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