1 /*
2 * Copyright (c) 2010, 2016, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package jdk.nashorn.internal.codegen;
27
28 import static jdk.nashorn.internal.codegen.ClassEmitter.Flag.PRIVATE;
29 import static jdk.nashorn.internal.codegen.ClassEmitter.Flag.STATIC;
30 import static jdk.nashorn.internal.codegen.CompilerConstants.ARGUMENTS;
31 import static jdk.nashorn.internal.codegen.CompilerConstants.CALLEE;
32 import static jdk.nashorn.internal.codegen.CompilerConstants.CREATE_PROGRAM_FUNCTION;
33 import static jdk.nashorn.internal.codegen.CompilerConstants.GET_MAP;
34 import static jdk.nashorn.internal.codegen.CompilerConstants.GET_STRING;
35 import static jdk.nashorn.internal.codegen.CompilerConstants.QUICK_PREFIX;
36 import static jdk.nashorn.internal.codegen.CompilerConstants.REGEX_PREFIX;
37 import static jdk.nashorn.internal.codegen.CompilerConstants.SCOPE;
38 import static jdk.nashorn.internal.codegen.CompilerConstants.SPLIT_PREFIX;
39 import static jdk.nashorn.internal.codegen.CompilerConstants.THIS;
40 import static jdk.nashorn.internal.codegen.CompilerConstants.VARARGS;
41 import static jdk.nashorn.internal.codegen.CompilerConstants.interfaceCallNoLookup;
42 import static jdk.nashorn.internal.codegen.CompilerConstants.methodDescriptor;
43 import static jdk.nashorn.internal.codegen.CompilerConstants.staticCallNoLookup;
44 import static jdk.nashorn.internal.codegen.CompilerConstants.typeDescriptor;
45 import static jdk.nashorn.internal.codegen.CompilerConstants.virtualCallNoLookup;
46 import static jdk.nashorn.internal.ir.Symbol.HAS_SLOT;
47 import static jdk.nashorn.internal.ir.Symbol.IS_INTERNAL;
48 import static jdk.nashorn.internal.runtime.UnwarrantedOptimismException.INVALID_PROGRAM_POINT;
49 import static jdk.nashorn.internal.runtime.UnwarrantedOptimismException.isValid;
50 import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_APPLY_TO_CALL;
51 import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_DECLARE;
52 import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_FAST_SCOPE;
53 import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_OPTIMISTIC;
54 import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_PROGRAM_POINT_SHIFT;
55 import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_SCOPE;
56
57 import java.io.PrintWriter;
58 import java.util.ArrayDeque;
59 import java.util.ArrayList;
60 import java.util.Arrays;
61 import java.util.BitSet;
62 import java.util.Collection;
63 import java.util.Collections;
64 import java.util.Deque;
65 import java.util.EnumSet;
66 import java.util.HashMap;
67 import java.util.HashSet;
68 import java.util.Iterator;
69 import java.util.LinkedList;
70 import java.util.List;
71 import java.util.Map;
72 import java.util.Set;
73 import java.util.TreeMap;
74 import java.util.function.Supplier;
75 import jdk.nashorn.internal.AssertsEnabled;
76 import jdk.nashorn.internal.IntDeque;
77 import jdk.nashorn.internal.codegen.ClassEmitter.Flag;
78 import jdk.nashorn.internal.codegen.CompilerConstants.Call;
79 import jdk.nashorn.internal.codegen.types.ArrayType;
80 import jdk.nashorn.internal.codegen.types.Type;
81 import jdk.nashorn.internal.ir.AccessNode;
82 import jdk.nashorn.internal.ir.BaseNode;
83 import jdk.nashorn.internal.ir.BinaryNode;
84 import jdk.nashorn.internal.ir.Block;
85 import jdk.nashorn.internal.ir.BlockStatement;
86 import jdk.nashorn.internal.ir.BreakNode;
87 import jdk.nashorn.internal.ir.CallNode;
88 import jdk.nashorn.internal.ir.CaseNode;
89 import jdk.nashorn.internal.ir.CatchNode;
90 import jdk.nashorn.internal.ir.ContinueNode;
91 import jdk.nashorn.internal.ir.EmptyNode;
92 import jdk.nashorn.internal.ir.Expression;
93 import jdk.nashorn.internal.ir.ExpressionStatement;
94 import jdk.nashorn.internal.ir.ForNode;
95 import jdk.nashorn.internal.ir.FunctionNode;
96 import jdk.nashorn.internal.ir.GetSplitState;
97 import jdk.nashorn.internal.ir.IdentNode;
98 import jdk.nashorn.internal.ir.IfNode;
99 import jdk.nashorn.internal.ir.IndexNode;
100 import jdk.nashorn.internal.ir.JoinPredecessorExpression;
101 import jdk.nashorn.internal.ir.JumpStatement;
102 import jdk.nashorn.internal.ir.JumpToInlinedFinally;
103 import jdk.nashorn.internal.ir.LabelNode;
104 import jdk.nashorn.internal.ir.LexicalContext;
105 import jdk.nashorn.internal.ir.LexicalContextNode;
106 import jdk.nashorn.internal.ir.LiteralNode;
107 import jdk.nashorn.internal.ir.LiteralNode.ArrayLiteralNode;
108 import jdk.nashorn.internal.ir.LiteralNode.PrimitiveLiteralNode;
109 import jdk.nashorn.internal.ir.LocalVariableConversion;
110 import jdk.nashorn.internal.ir.LoopNode;
111 import jdk.nashorn.internal.ir.Node;
112 import jdk.nashorn.internal.ir.ObjectNode;
113 import jdk.nashorn.internal.ir.Optimistic;
114 import jdk.nashorn.internal.ir.PropertyNode;
115 import jdk.nashorn.internal.ir.ReturnNode;
116 import jdk.nashorn.internal.ir.RuntimeNode;
117 import jdk.nashorn.internal.ir.RuntimeNode.Request;
118 import jdk.nashorn.internal.ir.SetSplitState;
119 import jdk.nashorn.internal.ir.SplitReturn;
120 import jdk.nashorn.internal.ir.Splittable;
121 import jdk.nashorn.internal.ir.Statement;
122 import jdk.nashorn.internal.ir.SwitchNode;
123 import jdk.nashorn.internal.ir.Symbol;
124 import jdk.nashorn.internal.ir.TernaryNode;
125 import jdk.nashorn.internal.ir.ThrowNode;
126 import jdk.nashorn.internal.ir.TryNode;
127 import jdk.nashorn.internal.ir.UnaryNode;
128 import jdk.nashorn.internal.ir.VarNode;
129 import jdk.nashorn.internal.ir.WhileNode;
130 import jdk.nashorn.internal.ir.WithNode;
131 import jdk.nashorn.internal.ir.visitor.NodeOperatorVisitor;
132 import jdk.nashorn.internal.ir.visitor.SimpleNodeVisitor;
133 import jdk.nashorn.internal.objects.Global;
134 import jdk.nashorn.internal.parser.Lexer.RegexToken;
135 import jdk.nashorn.internal.parser.TokenType;
136 import jdk.nashorn.internal.runtime.Context;
137 import jdk.nashorn.internal.runtime.Debug;
138 import jdk.nashorn.internal.runtime.ECMAException;
139 import jdk.nashorn.internal.runtime.JSType;
140 import jdk.nashorn.internal.runtime.OptimisticReturnFilters;
141 import jdk.nashorn.internal.runtime.PropertyMap;
142 import jdk.nashorn.internal.runtime.RecompilableScriptFunctionData;
143 import jdk.nashorn.internal.runtime.RewriteException;
144 import jdk.nashorn.internal.runtime.Scope;
145 import jdk.nashorn.internal.runtime.ScriptEnvironment;
146 import jdk.nashorn.internal.runtime.ScriptFunction;
147 import jdk.nashorn.internal.runtime.ScriptObject;
148 import jdk.nashorn.internal.runtime.ScriptRuntime;
149 import jdk.nashorn.internal.runtime.Source;
150 import jdk.nashorn.internal.runtime.Undefined;
151 import jdk.nashorn.internal.runtime.UnwarrantedOptimismException;
152 import jdk.nashorn.internal.runtime.arrays.ArrayData;
153 import jdk.nashorn.internal.runtime.linker.LinkerCallSite;
154 import jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor;
155 import jdk.nashorn.internal.runtime.logging.DebugLogger;
156 import jdk.nashorn.internal.runtime.logging.Loggable;
157 import jdk.nashorn.internal.runtime.logging.Logger;
158 import jdk.nashorn.internal.runtime.options.Options;
159
160 /**
161 * This is the lowest tier of the code generator. It takes lowered ASTs emitted
162 * from Lower and emits Java byte code. The byte code emission logic is broken
163 * out into MethodEmitter. MethodEmitter works internally with a type stack, and
164 * keeps track of the contents of the byte code stack. This way we avoid a large
165 * number of special cases on the form
166 * <pre>
167 * if (type == INT) {
168 * visitInsn(ILOAD, slot);
169 * } else if (type == DOUBLE) {
170 * visitInsn(DOUBLE, slot);
171 * }
172 * </pre>
173 * This quickly became apparent when the code generator was generalized to work
174 * with all types, and not just numbers or objects.
175 * <p>
176 * The CodeGenerator visits nodes only once and emits bytecode for them.
177 */
178 @Logger(name="codegen")
179 final class CodeGenerator extends NodeOperatorVisitor<CodeGeneratorLexicalContext> implements Loggable {
180
181 private static final Type SCOPE_TYPE = Type.typeFor(ScriptObject.class);
182
183 private static final String GLOBAL_OBJECT = Type.getInternalName(Global.class);
184
185 private static final Call CREATE_REWRITE_EXCEPTION = CompilerConstants.staticCallNoLookup(RewriteException.class,
186 "create", RewriteException.class, UnwarrantedOptimismException.class, Object[].class, String[].class);
187 private static final Call CREATE_REWRITE_EXCEPTION_REST_OF = CompilerConstants.staticCallNoLookup(RewriteException.class,
188 "create", RewriteException.class, UnwarrantedOptimismException.class, Object[].class, String[].class, int[].class);
189
190 private static final Call ENSURE_INT = CompilerConstants.staticCallNoLookup(OptimisticReturnFilters.class,
191 "ensureInt", int.class, Object.class, int.class);
192 private static final Call ENSURE_NUMBER = CompilerConstants.staticCallNoLookup(OptimisticReturnFilters.class,
193 "ensureNumber", double.class, Object.class, int.class);
194
195 private static final Call CREATE_FUNCTION_OBJECT = CompilerConstants.staticCallNoLookup(ScriptFunction.class,
196 "create", ScriptFunction.class, Object[].class, int.class, ScriptObject.class);
197 private static final Call CREATE_FUNCTION_OBJECT_NO_SCOPE = CompilerConstants.staticCallNoLookup(ScriptFunction.class,
198 "create", ScriptFunction.class, Object[].class, int.class);
199
200 private static final Call TO_NUMBER_FOR_EQ = CompilerConstants.staticCallNoLookup(JSType.class,
201 "toNumberForEq", double.class, Object.class);
202 private static final Call TO_NUMBER_FOR_STRICT_EQ = CompilerConstants.staticCallNoLookup(JSType.class,
203 "toNumberForStrictEq", double.class, Object.class);
204
205
206 private static final Class<?> ITERATOR_CLASS = Iterator.class;
207 static {
208 assert ITERATOR_CLASS == CompilerConstants.ITERATOR_PREFIX.type();
209 }
210 private static final Type ITERATOR_TYPE = Type.typeFor(ITERATOR_CLASS);
211 private static final Type EXCEPTION_TYPE = Type.typeFor(CompilerConstants.EXCEPTION_PREFIX.type());
212
213 private static final Integer INT_ZERO = 0;
214
215 /** Constant data & installation. The only reason the compiler keeps this is because it is assigned
216 * by reflection in class installation */
217 private final Compiler compiler;
218
219 /** Is the current code submitted by 'eval' call? */
220 private final boolean evalCode;
221
222 /** Call site flags given to the code generator to be used for all generated call sites */
223 private final int callSiteFlags;
224
225 /** How many regexp fields have been emitted */
226 private int regexFieldCount;
227
228 /** Line number for last statement. If we encounter a new line number, line number bytecode information
229 * needs to be generated */
230 private int lastLineNumber = -1;
231
232 /** When should we stop caching regexp expressions in fields to limit bytecode size? */
233 private static final int MAX_REGEX_FIELDS = 2 * 1024;
234
235 /** Current method emitter */
236 private MethodEmitter method;
237
238 /** Current compile unit */
239 private CompileUnit unit;
240
241 private final DebugLogger log;
242
243 /** From what size should we use spill instead of fields for JavaScript objects? */
244 static final int OBJECT_SPILL_THRESHOLD = Options.getIntProperty("nashorn.spill.threshold", 256);
245
246 private final Set<String> emittedMethods = new HashSet<>();
247
248 // Function Id -> ContinuationInfo. Used by compilation of rest-of function only.
249 private ContinuationInfo continuationInfo;
250
251 private final Deque<Label> scopeEntryLabels = new ArrayDeque<>();
252
253 private static final Label METHOD_BOUNDARY = new Label("");
254 private final Deque<Label> catchLabels = new ArrayDeque<>();
255 // Number of live locals on entry to (and thus also break from) labeled blocks.
256 private final IntDeque labeledBlockBreakLiveLocals = new IntDeque();
257
258 //is this a rest of compilation
259 private final int[] continuationEntryPoints;
260
261 // Scope object creators needed for for-of and for-in loops
262 private final Deque<FieldObjectCreator<?>> scopeObjectCreators = new ArrayDeque<>();
263
264 /**
265 * Constructor.
266 *
267 * @param compiler
268 */
269 CodeGenerator(final Compiler compiler, final int[] continuationEntryPoints) {
270 super(new CodeGeneratorLexicalContext());
271 this.compiler = compiler;
272 this.evalCode = compiler.getSource().isEvalCode();
273 this.continuationEntryPoints = continuationEntryPoints;
274 this.callSiteFlags = compiler.getScriptEnvironment()._callsite_flags;
275 this.log = initLogger(compiler.getContext());
276 }
277
278 @Override
279 public DebugLogger getLogger() {
280 return log;
281 }
282
283 @Override
284 public DebugLogger initLogger(final Context context) {
285 return context.getLogger(this.getClass());
286 }
287
288 /**
289 * Gets the call site flags, adding the strict flag if the current function
290 * being generated is in strict mode
291 *
292 * @return the correct flags for a call site in the current function
293 */
294 int getCallSiteFlags() {
295 return lc.getCurrentFunction().getCallSiteFlags() | callSiteFlags;
296 }
297
298 /**
299 * Gets the flags for a scope call site.
300 * @param symbol a scope symbol
301 * @return the correct flags for the scope call site
302 */
303 private int getScopeCallSiteFlags(final Symbol symbol) {
304 assert symbol.isScope();
305 final int flags = getCallSiteFlags() | CALLSITE_SCOPE;
306 if (isEvalCode() && symbol.isGlobal()) {
307 return flags; // Don't set fast-scope flag on non-declared globals in eval code - see JDK-8077955.
308 }
309 return isFastScope(symbol) ? flags | CALLSITE_FAST_SCOPE : flags;
310 }
311
312 /**
313 * Are we generating code for 'eval' code?
314 * @return true if currently compiled code is 'eval' code.
315 */
316 boolean isEvalCode() {
317 return evalCode;
318 }
319
320 /**
321 * Are we using dual primitive/object field representation?
322 * @return true if using dual field representation, false for object-only fields
323 */
324 boolean useDualFields() {
325 return compiler.getContext().useDualFields();
326 }
327
328 /**
329 * Load an identity node
330 *
331 * @param identNode an identity node to load
332 * @return the method generator used
333 */
334 private MethodEmitter loadIdent(final IdentNode identNode, final TypeBounds resultBounds) {
335 checkTemporalDeadZone(identNode);
336 final Symbol symbol = identNode.getSymbol();
337
338 if (!symbol.isScope()) {
339 final Type type = identNode.getType();
340 if(type == Type.UNDEFINED) {
341 return method.loadUndefined(resultBounds.widest);
342 }
343
344 assert symbol.hasSlot() || symbol.isParam();
345 return method.load(identNode);
346 }
347
348 assert identNode.getSymbol().isScope() : identNode + " is not in scope!";
349 final int flags = getScopeCallSiteFlags(symbol);
350 if (!isFastScope(symbol)) {
351 // slow scope load, prototype chain must be inspected at runtime
352 new LoadScopeVar(identNode, resultBounds, flags).emit();
353 } else if (identNode.isCompileTimePropertyName() || symbol.getUseCount() < SharedScopeCall.SHARED_GET_THRESHOLD) {
354 // fast scope load with known prototype depth
355 new LoadFastScopeVar(identNode, resultBounds, flags).emit();
356 } else {
357 // Only generate shared scope getter for often used fast-scope symbols.
358 new OptimisticOperation(identNode, resultBounds) {
359 @Override
360 void loadStack() {
361 method.loadCompilerConstant(SCOPE);
362 final int depth = getScopeProtoDepth(lc.getCurrentBlock(), symbol);
363 assert depth >= 0;
364 method.load(depth);
365 method.load(getProgramPoint());
366 }
367
368 @Override
369 void consumeStack() {
370 final Type resultType = isOptimistic ? getOptimisticCoercedType() : resultBounds.widest;
371 lc.getScopeGet(unit, symbol, resultType, flags, isOptimistic).generateInvoke(method);
372 }
373 }.emit();
374 }
375
376 return method;
377 }
378
379 // Any access to LET and CONST variables before their declaration must throw ReferenceError.
380 // This is called the temporal dead zone (TDZ). See https://gist.github.com/rwaldron/f0807a758aa03bcdd58a
381 private void checkTemporalDeadZone(final IdentNode identNode) {
382 if (identNode.isDead()) {
383 method.load(identNode.getSymbol().getName()).invoke(ScriptRuntime.THROW_REFERENCE_ERROR);
384 }
385 }
386
387 // Runtime check for assignment to ES6 const
388 private void checkAssignTarget(final Expression expression) {
389 if (expression instanceof IdentNode && ((IdentNode)expression).getSymbol().isConst()) {
390 method.load(((IdentNode)expression).getSymbol().getName()).invoke(ScriptRuntime.THROW_CONST_TYPE_ERROR);
391 }
392 }
393
394 private boolean isRestOf() {
395 return continuationEntryPoints != null;
396 }
397
398 private boolean isCurrentContinuationEntryPoint(final int programPoint) {
399 return isRestOf() && getCurrentContinuationEntryPoint() == programPoint;
400 }
401
402 private int[] getContinuationEntryPoints() {
403 return isRestOf() ? continuationEntryPoints : null;
404 }
405
406 private int getCurrentContinuationEntryPoint() {
407 return isRestOf() ? continuationEntryPoints[0] : INVALID_PROGRAM_POINT;
408 }
409
410 private boolean isContinuationEntryPoint(final int programPoint) {
411 if (isRestOf()) {
412 assert continuationEntryPoints != null;
413 for (final int cep : continuationEntryPoints) {
414 if (cep == programPoint) {
415 return true;
416 }
417 }
418 }
419 return false;
420 }
421
422 /**
423 * Check if this symbol can be accessed directly with a putfield or getfield or dynamic load
424 *
425 * @param symbol symbol to check for fast scope
426 * @return true if fast scope
427 */
428 private boolean isFastScope(final Symbol symbol) {
429 if (!symbol.isScope()) {
430 return false;
431 }
432
433 if (!lc.inDynamicScope()) {
434 // If there's no with or eval in context, and the symbol is marked as scoped, it is fast scoped. Such a
435 // symbol must either be global, or its defining block must need scope.
436 assert symbol.isGlobal() || lc.getDefiningBlock(symbol).needsScope() : symbol.getName();
437 return true;
438 }
439
440 if (symbol.isGlobal()) {
441 // Shortcut: if there's a with or eval in context, globals can't be fast scoped
442 return false;
443 }
444
445 // Otherwise, check if there's a dynamic scope between use of the symbol and its definition
446 final String name = symbol.getName();
447 boolean previousWasBlock = false;
448 for (final Iterator<LexicalContextNode> it = lc.getAllNodes(); it.hasNext();) {
449 final LexicalContextNode node = it.next();
450 if (node instanceof Block) {
451 // If this block defines the symbol, then we can fast scope the symbol.
452 final Block block = (Block)node;
453 if (block.getExistingSymbol(name) == symbol) {
454 assert block.needsScope();
455 return true;
456 }
457 previousWasBlock = true;
458 } else {
459 if (node instanceof WithNode && previousWasBlock || node instanceof FunctionNode && ((FunctionNode)node).needsDynamicScope()) {
460 // If we hit a scope that can have symbols introduced into it at run time before finding the defining
461 // block, the symbol can't be fast scoped. A WithNode only counts if we've immediately seen a block
462 // before - its block. Otherwise, we are currently processing the WithNode's expression, and that's
463 // obviously not subjected to introducing new symbols.
464 return false;
465 }
466 previousWasBlock = false;
467 }
468 }
469 // Should've found the symbol defined in a block
470 throw new AssertionError();
471 }
472
473 private class LoadScopeVar extends OptimisticOperation {
474 final IdentNode identNode;
475 private final int flags;
476
477 LoadScopeVar(final IdentNode identNode, final TypeBounds resultBounds, final int flags) {
478 super(identNode, resultBounds);
479 this.identNode = identNode;
480 this.flags = flags;
481 }
482
483 @Override
484 void loadStack() {
485 method.loadCompilerConstant(SCOPE);
486 getProto();
487 }
488
489 void getProto() {
490 //empty
491 }
492
493 @Override
494 void consumeStack() {
495 // If this is either __FILE__, __DIR__, or __LINE__ then load the property initially as Object as we'd convert
496 // it anyway for replaceLocationPropertyPlaceholder.
497 if(identNode.isCompileTimePropertyName()) {
498 method.dynamicGet(Type.OBJECT, identNode.getSymbol().getName(), flags, identNode.isFunction(), false);
499 replaceCompileTimeProperty();
500 } else {
501 dynamicGet(identNode.getSymbol().getName(), flags, identNode.isFunction(), false);
502 }
503 }
504 }
505
506 private class LoadFastScopeVar extends LoadScopeVar {
507 LoadFastScopeVar(final IdentNode identNode, final TypeBounds resultBounds, final int flags) {
508 super(identNode, resultBounds, flags);
509 }
510
511 @Override
512 void getProto() {
513 loadFastScopeProto(identNode.getSymbol(), false);
514 }
515 }
516
517 private MethodEmitter storeFastScopeVar(final Symbol symbol, final int flags) {
518 loadFastScopeProto(symbol, true);
519 method.dynamicSet(symbol.getName(), flags, false);
520 return method;
521 }
522
523 private int getScopeProtoDepth(final Block startingBlock, final Symbol symbol) {
524 //walk up the chain from starting block and when we bump into the current function boundary, add the external
525 //information.
526 final FunctionNode fn = lc.getCurrentFunction();
527 final int externalDepth = compiler.getScriptFunctionData(fn.getId()).getExternalSymbolDepth(symbol.getName());
528
529 //count the number of scopes from this place to the start of the function
530
531 final int internalDepth = FindScopeDepths.findInternalDepth(lc, fn, startingBlock, symbol);
532 final int scopesToStart = FindScopeDepths.findScopesToStart(lc, fn, startingBlock);
533 int depth = 0;
534 if (internalDepth == -1) {
535 depth = scopesToStart + externalDepth;
536 } else {
537 assert internalDepth <= scopesToStart;
538 depth = internalDepth;
539 }
540
541 return depth;
542 }
543
544 private void loadFastScopeProto(final Symbol symbol, final boolean swap) {
545 final int depth = getScopeProtoDepth(lc.getCurrentBlock(), symbol);
546 assert depth != -1 : "Couldn't find scope depth for symbol " + symbol.getName() + " in " + lc.getCurrentFunction();
547 if (depth > 0) {
548 if (swap) {
549 method.swap();
550 }
551 invokeGetProto(depth);
552 if (swap) {
553 method.swap();
554 }
555 }
556 }
557
558 private void invokeGetProto(final int depth) {
559 assert depth > 0;
560 if (depth > 1) {
561 method.load(depth);
562 method.invoke(ScriptObject.GET_PROTO_DEPTH);
563 } else {
564 method.invoke(ScriptObject.GET_PROTO);
565 }
566 }
567
568 /**
569 * Generate code that loads this node to the stack, not constraining its type
570 *
571 * @param expr node to load
572 *
573 * @return the method emitter used
574 */
575 private MethodEmitter loadExpressionUnbounded(final Expression expr) {
576 return loadExpression(expr, TypeBounds.UNBOUNDED);
577 }
578
579 private MethodEmitter loadExpressionAsObject(final Expression expr) {
580 return loadExpression(expr, TypeBounds.OBJECT);
581 }
582
583 MethodEmitter loadExpressionAsBoolean(final Expression expr) {
584 return loadExpression(expr, TypeBounds.BOOLEAN);
585 }
586
587 // Test whether conversion from source to target involves a call of ES 9.1 ToPrimitive
588 // with possible side effects from calling an object's toString or valueOf methods.
589 private static boolean noToPrimitiveConversion(final Type source, final Type target) {
590 // Object to boolean conversion does not cause ToPrimitive call
591 return source.isJSPrimitive() || !target.isJSPrimitive() || target.isBoolean();
592 }
593
594 MethodEmitter loadBinaryOperands(final BinaryNode binaryNode) {
595 return loadBinaryOperands(binaryNode.lhs(), binaryNode.rhs(), TypeBounds.UNBOUNDED.notWiderThan(binaryNode.getWidestOperandType()), false, false);
596 }
597
598 private MethodEmitter loadBinaryOperands(final Expression lhs, final Expression rhs, final TypeBounds explicitOperandBounds, final boolean baseAlreadyOnStack, final boolean forceConversionSeparation) {
599 // ECMAScript 5.1 specification (sections 11.5-11.11 and 11.13) prescribes that when evaluating a binary
600 // expression "LEFT op RIGHT", the order of operations must be: LOAD LEFT, LOAD RIGHT, CONVERT LEFT, CONVERT
601 // RIGHT, EXECUTE OP. Unfortunately, doing it in this order defeats potential optimizations that arise when we
602 // can combine a LOAD with a CONVERT operation (e.g. use a dynamic getter with the conversion target type as its
603 // return value). What we do here is reorder LOAD RIGHT and CONVERT LEFT when possible; it is possible only when
604 // we can prove that executing CONVERT LEFT can't have a side effect that changes the value of LOAD RIGHT.
605 // Basically, if we know that either LEFT already is a primitive value, or does not have to be converted to
606 // a primitive value, or RIGHT is an expression that loads without side effects, then we can do the
607 // reordering and collapse LOAD/CONVERT into a single operation; otherwise we need to do the more costly
608 // separate operations to preserve specification semantics.
609
610 // Operands' load type should not be narrower than the narrowest of the individual operand types, nor narrower
611 // than the lower explicit bound, but it should also not be wider than
612 final Type lhsType = undefinedToNumber(lhs.getType());
613 final Type rhsType = undefinedToNumber(rhs.getType());
614 final Type narrowestOperandType = Type.narrowest(Type.widest(lhsType, rhsType), explicitOperandBounds.widest);
615 final TypeBounds operandBounds = explicitOperandBounds.notNarrowerThan(narrowestOperandType);
616 if (noToPrimitiveConversion(lhsType, explicitOperandBounds.widest) || rhs.isLocal()) {
617 // Can reorder. We might still need to separate conversion, but at least we can do it with reordering
618 if (forceConversionSeparation) {
619 // Can reorder, but can't move conversion into the operand as the operation depends on operands
620 // exact types for its overflow guarantees. E.g. with {L}{%I}expr1 {L}* {L}{%I}expr2 we are not allowed
621 // to merge {L}{%I} into {%L}, as that can cause subsequent overflows; test for JDK-8058610 contains
622 // concrete cases where this could happen.
623 final TypeBounds safeConvertBounds = TypeBounds.UNBOUNDED.notNarrowerThan(narrowestOperandType);
624 loadExpression(lhs, safeConvertBounds, baseAlreadyOnStack);
625 method.convert(operandBounds.within(method.peekType()));
626 loadExpression(rhs, safeConvertBounds, false);
627 method.convert(operandBounds.within(method.peekType()));
628 } else {
629 // Can reorder and move conversion into the operand. Combine load and convert into single operations.
630 loadExpression(lhs, operandBounds, baseAlreadyOnStack);
631 loadExpression(rhs, operandBounds, false);
632 }
633 } else {
634 // Can't reorder. Load and convert separately.
635 final TypeBounds safeConvertBounds = TypeBounds.UNBOUNDED.notNarrowerThan(narrowestOperandType);
636 loadExpression(lhs, safeConvertBounds, baseAlreadyOnStack);
637 final Type lhsLoadedType = method.peekType();
638 loadExpression(rhs, safeConvertBounds, false);
639 final Type convertedLhsType = operandBounds.within(method.peekType());
640 if (convertedLhsType != lhsLoadedType) {
641 // Do it conditionally, so that if conversion is a no-op we don't introduce a SWAP, SWAP.
642 method.swap().convert(convertedLhsType).swap();
643 }
644 method.convert(operandBounds.within(method.peekType()));
645 }
646 assert Type.generic(method.peekType()) == operandBounds.narrowest;
647 assert Type.generic(method.peekType(1)) == operandBounds.narrowest;
648
649 return method;
650 }
651
652 /**
653 * Similar to {@link #loadBinaryOperands(BinaryNode)} but used specifically for loading operands of
654 * relational and equality comparison operators where at least one argument is non-object. (When both
655 * arguments are objects, we use {@link ScriptRuntime#EQ(Object, Object)}, {@link ScriptRuntime#LT(Object, Object)}
656 * etc. methods instead. Additionally, {@code ScriptRuntime} methods are used for strict (in)equality comparison
657 * of a boolean to anything that isn't a boolean.) This method handles the special case where one argument
658 * is an object and another is a primitive. Naively, these could also be delegated to {@code ScriptRuntime} methods
659 * by boxing the primitive. However, in all such cases the comparison is performed on numeric values, so it is
660 * possible to strength-reduce the operation by taking the number value of the object argument instead and
661 * comparing that to the primitive value ("primitive" will always be int, long, double, or boolean, and booleans
662 * compare as ints in these cases, so they're essentially numbers too). This method will emit code for loading
663 * arguments for such strength-reduced comparison. When both arguments are primitives, it just delegates to
664 * {@link #loadBinaryOperands(BinaryNode)}.
665 *
666 * @param cmp the comparison operation for which the operands need to be loaded on stack.
667 * @return the current method emitter.
668 */
669 MethodEmitter loadComparisonOperands(final BinaryNode cmp) {
670 final Expression lhs = cmp.lhs();
671 final Expression rhs = cmp.rhs();
672 final Type lhsType = lhs.getType();
673 final Type rhsType = rhs.getType();
674
675 // Only used when not both are object, for that we have ScriptRuntime.LT etc.
676 assert !(lhsType.isObject() && rhsType.isObject());
677
678 if (lhsType.isObject() || rhsType.isObject()) {
679 // We can reorder CONVERT LEFT and LOAD RIGHT only if either the left is a primitive, or the right
680 // is a local. This is more strict than loadBinaryNode reorder criteria, as it can allow JS primitive
681 // types too (notably: String is a JS primitive, but not a JVM primitive). We disallow String otherwise
682 // we would prematurely convert it to number when comparing to an optimistic expression, e.g. in
683 // "Hello" === String("Hello") the RHS starts out as an optimistic-int function call. If we allowed
684 // reordering, we'd end up with ToNumber("Hello") === {I%}String("Hello") that is obviously incorrect.
685 final boolean canReorder = lhsType.isPrimitive() || rhs.isLocal();
686 // If reordering is allowed, and we're using a relational operator (that is, <, <=, >, >=) and not an
687 // (in)equality operator, then we encourage combining of LOAD and CONVERT into a single operation.
688 // This is because relational operators' semantics prescribes vanilla ToNumber() conversion, while
689 // (in)equality operators need the specialized JSType.toNumberFor[Strict]Equals. E.g. in the code snippet
690 // "i < obj.size" (where i is primitive and obj.size is statically an object), ".size" will thus be allowed
691 // to compile as:
692 // invokedynamic GET_PROPERTY:size(Object;)D
693 // instead of the more costly:
694 // invokedynamic GET_PROPERTY:size(Object;)Object
695 // invokestatic JSType.toNumber(Object)D
696 // Note also that even if this is allowed, we're only using it on operands that are non-optimistic, as
697 // otherwise the logic for determining effective optimistic-ness would turn an optimistic double return
698 // into a freely coercible one, which would be wrong.
699 final boolean canCombineLoadAndConvert = canReorder && cmp.isRelational();
700
701 // LOAD LEFT
702 loadExpression(lhs, canCombineLoadAndConvert && !lhs.isOptimistic() ? TypeBounds.NUMBER : TypeBounds.UNBOUNDED);
703
704 final Type lhsLoadedType = method.peekType();
705 final TokenType tt = cmp.tokenType();
706 if (canReorder) {
707 // Can reorder CONVERT LEFT and LOAD RIGHT
708 emitObjectToNumberComparisonConversion(method, tt);
709 loadExpression(rhs, canCombineLoadAndConvert && !rhs.isOptimistic() ? TypeBounds.NUMBER : TypeBounds.UNBOUNDED);
710 } else {
711 // Can't reorder CONVERT LEFT and LOAD RIGHT
712 loadExpression(rhs, TypeBounds.UNBOUNDED);
713 if (lhsLoadedType != Type.NUMBER) {
714 method.swap();
715 emitObjectToNumberComparisonConversion(method, tt);
716 method.swap();
717 }
718 }
719
720 // CONVERT RIGHT
721 emitObjectToNumberComparisonConversion(method, tt);
722 return method;
723 }
724 // For primitive operands, just don't do anything special.
725 return loadBinaryOperands(cmp);
726 }
727
728 private static void emitObjectToNumberComparisonConversion(final MethodEmitter method, final TokenType tt) {
729 switch(tt) {
730 case EQ:
731 case NE:
732 if (method.peekType().isObject()) {
733 TO_NUMBER_FOR_EQ.invoke(method);
734 return;
735 }
736 break;
737 case EQ_STRICT:
738 case NE_STRICT:
739 if (method.peekType().isObject()) {
740 TO_NUMBER_FOR_STRICT_EQ.invoke(method);
741 return;
742 }
743 break;
744 default:
745 break;
746 }
747 method.convert(Type.NUMBER);
748 }
749
750 private static Type undefinedToNumber(final Type type) {
751 return type == Type.UNDEFINED ? Type.NUMBER : type;
752 }
753
754 private static final class TypeBounds {
755 final Type narrowest;
756 final Type widest;
757
758 static final TypeBounds UNBOUNDED = new TypeBounds(Type.UNKNOWN, Type.OBJECT);
759 static final TypeBounds INT = exact(Type.INT);
760 static final TypeBounds NUMBER = exact(Type.NUMBER);
761 static final TypeBounds OBJECT = exact(Type.OBJECT);
762 static final TypeBounds BOOLEAN = exact(Type.BOOLEAN);
763
764 static TypeBounds exact(final Type type) {
765 return new TypeBounds(type, type);
766 }
767
768 TypeBounds(final Type narrowest, final Type widest) {
769 assert widest != null && widest != Type.UNDEFINED && widest != Type.UNKNOWN : widest;
770 assert narrowest != null && narrowest != Type.UNDEFINED : narrowest;
771 assert !narrowest.widerThan(widest) : narrowest + " wider than " + widest;
772 assert !widest.narrowerThan(narrowest);
773 this.narrowest = Type.generic(narrowest);
774 this.widest = Type.generic(widest);
775 }
776
777 TypeBounds notNarrowerThan(final Type type) {
778 return maybeNew(Type.narrowest(Type.widest(narrowest, type), widest), widest);
779 }
780
781 TypeBounds notWiderThan(final Type type) {
782 return maybeNew(Type.narrowest(narrowest, type), Type.narrowest(widest, type));
783 }
784
785 boolean canBeNarrowerThan(final Type type) {
786 return narrowest.narrowerThan(type);
787 }
788
789 TypeBounds maybeNew(final Type newNarrowest, final Type newWidest) {
790 if(newNarrowest == narrowest && newWidest == widest) {
791 return this;
792 }
793 return new TypeBounds(newNarrowest, newWidest);
794 }
795
796 TypeBounds booleanToInt() {
797 return maybeNew(CodeGenerator.booleanToInt(narrowest), CodeGenerator.booleanToInt(widest));
798 }
799
800 TypeBounds objectToNumber() {
801 return maybeNew(CodeGenerator.objectToNumber(narrowest), CodeGenerator.objectToNumber(widest));
802 }
803
804 Type within(final Type type) {
805 if(type.narrowerThan(narrowest)) {
806 return narrowest;
807 }
808 if(type.widerThan(widest)) {
809 return widest;
810 }
811 return type;
812 }
813
814 @Override
815 public String toString() {
816 return "[" + narrowest + ", " + widest + "]";
817 }
818 }
819
820 private static Type booleanToInt(final Type t) {
821 return t == Type.BOOLEAN ? Type.INT : t;
822 }
823
824 private static Type objectToNumber(final Type t) {
825 return t.isObject() ? Type.NUMBER : t;
826 }
827
828 MethodEmitter loadExpressionAsType(final Expression expr, final Type type) {
829 if(type == Type.BOOLEAN) {
830 return loadExpressionAsBoolean(expr);
831 } else if(type == Type.UNDEFINED) {
832 assert expr.getType() == Type.UNDEFINED;
833 return loadExpressionAsObject(expr);
834 }
835 // having no upper bound preserves semantics of optimistic operations in the expression (by not having them
836 // converted early) and then applies explicit conversion afterwards.
837 return loadExpression(expr, TypeBounds.UNBOUNDED.notNarrowerThan(type)).convert(type);
838 }
839
840 private MethodEmitter loadExpression(final Expression expr, final TypeBounds resultBounds) {
841 return loadExpression(expr, resultBounds, false);
842 }
843
844 /**
845 * Emits code for evaluating an expression and leaving its value on top of the stack, narrowing or widening it if
846 * necessary.
847 * @param expr the expression to load
848 * @param resultBounds the incoming type bounds. The value on the top of the stack is guaranteed to not be of narrower
849 * type than the narrowest bound, or wider type than the widest bound after it is loaded.
850 * @param baseAlreadyOnStack true if the base of an access or index node is already on the stack. Used to avoid
851 * double evaluation of bases in self-assignment expressions to access and index nodes. {@code Type.OBJECT} is used
852 * to indicate the widest possible type.
853 * @return the method emitter
854 */
855 private MethodEmitter loadExpression(final Expression expr, final TypeBounds resultBounds, final boolean baseAlreadyOnStack) {
856
857 /*
858 * The load may be of type IdentNode, e.g. "x", AccessNode, e.g. "x.y"
859 * or IndexNode e.g. "x[y]". Both AccessNodes and IndexNodes are
860 * BaseNodes and the logic for loading the base object is reused
861 */
862 final CodeGenerator codegen = this;
863
864 final boolean isCurrentDiscard = codegen.lc.isCurrentDiscard(expr);
865 expr.accept(new NodeOperatorVisitor<LexicalContext>(new LexicalContext()) {
866 @Override
867 public boolean enterIdentNode(final IdentNode identNode) {
868 loadIdent(identNode, resultBounds);
869 return false;
870 }
871
872 @Override
873 public boolean enterAccessNode(final AccessNode accessNode) {
874 new OptimisticOperation(accessNode, resultBounds) {
875 @Override
876 void loadStack() {
877 if (!baseAlreadyOnStack) {
878 loadExpressionAsObject(accessNode.getBase());
879 }
880 assert method.peekType().isObject();
881 }
882 @Override
883 void consumeStack() {
884 final int flags = getCallSiteFlags();
885 dynamicGet(accessNode.getProperty(), flags, accessNode.isFunction(), accessNode.isIndex());
886 }
887 }.emit(baseAlreadyOnStack ? 1 : 0);
888 return false;
889 }
890
891 @Override
892 public boolean enterIndexNode(final IndexNode indexNode) {
893 new OptimisticOperation(indexNode, resultBounds) {
894 @Override
895 void loadStack() {
896 if (!baseAlreadyOnStack) {
897 loadExpressionAsObject(indexNode.getBase());
898 loadExpressionUnbounded(indexNode.getIndex());
899 }
900 }
901 @Override
902 void consumeStack() {
903 final int flags = getCallSiteFlags();
904 dynamicGetIndex(flags, indexNode.isFunction());
905 }
906 }.emit(baseAlreadyOnStack ? 2 : 0);
907 return false;
908 }
909
910 @Override
911 public boolean enterFunctionNode(final FunctionNode functionNode) {
912 // function nodes will always leave a constructed function object on stack, no need to load the symbol
913 // separately as in enterDefault()
914 lc.pop(functionNode);
915 functionNode.accept(codegen);
916 // NOTE: functionNode.accept() will produce a different FunctionNode that we discard. This incidentally
917 // doesn't cause problems as we're never touching FunctionNode again after it's visited here - codegen
918 // is the last element in the compilation pipeline, the AST it produces is not used externally. So, we
919 // re-push the original functionNode.
920 lc.push(functionNode);
921 return false;
922 }
923
924 @Override
925 public boolean enterASSIGN(final BinaryNode binaryNode) {
926 checkAssignTarget(binaryNode.lhs());
927 loadASSIGN(binaryNode);
928 return false;
929 }
930
931 @Override
932 public boolean enterASSIGN_ADD(final BinaryNode binaryNode) {
933 checkAssignTarget(binaryNode.lhs());
934 loadASSIGN_ADD(binaryNode);
935 return false;
936 }
937
938 @Override
939 public boolean enterASSIGN_BIT_AND(final BinaryNode binaryNode) {
940 checkAssignTarget(binaryNode.lhs());
941 loadASSIGN_BIT_AND(binaryNode);
942 return false;
943 }
944
945 @Override
946 public boolean enterASSIGN_BIT_OR(final BinaryNode binaryNode) {
947 checkAssignTarget(binaryNode.lhs());
948 loadASSIGN_BIT_OR(binaryNode);
949 return false;
950 }
951
952 @Override
953 public boolean enterASSIGN_BIT_XOR(final BinaryNode binaryNode) {
954 checkAssignTarget(binaryNode.lhs());
955 loadASSIGN_BIT_XOR(binaryNode);
956 return false;
957 }
958
959 @Override
960 public boolean enterASSIGN_DIV(final BinaryNode binaryNode) {
961 checkAssignTarget(binaryNode.lhs());
962 loadASSIGN_DIV(binaryNode);
963 return false;
964 }
965
966 @Override
967 public boolean enterASSIGN_MOD(final BinaryNode binaryNode) {
968 checkAssignTarget(binaryNode.lhs());
969 loadASSIGN_MOD(binaryNode);
970 return false;
971 }
972
973 @Override
974 public boolean enterASSIGN_MUL(final BinaryNode binaryNode) {
975 checkAssignTarget(binaryNode.lhs());
976 loadASSIGN_MUL(binaryNode);
977 return false;
978 }
979
980 @Override
981 public boolean enterASSIGN_SAR(final BinaryNode binaryNode) {
982 checkAssignTarget(binaryNode.lhs());
983 loadASSIGN_SAR(binaryNode);
984 return false;
985 }
986
987 @Override
988 public boolean enterASSIGN_SHL(final BinaryNode binaryNode) {
989 checkAssignTarget(binaryNode.lhs());
990 loadASSIGN_SHL(binaryNode);
991 return false;
992 }
993
994 @Override
995 public boolean enterASSIGN_SHR(final BinaryNode binaryNode) {
996 checkAssignTarget(binaryNode.lhs());
997 loadASSIGN_SHR(binaryNode);
998 return false;
999 }
1000
1001 @Override
1002 public boolean enterASSIGN_SUB(final BinaryNode binaryNode) {
1003 checkAssignTarget(binaryNode.lhs());
1004 loadASSIGN_SUB(binaryNode);
1005 return false;
1006 }
1007
1008 @Override
1009 public boolean enterCallNode(final CallNode callNode) {
1010 return loadCallNode(callNode, resultBounds);
1011 }
1012
1013 @Override
1014 public boolean enterLiteralNode(final LiteralNode<?> literalNode) {
1015 loadLiteral(literalNode, resultBounds);
1016 return false;
1017 }
1018
1019 @Override
1020 public boolean enterTernaryNode(final TernaryNode ternaryNode) {
1021 loadTernaryNode(ternaryNode, resultBounds);
1022 return false;
1023 }
1024
1025 @Override
1026 public boolean enterADD(final BinaryNode binaryNode) {
1027 loadADD(binaryNode, resultBounds);
1028 return false;
1029 }
1030
1031 @Override
1032 public boolean enterNEG(final UnaryNode unaryNode) {
1033 loadSUB(unaryNode, resultBounds);
1034 return false;
1035 }
1036
1037 @Override
1038 public boolean enterSUB(final BinaryNode binaryNode) {
1039 loadSUB(binaryNode, resultBounds);
1040 return false;
1041 }
1042
1043 @Override
1044 public boolean enterMUL(final BinaryNode binaryNode) {
1045 loadMUL(binaryNode, resultBounds);
1046 return false;
1047 }
1048
1049 @Override
1050 public boolean enterDIV(final BinaryNode binaryNode) {
1051 loadDIV(binaryNode, resultBounds);
1052 return false;
1053 }
1054
1055 @Override
1056 public boolean enterMOD(final BinaryNode binaryNode) {
1057 loadMOD(binaryNode, resultBounds);
1058 return false;
1059 }
1060
1061 @Override
1062 public boolean enterSAR(final BinaryNode binaryNode) {
1063 loadSAR(binaryNode);
1064 return false;
1065 }
1066
1067 @Override
1068 public boolean enterSHL(final BinaryNode binaryNode) {
1069 loadSHL(binaryNode);
1070 return false;
1071 }
1072
1073 @Override
1074 public boolean enterSHR(final BinaryNode binaryNode) {
1075 loadSHR(binaryNode);
1076 return false;
1077 }
1078
1079 @Override
1080 public boolean enterCOMMARIGHT(final BinaryNode binaryNode) {
1081 loadCOMMARIGHT(binaryNode, resultBounds);
1082 return false;
1083 }
1084
1085 @Override
1086 public boolean enterAND(final BinaryNode binaryNode) {
1087 loadAND_OR(binaryNode, resultBounds, true);
1088 return false;
1089 }
1090
1091 @Override
1092 public boolean enterOR(final BinaryNode binaryNode) {
1093 loadAND_OR(binaryNode, resultBounds, false);
1094 return false;
1095 }
1096
1097 @Override
1098 public boolean enterNOT(final UnaryNode unaryNode) {
1099 loadNOT(unaryNode);
1100 return false;
1101 }
1102
1103 @Override
1104 public boolean enterPOS(final UnaryNode unaryNode) {
1105 loadADD(unaryNode, resultBounds);
1106 return false;
1107 }
1108
1109 @Override
1110 public boolean enterBIT_NOT(final UnaryNode unaryNode) {
1111 loadBIT_NOT(unaryNode);
1112 return false;
1113 }
1114
1115 @Override
1116 public boolean enterBIT_AND(final BinaryNode binaryNode) {
1117 loadBIT_AND(binaryNode);
1118 return false;
1119 }
1120
1121 @Override
1122 public boolean enterBIT_OR(final BinaryNode binaryNode) {
1123 loadBIT_OR(binaryNode);
1124 return false;
1125 }
1126
1127 @Override
1128 public boolean enterBIT_XOR(final BinaryNode binaryNode) {
1129 loadBIT_XOR(binaryNode);
1130 return false;
1131 }
1132
1133 @Override
1134 public boolean enterVOID(final UnaryNode unaryNode) {
1135 loadVOID(unaryNode, resultBounds);
1136 return false;
1137 }
1138
1139 @Override
1140 public boolean enterDELETE(final UnaryNode unaryNode) {
1141 loadDELETE(unaryNode);
1142 return false;
1143 }
1144
1145 @Override
1146 public boolean enterEQ(final BinaryNode binaryNode) {
1147 loadCmp(binaryNode, Condition.EQ);
1148 return false;
1149 }
1150
1151 @Override
1152 public boolean enterEQ_STRICT(final BinaryNode binaryNode) {
1153 loadCmp(binaryNode, Condition.EQ);
1154 return false;
1155 }
1156
1157 @Override
1158 public boolean enterGE(final BinaryNode binaryNode) {
1159 loadCmp(binaryNode, Condition.GE);
1160 return false;
1161 }
1162
1163 @Override
1164 public boolean enterGT(final BinaryNode binaryNode) {
1165 loadCmp(binaryNode, Condition.GT);
1166 return false;
1167 }
1168
1169 @Override
1170 public boolean enterLE(final BinaryNode binaryNode) {
1171 loadCmp(binaryNode, Condition.LE);
1172 return false;
1173 }
1174
1175 @Override
1176 public boolean enterLT(final BinaryNode binaryNode) {
1177 loadCmp(binaryNode, Condition.LT);
1178 return false;
1179 }
1180
1181 @Override
1182 public boolean enterNE(final BinaryNode binaryNode) {
1183 loadCmp(binaryNode, Condition.NE);
1184 return false;
1185 }
1186
1187 @Override
1188 public boolean enterNE_STRICT(final BinaryNode binaryNode) {
1189 loadCmp(binaryNode, Condition.NE);
1190 return false;
1191 }
1192
1193 @Override
1194 public boolean enterObjectNode(final ObjectNode objectNode) {
1195 loadObjectNode(objectNode);
1196 return false;
1197 }
1198
1199 @Override
1200 public boolean enterRuntimeNode(final RuntimeNode runtimeNode) {
1201 loadRuntimeNode(runtimeNode);
1202 return false;
1203 }
1204
1205 @Override
1206 public boolean enterNEW(final UnaryNode unaryNode) {
1207 loadNEW(unaryNode);
1208 return false;
1209 }
1210
1211 @Override
1212 public boolean enterDECINC(final UnaryNode unaryNode) {
1213 checkAssignTarget(unaryNode.getExpression());
1214 loadDECINC(unaryNode);
1215 return false;
1216 }
1217
1218 @Override
1219 public boolean enterJoinPredecessorExpression(final JoinPredecessorExpression joinExpr) {
1220 loadMaybeDiscard(joinExpr, joinExpr.getExpression(), resultBounds);
1221 return false;
1222 }
1223
1224 @Override
1225 public boolean enterGetSplitState(final GetSplitState getSplitState) {
1226 method.loadScope();
1227 method.invoke(Scope.GET_SPLIT_STATE);
1228 return false;
1229 }
1230
1231 @Override
1232 public boolean enterDefault(final Node otherNode) {
1233 // Must have handled all expressions that can legally be encountered.
1234 throw new AssertionError(otherNode.getClass().getName());
1235 }
1236 });
1237 if(!isCurrentDiscard) {
1238 coerceStackTop(resultBounds);
1239 }
1240 return method;
1241 }
1242
1243 private MethodEmitter coerceStackTop(final TypeBounds typeBounds) {
1244 return method.convert(typeBounds.within(method.peekType()));
1245 }
1246
1247 /**
1248 * Closes any still open entries for this block's local variables in the bytecode local variable table.
1249 *
1250 * @param block block containing symbols.
1251 */
1252 private void closeBlockVariables(final Block block) {
1253 for (final Symbol symbol : block.getSymbols()) {
1254 if (symbol.isBytecodeLocal()) {
1255 method.closeLocalVariable(symbol, block.getBreakLabel());
1256 }
1257 }
1258 }
1259
1260 @Override
1261 public boolean enterBlock(final Block block) {
1262 final Label entryLabel = block.getEntryLabel();
1263 if (entryLabel.isBreakTarget()) {
1264 // Entry label is a break target only for an inlined finally block.
1265 assert !method.isReachable();
1266 method.breakLabel(entryLabel, lc.getUsedSlotCount());
1267 } else {
1268 method.label(entryLabel);
1269 }
1270 if(!method.isReachable()) {
1271 return false;
1272 }
1273 if(lc.isFunctionBody() && emittedMethods.contains(lc.getCurrentFunction().getName())) {
1274 return false;
1275 }
1276 initLocals(block);
1277
1278 assert lc.getUsedSlotCount() == method.getFirstTemp();
1279 return true;
1280 }
1281
1282 boolean useOptimisticTypes() {
1283 return !lc.inSplitLiteral() && compiler.useOptimisticTypes();
1284 }
1285
1286 @Override
1287 public Node leaveBlock(final Block block) {
1288 popBlockScope(block);
1289 method.beforeJoinPoint(block);
1290
1291 closeBlockVariables(block);
1292 lc.releaseSlots();
1293 assert !method.isReachable() || (lc.isFunctionBody() ? 0 : lc.getUsedSlotCount()) == method.getFirstTemp() :
1294 "reachable="+method.isReachable() +
1295 " isFunctionBody=" + lc.isFunctionBody() +
1296 " usedSlotCount=" + lc.getUsedSlotCount() +
1297 " firstTemp=" + method.getFirstTemp();
1298
1299 return block;
1300 }
1301
1302 private void popBlockScope(final Block block) {
1303 final Label breakLabel = block.getBreakLabel();
1304
1305 if (block.providesScopeCreator()) {
1306 scopeObjectCreators.pop();
1307 }
1308 if(!block.needsScope() || lc.isFunctionBody()) {
1309 emitBlockBreakLabel(breakLabel);
1310 return;
1311 }
1312
1313 final Label beginTryLabel = scopeEntryLabels.pop();
1314 final Label recoveryLabel = new Label("block_popscope_catch");
1315 emitBlockBreakLabel(breakLabel);
1316 final boolean bodyCanThrow = breakLabel.isAfter(beginTryLabel);
1317 if(bodyCanThrow) {
1318 method._try(beginTryLabel, breakLabel, recoveryLabel);
1319 }
1320
1321 Label afterCatchLabel = null;
1322
1323 if(method.isReachable()) {
1324 popScope();
1325 if(bodyCanThrow) {
1326 afterCatchLabel = new Label("block_after_catch");
1327 method._goto(afterCatchLabel);
1328 }
1329 }
1330
1331 if(bodyCanThrow) {
1332 assert !method.isReachable();
1333 method._catch(recoveryLabel);
1334 popScopeException();
1335 method.athrow();
1336 }
1337 if(afterCatchLabel != null) {
1338 method.label(afterCatchLabel);
1339 }
1340 }
1341
1342 private void emitBlockBreakLabel(final Label breakLabel) {
1343 // TODO: this is totally backwards. Block should not be breakable, LabelNode should be breakable.
1344 final LabelNode labelNode = lc.getCurrentBlockLabelNode();
1345 if(labelNode != null) {
1346 // Only have conversions if we're reachable
1347 assert labelNode.getLocalVariableConversion() == null || method.isReachable();
1348 method.beforeJoinPoint(labelNode);
1349 method.breakLabel(breakLabel, labeledBlockBreakLiveLocals.pop());
1350 } else {
1351 method.label(breakLabel);
1352 }
1353 }
1354
1355 private void popScope() {
1356 popScopes(1);
1357 }
1358
1359 /**
1360 * Pop scope as part of an exception handler. Similar to {@code popScope()} but also takes care of adjusting the
1361 * number of scopes that needs to be popped in case a rest-of continuation handler encounters an exception while
1362 * performing a ToPrimitive conversion.
1363 */
1364 private void popScopeException() {
1365 popScope();
1366 final ContinuationInfo ci = getContinuationInfo();
1367 if(ci != null) {
1368 final Label catchLabel = ci.catchLabel;
1369 if(catchLabel != METHOD_BOUNDARY && catchLabel == catchLabels.peek()) {
1370 ++ci.exceptionScopePops;
1371 }
1372 }
1373 }
1374
1375 private void popScopesUntil(final LexicalContextNode until) {
1376 popScopes(lc.getScopeNestingLevelTo(until));
1377 }
1378
1379 private void popScopes(final int count) {
1380 if(count == 0) {
1381 return;
1382 }
1383 assert count > 0; // together with count == 0 check, asserts nonnegative count
1384 if (!method.hasScope()) {
1385 // We can sometimes invoke this method even if the method has no slot for the scope object. Typical example:
1386 // for(;;) { with({}) { break; } }. WithNode normally creates a scope, but if it uses no identifiers and
1387 // nothing else forces creation of a scope in the method, we just won't have the :scope local variable.
1388 return;
1389 }
1390 method.loadCompilerConstant(SCOPE);
1391 invokeGetProto(count);
1392 method.storeCompilerConstant(SCOPE);
1393 }
1394
1395 @Override
1396 public boolean enterBreakNode(final BreakNode breakNode) {
1397 return enterJumpStatement(breakNode);
1398 }
1399
1400 @Override
1401 public boolean enterJumpToInlinedFinally(final JumpToInlinedFinally jumpToInlinedFinally) {
1402 return enterJumpStatement(jumpToInlinedFinally);
1403 }
1404
1405 private boolean enterJumpStatement(final JumpStatement jump) {
1406 if(!method.isReachable()) {
1407 return false;
1408 }
1409 enterStatement(jump);
1410
1411 method.beforeJoinPoint(jump);
1412 popScopesUntil(jump.getPopScopeLimit(lc));
1413 final Label targetLabel = jump.getTargetLabel(lc);
1414 targetLabel.markAsBreakTarget();
1415 method._goto(targetLabel);
1416
1417 return false;
1418 }
1419
1420 private int loadArgs(final List<Expression> args) {
1421 final int argCount = args.size();
1422 // arg have already been converted to objects here.
1423 if (argCount > LinkerCallSite.ARGLIMIT) {
1424 loadArgsArray(args);
1425 return 1;
1426 }
1427
1428 for (final Expression arg : args) {
1429 assert arg != null;
1430 loadExpressionUnbounded(arg);
1431 }
1432 return argCount;
1433 }
1434
1435 private boolean loadCallNode(final CallNode callNode, final TypeBounds resultBounds) {
1436 lineNumber(callNode.getLineNumber());
1437
1438 final List<Expression> args = callNode.getArgs();
1439 final Expression function = callNode.getFunction();
1440 final Block currentBlock = lc.getCurrentBlock();
1441 final CodeGeneratorLexicalContext codegenLexicalContext = lc;
1442
1443 function.accept(new SimpleNodeVisitor() {
1444
1445 private MethodEmitter sharedScopeCall(final IdentNode identNode, final int flags) {
1446 final Symbol symbol = identNode.getSymbol();
1447 assert isFastScope(symbol);
1448
1449 new OptimisticOperation(callNode, resultBounds) {
1450 @Override
1451 void loadStack() {
1452 method.loadCompilerConstant(SCOPE);
1453 final int depth = getScopeProtoDepth(currentBlock, symbol);
1454 assert depth >= 0;
1455 method.load(depth);
1456 method.load(getProgramPoint());
1457 loadArgs(args);
1458 }
1459
1460 @Override
1461 void consumeStack() {
1462 final Type[] paramTypes = method.getTypesFromStack(args.size());
1463 // We have trouble finding e.g. in Type.typeFor(asm.Type) because it can't see the Context class
1464 // loader, so we need to weaken reference signatures to Object.
1465 for(int i = 0; i < paramTypes.length; ++i) {
1466 paramTypes[i] = Type.generic(paramTypes[i]);
1467 }
1468
1469 final Type resultType = isOptimistic ? getOptimisticCoercedType() : resultBounds.widest;
1470 final SharedScopeCall scopeCall = codegenLexicalContext.getScopeCall(unit, symbol,
1471 identNode.getType(), resultType, paramTypes, flags, isOptimistic);
1472 scopeCall.generateInvoke(method);
1473 }
1474 }.emit();
1475
1476 return method;
1477 }
1478
1479 private void scopeCall(final IdentNode ident, final int flags) {
1480 new OptimisticOperation(callNode, resultBounds) {
1481 int argsCount;
1482 @Override
1483 void loadStack() {
1484 loadExpressionAsObject(ident); // foo() makes no sense if foo == 3
1485 // ScriptFunction will see CALLSITE_SCOPE and will bind scope accordingly.
1486 method.loadUndefined(Type.OBJECT); //the 'this'
1487 argsCount = loadArgs(args);
1488 }
1489 @Override
1490 void consumeStack() {
1491 dynamicCall(2 + argsCount, flags, ident.getName());
1492 }
1493 }.emit();
1494 }
1495
1496 private void evalCall(final IdentNode ident, final int flags) {
1497 final Label invoke_direct_eval = new Label("invoke_direct_eval");
1498 final Label is_not_eval = new Label("is_not_eval");
1499 final Label eval_done = new Label("eval_done");
1500
1501 new OptimisticOperation(callNode, resultBounds) {
1502 int argsCount;
1503 @Override
1504 void loadStack() {
1505 /*
1506 * We want to load 'eval' to check if it is indeed global builtin eval.
1507 * If this eval call is inside a 'with' statement, GET_METHOD_PROPERTY
1508 * would be generated if ident is a "isFunction". But, that would result in a
1509 * bound function from WithObject. We don't want that as bound function as that
1510 * won't be detected as builtin eval. So, we make ident as "not a function" which
1511 * results in GET_PROPERTY being generated and so WithObject
1512 * would return unbounded eval function.
1513 *
1514 * Example:
1515 *
1516 * var global = this;
1517 * function func() {
1518 * with({ eval: global.eval) { eval("var x = 10;") }
1519 * }
1520 */
1521 loadExpressionAsObject(ident.setIsNotFunction()); // Type.OBJECT as foo() makes no sense if foo == 3
1522 globalIsEval();
1523 method.ifeq(is_not_eval);
1524
1525 // Load up self (scope).
1526 method.loadCompilerConstant(SCOPE);
1527 final List<Expression> evalArgs = callNode.getEvalArgs().getArgs();
1528 // load evaluated code
1529 loadExpressionAsObject(evalArgs.get(0));
1530 // load second and subsequent args for side-effect
1531 final int numArgs = evalArgs.size();
1532 for (int i = 1; i < numArgs; i++) {
1533 loadAndDiscard(evalArgs.get(i));
1534 }
1535 method._goto(invoke_direct_eval);
1536
1537 method.label(is_not_eval);
1538 // load this time but with GET_METHOD_PROPERTY
1539 loadExpressionAsObject(ident); // Type.OBJECT as foo() makes no sense if foo == 3
1540 // This is some scope 'eval' or global eval replaced by user
1541 // but not the built-in ECMAScript 'eval' function call
1542 method.loadNull();
1543 argsCount = loadArgs(callNode.getArgs());
1544 }
1545
1546 @Override
1547 void consumeStack() {
1548 // Ordinary call
1549 dynamicCall(2 + argsCount, flags, "eval");
1550 method._goto(eval_done);
1551
1552 method.label(invoke_direct_eval);
1553 // Special/extra 'eval' arguments. These can be loaded late (in consumeStack) as we know none of
1554 // them can ever be optimistic.
1555 method.loadCompilerConstant(THIS);
1556 method.load(callNode.getEvalArgs().getLocation());
1557 method.load(CodeGenerator.this.lc.getCurrentFunction().isStrict());
1558 // direct call to Global.directEval
1559 globalDirectEval();
1560 convertOptimisticReturnValue();
1561 coerceStackTop(resultBounds);
1562 }
1563 }.emit();
1564
1565 method.label(eval_done);
1566 }
1567
1568 @Override
1569 public boolean enterIdentNode(final IdentNode node) {
1570 final Symbol symbol = node.getSymbol();
1571
1572 if (symbol.isScope()) {
1573 final int flags = getScopeCallSiteFlags(symbol);
1574 final int useCount = symbol.getUseCount();
1575
1576 // We only use shared scope calls for fast scopes
1577 if (callNode.isEval()) {
1578 evalCall(node, flags);
1579 } else if (!isFastScope(symbol) || symbol.getUseCount() < SharedScopeCall.SHARED_CALL_THRESHOLD) {
1580 scopeCall(node, flags);
1581 } else {
1582 sharedScopeCall(node, flags);
1583 }
1584 assert method.peekType().equals(resultBounds.within(callNode.getType())) : method.peekType() + " != " + resultBounds + "(" + callNode.getType() + ")";
1585 } else {
1586 enterDefault(node);
1587 }
1588
1589 return false;
1590 }
1591
1592 @Override
1593 public boolean enterAccessNode(final AccessNode node) {
1594 //check if this is an apply to call node. only real applies, that haven't been
1595 //shadowed from their way to the global scope counts
1596
1597 //call nodes have program points.
1598
1599 final int flags = getCallSiteFlags() | (callNode.isApplyToCall() ? CALLSITE_APPLY_TO_CALL : 0);
1600
1601 new OptimisticOperation(callNode, resultBounds) {
1602 int argCount;
1603 @Override
1604 void loadStack() {
1605 loadExpressionAsObject(node.getBase());
1606 method.dup();
1607 // NOTE: not using a nested OptimisticOperation on this dynamicGet, as we expect to get back
1608 // a callable object. Nobody in their right mind would optimistically type this call site.
1609 assert !node.isOptimistic();
1610 method.dynamicGet(node.getType(), node.getProperty(), flags, true, node.isIndex());
1611 method.swap();
1612 argCount = loadArgs(args);
1613 }
1614 @Override
1615 void consumeStack() {
1616 dynamicCall(2 + argCount, flags, node.toString(false));
1617 }
1618 }.emit();
1619
1620 return false;
1621 }
1622
1623 @Override
1624 public boolean enterFunctionNode(final FunctionNode origCallee) {
1625 new OptimisticOperation(callNode, resultBounds) {
1626 FunctionNode callee;
1627 int argsCount;
1628 @Override
1629 void loadStack() {
1630 callee = (FunctionNode)origCallee.accept(CodeGenerator.this);
1631 if (callee.isStrict()) { // "this" is undefined
1632 method.loadUndefined(Type.OBJECT);
1633 } else { // get global from scope (which is the self)
1634 globalInstance();
1635 }
1636 argsCount = loadArgs(args);
1637 }
1638
1639 @Override
1640 void consumeStack() {
1641 dynamicCall(2 + argsCount, getCallSiteFlags(), null);
1642 }
1643 }.emit();
1644 return false;
1645 }
1646
1647 @Override
1648 public boolean enterIndexNode(final IndexNode node) {
1649 new OptimisticOperation(callNode, resultBounds) {
1650 int argsCount;
1651 @Override
1652 void loadStack() {
1653 loadExpressionAsObject(node.getBase());
1654 method.dup();
1655 final Type indexType = node.getIndex().getType();
1656 if (indexType.isObject() || indexType.isBoolean()) {
1657 loadExpressionAsObject(node.getIndex()); //TODO boolean
1658 } else {
1659 loadExpressionUnbounded(node.getIndex());
1660 }
1661 // NOTE: not using a nested OptimisticOperation on this dynamicGetIndex, as we expect to get
1662 // back a callable object. Nobody in their right mind would optimistically type this call site.
1663 assert !node.isOptimistic();
1664 method.dynamicGetIndex(node.getType(), getCallSiteFlags(), true);
1665 method.swap();
1666 argsCount = loadArgs(args);
1667 }
1668 @Override
1669 void consumeStack() {
1670 dynamicCall(2 + argsCount, getCallSiteFlags(), node.toString(false));
1671 }
1672 }.emit();
1673 return false;
1674 }
1675
1676 @Override
1677 protected boolean enterDefault(final Node node) {
1678 new OptimisticOperation(callNode, resultBounds) {
1679 int argsCount;
1680 @Override
1681 void loadStack() {
1682 // Load up function.
1683 loadExpressionAsObject(function); //TODO, e.g. booleans can be used as functions
1684 method.loadUndefined(Type.OBJECT); // ScriptFunction will figure out the correct this when it sees CALLSITE_SCOPE
1685 argsCount = loadArgs(args);
1686 }
1687 @Override
1688 void consumeStack() {
1689 final int flags = getCallSiteFlags() | CALLSITE_SCOPE;
1690 dynamicCall(2 + argsCount, flags, node.toString(false));
1691 }
1692 }.emit();
1693 return false;
1694 }
1695 });
1696
1697 return false;
1698 }
1699
1700 /**
1701 * Returns the flags with optimistic flag and program point removed.
1702 * @param flags the flags that need optimism stripped from them.
1703 * @return flags without optimism
1704 */
1705 static int nonOptimisticFlags(final int flags) {
1706 return flags & ~(CALLSITE_OPTIMISTIC | -1 << CALLSITE_PROGRAM_POINT_SHIFT);
1707 }
1708
1709 @Override
1710 public boolean enterContinueNode(final ContinueNode continueNode) {
1711 return enterJumpStatement(continueNode);
1712 }
1713
1714 @Override
1715 public boolean enterEmptyNode(final EmptyNode emptyNode) {
1716 // Don't even record the line number, it's irrelevant as there's no code.
1717 return false;
1718 }
1719
1720 @Override
1721 public boolean enterExpressionStatement(final ExpressionStatement expressionStatement) {
1722 if(!method.isReachable()) {
1723 return false;
1724 }
1725 enterStatement(expressionStatement);
1726
1727 loadAndDiscard(expressionStatement.getExpression());
1728 assert method.getStackSize() == 0 : "stack not empty in " + expressionStatement;
1729
1730 return false;
1731 }
1732
1733 @Override
1734 public boolean enterBlockStatement(final BlockStatement blockStatement) {
1735 if(!method.isReachable()) {
1736 return false;
1737 }
1738 enterStatement(blockStatement);
1739
1740 blockStatement.getBlock().accept(this);
1741
1742 return false;
1743 }
1744
1745 @Override
1746 public boolean enterForNode(final ForNode forNode) {
1747 if(!method.isReachable()) {
1748 return false;
1749 }
1750 enterStatement(forNode);
1751 if (forNode.isForInOrOf()) {
1752 enterForIn(forNode);
1753 } else {
1754 final Expression init = forNode.getInit();
1755 if (init != null) {
1756 loadAndDiscard(init);
1757 }
1758 enterForOrWhile(forNode, forNode.getModify());
1759 }
1760
1761 return false;
1762 }
1763
1764 private void enterForIn(final ForNode forNode) {
1765 loadExpression(forNode.getModify(), TypeBounds.OBJECT);
1766 if (forNode.isForEach()) {
1767 method.invoke(ScriptRuntime.TO_VALUE_ITERATOR);
1768 } else if (forNode.isForIn()) {
1769 method.invoke(ScriptRuntime.TO_PROPERTY_ITERATOR);
1770 } else if (forNode.isForOf()) {
1771 method.invoke(ScriptRuntime.TO_ES6_ITERATOR);
1772 } else {
1773 throw new IllegalArgumentException("Unexpected for node");
1774 }
1775 final Symbol iterSymbol = forNode.getIterator();
1776 final int iterSlot = iterSymbol.getSlot(Type.OBJECT);
1777 method.store(iterSymbol, ITERATOR_TYPE);
1778
1779 method.beforeJoinPoint(forNode);
1780
1781 final Label continueLabel = forNode.getContinueLabel();
1782 final Label breakLabel = forNode.getBreakLabel();
1783
1784 method.label(continueLabel);
1785 method.load(ITERATOR_TYPE, iterSlot);
1786 method.invoke(interfaceCallNoLookup(ITERATOR_CLASS, "hasNext", boolean.class));
1787 final JoinPredecessorExpression test = forNode.getTest();
1788 final Block body = forNode.getBody();
1789 if(LocalVariableConversion.hasLiveConversion(test)) {
1790 final Label afterConversion = new Label("for_in_after_test_conv");
1791 method.ifne(afterConversion);
1792 method.beforeJoinPoint(test);
1793 method._goto(breakLabel);
1794 method.label(afterConversion);
1795 } else {
1796 method.ifeq(breakLabel);
1797 }
1798
1799 new Store<Expression>(forNode.getInit()) {
1800 @Override
1801 protected void storeNonDiscard() {
1802 // This expression is neither part of a discard, nor needs to be left on the stack after it was
1803 // stored, so we override storeNonDiscard to be a no-op.
1804 }
1805
1806 @Override
1807 protected void evaluate() {
1808 new OptimisticOperation((Optimistic)forNode.getInit(), TypeBounds.UNBOUNDED) {
1809 @Override
1810 void loadStack() {
1811 method.load(ITERATOR_TYPE, iterSlot);
1812 }
1813
1814 @Override
1815 void consumeStack() {
1816 method.invoke(interfaceCallNoLookup(ITERATOR_CLASS, "next", Object.class));
1817 convertOptimisticReturnValue();
1818 }
1819 }.emit();
1820 }
1821 }.store();
1822 body.accept(this);
1823
1824 if (forNode.needsScopeCreator() && lc.getCurrentBlock().providesScopeCreator()) {
1825 // for-in loops with lexical declaration need a new scope for each iteration.
1826 final FieldObjectCreator<?> creator = scopeObjectCreators.peek();
1827 assert creator != null;
1828 creator.createForInIterationScope(method);
1829 method.storeCompilerConstant(SCOPE);
1830 }
1831
1832 if(method.isReachable()) {
1833 method._goto(continueLabel);
1834 }
1835 method.label(breakLabel);
1836 }
1837
1838 /**
1839 * Initialize the slots in a frame to undefined.
1840 *
1841 * @param block block with local vars.
1842 */
1843 private void initLocals(final Block block) {
1844 lc.onEnterBlock(block);
1845
1846 final boolean isFunctionBody = lc.isFunctionBody();
1847 final FunctionNode function = lc.getCurrentFunction();
1848 if (isFunctionBody) {
1849 initializeMethodParameters(function);
1850 if(!function.isVarArg()) {
1851 expandParameterSlots(function);
1852 }
1853 if (method.hasScope()) {
1854 if (function.needsParentScope()) {
1855 method.loadCompilerConstant(CALLEE);
1856 method.invoke(ScriptFunction.GET_SCOPE);
1857 } else {
1858 assert function.hasScopeBlock();
1859 method.loadNull();
1860 }
1861 method.storeCompilerConstant(SCOPE);
1862 }
1863 if (function.needsArguments()) {
1864 initArguments(function);
1865 }
1866 }
1867
1868 /*
1869 * Determine if block needs scope, if not, just do initSymbols for this block.
1870 */
1871 if (block.needsScope()) {
1872 /*
1873 * Determine if function is varargs and consequently variables have to
1874 * be in the scope.
1875 */
1876 final boolean varsInScope = function.allVarsInScope();
1877
1878 // TODO for LET we can do better: if *block* does not contain any eval/with, we don't need its vars in scope.
1879
1880 final boolean hasArguments = function.needsArguments();
1881 final List<MapTuple<Symbol>> tuples = new ArrayList<>();
1882 final Iterator<IdentNode> paramIter = function.getParameters().iterator();
1883 for (final Symbol symbol : block.getSymbols()) {
1884 if (symbol.isInternal() || symbol.isThis()) {
1885 continue;
1886 }
1887
1888 if (symbol.isVar()) {
1889 assert !varsInScope || symbol.isScope();
1890 if (varsInScope || symbol.isScope()) {
1891 assert symbol.isScope() : "scope for " + symbol + " should have been set in Lower already " + function.getName();
1892 assert !symbol.hasSlot() : "slot for " + symbol + " should have been removed in Lower already" + function.getName();
1893
1894 //this tuple will not be put fielded, as it has no value, just a symbol
1895 tuples.add(new MapTuple<Symbol>(symbol.getName(), symbol, null));
1896 } else {
1897 assert symbol.hasSlot() || symbol.slotCount() == 0 : symbol + " should have a slot only, no scope";
1898 }
1899 } else if (symbol.isParam() && (varsInScope || hasArguments || symbol.isScope())) {
1900 assert symbol.isScope() : "scope for " + symbol + " should have been set in AssignSymbols already " + function.getName() + " varsInScope="+varsInScope+" hasArguments="+hasArguments+" symbol.isScope()=" + symbol.isScope();
1901 assert !(hasArguments && symbol.hasSlot()) : "slot for " + symbol + " should have been removed in Lower already " + function.getName();
1902
1903 final Type paramType;
1904 final Symbol paramSymbol;
1905
1906 if (hasArguments) {
1907 assert !symbol.hasSlot() : "slot for " + symbol + " should have been removed in Lower already ";
1908 paramSymbol = null;
1909 paramType = null;
1910 } else {
1911 paramSymbol = symbol;
1912 // NOTE: We're relying on the fact here that Block.symbols is a LinkedHashMap, hence it will
1913 // return symbols in the order they were defined, and parameters are defined in the same order
1914 // they appear in the function. That's why we can have a single pass over the parameter list
1915 // with an iterator, always just scanning forward for the next parameter that matches the symbol
1916 // name.
1917 for(;;) {
1918 final IdentNode nextParam = paramIter.next();
1919 if(nextParam.getName().equals(symbol.getName())) {
1920 paramType = nextParam.getType();
1921 break;
1922 }
1923 }
1924 }
1925
1926 tuples.add(new MapTuple<Symbol>(symbol.getName(), symbol, paramType, paramSymbol) {
1927 //this symbol will be put fielded, we can't initialize it as undefined with a known type
1928 @Override
1929 public Class<?> getValueType() {
1930 if (!useDualFields() || value == null || paramType == null || paramType.isBoolean()) {
1931 return Object.class;
1932 }
1933 return paramType.getTypeClass();
1934 }
1935 });
1936 }
1937 }
1938
1939 /*
1940 * Create a new object based on the symbols and values, generate
1941 * bootstrap code for object
1942 */
1943 final FieldObjectCreator<Symbol> creator = new FieldObjectCreator<Symbol>(this, tuples, true, hasArguments) {
1944 @Override
1945 protected void loadValue(final Symbol value, final Type type) {
1946 method.load(value, type);
1947 }
1948 };
1949 creator.makeObject(method);
1950 if (block.providesScopeCreator()) {
1951 scopeObjectCreators.push(creator);
1952 }
1953 // program function: merge scope into global
1954 if (isFunctionBody && function.isProgram()) {
1955 method.invoke(ScriptRuntime.MERGE_SCOPE);
1956 }
1957
1958 method.storeCompilerConstant(SCOPE);
1959 if(!isFunctionBody) {
1960 // Function body doesn't need a try/catch to restore scope, as it'd be a dead store anyway. Allowing it
1961 // actually causes issues with UnwarrantedOptimismException handlers as ASM will sort this handler to
1962 // the top of the exception handler table, so it'll be triggered instead of the UOE handlers.
1963 final Label scopeEntryLabel = new Label("scope_entry");
1964 scopeEntryLabels.push(scopeEntryLabel);
1965 method.label(scopeEntryLabel);
1966 }
1967 } else if (isFunctionBody && function.isVarArg()) {
1968 // Since we don't have a scope, parameters didn't get assigned array indices by the FieldObjectCreator, so
1969 // we need to assign them separately here.
1970 int nextParam = 0;
1971 for (final IdentNode param : function.getParameters()) {
1972 param.getSymbol().setFieldIndex(nextParam++);
1973 }
1974 }
1975
1976 // Debugging: print symbols? @see --print-symbols flag
1977 printSymbols(block, function, (isFunctionBody ? "Function " : "Block in ") + (function.getIdent() == null ? "<anonymous>" : function.getIdent().getName()));
1978 }
1979
1980 /**
1981 * Incoming method parameters are always declared on method entry; declare them in the local variable table.
1982 * @param function function for which code is being generated.
1983 */
1984 private void initializeMethodParameters(final FunctionNode function) {
1985 final Label functionStart = new Label("fn_start");
1986 method.label(functionStart);
1987 int nextSlot = 0;
1988 if(function.needsCallee()) {
1989 initializeInternalFunctionParameter(CALLEE, function, functionStart, nextSlot++);
1990 }
1991 initializeInternalFunctionParameter(THIS, function, functionStart, nextSlot++);
1992 if(function.isVarArg()) {
1993 initializeInternalFunctionParameter(VARARGS, function, functionStart, nextSlot++);
1994 } else {
1995 for(final IdentNode param: function.getParameters()) {
1996 final Symbol symbol = param.getSymbol();
1997 if(symbol.isBytecodeLocal()) {
1998 method.initializeMethodParameter(symbol, param.getType(), functionStart);
1999 }
2000 }
2001 }
2002 }
2003
2004 private void initializeInternalFunctionParameter(final CompilerConstants cc, final FunctionNode fn, final Label functionStart, final int slot) {
2005 final Symbol symbol = initializeInternalFunctionOrSplitParameter(cc, fn, functionStart, slot);
2006 // Internal function params (:callee, this, and :varargs) are never expanded to multiple slots
2007 assert symbol.getFirstSlot() == slot;
2008 }
2009
2010 private Symbol initializeInternalFunctionOrSplitParameter(final CompilerConstants cc, final FunctionNode fn, final Label functionStart, final int slot) {
2011 final Symbol symbol = fn.getBody().getExistingSymbol(cc.symbolName());
2012 final Type type = Type.typeFor(cc.type());
2013 method.initializeMethodParameter(symbol, type, functionStart);
2014 method.onLocalStore(type, slot);
2015 return symbol;
2016 }
2017
2018 /**
2019 * Parameters come into the method packed into local variable slots next to each other. Nashorn on the other hand
2020 * can use 1-6 slots for a local variable depending on all the types it needs to store. When this method is invoked,
2021 * the symbols are already allocated such wider slots, but the values are still in tightly packed incoming slots,
2022 * and we need to spread them into their new locations.
2023 * @param function the function for which parameter-spreading code needs to be emitted
2024 */
2025 private void expandParameterSlots(final FunctionNode function) {
2026 final List<IdentNode> parameters = function.getParameters();
2027 // Calculate the total number of incoming parameter slots
2028 int currentIncomingSlot = function.needsCallee() ? 2 : 1;
2029 for(final IdentNode parameter: parameters) {
2030 currentIncomingSlot += parameter.getType().getSlots();
2031 }
2032 // Starting from last parameter going backwards, move the parameter values into their new slots.
2033 for(int i = parameters.size(); i-- > 0;) {
2034 final IdentNode parameter = parameters.get(i);
2035 final Type parameterType = parameter.getType();
2036 final int typeWidth = parameterType.getSlots();
2037 currentIncomingSlot -= typeWidth;
2038 final Symbol symbol = parameter.getSymbol();
2039 final int slotCount = symbol.slotCount();
2040 assert slotCount > 0;
2041 // Scoped parameters must not hold more than one value
2042 assert symbol.isBytecodeLocal() || slotCount == typeWidth;
2043
2044 // Mark it as having its value stored into it by the method invocation.
2045 method.onLocalStore(parameterType, currentIncomingSlot);
2046 if(currentIncomingSlot != symbol.getSlot(parameterType)) {
2047 method.load(parameterType, currentIncomingSlot);
2048 method.store(symbol, parameterType);
2049 }
2050 }
2051 }
2052
2053 private void initArguments(final FunctionNode function) {
2054 method.loadCompilerConstant(VARARGS);
2055 if (function.needsCallee()) {
2056 method.loadCompilerConstant(CALLEE);
2057 } else {
2058 // If function is strict mode, "arguments.callee" is not populated, so we don't necessarily need the
2059 // caller.
2060 assert function.isStrict();
2061 method.loadNull();
2062 }
2063 method.load(function.getParameters().size());
2064 globalAllocateArguments();
2065 method.storeCompilerConstant(ARGUMENTS);
2066 }
2067
2068 private boolean skipFunction(final FunctionNode functionNode) {
2069 final ScriptEnvironment env = compiler.getScriptEnvironment();
2070 final boolean lazy = env._lazy_compilation;
2071 final boolean onDemand = compiler.isOnDemandCompilation();
2072
2073 // If this is on-demand or lazy compilation, don't compile a nested (not topmost) function.
2074 if((onDemand || lazy) && lc.getOutermostFunction() != functionNode) {
2075 return true;
2076 }
2077
2078 // If lazy compiling with optimistic types, don't compile the program eagerly either. It will soon be
2079 // invalidated anyway. In presence of a class cache, this further means that an obsoleted program version
2080 // lingers around. Also, currently loading previously persisted optimistic types information only works if
2081 // we're on-demand compiling a function, so with this strategy the :program method can also have the warmup
2082 // benefit of using previously persisted types.
2083 //
2084 // NOTE that this means the first compiled class will effectively just have a :createProgramFunction method, and
2085 // the RecompilableScriptFunctionData (RSFD) object in its constants array. It won't even have the :program
2086 // method. This is by design. It does mean that we're wasting one compiler execution (and we could minimize this
2087 // by just running it up to scope depth calculation, which creates the RSFDs and then this limited codegen).
2088 // We could emit an initial separate compile unit with the initial version of :program in it to better utilize
2089 // the compilation pipeline, but that would need more invasive changes, as currently the assumption that
2090 // :program is emitted into the first compilation unit of the function lives in many places.
2091 return !onDemand && lazy && env._optimistic_types && functionNode.isProgram();
2092 }
2093
2094 @Override
2095 public boolean enterFunctionNode(final FunctionNode functionNode) {
2096 if (skipFunction(functionNode)) {
2097 // In case we are not generating code for the function, we must create or retrieve the function object and
2098 // load it on the stack here.
2099 newFunctionObject(functionNode, false);
2100 return false;
2101 }
2102
2103 final String fnName = functionNode.getName();
2104
2105 // NOTE: we only emit the method for a function with the given name once. We can have multiple functions with
2106 // the same name as a result of inlining finally blocks. However, in the future -- with type specialization,
2107 // notably -- we might need to check for both name *and* signature. Of course, even that might not be
2108 // sufficient; the function might have a code dependency on the type of the variables in its enclosing scopes,
2109 // and the type of such a variable can be different in catch and finally blocks. So, in the future we will have
2110 // to decide to either generate a unique method for each inlined copy of the function, maybe figure out its
2111 // exact type closure and deduplicate based on that, or just decide that functions in finally blocks aren't
2112 // worth it, and generate one method with most generic type closure.
2113 if (!emittedMethods.contains(fnName)) {
2114 log.info("=== BEGIN ", fnName);
2115
2116 assert functionNode.getCompileUnit() != null : "no compile unit for " + fnName + " " + Debug.id(functionNode);
2117 unit = lc.pushCompileUnit(functionNode.getCompileUnit());
2118 assert lc.hasCompileUnits();
2119
2120 final ClassEmitter classEmitter = unit.getClassEmitter();
2121 pushMethodEmitter(isRestOf() ? classEmitter.restOfMethod(functionNode) : classEmitter.method(functionNode));
2122 method.setPreventUndefinedLoad();
2123 if(useOptimisticTypes()) {
2124 lc.pushUnwarrantedOptimismHandlers();
2125 }
2126
2127 // new method - reset last line number
2128 lastLineNumber = -1;
2129
2130 method.begin();
2131
2132 if (isRestOf()) {
2133 assert continuationInfo == null;
2134 continuationInfo = new ContinuationInfo();
2135 method.gotoLoopStart(continuationInfo.getHandlerLabel());
2136 }
2137 }
2138
2139 return true;
2140 }
2141
2142 private void pushMethodEmitter(final MethodEmitter newMethod) {
2143 method = lc.pushMethodEmitter(newMethod);
2144 catchLabels.push(METHOD_BOUNDARY);
2145 }
2146
2147 private void popMethodEmitter() {
2148 method = lc.popMethodEmitter(method);
2149 assert catchLabels.peek() == METHOD_BOUNDARY;
2150 catchLabels.pop();
2151 }
2152
2153 @Override
2154 public Node leaveFunctionNode(final FunctionNode functionNode) {
2155 try {
2156 final boolean markOptimistic;
2157 if (emittedMethods.add(functionNode.getName())) {
2158 markOptimistic = generateUnwarrantedOptimismExceptionHandlers(functionNode);
2159 generateContinuationHandler();
2160 method.end(); // wrap up this method
2161 unit = lc.popCompileUnit(functionNode.getCompileUnit());
2162 popMethodEmitter();
2163 log.info("=== END ", functionNode.getName());
2164 } else {
2165 markOptimistic = false;
2166 }
2167
2168 FunctionNode newFunctionNode = functionNode;
2169 if (markOptimistic) {
2170 newFunctionNode = newFunctionNode.setFlag(lc, FunctionNode.IS_DEOPTIMIZABLE);
2171 }
2172
2173 newFunctionObject(newFunctionNode, true);
2174 return newFunctionNode;
2175 } catch (final Throwable t) {
2176 Context.printStackTrace(t);
2177 final VerifyError e = new VerifyError("Code generation bug in \"" + functionNode.getName() + "\": likely stack misaligned: " + t + " " + functionNode.getSource().getName());
2178 e.initCause(t);
2179 throw e;
2180 }
2181 }
2182
2183 @Override
2184 public boolean enterIfNode(final IfNode ifNode) {
2185 if(!method.isReachable()) {
2186 return false;
2187 }
2188 enterStatement(ifNode);
2189
2190 final Expression test = ifNode.getTest();
2191 final Block pass = ifNode.getPass();
2192 final Block fail = ifNode.getFail();
2193
2194 if (Expression.isAlwaysTrue(test)) {
2195 loadAndDiscard(test);
2196 pass.accept(this);
2197 return false;
2198 } else if (Expression.isAlwaysFalse(test)) {
2199 loadAndDiscard(test);
2200 if (fail != null) {
2201 fail.accept(this);
2202 }
2203 return false;
2204 }
2205
2206 final boolean hasFailConversion = LocalVariableConversion.hasLiveConversion(ifNode);
2207
2208 final Label failLabel = new Label("if_fail");
2209 final Label afterLabel = (fail == null && !hasFailConversion) ? null : new Label("if_done");
2210
2211 emitBranch(test, failLabel, false);
2212
2213 pass.accept(this);
2214 if(method.isReachable() && afterLabel != null) {
2215 method._goto(afterLabel); //don't fallthru to fail block
2216 }
2217 method.label(failLabel);
2218
2219 if (fail != null) {
2220 fail.accept(this);
2221 } else if(hasFailConversion) {
2222 method.beforeJoinPoint(ifNode);
2223 }
2224
2225 if(afterLabel != null && afterLabel.isReachable()) {
2226 method.label(afterLabel);
2227 }
2228
2229 return false;
2230 }
2231
2232 private void emitBranch(final Expression test, final Label label, final boolean jumpWhenTrue) {
2233 new BranchOptimizer(this, method).execute(test, label, jumpWhenTrue);
2234 }
2235
2236 private void enterStatement(final Statement statement) {
2237 lineNumber(statement);
2238 }
2239
2240 private void lineNumber(final Statement statement) {
2241 lineNumber(statement.getLineNumber());
2242 }
2243
2244 private void lineNumber(final int lineNumber) {
2245 if (lineNumber != lastLineNumber && lineNumber != Node.NO_LINE_NUMBER) {
2246 method.lineNumber(lineNumber);
2247 lastLineNumber = lineNumber;
2248 }
2249 }
2250
2251 int getLastLineNumber() {
2252 return lastLineNumber;
2253 }
2254
2255 /**
2256 * Load a list of nodes as an array of a specific type
2257 * The array will contain the visited nodes.
2258 *
2259 * @param arrayLiteralNode the array of contents
2260 * @param arrayType the type of the array, e.g. ARRAY_NUMBER or ARRAY_OBJECT
2261 */
2262 private void loadArray(final ArrayLiteralNode arrayLiteralNode, final ArrayType arrayType) {
2263 assert arrayType == Type.INT_ARRAY || arrayType == Type.NUMBER_ARRAY || arrayType == Type.OBJECT_ARRAY;
2264
2265 final Expression[] nodes = arrayLiteralNode.getValue();
2266 final Object presets = arrayLiteralNode.getPresets();
2267 final int[] postsets = arrayLiteralNode.getPostsets();
2268 final List<Splittable.SplitRange> ranges = arrayLiteralNode.getSplitRanges();
2269
2270 loadConstant(presets);
2271
2272 final Type elementType = arrayType.getElementType();
2273
2274 if (ranges != null) {
2275
2276 loadSplitLiteral(new SplitLiteralCreator() {
2277 @Override
2278 public void populateRange(final MethodEmitter method, final Type type, final int slot, final int start, final int end) {
2279 for (int i = start; i < end; i++) {
2280 method.load(type, slot);
2281 storeElement(nodes, elementType, postsets[i]);
2282 }
2283 method.load(type, slot);
2284 }
2285 }, ranges, arrayType);
2286
2287 return;
2288 }
2289
2290 if(postsets.length > 0) {
2291 final int arraySlot = method.getUsedSlotsWithLiveTemporaries();
2292 method.storeTemp(arrayType, arraySlot);
2293 for (final int postset : postsets) {
2294 method.load(arrayType, arraySlot);
2295 storeElement(nodes, elementType, postset);
2296 }
2297 method.load(arrayType, arraySlot);
2298 }
2299 }
2300
2301 private void storeElement(final Expression[] nodes, final Type elementType, final int index) {
2302 method.load(index);
2303
2304 final Expression element = nodes[index];
2305
2306 if (element == null) {
2307 method.loadEmpty(elementType);
2308 } else {
2309 loadExpressionAsType(element, elementType);
2310 }
2311
2312 method.arraystore();
2313 }
2314
2315 private MethodEmitter loadArgsArray(final List<Expression> args) {
2316 final Object[] array = new Object[args.size()];
2317 loadConstant(array);
2318
2319 for (int i = 0; i < args.size(); i++) {
2320 method.dup();
2321 method.load(i);
2322 loadExpression(args.get(i), TypeBounds.OBJECT); // variable arity methods always take objects
2323 method.arraystore();
2324 }
2325
2326 return method;
2327 }
2328
2329 /**
2330 * Load a constant from the constant array. This is only public to be callable from the objects
2331 * subpackage. Do not call directly.
2332 *
2333 * @param string string to load
2334 */
2335 void loadConstant(final String string) {
2336 final String unitClassName = unit.getUnitClassName();
2337 final ClassEmitter classEmitter = unit.getClassEmitter();
2338 final int index = compiler.getConstantData().add(string);
2339
2340 method.load(index);
2341 method.invokestatic(unitClassName, GET_STRING.symbolName(), methodDescriptor(String.class, int.class));
2342 classEmitter.needGetConstantMethod(String.class);
2343 }
2344
2345 /**
2346 * Load a constant from the constant array. This is only public to be callable from the objects
2347 * subpackage. Do not call directly.
2348 *
2349 * @param object object to load
2350 */
2351 void loadConstant(final Object object) {
2352 loadConstant(object, unit, method);
2353 }
2354
2355 private void loadConstant(final Object object, final CompileUnit compileUnit, final MethodEmitter methodEmitter) {
2356 final String unitClassName = compileUnit.getUnitClassName();
2357 final ClassEmitter classEmitter = compileUnit.getClassEmitter();
2358 final int index = compiler.getConstantData().add(object);
2359 final Class<?> cls = object.getClass();
2360
2361 if (cls == PropertyMap.class) {
2362 methodEmitter.load(index);
2363 methodEmitter.invokestatic(unitClassName, GET_MAP.symbolName(), methodDescriptor(PropertyMap.class, int.class));
2364 classEmitter.needGetConstantMethod(PropertyMap.class);
2365 } else if (cls.isArray()) {
2366 methodEmitter.load(index);
2367 final String methodName = ClassEmitter.getArrayMethodName(cls);
2368 methodEmitter.invokestatic(unitClassName, methodName, methodDescriptor(cls, int.class));
2369 classEmitter.needGetConstantMethod(cls);
2370 } else {
2371 methodEmitter.loadConstants().load(index).arrayload();
2372 if (object instanceof ArrayData) {
2373 methodEmitter.checkcast(ArrayData.class);
2374 methodEmitter.invoke(virtualCallNoLookup(ArrayData.class, "copy", ArrayData.class));
2375 } else if (cls != Object.class) {
2376 methodEmitter.checkcast(cls);
2377 }
2378 }
2379 }
2380
2381 private void loadConstantsAndIndex(final Object object, final MethodEmitter methodEmitter) {
2382 methodEmitter.loadConstants().load(compiler.getConstantData().add(object));
2383 }
2384
2385 // literal values
2386 private void loadLiteral(final LiteralNode<?> node, final TypeBounds resultBounds) {
2387 final Object value = node.getValue();
2388
2389 if (value == null) {
2390 method.loadNull();
2391 } else if (value instanceof Undefined) {
2392 method.loadUndefined(resultBounds.within(Type.OBJECT));
2393 } else if (value instanceof String) {
2394 final String string = (String)value;
2395
2396 if (string.length() > MethodEmitter.LARGE_STRING_THRESHOLD / 3) { // 3 == max bytes per encoded char
2397 loadConstant(string);
2398 } else {
2399 method.load(string);
2400 }
2401 } else if (value instanceof RegexToken) {
2402 loadRegex((RegexToken)value);
2403 } else if (value instanceof Boolean) {
2404 method.load((Boolean)value);
2405 } else if (value instanceof Integer) {
2406 if(!resultBounds.canBeNarrowerThan(Type.OBJECT)) {
2407 method.load((Integer)value);
2408 method.convert(Type.OBJECT);
2409 } else if(!resultBounds.canBeNarrowerThan(Type.NUMBER)) {
2410 method.load(((Integer)value).doubleValue());
2411 } else {
2412 method.load((Integer)value);
2413 }
2414 } else if (value instanceof Double) {
2415 if(!resultBounds.canBeNarrowerThan(Type.OBJECT)) {
2416 method.load((Double)value);
2417 method.convert(Type.OBJECT);
2418 } else {
2419 method.load((Double)value);
2420 }
2421 } else if (node instanceof ArrayLiteralNode) {
2422 final ArrayLiteralNode arrayLiteral = (ArrayLiteralNode)node;
2423 final ArrayType atype = arrayLiteral.getArrayType();
2424 loadArray(arrayLiteral, atype);
2425 globalAllocateArray(atype);
2426 } else {
2427 throw new UnsupportedOperationException("Unknown literal for " + node.getClass() + " " + value.getClass() + " " + value);
2428 }
2429 }
2430
2431 private MethodEmitter loadRegexToken(final RegexToken value) {
2432 method.load(value.getExpression());
2433 method.load(value.getOptions());
2434 return globalNewRegExp();
2435 }
2436
2437 private MethodEmitter loadRegex(final RegexToken regexToken) {
2438 if (regexFieldCount > MAX_REGEX_FIELDS) {
2439 return loadRegexToken(regexToken);
2440 }
2441 // emit field
2442 final String regexName = lc.getCurrentFunction().uniqueName(REGEX_PREFIX.symbolName());
2443 final ClassEmitter classEmitter = unit.getClassEmitter();
2444
2445 classEmitter.field(EnumSet.of(PRIVATE, STATIC), regexName, Object.class);
2446 regexFieldCount++;
2447
2448 // get field, if null create new regex, finally clone regex object
2449 method.getStatic(unit.getUnitClassName(), regexName, typeDescriptor(Object.class));
2450 method.dup();
2451 final Label cachedLabel = new Label("cached");
2452 method.ifnonnull(cachedLabel);
2453
2454 method.pop();
2455 loadRegexToken(regexToken);
2456 method.dup();
2457 method.putStatic(unit.getUnitClassName(), regexName, typeDescriptor(Object.class));
2458
2459 method.label(cachedLabel);
2460 globalRegExpCopy();
2461
2462 return method;
2463 }
2464
2465 /**
2466 * Check if a property value contains a particular program point
2467 * @param value value
2468 * @param pp program point
2469 * @return true if it's there.
2470 */
2471 private static boolean propertyValueContains(final Expression value, final int pp) {
2472 return new Supplier<Boolean>() {
2473 boolean contains;
2474
2475 @Override
2476 public Boolean get() {
2477 value.accept(new SimpleNodeVisitor() {
2478 @Override
2479 public boolean enterFunctionNode(final FunctionNode functionNode) {
2480 return false;
2481 }
2482
2483 @Override
2484 public boolean enterDefault(final Node node) {
2485 if (contains) {
2486 return false;
2487 }
2488 if (node instanceof Optimistic && ((Optimistic)node).getProgramPoint() == pp) {
2489 contains = true;
2490 return false;
2491 }
2492 return true;
2493 }
2494 });
2495
2496 return contains;
2497 }
2498 }.get();
2499 }
2500
2501 private void loadObjectNode(final ObjectNode objectNode) {
2502 final List<PropertyNode> elements = objectNode.getElements();
2503
2504 final List<MapTuple<Expression>> tuples = new ArrayList<>();
2505 // List below will contain getter/setter properties and properties with computed keys (ES6)
2506 final List<PropertyNode> specialProperties = new ArrayList<>();
2507 final int ccp = getCurrentContinuationEntryPoint();
2508 final List<Splittable.SplitRange> ranges = objectNode.getSplitRanges();
2509
2510 Expression protoNode = null;
2511 boolean restOfProperty = false;
2512
2513 for (final PropertyNode propertyNode : elements) {
2514 final Expression value = propertyNode.getValue();
2515 final String key = propertyNode.getKeyName();
2516 final boolean isComputedOrAccessor = propertyNode.isComputed() || value == null;
2517
2518 // Just use a pseudo-symbol. We just need something non null; use the name and zero flags.
2519 final Symbol symbol = isComputedOrAccessor ? null : new Symbol(key, 0);
2520
2521 if (isComputedOrAccessor) {
2522 // Properties with computed names or getter/setters need special handling.
2523 specialProperties.add(propertyNode);
2524 } else if (propertyNode.getKey() instanceof IdentNode &&
2525 key.equals(ScriptObject.PROTO_PROPERTY_NAME)) {
2526 // ES6 draft compliant __proto__ inside object literal
2527 // Identifier key and name is __proto__
2528 protoNode = value;
2529 continue;
2530 }
2531
2532 restOfProperty |=
2533 value != null &&
2534 isValid(ccp) &&
2535 propertyValueContains(value, ccp);
2536
2537 //for literals, a value of null means object type, i.e. the value null or getter setter function
2538 //(I think)
2539 final Class<?> valueType = (!useDualFields() || isComputedOrAccessor || value.getType().isBoolean()) ? Object.class : value.getType().getTypeClass();
2540 tuples.add(new MapTuple<Expression>(key, symbol, Type.typeFor(valueType), value) {
2541 @Override
2542 public Class<?> getValueType() {
2543 return type.getTypeClass();
2544 }
2545 });
2546 }
2547
2548 final ObjectCreator<?> oc;
2549 if (elements.size() > OBJECT_SPILL_THRESHOLD) {
2550 oc = new SpillObjectCreator(this, tuples);
2551 } else {
2552 oc = new FieldObjectCreator<Expression>(this, tuples) {
2553 @Override
2554 protected void loadValue(final Expression node, final Type type) {
2555 // Use generic type in order to avoid conversion between object types
2556 loadExpressionAsType(node, Type.generic(type));
2557 }};
2558 }
2559
2560 if (ranges != null) {
2561 oc.createObject(method);
2562 loadSplitLiteral(oc, ranges, Type.typeFor(oc.getAllocatorClass()));
2563 } else {
2564 oc.makeObject(method);
2565 }
2566
2567 //if this is a rest of method and our continuation point was found as one of the values
2568 //in the properties above, we need to reset the map to oc.getMap() in the continuation
2569 //handler
2570 if (restOfProperty) {
2571 final ContinuationInfo ci = getContinuationInfo();
2572 ci.setObjectLiteralMap(method.getStackSize(), oc.getMap());
2573 }
2574
2575 method.dup();
2576 if (protoNode != null) {
2577 loadExpressionAsObject(protoNode);
2578 // take care of { __proto__: 34 } or some such!
2579 method.convert(Type.OBJECT);
2580 method.invoke(ScriptObject.SET_PROTO_FROM_LITERAL);
2581 } else {
2582 method.invoke(ScriptObject.SET_GLOBAL_OBJECT_PROTO);
2583 }
2584
2585 for (final PropertyNode propertyNode : specialProperties) {
2586
2587 method.dup();
2588
2589 if (propertyNode.isComputed()) {
2590 assert propertyNode.getKeyName() == null;
2591 loadExpressionAsObject(propertyNode.getKey());
2592 } else {
2593 method.loadKey(propertyNode.getKey());
2594 }
2595
2596 if (propertyNode.getValue() != null) {
2597 loadExpressionAsObject(propertyNode.getValue());
2598 method.load(0);
2599 method.invoke(ScriptObject.GENERIC_SET);
2600 } else {
2601 final FunctionNode getter = propertyNode.getGetter();
2602 final FunctionNode setter = propertyNode.getSetter();
2603
2604 assert getter != null || setter != null;
2605
2606 if (getter == null) {
2607 method.loadNull();
2608 } else {
2609 getter.accept(this);
2610 }
2611
2612 if (setter == null) {
2613 method.loadNull();
2614 } else {
2615 setter.accept(this);
2616 }
2617
2618 method.invoke(ScriptObject.SET_USER_ACCESSORS);
2619 }
2620 }
2621 }
2622
2623 @Override
2624 public boolean enterReturnNode(final ReturnNode returnNode) {
2625 if(!method.isReachable()) {
2626 return false;
2627 }
2628 enterStatement(returnNode);
2629
2630 final Type returnType = lc.getCurrentFunction().getReturnType();
2631
2632 final Expression expression = returnNode.getExpression();
2633 if (expression != null) {
2634 loadExpressionUnbounded(expression);
2635 } else {
2636 method.loadUndefined(returnType);
2637 }
2638
2639 method._return(returnType);
2640
2641 return false;
2642 }
2643
2644 private boolean undefinedCheck(final RuntimeNode runtimeNode, final List<Expression> args) {
2645 final Request request = runtimeNode.getRequest();
2646
2647 if (!Request.isUndefinedCheck(request)) {
2648 return false;
2649 }
2650
2651 final Expression lhs = args.get(0);
2652 final Expression rhs = args.get(1);
2653
2654 final Symbol lhsSymbol = lhs instanceof IdentNode ? ((IdentNode)lhs).getSymbol() : null;
2655 final Symbol rhsSymbol = rhs instanceof IdentNode ? ((IdentNode)rhs).getSymbol() : null;
2656 // One must be a "undefined" identifier, otherwise we can't get here
2657 assert lhsSymbol != null || rhsSymbol != null;
2658
2659 final Symbol undefinedSymbol;
2660 if (isUndefinedSymbol(lhsSymbol)) {
2661 undefinedSymbol = lhsSymbol;
2662 } else {
2663 assert isUndefinedSymbol(rhsSymbol);
2664 undefinedSymbol = rhsSymbol;
2665 }
2666
2667 assert undefinedSymbol != null; //remove warning
2668 if (!undefinedSymbol.isScope()) {
2669 return false; //disallow undefined as local var or parameter
2670 }
2671
2672 if (lhsSymbol == undefinedSymbol && lhs.getType().isPrimitive()) {
2673 //we load the undefined first. never mind, because this will deoptimize anyway
2674 return false;
2675 }
2676
2677 if(containsOptimisticExpression(lhs)) {
2678 // Any optimistic expression within lhs could be deoptimized and trigger a rest-of compilation.
2679 // We must not perform undefined check specialization for them, as then we'd violate the basic rule of
2680 // "Thou shalt not alter the stack shape between a deoptimized method and any of its (transitive) rest-ofs."
2681 return false;
2682 }
2683
2684 //make sure that undefined has not been overridden or scoped as a local var
2685 //between us and global
2686 if (!compiler.isGlobalSymbol(lc.getCurrentFunction(), "undefined")) {
2687 return false;
2688 }
2689
2690 final boolean isUndefinedCheck = request == Request.IS_UNDEFINED;
2691 final Expression expr = undefinedSymbol == lhsSymbol ? rhs : lhs;
2692 if (expr.getType().isPrimitive()) {
2693 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
2694 method.load(!isUndefinedCheck);
2695 } else {
2696 final Label checkTrue = new Label("ud_check_true");
2697 final Label end = new Label("end");
2698 loadExpressionAsObject(expr);
2699 method.loadUndefined(Type.OBJECT);
2700 method.if_acmpeq(checkTrue);
2701 method.load(!isUndefinedCheck);
2702 method._goto(end);
2703 method.label(checkTrue);
2704 method.load(isUndefinedCheck);
2705 method.label(end);
2706 }
2707
2708 return true;
2709 }
2710
2711 private static boolean isUndefinedSymbol(final Symbol symbol) {
2712 return symbol != null && "undefined".equals(symbol.getName());
2713 }
2714
2715 private static boolean isNullLiteral(final Node node) {
2716 return node instanceof LiteralNode<?> && ((LiteralNode<?>) node).isNull();
2717 }
2718
2719 private boolean nullCheck(final RuntimeNode runtimeNode, final List<Expression> args) {
2720 final Request request = runtimeNode.getRequest();
2721
2722 if (!Request.isEQ(request) && !Request.isNE(request)) {
2723 return false;
2724 }
2725
2726 assert args.size() == 2 : "EQ or NE or TYPEOF need two args";
2727
2728 Expression lhs = args.get(0);
2729 Expression rhs = args.get(1);
2730
2731 if (isNullLiteral(lhs)) {
2732 final Expression tmp = lhs;
2733 lhs = rhs;
2734 rhs = tmp;
2735 }
2736
2737 if (!isNullLiteral(rhs)) {
2738 return false;
2739 }
2740
2741 if (!lhs.getType().isObject()) {
2742 return false;
2743 }
2744
2745 if(containsOptimisticExpression(lhs)) {
2746 // Any optimistic expression within lhs could be deoptimized and trigger a rest-of compilation.
2747 // We must not perform null check specialization for them, as then we'd no longer be loading aconst_null
2748 // on stack and thus violate the basic rule of "Thou shalt not alter the stack shape between a deoptimized
2749 // method and any of its (transitive) rest-ofs."
2750 // NOTE also that if we had a representation for well-known constants (e.g. null, 0, 1, -1, etc.) in
2751 // Label$Stack.localLoads then this wouldn't be an issue, as we would never (somewhat ridiculously)
2752 // allocate a temporary local to hold the result of aconst_null before attempting an optimistic
2753 // operation.
2754 return false;
2755 }
2756
2757 // this is a null literal check, so if there is implicit coercion
2758 // involved like {D}x=null, we will fail - this is very rare
2759 final Label trueLabel = new Label("trueLabel");
2760 final Label falseLabel = new Label("falseLabel");
2761 final Label endLabel = new Label("end");
2762
2763 loadExpressionUnbounded(lhs); //lhs
2764 final Label popLabel;
2765 if (!Request.isStrict(request)) {
2766 method.dup(); //lhs lhs
2767 popLabel = new Label("pop");
2768 } else {
2769 popLabel = null;
2770 }
2771
2772 if (Request.isEQ(request)) {
2773 method.ifnull(!Request.isStrict(request) ? popLabel : trueLabel);
2774 if (!Request.isStrict(request)) {
2775 method.loadUndefined(Type.OBJECT);
2776 method.if_acmpeq(trueLabel);
2777 }
2778 method.label(falseLabel);
2779 method.load(false);
2780 method._goto(endLabel);
2781 if (!Request.isStrict(request)) {
2782 method.label(popLabel);
2783 method.pop();
2784 }
2785 method.label(trueLabel);
2786 method.load(true);
2787 method.label(endLabel);
2788 } else if (Request.isNE(request)) {
2789 method.ifnull(!Request.isStrict(request) ? popLabel : falseLabel);
2790 if (!Request.isStrict(request)) {
2791 method.loadUndefined(Type.OBJECT);
2792 method.if_acmpeq(falseLabel);
2793 }
2794 method.label(trueLabel);
2795 method.load(true);
2796 method._goto(endLabel);
2797 if (!Request.isStrict(request)) {
2798 method.label(popLabel);
2799 method.pop();
2800 }
2801 method.label(falseLabel);
2802 method.load(false);
2803 method.label(endLabel);
2804 }
2805
2806 assert runtimeNode.getType().isBoolean();
2807 method.convert(runtimeNode.getType());
2808
2809 return true;
2810 }
2811
2812 /**
2813 * Is this expression or any of its subexpressions optimistic? This includes formerly optimistic
2814 * expressions that have been deoptimized in a subsequent compilation.
2815 *
2816 * @param rootExpr the expression being tested
2817 * @return true if the expression or any of its subexpressions is optimistic in the current compilation.
2818 */
2819 private boolean containsOptimisticExpression(final Expression rootExpr) {
2820 if(!useOptimisticTypes()) {
2821 return false;
2822 }
2823 return new Supplier<Boolean>() {
2824 boolean contains;
2825 @Override
2826 public Boolean get() {
2827 rootExpr.accept(new SimpleNodeVisitor() {
2828 @Override
2829 public boolean enterFunctionNode(final FunctionNode functionNode) {
2830 return false;
2831 }
2832 @Override
2833 public boolean enterDefault(final Node node) {
2834 if(!contains && node instanceof Optimistic) {
2835 final int pp = ((Optimistic)node).getProgramPoint();
2836 contains = isValid(pp);
2837 }
2838 return !contains;
2839 }
2840 });
2841 return contains;
2842 }
2843 }.get();
2844 }
2845
2846 private void loadRuntimeNode(final RuntimeNode runtimeNode) {
2847 final List<Expression> args = new ArrayList<>(runtimeNode.getArgs());
2848 if (nullCheck(runtimeNode, args)) {
2849 return;
2850 } else if(undefinedCheck(runtimeNode, args)) {
2851 return;
2852 }
2853 // Revert a false undefined check to a strict equality check
2854 final RuntimeNode newRuntimeNode;
2855 final Request request = runtimeNode.getRequest();
2856 if (Request.isUndefinedCheck(request)) {
2857 newRuntimeNode = runtimeNode.setRequest(request == Request.IS_UNDEFINED ? Request.EQ_STRICT : Request.NE_STRICT);
2858 } else {
2859 newRuntimeNode = runtimeNode;
2860 }
2861
2862 for (final Expression arg : args) {
2863 loadExpression(arg, TypeBounds.OBJECT);
2864 }
2865
2866 method.invokestatic(
2867 CompilerConstants.className(ScriptRuntime.class),
2868 newRuntimeNode.getRequest().toString(),
2869 new FunctionSignature(
2870 false,
2871 false,
2872 newRuntimeNode.getType(),
2873 args.size()).toString());
2874
2875 method.convert(newRuntimeNode.getType());
2876 }
2877
2878 private void defineCommonSplitMethodParameters() {
2879 defineSplitMethodParameter(0, CALLEE);
2880 defineSplitMethodParameter(1, THIS);
2881 defineSplitMethodParameter(2, SCOPE);
2882 }
2883
2884 private void defineSplitMethodParameter(final int slot, final CompilerConstants cc) {
2885 defineSplitMethodParameter(slot, Type.typeFor(cc.type()));
2886 }
2887
2888 private void defineSplitMethodParameter(final int slot, final Type type) {
2889 method.defineBlockLocalVariable(slot, slot + type.getSlots());
2890 method.onLocalStore(type, slot);
2891 }
2892
2893 private void loadSplitLiteral(final SplitLiteralCreator creator, final List<Splittable.SplitRange> ranges, final Type literalType) {
2894 assert ranges != null;
2895
2896 // final Type literalType = Type.typeFor(literalClass);
2897 final MethodEmitter savedMethod = method;
2898 final FunctionNode currentFunction = lc.getCurrentFunction();
2899
2900 for (final Splittable.SplitRange splitRange : ranges) {
2901 unit = lc.pushCompileUnit(splitRange.getCompileUnit());
2902
2903 assert unit != null;
2904 final String className = unit.getUnitClassName();
2905 final String name = currentFunction.uniqueName(SPLIT_PREFIX.symbolName());
2906 final Class<?> clazz = literalType.getTypeClass();
2907 final String signature = methodDescriptor(clazz, ScriptFunction.class, Object.class, ScriptObject.class, clazz);
2908
2909 pushMethodEmitter(unit.getClassEmitter().method(EnumSet.of(Flag.PUBLIC, Flag.STATIC), name, signature));
2910
2911 method.setFunctionNode(currentFunction);
2912 method.begin();
2913
2914 defineCommonSplitMethodParameters();
2915 defineSplitMethodParameter(CompilerConstants.SPLIT_ARRAY_ARG.slot(), literalType);
2916
2917 // NOTE: when this is no longer needed, SplitIntoFunctions will no longer have to add IS_SPLIT
2918 // to synthetic functions, and FunctionNode.needsCallee() will no longer need to test for isSplit().
2919 final int literalSlot = fixScopeSlot(currentFunction, 3);
2920
2921 lc.enterSplitLiteral();
2922
2923 creator.populateRange(method, literalType, literalSlot, splitRange.getLow(), splitRange.getHigh());
2924
2925 method._return();
2926 lc.exitSplitLiteral();
2927 method.end();
2928 lc.releaseSlots();
2929 popMethodEmitter();
2930
2931 assert method == savedMethod;
2932 method.loadCompilerConstant(CALLEE).swap();
2933 method.loadCompilerConstant(THIS).swap();
2934 method.loadCompilerConstant(SCOPE).swap();
2935 method.invokestatic(className, name, signature);
2936
2937 unit = lc.popCompileUnit(unit);
2938 }
2939 }
2940
2941 private int fixScopeSlot(final FunctionNode functionNode, final int extraSlot) {
2942 // TODO hack to move the scope to the expected slot (needed because split methods reuse the same slots as the root method)
2943 final int actualScopeSlot = functionNode.compilerConstant(SCOPE).getSlot(SCOPE_TYPE);
2944 final int defaultScopeSlot = SCOPE.slot();
2945 int newExtraSlot = extraSlot;
2946 if (actualScopeSlot != defaultScopeSlot) {
2947 if (actualScopeSlot == extraSlot) {
2948 newExtraSlot = extraSlot + 1;
2949 method.defineBlockLocalVariable(newExtraSlot, newExtraSlot + 1);
2950 method.load(Type.OBJECT, extraSlot);
2951 method.storeHidden(Type.OBJECT, newExtraSlot);
2952 } else {
2953 method.defineBlockLocalVariable(actualScopeSlot, actualScopeSlot + 1);
2954 }
2955 method.load(SCOPE_TYPE, defaultScopeSlot);
2956 method.storeCompilerConstant(SCOPE);
2957 }
2958 return newExtraSlot;
2959 }
2960
2961 @Override
2962 public boolean enterSplitReturn(final SplitReturn splitReturn) {
2963 if (method.isReachable()) {
2964 method.loadUndefined(lc.getCurrentFunction().getReturnType())._return();
2965 }
2966 return false;
2967 }
2968
2969 @Override
2970 public boolean enterSetSplitState(final SetSplitState setSplitState) {
2971 if (method.isReachable()) {
2972 method.setSplitState(setSplitState.getState());
2973 }
2974 return false;
2975 }
2976
2977 @Override
2978 public boolean enterSwitchNode(final SwitchNode switchNode) {
2979 if(!method.isReachable()) {
2980 return false;
2981 }
2982 enterStatement(switchNode);
2983
2984 final Expression expression = switchNode.getExpression();
2985 final List<CaseNode> cases = switchNode.getCases();
2986
2987 if (cases.isEmpty()) {
2988 // still evaluate expression for side-effects.
2989 loadAndDiscard(expression);
2990 return false;
2991 }
2992
2993 final CaseNode defaultCase = switchNode.getDefaultCase();
2994 final Label breakLabel = switchNode.getBreakLabel();
2995 final int liveLocalsOnBreak = method.getUsedSlotsWithLiveTemporaries();
2996
2997 if (defaultCase != null && cases.size() == 1) {
2998 // default case only
2999 assert cases.get(0) == defaultCase;
3000 loadAndDiscard(expression);
3001 defaultCase.getBody().accept(this);
3002 method.breakLabel(breakLabel, liveLocalsOnBreak);
3003 return false;
3004 }
3005
3006 // NOTE: it can still change in the tableswitch/lookupswitch case if there's no default case
3007 // but we need to add a synthetic default case for local variable conversions
3008 Label defaultLabel = defaultCase != null ? defaultCase.getEntry() : breakLabel;
3009 final boolean hasSkipConversion = LocalVariableConversion.hasLiveConversion(switchNode);
3010
3011 if (switchNode.isUniqueInteger()) {
3012 // Tree for sorting values.
3013 final TreeMap<Integer, Label> tree = new TreeMap<>();
3014
3015 // Build up sorted tree.
3016 for (final CaseNode caseNode : cases) {
3017 final Node test = caseNode.getTest();
3018
3019 if (test != null) {
3020 final Integer value = (Integer)((LiteralNode<?>)test).getValue();
3021 final Label entry = caseNode.getEntry();
3022
3023 // Take first duplicate.
3024 if (!tree.containsKey(value)) {
3025 tree.put(value, entry);
3026 }
3027 }
3028 }
3029
3030 // Copy values and labels to arrays.
3031 final int size = tree.size();
3032 final Integer[] values = tree.keySet().toArray(new Integer[0]);
3033 final Label[] labels = tree.values().toArray(new Label[0]);
3034
3035 // Discern low, high and range.
3036 final int lo = values[0];
3037 final int hi = values[size - 1];
3038 final long range = (long)hi - (long)lo + 1;
3039
3040 // Find an unused value for default.
3041 int deflt = Integer.MIN_VALUE;
3042 for (final int value : values) {
3043 if (deflt == value) {
3044 deflt++;
3045 } else if (deflt < value) {
3046 break;
3047 }
3048 }
3049
3050 // Load switch expression.
3051 loadExpressionUnbounded(expression);
3052 final Type type = expression.getType();
3053
3054 // If expression not int see if we can convert, if not use deflt to trigger default.
3055 if (!type.isInteger()) {
3056 method.load(deflt);
3057 final Class<?> exprClass = type.getTypeClass();
3058 method.invoke(staticCallNoLookup(ScriptRuntime.class, "switchTagAsInt", int.class, exprClass.isPrimitive()? exprClass : Object.class, int.class));
3059 }
3060
3061 if(hasSkipConversion) {
3062 assert defaultLabel == breakLabel;
3063 defaultLabel = new Label("switch_skip");
3064 }
3065 // TABLESWITCH needs (range + 3) 32-bit values; LOOKUPSWITCH needs ((size * 2) + 2). Choose the one with
3066 // smaller representation, favor TABLESWITCH when they're equal size.
3067 if (range + 1 <= (size * 2) && range <= Integer.MAX_VALUE) {
3068 final Label[] table = new Label[(int)range];
3069 Arrays.fill(table, defaultLabel);
3070 for (int i = 0; i < size; i++) {
3071 final int value = values[i];
3072 table[value - lo] = labels[i];
3073 }
3074
3075 method.tableswitch(lo, hi, defaultLabel, table);
3076 } else {
3077 final int[] ints = new int[size];
3078 for (int i = 0; i < size; i++) {
3079 ints[i] = values[i];
3080 }
3081
3082 method.lookupswitch(defaultLabel, ints, labels);
3083 }
3084 // This is a synthetic "default case" used in absence of actual default case, created if we need to apply
3085 // local variable conversions if neither case is taken.
3086 if(hasSkipConversion) {
3087 method.label(defaultLabel);
3088 method.beforeJoinPoint(switchNode);
3089 method._goto(breakLabel);
3090 }
3091 } else {
3092 final Symbol tagSymbol = switchNode.getTag();
3093 // TODO: we could have non-object tag
3094 final int tagSlot = tagSymbol.getSlot(Type.OBJECT);
3095 loadExpressionAsObject(expression);
3096 method.store(tagSymbol, Type.OBJECT);
3097
3098 for (final CaseNode caseNode : cases) {
3099 final Expression test = caseNode.getTest();
3100
3101 if (test != null) {
3102 method.load(Type.OBJECT, tagSlot);
3103 loadExpressionAsObject(test);
3104 method.invoke(ScriptRuntime.EQ_STRICT);
3105 method.ifne(caseNode.getEntry());
3106 }
3107 }
3108
3109 if (defaultCase != null) {
3110 method._goto(defaultLabel);
3111 } else {
3112 method.beforeJoinPoint(switchNode);
3113 method._goto(breakLabel);
3114 }
3115 }
3116
3117 // First case is only reachable through jump
3118 assert !method.isReachable();
3119
3120 for (final CaseNode caseNode : cases) {
3121 final Label fallThroughLabel;
3122 if(caseNode.getLocalVariableConversion() != null && method.isReachable()) {
3123 fallThroughLabel = new Label("fallthrough");
3124 method._goto(fallThroughLabel);
3125 } else {
3126 fallThroughLabel = null;
3127 }
3128 method.label(caseNode.getEntry());
3129 method.beforeJoinPoint(caseNode);
3130 if(fallThroughLabel != null) {
3131 method.label(fallThroughLabel);
3132 }
3133 caseNode.getBody().accept(this);
3134 }
3135
3136 method.breakLabel(breakLabel, liveLocalsOnBreak);
3137
3138 return false;
3139 }
3140
3141 @Override
3142 public boolean enterThrowNode(final ThrowNode throwNode) {
3143 if(!method.isReachable()) {
3144 return false;
3145 }
3146 enterStatement(throwNode);
3147
3148 if (throwNode.isSyntheticRethrow()) {
3149 method.beforeJoinPoint(throwNode);
3150
3151 //do not wrap whatever this is in an ecma exception, just rethrow it
3152 final IdentNode exceptionExpr = (IdentNode)throwNode.getExpression();
3153 final Symbol exceptionSymbol = exceptionExpr.getSymbol();
3154 method.load(exceptionSymbol, EXCEPTION_TYPE);
3155 method.checkcast(EXCEPTION_TYPE.getTypeClass());
3156 method.athrow();
3157 return false;
3158 }
3159
3160 final Source source = getCurrentSource();
3161 final Expression expression = throwNode.getExpression();
3162 final int position = throwNode.position();
3163 final int line = throwNode.getLineNumber();
3164 final int column = source.getColumn(position);
3165
3166 // NOTE: we first evaluate the expression, and only after it was evaluated do we create the new ECMAException
3167 // object and then somewhat cumbersomely move it beneath the evaluated expression on the stack. The reason for
3168 // this is that if expression is optimistic (or contains an optimistic subexpression), we'd potentially access
3169 // the not-yet-<init>ialized object on the stack from the UnwarrantedOptimismException handler, and bytecode
3170 // verifier forbids that.
3171 loadExpressionAsObject(expression);
3172
3173 method.load(source.getName());
3174 method.load(line);
3175 method.load(column);
3176 method.invoke(ECMAException.CREATE);
3177
3178 method.beforeJoinPoint(throwNode);
3179 method.athrow();
3180
3181 return false;
3182 }
3183
3184 private Source getCurrentSource() {
3185 return lc.getCurrentFunction().getSource();
3186 }
3187
3188 @Override
3189 public boolean enterTryNode(final TryNode tryNode) {
3190 if(!method.isReachable()) {
3191 return false;
3192 }
3193 enterStatement(tryNode);
3194
3195 final Block body = tryNode.getBody();
3196 final List<Block> catchBlocks = tryNode.getCatchBlocks();
3197 final Symbol vmException = tryNode.getException();
3198 final Label entry = new Label("try");
3199 final Label recovery = new Label("catch");
3200 final Label exit = new Label("end_try");
3201 final Label skip = new Label("skip");
3202
3203 method.canThrow(recovery);
3204 // Effect any conversions that might be observed at the entry of the catch node before entering the try node.
3205 // This is because even the first instruction in the try block must be presumed to be able to transfer control
3206 // to the catch block. Note that this doesn't kill the original values; in this regard it works a lot like
3207 // conversions of assignments within the try block.
3208 method.beforeTry(tryNode, recovery);
3209 method.label(entry);
3210 catchLabels.push(recovery);
3211 try {
3212 body.accept(this);
3213 } finally {
3214 assert catchLabels.peek() == recovery;
3215 catchLabels.pop();
3216 }
3217
3218 method.label(exit);
3219 final boolean bodyCanThrow = exit.isAfter(entry);
3220 if(!bodyCanThrow) {
3221 // The body can't throw an exception; don't even bother emitting the catch handlers, they're all dead code.
3222 return false;
3223 }
3224
3225 method._try(entry, exit, recovery, Throwable.class);
3226
3227 if (method.isReachable()) {
3228 method._goto(skip);
3229 }
3230
3231 for (final Block inlinedFinally : tryNode.getInlinedFinallies()) {
3232 TryNode.getLabelledInlinedFinallyBlock(inlinedFinally).accept(this);
3233 // All inlined finallies end with a jump or a return
3234 assert !method.isReachable();
3235 }
3236
3237
3238 method._catch(recovery);
3239 method.store(vmException, EXCEPTION_TYPE);
3240
3241 final int catchBlockCount = catchBlocks.size();
3242 final Label afterCatch = new Label("after_catch");
3243 for (int i = 0; i < catchBlockCount; i++) {
3244 assert method.isReachable();
3245 final Block catchBlock = catchBlocks.get(i);
3246
3247 // Because of the peculiarities of the flow control, we need to use an explicit push/enterBlock/leaveBlock
3248 // here.
3249 lc.push(catchBlock);
3250 enterBlock(catchBlock);
3251
3252 final CatchNode catchNode = (CatchNode)catchBlocks.get(i).getStatements().get(0);
3253 final IdentNode exception = catchNode.getExceptionIdentifier();
3254 final Expression exceptionCondition = catchNode.getExceptionCondition();
3255 final Block catchBody = catchNode.getBody();
3256
3257 new Store<IdentNode>(exception) {
3258 @Override
3259 protected void storeNonDiscard() {
3260 // This expression is neither part of a discard, nor needs to be left on the stack after it was
3261 // stored, so we override storeNonDiscard to be a no-op.
3262 }
3263
3264 @Override
3265 protected void evaluate() {
3266 if (catchNode.isSyntheticRethrow()) {
3267 method.load(vmException, EXCEPTION_TYPE);
3268 return;
3269 }
3270 /*
3271 * If caught object is an instance of ECMAException, then
3272 * bind obj.thrown to the script catch var. Or else bind the
3273 * caught object itself to the script catch var.
3274 */
3275 final Label notEcmaException = new Label("no_ecma_exception");
3276 method.load(vmException, EXCEPTION_TYPE).dup()._instanceof(ECMAException.class).ifeq(notEcmaException);
3277 method.checkcast(ECMAException.class); //TODO is this necessary?
3278 method.getField(ECMAException.THROWN);
3279 method.label(notEcmaException);
3280 }
3281 }.store();
3282
3283 final boolean isConditionalCatch = exceptionCondition != null;
3284 final Label nextCatch;
3285 if (isConditionalCatch) {
3286 loadExpressionAsBoolean(exceptionCondition);
3287 nextCatch = new Label("next_catch");
3288 nextCatch.markAsBreakTarget();
3289 method.ifeq(nextCatch);
3290 } else {
3291 nextCatch = null;
3292 }
3293
3294 catchBody.accept(this);
3295 leaveBlock(catchBlock);
3296 lc.pop(catchBlock);
3297 if(nextCatch != null) {
3298 if(method.isReachable()) {
3299 method._goto(afterCatch);
3300 }
3301 method.breakLabel(nextCatch, lc.getUsedSlotCount());
3302 }
3303 }
3304
3305 // afterCatch could be the same as skip, except that we need to establish that the vmException is dead.
3306 method.label(afterCatch);
3307 if(method.isReachable()) {
3308 method.markDeadLocalVariable(vmException);
3309 }
3310 method.label(skip);
3311
3312 // Finally body is always inlined elsewhere so it doesn't need to be emitted
3313 assert tryNode.getFinallyBody() == null;
3314
3315 return false;
3316 }
3317
3318 @Override
3319 public boolean enterVarNode(final VarNode varNode) {
3320 if(!method.isReachable()) {
3321 return false;
3322 }
3323 final Expression init = varNode.getInit();
3324 final IdentNode identNode = varNode.getName();
3325 final Symbol identSymbol = identNode.getSymbol();
3326 assert identSymbol != null : "variable node " + varNode + " requires a name with a symbol";
3327 final boolean needsScope = identSymbol.isScope();
3328
3329 if (init == null) {
3330 // Block-scoped variables need a DECLARE flag to signal end of temporal dead zone (TDZ).
3331 // However, don't do this for CONST which always has an initializer except in the special case of
3332 // for-in/of loops, in which it is initialized in the loop header and should be left untouched here.
3333 if (needsScope && varNode.isLet()) {
3334 method.loadCompilerConstant(SCOPE);
3335 method.loadUndefined(Type.OBJECT);
3336 final int flags = getScopeCallSiteFlags(identSymbol) | CALLSITE_DECLARE;
3337 assert isFastScope(identSymbol);
3338 storeFastScopeVar(identSymbol, flags);
3339 }
3340 return false;
3341 }
3342
3343 enterStatement(varNode);
3344 assert method != null;
3345
3346 if (needsScope) {
3347 method.loadCompilerConstant(SCOPE);
3348 loadExpressionUnbounded(init);
3349 // block scoped variables need a DECLARE flag to signal end of temporal dead zone (TDZ)
3350 final int flags = getScopeCallSiteFlags(identSymbol) | (varNode.isBlockScoped() ? CALLSITE_DECLARE : 0);
3351 if (isFastScope(identSymbol)) {
3352 storeFastScopeVar(identSymbol, flags);
3353 } else {
3354 method.dynamicSet(identNode.getName(), flags, false);
3355 }
3356 } else {
3357 final Type identType = identNode.getType();
3358 if(identType == Type.UNDEFINED) {
3359 // The initializer is either itself undefined (explicit assignment of undefined to undefined),
3360 // or the left hand side is a dead variable.
3361 assert init.getType() == Type.UNDEFINED || identNode.getSymbol().slotCount() == 0;
3362 loadAndDiscard(init);
3363 return false;
3364 }
3365 loadExpressionAsType(init, identType);
3366 storeIdentWithCatchConversion(identNode, identType);
3367 }
3368
3369 return false;
3370 }
3371
3372 private void storeIdentWithCatchConversion(final IdentNode identNode, final Type type) {
3373 // Assignments happening in try/catch blocks need to ensure that they also store a possibly wider typed value
3374 // that will be live at the exit from the try block
3375 final LocalVariableConversion conversion = identNode.getLocalVariableConversion();
3376 final Symbol symbol = identNode.getSymbol();
3377 if(conversion != null && conversion.isLive()) {
3378 assert symbol == conversion.getSymbol();
3379 assert symbol.isBytecodeLocal();
3380 // Only a single conversion from the target type to the join type is expected.
3381 assert conversion.getNext() == null;
3382 assert conversion.getFrom() == type;
3383 // We must propagate potential type change to the catch block
3384 final Label catchLabel = catchLabels.peek();
3385 assert catchLabel != METHOD_BOUNDARY; // ident conversion only exists in try blocks
3386 assert catchLabel.isReachable();
3387 final Type joinType = conversion.getTo();
3388 final Label.Stack catchStack = catchLabel.getStack();
3389 final int joinSlot = symbol.getSlot(joinType);
3390 // With nested try/catch blocks (incl. synthetic ones for finally), we can have a supposed conversion for
3391 // the exception symbol in the nested catch, but it isn't live in the outer catch block, so prevent doing
3392 // conversions for it. E.g. in "try { try { ... } catch(e) { e = 1; } } catch(e2) { ... }", we must not
3393 // introduce an I->O conversion on "e = 1" assignment as "e" is not live in "catch(e2)".
3394 if(catchStack.getUsedSlotsWithLiveTemporaries() > joinSlot) {
3395 method.dup();
3396 method.convert(joinType);
3397 method.store(symbol, joinType);
3398 catchLabel.getStack().onLocalStore(joinType, joinSlot, true);
3399 method.canThrow(catchLabel);
3400 // Store but keep the previous store live too.
3401 method.store(symbol, type, false);
3402 return;
3403 }
3404 }
3405
3406 method.store(symbol, type, true);
3407 }
3408
3409 @Override
3410 public boolean enterWhileNode(final WhileNode whileNode) {
3411 if(!method.isReachable()) {
3412 return false;
3413 }
3414 if(whileNode.isDoWhile()) {
3415 enterDoWhile(whileNode);
3416 } else {
3417 enterStatement(whileNode);
3418 enterForOrWhile(whileNode, null);
3419 }
3420 return false;
3421 }
3422
3423 private void enterForOrWhile(final LoopNode loopNode, final JoinPredecessorExpression modify) {
3424 // NOTE: the usual pattern for compiling test-first loops is "GOTO test; body; test; IFNE body". We use the less
3425 // conventional "test; IFEQ break; body; GOTO test; break;". It has one extra unconditional GOTO in each repeat
3426 // of the loop, but it's not a problem for modern JIT compilers. We do this because our local variable type
3427 // tracking is unfortunately not really prepared for out-of-order execution, e.g. compiling the following
3428 // contrived but legal JavaScript code snippet would fail because the test changes the type of "i" from object
3429 // to double: var i = {valueOf: function() { return 1} }; while(--i >= 0) { ... }
3430 // Instead of adding more complexity to the local variable type tracking, we instead choose to emit this
3431 // different code shape.
3432 final int liveLocalsOnBreak = method.getUsedSlotsWithLiveTemporaries();
3433 final JoinPredecessorExpression test = loopNode.getTest();
3434 if(Expression.isAlwaysFalse(test)) {
3435 loadAndDiscard(test);
3436 return;
3437 }
3438
3439 method.beforeJoinPoint(loopNode);
3440
3441 final Label continueLabel = loopNode.getContinueLabel();
3442 final Label repeatLabel = modify != null ? new Label("for_repeat") : continueLabel;
3443 method.label(repeatLabel);
3444 final int liveLocalsOnContinue = method.getUsedSlotsWithLiveTemporaries();
3445
3446 final Block body = loopNode.getBody();
3447 final Label breakLabel = loopNode.getBreakLabel();
3448 final boolean testHasLiveConversion = test != null && LocalVariableConversion.hasLiveConversion(test);
3449
3450 if(Expression.isAlwaysTrue(test)) {
3451 if(test != null) {
3452 loadAndDiscard(test);
3453 if(testHasLiveConversion) {
3454 method.beforeJoinPoint(test);
3455 }
3456 }
3457 } else if (test != null) {
3458 if (testHasLiveConversion) {
3459 emitBranch(test.getExpression(), body.getEntryLabel(), true);
3460 method.beforeJoinPoint(test);
3461 method._goto(breakLabel);
3462 } else {
3463 emitBranch(test.getExpression(), breakLabel, false);
3464 }
3465 }
3466
3467 body.accept(this);
3468 if(repeatLabel != continueLabel) {
3469 emitContinueLabel(continueLabel, liveLocalsOnContinue);
3470 }
3471
3472 if (loopNode.hasPerIterationScope() && lc.getCurrentBlock().needsScope()) {
3473 // ES6 for loops with LET init need a new scope for each iteration. We just create a shallow copy here.
3474 method.loadCompilerConstant(SCOPE);
3475 method.invoke(virtualCallNoLookup(ScriptObject.class, "copy", ScriptObject.class));
3476 method.storeCompilerConstant(SCOPE);
3477 }
3478
3479 if(method.isReachable()) {
3480 if(modify != null) {
3481 lineNumber(loopNode);
3482 loadAndDiscard(modify);
3483 method.beforeJoinPoint(modify);
3484 }
3485 method._goto(repeatLabel);
3486 }
3487
3488 method.breakLabel(breakLabel, liveLocalsOnBreak);
3489 }
3490
3491 private void emitContinueLabel(final Label continueLabel, final int liveLocals) {
3492 final boolean reachable = method.isReachable();
3493 method.breakLabel(continueLabel, liveLocals);
3494 // If we reach here only through a continue statement (e.g. body does not exit normally) then the
3495 // continueLabel can have extra non-temp symbols (e.g. exception from a try/catch contained in the body). We
3496 // must make sure those are thrown away.
3497 if(!reachable) {
3498 method.undefineLocalVariables(lc.getUsedSlotCount(), false);
3499 }
3500 }
3501
3502 private void enterDoWhile(final WhileNode whileNode) {
3503 final int liveLocalsOnContinueOrBreak = method.getUsedSlotsWithLiveTemporaries();
3504 method.beforeJoinPoint(whileNode);
3505
3506 final Block body = whileNode.getBody();
3507 body.accept(this);
3508
3509 emitContinueLabel(whileNode.getContinueLabel(), liveLocalsOnContinueOrBreak);
3510 if(method.isReachable()) {
3511 lineNumber(whileNode);
3512 final JoinPredecessorExpression test = whileNode.getTest();
3513 final Label bodyEntryLabel = body.getEntryLabel();
3514 final boolean testHasLiveConversion = LocalVariableConversion.hasLiveConversion(test);
3515 if(Expression.isAlwaysFalse(test)) {
3516 loadAndDiscard(test);
3517 if(testHasLiveConversion) {
3518 method.beforeJoinPoint(test);
3519 }
3520 } else if(testHasLiveConversion) {
3521 // If we have conversions after the test in do-while, they need to be effected on both branches.
3522 final Label beforeExit = new Label("do_while_preexit");
3523 emitBranch(test.getExpression(), beforeExit, false);
3524 method.beforeJoinPoint(test);
3525 method._goto(bodyEntryLabel);
3526 method.label(beforeExit);
3527 method.beforeJoinPoint(test);
3528 } else {
3529 emitBranch(test.getExpression(), bodyEntryLabel, true);
3530 }
3531 }
3532 method.breakLabel(whileNode.getBreakLabel(), liveLocalsOnContinueOrBreak);
3533 }
3534
3535
3536 @Override
3537 public boolean enterWithNode(final WithNode withNode) {
3538 if(!method.isReachable()) {
3539 return false;
3540 }
3541 enterStatement(withNode);
3542 final Expression expression = withNode.getExpression();
3543 final Block body = withNode.getBody();
3544
3545 // It is possible to have a "pathological" case where the with block does not reference *any* identifiers. It's
3546 // pointless, but legal. In that case, if nothing else in the method forced the assignment of a slot to the
3547 // scope object, its' possible that it won't have a slot assigned. In this case we'll only evaluate expression
3548 // for its side effect and visit the body, and not bother opening and closing a WithObject.
3549 final boolean hasScope = method.hasScope();
3550
3551 if (hasScope) {
3552 method.loadCompilerConstant(SCOPE);
3553 }
3554
3555 loadExpressionAsObject(expression);
3556
3557 final Label tryLabel;
3558 if (hasScope) {
3559 // Construct a WithObject if we have a scope
3560 method.invoke(ScriptRuntime.OPEN_WITH);
3561 method.storeCompilerConstant(SCOPE);
3562 tryLabel = new Label("with_try");
3563 method.label(tryLabel);
3564 } else {
3565 // We just loaded the expression for its side effect and to check
3566 // for null or undefined value.
3567 globalCheckObjectCoercible();
3568 tryLabel = null;
3569 }
3570
3571 // Always process body
3572 body.accept(this);
3573
3574 if (hasScope) {
3575 // Ensure we always close the WithObject
3576 final Label endLabel = new Label("with_end");
3577 final Label catchLabel = new Label("with_catch");
3578 final Label exitLabel = new Label("with_exit");
3579
3580 method.label(endLabel);
3581 // Somewhat conservatively presume that if the body is not empty, it can throw an exception. In any case,
3582 // we must prevent trying to emit a try-catch for empty range, as it causes a verification error.
3583 final boolean bodyCanThrow = endLabel.isAfter(tryLabel);
3584 if(bodyCanThrow) {
3585 method._try(tryLabel, endLabel, catchLabel);
3586 }
3587
3588 final boolean reachable = method.isReachable();
3589 if(reachable) {
3590 popScope();
3591 if(bodyCanThrow) {
3592 method._goto(exitLabel);
3593 }
3594 }
3595
3596 if(bodyCanThrow) {
3597 method._catch(catchLabel);
3598 popScopeException();
3599 method.athrow();
3600 if(reachable) {
3601 method.label(exitLabel);
3602 }
3603 }
3604 }
3605 return false;
3606 }
3607
3608 private void loadADD(final UnaryNode unaryNode, final TypeBounds resultBounds) {
3609 loadExpression(unaryNode.getExpression(), resultBounds.booleanToInt().notWiderThan(Type.NUMBER));
3610 if(method.peekType() == Type.BOOLEAN) {
3611 // It's a no-op in bytecode, but we must make sure it is treated as an int for purposes of type signatures
3612 method.convert(Type.INT);
3613 }
3614 }
3615
3616 private void loadBIT_NOT(final UnaryNode unaryNode) {
3617 loadExpression(unaryNode.getExpression(), TypeBounds.INT).load(-1).xor();
3618 }
3619
3620 private void loadDECINC(final UnaryNode unaryNode) {
3621 final Expression operand = unaryNode.getExpression();
3622 final Type type = unaryNode.getType();
3623 final TypeBounds typeBounds = new TypeBounds(type, Type.NUMBER);
3624 final TokenType tokenType = unaryNode.tokenType();
3625 final boolean isPostfix = tokenType == TokenType.DECPOSTFIX || tokenType == TokenType.INCPOSTFIX;
3626 final boolean isIncrement = tokenType == TokenType.INCPREFIX || tokenType == TokenType.INCPOSTFIX;
3627
3628 assert !type.isObject();
3629
3630 new SelfModifyingStore<UnaryNode>(unaryNode, operand) {
3631
3632 private void loadRhs() {
3633 loadExpression(operand, typeBounds, true);
3634 }
3635
3636 @Override
3637 protected void evaluate() {
3638 if(isPostfix) {
3639 loadRhs();
3640 } else {
3641 new OptimisticOperation(unaryNode, typeBounds) {
3642 @Override
3643 void loadStack() {
3644 loadRhs();
3645 loadMinusOne();
3646 }
3647 @Override
3648 void consumeStack() {
3649 doDecInc(getProgramPoint());
3650 }
3651 }.emit(getOptimisticIgnoreCountForSelfModifyingExpression(operand));
3652 }
3653 }
3654
3655 @Override
3656 protected void storeNonDiscard() {
3657 super.storeNonDiscard();
3658 if (isPostfix) {
3659 new OptimisticOperation(unaryNode, typeBounds) {
3660 @Override
3661 void loadStack() {
3662 loadMinusOne();
3663 }
3664 @Override
3665 void consumeStack() {
3666 doDecInc(getProgramPoint());
3667 }
3668 }.emit(1); // 1 for non-incremented result on the top of the stack pushed in evaluate()
3669 }
3670 }
3671
3672 private void loadMinusOne() {
3673 if (type.isInteger()) {
3674 method.load(isIncrement ? 1 : -1);
3675 } else {
3676 method.load(isIncrement ? 1.0 : -1.0);
3677 }
3678 }
3679
3680 private void doDecInc(final int programPoint) {
3681 method.add(programPoint);
3682 }
3683 }.store();
3684 }
3685
3686 private static int getOptimisticIgnoreCountForSelfModifyingExpression(final Expression target) {
3687 return target instanceof AccessNode ? 1 : target instanceof IndexNode ? 2 : 0;
3688 }
3689
3690 private void loadAndDiscard(final Expression expr) {
3691 // TODO: move checks for discarding to actual expression load code (e.g. as we do with void). That way we might
3692 // be able to eliminate even more checks.
3693 if(expr instanceof PrimitiveLiteralNode | isLocalVariable(expr)) {
3694 assert !lc.isCurrentDiscard(expr);
3695 // Don't bother evaluating expressions without side effects. Typical usage is "void 0" for reliably generating
3696 // undefined.
3697 return;
3698 }
3699
3700 lc.pushDiscard(expr);
3701 loadExpression(expr, TypeBounds.UNBOUNDED);
3702 if (lc.popDiscardIfCurrent(expr)) {
3703 assert !expr.isAssignment();
3704 // NOTE: if we had a way to load with type void, we could avoid popping
3705 method.pop();
3706 }
3707 }
3708
3709 /**
3710 * Loads the expression with the specified type bounds, but if the parent expression is the current discard,
3711 * then instead loads and discards the expression.
3712 * @param parent the parent expression that's tested for being the current discard
3713 * @param expr the expression that's either normally loaded or discard-loaded
3714 * @param resultBounds result bounds for when loading the expression normally
3715 */
3716 private void loadMaybeDiscard(final Expression parent, final Expression expr, final TypeBounds resultBounds) {
3717 loadMaybeDiscard(lc.popDiscardIfCurrent(parent), expr, resultBounds);
3718 }
3719
3720 /**
3721 * Loads the expression with the specified type bounds, or loads and discards the expression, depending on the
3722 * value of the discard flag. Useful as a helper for expressions with control flow where you often can't combine
3723 * testing for being the current discard and loading the subexpressions.
3724 * @param discard if true, the expression is loaded and discarded
3725 * @param expr the expression that's either normally loaded or discard-loaded
3726 * @param resultBounds result bounds for when loading the expression normally
3727 */
3728 private void loadMaybeDiscard(final boolean discard, final Expression expr, final TypeBounds resultBounds) {
3729 if (discard) {
3730 loadAndDiscard(expr);
3731 } else {
3732 loadExpression(expr, resultBounds);
3733 }
3734 }
3735
3736 private void loadNEW(final UnaryNode unaryNode) {
3737 final CallNode callNode = (CallNode)unaryNode.getExpression();
3738 final List<Expression> args = callNode.getArgs();
3739
3740 final Expression func = callNode.getFunction();
3741 // Load function reference.
3742 loadExpressionAsObject(func); // must detect type error
3743
3744 method.dynamicNew(1 + loadArgs(args), getCallSiteFlags(), func.toString(false));
3745 }
3746
3747 private void loadNOT(final UnaryNode unaryNode) {
3748 final Expression expr = unaryNode.getExpression();
3749 if(expr instanceof UnaryNode && expr.isTokenType(TokenType.NOT)) {
3750 // !!x is idiomatic boolean cast in JavaScript
3751 loadExpressionAsBoolean(((UnaryNode)expr).getExpression());
3752 } else {
3753 final Label trueLabel = new Label("true");
3754 final Label afterLabel = new Label("after");
3755
3756 emitBranch(expr, trueLabel, true);
3757 method.load(true);
3758 method._goto(afterLabel);
3759 method.label(trueLabel);
3760 method.load(false);
3761 method.label(afterLabel);
3762 }
3763 }
3764
3765 private void loadSUB(final UnaryNode unaryNode, final TypeBounds resultBounds) {
3766 final Type type = unaryNode.getType();
3767 assert type.isNumeric();
3768 final TypeBounds numericBounds = resultBounds.booleanToInt();
3769 new OptimisticOperation(unaryNode, numericBounds) {
3770 @Override
3771 void loadStack() {
3772 final Expression expr = unaryNode.getExpression();
3773 loadExpression(expr, numericBounds.notWiderThan(Type.NUMBER));
3774 }
3775 @Override
3776 void consumeStack() {
3777 // Must do an explicit conversion to the operation's type when it's double so that we correctly handle
3778 // negation of an int 0 to a double -0. With this, we get the correct negation of a local variable after
3779 // it deoptimized, e.g. "iload_2; i2d; dneg". Without this, we get "iload_2; ineg; i2d".
3780 if(type.isNumber()) {
3781 method.convert(type);
3782 }
3783 method.neg(getProgramPoint());
3784 }
3785 }.emit();
3786 }
3787
3788 public void loadVOID(final UnaryNode unaryNode, final TypeBounds resultBounds) {
3789 loadAndDiscard(unaryNode.getExpression());
3790 if (!lc.popDiscardIfCurrent(unaryNode)) {
3791 method.loadUndefined(resultBounds.widest);
3792 }
3793 }
3794
3795 public void loadDELETE(final UnaryNode unaryNode) {
3796 final Expression expression = unaryNode.getExpression();
3797 if (expression instanceof IdentNode) {
3798 final IdentNode ident = (IdentNode)expression;
3799 final Symbol symbol = ident.getSymbol();
3800 final String name = ident.getName();
3801
3802 if (symbol.isThis()) {
3803 // Can't delete "this", ignore and return true
3804 if (!lc.popDiscardIfCurrent(unaryNode)) {
3805 method.load(true);
3806 }
3807 } else if (lc.getCurrentFunction().isStrict()) {
3808 // All other scope identifier delete attempts fail for strict mode
3809 method.load(name);
3810 method.invoke(ScriptRuntime.STRICT_FAIL_DELETE);
3811 } else if (!symbol.isScope() && (symbol.isParam() || (symbol.isVar() && !symbol.isProgramLevel()))) {
3812 // If symbol is a function parameter, or a declared non-global variable, delete is a no-op and returns false.
3813 if (!lc.popDiscardIfCurrent(unaryNode)) {
3814 method.load(false);
3815 }
3816 } else {
3817 method.loadCompilerConstant(SCOPE);
3818 method.load(name);
3819 if ((symbol.isGlobal() && !symbol.isFunctionDeclaration()) || symbol.isProgramLevel()) {
3820 method.invoke(ScriptRuntime.SLOW_DELETE);
3821 } else {
3822 method.load(false); // never strict here; that was handled with STRICT_FAIL_DELETE above.
3823 method.invoke(ScriptObject.DELETE);
3824 }
3825 }
3826 } else if (expression instanceof BaseNode) {
3827 loadExpressionAsObject(((BaseNode)expression).getBase());
3828 if (expression instanceof AccessNode) {
3829 final AccessNode accessNode = (AccessNode) expression;
3830 method.dynamicRemove(accessNode.getProperty(), getCallSiteFlags(), accessNode.isIndex());
3831 } else if (expression instanceof IndexNode) {
3832 loadExpressionAsObject(((IndexNode) expression).getIndex());
3833 method.dynamicRemoveIndex(getCallSiteFlags());
3834 } else {
3835 throw new AssertionError(expression.getClass().getName());
3836 }
3837 } else {
3838 throw new AssertionError(expression.getClass().getName());
3839 }
3840 }
3841
3842 public void loadADD(final BinaryNode binaryNode, final TypeBounds resultBounds) {
3843 new OptimisticOperation(binaryNode, resultBounds) {
3844 @Override
3845 void loadStack() {
3846 final TypeBounds operandBounds;
3847 final boolean isOptimistic = isValid(getProgramPoint());
3848 boolean forceConversionSeparation = false;
3849 if(isOptimistic) {
3850 operandBounds = new TypeBounds(binaryNode.getType(), Type.OBJECT);
3851 } else {
3852 // Non-optimistic, non-FP +. Allow it to overflow.
3853 final Type widestOperationType = binaryNode.getWidestOperationType();
3854 operandBounds = new TypeBounds(Type.narrowest(binaryNode.getWidestOperandType(), resultBounds.widest), widestOperationType);
3855 forceConversionSeparation = widestOperationType.narrowerThan(resultBounds.widest);
3856 }
3857 loadBinaryOperands(binaryNode.lhs(), binaryNode.rhs(), operandBounds, false, forceConversionSeparation);
3858 }
3859
3860 @Override
3861 void consumeStack() {
3862 method.add(getProgramPoint());
3863 }
3864 }.emit();
3865 }
3866
3867 private void loadAND_OR(final BinaryNode binaryNode, final TypeBounds resultBounds, final boolean isAnd) {
3868 final Type narrowestOperandType = Type.widestReturnType(binaryNode.lhs().getType(), binaryNode.rhs().getType());
3869
3870 final boolean isCurrentDiscard = lc.popDiscardIfCurrent(binaryNode);
3871
3872 final Label skip = new Label("skip");
3873 if(narrowestOperandType == Type.BOOLEAN) {
3874 // optimize all-boolean logical expressions
3875 final Label onTrue = new Label("andor_true");
3876 emitBranch(binaryNode, onTrue, true);
3877 if (isCurrentDiscard) {
3878 method.label(onTrue);
3879 } else {
3880 method.load(false);
3881 method._goto(skip);
3882 method.label(onTrue);
3883 method.load(true);
3884 method.label(skip);
3885 }
3886 return;
3887 }
3888
3889 final TypeBounds outBounds = resultBounds.notNarrowerThan(narrowestOperandType);
3890 final JoinPredecessorExpression lhs = (JoinPredecessorExpression)binaryNode.lhs();
3891 final boolean lhsConvert = LocalVariableConversion.hasLiveConversion(lhs);
3892 final Label evalRhs = lhsConvert ? new Label("eval_rhs") : null;
3893
3894 loadExpression(lhs, outBounds);
3895 if (!isCurrentDiscard) {
3896 method.dup();
3897 }
3898 method.convert(Type.BOOLEAN);
3899 if (isAnd) {
3900 if(lhsConvert) {
3901 method.ifne(evalRhs);
3902 } else {
3903 method.ifeq(skip);
3904 }
3905 } else if(lhsConvert) {
3906 method.ifeq(evalRhs);
3907 } else {
3908 method.ifne(skip);
3909 }
3910
3911 if(lhsConvert) {
3912 method.beforeJoinPoint(lhs);
3913 method._goto(skip);
3914 method.label(evalRhs);
3915 }
3916
3917 if (!isCurrentDiscard) {
3918 method.pop();
3919 }
3920 final JoinPredecessorExpression rhs = (JoinPredecessorExpression)binaryNode.rhs();
3921 loadMaybeDiscard(isCurrentDiscard, rhs, outBounds);
3922 method.beforeJoinPoint(rhs);
3923 method.label(skip);
3924 }
3925
3926 private static boolean isLocalVariable(final Expression lhs) {
3927 return lhs instanceof IdentNode && isLocalVariable((IdentNode)lhs);
3928 }
3929
3930 private static boolean isLocalVariable(final IdentNode lhs) {
3931 return lhs.getSymbol().isBytecodeLocal();
3932 }
3933
3934 // NOTE: does not use resultBounds as the assignment is driven by the type of the RHS
3935 private void loadASSIGN(final BinaryNode binaryNode) {
3936 final Expression lhs = binaryNode.lhs();
3937 final Expression rhs = binaryNode.rhs();
3938
3939 final Type rhsType = rhs.getType();
3940 // Detect dead assignments
3941 if(lhs instanceof IdentNode) {
3942 final Symbol symbol = ((IdentNode)lhs).getSymbol();
3943 if(!symbol.isScope() && !symbol.hasSlotFor(rhsType) && lc.popDiscardIfCurrent(binaryNode)) {
3944 loadAndDiscard(rhs);
3945 method.markDeadLocalVariable(symbol);
3946 return;
3947 }
3948 }
3949
3950 new Store<BinaryNode>(binaryNode, lhs) {
3951 @Override
3952 protected void evaluate() {
3953 // NOTE: we're loading with "at least as wide as" so optimistic operations on the right hand side
3954 // remain optimistic, and then explicitly convert to the required type if needed.
3955 loadExpressionAsType(rhs, rhsType);
3956 }
3957 }.store();
3958 }
3959
3960 /**
3961 * Binary self-assignment that can be optimistic: +=, -=, *=, and /=.
3962 */
3963 private abstract class BinaryOptimisticSelfAssignment extends SelfModifyingStore<BinaryNode> {
3964
3965 /**
3966 * Constructor
3967 *
3968 * @param node the assign op node
3969 */
3970 BinaryOptimisticSelfAssignment(final BinaryNode node) {
3971 super(node, node.lhs());
3972 }
3973
3974 protected abstract void op(OptimisticOperation oo);
3975
3976 @Override
3977 protected void evaluate() {
3978 final Expression lhs = assignNode.lhs();
3979 final Expression rhs = assignNode.rhs();
3980 final Type widestOperationType = assignNode.getWidestOperationType();
3981 final TypeBounds bounds = new TypeBounds(assignNode.getType(), widestOperationType);
3982 new OptimisticOperation(assignNode, bounds) {
3983 @Override
3984 void loadStack() {
3985 final boolean forceConversionSeparation;
3986 if (isValid(getProgramPoint()) || widestOperationType == Type.NUMBER) {
3987 forceConversionSeparation = false;
3988 } else {
3989 final Type operandType = Type.widest(booleanToInt(objectToNumber(lhs.getType())), booleanToInt(objectToNumber(rhs.getType())));
3990 forceConversionSeparation = operandType.narrowerThan(widestOperationType);
3991 }
3992 loadBinaryOperands(lhs, rhs, bounds, true, forceConversionSeparation);
3993 }
3994 @Override
3995 void consumeStack() {
3996 op(this);
3997 }
3998 }.emit(getOptimisticIgnoreCountForSelfModifyingExpression(lhs));
3999 method.convert(assignNode.getType());
4000 }
4001 }
4002
4003 /**
4004 * Non-optimistic binary self-assignment operation. Basically, everything except +=, -=, *=, and /=.
4005 */
4006 private abstract class BinarySelfAssignment extends SelfModifyingStore<BinaryNode> {
4007 BinarySelfAssignment(final BinaryNode node) {
4008 super(node, node.lhs());
4009 }
4010
4011 protected abstract void op();
4012
4013 @Override
4014 protected void evaluate() {
4015 loadBinaryOperands(assignNode.lhs(), assignNode.rhs(), TypeBounds.UNBOUNDED.notWiderThan(assignNode.getWidestOperandType()), true, false);
4016 op();
4017 }
4018 }
4019
4020 private void loadASSIGN_ADD(final BinaryNode binaryNode) {
4021 new BinaryOptimisticSelfAssignment(binaryNode) {
4022 @Override
4023 protected void op(final OptimisticOperation oo) {
4024 assert !(binaryNode.getType().isObject() && oo.isOptimistic);
4025 method.add(oo.getProgramPoint());
4026 }
4027 }.store();
4028 }
4029
4030 private void loadASSIGN_BIT_AND(final BinaryNode binaryNode) {
4031 new BinarySelfAssignment(binaryNode) {
4032 @Override
4033 protected void op() {
4034 method.and();
4035 }
4036 }.store();
4037 }
4038
4039 private void loadASSIGN_BIT_OR(final BinaryNode binaryNode) {
4040 new BinarySelfAssignment(binaryNode) {
4041 @Override
4042 protected void op() {
4043 method.or();
4044 }
4045 }.store();
4046 }
4047
4048 private void loadASSIGN_BIT_XOR(final BinaryNode binaryNode) {
4049 new BinarySelfAssignment(binaryNode) {
4050 @Override
4051 protected void op() {
4052 method.xor();
4053 }
4054 }.store();
4055 }
4056
4057 private void loadASSIGN_DIV(final BinaryNode binaryNode) {
4058 new BinaryOptimisticSelfAssignment(binaryNode) {
4059 @Override
4060 protected void op(final OptimisticOperation oo) {
4061 method.div(oo.getProgramPoint());
4062 }
4063 }.store();
4064 }
4065
4066 private void loadASSIGN_MOD(final BinaryNode binaryNode) {
4067 new BinaryOptimisticSelfAssignment(binaryNode) {
4068 @Override
4069 protected void op(final OptimisticOperation oo) {
4070 method.rem(oo.getProgramPoint());
4071 }
4072 }.store();
4073 }
4074
4075 private void loadASSIGN_MUL(final BinaryNode binaryNode) {
4076 new BinaryOptimisticSelfAssignment(binaryNode) {
4077 @Override
4078 protected void op(final OptimisticOperation oo) {
4079 method.mul(oo.getProgramPoint());
4080 }
4081 }.store();
4082 }
4083
4084 private void loadASSIGN_SAR(final BinaryNode binaryNode) {
4085 new BinarySelfAssignment(binaryNode) {
4086 @Override
4087 protected void op() {
4088 method.sar();
4089 }
4090 }.store();
4091 }
4092
4093 private void loadASSIGN_SHL(final BinaryNode binaryNode) {
4094 new BinarySelfAssignment(binaryNode) {
4095 @Override
4096 protected void op() {
4097 method.shl();
4098 }
4099 }.store();
4100 }
4101
4102 private void loadASSIGN_SHR(final BinaryNode binaryNode) {
4103 new SelfModifyingStore<BinaryNode>(binaryNode, binaryNode.lhs()) {
4104 @Override
4105 protected void evaluate() {
4106 new OptimisticOperation(assignNode, new TypeBounds(Type.INT, Type.NUMBER)) {
4107 @Override
4108 void loadStack() {
4109 assert assignNode.getWidestOperandType() == Type.INT;
4110 if (isRhsZero(binaryNode)) {
4111 loadExpression(binaryNode.lhs(), TypeBounds.INT, true);
4112 } else {
4113 loadBinaryOperands(binaryNode.lhs(), binaryNode.rhs(), TypeBounds.INT, true, false);
4114 method.shr();
4115 }
4116 }
4117
4118 @Override
4119 void consumeStack() {
4120 if (isOptimistic(binaryNode)) {
4121 toUint32Optimistic(binaryNode.getProgramPoint());
4122 } else {
4123 toUint32Double();
4124 }
4125 }
4126 }.emit(getOptimisticIgnoreCountForSelfModifyingExpression(binaryNode.lhs()));
4127 method.convert(assignNode.getType());
4128 }
4129 }.store();
4130 }
4131
4132 private void doSHR(final BinaryNode binaryNode) {
4133 new OptimisticOperation(binaryNode, new TypeBounds(Type.INT, Type.NUMBER)) {
4134 @Override
4135 void loadStack() {
4136 if (isRhsZero(binaryNode)) {
4137 loadExpressionAsType(binaryNode.lhs(), Type.INT);
4138 } else {
4139 loadBinaryOperands(binaryNode);
4140 method.shr();
4141 }
4142 }
4143
4144 @Override
4145 void consumeStack() {
4146 if (isOptimistic(binaryNode)) {
4147 toUint32Optimistic(binaryNode.getProgramPoint());
4148 } else {
4149 toUint32Double();
4150 }
4151 }
4152 }.emit();
4153
4154 }
4155
4156 private void toUint32Optimistic(final int programPoint) {
4157 method.load(programPoint);
4158 JSType.TO_UINT32_OPTIMISTIC.invoke(method);
4159 }
4160
4161 private void toUint32Double() {
4162 JSType.TO_UINT32_DOUBLE.invoke(method);
4163 }
4164
4165 private void loadASSIGN_SUB(final BinaryNode binaryNode) {
4166 new BinaryOptimisticSelfAssignment(binaryNode) {
4167 @Override
4168 protected void op(final OptimisticOperation oo) {
4169 method.sub(oo.getProgramPoint());
4170 }
4171 }.store();
4172 }
4173
4174 /**
4175 * Helper class for binary arithmetic ops
4176 */
4177 private abstract class BinaryArith {
4178 protected abstract void op(int programPoint);
4179
4180 protected void evaluate(final BinaryNode node, final TypeBounds resultBounds) {
4181 final TypeBounds numericBounds = resultBounds.booleanToInt().objectToNumber();
4182 new OptimisticOperation(node, numericBounds) {
4183 @Override
4184 void loadStack() {
4185 final TypeBounds operandBounds;
4186 boolean forceConversionSeparation = false;
4187 if(numericBounds.narrowest == Type.NUMBER) {
4188 // Result should be double always. Propagate it into the operands so we don't have lots of I2D
4189 // and L2D after operand evaluation.
4190 assert numericBounds.widest == Type.NUMBER;
4191 operandBounds = numericBounds;
4192 } else {
4193 final boolean isOptimistic = isValid(getProgramPoint());
4194 if(isOptimistic || node.isTokenType(TokenType.DIV) || node.isTokenType(TokenType.MOD)) {
4195 operandBounds = new TypeBounds(node.getType(), Type.NUMBER);
4196 } else {
4197 // Non-optimistic, non-FP subtraction or multiplication. Allow them to overflow.
4198 operandBounds = new TypeBounds(Type.narrowest(node.getWidestOperandType(),
4199 numericBounds.widest), Type.NUMBER);
4200 forceConversionSeparation = true;
4201 }
4202 }
4203 loadBinaryOperands(node.lhs(), node.rhs(), operandBounds, false, forceConversionSeparation);
4204 }
4205
4206 @Override
4207 void consumeStack() {
4208 op(getProgramPoint());
4209 }
4210 }.emit();
4211 }
4212 }
4213
4214 private void loadBIT_AND(final BinaryNode binaryNode) {
4215 loadBinaryOperands(binaryNode);
4216 method.and();
4217 }
4218
4219 private void loadBIT_OR(final BinaryNode binaryNode) {
4220 // Optimize x|0 to (int)x
4221 if (isRhsZero(binaryNode)) {
4222 loadExpressionAsType(binaryNode.lhs(), Type.INT);
4223 } else {
4224 loadBinaryOperands(binaryNode);
4225 method.or();
4226 }
4227 }
4228
4229 private static boolean isRhsZero(final BinaryNode binaryNode) {
4230 final Expression rhs = binaryNode.rhs();
4231 return rhs instanceof LiteralNode && INT_ZERO.equals(((LiteralNode<?>)rhs).getValue());
4232 }
4233
4234 private void loadBIT_XOR(final BinaryNode binaryNode) {
4235 loadBinaryOperands(binaryNode);
4236 method.xor();
4237 }
4238
4239 private void loadCOMMARIGHT(final BinaryNode binaryNode, final TypeBounds resultBounds) {
4240 loadAndDiscard(binaryNode.lhs());
4241 loadMaybeDiscard(binaryNode, binaryNode.rhs(), resultBounds);
4242 }
4243
4244 private void loadDIV(final BinaryNode binaryNode, final TypeBounds resultBounds) {
4245 new BinaryArith() {
4246 @Override
4247 protected void op(final int programPoint) {
4248 method.div(programPoint);
4249 }
4250 }.evaluate(binaryNode, resultBounds);
4251 }
4252
4253 private void loadCmp(final BinaryNode binaryNode, final Condition cond) {
4254 loadComparisonOperands(binaryNode);
4255
4256 final Label trueLabel = new Label("trueLabel");
4257 final Label afterLabel = new Label("skip");
4258
4259 method.conditionalJump(cond, trueLabel);
4260
4261 method.load(Boolean.FALSE);
4262 method._goto(afterLabel);
4263 method.label(trueLabel);
4264 method.load(Boolean.TRUE);
4265 method.label(afterLabel);
4266 }
4267
4268 private void loadMOD(final BinaryNode binaryNode, final TypeBounds resultBounds) {
4269 new BinaryArith() {
4270 @Override
4271 protected void op(final int programPoint) {
4272 method.rem(programPoint);
4273 }
4274 }.evaluate(binaryNode, resultBounds);
4275 }
4276
4277 private void loadMUL(final BinaryNode binaryNode, final TypeBounds resultBounds) {
4278 new BinaryArith() {
4279 @Override
4280 protected void op(final int programPoint) {
4281 method.mul(programPoint);
4282 }
4283 }.evaluate(binaryNode, resultBounds);
4284 }
4285
4286 private void loadSAR(final BinaryNode binaryNode) {
4287 loadBinaryOperands(binaryNode);
4288 method.sar();
4289 }
4290
4291 private void loadSHL(final BinaryNode binaryNode) {
4292 loadBinaryOperands(binaryNode);
4293 method.shl();
4294 }
4295
4296 private void loadSHR(final BinaryNode binaryNode) {
4297 doSHR(binaryNode);
4298 }
4299
4300 private void loadSUB(final BinaryNode binaryNode, final TypeBounds resultBounds) {
4301 new BinaryArith() {
4302 @Override
4303 protected void op(final int programPoint) {
4304 method.sub(programPoint);
4305 }
4306 }.evaluate(binaryNode, resultBounds);
4307 }
4308
4309 @Override
4310 public boolean enterLabelNode(final LabelNode labelNode) {
4311 labeledBlockBreakLiveLocals.push(lc.getUsedSlotCount());
4312 return true;
4313 }
4314
4315 @Override
4316 protected boolean enterDefault(final Node node) {
4317 throw new AssertionError("Code generator entered node of type " + node.getClass().getName());
4318 }
4319
4320 private void loadTernaryNode(final TernaryNode ternaryNode, final TypeBounds resultBounds) {
4321 final Expression test = ternaryNode.getTest();
4322 final JoinPredecessorExpression trueExpr = ternaryNode.getTrueExpression();
4323 final JoinPredecessorExpression falseExpr = ternaryNode.getFalseExpression();
4324
4325 final Label falseLabel = new Label("ternary_false");
4326 final Label exitLabel = new Label("ternary_exit");
4327
4328 final Type outNarrowest = Type.narrowest(resultBounds.widest, Type.generic(Type.widestReturnType(trueExpr.getType(), falseExpr.getType())));
4329 final TypeBounds outBounds = resultBounds.notNarrowerThan(outNarrowest);
4330
4331 emitBranch(test, falseLabel, false);
4332
4333 final boolean isCurrentDiscard = lc.popDiscardIfCurrent(ternaryNode);
4334 loadMaybeDiscard(isCurrentDiscard, trueExpr.getExpression(), outBounds);
4335 assert isCurrentDiscard || Type.generic(method.peekType()) == outBounds.narrowest;
4336 method.beforeJoinPoint(trueExpr);
4337 method._goto(exitLabel);
4338 method.label(falseLabel);
4339 loadMaybeDiscard(isCurrentDiscard, falseExpr.getExpression(), outBounds);
4340 assert isCurrentDiscard || Type.generic(method.peekType()) == outBounds.narrowest;
4341 method.beforeJoinPoint(falseExpr);
4342 method.label(exitLabel);
4343 }
4344
4345 /**
4346 * Generate all shared scope calls generated during codegen.
4347 */
4348 void generateScopeCalls() {
4349 for (final SharedScopeCall scopeAccess : lc.getScopeCalls()) {
4350 scopeAccess.generateScopeCall();
4351 }
4352 }
4353
4354 /**
4355 * Debug code used to print symbols
4356 *
4357 * @param block the block we are in
4358 * @param function the function we are in
4359 * @param ident identifier for block or function where applicable
4360 */
4361 private void printSymbols(final Block block, final FunctionNode function, final String ident) {
4362 if (compiler.getScriptEnvironment()._print_symbols || function.getDebugFlag(FunctionNode.DEBUG_PRINT_SYMBOLS)) {
4363 final PrintWriter out = compiler.getScriptEnvironment().getErr();
4364 out.println("[BLOCK in '" + ident + "']");
4365 if (!block.printSymbols(out)) {
4366 out.println("<no symbols>");
4367 }
4368 out.println();
4369 }
4370 }
4371
4372
4373 /**
4374 * The difference between a store and a self modifying store is that
4375 * the latter may load part of the target on the stack, e.g. the base
4376 * of an AccessNode or the base and index of an IndexNode. These are used
4377 * both as target and as an extra source. Previously it was problematic
4378 * for self modifying stores if the target/lhs didn't belong to one
4379 * of three trivial categories: IdentNode, AcessNodes, IndexNodes. In that
4380 * case it was evaluated and tagged as "resolved", which meant at the second
4381 * time the lhs of this store was read (e.g. in a = a (second) + b for a += b,
4382 * it would be evaluated to a nop in the scope and cause stack underflow
4383 *
4384 * see NASHORN-703
4385 *
4386 * @param <T>
4387 */
4388 private abstract class SelfModifyingStore<T extends Expression> extends Store<T> {
4389 protected SelfModifyingStore(final T assignNode, final Expression target) {
4390 super(assignNode, target);
4391 }
4392
4393 @Override
4394 protected boolean isSelfModifying() {
4395 return true;
4396 }
4397 }
4398
4399 /**
4400 * Helper class to generate stores
4401 */
4402 private abstract class Store<T extends Expression> {
4403
4404 /** An assignment node, e.g. x += y */
4405 protected final T assignNode;
4406
4407 /** The target node to store to, e.g. x */
4408 private final Expression target;
4409
4410 /** How deep on the stack do the arguments go if this generates an indy call */
4411 private int depth;
4412
4413 /** If we have too many arguments, we need temporary storage, this is stored in 'quick' */
4414 private IdentNode quick;
4415
4416 /**
4417 * Constructor
4418 *
4419 * @param assignNode the node representing the whole assignment
4420 * @param target the target node of the assignment (destination)
4421 */
4422 protected Store(final T assignNode, final Expression target) {
4423 this.assignNode = assignNode;
4424 this.target = target;
4425 }
4426
4427 /**
4428 * Constructor
4429 *
4430 * @param assignNode the node representing the whole assignment
4431 */
4432 protected Store(final T assignNode) {
4433 this(assignNode, assignNode);
4434 }
4435
4436 /**
4437 * Is this a self modifying store operation, e.g. *= or ++
4438 * @return true if self modifying store
4439 */
4440 protected boolean isSelfModifying() {
4441 return false;
4442 }
4443
4444 private void prologue() {
4445 /*
4446 * This loads the parts of the target, e.g base and index. they are kept
4447 * on the stack throughout the store and used at the end to execute it
4448 */
4449
4450 target.accept(new SimpleNodeVisitor() {
4451 @Override
4452 public boolean enterIdentNode(final IdentNode node) {
4453 if (node.getSymbol().isScope()) {
4454 method.loadCompilerConstant(SCOPE);
4455 depth += Type.SCOPE.getSlots();
4456 assert depth == 1;
4457 }
4458 return false;
4459 }
4460
4461 private void enterBaseNode() {
4462 assert target instanceof BaseNode : "error - base node " + target + " must be instanceof BaseNode";
4463 final BaseNode baseNode = (BaseNode)target;
4464 final Expression base = baseNode.getBase();
4465
4466 loadExpressionAsObject(base);
4467 depth += Type.OBJECT.getSlots();
4468 assert depth == 1;
4469
4470 if (isSelfModifying()) {
4471 method.dup();
4472 }
4473 }
4474
4475 @Override
4476 public boolean enterAccessNode(final AccessNode node) {
4477 enterBaseNode();
4478 return false;
4479 }
4480
4481 @Override
4482 public boolean enterIndexNode(final IndexNode node) {
4483 enterBaseNode();
4484
4485 final Expression index = node.getIndex();
4486 if (!index.getType().isNumeric()) {
4487 // could be boolean here as well
4488 loadExpressionAsObject(index);
4489 } else {
4490 loadExpressionUnbounded(index);
4491 }
4492 depth += index.getType().getSlots();
4493
4494 if (isSelfModifying()) {
4495 //convert "base base index" to "base index base index"
4496 method.dup(1);
4497 }
4498
4499 return false;
4500 }
4501
4502 });
4503 }
4504
4505 /**
4506 * Generates an extra local variable, always using the same slot, one that is available after the end of the
4507 * frame.
4508 *
4509 * @param type the type of the variable
4510 *
4511 * @return the quick variable
4512 */
4513 private IdentNode quickLocalVariable(final Type type) {
4514 final String name = lc.getCurrentFunction().uniqueName(QUICK_PREFIX.symbolName());
4515 final Symbol symbol = new Symbol(name, IS_INTERNAL | HAS_SLOT);
4516 symbol.setHasSlotFor(type);
4517 symbol.setFirstSlot(lc.quickSlot(type));
4518
4519 final IdentNode quickIdent = IdentNode.createInternalIdentifier(symbol).setType(type);
4520
4521 return quickIdent;
4522 }
4523
4524 // store the result that "lives on" after the op, e.g. "i" in i++ postfix.
4525 protected void storeNonDiscard() {
4526 if (lc.popDiscardIfCurrent(assignNode)) {
4527 assert assignNode.isAssignment();
4528 return;
4529 }
4530
4531 if (method.dup(depth) == null) {
4532 method.dup();
4533 final Type quickType = method.peekType();
4534 this.quick = quickLocalVariable(quickType);
4535 final Symbol quickSymbol = quick.getSymbol();
4536 method.storeTemp(quickType, quickSymbol.getFirstSlot());
4537 }
4538 }
4539
4540 private void epilogue() {
4541 /**
4542 * Take the original target args from the stack and use them
4543 * together with the value to be stored to emit the store code
4544 *
4545 * The case that targetSymbol is in scope (!hasSlot) and we actually
4546 * need to do a conversion on non-equivalent types exists, but is
4547 * very rare. See for example test/script/basic/access-specializer.js
4548 */
4549 target.accept(new SimpleNodeVisitor() {
4550 @Override
4551 protected boolean enterDefault(final Node node) {
4552 throw new AssertionError("Unexpected node " + node + " in store epilogue");
4553 }
4554
4555 @Override
4556 public boolean enterIdentNode(final IdentNode node) {
4557 final Symbol symbol = node.getSymbol();
4558 assert symbol != null;
4559 if (symbol.isScope()) {
4560 final int flags = getScopeCallSiteFlags(symbol) | (node.isDeclaredHere() ? CALLSITE_DECLARE : 0);
4561 if (isFastScope(symbol)) {
4562 storeFastScopeVar(symbol, flags);
4563 } else {
4564 method.dynamicSet(node.getName(), flags, false);
4565 }
4566 } else {
4567 final Type storeType = assignNode.getType();
4568 assert storeType != Type.LONG;
4569 if (symbol.hasSlotFor(storeType)) {
4570 // Only emit a convert for a store known to be live; converts for dead stores can
4571 // give us an unnecessary ClassCastException.
4572 method.convert(storeType);
4573 }
4574 storeIdentWithCatchConversion(node, storeType);
4575 }
4576 return false;
4577
4578 }
4579
4580 @Override
4581 public boolean enterAccessNode(final AccessNode node) {
4582 method.dynamicSet(node.getProperty(), getCallSiteFlags(), node.isIndex());
4583 return false;
4584 }
4585
4586 @Override
4587 public boolean enterIndexNode(final IndexNode node) {
4588 method.dynamicSetIndex(getCallSiteFlags());
4589 return false;
4590 }
4591 });
4592
4593
4594 // whatever is on the stack now is the final answer
4595 }
4596
4597 protected abstract void evaluate();
4598
4599 void store() {
4600 if (target instanceof IdentNode) {
4601 checkTemporalDeadZone((IdentNode)target);
4602 }
4603 prologue();
4604 evaluate(); // leaves an operation of whatever the operationType was on the stack
4605 storeNonDiscard();
4606 epilogue();
4607 if (quick != null) {
4608 method.load(quick);
4609 }
4610 }
4611 }
4612
4613 private void newFunctionObject(final FunctionNode functionNode, final boolean addInitializer) {
4614 assert lc.peek() == functionNode;
4615
4616 final RecompilableScriptFunctionData data = compiler.getScriptFunctionData(functionNode.getId());
4617
4618 if (functionNode.isProgram() && !compiler.isOnDemandCompilation()) {
4619 final MethodEmitter createFunction = functionNode.getCompileUnit().getClassEmitter().method(
4620 EnumSet.of(Flag.PUBLIC, Flag.STATIC), CREATE_PROGRAM_FUNCTION.symbolName(),
4621 ScriptFunction.class, ScriptObject.class);
4622 createFunction.begin();
4623 loadConstantsAndIndex(data, createFunction);
4624 createFunction.load(SCOPE_TYPE, 0);
4625 createFunction.invoke(CREATE_FUNCTION_OBJECT);
4626 createFunction._return();
4627 createFunction.end();
4628 }
4629
4630 if (addInitializer && !compiler.isOnDemandCompilation()) {
4631 functionNode.getCompileUnit().addFunctionInitializer(data, functionNode);
4632 }
4633
4634 // We don't emit a ScriptFunction on stack for the outermost compiled function (as there's no code being
4635 // generated in its outer context that'd need it as a callee).
4636 if (lc.getOutermostFunction() == functionNode) {
4637 return;
4638 }
4639
4640 loadConstantsAndIndex(data, method);
4641
4642 if (functionNode.needsParentScope()) {
4643 method.loadCompilerConstant(SCOPE);
4644 method.invoke(CREATE_FUNCTION_OBJECT);
4645 } else {
4646 method.invoke(CREATE_FUNCTION_OBJECT_NO_SCOPE);
4647 }
4648 }
4649
4650 // calls on Global class.
4651 private MethodEmitter globalInstance() {
4652 return method.invokestatic(GLOBAL_OBJECT, "instance", "()L" + GLOBAL_OBJECT + ';');
4653 }
4654
4655 private MethodEmitter globalAllocateArguments() {
4656 return method.invokestatic(GLOBAL_OBJECT, "allocateArguments", methodDescriptor(ScriptObject.class, Object[].class, Object.class, int.class));
4657 }
4658
4659 private MethodEmitter globalNewRegExp() {
4660 return method.invokestatic(GLOBAL_OBJECT, "newRegExp", methodDescriptor(Object.class, String.class, String.class));
4661 }
4662
4663 private MethodEmitter globalRegExpCopy() {
4664 return method.invokestatic(GLOBAL_OBJECT, "regExpCopy", methodDescriptor(Object.class, Object.class));
4665 }
4666
4667 private MethodEmitter globalAllocateArray(final ArrayType type) {
4668 //make sure the native array is treated as an array type
4669 return method.invokestatic(GLOBAL_OBJECT, "allocate", "(" + type.getDescriptor() + ")Ljdk/nashorn/internal/objects/NativeArray;");
4670 }
4671
4672 private MethodEmitter globalIsEval() {
4673 return method.invokestatic(GLOBAL_OBJECT, "isEval", methodDescriptor(boolean.class, Object.class));
4674 }
4675
4676 private MethodEmitter globalReplaceLocationPropertyPlaceholder() {
4677 return method.invokestatic(GLOBAL_OBJECT, "replaceLocationPropertyPlaceholder", methodDescriptor(Object.class, Object.class, Object.class));
4678 }
4679
4680 private MethodEmitter globalCheckObjectCoercible() {
4681 return method.invokestatic(GLOBAL_OBJECT, "checkObjectCoercible", methodDescriptor(void.class, Object.class));
4682 }
4683
4684 private MethodEmitter globalDirectEval() {
4685 return method.invokestatic(GLOBAL_OBJECT, "directEval",
4686 methodDescriptor(Object.class, Object.class, Object.class, Object.class, Object.class, boolean.class));
4687 }
4688
4689 private abstract class OptimisticOperation {
4690 final boolean isOptimistic;
4691 // expression and optimistic are the same reference
4692 private final Expression expression;
4693 private final Optimistic optimistic;
4694 private final TypeBounds resultBounds;
4695
4696 OptimisticOperation(final Optimistic optimistic, final TypeBounds resultBounds) {
4697 this.optimistic = optimistic;
4698 this.expression = (Expression)optimistic;
4699 this.resultBounds = resultBounds;
4700 this.isOptimistic = isOptimistic(optimistic)
4701 // Operation is only effectively optimistic if its type, after being coerced into the result bounds
4702 // is narrower than the upper bound.
4703 && resultBounds.within(Type.generic(((Expression)optimistic).getType())).narrowerThan(resultBounds.widest);
4704 // Optimistic operations need to be executed in optimistic context, else unwarranted optimism will go unnoticed
4705 assert !this.isOptimistic || useOptimisticTypes();
4706 }
4707
4708 MethodEmitter emit() {
4709 return emit(0);
4710 }
4711
4712 MethodEmitter emit(final int ignoredArgCount) {
4713 final int programPoint = optimistic.getProgramPoint();
4714 final boolean optimisticOrContinuation = isOptimistic || isContinuationEntryPoint(programPoint);
4715 final boolean currentContinuationEntryPoint = isCurrentContinuationEntryPoint(programPoint);
4716 final int stackSizeOnEntry = method.getStackSize() - ignoredArgCount;
4717
4718 // First store the values on the stack opportunistically into local variables. Doing it before loadStack()
4719 // allows us to not have to pop/load any arguments that are pushed onto it by loadStack() in the second
4720 // storeStack().
4721 storeStack(ignoredArgCount, optimisticOrContinuation);
4722
4723 // Now, load the stack
4724 loadStack();
4725
4726 // Now store the values on the stack ultimately into local variables. In vast majority of cases, this is
4727 // (aside from creating the local types map) a no-op, as the first opportunistic stack store will already
4728 // store all variables. However, there can be operations in the loadStack() that invalidate some of the
4729 // stack stores, e.g. in "x[i] = x[++i]", "++i" will invalidate the already stored value for "i". In such
4730 // unfortunate cases this second storeStack() will restore the invariant that everything on the stack is
4731 // stored into a local variable, although at the cost of doing a store/load on the loaded arguments as well.
4732 final int liveLocalsCount = storeStack(method.getStackSize() - stackSizeOnEntry, optimisticOrContinuation);
4733 assert optimisticOrContinuation == (liveLocalsCount != -1);
4734
4735 final Label beginTry;
4736 final Label catchLabel;
4737 final Label afterConsumeStack = isOptimistic || currentContinuationEntryPoint ? new Label("after_consume_stack") : null;
4738 if(isOptimistic) {
4739 beginTry = new Label("try_optimistic");
4740 final String catchLabelName = (afterConsumeStack == null ? "" : afterConsumeStack.toString()) + "_handler";
4741 catchLabel = new Label(catchLabelName);
4742 method.label(beginTry);
4743 } else {
4744 beginTry = catchLabel = null;
4745 }
4746
4747 consumeStack();
4748
4749 if(isOptimistic) {
4750 method._try(beginTry, afterConsumeStack, catchLabel, UnwarrantedOptimismException.class);
4751 }
4752
4753 if(isOptimistic || currentContinuationEntryPoint) {
4754 method.label(afterConsumeStack);
4755
4756 final int[] localLoads = method.getLocalLoadsOnStack(0, stackSizeOnEntry);
4757 assert everyStackValueIsLocalLoad(localLoads) : Arrays.toString(localLoads) + ", " + stackSizeOnEntry + ", " + ignoredArgCount;
4758 final List<Type> localTypesList = method.getLocalVariableTypes();
4759 final int usedLocals = method.getUsedSlotsWithLiveTemporaries();
4760 final List<Type> localTypes = method.getWidestLiveLocals(localTypesList.subList(0, usedLocals));
4761 assert everyLocalLoadIsValid(localLoads, usedLocals) : Arrays.toString(localLoads) + " ~ " + localTypes;
4762
4763 if(isOptimistic) {
4764 addUnwarrantedOptimismHandlerLabel(localTypes, catchLabel);
4765 }
4766 if(currentContinuationEntryPoint) {
4767 final ContinuationInfo ci = getContinuationInfo();
4768 assert ci != null : "no continuation info found for " + lc.getCurrentFunction();
4769 assert !ci.hasTargetLabel(); // No duplicate program points
4770 ci.setTargetLabel(afterConsumeStack);
4771 ci.getHandlerLabel().markAsOptimisticContinuationHandlerFor(afterConsumeStack);
4772 // Can't rely on targetLabel.stack.localVariableTypes.length, as it can be higher due to effectively
4773 // dead local variables.
4774 ci.lvarCount = localTypes.size();
4775 ci.setStackStoreSpec(localLoads);
4776 ci.setStackTypes(Arrays.copyOf(method.getTypesFromStack(method.getStackSize()), stackSizeOnEntry));
4777 assert ci.getStackStoreSpec().length == ci.getStackTypes().length;
4778 ci.setReturnValueType(method.peekType());
4779 ci.lineNumber = getLastLineNumber();
4780 ci.catchLabel = catchLabels.peek();
4781 }
4782 }
4783 return method;
4784 }
4785
4786 /**
4787 * Stores the current contents of the stack into local variables so they are not lost before invoking something that
4788 * can result in an {@code UnwarantedOptimizationException}.
4789 * @param ignoreArgCount the number of topmost arguments on stack to ignore when deciding on the shape of the catch
4790 * block. Those are used in the situations when we could not place the call to {@code storeStack} early enough
4791 * (before emitting code for pushing the arguments that the optimistic call will pop). This is admittedly a
4792 * deficiency in the design of the code generator when it deals with self-assignments and we should probably look
4793 * into fixing it.
4794 * @return types of the significant local variables after the stack was stored (types for local variables used
4795 * for temporary storage of ignored arguments are not returned).
4796 * @param optimisticOrContinuation if false, this method should not execute
4797 * a label for a catch block for the {@code UnwarantedOptimizationException}, suitable for capturing the
4798 * currently live local variables, tailored to their types.
4799 */
4800 private int storeStack(final int ignoreArgCount, final boolean optimisticOrContinuation) {
4801 if(!optimisticOrContinuation) {
4802 return -1; // NOTE: correct value to return is lc.getUsedSlotCount(), but it wouldn't be used anyway
4803 }
4804
4805 final int stackSize = method.getStackSize();
4806 final Type[] stackTypes = method.getTypesFromStack(stackSize);
4807 final int[] localLoadsOnStack = method.getLocalLoadsOnStack(0, stackSize);
4808 final int usedSlots = method.getUsedSlotsWithLiveTemporaries();
4809
4810 final int firstIgnored = stackSize - ignoreArgCount;
4811 // Find the first value on the stack (from the bottom) that is not a load from a local variable.
4812 int firstNonLoad = 0;
4813 while(firstNonLoad < firstIgnored && localLoadsOnStack[firstNonLoad] != Label.Stack.NON_LOAD) {
4814 firstNonLoad++;
4815 }
4816
4817 // Only do the store/load if first non-load is not an ignored argument. Otherwise, do nothing and return
4818 // the number of used slots as the number of live local variables.
4819 if(firstNonLoad >= firstIgnored) {
4820 return usedSlots;
4821 }
4822
4823 // Find the number of new temporary local variables that we need; it's the number of values on the stack that
4824 // are not direct loads of existing local variables.
4825 int tempSlotsNeeded = 0;
4826 for(int i = firstNonLoad; i < stackSize; ++i) {
4827 if(localLoadsOnStack[i] == Label.Stack.NON_LOAD) {
4828 tempSlotsNeeded += stackTypes[i].getSlots();
4829 }
4830 }
4831
4832 // Ensure all values on the stack that weren't directly loaded from a local variable are stored in a local
4833 // variable. We're starting from highest local variable index, so that in case ignoreArgCount > 0 the ignored
4834 // ones end up at the end of the local variable table.
4835 int lastTempSlot = usedSlots + tempSlotsNeeded;
4836 int ignoreSlotCount = 0;
4837 for(int i = stackSize; i -- > firstNonLoad;) {
4838 final int loadSlot = localLoadsOnStack[i];
4839 if(loadSlot == Label.Stack.NON_LOAD) {
4840 final Type type = stackTypes[i];
4841 final int slots = type.getSlots();
4842 lastTempSlot -= slots;
4843 if(i >= firstIgnored) {
4844 ignoreSlotCount += slots;
4845 }
4846 method.storeTemp(type, lastTempSlot);
4847 } else {
4848 method.pop();
4849 }
4850 }
4851 assert lastTempSlot == usedSlots; // used all temporary locals
4852
4853 final List<Type> localTypesList = method.getLocalVariableTypes();
4854
4855 // Load values back on stack.
4856 for(int i = firstNonLoad; i < stackSize; ++i) {
4857 final int loadSlot = localLoadsOnStack[i];
4858 final Type stackType = stackTypes[i];
4859 final boolean isLoad = loadSlot != Label.Stack.NON_LOAD;
4860 final int lvarSlot = isLoad ? loadSlot : lastTempSlot;
4861 final Type lvarType = localTypesList.get(lvarSlot);
4862 method.load(lvarType, lvarSlot);
4863 if(isLoad) {
4864 // Conversion operators (I2L etc.) preserve "load"-ness of the value despite the fact that, in the
4865 // strict sense they are creating a derived value from the loaded value. This special behavior of
4866 // on-stack conversion operators is necessary to accommodate for differences in local variable types
4867 // after deoptimization; having a conversion operator throw away "load"-ness would create different
4868 // local variable table shapes between optimism-failed code and its deoptimized rest-of method).
4869 // After we load the value back, we need to redo the conversion to the stack type if stack type is
4870 // different.
4871 // NOTE: this would only strictly be necessary for widening conversions (I2L, L2D, I2D), and not for
4872 // narrowing ones (L2I, D2L, D2I) as only widening conversions are the ones that can get eliminated
4873 // in a deoptimized method, as their original input argument got widened. Maybe experiment with
4874 // throwing away "load"-ness for narrowing conversions in MethodEmitter.convert()?
4875 method.convert(stackType);
4876 } else {
4877 // temporary stores never needs a convert, as their type is always the same as the stack type.
4878 assert lvarType == stackType;
4879 lastTempSlot += lvarType.getSlots();
4880 }
4881 }
4882 // used all temporaries
4883 assert lastTempSlot == usedSlots + tempSlotsNeeded;
4884
4885 return lastTempSlot - ignoreSlotCount;
4886 }
4887
4888 private void addUnwarrantedOptimismHandlerLabel(final List<Type> localTypes, final Label label) {
4889 final String lvarTypesDescriptor = getLvarTypesDescriptor(localTypes);
4890 final Map<String, Collection<Label>> unwarrantedOptimismHandlers = lc.getUnwarrantedOptimismHandlers();
4891 Collection<Label> labels = unwarrantedOptimismHandlers.get(lvarTypesDescriptor);
4892 if(labels == null) {
4893 labels = new LinkedList<>();
4894 unwarrantedOptimismHandlers.put(lvarTypesDescriptor, labels);
4895 }
4896 method.markLabelAsOptimisticCatchHandler(label, localTypes.size());
4897 labels.add(label);
4898 }
4899
4900 abstract void loadStack();
4901
4902 // Make sure that whatever indy call site you emit from this method uses {@code getCallSiteFlagsOptimistic(node)}
4903 // or otherwise ensure optimistic flag is correctly set in the call site, otherwise it doesn't make much sense
4904 // to use OptimisticExpression for emitting it.
4905 abstract void consumeStack();
4906
4907 /**
4908 * Emits the correct dynamic getter code. Normally just delegates to method emitter, except when the target
4909 * expression is optimistic, and the desired type is narrower than the optimistic type. In that case, it'll emit a
4910 * dynamic getter with its original optimistic type, and explicitly insert a narrowing conversion. This way we can
4911 * preserve the optimism of the values even if they're subsequently immediately coerced into a narrower type. This
4912 * is beneficial because in this case we can still presume that since the original getter was optimistic, the
4913 * conversion has no side effects.
4914 * @param name the name of the property being get
4915 * @param flags call site flags
4916 * @param isMethod whether we're preferably retrieving a function
4917 * @return the current method emitter
4918 */
4919 MethodEmitter dynamicGet(final String name, final int flags, final boolean isMethod, final boolean isIndex) {
4920 if(isOptimistic) {
4921 return method.dynamicGet(getOptimisticCoercedType(), name, getOptimisticFlags(flags), isMethod, isIndex);
4922 }
4923 return method.dynamicGet(resultBounds.within(expression.getType()), name, nonOptimisticFlags(flags), isMethod, isIndex);
4924 }
4925
4926 MethodEmitter dynamicGetIndex(final int flags, final boolean isMethod) {
4927 if(isOptimistic) {
4928 return method.dynamicGetIndex(getOptimisticCoercedType(), getOptimisticFlags(flags), isMethod);
4929 }
4930 return method.dynamicGetIndex(resultBounds.within(expression.getType()), nonOptimisticFlags(flags), isMethod);
4931 }
4932
4933 MethodEmitter dynamicCall(final int argCount, final int flags, final String msg) {
4934 if (isOptimistic) {
4935 return method.dynamicCall(getOptimisticCoercedType(), argCount, getOptimisticFlags(flags), msg);
4936 }
4937 return method.dynamicCall(resultBounds.within(expression.getType()), argCount, nonOptimisticFlags(flags), msg);
4938 }
4939
4940 int getOptimisticFlags(final int flags) {
4941 return flags | CALLSITE_OPTIMISTIC | (optimistic.getProgramPoint() << CALLSITE_PROGRAM_POINT_SHIFT); //encode program point in high bits
4942 }
4943
4944 int getProgramPoint() {
4945 return isOptimistic ? optimistic.getProgramPoint() : INVALID_PROGRAM_POINT;
4946 }
4947
4948 void convertOptimisticReturnValue() {
4949 if (isOptimistic) {
4950 final Type optimisticType = getOptimisticCoercedType();
4951 if(!optimisticType.isObject()) {
4952 method.load(optimistic.getProgramPoint());
4953 if(optimisticType.isInteger()) {
4954 method.invoke(ENSURE_INT);
4955 } else if(optimisticType.isNumber()) {
4956 method.invoke(ENSURE_NUMBER);
4957 } else {
4958 throw new AssertionError(optimisticType);
4959 }
4960 }
4961 }
4962 }
4963
4964 void replaceCompileTimeProperty() {
4965 final IdentNode identNode = (IdentNode)expression;
4966 final String name = identNode.getSymbol().getName();
4967 if (CompilerConstants.__FILE__.name().equals(name)) {
4968 replaceCompileTimeProperty(getCurrentSource().getName());
4969 } else if (CompilerConstants.__DIR__.name().equals(name)) {
4970 replaceCompileTimeProperty(getCurrentSource().getBase());
4971 } else if (CompilerConstants.__LINE__.name().equals(name)) {
4972 replaceCompileTimeProperty(getCurrentSource().getLine(identNode.position()));
4973 }
4974 }
4975
4976 /**
4977 * When an ident with name __FILE__, __DIR__, or __LINE__ is loaded, we'll try to look it up as any other
4978 * identifier. However, if it gets all the way up to the Global object, it will send back a special value that
4979 * represents a placeholder for these compile-time location properties. This method will generate code that loads
4980 * the value of the compile-time location property and then invokes a method in Global that will replace the
4981 * placeholder with the value. Effectively, if the symbol for these properties is defined anywhere in the lexical
4982 * scope, they take precedence, but if they aren't, then they resolve to the compile-time location property.
4983 * @param propertyValue the actual value of the property
4984 */
4985 private void replaceCompileTimeProperty(final Object propertyValue) {
4986 assert method.peekType().isObject();
4987 if(propertyValue instanceof String || propertyValue == null) {
4988 method.load((String)propertyValue);
4989 } else if(propertyValue instanceof Integer) {
4990 method.load(((Integer)propertyValue));
4991 method.convert(Type.OBJECT);
4992 } else {
4993 throw new AssertionError();
4994 }
4995 globalReplaceLocationPropertyPlaceholder();
4996 convertOptimisticReturnValue();
4997 }
4998
4999 /**
5000 * Returns the type that should be used as the return type of the dynamic invocation that is emitted as the code
5001 * for the current optimistic operation. If the type bounds is exact boolean or narrower than the expression's
5002 * optimistic type, then the optimistic type is returned, otherwise the coercing type. Effectively, this method
5003 * allows for moving the coercion into the optimistic type when it won't adversely affect the optimistic
5004 * evaluation semantics, and for preserving the optimistic type and doing a separate coercion when it would
5005 * affect it.
5006 * @return
5007 */
5008 Type getOptimisticCoercedType() {
5009 final Type optimisticType = expression.getType();
5010 assert resultBounds.widest.widerThan(optimisticType);
5011 final Type narrowest = resultBounds.narrowest;
5012
5013 if(narrowest.isBoolean() || narrowest.narrowerThan(optimisticType)) {
5014 assert !optimisticType.isObject();
5015 return optimisticType;
5016 }
5017 assert !narrowest.isObject();
5018 return narrowest;
5019 }
5020 }
5021
5022 private static boolean isOptimistic(final Optimistic optimistic) {
5023 if(!optimistic.canBeOptimistic()) {
5024 return false;
5025 }
5026 final Expression expr = (Expression)optimistic;
5027 return expr.getType().narrowerThan(expr.getWidestOperationType());
5028 }
5029
5030 private static boolean everyLocalLoadIsValid(final int[] loads, final int localCount) {
5031 for (final int load : loads) {
5032 if(load < 0 || load >= localCount) {
5033 return false;
5034 }
5035 }
5036 return true;
5037 }
5038
5039 private static boolean everyStackValueIsLocalLoad(final int[] loads) {
5040 for (final int load : loads) {
5041 if(load == Label.Stack.NON_LOAD) {
5042 return false;
5043 }
5044 }
5045 return true;
5046 }
5047
5048 private String getLvarTypesDescriptor(final List<Type> localVarTypes) {
5049 final int count = localVarTypes.size();
5050 final StringBuilder desc = new StringBuilder(count);
5051 for(int i = 0; i < count;) {
5052 i += appendType(desc, localVarTypes.get(i));
5053 }
5054 return method.markSymbolBoundariesInLvarTypesDescriptor(desc.toString());
5055 }
5056
5057 private static int appendType(final StringBuilder b, final Type t) {
5058 b.append(t.getBytecodeStackType());
5059 return t.getSlots();
5060 }
5061
5062 private static int countSymbolsInLvarTypeDescriptor(final String lvarTypeDescriptor) {
5063 int count = 0;
5064 for(int i = 0; i < lvarTypeDescriptor.length(); ++i) {
5065 if(Character.isUpperCase(lvarTypeDescriptor.charAt(i))) {
5066 ++count;
5067 }
5068 }
5069 return count;
5070
5071 }
5072 /**
5073 * Generates all the required {@code UnwarrantedOptimismException} handlers for the current function. The employed
5074 * strategy strives to maximize code reuse. Every handler constructs an array to hold the local variables, then
5075 * fills in some trailing part of the local variables (those for which it has a unique suffix in the descriptor),
5076 * then jumps to a handler for a prefix that's shared with other handlers. A handler that fills up locals up to
5077 * position 0 will not jump to a prefix handler (as it has no prefix), but instead end with constructing and
5078 * throwing a {@code RewriteException}. Since we lexicographically sort the entries, we only need to check every
5079 * entry to its immediately preceding one for longest matching prefix.
5080 * @return true if there is at least one exception handler
5081 */
5082 private boolean generateUnwarrantedOptimismExceptionHandlers(final FunctionNode fn) {
5083 if(!useOptimisticTypes()) {
5084 return false;
5085 }
5086
5087 // Take the mapping of lvarSpecs -> labels, and turn them into a descending lexicographically sorted list of
5088 // handler specifications.
5089 final Map<String, Collection<Label>> unwarrantedOptimismHandlers = lc.popUnwarrantedOptimismHandlers();
5090 if(unwarrantedOptimismHandlers.isEmpty()) {
5091 return false;
5092 }
5093
5094 method.lineNumber(0);
5095
5096 final List<OptimismExceptionHandlerSpec> handlerSpecs = new ArrayList<>(unwarrantedOptimismHandlers.size() * 4/3);
5097 for(final String spec: unwarrantedOptimismHandlers.keySet()) {
5098 handlerSpecs.add(new OptimismExceptionHandlerSpec(spec, true));
5099 }
5100 Collections.sort(handlerSpecs, Collections.reverseOrder());
5101
5102 // Map of local variable specifications to labels for populating the array for that local variable spec.
5103 final Map<String, Label> delegationLabels = new HashMap<>();
5104
5105 // Do everything in a single pass over the handlerSpecs list. Note that the list can actually grow as we're
5106 // passing through it as we might add new prefix handlers into it, so can't hoist size() outside of the loop.
5107 for(int handlerIndex = 0; handlerIndex < handlerSpecs.size(); ++handlerIndex) {
5108 final OptimismExceptionHandlerSpec spec = handlerSpecs.get(handlerIndex);
5109 final String lvarSpec = spec.lvarSpec;
5110 if(spec.catchTarget) {
5111 assert !method.isReachable();
5112 // Start a catch block and assign the labels for this lvarSpec with it.
5113 method._catch(unwarrantedOptimismHandlers.get(lvarSpec));
5114 // This spec is a catch target, so emit array creation code. The length of the array is the number of
5115 // symbols - the number of uppercase characters.
5116 method.load(countSymbolsInLvarTypeDescriptor(lvarSpec));
5117 method.newarray(Type.OBJECT_ARRAY);
5118 }
5119 if(spec.delegationTarget) {
5120 // If another handler can delegate to this handler as its prefix, then put a jump target here for the
5121 // shared code (after the array creation code, which is never shared).
5122 method.label(delegationLabels.get(lvarSpec)); // label must exist
5123 }
5124
5125 final boolean lastHandler = handlerIndex == handlerSpecs.size() - 1;
5126
5127 int lvarIndex;
5128 final int firstArrayIndex;
5129 final int firstLvarIndex;
5130 Label delegationLabel;
5131 final String commonLvarSpec;
5132 if(lastHandler) {
5133 // Last handler block, doesn't delegate to anything.
5134 lvarIndex = 0;
5135 firstLvarIndex = 0;
5136 firstArrayIndex = 0;
5137 delegationLabel = null;
5138 commonLvarSpec = null;
5139 } else {
5140 // Not yet the last handler block, will definitely delegate to another handler; let's figure out which
5141 // one. It can be an already declared handler further down the list, or it might need to declare a new
5142 // prefix handler.
5143
5144 // Since we're lexicographically ordered, the common prefix handler is defined by the common prefix of
5145 // this handler and the next handler on the list.
5146 final int nextHandlerIndex = handlerIndex + 1;
5147 final String nextLvarSpec = handlerSpecs.get(nextHandlerIndex).lvarSpec;
5148 commonLvarSpec = commonPrefix(lvarSpec, nextLvarSpec);
5149 // We don't chop symbols in half
5150 assert Character.isUpperCase(commonLvarSpec.charAt(commonLvarSpec.length() - 1));
5151
5152 // Let's find if we already have a declaration for such handler, or we need to insert it.
5153 {
5154 boolean addNewHandler = true;
5155 int commonHandlerIndex = nextHandlerIndex;
5156 for(; commonHandlerIndex < handlerSpecs.size(); ++commonHandlerIndex) {
5157 final OptimismExceptionHandlerSpec forwardHandlerSpec = handlerSpecs.get(commonHandlerIndex);
5158 final String forwardLvarSpec = forwardHandlerSpec.lvarSpec;
5159 if(forwardLvarSpec.equals(commonLvarSpec)) {
5160 // We already have a handler for the common prefix.
5161 addNewHandler = false;
5162 // Make sure we mark it as a delegation target.
5163 forwardHandlerSpec.delegationTarget = true;
5164 break;
5165 } else if(!forwardLvarSpec.startsWith(commonLvarSpec)) {
5166 break;
5167 }
5168 }
5169 if(addNewHandler) {
5170 // We need to insert a common prefix handler. Note handlers created with catchTarget == false
5171 // will automatically have delegationTarget == true (because that's the only reason for their
5172 // existence).
5173 handlerSpecs.add(commonHandlerIndex, new OptimismExceptionHandlerSpec(commonLvarSpec, false));
5174 }
5175 }
5176
5177 firstArrayIndex = countSymbolsInLvarTypeDescriptor(commonLvarSpec);
5178 lvarIndex = 0;
5179 for(int j = 0; j < commonLvarSpec.length(); ++j) {
5180 lvarIndex += CodeGeneratorLexicalContext.getTypeForSlotDescriptor(commonLvarSpec.charAt(j)).getSlots();
5181 }
5182 firstLvarIndex = lvarIndex;
5183
5184 // Create a delegation label if not already present
5185 delegationLabel = delegationLabels.get(commonLvarSpec);
5186 if(delegationLabel == null) {
5187 // uo_pa == "unwarranted optimism, populate array"
5188 delegationLabel = new Label("uo_pa_" + commonLvarSpec);
5189 delegationLabels.put(commonLvarSpec, delegationLabel);
5190 }
5191 }
5192
5193 // Load local variables handled by this handler on stack
5194 int args = 0;
5195 boolean symbolHadValue = false;
5196 for(int typeIndex = commonLvarSpec == null ? 0 : commonLvarSpec.length(); typeIndex < lvarSpec.length(); ++typeIndex) {
5197 final char typeDesc = lvarSpec.charAt(typeIndex);
5198 final Type lvarType = CodeGeneratorLexicalContext.getTypeForSlotDescriptor(typeDesc);
5199 if (!lvarType.isUnknown()) {
5200 method.load(lvarType, lvarIndex);
5201 symbolHadValue = true;
5202 args++;
5203 } else if(typeDesc == 'U' && !symbolHadValue) {
5204 // Symbol boundary with undefined last value. Check if all previous values for this symbol were also
5205 // undefined; if so, emit one explicit Undefined. This serves to ensure that we're emiting exactly
5206 // one value for every symbol that uses local slots. While we could in theory ignore symbols that
5207 // are undefined (in other words, dead) at the point where this exception was thrown, unfortunately
5208 // we can't do it in practice. The reason for this is that currently our liveness analysis is
5209 // coarse (it can determine whether a symbol has not been read with a particular type anywhere in
5210 // the function being compiled, but that's it), and a symbol being promoted to Object due to a
5211 // deoptimization will suddenly show up as "live for Object type", and previously dead U->O
5212 // conversions on loop entries will suddenly become alive in the deoptimized method which will then
5213 // expect a value for that slot in its continuation handler. If we had precise liveness analysis, we
5214 // could go back to excluding known dead symbols from the payload of the RewriteException.
5215 if(method.peekType() == Type.UNDEFINED) {
5216 method.dup();
5217 } else {
5218 method.loadUndefined(Type.OBJECT);
5219 }
5220 args++;
5221 }
5222 if(Character.isUpperCase(typeDesc)) {
5223 // Reached symbol boundary; reset flag for the next symbol.
5224 symbolHadValue = false;
5225 }
5226 lvarIndex += lvarType.getSlots();
5227 }
5228 assert args > 0;
5229 // Delegate actual storing into array to an array populator utility method.
5230 //on the stack:
5231 // object array to be populated
5232 // start index
5233 // a lot of types
5234 method.dynamicArrayPopulatorCall(args + 1, firstArrayIndex);
5235 if(delegationLabel != null) {
5236 // We cascade to a prefix handler to fill out the rest of the local variables and throw the
5237 // RewriteException.
5238 assert !lastHandler;
5239 assert commonLvarSpec != null;
5240 // Must undefine the local variables that we have already processed for the sake of correct join on the
5241 // delegate label
5242 method.undefineLocalVariables(firstLvarIndex, true);
5243 final OptimismExceptionHandlerSpec nextSpec = handlerSpecs.get(handlerIndex + 1);
5244 // If the delegate immediately follows, and it's not a catch target (so it doesn't have array setup
5245 // code) don't bother emitting a jump, as we'd just jump to the next instruction.
5246 if(!nextSpec.lvarSpec.equals(commonLvarSpec) || nextSpec.catchTarget) {
5247 method._goto(delegationLabel);
5248 }
5249 } else {
5250 assert lastHandler;
5251 // Nothing to delegate to, so this handler must create and throw the RewriteException.
5252 // At this point we have the UnwarrantedOptimismException and the Object[] with local variables on
5253 // stack. We need to create a RewriteException, push two references to it below the constructor
5254 // arguments, invoke the constructor, and throw the exception.
5255 loadConstant(getByteCodeSymbolNames(fn));
5256 if (isRestOf()) {
5257 loadConstant(getContinuationEntryPoints());
5258 method.invoke(CREATE_REWRITE_EXCEPTION_REST_OF);
5259 } else {
5260 method.invoke(CREATE_REWRITE_EXCEPTION);
5261 }
5262 method.athrow();
5263 }
5264 }
5265 return true;
5266 }
5267
5268 private static String[] getByteCodeSymbolNames(final FunctionNode fn) {
5269 // Only names of local variables on the function level are captured. This information is used to reduce
5270 // deoptimizations, so as much as we can capture will help. We rely on the fact that function wide variables are
5271 // all live all the time, so the array passed to rewrite exception contains one element for every slotted symbol
5272 // here.
5273 final List<String> names = new ArrayList<>();
5274 for (final Symbol symbol: fn.getBody().getSymbols()) {
5275 if (symbol.hasSlot()) {
5276 if (symbol.isScope()) {
5277 // slot + scope can only be true for parameters
5278 assert symbol.isParam();
5279 names.add(null);
5280 } else {
5281 names.add(symbol.getName());
5282 }
5283 }
5284 }
5285 return names.toArray(new String[0]);
5286 }
5287
5288 private static String commonPrefix(final String s1, final String s2) {
5289 final int l1 = s1.length();
5290 final int l = Math.min(l1, s2.length());
5291 int lms = -1; // last matching symbol
5292 for(int i = 0; i < l; ++i) {
5293 final char c1 = s1.charAt(i);
5294 if(c1 != s2.charAt(i)) {
5295 return s1.substring(0, lms + 1);
5296 } else if(Character.isUpperCase(c1)) {
5297 lms = i;
5298 }
5299 }
5300 return l == l1 ? s1 : s2;
5301 }
5302
5303 private static class OptimismExceptionHandlerSpec implements Comparable<OptimismExceptionHandlerSpec> {
5304 private final String lvarSpec;
5305 private final boolean catchTarget;
5306 private boolean delegationTarget;
5307
5308 OptimismExceptionHandlerSpec(final String lvarSpec, final boolean catchTarget) {
5309 this.lvarSpec = lvarSpec;
5310 this.catchTarget = catchTarget;
5311 if(!catchTarget) {
5312 delegationTarget = true;
5313 }
5314 }
5315
5316 @Override
5317 public int compareTo(final OptimismExceptionHandlerSpec o) {
5318 return lvarSpec.compareTo(o.lvarSpec);
5319 }
5320
5321 @Override
5322 public String toString() {
5323 final StringBuilder b = new StringBuilder(64).append("[HandlerSpec ").append(lvarSpec);
5324 if(catchTarget) {
5325 b.append(", catchTarget");
5326 }
5327 if(delegationTarget) {
5328 b.append(", delegationTarget");
5329 }
5330 return b.append("]").toString();
5331 }
5332 }
5333
5334 private static class ContinuationInfo {
5335 private final Label handlerLabel;
5336 private Label targetLabel; // Label for the target instruction.
5337 int lvarCount;
5338 // Indices of local variables that need to be loaded on the stack when this node completes
5339 private int[] stackStoreSpec;
5340 // Types of values loaded on the stack
5341 private Type[] stackTypes;
5342 // If non-null, this node should perform the requisite type conversion
5343 private Type returnValueType;
5344 // If we are in the middle of an object literal initialization, we need to update the property maps
5345 private Map<Integer, PropertyMap> objectLiteralMaps;
5346 // The line number at the continuation point
5347 private int lineNumber;
5348 // The active catch label, in case the continuation point is in a try/catch block
5349 private Label catchLabel;
5350 // The number of scopes that need to be popped before control is transferred to the catch label.
5351 private int exceptionScopePops;
5352
5353 ContinuationInfo() {
5354 this.handlerLabel = new Label("continuation_handler");
5355 }
5356
5357 Label getHandlerLabel() {
5358 return handlerLabel;
5359 }
5360
5361 boolean hasTargetLabel() {
5362 return targetLabel != null;
5363 }
5364
5365 Label getTargetLabel() {
5366 return targetLabel;
5367 }
5368
5369 void setTargetLabel(final Label targetLabel) {
5370 this.targetLabel = targetLabel;
5371 }
5372
5373 int[] getStackStoreSpec() {
5374 return stackStoreSpec.clone();
5375 }
5376
5377 void setStackStoreSpec(final int[] stackStoreSpec) {
5378 this.stackStoreSpec = stackStoreSpec;
5379 }
5380
5381 Type[] getStackTypes() {
5382 return stackTypes.clone();
5383 }
5384
5385 void setStackTypes(final Type[] stackTypes) {
5386 this.stackTypes = stackTypes;
5387 }
5388
5389 Type getReturnValueType() {
5390 return returnValueType;
5391 }
5392
5393 void setReturnValueType(final Type returnValueType) {
5394 this.returnValueType = returnValueType;
5395 }
5396
5397 void setObjectLiteralMap(final int objectLiteralStackDepth, final PropertyMap objectLiteralMap) {
5398 if (objectLiteralMaps == null) {
5399 objectLiteralMaps = new HashMap<>();
5400 }
5401 objectLiteralMaps.put(objectLiteralStackDepth, objectLiteralMap);
5402 }
5403
5404 PropertyMap getObjectLiteralMap(final int stackDepth) {
5405 return objectLiteralMaps == null ? null : objectLiteralMaps.get(stackDepth);
5406 }
5407
5408 @Override
5409 public String toString() {
5410 return "[localVariableTypes=" + targetLabel.getStack().getLocalVariableTypesCopy() + ", stackStoreSpec=" +
5411 Arrays.toString(stackStoreSpec) + ", returnValueType=" + returnValueType + "]";
5412 }
5413 }
5414
5415 private ContinuationInfo getContinuationInfo() {
5416 return continuationInfo;
5417 }
5418
5419 private void generateContinuationHandler() {
5420 if (!isRestOf()) {
5421 return;
5422 }
5423
5424 final ContinuationInfo ci = getContinuationInfo();
5425 method.label(ci.getHandlerLabel());
5426
5427 // There should never be an exception thrown from the continuation handler, but in case there is (meaning,
5428 // Nashorn has a bug), then line number 0 will be an indication of where it came from (line numbers are Uint16).
5429 method.lineNumber(0);
5430
5431 final Label.Stack stack = ci.getTargetLabel().getStack();
5432 final List<Type> lvarTypes = stack.getLocalVariableTypesCopy();
5433 final BitSet symbolBoundary = stack.getSymbolBoundaryCopy();
5434 final int lvarCount = ci.lvarCount;
5435
5436 final Type rewriteExceptionType = Type.typeFor(RewriteException.class);
5437 // Store the RewriteException into an unused local variable slot.
5438 method.load(rewriteExceptionType, 0);
5439 method.storeTemp(rewriteExceptionType, lvarCount);
5440 // Get local variable array
5441 method.load(rewriteExceptionType, 0);
5442 method.invoke(RewriteException.GET_BYTECODE_SLOTS);
5443 // Store local variables. Note that deoptimization might introduce new value types for existing local variables,
5444 // so we must use both liveLocals and symbolBoundary, as in some cases (when the continuation is inside of a try
5445 // block) we need to store the incoming value into multiple slots. The optimism exception handlers will have
5446 // exactly one array element for every symbol that uses bytecode storage. If in the originating method the value
5447 // was undefined, there will be an explicit Undefined value in the array.
5448 int arrayIndex = 0;
5449 for(int lvarIndex = 0; lvarIndex < lvarCount;) {
5450 final Type lvarType = lvarTypes.get(lvarIndex);
5451 if(!lvarType.isUnknown()) {
5452 method.dup();
5453 method.load(arrayIndex).arrayload();
5454 final Class<?> typeClass = lvarType.getTypeClass();
5455 // Deoptimization in array initializers can cause arrays to undergo component type widening
5456 if(typeClass == long[].class) {
5457 method.load(rewriteExceptionType, lvarCount);
5458 method.invoke(RewriteException.TO_LONG_ARRAY);
5459 } else if(typeClass == double[].class) {
5460 method.load(rewriteExceptionType, lvarCount);
5461 method.invoke(RewriteException.TO_DOUBLE_ARRAY);
5462 } else if(typeClass == Object[].class) {
5463 method.load(rewriteExceptionType, lvarCount);
5464 method.invoke(RewriteException.TO_OBJECT_ARRAY);
5465 } else {
5466 if(!(typeClass.isPrimitive() || typeClass == Object.class)) {
5467 // NOTE: this can only happen with dead stores. E.g. for the program "1; []; f();" in which the
5468 // call to f() will deoptimize the call site, but it'll expect :return to have the type
5469 // NativeArray. However, in the more optimal version, :return's only live type is int, therefore
5470 // "{O}:return = []" is a dead store, and the variable will be sent into the continuation as
5471 // Undefined, however NativeArray can't hold Undefined instance.
5472 method.loadType(Type.getInternalName(typeClass));
5473 method.invoke(RewriteException.INSTANCE_OR_NULL);
5474 }
5475 method.convert(lvarType);
5476 }
5477 method.storeHidden(lvarType, lvarIndex, false);
5478 }
5479 final int nextLvarIndex = lvarIndex + lvarType.getSlots();
5480 if(symbolBoundary.get(nextLvarIndex - 1)) {
5481 ++arrayIndex;
5482 }
5483 lvarIndex = nextLvarIndex;
5484 }
5485 if (AssertsEnabled.assertsEnabled()) {
5486 method.load(arrayIndex);
5487 method.invoke(RewriteException.ASSERT_ARRAY_LENGTH);
5488 } else {
5489 method.pop();
5490 }
5491
5492 final int[] stackStoreSpec = ci.getStackStoreSpec();
5493 final Type[] stackTypes = ci.getStackTypes();
5494 final boolean isStackEmpty = stackStoreSpec.length == 0;
5495 int replacedObjectLiteralMaps = 0;
5496 if(!isStackEmpty) {
5497 // Load arguments on the stack
5498 for(int i = 0; i < stackStoreSpec.length; ++i) {
5499 final int slot = stackStoreSpec[i];
5500 method.load(lvarTypes.get(slot), slot);
5501 method.convert(stackTypes[i]);
5502 // stack: s0=object literal being initialized
5503 // change map of s0 so that the property we are initializing when we failed
5504 // is now ci.returnValueType
5505 final PropertyMap map = ci.getObjectLiteralMap(i);
5506 if (map != null) {
5507 method.dup();
5508 assert ScriptObject.class.isAssignableFrom(method.peekType().getTypeClass()) : method.peekType().getTypeClass() + " is not a script object";
5509 loadConstant(map);
5510 method.invoke(ScriptObject.SET_MAP);
5511 replacedObjectLiteralMaps++;
5512 }
5513 }
5514 }
5515 // Must have emitted the code for replacing all object literal maps
5516 assert ci.objectLiteralMaps == null || ci.objectLiteralMaps.size() == replacedObjectLiteralMaps;
5517 // Load RewriteException back.
5518 method.load(rewriteExceptionType, lvarCount);
5519 // Get rid of the stored reference
5520 method.loadNull();
5521 method.storeHidden(Type.OBJECT, lvarCount);
5522 // Mark it dead
5523 method.markDeadSlots(lvarCount, Type.OBJECT.getSlots());
5524
5525 // Load return value on the stack
5526 method.invoke(RewriteException.GET_RETURN_VALUE);
5527
5528 final Type returnValueType = ci.getReturnValueType();
5529
5530 // Set up an exception handler for primitive type conversion of return value if needed
5531 boolean needsCatch = false;
5532 final Label targetCatchLabel = ci.catchLabel;
5533 Label _try = null;
5534 if(returnValueType.isPrimitive()) {
5535 // If the conversion throws an exception, we want to report the line number of the continuation point.
5536 method.lineNumber(ci.lineNumber);
5537
5538 if(targetCatchLabel != METHOD_BOUNDARY) {
5539 _try = new Label("");
5540 method.label(_try);
5541 needsCatch = true;
5542 }
5543 }
5544
5545 // Convert return value
5546 method.convert(returnValueType);
5547
5548 final int scopePopCount = needsCatch ? ci.exceptionScopePops : 0;
5549
5550 // Declare a try/catch for the conversion. If no scopes need to be popped until the target catch block, just
5551 // jump into it. Otherwise, we'll need to create a scope-popping catch block below.
5552 final Label catchLabel = scopePopCount > 0 ? new Label("") : targetCatchLabel;
5553 if(needsCatch) {
5554 final Label _end_try = new Label("");
5555 method.label(_end_try);
5556 method._try(_try, _end_try, catchLabel);
5557 }
5558
5559 // Jump to continuation point
5560 method._goto(ci.getTargetLabel());
5561
5562 // Make a scope-popping exception delegate if needed
5563 if(catchLabel != targetCatchLabel) {
5564 method.lineNumber(0);
5565 assert scopePopCount > 0;
5566 method._catch(catchLabel);
5567 popScopes(scopePopCount);
5568 method.uncheckedGoto(targetCatchLabel);
5569 }
5570 }
5571
5572 /**
5573 * Interface implemented by object creators that support splitting over multiple methods.
5574 */
5575 interface SplitLiteralCreator {
5576 /**
5577 * Generate code to populate a range of the literal object. A reference to the object
5578 * should be left on the stack when the method terminates.
5579 *
5580 * @param method the method emitter
5581 * @param type the type of the literal object
5582 * @param slot the local slot containing the literal object
5583 * @param start the start index (inclusive)
5584 * @param end the end index (exclusive)
5585 */
5586 void populateRange(MethodEmitter method, Type type, int slot, int start, int end);
5587 }
5588 }