1 /*
2 * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package jdk.nashorn.internal.codegen;
27
28 import static jdk.nashorn.internal.codegen.ClassEmitter.Flag.PRIVATE;
29 import static jdk.nashorn.internal.codegen.ClassEmitter.Flag.STATIC;
30 import static jdk.nashorn.internal.codegen.CompilerConstants.ARGUMENTS;
31 import static jdk.nashorn.internal.codegen.CompilerConstants.CALLEE;
32 import static jdk.nashorn.internal.codegen.CompilerConstants.CREATE_PROGRAM_FUNCTION;
33 import static jdk.nashorn.internal.codegen.CompilerConstants.GET_MAP;
34 import static jdk.nashorn.internal.codegen.CompilerConstants.GET_STRING;
35 import static jdk.nashorn.internal.codegen.CompilerConstants.QUICK_PREFIX;
36 import static jdk.nashorn.internal.codegen.CompilerConstants.REGEX_PREFIX;
37 import static jdk.nashorn.internal.codegen.CompilerConstants.SCOPE;
38 import static jdk.nashorn.internal.codegen.CompilerConstants.SPLIT_PREFIX;
39 import static jdk.nashorn.internal.codegen.CompilerConstants.THIS;
40 import static jdk.nashorn.internal.codegen.CompilerConstants.VARARGS;
41 import static jdk.nashorn.internal.codegen.CompilerConstants.interfaceCallNoLookup;
42 import static jdk.nashorn.internal.codegen.CompilerConstants.methodDescriptor;
43 import static jdk.nashorn.internal.codegen.CompilerConstants.staticCallNoLookup;
44 import static jdk.nashorn.internal.codegen.CompilerConstants.typeDescriptor;
45 import static jdk.nashorn.internal.codegen.CompilerConstants.virtualCallNoLookup;
46 import static jdk.nashorn.internal.ir.Symbol.HAS_SLOT;
47 import static jdk.nashorn.internal.ir.Symbol.IS_INTERNAL;
48 import static jdk.nashorn.internal.runtime.UnwarrantedOptimismException.INVALID_PROGRAM_POINT;
49 import static jdk.nashorn.internal.runtime.UnwarrantedOptimismException.isValid;
50 import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_APPLY_TO_CALL;
51 import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_DECLARE;
52 import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_FAST_SCOPE;
53 import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_OPTIMISTIC;
54 import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_PROGRAM_POINT_SHIFT;
55 import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_SCOPE;
56
57 import java.io.PrintWriter;
58 import java.util.ArrayDeque;
59 import java.util.ArrayList;
60 import java.util.Arrays;
61 import java.util.BitSet;
62 import java.util.Collection;
63 import java.util.Collections;
64 import java.util.Deque;
65 import java.util.EnumSet;
66 import java.util.HashMap;
67 import java.util.HashSet;
68 import java.util.Iterator;
69 import java.util.LinkedList;
70 import java.util.List;
71 import java.util.Map;
72 import java.util.Set;
73 import java.util.TreeMap;
74 import java.util.function.Supplier;
75 import jdk.nashorn.internal.AssertsEnabled;
76 import jdk.nashorn.internal.IntDeque;
77 import jdk.nashorn.internal.codegen.ClassEmitter.Flag;
78 import jdk.nashorn.internal.codegen.CompilerConstants.Call;
79 import jdk.nashorn.internal.codegen.types.ArrayType;
80 import jdk.nashorn.internal.codegen.types.Type;
81 import jdk.nashorn.internal.ir.AccessNode;
82 import jdk.nashorn.internal.ir.BaseNode;
83 import jdk.nashorn.internal.ir.BinaryNode;
84 import jdk.nashorn.internal.ir.Block;
85 import jdk.nashorn.internal.ir.BlockStatement;
86 import jdk.nashorn.internal.ir.BreakNode;
87 import jdk.nashorn.internal.ir.CallNode;
88 import jdk.nashorn.internal.ir.CaseNode;
89 import jdk.nashorn.internal.ir.CatchNode;
90 import jdk.nashorn.internal.ir.ContinueNode;
91 import jdk.nashorn.internal.ir.EmptyNode;
92 import jdk.nashorn.internal.ir.Expression;
93 import jdk.nashorn.internal.ir.ExpressionStatement;
94 import jdk.nashorn.internal.ir.ForNode;
95 import jdk.nashorn.internal.ir.FunctionNode;
96 import jdk.nashorn.internal.ir.GetSplitState;
97 import jdk.nashorn.internal.ir.IdentNode;
98 import jdk.nashorn.internal.ir.IfNode;
99 import jdk.nashorn.internal.ir.IndexNode;
100 import jdk.nashorn.internal.ir.JoinPredecessorExpression;
101 import jdk.nashorn.internal.ir.JumpStatement;
102 import jdk.nashorn.internal.ir.JumpToInlinedFinally;
103 import jdk.nashorn.internal.ir.LabelNode;
104 import jdk.nashorn.internal.ir.LexicalContext;
105 import jdk.nashorn.internal.ir.LexicalContextNode;
106 import jdk.nashorn.internal.ir.LiteralNode;
107 import jdk.nashorn.internal.ir.LiteralNode.ArrayLiteralNode;
108 import jdk.nashorn.internal.ir.LiteralNode.PrimitiveLiteralNode;
109 import jdk.nashorn.internal.ir.LocalVariableConversion;
110 import jdk.nashorn.internal.ir.LoopNode;
111 import jdk.nashorn.internal.ir.Node;
112 import jdk.nashorn.internal.ir.ObjectNode;
113 import jdk.nashorn.internal.ir.Optimistic;
114 import jdk.nashorn.internal.ir.PropertyNode;
115 import jdk.nashorn.internal.ir.ReturnNode;
116 import jdk.nashorn.internal.ir.RuntimeNode;
117 import jdk.nashorn.internal.ir.RuntimeNode.Request;
118 import jdk.nashorn.internal.ir.SetSplitState;
119 import jdk.nashorn.internal.ir.SplitReturn;
120 import jdk.nashorn.internal.ir.Splittable;
121 import jdk.nashorn.internal.ir.Statement;
122 import jdk.nashorn.internal.ir.SwitchNode;
123 import jdk.nashorn.internal.ir.Symbol;
124 import jdk.nashorn.internal.ir.TernaryNode;
125 import jdk.nashorn.internal.ir.ThrowNode;
126 import jdk.nashorn.internal.ir.TryNode;
127 import jdk.nashorn.internal.ir.UnaryNode;
128 import jdk.nashorn.internal.ir.VarNode;
129 import jdk.nashorn.internal.ir.WhileNode;
130 import jdk.nashorn.internal.ir.WithNode;
131 import jdk.nashorn.internal.ir.visitor.NodeOperatorVisitor;
132 import jdk.nashorn.internal.ir.visitor.SimpleNodeVisitor;
133 import jdk.nashorn.internal.objects.Global;
134 import jdk.nashorn.internal.parser.Lexer.RegexToken;
135 import jdk.nashorn.internal.parser.TokenType;
136 import jdk.nashorn.internal.runtime.Context;
137 import jdk.nashorn.internal.runtime.Debug;
138 import jdk.nashorn.internal.runtime.ECMAException;
139 import jdk.nashorn.internal.runtime.JSType;
140 import jdk.nashorn.internal.runtime.OptimisticReturnFilters;
141 import jdk.nashorn.internal.runtime.PropertyMap;
142 import jdk.nashorn.internal.runtime.RecompilableScriptFunctionData;
143 import jdk.nashorn.internal.runtime.RewriteException;
144 import jdk.nashorn.internal.runtime.Scope;
145 import jdk.nashorn.internal.runtime.ScriptEnvironment;
146 import jdk.nashorn.internal.runtime.ScriptFunction;
147 import jdk.nashorn.internal.runtime.ScriptObject;
148 import jdk.nashorn.internal.runtime.ScriptRuntime;
149 import jdk.nashorn.internal.runtime.Source;
150 import jdk.nashorn.internal.runtime.Undefined;
151 import jdk.nashorn.internal.runtime.UnwarrantedOptimismException;
152 import jdk.nashorn.internal.runtime.arrays.ArrayData;
153 import jdk.nashorn.internal.runtime.linker.LinkerCallSite;
154 import jdk.nashorn.internal.runtime.logging.DebugLogger;
155 import jdk.nashorn.internal.runtime.logging.Loggable;
156 import jdk.nashorn.internal.runtime.logging.Logger;
157 import jdk.nashorn.internal.runtime.options.Options;
158
159 /**
160 * This is the lowest tier of the code generator. It takes lowered ASTs emitted
161 * from Lower and emits Java byte code. The byte code emission logic is broken
162 * out into MethodEmitter. MethodEmitter works internally with a type stack, and
163 * keeps track of the contents of the byte code stack. This way we avoid a large
164 * number of special cases on the form
165 * <pre>
166 * if (type == INT) {
167 * visitInsn(ILOAD, slot);
168 * } else if (type == DOUBLE) {
169 * visitInsn(DOUBLE, slot);
170 * }
171 * </pre>
172 * This quickly became apparent when the code generator was generalized to work
173 * with all types, and not just numbers or objects.
174 * <p>
175 * The CodeGenerator visits nodes only once and emits bytecode for them.
176 */
177 @Logger(name="codegen")
178 final class CodeGenerator extends NodeOperatorVisitor<CodeGeneratorLexicalContext> implements Loggable {
179
180 private static final Type SCOPE_TYPE = Type.typeFor(ScriptObject.class);
181
182 private static final String GLOBAL_OBJECT = Type.getInternalName(Global.class);
183
184 private static final Call CREATE_REWRITE_EXCEPTION = CompilerConstants.staticCallNoLookup(RewriteException.class,
185 "create", RewriteException.class, UnwarrantedOptimismException.class, Object[].class, String[].class);
186 private static final Call CREATE_REWRITE_EXCEPTION_REST_OF = CompilerConstants.staticCallNoLookup(RewriteException.class,
187 "create", RewriteException.class, UnwarrantedOptimismException.class, Object[].class, String[].class, int[].class);
188
189 private static final Call ENSURE_INT = CompilerConstants.staticCallNoLookup(OptimisticReturnFilters.class,
190 "ensureInt", int.class, Object.class, int.class);
191 private static final Call ENSURE_LONG = CompilerConstants.staticCallNoLookup(OptimisticReturnFilters.class,
192 "ensureLong", long.class, Object.class, int.class);
193 private static final Call ENSURE_NUMBER = CompilerConstants.staticCallNoLookup(OptimisticReturnFilters.class,
194 "ensureNumber", double.class, Object.class, int.class);
195
196 private static final Call CREATE_FUNCTION_OBJECT = CompilerConstants.staticCallNoLookup(ScriptFunction.class,
197 "create", ScriptFunction.class, Object[].class, int.class, ScriptObject.class);
198 private static final Call CREATE_FUNCTION_OBJECT_NO_SCOPE = CompilerConstants.staticCallNoLookup(ScriptFunction.class,
199 "create", ScriptFunction.class, Object[].class, int.class);
200
201 private static final Call TO_NUMBER_FOR_EQ = CompilerConstants.staticCallNoLookup(JSType.class,
202 "toNumberForEq", double.class, Object.class);
203 private static final Call TO_NUMBER_FOR_STRICT_EQ = CompilerConstants.staticCallNoLookup(JSType.class,
204 "toNumberForStrictEq", double.class, Object.class);
205
206
207 private static final Class<?> ITERATOR_CLASS = Iterator.class;
208 static {
209 assert ITERATOR_CLASS == CompilerConstants.ITERATOR_PREFIX.type();
210 }
211 private static final Type ITERATOR_TYPE = Type.typeFor(ITERATOR_CLASS);
212 private static final Type EXCEPTION_TYPE = Type.typeFor(CompilerConstants.EXCEPTION_PREFIX.type());
213
214 private static final Integer INT_ZERO = Integer.valueOf(0);
215
216 /** Constant data & installation. The only reason the compiler keeps this is because it is assigned
217 * by reflection in class installation */
218 private final Compiler compiler;
219
220 /** Is the current code submitted by 'eval' call? */
221 private final boolean evalCode;
222
223 /** Call site flags given to the code generator to be used for all generated call sites */
224 private final int callSiteFlags;
225
226 /** How many regexp fields have been emitted */
227 private int regexFieldCount;
228
229 /** Line number for last statement. If we encounter a new line number, line number bytecode information
230 * needs to be generated */
231 private int lastLineNumber = -1;
232
233 /** When should we stop caching regexp expressions in fields to limit bytecode size? */
234 private static final int MAX_REGEX_FIELDS = 2 * 1024;
235
236 /** Current method emitter */
237 private MethodEmitter method;
238
239 /** Current compile unit */
240 private CompileUnit unit;
241
242 private final DebugLogger log;
243
244 /** From what size should we use spill instead of fields for JavaScript objects? */
245 static final int OBJECT_SPILL_THRESHOLD = Options.getIntProperty("nashorn.spill.threshold", 256);
246
247 private final Set<String> emittedMethods = new HashSet<>();
248
249 // Function Id -> ContinuationInfo. Used by compilation of rest-of function only.
250 private ContinuationInfo continuationInfo;
251
252 private final Deque<Label> scopeEntryLabels = new ArrayDeque<>();
253
254 private static final Label METHOD_BOUNDARY = new Label("");
255 private final Deque<Label> catchLabels = new ArrayDeque<>();
256 // Number of live locals on entry to (and thus also break from) labeled blocks.
257 private final IntDeque labeledBlockBreakLiveLocals = new IntDeque();
258
259 //is this a rest of compilation
260 private final int[] continuationEntryPoints;
261
262 /**
263 * Constructor.
264 *
265 * @param compiler
266 */
267 CodeGenerator(final Compiler compiler, final int[] continuationEntryPoints) {
268 super(new CodeGeneratorLexicalContext());
269 this.compiler = compiler;
270 this.evalCode = compiler.getSource().isEvalCode();
271 this.continuationEntryPoints = continuationEntryPoints;
272 this.callSiteFlags = compiler.getScriptEnvironment()._callsite_flags;
273 this.log = initLogger(compiler.getContext());
274 }
275
276 @Override
277 public DebugLogger getLogger() {
278 return log;
279 }
280
281 @Override
282 public DebugLogger initLogger(final Context context) {
283 return context.getLogger(this.getClass());
284 }
285
286 /**
287 * Gets the call site flags, adding the strict flag if the current function
288 * being generated is in strict mode
289 *
290 * @return the correct flags for a call site in the current function
291 */
292 int getCallSiteFlags() {
293 return lc.getCurrentFunction().getCallSiteFlags() | callSiteFlags;
294 }
295
296 /**
297 * Gets the flags for a scope call site.
298 * @param symbol a scope symbol
299 * @return the correct flags for the scope call site
300 */
301 private int getScopeCallSiteFlags(final Symbol symbol) {
302 assert symbol.isScope();
303 final int flags = getCallSiteFlags() | CALLSITE_SCOPE;
304 if (isEvalCode() && symbol.isGlobal()) {
305 return flags; // Don't set fast-scope flag on non-declared globals in eval code - see JDK-8077955.
306 }
307 return isFastScope(symbol) ? flags | CALLSITE_FAST_SCOPE : flags;
308 }
309
310 /**
311 * Are we generating code for 'eval' code?
312 * @return true if currently compiled code is 'eval' code.
313 */
314 boolean isEvalCode() {
315 return evalCode;
316 }
317
318 /**
319 * Are we using dual primitive/object field representation?
320 * @return true if using dual field representation, false for object-only fields
321 */
322 boolean useDualFields() {
323 return compiler.getContext().useDualFields();
324 }
325
326 /**
327 * Load an identity node
328 *
329 * @param identNode an identity node to load
330 * @return the method generator used
331 */
332 private MethodEmitter loadIdent(final IdentNode identNode, final TypeBounds resultBounds) {
333 checkTemporalDeadZone(identNode);
334 final Symbol symbol = identNode.getSymbol();
335
336 if (!symbol.isScope()) {
337 final Type type = identNode.getType();
338 if(type == Type.UNDEFINED) {
339 return method.loadUndefined(resultBounds.widest);
340 }
341
342 assert symbol.hasSlot() || symbol.isParam();
343 return method.load(identNode);
344 }
345
346 assert identNode.getSymbol().isScope() : identNode + " is not in scope!";
347 final int flags = getScopeCallSiteFlags(symbol);
348 if (isFastScope(symbol)) {
349 // Only generate shared scope getter for fast-scope symbols so we know we can dial in correct scope.
350 if (symbol.getUseCount() > SharedScopeCall.FAST_SCOPE_GET_THRESHOLD && !identNode.isOptimistic()) {
351 // As shared scope vars are only used with non-optimistic identifiers, we switch from using TypeBounds to
352 // just a single definitive type, resultBounds.widest.
353 new OptimisticOperation(identNode, TypeBounds.OBJECT) {
354 @Override
355 void loadStack() {
356 method.loadCompilerConstant(SCOPE);
357 }
358
359 @Override
360 void consumeStack() {
361 loadSharedScopeVar(resultBounds.widest, symbol, flags);
362 }
363 }.emit();
364 } else {
365 new LoadFastScopeVar(identNode, resultBounds, flags).emit();
366 }
367 } else {
368 //slow scope load, we have no proto depth
369 new LoadScopeVar(identNode, resultBounds, flags).emit();
370 }
371
372 return method;
373 }
374
375 // Any access to LET and CONST variables before their declaration must throw ReferenceError.
376 // This is called the temporal dead zone (TDZ). See https://gist.github.com/rwaldron/f0807a758aa03bcdd58a
377 private void checkTemporalDeadZone(final IdentNode identNode) {
378 if (identNode.isDead()) {
379 method.load(identNode.getSymbol().getName()).invoke(ScriptRuntime.THROW_REFERENCE_ERROR);
380 }
381 }
382
383 // Runtime check for assignment to ES6 const
384 private void checkAssignTarget(final Expression expression) {
385 if (expression instanceof IdentNode && ((IdentNode)expression).getSymbol().isConst()) {
386 method.load(((IdentNode)expression).getSymbol().getName()).invoke(ScriptRuntime.THROW_CONST_TYPE_ERROR);
387 }
388 }
389
390 private boolean isRestOf() {
391 return continuationEntryPoints != null;
392 }
393
394 private boolean isCurrentContinuationEntryPoint(final int programPoint) {
395 return isRestOf() && getCurrentContinuationEntryPoint() == programPoint;
396 }
397
398 private int[] getContinuationEntryPoints() {
399 return isRestOf() ? continuationEntryPoints : null;
400 }
401
402 private int getCurrentContinuationEntryPoint() {
403 return isRestOf() ? continuationEntryPoints[0] : INVALID_PROGRAM_POINT;
404 }
405
406 private boolean isContinuationEntryPoint(final int programPoint) {
407 if (isRestOf()) {
408 assert continuationEntryPoints != null;
409 for (final int cep : continuationEntryPoints) {
410 if (cep == programPoint) {
411 return true;
412 }
413 }
414 }
415 return false;
416 }
417
418 /**
419 * Check if this symbol can be accessed directly with a putfield or getfield or dynamic load
420 *
421 * @param symbol symbol to check for fast scope
422 * @return true if fast scope
423 */
424 private boolean isFastScope(final Symbol symbol) {
425 if (!symbol.isScope()) {
426 return false;
427 }
428
429 if (!lc.inDynamicScope()) {
430 // If there's no with or eval in context, and the symbol is marked as scoped, it is fast scoped. Such a
431 // symbol must either be global, or its defining block must need scope.
432 assert symbol.isGlobal() || lc.getDefiningBlock(symbol).needsScope() : symbol.getName();
433 return true;
434 }
435
436 if (symbol.isGlobal()) {
437 // Shortcut: if there's a with or eval in context, globals can't be fast scoped
438 return false;
439 }
440
441 // Otherwise, check if there's a dynamic scope between use of the symbol and its definition
442 final String name = symbol.getName();
443 boolean previousWasBlock = false;
444 for (final Iterator<LexicalContextNode> it = lc.getAllNodes(); it.hasNext();) {
445 final LexicalContextNode node = it.next();
446 if (node instanceof Block) {
447 // If this block defines the symbol, then we can fast scope the symbol.
448 final Block block = (Block)node;
449 if (block.getExistingSymbol(name) == symbol) {
450 assert block.needsScope();
451 return true;
452 }
453 previousWasBlock = true;
454 } else {
455 if (node instanceof WithNode && previousWasBlock || node instanceof FunctionNode && ((FunctionNode)node).needsDynamicScope()) {
456 // If we hit a scope that can have symbols introduced into it at run time before finding the defining
457 // block, the symbol can't be fast scoped. A WithNode only counts if we've immediately seen a block
458 // before - its block. Otherwise, we are currently processing the WithNode's expression, and that's
459 // obviously not subjected to introducing new symbols.
460 return false;
461 }
462 previousWasBlock = false;
463 }
464 }
465 // Should've found the symbol defined in a block
466 throw new AssertionError();
467 }
468
469 private MethodEmitter loadSharedScopeVar(final Type valueType, final Symbol symbol, final int flags) {
470 assert isFastScope(symbol);
471 method.load(getScopeProtoDepth(lc.getCurrentBlock(), symbol));
472 return lc.getScopeGet(unit, symbol, valueType, flags).generateInvoke(method);
473 }
474
475 private class LoadScopeVar extends OptimisticOperation {
476 final IdentNode identNode;
477 private final int flags;
478
479 LoadScopeVar(final IdentNode identNode, final TypeBounds resultBounds, final int flags) {
480 super(identNode, resultBounds);
481 this.identNode = identNode;
482 this.flags = flags;
483 }
484
485 @Override
486 void loadStack() {
487 method.loadCompilerConstant(SCOPE);
488 getProto();
489 }
490
491 void getProto() {
492 //empty
493 }
494
495 @Override
496 void consumeStack() {
497 // If this is either __FILE__, __DIR__, or __LINE__ then load the property initially as Object as we'd convert
498 // it anyway for replaceLocationPropertyPlaceholder.
499 if(identNode.isCompileTimePropertyName()) {
500 method.dynamicGet(Type.OBJECT, identNode.getSymbol().getName(), flags, identNode.isFunction(), false);
501 replaceCompileTimeProperty();
502 } else {
503 dynamicGet(identNode.getSymbol().getName(), flags, identNode.isFunction(), false);
504 }
505 }
506 }
507
508 private class LoadFastScopeVar extends LoadScopeVar {
509 LoadFastScopeVar(final IdentNode identNode, final TypeBounds resultBounds, final int flags) {
510 super(identNode, resultBounds, flags);
511 }
512
513 @Override
514 void getProto() {
515 loadFastScopeProto(identNode.getSymbol(), false);
516 }
517 }
518
519 private MethodEmitter storeFastScopeVar(final Symbol symbol, final int flags) {
520 loadFastScopeProto(symbol, true);
521 method.dynamicSet(symbol.getName(), flags, false);
522 return method;
523 }
524
525 private int getScopeProtoDepth(final Block startingBlock, final Symbol symbol) {
526 //walk up the chain from starting block and when we bump into the current function boundary, add the external
527 //information.
528 final FunctionNode fn = lc.getCurrentFunction();
529 final int externalDepth = compiler.getScriptFunctionData(fn.getId()).getExternalSymbolDepth(symbol.getName());
530
531 //count the number of scopes from this place to the start of the function
532
533 final int internalDepth = FindScopeDepths.findInternalDepth(lc, fn, startingBlock, symbol);
534 final int scopesToStart = FindScopeDepths.findScopesToStart(lc, fn, startingBlock);
535 int depth = 0;
536 if (internalDepth == -1) {
537 depth = scopesToStart + externalDepth;
538 } else {
539 assert internalDepth <= scopesToStart;
540 depth = internalDepth;
541 }
542
543 return depth;
544 }
545
546 private void loadFastScopeProto(final Symbol symbol, final boolean swap) {
547 final int depth = getScopeProtoDepth(lc.getCurrentBlock(), symbol);
548 assert depth != -1 : "Couldn't find scope depth for symbol " + symbol.getName() + " in " + lc.getCurrentFunction();
549 if (depth > 0) {
550 if (swap) {
551 method.swap();
552 }
553 for (int i = 0; i < depth; i++) {
554 method.invoke(ScriptObject.GET_PROTO);
555 }
556 if (swap) {
557 method.swap();
558 }
559 }
560 }
561
562 /**
563 * Generate code that loads this node to the stack, not constraining its type
564 *
565 * @param expr node to load
566 *
567 * @return the method emitter used
568 */
569 private MethodEmitter loadExpressionUnbounded(final Expression expr) {
570 return loadExpression(expr, TypeBounds.UNBOUNDED);
571 }
572
573 private MethodEmitter loadExpressionAsObject(final Expression expr) {
574 return loadExpression(expr, TypeBounds.OBJECT);
575 }
576
577 MethodEmitter loadExpressionAsBoolean(final Expression expr) {
578 return loadExpression(expr, TypeBounds.BOOLEAN);
579 }
580
581 // Test whether conversion from source to target involves a call of ES 9.1 ToPrimitive
582 // with possible side effects from calling an object's toString or valueOf methods.
583 private static boolean noToPrimitiveConversion(final Type source, final Type target) {
584 // Object to boolean conversion does not cause ToPrimitive call
585 return source.isJSPrimitive() || !target.isJSPrimitive() || target.isBoolean();
586 }
587
588 MethodEmitter loadBinaryOperands(final BinaryNode binaryNode) {
589 return loadBinaryOperands(binaryNode.lhs(), binaryNode.rhs(), TypeBounds.UNBOUNDED.notWiderThan(binaryNode.getWidestOperandType()), false, false);
590 }
591
592 private MethodEmitter loadBinaryOperands(final Expression lhs, final Expression rhs, final TypeBounds explicitOperandBounds, final boolean baseAlreadyOnStack, final boolean forceConversionSeparation) {
593 // ECMAScript 5.1 specification (sections 11.5-11.11 and 11.13) prescribes that when evaluating a binary
594 // expression "LEFT op RIGHT", the order of operations must be: LOAD LEFT, LOAD RIGHT, CONVERT LEFT, CONVERT
595 // RIGHT, EXECUTE OP. Unfortunately, doing it in this order defeats potential optimizations that arise when we
596 // can combine a LOAD with a CONVERT operation (e.g. use a dynamic getter with the conversion target type as its
597 // return value). What we do here is reorder LOAD RIGHT and CONVERT LEFT when possible; it is possible only when
598 // we can prove that executing CONVERT LEFT can't have a side effect that changes the value of LOAD RIGHT.
599 // Basically, if we know that either LEFT already is a primitive value, or does not have to be converted to
600 // a primitive value, or RIGHT is an expression that loads without side effects, then we can do the
601 // reordering and collapse LOAD/CONVERT into a single operation; otherwise we need to do the more costly
602 // separate operations to preserve specification semantics.
603
604 // Operands' load type should not be narrower than the narrowest of the individual operand types, nor narrower
605 // than the lower explicit bound, but it should also not be wider than
606 final Type lhsType = undefinedToNumber(lhs.getType());
607 final Type rhsType = undefinedToNumber(rhs.getType());
608 final Type narrowestOperandType = Type.narrowest(Type.widest(lhsType, rhsType), explicitOperandBounds.widest);
609 final TypeBounds operandBounds = explicitOperandBounds.notNarrowerThan(narrowestOperandType);
610 if (noToPrimitiveConversion(lhsType, explicitOperandBounds.widest) || rhs.isLocal()) {
611 // Can reorder. We might still need to separate conversion, but at least we can do it with reordering
612 if (forceConversionSeparation) {
613 // Can reorder, but can't move conversion into the operand as the operation depends on operands
614 // exact types for its overflow guarantees. E.g. with {L}{%I}expr1 {L}* {L}{%I}expr2 we are not allowed
615 // to merge {L}{%I} into {%L}, as that can cause subsequent overflows; test for JDK-8058610 contains
616 // concrete cases where this could happen.
617 final TypeBounds safeConvertBounds = TypeBounds.UNBOUNDED.notNarrowerThan(narrowestOperandType);
618 loadExpression(lhs, safeConvertBounds, baseAlreadyOnStack);
619 method.convert(operandBounds.within(method.peekType()));
620 loadExpression(rhs, safeConvertBounds, false);
621 method.convert(operandBounds.within(method.peekType()));
622 } else {
623 // Can reorder and move conversion into the operand. Combine load and convert into single operations.
624 loadExpression(lhs, operandBounds, baseAlreadyOnStack);
625 loadExpression(rhs, operandBounds, false);
626 }
627 } else {
628 // Can't reorder. Load and convert separately.
629 final TypeBounds safeConvertBounds = TypeBounds.UNBOUNDED.notNarrowerThan(narrowestOperandType);
630 loadExpression(lhs, safeConvertBounds, baseAlreadyOnStack);
631 final Type lhsLoadedType = method.peekType();
632 loadExpression(rhs, safeConvertBounds, false);
633 final Type convertedLhsType = operandBounds.within(method.peekType());
634 if (convertedLhsType != lhsLoadedType) {
635 // Do it conditionally, so that if conversion is a no-op we don't introduce a SWAP, SWAP.
636 method.swap().convert(convertedLhsType).swap();
637 }
638 method.convert(operandBounds.within(method.peekType()));
639 }
640 assert Type.generic(method.peekType()) == operandBounds.narrowest;
641 assert Type.generic(method.peekType(1)) == operandBounds.narrowest;
642
643 return method;
644 }
645
646 /**
647 * Similar to {@link #loadBinaryOperands(BinaryNode)} but used specifically for loading operands of
648 * relational and equality comparison operators where at least one argument is non-object. (When both
649 * arguments are objects, we use {@link ScriptRuntime#EQ(Object, Object)}, {@link ScriptRuntime#LT(Object, Object)}
650 * etc. methods instead. Additionally, {@code ScriptRuntime} methods are used for strict (in)equality comparison
651 * of a boolean to anything that isn't a boolean.) This method handles the special case where one argument
652 * is an object and another is a primitive. Naively, these could also be delegated to {@code ScriptRuntime} methods
653 * by boxing the primitive. However, in all such cases the comparison is performed on numeric values, so it is
654 * possible to strength-reduce the operation by taking the number value of the object argument instead and
655 * comparing that to the primitive value ("primitive" will always be int, long, double, or boolean, and booleans
656 * compare as ints in these cases, so they're essentially numbers too). This method will emit code for loading
657 * arguments for such strength-reduced comparison. When both arguments are primitives, it just delegates to
658 * {@link #loadBinaryOperands(BinaryNode)}.
659 *
660 * @param cmp the comparison operation for which the operands need to be loaded on stack.
661 * @return the current method emitter.
662 */
663 MethodEmitter loadComparisonOperands(final BinaryNode cmp) {
664 final Expression lhs = cmp.lhs();
665 final Expression rhs = cmp.rhs();
666 final Type lhsType = lhs.getType();
667 final Type rhsType = rhs.getType();
668
669 // Only used when not both are object, for that we have ScriptRuntime.LT etc.
670 assert !(lhsType.isObject() && rhsType.isObject());
671
672 if (lhsType.isObject() || rhsType.isObject()) {
673 // We can reorder CONVERT LEFT and LOAD RIGHT only if either the left is a primitive, or the right
674 // is a local. This is more strict than loadBinaryNode reorder criteria, as it can allow JS primitive
675 // types too (notably: String is a JS primitive, but not a JVM primitive). We disallow String otherwise
676 // we would prematurely convert it to number when comparing to an optimistic expression, e.g. in
677 // "Hello" === String("Hello") the RHS starts out as an optimistic-int function call. If we allowed
678 // reordering, we'd end up with ToNumber("Hello") === {I%}String("Hello") that is obviously incorrect.
679 final boolean canReorder = lhsType.isPrimitive() || rhs.isLocal();
680 // If reordering is allowed, and we're using a relational operator (that is, <, <=, >, >=) and not an
681 // (in)equality operator, then we encourage combining of LOAD and CONVERT into a single operation.
682 // This is because relational operators' semantics prescribes vanilla ToNumber() conversion, while
683 // (in)equality operators need the specialized JSType.toNumberFor[Strict]Equals. E.g. in the code snippet
684 // "i < obj.size" (where i is primitive and obj.size is statically an object), ".size" will thus be allowed
685 // to compile as:
686 // invokedynamic dyn:getProp|getElem|getMethod:size(Object;)D
687 // instead of the more costly:
688 // invokedynamic dyn:getProp|getElem|getMethod:size(Object;)Object
689 // invokestatic JSType.toNumber(Object)D
690 // Note also that even if this is allowed, we're only using it on operands that are non-optimistic, as
691 // otherwise the logic for determining effective optimistic-ness would turn an optimistic double return
692 // into a freely coercible one, which would be wrong.
693 final boolean canCombineLoadAndConvert = canReorder && cmp.isRelational();
694
695 // LOAD LEFT
696 loadExpression(lhs, canCombineLoadAndConvert && !lhs.isOptimistic() ? TypeBounds.NUMBER : TypeBounds.UNBOUNDED);
697
698 final Type lhsLoadedType = method.peekType();
699 final TokenType tt = cmp.tokenType();
700 if (canReorder) {
701 // Can reorder CONVERT LEFT and LOAD RIGHT
702 emitObjectToNumberComparisonConversion(method, tt);
703 loadExpression(rhs, canCombineLoadAndConvert && !rhs.isOptimistic() ? TypeBounds.NUMBER : TypeBounds.UNBOUNDED);
704 } else {
705 // Can't reorder CONVERT LEFT and LOAD RIGHT
706 loadExpression(rhs, TypeBounds.UNBOUNDED);
707 if (lhsLoadedType != Type.NUMBER) {
708 method.swap();
709 emitObjectToNumberComparisonConversion(method, tt);
710 method.swap();
711 }
712 }
713
714 // CONVERT RIGHT
715 emitObjectToNumberComparisonConversion(method, tt);
716 return method;
717 }
718 // For primitive operands, just don't do anything special.
719 return loadBinaryOperands(cmp);
720 }
721
722 private static void emitObjectToNumberComparisonConversion(final MethodEmitter method, final TokenType tt) {
723 switch(tt) {
724 case EQ:
725 case NE:
726 if (method.peekType().isObject()) {
727 TO_NUMBER_FOR_EQ.invoke(method);
728 return;
729 }
730 break;
731 case EQ_STRICT:
732 case NE_STRICT:
733 if (method.peekType().isObject()) {
734 TO_NUMBER_FOR_STRICT_EQ.invoke(method);
735 return;
736 }
737 break;
738 default:
739 break;
740 }
741 method.convert(Type.NUMBER);
742 }
743
744 private static final Type undefinedToNumber(final Type type) {
745 return type == Type.UNDEFINED ? Type.NUMBER : type;
746 }
747
748 private static final class TypeBounds {
749 final Type narrowest;
750 final Type widest;
751
752 static final TypeBounds UNBOUNDED = new TypeBounds(Type.UNKNOWN, Type.OBJECT);
753 static final TypeBounds INT = exact(Type.INT);
754 static final TypeBounds NUMBER = exact(Type.NUMBER);
755 static final TypeBounds OBJECT = exact(Type.OBJECT);
756 static final TypeBounds BOOLEAN = exact(Type.BOOLEAN);
757
758 static TypeBounds exact(final Type type) {
759 return new TypeBounds(type, type);
760 }
761
762 TypeBounds(final Type narrowest, final Type widest) {
763 assert widest != null && widest != Type.UNDEFINED && widest != Type.UNKNOWN : widest;
764 assert narrowest != null && narrowest != Type.UNDEFINED : narrowest;
765 assert !narrowest.widerThan(widest) : narrowest + " wider than " + widest;
766 assert !widest.narrowerThan(narrowest);
767 this.narrowest = Type.generic(narrowest);
768 this.widest = Type.generic(widest);
769 }
770
771 TypeBounds notNarrowerThan(final Type type) {
772 return maybeNew(Type.narrowest(Type.widest(narrowest, type), widest), widest);
773 }
774
775 TypeBounds notWiderThan(final Type type) {
776 return maybeNew(Type.narrowest(narrowest, type), Type.narrowest(widest, type));
777 }
778
779 boolean canBeNarrowerThan(final Type type) {
780 return narrowest.narrowerThan(type);
781 }
782
783 TypeBounds maybeNew(final Type newNarrowest, final Type newWidest) {
784 if(newNarrowest == narrowest && newWidest == widest) {
785 return this;
786 }
787 return new TypeBounds(newNarrowest, newWidest);
788 }
789
790 TypeBounds booleanToInt() {
791 return maybeNew(CodeGenerator.booleanToInt(narrowest), CodeGenerator.booleanToInt(widest));
792 }
793
794 TypeBounds objectToNumber() {
795 return maybeNew(CodeGenerator.objectToNumber(narrowest), CodeGenerator.objectToNumber(widest));
796 }
797
798 Type within(final Type type) {
799 if(type.narrowerThan(narrowest)) {
800 return narrowest;
801 }
802 if(type.widerThan(widest)) {
803 return widest;
804 }
805 return type;
806 }
807
808 @Override
809 public String toString() {
810 return "[" + narrowest + ", " + widest + "]";
811 }
812 }
813
814 private static Type booleanToInt(final Type t) {
815 return t == Type.BOOLEAN ? Type.INT : t;
816 }
817
818 private static Type objectToNumber(final Type t) {
819 return t.isObject() ? Type.NUMBER : t;
820 }
821
822 MethodEmitter loadExpressionAsType(final Expression expr, final Type type) {
823 if(type == Type.BOOLEAN) {
824 return loadExpressionAsBoolean(expr);
825 } else if(type == Type.UNDEFINED) {
826 assert expr.getType() == Type.UNDEFINED;
827 return loadExpressionAsObject(expr);
828 }
829 // having no upper bound preserves semantics of optimistic operations in the expression (by not having them
830 // converted early) and then applies explicit conversion afterwards.
831 return loadExpression(expr, TypeBounds.UNBOUNDED.notNarrowerThan(type)).convert(type);
832 }
833
834 private MethodEmitter loadExpression(final Expression expr, final TypeBounds resultBounds) {
835 return loadExpression(expr, resultBounds, false);
836 }
837
838 /**
839 * Emits code for evaluating an expression and leaving its value on top of the stack, narrowing or widening it if
840 * necessary.
841 * @param expr the expression to load
842 * @param resultBounds the incoming type bounds. The value on the top of the stack is guaranteed to not be of narrower
843 * type than the narrowest bound, or wider type than the widest bound after it is loaded.
844 * @param baseAlreadyOnStack true if the base of an access or index node is already on the stack. Used to avoid
845 * double evaluation of bases in self-assignment expressions to access and index nodes. {@code Type.OBJECT} is used
846 * to indicate the widest possible type.
847 * @return the method emitter
848 */
849 private MethodEmitter loadExpression(final Expression expr, final TypeBounds resultBounds, final boolean baseAlreadyOnStack) {
850
851 /*
852 * The load may be of type IdentNode, e.g. "x", AccessNode, e.g. "x.y"
853 * or IndexNode e.g. "x[y]". Both AccessNodes and IndexNodes are
854 * BaseNodes and the logic for loading the base object is reused
855 */
856 final CodeGenerator codegen = this;
857
858 final boolean isCurrentDiscard = codegen.lc.isCurrentDiscard(expr);
859 expr.accept(new NodeOperatorVisitor<LexicalContext>(new LexicalContext()) {
860 @Override
861 public boolean enterIdentNode(final IdentNode identNode) {
862 loadIdent(identNode, resultBounds);
863 return false;
864 }
865
866 @Override
867 public boolean enterAccessNode(final AccessNode accessNode) {
868 new OptimisticOperation(accessNode, resultBounds) {
869 @Override
870 void loadStack() {
871 if (!baseAlreadyOnStack) {
872 loadExpressionAsObject(accessNode.getBase());
873 }
874 assert method.peekType().isObject();
875 }
876 @Override
877 void consumeStack() {
878 final int flags = getCallSiteFlags();
879 dynamicGet(accessNode.getProperty(), flags, accessNode.isFunction(), accessNode.isIndex());
880 }
881 }.emit(baseAlreadyOnStack ? 1 : 0);
882 return false;
883 }
884
885 @Override
886 public boolean enterIndexNode(final IndexNode indexNode) {
887 new OptimisticOperation(indexNode, resultBounds) {
888 @Override
889 void loadStack() {
890 if (!baseAlreadyOnStack) {
891 loadExpressionAsObject(indexNode.getBase());
892 loadExpressionUnbounded(indexNode.getIndex());
893 }
894 }
895 @Override
896 void consumeStack() {
897 final int flags = getCallSiteFlags();
898 dynamicGetIndex(flags, indexNode.isFunction());
899 }
900 }.emit(baseAlreadyOnStack ? 2 : 0);
901 return false;
902 }
903
904 @Override
905 public boolean enterFunctionNode(final FunctionNode functionNode) {
906 // function nodes will always leave a constructed function object on stack, no need to load the symbol
907 // separately as in enterDefault()
908 lc.pop(functionNode);
909 functionNode.accept(codegen);
910 // NOTE: functionNode.accept() will produce a different FunctionNode that we discard. This incidentally
911 // doesn't cause problems as we're never touching FunctionNode again after it's visited here - codegen
912 // is the last element in the compilation pipeline, the AST it produces is not used externally. So, we
913 // re-push the original functionNode.
914 lc.push(functionNode);
915 return false;
916 }
917
918 @Override
919 public boolean enterASSIGN(final BinaryNode binaryNode) {
920 checkAssignTarget(binaryNode.lhs());
921 loadASSIGN(binaryNode);
922 return false;
923 }
924
925 @Override
926 public boolean enterASSIGN_ADD(final BinaryNode binaryNode) {
927 checkAssignTarget(binaryNode.lhs());
928 loadASSIGN_ADD(binaryNode);
929 return false;
930 }
931
932 @Override
933 public boolean enterASSIGN_BIT_AND(final BinaryNode binaryNode) {
934 checkAssignTarget(binaryNode.lhs());
935 loadASSIGN_BIT_AND(binaryNode);
936 return false;
937 }
938
939 @Override
940 public boolean enterASSIGN_BIT_OR(final BinaryNode binaryNode) {
941 checkAssignTarget(binaryNode.lhs());
942 loadASSIGN_BIT_OR(binaryNode);
943 return false;
944 }
945
946 @Override
947 public boolean enterASSIGN_BIT_XOR(final BinaryNode binaryNode) {
948 checkAssignTarget(binaryNode.lhs());
949 loadASSIGN_BIT_XOR(binaryNode);
950 return false;
951 }
952
953 @Override
954 public boolean enterASSIGN_DIV(final BinaryNode binaryNode) {
955 checkAssignTarget(binaryNode.lhs());
956 loadASSIGN_DIV(binaryNode);
957 return false;
958 }
959
960 @Override
961 public boolean enterASSIGN_MOD(final BinaryNode binaryNode) {
962 checkAssignTarget(binaryNode.lhs());
963 loadASSIGN_MOD(binaryNode);
964 return false;
965 }
966
967 @Override
968 public boolean enterASSIGN_MUL(final BinaryNode binaryNode) {
969 checkAssignTarget(binaryNode.lhs());
970 loadASSIGN_MUL(binaryNode);
971 return false;
972 }
973
974 @Override
975 public boolean enterASSIGN_SAR(final BinaryNode binaryNode) {
976 checkAssignTarget(binaryNode.lhs());
977 loadASSIGN_SAR(binaryNode);
978 return false;
979 }
980
981 @Override
982 public boolean enterASSIGN_SHL(final BinaryNode binaryNode) {
983 checkAssignTarget(binaryNode.lhs());
984 loadASSIGN_SHL(binaryNode);
985 return false;
986 }
987
988 @Override
989 public boolean enterASSIGN_SHR(final BinaryNode binaryNode) {
990 checkAssignTarget(binaryNode.lhs());
991 loadASSIGN_SHR(binaryNode);
992 return false;
993 }
994
995 @Override
996 public boolean enterASSIGN_SUB(final BinaryNode binaryNode) {
997 checkAssignTarget(binaryNode.lhs());
998 loadASSIGN_SUB(binaryNode);
999 return false;
1000 }
1001
1002 @Override
1003 public boolean enterCallNode(final CallNode callNode) {
1004 return loadCallNode(callNode, resultBounds);
1005 }
1006
1007 @Override
1008 public boolean enterLiteralNode(final LiteralNode<?> literalNode) {
1009 loadLiteral(literalNode, resultBounds);
1010 return false;
1011 }
1012
1013 @Override
1014 public boolean enterTernaryNode(final TernaryNode ternaryNode) {
1015 loadTernaryNode(ternaryNode, resultBounds);
1016 return false;
1017 }
1018
1019 @Override
1020 public boolean enterADD(final BinaryNode binaryNode) {
1021 loadADD(binaryNode, resultBounds);
1022 return false;
1023 }
1024
1025 @Override
1026 public boolean enterSUB(final UnaryNode unaryNode) {
1027 loadSUB(unaryNode, resultBounds);
1028 return false;
1029 }
1030
1031 @Override
1032 public boolean enterSUB(final BinaryNode binaryNode) {
1033 loadSUB(binaryNode, resultBounds);
1034 return false;
1035 }
1036
1037 @Override
1038 public boolean enterMUL(final BinaryNode binaryNode) {
1039 loadMUL(binaryNode, resultBounds);
1040 return false;
1041 }
1042
1043 @Override
1044 public boolean enterDIV(final BinaryNode binaryNode) {
1045 loadDIV(binaryNode, resultBounds);
1046 return false;
1047 }
1048
1049 @Override
1050 public boolean enterMOD(final BinaryNode binaryNode) {
1051 loadMOD(binaryNode, resultBounds);
1052 return false;
1053 }
1054
1055 @Override
1056 public boolean enterSAR(final BinaryNode binaryNode) {
1057 loadSAR(binaryNode);
1058 return false;
1059 }
1060
1061 @Override
1062 public boolean enterSHL(final BinaryNode binaryNode) {
1063 loadSHL(binaryNode);
1064 return false;
1065 }
1066
1067 @Override
1068 public boolean enterSHR(final BinaryNode binaryNode) {
1069 loadSHR(binaryNode);
1070 return false;
1071 }
1072
1073 @Override
1074 public boolean enterCOMMALEFT(final BinaryNode binaryNode) {
1075 loadCOMMALEFT(binaryNode, resultBounds);
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 enterADD(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 enterEQ(final BinaryNode binaryNode) {
1141 loadCmp(binaryNode, Condition.EQ);
1142 return false;
1143 }
1144
1145 @Override
1146 public boolean enterEQ_STRICT(final BinaryNode binaryNode) {
1147 loadCmp(binaryNode, Condition.EQ);
1148 return false;
1149 }
1150
1151 @Override
1152 public boolean enterGE(final BinaryNode binaryNode) {
1153 loadCmp(binaryNode, Condition.GE);
1154 return false;
1155 }
1156
1157 @Override
1158 public boolean enterGT(final BinaryNode binaryNode) {
1159 loadCmp(binaryNode, Condition.GT);
1160 return false;
1161 }
1162
1163 @Override
1164 public boolean enterLE(final BinaryNode binaryNode) {
1165 loadCmp(binaryNode, Condition.LE);
1166 return false;
1167 }
1168
1169 @Override
1170 public boolean enterLT(final BinaryNode binaryNode) {
1171 loadCmp(binaryNode, Condition.LT);
1172 return false;
1173 }
1174
1175 @Override
1176 public boolean enterNE(final BinaryNode binaryNode) {
1177 loadCmp(binaryNode, Condition.NE);
1178 return false;
1179 }
1180
1181 @Override
1182 public boolean enterNE_STRICT(final BinaryNode binaryNode) {
1183 loadCmp(binaryNode, Condition.NE);
1184 return false;
1185 }
1186
1187 @Override
1188 public boolean enterObjectNode(final ObjectNode objectNode) {
1189 loadObjectNode(objectNode);
1190 return false;
1191 }
1192
1193 @Override
1194 public boolean enterRuntimeNode(final RuntimeNode runtimeNode) {
1195 loadRuntimeNode(runtimeNode);
1196 return false;
1197 }
1198
1199 @Override
1200 public boolean enterNEW(final UnaryNode unaryNode) {
1201 loadNEW(unaryNode);
1202 return false;
1203 }
1204
1205 @Override
1206 public boolean enterDECINC(final UnaryNode unaryNode) {
1207 checkAssignTarget(unaryNode.getExpression());
1208 loadDECINC(unaryNode);
1209 return false;
1210 }
1211
1212 @Override
1213 public boolean enterJoinPredecessorExpression(final JoinPredecessorExpression joinExpr) {
1214 loadMaybeDiscard(joinExpr, joinExpr.getExpression(), resultBounds);
1215 return false;
1216 }
1217
1218 @Override
1219 public boolean enterGetSplitState(final GetSplitState getSplitState) {
1220 method.loadScope();
1221 method.invoke(Scope.GET_SPLIT_STATE);
1222 return false;
1223 }
1224
1225 @Override
1226 public boolean enterDefault(final Node otherNode) {
1227 // Must have handled all expressions that can legally be encountered.
1228 throw new AssertionError(otherNode.getClass().getName());
1229 }
1230 });
1231 if(!isCurrentDiscard) {
1232 coerceStackTop(resultBounds);
1233 }
1234 return method;
1235 }
1236
1237 private MethodEmitter coerceStackTop(final TypeBounds typeBounds) {
1238 return method.convert(typeBounds.within(method.peekType()));
1239 }
1240
1241 /**
1242 * Closes any still open entries for this block's local variables in the bytecode local variable table.
1243 *
1244 * @param block block containing symbols.
1245 */
1246 private void closeBlockVariables(final Block block) {
1247 for (final Symbol symbol : block.getSymbols()) {
1248 if (symbol.isBytecodeLocal()) {
1249 method.closeLocalVariable(symbol, block.getBreakLabel());
1250 }
1251 }
1252 }
1253
1254 @Override
1255 public boolean enterBlock(final Block block) {
1256 final Label entryLabel = block.getEntryLabel();
1257 if (entryLabel.isBreakTarget()) {
1258 // Entry label is a break target only for an inlined finally block.
1259 assert !method.isReachable();
1260 method.breakLabel(entryLabel, lc.getUsedSlotCount());
1261 } else {
1262 method.label(entryLabel);
1263 }
1264 if(!method.isReachable()) {
1265 return false;
1266 }
1267 if(lc.isFunctionBody() && emittedMethods.contains(lc.getCurrentFunction().getName())) {
1268 return false;
1269 }
1270 initLocals(block);
1271
1272 assert lc.getUsedSlotCount() == method.getFirstTemp();
1273 return true;
1274 }
1275
1276 boolean useOptimisticTypes() {
1277 return !lc.inSplitNode() && compiler.useOptimisticTypes();
1278 }
1279
1280 @Override
1281 public Node leaveBlock(final Block block) {
1282 popBlockScope(block);
1283 method.beforeJoinPoint(block);
1284
1285 closeBlockVariables(block);
1286 lc.releaseSlots();
1287 assert !method.isReachable() || (lc.isFunctionBody() ? 0 : lc.getUsedSlotCount()) == method.getFirstTemp() :
1288 "reachable="+method.isReachable() +
1289 " isFunctionBody=" + lc.isFunctionBody() +
1290 " usedSlotCount=" + lc.getUsedSlotCount() +
1291 " firstTemp=" + method.getFirstTemp();
1292
1293 return block;
1294 }
1295
1296 private void popBlockScope(final Block block) {
1297 final Label breakLabel = block.getBreakLabel();
1298
1299 if(!block.needsScope() || lc.isFunctionBody()) {
1300 emitBlockBreakLabel(breakLabel);
1301 return;
1302 }
1303
1304 final Label beginTryLabel = scopeEntryLabels.pop();
1305 final Label recoveryLabel = new Label("block_popscope_catch");
1306 emitBlockBreakLabel(breakLabel);
1307 final boolean bodyCanThrow = breakLabel.isAfter(beginTryLabel);
1308 if(bodyCanThrow) {
1309 method._try(beginTryLabel, breakLabel, recoveryLabel);
1310 }
1311
1312 Label afterCatchLabel = null;
1313
1314 if(method.isReachable()) {
1315 popScope();
1316 if(bodyCanThrow) {
1317 afterCatchLabel = new Label("block_after_catch");
1318 method._goto(afterCatchLabel);
1319 }
1320 }
1321
1322 if(bodyCanThrow) {
1323 assert !method.isReachable();
1324 method._catch(recoveryLabel);
1325 popScopeException();
1326 method.athrow();
1327 }
1328 if(afterCatchLabel != null) {
1329 method.label(afterCatchLabel);
1330 }
1331 }
1332
1333 private void emitBlockBreakLabel(final Label breakLabel) {
1334 // TODO: this is totally backwards. Block should not be breakable, LabelNode should be breakable.
1335 final LabelNode labelNode = lc.getCurrentBlockLabelNode();
1336 if(labelNode != null) {
1337 // Only have conversions if we're reachable
1338 assert labelNode.getLocalVariableConversion() == null || method.isReachable();
1339 method.beforeJoinPoint(labelNode);
1340 method.breakLabel(breakLabel, labeledBlockBreakLiveLocals.pop());
1341 } else {
1342 method.label(breakLabel);
1343 }
1344 }
1345
1346 private void popScope() {
1347 popScopes(1);
1348 }
1349
1350 /**
1351 * Pop scope as part of an exception handler. Similar to {@code popScope()} but also takes care of adjusting the
1352 * number of scopes that needs to be popped in case a rest-of continuation handler encounters an exception while
1353 * performing a ToPrimitive conversion.
1354 */
1355 private void popScopeException() {
1356 popScope();
1357 final ContinuationInfo ci = getContinuationInfo();
1358 if(ci != null) {
1359 final Label catchLabel = ci.catchLabel;
1360 if(catchLabel != METHOD_BOUNDARY && catchLabel == catchLabels.peek()) {
1361 ++ci.exceptionScopePops;
1362 }
1363 }
1364 }
1365
1366 private void popScopesUntil(final LexicalContextNode until) {
1367 popScopes(lc.getScopeNestingLevelTo(until));
1368 }
1369
1370 private void popScopes(final int count) {
1371 if(count == 0) {
1372 return;
1373 }
1374 assert count > 0; // together with count == 0 check, asserts nonnegative count
1375 if (!method.hasScope()) {
1376 // We can sometimes invoke this method even if the method has no slot for the scope object. Typical example:
1377 // for(;;) { with({}) { break; } }. WithNode normally creates a scope, but if it uses no identifiers and
1378 // nothing else forces creation of a scope in the method, we just won't have the :scope local variable.
1379 return;
1380 }
1381 method.loadCompilerConstant(SCOPE);
1382 for(int i = 0; i < count; ++i) {
1383 method.invoke(ScriptObject.GET_PROTO);
1384 }
1385 method.storeCompilerConstant(SCOPE);
1386 }
1387
1388 @Override
1389 public boolean enterBreakNode(final BreakNode breakNode) {
1390 return enterJumpStatement(breakNode);
1391 }
1392
1393 @Override
1394 public boolean enterJumpToInlinedFinally(final JumpToInlinedFinally jumpToInlinedFinally) {
1395 return enterJumpStatement(jumpToInlinedFinally);
1396 }
1397
1398 private boolean enterJumpStatement(final JumpStatement jump) {
1399 if(!method.isReachable()) {
1400 return false;
1401 }
1402 enterStatement(jump);
1403
1404 method.beforeJoinPoint(jump);
1405 popScopesUntil(jump.getPopScopeLimit(lc));
1406 final Label targetLabel = jump.getTargetLabel(lc);
1407 targetLabel.markAsBreakTarget();
1408 method._goto(targetLabel);
1409
1410 return false;
1411 }
1412
1413 private int loadArgs(final List<Expression> args) {
1414 final int argCount = args.size();
1415 // arg have already been converted to objects here.
1416 if (argCount > LinkerCallSite.ARGLIMIT) {
1417 loadArgsArray(args);
1418 return 1;
1419 }
1420
1421 for (final Expression arg : args) {
1422 assert arg != null;
1423 loadExpressionUnbounded(arg);
1424 }
1425 return argCount;
1426 }
1427
1428 private boolean loadCallNode(final CallNode callNode, final TypeBounds resultBounds) {
1429 lineNumber(callNode.getLineNumber());
1430
1431 final List<Expression> args = callNode.getArgs();
1432 final Expression function = callNode.getFunction();
1433 final Block currentBlock = lc.getCurrentBlock();
1434 final CodeGeneratorLexicalContext codegenLexicalContext = lc;
1435
1436 function.accept(new SimpleNodeVisitor() {
1437 private MethodEmitter sharedScopeCall(final IdentNode identNode, final int flags) {
1438 final Symbol symbol = identNode.getSymbol();
1439 final boolean isFastScope = isFastScope(symbol);
1440 new OptimisticOperation(callNode, resultBounds) {
1441 @Override
1442 void loadStack() {
1443 method.loadCompilerConstant(SCOPE);
1444 if (isFastScope) {
1445 method.load(getScopeProtoDepth(currentBlock, symbol));
1446 } else {
1447 method.load(-1); // Bypass fast-scope code in shared callsite
1448 }
1449 loadArgs(args);
1450 }
1451 @Override
1452 void consumeStack() {
1453 final Type[] paramTypes = method.getTypesFromStack(args.size());
1454 // We have trouble finding e.g. in Type.typeFor(asm.Type) because it can't see the Context class
1455 // loader, so we need to weaken reference signatures to Object.
1456 for(int i = 0; i < paramTypes.length; ++i) {
1457 paramTypes[i] = Type.generic(paramTypes[i]);
1458 }
1459 // As shared scope calls are only used in non-optimistic compilation, we switch from using
1460 // TypeBounds to just a single definitive type, resultBounds.widest.
1461 final SharedScopeCall scopeCall = codegenLexicalContext.getScopeCall(unit, symbol,
1462 identNode.getType(), resultBounds.widest, paramTypes, flags);
1463 scopeCall.generateInvoke(method);
1464 }
1465 }.emit();
1466 return method;
1467 }
1468
1469 private void scopeCall(final IdentNode ident, final int flags) {
1470 new OptimisticOperation(callNode, resultBounds) {
1471 int argsCount;
1472 @Override
1473 void loadStack() {
1474 loadExpressionAsObject(ident); // foo() makes no sense if foo == 3
1475 // ScriptFunction will see CALLSITE_SCOPE and will bind scope accordingly.
1476 method.loadUndefined(Type.OBJECT); //the 'this'
1477 argsCount = loadArgs(args);
1478 }
1479 @Override
1480 void consumeStack() {
1481 dynamicCall(2 + argsCount, flags, ident.getName());
1482 }
1483 }.emit();
1484 }
1485
1486 private void evalCall(final IdentNode ident, final int flags) {
1487 final Label invoke_direct_eval = new Label("invoke_direct_eval");
1488 final Label is_not_eval = new Label("is_not_eval");
1489 final Label eval_done = new Label("eval_done");
1490
1491 new OptimisticOperation(callNode, resultBounds) {
1492 int argsCount;
1493 @Override
1494 void loadStack() {
1495 /*
1496 * We want to load 'eval' to check if it is indeed global builtin eval.
1497 * If this eval call is inside a 'with' statement, dyn:getMethod|getProp|getElem
1498 * would be generated if ident is a "isFunction". But, that would result in a
1499 * bound function from WithObject. We don't want that as bound function as that
1500 * won't be detected as builtin eval. So, we make ident as "not a function" which
1501 * results in "dyn:getProp|getElem|getMethod" being generated and so WithObject
1502 * would return unbounded eval function.
1503 *
1504 * Example:
1505 *
1506 * var global = this;
1507 * function func() {
1508 * with({ eval: global.eval) { eval("var x = 10;") }
1509 * }
1510 */
1511 loadExpressionAsObject(ident.setIsNotFunction()); // Type.OBJECT as foo() makes no sense if foo == 3
1512 globalIsEval();
1513 method.ifeq(is_not_eval);
1514
1515 // Load up self (scope).
1516 method.loadCompilerConstant(SCOPE);
1517 final List<Expression> evalArgs = callNode.getEvalArgs().getArgs();
1518 // load evaluated code
1519 loadExpressionAsObject(evalArgs.get(0));
1520 // load second and subsequent args for side-effect
1521 final int numArgs = evalArgs.size();
1522 for (int i = 1; i < numArgs; i++) {
1523 loadAndDiscard(evalArgs.get(i));
1524 }
1525 method._goto(invoke_direct_eval);
1526
1527 method.label(is_not_eval);
1528 // load this time but with dyn:getMethod|getProp|getElem
1529 loadExpressionAsObject(ident); // Type.OBJECT as foo() makes no sense if foo == 3
1530 // This is some scope 'eval' or global eval replaced by user
1531 // but not the built-in ECMAScript 'eval' function call
1532 method.loadNull();
1533 argsCount = loadArgs(callNode.getArgs());
1534 }
1535
1536 @Override
1537 void consumeStack() {
1538 // Ordinary call
1539 dynamicCall(2 + argsCount, flags, "eval");
1540 method._goto(eval_done);
1541
1542 method.label(invoke_direct_eval);
1543 // Special/extra 'eval' arguments. These can be loaded late (in consumeStack) as we know none of
1544 // them can ever be optimistic.
1545 method.loadCompilerConstant(THIS);
1546 method.load(callNode.getEvalArgs().getLocation());
1547 method.load(CodeGenerator.this.lc.getCurrentFunction().isStrict());
1548 // direct call to Global.directEval
1549 globalDirectEval();
1550 convertOptimisticReturnValue();
1551 coerceStackTop(resultBounds);
1552 }
1553 }.emit();
1554
1555 method.label(eval_done);
1556 }
1557
1558 @Override
1559 public boolean enterIdentNode(final IdentNode node) {
1560 final Symbol symbol = node.getSymbol();
1561
1562 if (symbol.isScope()) {
1563 final int flags = getScopeCallSiteFlags(symbol);
1564 final int useCount = symbol.getUseCount();
1565
1566 // Threshold for generating shared scope callsite is lower for fast scope symbols because we know
1567 // we can dial in the correct scope. However, we also need to enable it for non-fast scopes to
1568 // support huge scripts like mandreel.js.
1569 if (callNode.isEval()) {
1570 evalCall(node, flags);
1571 } else if (useCount <= SharedScopeCall.FAST_SCOPE_CALL_THRESHOLD
1572 || !isFastScope(symbol) && useCount <= SharedScopeCall.SLOW_SCOPE_CALL_THRESHOLD
1573 || CodeGenerator.this.lc.inDynamicScope()
1574 || callNode.isOptimistic()) {
1575 scopeCall(node, flags);
1576 } else {
1577 sharedScopeCall(node, flags);
1578 }
1579 assert method.peekType().equals(resultBounds.within(callNode.getType())) : method.peekType() + " != " + resultBounds + "(" + callNode.getType() + ")";
1580 } else {
1581 enterDefault(node);
1582 }
1583
1584 return false;
1585 }
1586
1587 @Override
1588 public boolean enterAccessNode(final AccessNode node) {
1589 //check if this is an apply to call node. only real applies, that haven't been
1590 //shadowed from their way to the global scope counts
1591
1592 //call nodes have program points.
1593
1594 final int flags = getCallSiteFlags() | (callNode.isApplyToCall() ? CALLSITE_APPLY_TO_CALL : 0);
1595
1596 new OptimisticOperation(callNode, resultBounds) {
1597 int argCount;
1598 @Override
1599 void loadStack() {
1600 loadExpressionAsObject(node.getBase());
1601 method.dup();
1602 // NOTE: not using a nested OptimisticOperation on this dynamicGet, as we expect to get back
1603 // a callable object. Nobody in their right mind would optimistically type this call site.
1604 assert !node.isOptimistic();
1605 method.dynamicGet(node.getType(), node.getProperty(), flags, true, node.isIndex());
1606 method.swap();
1607 argCount = loadArgs(args);
1608 }
1609 @Override
1610 void consumeStack() {
1611 dynamicCall(2 + argCount, flags, node.toString(false));
1612 }
1613 }.emit();
1614
1615 return false;
1616 }
1617
1618 @Override
1619 public boolean enterFunctionNode(final FunctionNode origCallee) {
1620 new OptimisticOperation(callNode, resultBounds) {
1621 FunctionNode callee;
1622 int argsCount;
1623 @Override
1624 void loadStack() {
1625 callee = (FunctionNode)origCallee.accept(CodeGenerator.this);
1626 if (callee.isStrict()) { // "this" is undefined
1627 method.loadUndefined(Type.OBJECT);
1628 } else { // get global from scope (which is the self)
1629 globalInstance();
1630 }
1631 argsCount = loadArgs(args);
1632 }
1633
1634 @Override
1635 void consumeStack() {
1636 dynamicCall(2 + argsCount, getCallSiteFlags(), null);
1637 }
1638 }.emit();
1639 return false;
1640 }
1641
1642 @Override
1643 public boolean enterIndexNode(final IndexNode node) {
1644 new OptimisticOperation(callNode, resultBounds) {
1645 int argsCount;
1646 @Override
1647 void loadStack() {
1648 loadExpressionAsObject(node.getBase());
1649 method.dup();
1650 final Type indexType = node.getIndex().getType();
1651 if (indexType.isObject() || indexType.isBoolean()) {
1652 loadExpressionAsObject(node.getIndex()); //TODO boolean
1653 } else {
1654 loadExpressionUnbounded(node.getIndex());
1655 }
1656 // NOTE: not using a nested OptimisticOperation on this dynamicGetIndex, as we expect to get
1657 // back a callable object. Nobody in their right mind would optimistically type this call site.
1658 assert !node.isOptimistic();
1659 method.dynamicGetIndex(node.getType(), getCallSiteFlags(), true);
1660 method.swap();
1661 argsCount = loadArgs(args);
1662 }
1663 @Override
1664 void consumeStack() {
1665 dynamicCall(2 + argsCount, getCallSiteFlags(), node.toString(false));
1666 }
1667 }.emit();
1668 return false;
1669 }
1670
1671 @Override
1672 protected boolean enterDefault(final Node node) {
1673 new OptimisticOperation(callNode, resultBounds) {
1674 int argsCount;
1675 @Override
1676 void loadStack() {
1677 // Load up function.
1678 loadExpressionAsObject(function); //TODO, e.g. booleans can be used as functions
1679 method.loadUndefined(Type.OBJECT); // ScriptFunction will figure out the correct this when it sees CALLSITE_SCOPE
1680 argsCount = loadArgs(args);
1681 }
1682 @Override
1683 void consumeStack() {
1684 final int flags = getCallSiteFlags() | CALLSITE_SCOPE;
1685 dynamicCall(2 + argsCount, flags, node.toString(false));
1686 }
1687 }.emit();
1688 return false;
1689 }
1690 });
1691
1692 return false;
1693 }
1694
1695 /**
1696 * Returns the flags with optimistic flag and program point removed.
1697 * @param flags the flags that need optimism stripped from them.
1698 * @return flags without optimism
1699 */
1700 static int nonOptimisticFlags(final int flags) {
1701 return flags & ~(CALLSITE_OPTIMISTIC | -1 << CALLSITE_PROGRAM_POINT_SHIFT);
1702 }
1703
1704 @Override
1705 public boolean enterContinueNode(final ContinueNode continueNode) {
1706 return enterJumpStatement(continueNode);
1707 }
1708
1709 @Override
1710 public boolean enterEmptyNode(final EmptyNode emptyNode) {
1711 // Don't even record the line number, it's irrelevant as there's no code.
1712 return false;
1713 }
1714
1715 @Override
1716 public boolean enterExpressionStatement(final ExpressionStatement expressionStatement) {
1717 if(!method.isReachable()) {
1718 return false;
1719 }
1720 enterStatement(expressionStatement);
1721
1722 loadAndDiscard(expressionStatement.getExpression());
1723 assert method.getStackSize() == 0;
1724
1725 return false;
1726 }
1727
1728 @Override
1729 public boolean enterBlockStatement(final BlockStatement blockStatement) {
1730 if(!method.isReachable()) {
1731 return false;
1732 }
1733 enterStatement(blockStatement);
1734
1735 blockStatement.getBlock().accept(this);
1736
1737 return false;
1738 }
1739
1740 @Override
1741 public boolean enterForNode(final ForNode forNode) {
1742 if(!method.isReachable()) {
1743 return false;
1744 }
1745 enterStatement(forNode);
1746 if (forNode.isForIn()) {
1747 enterForIn(forNode);
1748 } else {
1749 final Expression init = forNode.getInit();
1750 if (init != null) {
1751 loadAndDiscard(init);
1752 }
1753 enterForOrWhile(forNode, forNode.getModify());
1754 }
1755
1756 return false;
1757 }
1758
1759 private void enterForIn(final ForNode forNode) {
1760 loadExpression(forNode.getModify(), TypeBounds.OBJECT);
1761 method.invoke(forNode.isForEach() ? ScriptRuntime.TO_VALUE_ITERATOR : ScriptRuntime.TO_PROPERTY_ITERATOR);
1762 final Symbol iterSymbol = forNode.getIterator();
1763 final int iterSlot = iterSymbol.getSlot(Type.OBJECT);
1764 method.store(iterSymbol, ITERATOR_TYPE);
1765
1766 method.beforeJoinPoint(forNode);
1767
1768 final Label continueLabel = forNode.getContinueLabel();
1769 final Label breakLabel = forNode.getBreakLabel();
1770
1771 method.label(continueLabel);
1772 method.load(ITERATOR_TYPE, iterSlot);
1773 method.invoke(interfaceCallNoLookup(ITERATOR_CLASS, "hasNext", boolean.class));
1774 final JoinPredecessorExpression test = forNode.getTest();
1775 final Block body = forNode.getBody();
1776 if(LocalVariableConversion.hasLiveConversion(test)) {
1777 final Label afterConversion = new Label("for_in_after_test_conv");
1778 method.ifne(afterConversion);
1779 method.beforeJoinPoint(test);
1780 method._goto(breakLabel);
1781 method.label(afterConversion);
1782 } else {
1783 method.ifeq(breakLabel);
1784 }
1785
1786 new Store<Expression>(forNode.getInit()) {
1787 @Override
1788 protected void storeNonDiscard() {
1789 // This expression is neither part of a discard, nor needs to be left on the stack after it was
1790 // stored, so we override storeNonDiscard to be a no-op.
1791 }
1792
1793 @Override
1794 protected void evaluate() {
1795 new OptimisticOperation((Optimistic)forNode.getInit(), TypeBounds.UNBOUNDED) {
1796 @Override
1797 void loadStack() {
1798 method.load(ITERATOR_TYPE, iterSlot);
1799 }
1800
1801 @Override
1802 void consumeStack() {
1803 method.invoke(interfaceCallNoLookup(ITERATOR_CLASS, "next", Object.class));
1804 convertOptimisticReturnValue();
1805 }
1806 }.emit();
1807 }
1808 }.store();
1809 body.accept(this);
1810
1811 if(method.isReachable()) {
1812 method._goto(continueLabel);
1813 }
1814 method.label(breakLabel);
1815 }
1816
1817 /**
1818 * Initialize the slots in a frame to undefined.
1819 *
1820 * @param block block with local vars.
1821 */
1822 private void initLocals(final Block block) {
1823 lc.onEnterBlock(block);
1824
1825 final boolean isFunctionBody = lc.isFunctionBody();
1826 final FunctionNode function = lc.getCurrentFunction();
1827 if (isFunctionBody) {
1828 initializeMethodParameters(function);
1829 if(!function.isVarArg()) {
1830 expandParameterSlots(function);
1831 }
1832 if (method.hasScope()) {
1833 if (function.needsParentScope()) {
1834 method.loadCompilerConstant(CALLEE);
1835 method.invoke(ScriptFunction.GET_SCOPE);
1836 } else {
1837 assert function.hasScopeBlock();
1838 method.loadNull();
1839 }
1840 method.storeCompilerConstant(SCOPE);
1841 }
1842 if (function.needsArguments()) {
1843 initArguments(function);
1844 }
1845 }
1846
1847 /*
1848 * Determine if block needs scope, if not, just do initSymbols for this block.
1849 */
1850 if (block.needsScope()) {
1851 /*
1852 * Determine if function is varargs and consequently variables have to
1853 * be in the scope.
1854 */
1855 final boolean varsInScope = function.allVarsInScope();
1856
1857 // TODO for LET we can do better: if *block* does not contain any eval/with, we don't need its vars in scope.
1858
1859 final boolean hasArguments = function.needsArguments();
1860 final List<MapTuple<Symbol>> tuples = new ArrayList<>();
1861 final Iterator<IdentNode> paramIter = function.getParameters().iterator();
1862 for (final Symbol symbol : block.getSymbols()) {
1863 if (symbol.isInternal() || symbol.isThis()) {
1864 continue;
1865 }
1866
1867 if (symbol.isVar()) {
1868 assert !varsInScope || symbol.isScope();
1869 if (varsInScope || symbol.isScope()) {
1870 assert symbol.isScope() : "scope for " + symbol + " should have been set in Lower already " + function.getName();
1871 assert !symbol.hasSlot() : "slot for " + symbol + " should have been removed in Lower already" + function.getName();
1872
1873 //this tuple will not be put fielded, as it has no value, just a symbol
1874 tuples.add(new MapTuple<Symbol>(symbol.getName(), symbol, null));
1875 } else {
1876 assert symbol.hasSlot() || symbol.slotCount() == 0 : symbol + " should have a slot only, no scope";
1877 }
1878 } else if (symbol.isParam() && (varsInScope || hasArguments || symbol.isScope())) {
1879 assert symbol.isScope() : "scope for " + symbol + " should have been set in AssignSymbols already " + function.getName() + " varsInScope="+varsInScope+" hasArguments="+hasArguments+" symbol.isScope()=" + symbol.isScope();
1880 assert !(hasArguments && symbol.hasSlot()) : "slot for " + symbol + " should have been removed in Lower already " + function.getName();
1881
1882 final Type paramType;
1883 final Symbol paramSymbol;
1884
1885 if (hasArguments) {
1886 assert !symbol.hasSlot() : "slot for " + symbol + " should have been removed in Lower already ";
1887 paramSymbol = null;
1888 paramType = null;
1889 } else {
1890 paramSymbol = symbol;
1891 // NOTE: We're relying on the fact here that Block.symbols is a LinkedHashMap, hence it will
1892 // return symbols in the order they were defined, and parameters are defined in the same order
1893 // they appear in the function. That's why we can have a single pass over the parameter list
1894 // with an iterator, always just scanning forward for the next parameter that matches the symbol
1895 // name.
1896 for(;;) {
1897 final IdentNode nextParam = paramIter.next();
1898 if(nextParam.getName().equals(symbol.getName())) {
1899 paramType = nextParam.getType();
1900 break;
1901 }
1902 }
1903 }
1904
1905 tuples.add(new MapTuple<Symbol>(symbol.getName(), symbol, paramType, paramSymbol) {
1906 //this symbol will be put fielded, we can't initialize it as undefined with a known type
1907 @Override
1908 public Class<?> getValueType() {
1909 if (!useDualFields() || value == null || paramType == null || paramType.isBoolean()) {
1910 return Object.class;
1911 }
1912 return paramType.getTypeClass();
1913 }
1914 });
1915 }
1916 }
1917
1918 /*
1919 * Create a new object based on the symbols and values, generate
1920 * bootstrap code for object
1921 */
1922 new FieldObjectCreator<Symbol>(this, tuples, true, hasArguments) {
1923 @Override
1924 protected void loadValue(final Symbol value, final Type type) {
1925 method.load(value, type);
1926 }
1927 }.makeObject(method);
1928 // program function: merge scope into global
1929 if (isFunctionBody && function.isProgram()) {
1930 method.invoke(ScriptRuntime.MERGE_SCOPE);
1931 }
1932
1933 method.storeCompilerConstant(SCOPE);
1934 if(!isFunctionBody) {
1935 // Function body doesn't need a try/catch to restore scope, as it'd be a dead store anyway. Allowing it
1936 // actually causes issues with UnwarrantedOptimismException handlers as ASM will sort this handler to
1937 // the top of the exception handler table, so it'll be triggered instead of the UOE handlers.
1938 final Label scopeEntryLabel = new Label("scope_entry");
1939 scopeEntryLabels.push(scopeEntryLabel);
1940 method.label(scopeEntryLabel);
1941 }
1942 } else if (isFunctionBody && function.isVarArg()) {
1943 // Since we don't have a scope, parameters didn't get assigned array indices by the FieldObjectCreator, so
1944 // we need to assign them separately here.
1945 int nextParam = 0;
1946 for (final IdentNode param : function.getParameters()) {
1947 param.getSymbol().setFieldIndex(nextParam++);
1948 }
1949 }
1950
1951 // Debugging: print symbols? @see --print-symbols flag
1952 printSymbols(block, function, (isFunctionBody ? "Function " : "Block in ") + (function.getIdent() == null ? "<anonymous>" : function.getIdent().getName()));
1953 }
1954
1955 /**
1956 * Incoming method parameters are always declared on method entry; declare them in the local variable table.
1957 * @param function function for which code is being generated.
1958 */
1959 private void initializeMethodParameters(final FunctionNode function) {
1960 final Label functionStart = new Label("fn_start");
1961 method.label(functionStart);
1962 int nextSlot = 0;
1963 if(function.needsCallee()) {
1964 initializeInternalFunctionParameter(CALLEE, function, functionStart, nextSlot++);
1965 }
1966 initializeInternalFunctionParameter(THIS, function, functionStart, nextSlot++);
1967 if(function.isVarArg()) {
1968 initializeInternalFunctionParameter(VARARGS, function, functionStart, nextSlot++);
1969 } else {
1970 for(final IdentNode param: function.getParameters()) {
1971 final Symbol symbol = param.getSymbol();
1972 if(symbol.isBytecodeLocal()) {
1973 method.initializeMethodParameter(symbol, param.getType(), functionStart);
1974 }
1975 }
1976 }
1977 }
1978
1979 private void initializeInternalFunctionParameter(final CompilerConstants cc, final FunctionNode fn, final Label functionStart, final int slot) {
1980 final Symbol symbol = initializeInternalFunctionOrSplitParameter(cc, fn, functionStart, slot);
1981 // Internal function params (:callee, this, and :varargs) are never expanded to multiple slots
1982 assert symbol.getFirstSlot() == slot;
1983 }
1984
1985 private Symbol initializeInternalFunctionOrSplitParameter(final CompilerConstants cc, final FunctionNode fn, final Label functionStart, final int slot) {
1986 final Symbol symbol = fn.getBody().getExistingSymbol(cc.symbolName());
1987 final Type type = Type.typeFor(cc.type());
1988 method.initializeMethodParameter(symbol, type, functionStart);
1989 method.onLocalStore(type, slot);
1990 return symbol;
1991 }
1992
1993 /**
1994 * Parameters come into the method packed into local variable slots next to each other. Nashorn on the other hand
1995 * can use 1-6 slots for a local variable depending on all the types it needs to store. When this method is invoked,
1996 * the symbols are already allocated such wider slots, but the values are still in tightly packed incoming slots,
1997 * and we need to spread them into their new locations.
1998 * @param function the function for which parameter-spreading code needs to be emitted
1999 */
2000 private void expandParameterSlots(final FunctionNode function) {
2001 final List<IdentNode> parameters = function.getParameters();
2002 // Calculate the total number of incoming parameter slots
2003 int currentIncomingSlot = function.needsCallee() ? 2 : 1;
2004 for(final IdentNode parameter: parameters) {
2005 currentIncomingSlot += parameter.getType().getSlots();
2006 }
2007 // Starting from last parameter going backwards, move the parameter values into their new slots.
2008 for(int i = parameters.size(); i-- > 0;) {
2009 final IdentNode parameter = parameters.get(i);
2010 final Type parameterType = parameter.getType();
2011 final int typeWidth = parameterType.getSlots();
2012 currentIncomingSlot -= typeWidth;
2013 final Symbol symbol = parameter.getSymbol();
2014 final int slotCount = symbol.slotCount();
2015 assert slotCount > 0;
2016 // Scoped parameters must not hold more than one value
2017 assert symbol.isBytecodeLocal() || slotCount == typeWidth;
2018
2019 // Mark it as having its value stored into it by the method invocation.
2020 method.onLocalStore(parameterType, currentIncomingSlot);
2021 if(currentIncomingSlot != symbol.getSlot(parameterType)) {
2022 method.load(parameterType, currentIncomingSlot);
2023 method.store(symbol, parameterType);
2024 }
2025 }
2026 }
2027
2028 private void initArguments(final FunctionNode function) {
2029 method.loadCompilerConstant(VARARGS);
2030 if (function.needsCallee()) {
2031 method.loadCompilerConstant(CALLEE);
2032 } else {
2033 // If function is strict mode, "arguments.callee" is not populated, so we don't necessarily need the
2034 // caller.
2035 assert function.isStrict();
2036 method.loadNull();
2037 }
2038 method.load(function.getParameters().size());
2039 globalAllocateArguments();
2040 method.storeCompilerConstant(ARGUMENTS);
2041 }
2042
2043 private boolean skipFunction(final FunctionNode functionNode) {
2044 final ScriptEnvironment env = compiler.getScriptEnvironment();
2045 final boolean lazy = env._lazy_compilation;
2046 final boolean onDemand = compiler.isOnDemandCompilation();
2047
2048 // If this is on-demand or lazy compilation, don't compile a nested (not topmost) function.
2049 if((onDemand || lazy) && lc.getOutermostFunction() != functionNode) {
2050 return true;
2051 }
2052
2053 // If lazy compiling with optimistic types, don't compile the program eagerly either. It will soon be
2054 // invalidated anyway. In presence of a class cache, this further means that an obsoleted program version
2055 // lingers around. Also, currently loading previously persisted optimistic types information only works if
2056 // we're on-demand compiling a function, so with this strategy the :program method can also have the warmup
2057 // benefit of using previously persisted types.
2058 //
2059 // NOTE that this means the first compiled class will effectively just have a :createProgramFunction method, and
2060 // the RecompilableScriptFunctionData (RSFD) object in its constants array. It won't even have the :program
2061 // method. This is by design. It does mean that we're wasting one compiler execution (and we could minimize this
2062 // by just running it up to scope depth calculation, which creates the RSFDs and then this limited codegen).
2063 // We could emit an initial separate compile unit with the initial version of :program in it to better utilize
2064 // the compilation pipeline, but that would need more invasive changes, as currently the assumption that
2065 // :program is emitted into the first compilation unit of the function lives in many places.
2066 return !onDemand && lazy && env._optimistic_types && functionNode.isProgram();
2067 }
2068
2069 @Override
2070 public boolean enterFunctionNode(final FunctionNode functionNode) {
2071 if (skipFunction(functionNode)) {
2072 // In case we are not generating code for the function, we must create or retrieve the function object and
2073 // load it on the stack here.
2074 newFunctionObject(functionNode, false);
2075 return false;
2076 }
2077
2078 final String fnName = functionNode.getName();
2079
2080 // NOTE: we only emit the method for a function with the given name once. We can have multiple functions with
2081 // the same name as a result of inlining finally blocks. However, in the future -- with type specialization,
2082 // notably -- we might need to check for both name *and* signature. Of course, even that might not be
2083 // sufficient; the function might have a code dependency on the type of the variables in its enclosing scopes,
2084 // and the type of such a variable can be different in catch and finally blocks. So, in the future we will have
2085 // to decide to either generate a unique method for each inlined copy of the function, maybe figure out its
2086 // exact type closure and deduplicate based on that, or just decide that functions in finally blocks aren't
2087 // worth it, and generate one method with most generic type closure.
2088 if (!emittedMethods.contains(fnName)) {
2089 log.info("=== BEGIN ", fnName);
2090
2091 assert functionNode.getCompileUnit() != null : "no compile unit for " + fnName + " " + Debug.id(functionNode);
2092 unit = lc.pushCompileUnit(functionNode.getCompileUnit());
2093 assert lc.hasCompileUnits();
2094
2095 final ClassEmitter classEmitter = unit.getClassEmitter();
2096 pushMethodEmitter(isRestOf() ? classEmitter.restOfMethod(functionNode) : classEmitter.method(functionNode));
2097 method.setPreventUndefinedLoad();
2098 if(useOptimisticTypes()) {
2099 lc.pushUnwarrantedOptimismHandlers();
2100 }
2101
2102 // new method - reset last line number
2103 lastLineNumber = -1;
2104
2105 method.begin();
2106
2107 if (isRestOf()) {
2108 assert continuationInfo == null;
2109 continuationInfo = new ContinuationInfo();
2110 method.gotoLoopStart(continuationInfo.getHandlerLabel());
2111 }
2112 }
2113
2114 return true;
2115 }
2116
2117 private void pushMethodEmitter(final MethodEmitter newMethod) {
2118 method = lc.pushMethodEmitter(newMethod);
2119 catchLabels.push(METHOD_BOUNDARY);
2120 }
2121
2122 private void popMethodEmitter() {
2123 method = lc.popMethodEmitter(method);
2124 assert catchLabels.peek() == METHOD_BOUNDARY;
2125 catchLabels.pop();
2126 }
2127
2128 @Override
2129 public Node leaveFunctionNode(final FunctionNode functionNode) {
2130 try {
2131 final boolean markOptimistic;
2132 if (emittedMethods.add(functionNode.getName())) {
2133 markOptimistic = generateUnwarrantedOptimismExceptionHandlers(functionNode);
2134 generateContinuationHandler();
2135 method.end(); // wrap up this method
2136 unit = lc.popCompileUnit(functionNode.getCompileUnit());
2137 popMethodEmitter();
2138 log.info("=== END ", functionNode.getName());
2139 } else {
2140 markOptimistic = false;
2141 }
2142
2143 FunctionNode newFunctionNode = functionNode;
2144 if (markOptimistic) {
2145 newFunctionNode = newFunctionNode.setFlag(lc, FunctionNode.IS_DEOPTIMIZABLE);
2146 }
2147
2148 newFunctionObject(newFunctionNode, true);
2149 return newFunctionNode;
2150 } catch (final Throwable t) {
2151 Context.printStackTrace(t);
2152 final VerifyError e = new VerifyError("Code generation bug in \"" + functionNode.getName() + "\": likely stack misaligned: " + t + " " + functionNode.getSource().getName());
2153 e.initCause(t);
2154 throw e;
2155 }
2156 }
2157
2158 @Override
2159 public boolean enterIfNode(final IfNode ifNode) {
2160 if(!method.isReachable()) {
2161 return false;
2162 }
2163 enterStatement(ifNode);
2164
2165 final Expression test = ifNode.getTest();
2166 final Block pass = ifNode.getPass();
2167 final Block fail = ifNode.getFail();
2168
2169 if (Expression.isAlwaysTrue(test)) {
2170 loadAndDiscard(test);
2171 pass.accept(this);
2172 return false;
2173 } else if (Expression.isAlwaysFalse(test)) {
2174 loadAndDiscard(test);
2175 if (fail != null) {
2176 fail.accept(this);
2177 }
2178 return false;
2179 }
2180
2181 final boolean hasFailConversion = LocalVariableConversion.hasLiveConversion(ifNode);
2182
2183 final Label failLabel = new Label("if_fail");
2184 final Label afterLabel = (fail == null && !hasFailConversion) ? null : new Label("if_done");
2185
2186 emitBranch(test, failLabel, false);
2187
2188 pass.accept(this);
2189 if(method.isReachable() && afterLabel != null) {
2190 method._goto(afterLabel); //don't fallthru to fail block
2191 }
2192 method.label(failLabel);
2193
2194 if (fail != null) {
2195 fail.accept(this);
2196 } else if(hasFailConversion) {
2197 method.beforeJoinPoint(ifNode);
2198 }
2199
2200 if(afterLabel != null && afterLabel.isReachable()) {
2201 method.label(afterLabel);
2202 }
2203
2204 return false;
2205 }
2206
2207 private void emitBranch(final Expression test, final Label label, final boolean jumpWhenTrue) {
2208 new BranchOptimizer(this, method).execute(test, label, jumpWhenTrue);
2209 }
2210
2211 private void enterStatement(final Statement statement) {
2212 lineNumber(statement);
2213 }
2214
2215 private void lineNumber(final Statement statement) {
2216 lineNumber(statement.getLineNumber());
2217 }
2218
2219 private void lineNumber(final int lineNumber) {
2220 if (lineNumber != lastLineNumber && lineNumber != Node.NO_LINE_NUMBER) {
2221 method.lineNumber(lineNumber);
2222 lastLineNumber = lineNumber;
2223 }
2224 }
2225
2226 int getLastLineNumber() {
2227 return lastLineNumber;
2228 }
2229
2230 /**
2231 * Load a list of nodes as an array of a specific type
2232 * The array will contain the visited nodes.
2233 *
2234 * @param arrayLiteralNode the array of contents
2235 * @param arrayType the type of the array, e.g. ARRAY_NUMBER or ARRAY_OBJECT
2236 */
2237 private void loadArray(final ArrayLiteralNode arrayLiteralNode, final ArrayType arrayType) {
2238 assert arrayType == Type.INT_ARRAY || arrayType == Type.LONG_ARRAY || arrayType == Type.NUMBER_ARRAY || arrayType == Type.OBJECT_ARRAY;
2239
2240 final Expression[] nodes = arrayLiteralNode.getValue();
2241 final Object presets = arrayLiteralNode.getPresets();
2242 final int[] postsets = arrayLiteralNode.getPostsets();
2243 final List<Splittable.SplitRange> ranges = arrayLiteralNode.getSplitRanges();
2244
2245 loadConstant(presets);
2246
2247 final Type elementType = arrayType.getElementType();
2248
2249 if (ranges != null) {
2250
2251 loadSplitLiteral(new SplitLiteralCreator() {
2252 @Override
2253 public void populateRange(final MethodEmitter method, final Type type, final int slot, final int start, final int end) {
2254 for (int i = start; i < end; i++) {
2255 method.load(type, slot);
2256 storeElement(nodes, elementType, postsets[i]);
2257 }
2258 method.load(type, slot);
2259 }
2260 }, ranges, arrayType);
2261
2262 return;
2263 }
2264
2265 if(postsets.length > 0) {
2266 final int arraySlot = method.getUsedSlotsWithLiveTemporaries();
2267 method.storeTemp(arrayType, arraySlot);
2268 for (final int postset : postsets) {
2269 method.load(arrayType, arraySlot);
2270 storeElement(nodes, elementType, postset);
2271 }
2272 method.load(arrayType, arraySlot);
2273 }
2274 }
2275
2276 private void storeElement(final Expression[] nodes, final Type elementType, final int index) {
2277 method.load(index);
2278
2279 final Expression element = nodes[index];
2280
2281 if (element == null) {
2282 method.loadEmpty(elementType);
2283 } else {
2284 loadExpressionAsType(element, elementType);
2285 }
2286
2287 method.arraystore();
2288 }
2289
2290 private MethodEmitter loadArgsArray(final List<Expression> args) {
2291 final Object[] array = new Object[args.size()];
2292 loadConstant(array);
2293
2294 for (int i = 0; i < args.size(); i++) {
2295 method.dup();
2296 method.load(i);
2297 loadExpression(args.get(i), TypeBounds.OBJECT); // variable arity methods always take objects
2298 method.arraystore();
2299 }
2300
2301 return method;
2302 }
2303
2304 /**
2305 * Load a constant from the constant array. This is only public to be callable from the objects
2306 * subpackage. Do not call directly.
2307 *
2308 * @param string string to load
2309 */
2310 void loadConstant(final String string) {
2311 final String unitClassName = unit.getUnitClassName();
2312 final ClassEmitter classEmitter = unit.getClassEmitter();
2313 final int index = compiler.getConstantData().add(string);
2314
2315 method.load(index);
2316 method.invokestatic(unitClassName, GET_STRING.symbolName(), methodDescriptor(String.class, int.class));
2317 classEmitter.needGetConstantMethod(String.class);
2318 }
2319
2320 /**
2321 * Load a constant from the constant array. This is only public to be callable from the objects
2322 * subpackage. Do not call directly.
2323 *
2324 * @param object object to load
2325 */
2326 void loadConstant(final Object object) {
2327 loadConstant(object, unit, method);
2328 }
2329
2330 private void loadConstant(final Object object, final CompileUnit compileUnit, final MethodEmitter methodEmitter) {
2331 final String unitClassName = compileUnit.getUnitClassName();
2332 final ClassEmitter classEmitter = compileUnit.getClassEmitter();
2333 final int index = compiler.getConstantData().add(object);
2334 final Class<?> cls = object.getClass();
2335
2336 if (cls == PropertyMap.class) {
2337 methodEmitter.load(index);
2338 methodEmitter.invokestatic(unitClassName, GET_MAP.symbolName(), methodDescriptor(PropertyMap.class, int.class));
2339 classEmitter.needGetConstantMethod(PropertyMap.class);
2340 } else if (cls.isArray()) {
2341 methodEmitter.load(index);
2342 final String methodName = ClassEmitter.getArrayMethodName(cls);
2343 methodEmitter.invokestatic(unitClassName, methodName, methodDescriptor(cls, int.class));
2344 classEmitter.needGetConstantMethod(cls);
2345 } else {
2346 methodEmitter.loadConstants().load(index).arrayload();
2347 if (object instanceof ArrayData) {
2348 methodEmitter.checkcast(ArrayData.class);
2349 methodEmitter.invoke(virtualCallNoLookup(ArrayData.class, "copy", ArrayData.class));
2350 } else if (cls != Object.class) {
2351 methodEmitter.checkcast(cls);
2352 }
2353 }
2354 }
2355
2356 private void loadConstantsAndIndex(final Object object, final MethodEmitter methodEmitter) {
2357 methodEmitter.loadConstants().load(compiler.getConstantData().add(object));
2358 }
2359
2360 // literal values
2361 private void loadLiteral(final LiteralNode<?> node, final TypeBounds resultBounds) {
2362 final Object value = node.getValue();
2363
2364 if (value == null) {
2365 method.loadNull();
2366 } else if (value instanceof Undefined) {
2367 method.loadUndefined(resultBounds.within(Type.OBJECT));
2368 } else if (value instanceof String) {
2369 final String string = (String)value;
2370
2371 if (string.length() > MethodEmitter.LARGE_STRING_THRESHOLD / 3) { // 3 == max bytes per encoded char
2372 loadConstant(string);
2373 } else {
2374 method.load(string);
2375 }
2376 } else if (value instanceof RegexToken) {
2377 loadRegex((RegexToken)value);
2378 } else if (value instanceof Boolean) {
2379 method.load((Boolean)value);
2380 } else if (value instanceof Integer) {
2381 if(!resultBounds.canBeNarrowerThan(Type.OBJECT)) {
2382 method.load((Integer)value);
2383 method.convert(Type.OBJECT);
2384 } else if(!resultBounds.canBeNarrowerThan(Type.NUMBER)) {
2385 method.load(((Integer)value).doubleValue());
2386 } else if(!resultBounds.canBeNarrowerThan(Type.LONG)) {
2387 method.load(((Integer)value).longValue());
2388 } else {
2389 method.load((Integer)value);
2390 }
2391 } else if (value instanceof Long) {
2392 if(!resultBounds.canBeNarrowerThan(Type.OBJECT)) {
2393 method.load((Long)value);
2394 method.convert(Type.OBJECT);
2395 } else if(!resultBounds.canBeNarrowerThan(Type.NUMBER)) {
2396 method.load(((Long)value).doubleValue());
2397 } else {
2398 method.load((Long)value);
2399 }
2400 } else if (value instanceof Double) {
2401 if(!resultBounds.canBeNarrowerThan(Type.OBJECT)) {
2402 method.load((Double)value);
2403 method.convert(Type.OBJECT);
2404 } else {
2405 method.load((Double)value);
2406 }
2407 } else if (node instanceof ArrayLiteralNode) {
2408 final ArrayLiteralNode arrayLiteral = (ArrayLiteralNode)node;
2409 final ArrayType atype = arrayLiteral.getArrayType();
2410 loadArray(arrayLiteral, atype);
2411 globalAllocateArray(atype);
2412 } else {
2413 throw new UnsupportedOperationException("Unknown literal for " + node.getClass() + " " + value.getClass() + " " + value);
2414 }
2415 }
2416
2417 private MethodEmitter loadRegexToken(final RegexToken value) {
2418 method.load(value.getExpression());
2419 method.load(value.getOptions());
2420 return globalNewRegExp();
2421 }
2422
2423 private MethodEmitter loadRegex(final RegexToken regexToken) {
2424 if (regexFieldCount > MAX_REGEX_FIELDS) {
2425 return loadRegexToken(regexToken);
2426 }
2427 // emit field
2428 final String regexName = lc.getCurrentFunction().uniqueName(REGEX_PREFIX.symbolName());
2429 final ClassEmitter classEmitter = unit.getClassEmitter();
2430
2431 classEmitter.field(EnumSet.of(PRIVATE, STATIC), regexName, Object.class);
2432 regexFieldCount++;
2433
2434 // get field, if null create new regex, finally clone regex object
2435 method.getStatic(unit.getUnitClassName(), regexName, typeDescriptor(Object.class));
2436 method.dup();
2437 final Label cachedLabel = new Label("cached");
2438 method.ifnonnull(cachedLabel);
2439
2440 method.pop();
2441 loadRegexToken(regexToken);
2442 method.dup();
2443 method.putStatic(unit.getUnitClassName(), regexName, typeDescriptor(Object.class));
2444
2445 method.label(cachedLabel);
2446 globalRegExpCopy();
2447
2448 return method;
2449 }
2450
2451 /**
2452 * Check if a property value contains a particular program point
2453 * @param value value
2454 * @param pp program point
2455 * @return true if it's there.
2456 */
2457 private static boolean propertyValueContains(final Expression value, final int pp) {
2458 return new Supplier<Boolean>() {
2459 boolean contains;
2460
2461 @Override
2462 public Boolean get() {
2463 value.accept(new SimpleNodeVisitor() {
2464 @Override
2465 public boolean enterFunctionNode(final FunctionNode functionNode) {
2466 return false;
2467 }
2468
2469 @Override
2470 public boolean enterObjectNode(final ObjectNode objectNode) {
2471 return false;
2472 }
2473
2474 @Override
2475 public boolean enterDefault(final Node node) {
2476 if (contains) {
2477 return false;
2478 }
2479 if (node instanceof Optimistic && ((Optimistic)node).getProgramPoint() == pp) {
2480 contains = true;
2481 return false;
2482 }
2483 return true;
2484 }
2485 });
2486
2487 return contains;
2488 }
2489 }.get();
2490 }
2491
2492 private void loadObjectNode(final ObjectNode objectNode) {
2493 final List<PropertyNode> elements = objectNode.getElements();
2494
2495 final List<MapTuple<Expression>> tuples = new ArrayList<>();
2496 final List<PropertyNode> gettersSetters = new ArrayList<>();
2497 final int ccp = getCurrentContinuationEntryPoint();
2498 final List<Splittable.SplitRange> ranges = objectNode.getSplitRanges();
2499
2500 Expression protoNode = null;
2501 boolean restOfProperty = false;
2502
2503 for (final PropertyNode propertyNode : elements) {
2504 final Expression value = propertyNode.getValue();
2505 final String key = propertyNode.getKeyName();
2506 // Just use a pseudo-symbol. We just need something non null; use the name and zero flags.
2507 final Symbol symbol = value == null ? null : new Symbol(key, 0);
2508
2509 if (value == null) {
2510 gettersSetters.add(propertyNode);
2511 } else if (propertyNode.getKey() instanceof IdentNode &&
2512 key.equals(ScriptObject.PROTO_PROPERTY_NAME)) {
2513 // ES6 draft compliant __proto__ inside object literal
2514 // Identifier key and name is __proto__
2515 protoNode = value;
2516 continue;
2517 }
2518
2519 restOfProperty |=
2520 value != null &&
2521 isValid(ccp) &&
2522 propertyValueContains(value, ccp);
2523
2524 //for literals, a value of null means object type, i.e. the value null or getter setter function
2525 //(I think)
2526 final Class<?> valueType = (!useDualFields() || value == null || value.getType().isBoolean()) ? Object.class : value.getType().getTypeClass();
2527 tuples.add(new MapTuple<Expression>(key, symbol, Type.typeFor(valueType), value) {
2528 @Override
2529 public Class<?> getValueType() {
2530 return type.getTypeClass();
2531 }
2532 });
2533 }
2534
2535 final ObjectCreator<?> oc;
2536 if (elements.size() > OBJECT_SPILL_THRESHOLD) {
2537 oc = new SpillObjectCreator(this, tuples);
2538 } else {
2539 oc = new FieldObjectCreator<Expression>(this, tuples) {
2540 @Override
2541 protected void loadValue(final Expression node, final Type type) {
2542 loadExpressionAsType(node, type);
2543 }};
2544 }
2545
2546 if (ranges != null) {
2547 oc.createObject(method);
2548 loadSplitLiteral(oc, ranges, Type.typeFor(oc.getAllocatorClass()));
2549 } else {
2550 oc.makeObject(method);
2551 }
2552
2553 //if this is a rest of method and our continuation point was found as one of the values
2554 //in the properties above, we need to reset the map to oc.getMap() in the continuation
2555 //handler
2556 if (restOfProperty) {
2557 final ContinuationInfo ci = getContinuationInfo();
2558 // Can be set at most once for a single rest-of method
2559 assert ci.getObjectLiteralMap() == null;
2560 ci.setObjectLiteralMap(oc.getMap());
2561 ci.setObjectLiteralStackDepth(method.getStackSize());
2562 }
2563
2564 method.dup();
2565 if (protoNode != null) {
2566 loadExpressionAsObject(protoNode);
2567 // take care of { __proto__: 34 } or some such!
2568 method.convert(Type.OBJECT);
2569 method.invoke(ScriptObject.SET_PROTO_FROM_LITERAL);
2570 } else {
2571 method.invoke(ScriptObject.SET_GLOBAL_OBJECT_PROTO);
2572 }
2573
2574 for (final PropertyNode propertyNode : gettersSetters) {
2575 final FunctionNode getter = propertyNode.getGetter();
2576 final FunctionNode setter = propertyNode.getSetter();
2577
2578 assert getter != null || setter != null;
2579
2580 method.dup().loadKey(propertyNode.getKey());
2581 if (getter == null) {
2582 method.loadNull();
2583 } else {
2584 getter.accept(this);
2585 }
2586
2587 if (setter == null) {
2588 method.loadNull();
2589 } else {
2590 setter.accept(this);
2591 }
2592
2593 method.invoke(ScriptObject.SET_USER_ACCESSORS);
2594 }
2595 }
2596
2597 @Override
2598 public boolean enterReturnNode(final ReturnNode returnNode) {
2599 if(!method.isReachable()) {
2600 return false;
2601 }
2602 enterStatement(returnNode);
2603
2604 final Type returnType = lc.getCurrentFunction().getReturnType();
2605
2606 final Expression expression = returnNode.getExpression();
2607 if (expression != null) {
2608 loadExpressionUnbounded(expression);
2609 } else {
2610 method.loadUndefined(returnType);
2611 }
2612
2613 method._return(returnType);
2614
2615 return false;
2616 }
2617
2618 private boolean undefinedCheck(final RuntimeNode runtimeNode, final List<Expression> args) {
2619 final Request request = runtimeNode.getRequest();
2620
2621 if (!Request.isUndefinedCheck(request)) {
2622 return false;
2623 }
2624
2625 final Expression lhs = args.get(0);
2626 final Expression rhs = args.get(1);
2627
2628 final Symbol lhsSymbol = lhs instanceof IdentNode ? ((IdentNode)lhs).getSymbol() : null;
2629 final Symbol rhsSymbol = rhs instanceof IdentNode ? ((IdentNode)rhs).getSymbol() : null;
2630 // One must be a "undefined" identifier, otherwise we can't get here
2631 assert lhsSymbol != null || rhsSymbol != null;
2632
2633 final Symbol undefinedSymbol;
2634 if (isUndefinedSymbol(lhsSymbol)) {
2635 undefinedSymbol = lhsSymbol;
2636 } else {
2637 assert isUndefinedSymbol(rhsSymbol);
2638 undefinedSymbol = rhsSymbol;
2639 }
2640
2641 assert undefinedSymbol != null; //remove warning
2642 if (!undefinedSymbol.isScope()) {
2643 return false; //disallow undefined as local var or parameter
2644 }
2645
2646 if (lhsSymbol == undefinedSymbol && lhs.getType().isPrimitive()) {
2647 //we load the undefined first. never mind, because this will deoptimize anyway
2648 return false;
2649 }
2650
2651 if(isDeoptimizedExpression(lhs)) {
2652 // This is actually related to "lhs.getType().isPrimitive()" above: any expression being deoptimized in
2653 // the current chain of rest-of compilations used to have a type narrower than Object (so it was primitive).
2654 // We must not perform undefined check specialization for them, as then we'd violate the basic rule of
2655 // "Thou shalt not alter the stack shape between a deoptimized method and any of its (transitive) rest-ofs."
2656 return false;
2657 }
2658
2659 //make sure that undefined has not been overridden or scoped as a local var
2660 //between us and global
2661 if (!compiler.isGlobalSymbol(lc.getCurrentFunction(), "undefined")) {
2662 return false;
2663 }
2664
2665 final boolean isUndefinedCheck = request == Request.IS_UNDEFINED;
2666 final Expression expr = undefinedSymbol == lhsSymbol ? rhs : lhs;
2667 if (expr.getType().isPrimitive()) {
2668 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
2669 method.load(!isUndefinedCheck);
2670 } else {
2671 final Label checkTrue = new Label("ud_check_true");
2672 final Label end = new Label("end");
2673 loadExpressionAsObject(expr);
2674 method.loadUndefined(Type.OBJECT);
2675 method.if_acmpeq(checkTrue);
2676 method.load(!isUndefinedCheck);
2677 method._goto(end);
2678 method.label(checkTrue);
2679 method.load(isUndefinedCheck);
2680 method.label(end);
2681 }
2682
2683 return true;
2684 }
2685
2686 private static boolean isUndefinedSymbol(final Symbol symbol) {
2687 return symbol != null && "undefined".equals(symbol.getName());
2688 }
2689
2690 private static boolean isNullLiteral(final Node node) {
2691 return node instanceof LiteralNode<?> && ((LiteralNode<?>) node).isNull();
2692 }
2693
2694 private boolean nullCheck(final RuntimeNode runtimeNode, final List<Expression> args) {
2695 final Request request = runtimeNode.getRequest();
2696
2697 if (!Request.isEQ(request) && !Request.isNE(request)) {
2698 return false;
2699 }
2700
2701 assert args.size() == 2 : "EQ or NE or TYPEOF need two args";
2702
2703 Expression lhs = args.get(0);
2704 Expression rhs = args.get(1);
2705
2706 if (isNullLiteral(lhs)) {
2707 final Expression tmp = lhs;
2708 lhs = rhs;
2709 rhs = tmp;
2710 }
2711
2712 if (!isNullLiteral(rhs)) {
2713 return false;
2714 }
2715
2716 if (!lhs.getType().isObject()) {
2717 return false;
2718 }
2719
2720 if(isDeoptimizedExpression(lhs)) {
2721 // This is actually related to "!lhs.getType().isObject()" above: any expression being deoptimized in
2722 // the current chain of rest-of compilations used to have a type narrower than Object. We must not
2723 // perform null check specialization for them, as then we'd no longer be loading aconst_null on stack
2724 // and thus violate the basic rule of "Thou shalt not alter the stack shape between a deoptimized
2725 // method and any of its (transitive) rest-ofs."
2726 // NOTE also that if we had a representation for well-known constants (e.g. null, 0, 1, -1, etc.) in
2727 // Label$Stack.localLoads then this wouldn't be an issue, as we would never (somewhat ridiculously)
2728 // allocate a temporary local to hold the result of aconst_null before attempting an optimistic
2729 // operation.
2730 return false;
2731 }
2732
2733 // this is a null literal check, so if there is implicit coercion
2734 // involved like {D}x=null, we will fail - this is very rare
2735 final Label trueLabel = new Label("trueLabel");
2736 final Label falseLabel = new Label("falseLabel");
2737 final Label endLabel = new Label("end");
2738
2739 loadExpressionUnbounded(lhs); //lhs
2740 final Label popLabel;
2741 if (!Request.isStrict(request)) {
2742 method.dup(); //lhs lhs
2743 popLabel = new Label("pop");
2744 } else {
2745 popLabel = null;
2746 }
2747
2748 if (Request.isEQ(request)) {
2749 method.ifnull(!Request.isStrict(request) ? popLabel : trueLabel);
2750 if (!Request.isStrict(request)) {
2751 method.loadUndefined(Type.OBJECT);
2752 method.if_acmpeq(trueLabel);
2753 }
2754 method.label(falseLabel);
2755 method.load(false);
2756 method._goto(endLabel);
2757 if (!Request.isStrict(request)) {
2758 method.label(popLabel);
2759 method.pop();
2760 }
2761 method.label(trueLabel);
2762 method.load(true);
2763 method.label(endLabel);
2764 } else if (Request.isNE(request)) {
2765 method.ifnull(!Request.isStrict(request) ? popLabel : falseLabel);
2766 if (!Request.isStrict(request)) {
2767 method.loadUndefined(Type.OBJECT);
2768 method.if_acmpeq(falseLabel);
2769 }
2770 method.label(trueLabel);
2771 method.load(true);
2772 method._goto(endLabel);
2773 if (!Request.isStrict(request)) {
2774 method.label(popLabel);
2775 method.pop();
2776 }
2777 method.label(falseLabel);
2778 method.load(false);
2779 method.label(endLabel);
2780 }
2781
2782 assert runtimeNode.getType().isBoolean();
2783 method.convert(runtimeNode.getType());
2784
2785 return true;
2786 }
2787
2788 /**
2789 * Was this expression or any of its subexpressions deoptimized in the current recompilation chain of rest-of methods?
2790 * @param rootExpr the expression being tested
2791 * @return true if the expression or any of its subexpressions was deoptimized in the current recompilation chain.
2792 */
2793 private boolean isDeoptimizedExpression(final Expression rootExpr) {
2794 if(!isRestOf()) {
2795 return false;
2796 }
2797 return new Supplier<Boolean>() {
2798 boolean contains;
2799 @Override
2800 public Boolean get() {
2801 rootExpr.accept(new SimpleNodeVisitor() {
2802 @Override
2803 public boolean enterFunctionNode(final FunctionNode functionNode) {
2804 return false;
2805 }
2806 @Override
2807 public boolean enterDefault(final Node node) {
2808 if(!contains && node instanceof Optimistic) {
2809 final int pp = ((Optimistic)node).getProgramPoint();
2810 contains = isValid(pp) && isContinuationEntryPoint(pp);
2811 }
2812 return !contains;
2813 }
2814 });
2815 return contains;
2816 }
2817 }.get();
2818 }
2819
2820 private void loadRuntimeNode(final RuntimeNode runtimeNode) {
2821 final List<Expression> args = new ArrayList<>(runtimeNode.getArgs());
2822 if (nullCheck(runtimeNode, args)) {
2823 return;
2824 } else if(undefinedCheck(runtimeNode, args)) {
2825 return;
2826 }
2827 // Revert a false undefined check to a strict equality check
2828 final RuntimeNode newRuntimeNode;
2829 final Request request = runtimeNode.getRequest();
2830 if (Request.isUndefinedCheck(request)) {
2831 newRuntimeNode = runtimeNode.setRequest(request == Request.IS_UNDEFINED ? Request.EQ_STRICT : Request.NE_STRICT);
2832 } else {
2833 newRuntimeNode = runtimeNode;
2834 }
2835
2836 for (final Expression arg : args) {
2837 loadExpression(arg, TypeBounds.OBJECT);
2838 }
2839
2840 method.invokestatic(
2841 CompilerConstants.className(ScriptRuntime.class),
2842 newRuntimeNode.getRequest().toString(),
2843 new FunctionSignature(
2844 false,
2845 false,
2846 newRuntimeNode.getType(),
2847 args.size()).toString());
2848
2849 method.convert(newRuntimeNode.getType());
2850 }
2851
2852 private void defineCommonSplitMethodParameters() {
2853 defineSplitMethodParameter(0, CALLEE);
2854 defineSplitMethodParameter(1, THIS);
2855 defineSplitMethodParameter(2, SCOPE);
2856 }
2857
2858 private void defineSplitMethodParameter(final int slot, final CompilerConstants cc) {
2859 defineSplitMethodParameter(slot, Type.typeFor(cc.type()));
2860 }
2861
2862 private void defineSplitMethodParameter(final int slot, final Type type) {
2863 method.defineBlockLocalVariable(slot, slot + type.getSlots());
2864 method.onLocalStore(type, slot);
2865 }
2866
2867 private void loadSplitLiteral(final SplitLiteralCreator creator, final List<Splittable.SplitRange> ranges, final Type literalType) {
2868 assert ranges != null;
2869
2870 // final Type literalType = Type.typeFor(literalClass);
2871 final MethodEmitter savedMethod = method;
2872 final FunctionNode currentFunction = lc.getCurrentFunction();
2873
2874 for (final Splittable.SplitRange splitRange : ranges) {
2875 unit = lc.pushCompileUnit(splitRange.getCompileUnit());
2876
2877 assert unit != null;
2878 final String className = unit.getUnitClassName();
2879 final String name = currentFunction.uniqueName(SPLIT_PREFIX.symbolName());
2880 final Class<?> clazz = literalType.getTypeClass();
2881 final String signature = methodDescriptor(clazz, ScriptFunction.class, Object.class, ScriptObject.class, clazz);
2882
2883 pushMethodEmitter(unit.getClassEmitter().method(EnumSet.of(Flag.PUBLIC, Flag.STATIC), name, signature));
2884
2885 method.setFunctionNode(currentFunction);
2886 method.begin();
2887
2888 defineCommonSplitMethodParameters();
2889 defineSplitMethodParameter(CompilerConstants.SPLIT_ARRAY_ARG.slot(), literalType);
2890
2891 // NOTE: when this is no longer needed, SplitIntoFunctions will no longer have to add IS_SPLIT
2892 // to synthetic functions, and FunctionNode.needsCallee() will no longer need to test for isSplit().
2893 final int literalSlot = fixScopeSlot(currentFunction, 3);
2894
2895 lc.enterSplitNode();
2896
2897 creator.populateRange(method, literalType, literalSlot, splitRange.getLow(), splitRange.getHigh());
2898
2899 method._return();
2900 lc.exitSplitNode();
2901 method.end();
2902 lc.releaseSlots();
2903 popMethodEmitter();
2904
2905 assert method == savedMethod;
2906 method.loadCompilerConstant(CALLEE).swap();
2907 method.loadCompilerConstant(THIS).swap();
2908 method.loadCompilerConstant(SCOPE).swap();
2909 method.invokestatic(className, name, signature);
2910
2911 unit = lc.popCompileUnit(unit);
2912 }
2913 }
2914
2915 private int fixScopeSlot(final FunctionNode functionNode, final int extraSlot) {
2916 // TODO hack to move the scope to the expected slot (needed because split methods reuse the same slots as the root method)
2917 final int actualScopeSlot = functionNode.compilerConstant(SCOPE).getSlot(SCOPE_TYPE);
2918 final int defaultScopeSlot = SCOPE.slot();
2919 int newExtraSlot = extraSlot;
2920 if (actualScopeSlot != defaultScopeSlot) {
2921 if (actualScopeSlot == extraSlot) {
2922 newExtraSlot = extraSlot + 1;
2923 method.defineBlockLocalVariable(newExtraSlot, newExtraSlot + 1);
2924 method.load(Type.OBJECT, extraSlot);
2925 method.storeHidden(Type.OBJECT, newExtraSlot);
2926 } else {
2927 method.defineBlockLocalVariable(actualScopeSlot, actualScopeSlot + 1);
2928 }
2929 method.load(SCOPE_TYPE, defaultScopeSlot);
2930 method.storeCompilerConstant(SCOPE);
2931 }
2932 return newExtraSlot;
2933 }
2934
2935 @Override
2936 public boolean enterSplitReturn(final SplitReturn splitReturn) {
2937 if (method.isReachable()) {
2938 method.loadUndefined(lc.getCurrentFunction().getReturnType())._return();
2939 }
2940 return false;
2941 }
2942
2943 @Override
2944 public boolean enterSetSplitState(final SetSplitState setSplitState) {
2945 if (method.isReachable()) {
2946 method.setSplitState(setSplitState.getState());
2947 }
2948 return false;
2949 }
2950
2951 @Override
2952 public boolean enterSwitchNode(final SwitchNode switchNode) {
2953 if(!method.isReachable()) {
2954 return false;
2955 }
2956 enterStatement(switchNode);
2957
2958 final Expression expression = switchNode.getExpression();
2959 final List<CaseNode> cases = switchNode.getCases();
2960
2961 if (cases.isEmpty()) {
2962 // still evaluate expression for side-effects.
2963 loadAndDiscard(expression);
2964 return false;
2965 }
2966
2967 final CaseNode defaultCase = switchNode.getDefaultCase();
2968 final Label breakLabel = switchNode.getBreakLabel();
2969 final int liveLocalsOnBreak = method.getUsedSlotsWithLiveTemporaries();
2970
2971 if (defaultCase != null && cases.size() == 1) {
2972 // default case only
2973 assert cases.get(0) == defaultCase;
2974 loadAndDiscard(expression);
2975 defaultCase.getBody().accept(this);
2976 method.breakLabel(breakLabel, liveLocalsOnBreak);
2977 return false;
2978 }
2979
2980 // NOTE: it can still change in the tableswitch/lookupswitch case if there's no default case
2981 // but we need to add a synthetic default case for local variable conversions
2982 Label defaultLabel = defaultCase != null ? defaultCase.getEntry() : breakLabel;
2983 final boolean hasSkipConversion = LocalVariableConversion.hasLiveConversion(switchNode);
2984
2985 if (switchNode.isUniqueInteger()) {
2986 // Tree for sorting values.
2987 final TreeMap<Integer, Label> tree = new TreeMap<>();
2988
2989 // Build up sorted tree.
2990 for (final CaseNode caseNode : cases) {
2991 final Node test = caseNode.getTest();
2992
2993 if (test != null) {
2994 final Integer value = (Integer)((LiteralNode<?>)test).getValue();
2995 final Label entry = caseNode.getEntry();
2996
2997 // Take first duplicate.
2998 if (!tree.containsKey(value)) {
2999 tree.put(value, entry);
3000 }
3001 }
3002 }
3003
3004 // Copy values and labels to arrays.
3005 final int size = tree.size();
3006 final Integer[] values = tree.keySet().toArray(new Integer[size]);
3007 final Label[] labels = tree.values().toArray(new Label[size]);
3008
3009 // Discern low, high and range.
3010 final int lo = values[0];
3011 final int hi = values[size - 1];
3012 final long range = (long)hi - (long)lo + 1;
3013
3014 // Find an unused value for default.
3015 int deflt = Integer.MIN_VALUE;
3016 for (final int value : values) {
3017 if (deflt == value) {
3018 deflt++;
3019 } else if (deflt < value) {
3020 break;
3021 }
3022 }
3023
3024 // Load switch expression.
3025 loadExpressionUnbounded(expression);
3026 final Type type = expression.getType();
3027
3028 // If expression not int see if we can convert, if not use deflt to trigger default.
3029 if (!type.isInteger()) {
3030 method.load(deflt);
3031 final Class<?> exprClass = type.getTypeClass();
3032 method.invoke(staticCallNoLookup(ScriptRuntime.class, "switchTagAsInt", int.class, exprClass.isPrimitive()? exprClass : Object.class, int.class));
3033 }
3034
3035 if(hasSkipConversion) {
3036 assert defaultLabel == breakLabel;
3037 defaultLabel = new Label("switch_skip");
3038 }
3039 // TABLESWITCH needs (range + 3) 32-bit values; LOOKUPSWITCH needs ((size * 2) + 2). Choose the one with
3040 // smaller representation, favor TABLESWITCH when they're equal size.
3041 if (range + 1 <= (size * 2) && range <= Integer.MAX_VALUE) {
3042 final Label[] table = new Label[(int)range];
3043 Arrays.fill(table, defaultLabel);
3044 for (int i = 0; i < size; i++) {
3045 final int value = values[i];
3046 table[value - lo] = labels[i];
3047 }
3048
3049 method.tableswitch(lo, hi, defaultLabel, table);
3050 } else {
3051 final int[] ints = new int[size];
3052 for (int i = 0; i < size; i++) {
3053 ints[i] = values[i];
3054 }
3055
3056 method.lookupswitch(defaultLabel, ints, labels);
3057 }
3058 // This is a synthetic "default case" used in absence of actual default case, created if we need to apply
3059 // local variable conversions if neither case is taken.
3060 if(hasSkipConversion) {
3061 method.label(defaultLabel);
3062 method.beforeJoinPoint(switchNode);
3063 method._goto(breakLabel);
3064 }
3065 } else {
3066 final Symbol tagSymbol = switchNode.getTag();
3067 // TODO: we could have non-object tag
3068 final int tagSlot = tagSymbol.getSlot(Type.OBJECT);
3069 loadExpressionAsObject(expression);
3070 method.store(tagSymbol, Type.OBJECT);
3071
3072 for (final CaseNode caseNode : cases) {
3073 final Expression test = caseNode.getTest();
3074
3075 if (test != null) {
3076 method.load(Type.OBJECT, tagSlot);
3077 loadExpressionAsObject(test);
3078 method.invoke(ScriptRuntime.EQ_STRICT);
3079 method.ifne(caseNode.getEntry());
3080 }
3081 }
3082
3083 if (defaultCase != null) {
3084 method._goto(defaultLabel);
3085 } else {
3086 method.beforeJoinPoint(switchNode);
3087 method._goto(breakLabel);
3088 }
3089 }
3090
3091 // First case is only reachable through jump
3092 assert !method.isReachable();
3093
3094 for (final CaseNode caseNode : cases) {
3095 final Label fallThroughLabel;
3096 if(caseNode.getLocalVariableConversion() != null && method.isReachable()) {
3097 fallThroughLabel = new Label("fallthrough");
3098 method._goto(fallThroughLabel);
3099 } else {
3100 fallThroughLabel = null;
3101 }
3102 method.label(caseNode.getEntry());
3103 method.beforeJoinPoint(caseNode);
3104 if(fallThroughLabel != null) {
3105 method.label(fallThroughLabel);
3106 }
3107 caseNode.getBody().accept(this);
3108 }
3109
3110 method.breakLabel(breakLabel, liveLocalsOnBreak);
3111
3112 return false;
3113 }
3114
3115 @Override
3116 public boolean enterThrowNode(final ThrowNode throwNode) {
3117 if(!method.isReachable()) {
3118 return false;
3119 }
3120 enterStatement(throwNode);
3121
3122 if (throwNode.isSyntheticRethrow()) {
3123 method.beforeJoinPoint(throwNode);
3124
3125 //do not wrap whatever this is in an ecma exception, just rethrow it
3126 final IdentNode exceptionExpr = (IdentNode)throwNode.getExpression();
3127 final Symbol exceptionSymbol = exceptionExpr.getSymbol();
3128 method.load(exceptionSymbol, EXCEPTION_TYPE);
3129 method.checkcast(EXCEPTION_TYPE.getTypeClass());
3130 method.athrow();
3131 return false;
3132 }
3133
3134 final Source source = getCurrentSource();
3135 final Expression expression = throwNode.getExpression();
3136 final int position = throwNode.position();
3137 final int line = throwNode.getLineNumber();
3138 final int column = source.getColumn(position);
3139
3140 // NOTE: we first evaluate the expression, and only after it was evaluated do we create the new ECMAException
3141 // object and then somewhat cumbersomely move it beneath the evaluated expression on the stack. The reason for
3142 // this is that if expression is optimistic (or contains an optimistic subexpression), we'd potentially access
3143 // the not-yet-<init>ialized object on the stack from the UnwarrantedOptimismException handler, and bytecode
3144 // verifier forbids that.
3145 loadExpressionAsObject(expression);
3146
3147 method.load(source.getName());
3148 method.load(line);
3149 method.load(column);
3150 method.invoke(ECMAException.CREATE);
3151
3152 method.beforeJoinPoint(throwNode);
3153 method.athrow();
3154
3155 return false;
3156 }
3157
3158 private Source getCurrentSource() {
3159 return lc.getCurrentFunction().getSource();
3160 }
3161
3162 @Override
3163 public boolean enterTryNode(final TryNode tryNode) {
3164 if(!method.isReachable()) {
3165 return false;
3166 }
3167 enterStatement(tryNode);
3168
3169 final Block body = tryNode.getBody();
3170 final List<Block> catchBlocks = tryNode.getCatchBlocks();
3171 final Symbol vmException = tryNode.getException();
3172 final Label entry = new Label("try");
3173 final Label recovery = new Label("catch");
3174 final Label exit = new Label("end_try");
3175 final Label skip = new Label("skip");
3176
3177 method.canThrow(recovery);
3178 // Effect any conversions that might be observed at the entry of the catch node before entering the try node.
3179 // This is because even the first instruction in the try block must be presumed to be able to transfer control
3180 // to the catch block. Note that this doesn't kill the original values; in this regard it works a lot like
3181 // conversions of assignments within the try block.
3182 method.beforeTry(tryNode, recovery);
3183 method.label(entry);
3184 catchLabels.push(recovery);
3185 try {
3186 body.accept(this);
3187 } finally {
3188 assert catchLabels.peek() == recovery;
3189 catchLabels.pop();
3190 }
3191
3192 method.label(exit);
3193 final boolean bodyCanThrow = exit.isAfter(entry);
3194 if(!bodyCanThrow) {
3195 // The body can't throw an exception; don't even bother emitting the catch handlers, they're all dead code.
3196 return false;
3197 }
3198
3199 method._try(entry, exit, recovery, Throwable.class);
3200
3201 if (method.isReachable()) {
3202 method._goto(skip);
3203 }
3204
3205 for (final Block inlinedFinally : tryNode.getInlinedFinallies()) {
3206 TryNode.getLabelledInlinedFinallyBlock(inlinedFinally).accept(this);
3207 // All inlined finallies end with a jump or a return
3208 assert !method.isReachable();
3209 }
3210
3211
3212 method._catch(recovery);
3213 method.store(vmException, EXCEPTION_TYPE);
3214
3215 final int catchBlockCount = catchBlocks.size();
3216 final Label afterCatch = new Label("after_catch");
3217 for (int i = 0; i < catchBlockCount; i++) {
3218 assert method.isReachable();
3219 final Block catchBlock = catchBlocks.get(i);
3220
3221 // Because of the peculiarities of the flow control, we need to use an explicit push/enterBlock/leaveBlock
3222 // here.
3223 lc.push(catchBlock);
3224 enterBlock(catchBlock);
3225
3226 final CatchNode catchNode = (CatchNode)catchBlocks.get(i).getStatements().get(0);
3227 final IdentNode exception = catchNode.getException();
3228 final Expression exceptionCondition = catchNode.getExceptionCondition();
3229 final Block catchBody = catchNode.getBody();
3230
3231 new Store<IdentNode>(exception) {
3232 @Override
3233 protected void storeNonDiscard() {
3234 // This expression is neither part of a discard, nor needs to be left on the stack after it was
3235 // stored, so we override storeNonDiscard to be a no-op.
3236 }
3237
3238 @Override
3239 protected void evaluate() {
3240 if (catchNode.isSyntheticRethrow()) {
3241 method.load(vmException, EXCEPTION_TYPE);
3242 return;
3243 }
3244 /*
3245 * If caught object is an instance of ECMAException, then
3246 * bind obj.thrown to the script catch var. Or else bind the
3247 * caught object itself to the script catch var.
3248 */
3249 final Label notEcmaException = new Label("no_ecma_exception");
3250 method.load(vmException, EXCEPTION_TYPE).dup()._instanceof(ECMAException.class).ifeq(notEcmaException);
3251 method.checkcast(ECMAException.class); //TODO is this necessary?
3252 method.getField(ECMAException.THROWN);
3253 method.label(notEcmaException);
3254 }
3255 }.store();
3256
3257 final boolean isConditionalCatch = exceptionCondition != null;
3258 final Label nextCatch;
3259 if (isConditionalCatch) {
3260 loadExpressionAsBoolean(exceptionCondition);
3261 nextCatch = new Label("next_catch");
3262 nextCatch.markAsBreakTarget();
3263 method.ifeq(nextCatch);
3264 } else {
3265 nextCatch = null;
3266 }
3267
3268 catchBody.accept(this);
3269 leaveBlock(catchBlock);
3270 lc.pop(catchBlock);
3271 if(nextCatch != null) {
3272 if(method.isReachable()) {
3273 method._goto(afterCatch);
3274 }
3275 method.breakLabel(nextCatch, lc.getUsedSlotCount());
3276 }
3277 }
3278
3279 // afterCatch could be the same as skip, except that we need to establish that the vmException is dead.
3280 method.label(afterCatch);
3281 if(method.isReachable()) {
3282 method.markDeadLocalVariable(vmException);
3283 }
3284 method.label(skip);
3285
3286 // Finally body is always inlined elsewhere so it doesn't need to be emitted
3287 assert tryNode.getFinallyBody() == null;
3288
3289 return false;
3290 }
3291
3292 @Override
3293 public boolean enterVarNode(final VarNode varNode) {
3294 if(!method.isReachable()) {
3295 return false;
3296 }
3297 final Expression init = varNode.getInit();
3298 final IdentNode identNode = varNode.getName();
3299 final Symbol identSymbol = identNode.getSymbol();
3300 assert identSymbol != null : "variable node " + varNode + " requires a name with a symbol";
3301 final boolean needsScope = identSymbol.isScope();
3302
3303 if (init == null) {
3304 if (needsScope && varNode.isBlockScoped()) {
3305 // block scoped variables need a DECLARE flag to signal end of temporal dead zone (TDZ)
3306 method.loadCompilerConstant(SCOPE);
3307 method.loadUndefined(Type.OBJECT);
3308 final int flags = getScopeCallSiteFlags(identSymbol) | (varNode.isBlockScoped() ? CALLSITE_DECLARE : 0);
3309 assert isFastScope(identSymbol);
3310 storeFastScopeVar(identSymbol, flags);
3311 }
3312 return false;
3313 }
3314
3315 enterStatement(varNode);
3316 assert method != null;
3317
3318 if (needsScope) {
3319 method.loadCompilerConstant(SCOPE);
3320 }
3321
3322 if (needsScope) {
3323 loadExpressionUnbounded(init);
3324 // block scoped variables need a DECLARE flag to signal end of temporal dead zone (TDZ)
3325 final int flags = getScopeCallSiteFlags(identSymbol) | (varNode.isBlockScoped() ? CALLSITE_DECLARE : 0);
3326 if (isFastScope(identSymbol)) {
3327 storeFastScopeVar(identSymbol, flags);
3328 } else {
3329 method.dynamicSet(identNode.getName(), flags, false);
3330 }
3331 } else {
3332 final Type identType = identNode.getType();
3333 if(identType == Type.UNDEFINED) {
3334 // The initializer is either itself undefined (explicit assignment of undefined to undefined),
3335 // or the left hand side is a dead variable.
3336 assert init.getType() == Type.UNDEFINED || identNode.getSymbol().slotCount() == 0;
3337 loadAndDiscard(init);
3338 return false;
3339 }
3340 loadExpressionAsType(init, identType);
3341 storeIdentWithCatchConversion(identNode, identType);
3342 }
3343
3344 return false;
3345 }
3346
3347 private void storeIdentWithCatchConversion(final IdentNode identNode, final Type type) {
3348 // Assignments happening in try/catch blocks need to ensure that they also store a possibly wider typed value
3349 // that will be live at the exit from the try block
3350 final LocalVariableConversion conversion = identNode.getLocalVariableConversion();
3351 final Symbol symbol = identNode.getSymbol();
3352 if(conversion != null && conversion.isLive()) {
3353 assert symbol == conversion.getSymbol();
3354 assert symbol.isBytecodeLocal();
3355 // Only a single conversion from the target type to the join type is expected.
3356 assert conversion.getNext() == null;
3357 assert conversion.getFrom() == type;
3358 // We must propagate potential type change to the catch block
3359 final Label catchLabel = catchLabels.peek();
3360 assert catchLabel != METHOD_BOUNDARY; // ident conversion only exists in try blocks
3361 assert catchLabel.isReachable();
3362 final Type joinType = conversion.getTo();
3363 final Label.Stack catchStack = catchLabel.getStack();
3364 final int joinSlot = symbol.getSlot(joinType);
3365 // With nested try/catch blocks (incl. synthetic ones for finally), we can have a supposed conversion for
3366 // the exception symbol in the nested catch, but it isn't live in the outer catch block, so prevent doing
3367 // conversions for it. E.g. in "try { try { ... } catch(e) { e = 1; } } catch(e2) { ... }", we must not
3368 // introduce an I->O conversion on "e = 1" assignment as "e" is not live in "catch(e2)".
3369 if(catchStack.getUsedSlotsWithLiveTemporaries() > joinSlot) {
3370 method.dup();
3371 method.convert(joinType);
3372 method.store(symbol, joinType);
3373 catchLabel.getStack().onLocalStore(joinType, joinSlot, true);
3374 method.canThrow(catchLabel);
3375 // Store but keep the previous store live too.
3376 method.store(symbol, type, false);
3377 return;
3378 }
3379 }
3380
3381 method.store(symbol, type, true);
3382 }
3383
3384 @Override
3385 public boolean enterWhileNode(final WhileNode whileNode) {
3386 if(!method.isReachable()) {
3387 return false;
3388 }
3389 if(whileNode.isDoWhile()) {
3390 enterDoWhile(whileNode);
3391 } else {
3392 enterStatement(whileNode);
3393 enterForOrWhile(whileNode, null);
3394 }
3395 return false;
3396 }
3397
3398 private void enterForOrWhile(final LoopNode loopNode, final JoinPredecessorExpression modify) {
3399 // NOTE: the usual pattern for compiling test-first loops is "GOTO test; body; test; IFNE body". We use the less
3400 // conventional "test; IFEQ break; body; GOTO test; break;". It has one extra unconditional GOTO in each repeat
3401 // of the loop, but it's not a problem for modern JIT compilers. We do this because our local variable type
3402 // tracking is unfortunately not really prepared for out-of-order execution, e.g. compiling the following
3403 // contrived but legal JavaScript code snippet would fail because the test changes the type of "i" from object
3404 // to double: var i = {valueOf: function() { return 1} }; while(--i >= 0) { ... }
3405 // Instead of adding more complexity to the local variable type tracking, we instead choose to emit this
3406 // different code shape.
3407 final int liveLocalsOnBreak = method.getUsedSlotsWithLiveTemporaries();
3408 final JoinPredecessorExpression test = loopNode.getTest();
3409 if(Expression.isAlwaysFalse(test)) {
3410 loadAndDiscard(test);
3411 return;
3412 }
3413
3414 method.beforeJoinPoint(loopNode);
3415
3416 final Label continueLabel = loopNode.getContinueLabel();
3417 final Label repeatLabel = modify != null ? new Label("for_repeat") : continueLabel;
3418 method.label(repeatLabel);
3419 final int liveLocalsOnContinue = method.getUsedSlotsWithLiveTemporaries();
3420
3421 final Block body = loopNode.getBody();
3422 final Label breakLabel = loopNode.getBreakLabel();
3423 final boolean testHasLiveConversion = test != null && LocalVariableConversion.hasLiveConversion(test);
3424
3425 if(Expression.isAlwaysTrue(test)) {
3426 if(test != null) {
3427 loadAndDiscard(test);
3428 if(testHasLiveConversion) {
3429 method.beforeJoinPoint(test);
3430 }
3431 }
3432 } else if (test != null) {
3433 if (testHasLiveConversion) {
3434 emitBranch(test.getExpression(), body.getEntryLabel(), true);
3435 method.beforeJoinPoint(test);
3436 method._goto(breakLabel);
3437 } else {
3438 emitBranch(test.getExpression(), breakLabel, false);
3439 }
3440 }
3441
3442 body.accept(this);
3443 if(repeatLabel != continueLabel) {
3444 emitContinueLabel(continueLabel, liveLocalsOnContinue);
3445 }
3446
3447 if (loopNode.hasPerIterationScope() && lc.getCurrentBlock().needsScope()) {
3448 // ES6 for loops with LET init need a new scope for each iteration. We just create a shallow copy here.
3449 method.loadCompilerConstant(SCOPE);
3450 method.invoke(virtualCallNoLookup(ScriptObject.class, "copy", ScriptObject.class));
3451 method.storeCompilerConstant(SCOPE);
3452 }
3453
3454 if(method.isReachable()) {
3455 if(modify != null) {
3456 lineNumber(loopNode);
3457 loadAndDiscard(modify);
3458 method.beforeJoinPoint(modify);
3459 }
3460 method._goto(repeatLabel);
3461 }
3462
3463 method.breakLabel(breakLabel, liveLocalsOnBreak);
3464 }
3465
3466 private void emitContinueLabel(final Label continueLabel, final int liveLocals) {
3467 final boolean reachable = method.isReachable();
3468 method.breakLabel(continueLabel, liveLocals);
3469 // If we reach here only through a continue statement (e.g. body does not exit normally) then the
3470 // continueLabel can have extra non-temp symbols (e.g. exception from a try/catch contained in the body). We
3471 // must make sure those are thrown away.
3472 if(!reachable) {
3473 method.undefineLocalVariables(lc.getUsedSlotCount(), false);
3474 }
3475 }
3476
3477 private void enterDoWhile(final WhileNode whileNode) {
3478 final int liveLocalsOnContinueOrBreak = method.getUsedSlotsWithLiveTemporaries();
3479 method.beforeJoinPoint(whileNode);
3480
3481 final Block body = whileNode.getBody();
3482 body.accept(this);
3483
3484 emitContinueLabel(whileNode.getContinueLabel(), liveLocalsOnContinueOrBreak);
3485 if(method.isReachable()) {
3486 lineNumber(whileNode);
3487 final JoinPredecessorExpression test = whileNode.getTest();
3488 final Label bodyEntryLabel = body.getEntryLabel();
3489 final boolean testHasLiveConversion = LocalVariableConversion.hasLiveConversion(test);
3490 if(Expression.isAlwaysFalse(test)) {
3491 loadAndDiscard(test);
3492 if(testHasLiveConversion) {
3493 method.beforeJoinPoint(test);
3494 }
3495 } else if(testHasLiveConversion) {
3496 // If we have conversions after the test in do-while, they need to be effected on both branches.
3497 final Label beforeExit = new Label("do_while_preexit");
3498 emitBranch(test.getExpression(), beforeExit, false);
3499 method.beforeJoinPoint(test);
3500 method._goto(bodyEntryLabel);
3501 method.label(beforeExit);
3502 method.beforeJoinPoint(test);
3503 } else {
3504 emitBranch(test.getExpression(), bodyEntryLabel, true);
3505 }
3506 }
3507 method.breakLabel(whileNode.getBreakLabel(), liveLocalsOnContinueOrBreak);
3508 }
3509
3510
3511 @Override
3512 public boolean enterWithNode(final WithNode withNode) {
3513 if(!method.isReachable()) {
3514 return false;
3515 }
3516 enterStatement(withNode);
3517 final Expression expression = withNode.getExpression();
3518 final Block body = withNode.getBody();
3519
3520 // It is possible to have a "pathological" case where the with block does not reference *any* identifiers. It's
3521 // pointless, but legal. In that case, if nothing else in the method forced the assignment of a slot to the
3522 // scope object, its' possible that it won't have a slot assigned. In this case we'll only evaluate expression
3523 // for its side effect and visit the body, and not bother opening and closing a WithObject.
3524 final boolean hasScope = method.hasScope();
3525
3526 if (hasScope) {
3527 method.loadCompilerConstant(SCOPE);
3528 }
3529
3530 loadExpressionAsObject(expression);
3531
3532 final Label tryLabel;
3533 if (hasScope) {
3534 // Construct a WithObject if we have a scope
3535 method.invoke(ScriptRuntime.OPEN_WITH);
3536 method.storeCompilerConstant(SCOPE);
3537 tryLabel = new Label("with_try");
3538 method.label(tryLabel);
3539 } else {
3540 // We just loaded the expression for its side effect and to check
3541 // for null or undefined value.
3542 globalCheckObjectCoercible();
3543 tryLabel = null;
3544 }
3545
3546 // Always process body
3547 body.accept(this);
3548
3549 if (hasScope) {
3550 // Ensure we always close the WithObject
3551 final Label endLabel = new Label("with_end");
3552 final Label catchLabel = new Label("with_catch");
3553 final Label exitLabel = new Label("with_exit");
3554
3555 method.label(endLabel);
3556 // Somewhat conservatively presume that if the body is not empty, it can throw an exception. In any case,
3557 // we must prevent trying to emit a try-catch for empty range, as it causes a verification error.
3558 final boolean bodyCanThrow = endLabel.isAfter(tryLabel);
3559 if(bodyCanThrow) {
3560 method._try(tryLabel, endLabel, catchLabel);
3561 }
3562
3563 final boolean reachable = method.isReachable();
3564 if(reachable) {
3565 popScope();
3566 if(bodyCanThrow) {
3567 method._goto(exitLabel);
3568 }
3569 }
3570
3571 if(bodyCanThrow) {
3572 method._catch(catchLabel);
3573 popScopeException();
3574 method.athrow();
3575 if(reachable) {
3576 method.label(exitLabel);
3577 }
3578 }
3579 }
3580 return false;
3581 }
3582
3583 private void loadADD(final UnaryNode unaryNode, final TypeBounds resultBounds) {
3584 loadExpression(unaryNode.getExpression(), resultBounds.booleanToInt().notWiderThan(Type.NUMBER));
3585 if(method.peekType() == Type.BOOLEAN) {
3586 // It's a no-op in bytecode, but we must make sure it is treated as an int for purposes of type signatures
3587 method.convert(Type.INT);
3588 }
3589 }
3590
3591 private void loadBIT_NOT(final UnaryNode unaryNode) {
3592 loadExpression(unaryNode.getExpression(), TypeBounds.INT).load(-1).xor();
3593 }
3594
3595 private void loadDECINC(final UnaryNode unaryNode) {
3596 final Expression operand = unaryNode.getExpression();
3597 final Type type = unaryNode.getType();
3598 final TypeBounds typeBounds = new TypeBounds(type, Type.NUMBER);
3599 final TokenType tokenType = unaryNode.tokenType();
3600 final boolean isPostfix = tokenType == TokenType.DECPOSTFIX || tokenType == TokenType.INCPOSTFIX;
3601 final boolean isIncrement = tokenType == TokenType.INCPREFIX || tokenType == TokenType.INCPOSTFIX;
3602
3603 assert !type.isObject();
3604
3605 new SelfModifyingStore<UnaryNode>(unaryNode, operand) {
3606
3607 private void loadRhs() {
3608 loadExpression(operand, typeBounds, true);
3609 }
3610
3611 @Override
3612 protected void evaluate() {
3613 if(isPostfix) {
3614 loadRhs();
3615 } else {
3616 new OptimisticOperation(unaryNode, typeBounds) {
3617 @Override
3618 void loadStack() {
3619 loadRhs();
3620 loadMinusOne();
3621 }
3622 @Override
3623 void consumeStack() {
3624 doDecInc(getProgramPoint());
3625 }
3626 }.emit(getOptimisticIgnoreCountForSelfModifyingExpression(operand));
3627 }
3628 }
3629
3630 @Override
3631 protected void storeNonDiscard() {
3632 super.storeNonDiscard();
3633 if (isPostfix) {
3634 new OptimisticOperation(unaryNode, typeBounds) {
3635 @Override
3636 void loadStack() {
3637 loadMinusOne();
3638 }
3639 @Override
3640 void consumeStack() {
3641 doDecInc(getProgramPoint());
3642 }
3643 }.emit(1); // 1 for non-incremented result on the top of the stack pushed in evaluate()
3644 }
3645 }
3646
3647 private void loadMinusOne() {
3648 if (type.isInteger()) {
3649 method.load(isIncrement ? 1 : -1);
3650 } else if (type.isLong()) {
3651 method.load(isIncrement ? 1L : -1L);
3652 } else {
3653 method.load(isIncrement ? 1.0 : -1.0);
3654 }
3655 }
3656
3657 private void doDecInc(final int programPoint) {
3658 method.add(programPoint);
3659 }
3660 }.store();
3661 }
3662
3663 private static int getOptimisticIgnoreCountForSelfModifyingExpression(final Expression target) {
3664 return target instanceof AccessNode ? 1 : target instanceof IndexNode ? 2 : 0;
3665 }
3666
3667 private void loadAndDiscard(final Expression expr) {
3668 // TODO: move checks for discarding to actual expression load code (e.g. as we do with void). That way we might
3669 // be able to eliminate even more checks.
3670 if(expr instanceof PrimitiveLiteralNode | isLocalVariable(expr)) {
3671 assert !lc.isCurrentDiscard(expr);
3672 // Don't bother evaluating expressions without side effects. Typical usage is "void 0" for reliably generating
3673 // undefined.
3674 return;
3675 }
3676
3677 lc.pushDiscard(expr);
3678 loadExpression(expr, TypeBounds.UNBOUNDED);
3679 if (lc.popDiscardIfCurrent(expr)) {
3680 assert !expr.isAssignment();
3681 // NOTE: if we had a way to load with type void, we could avoid popping
3682 method.pop();
3683 }
3684 }
3685
3686 /**
3687 * Loads the expression with the specified type bounds, but if the parent expression is the current discard,
3688 * then instead loads and discards the expression.
3689 * @param parent the parent expression that's tested for being the current discard
3690 * @param expr the expression that's either normally loaded or discard-loaded
3691 * @param resultBounds result bounds for when loading the expression normally
3692 */
3693 private void loadMaybeDiscard(final Expression parent, final Expression expr, final TypeBounds resultBounds) {
3694 loadMaybeDiscard(lc.popDiscardIfCurrent(parent), expr, resultBounds);
3695 }
3696
3697 /**
3698 * Loads the expression with the specified type bounds, or loads and discards the expression, depending on the
3699 * value of the discard flag. Useful as a helper for expressions with control flow where you often can't combine
3700 * testing for being the current discard and loading the subexpressions.
3701 * @param discard if true, the expression is loaded and discarded
3702 * @param expr the expression that's either normally loaded or discard-loaded
3703 * @param resultBounds result bounds for when loading the expression normally
3704 */
3705 private void loadMaybeDiscard(final boolean discard, final Expression expr, final TypeBounds resultBounds) {
3706 if (discard) {
3707 loadAndDiscard(expr);
3708 } else {
3709 loadExpression(expr, resultBounds);
3710 }
3711 }
3712
3713 private void loadNEW(final UnaryNode unaryNode) {
3714 final CallNode callNode = (CallNode)unaryNode.getExpression();
3715 final List<Expression> args = callNode.getArgs();
3716
3717 final Expression func = callNode.getFunction();
3718 // Load function reference.
3719 loadExpressionAsObject(func); // must detect type error
3720
3721 method.dynamicNew(1 + loadArgs(args), getCallSiteFlags(), func.toString(false));
3722 }
3723
3724 private void loadNOT(final UnaryNode unaryNode) {
3725 final Expression expr = unaryNode.getExpression();
3726 if(expr instanceof UnaryNode && expr.isTokenType(TokenType.NOT)) {
3727 // !!x is idiomatic boolean cast in JavaScript
3728 loadExpressionAsBoolean(((UnaryNode)expr).getExpression());
3729 } else {
3730 final Label trueLabel = new Label("true");
3731 final Label afterLabel = new Label("after");
3732
3733 emitBranch(expr, trueLabel, true);
3734 method.load(true);
3735 method._goto(afterLabel);
3736 method.label(trueLabel);
3737 method.load(false);
3738 method.label(afterLabel);
3739 }
3740 }
3741
3742 private void loadSUB(final UnaryNode unaryNode, final TypeBounds resultBounds) {
3743 final Type type = unaryNode.getType();
3744 assert type.isNumeric();
3745 final TypeBounds numericBounds = resultBounds.booleanToInt();
3746 new OptimisticOperation(unaryNode, numericBounds) {
3747 @Override
3748 void loadStack() {
3749 final Expression expr = unaryNode.getExpression();
3750 loadExpression(expr, numericBounds.notWiderThan(Type.NUMBER));
3751 }
3752 @Override
3753 void consumeStack() {
3754 // Must do an explicit conversion to the operation's type when it's double so that we correctly handle
3755 // negation of an int 0 to a double -0. With this, we get the correct negation of a local variable after
3756 // it deoptimized, e.g. "iload_2; i2d; dneg". Without this, we get "iload_2; ineg; i2d".
3757 if(type.isNumber()) {
3758 method.convert(type);
3759 }
3760 method.neg(getProgramPoint());
3761 }
3762 }.emit();
3763 }
3764
3765 public void loadVOID(final UnaryNode unaryNode, final TypeBounds resultBounds) {
3766 loadAndDiscard(unaryNode.getExpression());
3767 if (!lc.popDiscardIfCurrent(unaryNode)) {
3768 method.loadUndefined(resultBounds.widest);
3769 }
3770 }
3771
3772 public void loadADD(final BinaryNode binaryNode, final TypeBounds resultBounds) {
3773 new OptimisticOperation(binaryNode, resultBounds) {
3774 @Override
3775 void loadStack() {
3776 final TypeBounds operandBounds;
3777 final boolean isOptimistic = isValid(getProgramPoint());
3778 boolean forceConversionSeparation = false;
3779 if(isOptimistic) {
3780 operandBounds = new TypeBounds(binaryNode.getType(), Type.OBJECT);
3781 } else {
3782 // Non-optimistic, non-FP +. Allow it to overflow.
3783 final Type widestOperationType = binaryNode.getWidestOperationType();
3784 operandBounds = new TypeBounds(Type.narrowest(binaryNode.getWidestOperandType(), resultBounds.widest), widestOperationType);
3785 forceConversionSeparation = widestOperationType.narrowerThan(resultBounds.widest);
3786 }
3787 loadBinaryOperands(binaryNode.lhs(), binaryNode.rhs(), operandBounds, false, forceConversionSeparation);
3788 }
3789
3790 @Override
3791 void consumeStack() {
3792 method.add(getProgramPoint());
3793 }
3794 }.emit();
3795 }
3796
3797 private void loadAND_OR(final BinaryNode binaryNode, final TypeBounds resultBounds, final boolean isAnd) {
3798 final Type narrowestOperandType = Type.widestReturnType(binaryNode.lhs().getType(), binaryNode.rhs().getType());
3799
3800 final boolean isCurrentDiscard = lc.popDiscardIfCurrent(binaryNode);
3801
3802 final Label skip = new Label("skip");
3803 if(narrowestOperandType == Type.BOOLEAN) {
3804 // optimize all-boolean logical expressions
3805 final Label onTrue = new Label("andor_true");
3806 emitBranch(binaryNode, onTrue, true);
3807 if (isCurrentDiscard) {
3808 method.label(onTrue);
3809 } else {
3810 method.load(false);
3811 method._goto(skip);
3812 method.label(onTrue);
3813 method.load(true);
3814 method.label(skip);
3815 }
3816 return;
3817 }
3818
3819 final TypeBounds outBounds = resultBounds.notNarrowerThan(narrowestOperandType);
3820 final JoinPredecessorExpression lhs = (JoinPredecessorExpression)binaryNode.lhs();
3821 final boolean lhsConvert = LocalVariableConversion.hasLiveConversion(lhs);
3822 final Label evalRhs = lhsConvert ? new Label("eval_rhs") : null;
3823
3824 loadExpression(lhs, outBounds);
3825 if (!isCurrentDiscard) {
3826 method.dup();
3827 }
3828 method.convert(Type.BOOLEAN);
3829 if (isAnd) {
3830 if(lhsConvert) {
3831 method.ifne(evalRhs);
3832 } else {
3833 method.ifeq(skip);
3834 }
3835 } else if(lhsConvert) {
3836 method.ifeq(evalRhs);
3837 } else {
3838 method.ifne(skip);
3839 }
3840
3841 if(lhsConvert) {
3842 method.beforeJoinPoint(lhs);
3843 method._goto(skip);
3844 method.label(evalRhs);
3845 }
3846
3847 if (!isCurrentDiscard) {
3848 method.pop();
3849 }
3850 final JoinPredecessorExpression rhs = (JoinPredecessorExpression)binaryNode.rhs();
3851 loadMaybeDiscard(isCurrentDiscard, rhs, outBounds);
3852 method.beforeJoinPoint(rhs);
3853 method.label(skip);
3854 }
3855
3856 private static boolean isLocalVariable(final Expression lhs) {
3857 return lhs instanceof IdentNode && isLocalVariable((IdentNode)lhs);
3858 }
3859
3860 private static boolean isLocalVariable(final IdentNode lhs) {
3861 return lhs.getSymbol().isBytecodeLocal();
3862 }
3863
3864 // NOTE: does not use resultBounds as the assignment is driven by the type of the RHS
3865 private void loadASSIGN(final BinaryNode binaryNode) {
3866 final Expression lhs = binaryNode.lhs();
3867 final Expression rhs = binaryNode.rhs();
3868
3869 final Type rhsType = rhs.getType();
3870 // Detect dead assignments
3871 if(lhs instanceof IdentNode) {
3872 final Symbol symbol = ((IdentNode)lhs).getSymbol();
3873 if(!symbol.isScope() && !symbol.hasSlotFor(rhsType) && lc.popDiscardIfCurrent(binaryNode)) {
3874 loadAndDiscard(rhs);
3875 method.markDeadLocalVariable(symbol);
3876 return;
3877 }
3878 }
3879
3880 new Store<BinaryNode>(binaryNode, lhs) {
3881 @Override
3882 protected void evaluate() {
3883 // NOTE: we're loading with "at least as wide as" so optimistic operations on the right hand side
3884 // remain optimistic, and then explicitly convert to the required type if needed.
3885 loadExpressionAsType(rhs, rhsType);
3886 }
3887 }.store();
3888 }
3889
3890 /**
3891 * Binary self-assignment that can be optimistic: +=, -=, *=, and /=.
3892 */
3893 private abstract class BinaryOptimisticSelfAssignment extends SelfModifyingStore<BinaryNode> {
3894
3895 /**
3896 * Constructor
3897 *
3898 * @param node the assign op node
3899 */
3900 BinaryOptimisticSelfAssignment(final BinaryNode node) {
3901 super(node, node.lhs());
3902 }
3903
3904 protected abstract void op(OptimisticOperation oo);
3905
3906 @Override
3907 protected void evaluate() {
3908 final Expression lhs = assignNode.lhs();
3909 final Expression rhs = assignNode.rhs();
3910 final Type widestOperationType = assignNode.getWidestOperationType();
3911 final TypeBounds bounds = new TypeBounds(assignNode.getType(), widestOperationType);
3912 new OptimisticOperation(assignNode, bounds) {
3913 @Override
3914 void loadStack() {
3915 final boolean forceConversionSeparation;
3916 if (isValid(getProgramPoint()) || widestOperationType == Type.NUMBER) {
3917 forceConversionSeparation = false;
3918 } else {
3919 final Type operandType = Type.widest(booleanToInt(objectToNumber(lhs.getType())), booleanToInt(objectToNumber(rhs.getType())));
3920 forceConversionSeparation = operandType.narrowerThan(widestOperationType);
3921 }
3922 loadBinaryOperands(lhs, rhs, bounds, true, forceConversionSeparation);
3923 }
3924 @Override
3925 void consumeStack() {
3926 op(this);
3927 }
3928 }.emit(getOptimisticIgnoreCountForSelfModifyingExpression(lhs));
3929 method.convert(assignNode.getType());
3930 }
3931 }
3932
3933 /**
3934 * Non-optimistic binary self-assignment operation. Basically, everything except +=, -=, *=, and /=.
3935 */
3936 private abstract class BinarySelfAssignment extends SelfModifyingStore<BinaryNode> {
3937 BinarySelfAssignment(final BinaryNode node) {
3938 super(node, node.lhs());
3939 }
3940
3941 protected abstract void op();
3942
3943 @Override
3944 protected void evaluate() {
3945 loadBinaryOperands(assignNode.lhs(), assignNode.rhs(), TypeBounds.UNBOUNDED.notWiderThan(assignNode.getWidestOperandType()), true, false);
3946 op();
3947 }
3948 }
3949
3950 private void loadASSIGN_ADD(final BinaryNode binaryNode) {
3951 new BinaryOptimisticSelfAssignment(binaryNode) {
3952 @Override
3953 protected void op(final OptimisticOperation oo) {
3954 assert !(binaryNode.getType().isObject() && oo.isOptimistic);
3955 method.add(oo.getProgramPoint());
3956 }
3957 }.store();
3958 }
3959
3960 private void loadASSIGN_BIT_AND(final BinaryNode binaryNode) {
3961 new BinarySelfAssignment(binaryNode) {
3962 @Override
3963 protected void op() {
3964 method.and();
3965 }
3966 }.store();
3967 }
3968
3969 private void loadASSIGN_BIT_OR(final BinaryNode binaryNode) {
3970 new BinarySelfAssignment(binaryNode) {
3971 @Override
3972 protected void op() {
3973 method.or();
3974 }
3975 }.store();
3976 }
3977
3978 private void loadASSIGN_BIT_XOR(final BinaryNode binaryNode) {
3979 new BinarySelfAssignment(binaryNode) {
3980 @Override
3981 protected void op() {
3982 method.xor();
3983 }
3984 }.store();
3985 }
3986
3987 private void loadASSIGN_DIV(final BinaryNode binaryNode) {
3988 new BinaryOptimisticSelfAssignment(binaryNode) {
3989 @Override
3990 protected void op(final OptimisticOperation oo) {
3991 method.div(oo.getProgramPoint());
3992 }
3993 }.store();
3994 }
3995
3996 private void loadASSIGN_MOD(final BinaryNode binaryNode) {
3997 new BinaryOptimisticSelfAssignment(binaryNode) {
3998 @Override
3999 protected void op(final OptimisticOperation oo) {
4000 method.rem(oo.getProgramPoint());
4001 }
4002 }.store();
4003 }
4004
4005 private void loadASSIGN_MUL(final BinaryNode binaryNode) {
4006 new BinaryOptimisticSelfAssignment(binaryNode) {
4007 @Override
4008 protected void op(final OptimisticOperation oo) {
4009 method.mul(oo.getProgramPoint());
4010 }
4011 }.store();
4012 }
4013
4014 private void loadASSIGN_SAR(final BinaryNode binaryNode) {
4015 new BinarySelfAssignment(binaryNode) {
4016 @Override
4017 protected void op() {
4018 method.sar();
4019 }
4020 }.store();
4021 }
4022
4023 private void loadASSIGN_SHL(final BinaryNode binaryNode) {
4024 new BinarySelfAssignment(binaryNode) {
4025 @Override
4026 protected void op() {
4027 method.shl();
4028 }
4029 }.store();
4030 }
4031
4032 private void loadASSIGN_SHR(final BinaryNode binaryNode) {
4033 new BinarySelfAssignment(binaryNode) {
4034 @Override
4035 protected void op() {
4036 doSHR();
4037 }
4038
4039 }.store();
4040 }
4041
4042 private void doSHR() {
4043 // TODO: make SHR optimistic
4044 method.shr();
4045 toUint();
4046 }
4047
4048 private void toUint() {
4049 JSType.TO_UINT32_I.invoke(method);
4050 }
4051
4052 private void loadASSIGN_SUB(final BinaryNode binaryNode) {
4053 new BinaryOptimisticSelfAssignment(binaryNode) {
4054 @Override
4055 protected void op(final OptimisticOperation oo) {
4056 method.sub(oo.getProgramPoint());
4057 }
4058 }.store();
4059 }
4060
4061 /**
4062 * Helper class for binary arithmetic ops
4063 */
4064 private abstract class BinaryArith {
4065 protected abstract void op(int programPoint);
4066
4067 protected void evaluate(final BinaryNode node, final TypeBounds resultBounds) {
4068 final TypeBounds numericBounds = resultBounds.booleanToInt().objectToNumber();
4069 new OptimisticOperation(node, numericBounds) {
4070 @Override
4071 void loadStack() {
4072 final TypeBounds operandBounds;
4073 boolean forceConversionSeparation = false;
4074 if(numericBounds.narrowest == Type.NUMBER) {
4075 // Result should be double always. Propagate it into the operands so we don't have lots of I2D
4076 // and L2D after operand evaluation.
4077 assert numericBounds.widest == Type.NUMBER;
4078 operandBounds = numericBounds;
4079 } else {
4080 final boolean isOptimistic = isValid(getProgramPoint());
4081 if(isOptimistic || node.isTokenType(TokenType.DIV) || node.isTokenType(TokenType.MOD)) {
4082 operandBounds = new TypeBounds(node.getType(), Type.NUMBER);
4083 } else {
4084 // Non-optimistic, non-FP subtraction or multiplication. Allow them to overflow.
4085 operandBounds = new TypeBounds(Type.narrowest(node.getWidestOperandType(),
4086 numericBounds.widest), Type.NUMBER);
4087 forceConversionSeparation = node.getWidestOperationType().narrowerThan(numericBounds.widest);
4088 }
4089 }
4090 loadBinaryOperands(node.lhs(), node.rhs(), operandBounds, false, forceConversionSeparation);
4091 }
4092
4093 @Override
4094 void consumeStack() {
4095 op(getProgramPoint());
4096 }
4097 }.emit();
4098 }
4099 }
4100
4101 private void loadBIT_AND(final BinaryNode binaryNode) {
4102 loadBinaryOperands(binaryNode);
4103 method.and();
4104 }
4105
4106 private void loadBIT_OR(final BinaryNode binaryNode) {
4107 // Optimize x|0 to (int)x
4108 if (isRhsZero(binaryNode)) {
4109 loadExpressionAsType(binaryNode.lhs(), Type.INT);
4110 } else {
4111 loadBinaryOperands(binaryNode);
4112 method.or();
4113 }
4114 }
4115
4116 private static boolean isRhsZero(final BinaryNode binaryNode) {
4117 final Expression rhs = binaryNode.rhs();
4118 return rhs instanceof LiteralNode && INT_ZERO.equals(((LiteralNode<?>)rhs).getValue());
4119 }
4120
4121 private void loadBIT_XOR(final BinaryNode binaryNode) {
4122 loadBinaryOperands(binaryNode);
4123 method.xor();
4124 }
4125
4126 private void loadCOMMARIGHT(final BinaryNode binaryNode, final TypeBounds resultBounds) {
4127 loadAndDiscard(binaryNode.lhs());
4128 loadMaybeDiscard(binaryNode, binaryNode.rhs(), resultBounds);
4129 }
4130
4131 private void loadCOMMALEFT(final BinaryNode binaryNode, final TypeBounds resultBounds) {
4132 loadMaybeDiscard(binaryNode, binaryNode.lhs(), resultBounds);
4133 loadAndDiscard(binaryNode.rhs());
4134 }
4135
4136 private void loadDIV(final BinaryNode binaryNode, final TypeBounds resultBounds) {
4137 new BinaryArith() {
4138 @Override
4139 protected void op(final int programPoint) {
4140 method.div(programPoint);
4141 }
4142 }.evaluate(binaryNode, resultBounds);
4143 }
4144
4145 private void loadCmp(final BinaryNode binaryNode, final Condition cond) {
4146 loadComparisonOperands(binaryNode);
4147
4148 final Label trueLabel = new Label("trueLabel");
4149 final Label afterLabel = new Label("skip");
4150
4151 method.conditionalJump(cond, trueLabel);
4152
4153 method.load(Boolean.FALSE);
4154 method._goto(afterLabel);
4155 method.label(trueLabel);
4156 method.load(Boolean.TRUE);
4157 method.label(afterLabel);
4158 }
4159
4160 private void loadMOD(final BinaryNode binaryNode, final TypeBounds resultBounds) {
4161 new BinaryArith() {
4162 @Override
4163 protected void op(final int programPoint) {
4164 method.rem(programPoint);
4165 }
4166 }.evaluate(binaryNode, resultBounds);
4167 }
4168
4169 private void loadMUL(final BinaryNode binaryNode, final TypeBounds resultBounds) {
4170 new BinaryArith() {
4171 @Override
4172 protected void op(final int programPoint) {
4173 method.mul(programPoint);
4174 }
4175 }.evaluate(binaryNode, resultBounds);
4176 }
4177
4178 private void loadSAR(final BinaryNode binaryNode) {
4179 loadBinaryOperands(binaryNode);
4180 method.sar();
4181 }
4182
4183 private void loadSHL(final BinaryNode binaryNode) {
4184 loadBinaryOperands(binaryNode);
4185 method.shl();
4186 }
4187
4188 private void loadSHR(final BinaryNode binaryNode) {
4189 // Optimize x >>> 0 to (uint)x
4190 if (isRhsZero(binaryNode)) {
4191 loadExpressionAsType(binaryNode.lhs(), Type.INT);
4192 toUint();
4193 } else {
4194 loadBinaryOperands(binaryNode);
4195 doSHR();
4196 }
4197 }
4198
4199 private void loadSUB(final BinaryNode binaryNode, final TypeBounds resultBounds) {
4200 new BinaryArith() {
4201 @Override
4202 protected void op(final int programPoint) {
4203 method.sub(programPoint);
4204 }
4205 }.evaluate(binaryNode, resultBounds);
4206 }
4207
4208 @Override
4209 public boolean enterLabelNode(final LabelNode labelNode) {
4210 labeledBlockBreakLiveLocals.push(lc.getUsedSlotCount());
4211 return true;
4212 }
4213
4214 @Override
4215 protected boolean enterDefault(final Node node) {
4216 throw new AssertionError("Code generator entered node of type " + node.getClass().getName());
4217 }
4218
4219 private void loadTernaryNode(final TernaryNode ternaryNode, final TypeBounds resultBounds) {
4220 final Expression test = ternaryNode.getTest();
4221 final JoinPredecessorExpression trueExpr = ternaryNode.getTrueExpression();
4222 final JoinPredecessorExpression falseExpr = ternaryNode.getFalseExpression();
4223
4224 final Label falseLabel = new Label("ternary_false");
4225 final Label exitLabel = new Label("ternary_exit");
4226
4227 final Type outNarrowest = Type.narrowest(resultBounds.widest, Type.generic(Type.widestReturnType(trueExpr.getType(), falseExpr.getType())));
4228 final TypeBounds outBounds = resultBounds.notNarrowerThan(outNarrowest);
4229
4230 emitBranch(test, falseLabel, false);
4231
4232 final boolean isCurrentDiscard = lc.popDiscardIfCurrent(ternaryNode);
4233 loadMaybeDiscard(isCurrentDiscard, trueExpr.getExpression(), outBounds);
4234 assert isCurrentDiscard || Type.generic(method.peekType()) == outBounds.narrowest;
4235 method.beforeJoinPoint(trueExpr);
4236 method._goto(exitLabel);
4237 method.label(falseLabel);
4238 loadMaybeDiscard(isCurrentDiscard, falseExpr.getExpression(), outBounds);
4239 assert isCurrentDiscard || Type.generic(method.peekType()) == outBounds.narrowest;
4240 method.beforeJoinPoint(falseExpr);
4241 method.label(exitLabel);
4242 }
4243
4244 /**
4245 * Generate all shared scope calls generated during codegen.
4246 */
4247 void generateScopeCalls() {
4248 for (final SharedScopeCall scopeAccess : lc.getScopeCalls()) {
4249 scopeAccess.generateScopeCall();
4250 }
4251 }
4252
4253 /**
4254 * Debug code used to print symbols
4255 *
4256 * @param block the block we are in
4257 * @param function the function we are in
4258 * @param ident identifier for block or function where applicable
4259 */
4260 private void printSymbols(final Block block, final FunctionNode function, final String ident) {
4261 if (compiler.getScriptEnvironment()._print_symbols || function.getFlag(FunctionNode.IS_PRINT_SYMBOLS)) {
4262 final PrintWriter out = compiler.getScriptEnvironment().getErr();
4263 out.println("[BLOCK in '" + ident + "']");
4264 if (!block.printSymbols(out)) {
4265 out.println("<no symbols>");
4266 }
4267 out.println();
4268 }
4269 }
4270
4271
4272 /**
4273 * The difference between a store and a self modifying store is that
4274 * the latter may load part of the target on the stack, e.g. the base
4275 * of an AccessNode or the base and index of an IndexNode. These are used
4276 * both as target and as an extra source. Previously it was problematic
4277 * for self modifying stores if the target/lhs didn't belong to one
4278 * of three trivial categories: IdentNode, AcessNodes, IndexNodes. In that
4279 * case it was evaluated and tagged as "resolved", which meant at the second
4280 * time the lhs of this store was read (e.g. in a = a (second) + b for a += b,
4281 * it would be evaluated to a nop in the scope and cause stack underflow
4282 *
4283 * see NASHORN-703
4284 *
4285 * @param <T>
4286 */
4287 private abstract class SelfModifyingStore<T extends Expression> extends Store<T> {
4288 protected SelfModifyingStore(final T assignNode, final Expression target) {
4289 super(assignNode, target);
4290 }
4291
4292 @Override
4293 protected boolean isSelfModifying() {
4294 return true;
4295 }
4296 }
4297
4298 /**
4299 * Helper class to generate stores
4300 */
4301 private abstract class Store<T extends Expression> {
4302
4303 /** An assignment node, e.g. x += y */
4304 protected final T assignNode;
4305
4306 /** The target node to store to, e.g. x */
4307 private final Expression target;
4308
4309 /** How deep on the stack do the arguments go if this generates an indy call */
4310 private int depth;
4311
4312 /** If we have too many arguments, we need temporary storage, this is stored in 'quick' */
4313 private IdentNode quick;
4314
4315 /**
4316 * Constructor
4317 *
4318 * @param assignNode the node representing the whole assignment
4319 * @param target the target node of the assignment (destination)
4320 */
4321 protected Store(final T assignNode, final Expression target) {
4322 this.assignNode = assignNode;
4323 this.target = target;
4324 }
4325
4326 /**
4327 * Constructor
4328 *
4329 * @param assignNode the node representing the whole assignment
4330 */
4331 protected Store(final T assignNode) {
4332 this(assignNode, assignNode);
4333 }
4334
4335 /**
4336 * Is this a self modifying store operation, e.g. *= or ++
4337 * @return true if self modifying store
4338 */
4339 protected boolean isSelfModifying() {
4340 return false;
4341 }
4342
4343 private void prologue() {
4344 /*
4345 * This loads the parts of the target, e.g base and index. they are kept
4346 * on the stack throughout the store and used at the end to execute it
4347 */
4348
4349 target.accept(new SimpleNodeVisitor() {
4350 @Override
4351 public boolean enterIdentNode(final IdentNode node) {
4352 if (node.getSymbol().isScope()) {
4353 method.loadCompilerConstant(SCOPE);
4354 depth += Type.SCOPE.getSlots();
4355 assert depth == 1;
4356 }
4357 return false;
4358 }
4359
4360 private void enterBaseNode() {
4361 assert target instanceof BaseNode : "error - base node " + target + " must be instanceof BaseNode";
4362 final BaseNode baseNode = (BaseNode)target;
4363 final Expression base = baseNode.getBase();
4364
4365 loadExpressionAsObject(base);
4366 depth += Type.OBJECT.getSlots();
4367 assert depth == 1;
4368
4369 if (isSelfModifying()) {
4370 method.dup();
4371 }
4372 }
4373
4374 @Override
4375 public boolean enterAccessNode(final AccessNode node) {
4376 enterBaseNode();
4377 return false;
4378 }
4379
4380 @Override
4381 public boolean enterIndexNode(final IndexNode node) {
4382 enterBaseNode();
4383
4384 final Expression index = node.getIndex();
4385 if (!index.getType().isNumeric()) {
4386 // could be boolean here as well
4387 loadExpressionAsObject(index);
4388 } else {
4389 loadExpressionUnbounded(index);
4390 }
4391 depth += index.getType().getSlots();
4392
4393 if (isSelfModifying()) {
4394 //convert "base base index" to "base index base index"
4395 method.dup(1);
4396 }
4397
4398 return false;
4399 }
4400
4401 });
4402 }
4403
4404 /**
4405 * Generates an extra local variable, always using the same slot, one that is available after the end of the
4406 * frame.
4407 *
4408 * @param type the type of the variable
4409 *
4410 * @return the quick variable
4411 */
4412 private IdentNode quickLocalVariable(final Type type) {
4413 final String name = lc.getCurrentFunction().uniqueName(QUICK_PREFIX.symbolName());
4414 final Symbol symbol = new Symbol(name, IS_INTERNAL | HAS_SLOT);
4415 symbol.setHasSlotFor(type);
4416 symbol.setFirstSlot(lc.quickSlot(type));
4417
4418 final IdentNode quickIdent = IdentNode.createInternalIdentifier(symbol).setType(type);
4419
4420 return quickIdent;
4421 }
4422
4423 // store the result that "lives on" after the op, e.g. "i" in i++ postfix.
4424 protected void storeNonDiscard() {
4425 if (lc.popDiscardIfCurrent(assignNode)) {
4426 assert assignNode.isAssignment();
4427 return;
4428 }
4429
4430 if (method.dup(depth) == null) {
4431 method.dup();
4432 final Type quickType = method.peekType();
4433 this.quick = quickLocalVariable(quickType);
4434 final Symbol quickSymbol = quick.getSymbol();
4435 method.storeTemp(quickType, quickSymbol.getFirstSlot());
4436 }
4437 }
4438
4439 private void epilogue() {
4440 /**
4441 * Take the original target args from the stack and use them
4442 * together with the value to be stored to emit the store code
4443 *
4444 * The case that targetSymbol is in scope (!hasSlot) and we actually
4445 * need to do a conversion on non-equivalent types exists, but is
4446 * very rare. See for example test/script/basic/access-specializer.js
4447 */
4448 target.accept(new SimpleNodeVisitor() {
4449 @Override
4450 protected boolean enterDefault(final Node node) {
4451 throw new AssertionError("Unexpected node " + node + " in store epilogue");
4452 }
4453
4454 @Override
4455 public boolean enterIdentNode(final IdentNode node) {
4456 final Symbol symbol = node.getSymbol();
4457 assert symbol != null;
4458 if (symbol.isScope()) {
4459 final int flags = getScopeCallSiteFlags(symbol);
4460 if (isFastScope(symbol)) {
4461 storeFastScopeVar(symbol, flags);
4462 } else {
4463 method.dynamicSet(node.getName(), flags, false);
4464 }
4465 } else {
4466 final Type storeType = assignNode.getType();
4467 if (symbol.hasSlotFor(storeType)) {
4468 // Only emit a convert for a store known to be live; converts for dead stores can
4469 // give us an unnecessary ClassCastException.
4470 method.convert(storeType);
4471 }
4472 storeIdentWithCatchConversion(node, storeType);
4473 }
4474 return false;
4475
4476 }
4477
4478 @Override
4479 public boolean enterAccessNode(final AccessNode node) {
4480 method.dynamicSet(node.getProperty(), getCallSiteFlags(), node.isIndex());
4481 return false;
4482 }
4483
4484 @Override
4485 public boolean enterIndexNode(final IndexNode node) {
4486 method.dynamicSetIndex(getCallSiteFlags());
4487 return false;
4488 }
4489 });
4490
4491
4492 // whatever is on the stack now is the final answer
4493 }
4494
4495 protected abstract void evaluate();
4496
4497 void store() {
4498 if (target instanceof IdentNode) {
4499 checkTemporalDeadZone((IdentNode)target);
4500 }
4501 prologue();
4502 evaluate(); // leaves an operation of whatever the operationType was on the stack
4503 storeNonDiscard();
4504 epilogue();
4505 if (quick != null) {
4506 method.load(quick);
4507 }
4508 }
4509 }
4510
4511 private void newFunctionObject(final FunctionNode functionNode, final boolean addInitializer) {
4512 assert lc.peek() == functionNode;
4513
4514 final RecompilableScriptFunctionData data = compiler.getScriptFunctionData(functionNode.getId());
4515
4516 if (functionNode.isProgram() && !compiler.isOnDemandCompilation()) {
4517 final MethodEmitter createFunction = functionNode.getCompileUnit().getClassEmitter().method(
4518 EnumSet.of(Flag.PUBLIC, Flag.STATIC), CREATE_PROGRAM_FUNCTION.symbolName(),
4519 ScriptFunction.class, ScriptObject.class);
4520 createFunction.begin();
4521 loadConstantsAndIndex(data, createFunction);
4522 createFunction.load(SCOPE_TYPE, 0);
4523 createFunction.invoke(CREATE_FUNCTION_OBJECT);
4524 createFunction._return();
4525 createFunction.end();
4526 }
4527
4528 if (addInitializer && !compiler.isOnDemandCompilation()) {
4529 functionNode.getCompileUnit().addFunctionInitializer(data, functionNode);
4530 }
4531
4532 // We don't emit a ScriptFunction on stack for the outermost compiled function (as there's no code being
4533 // generated in its outer context that'd need it as a callee).
4534 if (lc.getOutermostFunction() == functionNode) {
4535 return;
4536 }
4537
4538 loadConstantsAndIndex(data, method);
4539
4540 if (functionNode.needsParentScope()) {
4541 method.loadCompilerConstant(SCOPE);
4542 method.invoke(CREATE_FUNCTION_OBJECT);
4543 } else {
4544 method.invoke(CREATE_FUNCTION_OBJECT_NO_SCOPE);
4545 }
4546 }
4547
4548 // calls on Global class.
4549 private MethodEmitter globalInstance() {
4550 return method.invokestatic(GLOBAL_OBJECT, "instance", "()L" + GLOBAL_OBJECT + ';');
4551 }
4552
4553 private MethodEmitter globalAllocateArguments() {
4554 return method.invokestatic(GLOBAL_OBJECT, "allocateArguments", methodDescriptor(ScriptObject.class, Object[].class, Object.class, int.class));
4555 }
4556
4557 private MethodEmitter globalNewRegExp() {
4558 return method.invokestatic(GLOBAL_OBJECT, "newRegExp", methodDescriptor(Object.class, String.class, String.class));
4559 }
4560
4561 private MethodEmitter globalRegExpCopy() {
4562 return method.invokestatic(GLOBAL_OBJECT, "regExpCopy", methodDescriptor(Object.class, Object.class));
4563 }
4564
4565 private MethodEmitter globalAllocateArray(final ArrayType type) {
4566 //make sure the native array is treated as an array type
4567 return method.invokestatic(GLOBAL_OBJECT, "allocate", "(" + type.getDescriptor() + ")Ljdk/nashorn/internal/objects/NativeArray;");
4568 }
4569
4570 private MethodEmitter globalIsEval() {
4571 return method.invokestatic(GLOBAL_OBJECT, "isEval", methodDescriptor(boolean.class, Object.class));
4572 }
4573
4574 private MethodEmitter globalReplaceLocationPropertyPlaceholder() {
4575 return method.invokestatic(GLOBAL_OBJECT, "replaceLocationPropertyPlaceholder", methodDescriptor(Object.class, Object.class, Object.class));
4576 }
4577
4578 private MethodEmitter globalCheckObjectCoercible() {
4579 return method.invokestatic(GLOBAL_OBJECT, "checkObjectCoercible", methodDescriptor(void.class, Object.class));
4580 }
4581
4582 private MethodEmitter globalDirectEval() {
4583 return method.invokestatic(GLOBAL_OBJECT, "directEval",
4584 methodDescriptor(Object.class, Object.class, Object.class, Object.class, Object.class, boolean.class));
4585 }
4586
4587 private abstract class OptimisticOperation {
4588 private final boolean isOptimistic;
4589 // expression and optimistic are the same reference
4590 private final Expression expression;
4591 private final Optimistic optimistic;
4592 private final TypeBounds resultBounds;
4593
4594 OptimisticOperation(final Optimistic optimistic, final TypeBounds resultBounds) {
4595 this.optimistic = optimistic;
4596 this.expression = (Expression)optimistic;
4597 this.resultBounds = resultBounds;
4598 this.isOptimistic = isOptimistic(optimistic) && useOptimisticTypes() &&
4599 // Operation is only effectively optimistic if its type, after being coerced into the result bounds
4600 // is narrower than the upper bound.
4601 resultBounds.within(Type.generic(((Expression)optimistic).getType())).narrowerThan(resultBounds.widest);
4602 }
4603
4604 MethodEmitter emit() {
4605 return emit(0);
4606 }
4607
4608 MethodEmitter emit(final int ignoredArgCount) {
4609 final int programPoint = optimistic.getProgramPoint();
4610 final boolean optimisticOrContinuation = isOptimistic || isContinuationEntryPoint(programPoint);
4611 final boolean currentContinuationEntryPoint = isCurrentContinuationEntryPoint(programPoint);
4612 final int stackSizeOnEntry = method.getStackSize() - ignoredArgCount;
4613
4614 // First store the values on the stack opportunistically into local variables. Doing it before loadStack()
4615 // allows us to not have to pop/load any arguments that are pushed onto it by loadStack() in the second
4616 // storeStack().
4617 storeStack(ignoredArgCount, optimisticOrContinuation);
4618
4619 // Now, load the stack
4620 loadStack();
4621
4622 // Now store the values on the stack ultimately into local variables. In vast majority of cases, this is
4623 // (aside from creating the local types map) a no-op, as the first opportunistic stack store will already
4624 // store all variables. However, there can be operations in the loadStack() that invalidate some of the
4625 // stack stores, e.g. in "x[i] = x[++i]", "++i" will invalidate the already stored value for "i". In such
4626 // unfortunate cases this second storeStack() will restore the invariant that everything on the stack is
4627 // stored into a local variable, although at the cost of doing a store/load on the loaded arguments as well.
4628 final int liveLocalsCount = storeStack(method.getStackSize() - stackSizeOnEntry, optimisticOrContinuation);
4629 assert optimisticOrContinuation == (liveLocalsCount != -1);
4630
4631 final Label beginTry;
4632 final Label catchLabel;
4633 final Label afterConsumeStack = isOptimistic || currentContinuationEntryPoint ? new Label("after_consume_stack") : null;
4634 if(isOptimistic) {
4635 beginTry = new Label("try_optimistic");
4636 final String catchLabelName = (afterConsumeStack == null ? "" : afterConsumeStack.toString()) + "_handler";
4637 catchLabel = new Label(catchLabelName);
4638 method.label(beginTry);
4639 } else {
4640 beginTry = catchLabel = null;
4641 }
4642
4643 consumeStack();
4644
4645 if(isOptimistic) {
4646 method._try(beginTry, afterConsumeStack, catchLabel, UnwarrantedOptimismException.class);
4647 }
4648
4649 if(isOptimistic || currentContinuationEntryPoint) {
4650 method.label(afterConsumeStack);
4651
4652 final int[] localLoads = method.getLocalLoadsOnStack(0, stackSizeOnEntry);
4653 assert everyStackValueIsLocalLoad(localLoads) : Arrays.toString(localLoads) + ", " + stackSizeOnEntry + ", " + ignoredArgCount;
4654 final List<Type> localTypesList = method.getLocalVariableTypes();
4655 final int usedLocals = method.getUsedSlotsWithLiveTemporaries();
4656 final List<Type> localTypes = method.getWidestLiveLocals(localTypesList.subList(0, usedLocals));
4657 assert everyLocalLoadIsValid(localLoads, usedLocals) : Arrays.toString(localLoads) + " ~ " + localTypes;
4658
4659 if(isOptimistic) {
4660 addUnwarrantedOptimismHandlerLabel(localTypes, catchLabel);
4661 }
4662 if(currentContinuationEntryPoint) {
4663 final ContinuationInfo ci = getContinuationInfo();
4664 assert ci != null : "no continuation info found for " + lc.getCurrentFunction();
4665 assert !ci.hasTargetLabel(); // No duplicate program points
4666 ci.setTargetLabel(afterConsumeStack);
4667 ci.getHandlerLabel().markAsOptimisticContinuationHandlerFor(afterConsumeStack);
4668 // Can't rely on targetLabel.stack.localVariableTypes.length, as it can be higher due to effectively
4669 // dead local variables.
4670 ci.lvarCount = localTypes.size();
4671 ci.setStackStoreSpec(localLoads);
4672 ci.setStackTypes(Arrays.copyOf(method.getTypesFromStack(method.getStackSize()), stackSizeOnEntry));
4673 assert ci.getStackStoreSpec().length == ci.getStackTypes().length;
4674 ci.setReturnValueType(method.peekType());
4675 ci.lineNumber = getLastLineNumber();
4676 ci.catchLabel = catchLabels.peek();
4677 }
4678 }
4679 return method;
4680 }
4681
4682 /**
4683 * Stores the current contents of the stack into local variables so they are not lost before invoking something that
4684 * can result in an {@code UnwarantedOptimizationException}.
4685 * @param ignoreArgCount the number of topmost arguments on stack to ignore when deciding on the shape of the catch
4686 * block. Those are used in the situations when we could not place the call to {@code storeStack} early enough
4687 * (before emitting code for pushing the arguments that the optimistic call will pop). This is admittedly a
4688 * deficiency in the design of the code generator when it deals with self-assignments and we should probably look
4689 * into fixing it.
4690 * @return types of the significant local variables after the stack was stored (types for local variables used
4691 * for temporary storage of ignored arguments are not returned).
4692 * @param optimisticOrContinuation if false, this method should not execute
4693 * a label for a catch block for the {@code UnwarantedOptimizationException}, suitable for capturing the
4694 * currently live local variables, tailored to their types.
4695 */
4696 private int storeStack(final int ignoreArgCount, final boolean optimisticOrContinuation) {
4697 if(!optimisticOrContinuation) {
4698 return -1; // NOTE: correct value to return is lc.getUsedSlotCount(), but it wouldn't be used anyway
4699 }
4700
4701 final int stackSize = method.getStackSize();
4702 final Type[] stackTypes = method.getTypesFromStack(stackSize);
4703 final int[] localLoadsOnStack = method.getLocalLoadsOnStack(0, stackSize);
4704 final int usedSlots = method.getUsedSlotsWithLiveTemporaries();
4705
4706 final int firstIgnored = stackSize - ignoreArgCount;
4707 // Find the first value on the stack (from the bottom) that is not a load from a local variable.
4708 int firstNonLoad = 0;
4709 while(firstNonLoad < firstIgnored && localLoadsOnStack[firstNonLoad] != Label.Stack.NON_LOAD) {
4710 firstNonLoad++;
4711 }
4712
4713 // Only do the store/load if first non-load is not an ignored argument. Otherwise, do nothing and return
4714 // the number of used slots as the number of live local variables.
4715 if(firstNonLoad >= firstIgnored) {
4716 return usedSlots;
4717 }
4718
4719 // Find the number of new temporary local variables that we need; it's the number of values on the stack that
4720 // are not direct loads of existing local variables.
4721 int tempSlotsNeeded = 0;
4722 for(int i = firstNonLoad; i < stackSize; ++i) {
4723 if(localLoadsOnStack[i] == Label.Stack.NON_LOAD) {
4724 tempSlotsNeeded += stackTypes[i].getSlots();
4725 }
4726 }
4727
4728 // Ensure all values on the stack that weren't directly loaded from a local variable are stored in a local
4729 // variable. We're starting from highest local variable index, so that in case ignoreArgCount > 0 the ignored
4730 // ones end up at the end of the local variable table.
4731 int lastTempSlot = usedSlots + tempSlotsNeeded;
4732 int ignoreSlotCount = 0;
4733 for(int i = stackSize; i -- > firstNonLoad;) {
4734 final int loadSlot = localLoadsOnStack[i];
4735 if(loadSlot == Label.Stack.NON_LOAD) {
4736 final Type type = stackTypes[i];
4737 final int slots = type.getSlots();
4738 lastTempSlot -= slots;
4739 if(i >= firstIgnored) {
4740 ignoreSlotCount += slots;
4741 }
4742 method.storeTemp(type, lastTempSlot);
4743 } else {
4744 method.pop();
4745 }
4746 }
4747 assert lastTempSlot == usedSlots; // used all temporary locals
4748
4749 final List<Type> localTypesList = method.getLocalVariableTypes();
4750
4751 // Load values back on stack.
4752 for(int i = firstNonLoad; i < stackSize; ++i) {
4753 final int loadSlot = localLoadsOnStack[i];
4754 final Type stackType = stackTypes[i];
4755 final boolean isLoad = loadSlot != Label.Stack.NON_LOAD;
4756 final int lvarSlot = isLoad ? loadSlot : lastTempSlot;
4757 final Type lvarType = localTypesList.get(lvarSlot);
4758 method.load(lvarType, lvarSlot);
4759 if(isLoad) {
4760 // Conversion operators (I2L etc.) preserve "load"-ness of the value despite the fact that, in the
4761 // strict sense they are creating a derived value from the loaded value. This special behavior of
4762 // on-stack conversion operators is necessary to accommodate for differences in local variable types
4763 // after deoptimization; having a conversion operator throw away "load"-ness would create different
4764 // local variable table shapes between optimism-failed code and its deoptimized rest-of method).
4765 // After we load the value back, we need to redo the conversion to the stack type if stack type is
4766 // different.
4767 // NOTE: this would only strictly be necessary for widening conversions (I2L, L2D, I2D), and not for
4768 // narrowing ones (L2I, D2L, D2I) as only widening conversions are the ones that can get eliminated
4769 // in a deoptimized method, as their original input argument got widened. Maybe experiment with
4770 // throwing away "load"-ness for narrowing conversions in MethodEmitter.convert()?
4771 method.convert(stackType);
4772 } else {
4773 // temporary stores never needs a convert, as their type is always the same as the stack type.
4774 assert lvarType == stackType;
4775 lastTempSlot += lvarType.getSlots();
4776 }
4777 }
4778 // used all temporaries
4779 assert lastTempSlot == usedSlots + tempSlotsNeeded;
4780
4781 return lastTempSlot - ignoreSlotCount;
4782 }
4783
4784 private void addUnwarrantedOptimismHandlerLabel(final List<Type> localTypes, final Label label) {
4785 final String lvarTypesDescriptor = getLvarTypesDescriptor(localTypes);
4786 final Map<String, Collection<Label>> unwarrantedOptimismHandlers = lc.getUnwarrantedOptimismHandlers();
4787 Collection<Label> labels = unwarrantedOptimismHandlers.get(lvarTypesDescriptor);
4788 if(labels == null) {
4789 labels = new LinkedList<>();
4790 unwarrantedOptimismHandlers.put(lvarTypesDescriptor, labels);
4791 }
4792 method.markLabelAsOptimisticCatchHandler(label, localTypes.size());
4793 labels.add(label);
4794 }
4795
4796 abstract void loadStack();
4797
4798 // Make sure that whatever indy call site you emit from this method uses {@code getCallSiteFlagsOptimistic(node)}
4799 // or otherwise ensure optimistic flag is correctly set in the call site, otherwise it doesn't make much sense
4800 // to use OptimisticExpression for emitting it.
4801 abstract void consumeStack();
4802
4803 /**
4804 * Emits the correct dynamic getter code. Normally just delegates to method emitter, except when the target
4805 * expression is optimistic, and the desired type is narrower than the optimistic type. In that case, it'll emit a
4806 * dynamic getter with its original optimistic type, and explicitly insert a narrowing conversion. This way we can
4807 * preserve the optimism of the values even if they're subsequently immediately coerced into a narrower type. This
4808 * is beneficial because in this case we can still presume that since the original getter was optimistic, the
4809 * conversion has no side effects.
4810 * @param name the name of the property being get
4811 * @param flags call site flags
4812 * @param isMethod whether we're preferably retrieving a function
4813 * @return the current method emitter
4814 */
4815 MethodEmitter dynamicGet(final String name, final int flags, final boolean isMethod, final boolean isIndex) {
4816 if(isOptimistic) {
4817 return method.dynamicGet(getOptimisticCoercedType(), name, getOptimisticFlags(flags), isMethod, isIndex);
4818 }
4819 return method.dynamicGet(resultBounds.within(expression.getType()), name, nonOptimisticFlags(flags), isMethod, isIndex);
4820 }
4821
4822 MethodEmitter dynamicGetIndex(final int flags, final boolean isMethod) {
4823 if(isOptimistic) {
4824 return method.dynamicGetIndex(getOptimisticCoercedType(), getOptimisticFlags(flags), isMethod);
4825 }
4826 return method.dynamicGetIndex(resultBounds.within(expression.getType()), nonOptimisticFlags(flags), isMethod);
4827 }
4828
4829 MethodEmitter dynamicCall(final int argCount, final int flags, final String msg) {
4830 if (isOptimistic) {
4831 return method.dynamicCall(getOptimisticCoercedType(), argCount, getOptimisticFlags(flags), msg);
4832 }
4833 return method.dynamicCall(resultBounds.within(expression.getType()), argCount, nonOptimisticFlags(flags), msg);
4834 }
4835
4836 int getOptimisticFlags(final int flags) {
4837 return flags | CALLSITE_OPTIMISTIC | (optimistic.getProgramPoint() << CALLSITE_PROGRAM_POINT_SHIFT); //encode program point in high bits
4838 }
4839
4840 int getProgramPoint() {
4841 return isOptimistic ? optimistic.getProgramPoint() : INVALID_PROGRAM_POINT;
4842 }
4843
4844 void convertOptimisticReturnValue() {
4845 if (isOptimistic) {
4846 final Type optimisticType = getOptimisticCoercedType();
4847 if(!optimisticType.isObject()) {
4848 method.load(optimistic.getProgramPoint());
4849 if(optimisticType.isInteger()) {
4850 method.invoke(ENSURE_INT);
4851 } else if(optimisticType.isLong()) {
4852 method.invoke(ENSURE_LONG);
4853 } else if(optimisticType.isNumber()) {
4854 method.invoke(ENSURE_NUMBER);
4855 } else {
4856 throw new AssertionError(optimisticType);
4857 }
4858 }
4859 }
4860 }
4861
4862 void replaceCompileTimeProperty() {
4863 final IdentNode identNode = (IdentNode)expression;
4864 final String name = identNode.getSymbol().getName();
4865 if (CompilerConstants.__FILE__.name().equals(name)) {
4866 replaceCompileTimeProperty(getCurrentSource().getName());
4867 } else if (CompilerConstants.__DIR__.name().equals(name)) {
4868 replaceCompileTimeProperty(getCurrentSource().getBase());
4869 } else if (CompilerConstants.__LINE__.name().equals(name)) {
4870 replaceCompileTimeProperty(getCurrentSource().getLine(identNode.position()));
4871 }
4872 }
4873
4874 /**
4875 * When an ident with name __FILE__, __DIR__, or __LINE__ is loaded, we'll try to look it up as any other
4876 * identifier. However, if it gets all the way up to the Global object, it will send back a special value that
4877 * represents a placeholder for these compile-time location properties. This method will generate code that loads
4878 * the value of the compile-time location property and then invokes a method in Global that will replace the
4879 * placeholder with the value. Effectively, if the symbol for these properties is defined anywhere in the lexical
4880 * scope, they take precedence, but if they aren't, then they resolve to the compile-time location property.
4881 * @param propertyValue the actual value of the property
4882 */
4883 private void replaceCompileTimeProperty(final Object propertyValue) {
4884 assert method.peekType().isObject();
4885 if(propertyValue instanceof String || propertyValue == null) {
4886 method.load((String)propertyValue);
4887 } else if(propertyValue instanceof Integer) {
4888 method.load(((Integer)propertyValue).intValue());
4889 method.convert(Type.OBJECT);
4890 } else {
4891 throw new AssertionError();
4892 }
4893 globalReplaceLocationPropertyPlaceholder();
4894 convertOptimisticReturnValue();
4895 }
4896
4897 /**
4898 * Returns the type that should be used as the return type of the dynamic invocation that is emitted as the code
4899 * for the current optimistic operation. If the type bounds is exact boolean or narrower than the expression's
4900 * optimistic type, then the optimistic type is returned, otherwise the coercing type. Effectively, this method
4901 * allows for moving the coercion into the optimistic type when it won't adversely affect the optimistic
4902 * evaluation semantics, and for preserving the optimistic type and doing a separate coercion when it would
4903 * affect it.
4904 * @return
4905 */
4906 private Type getOptimisticCoercedType() {
4907 final Type optimisticType = expression.getType();
4908 assert resultBounds.widest.widerThan(optimisticType);
4909 final Type narrowest = resultBounds.narrowest;
4910
4911 if(narrowest.isBoolean() || narrowest.narrowerThan(optimisticType)) {
4912 assert !optimisticType.isObject();
4913 return optimisticType;
4914 }
4915 assert !narrowest.isObject();
4916 return narrowest;
4917 }
4918 }
4919
4920 private static boolean isOptimistic(final Optimistic optimistic) {
4921 if(!optimistic.canBeOptimistic()) {
4922 return false;
4923 }
4924 final Expression expr = (Expression)optimistic;
4925 return expr.getType().narrowerThan(expr.getWidestOperationType());
4926 }
4927
4928 private static boolean everyLocalLoadIsValid(final int[] loads, final int localCount) {
4929 for (final int load : loads) {
4930 if(load < 0 || load >= localCount) {
4931 return false;
4932 }
4933 }
4934 return true;
4935 }
4936
4937 private static boolean everyStackValueIsLocalLoad(final int[] loads) {
4938 for (final int load : loads) {
4939 if(load == Label.Stack.NON_LOAD) {
4940 return false;
4941 }
4942 }
4943 return true;
4944 }
4945
4946 private String getLvarTypesDescriptor(final List<Type> localVarTypes) {
4947 final int count = localVarTypes.size();
4948 final StringBuilder desc = new StringBuilder(count);
4949 for(int i = 0; i < count;) {
4950 i += appendType(desc, localVarTypes.get(i));
4951 }
4952 return method.markSymbolBoundariesInLvarTypesDescriptor(desc.toString());
4953 }
4954
4955 private static int appendType(final StringBuilder b, final Type t) {
4956 b.append(t.getBytecodeStackType());
4957 return t.getSlots();
4958 }
4959
4960 private static int countSymbolsInLvarTypeDescriptor(final String lvarTypeDescriptor) {
4961 int count = 0;
4962 for(int i = 0; i < lvarTypeDescriptor.length(); ++i) {
4963 if(Character.isUpperCase(lvarTypeDescriptor.charAt(i))) {
4964 ++count;
4965 }
4966 }
4967 return count;
4968
4969 }
4970 /**
4971 * Generates all the required {@code UnwarrantedOptimismException} handlers for the current function. The employed
4972 * strategy strives to maximize code reuse. Every handler constructs an array to hold the local variables, then
4973 * fills in some trailing part of the local variables (those for which it has a unique suffix in the descriptor),
4974 * then jumps to a handler for a prefix that's shared with other handlers. A handler that fills up locals up to
4975 * position 0 will not jump to a prefix handler (as it has no prefix), but instead end with constructing and
4976 * throwing a {@code RewriteException}. Since we lexicographically sort the entries, we only need to check every
4977 * entry to its immediately preceding one for longest matching prefix.
4978 * @return true if there is at least one exception handler
4979 */
4980 private boolean generateUnwarrantedOptimismExceptionHandlers(final FunctionNode fn) {
4981 if(!useOptimisticTypes()) {
4982 return false;
4983 }
4984
4985 // Take the mapping of lvarSpecs -> labels, and turn them into a descending lexicographically sorted list of
4986 // handler specifications.
4987 final Map<String, Collection<Label>> unwarrantedOptimismHandlers = lc.popUnwarrantedOptimismHandlers();
4988 if(unwarrantedOptimismHandlers.isEmpty()) {
4989 return false;
4990 }
4991
4992 method.lineNumber(0);
4993
4994 final List<OptimismExceptionHandlerSpec> handlerSpecs = new ArrayList<>(unwarrantedOptimismHandlers.size() * 4/3);
4995 for(final String spec: unwarrantedOptimismHandlers.keySet()) {
4996 handlerSpecs.add(new OptimismExceptionHandlerSpec(spec, true));
4997 }
4998 Collections.sort(handlerSpecs, Collections.reverseOrder());
4999
5000 // Map of local variable specifications to labels for populating the array for that local variable spec.
5001 final Map<String, Label> delegationLabels = new HashMap<>();
5002
5003 // Do everything in a single pass over the handlerSpecs list. Note that the list can actually grow as we're
5004 // passing through it as we might add new prefix handlers into it, so can't hoist size() outside of the loop.
5005 for(int handlerIndex = 0; handlerIndex < handlerSpecs.size(); ++handlerIndex) {
5006 final OptimismExceptionHandlerSpec spec = handlerSpecs.get(handlerIndex);
5007 final String lvarSpec = spec.lvarSpec;
5008 if(spec.catchTarget) {
5009 assert !method.isReachable();
5010 // Start a catch block and assign the labels for this lvarSpec with it.
5011 method._catch(unwarrantedOptimismHandlers.get(lvarSpec));
5012 // This spec is a catch target, so emit array creation code. The length of the array is the number of
5013 // symbols - the number of uppercase characters.
5014 method.load(countSymbolsInLvarTypeDescriptor(lvarSpec));
5015 method.newarray(Type.OBJECT_ARRAY);
5016 }
5017 if(spec.delegationTarget) {
5018 // If another handler can delegate to this handler as its prefix, then put a jump target here for the
5019 // shared code (after the array creation code, which is never shared).
5020 method.label(delegationLabels.get(lvarSpec)); // label must exist
5021 }
5022
5023 final boolean lastHandler = handlerIndex == handlerSpecs.size() - 1;
5024
5025 int lvarIndex;
5026 final int firstArrayIndex;
5027 final int firstLvarIndex;
5028 Label delegationLabel;
5029 final String commonLvarSpec;
5030 if(lastHandler) {
5031 // Last handler block, doesn't delegate to anything.
5032 lvarIndex = 0;
5033 firstLvarIndex = 0;
5034 firstArrayIndex = 0;
5035 delegationLabel = null;
5036 commonLvarSpec = null;
5037 } else {
5038 // Not yet the last handler block, will definitely delegate to another handler; let's figure out which
5039 // one. It can be an already declared handler further down the list, or it might need to declare a new
5040 // prefix handler.
5041
5042 // Since we're lexicographically ordered, the common prefix handler is defined by the common prefix of
5043 // this handler and the next handler on the list.
5044 final int nextHandlerIndex = handlerIndex + 1;
5045 final String nextLvarSpec = handlerSpecs.get(nextHandlerIndex).lvarSpec;
5046 commonLvarSpec = commonPrefix(lvarSpec, nextLvarSpec);
5047 // We don't chop symbols in half
5048 assert Character.isUpperCase(commonLvarSpec.charAt(commonLvarSpec.length() - 1));
5049
5050 // Let's find if we already have a declaration for such handler, or we need to insert it.
5051 {
5052 boolean addNewHandler = true;
5053 int commonHandlerIndex = nextHandlerIndex;
5054 for(; commonHandlerIndex < handlerSpecs.size(); ++commonHandlerIndex) {
5055 final OptimismExceptionHandlerSpec forwardHandlerSpec = handlerSpecs.get(commonHandlerIndex);
5056 final String forwardLvarSpec = forwardHandlerSpec.lvarSpec;
5057 if(forwardLvarSpec.equals(commonLvarSpec)) {
5058 // We already have a handler for the common prefix.
5059 addNewHandler = false;
5060 // Make sure we mark it as a delegation target.
5061 forwardHandlerSpec.delegationTarget = true;
5062 break;
5063 } else if(!forwardLvarSpec.startsWith(commonLvarSpec)) {
5064 break;
5065 }
5066 }
5067 if(addNewHandler) {
5068 // We need to insert a common prefix handler. Note handlers created with catchTarget == false
5069 // will automatically have delegationTarget == true (because that's the only reason for their
5070 // existence).
5071 handlerSpecs.add(commonHandlerIndex, new OptimismExceptionHandlerSpec(commonLvarSpec, false));
5072 }
5073 }
5074
5075 firstArrayIndex = countSymbolsInLvarTypeDescriptor(commonLvarSpec);
5076 lvarIndex = 0;
5077 for(int j = 0; j < commonLvarSpec.length(); ++j) {
5078 lvarIndex += CodeGeneratorLexicalContext.getTypeForSlotDescriptor(commonLvarSpec.charAt(j)).getSlots();
5079 }
5080 firstLvarIndex = lvarIndex;
5081
5082 // Create a delegation label if not already present
5083 delegationLabel = delegationLabels.get(commonLvarSpec);
5084 if(delegationLabel == null) {
5085 // uo_pa == "unwarranted optimism, populate array"
5086 delegationLabel = new Label("uo_pa_" + commonLvarSpec);
5087 delegationLabels.put(commonLvarSpec, delegationLabel);
5088 }
5089 }
5090
5091 // Load local variables handled by this handler on stack
5092 int args = 0;
5093 boolean symbolHadValue = false;
5094 for(int typeIndex = commonLvarSpec == null ? 0 : commonLvarSpec.length(); typeIndex < lvarSpec.length(); ++typeIndex) {
5095 final char typeDesc = lvarSpec.charAt(typeIndex);
5096 final Type lvarType = CodeGeneratorLexicalContext.getTypeForSlotDescriptor(typeDesc);
5097 if (!lvarType.isUnknown()) {
5098 method.load(lvarType, lvarIndex);
5099 symbolHadValue = true;
5100 args++;
5101 } else if(typeDesc == 'U' && !symbolHadValue) {
5102 // Symbol boundary with undefined last value. Check if all previous values for this symbol were also
5103 // undefined; if so, emit one explicit Undefined. This serves to ensure that we're emiting exactly
5104 // one value for every symbol that uses local slots. While we could in theory ignore symbols that
5105 // are undefined (in other words, dead) at the point where this exception was thrown, unfortunately
5106 // we can't do it in practice. The reason for this is that currently our liveness analysis is
5107 // coarse (it can determine whether a symbol has not been read with a particular type anywhere in
5108 // the function being compiled, but that's it), and a symbol being promoted to Object due to a
5109 // deoptimization will suddenly show up as "live for Object type", and previously dead U->O
5110 // conversions on loop entries will suddenly become alive in the deoptimized method which will then
5111 // expect a value for that slot in its continuation handler. If we had precise liveness analysis, we
5112 // could go back to excluding known dead symbols from the payload of the RewriteException.
5113 if(method.peekType() == Type.UNDEFINED) {
5114 method.dup();
5115 } else {
5116 method.loadUndefined(Type.OBJECT);
5117 }
5118 args++;
5119 }
5120 if(Character.isUpperCase(typeDesc)) {
5121 // Reached symbol boundary; reset flag for the next symbol.
5122 symbolHadValue = false;
5123 }
5124 lvarIndex += lvarType.getSlots();
5125 }
5126 assert args > 0;
5127 // Delegate actual storing into array to an array populator utility method.
5128 //on the stack:
5129 // object array to be populated
5130 // start index
5131 // a lot of types
5132 method.dynamicArrayPopulatorCall(args + 1, firstArrayIndex);
5133 if(delegationLabel != null) {
5134 // We cascade to a prefix handler to fill out the rest of the local variables and throw the
5135 // RewriteException.
5136 assert !lastHandler;
5137 assert commonLvarSpec != null;
5138 // Must undefine the local variables that we have already processed for the sake of correct join on the
5139 // delegate label
5140 method.undefineLocalVariables(firstLvarIndex, true);
5141 final OptimismExceptionHandlerSpec nextSpec = handlerSpecs.get(handlerIndex + 1);
5142 // If the delegate immediately follows, and it's not a catch target (so it doesn't have array setup
5143 // code) don't bother emitting a jump, as we'd just jump to the next instruction.
5144 if(!nextSpec.lvarSpec.equals(commonLvarSpec) || nextSpec.catchTarget) {
5145 method._goto(delegationLabel);
5146 }
5147 } else {
5148 assert lastHandler;
5149 // Nothing to delegate to, so this handler must create and throw the RewriteException.
5150 // At this point we have the UnwarrantedOptimismException and the Object[] with local variables on
5151 // stack. We need to create a RewriteException, push two references to it below the constructor
5152 // arguments, invoke the constructor, and throw the exception.
5153 loadConstant(getByteCodeSymbolNames(fn));
5154 if (isRestOf()) {
5155 loadConstant(getContinuationEntryPoints());
5156 method.invoke(CREATE_REWRITE_EXCEPTION_REST_OF);
5157 } else {
5158 method.invoke(CREATE_REWRITE_EXCEPTION);
5159 }
5160 method.athrow();
5161 }
5162 }
5163 return true;
5164 }
5165
5166 private static String[] getByteCodeSymbolNames(final FunctionNode fn) {
5167 // Only names of local variables on the function level are captured. This information is used to reduce
5168 // deoptimizations, so as much as we can capture will help. We rely on the fact that function wide variables are
5169 // all live all the time, so the array passed to rewrite exception contains one element for every slotted symbol
5170 // here.
5171 final List<String> names = new ArrayList<>();
5172 for (final Symbol symbol: fn.getBody().getSymbols()) {
5173 if (symbol.hasSlot()) {
5174 if (symbol.isScope()) {
5175 // slot + scope can only be true for parameters
5176 assert symbol.isParam();
5177 names.add(null);
5178 } else {
5179 names.add(symbol.getName());
5180 }
5181 }
5182 }
5183 return names.toArray(new String[names.size()]);
5184 }
5185
5186 private static String commonPrefix(final String s1, final String s2) {
5187 final int l1 = s1.length();
5188 final int l = Math.min(l1, s2.length());
5189 int lms = -1; // last matching symbol
5190 for(int i = 0; i < l; ++i) {
5191 final char c1 = s1.charAt(i);
5192 if(c1 != s2.charAt(i)) {
5193 return s1.substring(0, lms + 1);
5194 } else if(Character.isUpperCase(c1)) {
5195 lms = i;
5196 }
5197 }
5198 return l == l1 ? s1 : s2;
5199 }
5200
5201 private static class OptimismExceptionHandlerSpec implements Comparable<OptimismExceptionHandlerSpec> {
5202 private final String lvarSpec;
5203 private final boolean catchTarget;
5204 private boolean delegationTarget;
5205
5206 OptimismExceptionHandlerSpec(final String lvarSpec, final boolean catchTarget) {
5207 this.lvarSpec = lvarSpec;
5208 this.catchTarget = catchTarget;
5209 if(!catchTarget) {
5210 delegationTarget = true;
5211 }
5212 }
5213
5214 @Override
5215 public int compareTo(final OptimismExceptionHandlerSpec o) {
5216 return lvarSpec.compareTo(o.lvarSpec);
5217 }
5218
5219 @Override
5220 public String toString() {
5221 final StringBuilder b = new StringBuilder(64).append("[HandlerSpec ").append(lvarSpec);
5222 if(catchTarget) {
5223 b.append(", catchTarget");
5224 }
5225 if(delegationTarget) {
5226 b.append(", delegationTarget");
5227 }
5228 return b.append("]").toString();
5229 }
5230 }
5231
5232 private static class ContinuationInfo {
5233 private final Label handlerLabel;
5234 private Label targetLabel; // Label for the target instruction.
5235 int lvarCount;
5236 // Indices of local variables that need to be loaded on the stack when this node completes
5237 private int[] stackStoreSpec;
5238 // Types of values loaded on the stack
5239 private Type[] stackTypes;
5240 // If non-null, this node should perform the requisite type conversion
5241 private Type returnValueType;
5242 // If we are in the middle of an object literal initialization, we need to update the map
5243 private PropertyMap objectLiteralMap;
5244 // Object literal stack depth for object literal - not necessarily top if property is a tree
5245 private int objectLiteralStackDepth = -1;
5246 // The line number at the continuation point
5247 private int lineNumber;
5248 // The active catch label, in case the continuation point is in a try/catch block
5249 private Label catchLabel;
5250 // The number of scopes that need to be popped before control is transferred to the catch label.
5251 private int exceptionScopePops;
5252
5253 ContinuationInfo() {
5254 this.handlerLabel = new Label("continuation_handler");
5255 }
5256
5257 Label getHandlerLabel() {
5258 return handlerLabel;
5259 }
5260
5261 boolean hasTargetLabel() {
5262 return targetLabel != null;
5263 }
5264
5265 Label getTargetLabel() {
5266 return targetLabel;
5267 }
5268
5269 void setTargetLabel(final Label targetLabel) {
5270 this.targetLabel = targetLabel;
5271 }
5272
5273 int[] getStackStoreSpec() {
5274 return stackStoreSpec.clone();
5275 }
5276
5277 void setStackStoreSpec(final int[] stackStoreSpec) {
5278 this.stackStoreSpec = stackStoreSpec;
5279 }
5280
5281 Type[] getStackTypes() {
5282 return stackTypes.clone();
5283 }
5284
5285 void setStackTypes(final Type[] stackTypes) {
5286 this.stackTypes = stackTypes;
5287 }
5288
5289 Type getReturnValueType() {
5290 return returnValueType;
5291 }
5292
5293 void setReturnValueType(final Type returnValueType) {
5294 this.returnValueType = returnValueType;
5295 }
5296
5297 int getObjectLiteralStackDepth() {
5298 return objectLiteralStackDepth;
5299 }
5300
5301 void setObjectLiteralStackDepth(final int objectLiteralStackDepth) {
5302 this.objectLiteralStackDepth = objectLiteralStackDepth;
5303 }
5304
5305 PropertyMap getObjectLiteralMap() {
5306 return objectLiteralMap;
5307 }
5308
5309 void setObjectLiteralMap(final PropertyMap objectLiteralMap) {
5310 this.objectLiteralMap = objectLiteralMap;
5311 }
5312
5313 @Override
5314 public String toString() {
5315 return "[localVariableTypes=" + targetLabel.getStack().getLocalVariableTypesCopy() + ", stackStoreSpec=" +
5316 Arrays.toString(stackStoreSpec) + ", returnValueType=" + returnValueType + "]";
5317 }
5318 }
5319
5320 private ContinuationInfo getContinuationInfo() {
5321 return continuationInfo;
5322 }
5323
5324 private void generateContinuationHandler() {
5325 if (!isRestOf()) {
5326 return;
5327 }
5328
5329 final ContinuationInfo ci = getContinuationInfo();
5330 method.label(ci.getHandlerLabel());
5331
5332 // There should never be an exception thrown from the continuation handler, but in case there is (meaning,
5333 // Nashorn has a bug), then line number 0 will be an indication of where it came from (line numbers are Uint16).
5334 method.lineNumber(0);
5335
5336 final Label.Stack stack = ci.getTargetLabel().getStack();
5337 final List<Type> lvarTypes = stack.getLocalVariableTypesCopy();
5338 final BitSet symbolBoundary = stack.getSymbolBoundaryCopy();
5339 final int lvarCount = ci.lvarCount;
5340
5341 final Type rewriteExceptionType = Type.typeFor(RewriteException.class);
5342 // Store the RewriteException into an unused local variable slot.
5343 method.load(rewriteExceptionType, 0);
5344 method.storeTemp(rewriteExceptionType, lvarCount);
5345 // Get local variable array
5346 method.load(rewriteExceptionType, 0);
5347 method.invoke(RewriteException.GET_BYTECODE_SLOTS);
5348 // Store local variables. Note that deoptimization might introduce new value types for existing local variables,
5349 // so we must use both liveLocals and symbolBoundary, as in some cases (when the continuation is inside of a try
5350 // block) we need to store the incoming value into multiple slots. The optimism exception handlers will have
5351 // exactly one array element for every symbol that uses bytecode storage. If in the originating method the value
5352 // was undefined, there will be an explicit Undefined value in the array.
5353 int arrayIndex = 0;
5354 for(int lvarIndex = 0; lvarIndex < lvarCount;) {
5355 final Type lvarType = lvarTypes.get(lvarIndex);
5356 if(!lvarType.isUnknown()) {
5357 method.dup();
5358 method.load(arrayIndex).arrayload();
5359 final Class<?> typeClass = lvarType.getTypeClass();
5360 // Deoptimization in array initializers can cause arrays to undergo component type widening
5361 if(typeClass == long[].class) {
5362 method.load(rewriteExceptionType, lvarCount);
5363 method.invoke(RewriteException.TO_LONG_ARRAY);
5364 } else if(typeClass == double[].class) {
5365 method.load(rewriteExceptionType, lvarCount);
5366 method.invoke(RewriteException.TO_DOUBLE_ARRAY);
5367 } else if(typeClass == Object[].class) {
5368 method.load(rewriteExceptionType, lvarCount);
5369 method.invoke(RewriteException.TO_OBJECT_ARRAY);
5370 } else {
5371 if(!(typeClass.isPrimitive() || typeClass == Object.class)) {
5372 // NOTE: this can only happen with dead stores. E.g. for the program "1; []; f();" in which the
5373 // call to f() will deoptimize the call site, but it'll expect :return to have the type
5374 // NativeArray. However, in the more optimal version, :return's only live type is int, therefore
5375 // "{O}:return = []" is a dead store, and the variable will be sent into the continuation as
5376 // Undefined, however NativeArray can't hold Undefined instance.
5377 method.loadType(Type.getInternalName(typeClass));
5378 method.invoke(RewriteException.INSTANCE_OR_NULL);
5379 }
5380 method.convert(lvarType);
5381 }
5382 method.storeHidden(lvarType, lvarIndex, false);
5383 }
5384 final int nextLvarIndex = lvarIndex + lvarType.getSlots();
5385 if(symbolBoundary.get(nextLvarIndex - 1)) {
5386 ++arrayIndex;
5387 }
5388 lvarIndex = nextLvarIndex;
5389 }
5390 if (AssertsEnabled.assertsEnabled()) {
5391 method.load(arrayIndex);
5392 method.invoke(RewriteException.ASSERT_ARRAY_LENGTH);
5393 } else {
5394 method.pop();
5395 }
5396
5397 final int[] stackStoreSpec = ci.getStackStoreSpec();
5398 final Type[] stackTypes = ci.getStackTypes();
5399 final boolean isStackEmpty = stackStoreSpec.length == 0;
5400 boolean replacedObjectLiteralMap = false;
5401 if(!isStackEmpty) {
5402 // Load arguments on the stack
5403 final int objectLiteralStackDepth = ci.getObjectLiteralStackDepth();
5404 for(int i = 0; i < stackStoreSpec.length; ++i) {
5405 final int slot = stackStoreSpec[i];
5406 method.load(lvarTypes.get(slot), slot);
5407 method.convert(stackTypes[i]);
5408 // stack: s0=object literal being initialized
5409 // change map of s0 so that the property we are initializing when we failed
5410 // is now ci.returnValueType
5411 if (i == objectLiteralStackDepth) {
5412 method.dup();
5413 assert ci.getObjectLiteralMap() != null;
5414 assert ScriptObject.class.isAssignableFrom(method.peekType().getTypeClass()) : method.peekType().getTypeClass() + " is not a script object";
5415 loadConstant(ci.getObjectLiteralMap());
5416 method.invoke(ScriptObject.SET_MAP);
5417 replacedObjectLiteralMap = true;
5418 }
5419 }
5420 }
5421 // Must have emitted the code for replacing the map of an object literal if we have a set object literal stack depth
5422 assert ci.getObjectLiteralStackDepth() == -1 || replacedObjectLiteralMap;
5423 // Load RewriteException back.
5424 method.load(rewriteExceptionType, lvarCount);
5425 // Get rid of the stored reference
5426 method.loadNull();
5427 method.storeHidden(Type.OBJECT, lvarCount);
5428 // Mark it dead
5429 method.markDeadSlots(lvarCount, Type.OBJECT.getSlots());
5430
5431 // Load return value on the stack
5432 method.invoke(RewriteException.GET_RETURN_VALUE);
5433
5434 final Type returnValueType = ci.getReturnValueType();
5435
5436 // Set up an exception handler for primitive type conversion of return value if needed
5437 boolean needsCatch = false;
5438 final Label targetCatchLabel = ci.catchLabel;
5439 Label _try = null;
5440 if(returnValueType.isPrimitive()) {
5441 // If the conversion throws an exception, we want to report the line number of the continuation point.
5442 method.lineNumber(ci.lineNumber);
5443
5444 if(targetCatchLabel != METHOD_BOUNDARY) {
5445 _try = new Label("");
5446 method.label(_try);
5447 needsCatch = true;
5448 }
5449 }
5450
5451 // Convert return value
5452 method.convert(returnValueType);
5453
5454 final int scopePopCount = needsCatch ? ci.exceptionScopePops : 0;
5455
5456 // Declare a try/catch for the conversion. If no scopes need to be popped until the target catch block, just
5457 // jump into it. Otherwise, we'll need to create a scope-popping catch block below.
5458 final Label catchLabel = scopePopCount > 0 ? new Label("") : targetCatchLabel;
5459 if(needsCatch) {
5460 final Label _end_try = new Label("");
5461 method.label(_end_try);
5462 method._try(_try, _end_try, catchLabel);
5463 }
5464
5465 // Jump to continuation point
5466 method._goto(ci.getTargetLabel());
5467
5468 // Make a scope-popping exception delegate if needed
5469 if(catchLabel != targetCatchLabel) {
5470 method.lineNumber(0);
5471 assert scopePopCount > 0;
5472 method._catch(catchLabel);
5473 popScopes(scopePopCount);
5474 method.uncheckedGoto(targetCatchLabel);
5475 }
5476 }
5477
5478 /**
5479 * Interface implemented by object creators that support splitting over multiple methods.
5480 */
5481 interface SplitLiteralCreator {
5482 /**
5483 * Generate code to populate a range of the literal object. A reference to the object
5484 * should be left on the stack when the method terminates.
5485 *
5486 * @param method the method emitter
5487 * @param type the type of the literal object
5488 * @param slot the local slot containing the literal object
5489 * @param start the start index (inclusive)
5490 * @param end the end index (exclusive)
5491 */
5492 void populateRange(MethodEmitter method, Type type, int slot, int start, int end);
5493 }
5494 }