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_LONG = CompilerConstants.staticCallNoLookup(OptimisticReturnFilters.class,
192 "ensureLong", long.class, Object.class, int.class);
193 private static final Call ENSURE_NUMBER = CompilerConstants.staticCallNoLookup(OptimisticReturnFilters.class,
194 "ensureNumber", double.class, Object.class, int.class);
195
196 private static final Call CREATE_FUNCTION_OBJECT = CompilerConstants.staticCallNoLookup(ScriptFunction.class,
197 "create", ScriptFunction.class, Object[].class, int.class, ScriptObject.class);
198 private static final Call CREATE_FUNCTION_OBJECT_NO_SCOPE = CompilerConstants.staticCallNoLookup(ScriptFunction.class,
199 "create", ScriptFunction.class, Object[].class, int.class);
200
201 private static final Call TO_NUMBER_FOR_EQ = CompilerConstants.staticCallNoLookup(JSType.class,
202 "toNumberForEq", double.class, Object.class);
203 private static final Call TO_NUMBER_FOR_STRICT_EQ = CompilerConstants.staticCallNoLookup(JSType.class,
204 "toNumberForStrictEq", double.class, Object.class);
205
206
207 private static final Class<?> ITERATOR_CLASS = Iterator.class;
208 static {
209 assert ITERATOR_CLASS == CompilerConstants.ITERATOR_PREFIX.type();
210 }
211 private static final Type ITERATOR_TYPE = Type.typeFor(ITERATOR_CLASS);
212 private static final Type EXCEPTION_TYPE = Type.typeFor(CompilerConstants.EXCEPTION_PREFIX.type());
213
214 private static final Integer INT_ZERO = 0;
215
216 /** Constant data & installation. The only reason the compiler keeps this is because it is assigned
217 * by reflection in class installation */
218 private final Compiler compiler;
219
220 /** Is the current code submitted by 'eval' call? */
221 private final boolean evalCode;
222
223 /** Call site flags given to the code generator to be used for all generated call sites */
224 private final int callSiteFlags;
225
226 /** How many regexp fields have been emitted */
227 private int regexFieldCount;
228
229 /** Line number for last statement. If we encounter a new line number, line number bytecode information
230 * needs to be generated */
231 private int lastLineNumber = -1;
232
233 /** When should we stop caching regexp expressions in fields to limit bytecode size? */
234 private static final int MAX_REGEX_FIELDS = 2 * 1024;
235
236 /** Current method emitter */
237 private MethodEmitter method;
238
239 /** Current compile unit */
240 private CompileUnit unit;
241
242 private final DebugLogger log;
243
244 /** From what size should we use spill instead of fields for JavaScript objects? */
245 static final int OBJECT_SPILL_THRESHOLD = Options.getIntProperty("nashorn.spill.threshold", 256);
246
247 private final Set<String> emittedMethods = new HashSet<>();
248
249 // Function Id -> ContinuationInfo. Used by compilation of rest-of function only.
250 private ContinuationInfo continuationInfo;
251
252 private final Deque<Label> scopeEntryLabels = new ArrayDeque<>();
253
254 private static final Label METHOD_BOUNDARY = new Label("");
255 private final Deque<Label> catchLabels = new ArrayDeque<>();
256 // Number of live locals on entry to (and thus also break from) labeled blocks.
257 private final IntDeque labeledBlockBreakLiveLocals = new IntDeque();
258
259 //is this a rest of compilation
260 private final int[] continuationEntryPoints;
261
262 /**
263 * Constructor.
264 *
265 * @param compiler
266 */
267 CodeGenerator(final Compiler compiler, final int[] continuationEntryPoints) {
268 super(new CodeGeneratorLexicalContext());
269 this.compiler = compiler;
270 this.evalCode = compiler.getSource().isEvalCode();
271 this.continuationEntryPoints = continuationEntryPoints;
272 this.callSiteFlags = compiler.getScriptEnvironment()._callsite_flags;
273 this.log = initLogger(compiler.getContext());
274 }
275
276 @Override
277 public DebugLogger getLogger() {
278 return log;
279 }
280
281 @Override
282 public DebugLogger initLogger(final Context context) {
283 return context.getLogger(this.getClass());
284 }
285
286 /**
287 * Gets the call site flags, adding the strict flag if the current function
288 * being generated is in strict mode
289 *
290 * @return the correct flags for a call site in the current function
291 */
292 int getCallSiteFlags() {
293 return lc.getCurrentFunction().getCallSiteFlags() | callSiteFlags;
294 }
295
296 /**
297 * Gets the flags for a scope call site.
298 * @param symbol a scope symbol
299 * @return the correct flags for the scope call site
300 */
301 private int getScopeCallSiteFlags(final Symbol symbol) {
302 assert symbol.isScope();
303 final int flags = getCallSiteFlags() | CALLSITE_SCOPE;
304 if (isEvalCode() && symbol.isGlobal()) {
305 return flags; // Don't set fast-scope flag on non-declared globals in eval code - see JDK-8077955.
306 }
307 return isFastScope(symbol) ? flags | CALLSITE_FAST_SCOPE : flags;
308 }
309
310 /**
311 * Are we generating code for 'eval' code?
312 * @return true if currently compiled code is 'eval' code.
313 */
314 boolean isEvalCode() {
315 return evalCode;
316 }
317
318 /**
319 * Are we using dual primitive/object field representation?
320 * @return true if using dual field representation, false for object-only fields
321 */
322 boolean useDualFields() {
323 return compiler.getContext().useDualFields();
324 }
325
326 /**
327 * Load an identity node
328 *
329 * @param identNode an identity node to load
330 * @return the method generator used
331 */
332 private MethodEmitter loadIdent(final IdentNode identNode, final TypeBounds resultBounds) {
333 checkTemporalDeadZone(identNode);
334 final Symbol symbol = identNode.getSymbol();
335
336 if (!symbol.isScope()) {
337 final Type type = identNode.getType();
338 if(type == Type.UNDEFINED) {
339 return method.loadUndefined(resultBounds.widest);
340 }
341
342 assert symbol.hasSlot() || symbol.isParam();
343 return method.load(identNode);
344 }
345
346 assert identNode.getSymbol().isScope() : identNode + " is not in scope!";
347 final int flags = getScopeCallSiteFlags(symbol);
348 if (isFastScope(symbol)) {
349 // Only generate shared scope getter for fast-scope symbols so we know we can dial in correct scope.
350 if (symbol.getUseCount() > SharedScopeCall.FAST_SCOPE_GET_THRESHOLD && !identNode.isOptimistic()) {
351 // As shared scope vars are only used with non-optimistic identifiers, we switch from using TypeBounds to
352 // just a single definitive type, resultBounds.widest.
353 new OptimisticOperation(identNode, TypeBounds.OBJECT) {
354 @Override
355 void loadStack() {
356 method.loadCompilerConstant(SCOPE);
357 }
358
359 @Override
360 void consumeStack() {
361 loadSharedScopeVar(resultBounds.widest, symbol, flags);
362 }
363 }.emit();
364 } else {
365 new LoadFastScopeVar(identNode, resultBounds, flags).emit();
366 }
367 } else {
368 //slow scope load, we have no proto depth
369 new LoadScopeVar(identNode, resultBounds, flags).emit();
370 }
371
372 return method;
373 }
374
375 // Any access to LET and CONST variables before their declaration must throw ReferenceError.
376 // This is called the temporal dead zone (TDZ). See https://gist.github.com/rwaldron/f0807a758aa03bcdd58a
377 private void checkTemporalDeadZone(final IdentNode identNode) {
378 if (identNode.isDead()) {
379 method.load(identNode.getSymbol().getName()).invoke(ScriptRuntime.THROW_REFERENCE_ERROR);
380 }
381 }
382
383 // Runtime check for assignment to ES6 const
384 private void checkAssignTarget(final Expression expression) {
385 if (expression instanceof IdentNode && ((IdentNode)expression).getSymbol().isConst()) {
386 method.load(((IdentNode)expression).getSymbol().getName()).invoke(ScriptRuntime.THROW_CONST_TYPE_ERROR);
387 }
388 }
389
390 private boolean isRestOf() {
391 return continuationEntryPoints != null;
392 }
393
394 private boolean isCurrentContinuationEntryPoint(final int programPoint) {
395 return isRestOf() && getCurrentContinuationEntryPoint() == programPoint;
396 }
397
398 private int[] getContinuationEntryPoints() {
399 return isRestOf() ? continuationEntryPoints : null;
400 }
401
402 private int getCurrentContinuationEntryPoint() {
403 return isRestOf() ? continuationEntryPoints[0] : INVALID_PROGRAM_POINT;
404 }
405
406 private boolean isContinuationEntryPoint(final int programPoint) {
407 if (isRestOf()) {
408 assert continuationEntryPoints != null;
409 for (final int cep : continuationEntryPoints) {
410 if (cep == programPoint) {
411 return true;
412 }
413 }
414 }
415 return false;
416 }
417
418 /**
419 * Check if this symbol can be accessed directly with a putfield or getfield or dynamic load
420 *
421 * @param symbol symbol to check for fast scope
422 * @return true if fast scope
423 */
424 private boolean isFastScope(final Symbol symbol) {
425 if (!symbol.isScope()) {
426 return false;
427 }
428
429 if (!lc.inDynamicScope()) {
430 // If there's no with or eval in context, and the symbol is marked as scoped, it is fast scoped. Such a
431 // symbol must either be global, or its defining block must need scope.
432 assert symbol.isGlobal() || lc.getDefiningBlock(symbol).needsScope() : symbol.getName();
433 return true;
434 }
435
436 if (symbol.isGlobal()) {
437 // Shortcut: if there's a with or eval in context, globals can't be fast scoped
438 return false;
439 }
440
441 // Otherwise, check if there's a dynamic scope between use of the symbol and its definition
442 final String name = symbol.getName();
443 boolean previousWasBlock = false;
444 for (final Iterator<LexicalContextNode> it = lc.getAllNodes(); it.hasNext();) {
445 final LexicalContextNode node = it.next();
446 if (node instanceof Block) {
447 // If this block defines the symbol, then we can fast scope the symbol.
448 final Block block = (Block)node;
449 if (block.getExistingSymbol(name) == symbol) {
450 assert block.needsScope();
451 return true;
452 }
453 previousWasBlock = true;
454 } else {
455 if (node instanceof WithNode && previousWasBlock || node instanceof FunctionNode && ((FunctionNode)node).needsDynamicScope()) {
456 // If we hit a scope that can have symbols introduced into it at run time before finding the defining
457 // block, the symbol can't be fast scoped. A WithNode only counts if we've immediately seen a block
458 // before - its block. Otherwise, we are currently processing the WithNode's expression, and that's
459 // obviously not subjected to introducing new symbols.
460 return false;
461 }
462 previousWasBlock = false;
463 }
464 }
465 // Should've found the symbol defined in a block
466 throw new AssertionError();
467 }
468
469 private MethodEmitter loadSharedScopeVar(final Type valueType, final Symbol symbol, final int flags) {
470 assert isFastScope(symbol);
471 method.load(getScopeProtoDepth(lc.getCurrentBlock(), symbol));
472 return lc.getScopeGet(unit, symbol, valueType, flags).generateInvoke(method);
473 }
474
475 private class LoadScopeVar extends OptimisticOperation {
476 final IdentNode identNode;
477 private final int flags;
478
479 LoadScopeVar(final IdentNode identNode, final TypeBounds resultBounds, final int flags) {
480 super(identNode, resultBounds);
481 this.identNode = identNode;
482 this.flags = flags;
483 }
484
485 @Override
486 void loadStack() {
487 method.loadCompilerConstant(SCOPE);
488 getProto();
489 }
490
491 void getProto() {
492 //empty
493 }
494
495 @Override
496 void consumeStack() {
497 // If this is either __FILE__, __DIR__, or __LINE__ then load the property initially as Object as we'd convert
498 // it anyway for replaceLocationPropertyPlaceholder.
499 if(identNode.isCompileTimePropertyName()) {
500 method.dynamicGet(Type.OBJECT, identNode.getSymbol().getName(), flags, identNode.isFunction(), false);
501 replaceCompileTimeProperty();
502 } else {
503 dynamicGet(identNode.getSymbol().getName(), flags, identNode.isFunction(), false);
504 }
505 }
506 }
507
508 private class LoadFastScopeVar extends LoadScopeVar {
509 LoadFastScopeVar(final IdentNode identNode, final TypeBounds resultBounds, final int flags) {
510 super(identNode, resultBounds, flags);
511 }
512
513 @Override
514 void getProto() {
515 loadFastScopeProto(identNode.getSymbol(), false);
516 }
517 }
518
519 private MethodEmitter storeFastScopeVar(final Symbol symbol, final int flags) {
520 loadFastScopeProto(symbol, true);
521 method.dynamicSet(symbol.getName(), flags, false);
522 return method;
523 }
524
525 private int getScopeProtoDepth(final Block startingBlock, final Symbol symbol) {
526 //walk up the chain from starting block and when we bump into the current function boundary, add the external
527 //information.
528 final FunctionNode fn = lc.getCurrentFunction();
529 final int externalDepth = compiler.getScriptFunctionData(fn.getId()).getExternalSymbolDepth(symbol.getName());
530
531 //count the number of scopes from this place to the start of the function
532
533 final int internalDepth = FindScopeDepths.findInternalDepth(lc, fn, startingBlock, symbol);
534 final int scopesToStart = FindScopeDepths.findScopesToStart(lc, fn, startingBlock);
535 int depth = 0;
536 if (internalDepth == -1) {
537 depth = scopesToStart + externalDepth;
538 } else {
539 assert internalDepth <= scopesToStart;
540 depth = internalDepth;
541 }
542
543 return depth;
544 }
545
546 private void loadFastScopeProto(final Symbol symbol, final boolean swap) {
547 final int depth = getScopeProtoDepth(lc.getCurrentBlock(), symbol);
548 assert depth != -1 : "Couldn't find scope depth for symbol " + symbol.getName() + " in " + lc.getCurrentFunction();
549 if (depth > 0) {
550 if (swap) {
551 method.swap();
552 }
553 if (depth > 1) {
554 method.load(depth);
555 method.invoke(ScriptObject.GET_PROTO_DEPTH);
556 } else {
557 method.invoke(ScriptObject.GET_PROTO);
558 }
559 if (swap) {
560 method.swap();
561 }
562 }
563 }
564
565 /**
566 * Generate code that loads this node to the stack, not constraining its type
567 *
568 * @param expr node to load
569 *
570 * @return the method emitter used
571 */
572 private MethodEmitter loadExpressionUnbounded(final Expression expr) {
573 return loadExpression(expr, TypeBounds.UNBOUNDED);
574 }
575
576 private MethodEmitter loadExpressionAsObject(final Expression expr) {
577 return loadExpression(expr, TypeBounds.OBJECT);
578 }
579
580 MethodEmitter loadExpressionAsBoolean(final Expression expr) {
581 return loadExpression(expr, TypeBounds.BOOLEAN);
582 }
583
584 // Test whether conversion from source to target involves a call of ES 9.1 ToPrimitive
585 // with possible side effects from calling an object's toString or valueOf methods.
586 private static boolean noToPrimitiveConversion(final Type source, final Type target) {
587 // Object to boolean conversion does not cause ToPrimitive call
588 return source.isJSPrimitive() || !target.isJSPrimitive() || target.isBoolean();
589 }
590
591 MethodEmitter loadBinaryOperands(final BinaryNode binaryNode) {
592 return loadBinaryOperands(binaryNode.lhs(), binaryNode.rhs(), TypeBounds.UNBOUNDED.notWiderThan(binaryNode.getWidestOperandType()), false, false);
593 }
594
595 private MethodEmitter loadBinaryOperands(final Expression lhs, final Expression rhs, final TypeBounds explicitOperandBounds, final boolean baseAlreadyOnStack, final boolean forceConversionSeparation) {
596 // ECMAScript 5.1 specification (sections 11.5-11.11 and 11.13) prescribes that when evaluating a binary
597 // expression "LEFT op RIGHT", the order of operations must be: LOAD LEFT, LOAD RIGHT, CONVERT LEFT, CONVERT
598 // RIGHT, EXECUTE OP. Unfortunately, doing it in this order defeats potential optimizations that arise when we
599 // can combine a LOAD with a CONVERT operation (e.g. use a dynamic getter with the conversion target type as its
600 // return value). What we do here is reorder LOAD RIGHT and CONVERT LEFT when possible; it is possible only when
601 // we can prove that executing CONVERT LEFT can't have a side effect that changes the value of LOAD RIGHT.
602 // Basically, if we know that either LEFT already is a primitive value, or does not have to be converted to
603 // a primitive value, or RIGHT is an expression that loads without side effects, then we can do the
604 // reordering and collapse LOAD/CONVERT into a single operation; otherwise we need to do the more costly
605 // separate operations to preserve specification semantics.
606
607 // Operands' load type should not be narrower than the narrowest of the individual operand types, nor narrower
608 // than the lower explicit bound, but it should also not be wider than
609 final Type lhsType = undefinedToNumber(lhs.getType());
610 final Type rhsType = undefinedToNumber(rhs.getType());
611 final Type narrowestOperandType = Type.narrowest(Type.widest(lhsType, rhsType), explicitOperandBounds.widest);
612 final TypeBounds operandBounds = explicitOperandBounds.notNarrowerThan(narrowestOperandType);
613 if (noToPrimitiveConversion(lhsType, explicitOperandBounds.widest) || rhs.isLocal()) {
614 // Can reorder. We might still need to separate conversion, but at least we can do it with reordering
615 if (forceConversionSeparation) {
616 // Can reorder, but can't move conversion into the operand as the operation depends on operands
617 // exact types for its overflow guarantees. E.g. with {L}{%I}expr1 {L}* {L}{%I}expr2 we are not allowed
618 // to merge {L}{%I} into {%L}, as that can cause subsequent overflows; test for JDK-8058610 contains
619 // concrete cases where this could happen.
620 final TypeBounds safeConvertBounds = TypeBounds.UNBOUNDED.notNarrowerThan(narrowestOperandType);
621 loadExpression(lhs, safeConvertBounds, baseAlreadyOnStack);
622 method.convert(operandBounds.within(method.peekType()));
623 loadExpression(rhs, safeConvertBounds, false);
624 method.convert(operandBounds.within(method.peekType()));
625 } else {
626 // Can reorder and move conversion into the operand. Combine load and convert into single operations.
627 loadExpression(lhs, operandBounds, baseAlreadyOnStack);
628 loadExpression(rhs, operandBounds, false);
629 }
630 } else {
631 // Can't reorder. Load and convert separately.
632 final TypeBounds safeConvertBounds = TypeBounds.UNBOUNDED.notNarrowerThan(narrowestOperandType);
633 loadExpression(lhs, safeConvertBounds, baseAlreadyOnStack);
634 final Type lhsLoadedType = method.peekType();
635 loadExpression(rhs, safeConvertBounds, false);
636 final Type convertedLhsType = operandBounds.within(method.peekType());
637 if (convertedLhsType != lhsLoadedType) {
638 // Do it conditionally, so that if conversion is a no-op we don't introduce a SWAP, SWAP.
639 method.swap().convert(convertedLhsType).swap();
640 }
641 method.convert(operandBounds.within(method.peekType()));
642 }
643 assert Type.generic(method.peekType()) == operandBounds.narrowest;
644 assert Type.generic(method.peekType(1)) == operandBounds.narrowest;
645
646 return method;
647 }
648
649 /**
650 * Similar to {@link #loadBinaryOperands(BinaryNode)} but used specifically for loading operands of
651 * relational and equality comparison operators where at least one argument is non-object. (When both
652 * arguments are objects, we use {@link ScriptRuntime#EQ(Object, Object)}, {@link ScriptRuntime#LT(Object, Object)}
653 * etc. methods instead. Additionally, {@code ScriptRuntime} methods are used for strict (in)equality comparison
654 * of a boolean to anything that isn't a boolean.) This method handles the special case where one argument
655 * is an object and another is a primitive. Naively, these could also be delegated to {@code ScriptRuntime} methods
656 * by boxing the primitive. However, in all such cases the comparison is performed on numeric values, so it is
657 * possible to strength-reduce the operation by taking the number value of the object argument instead and
658 * comparing that to the primitive value ("primitive" will always be int, long, double, or boolean, and booleans
659 * compare as ints in these cases, so they're essentially numbers too). This method will emit code for loading
660 * arguments for such strength-reduced comparison. When both arguments are primitives, it just delegates to
661 * {@link #loadBinaryOperands(BinaryNode)}.
662 *
663 * @param cmp the comparison operation for which the operands need to be loaded on stack.
664 * @return the current method emitter.
665 */
666 MethodEmitter loadComparisonOperands(final BinaryNode cmp) {
667 final Expression lhs = cmp.lhs();
668 final Expression rhs = cmp.rhs();
669 final Type lhsType = lhs.getType();
670 final Type rhsType = rhs.getType();
671
672 // Only used when not both are object, for that we have ScriptRuntime.LT etc.
673 assert !(lhsType.isObject() && rhsType.isObject());
674
675 if (lhsType.isObject() || rhsType.isObject()) {
676 // We can reorder CONVERT LEFT and LOAD RIGHT only if either the left is a primitive, or the right
677 // is a local. This is more strict than loadBinaryNode reorder criteria, as it can allow JS primitive
678 // types too (notably: String is a JS primitive, but not a JVM primitive). We disallow String otherwise
679 // we would prematurely convert it to number when comparing to an optimistic expression, e.g. in
680 // "Hello" === String("Hello") the RHS starts out as an optimistic-int function call. If we allowed
681 // reordering, we'd end up with ToNumber("Hello") === {I%}String("Hello") that is obviously incorrect.
682 final boolean canReorder = lhsType.isPrimitive() || rhs.isLocal();
683 // If reordering is allowed, and we're using a relational operator (that is, <, <=, >, >=) and not an
684 // (in)equality operator, then we encourage combining of LOAD and CONVERT into a single operation.
685 // This is because relational operators' semantics prescribes vanilla ToNumber() conversion, while
686 // (in)equality operators need the specialized JSType.toNumberFor[Strict]Equals. E.g. in the code snippet
687 // "i < obj.size" (where i is primitive and obj.size is statically an object), ".size" will thus be allowed
688 // to compile as:
689 // invokedynamic GET_PROPERTY:size(Object;)D
690 // instead of the more costly:
691 // invokedynamic GET_PROPERTY:size(Object;)Object
692 // invokestatic JSType.toNumber(Object)D
693 // Note also that even if this is allowed, we're only using it on operands that are non-optimistic, as
694 // otherwise the logic for determining effective optimistic-ness would turn an optimistic double return
695 // into a freely coercible one, which would be wrong.
696 final boolean canCombineLoadAndConvert = canReorder && cmp.isRelational();
697
698 // LOAD LEFT
699 loadExpression(lhs, canCombineLoadAndConvert && !lhs.isOptimistic() ? TypeBounds.NUMBER : TypeBounds.UNBOUNDED);
700
701 final Type lhsLoadedType = method.peekType();
702 final TokenType tt = cmp.tokenType();
703 if (canReorder) {
704 // Can reorder CONVERT LEFT and LOAD RIGHT
705 emitObjectToNumberComparisonConversion(method, tt);
706 loadExpression(rhs, canCombineLoadAndConvert && !rhs.isOptimistic() ? TypeBounds.NUMBER : TypeBounds.UNBOUNDED);
707 } else {
708 // Can't reorder CONVERT LEFT and LOAD RIGHT
709 loadExpression(rhs, TypeBounds.UNBOUNDED);
710 if (lhsLoadedType != Type.NUMBER) {
711 method.swap();
712 emitObjectToNumberComparisonConversion(method, tt);
713 method.swap();
714 }
715 }
716
717 // CONVERT RIGHT
718 emitObjectToNumberComparisonConversion(method, tt);
719 return method;
720 }
721 // For primitive operands, just don't do anything special.
722 return loadBinaryOperands(cmp);
723 }
724
725 private static void emitObjectToNumberComparisonConversion(final MethodEmitter method, final TokenType tt) {
726 switch(tt) {
727 case EQ:
728 case NE:
729 if (method.peekType().isObject()) {
730 TO_NUMBER_FOR_EQ.invoke(method);
731 return;
732 }
733 break;
734 case EQ_STRICT:
735 case NE_STRICT:
736 if (method.peekType().isObject()) {
737 TO_NUMBER_FOR_STRICT_EQ.invoke(method);
738 return;
739 }
740 break;
741 default:
742 break;
743 }
744 method.convert(Type.NUMBER);
745 }
746
747 private static Type undefinedToNumber(final Type type) {
748 return type == Type.UNDEFINED ? Type.NUMBER : type;
749 }
750
751 private static final class TypeBounds {
752 final Type narrowest;
753 final Type widest;
754
755 static final TypeBounds UNBOUNDED = new TypeBounds(Type.UNKNOWN, Type.OBJECT);
756 static final TypeBounds INT = exact(Type.INT);
757 static final TypeBounds NUMBER = exact(Type.NUMBER);
758 static final TypeBounds OBJECT = exact(Type.OBJECT);
759 static final TypeBounds BOOLEAN = exact(Type.BOOLEAN);
760
761 static TypeBounds exact(final Type type) {
762 return new TypeBounds(type, type);
763 }
764
765 TypeBounds(final Type narrowest, final Type widest) {
766 assert widest != null && widest != Type.UNDEFINED && widest != Type.UNKNOWN : widest;
767 assert narrowest != null && narrowest != Type.UNDEFINED : narrowest;
768 assert !narrowest.widerThan(widest) : narrowest + " wider than " + widest;
769 assert !widest.narrowerThan(narrowest);
770 this.narrowest = Type.generic(narrowest);
771 this.widest = Type.generic(widest);
772 }
773
774 TypeBounds notNarrowerThan(final Type type) {
775 return maybeNew(Type.narrowest(Type.widest(narrowest, type), widest), widest);
776 }
777
778 TypeBounds notWiderThan(final Type type) {
779 return maybeNew(Type.narrowest(narrowest, type), Type.narrowest(widest, type));
780 }
781
782 boolean canBeNarrowerThan(final Type type) {
783 return narrowest.narrowerThan(type);
784 }
785
786 TypeBounds maybeNew(final Type newNarrowest, final Type newWidest) {
787 if(newNarrowest == narrowest && newWidest == widest) {
788 return this;
789 }
790 return new TypeBounds(newNarrowest, newWidest);
791 }
792
793 TypeBounds booleanToInt() {
794 return maybeNew(CodeGenerator.booleanToInt(narrowest), CodeGenerator.booleanToInt(widest));
795 }
796
797 TypeBounds objectToNumber() {
798 return maybeNew(CodeGenerator.objectToNumber(narrowest), CodeGenerator.objectToNumber(widest));
799 }
800
801 Type within(final Type type) {
802 if(type.narrowerThan(narrowest)) {
803 return narrowest;
804 }
805 if(type.widerThan(widest)) {
806 return widest;
807 }
808 return type;
809 }
810
811 @Override
812 public String toString() {
813 return "[" + narrowest + ", " + widest + "]";
814 }
815 }
816
817 private static Type booleanToInt(final Type t) {
818 return t == Type.BOOLEAN ? Type.INT : t;
819 }
820
821 private static Type objectToNumber(final Type t) {
822 return t.isObject() ? Type.NUMBER : t;
823 }
824
825 MethodEmitter loadExpressionAsType(final Expression expr, final Type type) {
826 if(type == Type.BOOLEAN) {
827 return loadExpressionAsBoolean(expr);
828 } else if(type == Type.UNDEFINED) {
829 assert expr.getType() == Type.UNDEFINED;
830 return loadExpressionAsObject(expr);
831 }
832 // having no upper bound preserves semantics of optimistic operations in the expression (by not having them
833 // converted early) and then applies explicit conversion afterwards.
834 return loadExpression(expr, TypeBounds.UNBOUNDED.notNarrowerThan(type)).convert(type);
835 }
836
837 private MethodEmitter loadExpression(final Expression expr, final TypeBounds resultBounds) {
838 return loadExpression(expr, resultBounds, false);
839 }
840
841 /**
842 * Emits code for evaluating an expression and leaving its value on top of the stack, narrowing or widening it if
843 * necessary.
844 * @param expr the expression to load
845 * @param resultBounds the incoming type bounds. The value on the top of the stack is guaranteed to not be of narrower
846 * type than the narrowest bound, or wider type than the widest bound after it is loaded.
847 * @param baseAlreadyOnStack true if the base of an access or index node is already on the stack. Used to avoid
848 * double evaluation of bases in self-assignment expressions to access and index nodes. {@code Type.OBJECT} is used
849 * to indicate the widest possible type.
850 * @return the method emitter
851 */
852 private MethodEmitter loadExpression(final Expression expr, final TypeBounds resultBounds, final boolean baseAlreadyOnStack) {
853
854 /*
855 * The load may be of type IdentNode, e.g. "x", AccessNode, e.g. "x.y"
856 * or IndexNode e.g. "x[y]". Both AccessNodes and IndexNodes are
857 * BaseNodes and the logic for loading the base object is reused
858 */
859 final CodeGenerator codegen = this;
860
861 final boolean isCurrentDiscard = codegen.lc.isCurrentDiscard(expr);
862 expr.accept(new NodeOperatorVisitor<LexicalContext>(new LexicalContext()) {
863 @Override
864 public boolean enterIdentNode(final IdentNode identNode) {
865 loadIdent(identNode, resultBounds);
866 return false;
867 }
868
869 @Override
870 public boolean enterAccessNode(final AccessNode accessNode) {
871 new OptimisticOperation(accessNode, resultBounds) {
872 @Override
873 void loadStack() {
874 if (!baseAlreadyOnStack) {
875 loadExpressionAsObject(accessNode.getBase());
876 }
877 assert method.peekType().isObject();
878 }
879 @Override
880 void consumeStack() {
881 final int flags = getCallSiteFlags();
882 dynamicGet(accessNode.getProperty(), flags, accessNode.isFunction(), accessNode.isIndex());
883 }
884 }.emit(baseAlreadyOnStack ? 1 : 0);
885 return false;
886 }
887
888 @Override
889 public boolean enterIndexNode(final IndexNode indexNode) {
890 new OptimisticOperation(indexNode, resultBounds) {
891 @Override
892 void loadStack() {
893 if (!baseAlreadyOnStack) {
894 loadExpressionAsObject(indexNode.getBase());
895 loadExpressionUnbounded(indexNode.getIndex());
896 }
897 }
898 @Override
899 void consumeStack() {
900 final int flags = getCallSiteFlags();
901 dynamicGetIndex(flags, indexNode.isFunction());
902 }
903 }.emit(baseAlreadyOnStack ? 2 : 0);
904 return false;
905 }
906
907 @Override
908 public boolean enterFunctionNode(final FunctionNode functionNode) {
909 // function nodes will always leave a constructed function object on stack, no need to load the symbol
910 // separately as in enterDefault()
911 lc.pop(functionNode);
912 functionNode.accept(codegen);
913 // NOTE: functionNode.accept() will produce a different FunctionNode that we discard. This incidentally
914 // doesn't cause problems as we're never touching FunctionNode again after it's visited here - codegen
915 // is the last element in the compilation pipeline, the AST it produces is not used externally. So, we
916 // re-push the original functionNode.
917 lc.push(functionNode);
918 return false;
919 }
920
921 @Override
922 public boolean enterASSIGN(final BinaryNode binaryNode) {
923 checkAssignTarget(binaryNode.lhs());
924 loadASSIGN(binaryNode);
925 return false;
926 }
927
928 @Override
929 public boolean enterASSIGN_ADD(final BinaryNode binaryNode) {
930 checkAssignTarget(binaryNode.lhs());
931 loadASSIGN_ADD(binaryNode);
932 return false;
933 }
934
935 @Override
936 public boolean enterASSIGN_BIT_AND(final BinaryNode binaryNode) {
937 checkAssignTarget(binaryNode.lhs());
938 loadASSIGN_BIT_AND(binaryNode);
939 return false;
940 }
941
942 @Override
943 public boolean enterASSIGN_BIT_OR(final BinaryNode binaryNode) {
944 checkAssignTarget(binaryNode.lhs());
945 loadASSIGN_BIT_OR(binaryNode);
946 return false;
947 }
948
949 @Override
950 public boolean enterASSIGN_BIT_XOR(final BinaryNode binaryNode) {
951 checkAssignTarget(binaryNode.lhs());
952 loadASSIGN_BIT_XOR(binaryNode);
953 return false;
954 }
955
956 @Override
957 public boolean enterASSIGN_DIV(final BinaryNode binaryNode) {
958 checkAssignTarget(binaryNode.lhs());
959 loadASSIGN_DIV(binaryNode);
960 return false;
961 }
962
963 @Override
964 public boolean enterASSIGN_MOD(final BinaryNode binaryNode) {
965 checkAssignTarget(binaryNode.lhs());
966 loadASSIGN_MOD(binaryNode);
967 return false;
968 }
969
970 @Override
971 public boolean enterASSIGN_MUL(final BinaryNode binaryNode) {
972 checkAssignTarget(binaryNode.lhs());
973 loadASSIGN_MUL(binaryNode);
974 return false;
975 }
976
977 @Override
978 public boolean enterASSIGN_SAR(final BinaryNode binaryNode) {
979 checkAssignTarget(binaryNode.lhs());
980 loadASSIGN_SAR(binaryNode);
981 return false;
982 }
983
984 @Override
985 public boolean enterASSIGN_SHL(final BinaryNode binaryNode) {
986 checkAssignTarget(binaryNode.lhs());
987 loadASSIGN_SHL(binaryNode);
988 return false;
989 }
990
991 @Override
992 public boolean enterASSIGN_SHR(final BinaryNode binaryNode) {
993 checkAssignTarget(binaryNode.lhs());
994 loadASSIGN_SHR(binaryNode);
995 return false;
996 }
997
998 @Override
999 public boolean enterASSIGN_SUB(final BinaryNode binaryNode) {
1000 checkAssignTarget(binaryNode.lhs());
1001 loadASSIGN_SUB(binaryNode);
1002 return false;
1003 }
1004
1005 @Override
1006 public boolean enterCallNode(final CallNode callNode) {
1007 return loadCallNode(callNode, resultBounds);
1008 }
1009
1010 @Override
1011 public boolean enterLiteralNode(final LiteralNode<?> literalNode) {
1012 loadLiteral(literalNode, resultBounds);
1013 return false;
1014 }
1015
1016 @Override
1017 public boolean enterTernaryNode(final TernaryNode ternaryNode) {
1018 loadTernaryNode(ternaryNode, resultBounds);
1019 return false;
1020 }
1021
1022 @Override
1023 public boolean enterADD(final BinaryNode binaryNode) {
1024 loadADD(binaryNode, resultBounds);
1025 return false;
1026 }
1027
1028 @Override
1029 public boolean enterSUB(final UnaryNode unaryNode) {
1030 loadSUB(unaryNode, resultBounds);
1031 return false;
1032 }
1033
1034 @Override
1035 public boolean enterSUB(final BinaryNode binaryNode) {
1036 loadSUB(binaryNode, resultBounds);
1037 return false;
1038 }
1039
1040 @Override
1041 public boolean enterMUL(final BinaryNode binaryNode) {
1042 loadMUL(binaryNode, resultBounds);
1043 return false;
1044 }
1045
1046 @Override
1047 public boolean enterDIV(final BinaryNode binaryNode) {
1048 loadDIV(binaryNode, resultBounds);
1049 return false;
1050 }
1051
1052 @Override
1053 public boolean enterMOD(final BinaryNode binaryNode) {
1054 loadMOD(binaryNode, resultBounds);
1055 return false;
1056 }
1057
1058 @Override
1059 public boolean enterSAR(final BinaryNode binaryNode) {
1060 loadSAR(binaryNode);
1061 return false;
1062 }
1063
1064 @Override
1065 public boolean enterSHL(final BinaryNode binaryNode) {
1066 loadSHL(binaryNode);
1067 return false;
1068 }
1069
1070 @Override
1071 public boolean enterSHR(final BinaryNode binaryNode) {
1072 loadSHR(binaryNode);
1073 return false;
1074 }
1075
1076 @Override
1077 public boolean enterCOMMALEFT(final BinaryNode binaryNode) {
1078 loadCOMMALEFT(binaryNode, resultBounds);
1079 return false;
1080 }
1081
1082 @Override
1083 public boolean enterCOMMARIGHT(final BinaryNode binaryNode) {
1084 loadCOMMARIGHT(binaryNode, resultBounds);
1085 return false;
1086 }
1087
1088 @Override
1089 public boolean enterAND(final BinaryNode binaryNode) {
1090 loadAND_OR(binaryNode, resultBounds, true);
1091 return false;
1092 }
1093
1094 @Override
1095 public boolean enterOR(final BinaryNode binaryNode) {
1096 loadAND_OR(binaryNode, resultBounds, false);
1097 return false;
1098 }
1099
1100 @Override
1101 public boolean enterNOT(final UnaryNode unaryNode) {
1102 loadNOT(unaryNode);
1103 return false;
1104 }
1105
1106 @Override
1107 public boolean enterADD(final UnaryNode unaryNode) {
1108 loadADD(unaryNode, resultBounds);
1109 return false;
1110 }
1111
1112 @Override
1113 public boolean enterBIT_NOT(final UnaryNode unaryNode) {
1114 loadBIT_NOT(unaryNode);
1115 return false;
1116 }
1117
1118 @Override
1119 public boolean enterBIT_AND(final BinaryNode binaryNode) {
1120 loadBIT_AND(binaryNode);
1121 return false;
1122 }
1123
1124 @Override
1125 public boolean enterBIT_OR(final BinaryNode binaryNode) {
1126 loadBIT_OR(binaryNode);
1127 return false;
1128 }
1129
1130 @Override
1131 public boolean enterBIT_XOR(final BinaryNode binaryNode) {
1132 loadBIT_XOR(binaryNode);
1133 return false;
1134 }
1135
1136 @Override
1137 public boolean enterVOID(final UnaryNode unaryNode) {
1138 loadVOID(unaryNode, resultBounds);
1139 return false;
1140 }
1141
1142 @Override
1143 public boolean enterEQ(final BinaryNode binaryNode) {
1144 loadCmp(binaryNode, Condition.EQ);
1145 return false;
1146 }
1147
1148 @Override
1149 public boolean enterEQ_STRICT(final BinaryNode binaryNode) {
1150 loadCmp(binaryNode, Condition.EQ);
1151 return false;
1152 }
1153
1154 @Override
1155 public boolean enterGE(final BinaryNode binaryNode) {
1156 loadCmp(binaryNode, Condition.GE);
1157 return false;
1158 }
1159
1160 @Override
1161 public boolean enterGT(final BinaryNode binaryNode) {
1162 loadCmp(binaryNode, Condition.GT);
1163 return false;
1164 }
1165
1166 @Override
1167 public boolean enterLE(final BinaryNode binaryNode) {
1168 loadCmp(binaryNode, Condition.LE);
1169 return false;
1170 }
1171
1172 @Override
1173 public boolean enterLT(final BinaryNode binaryNode) {
1174 loadCmp(binaryNode, Condition.LT);
1175 return false;
1176 }
1177
1178 @Override
1179 public boolean enterNE(final BinaryNode binaryNode) {
1180 loadCmp(binaryNode, Condition.NE);
1181 return false;
1182 }
1183
1184 @Override
1185 public boolean enterNE_STRICT(final BinaryNode binaryNode) {
1186 loadCmp(binaryNode, Condition.NE);
1187 return false;
1188 }
1189
1190 @Override
1191 public boolean enterObjectNode(final ObjectNode objectNode) {
1192 loadObjectNode(objectNode);
1193 return false;
1194 }
1195
1196 @Override
1197 public boolean enterRuntimeNode(final RuntimeNode runtimeNode) {
1198 loadRuntimeNode(runtimeNode);
1199 return false;
1200 }
1201
1202 @Override
1203 public boolean enterNEW(final UnaryNode unaryNode) {
1204 loadNEW(unaryNode);
1205 return false;
1206 }
1207
1208 @Override
1209 public boolean enterDECINC(final UnaryNode unaryNode) {
1210 checkAssignTarget(unaryNode.getExpression());
1211 loadDECINC(unaryNode);
1212 return false;
1213 }
1214
1215 @Override
1216 public boolean enterJoinPredecessorExpression(final JoinPredecessorExpression joinExpr) {
1217 loadMaybeDiscard(joinExpr, joinExpr.getExpression(), resultBounds);
1218 return false;
1219 }
1220
1221 @Override
1222 public boolean enterGetSplitState(final GetSplitState getSplitState) {
1223 method.loadScope();
1224 method.invoke(Scope.GET_SPLIT_STATE);
1225 return false;
1226 }
1227
1228 @Override
1229 public boolean enterDefault(final Node otherNode) {
1230 // Must have handled all expressions that can legally be encountered.
1231 throw new AssertionError(otherNode.getClass().getName());
1232 }
1233 });
1234 if(!isCurrentDiscard) {
1235 coerceStackTop(resultBounds);
1236 }
1237 return method;
1238 }
1239
1240 private MethodEmitter coerceStackTop(final TypeBounds typeBounds) {
1241 return method.convert(typeBounds.within(method.peekType()));
1242 }
1243
1244 /**
1245 * Closes any still open entries for this block's local variables in the bytecode local variable table.
1246 *
1247 * @param block block containing symbols.
1248 */
1249 private void closeBlockVariables(final Block block) {
1250 for (final Symbol symbol : block.getSymbols()) {
1251 if (symbol.isBytecodeLocal()) {
1252 method.closeLocalVariable(symbol, block.getBreakLabel());
1253 }
1254 }
1255 }
1256
1257 @Override
1258 public boolean enterBlock(final Block block) {
1259 final Label entryLabel = block.getEntryLabel();
1260 if (entryLabel.isBreakTarget()) {
1261 // Entry label is a break target only for an inlined finally block.
1262 assert !method.isReachable();
1263 method.breakLabel(entryLabel, lc.getUsedSlotCount());
1264 } else {
1265 method.label(entryLabel);
1266 }
1267 if(!method.isReachable()) {
1268 return false;
1269 }
1270 if(lc.isFunctionBody() && emittedMethods.contains(lc.getCurrentFunction().getName())) {
1271 return false;
1272 }
1273 initLocals(block);
1274
1275 assert lc.getUsedSlotCount() == method.getFirstTemp();
1276 return true;
1277 }
1278
1279 boolean useOptimisticTypes() {
1280 return !lc.inSplitNode() && compiler.useOptimisticTypes();
1281 }
1282
1283 @Override
1284 public Node leaveBlock(final Block block) {
1285 popBlockScope(block);
1286 method.beforeJoinPoint(block);
1287
1288 closeBlockVariables(block);
1289 lc.releaseSlots();
1290 assert !method.isReachable() || (lc.isFunctionBody() ? 0 : lc.getUsedSlotCount()) == method.getFirstTemp() :
1291 "reachable="+method.isReachable() +
1292 " isFunctionBody=" + lc.isFunctionBody() +
1293 " usedSlotCount=" + lc.getUsedSlotCount() +
1294 " firstTemp=" + method.getFirstTemp();
1295
1296 return block;
1297 }
1298
1299 private void popBlockScope(final Block block) {
1300 final Label breakLabel = block.getBreakLabel();
1301
1302 if(!block.needsScope() || lc.isFunctionBody()) {
1303 emitBlockBreakLabel(breakLabel);
1304 return;
1305 }
1306
1307 final Label beginTryLabel = scopeEntryLabels.pop();
1308 final Label recoveryLabel = new Label("block_popscope_catch");
1309 emitBlockBreakLabel(breakLabel);
1310 final boolean bodyCanThrow = breakLabel.isAfter(beginTryLabel);
1311 if(bodyCanThrow) {
1312 method._try(beginTryLabel, breakLabel, recoveryLabel);
1313 }
1314
1315 Label afterCatchLabel = null;
1316
1317 if(method.isReachable()) {
1318 popScope();
1319 if(bodyCanThrow) {
1320 afterCatchLabel = new Label("block_after_catch");
1321 method._goto(afterCatchLabel);
1322 }
1323 }
1324
1325 if(bodyCanThrow) {
1326 assert !method.isReachable();
1327 method._catch(recoveryLabel);
1328 popScopeException();
1329 method.athrow();
1330 }
1331 if(afterCatchLabel != null) {
1332 method.label(afterCatchLabel);
1333 }
1334 }
1335
1336 private void emitBlockBreakLabel(final Label breakLabel) {
1337 // TODO: this is totally backwards. Block should not be breakable, LabelNode should be breakable.
1338 final LabelNode labelNode = lc.getCurrentBlockLabelNode();
1339 if(labelNode != null) {
1340 // Only have conversions if we're reachable
1341 assert labelNode.getLocalVariableConversion() == null || method.isReachable();
1342 method.beforeJoinPoint(labelNode);
1343 method.breakLabel(breakLabel, labeledBlockBreakLiveLocals.pop());
1344 } else {
1345 method.label(breakLabel);
1346 }
1347 }
1348
1349 private void popScope() {
1350 popScopes(1);
1351 }
1352
1353 /**
1354 * Pop scope as part of an exception handler. Similar to {@code popScope()} but also takes care of adjusting the
1355 * number of scopes that needs to be popped in case a rest-of continuation handler encounters an exception while
1356 * performing a ToPrimitive conversion.
1357 */
1358 private void popScopeException() {
1359 popScope();
1360 final ContinuationInfo ci = getContinuationInfo();
1361 if(ci != null) {
1362 final Label catchLabel = ci.catchLabel;
1363 if(catchLabel != METHOD_BOUNDARY && catchLabel == catchLabels.peek()) {
1364 ++ci.exceptionScopePops;
1365 }
1366 }
1367 }
1368
1369 private void popScopesUntil(final LexicalContextNode until) {
1370 popScopes(lc.getScopeNestingLevelTo(until));
1371 }
1372
1373 private void popScopes(final int count) {
1374 if(count == 0) {
1375 return;
1376 }
1377 assert count > 0; // together with count == 0 check, asserts nonnegative count
1378 if (!method.hasScope()) {
1379 // We can sometimes invoke this method even if the method has no slot for the scope object. Typical example:
1380 // for(;;) { with({}) { break; } }. WithNode normally creates a scope, but if it uses no identifiers and
1381 // nothing else forces creation of a scope in the method, we just won't have the :scope local variable.
1382 return;
1383 }
1384 method.loadCompilerConstant(SCOPE);
1385 if (count > 1) {
1386 method.load(count);
1387 method.invoke(ScriptObject.GET_PROTO_DEPTH);
1388 } else {
1389 method.invoke(ScriptObject.GET_PROTO);
1390 }
1391 method.storeCompilerConstant(SCOPE);
1392 }
1393
1394 @Override
1395 public boolean enterBreakNode(final BreakNode breakNode) {
1396 return enterJumpStatement(breakNode);
1397 }
1398
1399 @Override
1400 public boolean enterJumpToInlinedFinally(final JumpToInlinedFinally jumpToInlinedFinally) {
1401 return enterJumpStatement(jumpToInlinedFinally);
1402 }
1403
1404 private boolean enterJumpStatement(final JumpStatement jump) {
1405 if(!method.isReachable()) {
1406 return false;
1407 }
1408 enterStatement(jump);
1409
1410 method.beforeJoinPoint(jump);
1411 popScopesUntil(jump.getPopScopeLimit(lc));
1412 final Label targetLabel = jump.getTargetLabel(lc);
1413 targetLabel.markAsBreakTarget();
1414 method._goto(targetLabel);
1415
1416 return false;
1417 }
1418
1419 private int loadArgs(final List<Expression> args) {
1420 final int argCount = args.size();
1421 // arg have already been converted to objects here.
1422 if (argCount > LinkerCallSite.ARGLIMIT) {
1423 loadArgsArray(args);
1424 return 1;
1425 }
1426
1427 for (final Expression arg : args) {
1428 assert arg != null;
1429 loadExpressionUnbounded(arg);
1430 }
1431 return argCount;
1432 }
1433
1434 private boolean loadCallNode(final CallNode callNode, final TypeBounds resultBounds) {
1435 lineNumber(callNode.getLineNumber());
1436
1437 final List<Expression> args = callNode.getArgs();
1438 final Expression function = callNode.getFunction();
1439 final Block currentBlock = lc.getCurrentBlock();
1440 final CodeGeneratorLexicalContext codegenLexicalContext = lc;
1441
1442 function.accept(new SimpleNodeVisitor() {
1443 private MethodEmitter sharedScopeCall(final IdentNode identNode, final int flags) {
1444 final Symbol symbol = identNode.getSymbol();
1445 final boolean isFastScope = isFastScope(symbol);
1446 new OptimisticOperation(callNode, resultBounds) {
1447 @Override
1448 void loadStack() {
1449 method.loadCompilerConstant(SCOPE);
1450 if (isFastScope) {
1451 method.load(getScopeProtoDepth(currentBlock, symbol));
1452 } else {
1453 method.load(-1); // Bypass fast-scope code in shared callsite
1454 }
1455 loadArgs(args);
1456 }
1457 @Override
1458 void consumeStack() {
1459 final Type[] paramTypes = method.getTypesFromStack(args.size());
1460 // We have trouble finding e.g. in Type.typeFor(asm.Type) because it can't see the Context class
1461 // loader, so we need to weaken reference signatures to Object.
1462 for(int i = 0; i < paramTypes.length; ++i) {
1463 paramTypes[i] = Type.generic(paramTypes[i]);
1464 }
1465 // As shared scope calls are only used in non-optimistic compilation, we switch from using
1466 // TypeBounds to just a single definitive type, resultBounds.widest.
1467 final SharedScopeCall scopeCall = codegenLexicalContext.getScopeCall(unit, symbol,
1468 identNode.getType(), resultBounds.widest, paramTypes, flags);
1469 scopeCall.generateInvoke(method);
1470 }
1471 }.emit();
1472 return method;
1473 }
1474
1475 private void scopeCall(final IdentNode ident, final int flags) {
1476 new OptimisticOperation(callNode, resultBounds) {
1477 int argsCount;
1478 @Override
1479 void loadStack() {
1480 loadExpressionAsObject(ident); // foo() makes no sense if foo == 3
1481 // ScriptFunction will see CALLSITE_SCOPE and will bind scope accordingly.
1482 method.loadUndefined(Type.OBJECT); //the 'this'
1483 argsCount = loadArgs(args);
1484 }
1485 @Override
1486 void consumeStack() {
1487 dynamicCall(2 + argsCount, flags, ident.getName());
1488 }
1489 }.emit();
1490 }
1491
1492 private void evalCall(final IdentNode ident, final int flags) {
1493 final Label invoke_direct_eval = new Label("invoke_direct_eval");
1494 final Label is_not_eval = new Label("is_not_eval");
1495 final Label eval_done = new Label("eval_done");
1496
1497 new OptimisticOperation(callNode, resultBounds) {
1498 int argsCount;
1499 @Override
1500 void loadStack() {
1501 /*
1502 * We want to load 'eval' to check if it is indeed global builtin eval.
1503 * If this eval call is inside a 'with' statement, GET_METHOD_PROPERTY
1504 * would be generated if ident is a "isFunction". But, that would result in a
1505 * bound function from WithObject. We don't want that as bound function as that
1506 * won't be detected as builtin eval. So, we make ident as "not a function" which
1507 * results in GET_PROPERTY being generated and so WithObject
1508 * would return unbounded eval function.
1509 *
1510 * Example:
1511 *
1512 * var global = this;
1513 * function func() {
1514 * with({ eval: global.eval) { eval("var x = 10;") }
1515 * }
1516 */
1517 loadExpressionAsObject(ident.setIsNotFunction()); // Type.OBJECT as foo() makes no sense if foo == 3
1518 globalIsEval();
1519 method.ifeq(is_not_eval);
1520
1521 // Load up self (scope).
1522 method.loadCompilerConstant(SCOPE);
1523 final List<Expression> evalArgs = callNode.getEvalArgs().getArgs();
1524 // load evaluated code
1525 loadExpressionAsObject(evalArgs.get(0));
1526 // load second and subsequent args for side-effect
1527 final int numArgs = evalArgs.size();
1528 for (int i = 1; i < numArgs; i++) {
1529 loadAndDiscard(evalArgs.get(i));
1530 }
1531 method._goto(invoke_direct_eval);
1532
1533 method.label(is_not_eval);
1534 // load this time but with GET_METHOD_PROPERTY
1535 loadExpressionAsObject(ident); // Type.OBJECT as foo() makes no sense if foo == 3
1536 // This is some scope 'eval' or global eval replaced by user
1537 // but not the built-in ECMAScript 'eval' function call
1538 method.loadNull();
1539 argsCount = loadArgs(callNode.getArgs());
1540 }
1541
1542 @Override
1543 void consumeStack() {
1544 // Ordinary call
1545 dynamicCall(2 + argsCount, flags, "eval");
1546 method._goto(eval_done);
1547
1548 method.label(invoke_direct_eval);
1549 // Special/extra 'eval' arguments. These can be loaded late (in consumeStack) as we know none of
1550 // them can ever be optimistic.
1551 method.loadCompilerConstant(THIS);
1552 method.load(callNode.getEvalArgs().getLocation());
1553 method.load(CodeGenerator.this.lc.getCurrentFunction().isStrict());
1554 // direct call to Global.directEval
1555 globalDirectEval();
1556 convertOptimisticReturnValue();
1557 coerceStackTop(resultBounds);
1558 }
1559 }.emit();
1560
1561 method.label(eval_done);
1562 }
1563
1564 @Override
1565 public boolean enterIdentNode(final IdentNode node) {
1566 final Symbol symbol = node.getSymbol();
1567
1568 if (symbol.isScope()) {
1569 final int flags = getScopeCallSiteFlags(symbol);
1570 final int useCount = symbol.getUseCount();
1571
1572 // Threshold for generating shared scope callsite is lower for fast scope symbols because we know
1573 // we can dial in the correct scope. However, we also need to enable it for non-fast scopes to
1574 // support huge scripts like mandreel.js.
1575 if (callNode.isEval()) {
1576 evalCall(node, flags);
1577 } else if (useCount <= SharedScopeCall.FAST_SCOPE_CALL_THRESHOLD
1578 || !isFastScope(symbol) && useCount <= SharedScopeCall.SLOW_SCOPE_CALL_THRESHOLD
1579 || CodeGenerator.this.lc.inDynamicScope()
1580 || callNode.isOptimistic()) {
1581 scopeCall(node, flags);
1582 } else {
1583 sharedScopeCall(node, flags);
1584 }
1585 assert method.peekType().equals(resultBounds.within(callNode.getType())) : method.peekType() + " != " + resultBounds + "(" + callNode.getType() + ")";
1586 } else {
1587 enterDefault(node);
1588 }
1589
1590 return false;
1591 }
1592
1593 @Override
1594 public boolean enterAccessNode(final AccessNode node) {
1595 //check if this is an apply to call node. only real applies, that haven't been
1596 //shadowed from their way to the global scope counts
1597
1598 //call nodes have program points.
1599
1600 final int flags = getCallSiteFlags() | (callNode.isApplyToCall() ? CALLSITE_APPLY_TO_CALL : 0);
1601
1602 new OptimisticOperation(callNode, resultBounds) {
1603 int argCount;
1604 @Override
1605 void loadStack() {
1606 loadExpressionAsObject(node.getBase());
1607 method.dup();
1608 // NOTE: not using a nested OptimisticOperation on this dynamicGet, as we expect to get back
1609 // a callable object. Nobody in their right mind would optimistically type this call site.
1610 assert !node.isOptimistic();
1611 method.dynamicGet(node.getType(), node.getProperty(), flags, true, node.isIndex());
1612 method.swap();
1613 argCount = loadArgs(args);
1614 }
1615 @Override
1616 void consumeStack() {
1617 dynamicCall(2 + argCount, flags, node.toString(false));
1618 }
1619 }.emit();
1620
1621 return false;
1622 }
1623
1624 @Override
1625 public boolean enterFunctionNode(final FunctionNode origCallee) {
1626 new OptimisticOperation(callNode, resultBounds) {
1627 FunctionNode callee;
1628 int argsCount;
1629 @Override
1630 void loadStack() {
1631 callee = (FunctionNode)origCallee.accept(CodeGenerator.this);
1632 if (callee.isStrict()) { // "this" is undefined
1633 method.loadUndefined(Type.OBJECT);
1634 } else { // get global from scope (which is the self)
1635 globalInstance();
1636 }
1637 argsCount = loadArgs(args);
1638 }
1639
1640 @Override
1641 void consumeStack() {
1642 dynamicCall(2 + argsCount, getCallSiteFlags(), null);
1643 }
1644 }.emit();
1645 return false;
1646 }
1647
1648 @Override
1649 public boolean enterIndexNode(final IndexNode node) {
1650 new OptimisticOperation(callNode, resultBounds) {
1651 int argsCount;
1652 @Override
1653 void loadStack() {
1654 loadExpressionAsObject(node.getBase());
1655 method.dup();
1656 final Type indexType = node.getIndex().getType();
1657 if (indexType.isObject() || indexType.isBoolean()) {
1658 loadExpressionAsObject(node.getIndex()); //TODO boolean
1659 } else {
1660 loadExpressionUnbounded(node.getIndex());
1661 }
1662 // NOTE: not using a nested OptimisticOperation on this dynamicGetIndex, as we expect to get
1663 // back a callable object. Nobody in their right mind would optimistically type this call site.
1664 assert !node.isOptimistic();
1665 method.dynamicGetIndex(node.getType(), getCallSiteFlags(), true);
1666 method.swap();
1667 argsCount = loadArgs(args);
1668 }
1669 @Override
1670 void consumeStack() {
1671 dynamicCall(2 + argsCount, getCallSiteFlags(), node.toString(false));
1672 }
1673 }.emit();
1674 return false;
1675 }
1676
1677 @Override
1678 protected boolean enterDefault(final Node node) {
1679 new OptimisticOperation(callNode, resultBounds) {
1680 int argsCount;
1681 @Override
1682 void loadStack() {
1683 // Load up function.
1684 loadExpressionAsObject(function); //TODO, e.g. booleans can be used as functions
1685 method.loadUndefined(Type.OBJECT); // ScriptFunction will figure out the correct this when it sees CALLSITE_SCOPE
1686 argsCount = loadArgs(args);
1687 }
1688 @Override
1689 void consumeStack() {
1690 final int flags = getCallSiteFlags() | CALLSITE_SCOPE;
1691 dynamicCall(2 + argsCount, flags, node.toString(false));
1692 }
1693 }.emit();
1694 return false;
1695 }
1696 });
1697
1698 return false;
1699 }
1700
1701 /**
1702 * Returns the flags with optimistic flag and program point removed.
1703 * @param flags the flags that need optimism stripped from them.
1704 * @return flags without optimism
1705 */
1706 static int nonOptimisticFlags(final int flags) {
1707 return flags & ~(CALLSITE_OPTIMISTIC | -1 << CALLSITE_PROGRAM_POINT_SHIFT);
1708 }
1709
1710 @Override
1711 public boolean enterContinueNode(final ContinueNode continueNode) {
1712 return enterJumpStatement(continueNode);
1713 }
1714
1715 @Override
1716 public boolean enterEmptyNode(final EmptyNode emptyNode) {
1717 // Don't even record the line number, it's irrelevant as there's no code.
1718 return false;
1719 }
1720
1721 @Override
1722 public boolean enterExpressionStatement(final ExpressionStatement expressionStatement) {
1723 if(!method.isReachable()) {
1724 return false;
1725 }
1726 enterStatement(expressionStatement);
1727
1728 loadAndDiscard(expressionStatement.getExpression());
1729 assert method.getStackSize() == 0;
1730
1731 return false;
1732 }
1733
1734 @Override
1735 public boolean enterBlockStatement(final BlockStatement blockStatement) {
1736 if(!method.isReachable()) {
1737 return false;
1738 }
1739 enterStatement(blockStatement);
1740
1741 blockStatement.getBlock().accept(this);
1742
1743 return false;
1744 }
1745
1746 @Override
1747 public boolean enterForNode(final ForNode forNode) {
1748 if(!method.isReachable()) {
1749 return false;
1750 }
1751 enterStatement(forNode);
1752 if (forNode.isForIn()) {
1753 enterForIn(forNode);
1754 } else {
1755 final Expression init = forNode.getInit();
1756 if (init != null) {
1757 loadAndDiscard(init);
1758 }
1759 enterForOrWhile(forNode, forNode.getModify());
1760 }
1761
1762 return false;
1763 }
1764
1765 private void enterForIn(final ForNode forNode) {
1766 loadExpression(forNode.getModify(), TypeBounds.OBJECT);
1767 method.invoke(forNode.isForEach() ? ScriptRuntime.TO_VALUE_ITERATOR : ScriptRuntime.TO_PROPERTY_ITERATOR);
1768 final Symbol iterSymbol = forNode.getIterator();
1769 final int iterSlot = iterSymbol.getSlot(Type.OBJECT);
1770 method.store(iterSymbol, ITERATOR_TYPE);
1771
1772 method.beforeJoinPoint(forNode);
1773
1774 final Label continueLabel = forNode.getContinueLabel();
1775 final Label breakLabel = forNode.getBreakLabel();
1776
1777 method.label(continueLabel);
1778 method.load(ITERATOR_TYPE, iterSlot);
1779 method.invoke(interfaceCallNoLookup(ITERATOR_CLASS, "hasNext", boolean.class));
1780 final JoinPredecessorExpression test = forNode.getTest();
1781 final Block body = forNode.getBody();
1782 if(LocalVariableConversion.hasLiveConversion(test)) {
1783 final Label afterConversion = new Label("for_in_after_test_conv");
1784 method.ifne(afterConversion);
1785 method.beforeJoinPoint(test);
1786 method._goto(breakLabel);
1787 method.label(afterConversion);
1788 } else {
1789 method.ifeq(breakLabel);
1790 }
1791
1792 new Store<Expression>(forNode.getInit()) {
1793 @Override
1794 protected void storeNonDiscard() {
1795 // This expression is neither part of a discard, nor needs to be left on the stack after it was
1796 // stored, so we override storeNonDiscard to be a no-op.
1797 }
1798
1799 @Override
1800 protected void evaluate() {
1801 new OptimisticOperation((Optimistic)forNode.getInit(), TypeBounds.UNBOUNDED) {
1802 @Override
1803 void loadStack() {
1804 method.load(ITERATOR_TYPE, iterSlot);
1805 }
1806
1807 @Override
1808 void consumeStack() {
1809 method.invoke(interfaceCallNoLookup(ITERATOR_CLASS, "next", Object.class));
1810 convertOptimisticReturnValue();
1811 }
1812 }.emit();
1813 }
1814 }.store();
1815 body.accept(this);
1816
1817 if(method.isReachable()) {
1818 method._goto(continueLabel);
1819 }
1820 method.label(breakLabel);
1821 }
1822
1823 /**
1824 * Initialize the slots in a frame to undefined.
1825 *
1826 * @param block block with local vars.
1827 */
1828 private void initLocals(final Block block) {
1829 lc.onEnterBlock(block);
1830
1831 final boolean isFunctionBody = lc.isFunctionBody();
1832 final FunctionNode function = lc.getCurrentFunction();
1833 if (isFunctionBody) {
1834 initializeMethodParameters(function);
1835 if(!function.isVarArg()) {
1836 expandParameterSlots(function);
1837 }
1838 if (method.hasScope()) {
1839 if (function.needsParentScope()) {
1840 method.loadCompilerConstant(CALLEE);
1841 method.invoke(ScriptFunction.GET_SCOPE);
1842 } else {
1843 assert function.hasScopeBlock();
1844 method.loadNull();
1845 }
1846 method.storeCompilerConstant(SCOPE);
1847 }
1848 if (function.needsArguments()) {
1849 initArguments(function);
1850 }
1851 }
1852
1853 /*
1854 * Determine if block needs scope, if not, just do initSymbols for this block.
1855 */
1856 if (block.needsScope()) {
1857 /*
1858 * Determine if function is varargs and consequently variables have to
1859 * be in the scope.
1860 */
1861 final boolean varsInScope = function.allVarsInScope();
1862
1863 // TODO for LET we can do better: if *block* does not contain any eval/with, we don't need its vars in scope.
1864
1865 final boolean hasArguments = function.needsArguments();
1866 final List<MapTuple<Symbol>> tuples = new ArrayList<>();
1867 final Iterator<IdentNode> paramIter = function.getParameters().iterator();
1868 for (final Symbol symbol : block.getSymbols()) {
1869 if (symbol.isInternal() || symbol.isThis()) {
1870 continue;
1871 }
1872
1873 if (symbol.isVar()) {
1874 assert !varsInScope || symbol.isScope();
1875 if (varsInScope || symbol.isScope()) {
1876 assert symbol.isScope() : "scope for " + symbol + " should have been set in Lower already " + function.getName();
1877 assert !symbol.hasSlot() : "slot for " + symbol + " should have been removed in Lower already" + function.getName();
1878
1879 //this tuple will not be put fielded, as it has no value, just a symbol
1880 tuples.add(new MapTuple<Symbol>(symbol.getName(), symbol, null));
1881 } else {
1882 assert symbol.hasSlot() || symbol.slotCount() == 0 : symbol + " should have a slot only, no scope";
1883 }
1884 } else if (symbol.isParam() && (varsInScope || hasArguments || symbol.isScope())) {
1885 assert symbol.isScope() : "scope for " + symbol + " should have been set in AssignSymbols already " + function.getName() + " varsInScope="+varsInScope+" hasArguments="+hasArguments+" symbol.isScope()=" + symbol.isScope();
1886 assert !(hasArguments && symbol.hasSlot()) : "slot for " + symbol + " should have been removed in Lower already " + function.getName();
1887
1888 final Type paramType;
1889 final Symbol paramSymbol;
1890
1891 if (hasArguments) {
1892 assert !symbol.hasSlot() : "slot for " + symbol + " should have been removed in Lower already ";
1893 paramSymbol = null;
1894 paramType = null;
1895 } else {
1896 paramSymbol = symbol;
1897 // NOTE: We're relying on the fact here that Block.symbols is a LinkedHashMap, hence it will
1898 // return symbols in the order they were defined, and parameters are defined in the same order
1899 // they appear in the function. That's why we can have a single pass over the parameter list
1900 // with an iterator, always just scanning forward for the next parameter that matches the symbol
1901 // name.
1902 for(;;) {
1903 final IdentNode nextParam = paramIter.next();
1904 if(nextParam.getName().equals(symbol.getName())) {
1905 paramType = nextParam.getType();
1906 break;
1907 }
1908 }
1909 }
1910
1911 tuples.add(new MapTuple<Symbol>(symbol.getName(), symbol, paramType, paramSymbol) {
1912 //this symbol will be put fielded, we can't initialize it as undefined with a known type
1913 @Override
1914 public Class<?> getValueType() {
1915 if (!useDualFields() || value == null || paramType == null || paramType.isBoolean()) {
1916 return Object.class;
1917 }
1918 return paramType.getTypeClass();
1919 }
1920 });
1921 }
1922 }
1923
1924 /*
1925 * Create a new object based on the symbols and values, generate
1926 * bootstrap code for object
1927 */
1928 new FieldObjectCreator<Symbol>(this, tuples, true, hasArguments) {
1929 @Override
1930 protected void loadValue(final Symbol value, final Type type) {
1931 method.load(value, type);
1932 }
1933 }.makeObject(method);
1934 // program function: merge scope into global
1935 if (isFunctionBody && function.isProgram()) {
1936 method.invoke(ScriptRuntime.MERGE_SCOPE);
1937 }
1938
1939 method.storeCompilerConstant(SCOPE);
1940 if(!isFunctionBody) {
1941 // Function body doesn't need a try/catch to restore scope, as it'd be a dead store anyway. Allowing it
1942 // actually causes issues with UnwarrantedOptimismException handlers as ASM will sort this handler to
1943 // the top of the exception handler table, so it'll be triggered instead of the UOE handlers.
1944 final Label scopeEntryLabel = new Label("scope_entry");
1945 scopeEntryLabels.push(scopeEntryLabel);
1946 method.label(scopeEntryLabel);
1947 }
1948 } else if (isFunctionBody && function.isVarArg()) {
1949 // Since we don't have a scope, parameters didn't get assigned array indices by the FieldObjectCreator, so
1950 // we need to assign them separately here.
1951 int nextParam = 0;
1952 for (final IdentNode param : function.getParameters()) {
1953 param.getSymbol().setFieldIndex(nextParam++);
1954 }
1955 }
1956
1957 // Debugging: print symbols? @see --print-symbols flag
1958 printSymbols(block, function, (isFunctionBody ? "Function " : "Block in ") + (function.getIdent() == null ? "<anonymous>" : function.getIdent().getName()));
1959 }
1960
1961 /**
1962 * Incoming method parameters are always declared on method entry; declare them in the local variable table.
1963 * @param function function for which code is being generated.
1964 */
1965 private void initializeMethodParameters(final FunctionNode function) {
1966 final Label functionStart = new Label("fn_start");
1967 method.label(functionStart);
1968 int nextSlot = 0;
1969 if(function.needsCallee()) {
1970 initializeInternalFunctionParameter(CALLEE, function, functionStart, nextSlot++);
1971 }
1972 initializeInternalFunctionParameter(THIS, function, functionStart, nextSlot++);
1973 if(function.isVarArg()) {
1974 initializeInternalFunctionParameter(VARARGS, function, functionStart, nextSlot++);
1975 } else {
1976 for(final IdentNode param: function.getParameters()) {
1977 final Symbol symbol = param.getSymbol();
1978 if(symbol.isBytecodeLocal()) {
1979 method.initializeMethodParameter(symbol, param.getType(), functionStart);
1980 }
1981 }
1982 }
1983 }
1984
1985 private void initializeInternalFunctionParameter(final CompilerConstants cc, final FunctionNode fn, final Label functionStart, final int slot) {
1986 final Symbol symbol = initializeInternalFunctionOrSplitParameter(cc, fn, functionStart, slot);
1987 // Internal function params (:callee, this, and :varargs) are never expanded to multiple slots
1988 assert symbol.getFirstSlot() == slot;
1989 }
1990
1991 private Symbol initializeInternalFunctionOrSplitParameter(final CompilerConstants cc, final FunctionNode fn, final Label functionStart, final int slot) {
1992 final Symbol symbol = fn.getBody().getExistingSymbol(cc.symbolName());
1993 final Type type = Type.typeFor(cc.type());
1994 method.initializeMethodParameter(symbol, type, functionStart);
1995 method.onLocalStore(type, slot);
1996 return symbol;
1997 }
1998
1999 /**
2000 * Parameters come into the method packed into local variable slots next to each other. Nashorn on the other hand
2001 * can use 1-6 slots for a local variable depending on all the types it needs to store. When this method is invoked,
2002 * the symbols are already allocated such wider slots, but the values are still in tightly packed incoming slots,
2003 * and we need to spread them into their new locations.
2004 * @param function the function for which parameter-spreading code needs to be emitted
2005 */
2006 private void expandParameterSlots(final FunctionNode function) {
2007 final List<IdentNode> parameters = function.getParameters();
2008 // Calculate the total number of incoming parameter slots
2009 int currentIncomingSlot = function.needsCallee() ? 2 : 1;
2010 for(final IdentNode parameter: parameters) {
2011 currentIncomingSlot += parameter.getType().getSlots();
2012 }
2013 // Starting from last parameter going backwards, move the parameter values into their new slots.
2014 for(int i = parameters.size(); i-- > 0;) {
2015 final IdentNode parameter = parameters.get(i);
2016 final Type parameterType = parameter.getType();
2017 final int typeWidth = parameterType.getSlots();
2018 currentIncomingSlot -= typeWidth;
2019 final Symbol symbol = parameter.getSymbol();
2020 final int slotCount = symbol.slotCount();
2021 assert slotCount > 0;
2022 // Scoped parameters must not hold more than one value
2023 assert symbol.isBytecodeLocal() || slotCount == typeWidth;
2024
2025 // Mark it as having its value stored into it by the method invocation.
2026 method.onLocalStore(parameterType, currentIncomingSlot);
2027 if(currentIncomingSlot != symbol.getSlot(parameterType)) {
2028 method.load(parameterType, currentIncomingSlot);
2029 method.store(symbol, parameterType);
2030 }
2031 }
2032 }
2033
2034 private void initArguments(final FunctionNode function) {
2035 method.loadCompilerConstant(VARARGS);
2036 if (function.needsCallee()) {
2037 method.loadCompilerConstant(CALLEE);
2038 } else {
2039 // If function is strict mode, "arguments.callee" is not populated, so we don't necessarily need the
2040 // caller.
2041 assert function.isStrict();
2042 method.loadNull();
2043 }
2044 method.load(function.getParameters().size());
2045 globalAllocateArguments();
2046 method.storeCompilerConstant(ARGUMENTS);
2047 }
2048
2049 private boolean skipFunction(final FunctionNode functionNode) {
2050 final ScriptEnvironment env = compiler.getScriptEnvironment();
2051 final boolean lazy = env._lazy_compilation;
2052 final boolean onDemand = compiler.isOnDemandCompilation();
2053
2054 // If this is on-demand or lazy compilation, don't compile a nested (not topmost) function.
2055 if((onDemand || lazy) && lc.getOutermostFunction() != functionNode) {
2056 return true;
2057 }
2058
2059 // If lazy compiling with optimistic types, don't compile the program eagerly either. It will soon be
2060 // invalidated anyway. In presence of a class cache, this further means that an obsoleted program version
2061 // lingers around. Also, currently loading previously persisted optimistic types information only works if
2062 // we're on-demand compiling a function, so with this strategy the :program method can also have the warmup
2063 // benefit of using previously persisted types.
2064 //
2065 // NOTE that this means the first compiled class will effectively just have a :createProgramFunction method, and
2066 // the RecompilableScriptFunctionData (RSFD) object in its constants array. It won't even have the :program
2067 // method. This is by design. It does mean that we're wasting one compiler execution (and we could minimize this
2068 // by just running it up to scope depth calculation, which creates the RSFDs and then this limited codegen).
2069 // We could emit an initial separate compile unit with the initial version of :program in it to better utilize
2070 // the compilation pipeline, but that would need more invasive changes, as currently the assumption that
2071 // :program is emitted into the first compilation unit of the function lives in many places.
2072 return !onDemand && lazy && env._optimistic_types && functionNode.isProgram();
2073 }
2074
2075 @Override
2076 public boolean enterFunctionNode(final FunctionNode functionNode) {
2077 if (skipFunction(functionNode)) {
2078 // In case we are not generating code for the function, we must create or retrieve the function object and
2079 // load it on the stack here.
2080 newFunctionObject(functionNode, false);
2081 return false;
2082 }
2083
2084 final String fnName = functionNode.getName();
2085
2086 // NOTE: we only emit the method for a function with the given name once. We can have multiple functions with
2087 // the same name as a result of inlining finally blocks. However, in the future -- with type specialization,
2088 // notably -- we might need to check for both name *and* signature. Of course, even that might not be
2089 // sufficient; the function might have a code dependency on the type of the variables in its enclosing scopes,
2090 // and the type of such a variable can be different in catch and finally blocks. So, in the future we will have
2091 // to decide to either generate a unique method for each inlined copy of the function, maybe figure out its
2092 // exact type closure and deduplicate based on that, or just decide that functions in finally blocks aren't
2093 // worth it, and generate one method with most generic type closure.
2094 if (!emittedMethods.contains(fnName)) {
2095 log.info("=== BEGIN ", fnName);
2096
2097 assert functionNode.getCompileUnit() != null : "no compile unit for " + fnName + " " + Debug.id(functionNode);
2098 unit = lc.pushCompileUnit(functionNode.getCompileUnit());
2099 assert lc.hasCompileUnits();
2100
2101 final ClassEmitter classEmitter = unit.getClassEmitter();
2102 pushMethodEmitter(isRestOf() ? classEmitter.restOfMethod(functionNode) : classEmitter.method(functionNode));
2103 method.setPreventUndefinedLoad();
2104 if(useOptimisticTypes()) {
2105 lc.pushUnwarrantedOptimismHandlers();
2106 }
2107
2108 // new method - reset last line number
2109 lastLineNumber = -1;
2110
2111 method.begin();
2112
2113 if (isRestOf()) {
2114 assert continuationInfo == null;
2115 continuationInfo = new ContinuationInfo();
2116 method.gotoLoopStart(continuationInfo.getHandlerLabel());
2117 }
2118 }
2119
2120 return true;
2121 }
2122
2123 private void pushMethodEmitter(final MethodEmitter newMethod) {
2124 method = lc.pushMethodEmitter(newMethod);
2125 catchLabels.push(METHOD_BOUNDARY);
2126 }
2127
2128 private void popMethodEmitter() {
2129 method = lc.popMethodEmitter(method);
2130 assert catchLabels.peek() == METHOD_BOUNDARY;
2131 catchLabels.pop();
2132 }
2133
2134 @Override
2135 public Node leaveFunctionNode(final FunctionNode functionNode) {
2136 try {
2137 final boolean markOptimistic;
2138 if (emittedMethods.add(functionNode.getName())) {
2139 markOptimistic = generateUnwarrantedOptimismExceptionHandlers(functionNode);
2140 generateContinuationHandler();
2141 method.end(); // wrap up this method
2142 unit = lc.popCompileUnit(functionNode.getCompileUnit());
2143 popMethodEmitter();
2144 log.info("=== END ", functionNode.getName());
2145 } else {
2146 markOptimistic = false;
2147 }
2148
2149 FunctionNode newFunctionNode = functionNode;
2150 if (markOptimistic) {
2151 newFunctionNode = newFunctionNode.setFlag(lc, FunctionNode.IS_DEOPTIMIZABLE);
2152 }
2153
2154 newFunctionObject(newFunctionNode, true);
2155 return newFunctionNode;
2156 } catch (final Throwable t) {
2157 Context.printStackTrace(t);
2158 final VerifyError e = new VerifyError("Code generation bug in \"" + functionNode.getName() + "\": likely stack misaligned: " + t + " " + functionNode.getSource().getName());
2159 e.initCause(t);
2160 throw e;
2161 }
2162 }
2163
2164 @Override
2165 public boolean enterIfNode(final IfNode ifNode) {
2166 if(!method.isReachable()) {
2167 return false;
2168 }
2169 enterStatement(ifNode);
2170
2171 final Expression test = ifNode.getTest();
2172 final Block pass = ifNode.getPass();
2173 final Block fail = ifNode.getFail();
2174
2175 if (Expression.isAlwaysTrue(test)) {
2176 loadAndDiscard(test);
2177 pass.accept(this);
2178 return false;
2179 } else if (Expression.isAlwaysFalse(test)) {
2180 loadAndDiscard(test);
2181 if (fail != null) {
2182 fail.accept(this);
2183 }
2184 return false;
2185 }
2186
2187 final boolean hasFailConversion = LocalVariableConversion.hasLiveConversion(ifNode);
2188
2189 final Label failLabel = new Label("if_fail");
2190 final Label afterLabel = (fail == null && !hasFailConversion) ? null : new Label("if_done");
2191
2192 emitBranch(test, failLabel, false);
2193
2194 pass.accept(this);
2195 if(method.isReachable() && afterLabel != null) {
2196 method._goto(afterLabel); //don't fallthru to fail block
2197 }
2198 method.label(failLabel);
2199
2200 if (fail != null) {
2201 fail.accept(this);
2202 } else if(hasFailConversion) {
2203 method.beforeJoinPoint(ifNode);
2204 }
2205
2206 if(afterLabel != null && afterLabel.isReachable()) {
2207 method.label(afterLabel);
2208 }
2209
2210 return false;
2211 }
2212
2213 private void emitBranch(final Expression test, final Label label, final boolean jumpWhenTrue) {
2214 new BranchOptimizer(this, method).execute(test, label, jumpWhenTrue);
2215 }
2216
2217 private void enterStatement(final Statement statement) {
2218 lineNumber(statement);
2219 }
2220
2221 private void lineNumber(final Statement statement) {
2222 lineNumber(statement.getLineNumber());
2223 }
2224
2225 private void lineNumber(final int lineNumber) {
2226 if (lineNumber != lastLineNumber && lineNumber != Node.NO_LINE_NUMBER) {
2227 method.lineNumber(lineNumber);
2228 lastLineNumber = lineNumber;
2229 }
2230 }
2231
2232 int getLastLineNumber() {
2233 return lastLineNumber;
2234 }
2235
2236 /**
2237 * Load a list of nodes as an array of a specific type
2238 * The array will contain the visited nodes.
2239 *
2240 * @param arrayLiteralNode the array of contents
2241 * @param arrayType the type of the array, e.g. ARRAY_NUMBER or ARRAY_OBJECT
2242 */
2243 private void loadArray(final ArrayLiteralNode arrayLiteralNode, final ArrayType arrayType) {
2244 assert arrayType == Type.INT_ARRAY || arrayType == Type.LONG_ARRAY || arrayType == Type.NUMBER_ARRAY || arrayType == Type.OBJECT_ARRAY;
2245
2246 final Expression[] nodes = arrayLiteralNode.getValue();
2247 final Object presets = arrayLiteralNode.getPresets();
2248 final int[] postsets = arrayLiteralNode.getPostsets();
2249 final List<Splittable.SplitRange> ranges = arrayLiteralNode.getSplitRanges();
2250
2251 loadConstant(presets);
2252
2253 final Type elementType = arrayType.getElementType();
2254
2255 if (ranges != null) {
2256
2257 loadSplitLiteral(new SplitLiteralCreator() {
2258 @Override
2259 public void populateRange(final MethodEmitter method, final Type type, final int slot, final int start, final int end) {
2260 for (int i = start; i < end; i++) {
2261 method.load(type, slot);
2262 storeElement(nodes, elementType, postsets[i]);
2263 }
2264 method.load(type, slot);
2265 }
2266 }, ranges, arrayType);
2267
2268 return;
2269 }
2270
2271 if(postsets.length > 0) {
2272 final int arraySlot = method.getUsedSlotsWithLiveTemporaries();
2273 method.storeTemp(arrayType, arraySlot);
2274 for (final int postset : postsets) {
2275 method.load(arrayType, arraySlot);
2276 storeElement(nodes, elementType, postset);
2277 }
2278 method.load(arrayType, arraySlot);
2279 }
2280 }
2281
2282 private void storeElement(final Expression[] nodes, final Type elementType, final int index) {
2283 method.load(index);
2284
2285 final Expression element = nodes[index];
2286
2287 if (element == null) {
2288 method.loadEmpty(elementType);
2289 } else {
2290 loadExpressionAsType(element, elementType);
2291 }
2292
2293 method.arraystore();
2294 }
2295
2296 private MethodEmitter loadArgsArray(final List<Expression> args) {
2297 final Object[] array = new Object[args.size()];
2298 loadConstant(array);
2299
2300 for (int i = 0; i < args.size(); i++) {
2301 method.dup();
2302 method.load(i);
2303 loadExpression(args.get(i), TypeBounds.OBJECT); // variable arity methods always take objects
2304 method.arraystore();
2305 }
2306
2307 return method;
2308 }
2309
2310 /**
2311 * Load a constant from the constant array. This is only public to be callable from the objects
2312 * subpackage. Do not call directly.
2313 *
2314 * @param string string to load
2315 */
2316 void loadConstant(final String string) {
2317 final String unitClassName = unit.getUnitClassName();
2318 final ClassEmitter classEmitter = unit.getClassEmitter();
2319 final int index = compiler.getConstantData().add(string);
2320
2321 method.load(index);
2322 method.invokestatic(unitClassName, GET_STRING.symbolName(), methodDescriptor(String.class, int.class));
2323 classEmitter.needGetConstantMethod(String.class);
2324 }
2325
2326 /**
2327 * Load a constant from the constant array. This is only public to be callable from the objects
2328 * subpackage. Do not call directly.
2329 *
2330 * @param object object to load
2331 */
2332 void loadConstant(final Object object) {
2333 loadConstant(object, unit, method);
2334 }
2335
2336 private void loadConstant(final Object object, final CompileUnit compileUnit, final MethodEmitter methodEmitter) {
2337 final String unitClassName = compileUnit.getUnitClassName();
2338 final ClassEmitter classEmitter = compileUnit.getClassEmitter();
2339 final int index = compiler.getConstantData().add(object);
2340 final Class<?> cls = object.getClass();
2341
2342 if (cls == PropertyMap.class) {
2343 methodEmitter.load(index);
2344 methodEmitter.invokestatic(unitClassName, GET_MAP.symbolName(), methodDescriptor(PropertyMap.class, int.class));
2345 classEmitter.needGetConstantMethod(PropertyMap.class);
2346 } else if (cls.isArray()) {
2347 methodEmitter.load(index);
2348 final String methodName = ClassEmitter.getArrayMethodName(cls);
2349 methodEmitter.invokestatic(unitClassName, methodName, methodDescriptor(cls, int.class));
2350 classEmitter.needGetConstantMethod(cls);
2351 } else {
2352 methodEmitter.loadConstants().load(index).arrayload();
2353 if (object instanceof ArrayData) {
2354 methodEmitter.checkcast(ArrayData.class);
2355 methodEmitter.invoke(virtualCallNoLookup(ArrayData.class, "copy", ArrayData.class));
2356 } else if (cls != Object.class) {
2357 methodEmitter.checkcast(cls);
2358 }
2359 }
2360 }
2361
2362 private void loadConstantsAndIndex(final Object object, final MethodEmitter methodEmitter) {
2363 methodEmitter.loadConstants().load(compiler.getConstantData().add(object));
2364 }
2365
2366 // literal values
2367 private void loadLiteral(final LiteralNode<?> node, final TypeBounds resultBounds) {
2368 final Object value = node.getValue();
2369
2370 if (value == null) {
2371 method.loadNull();
2372 } else if (value instanceof Undefined) {
2373 method.loadUndefined(resultBounds.within(Type.OBJECT));
2374 } else if (value instanceof String) {
2375 final String string = (String)value;
2376
2377 if (string.length() > MethodEmitter.LARGE_STRING_THRESHOLD / 3) { // 3 == max bytes per encoded char
2378 loadConstant(string);
2379 } else {
2380 method.load(string);
2381 }
2382 } else if (value instanceof RegexToken) {
2383 loadRegex((RegexToken)value);
2384 } else if (value instanceof Boolean) {
2385 method.load((Boolean)value);
2386 } else if (value instanceof Integer) {
2387 if(!resultBounds.canBeNarrowerThan(Type.OBJECT)) {
2388 method.load((Integer)value);
2389 method.convert(Type.OBJECT);
2390 } else if(!resultBounds.canBeNarrowerThan(Type.NUMBER)) {
2391 method.load(((Integer)value).doubleValue());
2392 } else if(!resultBounds.canBeNarrowerThan(Type.LONG)) {
2393 method.load(((Integer)value).longValue());
2394 } else {
2395 method.load((Integer)value);
2396 }
2397 } else if (value instanceof Long) {
2398 if(!resultBounds.canBeNarrowerThan(Type.OBJECT)) {
2399 method.load((Long)value);
2400 method.convert(Type.OBJECT);
2401 } else if(!resultBounds.canBeNarrowerThan(Type.NUMBER)) {
2402 method.load(((Long)value).doubleValue());
2403 } else {
2404 method.load((Long)value);
2405 }
2406 } else if (value instanceof Double) {
2407 if(!resultBounds.canBeNarrowerThan(Type.OBJECT)) {
2408 method.load((Double)value);
2409 method.convert(Type.OBJECT);
2410 } else {
2411 method.load((Double)value);
2412 }
2413 } else if (node instanceof ArrayLiteralNode) {
2414 final ArrayLiteralNode arrayLiteral = (ArrayLiteralNode)node;
2415 final ArrayType atype = arrayLiteral.getArrayType();
2416 loadArray(arrayLiteral, atype);
2417 globalAllocateArray(atype);
2418 } else {
2419 throw new UnsupportedOperationException("Unknown literal for " + node.getClass() + " " + value.getClass() + " " + value);
2420 }
2421 }
2422
2423 private MethodEmitter loadRegexToken(final RegexToken value) {
2424 method.load(value.getExpression());
2425 method.load(value.getOptions());
2426 return globalNewRegExp();
2427 }
2428
2429 private MethodEmitter loadRegex(final RegexToken regexToken) {
2430 if (regexFieldCount > MAX_REGEX_FIELDS) {
2431 return loadRegexToken(regexToken);
2432 }
2433 // emit field
2434 final String regexName = lc.getCurrentFunction().uniqueName(REGEX_PREFIX.symbolName());
2435 final ClassEmitter classEmitter = unit.getClassEmitter();
2436
2437 classEmitter.field(EnumSet.of(PRIVATE, STATIC), regexName, Object.class);
2438 regexFieldCount++;
2439
2440 // get field, if null create new regex, finally clone regex object
2441 method.getStatic(unit.getUnitClassName(), regexName, typeDescriptor(Object.class));
2442 method.dup();
2443 final Label cachedLabel = new Label("cached");
2444 method.ifnonnull(cachedLabel);
2445
2446 method.pop();
2447 loadRegexToken(regexToken);
2448 method.dup();
2449 method.putStatic(unit.getUnitClassName(), regexName, typeDescriptor(Object.class));
2450
2451 method.label(cachedLabel);
2452 globalRegExpCopy();
2453
2454 return method;
2455 }
2456
2457 /**
2458 * Check if a property value contains a particular program point
2459 * @param value value
2460 * @param pp program point
2461 * @return true if it's there.
2462 */
2463 private static boolean propertyValueContains(final Expression value, final int pp) {
2464 return new Supplier<Boolean>() {
2465 boolean contains;
2466
2467 @Override
2468 public Boolean get() {
2469 value.accept(new SimpleNodeVisitor() {
2470 @Override
2471 public boolean enterFunctionNode(final FunctionNode functionNode) {
2472 return false;
2473 }
2474
2475 @Override
2476 public boolean enterObjectNode(final ObjectNode objectNode) {
2477 return false;
2478 }
2479
2480 @Override
2481 public boolean enterDefault(final Node node) {
2482 if (contains) {
2483 return false;
2484 }
2485 if (node instanceof Optimistic && ((Optimistic)node).getProgramPoint() == pp) {
2486 contains = true;
2487 return false;
2488 }
2489 return true;
2490 }
2491 });
2492
2493 return contains;
2494 }
2495 }.get();
2496 }
2497
2498 private void loadObjectNode(final ObjectNode objectNode) {
2499 final List<PropertyNode> elements = objectNode.getElements();
2500
2501 final List<MapTuple<Expression>> tuples = new ArrayList<>();
2502 final List<PropertyNode> gettersSetters = new ArrayList<>();
2503 final int ccp = getCurrentContinuationEntryPoint();
2504 final List<Splittable.SplitRange> ranges = objectNode.getSplitRanges();
2505
2506 Expression protoNode = null;
2507 boolean restOfProperty = false;
2508
2509 for (final PropertyNode propertyNode : elements) {
2510 final Expression value = propertyNode.getValue();
2511 final String key = propertyNode.getKeyName();
2512 // Just use a pseudo-symbol. We just need something non null; use the name and zero flags.
2513 final Symbol symbol = value == null ? null : new Symbol(key, 0);
2514
2515 if (value == null) {
2516 gettersSetters.add(propertyNode);
2517 } else if (propertyNode.getKey() instanceof IdentNode &&
2518 key.equals(ScriptObject.PROTO_PROPERTY_NAME)) {
2519 // ES6 draft compliant __proto__ inside object literal
2520 // Identifier key and name is __proto__
2521 protoNode = value;
2522 continue;
2523 }
2524
2525 restOfProperty |=
2526 value != null &&
2527 isValid(ccp) &&
2528 propertyValueContains(value, ccp);
2529
2530 //for literals, a value of null means object type, i.e. the value null or getter setter function
2531 //(I think)
2532 final Class<?> valueType = (!useDualFields() || value == null || value.getType().isBoolean()) ? Object.class : value.getType().getTypeClass();
2533 tuples.add(new MapTuple<Expression>(key, symbol, Type.typeFor(valueType), value) {
2534 @Override
2535 public Class<?> getValueType() {
2536 return type.getTypeClass();
2537 }
2538 });
2539 }
2540
2541 final ObjectCreator<?> oc;
2542 if (elements.size() > OBJECT_SPILL_THRESHOLD) {
2543 oc = new SpillObjectCreator(this, tuples);
2544 } else {
2545 oc = new FieldObjectCreator<Expression>(this, tuples) {
2546 @Override
2547 protected void loadValue(final Expression node, final Type type) {
2548 loadExpressionAsType(node, type);
2549 }};
2550 }
2551
2552 if (ranges != null) {
2553 oc.createObject(method);
2554 loadSplitLiteral(oc, ranges, Type.typeFor(oc.getAllocatorClass()));
2555 } else {
2556 oc.makeObject(method);
2557 }
2558
2559 //if this is a rest of method and our continuation point was found as one of the values
2560 //in the properties above, we need to reset the map to oc.getMap() in the continuation
2561 //handler
2562 if (restOfProperty) {
2563 final ContinuationInfo ci = getContinuationInfo();
2564 // Can be set at most once for a single rest-of method
2565 assert ci.getObjectLiteralMap() == null;
2566 ci.setObjectLiteralMap(oc.getMap());
2567 ci.setObjectLiteralStackDepth(method.getStackSize());
2568 }
2569
2570 method.dup();
2571 if (protoNode != null) {
2572 loadExpressionAsObject(protoNode);
2573 // take care of { __proto__: 34 } or some such!
2574 method.convert(Type.OBJECT);
2575 method.invoke(ScriptObject.SET_PROTO_FROM_LITERAL);
2576 } else {
2577 method.invoke(ScriptObject.SET_GLOBAL_OBJECT_PROTO);
2578 }
2579
2580 for (final PropertyNode propertyNode : gettersSetters) {
2581 final FunctionNode getter = propertyNode.getGetter();
2582 final FunctionNode setter = propertyNode.getSetter();
2583
2584 assert getter != null || setter != null;
2585
2586 method.dup().loadKey(propertyNode.getKey());
2587 if (getter == null) {
2588 method.loadNull();
2589 } else {
2590 getter.accept(this);
2591 }
2592
2593 if (setter == null) {
2594 method.loadNull();
2595 } else {
2596 setter.accept(this);
2597 }
2598
2599 method.invoke(ScriptObject.SET_USER_ACCESSORS);
2600 }
2601 }
2602
2603 @Override
2604 public boolean enterReturnNode(final ReturnNode returnNode) {
2605 if(!method.isReachable()) {
2606 return false;
2607 }
2608 enterStatement(returnNode);
2609
2610 final Type returnType = lc.getCurrentFunction().getReturnType();
2611
2612 final Expression expression = returnNode.getExpression();
2613 if (expression != null) {
2614 loadExpressionUnbounded(expression);
2615 } else {
2616 method.loadUndefined(returnType);
2617 }
2618
2619 method._return(returnType);
2620
2621 return false;
2622 }
2623
2624 private boolean undefinedCheck(final RuntimeNode runtimeNode, final List<Expression> args) {
2625 final Request request = runtimeNode.getRequest();
2626
2627 if (!Request.isUndefinedCheck(request)) {
2628 return false;
2629 }
2630
2631 final Expression lhs = args.get(0);
2632 final Expression rhs = args.get(1);
2633
2634 final Symbol lhsSymbol = lhs instanceof IdentNode ? ((IdentNode)lhs).getSymbol() : null;
2635 final Symbol rhsSymbol = rhs instanceof IdentNode ? ((IdentNode)rhs).getSymbol() : null;
2636 // One must be a "undefined" identifier, otherwise we can't get here
2637 assert lhsSymbol != null || rhsSymbol != null;
2638
2639 final Symbol undefinedSymbol;
2640 if (isUndefinedSymbol(lhsSymbol)) {
2641 undefinedSymbol = lhsSymbol;
2642 } else {
2643 assert isUndefinedSymbol(rhsSymbol);
2644 undefinedSymbol = rhsSymbol;
2645 }
2646
2647 assert undefinedSymbol != null; //remove warning
2648 if (!undefinedSymbol.isScope()) {
2649 return false; //disallow undefined as local var or parameter
2650 }
2651
2652 if (lhsSymbol == undefinedSymbol && lhs.getType().isPrimitive()) {
2653 //we load the undefined first. never mind, because this will deoptimize anyway
2654 return false;
2655 }
2656
2657 if(isDeoptimizedExpression(lhs)) {
2658 // This is actually related to "lhs.getType().isPrimitive()" above: any expression being deoptimized in
2659 // the current chain of rest-of compilations used to have a type narrower than Object (so it was primitive).
2660 // We must not perform undefined check specialization for them, as then we'd violate the basic rule of
2661 // "Thou shalt not alter the stack shape between a deoptimized method and any of its (transitive) rest-ofs."
2662 return false;
2663 }
2664
2665 //make sure that undefined has not been overridden or scoped as a local var
2666 //between us and global
2667 if (!compiler.isGlobalSymbol(lc.getCurrentFunction(), "undefined")) {
2668 return false;
2669 }
2670
2671 final boolean isUndefinedCheck = request == Request.IS_UNDEFINED;
2672 final Expression expr = undefinedSymbol == lhsSymbol ? rhs : lhs;
2673 if (expr.getType().isPrimitive()) {
2674 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
2675 method.load(!isUndefinedCheck);
2676 } else {
2677 final Label checkTrue = new Label("ud_check_true");
2678 final Label end = new Label("end");
2679 loadExpressionAsObject(expr);
2680 method.loadUndefined(Type.OBJECT);
2681 method.if_acmpeq(checkTrue);
2682 method.load(!isUndefinedCheck);
2683 method._goto(end);
2684 method.label(checkTrue);
2685 method.load(isUndefinedCheck);
2686 method.label(end);
2687 }
2688
2689 return true;
2690 }
2691
2692 private static boolean isUndefinedSymbol(final Symbol symbol) {
2693 return symbol != null && "undefined".equals(symbol.getName());
2694 }
2695
2696 private static boolean isNullLiteral(final Node node) {
2697 return node instanceof LiteralNode<?> && ((LiteralNode<?>) node).isNull();
2698 }
2699
2700 private boolean nullCheck(final RuntimeNode runtimeNode, final List<Expression> args) {
2701 final Request request = runtimeNode.getRequest();
2702
2703 if (!Request.isEQ(request) && !Request.isNE(request)) {
2704 return false;
2705 }
2706
2707 assert args.size() == 2 : "EQ or NE or TYPEOF need two args";
2708
2709 Expression lhs = args.get(0);
2710 Expression rhs = args.get(1);
2711
2712 if (isNullLiteral(lhs)) {
2713 final Expression tmp = lhs;
2714 lhs = rhs;
2715 rhs = tmp;
2716 }
2717
2718 if (!isNullLiteral(rhs)) {
2719 return false;
2720 }
2721
2722 if (!lhs.getType().isObject()) {
2723 return false;
2724 }
2725
2726 if(isDeoptimizedExpression(lhs)) {
2727 // This is actually related to "!lhs.getType().isObject()" above: any expression being deoptimized in
2728 // the current chain of rest-of compilations used to have a type narrower than Object. We must not
2729 // perform null check specialization for them, as then we'd no longer be loading aconst_null on stack
2730 // and thus violate the basic rule of "Thou shalt not alter the stack shape between a deoptimized
2731 // method and any of its (transitive) rest-ofs."
2732 // NOTE also that if we had a representation for well-known constants (e.g. null, 0, 1, -1, etc.) in
2733 // Label$Stack.localLoads then this wouldn't be an issue, as we would never (somewhat ridiculously)
2734 // allocate a temporary local to hold the result of aconst_null before attempting an optimistic
2735 // operation.
2736 return false;
2737 }
2738
2739 // this is a null literal check, so if there is implicit coercion
2740 // involved like {D}x=null, we will fail - this is very rare
2741 final Label trueLabel = new Label("trueLabel");
2742 final Label falseLabel = new Label("falseLabel");
2743 final Label endLabel = new Label("end");
2744
2745 loadExpressionUnbounded(lhs); //lhs
2746 final Label popLabel;
2747 if (!Request.isStrict(request)) {
2748 method.dup(); //lhs lhs
2749 popLabel = new Label("pop");
2750 } else {
2751 popLabel = null;
2752 }
2753
2754 if (Request.isEQ(request)) {
2755 method.ifnull(!Request.isStrict(request) ? popLabel : trueLabel);
2756 if (!Request.isStrict(request)) {
2757 method.loadUndefined(Type.OBJECT);
2758 method.if_acmpeq(trueLabel);
2759 }
2760 method.label(falseLabel);
2761 method.load(false);
2762 method._goto(endLabel);
2763 if (!Request.isStrict(request)) {
2764 method.label(popLabel);
2765 method.pop();
2766 }
2767 method.label(trueLabel);
2768 method.load(true);
2769 method.label(endLabel);
2770 } else if (Request.isNE(request)) {
2771 method.ifnull(!Request.isStrict(request) ? popLabel : falseLabel);
2772 if (!Request.isStrict(request)) {
2773 method.loadUndefined(Type.OBJECT);
2774 method.if_acmpeq(falseLabel);
2775 }
2776 method.label(trueLabel);
2777 method.load(true);
2778 method._goto(endLabel);
2779 if (!Request.isStrict(request)) {
2780 method.label(popLabel);
2781 method.pop();
2782 }
2783 method.label(falseLabel);
2784 method.load(false);
2785 method.label(endLabel);
2786 }
2787
2788 assert runtimeNode.getType().isBoolean();
2789 method.convert(runtimeNode.getType());
2790
2791 return true;
2792 }
2793
2794 /**
2795 * Was this expression or any of its subexpressions deoptimized in the current recompilation chain of rest-of methods?
2796 * @param rootExpr the expression being tested
2797 * @return true if the expression or any of its subexpressions was deoptimized in the current recompilation chain.
2798 */
2799 private boolean isDeoptimizedExpression(final Expression rootExpr) {
2800 if(!isRestOf()) {
2801 return false;
2802 }
2803 return new Supplier<Boolean>() {
2804 boolean contains;
2805 @Override
2806 public Boolean get() {
2807 rootExpr.accept(new SimpleNodeVisitor() {
2808 @Override
2809 public boolean enterFunctionNode(final FunctionNode functionNode) {
2810 return false;
2811 }
2812 @Override
2813 public boolean enterDefault(final Node node) {
2814 if(!contains && node instanceof Optimistic) {
2815 final int pp = ((Optimistic)node).getProgramPoint();
2816 contains = isValid(pp) && isContinuationEntryPoint(pp);
2817 }
2818 return !contains;
2819 }
2820 });
2821 return contains;
2822 }
2823 }.get();
2824 }
2825
2826 private void loadRuntimeNode(final RuntimeNode runtimeNode) {
2827 final List<Expression> args = new ArrayList<>(runtimeNode.getArgs());
2828 if (nullCheck(runtimeNode, args)) {
2829 return;
2830 } else if(undefinedCheck(runtimeNode, args)) {
2831 return;
2832 }
2833 // Revert a false undefined check to a strict equality check
2834 final RuntimeNode newRuntimeNode;
2835 final Request request = runtimeNode.getRequest();
2836 if (Request.isUndefinedCheck(request)) {
2837 newRuntimeNode = runtimeNode.setRequest(request == Request.IS_UNDEFINED ? Request.EQ_STRICT : Request.NE_STRICT);
2838 } else {
2839 newRuntimeNode = runtimeNode;
2840 }
2841
2842 for (final Expression arg : args) {
2843 loadExpression(arg, TypeBounds.OBJECT);
2844 }
2845
2846 method.invokestatic(
2847 CompilerConstants.className(ScriptRuntime.class),
2848 newRuntimeNode.getRequest().toString(),
2849 new FunctionSignature(
2850 false,
2851 false,
2852 newRuntimeNode.getType(),
2853 args.size()).toString());
2854
2855 method.convert(newRuntimeNode.getType());
2856 }
2857
2858 private void defineCommonSplitMethodParameters() {
2859 defineSplitMethodParameter(0, CALLEE);
2860 defineSplitMethodParameter(1, THIS);
2861 defineSplitMethodParameter(2, SCOPE);
2862 }
2863
2864 private void defineSplitMethodParameter(final int slot, final CompilerConstants cc) {
2865 defineSplitMethodParameter(slot, Type.typeFor(cc.type()));
2866 }
2867
2868 private void defineSplitMethodParameter(final int slot, final Type type) {
2869 method.defineBlockLocalVariable(slot, slot + type.getSlots());
2870 method.onLocalStore(type, slot);
2871 }
2872
2873 private void loadSplitLiteral(final SplitLiteralCreator creator, final List<Splittable.SplitRange> ranges, final Type literalType) {
2874 assert ranges != null;
2875
2876 // final Type literalType = Type.typeFor(literalClass);
2877 final MethodEmitter savedMethod = method;
2878 final FunctionNode currentFunction = lc.getCurrentFunction();
2879
2880 for (final Splittable.SplitRange splitRange : ranges) {
2881 unit = lc.pushCompileUnit(splitRange.getCompileUnit());
2882
2883 assert unit != null;
2884 final String className = unit.getUnitClassName();
2885 final String name = currentFunction.uniqueName(SPLIT_PREFIX.symbolName());
2886 final Class<?> clazz = literalType.getTypeClass();
2887 final String signature = methodDescriptor(clazz, ScriptFunction.class, Object.class, ScriptObject.class, clazz);
2888
2889 pushMethodEmitter(unit.getClassEmitter().method(EnumSet.of(Flag.PUBLIC, Flag.STATIC), name, signature));
2890
2891 method.setFunctionNode(currentFunction);
2892 method.begin();
2893
2894 defineCommonSplitMethodParameters();
2895 defineSplitMethodParameter(CompilerConstants.SPLIT_ARRAY_ARG.slot(), literalType);
2896
2897 // NOTE: when this is no longer needed, SplitIntoFunctions will no longer have to add IS_SPLIT
2898 // to synthetic functions, and FunctionNode.needsCallee() will no longer need to test for isSplit().
2899 final int literalSlot = fixScopeSlot(currentFunction, 3);
2900
2901 lc.enterSplitNode();
2902
2903 creator.populateRange(method, literalType, literalSlot, splitRange.getLow(), splitRange.getHigh());
2904
2905 method._return();
2906 lc.exitSplitNode();
2907 method.end();
2908 lc.releaseSlots();
2909 popMethodEmitter();
2910
2911 assert method == savedMethod;
2912 method.loadCompilerConstant(CALLEE).swap();
2913 method.loadCompilerConstant(THIS).swap();
2914 method.loadCompilerConstant(SCOPE).swap();
2915 method.invokestatic(className, name, signature);
2916
2917 unit = lc.popCompileUnit(unit);
2918 }
2919 }
2920
2921 private int fixScopeSlot(final FunctionNode functionNode, final int extraSlot) {
2922 // TODO hack to move the scope to the expected slot (needed because split methods reuse the same slots as the root method)
2923 final int actualScopeSlot = functionNode.compilerConstant(SCOPE).getSlot(SCOPE_TYPE);
2924 final int defaultScopeSlot = SCOPE.slot();
2925 int newExtraSlot = extraSlot;
2926 if (actualScopeSlot != defaultScopeSlot) {
2927 if (actualScopeSlot == extraSlot) {
2928 newExtraSlot = extraSlot + 1;
2929 method.defineBlockLocalVariable(newExtraSlot, newExtraSlot + 1);
2930 method.load(Type.OBJECT, extraSlot);
2931 method.storeHidden(Type.OBJECT, newExtraSlot);
2932 } else {
2933 method.defineBlockLocalVariable(actualScopeSlot, actualScopeSlot + 1);
2934 }
2935 method.load(SCOPE_TYPE, defaultScopeSlot);
2936 method.storeCompilerConstant(SCOPE);
2937 }
2938 return newExtraSlot;
2939 }
2940
2941 @Override
2942 public boolean enterSplitReturn(final SplitReturn splitReturn) {
2943 if (method.isReachable()) {
2944 method.loadUndefined(lc.getCurrentFunction().getReturnType())._return();
2945 }
2946 return false;
2947 }
2948
2949 @Override
2950 public boolean enterSetSplitState(final SetSplitState setSplitState) {
2951 if (method.isReachable()) {
2952 method.setSplitState(setSplitState.getState());
2953 }
2954 return false;
2955 }
2956
2957 @Override
2958 public boolean enterSwitchNode(final SwitchNode switchNode) {
2959 if(!method.isReachable()) {
2960 return false;
2961 }
2962 enterStatement(switchNode);
2963
2964 final Expression expression = switchNode.getExpression();
2965 final List<CaseNode> cases = switchNode.getCases();
2966
2967 if (cases.isEmpty()) {
2968 // still evaluate expression for side-effects.
2969 loadAndDiscard(expression);
2970 return false;
2971 }
2972
2973 final CaseNode defaultCase = switchNode.getDefaultCase();
2974 final Label breakLabel = switchNode.getBreakLabel();
2975 final int liveLocalsOnBreak = method.getUsedSlotsWithLiveTemporaries();
2976
2977 if (defaultCase != null && cases.size() == 1) {
2978 // default case only
2979 assert cases.get(0) == defaultCase;
2980 loadAndDiscard(expression);
2981 defaultCase.getBody().accept(this);
2982 method.breakLabel(breakLabel, liveLocalsOnBreak);
2983 return false;
2984 }
2985
2986 // NOTE: it can still change in the tableswitch/lookupswitch case if there's no default case
2987 // but we need to add a synthetic default case for local variable conversions
2988 Label defaultLabel = defaultCase != null ? defaultCase.getEntry() : breakLabel;
2989 final boolean hasSkipConversion = LocalVariableConversion.hasLiveConversion(switchNode);
2990
2991 if (switchNode.isUniqueInteger()) {
2992 // Tree for sorting values.
2993 final TreeMap<Integer, Label> tree = new TreeMap<>();
2994
2995 // Build up sorted tree.
2996 for (final CaseNode caseNode : cases) {
2997 final Node test = caseNode.getTest();
2998
2999 if (test != null) {
3000 final Integer value = (Integer)((LiteralNode<?>)test).getValue();
3001 final Label entry = caseNode.getEntry();
3002
3003 // Take first duplicate.
3004 if (!tree.containsKey(value)) {
3005 tree.put(value, entry);
3006 }
3007 }
3008 }
3009
3010 // Copy values and labels to arrays.
3011 final int size = tree.size();
3012 final Integer[] values = tree.keySet().toArray(new Integer[size]);
3013 final Label[] labels = tree.values().toArray(new Label[size]);
3014
3015 // Discern low, high and range.
3016 final int lo = values[0];
3017 final int hi = values[size - 1];
3018 final long range = (long)hi - (long)lo + 1;
3019
3020 // Find an unused value for default.
3021 int deflt = Integer.MIN_VALUE;
3022 for (final int value : values) {
3023 if (deflt == value) {
3024 deflt++;
3025 } else if (deflt < value) {
3026 break;
3027 }
3028 }
3029
3030 // Load switch expression.
3031 loadExpressionUnbounded(expression);
3032 final Type type = expression.getType();
3033
3034 // If expression not int see if we can convert, if not use deflt to trigger default.
3035 if (!type.isInteger()) {
3036 method.load(deflt);
3037 final Class<?> exprClass = type.getTypeClass();
3038 method.invoke(staticCallNoLookup(ScriptRuntime.class, "switchTagAsInt", int.class, exprClass.isPrimitive()? exprClass : Object.class, int.class));
3039 }
3040
3041 if(hasSkipConversion) {
3042 assert defaultLabel == breakLabel;
3043 defaultLabel = new Label("switch_skip");
3044 }
3045 // TABLESWITCH needs (range + 3) 32-bit values; LOOKUPSWITCH needs ((size * 2) + 2). Choose the one with
3046 // smaller representation, favor TABLESWITCH when they're equal size.
3047 if (range + 1 <= (size * 2) && range <= Integer.MAX_VALUE) {
3048 final Label[] table = new Label[(int)range];
3049 Arrays.fill(table, defaultLabel);
3050 for (int i = 0; i < size; i++) {
3051 final int value = values[i];
3052 table[value - lo] = labels[i];
3053 }
3054
3055 method.tableswitch(lo, hi, defaultLabel, table);
3056 } else {
3057 final int[] ints = new int[size];
3058 for (int i = 0; i < size; i++) {
3059 ints[i] = values[i];
3060 }
3061
3062 method.lookupswitch(defaultLabel, ints, labels);
3063 }
3064 // This is a synthetic "default case" used in absence of actual default case, created if we need to apply
3065 // local variable conversions if neither case is taken.
3066 if(hasSkipConversion) {
3067 method.label(defaultLabel);
3068 method.beforeJoinPoint(switchNode);
3069 method._goto(breakLabel);
3070 }
3071 } else {
3072 final Symbol tagSymbol = switchNode.getTag();
3073 // TODO: we could have non-object tag
3074 final int tagSlot = tagSymbol.getSlot(Type.OBJECT);
3075 loadExpressionAsObject(expression);
3076 method.store(tagSymbol, Type.OBJECT);
3077
3078 for (final CaseNode caseNode : cases) {
3079 final Expression test = caseNode.getTest();
3080
3081 if (test != null) {
3082 method.load(Type.OBJECT, tagSlot);
3083 loadExpressionAsObject(test);
3084 method.invoke(ScriptRuntime.EQ_STRICT);
3085 method.ifne(caseNode.getEntry());
3086 }
3087 }
3088
3089 if (defaultCase != null) {
3090 method._goto(defaultLabel);
3091 } else {
3092 method.beforeJoinPoint(switchNode);
3093 method._goto(breakLabel);
3094 }
3095 }
3096
3097 // First case is only reachable through jump
3098 assert !method.isReachable();
3099
3100 for (final CaseNode caseNode : cases) {
3101 final Label fallThroughLabel;
3102 if(caseNode.getLocalVariableConversion() != null && method.isReachable()) {
3103 fallThroughLabel = new Label("fallthrough");
3104 method._goto(fallThroughLabel);
3105 } else {
3106 fallThroughLabel = null;
3107 }
3108 method.label(caseNode.getEntry());
3109 method.beforeJoinPoint(caseNode);
3110 if(fallThroughLabel != null) {
3111 method.label(fallThroughLabel);
3112 }
3113 caseNode.getBody().accept(this);
3114 }
3115
3116 method.breakLabel(breakLabel, liveLocalsOnBreak);
3117
3118 return false;
3119 }
3120
3121 @Override
3122 public boolean enterThrowNode(final ThrowNode throwNode) {
3123 if(!method.isReachable()) {
3124 return false;
3125 }
3126 enterStatement(throwNode);
3127
3128 if (throwNode.isSyntheticRethrow()) {
3129 method.beforeJoinPoint(throwNode);
3130
3131 //do not wrap whatever this is in an ecma exception, just rethrow it
3132 final IdentNode exceptionExpr = (IdentNode)throwNode.getExpression();
3133 final Symbol exceptionSymbol = exceptionExpr.getSymbol();
3134 method.load(exceptionSymbol, EXCEPTION_TYPE);
3135 method.checkcast(EXCEPTION_TYPE.getTypeClass());
3136 method.athrow();
3137 return false;
3138 }
3139
3140 final Source source = getCurrentSource();
3141 final Expression expression = throwNode.getExpression();
3142 final int position = throwNode.position();
3143 final int line = throwNode.getLineNumber();
3144 final int column = source.getColumn(position);
3145
3146 // NOTE: we first evaluate the expression, and only after it was evaluated do we create the new ECMAException
3147 // object and then somewhat cumbersomely move it beneath the evaluated expression on the stack. The reason for
3148 // this is that if expression is optimistic (or contains an optimistic subexpression), we'd potentially access
3149 // the not-yet-<init>ialized object on the stack from the UnwarrantedOptimismException handler, and bytecode
3150 // verifier forbids that.
3151 loadExpressionAsObject(expression);
3152
3153 method.load(source.getName());
3154 method.load(line);
3155 method.load(column);
3156 method.invoke(ECMAException.CREATE);
3157
3158 method.beforeJoinPoint(throwNode);
3159 method.athrow();
3160
3161 return false;
3162 }
3163
3164 private Source getCurrentSource() {
3165 return lc.getCurrentFunction().getSource();
3166 }
3167
3168 @Override
3169 public boolean enterTryNode(final TryNode tryNode) {
3170 if(!method.isReachable()) {
3171 return false;
3172 }
3173 enterStatement(tryNode);
3174
3175 final Block body = tryNode.getBody();
3176 final List<Block> catchBlocks = tryNode.getCatchBlocks();
3177 final Symbol vmException = tryNode.getException();
3178 final Label entry = new Label("try");
3179 final Label recovery = new Label("catch");
3180 final Label exit = new Label("end_try");
3181 final Label skip = new Label("skip");
3182
3183 method.canThrow(recovery);
3184 // Effect any conversions that might be observed at the entry of the catch node before entering the try node.
3185 // This is because even the first instruction in the try block must be presumed to be able to transfer control
3186 // to the catch block. Note that this doesn't kill the original values; in this regard it works a lot like
3187 // conversions of assignments within the try block.
3188 method.beforeTry(tryNode, recovery);
3189 method.label(entry);
3190 catchLabels.push(recovery);
3191 try {
3192 body.accept(this);
3193 } finally {
3194 assert catchLabels.peek() == recovery;
3195 catchLabels.pop();
3196 }
3197
3198 method.label(exit);
3199 final boolean bodyCanThrow = exit.isAfter(entry);
3200 if(!bodyCanThrow) {
3201 // The body can't throw an exception; don't even bother emitting the catch handlers, they're all dead code.
3202 return false;
3203 }
3204
3205 method._try(entry, exit, recovery, Throwable.class);
3206
3207 if (method.isReachable()) {
3208 method._goto(skip);
3209 }
3210
3211 for (final Block inlinedFinally : tryNode.getInlinedFinallies()) {
3212 TryNode.getLabelledInlinedFinallyBlock(inlinedFinally).accept(this);
3213 // All inlined finallies end with a jump or a return
3214 assert !method.isReachable();
3215 }
3216
3217
3218 method._catch(recovery);
3219 method.store(vmException, EXCEPTION_TYPE);
3220
3221 final int catchBlockCount = catchBlocks.size();
3222 final Label afterCatch = new Label("after_catch");
3223 for (int i = 0; i < catchBlockCount; i++) {
3224 assert method.isReachable();
3225 final Block catchBlock = catchBlocks.get(i);
3226
3227 // Because of the peculiarities of the flow control, we need to use an explicit push/enterBlock/leaveBlock
3228 // here.
3229 lc.push(catchBlock);
3230 enterBlock(catchBlock);
3231
3232 final CatchNode catchNode = (CatchNode)catchBlocks.get(i).getStatements().get(0);
3233 final IdentNode exception = catchNode.getException();
3234 final Expression exceptionCondition = catchNode.getExceptionCondition();
3235 final Block catchBody = catchNode.getBody();
3236
3237 new Store<IdentNode>(exception) {
3238 @Override
3239 protected void storeNonDiscard() {
3240 // This expression is neither part of a discard, nor needs to be left on the stack after it was
3241 // stored, so we override storeNonDiscard to be a no-op.
3242 }
3243
3244 @Override
3245 protected void evaluate() {
3246 if (catchNode.isSyntheticRethrow()) {
3247 method.load(vmException, EXCEPTION_TYPE);
3248 return;
3249 }
3250 /*
3251 * If caught object is an instance of ECMAException, then
3252 * bind obj.thrown to the script catch var. Or else bind the
3253 * caught object itself to the script catch var.
3254 */
3255 final Label notEcmaException = new Label("no_ecma_exception");
3256 method.load(vmException, EXCEPTION_TYPE).dup()._instanceof(ECMAException.class).ifeq(notEcmaException);
3257 method.checkcast(ECMAException.class); //TODO is this necessary?
3258 method.getField(ECMAException.THROWN);
3259 method.label(notEcmaException);
3260 }
3261 }.store();
3262
3263 final boolean isConditionalCatch = exceptionCondition != null;
3264 final Label nextCatch;
3265 if (isConditionalCatch) {
3266 loadExpressionAsBoolean(exceptionCondition);
3267 nextCatch = new Label("next_catch");
3268 nextCatch.markAsBreakTarget();
3269 method.ifeq(nextCatch);
3270 } else {
3271 nextCatch = null;
3272 }
3273
3274 catchBody.accept(this);
3275 leaveBlock(catchBlock);
3276 lc.pop(catchBlock);
3277 if(nextCatch != null) {
3278 if(method.isReachable()) {
3279 method._goto(afterCatch);
3280 }
3281 method.breakLabel(nextCatch, lc.getUsedSlotCount());
3282 }
3283 }
3284
3285 // afterCatch could be the same as skip, except that we need to establish that the vmException is dead.
3286 method.label(afterCatch);
3287 if(method.isReachable()) {
3288 method.markDeadLocalVariable(vmException);
3289 }
3290 method.label(skip);
3291
3292 // Finally body is always inlined elsewhere so it doesn't need to be emitted
3293 assert tryNode.getFinallyBody() == null;
3294
3295 return false;
3296 }
3297
3298 @Override
3299 public boolean enterVarNode(final VarNode varNode) {
3300 if(!method.isReachable()) {
3301 return false;
3302 }
3303 final Expression init = varNode.getInit();
3304 final IdentNode identNode = varNode.getName();
3305 final Symbol identSymbol = identNode.getSymbol();
3306 assert identSymbol != null : "variable node " + varNode + " requires a name with a symbol";
3307 final boolean needsScope = identSymbol.isScope();
3308
3309 if (init == null) {
3310 if (needsScope && varNode.isBlockScoped()) {
3311 // block scoped variables need a DECLARE flag to signal end of temporal dead zone (TDZ)
3312 method.loadCompilerConstant(SCOPE);
3313 method.loadUndefined(Type.OBJECT);
3314 final int flags = getScopeCallSiteFlags(identSymbol) | (varNode.isBlockScoped() ? CALLSITE_DECLARE : 0);
3315 assert isFastScope(identSymbol);
3316 storeFastScopeVar(identSymbol, flags);
3317 }
3318 return false;
3319 }
3320
3321 enterStatement(varNode);
3322 assert method != null;
3323
3324 if (needsScope) {
3325 method.loadCompilerConstant(SCOPE);
3326 loadExpressionUnbounded(init);
3327 // block scoped variables need a DECLARE flag to signal end of temporal dead zone (TDZ)
3328 final int flags = getScopeCallSiteFlags(identSymbol) | (varNode.isBlockScoped() ? CALLSITE_DECLARE : 0);
3329 if (isFastScope(identSymbol)) {
3330 storeFastScopeVar(identSymbol, flags);
3331 } else {
3332 method.dynamicSet(identNode.getName(), flags, false);
3333 }
3334 } else {
3335 final Type identType = identNode.getType();
3336 if(identType == Type.UNDEFINED) {
3337 // The initializer is either itself undefined (explicit assignment of undefined to undefined),
3338 // or the left hand side is a dead variable.
3339 assert init.getType() == Type.UNDEFINED || identNode.getSymbol().slotCount() == 0;
3340 loadAndDiscard(init);
3341 return false;
3342 }
3343 loadExpressionAsType(init, identType);
3344 storeIdentWithCatchConversion(identNode, identType);
3345 }
3346
3347 return false;
3348 }
3349
3350 private void storeIdentWithCatchConversion(final IdentNode identNode, final Type type) {
3351 // Assignments happening in try/catch blocks need to ensure that they also store a possibly wider typed value
3352 // that will be live at the exit from the try block
3353 final LocalVariableConversion conversion = identNode.getLocalVariableConversion();
3354 final Symbol symbol = identNode.getSymbol();
3355 if(conversion != null && conversion.isLive()) {
3356 assert symbol == conversion.getSymbol();
3357 assert symbol.isBytecodeLocal();
3358 // Only a single conversion from the target type to the join type is expected.
3359 assert conversion.getNext() == null;
3360 assert conversion.getFrom() == type;
3361 // We must propagate potential type change to the catch block
3362 final Label catchLabel = catchLabels.peek();
3363 assert catchLabel != METHOD_BOUNDARY; // ident conversion only exists in try blocks
3364 assert catchLabel.isReachable();
3365 final Type joinType = conversion.getTo();
3366 final Label.Stack catchStack = catchLabel.getStack();
3367 final int joinSlot = symbol.getSlot(joinType);
3368 // With nested try/catch blocks (incl. synthetic ones for finally), we can have a supposed conversion for
3369 // the exception symbol in the nested catch, but it isn't live in the outer catch block, so prevent doing
3370 // conversions for it. E.g. in "try { try { ... } catch(e) { e = 1; } } catch(e2) { ... }", we must not
3371 // introduce an I->O conversion on "e = 1" assignment as "e" is not live in "catch(e2)".
3372 if(catchStack.getUsedSlotsWithLiveTemporaries() > joinSlot) {
3373 method.dup();
3374 method.convert(joinType);
3375 method.store(symbol, joinType);
3376 catchLabel.getStack().onLocalStore(joinType, joinSlot, true);
3377 method.canThrow(catchLabel);
3378 // Store but keep the previous store live too.
3379 method.store(symbol, type, false);
3380 return;
3381 }
3382 }
3383
3384 method.store(symbol, type, true);
3385 }
3386
3387 @Override
3388 public boolean enterWhileNode(final WhileNode whileNode) {
3389 if(!method.isReachable()) {
3390 return false;
3391 }
3392 if(whileNode.isDoWhile()) {
3393 enterDoWhile(whileNode);
3394 } else {
3395 enterStatement(whileNode);
3396 enterForOrWhile(whileNode, null);
3397 }
3398 return false;
3399 }
3400
3401 private void enterForOrWhile(final LoopNode loopNode, final JoinPredecessorExpression modify) {
3402 // NOTE: the usual pattern for compiling test-first loops is "GOTO test; body; test; IFNE body". We use the less
3403 // conventional "test; IFEQ break; body; GOTO test; break;". It has one extra unconditional GOTO in each repeat
3404 // of the loop, but it's not a problem for modern JIT compilers. We do this because our local variable type
3405 // tracking is unfortunately not really prepared for out-of-order execution, e.g. compiling the following
3406 // contrived but legal JavaScript code snippet would fail because the test changes the type of "i" from object
3407 // to double: var i = {valueOf: function() { return 1} }; while(--i >= 0) { ... }
3408 // Instead of adding more complexity to the local variable type tracking, we instead choose to emit this
3409 // different code shape.
3410 final int liveLocalsOnBreak = method.getUsedSlotsWithLiveTemporaries();
3411 final JoinPredecessorExpression test = loopNode.getTest();
3412 if(Expression.isAlwaysFalse(test)) {
3413 loadAndDiscard(test);
3414 return;
3415 }
3416
3417 method.beforeJoinPoint(loopNode);
3418
3419 final Label continueLabel = loopNode.getContinueLabel();
3420 final Label repeatLabel = modify != null ? new Label("for_repeat") : continueLabel;
3421 method.label(repeatLabel);
3422 final int liveLocalsOnContinue = method.getUsedSlotsWithLiveTemporaries();
3423
3424 final Block body = loopNode.getBody();
3425 final Label breakLabel = loopNode.getBreakLabel();
3426 final boolean testHasLiveConversion = test != null && LocalVariableConversion.hasLiveConversion(test);
3427
3428 if(Expression.isAlwaysTrue(test)) {
3429 if(test != null) {
3430 loadAndDiscard(test);
3431 if(testHasLiveConversion) {
3432 method.beforeJoinPoint(test);
3433 }
3434 }
3435 } else if (test != null) {
3436 if (testHasLiveConversion) {
3437 emitBranch(test.getExpression(), body.getEntryLabel(), true);
3438 method.beforeJoinPoint(test);
3439 method._goto(breakLabel);
3440 } else {
3441 emitBranch(test.getExpression(), breakLabel, false);
3442 }
3443 }
3444
3445 body.accept(this);
3446 if(repeatLabel != continueLabel) {
3447 emitContinueLabel(continueLabel, liveLocalsOnContinue);
3448 }
3449
3450 if (loopNode.hasPerIterationScope() && lc.getCurrentBlock().needsScope()) {
3451 // ES6 for loops with LET init need a new scope for each iteration. We just create a shallow copy here.
3452 method.loadCompilerConstant(SCOPE);
3453 method.invoke(virtualCallNoLookup(ScriptObject.class, "copy", ScriptObject.class));
3454 method.storeCompilerConstant(SCOPE);
3455 }
3456
3457 if(method.isReachable()) {
3458 if(modify != null) {
3459 lineNumber(loopNode);
3460 loadAndDiscard(modify);
3461 method.beforeJoinPoint(modify);
3462 }
3463 method._goto(repeatLabel);
3464 }
3465
3466 method.breakLabel(breakLabel, liveLocalsOnBreak);
3467 }
3468
3469 private void emitContinueLabel(final Label continueLabel, final int liveLocals) {
3470 final boolean reachable = method.isReachable();
3471 method.breakLabel(continueLabel, liveLocals);
3472 // If we reach here only through a continue statement (e.g. body does not exit normally) then the
3473 // continueLabel can have extra non-temp symbols (e.g. exception from a try/catch contained in the body). We
3474 // must make sure those are thrown away.
3475 if(!reachable) {
3476 method.undefineLocalVariables(lc.getUsedSlotCount(), false);
3477 }
3478 }
3479
3480 private void enterDoWhile(final WhileNode whileNode) {
3481 final int liveLocalsOnContinueOrBreak = method.getUsedSlotsWithLiveTemporaries();
3482 method.beforeJoinPoint(whileNode);
3483
3484 final Block body = whileNode.getBody();
3485 body.accept(this);
3486
3487 emitContinueLabel(whileNode.getContinueLabel(), liveLocalsOnContinueOrBreak);
3488 if(method.isReachable()) {
3489 lineNumber(whileNode);
3490 final JoinPredecessorExpression test = whileNode.getTest();
3491 final Label bodyEntryLabel = body.getEntryLabel();
3492 final boolean testHasLiveConversion = LocalVariableConversion.hasLiveConversion(test);
3493 if(Expression.isAlwaysFalse(test)) {
3494 loadAndDiscard(test);
3495 if(testHasLiveConversion) {
3496 method.beforeJoinPoint(test);
3497 }
3498 } else if(testHasLiveConversion) {
3499 // If we have conversions after the test in do-while, they need to be effected on both branches.
3500 final Label beforeExit = new Label("do_while_preexit");
3501 emitBranch(test.getExpression(), beforeExit, false);
3502 method.beforeJoinPoint(test);
3503 method._goto(bodyEntryLabel);
3504 method.label(beforeExit);
3505 method.beforeJoinPoint(test);
3506 } else {
3507 emitBranch(test.getExpression(), bodyEntryLabel, true);
3508 }
3509 }
3510 method.breakLabel(whileNode.getBreakLabel(), liveLocalsOnContinueOrBreak);
3511 }
3512
3513
3514 @Override
3515 public boolean enterWithNode(final WithNode withNode) {
3516 if(!method.isReachable()) {
3517 return false;
3518 }
3519 enterStatement(withNode);
3520 final Expression expression = withNode.getExpression();
3521 final Block body = withNode.getBody();
3522
3523 // It is possible to have a "pathological" case where the with block does not reference *any* identifiers. It's
3524 // pointless, but legal. In that case, if nothing else in the method forced the assignment of a slot to the
3525 // scope object, its' possible that it won't have a slot assigned. In this case we'll only evaluate expression
3526 // for its side effect and visit the body, and not bother opening and closing a WithObject.
3527 final boolean hasScope = method.hasScope();
3528
3529 if (hasScope) {
3530 method.loadCompilerConstant(SCOPE);
3531 }
3532
3533 loadExpressionAsObject(expression);
3534
3535 final Label tryLabel;
3536 if (hasScope) {
3537 // Construct a WithObject if we have a scope
3538 method.invoke(ScriptRuntime.OPEN_WITH);
3539 method.storeCompilerConstant(SCOPE);
3540 tryLabel = new Label("with_try");
3541 method.label(tryLabel);
3542 } else {
3543 // We just loaded the expression for its side effect and to check
3544 // for null or undefined value.
3545 globalCheckObjectCoercible();
3546 tryLabel = null;
3547 }
3548
3549 // Always process body
3550 body.accept(this);
3551
3552 if (hasScope) {
3553 // Ensure we always close the WithObject
3554 final Label endLabel = new Label("with_end");
3555 final Label catchLabel = new Label("with_catch");
3556 final Label exitLabel = new Label("with_exit");
3557
3558 method.label(endLabel);
3559 // Somewhat conservatively presume that if the body is not empty, it can throw an exception. In any case,
3560 // we must prevent trying to emit a try-catch for empty range, as it causes a verification error.
3561 final boolean bodyCanThrow = endLabel.isAfter(tryLabel);
3562 if(bodyCanThrow) {
3563 method._try(tryLabel, endLabel, catchLabel);
3564 }
3565
3566 final boolean reachable = method.isReachable();
3567 if(reachable) {
3568 popScope();
3569 if(bodyCanThrow) {
3570 method._goto(exitLabel);
3571 }
3572 }
3573
3574 if(bodyCanThrow) {
3575 method._catch(catchLabel);
3576 popScopeException();
3577 method.athrow();
3578 if(reachable) {
3579 method.label(exitLabel);
3580 }
3581 }
3582 }
3583 return false;
3584 }
3585
3586 private void loadADD(final UnaryNode unaryNode, final TypeBounds resultBounds) {
3587 loadExpression(unaryNode.getExpression(), resultBounds.booleanToInt().notWiderThan(Type.NUMBER));
3588 if(method.peekType() == Type.BOOLEAN) {
3589 // It's a no-op in bytecode, but we must make sure it is treated as an int for purposes of type signatures
3590 method.convert(Type.INT);
3591 }
3592 }
3593
3594 private void loadBIT_NOT(final UnaryNode unaryNode) {
3595 loadExpression(unaryNode.getExpression(), TypeBounds.INT).load(-1).xor();
3596 }
3597
3598 private void loadDECINC(final UnaryNode unaryNode) {
3599 final Expression operand = unaryNode.getExpression();
3600 final Type type = unaryNode.getType();
3601 final TypeBounds typeBounds = new TypeBounds(type, Type.NUMBER);
3602 final TokenType tokenType = unaryNode.tokenType();
3603 final boolean isPostfix = tokenType == TokenType.DECPOSTFIX || tokenType == TokenType.INCPOSTFIX;
3604 final boolean isIncrement = tokenType == TokenType.INCPREFIX || tokenType == TokenType.INCPOSTFIX;
3605
3606 assert !type.isObject();
3607
3608 new SelfModifyingStore<UnaryNode>(unaryNode, operand) {
3609
3610 private void loadRhs() {
3611 loadExpression(operand, typeBounds, true);
3612 }
3613
3614 @Override
3615 protected void evaluate() {
3616 if(isPostfix) {
3617 loadRhs();
3618 } else {
3619 new OptimisticOperation(unaryNode, typeBounds) {
3620 @Override
3621 void loadStack() {
3622 loadRhs();
3623 loadMinusOne();
3624 }
3625 @Override
3626 void consumeStack() {
3627 doDecInc(getProgramPoint());
3628 }
3629 }.emit(getOptimisticIgnoreCountForSelfModifyingExpression(operand));
3630 }
3631 }
3632
3633 @Override
3634 protected void storeNonDiscard() {
3635 super.storeNonDiscard();
3636 if (isPostfix) {
3637 new OptimisticOperation(unaryNode, typeBounds) {
3638 @Override
3639 void loadStack() {
3640 loadMinusOne();
3641 }
3642 @Override
3643 void consumeStack() {
3644 doDecInc(getProgramPoint());
3645 }
3646 }.emit(1); // 1 for non-incremented result on the top of the stack pushed in evaluate()
3647 }
3648 }
3649
3650 private void loadMinusOne() {
3651 if (type.isInteger()) {
3652 method.load(isIncrement ? 1 : -1);
3653 } else if (type.isLong()) {
3654 method.load(isIncrement ? 1L : -1L);
3655 } else {
3656 method.load(isIncrement ? 1.0 : -1.0);
3657 }
3658 }
3659
3660 private void doDecInc(final int programPoint) {
3661 method.add(programPoint);
3662 }
3663 }.store();
3664 }
3665
3666 private static int getOptimisticIgnoreCountForSelfModifyingExpression(final Expression target) {
3667 return target instanceof AccessNode ? 1 : target instanceof IndexNode ? 2 : 0;
3668 }
3669
3670 private void loadAndDiscard(final Expression expr) {
3671 // TODO: move checks for discarding to actual expression load code (e.g. as we do with void). That way we might
3672 // be able to eliminate even more checks.
3673 if(expr instanceof PrimitiveLiteralNode | isLocalVariable(expr)) {
3674 assert !lc.isCurrentDiscard(expr);
3675 // Don't bother evaluating expressions without side effects. Typical usage is "void 0" for reliably generating
3676 // undefined.
3677 return;
3678 }
3679
3680 lc.pushDiscard(expr);
3681 loadExpression(expr, TypeBounds.UNBOUNDED);
3682 if (lc.popDiscardIfCurrent(expr)) {
3683 assert !expr.isAssignment();
3684 // NOTE: if we had a way to load with type void, we could avoid popping
3685 method.pop();
3686 }
3687 }
3688
3689 /**
3690 * Loads the expression with the specified type bounds, but if the parent expression is the current discard,
3691 * then instead loads and discards the expression.
3692 * @param parent the parent expression that's tested for being the current discard
3693 * @param expr the expression that's either normally loaded or discard-loaded
3694 * @param resultBounds result bounds for when loading the expression normally
3695 */
3696 private void loadMaybeDiscard(final Expression parent, final Expression expr, final TypeBounds resultBounds) {
3697 loadMaybeDiscard(lc.popDiscardIfCurrent(parent), expr, resultBounds);
3698 }
3699
3700 /**
3701 * Loads the expression with the specified type bounds, or loads and discards the expression, depending on the
3702 * value of the discard flag. Useful as a helper for expressions with control flow where you often can't combine
3703 * testing for being the current discard and loading the subexpressions.
3704 * @param discard if true, the expression is loaded and discarded
3705 * @param expr the expression that's either normally loaded or discard-loaded
3706 * @param resultBounds result bounds for when loading the expression normally
3707 */
3708 private void loadMaybeDiscard(final boolean discard, final Expression expr, final TypeBounds resultBounds) {
3709 if (discard) {
3710 loadAndDiscard(expr);
3711 } else {
3712 loadExpression(expr, resultBounds);
3713 }
3714 }
3715
3716 private void loadNEW(final UnaryNode unaryNode) {
3717 final CallNode callNode = (CallNode)unaryNode.getExpression();
3718 final List<Expression> args = callNode.getArgs();
3719
3720 final Expression func = callNode.getFunction();
3721 // Load function reference.
3722 loadExpressionAsObject(func); // must detect type error
3723
3724 method.dynamicNew(1 + loadArgs(args), getCallSiteFlags(), func.toString(false));
3725 }
3726
3727 private void loadNOT(final UnaryNode unaryNode) {
3728 final Expression expr = unaryNode.getExpression();
3729 if(expr instanceof UnaryNode && expr.isTokenType(TokenType.NOT)) {
3730 // !!x is idiomatic boolean cast in JavaScript
3731 loadExpressionAsBoolean(((UnaryNode)expr).getExpression());
3732 } else {
3733 final Label trueLabel = new Label("true");
3734 final Label afterLabel = new Label("after");
3735
3736 emitBranch(expr, trueLabel, true);
3737 method.load(true);
3738 method._goto(afterLabel);
3739 method.label(trueLabel);
3740 method.load(false);
3741 method.label(afterLabel);
3742 }
3743 }
3744
3745 private void loadSUB(final UnaryNode unaryNode, final TypeBounds resultBounds) {
3746 final Type type = unaryNode.getType();
3747 assert type.isNumeric();
3748 final TypeBounds numericBounds = resultBounds.booleanToInt();
3749 new OptimisticOperation(unaryNode, numericBounds) {
3750 @Override
3751 void loadStack() {
3752 final Expression expr = unaryNode.getExpression();
3753 loadExpression(expr, numericBounds.notWiderThan(Type.NUMBER));
3754 }
3755 @Override
3756 void consumeStack() {
3757 // Must do an explicit conversion to the operation's type when it's double so that we correctly handle
3758 // negation of an int 0 to a double -0. With this, we get the correct negation of a local variable after
3759 // it deoptimized, e.g. "iload_2; i2d; dneg". Without this, we get "iload_2; ineg; i2d".
3760 if(type.isNumber()) {
3761 method.convert(type);
3762 }
3763 method.neg(getProgramPoint());
3764 }
3765 }.emit();
3766 }
3767
3768 public void loadVOID(final UnaryNode unaryNode, final TypeBounds resultBounds) {
3769 loadAndDiscard(unaryNode.getExpression());
3770 if (!lc.popDiscardIfCurrent(unaryNode)) {
3771 method.loadUndefined(resultBounds.widest);
3772 }
3773 }
3774
3775 public void loadADD(final BinaryNode binaryNode, final TypeBounds resultBounds) {
3776 new OptimisticOperation(binaryNode, resultBounds) {
3777 @Override
3778 void loadStack() {
3779 final TypeBounds operandBounds;
3780 final boolean isOptimistic = isValid(getProgramPoint());
3781 boolean forceConversionSeparation = false;
3782 if(isOptimistic) {
3783 operandBounds = new TypeBounds(binaryNode.getType(), Type.OBJECT);
3784 } else {
3785 // Non-optimistic, non-FP +. Allow it to overflow.
3786 final Type widestOperationType = binaryNode.getWidestOperationType();
3787 operandBounds = new TypeBounds(Type.narrowest(binaryNode.getWidestOperandType(), resultBounds.widest), widestOperationType);
3788 forceConversionSeparation = widestOperationType.narrowerThan(resultBounds.widest);
3789 }
3790 loadBinaryOperands(binaryNode.lhs(), binaryNode.rhs(), operandBounds, false, forceConversionSeparation);
3791 }
3792
3793 @Override
3794 void consumeStack() {
3795 method.add(getProgramPoint());
3796 }
3797 }.emit();
3798 }
3799
3800 private void loadAND_OR(final BinaryNode binaryNode, final TypeBounds resultBounds, final boolean isAnd) {
3801 final Type narrowestOperandType = Type.widestReturnType(binaryNode.lhs().getType(), binaryNode.rhs().getType());
3802
3803 final boolean isCurrentDiscard = lc.popDiscardIfCurrent(binaryNode);
3804
3805 final Label skip = new Label("skip");
3806 if(narrowestOperandType == Type.BOOLEAN) {
3807 // optimize all-boolean logical expressions
3808 final Label onTrue = new Label("andor_true");
3809 emitBranch(binaryNode, onTrue, true);
3810 if (isCurrentDiscard) {
3811 method.label(onTrue);
3812 } else {
3813 method.load(false);
3814 method._goto(skip);
3815 method.label(onTrue);
3816 method.load(true);
3817 method.label(skip);
3818 }
3819 return;
3820 }
3821
3822 final TypeBounds outBounds = resultBounds.notNarrowerThan(narrowestOperandType);
3823 final JoinPredecessorExpression lhs = (JoinPredecessorExpression)binaryNode.lhs();
3824 final boolean lhsConvert = LocalVariableConversion.hasLiveConversion(lhs);
3825 final Label evalRhs = lhsConvert ? new Label("eval_rhs") : null;
3826
3827 loadExpression(lhs, outBounds);
3828 if (!isCurrentDiscard) {
3829 method.dup();
3830 }
3831 method.convert(Type.BOOLEAN);
3832 if (isAnd) {
3833 if(lhsConvert) {
3834 method.ifne(evalRhs);
3835 } else {
3836 method.ifeq(skip);
3837 }
3838 } else if(lhsConvert) {
3839 method.ifeq(evalRhs);
3840 } else {
3841 method.ifne(skip);
3842 }
3843
3844 if(lhsConvert) {
3845 method.beforeJoinPoint(lhs);
3846 method._goto(skip);
3847 method.label(evalRhs);
3848 }
3849
3850 if (!isCurrentDiscard) {
3851 method.pop();
3852 }
3853 final JoinPredecessorExpression rhs = (JoinPredecessorExpression)binaryNode.rhs();
3854 loadMaybeDiscard(isCurrentDiscard, rhs, outBounds);
3855 method.beforeJoinPoint(rhs);
3856 method.label(skip);
3857 }
3858
3859 private static boolean isLocalVariable(final Expression lhs) {
3860 return lhs instanceof IdentNode && isLocalVariable((IdentNode)lhs);
3861 }
3862
3863 private static boolean isLocalVariable(final IdentNode lhs) {
3864 return lhs.getSymbol().isBytecodeLocal();
3865 }
3866
3867 // NOTE: does not use resultBounds as the assignment is driven by the type of the RHS
3868 private void loadASSIGN(final BinaryNode binaryNode) {
3869 final Expression lhs = binaryNode.lhs();
3870 final Expression rhs = binaryNode.rhs();
3871
3872 final Type rhsType = rhs.getType();
3873 // Detect dead assignments
3874 if(lhs instanceof IdentNode) {
3875 final Symbol symbol = ((IdentNode)lhs).getSymbol();
3876 if(!symbol.isScope() && !symbol.hasSlotFor(rhsType) && lc.popDiscardIfCurrent(binaryNode)) {
3877 loadAndDiscard(rhs);
3878 method.markDeadLocalVariable(symbol);
3879 return;
3880 }
3881 }
3882
3883 new Store<BinaryNode>(binaryNode, lhs) {
3884 @Override
3885 protected void evaluate() {
3886 // NOTE: we're loading with "at least as wide as" so optimistic operations on the right hand side
3887 // remain optimistic, and then explicitly convert to the required type if needed.
3888 loadExpressionAsType(rhs, rhsType);
3889 }
3890 }.store();
3891 }
3892
3893 /**
3894 * Binary self-assignment that can be optimistic: +=, -=, *=, and /=.
3895 */
3896 private abstract class BinaryOptimisticSelfAssignment extends SelfModifyingStore<BinaryNode> {
3897
3898 /**
3899 * Constructor
3900 *
3901 * @param node the assign op node
3902 */
3903 BinaryOptimisticSelfAssignment(final BinaryNode node) {
3904 super(node, node.lhs());
3905 }
3906
3907 protected abstract void op(OptimisticOperation oo);
3908
3909 @Override
3910 protected void evaluate() {
3911 final Expression lhs = assignNode.lhs();
3912 final Expression rhs = assignNode.rhs();
3913 final Type widestOperationType = assignNode.getWidestOperationType();
3914 final TypeBounds bounds = new TypeBounds(assignNode.getType(), widestOperationType);
3915 new OptimisticOperation(assignNode, bounds) {
3916 @Override
3917 void loadStack() {
3918 final boolean forceConversionSeparation;
3919 if (isValid(getProgramPoint()) || widestOperationType == Type.NUMBER) {
3920 forceConversionSeparation = false;
3921 } else {
3922 final Type operandType = Type.widest(booleanToInt(objectToNumber(lhs.getType())), booleanToInt(objectToNumber(rhs.getType())));
3923 forceConversionSeparation = operandType.narrowerThan(widestOperationType);
3924 }
3925 loadBinaryOperands(lhs, rhs, bounds, true, forceConversionSeparation);
3926 }
3927 @Override
3928 void consumeStack() {
3929 op(this);
3930 }
3931 }.emit(getOptimisticIgnoreCountForSelfModifyingExpression(lhs));
3932 method.convert(assignNode.getType());
3933 }
3934 }
3935
3936 /**
3937 * Non-optimistic binary self-assignment operation. Basically, everything except +=, -=, *=, and /=.
3938 */
3939 private abstract class BinarySelfAssignment extends SelfModifyingStore<BinaryNode> {
3940 BinarySelfAssignment(final BinaryNode node) {
3941 super(node, node.lhs());
3942 }
3943
3944 protected abstract void op();
3945
3946 @Override
3947 protected void evaluate() {
3948 loadBinaryOperands(assignNode.lhs(), assignNode.rhs(), TypeBounds.UNBOUNDED.notWiderThan(assignNode.getWidestOperandType()), true, false);
3949 op();
3950 }
3951 }
3952
3953 private void loadASSIGN_ADD(final BinaryNode binaryNode) {
3954 new BinaryOptimisticSelfAssignment(binaryNode) {
3955 @Override
3956 protected void op(final OptimisticOperation oo) {
3957 assert !(binaryNode.getType().isObject() && oo.isOptimistic);
3958 method.add(oo.getProgramPoint());
3959 }
3960 }.store();
3961 }
3962
3963 private void loadASSIGN_BIT_AND(final BinaryNode binaryNode) {
3964 new BinarySelfAssignment(binaryNode) {
3965 @Override
3966 protected void op() {
3967 method.and();
3968 }
3969 }.store();
3970 }
3971
3972 private void loadASSIGN_BIT_OR(final BinaryNode binaryNode) {
3973 new BinarySelfAssignment(binaryNode) {
3974 @Override
3975 protected void op() {
3976 method.or();
3977 }
3978 }.store();
3979 }
3980
3981 private void loadASSIGN_BIT_XOR(final BinaryNode binaryNode) {
3982 new BinarySelfAssignment(binaryNode) {
3983 @Override
3984 protected void op() {
3985 method.xor();
3986 }
3987 }.store();
3988 }
3989
3990 private void loadASSIGN_DIV(final BinaryNode binaryNode) {
3991 new BinaryOptimisticSelfAssignment(binaryNode) {
3992 @Override
3993 protected void op(final OptimisticOperation oo) {
3994 method.div(oo.getProgramPoint());
3995 }
3996 }.store();
3997 }
3998
3999 private void loadASSIGN_MOD(final BinaryNode binaryNode) {
4000 new BinaryOptimisticSelfAssignment(binaryNode) {
4001 @Override
4002 protected void op(final OptimisticOperation oo) {
4003 method.rem(oo.getProgramPoint());
4004 }
4005 }.store();
4006 }
4007
4008 private void loadASSIGN_MUL(final BinaryNode binaryNode) {
4009 new BinaryOptimisticSelfAssignment(binaryNode) {
4010 @Override
4011 protected void op(final OptimisticOperation oo) {
4012 method.mul(oo.getProgramPoint());
4013 }
4014 }.store();
4015 }
4016
4017 private void loadASSIGN_SAR(final BinaryNode binaryNode) {
4018 new BinarySelfAssignment(binaryNode) {
4019 @Override
4020 protected void op() {
4021 method.sar();
4022 }
4023 }.store();
4024 }
4025
4026 private void loadASSIGN_SHL(final BinaryNode binaryNode) {
4027 new BinarySelfAssignment(binaryNode) {
4028 @Override
4029 protected void op() {
4030 method.shl();
4031 }
4032 }.store();
4033 }
4034
4035 private void loadASSIGN_SHR(final BinaryNode binaryNode) {
4036 new BinarySelfAssignment(binaryNode) {
4037 @Override
4038 protected void op() {
4039 doSHR();
4040 }
4041
4042 }.store();
4043 }
4044
4045 private void doSHR() {
4046 // TODO: make SHR optimistic
4047 method.shr();
4048 toUint();
4049 }
4050
4051 private void toUint() {
4052 JSType.TO_UINT32_I.invoke(method);
4053 }
4054
4055 private void loadASSIGN_SUB(final BinaryNode binaryNode) {
4056 new BinaryOptimisticSelfAssignment(binaryNode) {
4057 @Override
4058 protected void op(final OptimisticOperation oo) {
4059 method.sub(oo.getProgramPoint());
4060 }
4061 }.store();
4062 }
4063
4064 /**
4065 * Helper class for binary arithmetic ops
4066 */
4067 private abstract class BinaryArith {
4068 protected abstract void op(int programPoint);
4069
4070 protected void evaluate(final BinaryNode node, final TypeBounds resultBounds) {
4071 final TypeBounds numericBounds = resultBounds.booleanToInt().objectToNumber();
4072 new OptimisticOperation(node, numericBounds) {
4073 @Override
4074 void loadStack() {
4075 final TypeBounds operandBounds;
4076 boolean forceConversionSeparation = false;
4077 if(numericBounds.narrowest == Type.NUMBER) {
4078 // Result should be double always. Propagate it into the operands so we don't have lots of I2D
4079 // and L2D after operand evaluation.
4080 assert numericBounds.widest == Type.NUMBER;
4081 operandBounds = numericBounds;
4082 } else {
4083 final boolean isOptimistic = isValid(getProgramPoint());
4084 if(isOptimistic || node.isTokenType(TokenType.DIV) || node.isTokenType(TokenType.MOD)) {
4085 operandBounds = new TypeBounds(node.getType(), Type.NUMBER);
4086 } else {
4087 // Non-optimistic, non-FP subtraction or multiplication. Allow them to overflow.
4088 operandBounds = new TypeBounds(Type.narrowest(node.getWidestOperandType(),
4089 numericBounds.widest), Type.NUMBER);
4090 forceConversionSeparation = node.getWidestOperationType().narrowerThan(numericBounds.widest);
4091 }
4092 }
4093 loadBinaryOperands(node.lhs(), node.rhs(), operandBounds, false, forceConversionSeparation);
4094 }
4095
4096 @Override
4097 void consumeStack() {
4098 op(getProgramPoint());
4099 }
4100 }.emit();
4101 }
4102 }
4103
4104 private void loadBIT_AND(final BinaryNode binaryNode) {
4105 loadBinaryOperands(binaryNode);
4106 method.and();
4107 }
4108
4109 private void loadBIT_OR(final BinaryNode binaryNode) {
4110 // Optimize x|0 to (int)x
4111 if (isRhsZero(binaryNode)) {
4112 loadExpressionAsType(binaryNode.lhs(), Type.INT);
4113 } else {
4114 loadBinaryOperands(binaryNode);
4115 method.or();
4116 }
4117 }
4118
4119 private static boolean isRhsZero(final BinaryNode binaryNode) {
4120 final Expression rhs = binaryNode.rhs();
4121 return rhs instanceof LiteralNode && INT_ZERO.equals(((LiteralNode<?>)rhs).getValue());
4122 }
4123
4124 private void loadBIT_XOR(final BinaryNode binaryNode) {
4125 loadBinaryOperands(binaryNode);
4126 method.xor();
4127 }
4128
4129 private void loadCOMMARIGHT(final BinaryNode binaryNode, final TypeBounds resultBounds) {
4130 loadAndDiscard(binaryNode.lhs());
4131 loadMaybeDiscard(binaryNode, binaryNode.rhs(), resultBounds);
4132 }
4133
4134 private void loadCOMMALEFT(final BinaryNode binaryNode, final TypeBounds resultBounds) {
4135 loadMaybeDiscard(binaryNode, binaryNode.lhs(), resultBounds);
4136 loadAndDiscard(binaryNode.rhs());
4137 }
4138
4139 private void loadDIV(final BinaryNode binaryNode, final TypeBounds resultBounds) {
4140 new BinaryArith() {
4141 @Override
4142 protected void op(final int programPoint) {
4143 method.div(programPoint);
4144 }
4145 }.evaluate(binaryNode, resultBounds);
4146 }
4147
4148 private void loadCmp(final BinaryNode binaryNode, final Condition cond) {
4149 loadComparisonOperands(binaryNode);
4150
4151 final Label trueLabel = new Label("trueLabel");
4152 final Label afterLabel = new Label("skip");
4153
4154 method.conditionalJump(cond, trueLabel);
4155
4156 method.load(Boolean.FALSE);
4157 method._goto(afterLabel);
4158 method.label(trueLabel);
4159 method.load(Boolean.TRUE);
4160 method.label(afterLabel);
4161 }
4162
4163 private void loadMOD(final BinaryNode binaryNode, final TypeBounds resultBounds) {
4164 new BinaryArith() {
4165 @Override
4166 protected void op(final int programPoint) {
4167 method.rem(programPoint);
4168 }
4169 }.evaluate(binaryNode, resultBounds);
4170 }
4171
4172 private void loadMUL(final BinaryNode binaryNode, final TypeBounds resultBounds) {
4173 new BinaryArith() {
4174 @Override
4175 protected void op(final int programPoint) {
4176 method.mul(programPoint);
4177 }
4178 }.evaluate(binaryNode, resultBounds);
4179 }
4180
4181 private void loadSAR(final BinaryNode binaryNode) {
4182 loadBinaryOperands(binaryNode);
4183 method.sar();
4184 }
4185
4186 private void loadSHL(final BinaryNode binaryNode) {
4187 loadBinaryOperands(binaryNode);
4188 method.shl();
4189 }
4190
4191 private void loadSHR(final BinaryNode binaryNode) {
4192 // Optimize x >>> 0 to (uint)x
4193 if (isRhsZero(binaryNode)) {
4194 loadExpressionAsType(binaryNode.lhs(), Type.INT);
4195 toUint();
4196 } else {
4197 loadBinaryOperands(binaryNode);
4198 doSHR();
4199 }
4200 }
4201
4202 private void loadSUB(final BinaryNode binaryNode, final TypeBounds resultBounds) {
4203 new BinaryArith() {
4204 @Override
4205 protected void op(final int programPoint) {
4206 method.sub(programPoint);
4207 }
4208 }.evaluate(binaryNode, resultBounds);
4209 }
4210
4211 @Override
4212 public boolean enterLabelNode(final LabelNode labelNode) {
4213 labeledBlockBreakLiveLocals.push(lc.getUsedSlotCount());
4214 return true;
4215 }
4216
4217 @Override
4218 protected boolean enterDefault(final Node node) {
4219 throw new AssertionError("Code generator entered node of type " + node.getClass().getName());
4220 }
4221
4222 private void loadTernaryNode(final TernaryNode ternaryNode, final TypeBounds resultBounds) {
4223 final Expression test = ternaryNode.getTest();
4224 final JoinPredecessorExpression trueExpr = ternaryNode.getTrueExpression();
4225 final JoinPredecessorExpression falseExpr = ternaryNode.getFalseExpression();
4226
4227 final Label falseLabel = new Label("ternary_false");
4228 final Label exitLabel = new Label("ternary_exit");
4229
4230 final Type outNarrowest = Type.narrowest(resultBounds.widest, Type.generic(Type.widestReturnType(trueExpr.getType(), falseExpr.getType())));
4231 final TypeBounds outBounds = resultBounds.notNarrowerThan(outNarrowest);
4232
4233 emitBranch(test, falseLabel, false);
4234
4235 final boolean isCurrentDiscard = lc.popDiscardIfCurrent(ternaryNode);
4236 loadMaybeDiscard(isCurrentDiscard, trueExpr.getExpression(), outBounds);
4237 assert isCurrentDiscard || Type.generic(method.peekType()) == outBounds.narrowest;
4238 method.beforeJoinPoint(trueExpr);
4239 method._goto(exitLabel);
4240 method.label(falseLabel);
4241 loadMaybeDiscard(isCurrentDiscard, falseExpr.getExpression(), outBounds);
4242 assert isCurrentDiscard || Type.generic(method.peekType()) == outBounds.narrowest;
4243 method.beforeJoinPoint(falseExpr);
4244 method.label(exitLabel);
4245 }
4246
4247 /**
4248 * Generate all shared scope calls generated during codegen.
4249 */
4250 void generateScopeCalls() {
4251 for (final SharedScopeCall scopeAccess : lc.getScopeCalls()) {
4252 scopeAccess.generateScopeCall();
4253 }
4254 }
4255
4256 /**
4257 * Debug code used to print symbols
4258 *
4259 * @param block the block we are in
4260 * @param function the function we are in
4261 * @param ident identifier for block or function where applicable
4262 */
4263 private void printSymbols(final Block block, final FunctionNode function, final String ident) {
4264 if (compiler.getScriptEnvironment()._print_symbols || function.getFlag(FunctionNode.IS_PRINT_SYMBOLS)) {
4265 final PrintWriter out = compiler.getScriptEnvironment().getErr();
4266 out.println("[BLOCK in '" + ident + "']");
4267 if (!block.printSymbols(out)) {
4268 out.println("<no symbols>");
4269 }
4270 out.println();
4271 }
4272 }
4273
4274
4275 /**
4276 * The difference between a store and a self modifying store is that
4277 * the latter may load part of the target on the stack, e.g. the base
4278 * of an AccessNode or the base and index of an IndexNode. These are used
4279 * both as target and as an extra source. Previously it was problematic
4280 * for self modifying stores if the target/lhs didn't belong to one
4281 * of three trivial categories: IdentNode, AcessNodes, IndexNodes. In that
4282 * case it was evaluated and tagged as "resolved", which meant at the second
4283 * time the lhs of this store was read (e.g. in a = a (second) + b for a += b,
4284 * it would be evaluated to a nop in the scope and cause stack underflow
4285 *
4286 * see NASHORN-703
4287 *
4288 * @param <T>
4289 */
4290 private abstract class SelfModifyingStore<T extends Expression> extends Store<T> {
4291 protected SelfModifyingStore(final T assignNode, final Expression target) {
4292 super(assignNode, target);
4293 }
4294
4295 @Override
4296 protected boolean isSelfModifying() {
4297 return true;
4298 }
4299 }
4300
4301 /**
4302 * Helper class to generate stores
4303 */
4304 private abstract class Store<T extends Expression> {
4305
4306 /** An assignment node, e.g. x += y */
4307 protected final T assignNode;
4308
4309 /** The target node to store to, e.g. x */
4310 private final Expression target;
4311
4312 /** How deep on the stack do the arguments go if this generates an indy call */
4313 private int depth;
4314
4315 /** If we have too many arguments, we need temporary storage, this is stored in 'quick' */
4316 private IdentNode quick;
4317
4318 /**
4319 * Constructor
4320 *
4321 * @param assignNode the node representing the whole assignment
4322 * @param target the target node of the assignment (destination)
4323 */
4324 protected Store(final T assignNode, final Expression target) {
4325 this.assignNode = assignNode;
4326 this.target = target;
4327 }
4328
4329 /**
4330 * Constructor
4331 *
4332 * @param assignNode the node representing the whole assignment
4333 */
4334 protected Store(final T assignNode) {
4335 this(assignNode, assignNode);
4336 }
4337
4338 /**
4339 * Is this a self modifying store operation, e.g. *= or ++
4340 * @return true if self modifying store
4341 */
4342 protected boolean isSelfModifying() {
4343 return false;
4344 }
4345
4346 private void prologue() {
4347 /*
4348 * This loads the parts of the target, e.g base and index. they are kept
4349 * on the stack throughout the store and used at the end to execute it
4350 */
4351
4352 target.accept(new SimpleNodeVisitor() {
4353 @Override
4354 public boolean enterIdentNode(final IdentNode node) {
4355 if (node.getSymbol().isScope()) {
4356 method.loadCompilerConstant(SCOPE);
4357 depth += Type.SCOPE.getSlots();
4358 assert depth == 1;
4359 }
4360 return false;
4361 }
4362
4363 private void enterBaseNode() {
4364 assert target instanceof BaseNode : "error - base node " + target + " must be instanceof BaseNode";
4365 final BaseNode baseNode = (BaseNode)target;
4366 final Expression base = baseNode.getBase();
4367
4368 loadExpressionAsObject(base);
4369 depth += Type.OBJECT.getSlots();
4370 assert depth == 1;
4371
4372 if (isSelfModifying()) {
4373 method.dup();
4374 }
4375 }
4376
4377 @Override
4378 public boolean enterAccessNode(final AccessNode node) {
4379 enterBaseNode();
4380 return false;
4381 }
4382
4383 @Override
4384 public boolean enterIndexNode(final IndexNode node) {
4385 enterBaseNode();
4386
4387 final Expression index = node.getIndex();
4388 if (!index.getType().isNumeric()) {
4389 // could be boolean here as well
4390 loadExpressionAsObject(index);
4391 } else {
4392 loadExpressionUnbounded(index);
4393 }
4394 depth += index.getType().getSlots();
4395
4396 if (isSelfModifying()) {
4397 //convert "base base index" to "base index base index"
4398 method.dup(1);
4399 }
4400
4401 return false;
4402 }
4403
4404 });
4405 }
4406
4407 /**
4408 * Generates an extra local variable, always using the same slot, one that is available after the end of the
4409 * frame.
4410 *
4411 * @param type the type of the variable
4412 *
4413 * @return the quick variable
4414 */
4415 private IdentNode quickLocalVariable(final Type type) {
4416 final String name = lc.getCurrentFunction().uniqueName(QUICK_PREFIX.symbolName());
4417 final Symbol symbol = new Symbol(name, IS_INTERNAL | HAS_SLOT);
4418 symbol.setHasSlotFor(type);
4419 symbol.setFirstSlot(lc.quickSlot(type));
4420
4421 final IdentNode quickIdent = IdentNode.createInternalIdentifier(symbol).setType(type);
4422
4423 return quickIdent;
4424 }
4425
4426 // store the result that "lives on" after the op, e.g. "i" in i++ postfix.
4427 protected void storeNonDiscard() {
4428 if (lc.popDiscardIfCurrent(assignNode)) {
4429 assert assignNode.isAssignment();
4430 return;
4431 }
4432
4433 if (method.dup(depth) == null) {
4434 method.dup();
4435 final Type quickType = method.peekType();
4436 this.quick = quickLocalVariable(quickType);
4437 final Symbol quickSymbol = quick.getSymbol();
4438 method.storeTemp(quickType, quickSymbol.getFirstSlot());
4439 }
4440 }
4441
4442 private void epilogue() {
4443 /**
4444 * Take the original target args from the stack and use them
4445 * together with the value to be stored to emit the store code
4446 *
4447 * The case that targetSymbol is in scope (!hasSlot) and we actually
4448 * need to do a conversion on non-equivalent types exists, but is
4449 * very rare. See for example test/script/basic/access-specializer.js
4450 */
4451 target.accept(new SimpleNodeVisitor() {
4452 @Override
4453 protected boolean enterDefault(final Node node) {
4454 throw new AssertionError("Unexpected node " + node + " in store epilogue");
4455 }
4456
4457 @Override
4458 public boolean enterIdentNode(final IdentNode node) {
4459 final Symbol symbol = node.getSymbol();
4460 assert symbol != null;
4461 if (symbol.isScope()) {
4462 final int flags = getScopeCallSiteFlags(symbol);
4463 if (isFastScope(symbol)) {
4464 storeFastScopeVar(symbol, flags);
4465 } else {
4466 method.dynamicSet(node.getName(), flags, false);
4467 }
4468 } else {
4469 final Type storeType = assignNode.getType();
4470 if (symbol.hasSlotFor(storeType)) {
4471 // Only emit a convert for a store known to be live; converts for dead stores can
4472 // give us an unnecessary ClassCastException.
4473 method.convert(storeType);
4474 }
4475 storeIdentWithCatchConversion(node, storeType);
4476 }
4477 return false;
4478
4479 }
4480
4481 @Override
4482 public boolean enterAccessNode(final AccessNode node) {
4483 method.dynamicSet(node.getProperty(), getCallSiteFlags(), node.isIndex());
4484 return false;
4485 }
4486
4487 @Override
4488 public boolean enterIndexNode(final IndexNode node) {
4489 method.dynamicSetIndex(getCallSiteFlags());
4490 return false;
4491 }
4492 });
4493
4494
4495 // whatever is on the stack now is the final answer
4496 }
4497
4498 protected abstract void evaluate();
4499
4500 void store() {
4501 if (target instanceof IdentNode) {
4502 checkTemporalDeadZone((IdentNode)target);
4503 }
4504 prologue();
4505 evaluate(); // leaves an operation of whatever the operationType was on the stack
4506 storeNonDiscard();
4507 epilogue();
4508 if (quick != null) {
4509 method.load(quick);
4510 }
4511 }
4512 }
4513
4514 private void newFunctionObject(final FunctionNode functionNode, final boolean addInitializer) {
4515 assert lc.peek() == functionNode;
4516
4517 final RecompilableScriptFunctionData data = compiler.getScriptFunctionData(functionNode.getId());
4518
4519 if (functionNode.isProgram() && !compiler.isOnDemandCompilation()) {
4520 final MethodEmitter createFunction = functionNode.getCompileUnit().getClassEmitter().method(
4521 EnumSet.of(Flag.PUBLIC, Flag.STATIC), CREATE_PROGRAM_FUNCTION.symbolName(),
4522 ScriptFunction.class, ScriptObject.class);
4523 createFunction.begin();
4524 loadConstantsAndIndex(data, createFunction);
4525 createFunction.load(SCOPE_TYPE, 0);
4526 createFunction.invoke(CREATE_FUNCTION_OBJECT);
4527 createFunction._return();
4528 createFunction.end();
4529 }
4530
4531 if (addInitializer && !compiler.isOnDemandCompilation()) {
4532 functionNode.getCompileUnit().addFunctionInitializer(data, functionNode);
4533 }
4534
4535 // We don't emit a ScriptFunction on stack for the outermost compiled function (as there's no code being
4536 // generated in its outer context that'd need it as a callee).
4537 if (lc.getOutermostFunction() == functionNode) {
4538 return;
4539 }
4540
4541 loadConstantsAndIndex(data, method);
4542
4543 if (functionNode.needsParentScope()) {
4544 method.loadCompilerConstant(SCOPE);
4545 method.invoke(CREATE_FUNCTION_OBJECT);
4546 } else {
4547 method.invoke(CREATE_FUNCTION_OBJECT_NO_SCOPE);
4548 }
4549 }
4550
4551 // calls on Global class.
4552 private MethodEmitter globalInstance() {
4553 return method.invokestatic(GLOBAL_OBJECT, "instance", "()L" + GLOBAL_OBJECT + ';');
4554 }
4555
4556 private MethodEmitter globalAllocateArguments() {
4557 return method.invokestatic(GLOBAL_OBJECT, "allocateArguments", methodDescriptor(ScriptObject.class, Object[].class, Object.class, int.class));
4558 }
4559
4560 private MethodEmitter globalNewRegExp() {
4561 return method.invokestatic(GLOBAL_OBJECT, "newRegExp", methodDescriptor(Object.class, String.class, String.class));
4562 }
4563
4564 private MethodEmitter globalRegExpCopy() {
4565 return method.invokestatic(GLOBAL_OBJECT, "regExpCopy", methodDescriptor(Object.class, Object.class));
4566 }
4567
4568 private MethodEmitter globalAllocateArray(final ArrayType type) {
4569 //make sure the native array is treated as an array type
4570 return method.invokestatic(GLOBAL_OBJECT, "allocate", "(" + type.getDescriptor() + ")Ljdk/nashorn/internal/objects/NativeArray;");
4571 }
4572
4573 private MethodEmitter globalIsEval() {
4574 return method.invokestatic(GLOBAL_OBJECT, "isEval", methodDescriptor(boolean.class, Object.class));
4575 }
4576
4577 private MethodEmitter globalReplaceLocationPropertyPlaceholder() {
4578 return method.invokestatic(GLOBAL_OBJECT, "replaceLocationPropertyPlaceholder", methodDescriptor(Object.class, Object.class, Object.class));
4579 }
4580
4581 private MethodEmitter globalCheckObjectCoercible() {
4582 return method.invokestatic(GLOBAL_OBJECT, "checkObjectCoercible", methodDescriptor(void.class, Object.class));
4583 }
4584
4585 private MethodEmitter globalDirectEval() {
4586 return method.invokestatic(GLOBAL_OBJECT, "directEval",
4587 methodDescriptor(Object.class, Object.class, Object.class, Object.class, Object.class, boolean.class));
4588 }
4589
4590 private abstract class OptimisticOperation {
4591 private final boolean isOptimistic;
4592 // expression and optimistic are the same reference
4593 private final Expression expression;
4594 private final Optimistic optimistic;
4595 private final TypeBounds resultBounds;
4596
4597 OptimisticOperation(final Optimistic optimistic, final TypeBounds resultBounds) {
4598 this.optimistic = optimistic;
4599 this.expression = (Expression)optimistic;
4600 this.resultBounds = resultBounds;
4601 this.isOptimistic = isOptimistic(optimistic) && useOptimisticTypes() &&
4602 // Operation is only effectively optimistic if its type, after being coerced into the result bounds
4603 // is narrower than the upper bound.
4604 resultBounds.within(Type.generic(((Expression)optimistic).getType())).narrowerThan(resultBounds.widest);
4605 }
4606
4607 MethodEmitter emit() {
4608 return emit(0);
4609 }
4610
4611 MethodEmitter emit(final int ignoredArgCount) {
4612 final int programPoint = optimistic.getProgramPoint();
4613 final boolean optimisticOrContinuation = isOptimistic || isContinuationEntryPoint(programPoint);
4614 final boolean currentContinuationEntryPoint = isCurrentContinuationEntryPoint(programPoint);
4615 final int stackSizeOnEntry = method.getStackSize() - ignoredArgCount;
4616
4617 // First store the values on the stack opportunistically into local variables. Doing it before loadStack()
4618 // allows us to not have to pop/load any arguments that are pushed onto it by loadStack() in the second
4619 // storeStack().
4620 storeStack(ignoredArgCount, optimisticOrContinuation);
4621
4622 // Now, load the stack
4623 loadStack();
4624
4625 // Now store the values on the stack ultimately into local variables. In vast majority of cases, this is
4626 // (aside from creating the local types map) a no-op, as the first opportunistic stack store will already
4627 // store all variables. However, there can be operations in the loadStack() that invalidate some of the
4628 // stack stores, e.g. in "x[i] = x[++i]", "++i" will invalidate the already stored value for "i". In such
4629 // unfortunate cases this second storeStack() will restore the invariant that everything on the stack is
4630 // stored into a local variable, although at the cost of doing a store/load on the loaded arguments as well.
4631 final int liveLocalsCount = storeStack(method.getStackSize() - stackSizeOnEntry, optimisticOrContinuation);
4632 assert optimisticOrContinuation == (liveLocalsCount != -1);
4633
4634 final Label beginTry;
4635 final Label catchLabel;
4636 final Label afterConsumeStack = isOptimistic || currentContinuationEntryPoint ? new Label("after_consume_stack") : null;
4637 if(isOptimistic) {
4638 beginTry = new Label("try_optimistic");
4639 final String catchLabelName = (afterConsumeStack == null ? "" : afterConsumeStack.toString()) + "_handler";
4640 catchLabel = new Label(catchLabelName);
4641 method.label(beginTry);
4642 } else {
4643 beginTry = catchLabel = null;
4644 }
4645
4646 consumeStack();
4647
4648 if(isOptimistic) {
4649 method._try(beginTry, afterConsumeStack, catchLabel, UnwarrantedOptimismException.class);
4650 }
4651
4652 if(isOptimistic || currentContinuationEntryPoint) {
4653 method.label(afterConsumeStack);
4654
4655 final int[] localLoads = method.getLocalLoadsOnStack(0, stackSizeOnEntry);
4656 assert everyStackValueIsLocalLoad(localLoads) : Arrays.toString(localLoads) + ", " + stackSizeOnEntry + ", " + ignoredArgCount;
4657 final List<Type> localTypesList = method.getLocalVariableTypes();
4658 final int usedLocals = method.getUsedSlotsWithLiveTemporaries();
4659 final List<Type> localTypes = method.getWidestLiveLocals(localTypesList.subList(0, usedLocals));
4660 assert everyLocalLoadIsValid(localLoads, usedLocals) : Arrays.toString(localLoads) + " ~ " + localTypes;
4661
4662 if(isOptimistic) {
4663 addUnwarrantedOptimismHandlerLabel(localTypes, catchLabel);
4664 }
4665 if(currentContinuationEntryPoint) {
4666 final ContinuationInfo ci = getContinuationInfo();
4667 assert ci != null : "no continuation info found for " + lc.getCurrentFunction();
4668 assert !ci.hasTargetLabel(); // No duplicate program points
4669 ci.setTargetLabel(afterConsumeStack);
4670 ci.getHandlerLabel().markAsOptimisticContinuationHandlerFor(afterConsumeStack);
4671 // Can't rely on targetLabel.stack.localVariableTypes.length, as it can be higher due to effectively
4672 // dead local variables.
4673 ci.lvarCount = localTypes.size();
4674 ci.setStackStoreSpec(localLoads);
4675 ci.setStackTypes(Arrays.copyOf(method.getTypesFromStack(method.getStackSize()), stackSizeOnEntry));
4676 assert ci.getStackStoreSpec().length == ci.getStackTypes().length;
4677 ci.setReturnValueType(method.peekType());
4678 ci.lineNumber = getLastLineNumber();
4679 ci.catchLabel = catchLabels.peek();
4680 }
4681 }
4682 return method;
4683 }
4684
4685 /**
4686 * Stores the current contents of the stack into local variables so they are not lost before invoking something that
4687 * can result in an {@code UnwarantedOptimizationException}.
4688 * @param ignoreArgCount the number of topmost arguments on stack to ignore when deciding on the shape of the catch
4689 * block. Those are used in the situations when we could not place the call to {@code storeStack} early enough
4690 * (before emitting code for pushing the arguments that the optimistic call will pop). This is admittedly a
4691 * deficiency in the design of the code generator when it deals with self-assignments and we should probably look
4692 * into fixing it.
4693 * @return types of the significant local variables after the stack was stored (types for local variables used
4694 * for temporary storage of ignored arguments are not returned).
4695 * @param optimisticOrContinuation if false, this method should not execute
4696 * a label for a catch block for the {@code UnwarantedOptimizationException}, suitable for capturing the
4697 * currently live local variables, tailored to their types.
4698 */
4699 private int storeStack(final int ignoreArgCount, final boolean optimisticOrContinuation) {
4700 if(!optimisticOrContinuation) {
4701 return -1; // NOTE: correct value to return is lc.getUsedSlotCount(), but it wouldn't be used anyway
4702 }
4703
4704 final int stackSize = method.getStackSize();
4705 final Type[] stackTypes = method.getTypesFromStack(stackSize);
4706 final int[] localLoadsOnStack = method.getLocalLoadsOnStack(0, stackSize);
4707 final int usedSlots = method.getUsedSlotsWithLiveTemporaries();
4708
4709 final int firstIgnored = stackSize - ignoreArgCount;
4710 // Find the first value on the stack (from the bottom) that is not a load from a local variable.
4711 int firstNonLoad = 0;
4712 while(firstNonLoad < firstIgnored && localLoadsOnStack[firstNonLoad] != Label.Stack.NON_LOAD) {
4713 firstNonLoad++;
4714 }
4715
4716 // Only do the store/load if first non-load is not an ignored argument. Otherwise, do nothing and return
4717 // the number of used slots as the number of live local variables.
4718 if(firstNonLoad >= firstIgnored) {
4719 return usedSlots;
4720 }
4721
4722 // Find the number of new temporary local variables that we need; it's the number of values on the stack that
4723 // are not direct loads of existing local variables.
4724 int tempSlotsNeeded = 0;
4725 for(int i = firstNonLoad; i < stackSize; ++i) {
4726 if(localLoadsOnStack[i] == Label.Stack.NON_LOAD) {
4727 tempSlotsNeeded += stackTypes[i].getSlots();
4728 }
4729 }
4730
4731 // Ensure all values on the stack that weren't directly loaded from a local variable are stored in a local
4732 // variable. We're starting from highest local variable index, so that in case ignoreArgCount > 0 the ignored
4733 // ones end up at the end of the local variable table.
4734 int lastTempSlot = usedSlots + tempSlotsNeeded;
4735 int ignoreSlotCount = 0;
4736 for(int i = stackSize; i -- > firstNonLoad;) {
4737 final int loadSlot = localLoadsOnStack[i];
4738 if(loadSlot == Label.Stack.NON_LOAD) {
4739 final Type type = stackTypes[i];
4740 final int slots = type.getSlots();
4741 lastTempSlot -= slots;
4742 if(i >= firstIgnored) {
4743 ignoreSlotCount += slots;
4744 }
4745 method.storeTemp(type, lastTempSlot);
4746 } else {
4747 method.pop();
4748 }
4749 }
4750 assert lastTempSlot == usedSlots; // used all temporary locals
4751
4752 final List<Type> localTypesList = method.getLocalVariableTypes();
4753
4754 // Load values back on stack.
4755 for(int i = firstNonLoad; i < stackSize; ++i) {
4756 final int loadSlot = localLoadsOnStack[i];
4757 final Type stackType = stackTypes[i];
4758 final boolean isLoad = loadSlot != Label.Stack.NON_LOAD;
4759 final int lvarSlot = isLoad ? loadSlot : lastTempSlot;
4760 final Type lvarType = localTypesList.get(lvarSlot);
4761 method.load(lvarType, lvarSlot);
4762 if(isLoad) {
4763 // Conversion operators (I2L etc.) preserve "load"-ness of the value despite the fact that, in the
4764 // strict sense they are creating a derived value from the loaded value. This special behavior of
4765 // on-stack conversion operators is necessary to accommodate for differences in local variable types
4766 // after deoptimization; having a conversion operator throw away "load"-ness would create different
4767 // local variable table shapes between optimism-failed code and its deoptimized rest-of method).
4768 // After we load the value back, we need to redo the conversion to the stack type if stack type is
4769 // different.
4770 // NOTE: this would only strictly be necessary for widening conversions (I2L, L2D, I2D), and not for
4771 // narrowing ones (L2I, D2L, D2I) as only widening conversions are the ones that can get eliminated
4772 // in a deoptimized method, as their original input argument got widened. Maybe experiment with
4773 // throwing away "load"-ness for narrowing conversions in MethodEmitter.convert()?
4774 method.convert(stackType);
4775 } else {
4776 // temporary stores never needs a convert, as their type is always the same as the stack type.
4777 assert lvarType == stackType;
4778 lastTempSlot += lvarType.getSlots();
4779 }
4780 }
4781 // used all temporaries
4782 assert lastTempSlot == usedSlots + tempSlotsNeeded;
4783
4784 return lastTempSlot - ignoreSlotCount;
4785 }
4786
4787 private void addUnwarrantedOptimismHandlerLabel(final List<Type> localTypes, final Label label) {
4788 final String lvarTypesDescriptor = getLvarTypesDescriptor(localTypes);
4789 final Map<String, Collection<Label>> unwarrantedOptimismHandlers = lc.getUnwarrantedOptimismHandlers();
4790 Collection<Label> labels = unwarrantedOptimismHandlers.get(lvarTypesDescriptor);
4791 if(labels == null) {
4792 labels = new LinkedList<>();
4793 unwarrantedOptimismHandlers.put(lvarTypesDescriptor, labels);
4794 }
4795 method.markLabelAsOptimisticCatchHandler(label, localTypes.size());
4796 labels.add(label);
4797 }
4798
4799 abstract void loadStack();
4800
4801 // Make sure that whatever indy call site you emit from this method uses {@code getCallSiteFlagsOptimistic(node)}
4802 // or otherwise ensure optimistic flag is correctly set in the call site, otherwise it doesn't make much sense
4803 // to use OptimisticExpression for emitting it.
4804 abstract void consumeStack();
4805
4806 /**
4807 * Emits the correct dynamic getter code. Normally just delegates to method emitter, except when the target
4808 * expression is optimistic, and the desired type is narrower than the optimistic type. In that case, it'll emit a
4809 * dynamic getter with its original optimistic type, and explicitly insert a narrowing conversion. This way we can
4810 * preserve the optimism of the values even if they're subsequently immediately coerced into a narrower type. This
4811 * is beneficial because in this case we can still presume that since the original getter was optimistic, the
4812 * conversion has no side effects.
4813 * @param name the name of the property being get
4814 * @param flags call site flags
4815 * @param isMethod whether we're preferably retrieving a function
4816 * @return the current method emitter
4817 */
4818 MethodEmitter dynamicGet(final String name, final int flags, final boolean isMethod, final boolean isIndex) {
4819 if(isOptimistic) {
4820 return method.dynamicGet(getOptimisticCoercedType(), name, getOptimisticFlags(flags), isMethod, isIndex);
4821 }
4822 return method.dynamicGet(resultBounds.within(expression.getType()), name, nonOptimisticFlags(flags), isMethod, isIndex);
4823 }
4824
4825 MethodEmitter dynamicGetIndex(final int flags, final boolean isMethod) {
4826 if(isOptimistic) {
4827 return method.dynamicGetIndex(getOptimisticCoercedType(), getOptimisticFlags(flags), isMethod);
4828 }
4829 return method.dynamicGetIndex(resultBounds.within(expression.getType()), nonOptimisticFlags(flags), isMethod);
4830 }
4831
4832 MethodEmitter dynamicCall(final int argCount, final int flags, final String msg) {
4833 if (isOptimistic) {
4834 return method.dynamicCall(getOptimisticCoercedType(), argCount, getOptimisticFlags(flags), msg);
4835 }
4836 return method.dynamicCall(resultBounds.within(expression.getType()), argCount, nonOptimisticFlags(flags), msg);
4837 }
4838
4839 int getOptimisticFlags(final int flags) {
4840 return flags | CALLSITE_OPTIMISTIC | (optimistic.getProgramPoint() << CALLSITE_PROGRAM_POINT_SHIFT); //encode program point in high bits
4841 }
4842
4843 int getProgramPoint() {
4844 return isOptimistic ? optimistic.getProgramPoint() : INVALID_PROGRAM_POINT;
4845 }
4846
4847 void convertOptimisticReturnValue() {
4848 if (isOptimistic) {
4849 final Type optimisticType = getOptimisticCoercedType();
4850 if(!optimisticType.isObject()) {
4851 method.load(optimistic.getProgramPoint());
4852 if(optimisticType.isInteger()) {
4853 method.invoke(ENSURE_INT);
4854 } else if(optimisticType.isLong()) {
4855 method.invoke(ENSURE_LONG);
4856 } else if(optimisticType.isNumber()) {
4857 method.invoke(ENSURE_NUMBER);
4858 } else {
4859 throw new AssertionError(optimisticType);
4860 }
4861 }
4862 }
4863 }
4864
4865 void replaceCompileTimeProperty() {
4866 final IdentNode identNode = (IdentNode)expression;
4867 final String name = identNode.getSymbol().getName();
4868 if (CompilerConstants.__FILE__.name().equals(name)) {
4869 replaceCompileTimeProperty(getCurrentSource().getName());
4870 } else if (CompilerConstants.__DIR__.name().equals(name)) {
4871 replaceCompileTimeProperty(getCurrentSource().getBase());
4872 } else if (CompilerConstants.__LINE__.name().equals(name)) {
4873 replaceCompileTimeProperty(getCurrentSource().getLine(identNode.position()));
4874 }
4875 }
4876
4877 /**
4878 * When an ident with name __FILE__, __DIR__, or __LINE__ is loaded, we'll try to look it up as any other
4879 * identifier. However, if it gets all the way up to the Global object, it will send back a special value that
4880 * represents a placeholder for these compile-time location properties. This method will generate code that loads
4881 * the value of the compile-time location property and then invokes a method in Global that will replace the
4882 * placeholder with the value. Effectively, if the symbol for these properties is defined anywhere in the lexical
4883 * scope, they take precedence, but if they aren't, then they resolve to the compile-time location property.
4884 * @param propertyValue the actual value of the property
4885 */
4886 private void replaceCompileTimeProperty(final Object propertyValue) {
4887 assert method.peekType().isObject();
4888 if(propertyValue instanceof String || propertyValue == null) {
4889 method.load((String)propertyValue);
4890 } else if(propertyValue instanceof Integer) {
4891 method.load(((Integer)propertyValue));
4892 method.convert(Type.OBJECT);
4893 } else {
4894 throw new AssertionError();
4895 }
4896 globalReplaceLocationPropertyPlaceholder();
4897 convertOptimisticReturnValue();
4898 }
4899
4900 /**
4901 * Returns the type that should be used as the return type of the dynamic invocation that is emitted as the code
4902 * for the current optimistic operation. If the type bounds is exact boolean or narrower than the expression's
4903 * optimistic type, then the optimistic type is returned, otherwise the coercing type. Effectively, this method
4904 * allows for moving the coercion into the optimistic type when it won't adversely affect the optimistic
4905 * evaluation semantics, and for preserving the optimistic type and doing a separate coercion when it would
4906 * affect it.
4907 * @return
4908 */
4909 private Type getOptimisticCoercedType() {
4910 final Type optimisticType = expression.getType();
4911 assert resultBounds.widest.widerThan(optimisticType);
4912 final Type narrowest = resultBounds.narrowest;
4913
4914 if(narrowest.isBoolean() || narrowest.narrowerThan(optimisticType)) {
4915 assert !optimisticType.isObject();
4916 return optimisticType;
4917 }
4918 assert !narrowest.isObject();
4919 return narrowest;
4920 }
4921 }
4922
4923 private static boolean isOptimistic(final Optimistic optimistic) {
4924 if(!optimistic.canBeOptimistic()) {
4925 return false;
4926 }
4927 final Expression expr = (Expression)optimistic;
4928 return expr.getType().narrowerThan(expr.getWidestOperationType());
4929 }
4930
4931 private static boolean everyLocalLoadIsValid(final int[] loads, final int localCount) {
4932 for (final int load : loads) {
4933 if(load < 0 || load >= localCount) {
4934 return false;
4935 }
4936 }
4937 return true;
4938 }
4939
4940 private static boolean everyStackValueIsLocalLoad(final int[] loads) {
4941 for (final int load : loads) {
4942 if(load == Label.Stack.NON_LOAD) {
4943 return false;
4944 }
4945 }
4946 return true;
4947 }
4948
4949 private String getLvarTypesDescriptor(final List<Type> localVarTypes) {
4950 final int count = localVarTypes.size();
4951 final StringBuilder desc = new StringBuilder(count);
4952 for(int i = 0; i < count;) {
4953 i += appendType(desc, localVarTypes.get(i));
4954 }
4955 return method.markSymbolBoundariesInLvarTypesDescriptor(desc.toString());
4956 }
4957
4958 private static int appendType(final StringBuilder b, final Type t) {
4959 b.append(t.getBytecodeStackType());
4960 return t.getSlots();
4961 }
4962
4963 private static int countSymbolsInLvarTypeDescriptor(final String lvarTypeDescriptor) {
4964 int count = 0;
4965 for(int i = 0; i < lvarTypeDescriptor.length(); ++i) {
4966 if(Character.isUpperCase(lvarTypeDescriptor.charAt(i))) {
4967 ++count;
4968 }
4969 }
4970 return count;
4971
4972 }
4973 /**
4974 * Generates all the required {@code UnwarrantedOptimismException} handlers for the current function. The employed
4975 * strategy strives to maximize code reuse. Every handler constructs an array to hold the local variables, then
4976 * fills in some trailing part of the local variables (those for which it has a unique suffix in the descriptor),
4977 * then jumps to a handler for a prefix that's shared with other handlers. A handler that fills up locals up to
4978 * position 0 will not jump to a prefix handler (as it has no prefix), but instead end with constructing and
4979 * throwing a {@code RewriteException}. Since we lexicographically sort the entries, we only need to check every
4980 * entry to its immediately preceding one for longest matching prefix.
4981 * @return true if there is at least one exception handler
4982 */
4983 private boolean generateUnwarrantedOptimismExceptionHandlers(final FunctionNode fn) {
4984 if(!useOptimisticTypes()) {
4985 return false;
4986 }
4987
4988 // Take the mapping of lvarSpecs -> labels, and turn them into a descending lexicographically sorted list of
4989 // handler specifications.
4990 final Map<String, Collection<Label>> unwarrantedOptimismHandlers = lc.popUnwarrantedOptimismHandlers();
4991 if(unwarrantedOptimismHandlers.isEmpty()) {
4992 return false;
4993 }
4994
4995 method.lineNumber(0);
4996
4997 final List<OptimismExceptionHandlerSpec> handlerSpecs = new ArrayList<>(unwarrantedOptimismHandlers.size() * 4/3);
4998 for(final String spec: unwarrantedOptimismHandlers.keySet()) {
4999 handlerSpecs.add(new OptimismExceptionHandlerSpec(spec, true));
5000 }
5001 Collections.sort(handlerSpecs, Collections.reverseOrder());
5002
5003 // Map of local variable specifications to labels for populating the array for that local variable spec.
5004 final Map<String, Label> delegationLabels = new HashMap<>();
5005
5006 // Do everything in a single pass over the handlerSpecs list. Note that the list can actually grow as we're
5007 // passing through it as we might add new prefix handlers into it, so can't hoist size() outside of the loop.
5008 for(int handlerIndex = 0; handlerIndex < handlerSpecs.size(); ++handlerIndex) {
5009 final OptimismExceptionHandlerSpec spec = handlerSpecs.get(handlerIndex);
5010 final String lvarSpec = spec.lvarSpec;
5011 if(spec.catchTarget) {
5012 assert !method.isReachable();
5013 // Start a catch block and assign the labels for this lvarSpec with it.
5014 method._catch(unwarrantedOptimismHandlers.get(lvarSpec));
5015 // This spec is a catch target, so emit array creation code. The length of the array is the number of
5016 // symbols - the number of uppercase characters.
5017 method.load(countSymbolsInLvarTypeDescriptor(lvarSpec));
5018 method.newarray(Type.OBJECT_ARRAY);
5019 }
5020 if(spec.delegationTarget) {
5021 // If another handler can delegate to this handler as its prefix, then put a jump target here for the
5022 // shared code (after the array creation code, which is never shared).
5023 method.label(delegationLabels.get(lvarSpec)); // label must exist
5024 }
5025
5026 final boolean lastHandler = handlerIndex == handlerSpecs.size() - 1;
5027
5028 int lvarIndex;
5029 final int firstArrayIndex;
5030 final int firstLvarIndex;
5031 Label delegationLabel;
5032 final String commonLvarSpec;
5033 if(lastHandler) {
5034 // Last handler block, doesn't delegate to anything.
5035 lvarIndex = 0;
5036 firstLvarIndex = 0;
5037 firstArrayIndex = 0;
5038 delegationLabel = null;
5039 commonLvarSpec = null;
5040 } else {
5041 // Not yet the last handler block, will definitely delegate to another handler; let's figure out which
5042 // one. It can be an already declared handler further down the list, or it might need to declare a new
5043 // prefix handler.
5044
5045 // Since we're lexicographically ordered, the common prefix handler is defined by the common prefix of
5046 // this handler and the next handler on the list.
5047 final int nextHandlerIndex = handlerIndex + 1;
5048 final String nextLvarSpec = handlerSpecs.get(nextHandlerIndex).lvarSpec;
5049 commonLvarSpec = commonPrefix(lvarSpec, nextLvarSpec);
5050 // We don't chop symbols in half
5051 assert Character.isUpperCase(commonLvarSpec.charAt(commonLvarSpec.length() - 1));
5052
5053 // Let's find if we already have a declaration for such handler, or we need to insert it.
5054 {
5055 boolean addNewHandler = true;
5056 int commonHandlerIndex = nextHandlerIndex;
5057 for(; commonHandlerIndex < handlerSpecs.size(); ++commonHandlerIndex) {
5058 final OptimismExceptionHandlerSpec forwardHandlerSpec = handlerSpecs.get(commonHandlerIndex);
5059 final String forwardLvarSpec = forwardHandlerSpec.lvarSpec;
5060 if(forwardLvarSpec.equals(commonLvarSpec)) {
5061 // We already have a handler for the common prefix.
5062 addNewHandler = false;
5063 // Make sure we mark it as a delegation target.
5064 forwardHandlerSpec.delegationTarget = true;
5065 break;
5066 } else if(!forwardLvarSpec.startsWith(commonLvarSpec)) {
5067 break;
5068 }
5069 }
5070 if(addNewHandler) {
5071 // We need to insert a common prefix handler. Note handlers created with catchTarget == false
5072 // will automatically have delegationTarget == true (because that's the only reason for their
5073 // existence).
5074 handlerSpecs.add(commonHandlerIndex, new OptimismExceptionHandlerSpec(commonLvarSpec, false));
5075 }
5076 }
5077
5078 firstArrayIndex = countSymbolsInLvarTypeDescriptor(commonLvarSpec);
5079 lvarIndex = 0;
5080 for(int j = 0; j < commonLvarSpec.length(); ++j) {
5081 lvarIndex += CodeGeneratorLexicalContext.getTypeForSlotDescriptor(commonLvarSpec.charAt(j)).getSlots();
5082 }
5083 firstLvarIndex = lvarIndex;
5084
5085 // Create a delegation label if not already present
5086 delegationLabel = delegationLabels.get(commonLvarSpec);
5087 if(delegationLabel == null) {
5088 // uo_pa == "unwarranted optimism, populate array"
5089 delegationLabel = new Label("uo_pa_" + commonLvarSpec);
5090 delegationLabels.put(commonLvarSpec, delegationLabel);
5091 }
5092 }
5093
5094 // Load local variables handled by this handler on stack
5095 int args = 0;
5096 boolean symbolHadValue = false;
5097 for(int typeIndex = commonLvarSpec == null ? 0 : commonLvarSpec.length(); typeIndex < lvarSpec.length(); ++typeIndex) {
5098 final char typeDesc = lvarSpec.charAt(typeIndex);
5099 final Type lvarType = CodeGeneratorLexicalContext.getTypeForSlotDescriptor(typeDesc);
5100 if (!lvarType.isUnknown()) {
5101 method.load(lvarType, lvarIndex);
5102 symbolHadValue = true;
5103 args++;
5104 } else if(typeDesc == 'U' && !symbolHadValue) {
5105 // Symbol boundary with undefined last value. Check if all previous values for this symbol were also
5106 // undefined; if so, emit one explicit Undefined. This serves to ensure that we're emiting exactly
5107 // one value for every symbol that uses local slots. While we could in theory ignore symbols that
5108 // are undefined (in other words, dead) at the point where this exception was thrown, unfortunately
5109 // we can't do it in practice. The reason for this is that currently our liveness analysis is
5110 // coarse (it can determine whether a symbol has not been read with a particular type anywhere in
5111 // the function being compiled, but that's it), and a symbol being promoted to Object due to a
5112 // deoptimization will suddenly show up as "live for Object type", and previously dead U->O
5113 // conversions on loop entries will suddenly become alive in the deoptimized method which will then
5114 // expect a value for that slot in its continuation handler. If we had precise liveness analysis, we
5115 // could go back to excluding known dead symbols from the payload of the RewriteException.
5116 if(method.peekType() == Type.UNDEFINED) {
5117 method.dup();
5118 } else {
5119 method.loadUndefined(Type.OBJECT);
5120 }
5121 args++;
5122 }
5123 if(Character.isUpperCase(typeDesc)) {
5124 // Reached symbol boundary; reset flag for the next symbol.
5125 symbolHadValue = false;
5126 }
5127 lvarIndex += lvarType.getSlots();
5128 }
5129 assert args > 0;
5130 // Delegate actual storing into array to an array populator utility method.
5131 //on the stack:
5132 // object array to be populated
5133 // start index
5134 // a lot of types
5135 method.dynamicArrayPopulatorCall(args + 1, firstArrayIndex);
5136 if(delegationLabel != null) {
5137 // We cascade to a prefix handler to fill out the rest of the local variables and throw the
5138 // RewriteException.
5139 assert !lastHandler;
5140 assert commonLvarSpec != null;
5141 // Must undefine the local variables that we have already processed for the sake of correct join on the
5142 // delegate label
5143 method.undefineLocalVariables(firstLvarIndex, true);
5144 final OptimismExceptionHandlerSpec nextSpec = handlerSpecs.get(handlerIndex + 1);
5145 // If the delegate immediately follows, and it's not a catch target (so it doesn't have array setup
5146 // code) don't bother emitting a jump, as we'd just jump to the next instruction.
5147 if(!nextSpec.lvarSpec.equals(commonLvarSpec) || nextSpec.catchTarget) {
5148 method._goto(delegationLabel);
5149 }
5150 } else {
5151 assert lastHandler;
5152 // Nothing to delegate to, so this handler must create and throw the RewriteException.
5153 // At this point we have the UnwarrantedOptimismException and the Object[] with local variables on
5154 // stack. We need to create a RewriteException, push two references to it below the constructor
5155 // arguments, invoke the constructor, and throw the exception.
5156 loadConstant(getByteCodeSymbolNames(fn));
5157 if (isRestOf()) {
5158 loadConstant(getContinuationEntryPoints());
5159 method.invoke(CREATE_REWRITE_EXCEPTION_REST_OF);
5160 } else {
5161 method.invoke(CREATE_REWRITE_EXCEPTION);
5162 }
5163 method.athrow();
5164 }
5165 }
5166 return true;
5167 }
5168
5169 private static String[] getByteCodeSymbolNames(final FunctionNode fn) {
5170 // Only names of local variables on the function level are captured. This information is used to reduce
5171 // deoptimizations, so as much as we can capture will help. We rely on the fact that function wide variables are
5172 // all live all the time, so the array passed to rewrite exception contains one element for every slotted symbol
5173 // here.
5174 final List<String> names = new ArrayList<>();
5175 for (final Symbol symbol: fn.getBody().getSymbols()) {
5176 if (symbol.hasSlot()) {
5177 if (symbol.isScope()) {
5178 // slot + scope can only be true for parameters
5179 assert symbol.isParam();
5180 names.add(null);
5181 } else {
5182 names.add(symbol.getName());
5183 }
5184 }
5185 }
5186 return names.toArray(new String[names.size()]);
5187 }
5188
5189 private static String commonPrefix(final String s1, final String s2) {
5190 final int l1 = s1.length();
5191 final int l = Math.min(l1, s2.length());
5192 int lms = -1; // last matching symbol
5193 for(int i = 0; i < l; ++i) {
5194 final char c1 = s1.charAt(i);
5195 if(c1 != s2.charAt(i)) {
5196 return s1.substring(0, lms + 1);
5197 } else if(Character.isUpperCase(c1)) {
5198 lms = i;
5199 }
5200 }
5201 return l == l1 ? s1 : s2;
5202 }
5203
5204 private static class OptimismExceptionHandlerSpec implements Comparable<OptimismExceptionHandlerSpec> {
5205 private final String lvarSpec;
5206 private final boolean catchTarget;
5207 private boolean delegationTarget;
5208
5209 OptimismExceptionHandlerSpec(final String lvarSpec, final boolean catchTarget) {
5210 this.lvarSpec = lvarSpec;
5211 this.catchTarget = catchTarget;
5212 if(!catchTarget) {
5213 delegationTarget = true;
5214 }
5215 }
5216
5217 @Override
5218 public int compareTo(final OptimismExceptionHandlerSpec o) {
5219 return lvarSpec.compareTo(o.lvarSpec);
5220 }
5221
5222 @Override
5223 public String toString() {
5224 final StringBuilder b = new StringBuilder(64).append("[HandlerSpec ").append(lvarSpec);
5225 if(catchTarget) {
5226 b.append(", catchTarget");
5227 }
5228 if(delegationTarget) {
5229 b.append(", delegationTarget");
5230 }
5231 return b.append("]").toString();
5232 }
5233 }
5234
5235 private static class ContinuationInfo {
5236 private final Label handlerLabel;
5237 private Label targetLabel; // Label for the target instruction.
5238 int lvarCount;
5239 // Indices of local variables that need to be loaded on the stack when this node completes
5240 private int[] stackStoreSpec;
5241 // Types of values loaded on the stack
5242 private Type[] stackTypes;
5243 // If non-null, this node should perform the requisite type conversion
5244 private Type returnValueType;
5245 // If we are in the middle of an object literal initialization, we need to update the map
5246 private PropertyMap objectLiteralMap;
5247 // Object literal stack depth for object literal - not necessarily top if property is a tree
5248 private int objectLiteralStackDepth = -1;
5249 // The line number at the continuation point
5250 private int lineNumber;
5251 // The active catch label, in case the continuation point is in a try/catch block
5252 private Label catchLabel;
5253 // The number of scopes that need to be popped before control is transferred to the catch label.
5254 private int exceptionScopePops;
5255
5256 ContinuationInfo() {
5257 this.handlerLabel = new Label("continuation_handler");
5258 }
5259
5260 Label getHandlerLabel() {
5261 return handlerLabel;
5262 }
5263
5264 boolean hasTargetLabel() {
5265 return targetLabel != null;
5266 }
5267
5268 Label getTargetLabel() {
5269 return targetLabel;
5270 }
5271
5272 void setTargetLabel(final Label targetLabel) {
5273 this.targetLabel = targetLabel;
5274 }
5275
5276 int[] getStackStoreSpec() {
5277 return stackStoreSpec.clone();
5278 }
5279
5280 void setStackStoreSpec(final int[] stackStoreSpec) {
5281 this.stackStoreSpec = stackStoreSpec;
5282 }
5283
5284 Type[] getStackTypes() {
5285 return stackTypes.clone();
5286 }
5287
5288 void setStackTypes(final Type[] stackTypes) {
5289 this.stackTypes = stackTypes;
5290 }
5291
5292 Type getReturnValueType() {
5293 return returnValueType;
5294 }
5295
5296 void setReturnValueType(final Type returnValueType) {
5297 this.returnValueType = returnValueType;
5298 }
5299
5300 int getObjectLiteralStackDepth() {
5301 return objectLiteralStackDepth;
5302 }
5303
5304 void setObjectLiteralStackDepth(final int objectLiteralStackDepth) {
5305 this.objectLiteralStackDepth = objectLiteralStackDepth;
5306 }
5307
5308 PropertyMap getObjectLiteralMap() {
5309 return objectLiteralMap;
5310 }
5311
5312 void setObjectLiteralMap(final PropertyMap objectLiteralMap) {
5313 this.objectLiteralMap = objectLiteralMap;
5314 }
5315
5316 @Override
5317 public String toString() {
5318 return "[localVariableTypes=" + targetLabel.getStack().getLocalVariableTypesCopy() + ", stackStoreSpec=" +
5319 Arrays.toString(stackStoreSpec) + ", returnValueType=" + returnValueType + "]";
5320 }
5321 }
5322
5323 private ContinuationInfo getContinuationInfo() {
5324 return continuationInfo;
5325 }
5326
5327 private void generateContinuationHandler() {
5328 if (!isRestOf()) {
5329 return;
5330 }
5331
5332 final ContinuationInfo ci = getContinuationInfo();
5333 method.label(ci.getHandlerLabel());
5334
5335 // There should never be an exception thrown from the continuation handler, but in case there is (meaning,
5336 // Nashorn has a bug), then line number 0 will be an indication of where it came from (line numbers are Uint16).
5337 method.lineNumber(0);
5338
5339 final Label.Stack stack = ci.getTargetLabel().getStack();
5340 final List<Type> lvarTypes = stack.getLocalVariableTypesCopy();
5341 final BitSet symbolBoundary = stack.getSymbolBoundaryCopy();
5342 final int lvarCount = ci.lvarCount;
5343
5344 final Type rewriteExceptionType = Type.typeFor(RewriteException.class);
5345 // Store the RewriteException into an unused local variable slot.
5346 method.load(rewriteExceptionType, 0);
5347 method.storeTemp(rewriteExceptionType, lvarCount);
5348 // Get local variable array
5349 method.load(rewriteExceptionType, 0);
5350 method.invoke(RewriteException.GET_BYTECODE_SLOTS);
5351 // Store local variables. Note that deoptimization might introduce new value types for existing local variables,
5352 // so we must use both liveLocals and symbolBoundary, as in some cases (when the continuation is inside of a try
5353 // block) we need to store the incoming value into multiple slots. The optimism exception handlers will have
5354 // exactly one array element for every symbol that uses bytecode storage. If in the originating method the value
5355 // was undefined, there will be an explicit Undefined value in the array.
5356 int arrayIndex = 0;
5357 for(int lvarIndex = 0; lvarIndex < lvarCount;) {
5358 final Type lvarType = lvarTypes.get(lvarIndex);
5359 if(!lvarType.isUnknown()) {
5360 method.dup();
5361 method.load(arrayIndex).arrayload();
5362 final Class<?> typeClass = lvarType.getTypeClass();
5363 // Deoptimization in array initializers can cause arrays to undergo component type widening
5364 if(typeClass == long[].class) {
5365 method.load(rewriteExceptionType, lvarCount);
5366 method.invoke(RewriteException.TO_LONG_ARRAY);
5367 } else if(typeClass == double[].class) {
5368 method.load(rewriteExceptionType, lvarCount);
5369 method.invoke(RewriteException.TO_DOUBLE_ARRAY);
5370 } else if(typeClass == Object[].class) {
5371 method.load(rewriteExceptionType, lvarCount);
5372 method.invoke(RewriteException.TO_OBJECT_ARRAY);
5373 } else {
5374 if(!(typeClass.isPrimitive() || typeClass == Object.class)) {
5375 // NOTE: this can only happen with dead stores. E.g. for the program "1; []; f();" in which the
5376 // call to f() will deoptimize the call site, but it'll expect :return to have the type
5377 // NativeArray. However, in the more optimal version, :return's only live type is int, therefore
5378 // "{O}:return = []" is a dead store, and the variable will be sent into the continuation as
5379 // Undefined, however NativeArray can't hold Undefined instance.
5380 method.loadType(Type.getInternalName(typeClass));
5381 method.invoke(RewriteException.INSTANCE_OR_NULL);
5382 }
5383 method.convert(lvarType);
5384 }
5385 method.storeHidden(lvarType, lvarIndex, false);
5386 }
5387 final int nextLvarIndex = lvarIndex + lvarType.getSlots();
5388 if(symbolBoundary.get(nextLvarIndex - 1)) {
5389 ++arrayIndex;
5390 }
5391 lvarIndex = nextLvarIndex;
5392 }
5393 if (AssertsEnabled.assertsEnabled()) {
5394 method.load(arrayIndex);
5395 method.invoke(RewriteException.ASSERT_ARRAY_LENGTH);
5396 } else {
5397 method.pop();
5398 }
5399
5400 final int[] stackStoreSpec = ci.getStackStoreSpec();
5401 final Type[] stackTypes = ci.getStackTypes();
5402 final boolean isStackEmpty = stackStoreSpec.length == 0;
5403 boolean replacedObjectLiteralMap = false;
5404 if(!isStackEmpty) {
5405 // Load arguments on the stack
5406 final int objectLiteralStackDepth = ci.getObjectLiteralStackDepth();
5407 for(int i = 0; i < stackStoreSpec.length; ++i) {
5408 final int slot = stackStoreSpec[i];
5409 method.load(lvarTypes.get(slot), slot);
5410 method.convert(stackTypes[i]);
5411 // stack: s0=object literal being initialized
5412 // change map of s0 so that the property we are initializing when we failed
5413 // is now ci.returnValueType
5414 if (i == objectLiteralStackDepth) {
5415 method.dup();
5416 assert ci.getObjectLiteralMap() != null;
5417 assert ScriptObject.class.isAssignableFrom(method.peekType().getTypeClass()) : method.peekType().getTypeClass() + " is not a script object";
5418 loadConstant(ci.getObjectLiteralMap());
5419 method.invoke(ScriptObject.SET_MAP);
5420 replacedObjectLiteralMap = true;
5421 }
5422 }
5423 }
5424 // Must have emitted the code for replacing the map of an object literal if we have a set object literal stack depth
5425 assert ci.getObjectLiteralStackDepth() == -1 || replacedObjectLiteralMap;
5426 // Load RewriteException back.
5427 method.load(rewriteExceptionType, lvarCount);
5428 // Get rid of the stored reference
5429 method.loadNull();
5430 method.storeHidden(Type.OBJECT, lvarCount);
5431 // Mark it dead
5432 method.markDeadSlots(lvarCount, Type.OBJECT.getSlots());
5433
5434 // Load return value on the stack
5435 method.invoke(RewriteException.GET_RETURN_VALUE);
5436
5437 final Type returnValueType = ci.getReturnValueType();
5438
5439 // Set up an exception handler for primitive type conversion of return value if needed
5440 boolean needsCatch = false;
5441 final Label targetCatchLabel = ci.catchLabel;
5442 Label _try = null;
5443 if(returnValueType.isPrimitive()) {
5444 // If the conversion throws an exception, we want to report the line number of the continuation point.
5445 method.lineNumber(ci.lineNumber);
5446
5447 if(targetCatchLabel != METHOD_BOUNDARY) {
5448 _try = new Label("");
5449 method.label(_try);
5450 needsCatch = true;
5451 }
5452 }
5453
5454 // Convert return value
5455 method.convert(returnValueType);
5456
5457 final int scopePopCount = needsCatch ? ci.exceptionScopePops : 0;
5458
5459 // Declare a try/catch for the conversion. If no scopes need to be popped until the target catch block, just
5460 // jump into it. Otherwise, we'll need to create a scope-popping catch block below.
5461 final Label catchLabel = scopePopCount > 0 ? new Label("") : targetCatchLabel;
5462 if(needsCatch) {
5463 final Label _end_try = new Label("");
5464 method.label(_end_try);
5465 method._try(_try, _end_try, catchLabel);
5466 }
5467
5468 // Jump to continuation point
5469 method._goto(ci.getTargetLabel());
5470
5471 // Make a scope-popping exception delegate if needed
5472 if(catchLabel != targetCatchLabel) {
5473 method.lineNumber(0);
5474 assert scopePopCount > 0;
5475 method._catch(catchLabel);
5476 popScopes(scopePopCount);
5477 method.uncheckedGoto(targetCatchLabel);
5478 }
5479 }
5480
5481 /**
5482 * Interface implemented by object creators that support splitting over multiple methods.
5483 */
5484 interface SplitLiteralCreator {
5485 /**
5486 * Generate code to populate a range of the literal object. A reference to the object
5487 * should be left on the stack when the method terminates.
5488 *
5489 * @param method the method emitter
5490 * @param type the type of the literal object
5491 * @param slot the local slot containing the literal object
5492 * @param start the start index (inclusive)
5493 * @param end the end index (exclusive)
5494 */
5495 void populateRange(MethodEmitter method, Type type, int slot, int start, int end);
5496 }
5497 }