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