gettersSetters) {
2602 final FunctionNode getter = propertyNode.getGetter();
2603 final FunctionNode setter = propertyNode.getSetter();
2604
2605 assert getter != null || setter != null;
2606
2607 method.dup().loadKey(propertyNode.getKey());
2608 if (getter == null) {
2609 method.loadNull();
2610 } else {
2611 getter.accept(this);
2612 }
2613
2614 if (setter == null) {
2615 method.loadNull();
2616 } else {
2617 setter.accept(this);
2618 }
2619
2620 method.invoke(ScriptObject.SET_USER_ACCESSORS);
2621 }
2622 }
2623
2624 @Override
2625 public boolean enterReturnNode(final ReturnNode returnNode) {
2626 if(!method.isReachable()) {
2627 return false;
2628 }
2629 enterStatement(returnNode);
2630
2631 final Type returnType = lc.getCurrentFunction().getReturnType();
2632
2633 final Expression expression = returnNode.getExpression();
2634 if (expression != null) {
2635 loadExpressionUnbounded(expression);
2636 } else {
2637 method.loadUndefined(returnType);
2638 }
2639
2640 method._return(returnType);
2641
2642 return false;
2643 }
2644
2645 private boolean undefinedCheck(final RuntimeNode runtimeNode, final List<Expression> args) {
2646 final Request request = runtimeNode.getRequest();
2647
2648 if (!Request.isUndefinedCheck(request)) {
2649 return false;
2650 }
2651
2652 final Expression lhs = args.get(0);
2653 final Expression rhs = args.get(1);
2654
2655 final Symbol lhsSymbol = lhs instanceof IdentNode ? ((IdentNode)lhs).getSymbol() : null;
2656 final Symbol rhsSymbol = rhs instanceof IdentNode ? ((IdentNode)rhs).getSymbol() : null;
2657 // One must be a "undefined" identifier, otherwise we can't get here
2658 assert lhsSymbol != null || rhsSymbol != null;
2659
2660 final Symbol undefinedSymbol;
2661 if (isUndefinedSymbol(lhsSymbol)) {
2662 undefinedSymbol = lhsSymbol;
2663 } else {
2664 assert isUndefinedSymbol(rhsSymbol);
2665 undefinedSymbol = rhsSymbol;
2666 }
2667
2668 assert undefinedSymbol != null; //remove warning
2669 if (!undefinedSymbol.isScope()) {
2670 return false; //disallow undefined as local var or parameter
2671 }
2672
2673 if (lhsSymbol == undefinedSymbol && lhs.getType().isPrimitive()) {
2674 //we load the undefined first. never mind, because this will deoptimize anyway
2675 return false;
2676 }
2677
2678 if(isDeoptimizedExpression(lhs)) {
2679 // This is actually related to "lhs.getType().isPrimitive()" above: any expression being deoptimized in
2680 // the current chain of rest-of compilations used to have a type narrower than Object (so it was primitive).
2681 // We must not perform undefined check specialization for them, as then we'd violate the basic rule of
2682 // "Thou shalt not alter the stack shape between a deoptimized method and any of its (transitive) rest-ofs."
2683 return false;
2684 }
2685
2686 //make sure that undefined has not been overridden or scoped as a local var
2687 //between us and global
2688 if (!compiler.isGlobalSymbol(lc.getCurrentFunction(), "undefined")) {
2689 return false;
2690 }
2691
2692 final boolean isUndefinedCheck = request == Request.IS_UNDEFINED;
2693 final Expression expr = undefinedSymbol == lhsSymbol ? rhs : lhs;
2694 if (expr.getType().isPrimitive()) {
2695 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
2696 method.load(!isUndefinedCheck);
2697 } else {
2698 final Label checkTrue = new Label("ud_check_true");
2699 final Label end = new Label("end");
2700 loadExpressionAsObject(expr);
2701 method.loadUndefined(Type.OBJECT);
2702 method.if_acmpeq(checkTrue);
2703 method.load(!isUndefinedCheck);
2704 method._goto(end);
2705 method.label(checkTrue);
2706 method.load(isUndefinedCheck);
2707 method.label(end);
2708 }
2709
2710 return true;
2711 }
2712
2713 private static boolean isUndefinedSymbol(final Symbol symbol) {
2714 return symbol != null && "undefined".equals(symbol.getName());
2715 }
2716
2717 private static boolean isNullLiteral(final Node node) {
2718 return node instanceof LiteralNode<?> && ((LiteralNode<?>) node).isNull();
2719 }
2720
2721 private boolean nullCheck(final RuntimeNode runtimeNode, final List<Expression> args) {
2722 final Request request = runtimeNode.getRequest();
2723
2724 if (!Request.isEQ(request) && !Request.isNE(request)) {
2725 return false;
2726 }
2727
2728 assert args.size() == 2 : "EQ or NE or TYPEOF need two args";
2729
2730 Expression lhs = args.get(0);
2731 Expression rhs = args.get(1);
2732
2733 if (isNullLiteral(lhs)) {
2734 final Expression tmp = lhs;
2735 lhs = rhs;
2736 rhs = tmp;
2737 }
2738
2739 if (!isNullLiteral(rhs)) {
2740 return false;
2741 }
2742
2743 if (!lhs.getType().isObject()) {
2744 return false;
2745 }
2746
2747 if(isDeoptimizedExpression(lhs)) {
2748 // This is actually related to "!lhs.getType().isObject()" above: any expression being deoptimized in
2749 // the current chain of rest-of compilations used to have a type narrower than Object. We must not
2750 // perform null check specialization for them, as then we'd no longer be loading aconst_null on stack
2751 // and thus violate the basic rule of "Thou shalt not alter the stack shape between a deoptimized
2752 // method and any of its (transitive) rest-ofs."
2753 // NOTE also that if we had a representation for well-known constants (e.g. null, 0, 1, -1, etc.) in
2754 // Label$Stack.localLoads then this wouldn't be an issue, as we would never (somewhat ridiculously)
2755 // allocate a temporary local to hold the result of aconst_null before attempting an optimistic
2756 // operation.
2757 return false;
2758 }
2759
2760 // this is a null literal check, so if there is implicit coercion
2761 // involved like {D}x=null, we will fail - this is very rare
2762 final Label trueLabel = new Label("trueLabel");
2763 final Label falseLabel = new Label("falseLabel");
2764 final Label endLabel = new Label("end");
2765
2766 loadExpressionUnbounded(lhs); //lhs
2767 final Label popLabel;
2768 if (!Request.isStrict(request)) {
2769 method.dup(); //lhs lhs
2770 popLabel = new Label("pop");
2771 } else {
2772 popLabel = null;
2773 }
2774
2775 if (Request.isEQ(request)) {
2776 method.ifnull(!Request.isStrict(request) ? popLabel : trueLabel);
2777 if (!Request.isStrict(request)) {
2778 method.loadUndefined(Type.OBJECT);
2779 method.if_acmpeq(trueLabel);
2780 }
2781 method.label(falseLabel);
2782 method.load(false);
2783 method._goto(endLabel);
2784 if (!Request.isStrict(request)) {
2785 method.label(popLabel);
2786 method.pop();
2787 }
2788 method.label(trueLabel);
2789 method.load(true);
2790 method.label(endLabel);
2791 } else if (Request.isNE(request)) {
2792 method.ifnull(!Request.isStrict(request) ? popLabel : falseLabel);
2793 if (!Request.isStrict(request)) {
2794 method.loadUndefined(Type.OBJECT);
2795 method.if_acmpeq(falseLabel);
2796 }
2797 method.label(trueLabel);
2798 method.load(true);
2799 method._goto(endLabel);
2800 if (!Request.isStrict(request)) {
2801 method.label(popLabel);
2802 method.pop();
2803 }
2804 method.label(falseLabel);
2805 method.load(false);
2806 method.label(endLabel);
2807 }
2808
2809 assert runtimeNode.getType().isBoolean();
2810 method.convert(runtimeNode.getType());
2811
2812 return true;
2813 }
2814
2815 /**
2816 * Was this expression or any of its subexpressions deoptimized in the current recompilation chain of rest-of methods?
2817 * @param rootExpr the expression being tested
2818 * @return true if the expression or any of its subexpressions was deoptimized in the current recompilation chain.
2819 */
2820 private boolean isDeoptimizedExpression(final Expression rootExpr) {
2821 if(!isRestOf()) {
2822 return false;
2823 }
2824 return new Supplier<Boolean>() {
2825 boolean contains;
2826 @Override
2827 public Boolean get() {
2828 rootExpr.accept(new SimpleNodeVisitor() {
2829 @Override
2830 public boolean enterFunctionNode(final FunctionNode functionNode) {
2831 return false;
2832 }
2833 @Override
2834 public boolean enterDefault(final Node node) {
2835 if(!contains && node instanceof Optimistic) {
2836 final int pp = ((Optimistic)node).getProgramPoint();
2837 contains = isValid(pp) && isContinuationEntryPoint(pp);
2838 }
2839 return !contains;
2840 }
2841 });
2842 return contains;
2843 }
2844 }.get();
2845 }
2846
2847 private void loadRuntimeNode(final RuntimeNode runtimeNode) {
2848 final List<Expression> args = new ArrayList<>(runtimeNode.getArgs());
2849 if (nullCheck(runtimeNode, args)) {
2850 return;
2851 } else if(undefinedCheck(runtimeNode, args)) {
2852 return;
2853 }
2854 // Revert a false undefined check to a strict equality check
2855 final RuntimeNode newRuntimeNode;
2856 final Request request = runtimeNode.getRequest();
2857 if (Request.isUndefinedCheck(request)) {
2858 newRuntimeNode = runtimeNode.setRequest(request == Request.IS_UNDEFINED ? Request.EQ_STRICT : Request.NE_STRICT);
2859 } else {
2860 newRuntimeNode = runtimeNode;
2861 }
2862
2863 for (final Expression arg : args) {
2864 loadExpression(arg, TypeBounds.OBJECT);
2865 }
2866
2867 method.invokestatic(
2868 CompilerConstants.className(ScriptRuntime.class),
2869 newRuntimeNode.getRequest().toString(),
2870 new FunctionSignature(
2871 false,
2872 false,
2873 newRuntimeNode.getType(),
2874 args.size()).toString());
2875
2876 method.convert(newRuntimeNode.getType());
2877 }
2878
2879 private void defineCommonSplitMethodParameters() {
2880 defineSplitMethodParameter(0, CALLEE);
2881 defineSplitMethodParameter(1, THIS);
2882 defineSplitMethodParameter(2, SCOPE);
2883 }
2884
2885 private void defineSplitMethodParameter(final int slot, final CompilerConstants cc) {
2886 defineSplitMethodParameter(slot, Type.typeFor(cc.type()));
2887 }
2888
2889 private void defineSplitMethodParameter(final int slot, final Type type) {
2890 method.defineBlockLocalVariable(slot, slot + type.getSlots());
2891 method.onLocalStore(type, slot);
2892 }
2893
2894 private void loadSplitLiteral(final SplitLiteralCreator creator, final List<Splittable.SplitRange> ranges, final Type literalType) {
2895 assert ranges != null;
2896
2897 // final Type literalType = Type.typeFor(literalClass);
2898 final MethodEmitter savedMethod = method;
2899 final FunctionNode currentFunction = lc.getCurrentFunction();
2900
2901 for (final Splittable.SplitRange splitRange : ranges) {
2902 unit = lc.pushCompileUnit(splitRange.getCompileUnit());
2903
2904 assert unit != null;
2905 final String className = unit.getUnitClassName();
2906 final String name = currentFunction.uniqueName(SPLIT_PREFIX.symbolName());
2907 final Class<?> clazz = literalType.getTypeClass();
2908 final String signature = methodDescriptor(clazz, ScriptFunction.class, Object.class, ScriptObject.class, clazz);
2909
2910 pushMethodEmitter(unit.getClassEmitter().method(EnumSet.of(Flag.PUBLIC, Flag.STATIC), name, signature));
2911
2912 method.setFunctionNode(currentFunction);
2913 method.begin();
2914
2915 defineCommonSplitMethodParameters();
2916 defineSplitMethodParameter(CompilerConstants.SPLIT_ARRAY_ARG.slot(), literalType);
2917
2918 // NOTE: when this is no longer needed, SplitIntoFunctions will no longer have to add IS_SPLIT
2919 // to synthetic functions, and FunctionNode.needsCallee() will no longer need to test for isSplit().
2920 final int literalSlot = fixScopeSlot(currentFunction, 3);
2921
2922 lc.enterSplitNode();
2923
2924 creator.populateRange(method, literalType, literalSlot, splitRange.getLow(), splitRange.getHigh());
2925
2926 method._return();
2927 lc.exitSplitNode();
2928 method.end();
2929 lc.releaseSlots();
2930 popMethodEmitter();
2931
2932 assert method == savedMethod;
2933 method.loadCompilerConstant(CALLEE).swap();
2934 method.loadCompilerConstant(THIS).swap();
2935 method.loadCompilerConstant(SCOPE).swap();
2936 method.invokestatic(className, name, signature);
2937
2938 unit = lc.popCompileUnit(unit);
2939 }
2940 }
2941
2942 private int fixScopeSlot(final FunctionNode functionNode, final int extraSlot) {
2943 // TODO hack to move the scope to the expected slot (needed because split methods reuse the same slots as the root method)
2944 final int actualScopeSlot = functionNode.compilerConstant(SCOPE).getSlot(SCOPE_TYPE);
2945 final int defaultScopeSlot = SCOPE.slot();
2946 int newExtraSlot = extraSlot;
2947 if (actualScopeSlot != defaultScopeSlot) {
2948 if (actualScopeSlot == extraSlot) {
2949 newExtraSlot = extraSlot + 1;
2950 method.defineBlockLocalVariable(newExtraSlot, newExtraSlot + 1);
2951 method.load(Type.OBJECT, extraSlot);
2952 method.storeHidden(Type.OBJECT, newExtraSlot);
2953 } else {
2954 method.defineBlockLocalVariable(actualScopeSlot, actualScopeSlot + 1);
2955 }
2956 method.load(SCOPE_TYPE, defaultScopeSlot);
2957 method.storeCompilerConstant(SCOPE);
2958 }
2959 return newExtraSlot;
2960 }
2961
2962 @Override
2963 public boolean enterSplitReturn(final SplitReturn splitReturn) {
2964 if (method.isReachable()) {
2965 method.loadUndefined(lc.getCurrentFunction().getReturnType())._return();
2966 }
2967 return false;
2968 }
2969
2970 @Override
2971 public boolean enterSetSplitState(final SetSplitState setSplitState) {
2972 if (method.isReachable()) {
2973 method.setSplitState(setSplitState.getState());
2974 }
2975 return false;
2976 }
2977
2978 @Override
2979 public boolean enterSwitchNode(final SwitchNode switchNode) {
2980 if(!method.isReachable()) {
2981 return false;
2982 }
2983 enterStatement(switchNode);
2984
2985 final Expression expression = switchNode.getExpression();
2986 final List<CaseNode> cases = switchNode.getCases();
2987
2988 if (cases.isEmpty()) {
2989 // still evaluate expression for side-effects.
2990 loadAndDiscard(expression);
2991 return false;
2992 }
2993
2994 final CaseNode defaultCase = switchNode.getDefaultCase();
2995 final Label breakLabel = switchNode.getBreakLabel();
2996 final int liveLocalsOnBreak = method.getUsedSlotsWithLiveTemporaries();
2997
2998 if (defaultCase != null && cases.size() == 1) {
2999 // default case only
3000 assert cases.get(0) == defaultCase;
3001 loadAndDiscard(expression);
3002 defaultCase.getBody().accept(this);
3003 method.breakLabel(breakLabel, liveLocalsOnBreak);
3004 return false;
3005 }
3006
3007 // NOTE: it can still change in the tableswitch/lookupswitch case if there's no default case
3008 // but we need to add a synthetic default case for local variable conversions
3009 Label defaultLabel = defaultCase != null ? defaultCase.getEntry() : breakLabel;
3010 final boolean hasSkipConversion = LocalVariableConversion.hasLiveConversion(switchNode);
3011
3012 if (switchNode.isUniqueInteger()) {
3013 // Tree for sorting values.
3014 final TreeMap<Integer, Label> tree = new TreeMap<>();
3015
3016 // Build up sorted tree.
3017 for (final CaseNode caseNode : cases) {
3018 final Node test = caseNode.getTest();
3019
3020 if (test != null) {
3021 final Integer value = (Integer)((LiteralNode<?>)test).getValue();
3022 final Label entry = caseNode.getEntry();
3023
3024 // Take first duplicate.
3025 if (!tree.containsKey(value)) {
3026 tree.put(value, entry);
3027 }
3028 }
3029 }
3030
3031 // Copy values and labels to arrays.
3032 final int size = tree.size();
3033 final Integer[] values = tree.keySet().toArray(new Integer[0]);
3034 final Label[] labels = tree.values().toArray(new Label[0]);
3035
3036 // Discern low, high and range.
3037 final int lo = values[0];
3038 final int hi = values[size - 1];
3039 final long range = (long)hi - (long)lo + 1;
3040
3041 // Find an unused value for default.
3042 int deflt = Integer.MIN_VALUE;
3043 for (final int value : values) {
3044 if (deflt == value) {
3045 deflt++;
3046 } else if (deflt < value) {
3047 break;
3048 }
3049 }
3050
3051 // Load switch expression.
3052 loadExpressionUnbounded(expression);
3053 final Type type = expression.getType();
3054
3055 // If expression not int see if we can convert, if not use deflt to trigger default.
3056 if (!type.isInteger()) {
3057 method.load(deflt);
3058 final Class<?> exprClass = type.getTypeClass();
3059 method.invoke(staticCallNoLookup(ScriptRuntime.class, "switchTagAsInt", int.class, exprClass.isPrimitive()? exprClass : Object.class, int.class));
3060 }
3061
3062 if(hasSkipConversion) {
3063 assert defaultLabel == breakLabel;
3064 defaultLabel = new Label("switch_skip");
3065 }
3066 // TABLESWITCH needs (range + 3) 32-bit values; LOOKUPSWITCH needs ((size * 2) + 2). Choose the one with
3067 // smaller representation, favor TABLESWITCH when they're equal size.
3068 if (range + 1 <= (size * 2) && range <= Integer.MAX_VALUE) {
3069 final Label[] table = new Label[(int)range];
3070 Arrays.fill(table, defaultLabel);
3071 for (int i = 0; i < size; i++) {
3072 final int value = values[i];
3073 table[value - lo] = labels[i];
3074 }
3075
3076 method.tableswitch(lo, hi, defaultLabel, table);
3077 } else {
3078 final int[] ints = new int[size];
3079 for (int i = 0; i < size; i++) {
3080 ints[i] = values[i];
3081 }
3082
3083 method.lookupswitch(defaultLabel, ints, labels);
3084 }
3085 // This is a synthetic "default case" used in absence of actual default case, created if we need to apply
3086 // local variable conversions if neither case is taken.
3087 if(hasSkipConversion) {
3088 method.label(defaultLabel);
3089 method.beforeJoinPoint(switchNode);
3090 method._goto(breakLabel);
3091 }
3092 } else {
3093 final Symbol tagSymbol = switchNode.getTag();
3094 // TODO: we could have non-object tag
3095 final int tagSlot = tagSymbol.getSlot(Type.OBJECT);
3096 loadExpressionAsObject(expression);
3097 method.store(tagSymbol, Type.OBJECT);
3098
3099 for (final CaseNode caseNode : cases) {
3100 final Expression test = caseNode.getTest();
3101
3102 if (test != null) {
3103 method.load(Type.OBJECT, tagSlot);
3104 loadExpressionAsObject(test);
3105 method.invoke(ScriptRuntime.EQ_STRICT);
3106 method.ifne(caseNode.getEntry());
3107 }
3108 }
3109
3110 if (defaultCase != null) {
3111 method._goto(defaultLabel);
3112 } else {
3113 method.beforeJoinPoint(switchNode);
3114 method._goto(breakLabel);
3115 }
3116 }
3117
3118 // First case is only reachable through jump
3119 assert !method.isReachable();
3120
3121 for (final CaseNode caseNode : cases) {
3122 final Label fallThroughLabel;
3123 if(caseNode.getLocalVariableConversion() != null && method.isReachable()) {
3124 fallThroughLabel = new Label("fallthrough");
3125 method._goto(fallThroughLabel);
3126 } else {
3127 fallThroughLabel = null;
3128 }
3129 method.label(caseNode.getEntry());
3130 method.beforeJoinPoint(caseNode);
3131 if(fallThroughLabel != null) {
3132 method.label(fallThroughLabel);
3133 }
3134 caseNode.getBody().accept(this);
3135 }
3136
3137 method.breakLabel(breakLabel, liveLocalsOnBreak);
3138
3139 return false;
3140 }
3141
3142 @Override
3143 public boolean enterThrowNode(final ThrowNode throwNode) {
3144 if(!method.isReachable()) {
3145 return false;
3146 }
3147 enterStatement(throwNode);
3148
3149 if (throwNode.isSyntheticRethrow()) {
3150 method.beforeJoinPoint(throwNode);
3151
3152 //do not wrap whatever this is in an ecma exception, just rethrow it
3153 final IdentNode exceptionExpr = (IdentNode)throwNode.getExpression();
3154 final Symbol exceptionSymbol = exceptionExpr.getSymbol();
3155 method.load(exceptionSymbol, EXCEPTION_TYPE);
3156 method.checkcast(EXCEPTION_TYPE.getTypeClass());
3157 method.athrow();
3158 return false;
3159 }
3160
3161 final Source source = getCurrentSource();
3162 final Expression expression = throwNode.getExpression();
3163 final int position = throwNode.position();
3164 final int line = throwNode.getLineNumber();
3165 final int column = source.getColumn(position);
3166
3167 // NOTE: we first evaluate the expression, and only after it was evaluated do we create the new ECMAException
3168 // object and then somewhat cumbersomely move it beneath the evaluated expression on the stack. The reason for
3169 // this is that if expression is optimistic (or contains an optimistic subexpression), we'd potentially access
3170 // the not-yet-<init>ialized object on the stack from the UnwarrantedOptimismException handler, and bytecode
3171 // verifier forbids that.
3172 loadExpressionAsObject(expression);
3173
3174 method.load(source.getName());
3175 method.load(line);
3176 method.load(column);
3177 method.invoke(ECMAException.CREATE);
3178
3179 method.beforeJoinPoint(throwNode);
3180 method.athrow();
3181
3182 return false;
3183 }
3184
3185 private Source getCurrentSource() {
3186 return lc.getCurrentFunction().getSource();
3187 }
3188
3189 @Override
3190 public boolean enterTryNode(final TryNode tryNode) {
3191 if(!method.isReachable()) {
3192 return false;
3193 }
3194 enterStatement(tryNode);
3195
3196 final Block body = tryNode.getBody();
3197 final List<Block> catchBlocks = tryNode.getCatchBlocks();
3198 final Symbol vmException = tryNode.getException();
3199 final Label entry = new Label("try");
3200 final Label recovery = new Label("catch");
3201 final Label exit = new Label("end_try");
3202 final Label skip = new Label("skip");
3203
3204 method.canThrow(recovery);
3205 // Effect any conversions that might be observed at the entry of the catch node before entering the try node.
3206 // This is because even the first instruction in the try block must be presumed to be able to transfer control
3207 // to the catch block. Note that this doesn't kill the original values; in this regard it works a lot like
3208 // conversions of assignments within the try block.
3209 method.beforeTry(tryNode, recovery);
3210 method.label(entry);
3211 catchLabels.push(recovery);
3212 try {
3213 body.accept(this);
3214 } finally {
3215 assert catchLabels.peek() == recovery;
3216 catchLabels.pop();
3217 }
3218
3219 method.label(exit);
3220 final boolean bodyCanThrow = exit.isAfter(entry);
3221 if(!bodyCanThrow) {
3222 // The body can't throw an exception; don't even bother emitting the catch handlers, they're all dead code.
3223 return false;
3224 }
3225
3226 method._try(entry, exit, recovery, Throwable.class);
3227
3228 if (method.isReachable()) {
3229 method._goto(skip);
3230 }
3231
3232 for (final Block inlinedFinally : tryNode.getInlinedFinallies()) {
3233 TryNode.getLabelledInlinedFinallyBlock(inlinedFinally).accept(this);
3234 // All inlined finallies end with a jump or a return
3235 assert !method.isReachable();
3236 }
3237
3238
3239 method._catch(recovery);
3240 method.store(vmException, EXCEPTION_TYPE);
3241
3242 final int catchBlockCount = catchBlocks.size();
3243 final Label afterCatch = new Label("after_catch");
3244 for (int i = 0; i < catchBlockCount; i++) {
3245 assert method.isReachable();
3246 final Block catchBlock = catchBlocks.get(i);
3247
3248 // Because of the peculiarities of the flow control, we need to use an explicit push/enterBlock/leaveBlock
3249 // here.
3250 lc.push(catchBlock);
3251 enterBlock(catchBlock);
3252
3253 final CatchNode catchNode = (CatchNode)catchBlocks.get(i).getStatements().get(0);
3254 final IdentNode exception = catchNode.getException();
3255 final Expression exceptionCondition = catchNode.getExceptionCondition();
3256 final Block catchBody = catchNode.getBody();
3257
3258 new Store<IdentNode>(exception) {
3259 @Override
3260 protected void storeNonDiscard() {
3261 // This expression is neither part of a discard, nor needs to be left on the stack after it was
3262 // stored, so we override storeNonDiscard to be a no-op.
3263 }
3264
3265 @Override
3266 protected void evaluate() {
3267 if (catchNode.isSyntheticRethrow()) {
3268 method.load(vmException, EXCEPTION_TYPE);
3269 return;
3270 }
3271 /*
3272 * If caught object is an instance of ECMAException, then
3273 * bind obj.thrown to the script catch var. Or else bind the
3274 * caught object itself to the script catch var.
3275 */
3276 final Label notEcmaException = new Label("no_ecma_exception");
3277 method.load(vmException, EXCEPTION_TYPE).dup()._instanceof(ECMAException.class).ifeq(notEcmaException);
3278 method.checkcast(ECMAException.class); //TODO is this necessary?
3279 method.getField(ECMAException.THROWN);
3280 method.label(notEcmaException);
3281 }
3282 }.store();
3283
3284 final boolean isConditionalCatch = exceptionCondition != null;
3285 final Label nextCatch;
3286 if (isConditionalCatch) {
3287 loadExpressionAsBoolean(exceptionCondition);
3288 nextCatch = new Label("next_catch");
3289 nextCatch.markAsBreakTarget();
3290 method.ifeq(nextCatch);
3291 } else {
3292 nextCatch = null;
3293 }
3294
3295 catchBody.accept(this);
3296 leaveBlock(catchBlock);
3297 lc.pop(catchBlock);
3298 if(nextCatch != null) {
3299 if(method.isReachable()) {
3300 method._goto(afterCatch);
3301 }
3302 method.breakLabel(nextCatch, lc.getUsedSlotCount());
3303 }
3304 }
3305
3306 // afterCatch could be the same as skip, except that we need to establish that the vmException is dead.
3307 method.label(afterCatch);
3308 if(method.isReachable()) {
3309 method.markDeadLocalVariable(vmException);
3310 }
3311 method.label(skip);
3312
3313 // Finally body is always inlined elsewhere so it doesn't need to be emitted
3314 assert tryNode.getFinallyBody() == null;
3315
3316 return false;
3317 }
3318
3319 @Override
3320 public boolean enterVarNode(final VarNode varNode) {
3321 if(!method.isReachable()) {
3322 return false;
3323 }
3324 final Expression init = varNode.getInit();
3325 final IdentNode identNode = varNode.getName();
3326 final Symbol identSymbol = identNode.getSymbol();
3327 assert identSymbol != null : "variable node " + varNode + " requires a name with a symbol";
3328 final boolean needsScope = identSymbol.isScope();
3329
3330 if (init == null) {
3331 // Block-scoped variables need a DECLARE flag to signal end of temporal dead zone (TDZ).
3332 // However, don't do this for CONST which always has an initializer except in the special case of
3333 // for-in/of loops, in which it is initialized in the loop header and should be left untouched here.
3334 if (needsScope && varNode.isLet()) {
3335 method.loadCompilerConstant(SCOPE);
3336 method.loadUndefined(Type.OBJECT);
3337 final int flags = getScopeCallSiteFlags(identSymbol) | CALLSITE_DECLARE;
3338 assert isFastScope(identSymbol);
3339 storeFastScopeVar(identSymbol, flags);
3340 }
3341 return false;
3342 }
3343
3344 enterStatement(varNode);
3345 assert method != null;
3346
3347 if (needsScope) {
3348 method.loadCompilerConstant(SCOPE);
3349 loadExpressionUnbounded(init);
3350 // block scoped variables need a DECLARE flag to signal end of temporal dead zone (TDZ)
3351 final int flags = getScopeCallSiteFlags(identSymbol) | (varNode.isBlockScoped() ? CALLSITE_DECLARE : 0);
3352 if (isFastScope(identSymbol)) {
3353 storeFastScopeVar(identSymbol, flags);
3354 } else {
3355 method.dynamicSet(identNode.getName(), flags, false);
3356 }
3357 } else {
3358 final Type identType = identNode.getType();
3359 if(identType == Type.UNDEFINED) {
3360 // The initializer is either itself undefined (explicit assignment of undefined to undefined),
3361 // or the left hand side is a dead variable.
3362 assert init.getType() == Type.UNDEFINED || identNode.getSymbol().slotCount() == 0;
3363 loadAndDiscard(init);
3364 return false;
3365 }
3366 loadExpressionAsType(init, identType);
3367 storeIdentWithCatchConversion(identNode, identType);
3368 }
3369
3370 return false;
3371 }
3372
3373 private void storeIdentWithCatchConversion(final IdentNode identNode, final Type type) {
3374 // Assignments happening in try/catch blocks need to ensure that they also store a possibly wider typed value
3375 // that will be live at the exit from the try block
3376 final LocalVariableConversion conversion = identNode.getLocalVariableConversion();
3377 final Symbol symbol = identNode.getSymbol();
3378 if(conversion != null && conversion.isLive()) {
3379 assert symbol == conversion.getSymbol();
3380 assert symbol.isBytecodeLocal();
3381 // Only a single conversion from the target type to the join type is expected.
3382 assert conversion.getNext() == null;
3383 assert conversion.getFrom() == type;
3384 // We must propagate potential type change to the catch block
3385 final Label catchLabel = catchLabels.peek();
3386 assert catchLabel != METHOD_BOUNDARY; // ident conversion only exists in try blocks
3387 assert catchLabel.isReachable();
3388 final Type joinType = conversion.getTo();
3389 final Label.Stack catchStack = catchLabel.getStack();
3390 final int joinSlot = symbol.getSlot(joinType);
3391 // With nested try/catch blocks (incl. synthetic ones for finally), we can have a supposed conversion for
3392 // the exception symbol in the nested catch, but it isn't live in the outer catch block, so prevent doing
3393 // conversions for it. E.g. in "try { try { ... } catch(e) { e = 1; } } catch(e2) { ... }", we must not
3394 // introduce an I->O conversion on "e = 1" assignment as "e" is not live in "catch(e2)".
3395 if(catchStack.getUsedSlotsWithLiveTemporaries() > joinSlot) {
3396 method.dup();
3397 method.convert(joinType);
3398 method.store(symbol, joinType);
3399 catchLabel.getStack().onLocalStore(joinType, joinSlot, true);
3400 method.canThrow(catchLabel);
3401 // Store but keep the previous store live too.
3402 method.store(symbol, type, false);
3403 return;
3404 }
3405 }
3406
3407 method.store(symbol, type, true);
3408 }
3409
3410 @Override
3411 public boolean enterWhileNode(final WhileNode whileNode) {
3412 if(!method.isReachable()) {
3413 return false;
3414 }
3415 if(whileNode.isDoWhile()) {
3416 enterDoWhile(whileNode);
3417 } else {
3418 enterStatement(whileNode);
3419 enterForOrWhile(whileNode, null);
3420 }
3421 return false;
3422 }
3423
3424 private void enterForOrWhile(final LoopNode loopNode, final JoinPredecessorExpression modify) {
3425 // NOTE: the usual pattern for compiling test-first loops is "GOTO test; body; test; IFNE body". We use the less
3426 // conventional "test; IFEQ break; body; GOTO test; break;". It has one extra unconditional GOTO in each repeat
3427 // of the loop, but it's not a problem for modern JIT compilers. We do this because our local variable type
3428 // tracking is unfortunately not really prepared for out-of-order execution, e.g. compiling the following
3429 // contrived but legal JavaScript code snippet would fail because the test changes the type of "i" from object
3430 // to double: var i = {valueOf: function() { return 1} }; while(--i >= 0) { ... }
3431 // Instead of adding more complexity to the local variable type tracking, we instead choose to emit this
3432 // different code shape.
3433 final int liveLocalsOnBreak = method.getUsedSlotsWithLiveTemporaries();
3434 final JoinPredecessorExpression test = loopNode.getTest();
3435 if(Expression.isAlwaysFalse(test)) {
3436 loadAndDiscard(test);
3437 return;
3438 }
3439
3440 method.beforeJoinPoint(loopNode);
3441
3442 final Label continueLabel = loopNode.getContinueLabel();
3443 final Label repeatLabel = modify != null ? new Label("for_repeat") : continueLabel;
3444 method.label(repeatLabel);
3445 final int liveLocalsOnContinue = method.getUsedSlotsWithLiveTemporaries();
3446
3447 final Block body = loopNode.getBody();
3448 final Label breakLabel = loopNode.getBreakLabel();
3449 final boolean testHasLiveConversion = test != null && LocalVariableConversion.hasLiveConversion(test);
3450
3451 if(Expression.isAlwaysTrue(test)) {
3452 if(test != null) {
3453 loadAndDiscard(test);
3454 if(testHasLiveConversion) {
3455 method.beforeJoinPoint(test);
3456 }
3457 }
3458 } else if (test != null) {
3459 if (testHasLiveConversion) {
3460 emitBranch(test.getExpression(), body.getEntryLabel(), true);
3461 method.beforeJoinPoint(test);
3462 method._goto(breakLabel);
3463 } else {
3464 emitBranch(test.getExpression(), breakLabel, false);
3465 }
3466 }
3467
3468 body.accept(this);
3469 if(repeatLabel != continueLabel) {
3470 emitContinueLabel(continueLabel, liveLocalsOnContinue);
3471 }
3472
3473 if (loopNode.hasPerIterationScope() && lc.getCurrentBlock().needsScope()) {
3474 // ES6 for loops with LET init need a new scope for each iteration. We just create a shallow copy here.
3475 method.loadCompilerConstant(SCOPE);
3476 method.invoke(virtualCallNoLookup(ScriptObject.class, "copy", ScriptObject.class));
3477 method.storeCompilerConstant(SCOPE);
3478 }
3479
3480 if(method.isReachable()) {
3481 if(modify != null) {
3482 lineNumber(loopNode);
3483 loadAndDiscard(modify);
3484 method.beforeJoinPoint(modify);
3485 }
3486 method._goto(repeatLabel);
3487 }
3488
3489 method.breakLabel(breakLabel, liveLocalsOnBreak);
3490 }
3491
3492 private void emitContinueLabel(final Label continueLabel, final int liveLocals) {
3493 final boolean reachable = method.isReachable();
3494 method.breakLabel(continueLabel, liveLocals);
3495 // If we reach here only through a continue statement (e.g. body does not exit normally) then the
3496 // continueLabel can have extra non-temp symbols (e.g. exception from a try/catch contained in the body). We
3497 // must make sure those are thrown away.
3498 if(!reachable) {
3499 method.undefineLocalVariables(lc.getUsedSlotCount(), false);
3500 }
3501 }
3502
3503 private void enterDoWhile(final WhileNode whileNode) {
3504 final int liveLocalsOnContinueOrBreak = method.getUsedSlotsWithLiveTemporaries();
3505 method.beforeJoinPoint(whileNode);
3506
3507 final Block body = whileNode.getBody();
3508 body.accept(this);
3509
3510 emitContinueLabel(whileNode.getContinueLabel(), liveLocalsOnContinueOrBreak);
3511 if(method.isReachable()) {
3512 lineNumber(whileNode);
3513 final JoinPredecessorExpression test = whileNode.getTest();
3514 final Label bodyEntryLabel = body.getEntryLabel();
3515 final boolean testHasLiveConversion = LocalVariableConversion.hasLiveConversion(test);
3516 if(Expression.isAlwaysFalse(test)) {
3517 loadAndDiscard(test);
3518 if(testHasLiveConversion) {
3519 method.beforeJoinPoint(test);
3520 }
3521 } else if(testHasLiveConversion) {
3522 // If we have conversions after the test in do-while, they need to be effected on both branches.
3523 final Label beforeExit = new Label("do_while_preexit");
3524 emitBranch(test.getExpression(), beforeExit, false);
3525 method.beforeJoinPoint(test);
3526 method._goto(bodyEntryLabel);
3527 method.label(beforeExit);
3528 method.beforeJoinPoint(test);
3529 } else {
3530 emitBranch(test.getExpression(), bodyEntryLabel, true);
3531 }
3532 }
3533 method.breakLabel(whileNode.getBreakLabel(), liveLocalsOnContinueOrBreak);
3534 }
3535
3536
3537 @Override
3538 public boolean enterWithNode(final WithNode withNode) {
3539 if(!method.isReachable()) {
3540 return false;
3541 }
3542 enterStatement(withNode);
3543 final Expression expression = withNode.getExpression();
3544 final Block body = withNode.getBody();
3545
3546 // It is possible to have a "pathological" case where the with block does not reference *any* identifiers. It's
3547 // pointless, but legal. In that case, if nothing else in the method forced the assignment of a slot to the
3548 // scope object, its' possible that it won't have a slot assigned. In this case we'll only evaluate expression
3549 // for its side effect and visit the body, and not bother opening and closing a WithObject.
3550 final boolean hasScope = method.hasScope();
3551
3552 if (hasScope) {
3553 method.loadCompilerConstant(SCOPE);
3554 }
3555
3556 loadExpressionAsObject(expression);
3557
3558 final Label tryLabel;
3559 if (hasScope) {
3560 // Construct a WithObject if we have a scope
3561 method.invoke(ScriptRuntime.OPEN_WITH);
3562 method.storeCompilerConstant(SCOPE);
3563 tryLabel = new Label("with_try");
3564 method.label(tryLabel);
3565 } else {
3566 // We just loaded the expression for its side effect and to check
3567 // for null or undefined value.
3568 globalCheckObjectCoercible();
3569 tryLabel = null;
3570 }
3571
3572 // Always process body
3573 body.accept(this);
3574
3575 if (hasScope) {
3576 // Ensure we always close the WithObject
3577 final Label endLabel = new Label("with_end");
3578 final Label catchLabel = new Label("with_catch");
3579 final Label exitLabel = new Label("with_exit");
3580
3581 method.label(endLabel);
3582 // Somewhat conservatively presume that if the body is not empty, it can throw an exception. In any case,
3583 // we must prevent trying to emit a try-catch for empty range, as it causes a verification error.
3584 final boolean bodyCanThrow = endLabel.isAfter(tryLabel);
3585 if(bodyCanThrow) {
3586 method._try(tryLabel, endLabel, catchLabel);
3587 }
3588
3589 final boolean reachable = method.isReachable();
3590 if(reachable) {
3591 popScope();
3592 if(bodyCanThrow) {
3593 method._goto(exitLabel);
3594 }
3595 }
3596
3597 if(bodyCanThrow) {
3598 method._catch(catchLabel);
3599 popScopeException();
3600 method.athrow();
3601 if(reachable) {
3602 method.label(exitLabel);
3603 }
3604 }
3605 }
3606 return false;
3607 }
3608
3609 private void loadADD(final UnaryNode unaryNode, final TypeBounds resultBounds) {
3610 loadExpression(unaryNode.getExpression(), resultBounds.booleanToInt().notWiderThan(Type.NUMBER));
3611 if(method.peekType() == Type.BOOLEAN) {
3612 // It's a no-op in bytecode, but we must make sure it is treated as an int for purposes of type signatures
3613 method.convert(Type.INT);
3614 }
3615 }
3616
3617 private void loadBIT_NOT(final UnaryNode unaryNode) {
3618 loadExpression(unaryNode.getExpression(), TypeBounds.INT).load(-1).xor();
3619 }
3620
3621 private void loadDECINC(final UnaryNode unaryNode) {
3622 final Expression operand = unaryNode.getExpression();
3623 final Type type = unaryNode.getType();
3624 final TypeBounds typeBounds = new TypeBounds(type, Type.NUMBER);
3625 final TokenType tokenType = unaryNode.tokenType();
3626 final boolean isPostfix = tokenType == TokenType.DECPOSTFIX || tokenType == TokenType.INCPOSTFIX;
3627 final boolean isIncrement = tokenType == TokenType.INCPREFIX || tokenType == TokenType.INCPOSTFIX;
3628
3629 assert !type.isObject();
3630
3631 new SelfModifyingStore<UnaryNode>(unaryNode, operand) {
3632
3633 private void loadRhs() {
3634 loadExpression(operand, typeBounds, true);
3635 }
3636
3637 @Override
3638 protected void evaluate() {
3639 if(isPostfix) {
3640 loadRhs();
3641 } else {
3642 new OptimisticOperation(unaryNode, typeBounds) {
3643 @Override
3644 void loadStack() {
3645 loadRhs();
3646 loadMinusOne();
3647 }
3648 @Override
3649 void consumeStack() {
3650 doDecInc(getProgramPoint());
3651 }
3652 }.emit(getOptimisticIgnoreCountForSelfModifyingExpression(operand));
3653 }
3654 }
3655
3656 @Override
3657 protected void storeNonDiscard() {
3658 super.storeNonDiscard();
3659 if (isPostfix) {
3660 new OptimisticOperation(unaryNode, typeBounds) {
3661 @Override
3662 void loadStack() {
3663 loadMinusOne();
3664 }
3665 @Override
3666 void consumeStack() {
3667 doDecInc(getProgramPoint());
3668 }
3669 }.emit(1); // 1 for non-incremented result on the top of the stack pushed in evaluate()
3670 }
3671 }
3672
3673 private void loadMinusOne() {
3674 if (type.isInteger()) {
3675 method.load(isIncrement ? 1 : -1);
3676 } else {
3677 method.load(isIncrement ? 1.0 : -1.0);
3678 }
3679 }
3680
3681 private void doDecInc(final int programPoint) {
3682 method.add(programPoint);
3683 }
3684 }.store();
3685 }
3686
3687 private static int getOptimisticIgnoreCountForSelfModifyingExpression(final Expression target) {
3688 return target instanceof AccessNode ? 1 : target instanceof IndexNode ? 2 : 0;
3689 }
3690
3691 private void loadAndDiscard(final Expression expr) {
3692 // TODO: move checks for discarding to actual expression load code (e.g. as we do with void). That way we might
3693 // be able to eliminate even more checks.
3694 if(expr instanceof PrimitiveLiteralNode | isLocalVariable(expr)) {
3695 assert !lc.isCurrentDiscard(expr);
3696 // Don't bother evaluating expressions without side effects. Typical usage is "void 0" for reliably generating
3697 // undefined.
3698 return;
3699 }
3700
3701 lc.pushDiscard(expr);
3702 loadExpression(expr, TypeBounds.UNBOUNDED);
3703 if (lc.popDiscardIfCurrent(expr)) {
3704 assert !expr.isAssignment();
3705 // NOTE: if we had a way to load with type void, we could avoid popping
3706 method.pop();
3707 }
3708 }
3709
3710 /**
3711 * Loads the expression with the specified type bounds, but if the parent expression is the current discard,
3712 * then instead loads and discards the expression.
3713 * @param parent the parent expression that's tested for being the current discard
3714 * @param expr the expression that's either normally loaded or discard-loaded
3715 * @param resultBounds result bounds for when loading the expression normally
3716 */
3717 private void loadMaybeDiscard(final Expression parent, final Expression expr, final TypeBounds resultBounds) {
3718 loadMaybeDiscard(lc.popDiscardIfCurrent(parent), expr, resultBounds);
3719 }
3720
3721 /**
3722 * Loads the expression with the specified type bounds, or loads and discards the expression, depending on the
3723 * value of the discard flag. Useful as a helper for expressions with control flow where you often can't combine
3724 * testing for being the current discard and loading the subexpressions.
3725 * @param discard if true, the expression is loaded and discarded
3726 * @param expr the expression that's either normally loaded or discard-loaded
3727 * @param resultBounds result bounds for when loading the expression normally
3728 */
3729 private void loadMaybeDiscard(final boolean discard, final Expression expr, final TypeBounds resultBounds) {
3730 if (discard) {
3731 loadAndDiscard(expr);
3732 } else {
3733 loadExpression(expr, resultBounds);
3734 }
3735 }
3736
3737 private void loadNEW(final UnaryNode unaryNode) {
3738 final CallNode callNode = (CallNode)unaryNode.getExpression();
3739 final List<Expression> args = callNode.getArgs();
3740
3741 final Expression func = callNode.getFunction();
3742 // Load function reference.
3743 loadExpressionAsObject(func); // must detect type error
3744
3745 method.dynamicNew(1 + loadArgs(args), getCallSiteFlags(), func.toString(false));
3746 }
3747
3748 private void loadNOT(final UnaryNode unaryNode) {
3749 final Expression expr = unaryNode.getExpression();
3750 if(expr instanceof UnaryNode && expr.isTokenType(TokenType.NOT)) {
3751 // !!x is idiomatic boolean cast in JavaScript
3752 loadExpressionAsBoolean(((UnaryNode)expr).getExpression());
3753 } else {
3754 final Label trueLabel = new Label("true");
3755 final Label afterLabel = new Label("after");
3756
3757 emitBranch(expr, trueLabel, true);
3758 method.load(true);
3759 method._goto(afterLabel);
3760 method.label(trueLabel);
3761 method.load(false);
3762 method.label(afterLabel);
3763 }
3764 }
3765
3766 private void loadSUB(final UnaryNode unaryNode, final TypeBounds resultBounds) {
3767 final Type type = unaryNode.getType();
3768 assert type.isNumeric();
3769 final TypeBounds numericBounds = resultBounds.booleanToInt();
3770 new OptimisticOperation(unaryNode, numericBounds) {
3771 @Override
3772 void loadStack() {
3773 final Expression expr = unaryNode.getExpression();
3774 loadExpression(expr, numericBounds.notWiderThan(Type.NUMBER));
3775 }
3776 @Override
3777 void consumeStack() {
3778 // Must do an explicit conversion to the operation's type when it's double so that we correctly handle
3779 // negation of an int 0 to a double -0. With this, we get the correct negation of a local variable after
3780 // it deoptimized, e.g. "iload_2; i2d; dneg". Without this, we get "iload_2; ineg; i2d".
3781 if(type.isNumber()) {
3782 method.convert(type);
3783 }
3784 method.neg(getProgramPoint());
3785 }
3786 }.emit();
3787 }
3788
3789 public void loadVOID(final UnaryNode unaryNode, final TypeBounds resultBounds) {
3790 loadAndDiscard(unaryNode.getExpression());
3791 if (!lc.popDiscardIfCurrent(unaryNode)) {
3792 method.loadUndefined(resultBounds.widest);
3793 }
3794 }
3795
3796 public void loadADD(final BinaryNode binaryNode, final TypeBounds resultBounds) {
3797 new OptimisticOperation(binaryNode, resultBounds) {
3798 @Override
3799 void loadStack() {
3800 final TypeBounds operandBounds;
3801 final boolean isOptimistic = isValid(getProgramPoint());
3802 boolean forceConversionSeparation = false;
3803 if(isOptimistic) {
3804 operandBounds = new TypeBounds(binaryNode.getType(), Type.OBJECT);
3805 } else {
3806 // Non-optimistic, non-FP +. Allow it to overflow.
3807 final Type widestOperationType = binaryNode.getWidestOperationType();
3808 operandBounds = new TypeBounds(Type.narrowest(binaryNode.getWidestOperandType(), resultBounds.widest), widestOperationType);
3809 forceConversionSeparation = widestOperationType.narrowerThan(resultBounds.widest);
3810 }
3811 loadBinaryOperands(binaryNode.lhs(), binaryNode.rhs(), operandBounds, false, forceConversionSeparation);
3812 }
3813
3814 @Override
3815 void consumeStack() {
3816 method.add(getProgramPoint());
3817 }
3818 }.emit();
3819 }
3820
3821 private void loadAND_OR(final BinaryNode binaryNode, final TypeBounds resultBounds, final boolean isAnd) {
3822 final Type narrowestOperandType = Type.widestReturnType(binaryNode.lhs().getType(), binaryNode.rhs().getType());
3823
3824 final boolean isCurrentDiscard = lc.popDiscardIfCurrent(binaryNode);
3825
3826 final Label skip = new Label("skip");
3827 if(narrowestOperandType == Type.BOOLEAN) {
3828 // optimize all-boolean logical expressions
3829 final Label onTrue = new Label("andor_true");
3830 emitBranch(binaryNode, onTrue, true);
3831 if (isCurrentDiscard) {
3832 method.label(onTrue);
3833 } else {
3834 method.load(false);
3835 method._goto(skip);
3836 method.label(onTrue);
3837 method.load(true);
3838 method.label(skip);
3839 }
3840 return;
3841 }
3842
3843 final TypeBounds outBounds = resultBounds.notNarrowerThan(narrowestOperandType);
3844 final JoinPredecessorExpression lhs = (JoinPredecessorExpression)binaryNode.lhs();
3845 final boolean lhsConvert = LocalVariableConversion.hasLiveConversion(lhs);
3846 final Label evalRhs = lhsConvert ? new Label("eval_rhs") : null;
3847
3848 loadExpression(lhs, outBounds);
3849 if (!isCurrentDiscard) {
3850 method.dup();
3851 }
3852 method.convert(Type.BOOLEAN);
3853 if (isAnd) {
3854 if(lhsConvert) {
3855 method.ifne(evalRhs);
3856 } else {
3857 method.ifeq(skip);
3858 }
3859 } else if(lhsConvert) {
3860 method.ifeq(evalRhs);
3861 } else {
3862 method.ifne(skip);
3863 }
3864
3865 if(lhsConvert) {
3866 method.beforeJoinPoint(lhs);
3867 method._goto(skip);
3868 method.label(evalRhs);
3869 }
3870
3871 if (!isCurrentDiscard) {
3872 method.pop();
3873 }
3874 final JoinPredecessorExpression rhs = (JoinPredecessorExpression)binaryNode.rhs();
3875 loadMaybeDiscard(isCurrentDiscard, rhs, outBounds);
3876 method.beforeJoinPoint(rhs);
3877 method.label(skip);
3878 }
3879
3880 private static boolean isLocalVariable(final Expression lhs) {
3881 return lhs instanceof IdentNode && isLocalVariable((IdentNode)lhs);
3882 }
3883
3884 private static boolean isLocalVariable(final IdentNode lhs) {
3885 return lhs.getSymbol().isBytecodeLocal();
3886 }
3887
3888 // NOTE: does not use resultBounds as the assignment is driven by the type of the RHS
3889 private void loadASSIGN(final BinaryNode binaryNode) {
3890 final Expression lhs = binaryNode.lhs();
3891 final Expression rhs = binaryNode.rhs();
3892
3893 final Type rhsType = rhs.getType();
3894 // Detect dead assignments
3895 if(lhs instanceof IdentNode) {
3896 final Symbol symbol = ((IdentNode)lhs).getSymbol();
3897 if(!symbol.isScope() && !symbol.hasSlotFor(rhsType) && lc.popDiscardIfCurrent(binaryNode)) {
3898 loadAndDiscard(rhs);
3899 method.markDeadLocalVariable(symbol);
3900 return;
3901 }
3902 }
3903
3904 new Store<BinaryNode>(binaryNode, lhs) {
3905 @Override
3906 protected void evaluate() {
3907 // NOTE: we're loading with "at least as wide as" so optimistic operations on the right hand side
3908 // remain optimistic, and then explicitly convert to the required type if needed.
3909 loadExpressionAsType(rhs, rhsType);
3910 }
3911 }.store();
3912 }
3913
3914 /**
3915 * Binary self-assignment that can be optimistic: +=, -=, *=, and /=.
3916 */
3917 private abstract class BinaryOptimisticSelfAssignment extends SelfModifyingStore<BinaryNode> {
3918
3919 /**
3920 * Constructor
3921 *
3922 * @param node the assign op node
3923 */
3924 BinaryOptimisticSelfAssignment(final BinaryNode node) {
3925 super(node, node.lhs());
3926 }
3927
3928 protected abstract void op(OptimisticOperation oo);
3929
3930 @Override
3931 protected void evaluate() {
3932 final Expression lhs = assignNode.lhs();
3933 final Expression rhs = assignNode.rhs();
3934 final Type widestOperationType = assignNode.getWidestOperationType();
3935 final TypeBounds bounds = new TypeBounds(assignNode.getType(), widestOperationType);
3936 new OptimisticOperation(assignNode, bounds) {
3937 @Override
3938 void loadStack() {
3939 final boolean forceConversionSeparation;
3940 if (isValid(getProgramPoint()) || widestOperationType == Type.NUMBER) {
3941 forceConversionSeparation = false;
3942 } else {
3943 final Type operandType = Type.widest(booleanToInt(objectToNumber(lhs.getType())), booleanToInt(objectToNumber(rhs.getType())));
3944 forceConversionSeparation = operandType.narrowerThan(widestOperationType);
3945 }
3946 loadBinaryOperands(lhs, rhs, bounds, true, forceConversionSeparation);
3947 }
3948 @Override
3949 void consumeStack() {
3950 op(this);
3951 }
3952 }.emit(getOptimisticIgnoreCountForSelfModifyingExpression(lhs));
3953 method.convert(assignNode.getType());
3954 }
3955 }
3956
3957 /**
3958 * Non-optimistic binary self-assignment operation. Basically, everything except +=, -=, *=, and /=.
3959 */
3960 private abstract class BinarySelfAssignment extends SelfModifyingStore<BinaryNode> {
3961 BinarySelfAssignment(final BinaryNode node) {
3962 super(node, node.lhs());
3963 }
3964
3965 protected abstract void op();
3966
3967 @Override
3968 protected void evaluate() {
3969 loadBinaryOperands(assignNode.lhs(), assignNode.rhs(), TypeBounds.UNBOUNDED.notWiderThan(assignNode.getWidestOperandType()), true, false);
3970 op();
3971 }
3972 }
3973
3974 private void loadASSIGN_ADD(final BinaryNode binaryNode) {
3975 new BinaryOptimisticSelfAssignment(binaryNode) {
3976 @Override
3977 protected void op(final OptimisticOperation oo) {
3978 assert !(binaryNode.getType().isObject() && oo.isOptimistic);
3979 method.add(oo.getProgramPoint());
3980 }
3981 }.store();
3982 }
3983
3984 private void loadASSIGN_BIT_AND(final BinaryNode binaryNode) {
3985 new BinarySelfAssignment(binaryNode) {
3986 @Override
3987 protected void op() {
3988 method.and();
3989 }
3990 }.store();
3991 }
3992
3993 private void loadASSIGN_BIT_OR(final BinaryNode binaryNode) {
3994 new BinarySelfAssignment(binaryNode) {
3995 @Override
3996 protected void op() {
3997 method.or();
3998 }
3999 }.store();
4000 }
4001
4002 private void loadASSIGN_BIT_XOR(final BinaryNode binaryNode) {
4003 new BinarySelfAssignment(binaryNode) {
4004 @Override
4005 protected void op() {
4006 method.xor();
4007 }
4008 }.store();
4009 }
4010
4011 private void loadASSIGN_DIV(final BinaryNode binaryNode) {
4012 new BinaryOptimisticSelfAssignment(binaryNode) {
4013 @Override
4014 protected void op(final OptimisticOperation oo) {
4015 method.div(oo.getProgramPoint());
4016 }
4017 }.store();
4018 }
4019
4020 private void loadASSIGN_MOD(final BinaryNode binaryNode) {
4021 new BinaryOptimisticSelfAssignment(binaryNode) {
4022 @Override
4023 protected void op(final OptimisticOperation oo) {
4024 method.rem(oo.getProgramPoint());
4025 }
4026 }.store();
4027 }
4028
4029 private void loadASSIGN_MUL(final BinaryNode binaryNode) {
4030 new BinaryOptimisticSelfAssignment(binaryNode) {
4031 @Override
4032 protected void op(final OptimisticOperation oo) {
4033 method.mul(oo.getProgramPoint());
4034 }
4035 }.store();
4036 }
4037
4038 private void loadASSIGN_SAR(final BinaryNode binaryNode) {
4039 new BinarySelfAssignment(binaryNode) {
4040 @Override
4041 protected void op() {
4042 method.sar();
4043 }
4044 }.store();
4045 }
4046
4047 private void loadASSIGN_SHL(final BinaryNode binaryNode) {
4048 new BinarySelfAssignment(binaryNode) {
4049 @Override
4050 protected void op() {
4051 method.shl();
4052 }
4053 }.store();
4054 }
4055
4056 private void loadASSIGN_SHR(final BinaryNode binaryNode) {
4057 new SelfModifyingStore<BinaryNode>(binaryNode, binaryNode.lhs()) {
4058 @Override
4059 protected void evaluate() {
4060 new OptimisticOperation(assignNode, new TypeBounds(Type.INT, Type.NUMBER)) {
4061 @Override
4062 void loadStack() {
4063 assert assignNode.getWidestOperandType() == Type.INT;
4064 if (isRhsZero(binaryNode)) {
4065 loadExpressionAsType(binaryNode.lhs(), Type.INT);
4066 } else {
4067 loadBinaryOperands(binaryNode.lhs(), binaryNode.rhs(), TypeBounds.INT, true, false);
4068 method.shr();
4069 }
4070 }
4071
4072 @Override
4073 void consumeStack() {
4074 if (isOptimistic(binaryNode)) {
4075 toUint32Optimistic(binaryNode.getProgramPoint());
4076 } else {
4077 toUint32Double();
4078 }
4079 }
4080 }.emit(getOptimisticIgnoreCountForSelfModifyingExpression(binaryNode.lhs()));
4081 method.convert(assignNode.getType());
4082 }
4083 }.store();
4084 }
4085
4086 private void doSHR(final BinaryNode binaryNode) {
4087 new OptimisticOperation(binaryNode, new TypeBounds(Type.INT, Type.NUMBER)) {
4088 @Override
4089 void loadStack() {
4090 if (isRhsZero(binaryNode)) {
4091 loadExpressionAsType(binaryNode.lhs(), Type.INT);
4092 } else {
4093 loadBinaryOperands(binaryNode);
4094 method.shr();
4095 }
4096 }
4097
4098 @Override
4099 void consumeStack() {
4100 if (isOptimistic(binaryNode)) {
4101 toUint32Optimistic(binaryNode.getProgramPoint());
4102 } else {
4103 toUint32Double();
4104 }
4105 }
4106 }.emit();
4107
4108 }
4109
4110 private void toUint32Optimistic(final int programPoint) {
4111 method.load(programPoint);
4112 JSType.TO_UINT32_OPTIMISTIC.invoke(method);
4113 }
4114
4115 private void toUint32Double() {
4116 JSType.TO_UINT32_DOUBLE.invoke(method);
4117 }
4118
4119 private void loadASSIGN_SUB(final BinaryNode binaryNode) {
4120 new BinaryOptimisticSelfAssignment(binaryNode) {
4121 @Override
4122 protected void op(final OptimisticOperation oo) {
4123 method.sub(oo.getProgramPoint());
4124 }
4125 }.store();
4126 }
4127
4128 /**
4129 * Helper class for binary arithmetic ops
4130 */
4131 private abstract class BinaryArith {
4132 protected abstract void op(int programPoint);
4133
4134 protected void evaluate(final BinaryNode node, final TypeBounds resultBounds) {
4135 final TypeBounds numericBounds = resultBounds.booleanToInt().objectToNumber();
4136 new OptimisticOperation(node, numericBounds) {
4137 @Override
4138 void loadStack() {
4139 final TypeBounds operandBounds;
4140 boolean forceConversionSeparation = false;
4141 if(numericBounds.narrowest == Type.NUMBER) {
4142 // Result should be double always. Propagate it into the operands so we don't have lots of I2D
4143 // and L2D after operand evaluation.
4144 assert numericBounds.widest == Type.NUMBER;
4145 operandBounds = numericBounds;
4146 } else {
4147 final boolean isOptimistic = isValid(getProgramPoint());
4148 if(isOptimistic || node.isTokenType(TokenType.DIV) || node.isTokenType(TokenType.MOD)) {
4149 operandBounds = new TypeBounds(node.getType(), Type.NUMBER);
4150 } else {
4151 // Non-optimistic, non-FP subtraction or multiplication. Allow them to overflow.
4152 operandBounds = new TypeBounds(Type.narrowest(node.getWidestOperandType(),
4153 numericBounds.widest), Type.NUMBER);
4154 forceConversionSeparation = true;
4155 }
4156 }
4157 loadBinaryOperands(node.lhs(), node.rhs(), operandBounds, false, forceConversionSeparation);
4158 }
4159
4160 @Override
4161 void consumeStack() {
4162 op(getProgramPoint());
4163 }
4164 }.emit();
4165 }
4166 }
4167
4168 private void loadBIT_AND(final BinaryNode binaryNode) {
4169 loadBinaryOperands(binaryNode);
4170 method.and();
4171 }
4172
4173 private void loadBIT_OR(final BinaryNode binaryNode) {
4174 // Optimize x|0 to (int)x
4175 if (isRhsZero(binaryNode)) {
4176 loadExpressionAsType(binaryNode.lhs(), Type.INT);
4177 } else {
4178 loadBinaryOperands(binaryNode);
4179 method.or();
4180 }
4181 }
4182
4183 private static boolean isRhsZero(final BinaryNode binaryNode) {
4184 final Expression rhs = binaryNode.rhs();
4185 return rhs instanceof LiteralNode && INT_ZERO.equals(((LiteralNode<?>)rhs).getValue());
4186 }
4187
4188 private void loadBIT_XOR(final BinaryNode binaryNode) {
4189 loadBinaryOperands(binaryNode);
4190 method.xor();
4191 }
4192
4193 private void loadCOMMARIGHT(final BinaryNode binaryNode, final TypeBounds resultBounds) {
4194 loadAndDiscard(binaryNode.lhs());
4195 loadMaybeDiscard(binaryNode, binaryNode.rhs(), resultBounds);
4196 }
4197
4198 private void loadCOMMALEFT(final BinaryNode binaryNode, final TypeBounds resultBounds) {
4199 loadMaybeDiscard(binaryNode, binaryNode.lhs(), resultBounds);
4200 loadAndDiscard(binaryNode.rhs());
4201 }
4202
4203 private void loadDIV(final BinaryNode binaryNode, final TypeBounds resultBounds) {
4204 new BinaryArith() {
4205 @Override
4206 protected void op(final int programPoint) {
4207 method.div(programPoint);
4208 }
4209 }.evaluate(binaryNode, resultBounds);
4210 }
4211
4212 private void loadCmp(final BinaryNode binaryNode, final Condition cond) {
4213 loadComparisonOperands(binaryNode);
4214
4215 final Label trueLabel = new Label("trueLabel");
4216 final Label afterLabel = new Label("skip");
4217
4218 method.conditionalJump(cond, trueLabel);
4219
4220 method.load(Boolean.FALSE);
4221 method._goto(afterLabel);
4222 method.label(trueLabel);
4223 method.load(Boolean.TRUE);
4224 method.label(afterLabel);
4225 }
4226
4227 private void loadMOD(final BinaryNode binaryNode, final TypeBounds resultBounds) {
4228 new BinaryArith() {
4229 @Override
4230 protected void op(final int programPoint) {
4231 method.rem(programPoint);
4232 }
4233 }.evaluate(binaryNode, resultBounds);
4234 }
4235
4236 private void loadMUL(final BinaryNode binaryNode, final TypeBounds resultBounds) {
4237 new BinaryArith() {
4238 @Override
4239 protected void op(final int programPoint) {
4240 method.mul(programPoint);
4241 }
4242 }.evaluate(binaryNode, resultBounds);
4243 }
4244
4245 private void loadSAR(final BinaryNode binaryNode) {
4246 loadBinaryOperands(binaryNode);
4247 method.sar();
4248 }
4249
4250 private void loadSHL(final BinaryNode binaryNode) {
4251 loadBinaryOperands(binaryNode);
4252 method.shl();
4253 }
4254
4255 private void loadSHR(final BinaryNode binaryNode) {
4256 doSHR(binaryNode);
4257 }
4258
4259 private void loadSUB(final BinaryNode binaryNode, final TypeBounds resultBounds) {
4260 new BinaryArith() {
4261 @Override
4262 protected void op(final int programPoint) {
4263 method.sub(programPoint);
4264 }
4265 }.evaluate(binaryNode, resultBounds);
4266 }
4267
4268 @Override
4269 public boolean enterLabelNode(final LabelNode labelNode) {
4270 labeledBlockBreakLiveLocals.push(lc.getUsedSlotCount());
4271 return true;
4272 }
4273
4274 @Override
4275 protected boolean enterDefault(final Node node) {
4276 throw new AssertionError("Code generator entered node of type " + node.getClass().getName());
4277 }
4278
4279 private void loadTernaryNode(final TernaryNode ternaryNode, final TypeBounds resultBounds) {
4280 final Expression test = ternaryNode.getTest();
4281 final JoinPredecessorExpression trueExpr = ternaryNode.getTrueExpression();
4282 final JoinPredecessorExpression falseExpr = ternaryNode.getFalseExpression();
4283
4284 final Label falseLabel = new Label("ternary_false");
4285 final Label exitLabel = new Label("ternary_exit");
4286
4287 final Type outNarrowest = Type.narrowest(resultBounds.widest, Type.generic(Type.widestReturnType(trueExpr.getType(), falseExpr.getType())));
4288 final TypeBounds outBounds = resultBounds.notNarrowerThan(outNarrowest);
4289
4290 emitBranch(test, falseLabel, false);
4291
4292 final boolean isCurrentDiscard = lc.popDiscardIfCurrent(ternaryNode);
4293 loadMaybeDiscard(isCurrentDiscard, trueExpr.getExpression(), outBounds);
4294 assert isCurrentDiscard || Type.generic(method.peekType()) == outBounds.narrowest;
4295 method.beforeJoinPoint(trueExpr);
4296 method._goto(exitLabel);
4297 method.label(falseLabel);
4298 loadMaybeDiscard(isCurrentDiscard, falseExpr.getExpression(), outBounds);
4299 assert isCurrentDiscard || Type.generic(method.peekType()) == outBounds.narrowest;
4300 method.beforeJoinPoint(falseExpr);
4301 method.label(exitLabel);
4302 }
4303
4304 /**
4305 * Generate all shared scope calls generated during codegen.
4306 */
4307 void generateScopeCalls() {
4308 for (final SharedScopeCall scopeAccess : lc.getScopeCalls()) {
4309 scopeAccess.generateScopeCall();
4310 }
4311 }
4312
4313 /**
4314 * Debug code used to print symbols
4315 *
4316 * @param block the block we are in
4317 * @param function the function we are in
4318 * @param ident identifier for block or function where applicable
4319 */
4320 private void printSymbols(final Block block, final FunctionNode function, final String ident) {
4321 if (compiler.getScriptEnvironment()._print_symbols || function.getFlag(FunctionNode.IS_PRINT_SYMBOLS)) {
4322 final PrintWriter out = compiler.getScriptEnvironment().getErr();
4323 out.println("[BLOCK in '" + ident + "']");
4324 if (!block.printSymbols(out)) {
4325 out.println("<no symbols>");
4326 }
4327 out.println();
4328 }
4329 }
4330
4331
4332 /**
4333 * The difference between a store and a self modifying store is that
4334 * the latter may load part of the target on the stack, e.g. the base
4335 * of an AccessNode or the base and index of an IndexNode. These are used
4336 * both as target and as an extra source. Previously it was problematic
4337 * for self modifying stores if the target/lhs didn't belong to one
4338 * of three trivial categories: IdentNode, AcessNodes, IndexNodes. In that
4339 * case it was evaluated and tagged as "resolved", which meant at the second
4340 * time the lhs of this store was read (e.g. in a = a (second) + b for a += b,
4341 * it would be evaluated to a nop in the scope and cause stack underflow
4342 *
4343 * see NASHORN-703
4344 *
4345 * @param <T>
4346 */
4347 private abstract class SelfModifyingStore<T extends Expression> extends Store<T> {
4348 protected SelfModifyingStore(final T assignNode, final Expression target) {
4349 super(assignNode, target);
4350 }
4351
4352 @Override
4353 protected boolean isSelfModifying() {
4354 return true;
4355 }
4356 }
4357
4358 /**
4359 * Helper class to generate stores
4360 */
4361 private abstract class Store<T extends Expression> {
4362
4363 /** An assignment node, e.g. x += y */
4364 protected final T assignNode;
4365
4366 /** The target node to store to, e.g. x */
4367 private final Expression target;
4368
4369 /** How deep on the stack do the arguments go if this generates an indy call */
4370 private int depth;
4371
4372 /** If we have too many arguments, we need temporary storage, this is stored in 'quick' */
4373 private IdentNode quick;
4374
4375 /**
4376 * Constructor
4377 *
4378 * @param assignNode the node representing the whole assignment
4379 * @param target the target node of the assignment (destination)
4380 */
4381 protected Store(final T assignNode, final Expression target) {
4382 this.assignNode = assignNode;
4383 this.target = target;
4384 }
4385
4386 /**
4387 * Constructor
4388 *
4389 * @param assignNode the node representing the whole assignment
4390 */
4391 protected Store(final T assignNode) {
4392 this(assignNode, assignNode);
4393 }
4394
4395 /**
4396 * Is this a self modifying store operation, e.g. *= or ++
4397 * @return true if self modifying store
4398 */
4399 protected boolean isSelfModifying() {
4400 return false;
4401 }
4402
4403 private void prologue() {
4404 /*
4405 * This loads the parts of the target, e.g base and index. they are kept
4406 * on the stack throughout the store and used at the end to execute it
4407 */
4408
4409 target.accept(new SimpleNodeVisitor() {
4410 @Override
4411 public boolean enterIdentNode(final IdentNode node) {
4412 if (node.getSymbol().isScope()) {
4413 method.loadCompilerConstant(SCOPE);
4414 depth += Type.SCOPE.getSlots();
4415 assert depth == 1;
4416 }
4417 return false;
4418 }
4419
4420 private void enterBaseNode() {
4421 assert target instanceof BaseNode : "error - base node " + target + " must be instanceof BaseNode";
4422 final BaseNode baseNode = (BaseNode)target;
4423 final Expression base = baseNode.getBase();
4424
4425 loadExpressionAsObject(base);
4426 depth += Type.OBJECT.getSlots();
4427 assert depth == 1;
4428
4429 if (isSelfModifying()) {
4430 method.dup();
4431 }
4432 }
4433
4434 @Override
4435 public boolean enterAccessNode(final AccessNode node) {
4436 enterBaseNode();
4437 return false;
4438 }
4439
4440 @Override
4441 public boolean enterIndexNode(final IndexNode node) {
4442 enterBaseNode();
4443
4444 final Expression index = node.getIndex();
4445 if (!index.getType().isNumeric()) {
4446 // could be boolean here as well
4447 loadExpressionAsObject(index);
4448 } else {
4449 loadExpressionUnbounded(index);
4450 }
4451 depth += index.getType().getSlots();
4452
4453 if (isSelfModifying()) {
4454 //convert "base base index" to "base index base index"
4455 method.dup(1);
4456 }
4457
4458 return false;
4459 }
4460
4461 });
4462 }
4463
4464 /**
4465 * Generates an extra local variable, always using the same slot, one that is available after the end of the
4466 * frame.
4467 *
4468 * @param type the type of the variable
4469 *
4470 * @return the quick variable
4471 */
4472 private IdentNode quickLocalVariable(final Type type) {
4473 final String name = lc.getCurrentFunction().uniqueName(QUICK_PREFIX.symbolName());
4474 final Symbol symbol = new Symbol(name, IS_INTERNAL | HAS_SLOT);
4475 symbol.setHasSlotFor(type);
4476 symbol.setFirstSlot(lc.quickSlot(type));
4477
4478 final IdentNode quickIdent = IdentNode.createInternalIdentifier(symbol).setType(type);
4479
4480 return quickIdent;
4481 }
4482
4483 // store the result that "lives on" after the op, e.g. "i" in i++ postfix.
4484 protected void storeNonDiscard() {
4485 if (lc.popDiscardIfCurrent(assignNode)) {
4486 assert assignNode.isAssignment();
4487 return;
4488 }
4489
4490 if (method.dup(depth) == null) {
4491 method.dup();
4492 final Type quickType = method.peekType();
4493 this.quick = quickLocalVariable(quickType);
4494 final Symbol quickSymbol = quick.getSymbol();
4495 method.storeTemp(quickType, quickSymbol.getFirstSlot());
4496 }
4497 }
4498
4499 private void epilogue() {
4500 /**
4501 * Take the original target args from the stack and use them
4502 * together with the value to be stored to emit the store code
4503 *
4504 * The case that targetSymbol is in scope (!hasSlot) and we actually
4505 * need to do a conversion on non-equivalent types exists, but is
4506 * very rare. See for example test/script/basic/access-specializer.js
4507 */
4508 target.accept(new SimpleNodeVisitor() {
4509 @Override
4510 protected boolean enterDefault(final Node node) {
4511 throw new AssertionError("Unexpected node " + node + " in store epilogue");
4512 }
4513
4514 @Override
4515 public boolean enterIdentNode(final IdentNode node) {
4516 final Symbol symbol = node.getSymbol();
4517 assert symbol != null;
4518 if (symbol.isScope()) {
4519 final int flags = getScopeCallSiteFlags(symbol) | (node.isDeclaredHere() ? CALLSITE_DECLARE : 0);
4520 if (isFastScope(symbol)) {
4521 storeFastScopeVar(symbol, flags);
4522 } else {
4523 method.dynamicSet(node.getName(), flags, false);
4524 }
4525 } else {
4526 final Type storeType = assignNode.getType();
4527 assert storeType != Type.LONG;
4528 if (symbol.hasSlotFor(storeType)) {
4529 // Only emit a convert for a store known to be live; converts for dead stores can
4530 // give us an unnecessary ClassCastException.
4531 method.convert(storeType);
4532 }
4533 storeIdentWithCatchConversion(node, storeType);
4534 }
4535 return false;
4536
4537 }
4538
4539 @Override
4540 public boolean enterAccessNode(final AccessNode node) {
4541 method.dynamicSet(node.getProperty(), getCallSiteFlags(), node.isIndex());
4542 return false;
4543 }
4544
4545 @Override
4546 public boolean enterIndexNode(final IndexNode node) {
4547 method.dynamicSetIndex(getCallSiteFlags());
4548 return false;
4549 }
4550 });
4551
4552
4553 // whatever is on the stack now is the final answer
4554 }
4555
4556 protected abstract void evaluate();
4557
4558 void store() {
4559 if (target instanceof IdentNode) {
4560 checkTemporalDeadZone((IdentNode)target);
4561 }
4562 prologue();
4563 evaluate(); // leaves an operation of whatever the operationType was on the stack
4564 storeNonDiscard();
4565 epilogue();
4566 if (quick != null) {
4567 method.load(quick);
4568 }
4569 }
4570 }
4571
4572 private void newFunctionObject(final FunctionNode functionNode, final boolean addInitializer) {
4573 assert lc.peek() == functionNode;
4574
4575 final RecompilableScriptFunctionData data = compiler.getScriptFunctionData(functionNode.getId());
4576
4577 if (functionNode.isProgram() && !compiler.isOnDemandCompilation()) {
4578 final MethodEmitter createFunction = functionNode.getCompileUnit().getClassEmitter().method(
4579 EnumSet.of(Flag.PUBLIC, Flag.STATIC), CREATE_PROGRAM_FUNCTION.symbolName(),
4580 ScriptFunction.class, ScriptObject.class);
4581 createFunction.begin();
4582 loadConstantsAndIndex(data, createFunction);
4583 createFunction.load(SCOPE_TYPE, 0);
4584 createFunction.invoke(CREATE_FUNCTION_OBJECT);
4585 createFunction._return();
4586 createFunction.end();
4587 }
4588
4589 if (addInitializer && !compiler.isOnDemandCompilation()) {
4590 functionNode.getCompileUnit().addFunctionInitializer(data, functionNode);
4591 }
4592
4593 // We don't emit a ScriptFunction on stack for the outermost compiled function (as there's no code being
4594 // generated in its outer context that'd need it as a callee).
4595 if (lc.getOutermostFunction() == functionNode) {
4596 return;
4597 }
4598
4599 loadConstantsAndIndex(data, method);
4600
4601 if (functionNode.needsParentScope()) {
4602 method.loadCompilerConstant(SCOPE);
4603 method.invoke(CREATE_FUNCTION_OBJECT);
4604 } else {
4605 method.invoke(CREATE_FUNCTION_OBJECT_NO_SCOPE);
4606 }
4607 }
4608
4609 // calls on Global class.
4610 private MethodEmitter globalInstance() {
4611 return method.invokestatic(GLOBAL_OBJECT, "instance", "()L" + GLOBAL_OBJECT + ';');
4612 }
4613
4614 private MethodEmitter globalAllocateArguments() {
4615 return method.invokestatic(GLOBAL_OBJECT, "allocateArguments", methodDescriptor(ScriptObject.class, Object[].class, Object.class, int.class));
4616 }
4617
4618 private MethodEmitter globalNewRegExp() {
4619 return method.invokestatic(GLOBAL_OBJECT, "newRegExp", methodDescriptor(Object.class, String.class, String.class));
4620 }
4621
4622 private MethodEmitter globalRegExpCopy() {
4623 return method.invokestatic(GLOBAL_OBJECT, "regExpCopy", methodDescriptor(Object.class, Object.class));
4624 }
4625
4626 private MethodEmitter globalAllocateArray(final ArrayType type) {
4627 //make sure the native array is treated as an array type
4628 return method.invokestatic(GLOBAL_OBJECT, "allocate", "(" + type.getDescriptor() + ")Ljdk/nashorn/internal/objects/NativeArray;");
4629 }
4630
4631 private MethodEmitter globalIsEval() {
4632 return method.invokestatic(GLOBAL_OBJECT, "isEval", methodDescriptor(boolean.class, Object.class));
4633 }
4634
4635 private MethodEmitter globalReplaceLocationPropertyPlaceholder() {
4636 return method.invokestatic(GLOBAL_OBJECT, "replaceLocationPropertyPlaceholder", methodDescriptor(Object.class, Object.class, Object.class));
4637 }
4638
4639 private MethodEmitter globalCheckObjectCoercible() {
4640 return method.invokestatic(GLOBAL_OBJECT, "checkObjectCoercible", methodDescriptor(void.class, Object.class));
4641 }
4642
4643 private MethodEmitter globalDirectEval() {
4644 return method.invokestatic(GLOBAL_OBJECT, "directEval",
4645 methodDescriptor(Object.class, Object.class, Object.class, Object.class, Object.class, boolean.class));
4646 }
4647
4648 private abstract class OptimisticOperation {
4649 private final boolean isOptimistic;
4650 // expression and optimistic are the same reference
4651 private final Expression expression;
4652 private final Optimistic optimistic;
4653 private final TypeBounds resultBounds;
4654
4655 OptimisticOperation(final Optimistic optimistic, final TypeBounds resultBounds) {
4656 this.optimistic = optimistic;
4657 this.expression = (Expression)optimistic;
4658 this.resultBounds = resultBounds;
4659 this.isOptimistic = isOptimistic(optimistic) && useOptimisticTypes() &&
4660 // Operation is only effectively optimistic if its type, after being coerced into the result bounds
4661 // is narrower than the upper bound.
4662 resultBounds.within(Type.generic(((Expression)optimistic).getType())).narrowerThan(resultBounds.widest);
4663 }
4664
4665 MethodEmitter emit() {
4666 return emit(0);
4667 }
4668
4669 MethodEmitter emit(final int ignoredArgCount) {
4670 final int programPoint = optimistic.getProgramPoint();
4671 final boolean optimisticOrContinuation = isOptimistic || isContinuationEntryPoint(programPoint);
4672 final boolean currentContinuationEntryPoint = isCurrentContinuationEntryPoint(programPoint);
4673 final int stackSizeOnEntry = method.getStackSize() - ignoredArgCount;
4674
4675 // First store the values on the stack opportunistically into local variables. Doing it before loadStack()
4676 // allows us to not have to pop/load any arguments that are pushed onto it by loadStack() in the second
4677 // storeStack().
4678 storeStack(ignoredArgCount, optimisticOrContinuation);
4679
4680 // Now, load the stack
4681 loadStack();
4682
4683 // Now store the values on the stack ultimately into local variables. In vast majority of cases, this is
4684 // (aside from creating the local types map) a no-op, as the first opportunistic stack store will already
4685 // store all variables. However, there can be operations in the loadStack() that invalidate some of the
4686 // stack stores, e.g. in "x[i] = x[++i]", "++i" will invalidate the already stored value for "i". In such
4687 // unfortunate cases this second storeStack() will restore the invariant that everything on the stack is
4688 // stored into a local variable, although at the cost of doing a store/load on the loaded arguments as well.
4689 final int liveLocalsCount = storeStack(method.getStackSize() - stackSizeOnEntry, optimisticOrContinuation);
4690 assert optimisticOrContinuation == (liveLocalsCount != -1);
4691
4692 final Label beginTry;
4693 final Label catchLabel;
4694 final Label afterConsumeStack = isOptimistic || currentContinuationEntryPoint ? new Label("after_consume_stack") : null;
4695 if(isOptimistic) {
4696 beginTry = new Label("try_optimistic");
4697 final String catchLabelName = (afterConsumeStack == null ? "" : afterConsumeStack.toString()) + "_handler";
4698 catchLabel = new Label(catchLabelName);
4699 method.label(beginTry);
4700 } else {
4701 beginTry = catchLabel = null;
4702 }
4703
4704 consumeStack();
4705
4706 if(isOptimistic) {
4707 method._try(beginTry, afterConsumeStack, catchLabel, UnwarrantedOptimismException.class);
4708 }
4709
4710 if(isOptimistic || currentContinuationEntryPoint) {
4711 method.label(afterConsumeStack);
4712
4713 final int[] localLoads = method.getLocalLoadsOnStack(0, stackSizeOnEntry);
4714 assert everyStackValueIsLocalLoad(localLoads) : Arrays.toString(localLoads) + ", " + stackSizeOnEntry + ", " + ignoredArgCount;
4715 final List<Type> localTypesList = method.getLocalVariableTypes();
4716 final int usedLocals = method.getUsedSlotsWithLiveTemporaries();
4717 final List<Type> localTypes = method.getWidestLiveLocals(localTypesList.subList(0, usedLocals));
4718 assert everyLocalLoadIsValid(localLoads, usedLocals) : Arrays.toString(localLoads) + " ~ " + localTypes;
4719
4720 if(isOptimistic) {
4721 addUnwarrantedOptimismHandlerLabel(localTypes, catchLabel);
4722 }
4723 if(currentContinuationEntryPoint) {
4724 final ContinuationInfo ci = getContinuationInfo();
4725 assert ci != null : "no continuation info found for " + lc.getCurrentFunction();
4726 assert !ci.hasTargetLabel(); // No duplicate program points
4727 ci.setTargetLabel(afterConsumeStack);
4728 ci.getHandlerLabel().markAsOptimisticContinuationHandlerFor(afterConsumeStack);
4729 // Can't rely on targetLabel.stack.localVariableTypes.length, as it can be higher due to effectively
4730 // dead local variables.
4731 ci.lvarCount = localTypes.size();
4732 ci.setStackStoreSpec(localLoads);
4733 ci.setStackTypes(Arrays.copyOf(method.getTypesFromStack(method.getStackSize()), stackSizeOnEntry));
4734 assert ci.getStackStoreSpec().length == ci.getStackTypes().length;
4735 ci.setReturnValueType(method.peekType());
4736 ci.lineNumber = getLastLineNumber();
4737 ci.catchLabel = catchLabels.peek();
4738 }
4739 }
4740 return method;
4741 }
4742
4743 /**
4744 * Stores the current contents of the stack into local variables so they are not lost before invoking something that
4745 * can result in an {@code UnwarantedOptimizationException}.
4746 * @param ignoreArgCount the number of topmost arguments on stack to ignore when deciding on the shape of the catch
4747 * block. Those are used in the situations when we could not place the call to {@code storeStack} early enough
4748 * (before emitting code for pushing the arguments that the optimistic call will pop). This is admittedly a
4749 * deficiency in the design of the code generator when it deals with self-assignments and we should probably look
4750 * into fixing it.
4751 * @return types of the significant local variables after the stack was stored (types for local variables used
4752 * for temporary storage of ignored arguments are not returned).
4753 * @param optimisticOrContinuation if false, this method should not execute
4754 * a label for a catch block for the {@code UnwarantedOptimizationException}, suitable for capturing the
4755 * currently live local variables, tailored to their types.
4756 */
4757 private int storeStack(final int ignoreArgCount, final boolean optimisticOrContinuation) {
4758 if(!optimisticOrContinuation) {
4759 return -1; // NOTE: correct value to return is lc.getUsedSlotCount(), but it wouldn't be used anyway
4760 }
4761
4762 final int stackSize = method.getStackSize();
4763 final Type[] stackTypes = method.getTypesFromStack(stackSize);
4764 final int[] localLoadsOnStack = method.getLocalLoadsOnStack(0, stackSize);
4765 final int usedSlots = method.getUsedSlotsWithLiveTemporaries();
4766
4767 final int firstIgnored = stackSize - ignoreArgCount;
4768 // Find the first value on the stack (from the bottom) that is not a load from a local variable.
4769 int firstNonLoad = 0;
4770 while(firstNonLoad < firstIgnored && localLoadsOnStack[firstNonLoad] != Label.Stack.NON_LOAD) {
4771 firstNonLoad++;
4772 }
4773
4774 // Only do the store/load if first non-load is not an ignored argument. Otherwise, do nothing and return
4775 // the number of used slots as the number of live local variables.
4776 if(firstNonLoad >= firstIgnored) {
4777 return usedSlots;
4778 }
4779
4780 // Find the number of new temporary local variables that we need; it's the number of values on the stack that
4781 // are not direct loads of existing local variables.
4782 int tempSlotsNeeded = 0;
4783 for(int i = firstNonLoad; i < stackSize; ++i) {
4784 if(localLoadsOnStack[i] == Label.Stack.NON_LOAD) {
4785 tempSlotsNeeded += stackTypes[i].getSlots();
4786 }
4787 }
4788
4789 // Ensure all values on the stack that weren't directly loaded from a local variable are stored in a local
4790 // variable. We're starting from highest local variable index, so that in case ignoreArgCount > 0 the ignored
4791 // ones end up at the end of the local variable table.
4792 int lastTempSlot = usedSlots + tempSlotsNeeded;
4793 int ignoreSlotCount = 0;
4794 for(int i = stackSize; i -- > firstNonLoad;) {
4795 final int loadSlot = localLoadsOnStack[i];
4796 if(loadSlot == Label.Stack.NON_LOAD) {
4797 final Type type = stackTypes[i];
4798 final int slots = type.getSlots();
4799 lastTempSlot -= slots;
4800 if(i >= firstIgnored) {
4801 ignoreSlotCount += slots;
4802 }
4803 method.storeTemp(type, lastTempSlot);
4804 } else {
4805 method.pop();
4806 }
4807 }
4808 assert lastTempSlot == usedSlots; // used all temporary locals
4809
4810 final List<Type> localTypesList = method.getLocalVariableTypes();
4811
4812 // Load values back on stack.
4813 for(int i = firstNonLoad; i < stackSize; ++i) {
4814 final int loadSlot = localLoadsOnStack[i];
4815 final Type stackType = stackTypes[i];
4816 final boolean isLoad = loadSlot != Label.Stack.NON_LOAD;
4817 final int lvarSlot = isLoad ? loadSlot : lastTempSlot;
4818 final Type lvarType = localTypesList.get(lvarSlot);
4819 method.load(lvarType, lvarSlot);
4820 if(isLoad) {
4821 // Conversion operators (I2L etc.) preserve "load"-ness of the value despite the fact that, in the
4822 // strict sense they are creating a derived value from the loaded value. This special behavior of
4823 // on-stack conversion operators is necessary to accommodate for differences in local variable types
4824 // after deoptimization; having a conversion operator throw away "load"-ness would create different
4825 // local variable table shapes between optimism-failed code and its deoptimized rest-of method).
4826 // After we load the value back, we need to redo the conversion to the stack type if stack type is
4827 // different.
4828 // NOTE: this would only strictly be necessary for widening conversions (I2L, L2D, I2D), and not for
4829 // narrowing ones (L2I, D2L, D2I) as only widening conversions are the ones that can get eliminated
4830 // in a deoptimized method, as their original input argument got widened. Maybe experiment with
4831 // throwing away "load"-ness for narrowing conversions in MethodEmitter.convert()?
4832 method.convert(stackType);
4833 } else {
4834 // temporary stores never needs a convert, as their type is always the same as the stack type.
4835 assert lvarType == stackType;
4836 lastTempSlot += lvarType.getSlots();
4837 }
4838 }
4839 // used all temporaries
4840 assert lastTempSlot == usedSlots + tempSlotsNeeded;
4841
4842 return lastTempSlot - ignoreSlotCount;
4843 }
4844
4845 private void addUnwarrantedOptimismHandlerLabel(final List<Type> localTypes, final Label label) {
4846 final String lvarTypesDescriptor = getLvarTypesDescriptor(localTypes);
4847 final Map<String, Collection<Label>> unwarrantedOptimismHandlers = lc.getUnwarrantedOptimismHandlers();
4848 Collection<Label> labels = unwarrantedOptimismHandlers.get(lvarTypesDescriptor);
4849 if(labels == null) {
4850 labels = new LinkedList<>();
4851 unwarrantedOptimismHandlers.put(lvarTypesDescriptor, labels);
4852 }
4853 method.markLabelAsOptimisticCatchHandler(label, localTypes.size());
4854 labels.add(label);
4855 }
4856
4857 abstract void loadStack();
4858
4859 // Make sure that whatever indy call site you emit from this method uses {@code getCallSiteFlagsOptimistic(node)}
4860 // or otherwise ensure optimistic flag is correctly set in the call site, otherwise it doesn't make much sense
4861 // to use OptimisticExpression for emitting it.
4862 abstract void consumeStack();
4863
4864 /**
4865 * Emits the correct dynamic getter code. Normally just delegates to method emitter, except when the target
4866 * expression is optimistic, and the desired type is narrower than the optimistic type. In that case, it'll emit a
4867 * dynamic getter with its original optimistic type, and explicitly insert a narrowing conversion. This way we can
4868 * preserve the optimism of the values even if they're subsequently immediately coerced into a narrower type. This
4869 * is beneficial because in this case we can still presume that since the original getter was optimistic, the
4870 * conversion has no side effects.
4871 * @param name the name of the property being get
4872 * @param flags call site flags
4873 * @param isMethod whether we're preferably retrieving a function
4874 * @return the current method emitter
4875 */
4876 MethodEmitter dynamicGet(final String name, final int flags, final boolean isMethod, final boolean isIndex) {
4877 if(isOptimistic) {
4878 return method.dynamicGet(getOptimisticCoercedType(), name, getOptimisticFlags(flags), isMethod, isIndex);
4879 }
4880 return method.dynamicGet(resultBounds.within(expression.getType()), name, nonOptimisticFlags(flags), isMethod, isIndex);
4881 }
4882
4883 MethodEmitter dynamicGetIndex(final int flags, final boolean isMethod) {
4884 if(isOptimistic) {
4885 return method.dynamicGetIndex(getOptimisticCoercedType(), getOptimisticFlags(flags), isMethod);
4886 }
4887 return method.dynamicGetIndex(resultBounds.within(expression.getType()), nonOptimisticFlags(flags), isMethod);
4888 }
4889
4890 MethodEmitter dynamicCall(final int argCount, final int flags, final String msg) {
4891 if (isOptimistic) {
4892 return method.dynamicCall(getOptimisticCoercedType(), argCount, getOptimisticFlags(flags), msg);
4893 }
4894 return method.dynamicCall(resultBounds.within(expression.getType()), argCount, nonOptimisticFlags(flags), msg);
4895 }
4896
4897 int getOptimisticFlags(final int flags) {
4898 return flags | CALLSITE_OPTIMISTIC | (optimistic.getProgramPoint() << CALLSITE_PROGRAM_POINT_SHIFT); //encode program point in high bits
4899 }
4900
4901 int getProgramPoint() {
4902 return isOptimistic ? optimistic.getProgramPoint() : INVALID_PROGRAM_POINT;
4903 }
4904
4905 void convertOptimisticReturnValue() {
4906 if (isOptimistic) {
4907 final Type optimisticType = getOptimisticCoercedType();
4908 if(!optimisticType.isObject()) {
4909 method.load(optimistic.getProgramPoint());
4910 if(optimisticType.isInteger()) {
4911 method.invoke(ENSURE_INT);
4912 } else if(optimisticType.isNumber()) {
4913 method.invoke(ENSURE_NUMBER);
4914 } else {
4915 throw new AssertionError(optimisticType);
4916 }
4917 }
4918 }
4919 }
4920
4921 void replaceCompileTimeProperty() {
4922 final IdentNode identNode = (IdentNode)expression;
4923 final String name = identNode.getSymbol().getName();
4924 if (CompilerConstants.__FILE__.name().equals(name)) {
4925 replaceCompileTimeProperty(getCurrentSource().getName());
4926 } else if (CompilerConstants.__DIR__.name().equals(name)) {
4927 replaceCompileTimeProperty(getCurrentSource().getBase());
4928 } else if (CompilerConstants.__LINE__.name().equals(name)) {
4929 replaceCompileTimeProperty(getCurrentSource().getLine(identNode.position()));
4930 }
4931 }
4932
4933 /**
4934 * When an ident with name __FILE__, __DIR__, or __LINE__ is loaded, we'll try to look it up as any other
4935 * identifier. However, if it gets all the way up to the Global object, it will send back a special value that
4936 * represents a placeholder for these compile-time location properties. This method will generate code that loads
4937 * the value of the compile-time location property and then invokes a method in Global that will replace the
4938 * placeholder with the value. Effectively, if the symbol for these properties is defined anywhere in the lexical
4939 * scope, they take precedence, but if they aren't, then they resolve to the compile-time location property.
4940 * @param propertyValue the actual value of the property
4941 */
4942 private void replaceCompileTimeProperty(final Object propertyValue) {
4943 assert method.peekType().isObject();
4944 if(propertyValue instanceof String || propertyValue == null) {
4945 method.load((String)propertyValue);
4946 } else if(propertyValue instanceof Integer) {
4947 method.load(((Integer)propertyValue));
4948 method.convert(Type.OBJECT);
4949 } else {
4950 throw new AssertionError();
4951 }
4952 globalReplaceLocationPropertyPlaceholder();
4953 convertOptimisticReturnValue();
4954 }
4955
4956 /**
4957 * Returns the type that should be used as the return type of the dynamic invocation that is emitted as the code
4958 * for the current optimistic operation. If the type bounds is exact boolean or narrower than the expression's
4959 * optimistic type, then the optimistic type is returned, otherwise the coercing type. Effectively, this method
4960 * allows for moving the coercion into the optimistic type when it won't adversely affect the optimistic
4961 * evaluation semantics, and for preserving the optimistic type and doing a separate coercion when it would
4962 * affect it.
4963 * @return
4964 */
4965 private Type getOptimisticCoercedType() {
4966 final Type optimisticType = expression.getType();
4967 assert resultBounds.widest.widerThan(optimisticType);
4968 final Type narrowest = resultBounds.narrowest;
4969
4970 if(narrowest.isBoolean() || narrowest.narrowerThan(optimisticType)) {
4971 assert !optimisticType.isObject();
4972 return optimisticType;
4973 }
4974 assert !narrowest.isObject();
4975 return narrowest;
4976 }
4977 }
4978
4979 private static boolean isOptimistic(final Optimistic optimistic) {
4980 if(!optimistic.canBeOptimistic()) {
4981 return false;
4982 }
4983 final Expression expr = (Expression)optimistic;
4984 return expr.getType().narrowerThan(expr.getWidestOperationType());
4985 }
4986
4987 private static boolean everyLocalLoadIsValid(final int[] loads, final int localCount) {
4988 for (final int load : loads) {
4989 if(load < 0 || load >= localCount) {
4990 return false;
4991 }
4992 }
4993 return true;
4994 }
4995
4996 private static boolean everyStackValueIsLocalLoad(final int[] loads) {
4997 for (final int load : loads) {
4998 if(load == Label.Stack.NON_LOAD) {
4999 return false;
5000 }
5001 }
5002 return true;
5003 }
5004
5005 private String getLvarTypesDescriptor(final List<Type> localVarTypes) {
5006 final int count = localVarTypes.size();
5007 final StringBuilder desc = new StringBuilder(count);
5008 for(int i = 0; i < count;) {
5009 i += appendType(desc, localVarTypes.get(i));
5010 }
5011 return method.markSymbolBoundariesInLvarTypesDescriptor(desc.toString());
5012 }
5013
5014 private static int appendType(final StringBuilder b, final Type t) {
5015 b.append(t.getBytecodeStackType());
5016 return t.getSlots();
5017 }
5018
5019 private static int countSymbolsInLvarTypeDescriptor(final String lvarTypeDescriptor) {
5020 int count = 0;
5021 for(int i = 0; i < lvarTypeDescriptor.length(); ++i) {
5022 if(Character.isUpperCase(lvarTypeDescriptor.charAt(i))) {
5023 ++count;
5024 }
5025 }
5026 return count;
5027
5028 }
5029 /**
5030 * Generates all the required {@code UnwarrantedOptimismException} handlers for the current function. The employed
5031 * strategy strives to maximize code reuse. Every handler constructs an array to hold the local variables, then
5032 * fills in some trailing part of the local variables (those for which it has a unique suffix in the descriptor),
5033 * then jumps to a handler for a prefix that's shared with other handlers. A handler that fills up locals up to
5034 * position 0 will not jump to a prefix handler (as it has no prefix), but instead end with constructing and
5035 * throwing a {@code RewriteException}. Since we lexicographically sort the entries, we only need to check every
5036 * entry to its immediately preceding one for longest matching prefix.
5037 * @return true if there is at least one exception handler
5038 */
5039 private boolean generateUnwarrantedOptimismExceptionHandlers(final FunctionNode fn) {
5040 if(!useOptimisticTypes()) {
5041 return false;
5042 }
5043
5044 // Take the mapping of lvarSpecs -> labels, and turn them into a descending lexicographically sorted list of
5045 // handler specifications.
5046 final Map<String, Collection<Label>> unwarrantedOptimismHandlers = lc.popUnwarrantedOptimismHandlers();
5047 if(unwarrantedOptimismHandlers.isEmpty()) {
5048 return false;
5049 }
5050
5051 method.lineNumber(0);
5052
5053 final List<OptimismExceptionHandlerSpec> handlerSpecs = new ArrayList<>(unwarrantedOptimismHandlers.size() * 4/3);
5054 for(final String spec: unwarrantedOptimismHandlers.keySet()) {
5055 handlerSpecs.add(new OptimismExceptionHandlerSpec(spec, true));
5056 }
5057 Collections.sort(handlerSpecs, Collections.reverseOrder());
5058
5059 // Map of local variable specifications to labels for populating the array for that local variable spec.
5060 final Map<String, Label> delegationLabels = new HashMap<>();
5061
5062 // Do everything in a single pass over the handlerSpecs list. Note that the list can actually grow as we're
5063 // passing through it as we might add new prefix handlers into it, so can't hoist size() outside of the loop.
5064 for(int handlerIndex = 0; handlerIndex < handlerSpecs.size(); ++handlerIndex) {
5065 final OptimismExceptionHandlerSpec spec = handlerSpecs.get(handlerIndex);
5066 final String lvarSpec = spec.lvarSpec;
5067 if(spec.catchTarget) {
5068 assert !method.isReachable();
5069 // Start a catch block and assign the labels for this lvarSpec with it.
5070 method._catch(unwarrantedOptimismHandlers.get(lvarSpec));
5071 // This spec is a catch target, so emit array creation code. The length of the array is the number of
5072 // symbols - the number of uppercase characters.
5073 method.load(countSymbolsInLvarTypeDescriptor(lvarSpec));
5074 method.newarray(Type.OBJECT_ARRAY);
5075 }
5076 if(spec.delegationTarget) {
5077 // If another handler can delegate to this handler as its prefix, then put a jump target here for the
5078 // shared code (after the array creation code, which is never shared).
5079 method.label(delegationLabels.get(lvarSpec)); // label must exist
5080 }
5081
5082 final boolean lastHandler = handlerIndex == handlerSpecs.size() - 1;
5083
5084 int lvarIndex;
5085 final int firstArrayIndex;
5086 final int firstLvarIndex;
5087 Label delegationLabel;
5088 final String commonLvarSpec;
5089 if(lastHandler) {
5090 // Last handler block, doesn't delegate to anything.
5091 lvarIndex = 0;
5092 firstLvarIndex = 0;
5093 firstArrayIndex = 0;
5094 delegationLabel = null;
5095 commonLvarSpec = null;
5096 } else {
5097 // Not yet the last handler block, will definitely delegate to another handler; let's figure out which
5098 // one. It can be an already declared handler further down the list, or it might need to declare a new
5099 // prefix handler.
5100
5101 // Since we're lexicographically ordered, the common prefix handler is defined by the common prefix of
5102 // this handler and the next handler on the list.
5103 final int nextHandlerIndex = handlerIndex + 1;
5104 final String nextLvarSpec = handlerSpecs.get(nextHandlerIndex).lvarSpec;
5105 commonLvarSpec = commonPrefix(lvarSpec, nextLvarSpec);
5106 // We don't chop symbols in half
5107 assert Character.isUpperCase(commonLvarSpec.charAt(commonLvarSpec.length() - 1));
5108
5109 // Let's find if we already have a declaration for such handler, or we need to insert it.
5110 {
5111 boolean addNewHandler = true;
5112 int commonHandlerIndex = nextHandlerIndex;
5113 for(; commonHandlerIndex < handlerSpecs.size(); ++commonHandlerIndex) {
5114 final OptimismExceptionHandlerSpec forwardHandlerSpec = handlerSpecs.get(commonHandlerIndex);
5115 final String forwardLvarSpec = forwardHandlerSpec.lvarSpec;
5116 if(forwardLvarSpec.equals(commonLvarSpec)) {
5117 // We already have a handler for the common prefix.
5118 addNewHandler = false;
5119 // Make sure we mark it as a delegation target.
5120 forwardHandlerSpec.delegationTarget = true;
5121 break;
5122 } else if(!forwardLvarSpec.startsWith(commonLvarSpec)) {
5123 break;
5124 }
5125 }
5126 if(addNewHandler) {
5127 // We need to insert a common prefix handler. Note handlers created with catchTarget == false
5128 // will automatically have delegationTarget == true (because that's the only reason for their
5129 // existence).
5130 handlerSpecs.add(commonHandlerIndex, new OptimismExceptionHandlerSpec(commonLvarSpec, false));
5131 }
5132 }
5133
5134 firstArrayIndex = countSymbolsInLvarTypeDescriptor(commonLvarSpec);
5135 lvarIndex = 0;
5136 for(int j = 0; j < commonLvarSpec.length(); ++j) {
5137 lvarIndex += CodeGeneratorLexicalContext.getTypeForSlotDescriptor(commonLvarSpec.charAt(j)).getSlots();
5138 }
5139 firstLvarIndex = lvarIndex;
5140
5141 // Create a delegation label if not already present
5142 delegationLabel = delegationLabels.get(commonLvarSpec);
5143 if(delegationLabel == null) {
5144 // uo_pa == "unwarranted optimism, populate array"
5145 delegationLabel = new Label("uo_pa_" + commonLvarSpec);
5146 delegationLabels.put(commonLvarSpec, delegationLabel);
5147 }
5148 }
5149
5150 // Load local variables handled by this handler on stack
5151 int args = 0;
5152 boolean symbolHadValue = false;
5153 for(int typeIndex = commonLvarSpec == null ? 0 : commonLvarSpec.length(); typeIndex < lvarSpec.length(); ++typeIndex) {
5154 final char typeDesc = lvarSpec.charAt(typeIndex);
5155 final Type lvarType = CodeGeneratorLexicalContext.getTypeForSlotDescriptor(typeDesc);
5156 if (!lvarType.isUnknown()) {
5157 method.load(lvarType, lvarIndex);
5158 symbolHadValue = true;
5159 args++;
5160 } else if(typeDesc == 'U' && !symbolHadValue) {
5161 // Symbol boundary with undefined last value. Check if all previous values for this symbol were also
5162 // undefined; if so, emit one explicit Undefined. This serves to ensure that we're emiting exactly
5163 // one value for every symbol that uses local slots. While we could in theory ignore symbols that
5164 // are undefined (in other words, dead) at the point where this exception was thrown, unfortunately
5165 // we can't do it in practice. The reason for this is that currently our liveness analysis is
5166 // coarse (it can determine whether a symbol has not been read with a particular type anywhere in
5167 // the function being compiled, but that's it), and a symbol being promoted to Object due to a
5168 // deoptimization will suddenly show up as "live for Object type", and previously dead U->O
5169 // conversions on loop entries will suddenly become alive in the deoptimized method which will then
5170 // expect a value for that slot in its continuation handler. If we had precise liveness analysis, we
5171 // could go back to excluding known dead symbols from the payload of the RewriteException.
5172 if(method.peekType() == Type.UNDEFINED) {
5173 method.dup();
5174 } else {
5175 method.loadUndefined(Type.OBJECT);
5176 }
5177 args++;
5178 }
5179 if(Character.isUpperCase(typeDesc)) {
5180 // Reached symbol boundary; reset flag for the next symbol.
5181 symbolHadValue = false;
5182 }
5183 lvarIndex += lvarType.getSlots();
5184 }
5185 assert args > 0;
5186 // Delegate actual storing into array to an array populator utility method.
5187 //on the stack:
5188 // object array to be populated
5189 // start index
5190 // a lot of types
5191 method.dynamicArrayPopulatorCall(args + 1, firstArrayIndex);
5192 if(delegationLabel != null) {
5193 // We cascade to a prefix handler to fill out the rest of the local variables and throw the
5194 // RewriteException.
5195 assert !lastHandler;
5196 assert commonLvarSpec != null;
5197 // Must undefine the local variables that we have already processed for the sake of correct join on the
5198 // delegate label
5199 method.undefineLocalVariables(firstLvarIndex, true);
5200 final OptimismExceptionHandlerSpec nextSpec = handlerSpecs.get(handlerIndex + 1);
5201 // If the delegate immediately follows, and it's not a catch target (so it doesn't have array setup
5202 // code) don't bother emitting a jump, as we'd just jump to the next instruction.
5203 if(!nextSpec.lvarSpec.equals(commonLvarSpec) || nextSpec.catchTarget) {
5204 method._goto(delegationLabel);
5205 }
5206 } else {
5207 assert lastHandler;
5208 // Nothing to delegate to, so this handler must create and throw the RewriteException.
5209 // At this point we have the UnwarrantedOptimismException and the Object[] with local variables on
5210 // stack. We need to create a RewriteException, push two references to it below the constructor
5211 // arguments, invoke the constructor, and throw the exception.
5212 loadConstant(getByteCodeSymbolNames(fn));
5213 if (isRestOf()) {
5214 loadConstant(getContinuationEntryPoints());
5215 method.invoke(CREATE_REWRITE_EXCEPTION_REST_OF);
5216 } else {
5217 method.invoke(CREATE_REWRITE_EXCEPTION);
5218 }
5219 method.athrow();
5220 }
5221 }
5222 return true;
5223 }
5224
5225 private static String[] getByteCodeSymbolNames(final FunctionNode fn) {
5226 // Only names of local variables on the function level are captured. This information is used to reduce
5227 // deoptimizations, so as much as we can capture will help. We rely on the fact that function wide variables are
5228 // all live all the time, so the array passed to rewrite exception contains one element for every slotted symbol
5229 // here.
5230 final List<String> names = new ArrayList<>();
5231 for (final Symbol symbol: fn.getBody().getSymbols()) {
5232 if (symbol.hasSlot()) {
5233 if (symbol.isScope()) {
5234 // slot + scope can only be true for parameters
5235 assert symbol.isParam();
5236 names.add(null);
5237 } else {
5238 names.add(symbol.getName());
5239 }
5240 }
5241 }
5242 return names.toArray(new String[0]);
5243 }
5244
5245 private static String commonPrefix(final String s1, final String s2) {
5246 final int l1 = s1.length();
5247 final int l = Math.min(l1, s2.length());
5248 int lms = -1; // last matching symbol
5249 for(int i = 0; i < l; ++i) {
5250 final char c1 = s1.charAt(i);
5251 if(c1 != s2.charAt(i)) {
5252 return s1.substring(0, lms + 1);
5253 } else if(Character.isUpperCase(c1)) {
5254 lms = i;
5255 }
5256 }
5257 return l == l1 ? s1 : s2;
5258 }
5259
5260 private static class OptimismExceptionHandlerSpec implements Comparable<OptimismExceptionHandlerSpec> {
5261 private final String lvarSpec;
5262 private final boolean catchTarget;
5263 private boolean delegationTarget;
5264
5265 OptimismExceptionHandlerSpec(final String lvarSpec, final boolean catchTarget) {
5266 this.lvarSpec = lvarSpec;
5267 this.catchTarget = catchTarget;
5268 if(!catchTarget) {
5269 delegationTarget = true;
5270 }
5271 }
5272
5273 @Override
5274 public int compareTo(final OptimismExceptionHandlerSpec o) {
5275 return lvarSpec.compareTo(o.lvarSpec);
5276 }
5277
5278 @Override
5279 public String toString() {
5280 final StringBuilder b = new StringBuilder(64).append("[HandlerSpec ").append(lvarSpec);
5281 if(catchTarget) {
5282 b.append(", catchTarget");
5283 }
5284 if(delegationTarget) {
5285 b.append(", delegationTarget");
5286 }
5287 return b.append("]").toString();
5288 }
5289 }
5290
5291 private static class ContinuationInfo {
5292 private final Label handlerLabel;
5293 private Label targetLabel; // Label for the target instruction.
5294 int lvarCount;
5295 // Indices of local variables that need to be loaded on the stack when this node completes
5296 private int[] stackStoreSpec;
5297 // Types of values loaded on the stack
5298 private Type[] stackTypes;
5299 // If non-null, this node should perform the requisite type conversion
5300 private Type returnValueType;
5301 // If we are in the middle of an object literal initialization, we need to update the map
5302 private PropertyMap objectLiteralMap;
5303 // Object literal stack depth for object literal - not necessarily top if property is a tree
5304 private int objectLiteralStackDepth = -1;
5305 // The line number at the continuation point
5306 private int lineNumber;
5307 // The active catch label, in case the continuation point is in a try/catch block
5308 private Label catchLabel;
5309 // The number of scopes that need to be popped before control is transferred to the catch label.
5310 private int exceptionScopePops;
5311
5312 ContinuationInfo() {
5313 this.handlerLabel = new Label("continuation_handler");
5314 }
5315
5316 Label getHandlerLabel() {
5317 return handlerLabel;
5318 }
5319
5320 boolean hasTargetLabel() {
5321 return targetLabel != null;
5322 }
5323
5324 Label getTargetLabel() {
5325 return targetLabel;
5326 }
5327
5328 void setTargetLabel(final Label targetLabel) {
5329 this.targetLabel = targetLabel;
5330 }
5331
5332 int[] getStackStoreSpec() {
5333 return stackStoreSpec.clone();
5334 }
5335
5336 void setStackStoreSpec(final int[] stackStoreSpec) {
5337 this.stackStoreSpec = stackStoreSpec;
5338 }
5339
5340 Type[] getStackTypes() {
5341 return stackTypes.clone();
5342 }
5343
5344 void setStackTypes(final Type[] stackTypes) {
5345 this.stackTypes = stackTypes;
5346 }
5347
5348 Type getReturnValueType() {
5349 return returnValueType;
5350 }
5351
5352 void setReturnValueType(final Type returnValueType) {
5353 this.returnValueType = returnValueType;
5354 }
5355
5356 int getObjectLiteralStackDepth() {
5357 return objectLiteralStackDepth;
5358 }
5359
5360 void setObjectLiteralStackDepth(final int objectLiteralStackDepth) {
5361 this.objectLiteralStackDepth = objectLiteralStackDepth;
5362 }
5363
5364 PropertyMap getObjectLiteralMap() {
5365 return objectLiteralMap;
5366 }
5367
5368 void setObjectLiteralMap(final PropertyMap objectLiteralMap) {
5369 this.objectLiteralMap = objectLiteralMap;
5370 }
5371
5372 @Override
5373 public String toString() {
5374 return "[localVariableTypes=" + targetLabel.getStack().getLocalVariableTypesCopy() + ", stackStoreSpec=" +
5375 Arrays.toString(stackStoreSpec) + ", returnValueType=" + returnValueType + "]";
5376 }
5377 }
5378
5379 private ContinuationInfo getContinuationInfo() {
5380 return continuationInfo;
5381 }
5382
5383 private void generateContinuationHandler() {
5384 if (!isRestOf()) {
5385 return;
5386 }
5387
5388 final ContinuationInfo ci = getContinuationInfo();
5389 method.label(ci.getHandlerLabel());
5390
5391 // There should never be an exception thrown from the continuation handler, but in case there is (meaning,
5392 // Nashorn has a bug), then line number 0 will be an indication of where it came from (line numbers are Uint16).
5393 method.lineNumber(0);
5394
5395 final Label.Stack stack = ci.getTargetLabel().getStack();
5396 final List<Type> lvarTypes = stack.getLocalVariableTypesCopy();
5397 final BitSet symbolBoundary = stack.getSymbolBoundaryCopy();
5398 final int lvarCount = ci.lvarCount;
5399
5400 final Type rewriteExceptionType = Type.typeFor(RewriteException.class);
5401 // Store the RewriteException into an unused local variable slot.
5402 method.load(rewriteExceptionType, 0);
5403 method.storeTemp(rewriteExceptionType, lvarCount);
5404 // Get local variable array
5405 method.load(rewriteExceptionType, 0);
5406 method.invoke(RewriteException.GET_BYTECODE_SLOTS);
5407 // Store local variables. Note that deoptimization might introduce new value types for existing local variables,
5408 // so we must use both liveLocals and symbolBoundary, as in some cases (when the continuation is inside of a try
5409 // block) we need to store the incoming value into multiple slots. The optimism exception handlers will have
5410 // exactly one array element for every symbol that uses bytecode storage. If in the originating method the value
5411 // was undefined, there will be an explicit Undefined value in the array.
5412 int arrayIndex = 0;
5413 for(int lvarIndex = 0; lvarIndex < lvarCount;) {
5414 final Type lvarType = lvarTypes.get(lvarIndex);
5415 if(!lvarType.isUnknown()) {
5416 method.dup();
5417 method.load(arrayIndex).arrayload();
5418 final Class<?> typeClass = lvarType.getTypeClass();
5419 // Deoptimization in array initializers can cause arrays to undergo component type widening
5420 if(typeClass == long[].class) {
5421 method.load(rewriteExceptionType, lvarCount);
5422 method.invoke(RewriteException.TO_LONG_ARRAY);
5423 } else if(typeClass == double[].class) {
5424 method.load(rewriteExceptionType, lvarCount);
5425 method.invoke(RewriteException.TO_DOUBLE_ARRAY);
5426 } else if(typeClass == Object[].class) {
5427 method.load(rewriteExceptionType, lvarCount);
5428 method.invoke(RewriteException.TO_OBJECT_ARRAY);
5429 } else {
5430 if(!(typeClass.isPrimitive() || typeClass == Object.class)) {
5431 // NOTE: this can only happen with dead stores. E.g. for the program "1; []; f();" in which the
5432 // call to f() will deoptimize the call site, but it'll expect :return to have the type
5433 // NativeArray. However, in the more optimal version, :return's only live type is int, therefore
5434 // "{O}:return = []" is a dead store, and the variable will be sent into the continuation as
5435 // Undefined, however NativeArray can't hold Undefined instance.
5436 method.loadType(Type.getInternalName(typeClass));
5437 method.invoke(RewriteException.INSTANCE_OR_NULL);
5438 }
5439 method.convert(lvarType);
5440 }
5441 method.storeHidden(lvarType, lvarIndex, false);
5442 }
5443 final int nextLvarIndex = lvarIndex + lvarType.getSlots();
5444 if(symbolBoundary.get(nextLvarIndex - 1)) {
5445 ++arrayIndex;
5446 }
5447 lvarIndex = nextLvarIndex;
5448 }
5449 if (AssertsEnabled.assertsEnabled()) {
5450 method.load(arrayIndex);
5451 method.invoke(RewriteException.ASSERT_ARRAY_LENGTH);
5452 } else {
5453 method.pop();
5454 }
5455
5456 final int[] stackStoreSpec = ci.getStackStoreSpec();
5457 final Type[] stackTypes = ci.getStackTypes();
5458 final boolean isStackEmpty = stackStoreSpec.length == 0;
5459 boolean replacedObjectLiteralMap = false;
5460 if(!isStackEmpty) {
5461 // Load arguments on the stack
5462 final int objectLiteralStackDepth = ci.getObjectLiteralStackDepth();
5463 for(int i = 0; i < stackStoreSpec.length; ++i) {
5464 final int slot = stackStoreSpec[i];
5465 method.load(lvarTypes.get(slot), slot);
5466 method.convert(stackTypes[i]);
5467 // stack: s0=object literal being initialized
5468 // change map of s0 so that the property we are initializing when we failed
5469 // is now ci.returnValueType
5470 if (i == objectLiteralStackDepth) {
5471 method.dup();
5472 assert ci.getObjectLiteralMap() != null;
5473 assert ScriptObject.class.isAssignableFrom(method.peekType().getTypeClass()) : method.peekType().getTypeClass() + " is not a script object";
5474 loadConstant(ci.getObjectLiteralMap());
5475 method.invoke(ScriptObject.SET_MAP);
5476 replacedObjectLiteralMap = true;
5477 }
5478 }
5479 }
5480 // Must have emitted the code for replacing the map of an object literal if we have a set object literal stack depth
5481 assert ci.getObjectLiteralStackDepth() == -1 || replacedObjectLiteralMap;
5482 // Load RewriteException back.
5483 method.load(rewriteExceptionType, lvarCount);
5484 // Get rid of the stored reference
5485 method.loadNull();
5486 method.storeHidden(Type.OBJECT, lvarCount);
5487 // Mark it dead
5488 method.markDeadSlots(lvarCount, Type.OBJECT.getSlots());
5489
5490 // Load return value on the stack
5491 method.invoke(RewriteException.GET_RETURN_VALUE);
5492
5493 final Type returnValueType = ci.getReturnValueType();
5494
5495 // Set up an exception handler for primitive type conversion of return value if needed
5496 boolean needsCatch = false;
5497 final Label targetCatchLabel = ci.catchLabel;
5498 Label _try = null;
5499 if(returnValueType.isPrimitive()) {
5500 // If the conversion throws an exception, we want to report the line number of the continuation point.
5501 method.lineNumber(ci.lineNumber);
5502
5503 if(targetCatchLabel != METHOD_BOUNDARY) {
5504 _try = new Label("");
5505 method.label(_try);
5506 needsCatch = true;
5507 }
5508 }
5509
5510 // Convert return value
5511 method.convert(returnValueType);
5512
5513 final int scopePopCount = needsCatch ? ci.exceptionScopePops : 0;
5514
5515 // Declare a try/catch for the conversion. If no scopes need to be popped until the target catch block, just
5516 // jump into it. Otherwise, we'll need to create a scope-popping catch block below.
5517 final Label catchLabel = scopePopCount > 0 ? new Label("") : targetCatchLabel;
5518 if(needsCatch) {
5519 final Label _end_try = new Label("");
5520 method.label(_end_try);
5521 method._try(_try, _end_try, catchLabel);
5522 }
5523
5524 // Jump to continuation point
5525 method._goto(ci.getTargetLabel());
5526
5527 // Make a scope-popping exception delegate if needed
5528 if(catchLabel != targetCatchLabel) {
5529 method.lineNumber(0);
5530 assert scopePopCount > 0;
5531 method._catch(catchLabel);
5532 popScopes(scopePopCount);
5533 method.uncheckedGoto(targetCatchLabel);
5534 }
5535 }
5536
5537 /**
5538 * Interface implemented by object creators that support splitting over multiple methods.
5539 */
5540 interface SplitLiteralCreator {
5541 /**
5542 * Generate code to populate a range of the literal object. A reference to the object
5543 * should be left on the stack when the method terminates.
5544 *
5545 * @param method the method emitter
5546 * @param type the type of the literal object
5547 * @param slot the local slot containing the literal object
5548 * @param start the start index (inclusive)
5549 * @param end the end index (exclusive)
5550 */
5551 void populateRange(MethodEmitter method, Type type, int slot, int start, int end);
5552 }
5553 }