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