1 /*
2 * Copyright (c) 1999, 2021, 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 com.sun.tools.javac.jvm;
27
28 import java.util.HashMap;
29 import java.util.Map;
30 import java.util.Set;
31
32 import com.sun.tools.javac.jvm.PoolConstant.LoadableConstant;
33 import com.sun.tools.javac.tree.TreeInfo.PosKind;
34 import com.sun.tools.javac.util.*;
35 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
36 import com.sun.tools.javac.util.List;
37 import com.sun.tools.javac.code.*;
38 import com.sun.tools.javac.code.Attribute.TypeCompound;
39 import com.sun.tools.javac.code.Symbol.VarSymbol;
40 import com.sun.tools.javac.comp.*;
41 import com.sun.tools.javac.tree.*;
42
43 import com.sun.tools.javac.code.Symbol.*;
44 import com.sun.tools.javac.code.Type.*;
45 import com.sun.tools.javac.jvm.Code.*;
46 import com.sun.tools.javac.jvm.Items.*;
47 import com.sun.tools.javac.resources.CompilerProperties.Errors;
48 import com.sun.tools.javac.tree.EndPosTable;
49 import com.sun.tools.javac.tree.JCTree.*;
50
51 import static com.sun.tools.javac.code.Flags.*;
52 import static com.sun.tools.javac.code.Kinds.Kind.*;
53 import static com.sun.tools.javac.code.TypeTag.*;
54 import static com.sun.tools.javac.jvm.ByteCodes.*;
55 import static com.sun.tools.javac.jvm.CRTFlags.*;
56 import static com.sun.tools.javac.main.Option.*;
57 import static com.sun.tools.javac.tree.JCTree.Tag.*;
58
59 /** This pass maps flat Java (i.e. without inner classes) to bytecodes.
60 *
61 * <p><b>This is NOT part of any supported API.
62 * If you write code that depends on this, you do so at your own risk.
63 * This code and its internal interfaces are subject to change or
64 * deletion without notice.</b>
65 */
66 public class Gen extends JCTree.Visitor {
67 private static final Object[] NO_STATIC_ARGS = new Object[0];
68 protected static final Context.Key<Gen> genKey = new Context.Key<>();
69
70 private final Log log;
71 private final Symtab syms;
72 private final Check chk;
73 private final Resolve rs;
74 private final TreeMaker make;
75 private final Names names;
76 private final Target target;
77 private final Name accessDollar;
78 private final Types types;
79 private final Lower lower;
80 private final Annotate annotate;
81 private final StringConcat concat;
82 private final TransValues transValues;
83
84 /** Format of stackmap tables to be generated. */
85 private final Code.StackMapFormat stackMap;
86
87 /** A type that serves as the expected type for all method expressions.
88 */
89 private final Type methodType;
90
91 public static Gen instance(Context context) {
92 Gen instance = context.get(genKey);
93 if (instance == null)
94 instance = new Gen(context);
95 return instance;
96 }
97
98 /** Constant pool writer, set by genClass.
99 */
100 final PoolWriter poolWriter;
101
102 protected Gen(Context context) {
103 context.put(genKey, this);
104
105 names = Names.instance(context);
106 log = Log.instance(context);
107 syms = Symtab.instance(context);
108 chk = Check.instance(context);
109 rs = Resolve.instance(context);
110 make = TreeMaker.instance(context);
111 target = Target.instance(context);
112 types = Types.instance(context);
113 concat = StringConcat.instance(context);
114
115 methodType = new MethodType(null, null, null, syms.methodClass);
116 accessDollar = names.
117 fromString("access" + target.syntheticNameChar());
118 lower = Lower.instance(context);
119 transValues = TransValues.instance(context);
120
121 Options options = Options.instance(context);
122 lineDebugInfo =
123 options.isUnset(G_CUSTOM) ||
124 options.isSet(G_CUSTOM, "lines");
125 varDebugInfo =
126 options.isUnset(G_CUSTOM)
127 ? options.isSet(G)
128 : options.isSet(G_CUSTOM, "vars");
129 genCrt = options.isSet(XJCOV);
130 debugCode = options.isSet("debug.code");
131 disableVirtualizedPrivateInvoke = options.isSet("disableVirtualizedPrivateInvoke");
132 poolWriter = new PoolWriter(types, names);
133
134 // ignore cldc because we cannot have both stackmap formats
135 this.stackMap = StackMapFormat.JSR202;
136 annotate = Annotate.instance(context);
137 Source source = Source.instance(context);
138 allowPrimitiveClasses = Source.Feature.PRIMITIVE_CLASSES.allowedInSource(source) && options.isSet("enablePrimitiveClasses");
139 }
140
141 /** Switches
142 */
143 private final boolean lineDebugInfo;
144 private final boolean varDebugInfo;
145 private final boolean genCrt;
146 private final boolean debugCode;
147 private boolean disableVirtualizedPrivateInvoke;
148
149 /** Code buffer, set by genMethod.
150 */
151 private Code code;
152
153 /** Items structure, set by genMethod.
154 */
155 private Items items;
156
157 /** Environment for symbol lookup, set by genClass
158 */
159 private Env<AttrContext> attrEnv;
160
161 /** The top level tree.
162 */
163 private JCCompilationUnit toplevel;
164
165 /** The number of code-gen errors in this class.
166 */
167 private int nerrs = 0;
168
169 /** An object containing mappings of syntax trees to their
170 * ending source positions.
171 */
172 EndPosTable endPosTable;
173
174 boolean inCondSwitchExpression;
175 Chain switchExpressionTrueChain;
176 Chain switchExpressionFalseChain;
177 List<LocalItem> stackBeforeSwitchExpression;
178 LocalItem switchResult;
179 Set<JCMethodInvocation> invocationsWithPatternMatchingCatch = Set.of();
180 ListBuffer<int[]> patternMatchingInvocationRanges;
181
182 boolean allowPrimitiveClasses;
183
184 /** Generate code to load an integer constant.
185 * @param n The integer to be loaded.
186 */
187 void loadIntConst(int n) {
188 items.makeImmediateItem(syms.intType, n).load();
189 }
190
191 /** The opcode that loads a zero constant of a given type code.
192 * @param tc The given type code (@see ByteCode).
193 */
194 public static int zero(int tc) {
195 switch(tc) {
196 case INTcode: case BYTEcode: case SHORTcode: case CHARcode:
197 return iconst_0;
198 case LONGcode:
199 return lconst_0;
200 case FLOATcode:
201 return fconst_0;
202 case DOUBLEcode:
203 return dconst_0;
204 default:
205 throw new AssertionError("zero");
206 }
207 }
208
209 /** The opcode that loads a one constant of a given type code.
210 * @param tc The given type code (@see ByteCode).
211 */
212 public static int one(int tc) {
213 return zero(tc) + 1;
214 }
215
216 /** Generate code to load -1 of the given type code (either int or long).
217 * @param tc The given type code (@see ByteCode).
218 */
219 void emitMinusOne(int tc) {
220 if (tc == LONGcode) {
221 items.makeImmediateItem(syms.longType, Long.valueOf(-1)).load();
222 } else {
223 code.emitop0(iconst_m1);
224 }
225 }
226
227 /** Insert a reference to given type in the constant pool,
228 * checking for an array with too many dimensions;
229 * return the reference's index.
230 * @param type The type for which a reference is inserted.
231 */
232 int makeRef(DiagnosticPosition pos, Type type, boolean emitQtype) {
233 checkDimension(pos, type);
234 if (emitQtype) {
235 return poolWriter.putClass(new ConstantPoolQType(type, types));
236 } else {
237 return poolWriter.putClass(type);
238 }
239 }
240
241 /** Insert a reference to given type in the constant pool,
242 * checking for an array with too many dimensions;
243 * return the reference's index.
244 * @param type The type for which a reference is inserted.
245 */
246 int makeRef(DiagnosticPosition pos, Type type) {
247 return makeRef(pos, type, false);
248 }
249
250 /** Check if the given type is an array with too many dimensions.
251 */
252 private Type checkDimension(DiagnosticPosition pos, Type t) {
253 checkDimensionInternal(pos, t);
254 return t;
255 }
256
257 private void checkDimensionInternal(DiagnosticPosition pos, Type t) {
258 switch (t.getTag()) {
259 case METHOD:
260 checkDimension(pos, t.getReturnType());
261 for (List<Type> args = t.getParameterTypes(); args.nonEmpty(); args = args.tail)
262 checkDimension(pos, args.head);
263 break;
264 case ARRAY:
265 if (types.dimensions(t) > ClassFile.MAX_DIMENSIONS) {
266 log.error(pos, Errors.LimitDimensions);
267 nerrs++;
268 }
269 break;
270 default:
271 break;
272 }
273 }
274
275 /** Create a temporary variable.
276 * @param type The variable's type.
277 */
278 LocalItem makeTemp(Type type) {
279 VarSymbol v = new VarSymbol(Flags.SYNTHETIC,
280 names.empty,
281 type,
282 env.enclMethod.sym);
283 code.newLocal(v);
284 return items.makeLocalItem(v);
285 }
286
287 /** Generate code to call a non-private method or constructor.
288 * @param pos Position to be used for error reporting.
289 * @param site The type of which the method is a member.
290 * @param name The method's name.
291 * @param argtypes The method's argument types.
292 * @param isStatic A flag that indicates whether we call a
293 * static or instance method.
294 */
295 void callMethod(DiagnosticPosition pos,
296 Type site, Name name, List<Type> argtypes,
297 boolean isStatic) {
298 Symbol msym = rs.
299 resolveInternalMethod(pos, attrEnv, site, name, argtypes, null);
300 if (isStatic) items.makeStaticItem(msym).invoke();
301 else items.makeMemberItem(msym, names.isInitOrVNew(name)).invoke();
302 }
303
304 /** Is the given method definition an access method
305 * resulting from a qualified super? This is signified by an odd
306 * access code.
307 */
308 private boolean isAccessSuper(JCMethodDecl enclMethod) {
309 return
310 (enclMethod.mods.flags & SYNTHETIC) != 0 &&
311 isOddAccessName(enclMethod.name);
312 }
313
314 /** Does given name start with "access$" and end in an odd digit?
315 */
316 private boolean isOddAccessName(Name name) {
317 return
318 name.startsWith(accessDollar) &&
319 (name.getByteAt(name.getByteLength() - 1) & 1) == 1;
320 }
321
322 /* ************************************************************************
323 * Non-local exits
324 *************************************************************************/
325
326 /** Generate code to invoke the finalizer associated with given
327 * environment.
328 * Any calls to finalizers are appended to the environments `cont' chain.
329 * Mark beginning of gap in catch all range for finalizer.
330 */
331 void genFinalizer(Env<GenContext> env) {
332 if (code.isAlive() && env.info.finalize != null)
333 env.info.finalize.gen();
334 }
335
336 /** Generate code to call all finalizers of structures aborted by
337 * a non-local
338 * exit. Return target environment of the non-local exit.
339 * @param target The tree representing the structure that's aborted
340 * @param env The environment current at the non-local exit.
341 */
342 Env<GenContext> unwind(JCTree target, Env<GenContext> env) {
343 Env<GenContext> env1 = env;
344 while (true) {
345 genFinalizer(env1);
346 if (env1.tree == target) break;
347 env1 = env1.next;
348 }
349 return env1;
350 }
351
352 /** Mark end of gap in catch-all range for finalizer.
353 * @param env the environment which might contain the finalizer
354 * (if it does, env.info.gaps != null).
355 */
356 void endFinalizerGap(Env<GenContext> env) {
357 if (env.info.gaps != null && env.info.gaps.length() % 2 == 1)
358 env.info.gaps.append(code.curCP());
359 }
360
361 /** Mark end of all gaps in catch-all ranges for finalizers of environments
362 * lying between, and including to two environments.
363 * @param from the most deeply nested environment to mark
364 * @param to the least deeply nested environment to mark
365 */
366 void endFinalizerGaps(Env<GenContext> from, Env<GenContext> to) {
367 Env<GenContext> last = null;
368 while (last != to) {
369 endFinalizerGap(from);
370 last = from;
371 from = from.next;
372 }
373 }
374
375 /** Do any of the structures aborted by a non-local exit have
376 * finalizers that require an empty stack?
377 * @param target The tree representing the structure that's aborted
378 * @param env The environment current at the non-local exit.
379 */
380 boolean hasFinally(JCTree target, Env<GenContext> env) {
381 while (env.tree != target) {
382 if (env.tree.hasTag(TRY) && env.info.finalize.hasFinalizer())
383 return true;
384 env = env.next;
385 }
386 return false;
387 }
388
389 /* ************************************************************************
390 * Normalizing class-members.
391 *************************************************************************/
392
393 /** Distribute member initializer code into constructors and {@code <clinit>}
394 * method.
395 * @param defs The list of class member declarations.
396 * @param c The enclosing class.
397 */
398 List<JCTree> normalizeDefs(List<JCTree> defs, ClassSymbol c) {
399 ListBuffer<JCStatement> initCode = new ListBuffer<>();
400 ListBuffer<Attribute.TypeCompound> initTAs = new ListBuffer<>();
401 ListBuffer<JCStatement> clinitCode = new ListBuffer<>();
402 ListBuffer<Attribute.TypeCompound> clinitTAs = new ListBuffer<>();
403 ListBuffer<JCTree> methodDefs = new ListBuffer<>();
404 // Sort definitions into three listbuffers:
405 // - initCode for instance initializers
406 // - clinitCode for class initializers
407 // - methodDefs for method definitions
408 for (List<JCTree> l = defs; l.nonEmpty(); l = l.tail) {
409 JCTree def = l.head;
410 switch (def.getTag()) {
411 case BLOCK:
412 JCBlock block = (JCBlock)def;
413 if ((block.flags & STATIC) != 0)
414 clinitCode.append(block);
415 else if ((block.flags & SYNTHETIC) == 0)
416 initCode.append(block);
417 break;
418 case METHODDEF:
419 methodDefs.append(def);
420 break;
421 case VARDEF:
422 JCVariableDecl vdef = (JCVariableDecl) def;
423 VarSymbol sym = vdef.sym;
424 checkDimension(vdef.pos(), sym.type);
425 if (vdef.init != null) {
426 if ((sym.flags() & STATIC) == 0) {
427 // Always initialize instance variables.
428 JCStatement init = make.at(vdef.pos()).
429 Assignment(sym, vdef.init);
430 initCode.append(init);
431 endPosTable.replaceTree(vdef, init);
432 initTAs.addAll(getAndRemoveNonFieldTAs(sym));
433 } else if (sym.getConstValue() == null) {
434 // Initialize class (static) variables only if
435 // they are not compile-time constants.
436 JCStatement init = make.at(vdef.pos).
437 Assignment(sym, vdef.init);
438 clinitCode.append(init);
439 endPosTable.replaceTree(vdef, init);
440 clinitTAs.addAll(getAndRemoveNonFieldTAs(sym));
441 } else {
442 checkStringConstant(vdef.init.pos(), sym.getConstValue());
443 /* if the init contains a reference to an external class, add it to the
444 * constant's pool
445 */
446 vdef.init.accept(classReferenceVisitor);
447 }
448 }
449 break;
450 default:
451 Assert.error();
452 }
453 }
454 // Insert any instance initializers into all constructors.
455 if (initCode.length() != 0) {
456 List<JCStatement> inits = initCode.toList();
457 initTAs.addAll(c.getInitTypeAttributes());
458 List<Attribute.TypeCompound> initTAlist = initTAs.toList();
459 for (JCTree t : methodDefs) {
460 normalizeMethod((JCMethodDecl)t, inits, initTAlist);
461 }
462 }
463 // If there are class initializers, create a <clinit> method
464 // that contains them as its body.
465 if (clinitCode.length() != 0) {
466 MethodSymbol clinit = new MethodSymbol(
467 STATIC | (c.flags() & STRICTFP),
468 names.clinit,
469 new MethodType(
470 List.nil(), syms.voidType,
471 List.nil(), syms.methodClass),
472 c);
473 c.members().enter(clinit);
474 List<JCStatement> clinitStats = clinitCode.toList();
475 JCBlock block = make.at(clinitStats.head.pos()).Block(0, clinitStats);
476 block.endpos = TreeInfo.endPos(clinitStats.last());
477 methodDefs.append(make.MethodDef(clinit, block));
478
479 if (!clinitTAs.isEmpty())
480 clinit.appendUniqueTypeAttributes(clinitTAs.toList());
481 if (!c.getClassInitTypeAttributes().isEmpty())
482 clinit.appendUniqueTypeAttributes(c.getClassInitTypeAttributes());
483 }
484 // Return all method definitions.
485 return methodDefs.toList();
486 }
487
488 private List<Attribute.TypeCompound> getAndRemoveNonFieldTAs(VarSymbol sym) {
489 List<TypeCompound> tas = sym.getRawTypeAttributes();
490 ListBuffer<Attribute.TypeCompound> fieldTAs = new ListBuffer<>();
491 ListBuffer<Attribute.TypeCompound> nonfieldTAs = new ListBuffer<>();
492 for (TypeCompound ta : tas) {
493 Assert.check(ta.getPosition().type != TargetType.UNKNOWN);
494 if (ta.getPosition().type == TargetType.FIELD) {
495 fieldTAs.add(ta);
496 } else {
497 nonfieldTAs.add(ta);
498 }
499 }
500 sym.setTypeAttributes(fieldTAs.toList());
501 return nonfieldTAs.toList();
502 }
503
504 /** Check a constant value and report if it is a string that is
505 * too large.
506 */
507 private void checkStringConstant(DiagnosticPosition pos, Object constValue) {
508 if (nerrs != 0 || // only complain about a long string once
509 constValue == null ||
510 !(constValue instanceof String str) ||
511 str.length() < PoolWriter.MAX_STRING_LENGTH)
512 return;
513 log.error(pos, Errors.LimitString);
514 nerrs++;
515 }
516
517 /** Insert instance initializer code into initial constructor.
518 * @param md The tree potentially representing a
519 * constructor's definition.
520 * @param initCode The list of instance initializer statements.
521 * @param initTAs Type annotations from the initializer expression.
522 */
523 void normalizeMethod(JCMethodDecl md, List<JCStatement> initCode, List<TypeCompound> initTAs) {
524 if (names.isInitOrVNew(md.name) && TreeInfo.isInitialConstructor(md)) {
525 // We are seeing a constructor that does not call another
526 // constructor of the same class.
527 List<JCStatement> stats = md.body.stats;
528 ListBuffer<JCStatement> newstats = new ListBuffer<>();
529
530 if (stats.nonEmpty()) {
531 // Copy initializers of synthetic variables generated in
532 // the translation of inner classes.
533 while (TreeInfo.isSyntheticInit(stats.head)) {
534 newstats.append(stats.head);
535 stats = stats.tail;
536 }
537 // Copy superclass constructor call
538 newstats.append(stats.head);
539 stats = stats.tail;
540 // Copy remaining synthetic initializers.
541 while (stats.nonEmpty() &&
542 TreeInfo.isSyntheticInit(stats.head)) {
543 newstats.append(stats.head);
544 stats = stats.tail;
545 }
546 // Now insert the initializer code.
547 newstats.appendList(initCode);
548 // And copy all remaining statements.
549 while (stats.nonEmpty()) {
550 newstats.append(stats.head);
551 stats = stats.tail;
552 }
553 }
554 md.body.stats = newstats.toList();
555 if (md.body.endpos == Position.NOPOS)
556 md.body.endpos = TreeInfo.endPos(md.body.stats.last());
557
558 md.sym.appendUniqueTypeAttributes(initTAs);
559 }
560 }
561
562 /* ************************************************************************
563 * Traversal methods
564 *************************************************************************/
565
566 /** Visitor argument: The current environment.
567 */
568 Env<GenContext> env;
569
570 /** Visitor argument: The expected type (prototype).
571 */
572 Type pt;
573
574 /** Visitor result: The item representing the computed value.
575 */
576 Item result;
577
578 /** Visitor method: generate code for a definition, catching and reporting
579 * any completion failures.
580 * @param tree The definition to be visited.
581 * @param env The environment current at the definition.
582 */
583 public void genDef(JCTree tree, Env<GenContext> env) {
584 Env<GenContext> prevEnv = this.env;
585 try {
586 this.env = env;
587 tree.accept(this);
588 } catch (CompletionFailure ex) {
589 chk.completionError(tree.pos(), ex);
590 } finally {
591 this.env = prevEnv;
592 }
593 }
594
595 /** Derived visitor method: check whether CharacterRangeTable
596 * should be emitted, if so, put a new entry into CRTable
597 * and call method to generate bytecode.
598 * If not, just call method to generate bytecode.
599 * @see #genStat(JCTree, Env)
600 *
601 * @param tree The tree to be visited.
602 * @param env The environment to use.
603 * @param crtFlags The CharacterRangeTable flags
604 * indicating type of the entry.
605 */
606 public void genStat(JCTree tree, Env<GenContext> env, int crtFlags) {
607 if (!genCrt) {
608 genStat(tree, env);
609 return;
610 }
611 int startpc = code.curCP();
612 genStat(tree, env);
613 if (tree.hasTag(Tag.BLOCK)) crtFlags |= CRT_BLOCK;
614 code.crt.put(tree, crtFlags, startpc, code.curCP());
615 }
616
617 /** Derived visitor method: generate code for a statement.
618 */
619 public void genStat(JCTree tree, Env<GenContext> env) {
620 if (code.isAlive()) {
621 code.statBegin(tree.pos);
622 genDef(tree, env);
623 } else if (env.info.isSwitch && tree.hasTag(VARDEF)) {
624 // variables whose declarations are in a switch
625 // can be used even if the decl is unreachable.
626 code.newLocal(((JCVariableDecl) tree).sym);
627 }
628 }
629
630 /** Derived visitor method: check whether CharacterRangeTable
631 * should be emitted, if so, put a new entry into CRTable
632 * and call method to generate bytecode.
633 * If not, just call method to generate bytecode.
634 * @see #genStats(List, Env)
635 *
636 * @param trees The list of trees to be visited.
637 * @param env The environment to use.
638 * @param crtFlags The CharacterRangeTable flags
639 * indicating type of the entry.
640 */
641 public void genStats(List<JCStatement> trees, Env<GenContext> env, int crtFlags) {
642 if (!genCrt) {
643 genStats(trees, env);
644 return;
645 }
646 if (trees.length() == 1) { // mark one statement with the flags
647 genStat(trees.head, env, crtFlags | CRT_STATEMENT);
648 } else {
649 int startpc = code.curCP();
650 genStats(trees, env);
651 code.crt.put(trees, crtFlags, startpc, code.curCP());
652 }
653 }
654
655 /** Derived visitor method: generate code for a list of statements.
656 */
657 public void genStats(List<? extends JCTree> trees, Env<GenContext> env) {
658 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
659 genStat(l.head, env, CRT_STATEMENT);
660 }
661
662 /** Derived visitor method: check whether CharacterRangeTable
663 * should be emitted, if so, put a new entry into CRTable
664 * and call method to generate bytecode.
665 * If not, just call method to generate bytecode.
666 * @see #genCond(JCTree,boolean)
667 *
668 * @param tree The tree to be visited.
669 * @param crtFlags The CharacterRangeTable flags
670 * indicating type of the entry.
671 */
672 public CondItem genCond(JCTree tree, int crtFlags) {
673 if (!genCrt) return genCond(tree, false);
674 int startpc = code.curCP();
675 CondItem item = genCond(tree, (crtFlags & CRT_FLOW_CONTROLLER) != 0);
676 code.crt.put(tree, crtFlags, startpc, code.curCP());
677 return item;
678 }
679
680 /** Derived visitor method: generate code for a boolean
681 * expression in a control-flow context.
682 * @param _tree The expression to be visited.
683 * @param markBranches The flag to indicate that the condition is
684 * a flow controller so produced conditions
685 * should contain a proper tree to generate
686 * CharacterRangeTable branches for them.
687 */
688 public CondItem genCond(JCTree _tree, boolean markBranches) {
689 JCTree inner_tree = TreeInfo.skipParens(_tree);
690 if (inner_tree.hasTag(CONDEXPR)) {
691 JCConditional tree = (JCConditional)inner_tree;
692 CondItem cond = genCond(tree.cond, CRT_FLOW_CONTROLLER);
693 if (cond.isTrue()) {
694 code.resolve(cond.trueJumps);
695 CondItem result = genCond(tree.truepart, CRT_FLOW_TARGET);
696 if (markBranches) result.tree = tree.truepart;
697 return result;
698 }
699 if (cond.isFalse()) {
700 code.resolve(cond.falseJumps);
701 CondItem result = genCond(tree.falsepart, CRT_FLOW_TARGET);
702 if (markBranches) result.tree = tree.falsepart;
703 return result;
704 }
705 Chain secondJumps = cond.jumpFalse();
706 code.resolve(cond.trueJumps);
707 CondItem first = genCond(tree.truepart, CRT_FLOW_TARGET);
708 if (markBranches) first.tree = tree.truepart;
709 Chain falseJumps = first.jumpFalse();
710 code.resolve(first.trueJumps);
711 Chain trueJumps = code.branch(goto_);
712 code.resolve(secondJumps);
713 CondItem second = genCond(tree.falsepart, CRT_FLOW_TARGET);
714 CondItem result = items.makeCondItem(second.opcode,
715 Code.mergeChains(trueJumps, second.trueJumps),
716 Code.mergeChains(falseJumps, second.falseJumps));
717 if (markBranches) result.tree = tree.falsepart;
718 return result;
719 } else if (inner_tree.hasTag(SWITCH_EXPRESSION)) {
720 code.resolvePending();
721
722 boolean prevInCondSwitchExpression = inCondSwitchExpression;
723 Chain prevSwitchExpressionTrueChain = switchExpressionTrueChain;
724 Chain prevSwitchExpressionFalseChain = switchExpressionFalseChain;
725 try {
726 inCondSwitchExpression = true;
727 switchExpressionTrueChain = null;
728 switchExpressionFalseChain = null;
729 try {
730 doHandleSwitchExpression((JCSwitchExpression) inner_tree);
731 } catch (CompletionFailure ex) {
732 chk.completionError(_tree.pos(), ex);
733 code.state.stacksize = 1;
734 }
735 CondItem result = items.makeCondItem(goto_,
736 switchExpressionTrueChain,
737 switchExpressionFalseChain);
738 if (markBranches) result.tree = _tree;
739 return result;
740 } finally {
741 inCondSwitchExpression = prevInCondSwitchExpression;
742 switchExpressionTrueChain = prevSwitchExpressionTrueChain;
743 switchExpressionFalseChain = prevSwitchExpressionFalseChain;
744 }
745 } else if (inner_tree.hasTag(LETEXPR) && ((LetExpr) inner_tree).needsCond) {
746 code.resolvePending();
747
748 LetExpr tree = (LetExpr) inner_tree;
749 int limit = code.nextreg;
750 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
751 try {
752 genStats(tree.defs, env);
753 } finally {
754 code.setLetExprStackPos(prevLetExprStart);
755 }
756 CondItem result = genCond(tree.expr, markBranches);
757 code.endScopes(limit);
758 return result;
759 } else {
760 CondItem result = genExpr(_tree, syms.booleanType).mkCond();
761 if (markBranches) result.tree = _tree;
762 return result;
763 }
764 }
765
766 public Code getCode() {
767 return code;
768 }
769
770 public Items getItems() {
771 return items;
772 }
773
774 public Env<AttrContext> getAttrEnv() {
775 return attrEnv;
776 }
777
778 /** Visitor class for expressions which might be constant expressions.
779 * This class is a subset of TreeScanner. Intended to visit trees pruned by
780 * Lower as long as constant expressions looking for references to any
781 * ClassSymbol. Any such reference will be added to the constant pool so
782 * automated tools can detect class dependencies better.
783 */
784 class ClassReferenceVisitor extends JCTree.Visitor {
785
786 @Override
787 public void visitTree(JCTree tree) {}
788
789 @Override
790 public void visitBinary(JCBinary tree) {
791 tree.lhs.accept(this);
792 tree.rhs.accept(this);
793 }
794
795 @Override
796 public void visitSelect(JCFieldAccess tree) {
797 if (tree.selected.type.hasTag(CLASS)) {
798 makeRef(tree.selected.pos(), tree.selected.type);
799 }
800 }
801
802 @Override
803 public void visitIdent(JCIdent tree) {
804 if (tree.sym.owner instanceof ClassSymbol classSymbol) {
805 poolWriter.putClass(classSymbol);
806 }
807 }
808
809 @Override
810 public void visitConditional(JCConditional tree) {
811 tree.cond.accept(this);
812 tree.truepart.accept(this);
813 tree.falsepart.accept(this);
814 }
815
816 @Override
817 public void visitUnary(JCUnary tree) {
818 tree.arg.accept(this);
819 }
820
821 @Override
822 public void visitParens(JCParens tree) {
823 tree.expr.accept(this);
824 }
825
826 @Override
827 public void visitTypeCast(JCTypeCast tree) {
828 tree.expr.accept(this);
829 }
830 }
831
832 private ClassReferenceVisitor classReferenceVisitor = new ClassReferenceVisitor();
833
834 /** Visitor method: generate code for an expression, catching and reporting
835 * any completion failures.
836 * @param tree The expression to be visited.
837 * @param pt The expression's expected type (proto-type).
838 */
839 public Item genExpr(JCTree tree, Type pt) {
840 if (!code.isAlive()) {
841 return items.makeStackItem(pt);
842 }
843
844 Type prevPt = this.pt;
845 try {
846 if (tree.type.constValue() != null) {
847 // Short circuit any expressions which are constants
848 tree.accept(classReferenceVisitor);
849 checkStringConstant(tree.pos(), tree.type.constValue());
850 Symbol sym = TreeInfo.symbol(tree);
851 if (sym != null && isConstantDynamic(sym)) {
852 result = items.makeDynamicItem(sym);
853 } else {
854 result = items.makeImmediateItem(tree.type, tree.type.constValue());
855 }
856 } else {
857 this.pt = pt;
858 tree.accept(this);
859 }
860 return result.coerce(pt);
861 } catch (CompletionFailure ex) {
862 chk.completionError(tree.pos(), ex);
863 code.state.stacksize = 1;
864 return items.makeStackItem(pt);
865 } finally {
866 this.pt = prevPt;
867 }
868 }
869
870 public boolean isConstantDynamic(Symbol sym) {
871 return sym.kind == VAR &&
872 sym instanceof DynamicVarSymbol dynamicVarSymbol &&
873 dynamicVarSymbol.isDynamic();
874 }
875
876 /** Derived visitor method: generate code for a list of method arguments.
877 * @param trees The argument expressions to be visited.
878 * @param pts The expression's expected types (i.e. the formal parameter
879 * types of the invoked method).
880 */
881 public void genArgs(List<JCExpression> trees, List<Type> pts) {
882 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail) {
883 genExpr(l.head, pts.head).load();
884 pts = pts.tail;
885 }
886 // require lists be of same length
887 Assert.check(pts.isEmpty());
888 }
889
890 /* ************************************************************************
891 * Visitor methods for statements and definitions
892 *************************************************************************/
893
894 /** Thrown when the byte code size exceeds limit.
895 */
896 public static class CodeSizeOverflow extends RuntimeException {
897 private static final long serialVersionUID = 0;
898 public CodeSizeOverflow() {}
899 }
900
901 public void visitMethodDef(JCMethodDecl tree) {
902 // Create a new local environment that points pack at method
903 // definition.
904 Env<GenContext> localEnv = env.dup(tree);
905 localEnv.enclMethod = tree;
906 // The expected type of every return statement in this method
907 // is the method's return type.
908 this.pt = tree.sym.erasure(types).getReturnType();
909
910 checkDimension(tree.pos(), tree.sym.erasure(types));
911 genMethod(tree, localEnv, false);
912 }
913 //where
914 /** Generate code for a method.
915 * @param tree The tree representing the method definition.
916 * @param env The environment current for the method body.
917 * @param fatcode A flag that indicates whether all jumps are
918 * within 32K. We first invoke this method under
919 * the assumption that fatcode == false, i.e. all
920 * jumps are within 32K. If this fails, fatcode
921 * is set to true and we try again.
922 */
923 void genMethod(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
924 MethodSymbol meth = tree.sym;
925 int extras = 0;
926 // Count up extra parameters
927 if (meth.isInitOrVNew()) {
928 extras++;
929 if (meth.enclClass().isInner() &&
930 !meth.enclClass().isStatic()) {
931 extras++;
932 }
933 } else if ((tree.mods.flags & STATIC) == 0) {
934 extras++;
935 }
936 // System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG
937 if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes()) + extras >
938 ClassFile.MAX_PARAMETERS) {
939 log.error(tree.pos(), Errors.LimitParameters);
940 nerrs++;
941 }
942
943 else if (tree.body != null) {
944 // Create a new code structure and initialize it.
945 int startpcCrt = initCode(tree, env, fatcode);
946
947 try {
948 genStat(tree.body, env);
949 } catch (CodeSizeOverflow e) {
950 // Failed due to code limit, try again with jsr/ret
951 startpcCrt = initCode(tree, env, fatcode);
952 genStat(tree.body, env);
953 }
954
955 if (code.state.stacksize != 0) {
956 log.error(tree.body.pos(), Errors.StackSimError(tree.sym));
957 throw new AssertionError();
958 }
959
960 // If last statement could complete normally, insert a
961 // return at the end.
962 if (code.isAlive()) {
963 code.statBegin(TreeInfo.endPos(tree.body));
964 if (env.enclMethod == null ||
965 env.enclMethod.sym.type.getReturnType().hasTag(VOID)) {
966 code.emitop0(return_);
967 } else if (env.enclMethod.sym.isValueObjectFactory()) {
968 items.makeLocalItem(env.enclMethod.factoryProduct).load();
969 code.emitop0(areturn);
970 } else {
971 // sometime dead code seems alive (4415991);
972 // generate a small loop instead
973 int startpc = code.entryPoint();
974 CondItem c = items.makeCondItem(goto_);
975 code.resolve(c.jumpTrue(), startpc);
976 }
977 }
978 if (genCrt)
979 code.crt.put(tree.body,
980 CRT_BLOCK,
981 startpcCrt,
982 code.curCP());
983
984 code.endScopes(0);
985
986 // If we exceeded limits, panic
987 if (code.checkLimits(tree.pos(), log)) {
988 nerrs++;
989 return;
990 }
991
992 // If we generated short code but got a long jump, do it again
993 // with fatCode = true.
994 if (!fatcode && code.fatcode) genMethod(tree, env, true);
995
996 // Clean up
997 if(stackMap == StackMapFormat.JSR202) {
998 code.lastFrame = null;
999 code.frameBeforeLast = null;
1000 }
1001
1002 // Compress exception table
1003 code.compressCatchTable();
1004
1005 // Fill in type annotation positions for exception parameters
1006 code.fillExceptionParameterPositions();
1007 }
1008 }
1009
1010 private int initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
1011 MethodSymbol meth = tree.sym;
1012
1013 // Create a new code structure.
1014 meth.code = code = new Code(meth,
1015 fatcode,
1016 lineDebugInfo ? toplevel.lineMap : null,
1017 varDebugInfo,
1018 stackMap,
1019 debugCode,
1020 genCrt ? new CRTable(tree, env.toplevel.endPositions)
1021 : null,
1022 syms,
1023 types,
1024 poolWriter,
1025 allowPrimitiveClasses);
1026 items = new Items(poolWriter, code, syms, types);
1027 if (code.debugCode) {
1028 System.err.println(meth + " for body " + tree);
1029 }
1030
1031 // If method is not static, create a new local variable address
1032 // for `this'.
1033 if ((tree.mods.flags & STATIC) == 0) {
1034 Type selfType = meth.owner.type;
1035 if (meth.isInitOrVNew() && selfType != syms.objectType)
1036 selfType = UninitializedType.uninitializedThis(selfType);
1037 code.setDefined(
1038 code.newLocal(
1039 new VarSymbol(FINAL, names._this, selfType, meth.owner)));
1040 }
1041
1042 // Mark all parameters as defined from the beginning of
1043 // the method.
1044 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
1045 checkDimension(l.head.pos(), l.head.sym.type);
1046 code.setDefined(code.newLocal(l.head.sym));
1047 }
1048
1049 // Get ready to generate code for method body.
1050 int startpcCrt = genCrt ? code.curCP() : 0;
1051 code.entryPoint();
1052
1053 // Suppress initial stackmap
1054 code.pendingStackMap = false;
1055
1056 return startpcCrt;
1057 }
1058
1059 public void visitVarDef(JCVariableDecl tree) {
1060 VarSymbol v = tree.sym;
1061 if (tree.init != null) {
1062 checkStringConstant(tree.init.pos(), v.getConstValue());
1063 if (v.getConstValue() == null || varDebugInfo) {
1064 Assert.check(code.isStatementStart());
1065 code.newLocal(v);
1066 genExpr(tree.init, v.erasure(types)).load();
1067 items.makeLocalItem(v).store();
1068 Assert.check(code.isStatementStart());
1069 }
1070 } else {
1071 code.newLocal(v);
1072 }
1073 checkDimension(tree.pos(), v.type);
1074 Type localType = v.erasure(types);
1075 if (localType.requiresPreload(env.enclClass.sym)) {
1076 poolWriter.enterPreloadClass((ClassSymbol) localType.tsym);
1077 }
1078 }
1079
1080 public void visitSkip(JCSkip tree) {
1081 }
1082
1083 public void visitBlock(JCBlock tree) {
1084 if (tree.patternMatchingCatch != null) {
1085 Set<JCMethodInvocation> prevInvocationsWithPatternMatchingCatch = invocationsWithPatternMatchingCatch;
1086 ListBuffer<int[]> prevRanges = patternMatchingInvocationRanges;
1087 State startState = code.state.dup();
1088 try {
1089 invocationsWithPatternMatchingCatch = tree.patternMatchingCatch.calls2Handle();
1090 patternMatchingInvocationRanges = new ListBuffer<>();
1091 doVisitBlock(tree);
1092 } finally {
1093 Chain skipCatch = code.branch(goto_);
1094 JCCatch handler = tree.patternMatchingCatch.handler();
1095 code.entryPoint(startState, handler.param.sym.type);
1096 genPatternMatchingCatch(handler, env, patternMatchingInvocationRanges.toList());
1097 code.resolve(skipCatch);
1098 invocationsWithPatternMatchingCatch = prevInvocationsWithPatternMatchingCatch;
1099 patternMatchingInvocationRanges = prevRanges;
1100 }
1101 } else {
1102 doVisitBlock(tree);
1103 }
1104 }
1105
1106 private void doVisitBlock(JCBlock tree) {
1107 int limit = code.nextreg;
1108 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1109 genStats(tree.stats, localEnv);
1110 // End the scope of all block-local variables in variable info.
1111 if (!env.tree.hasTag(METHODDEF)) {
1112 code.statBegin(tree.endpos);
1113 code.endScopes(limit);
1114 code.pendingStatPos = Position.NOPOS;
1115 }
1116 }
1117
1118 public void visitDoLoop(JCDoWhileLoop tree) {
1119 genLoop(tree, tree.body, tree.cond, List.nil(), false);
1120 }
1121
1122 public void visitWhileLoop(JCWhileLoop tree) {
1123 genLoop(tree, tree.body, tree.cond, List.nil(), true);
1124 }
1125
1126 public void visitWithField(JCWithField tree) {
1127 switch(tree.field.getTag()) {
1128 case IDENT:
1129 Symbol sym = ((JCIdent) tree.field).sym;
1130 items.makeThisItem().load();
1131 genExpr(tree.value, tree.field.type).load();
1132 sym = types.binaryQualifier(sym, env.enclClass.type);
1133 code.emitop2(withfield, sym, PoolWriter::putMember);
1134 result = items.makeStackItem(tree.type);
1135 break;
1136 case SELECT:
1137 JCFieldAccess fieldAccess = (JCFieldAccess) tree.field;
1138 sym = TreeInfo.symbol(fieldAccess);
1139 // JDK-8207332: To maintain the order of side effects, must compute value ahead of field
1140 genExpr(tree.value, tree.field.type).load();
1141 genExpr(fieldAccess.selected, fieldAccess.selected.type).load();
1142 if (Code.width(tree.field.type) == 2) {
1143 code.emitop0(dup_x2);
1144 code.emitop0(pop);
1145 } else {
1146 code.emitop0(swap);
1147 }
1148 sym = types.binaryQualifier(sym, fieldAccess.selected.type);
1149 code.emitop2(withfield, sym, PoolWriter::putMember);
1150 result = items.makeStackItem(tree.type);
1151 break;
1152 default:
1153 Assert.check(false);
1154 }
1155 }
1156
1157 public void visitForLoop(JCForLoop tree) {
1158 int limit = code.nextreg;
1159 genStats(tree.init, env);
1160 genLoop(tree, tree.body, tree.cond, tree.step, true);
1161 code.endScopes(limit);
1162 }
1163 //where
1164 /** Generate code for a loop.
1165 * @param loop The tree representing the loop.
1166 * @param body The loop's body.
1167 * @param cond The loop's controlling condition.
1168 * @param step "Step" statements to be inserted at end of
1169 * each iteration.
1170 * @param testFirst True if the loop test belongs before the body.
1171 */
1172 private void genLoop(JCStatement loop,
1173 JCStatement body,
1174 JCExpression cond,
1175 List<JCExpressionStatement> step,
1176 boolean testFirst) {
1177 Env<GenContext> loopEnv = env.dup(loop, new GenContext());
1178 int startpc = code.entryPoint();
1179 if (testFirst) { //while or for loop
1180 CondItem c;
1181 if (cond != null) {
1182 code.statBegin(cond.pos);
1183 Assert.check(code.isStatementStart());
1184 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1185 } else {
1186 c = items.makeCondItem(goto_);
1187 }
1188 Chain loopDone = c.jumpFalse();
1189 code.resolve(c.trueJumps);
1190 Assert.check(code.isStatementStart());
1191 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1192 code.resolve(loopEnv.info.cont);
1193 genStats(step, loopEnv);
1194 code.resolve(code.branch(goto_), startpc);
1195 code.resolve(loopDone);
1196 } else {
1197 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1198 code.resolve(loopEnv.info.cont);
1199 genStats(step, loopEnv);
1200 if (code.isAlive()) {
1201 CondItem c;
1202 if (cond != null) {
1203 code.statBegin(cond.pos);
1204 Assert.check(code.isStatementStart());
1205 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1206 } else {
1207 c = items.makeCondItem(goto_);
1208 }
1209 code.resolve(c.jumpTrue(), startpc);
1210 Assert.check(code.isStatementStart());
1211 code.resolve(c.falseJumps);
1212 }
1213 }
1214 Chain exit = loopEnv.info.exit;
1215 if (exit != null) {
1216 code.resolve(exit);
1217 exit.state.defined.excludeFrom(code.nextreg);
1218 }
1219 }
1220
1221 public void visitForeachLoop(JCEnhancedForLoop tree) {
1222 throw new AssertionError(); // should have been removed by Lower.
1223 }
1224
1225 public void visitLabelled(JCLabeledStatement tree) {
1226 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1227 genStat(tree.body, localEnv, CRT_STATEMENT);
1228 Chain exit = localEnv.info.exit;
1229 if (exit != null) {
1230 code.resolve(exit);
1231 exit.state.defined.excludeFrom(code.nextreg);
1232 }
1233 }
1234
1235 public void visitSwitch(JCSwitch tree) {
1236 handleSwitch(tree, tree.selector, tree.cases, tree.patternSwitch);
1237 }
1238
1239 @Override
1240 public void visitSwitchExpression(JCSwitchExpression tree) {
1241 code.resolvePending();
1242 boolean prevInCondSwitchExpression = inCondSwitchExpression;
1243 try {
1244 inCondSwitchExpression = false;
1245 doHandleSwitchExpression(tree);
1246 } finally {
1247 inCondSwitchExpression = prevInCondSwitchExpression;
1248 }
1249 result = items.makeStackItem(pt);
1250 }
1251
1252 private void doHandleSwitchExpression(JCSwitchExpression tree) {
1253 List<LocalItem> prevStackBeforeSwitchExpression = stackBeforeSwitchExpression;
1254 LocalItem prevSwitchResult = switchResult;
1255 int limit = code.nextreg;
1256 try {
1257 stackBeforeSwitchExpression = List.nil();
1258 switchResult = null;
1259 if (hasTry(tree)) {
1260 //if the switch expression contains try-catch, the catch handlers need to have
1261 //an empty stack. So stash whole stack to local variables, and restore it before
1262 //breaks:
1263 while (code.state.stacksize > 0) {
1264 Type type = code.state.peek();
1265 Name varName = names.fromString(target.syntheticNameChar() +
1266 "stack" +
1267 target.syntheticNameChar() +
1268 tree.pos +
1269 target.syntheticNameChar() +
1270 code.state.stacksize);
1271 VarSymbol var = new VarSymbol(Flags.SYNTHETIC, varName, type,
1272 this.env.enclMethod.sym);
1273 LocalItem item = items.new LocalItem(type, code.newLocal(var));
1274 stackBeforeSwitchExpression = stackBeforeSwitchExpression.prepend(item);
1275 item.store();
1276 }
1277 switchResult = makeTemp(tree.type);
1278 }
1279 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
1280 try {
1281 handleSwitch(tree, tree.selector, tree.cases, tree.patternSwitch);
1282 } finally {
1283 code.setLetExprStackPos(prevLetExprStart);
1284 }
1285 } finally {
1286 stackBeforeSwitchExpression = prevStackBeforeSwitchExpression;
1287 switchResult = prevSwitchResult;
1288 code.endScopes(limit);
1289 }
1290 }
1291 //where:
1292 private boolean hasTry(JCSwitchExpression tree) {
1293 boolean[] hasTry = new boolean[1];
1294 new TreeScanner() {
1295 @Override
1296 public void visitTry(JCTry tree) {
1297 hasTry[0] = true;
1298 }
1299
1300 @Override
1301 public void visitClassDef(JCClassDecl tree) {
1302 }
1303
1304 @Override
1305 public void visitLambda(JCLambda tree) {
1306 }
1307 }.scan(tree);
1308 return hasTry[0];
1309 }
1310
1311 private void handleSwitch(JCTree swtch, JCExpression selector, List<JCCase> cases,
1312 boolean patternSwitch) {
1313 int limit = code.nextreg;
1314 Assert.check(!selector.type.hasTag(CLASS));
1315 int switchStart = patternSwitch ? code.entryPoint() : -1;
1316 int startpcCrt = genCrt ? code.curCP() : 0;
1317 Assert.check(code.isStatementStart());
1318 Item sel = genExpr(selector, syms.intType);
1319 if (cases.isEmpty()) {
1320 // We are seeing: switch <sel> {}
1321 sel.load().drop();
1322 if (genCrt)
1323 code.crt.put(TreeInfo.skipParens(selector),
1324 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1325 } else {
1326 // We are seeing a nonempty switch.
1327 sel.load();
1328 if (genCrt)
1329 code.crt.put(TreeInfo.skipParens(selector),
1330 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1331 Env<GenContext> switchEnv = env.dup(swtch, new GenContext());
1332 switchEnv.info.isSwitch = true;
1333
1334 // Compute number of labels and minimum and maximum label values.
1335 // For each case, store its label in an array.
1336 int lo = Integer.MAX_VALUE; // minimum label.
1337 int hi = Integer.MIN_VALUE; // maximum label.
1338 int nlabels = 0; // number of labels.
1339
1340 int[] labels = new int[cases.length()]; // the label array.
1341 int defaultIndex = -1; // the index of the default clause.
1342
1343 List<JCCase> l = cases;
1344 for (int i = 0; i < labels.length; i++) {
1345 if (l.head.labels.head instanceof JCConstantCaseLabel constLabel) {
1346 Assert.check(l.head.labels.size() == 1);
1347 int val = ((Number) constLabel.expr.type.constValue()).intValue();
1348 labels[i] = val;
1349 if (val < lo) lo = val;
1350 if (hi < val) hi = val;
1351 nlabels++;
1352 } else {
1353 Assert.check(defaultIndex == -1);
1354 defaultIndex = i;
1355 }
1356 l = l.tail;
1357 }
1358
1359 // Determine whether to issue a tableswitch or a lookupswitch
1360 // instruction.
1361 long table_space_cost = 4 + ((long) hi - lo + 1); // words
1362 long table_time_cost = 3; // comparisons
1363 long lookup_space_cost = 3 + 2 * (long) nlabels;
1364 long lookup_time_cost = nlabels;
1365 int opcode =
1366 nlabels > 0 &&
1367 table_space_cost + 3 * table_time_cost <=
1368 lookup_space_cost + 3 * lookup_time_cost
1369 ?
1370 tableswitch : lookupswitch;
1371
1372 int startpc = code.curCP(); // the position of the selector operation
1373 code.emitop0(opcode);
1374 code.align(4);
1375 int tableBase = code.curCP(); // the start of the jump table
1376 int[] offsets = null; // a table of offsets for a lookupswitch
1377 code.emit4(-1); // leave space for default offset
1378 if (opcode == tableswitch) {
1379 code.emit4(lo); // minimum label
1380 code.emit4(hi); // maximum label
1381 for (long i = lo; i <= hi; i++) { // leave space for jump table
1382 code.emit4(-1);
1383 }
1384 } else {
1385 code.emit4(nlabels); // number of labels
1386 for (int i = 0; i < nlabels; i++) {
1387 code.emit4(-1); code.emit4(-1); // leave space for lookup table
1388 }
1389 offsets = new int[labels.length];
1390 }
1391 Code.State stateSwitch = code.state.dup();
1392 code.markDead();
1393
1394 // For each case do:
1395 l = cases;
1396 for (int i = 0; i < labels.length; i++) {
1397 JCCase c = l.head;
1398 l = l.tail;
1399
1400 int pc = code.entryPoint(stateSwitch);
1401 // Insert offset directly into code or else into the
1402 // offsets table.
1403 if (i != defaultIndex) {
1404 if (opcode == tableswitch) {
1405 code.put4(
1406 tableBase + 4 * (labels[i] - lo + 3),
1407 pc - startpc);
1408 } else {
1409 offsets[i] = pc - startpc;
1410 }
1411 } else {
1412 code.put4(tableBase, pc - startpc);
1413 }
1414
1415 // Generate code for the statements in this case.
1416 genStats(c.stats, switchEnv, CRT_FLOW_TARGET);
1417 }
1418
1419 if (switchEnv.info.cont != null) {
1420 Assert.check(patternSwitch);
1421 code.resolve(switchEnv.info.cont, switchStart);
1422 }
1423
1424 // Resolve all breaks.
1425 Chain exit = switchEnv.info.exit;
1426 if (exit != null) {
1427 code.resolve(exit);
1428 exit.state.defined.excludeFrom(limit);
1429 }
1430
1431 // If we have not set the default offset, we do so now.
1432 if (code.get4(tableBase) == -1) {
1433 code.put4(tableBase, code.entryPoint(stateSwitch) - startpc);
1434 }
1435
1436 if (opcode == tableswitch) {
1437 // Let any unfilled slots point to the default case.
1438 int defaultOffset = code.get4(tableBase);
1439 for (long i = lo; i <= hi; i++) {
1440 int t = (int)(tableBase + 4 * (i - lo + 3));
1441 if (code.get4(t) == -1)
1442 code.put4(t, defaultOffset);
1443 }
1444 } else {
1445 // Sort non-default offsets and copy into lookup table.
1446 if (defaultIndex >= 0)
1447 for (int i = defaultIndex; i < labels.length - 1; i++) {
1448 labels[i] = labels[i+1];
1449 offsets[i] = offsets[i+1];
1450 }
1451 if (nlabels > 0)
1452 qsort2(labels, offsets, 0, nlabels - 1);
1453 for (int i = 0; i < nlabels; i++) {
1454 int caseidx = tableBase + 8 * (i + 1);
1455 code.put4(caseidx, labels[i]);
1456 code.put4(caseidx + 4, offsets[i]);
1457 }
1458 }
1459 }
1460 code.endScopes(limit);
1461 }
1462 //where
1463 /** Sort (int) arrays of keys and values
1464 */
1465 static void qsort2(int[] keys, int[] values, int lo, int hi) {
1466 int i = lo;
1467 int j = hi;
1468 int pivot = keys[(i+j)/2];
1469 do {
1470 while (keys[i] < pivot) i++;
1471 while (pivot < keys[j]) j--;
1472 if (i <= j) {
1473 int temp1 = keys[i];
1474 keys[i] = keys[j];
1475 keys[j] = temp1;
1476 int temp2 = values[i];
1477 values[i] = values[j];
1478 values[j] = temp2;
1479 i++;
1480 j--;
1481 }
1482 } while (i <= j);
1483 if (lo < j) qsort2(keys, values, lo, j);
1484 if (i < hi) qsort2(keys, values, i, hi);
1485 }
1486
1487 public void visitSynchronized(JCSynchronized tree) {
1488 int limit = code.nextreg;
1489 // Generate code to evaluate lock and save in temporary variable.
1490 final LocalItem lockVar = makeTemp(syms.objectType);
1491 Assert.check(code.isStatementStart());
1492 genExpr(tree.lock, tree.lock.type).load().duplicate();
1493 lockVar.store();
1494
1495 // Generate code to enter monitor.
1496 code.emitop0(monitorenter);
1497 code.state.lock(lockVar.reg);
1498
1499 // Generate code for a try statement with given body, no catch clauses
1500 // in a new environment with the "exit-monitor" operation as finalizer.
1501 final Env<GenContext> syncEnv = env.dup(tree, new GenContext());
1502 syncEnv.info.finalize = new GenFinalizer() {
1503 void gen() {
1504 genLast();
1505 Assert.check(syncEnv.info.gaps.length() % 2 == 0);
1506 syncEnv.info.gaps.append(code.curCP());
1507 }
1508 void genLast() {
1509 if (code.isAlive()) {
1510 lockVar.load();
1511 code.emitop0(monitorexit);
1512 code.state.unlock(lockVar.reg);
1513 }
1514 }
1515 };
1516 syncEnv.info.gaps = new ListBuffer<>();
1517 genTry(tree.body, List.nil(), syncEnv);
1518 code.endScopes(limit);
1519 }
1520
1521 public void visitTry(final JCTry tree) {
1522 // Generate code for a try statement with given body and catch clauses,
1523 // in a new environment which calls the finally block if there is one.
1524 final Env<GenContext> tryEnv = env.dup(tree, new GenContext());
1525 final Env<GenContext> oldEnv = env;
1526 tryEnv.info.finalize = new GenFinalizer() {
1527 void gen() {
1528 Assert.check(tryEnv.info.gaps.length() % 2 == 0);
1529 tryEnv.info.gaps.append(code.curCP());
1530 genLast();
1531 }
1532 void genLast() {
1533 if (tree.finalizer != null)
1534 genStat(tree.finalizer, oldEnv, CRT_BLOCK);
1535 }
1536 boolean hasFinalizer() {
1537 return tree.finalizer != null;
1538 }
1539
1540 @Override
1541 void afterBody() {
1542 if (tree.finalizer != null && (tree.finalizer.flags & BODY_ONLY_FINALIZE) != 0) {
1543 //for body-only finally, remove the GenFinalizer after try body
1544 //so that the finally is not generated to catch bodies:
1545 tryEnv.info.finalize = null;
1546 }
1547 }
1548
1549 };
1550 tryEnv.info.gaps = new ListBuffer<>();
1551 genTry(tree.body, tree.catchers, tryEnv);
1552 }
1553 //where
1554 /** Generate code for a try or synchronized statement
1555 * @param body The body of the try or synchronized statement.
1556 * @param catchers The list of catch clauses.
1557 * @param env The current environment of the body.
1558 */
1559 void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) {
1560 int limit = code.nextreg;
1561 int startpc = code.curCP();
1562 Code.State stateTry = code.state.dup();
1563 genStat(body, env, CRT_BLOCK);
1564 int endpc = code.curCP();
1565 List<Integer> gaps = env.info.gaps.toList();
1566 code.statBegin(TreeInfo.endPos(body));
1567 genFinalizer(env);
1568 code.statBegin(TreeInfo.endPos(env.tree));
1569 Chain exitChain;
1570 boolean actualTry = env.tree.hasTag(TRY);
1571 if (startpc == endpc && actualTry) {
1572 exitChain = code.branch(dontgoto);
1573 } else {
1574 exitChain = code.branch(goto_);
1575 }
1576 endFinalizerGap(env);
1577 env.info.finalize.afterBody();
1578 boolean hasFinalizer =
1579 env.info.finalize != null &&
1580 env.info.finalize.hasFinalizer();
1581 if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) {
1582 // start off with exception on stack
1583 code.entryPoint(stateTry, l.head.param.sym.type);
1584 genCatch(l.head, env, startpc, endpc, gaps);
1585 genFinalizer(env);
1586 if (hasFinalizer || l.tail.nonEmpty()) {
1587 code.statBegin(TreeInfo.endPos(env.tree));
1588 exitChain = Code.mergeChains(exitChain,
1589 code.branch(goto_));
1590 }
1591 endFinalizerGap(env);
1592 }
1593 if (hasFinalizer && (startpc != endpc || !actualTry)) {
1594 // Create a new register segment to avoid allocating
1595 // the same variables in finalizers and other statements.
1596 code.newRegSegment();
1597
1598 // Add a catch-all clause.
1599
1600 // start off with exception on stack
1601 int catchallpc = code.entryPoint(stateTry, syms.throwableType);
1602
1603 // Register all exception ranges for catch all clause.
1604 // The range of the catch all clause is from the beginning
1605 // of the try or synchronized block until the present
1606 // code pointer excluding all gaps in the current
1607 // environment's GenContext.
1608 int startseg = startpc;
1609 while (env.info.gaps.nonEmpty()) {
1610 int endseg = env.info.gaps.next().intValue();
1611 registerCatch(body.pos(), startseg, endseg,
1612 catchallpc, 0);
1613 startseg = env.info.gaps.next().intValue();
1614 }
1615 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1616 code.markStatBegin();
1617
1618 Item excVar = makeTemp(syms.throwableType);
1619 excVar.store();
1620 genFinalizer(env);
1621 code.resolvePending();
1622 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.END_POS));
1623 code.markStatBegin();
1624
1625 excVar.load();
1626 registerCatch(body.pos(), startseg,
1627 env.info.gaps.next().intValue(),
1628 catchallpc, 0);
1629 code.emitop0(athrow);
1630 code.markDead();
1631
1632 // If there are jsr's to this finalizer, ...
1633 if (env.info.cont != null) {
1634 // Resolve all jsr's.
1635 code.resolve(env.info.cont);
1636
1637 // Mark statement line number
1638 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1639 code.markStatBegin();
1640
1641 // Save return address.
1642 LocalItem retVar = makeTemp(syms.throwableType);
1643 retVar.store();
1644
1645 // Generate finalizer code.
1646 env.info.finalize.genLast();
1647
1648 // Return.
1649 code.emitop1w(ret, retVar.reg);
1650 code.markDead();
1651 }
1652 }
1653 // Resolve all breaks.
1654 code.resolve(exitChain);
1655
1656 code.endScopes(limit);
1657 }
1658
1659 /** Generate code for a catch clause.
1660 * @param tree The catch clause.
1661 * @param env The environment current in the enclosing try.
1662 * @param startpc Start pc of try-block.
1663 * @param endpc End pc of try-block.
1664 */
1665 void genCatch(JCCatch tree,
1666 Env<GenContext> env,
1667 int startpc, int endpc,
1668 List<Integer> gaps) {
1669 if (startpc != endpc) {
1670 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypeExprs
1671 = catchTypesWithAnnotations(tree);
1672 while (gaps.nonEmpty()) {
1673 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) {
1674 JCExpression subCatch = subCatch1.snd;
1675 int catchType = makeRef(tree.pos(), subCatch.type);
1676 int end = gaps.head.intValue();
1677 registerCatch(tree.pos(),
1678 startpc, end, code.curCP(),
1679 catchType);
1680 for (Attribute.TypeCompound tc : subCatch1.fst) {
1681 tc.position.setCatchInfo(catchType, startpc);
1682 }
1683 }
1684 gaps = gaps.tail;
1685 startpc = gaps.head.intValue();
1686 gaps = gaps.tail;
1687 }
1688 if (startpc < endpc) {
1689 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) {
1690 JCExpression subCatch = subCatch1.snd;
1691 int catchType = makeRef(tree.pos(), subCatch.type);
1692 registerCatch(tree.pos(),
1693 startpc, endpc, code.curCP(),
1694 catchType);
1695 for (Attribute.TypeCompound tc : subCatch1.fst) {
1696 tc.position.setCatchInfo(catchType, startpc);
1697 }
1698 }
1699 }
1700 genCatchBlock(tree, env);
1701 }
1702 }
1703 void genPatternMatchingCatch(JCCatch tree,
1704 Env<GenContext> env,
1705 List<int[]> ranges) {
1706 for (int[] range : ranges) {
1707 JCExpression subCatch = tree.param.vartype;
1708 int catchType = makeRef(tree.pos(), subCatch.type);
1709 registerCatch(tree.pos(),
1710 range[0], range[1], code.curCP(),
1711 catchType);
1712 }
1713 genCatchBlock(tree, env);
1714 }
1715 void genCatchBlock(JCCatch tree, Env<GenContext> env) {
1716 VarSymbol exparam = tree.param.sym;
1717 code.statBegin(tree.pos);
1718 code.markStatBegin();
1719 int limit = code.nextreg;
1720 code.newLocal(exparam);
1721 items.makeLocalItem(exparam).store();
1722 code.statBegin(TreeInfo.firstStatPos(tree.body));
1723 genStat(tree.body, env, CRT_BLOCK);
1724 code.endScopes(limit);
1725 code.statBegin(TreeInfo.endPos(tree.body));
1726 }
1727 // where
1728 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotations(JCCatch tree) {
1729 return TreeInfo.isMultiCatch(tree) ?
1730 catchTypesWithAnnotationsFromMulticatch((JCTypeUnion)tree.param.vartype, tree.param.sym.getRawTypeAttributes()) :
1731 List.of(new Pair<>(tree.param.sym.getRawTypeAttributes(), tree.param.vartype));
1732 }
1733 // where
1734 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotationsFromMulticatch(JCTypeUnion tree, List<TypeCompound> first) {
1735 List<JCExpression> alts = tree.alternatives;
1736 List<Pair<List<TypeCompound>, JCExpression>> res = List.of(new Pair<>(first, alts.head));
1737 alts = alts.tail;
1738
1739 while(alts != null && alts.head != null) {
1740 JCExpression alt = alts.head;
1741 if (alt instanceof JCAnnotatedType annotatedType) {
1742 res = res.prepend(new Pair<>(annotate.fromAnnotations(annotatedType.annotations), alt));
1743 } else {
1744 res = res.prepend(new Pair<>(List.nil(), alt));
1745 }
1746 alts = alts.tail;
1747 }
1748 return res.reverse();
1749 }
1750
1751 /** Register a catch clause in the "Exceptions" code-attribute.
1752 */
1753 void registerCatch(DiagnosticPosition pos,
1754 int startpc, int endpc,
1755 int handler_pc, int catch_type) {
1756 char startpc1 = (char)startpc;
1757 char endpc1 = (char)endpc;
1758 char handler_pc1 = (char)handler_pc;
1759 if (startpc1 == startpc &&
1760 endpc1 == endpc &&
1761 handler_pc1 == handler_pc) {
1762 code.addCatch(startpc1, endpc1, handler_pc1,
1763 (char)catch_type);
1764 } else {
1765 log.error(pos, Errors.LimitCodeTooLargeForTryStmt);
1766 nerrs++;
1767 }
1768 }
1769
1770 public void visitIf(JCIf tree) {
1771 int limit = code.nextreg;
1772 Chain thenExit = null;
1773 Assert.check(code.isStatementStart());
1774 CondItem c = genCond(TreeInfo.skipParens(tree.cond),
1775 CRT_FLOW_CONTROLLER);
1776 Chain elseChain = c.jumpFalse();
1777 Assert.check(code.isStatementStart());
1778 if (!c.isFalse()) {
1779 code.resolve(c.trueJumps);
1780 genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET);
1781 thenExit = code.branch(goto_);
1782 }
1783 if (elseChain != null) {
1784 code.resolve(elseChain);
1785 if (tree.elsepart != null) {
1786 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET);
1787 }
1788 }
1789 code.resolve(thenExit);
1790 code.endScopes(limit);
1791 Assert.check(code.isStatementStart());
1792 }
1793
1794 public void visitExec(JCExpressionStatement tree) {
1795 // Optimize x++ to ++x and x-- to --x.
1796 JCExpression e = tree.expr;
1797 switch (e.getTag()) {
1798 case POSTINC:
1799 ((JCUnary) e).setTag(PREINC);
1800 break;
1801 case POSTDEC:
1802 ((JCUnary) e).setTag(PREDEC);
1803 break;
1804 }
1805 Assert.check(code.isStatementStart());
1806 genExpr(tree.expr, tree.expr.type).drop();
1807 Assert.check(code.isStatementStart());
1808 }
1809
1810 public void visitBreak(JCBreak tree) {
1811 Assert.check(code.isStatementStart());
1812 final Env<GenContext> targetEnv = unwindBreak(tree.target);
1813 targetEnv.info.addExit(code.branch(goto_));
1814 endFinalizerGaps(env, targetEnv);
1815 }
1816
1817 public void visitYield(JCYield tree) {
1818 Assert.check(code.isStatementStart());
1819 final Env<GenContext> targetEnv;
1820 if (inCondSwitchExpression) {
1821 CondItem value = genCond(tree.value, CRT_FLOW_TARGET);
1822 Chain falseJumps = value.jumpFalse();
1823
1824 code.resolve(value.trueJumps);
1825 Env<GenContext> localEnv = unwindBreak(tree.target);
1826 reloadStackBeforeSwitchExpr();
1827 Chain trueJumps = code.branch(goto_);
1828
1829 endFinalizerGaps(env, localEnv);
1830
1831 code.resolve(falseJumps);
1832 targetEnv = unwindBreak(tree.target);
1833 reloadStackBeforeSwitchExpr();
1834 falseJumps = code.branch(goto_);
1835
1836 if (switchExpressionTrueChain == null) {
1837 switchExpressionTrueChain = trueJumps;
1838 } else {
1839 switchExpressionTrueChain =
1840 Code.mergeChains(switchExpressionTrueChain, trueJumps);
1841 }
1842 if (switchExpressionFalseChain == null) {
1843 switchExpressionFalseChain = falseJumps;
1844 } else {
1845 switchExpressionFalseChain =
1846 Code.mergeChains(switchExpressionFalseChain, falseJumps);
1847 }
1848 } else {
1849 genExpr(tree.value, pt).load();
1850 if (switchResult != null)
1851 switchResult.store();
1852
1853 targetEnv = unwindBreak(tree.target);
1854
1855 if (code.isAlive()) {
1856 reloadStackBeforeSwitchExpr();
1857 if (switchResult != null)
1858 switchResult.load();
1859
1860 code.state.forceStackTop(tree.target.type);
1861 targetEnv.info.addExit(code.branch(goto_));
1862 code.markDead();
1863 }
1864 }
1865 endFinalizerGaps(env, targetEnv);
1866 }
1867 //where:
1868 /** As side-effect, might mark code as dead disabling any further emission.
1869 */
1870 private Env<GenContext> unwindBreak(JCTree target) {
1871 int tmpPos = code.pendingStatPos;
1872 Env<GenContext> targetEnv = unwind(target, env);
1873 code.pendingStatPos = tmpPos;
1874 return targetEnv;
1875 }
1876
1877 private void reloadStackBeforeSwitchExpr() {
1878 for (LocalItem li : stackBeforeSwitchExpression)
1879 li.load();
1880 }
1881
1882 public void visitContinue(JCContinue tree) {
1883 int tmpPos = code.pendingStatPos;
1884 Env<GenContext> targetEnv = unwind(tree.target, env);
1885 code.pendingStatPos = tmpPos;
1886 Assert.check(code.isStatementStart());
1887 targetEnv.info.addCont(code.branch(goto_));
1888 endFinalizerGaps(env, targetEnv);
1889 }
1890
1891 public void visitReturn(JCReturn tree) {
1892 int limit = code.nextreg;
1893 final Env<GenContext> targetEnv;
1894
1895 /* Save and then restore the location of the return in case a finally
1896 * is expanded (with unwind()) in the middle of our bytecodes.
1897 */
1898 int tmpPos = code.pendingStatPos;
1899 if (tree.expr != null) {
1900 Assert.check(code.isStatementStart());
1901 Item r = genExpr(tree.expr, pt).load();
1902 if (hasFinally(env.enclMethod, env)) {
1903 r = makeTemp(pt);
1904 r.store();
1905 }
1906 targetEnv = unwind(env.enclMethod, env);
1907 code.pendingStatPos = tmpPos;
1908 r.load();
1909 code.emitop0(ireturn + Code.truncate(Code.typecode(pt)));
1910 } else {
1911 targetEnv = unwind(env.enclMethod, env);
1912 code.pendingStatPos = tmpPos;
1913 code.emitop0(return_);
1914 }
1915 endFinalizerGaps(env, targetEnv);
1916 code.endScopes(limit);
1917 }
1918
1919 public void visitThrow(JCThrow tree) {
1920 Assert.check(code.isStatementStart());
1921 genExpr(tree.expr, tree.expr.type).load();
1922 code.emitop0(athrow);
1923 Assert.check(code.isStatementStart());
1924 }
1925
1926 /* ************************************************************************
1927 * Visitor methods for expressions
1928 *************************************************************************/
1929
1930 public void visitApply(JCMethodInvocation tree) {
1931 setTypeAnnotationPositions(tree.pos);
1932 // Generate code for method.
1933 Item m = genExpr(tree.meth, methodType);
1934 // Generate code for all arguments, where the expected types are
1935 // the parameters of the method's external type (that is, any implicit
1936 // outer instance of a super(...) call appears as first parameter).
1937 MethodSymbol msym = (MethodSymbol)TreeInfo.symbol(tree.meth);
1938 genArgs(tree.args,
1939 msym.externalType(types).getParameterTypes());
1940 if (!msym.isDynamic()) {
1941 code.statBegin(tree.pos);
1942 }
1943 if (invocationsWithPatternMatchingCatch.contains(tree)) {
1944 int start = code.curCP();
1945 result = m.invoke();
1946 patternMatchingInvocationRanges.add(new int[] {start, code.curCP()});
1947 } else {
1948 result = m.invoke();
1949 }
1950 }
1951
1952 public void visitConditional(JCConditional tree) {
1953 Chain thenExit = null;
1954 code.statBegin(tree.cond.pos);
1955 CondItem c = genCond(tree.cond, CRT_FLOW_CONTROLLER);
1956 Chain elseChain = c.jumpFalse();
1957 if (!c.isFalse()) {
1958 code.resolve(c.trueJumps);
1959 int startpc = genCrt ? code.curCP() : 0;
1960 code.statBegin(tree.truepart.pos);
1961 genExpr(tree.truepart, pt).load();
1962 code.state.forceStackTop(tree.type);
1963 if (genCrt) code.crt.put(tree.truepart, CRT_FLOW_TARGET,
1964 startpc, code.curCP());
1965 thenExit = code.branch(goto_);
1966 }
1967 if (elseChain != null) {
1968 code.resolve(elseChain);
1969 int startpc = genCrt ? code.curCP() : 0;
1970 code.statBegin(tree.falsepart.pos);
1971 genExpr(tree.falsepart, pt).load();
1972 code.state.forceStackTop(tree.type);
1973 if (genCrt) code.crt.put(tree.falsepart, CRT_FLOW_TARGET,
1974 startpc, code.curCP());
1975 }
1976 code.resolve(thenExit);
1977 result = items.makeStackItem(pt);
1978 }
1979
1980 private void setTypeAnnotationPositions(int treePos) {
1981 MethodSymbol meth = code.meth;
1982 boolean initOrClinit = code.meth.getKind() == javax.lang.model.element.ElementKind.CONSTRUCTOR
1983 || code.meth.getKind() == javax.lang.model.element.ElementKind.STATIC_INIT;
1984
1985 for (Attribute.TypeCompound ta : meth.getRawTypeAttributes()) {
1986 if (ta.hasUnknownPosition())
1987 ta.tryFixPosition();
1988
1989 if (ta.position.matchesPos(treePos))
1990 ta.position.updatePosOffset(code.cp);
1991 }
1992
1993 if (!initOrClinit)
1994 return;
1995
1996 for (Attribute.TypeCompound ta : meth.owner.getRawTypeAttributes()) {
1997 if (ta.hasUnknownPosition())
1998 ta.tryFixPosition();
1999
2000 if (ta.position.matchesPos(treePos))
2001 ta.position.updatePosOffset(code.cp);
2002 }
2003
2004 ClassSymbol clazz = meth.enclClass();
2005 for (Symbol s : new com.sun.tools.javac.model.FilteredMemberList(clazz.members())) {
2006 if (!s.getKind().isField())
2007 continue;
2008
2009 for (Attribute.TypeCompound ta : s.getRawTypeAttributes()) {
2010 if (ta.hasUnknownPosition())
2011 ta.tryFixPosition();
2012
2013 if (ta.position.matchesPos(treePos))
2014 ta.position.updatePosOffset(code.cp);
2015 }
2016 }
2017 }
2018
2019 public void visitNewClass(JCNewClass tree) {
2020 // Enclosing instances or anonymous classes should have been eliminated
2021 // by now.
2022 Assert.check(tree.encl == null && tree.def == null);
2023 setTypeAnnotationPositions(tree.pos);
2024
2025 code.emitop2(new_, checkDimension(tree.pos(), tree.type), PoolWriter::putClass);
2026 code.emitop0(dup);
2027
2028 // Generate code for all arguments, where the expected types are
2029 // the parameters of the constructor's external type (that is,
2030 // any implicit outer instance appears as first parameter).
2031 genArgs(tree.args, tree.constructor.externalType(types).getParameterTypes());
2032
2033 items.makeMemberItem(tree.constructor, true).invoke();
2034 result = items.makeStackItem(tree.type);
2035 }
2036
2037 public void visitNewArray(JCNewArray tree) {
2038 setTypeAnnotationPositions(tree.pos);
2039
2040 if (tree.elems != null) {
2041 Type elemtype = types.elemtype(tree.type);
2042 loadIntConst(tree.elems.length());
2043 Item arr = makeNewArray(tree.pos(), tree.type, 1);
2044 int i = 0;
2045 for (List<JCExpression> l = tree.elems; l.nonEmpty(); l = l.tail) {
2046 arr.duplicate();
2047 loadIntConst(i);
2048 i++;
2049 genExpr(l.head, elemtype).load();
2050 items.makeIndexedItem(elemtype).store();
2051 }
2052 result = arr;
2053 } else {
2054 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
2055 genExpr(l.head, syms.intType).load();
2056 }
2057 result = makeNewArray(tree.pos(), tree.type, tree.dims.length());
2058 }
2059 }
2060 //where
2061 /** Generate code to create an array with given element type and number
2062 * of dimensions.
2063 */
2064 Item makeNewArray(DiagnosticPosition pos, Type type, int ndims) {
2065 Type elemtype = types.elemtype(type);
2066 if (types.dimensions(type) > ClassFile.MAX_DIMENSIONS) {
2067 log.error(pos, Errors.LimitDimensions);
2068 nerrs++;
2069 }
2070 int elemcode = Code.arraycode(elemtype);
2071 if (elemcode == 0 || (elemcode == 1 && ndims == 1)) {
2072 code.emitAnewarray(makeRef(pos, elemtype, elemtype.isPrimitiveClass()), type);
2073 } else if (elemcode == 1) {
2074 code.emitMultianewarray(ndims, makeRef(pos, type), type);
2075 } else {
2076 code.emitNewarray(elemcode, type);
2077 }
2078 return items.makeStackItem(type);
2079 }
2080
2081 public void visitParens(JCParens tree) {
2082 result = genExpr(tree.expr, tree.expr.type);
2083 }
2084
2085 public void visitAssign(JCAssign tree) {
2086 Item l = genExpr(tree.lhs, tree.lhs.type);
2087 genExpr(tree.rhs, tree.lhs.type).load();
2088 if (tree.rhs.type.hasTag(BOT)) {
2089 /* This is just a case of widening reference conversion that per 5.1.5 simply calls
2090 for "regarding a reference as having some other type in a manner that can be proved
2091 correct at compile time."
2092 */
2093 code.state.forceStackTop(tree.lhs.type);
2094 }
2095 result = items.makeAssignItem(l);
2096 }
2097
2098 public void visitAssignop(JCAssignOp tree) {
2099 OperatorSymbol operator = tree.operator;
2100 Item l;
2101 if (operator.opcode == string_add) {
2102 l = concat.makeConcat(tree);
2103 } else {
2104 // Generate code for first expression
2105 l = genExpr(tree.lhs, tree.lhs.type);
2106
2107 // If we have an increment of -32768 to +32767 of a local
2108 // int variable we can use an incr instruction instead of
2109 // proceeding further.
2110 if ((tree.hasTag(PLUS_ASG) || tree.hasTag(MINUS_ASG)) &&
2111 l instanceof LocalItem localItem &&
2112 tree.lhs.type.getTag().isSubRangeOf(INT) &&
2113 tree.rhs.type.getTag().isSubRangeOf(INT) &&
2114 tree.rhs.type.constValue() != null) {
2115 int ival = ((Number) tree.rhs.type.constValue()).intValue();
2116 if (tree.hasTag(MINUS_ASG)) ival = -ival;
2117 localItem.incr(ival);
2118 result = l;
2119 return;
2120 }
2121 // Otherwise, duplicate expression, load one copy
2122 // and complete binary operation.
2123 l.duplicate();
2124 l.coerce(operator.type.getParameterTypes().head).load();
2125 completeBinop(tree.lhs, tree.rhs, operator).coerce(tree.lhs.type);
2126 }
2127 result = items.makeAssignItem(l);
2128 }
2129
2130 public void visitUnary(JCUnary tree) {
2131 OperatorSymbol operator = tree.operator;
2132 if (tree.hasTag(NOT)) {
2133 CondItem od = genCond(tree.arg, false);
2134 result = od.negate();
2135 } else {
2136 Item od = genExpr(tree.arg, operator.type.getParameterTypes().head);
2137 switch (tree.getTag()) {
2138 case POS:
2139 result = od.load();
2140 break;
2141 case NEG:
2142 result = od.load();
2143 code.emitop0(operator.opcode);
2144 break;
2145 case COMPL:
2146 result = od.load();
2147 emitMinusOne(od.typecode);
2148 code.emitop0(operator.opcode);
2149 break;
2150 case PREINC: case PREDEC:
2151 od.duplicate();
2152 if (od instanceof LocalItem localItem &&
2153 (operator.opcode == iadd || operator.opcode == isub)) {
2154 localItem.incr(tree.hasTag(PREINC) ? 1 : -1);
2155 result = od;
2156 } else {
2157 od.load();
2158 code.emitop0(one(od.typecode));
2159 code.emitop0(operator.opcode);
2160 // Perform narrowing primitive conversion if byte,
2161 // char, or short. Fix for 4304655.
2162 if (od.typecode != INTcode &&
2163 Code.truncate(od.typecode) == INTcode)
2164 code.emitop0(int2byte + od.typecode - BYTEcode);
2165 result = items.makeAssignItem(od);
2166 }
2167 break;
2168 case POSTINC: case POSTDEC:
2169 od.duplicate();
2170 if (od instanceof LocalItem localItem &&
2171 (operator.opcode == iadd || operator.opcode == isub)) {
2172 Item res = od.load();
2173 localItem.incr(tree.hasTag(POSTINC) ? 1 : -1);
2174 result = res;
2175 } else {
2176 Item res = od.load();
2177 od.stash(od.typecode);
2178 code.emitop0(one(od.typecode));
2179 code.emitop0(operator.opcode);
2180 // Perform narrowing primitive conversion if byte,
2181 // char, or short. Fix for 4304655.
2182 if (od.typecode != INTcode &&
2183 Code.truncate(od.typecode) == INTcode)
2184 code.emitop0(int2byte + od.typecode - BYTEcode);
2185 od.store();
2186 result = res;
2187 }
2188 break;
2189 case NULLCHK:
2190 result = od.load();
2191 code.emitop0(dup);
2192 genNullCheck(tree);
2193 break;
2194 default:
2195 Assert.error();
2196 }
2197 }
2198 }
2199
2200 /** Generate a null check from the object value at stack top. */
2201 private void genNullCheck(JCTree tree) {
2202 code.statBegin(tree.pos);
2203 callMethod(tree.pos(), syms.objectsType, names.requireNonNull,
2204 List.of(syms.objectType), true);
2205 code.emitop0(pop);
2206 }
2207
2208 public void visitBinary(JCBinary tree) {
2209 OperatorSymbol operator = tree.operator;
2210 if (operator.opcode == string_add) {
2211 result = concat.makeConcat(tree);
2212 } else if (tree.hasTag(AND)) {
2213 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2214 if (!lcond.isFalse()) {
2215 Chain falseJumps = lcond.jumpFalse();
2216 code.resolve(lcond.trueJumps);
2217 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2218 result = items.
2219 makeCondItem(rcond.opcode,
2220 rcond.trueJumps,
2221 Code.mergeChains(falseJumps,
2222 rcond.falseJumps));
2223 } else {
2224 result = lcond;
2225 }
2226 } else if (tree.hasTag(OR)) {
2227 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2228 if (!lcond.isTrue()) {
2229 Chain trueJumps = lcond.jumpTrue();
2230 code.resolve(lcond.falseJumps);
2231 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2232 result = items.
2233 makeCondItem(rcond.opcode,
2234 Code.mergeChains(trueJumps, rcond.trueJumps),
2235 rcond.falseJumps);
2236 } else {
2237 result = lcond;
2238 }
2239 } else {
2240 Item od = genExpr(tree.lhs, operator.type.getParameterTypes().head);
2241 od.load();
2242 result = completeBinop(tree.lhs, tree.rhs, operator);
2243 }
2244 }
2245
2246
2247 /** Complete generating code for operation, with left operand
2248 * already on stack.
2249 * @param lhs The tree representing the left operand.
2250 * @param rhs The tree representing the right operand.
2251 * @param operator The operator symbol.
2252 */
2253 Item completeBinop(JCTree lhs, JCTree rhs, OperatorSymbol operator) {
2254 MethodType optype = (MethodType)operator.type;
2255 int opcode = operator.opcode;
2256 if (opcode >= if_icmpeq && opcode <= if_icmple &&
2257 rhs.type.constValue() instanceof Number number &&
2258 number.intValue() == 0) {
2259 opcode = opcode + (ifeq - if_icmpeq);
2260 } else if (opcode >= if_acmpeq && opcode <= if_acmpne &&
2261 TreeInfo.isNull(rhs)) {
2262 opcode = opcode + (if_acmp_null - if_acmpeq);
2263 } else {
2264 // The expected type of the right operand is
2265 // the second parameter type of the operator, except for
2266 // shifts with long shiftcount, where we convert the opcode
2267 // to a short shift and the expected type to int.
2268 Type rtype = operator.erasure(types).getParameterTypes().tail.head;
2269 if (opcode >= ishll && opcode <= lushrl) {
2270 opcode = opcode + (ishl - ishll);
2271 rtype = syms.intType;
2272 }
2273 // Generate code for right operand and load.
2274 genExpr(rhs, rtype).load();
2275 // If there are two consecutive opcode instructions,
2276 // emit the first now.
2277 if (opcode >= (1 << preShift)) {
2278 code.emitop0(opcode >> preShift);
2279 opcode = opcode & 0xFF;
2280 }
2281 }
2282 if (opcode >= ifeq && opcode <= if_acmpne ||
2283 opcode == if_acmp_null || opcode == if_acmp_nonnull) {
2284 return items.makeCondItem(opcode);
2285 } else {
2286 code.emitop0(opcode);
2287 return items.makeStackItem(optype.restype);
2288 }
2289 }
2290
2291 public void visitTypeCast(JCTypeCast tree) {
2292 result = genExpr(tree.expr, tree.clazz.type).load();
2293 setTypeAnnotationPositions(tree.pos);
2294 // Additional code is only needed if we cast to a reference type
2295 // which is not statically a supertype of the expression's type.
2296 // For basic types, the coerce(...) in genExpr(...) will do
2297 // the conversion.
2298 // primitive reference conversion is a nop when we bifurcate the primitive class, as the VM sees a subtyping relationship.
2299 if (!tree.clazz.type.isPrimitive() &&
2300 !types.isSameType(tree.expr.type, tree.clazz.type) &&
2301 (!tree.clazz.type.isReferenceProjection() || !types.isSameType(tree.clazz.type.valueProjection(), tree.expr.type) || true) &&
2302 !types.isSubtype(tree.expr.type, tree.clazz.type)) {
2303 checkDimension(tree.pos(), tree.clazz.type);
2304 if (tree.clazz.type.isPrimitiveClass()) {
2305 code.emitop2(checkcast, new ConstantPoolQType(tree.clazz.type, types), PoolWriter::putClass);
2306 } else {
2307 code.emitop2(checkcast, tree.clazz.type, PoolWriter::putClass);
2308 }
2309
2310 }
2311 }
2312
2313 public void visitWildcard(JCWildcard tree) {
2314 throw new AssertionError(this.getClass().getName());
2315 }
2316
2317 public void visitTypeTest(JCInstanceOf tree) {
2318 genExpr(tree.expr, tree.expr.type).load();
2319 setTypeAnnotationPositions(tree.pos);
2320 code.emitop2(instanceof_, makeRef(tree.pos(), tree.pattern.type));
2321 result = items.makeStackItem(syms.booleanType);
2322 }
2323
2324 public void visitIndexed(JCArrayAccess tree) {
2325 genExpr(tree.indexed, tree.indexed.type).load();
2326 genExpr(tree.index, syms.intType).load();
2327 result = items.makeIndexedItem(tree.type);
2328 }
2329
2330 public void visitIdent(JCIdent tree) {
2331 Symbol sym = tree.sym;
2332 if (tree.name == names._this || tree.name == names._super) {
2333 Item res = tree.name == names._this
2334 ? items.makeThisItem()
2335 : items.makeSuperItem();
2336 if (sym.kind == MTH) {
2337 // Generate code to address the constructor.
2338 res.load();
2339 res = items.makeMemberItem(sym, true);
2340 }
2341 result = res;
2342 } else if (isInvokeDynamic(sym) || isConstantDynamic(sym)) {
2343 if (isConstantDynamic(sym)) {
2344 setTypeAnnotationPositions(tree.pos);
2345 }
2346 result = items.makeDynamicItem(sym);
2347 } else if (sym.kind == VAR && (sym.owner.kind == MTH || sym.owner.kind == VAR)) {
2348 result = items.makeLocalItem((VarSymbol)sym);
2349 } else if ((sym.flags() & STATIC) != 0) {
2350 if (!isAccessSuper(env.enclMethod))
2351 sym = types.binaryQualifier(sym, env.enclClass.type);
2352 result = items.makeStaticItem(sym);
2353 } else {
2354 items.makeThisItem().load();
2355 sym = types.binaryQualifier(sym, env.enclClass.type);
2356 result = items.makeMemberItem(sym, nonVirtualForPrivateAccess(sym));
2357 }
2358 }
2359
2360 //where
2361 private boolean nonVirtualForPrivateAccess(Symbol sym) {
2362 boolean useVirtual = target.hasVirtualPrivateInvoke() &&
2363 !disableVirtualizedPrivateInvoke;
2364 return !useVirtual && ((sym.flags() & PRIVATE) != 0);
2365 }
2366
2367 public void visitSelect(JCFieldAccess tree) {
2368 Symbol sym = tree.sym;
2369
2370 if (tree.name == names._class) {
2371 code.emitLdc((LoadableConstant) tree.selected.type, makeRef(tree.pos(), tree.selected.type, tree.selected.type.isPrimitiveClass()));
2372 result = items.makeStackItem(pt);
2373 return;
2374 }
2375
2376 Symbol ssym = TreeInfo.symbol(tree.selected);
2377
2378 // Are we selecting via super?
2379 boolean selectSuper =
2380 ssym != null && (ssym.kind == TYP || ssym.name == names._super);
2381
2382 // Are we accessing a member of the superclass in an access method
2383 // resulting from a qualified super?
2384 boolean accessSuper = isAccessSuper(env.enclMethod);
2385
2386 Item base = (selectSuper)
2387 ? items.makeSuperItem()
2388 : genExpr(tree.selected, tree.selected.type);
2389
2390 if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) {
2391 // We are seeing a variable that is constant but its selecting
2392 // expression is not.
2393 if ((sym.flags() & STATIC) != 0) {
2394 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2395 base = base.load();
2396 base.drop();
2397 } else {
2398 base.load();
2399 genNullCheck(tree.selected);
2400 }
2401 result = items.
2402 makeImmediateItem(sym.type, ((VarSymbol) sym).getConstValue());
2403 } else {
2404 if (isInvokeDynamic(sym)) {
2405 result = items.makeDynamicItem(sym);
2406 return;
2407 } else {
2408 sym = types.binaryQualifier(sym, tree.selected.type);
2409 }
2410 if ((sym.flags() & STATIC) != 0) {
2411 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2412 base = base.load();
2413 base.drop();
2414 result = items.makeStaticItem(sym);
2415 } else {
2416 base.load();
2417 if (sym == syms.lengthVar) {
2418 code.emitop0(arraylength);
2419 result = items.makeStackItem(syms.intType);
2420 } else {
2421 result = items.
2422 makeMemberItem(sym,
2423 nonVirtualForPrivateAccess(sym) ||
2424 selectSuper || accessSuper);
2425 }
2426 }
2427 }
2428 }
2429
2430 public void visitDefaultValue(JCDefaultValue tree) {
2431 if (tree.type.isValueClass()) {
2432 code.emitop2(aconst_init, checkDimension(tree.pos(), tree.type), PoolWriter::putClass);
2433 } else if (tree.type.isReference()) {
2434 code.emitop0(aconst_null);
2435 } else {
2436 code.emitop0(zero(Code.typecode(tree.type)));
2437 }
2438 result = items.makeStackItem(tree.type);
2439 return;
2440 }
2441
2442 public boolean isInvokeDynamic(Symbol sym) {
2443 return sym.kind == MTH && ((MethodSymbol)sym).isDynamic();
2444 }
2445
2446 public void visitLiteral(JCLiteral tree) {
2447 if (tree.type.hasTag(BOT)) {
2448 code.emitop0(aconst_null);
2449 result = items.makeStackItem(tree.type);
2450 }
2451 else
2452 result = items.makeImmediateItem(tree.type, tree.value);
2453 }
2454
2455 public void visitLetExpr(LetExpr tree) {
2456 code.resolvePending();
2457
2458 int limit = code.nextreg;
2459 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
2460 try {
2461 genStats(tree.defs, env);
2462 } finally {
2463 code.setLetExprStackPos(prevLetExprStart);
2464 }
2465 result = genExpr(tree.expr, tree.expr.type).load();
2466 code.endScopes(limit);
2467 }
2468
2469 private void generateReferencesToPrunedTree(ClassSymbol classSymbol) {
2470 List<JCTree> prunedInfo = lower.prunedTree.get(classSymbol);
2471 if (prunedInfo != null) {
2472 for (JCTree prunedTree: prunedInfo) {
2473 prunedTree.accept(classReferenceVisitor);
2474 }
2475 }
2476 }
2477
2478 /* ************************************************************************
2479 * main method
2480 *************************************************************************/
2481
2482 /** Generate code for a class definition.
2483 * @param env The attribution environment that belongs to the
2484 * outermost class containing this class definition.
2485 * We need this for resolving some additional symbols.
2486 * @param cdef The tree representing the class definition.
2487 * @return True if code is generated with no errors.
2488 */
2489 public boolean genClass(Env<AttrContext> env, JCClassDecl cdef) {
2490 try {
2491 attrEnv = env;
2492 ClassSymbol c = cdef.sym;
2493 this.toplevel = env.toplevel;
2494 this.endPosTable = toplevel.endPositions;
2495 /* method normalizeDefs() can add references to external classes into the constant pool
2496 */
2497 cdef.defs = normalizeDefs(cdef.defs, c);
2498 cdef = transValues.translateTopLevelClass(cdef, make);
2499 generateReferencesToPrunedTree(c);
2500 Env<GenContext> localEnv = new Env<>(cdef, new GenContext());
2501 localEnv.toplevel = env.toplevel;
2502 localEnv.enclClass = cdef;
2503
2504 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2505 genDef(l.head, localEnv);
2506 }
2507 if (poolWriter.size() > PoolWriter.MAX_ENTRIES) {
2508 log.error(cdef.pos(), Errors.LimitPool);
2509 nerrs++;
2510 }
2511 if (nerrs != 0) {
2512 // if errors, discard code
2513 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2514 if (l.head.hasTag(METHODDEF))
2515 ((JCMethodDecl) l.head).sym.code = null;
2516 }
2517 }
2518 cdef.defs = List.nil(); // discard trees
2519 return nerrs == 0;
2520 } finally {
2521 // note: this method does NOT support recursion.
2522 attrEnv = null;
2523 this.env = null;
2524 toplevel = null;
2525 endPosTable = null;
2526 nerrs = 0;
2527 types.clearQualifiedSymbolCache();
2528 }
2529 }
2530
2531 /* ************************************************************************
2532 * Auxiliary classes
2533 *************************************************************************/
2534
2535 /** An abstract class for finalizer generation.
2536 */
2537 abstract class GenFinalizer {
2538 /** Generate code to clean up when unwinding. */
2539 abstract void gen();
2540
2541 /** Generate code to clean up at last. */
2542 abstract void genLast();
2543
2544 /** Does this finalizer have some nontrivial cleanup to perform? */
2545 boolean hasFinalizer() { return true; }
2546
2547 /** Should be invoked after the try's body has been visited. */
2548 void afterBody() {}
2549 }
2550
2551 /** code generation contexts,
2552 * to be used as type parameter for environments.
2553 */
2554 static class GenContext {
2555
2556 /** A chain for all unresolved jumps that exit the current environment.
2557 */
2558 Chain exit = null;
2559
2560 /** A chain for all unresolved jumps that continue in the
2561 * current environment.
2562 */
2563 Chain cont = null;
2564
2565 /** A closure that generates the finalizer of the current environment.
2566 * Only set for Synchronized and Try contexts.
2567 */
2568 GenFinalizer finalize = null;
2569
2570 /** Is this a switch statement? If so, allocate registers
2571 * even when the variable declaration is unreachable.
2572 */
2573 boolean isSwitch = false;
2574
2575 /** A list buffer containing all gaps in the finalizer range,
2576 * where a catch all exception should not apply.
2577 */
2578 ListBuffer<Integer> gaps = null;
2579
2580 /** Add given chain to exit chain.
2581 */
2582 void addExit(Chain c) {
2583 exit = Code.mergeChains(c, exit);
2584 }
2585
2586 /** Add given chain to cont chain.
2587 */
2588 void addCont(Chain c) {
2589 cont = Code.mergeChains(c, cont);
2590 }
2591 }
2592
2593 }