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 protected static final Context.Key<Gen> genKey = new Context.Key<>();
68
69 private final Log log;
70 private final Symtab syms;
71 private final Check chk;
72 private final Resolve rs;
73 private final TreeMaker make;
74 private final Names names;
75 private final Target target;
76 private final String accessDollar;
77 private final Types types;
78 private final Lower lower;
79 private final Annotate annotate;
80 private final StringConcat concat;
81
82 /** Format of stackmap tables to be generated. */
83 private final Code.StackMapFormat stackMap;
84
85 /** A type that serves as the expected type for all method expressions.
86 */
87 private final Type methodType;
88
89 public static Gen instance(Context context) {
90 Gen instance = context.get(genKey);
91 if (instance == null)
92 instance = new Gen(context);
93 return instance;
94 }
95
96 /** Constant pool writer, set by genClass.
97 */
98 final PoolWriter poolWriter;
99
100 @SuppressWarnings("this-escape")
101 protected Gen(Context context) {
102 context.put(genKey, this);
103
104 names = Names.instance(context);
105 log = Log.instance(context);
106 syms = Symtab.instance(context);
107 chk = Check.instance(context);
108 rs = Resolve.instance(context);
109 make = TreeMaker.instance(context);
110 target = Target.instance(context);
111 types = Types.instance(context);
112 concat = StringConcat.instance(context);
113
114 methodType = new MethodType(null, null, null, syms.methodClass);
115 accessDollar = "access" + target.syntheticNameChar();
116 lower = Lower.instance(context);
117
118 Options options = Options.instance(context);
119 lineDebugInfo =
120 options.isUnset(G_CUSTOM) ||
121 options.isSet(G_CUSTOM, "lines");
122 varDebugInfo =
123 options.isUnset(G_CUSTOM)
124 ? options.isSet(G)
125 : options.isSet(G_CUSTOM, "vars");
126 genCrt = options.isSet(XJCOV);
127 debugCode = options.isSet("debug.code");
128 disableVirtualizedPrivateInvoke = options.isSet("disableVirtualizedPrivateInvoke");
129 poolWriter = new PoolWriter(types, names);
130
131 // ignore cldc because we cannot have both stackmap formats
132 this.stackMap = StackMapFormat.JSR202;
133 annotate = Annotate.instance(context);
134 qualifiedSymbolCache = new HashMap<>();
135 }
136
137 /** Switches
138 */
139 private final boolean lineDebugInfo;
140 private final boolean varDebugInfo;
141 private final boolean genCrt;
142 private final boolean debugCode;
143 private boolean disableVirtualizedPrivateInvoke;
144
145 /** Code buffer, set by genMethod.
146 */
147 private Code code;
148
149 /** Items structure, set by genMethod.
150 */
151 private Items items;
152
153 /** Environment for symbol lookup, set by genClass
154 */
155 private Env<AttrContext> attrEnv;
156
157 /** The top level tree.
158 */
159 private JCCompilationUnit toplevel;
160
161 /** The number of code-gen errors in this class.
162 */
163 private int nerrs = 0;
164
165 /** An object containing mappings of syntax trees to their
166 * ending source positions.
167 */
168 EndPosTable endPosTable;
169
170 boolean inCondSwitchExpression;
171 Chain switchExpressionTrueChain;
172 Chain switchExpressionFalseChain;
173 List<LocalItem> stackBeforeSwitchExpression;
174 LocalItem switchResult;
175 PatternMatchingCatchConfiguration patternMatchingCatchConfiguration =
176 new PatternMatchingCatchConfiguration(Set.of(), null, null, null);
177
178 /** Cache the symbol to reflect the qualifying type.
179 * key: corresponding type
180 * value: qualified symbol
181 */
182 Map<Type, Symbol> qualifiedSymbolCache;
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 /** Construct a symbol to reflect the qualifying type that should
228 * appear in the byte code as per JLS 13.1.
229 *
230 * For {@literal target >= 1.2}: Clone a method with the qualifier as owner (except
231 * for those cases where we need to work around VM bugs).
232 *
233 * For {@literal target <= 1.1}: If qualified variable or method is defined in a
234 * non-accessible class, clone it with the qualifier class as owner.
235 *
236 * @param sym The accessed symbol
237 * @param site The qualifier's type.
238 */
239 Symbol binaryQualifier(Symbol sym, Type site) {
240
241 if (site.hasTag(ARRAY)) {
242 if (sym == syms.lengthVar ||
243 sym.owner != syms.arrayClass)
244 return sym;
245 // array clone can be qualified by the array type in later targets
246 Symbol qualifier;
247 if ((qualifier = qualifiedSymbolCache.get(site)) == null) {
248 qualifier = new ClassSymbol(Flags.PUBLIC, site.tsym.name, site, syms.noSymbol);
249 qualifiedSymbolCache.put(site, qualifier);
250 }
251 return sym.clone(qualifier);
252 }
253
254 if (sym.owner == site.tsym ||
255 (sym.flags() & (STATIC | SYNTHETIC)) == (STATIC | SYNTHETIC)) {
256 return sym;
257 }
258
259 // leave alone methods inherited from Object
260 // JLS 13.1.
261 if (sym.owner == syms.objectType.tsym)
262 return sym;
263
264 return sym.clone(site.tsym);
265 }
266
267 /** Insert a reference to given type in the constant pool,
268 * checking for an array with too many dimensions;
269 * return the reference's index.
270 * @param type The type for which a reference is inserted.
271 */
272 int makeRef(DiagnosticPosition pos, Type type) {
273 return poolWriter.putClass(checkDimension(pos, type));
274 }
275
276 /** Check if the given type is an array with too many dimensions.
277 */
278 private Type checkDimension(DiagnosticPosition pos, Type t) {
279 checkDimensionInternal(pos, t);
280 return t;
281 }
282
283 private void checkDimensionInternal(DiagnosticPosition pos, Type t) {
284 switch (t.getTag()) {
285 case METHOD:
286 checkDimension(pos, t.getReturnType());
287 for (List<Type> args = t.getParameterTypes(); args.nonEmpty(); args = args.tail)
288 checkDimension(pos, args.head);
289 break;
290 case ARRAY:
291 if (types.dimensions(t) > ClassFile.MAX_DIMENSIONS) {
292 log.error(pos, Errors.LimitDimensions);
293 nerrs++;
294 }
295 break;
296 default:
297 break;
298 }
299 }
300
301 /** Create a temporary variable.
302 * @param type The variable's type.
303 */
304 LocalItem makeTemp(Type type) {
305 VarSymbol v = new VarSymbol(Flags.SYNTHETIC,
306 names.empty,
307 type,
308 env.enclMethod.sym);
309 code.newLocal(v);
310 return items.makeLocalItem(v);
311 }
312
313 /** Generate code to call a non-private method or constructor.
314 * @param pos Position to be used for error reporting.
315 * @param site The type of which the method is a member.
316 * @param name The method's name.
317 * @param argtypes The method's argument types.
318 * @param isStatic A flag that indicates whether we call a
319 * static or instance method.
320 */
321 void callMethod(DiagnosticPosition pos,
322 Type site, Name name, List<Type> argtypes,
323 boolean isStatic) {
324 Symbol msym = rs.
325 resolveInternalMethod(pos, attrEnv, site, name, argtypes, null);
326 if (isStatic) items.makeStaticItem(msym).invoke();
327 else items.makeMemberItem(msym, name == names.init).invoke();
328 }
329
330 /** Is the given method definition an access method
331 * resulting from a qualified super? This is signified by an odd
332 * access code.
333 */
334 private boolean isAccessSuper(JCMethodDecl enclMethod) {
335 return
336 (enclMethod.mods.flags & SYNTHETIC) != 0 &&
337 isOddAccessName(enclMethod.name);
338 }
339
340 /** Does given name start with "access$" and end in an odd digit?
341 */
342 private boolean isOddAccessName(Name name) {
343 final String string = name.toString();
344 return
345 string.startsWith(accessDollar) &&
346 (string.charAt(string.length() - 1) & 1) != 0;
347 }
348
349 /* ************************************************************************
350 * Non-local exits
351 *************************************************************************/
352
353 /** Generate code to invoke the finalizer associated with given
354 * environment.
355 * Any calls to finalizers are appended to the environments `cont' chain.
356 * Mark beginning of gap in catch all range for finalizer.
357 */
358 void genFinalizer(Env<GenContext> env) {
359 if (code.isAlive() && env.info.finalize != null)
360 env.info.finalize.gen();
361 }
362
363 /** Generate code to call all finalizers of structures aborted by
364 * a non-local
365 * exit. Return target environment of the non-local exit.
366 * @param target The tree representing the structure that's aborted
367 * @param env The environment current at the non-local exit.
368 */
369 Env<GenContext> unwind(JCTree target, Env<GenContext> env) {
370 Env<GenContext> env1 = env;
371 while (true) {
372 genFinalizer(env1);
373 if (env1.tree == target) break;
374 env1 = env1.next;
375 }
376 return env1;
377 }
378
379 /** Mark end of gap in catch-all range for finalizer.
380 * @param env the environment which might contain the finalizer
381 * (if it does, env.info.gaps != null).
382 */
383 void endFinalizerGap(Env<GenContext> env) {
384 if (env.info.gaps != null && env.info.gaps.length() % 2 == 1)
385 env.info.gaps.append(code.curCP());
386 }
387
388 /** Mark end of all gaps in catch-all ranges for finalizers of environments
389 * lying between, and including to two environments.
390 * @param from the most deeply nested environment to mark
391 * @param to the least deeply nested environment to mark
392 */
393 void endFinalizerGaps(Env<GenContext> from, Env<GenContext> to) {
394 Env<GenContext> last = null;
395 while (last != to) {
396 endFinalizerGap(from);
397 last = from;
398 from = from.next;
399 }
400 }
401
402 /** Do any of the structures aborted by a non-local exit have
403 * finalizers that require an empty stack?
404 * @param target The tree representing the structure that's aborted
405 * @param env The environment current at the non-local exit.
406 */
407 boolean hasFinally(JCTree target, Env<GenContext> env) {
408 while (env.tree != target) {
409 if (env.tree.hasTag(TRY) && env.info.finalize.hasFinalizer())
410 return true;
411 env = env.next;
412 }
413 return false;
414 }
415
416 /* ************************************************************************
417 * Normalizing class-members.
418 *************************************************************************/
419
420 /** Distribute member initializer code into constructors and {@code <clinit>}
421 * method.
422 * @param defs The list of class member declarations.
423 * @param c The enclosing class.
424 */
425 List<JCTree> normalizeDefs(List<JCTree> defs, ClassSymbol c) {
426 ListBuffer<JCStatement> initCode = new ListBuffer<>();
427 // only used for value classes
428 ListBuffer<JCStatement> initBlocks = new ListBuffer<>();
429 ListBuffer<Attribute.TypeCompound> initTAs = new ListBuffer<>();
430 ListBuffer<JCStatement> clinitCode = new ListBuffer<>();
431 ListBuffer<Attribute.TypeCompound> clinitTAs = new ListBuffer<>();
432 ListBuffer<JCTree> methodDefs = new ListBuffer<>();
433 // Sort definitions into three listbuffers:
434 // - initCode for instance initializers
435 // - clinitCode for class initializers
436 // - methodDefs for method definitions
437 for (List<JCTree> l = defs; l.nonEmpty(); l = l.tail) {
438 JCTree def = l.head;
439 switch (def.getTag()) {
440 case BLOCK:
441 JCBlock block = (JCBlock)def;
442 if ((block.flags & STATIC) != 0)
443 clinitCode.append(block);
444 else if ((block.flags & SYNTHETIC) == 0) {
445 if (c.isValueClass()) {
446 initBlocks.append(block);
447 } else {
448 initCode.append(block);
449 }
450 }
451 break;
452 case METHODDEF:
453 methodDefs.append(def);
454 break;
455 case VARDEF:
456 JCVariableDecl vdef = (JCVariableDecl) def;
457 VarSymbol sym = vdef.sym;
458 checkDimension(vdef.pos(), sym.type);
459 if (vdef.init != null) {
460 if ((sym.flags() & STATIC) == 0) {
461 // Always initialize instance variables.
462 JCStatement init = make.at(vdef.pos()).
463 Assignment(sym, vdef.init);
464 initCode.append(init);
465 endPosTable.replaceTree(vdef, init);
466 initTAs.addAll(getAndRemoveNonFieldTAs(sym));
467 } else if (sym.getConstValue() == null) {
468 // Initialize class (static) variables only if
469 // they are not compile-time constants.
470 JCStatement init = make.at(vdef.pos).
471 Assignment(sym, vdef.init);
472 clinitCode.append(init);
473 endPosTable.replaceTree(vdef, init);
474 clinitTAs.addAll(getAndRemoveNonFieldTAs(sym));
475 } else {
476 checkStringConstant(vdef.init.pos(), sym.getConstValue());
477 /* if the init contains a reference to an external class, add it to the
478 * constant's pool
479 */
480 vdef.init.accept(classReferenceVisitor);
481 }
482 }
483 break;
484 default:
485 Assert.error();
486 }
487 }
488 // Insert any instance initializers into all constructors.
489 if (initCode.length() != 0 || initBlocks.length() != 0) {
490 initTAs.addAll(c.getInitTypeAttributes());
491 List<Attribute.TypeCompound> initTAlist = initTAs.toList();
492 for (JCTree t : methodDefs) {
493 normalizeMethod((JCMethodDecl)t, initCode.toList(), initBlocks.toList(), initTAlist);
494 }
495 }
496 // If there are class initializers, create a <clinit> method
497 // that contains them as its body.
498 if (clinitCode.length() != 0) {
499 MethodSymbol clinit = new MethodSymbol(
500 STATIC | (c.flags() & STRICTFP),
501 names.clinit,
502 new MethodType(
503 List.nil(), syms.voidType,
504 List.nil(), syms.methodClass),
505 c);
506 c.members().enter(clinit);
507 List<JCStatement> clinitStats = clinitCode.toList();
508 JCBlock block = make.at(clinitStats.head.pos()).Block(0, clinitStats);
509 block.endpos = TreeInfo.endPos(clinitStats.last());
510 methodDefs.append(make.MethodDef(clinit, block));
511
512 if (!clinitTAs.isEmpty())
513 clinit.appendUniqueTypeAttributes(clinitTAs.toList());
514 if (!c.getClassInitTypeAttributes().isEmpty())
515 clinit.appendUniqueTypeAttributes(c.getClassInitTypeAttributes());
516 }
517 // Return all method definitions.
518 return methodDefs.toList();
519 }
520
521 private List<Attribute.TypeCompound> getAndRemoveNonFieldTAs(VarSymbol sym) {
522 List<TypeCompound> tas = sym.getRawTypeAttributes();
523 ListBuffer<Attribute.TypeCompound> fieldTAs = new ListBuffer<>();
524 ListBuffer<Attribute.TypeCompound> nonfieldTAs = new ListBuffer<>();
525 for (TypeCompound ta : tas) {
526 Assert.check(ta.getPosition().type != TargetType.UNKNOWN);
527 if (ta.getPosition().type == TargetType.FIELD) {
528 fieldTAs.add(ta);
529 } else {
530 nonfieldTAs.add(ta);
531 }
532 }
533 sym.setTypeAttributes(fieldTAs.toList());
534 return nonfieldTAs.toList();
535 }
536
537 /** Check a constant value and report if it is a string that is
538 * too large.
539 */
540 private void checkStringConstant(DiagnosticPosition pos, Object constValue) {
541 if (nerrs != 0 || // only complain about a long string once
542 constValue == null ||
543 !(constValue instanceof String str) ||
544 str.length() < PoolWriter.MAX_STRING_LENGTH)
545 return;
546 log.error(pos, Errors.LimitString);
547 nerrs++;
548 }
549
550 /** Insert instance initializer code into constructors prior to the super() call.
551 * @param md The tree potentially representing a
552 * constructor's definition.
553 * @param initCode The list of instance initializer statements.
554 * @param initTAs Type annotations from the initializer expression.
555 */
556 void normalizeMethod(JCMethodDecl md, List<JCStatement> initCode, List<JCStatement> initBlocks, List<TypeCompound> initTAs) {
557 if (TreeInfo.isConstructor(md) && TreeInfo.hasConstructorCall(md, names._super)) {
558 // We are seeing a constructor that has a super() call.
559 // Find the super() invocation and append the given initializer code.
560 if (md.sym.owner.isValueClass()) {
561 rewriteInitializersIfNeeded(md, initCode);
562 TreeInfo.mapSuperCalls(md.body, supercall -> make.Block(0, initCode.append(supercall).appendList(initBlocks)));
563 } else {
564 TreeInfo.mapSuperCalls(md.body, supercall -> make.Block(0, initCode.prepend(supercall)));
565 }
566
567 if (md.body.endpos == Position.NOPOS)
568 md.body.endpos = TreeInfo.endPos(md.body.stats.last());
569
570 md.sym.appendUniqueTypeAttributes(initTAs);
571 }
572 }
573
574 void rewriteInitializersIfNeeded(JCMethodDecl md, List<JCStatement> initCode) {
575 if (lower.initializerOuterThis.containsKey(md.sym.owner)) {
576 InitializerVisitor initializerVisitor = new InitializerVisitor(md, lower.initializerOuterThis.get(md.sym.owner));
577 for (JCStatement init : initCode) {
578 initializerVisitor.scan(init);
579 }
580 }
581 }
582
583 class InitializerVisitor extends TreeScanner {
584 JCMethodDecl md;
585 Set<JCExpression> exprSet;
586
587 InitializerVisitor(JCMethodDecl md, Set<JCExpression> exprSet) {
588 this.md = md;
589 this.exprSet = exprSet;
590 }
591
592 @Override
593 public void visitTree(JCTree tree) {}
594
595 @Override
596 public void visitIdent(JCIdent tree) {
597 if (exprSet.contains(tree)) {
598 for (JCVariableDecl param: md.params) {
599 if (param.name == tree.name &&
600 ((param.sym.flags_field & (MANDATED | NOOUTERTHIS)) == (MANDATED | NOOUTERTHIS))) {
601 tree.sym = param.sym;
602 }
603 }
604 }
605 }
606 }
607
608 /* ************************************************************************
609 * Traversal methods
610 *************************************************************************/
611
612 /** Visitor argument: The current environment.
613 */
614 Env<GenContext> env;
615
616 /** Visitor argument: The expected type (prototype).
617 */
618 Type pt;
619
620 /** Visitor result: The item representing the computed value.
621 */
622 Item result;
623
624 /** Visitor method: generate code for a definition, catching and reporting
625 * any completion failures.
626 * @param tree The definition to be visited.
627 * @param env The environment current at the definition.
628 */
629 public void genDef(JCTree tree, Env<GenContext> env) {
630 Env<GenContext> prevEnv = this.env;
631 try {
632 this.env = env;
633 tree.accept(this);
634 } catch (CompletionFailure ex) {
635 chk.completionError(tree.pos(), ex);
636 } finally {
637 this.env = prevEnv;
638 }
639 }
640
641 /** Derived visitor method: check whether CharacterRangeTable
642 * should be emitted, if so, put a new entry into CRTable
643 * and call method to generate bytecode.
644 * If not, just call method to generate bytecode.
645 * @see #genStat(JCTree, Env)
646 *
647 * @param tree The tree to be visited.
648 * @param env The environment to use.
649 * @param crtFlags The CharacterRangeTable flags
650 * indicating type of the entry.
651 */
652 public void genStat(JCTree tree, Env<GenContext> env, int crtFlags) {
653 if (!genCrt) {
654 genStat(tree, env);
655 return;
656 }
657 int startpc = code.curCP();
658 genStat(tree, env);
659 if (tree.hasTag(Tag.BLOCK)) crtFlags |= CRT_BLOCK;
660 code.crt.put(tree, crtFlags, startpc, code.curCP());
661 }
662
663 /** Derived visitor method: generate code for a statement.
664 */
665 public void genStat(JCTree tree, Env<GenContext> env) {
666 if (code.isAlive()) {
667 code.statBegin(tree.pos);
668 genDef(tree, env);
669 } else if (env.info.isSwitch && tree.hasTag(VARDEF)) {
670 // variables whose declarations are in a switch
671 // can be used even if the decl is unreachable.
672 code.newLocal(((JCVariableDecl) tree).sym);
673 }
674 }
675
676 /** Derived visitor method: check whether CharacterRangeTable
677 * should be emitted, if so, put a new entry into CRTable
678 * and call method to generate bytecode.
679 * If not, just call method to generate bytecode.
680 * @see #genStats(List, Env)
681 *
682 * @param trees The list of trees to be visited.
683 * @param env The environment to use.
684 * @param crtFlags The CharacterRangeTable flags
685 * indicating type of the entry.
686 */
687 public void genStats(List<JCStatement> trees, Env<GenContext> env, int crtFlags) {
688 if (!genCrt) {
689 genStats(trees, env);
690 return;
691 }
692 if (trees.length() == 1) { // mark one statement with the flags
693 genStat(trees.head, env, crtFlags | CRT_STATEMENT);
694 } else {
695 int startpc = code.curCP();
696 genStats(trees, env);
697 code.crt.put(trees, crtFlags, startpc, code.curCP());
698 }
699 }
700
701 /** Derived visitor method: generate code for a list of statements.
702 */
703 public void genStats(List<? extends JCTree> trees, Env<GenContext> env) {
704 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
705 genStat(l.head, env, CRT_STATEMENT);
706 }
707
708 /** Derived visitor method: check whether CharacterRangeTable
709 * should be emitted, if so, put a new entry into CRTable
710 * and call method to generate bytecode.
711 * If not, just call method to generate bytecode.
712 * @see #genCond(JCTree,boolean)
713 *
714 * @param tree The tree to be visited.
715 * @param crtFlags The CharacterRangeTable flags
716 * indicating type of the entry.
717 */
718 public CondItem genCond(JCTree tree, int crtFlags) {
719 if (!genCrt) return genCond(tree, false);
720 int startpc = code.curCP();
721 CondItem item = genCond(tree, (crtFlags & CRT_FLOW_CONTROLLER) != 0);
722 code.crt.put(tree, crtFlags, startpc, code.curCP());
723 return item;
724 }
725
726 /** Derived visitor method: generate code for a boolean
727 * expression in a control-flow context.
728 * @param _tree The expression to be visited.
729 * @param markBranches The flag to indicate that the condition is
730 * a flow controller so produced conditions
731 * should contain a proper tree to generate
732 * CharacterRangeTable branches for them.
733 */
734 public CondItem genCond(JCTree _tree, boolean markBranches) {
735 JCTree inner_tree = TreeInfo.skipParens(_tree);
736 if (inner_tree.hasTag(CONDEXPR)) {
737 JCConditional tree = (JCConditional)inner_tree;
738 CondItem cond = genCond(tree.cond, CRT_FLOW_CONTROLLER);
739 if (cond.isTrue()) {
740 code.resolve(cond.trueJumps);
741 CondItem result = genCond(tree.truepart, CRT_FLOW_TARGET);
742 if (markBranches) result.tree = tree.truepart;
743 return result;
744 }
745 if (cond.isFalse()) {
746 code.resolve(cond.falseJumps);
747 CondItem result = genCond(tree.falsepart, CRT_FLOW_TARGET);
748 if (markBranches) result.tree = tree.falsepart;
749 return result;
750 }
751 Chain secondJumps = cond.jumpFalse();
752 code.resolve(cond.trueJumps);
753 CondItem first = genCond(tree.truepart, CRT_FLOW_TARGET);
754 if (markBranches) first.tree = tree.truepart;
755 Chain falseJumps = first.jumpFalse();
756 code.resolve(first.trueJumps);
757 Chain trueJumps = code.branch(goto_);
758 code.resolve(secondJumps);
759 CondItem second = genCond(tree.falsepart, CRT_FLOW_TARGET);
760 CondItem result = items.makeCondItem(second.opcode,
761 Code.mergeChains(trueJumps, second.trueJumps),
762 Code.mergeChains(falseJumps, second.falseJumps));
763 if (markBranches) result.tree = tree.falsepart;
764 return result;
765 } else if (inner_tree.hasTag(SWITCH_EXPRESSION)) {
766 code.resolvePending();
767
768 boolean prevInCondSwitchExpression = inCondSwitchExpression;
769 Chain prevSwitchExpressionTrueChain = switchExpressionTrueChain;
770 Chain prevSwitchExpressionFalseChain = switchExpressionFalseChain;
771 try {
772 inCondSwitchExpression = true;
773 switchExpressionTrueChain = null;
774 switchExpressionFalseChain = null;
775 try {
776 doHandleSwitchExpression((JCSwitchExpression) inner_tree);
777 } catch (CompletionFailure ex) {
778 chk.completionError(_tree.pos(), ex);
779 code.state.stacksize = 1;
780 }
781 CondItem result = items.makeCondItem(goto_,
782 switchExpressionTrueChain,
783 switchExpressionFalseChain);
784 if (markBranches) result.tree = _tree;
785 return result;
786 } finally {
787 inCondSwitchExpression = prevInCondSwitchExpression;
788 switchExpressionTrueChain = prevSwitchExpressionTrueChain;
789 switchExpressionFalseChain = prevSwitchExpressionFalseChain;
790 }
791 } else if (inner_tree.hasTag(LETEXPR) && ((LetExpr) inner_tree).needsCond) {
792 code.resolvePending();
793
794 LetExpr tree = (LetExpr) inner_tree;
795 int limit = code.nextreg;
796 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
797 try {
798 genStats(tree.defs, env);
799 } finally {
800 code.setLetExprStackPos(prevLetExprStart);
801 }
802 CondItem result = genCond(tree.expr, markBranches);
803 code.endScopes(limit);
804 return result;
805 } else {
806 CondItem result = genExpr(_tree, syms.booleanType).mkCond();
807 if (markBranches) result.tree = _tree;
808 return result;
809 }
810 }
811
812 public Code getCode() {
813 return code;
814 }
815
816 public Items getItems() {
817 return items;
818 }
819
820 public Env<AttrContext> getAttrEnv() {
821 return attrEnv;
822 }
823
824 /** Visitor class for expressions which might be constant expressions.
825 * This class is a subset of TreeScanner. Intended to visit trees pruned by
826 * Lower as long as constant expressions looking for references to any
827 * ClassSymbol. Any such reference will be added to the constant pool so
828 * automated tools can detect class dependencies better.
829 */
830 class ClassReferenceVisitor extends JCTree.Visitor {
831
832 @Override
833 public void visitTree(JCTree tree) {}
834
835 @Override
836 public void visitBinary(JCBinary tree) {
837 tree.lhs.accept(this);
838 tree.rhs.accept(this);
839 }
840
841 @Override
842 public void visitSelect(JCFieldAccess tree) {
843 if (tree.selected.type.hasTag(CLASS)) {
844 makeRef(tree.selected.pos(), tree.selected.type);
845 }
846 }
847
848 @Override
849 public void visitIdent(JCIdent tree) {
850 if (tree.sym.owner instanceof ClassSymbol classSymbol) {
851 poolWriter.putClass(classSymbol);
852 }
853 }
854
855 @Override
856 public void visitConditional(JCConditional tree) {
857 tree.cond.accept(this);
858 tree.truepart.accept(this);
859 tree.falsepart.accept(this);
860 }
861
862 @Override
863 public void visitUnary(JCUnary tree) {
864 tree.arg.accept(this);
865 }
866
867 @Override
868 public void visitParens(JCParens tree) {
869 tree.expr.accept(this);
870 }
871
872 @Override
873 public void visitTypeCast(JCTypeCast tree) {
874 tree.expr.accept(this);
875 }
876 }
877
878 private ClassReferenceVisitor classReferenceVisitor = new ClassReferenceVisitor();
879
880 /** Visitor method: generate code for an expression, catching and reporting
881 * any completion failures.
882 * @param tree The expression to be visited.
883 * @param pt The expression's expected type (proto-type).
884 */
885 public Item genExpr(JCTree tree, Type pt) {
886 if (!code.isAlive()) {
887 return items.makeStackItem(pt);
888 }
889
890 Type prevPt = this.pt;
891 try {
892 if (tree.type.constValue() != null) {
893 // Short circuit any expressions which are constants
894 tree.accept(classReferenceVisitor);
895 checkStringConstant(tree.pos(), tree.type.constValue());
896 Symbol sym = TreeInfo.symbol(tree);
897 if (sym != null && isConstantDynamic(sym)) {
898 result = items.makeDynamicItem(sym);
899 } else {
900 result = items.makeImmediateItem(tree.type, tree.type.constValue());
901 }
902 } else {
903 this.pt = pt;
904 tree.accept(this);
905 }
906 return result.coerce(pt);
907 } catch (CompletionFailure ex) {
908 chk.completionError(tree.pos(), ex);
909 code.state.stacksize = 1;
910 return items.makeStackItem(pt);
911 } finally {
912 this.pt = prevPt;
913 }
914 }
915
916 public boolean isConstantDynamic(Symbol sym) {
917 return sym.kind == VAR &&
918 sym instanceof DynamicVarSymbol dynamicVarSymbol &&
919 dynamicVarSymbol.isDynamic();
920 }
921
922 /** Derived visitor method: generate code for a list of method arguments.
923 * @param trees The argument expressions to be visited.
924 * @param pts The expression's expected types (i.e. the formal parameter
925 * types of the invoked method).
926 */
927 public void genArgs(List<JCExpression> trees, List<Type> pts) {
928 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail) {
929 genExpr(l.head, pts.head).load();
930 pts = pts.tail;
931 }
932 // require lists be of same length
933 Assert.check(pts.isEmpty());
934 }
935
936 /* ************************************************************************
937 * Visitor methods for statements and definitions
938 *************************************************************************/
939
940 /** Thrown when the byte code size exceeds limit.
941 */
942 public static class CodeSizeOverflow extends RuntimeException {
943 private static final long serialVersionUID = 0;
944 public CodeSizeOverflow() {}
945 }
946
947 public void visitMethodDef(JCMethodDecl tree) {
948 // Create a new local environment that points pack at method
949 // definition.
950 Env<GenContext> localEnv = env.dup(tree);
951 localEnv.enclMethod = tree;
952 // The expected type of every return statement in this method
953 // is the method's return type.
954 this.pt = tree.sym.erasure(types).getReturnType();
955
956 checkDimension(tree.pos(), tree.sym.erasure(types));
957 genMethod(tree, localEnv, false);
958 }
959 //where
960 /** Generate code for a method.
961 * @param tree The tree representing the method definition.
962 * @param env The environment current for the method body.
963 * @param fatcode A flag that indicates whether all jumps are
964 * within 32K. We first invoke this method under
965 * the assumption that fatcode == false, i.e. all
966 * jumps are within 32K. If this fails, fatcode
967 * is set to true and we try again.
968 */
969 void genMethod(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
970 MethodSymbol meth = tree.sym;
971 int extras = 0;
972 // Count up extra parameters
973 if (meth.isConstructor()) {
974 extras++;
975 if (meth.enclClass().isInner() &&
976 !meth.enclClass().isStatic()) {
977 extras++;
978 }
979 } else if ((tree.mods.flags & STATIC) == 0) {
980 extras++;
981 }
982 // System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG
983 if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes()) + extras >
984 ClassFile.MAX_PARAMETERS) {
985 log.error(tree.pos(), Errors.LimitParameters);
986 nerrs++;
987 }
988
989 else if (tree.body != null) {
990 // Create a new code structure and initialize it.
991 int startpcCrt = initCode(tree, env, fatcode);
992
993 try {
994 genStat(tree.body, env);
995 } catch (CodeSizeOverflow e) {
996 // Failed due to code limit, try again with jsr/ret
997 startpcCrt = initCode(tree, env, fatcode);
998 genStat(tree.body, env);
999 }
1000
1001 if (code.state.stacksize != 0) {
1002 log.error(tree.body.pos(), Errors.StackSimError(tree.sym));
1003 throw new AssertionError();
1004 }
1005
1006 // If last statement could complete normally, insert a
1007 // return at the end.
1008 if (code.isAlive()) {
1009 code.statBegin(TreeInfo.endPos(tree.body));
1010 if (env.enclMethod == null ||
1011 env.enclMethod.sym.type.getReturnType().hasTag(VOID)) {
1012 code.emitop0(return_);
1013 } else {
1014 // sometime dead code seems alive (4415991);
1015 // generate a small loop instead
1016 int startpc = code.entryPoint();
1017 CondItem c = items.makeCondItem(goto_);
1018 code.resolve(c.jumpTrue(), startpc);
1019 }
1020 }
1021 if (genCrt)
1022 code.crt.put(tree.body,
1023 CRT_BLOCK,
1024 startpcCrt,
1025 code.curCP());
1026
1027 code.endScopes(0);
1028
1029 // If we exceeded limits, panic
1030 if (code.checkLimits(tree.pos(), log)) {
1031 nerrs++;
1032 return;
1033 }
1034
1035 // If we generated short code but got a long jump, do it again
1036 // with fatCode = true.
1037 if (!fatcode && code.fatcode) genMethod(tree, env, true);
1038
1039 // Clean up
1040 if(stackMap == StackMapFormat.JSR202) {
1041 code.lastFrame = null;
1042 code.frameBeforeLast = null;
1043 }
1044
1045 // Compress exception table
1046 code.compressCatchTable();
1047
1048 // Fill in type annotation positions for exception parameters
1049 code.fillExceptionParameterPositions();
1050 }
1051 }
1052
1053 private int initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
1054 MethodSymbol meth = tree.sym;
1055
1056 // Create a new code structure.
1057 meth.code = code = new Code(meth,
1058 fatcode,
1059 lineDebugInfo ? toplevel.lineMap : null,
1060 varDebugInfo,
1061 stackMap,
1062 debugCode,
1063 genCrt ? new CRTable(tree, env.toplevel.endPositions)
1064 : null,
1065 syms,
1066 types,
1067 poolWriter);
1068 items = new Items(poolWriter, code, syms, types);
1069 if (code.debugCode) {
1070 System.err.println(meth + " for body " + tree);
1071 }
1072
1073 // If method is not static, create a new local variable address
1074 // for `this'.
1075 if ((tree.mods.flags & STATIC) == 0) {
1076 Type selfType = meth.owner.type;
1077 if (meth.isConstructor() && selfType != syms.objectType)
1078 selfType = UninitializedType.uninitializedThis(selfType);
1079 code.setDefined(
1080 code.newLocal(
1081 new VarSymbol(FINAL, names._this, selfType, meth.owner)));
1082 }
1083
1084 // Mark all parameters as defined from the beginning of
1085 // the method.
1086 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
1087 checkDimension(l.head.pos(), l.head.sym.type);
1088 code.setDefined(code.newLocal(l.head.sym));
1089 }
1090
1091 // Get ready to generate code for method body.
1092 int startpcCrt = genCrt ? code.curCP() : 0;
1093 code.entryPoint();
1094
1095 // Suppress initial stackmap
1096 code.pendingStackMap = false;
1097
1098 return startpcCrt;
1099 }
1100
1101 public void visitVarDef(JCVariableDecl tree) {
1102 VarSymbol v = tree.sym;
1103 if (tree.init != null) {
1104 checkStringConstant(tree.init.pos(), v.getConstValue());
1105 if (v.getConstValue() == null || varDebugInfo) {
1106 Assert.check(code.isStatementStart());
1107 code.newLocal(v);
1108 genExpr(tree.init, v.erasure(types)).load();
1109 items.makeLocalItem(v).store();
1110 Assert.check(code.isStatementStart());
1111 }
1112 } else {
1113 code.newLocal(v);
1114 }
1115 checkDimension(tree.pos(), v.type);
1116 }
1117
1118 public void visitSkip(JCSkip tree) {
1119 }
1120
1121 public void visitBlock(JCBlock tree) {
1122 /* this method is heavily invoked, as expected, for deeply nested blocks, if blocks doesn't happen to have
1123 * patterns there will be an unnecessary tax on memory consumption every time this method is executed, for this
1124 * reason we have created helper methods and here at a higher level we just discriminate depending on the
1125 * presence, or not, of patterns in a given block
1126 */
1127 if (tree.patternMatchingCatch != null) {
1128 visitBlockWithPatterns(tree);
1129 } else {
1130 internalVisitBlock(tree);
1131 }
1132 }
1133
1134 private void visitBlockWithPatterns(JCBlock tree) {
1135 PatternMatchingCatchConfiguration prevConfiguration = patternMatchingCatchConfiguration;
1136 try {
1137 patternMatchingCatchConfiguration =
1138 new PatternMatchingCatchConfiguration(tree.patternMatchingCatch.calls2Handle(),
1139 new ListBuffer<int[]>(),
1140 tree.patternMatchingCatch.handler(),
1141 code.state.dup());
1142 internalVisitBlock(tree);
1143 } finally {
1144 generatePatternMatchingCatch(env);
1145 patternMatchingCatchConfiguration = prevConfiguration;
1146 }
1147 }
1148
1149 private void generatePatternMatchingCatch(Env<GenContext> env) {
1150 if (patternMatchingCatchConfiguration.handler != null &&
1151 !patternMatchingCatchConfiguration.ranges.isEmpty()) {
1152 Chain skipCatch = code.branch(goto_);
1153 JCCatch handler = patternMatchingCatchConfiguration.handler();
1154 code.entryPoint(patternMatchingCatchConfiguration.startState(),
1155 handler.param.sym.type);
1156 genPatternMatchingCatch(handler,
1157 env,
1158 patternMatchingCatchConfiguration.ranges.toList());
1159 code.resolve(skipCatch);
1160 }
1161 }
1162
1163 private void internalVisitBlock(JCBlock tree) {
1164 int limit = code.nextreg;
1165 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1166 genStats(tree.stats, localEnv);
1167 // End the scope of all block-local variables in variable info.
1168 if (!env.tree.hasTag(METHODDEF)) {
1169 code.statBegin(tree.endpos);
1170 code.endScopes(limit);
1171 code.pendingStatPos = Position.NOPOS;
1172 }
1173 }
1174
1175 public void visitDoLoop(JCDoWhileLoop tree) {
1176 genLoop(tree, tree.body, tree.cond, List.nil(), false);
1177 }
1178
1179 public void visitWhileLoop(JCWhileLoop tree) {
1180 genLoop(tree, tree.body, tree.cond, List.nil(), true);
1181 }
1182
1183 public void visitForLoop(JCForLoop tree) {
1184 int limit = code.nextreg;
1185 genStats(tree.init, env);
1186 genLoop(tree, tree.body, tree.cond, tree.step, true);
1187 code.endScopes(limit);
1188 }
1189 //where
1190 /** Generate code for a loop.
1191 * @param loop The tree representing the loop.
1192 * @param body The loop's body.
1193 * @param cond The loop's controlling condition.
1194 * @param step "Step" statements to be inserted at end of
1195 * each iteration.
1196 * @param testFirst True if the loop test belongs before the body.
1197 */
1198 private void genLoop(JCStatement loop,
1199 JCStatement body,
1200 JCExpression cond,
1201 List<JCExpressionStatement> step,
1202 boolean testFirst) {
1203 Env<GenContext> loopEnv = env.dup(loop, new GenContext());
1204 int startpc = code.entryPoint();
1205 if (testFirst) { //while or for loop
1206 CondItem c;
1207 if (cond != null) {
1208 code.statBegin(cond.pos);
1209 Assert.check(code.isStatementStart());
1210 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1211 } else {
1212 c = items.makeCondItem(goto_);
1213 }
1214 Chain loopDone = c.jumpFalse();
1215 code.resolve(c.trueJumps);
1216 Assert.check(code.isStatementStart());
1217 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1218 code.resolve(loopEnv.info.cont);
1219 genStats(step, loopEnv);
1220 code.resolve(code.branch(goto_), startpc);
1221 code.resolve(loopDone);
1222 } else {
1223 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1224 code.resolve(loopEnv.info.cont);
1225 genStats(step, loopEnv);
1226 if (code.isAlive()) {
1227 CondItem c;
1228 if (cond != null) {
1229 code.statBegin(cond.pos);
1230 Assert.check(code.isStatementStart());
1231 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1232 } else {
1233 c = items.makeCondItem(goto_);
1234 }
1235 code.resolve(c.jumpTrue(), startpc);
1236 Assert.check(code.isStatementStart());
1237 code.resolve(c.falseJumps);
1238 }
1239 }
1240 Chain exit = loopEnv.info.exit;
1241 if (exit != null) {
1242 code.resolve(exit);
1243 exit.state.defined.excludeFrom(code.nextreg);
1244 }
1245 }
1246
1247 public void visitForeachLoop(JCEnhancedForLoop tree) {
1248 throw new AssertionError(); // should have been removed by Lower.
1249 }
1250
1251 public void visitLabelled(JCLabeledStatement tree) {
1252 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1253 genStat(tree.body, localEnv, CRT_STATEMENT);
1254 Chain exit = localEnv.info.exit;
1255 if (exit != null) {
1256 code.resolve(exit);
1257 exit.state.defined.excludeFrom(code.nextreg);
1258 }
1259 }
1260
1261 public void visitSwitch(JCSwitch tree) {
1262 handleSwitch(tree, tree.selector, tree.cases, tree.patternSwitch);
1263 }
1264
1265 @Override
1266 public void visitSwitchExpression(JCSwitchExpression tree) {
1267 code.resolvePending();
1268 boolean prevInCondSwitchExpression = inCondSwitchExpression;
1269 try {
1270 inCondSwitchExpression = false;
1271 doHandleSwitchExpression(tree);
1272 } finally {
1273 inCondSwitchExpression = prevInCondSwitchExpression;
1274 }
1275 result = items.makeStackItem(pt);
1276 }
1277
1278 private void doHandleSwitchExpression(JCSwitchExpression tree) {
1279 List<LocalItem> prevStackBeforeSwitchExpression = stackBeforeSwitchExpression;
1280 LocalItem prevSwitchResult = switchResult;
1281 int limit = code.nextreg;
1282 try {
1283 stackBeforeSwitchExpression = List.nil();
1284 switchResult = null;
1285 if (hasTry(tree)) {
1286 //if the switch expression contains try-catch, the catch handlers need to have
1287 //an empty stack. So stash whole stack to local variables, and restore it before
1288 //breaks:
1289 while (code.state.stacksize > 0) {
1290 Type type = code.state.peek();
1291 Name varName = names.fromString(target.syntheticNameChar() +
1292 "stack" +
1293 target.syntheticNameChar() +
1294 tree.pos +
1295 target.syntheticNameChar() +
1296 code.state.stacksize);
1297 VarSymbol var = new VarSymbol(Flags.SYNTHETIC, varName, type,
1298 this.env.enclMethod.sym);
1299 LocalItem item = items.new LocalItem(type, code.newLocal(var));
1300 stackBeforeSwitchExpression = stackBeforeSwitchExpression.prepend(item);
1301 item.store();
1302 }
1303 switchResult = makeTemp(tree.type);
1304 }
1305 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
1306 try {
1307 handleSwitch(tree, tree.selector, tree.cases, tree.patternSwitch);
1308 } finally {
1309 code.setLetExprStackPos(prevLetExprStart);
1310 }
1311 } finally {
1312 stackBeforeSwitchExpression = prevStackBeforeSwitchExpression;
1313 switchResult = prevSwitchResult;
1314 code.endScopes(limit);
1315 }
1316 }
1317 //where:
1318 private boolean hasTry(JCSwitchExpression tree) {
1319 class HasTryScanner extends TreeScanner {
1320 private boolean hasTry;
1321
1322 @Override
1323 public void visitTry(JCTry tree) {
1324 hasTry = true;
1325 }
1326
1327 @Override
1328 public void visitSynchronized(JCSynchronized tree) {
1329 hasTry = true;
1330 }
1331
1332 @Override
1333 public void visitClassDef(JCClassDecl tree) {
1334 }
1335
1336 @Override
1337 public void visitLambda(JCLambda tree) {
1338 }
1339 };
1340
1341 HasTryScanner hasTryScanner = new HasTryScanner();
1342
1343 hasTryScanner.scan(tree);
1344 return hasTryScanner.hasTry;
1345 }
1346
1347 private void handleSwitch(JCTree swtch, JCExpression selector, List<JCCase> cases,
1348 boolean patternSwitch) {
1349 int limit = code.nextreg;
1350 Assert.check(!selector.type.hasTag(CLASS));
1351 int switchStart = patternSwitch ? code.entryPoint() : -1;
1352 int startpcCrt = genCrt ? code.curCP() : 0;
1353 Assert.check(code.isStatementStart());
1354 Item sel = genExpr(selector, syms.intType);
1355 if (cases.isEmpty()) {
1356 // We are seeing: switch <sel> {}
1357 sel.load().drop();
1358 if (genCrt)
1359 code.crt.put(TreeInfo.skipParens(selector),
1360 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1361 } else {
1362 // We are seeing a nonempty switch.
1363 sel.load();
1364 if (genCrt)
1365 code.crt.put(TreeInfo.skipParens(selector),
1366 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1367 Env<GenContext> switchEnv = env.dup(swtch, new GenContext());
1368 switchEnv.info.isSwitch = true;
1369
1370 // Compute number of labels and minimum and maximum label values.
1371 // For each case, store its label in an array.
1372 int lo = Integer.MAX_VALUE; // minimum label.
1373 int hi = Integer.MIN_VALUE; // maximum label.
1374 int nlabels = 0; // number of labels.
1375
1376 int[] labels = new int[cases.length()]; // the label array.
1377 int defaultIndex = -1; // the index of the default clause.
1378
1379 List<JCCase> l = cases;
1380 for (int i = 0; i < labels.length; i++) {
1381 if (l.head.labels.head instanceof JCConstantCaseLabel constLabel) {
1382 Assert.check(l.head.labels.size() == 1);
1383 int val = ((Number) constLabel.expr.type.constValue()).intValue();
1384 labels[i] = val;
1385 if (val < lo) lo = val;
1386 if (hi < val) hi = val;
1387 nlabels++;
1388 } else {
1389 Assert.check(defaultIndex == -1);
1390 defaultIndex = i;
1391 }
1392 l = l.tail;
1393 }
1394
1395 // Determine whether to issue a tableswitch or a lookupswitch
1396 // instruction.
1397 long table_space_cost = 4 + ((long) hi - lo + 1); // words
1398 long table_time_cost = 3; // comparisons
1399 long lookup_space_cost = 3 + 2 * (long) nlabels;
1400 long lookup_time_cost = nlabels;
1401 int opcode =
1402 nlabels > 0 &&
1403 table_space_cost + 3 * table_time_cost <=
1404 lookup_space_cost + 3 * lookup_time_cost
1405 ?
1406 tableswitch : lookupswitch;
1407
1408 int startpc = code.curCP(); // the position of the selector operation
1409 code.emitop0(opcode);
1410 code.align(4);
1411 int tableBase = code.curCP(); // the start of the jump table
1412 int[] offsets = null; // a table of offsets for a lookupswitch
1413 code.emit4(-1); // leave space for default offset
1414 if (opcode == tableswitch) {
1415 code.emit4(lo); // minimum label
1416 code.emit4(hi); // maximum label
1417 for (long i = lo; i <= hi; i++) { // leave space for jump table
1418 code.emit4(-1);
1419 }
1420 } else {
1421 code.emit4(nlabels); // number of labels
1422 for (int i = 0; i < nlabels; i++) {
1423 code.emit4(-1); code.emit4(-1); // leave space for lookup table
1424 }
1425 offsets = new int[labels.length];
1426 }
1427 Code.State stateSwitch = code.state.dup();
1428 code.markDead();
1429
1430 // For each case do:
1431 l = cases;
1432 for (int i = 0; i < labels.length; i++) {
1433 JCCase c = l.head;
1434 l = l.tail;
1435
1436 int pc = code.entryPoint(stateSwitch);
1437 // Insert offset directly into code or else into the
1438 // offsets table.
1439 if (i != defaultIndex) {
1440 if (opcode == tableswitch) {
1441 code.put4(
1442 tableBase + 4 * (labels[i] - lo + 3),
1443 pc - startpc);
1444 } else {
1445 offsets[i] = pc - startpc;
1446 }
1447 } else {
1448 code.put4(tableBase, pc - startpc);
1449 }
1450
1451 // Generate code for the statements in this case.
1452 genStats(c.stats, switchEnv, CRT_FLOW_TARGET);
1453 }
1454
1455 if (switchEnv.info.cont != null) {
1456 Assert.check(patternSwitch);
1457 code.resolve(switchEnv.info.cont, switchStart);
1458 }
1459
1460 // Resolve all breaks.
1461 Chain exit = switchEnv.info.exit;
1462 if (exit != null) {
1463 code.resolve(exit);
1464 exit.state.defined.excludeFrom(limit);
1465 }
1466
1467 // If we have not set the default offset, we do so now.
1468 if (code.get4(tableBase) == -1) {
1469 code.put4(tableBase, code.entryPoint(stateSwitch) - startpc);
1470 }
1471
1472 if (opcode == tableswitch) {
1473 // Let any unfilled slots point to the default case.
1474 int defaultOffset = code.get4(tableBase);
1475 for (long i = lo; i <= hi; i++) {
1476 int t = (int)(tableBase + 4 * (i - lo + 3));
1477 if (code.get4(t) == -1)
1478 code.put4(t, defaultOffset);
1479 }
1480 } else {
1481 // Sort non-default offsets and copy into lookup table.
1482 if (defaultIndex >= 0)
1483 for (int i = defaultIndex; i < labels.length - 1; i++) {
1484 labels[i] = labels[i+1];
1485 offsets[i] = offsets[i+1];
1486 }
1487 if (nlabels > 0)
1488 qsort2(labels, offsets, 0, nlabels - 1);
1489 for (int i = 0; i < nlabels; i++) {
1490 int caseidx = tableBase + 8 * (i + 1);
1491 code.put4(caseidx, labels[i]);
1492 code.put4(caseidx + 4, offsets[i]);
1493 }
1494 }
1495
1496 if (swtch instanceof JCSwitchExpression) {
1497 // Emit line position for the end of a switch expression
1498 code.statBegin(TreeInfo.endPos(swtch));
1499 }
1500 }
1501 code.endScopes(limit);
1502 }
1503 //where
1504 /** Sort (int) arrays of keys and values
1505 */
1506 static void qsort2(int[] keys, int[] values, int lo, int hi) {
1507 int i = lo;
1508 int j = hi;
1509 int pivot = keys[(i+j)/2];
1510 do {
1511 while (keys[i] < pivot) i++;
1512 while (pivot < keys[j]) j--;
1513 if (i <= j) {
1514 int temp1 = keys[i];
1515 keys[i] = keys[j];
1516 keys[j] = temp1;
1517 int temp2 = values[i];
1518 values[i] = values[j];
1519 values[j] = temp2;
1520 i++;
1521 j--;
1522 }
1523 } while (i <= j);
1524 if (lo < j) qsort2(keys, values, lo, j);
1525 if (i < hi) qsort2(keys, values, i, hi);
1526 }
1527
1528 public void visitSynchronized(JCSynchronized tree) {
1529 int limit = code.nextreg;
1530 // Generate code to evaluate lock and save in temporary variable.
1531 final LocalItem lockVar = makeTemp(syms.objectType);
1532 Assert.check(code.isStatementStart());
1533 genExpr(tree.lock, tree.lock.type).load().duplicate();
1534 lockVar.store();
1535
1536 // Generate code to enter monitor.
1537 code.emitop0(monitorenter);
1538 code.state.lock(lockVar.reg);
1539
1540 // Generate code for a try statement with given body, no catch clauses
1541 // in a new environment with the "exit-monitor" operation as finalizer.
1542 final Env<GenContext> syncEnv = env.dup(tree, new GenContext());
1543 syncEnv.info.finalize = new GenFinalizer() {
1544 void gen() {
1545 genLast();
1546 Assert.check(syncEnv.info.gaps.length() % 2 == 0);
1547 syncEnv.info.gaps.append(code.curCP());
1548 }
1549 void genLast() {
1550 if (code.isAlive()) {
1551 lockVar.load();
1552 code.emitop0(monitorexit);
1553 code.state.unlock(lockVar.reg);
1554 }
1555 }
1556 };
1557 syncEnv.info.gaps = new ListBuffer<>();
1558 genTry(tree.body, List.nil(), syncEnv);
1559 code.endScopes(limit);
1560 }
1561
1562 public void visitTry(final JCTry tree) {
1563 // Generate code for a try statement with given body and catch clauses,
1564 // in a new environment which calls the finally block if there is one.
1565 final Env<GenContext> tryEnv = env.dup(tree, new GenContext());
1566 final Env<GenContext> oldEnv = env;
1567 tryEnv.info.finalize = new GenFinalizer() {
1568 void gen() {
1569 Assert.check(tryEnv.info.gaps.length() % 2 == 0);
1570 tryEnv.info.gaps.append(code.curCP());
1571 genLast();
1572 }
1573 void genLast() {
1574 if (tree.finalizer != null)
1575 genStat(tree.finalizer, oldEnv, CRT_BLOCK);
1576 }
1577 boolean hasFinalizer() {
1578 return tree.finalizer != null;
1579 }
1580
1581 @Override
1582 void afterBody() {
1583 if (tree.finalizer != null && (tree.finalizer.flags & BODY_ONLY_FINALIZE) != 0) {
1584 //for body-only finally, remove the GenFinalizer after try body
1585 //so that the finally is not generated to catch bodies:
1586 tryEnv.info.finalize = null;
1587 }
1588 }
1589
1590 };
1591 tryEnv.info.gaps = new ListBuffer<>();
1592 genTry(tree.body, tree.catchers, tryEnv);
1593 }
1594 //where
1595 /** Generate code for a try or synchronized statement
1596 * @param body The body of the try or synchronized statement.
1597 * @param catchers The list of catch clauses.
1598 * @param env The current environment of the body.
1599 */
1600 void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) {
1601 int limit = code.nextreg;
1602 int startpc = code.curCP();
1603 Code.State stateTry = code.state.dup();
1604 genStat(body, env, CRT_BLOCK);
1605 int endpc = code.curCP();
1606 List<Integer> gaps = env.info.gaps.toList();
1607 code.statBegin(TreeInfo.endPos(body));
1608 genFinalizer(env);
1609 code.statBegin(TreeInfo.endPos(env.tree));
1610 Chain exitChain;
1611 boolean actualTry = env.tree.hasTag(TRY);
1612 if (startpc == endpc && actualTry) {
1613 exitChain = code.branch(dontgoto);
1614 } else {
1615 exitChain = code.branch(goto_);
1616 }
1617 endFinalizerGap(env);
1618 env.info.finalize.afterBody();
1619 boolean hasFinalizer =
1620 env.info.finalize != null &&
1621 env.info.finalize.hasFinalizer();
1622 if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) {
1623 // start off with exception on stack
1624 code.entryPoint(stateTry, l.head.param.sym.type);
1625 genCatch(l.head, env, startpc, endpc, gaps);
1626 genFinalizer(env);
1627 if (hasFinalizer || l.tail.nonEmpty()) {
1628 code.statBegin(TreeInfo.endPos(env.tree));
1629 exitChain = Code.mergeChains(exitChain,
1630 code.branch(goto_));
1631 }
1632 endFinalizerGap(env);
1633 }
1634 if (hasFinalizer && (startpc != endpc || !actualTry)) {
1635 // Create a new register segment to avoid allocating
1636 // the same variables in finalizers and other statements.
1637 code.newRegSegment();
1638
1639 // Add a catch-all clause.
1640
1641 // start off with exception on stack
1642 int catchallpc = code.entryPoint(stateTry, syms.throwableType);
1643
1644 // Register all exception ranges for catch all clause.
1645 // The range of the catch all clause is from the beginning
1646 // of the try or synchronized block until the present
1647 // code pointer excluding all gaps in the current
1648 // environment's GenContext.
1649 int startseg = startpc;
1650 while (env.info.gaps.nonEmpty()) {
1651 int endseg = env.info.gaps.next().intValue();
1652 registerCatch(body.pos(), startseg, endseg,
1653 catchallpc, 0);
1654 startseg = env.info.gaps.next().intValue();
1655 }
1656 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1657 code.markStatBegin();
1658
1659 Item excVar = makeTemp(syms.throwableType);
1660 excVar.store();
1661 genFinalizer(env);
1662 code.resolvePending();
1663 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.END_POS));
1664 code.markStatBegin();
1665
1666 excVar.load();
1667 registerCatch(body.pos(), startseg,
1668 env.info.gaps.next().intValue(),
1669 catchallpc, 0);
1670 code.emitop0(athrow);
1671 code.markDead();
1672
1673 // If there are jsr's to this finalizer, ...
1674 if (env.info.cont != null) {
1675 // Resolve all jsr's.
1676 code.resolve(env.info.cont);
1677
1678 // Mark statement line number
1679 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1680 code.markStatBegin();
1681
1682 // Save return address.
1683 LocalItem retVar = makeTemp(syms.throwableType);
1684 retVar.store();
1685
1686 // Generate finalizer code.
1687 env.info.finalize.genLast();
1688
1689 // Return.
1690 code.emitop1w(ret, retVar.reg);
1691 code.markDead();
1692 }
1693 }
1694 // Resolve all breaks.
1695 code.resolve(exitChain);
1696
1697 code.endScopes(limit);
1698 }
1699
1700 /** Generate code for a catch clause.
1701 * @param tree The catch clause.
1702 * @param env The environment current in the enclosing try.
1703 * @param startpc Start pc of try-block.
1704 * @param endpc End pc of try-block.
1705 */
1706 void genCatch(JCCatch tree,
1707 Env<GenContext> env,
1708 int startpc, int endpc,
1709 List<Integer> gaps) {
1710 if (startpc != endpc) {
1711 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypeExprs
1712 = catchTypesWithAnnotations(tree);
1713 while (gaps.nonEmpty()) {
1714 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) {
1715 JCExpression subCatch = subCatch1.snd;
1716 int catchType = makeRef(tree.pos(), subCatch.type);
1717 int end = gaps.head.intValue();
1718 registerCatch(tree.pos(),
1719 startpc, end, code.curCP(),
1720 catchType);
1721 for (Attribute.TypeCompound tc : subCatch1.fst) {
1722 tc.position.setCatchInfo(catchType, startpc);
1723 }
1724 }
1725 gaps = gaps.tail;
1726 startpc = gaps.head.intValue();
1727 gaps = gaps.tail;
1728 }
1729 if (startpc < endpc) {
1730 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) {
1731 JCExpression subCatch = subCatch1.snd;
1732 int catchType = makeRef(tree.pos(), subCatch.type);
1733 registerCatch(tree.pos(),
1734 startpc, endpc, code.curCP(),
1735 catchType);
1736 for (Attribute.TypeCompound tc : subCatch1.fst) {
1737 tc.position.setCatchInfo(catchType, startpc);
1738 }
1739 }
1740 }
1741 genCatchBlock(tree, env);
1742 }
1743 }
1744 void genPatternMatchingCatch(JCCatch tree,
1745 Env<GenContext> env,
1746 List<int[]> ranges) {
1747 for (int[] range : ranges) {
1748 JCExpression subCatch = tree.param.vartype;
1749 int catchType = makeRef(tree.pos(), subCatch.type);
1750 registerCatch(tree.pos(),
1751 range[0], range[1], code.curCP(),
1752 catchType);
1753 }
1754 genCatchBlock(tree, env);
1755 }
1756 void genCatchBlock(JCCatch tree, Env<GenContext> env) {
1757 VarSymbol exparam = tree.param.sym;
1758 code.statBegin(tree.pos);
1759 code.markStatBegin();
1760 int limit = code.nextreg;
1761 code.newLocal(exparam);
1762 items.makeLocalItem(exparam).store();
1763 code.statBegin(TreeInfo.firstStatPos(tree.body));
1764 genStat(tree.body, env, CRT_BLOCK);
1765 code.endScopes(limit);
1766 code.statBegin(TreeInfo.endPos(tree.body));
1767 }
1768 // where
1769 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotations(JCCatch tree) {
1770 return TreeInfo.isMultiCatch(tree) ?
1771 catchTypesWithAnnotationsFromMulticatch((JCTypeUnion)tree.param.vartype, tree.param.sym.getRawTypeAttributes()) :
1772 List.of(new Pair<>(tree.param.sym.getRawTypeAttributes(), tree.param.vartype));
1773 }
1774 // where
1775 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotationsFromMulticatch(JCTypeUnion tree, List<TypeCompound> first) {
1776 List<JCExpression> alts = tree.alternatives;
1777 List<Pair<List<TypeCompound>, JCExpression>> res = List.of(new Pair<>(first, alts.head));
1778 alts = alts.tail;
1779
1780 while(alts != null && alts.head != null) {
1781 JCExpression alt = alts.head;
1782 if (alt instanceof JCAnnotatedType annotatedType) {
1783 res = res.prepend(new Pair<>(annotate.fromAnnotations(annotatedType.annotations), alt));
1784 } else {
1785 res = res.prepend(new Pair<>(List.nil(), alt));
1786 }
1787 alts = alts.tail;
1788 }
1789 return res.reverse();
1790 }
1791
1792 /** Register a catch clause in the "Exceptions" code-attribute.
1793 */
1794 void registerCatch(DiagnosticPosition pos,
1795 int startpc, int endpc,
1796 int handler_pc, int catch_type) {
1797 char startpc1 = (char)startpc;
1798 char endpc1 = (char)endpc;
1799 char handler_pc1 = (char)handler_pc;
1800 if (startpc1 == startpc &&
1801 endpc1 == endpc &&
1802 handler_pc1 == handler_pc) {
1803 code.addCatch(startpc1, endpc1, handler_pc1,
1804 (char)catch_type);
1805 } else {
1806 log.error(pos, Errors.LimitCodeTooLargeForTryStmt);
1807 nerrs++;
1808 }
1809 }
1810
1811 public void visitIf(JCIf tree) {
1812 int limit = code.nextreg;
1813 Chain thenExit = null;
1814 Assert.check(code.isStatementStart());
1815 CondItem c = genCond(TreeInfo.skipParens(tree.cond),
1816 CRT_FLOW_CONTROLLER);
1817 Chain elseChain = c.jumpFalse();
1818 Assert.check(code.isStatementStart());
1819 if (!c.isFalse()) {
1820 code.resolve(c.trueJumps);
1821 genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET);
1822 thenExit = code.branch(goto_);
1823 }
1824 if (elseChain != null) {
1825 code.resolve(elseChain);
1826 if (tree.elsepart != null) {
1827 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET);
1828 }
1829 }
1830 code.resolve(thenExit);
1831 code.endScopes(limit);
1832 Assert.check(code.isStatementStart());
1833 }
1834
1835 public void visitExec(JCExpressionStatement tree) {
1836 // Optimize x++ to ++x and x-- to --x.
1837 JCExpression e = tree.expr;
1838 switch (e.getTag()) {
1839 case POSTINC:
1840 ((JCUnary) e).setTag(PREINC);
1841 break;
1842 case POSTDEC:
1843 ((JCUnary) e).setTag(PREDEC);
1844 break;
1845 }
1846 Assert.check(code.isStatementStart());
1847 genExpr(tree.expr, tree.expr.type).drop();
1848 Assert.check(code.isStatementStart());
1849 }
1850
1851 public void visitBreak(JCBreak tree) {
1852 Assert.check(code.isStatementStart());
1853 final Env<GenContext> targetEnv = unwindBreak(tree.target);
1854 targetEnv.info.addExit(code.branch(goto_));
1855 endFinalizerGaps(env, targetEnv);
1856 }
1857
1858 public void visitYield(JCYield tree) {
1859 Assert.check(code.isStatementStart());
1860 final Env<GenContext> targetEnv;
1861 if (inCondSwitchExpression) {
1862 CondItem value = genCond(tree.value, CRT_FLOW_TARGET);
1863 Chain falseJumps = value.jumpFalse();
1864
1865 code.resolve(value.trueJumps);
1866 Env<GenContext> localEnv = unwindBreak(tree.target);
1867 reloadStackBeforeSwitchExpr();
1868 Chain trueJumps = code.branch(goto_);
1869
1870 endFinalizerGaps(env, localEnv);
1871
1872 code.resolve(falseJumps);
1873 targetEnv = unwindBreak(tree.target);
1874 reloadStackBeforeSwitchExpr();
1875 falseJumps = code.branch(goto_);
1876
1877 if (switchExpressionTrueChain == null) {
1878 switchExpressionTrueChain = trueJumps;
1879 } else {
1880 switchExpressionTrueChain =
1881 Code.mergeChains(switchExpressionTrueChain, trueJumps);
1882 }
1883 if (switchExpressionFalseChain == null) {
1884 switchExpressionFalseChain = falseJumps;
1885 } else {
1886 switchExpressionFalseChain =
1887 Code.mergeChains(switchExpressionFalseChain, falseJumps);
1888 }
1889 } else {
1890 genExpr(tree.value, pt).load();
1891 if (switchResult != null)
1892 switchResult.store();
1893
1894 targetEnv = unwindBreak(tree.target);
1895
1896 if (code.isAlive()) {
1897 reloadStackBeforeSwitchExpr();
1898 if (switchResult != null)
1899 switchResult.load();
1900
1901 code.state.forceStackTop(tree.target.type);
1902 targetEnv.info.addExit(code.branch(goto_));
1903 code.markDead();
1904 }
1905 }
1906 endFinalizerGaps(env, targetEnv);
1907 }
1908 //where:
1909 /** As side-effect, might mark code as dead disabling any further emission.
1910 */
1911 private Env<GenContext> unwindBreak(JCTree target) {
1912 int tmpPos = code.pendingStatPos;
1913 Env<GenContext> targetEnv = unwind(target, env);
1914 code.pendingStatPos = tmpPos;
1915 return targetEnv;
1916 }
1917
1918 private void reloadStackBeforeSwitchExpr() {
1919 for (LocalItem li : stackBeforeSwitchExpression)
1920 li.load();
1921 }
1922
1923 public void visitContinue(JCContinue tree) {
1924 int tmpPos = code.pendingStatPos;
1925 Env<GenContext> targetEnv = unwind(tree.target, env);
1926 code.pendingStatPos = tmpPos;
1927 Assert.check(code.isStatementStart());
1928 targetEnv.info.addCont(code.branch(goto_));
1929 endFinalizerGaps(env, targetEnv);
1930 }
1931
1932 public void visitReturn(JCReturn tree) {
1933 int limit = code.nextreg;
1934 final Env<GenContext> targetEnv;
1935
1936 /* Save and then restore the location of the return in case a finally
1937 * is expanded (with unwind()) in the middle of our bytecodes.
1938 */
1939 int tmpPos = code.pendingStatPos;
1940 if (tree.expr != null) {
1941 Assert.check(code.isStatementStart());
1942 Item r = genExpr(tree.expr, pt).load();
1943 if (hasFinally(env.enclMethod, env)) {
1944 r = makeTemp(pt);
1945 r.store();
1946 }
1947 targetEnv = unwind(env.enclMethod, env);
1948 code.pendingStatPos = tmpPos;
1949 r.load();
1950 code.emitop0(ireturn + Code.truncate(Code.typecode(pt)));
1951 } else {
1952 targetEnv = unwind(env.enclMethod, env);
1953 code.pendingStatPos = tmpPos;
1954 code.emitop0(return_);
1955 }
1956 endFinalizerGaps(env, targetEnv);
1957 code.endScopes(limit);
1958 }
1959
1960 public void visitThrow(JCThrow tree) {
1961 Assert.check(code.isStatementStart());
1962 genExpr(tree.expr, tree.expr.type).load();
1963 code.emitop0(athrow);
1964 Assert.check(code.isStatementStart());
1965 }
1966
1967 /* ************************************************************************
1968 * Visitor methods for expressions
1969 *************************************************************************/
1970
1971 public void visitApply(JCMethodInvocation tree) {
1972 setTypeAnnotationPositions(tree.pos);
1973 // Generate code for method.
1974 Item m = genExpr(tree.meth, methodType);
1975 // Generate code for all arguments, where the expected types are
1976 // the parameters of the method's external type (that is, any implicit
1977 // outer instance of a super(...) call appears as first parameter).
1978 MethodSymbol msym = (MethodSymbol)TreeInfo.symbol(tree.meth);
1979 genArgs(tree.args,
1980 msym.externalType(types).getParameterTypes());
1981 if (!msym.isDynamic()) {
1982 code.statBegin(tree.pos);
1983 }
1984 if (patternMatchingCatchConfiguration.invocations().contains(tree)) {
1985 int start = code.curCP();
1986 result = m.invoke();
1987 patternMatchingCatchConfiguration.ranges().add(new int[] {start, code.curCP()});
1988 } else {
1989 if (msym.isConstructor() && TreeInfo.isConstructorCall(tree)) {
1990 //if this is a this(...) or super(...) call, there is a pending
1991 //"uninitialized this" before this call. One catch handler cannot
1992 //handle exceptions that may come from places with "uninitialized this"
1993 //and (initialized) this, hence generate one set of handlers here
1994 //for the "uninitialized this" case, and another set of handlers
1995 //will be generated at the end of the method for the initialized this,
1996 //if needed:
1997 generatePatternMatchingCatch(env);
1998 result = m.invoke();
1999 patternMatchingCatchConfiguration =
2000 patternMatchingCatchConfiguration.restart(code.state.dup());
2001 } else {
2002 result = m.invoke();
2003 }
2004 }
2005 }
2006
2007 public void visitConditional(JCConditional tree) {
2008 Chain thenExit = null;
2009 code.statBegin(tree.cond.pos);
2010 CondItem c = genCond(tree.cond, CRT_FLOW_CONTROLLER);
2011 Chain elseChain = c.jumpFalse();
2012 if (!c.isFalse()) {
2013 code.resolve(c.trueJumps);
2014 int startpc = genCrt ? code.curCP() : 0;
2015 code.statBegin(tree.truepart.pos);
2016 genExpr(tree.truepart, pt).load();
2017 code.state.forceStackTop(tree.type);
2018 if (genCrt) code.crt.put(tree.truepart, CRT_FLOW_TARGET,
2019 startpc, code.curCP());
2020 thenExit = code.branch(goto_);
2021 }
2022 if (elseChain != null) {
2023 code.resolve(elseChain);
2024 int startpc = genCrt ? code.curCP() : 0;
2025 code.statBegin(tree.falsepart.pos);
2026 genExpr(tree.falsepart, pt).load();
2027 code.state.forceStackTop(tree.type);
2028 if (genCrt) code.crt.put(tree.falsepart, CRT_FLOW_TARGET,
2029 startpc, code.curCP());
2030 }
2031 code.resolve(thenExit);
2032 result = items.makeStackItem(pt);
2033 }
2034
2035 private void setTypeAnnotationPositions(int treePos) {
2036 MethodSymbol meth = code.meth;
2037 boolean initOrClinit = code.meth.getKind() == javax.lang.model.element.ElementKind.CONSTRUCTOR
2038 || code.meth.getKind() == javax.lang.model.element.ElementKind.STATIC_INIT;
2039
2040 for (Attribute.TypeCompound ta : meth.getRawTypeAttributes()) {
2041 if (ta.hasUnknownPosition())
2042 ta.tryFixPosition();
2043
2044 if (ta.position.matchesPos(treePos))
2045 ta.position.updatePosOffset(code.cp);
2046 }
2047
2048 if (!initOrClinit)
2049 return;
2050
2051 for (Attribute.TypeCompound ta : meth.owner.getRawTypeAttributes()) {
2052 if (ta.hasUnknownPosition())
2053 ta.tryFixPosition();
2054
2055 if (ta.position.matchesPos(treePos))
2056 ta.position.updatePosOffset(code.cp);
2057 }
2058
2059 ClassSymbol clazz = meth.enclClass();
2060 for (Symbol s : new com.sun.tools.javac.model.FilteredMemberList(clazz.members())) {
2061 if (!s.getKind().isField())
2062 continue;
2063
2064 for (Attribute.TypeCompound ta : s.getRawTypeAttributes()) {
2065 if (ta.hasUnknownPosition())
2066 ta.tryFixPosition();
2067
2068 if (ta.position.matchesPos(treePos))
2069 ta.position.updatePosOffset(code.cp);
2070 }
2071 }
2072 }
2073
2074 public void visitNewClass(JCNewClass tree) {
2075 // Enclosing instances or anonymous classes should have been eliminated
2076 // by now.
2077 Assert.check(tree.encl == null && tree.def == null);
2078 setTypeAnnotationPositions(tree.pos);
2079
2080 code.emitop2(new_, checkDimension(tree.pos(), tree.type), PoolWriter::putClass);
2081 code.emitop0(dup);
2082
2083 // Generate code for all arguments, where the expected types are
2084 // the parameters of the constructor's external type (that is,
2085 // any implicit outer instance appears as first parameter).
2086 genArgs(tree.args, tree.constructor.externalType(types).getParameterTypes());
2087
2088 items.makeMemberItem(tree.constructor, true).invoke();
2089 result = items.makeStackItem(tree.type);
2090 }
2091
2092 public void visitNewArray(JCNewArray tree) {
2093 setTypeAnnotationPositions(tree.pos);
2094
2095 if (tree.elems != null) {
2096 Type elemtype = types.elemtype(tree.type);
2097 loadIntConst(tree.elems.length());
2098 Item arr = makeNewArray(tree.pos(), tree.type, 1);
2099 int i = 0;
2100 for (List<JCExpression> l = tree.elems; l.nonEmpty(); l = l.tail) {
2101 arr.duplicate();
2102 loadIntConst(i);
2103 i++;
2104 genExpr(l.head, elemtype).load();
2105 items.makeIndexedItem(elemtype).store();
2106 }
2107 result = arr;
2108 } else {
2109 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
2110 genExpr(l.head, syms.intType).load();
2111 }
2112 result = makeNewArray(tree.pos(), tree.type, tree.dims.length());
2113 }
2114 }
2115 //where
2116 /** Generate code to create an array with given element type and number
2117 * of dimensions.
2118 */
2119 Item makeNewArray(DiagnosticPosition pos, Type type, int ndims) {
2120 Type elemtype = types.elemtype(type);
2121 if (types.dimensions(type) > ClassFile.MAX_DIMENSIONS) {
2122 log.error(pos, Errors.LimitDimensions);
2123 nerrs++;
2124 }
2125 int elemcode = Code.arraycode(elemtype);
2126 if (elemcode == 0 || (elemcode == 1 && ndims == 1)) {
2127 code.emitAnewarray(makeRef(pos, elemtype), type);
2128 } else if (elemcode == 1) {
2129 code.emitMultianewarray(ndims, makeRef(pos, type), type);
2130 } else {
2131 code.emitNewarray(elemcode, type);
2132 }
2133 return items.makeStackItem(type);
2134 }
2135
2136 public void visitParens(JCParens tree) {
2137 result = genExpr(tree.expr, tree.expr.type);
2138 }
2139
2140 public void visitAssign(JCAssign tree) {
2141 Item l = genExpr(tree.lhs, tree.lhs.type);
2142 genExpr(tree.rhs, tree.lhs.type).load();
2143 if (tree.rhs.type.hasTag(BOT)) {
2144 /* This is just a case of widening reference conversion that per 5.1.5 simply calls
2145 for "regarding a reference as having some other type in a manner that can be proved
2146 correct at compile time."
2147 */
2148 code.state.forceStackTop(tree.lhs.type);
2149 }
2150 result = items.makeAssignItem(l);
2151 }
2152
2153 public void visitAssignop(JCAssignOp tree) {
2154 OperatorSymbol operator = tree.operator;
2155 Item l;
2156 if (operator.opcode == string_add) {
2157 l = concat.makeConcat(tree);
2158 } else {
2159 // Generate code for first expression
2160 l = genExpr(tree.lhs, tree.lhs.type);
2161
2162 // If we have an increment of -32768 to +32767 of a local
2163 // int variable we can use an incr instruction instead of
2164 // proceeding further.
2165 if ((tree.hasTag(PLUS_ASG) || tree.hasTag(MINUS_ASG)) &&
2166 l instanceof LocalItem localItem &&
2167 tree.lhs.type.getTag().isSubRangeOf(INT) &&
2168 tree.rhs.type.getTag().isSubRangeOf(INT) &&
2169 tree.rhs.type.constValue() != null) {
2170 int ival = ((Number) tree.rhs.type.constValue()).intValue();
2171 if (tree.hasTag(MINUS_ASG)) ival = -ival;
2172 localItem.incr(ival);
2173 result = l;
2174 return;
2175 }
2176 // Otherwise, duplicate expression, load one copy
2177 // and complete binary operation.
2178 l.duplicate();
2179 l.coerce(operator.type.getParameterTypes().head).load();
2180 completeBinop(tree.lhs, tree.rhs, operator).coerce(tree.lhs.type);
2181 }
2182 result = items.makeAssignItem(l);
2183 }
2184
2185 public void visitUnary(JCUnary tree) {
2186 OperatorSymbol operator = tree.operator;
2187 if (tree.hasTag(NOT)) {
2188 CondItem od = genCond(tree.arg, false);
2189 result = od.negate();
2190 } else {
2191 Item od = genExpr(tree.arg, operator.type.getParameterTypes().head);
2192 switch (tree.getTag()) {
2193 case POS:
2194 result = od.load();
2195 break;
2196 case NEG:
2197 result = od.load();
2198 code.emitop0(operator.opcode);
2199 break;
2200 case COMPL:
2201 result = od.load();
2202 emitMinusOne(od.typecode);
2203 code.emitop0(operator.opcode);
2204 break;
2205 case PREINC: case PREDEC:
2206 od.duplicate();
2207 if (od instanceof LocalItem localItem &&
2208 (operator.opcode == iadd || operator.opcode == isub)) {
2209 localItem.incr(tree.hasTag(PREINC) ? 1 : -1);
2210 result = od;
2211 } else {
2212 od.load();
2213 code.emitop0(one(od.typecode));
2214 code.emitop0(operator.opcode);
2215 // Perform narrowing primitive conversion if byte,
2216 // char, or short. Fix for 4304655.
2217 if (od.typecode != INTcode &&
2218 Code.truncate(od.typecode) == INTcode)
2219 code.emitop0(int2byte + od.typecode - BYTEcode);
2220 result = items.makeAssignItem(od);
2221 }
2222 break;
2223 case POSTINC: case POSTDEC:
2224 od.duplicate();
2225 if (od instanceof LocalItem localItem &&
2226 (operator.opcode == iadd || operator.opcode == isub)) {
2227 Item res = od.load();
2228 localItem.incr(tree.hasTag(POSTINC) ? 1 : -1);
2229 result = res;
2230 } else {
2231 Item res = od.load();
2232 od.stash(od.typecode);
2233 code.emitop0(one(od.typecode));
2234 code.emitop0(operator.opcode);
2235 // Perform narrowing primitive conversion if byte,
2236 // char, or short. Fix for 4304655.
2237 if (od.typecode != INTcode &&
2238 Code.truncate(od.typecode) == INTcode)
2239 code.emitop0(int2byte + od.typecode - BYTEcode);
2240 od.store();
2241 result = res;
2242 }
2243 break;
2244 case NULLCHK:
2245 result = od.load();
2246 code.emitop0(dup);
2247 genNullCheck(tree);
2248 break;
2249 default:
2250 Assert.error();
2251 }
2252 }
2253 }
2254
2255 /** Generate a null check from the object value at stack top. */
2256 private void genNullCheck(JCTree tree) {
2257 code.statBegin(tree.pos);
2258 callMethod(tree.pos(), syms.objectsType, names.requireNonNull,
2259 List.of(syms.objectType), true);
2260 code.emitop0(pop);
2261 }
2262
2263 public void visitBinary(JCBinary tree) {
2264 OperatorSymbol operator = tree.operator;
2265 if (operator.opcode == string_add) {
2266 result = concat.makeConcat(tree);
2267 } else if (tree.hasTag(AND)) {
2268 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2269 if (!lcond.isFalse()) {
2270 Chain falseJumps = lcond.jumpFalse();
2271 code.resolve(lcond.trueJumps);
2272 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2273 result = items.
2274 makeCondItem(rcond.opcode,
2275 rcond.trueJumps,
2276 Code.mergeChains(falseJumps,
2277 rcond.falseJumps));
2278 } else {
2279 result = lcond;
2280 }
2281 } else if (tree.hasTag(OR)) {
2282 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2283 if (!lcond.isTrue()) {
2284 Chain trueJumps = lcond.jumpTrue();
2285 code.resolve(lcond.falseJumps);
2286 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2287 result = items.
2288 makeCondItem(rcond.opcode,
2289 Code.mergeChains(trueJumps, rcond.trueJumps),
2290 rcond.falseJumps);
2291 } else {
2292 result = lcond;
2293 }
2294 } else {
2295 Item od = genExpr(tree.lhs, operator.type.getParameterTypes().head);
2296 od.load();
2297 result = completeBinop(tree.lhs, tree.rhs, operator);
2298 }
2299 }
2300
2301
2302 /** Complete generating code for operation, with left operand
2303 * already on stack.
2304 * @param lhs The tree representing the left operand.
2305 * @param rhs The tree representing the right operand.
2306 * @param operator The operator symbol.
2307 */
2308 Item completeBinop(JCTree lhs, JCTree rhs, OperatorSymbol operator) {
2309 MethodType optype = (MethodType)operator.type;
2310 int opcode = operator.opcode;
2311 if (opcode >= if_icmpeq && opcode <= if_icmple &&
2312 rhs.type.constValue() instanceof Number number &&
2313 number.intValue() == 0) {
2314 opcode = opcode + (ifeq - if_icmpeq);
2315 } else if (opcode >= if_acmpeq && opcode <= if_acmpne &&
2316 TreeInfo.isNull(rhs)) {
2317 opcode = opcode + (if_acmp_null - if_acmpeq);
2318 } else {
2319 // The expected type of the right operand is
2320 // the second parameter type of the operator, except for
2321 // shifts with long shiftcount, where we convert the opcode
2322 // to a short shift and the expected type to int.
2323 Type rtype = operator.erasure(types).getParameterTypes().tail.head;
2324 if (opcode >= ishll && opcode <= lushrl) {
2325 opcode = opcode + (ishl - ishll);
2326 rtype = syms.intType;
2327 }
2328 // Generate code for right operand and load.
2329 genExpr(rhs, rtype).load();
2330 // If there are two consecutive opcode instructions,
2331 // emit the first now.
2332 if (opcode >= (1 << preShift)) {
2333 code.emitop0(opcode >> preShift);
2334 opcode = opcode & 0xFF;
2335 }
2336 }
2337 if (opcode >= ifeq && opcode <= if_acmpne ||
2338 opcode == if_acmp_null || opcode == if_acmp_nonnull) {
2339 return items.makeCondItem(opcode);
2340 } else {
2341 code.emitop0(opcode);
2342 return items.makeStackItem(optype.restype);
2343 }
2344 }
2345
2346 public void visitTypeCast(JCTypeCast tree) {
2347 result = genExpr(tree.expr, tree.clazz.type).load();
2348 setTypeAnnotationPositions(tree.pos);
2349 // Additional code is only needed if we cast to a reference type
2350 // which is not statically a supertype of the expression's type.
2351 // For basic types, the coerce(...) in genExpr(...) will do
2352 // the conversion.
2353 if (!tree.clazz.type.isPrimitive() &&
2354 !types.isSameType(tree.expr.type, tree.clazz.type) &&
2355 types.asSuper(tree.expr.type, tree.clazz.type.tsym) == null) {
2356 code.emitop2(checkcast, checkDimension(tree.pos(), tree.clazz.type), PoolWriter::putClass);
2357 }
2358 }
2359
2360 public void visitWildcard(JCWildcard tree) {
2361 throw new AssertionError(this.getClass().getName());
2362 }
2363
2364 public void visitTypeTest(JCInstanceOf tree) {
2365 genExpr(tree.expr, tree.expr.type).load();
2366 setTypeAnnotationPositions(tree.pos);
2367 code.emitop2(instanceof_, makeRef(tree.pos(), tree.pattern.type));
2368 result = items.makeStackItem(syms.booleanType);
2369 }
2370
2371 public void visitIndexed(JCArrayAccess tree) {
2372 genExpr(tree.indexed, tree.indexed.type).load();
2373 genExpr(tree.index, syms.intType).load();
2374 result = items.makeIndexedItem(tree.type);
2375 }
2376
2377 public void visitIdent(JCIdent tree) {
2378 Symbol sym = tree.sym;
2379 if (tree.name == names._this || tree.name == names._super) {
2380 Item res = tree.name == names._this
2381 ? items.makeThisItem()
2382 : items.makeSuperItem();
2383 if (sym.kind == MTH) {
2384 // Generate code to address the constructor.
2385 res.load();
2386 res = items.makeMemberItem(sym, true);
2387 }
2388 result = res;
2389 } else if (isInvokeDynamic(sym) || isConstantDynamic(sym)) {
2390 if (isConstantDynamic(sym)) {
2391 setTypeAnnotationPositions(tree.pos);
2392 }
2393 result = items.makeDynamicItem(sym);
2394 } else if (sym.kind == VAR && (sym.owner.kind == MTH || sym.owner.kind == VAR)) {
2395 result = items.makeLocalItem((VarSymbol)sym);
2396 } else if ((sym.flags() & STATIC) != 0) {
2397 if (!isAccessSuper(env.enclMethod))
2398 sym = binaryQualifier(sym, env.enclClass.type);
2399 result = items.makeStaticItem(sym);
2400 } else {
2401 items.makeThisItem().load();
2402 sym = binaryQualifier(sym, env.enclClass.type);
2403 result = items.makeMemberItem(sym, nonVirtualForPrivateAccess(sym));
2404 }
2405 }
2406
2407 //where
2408 private boolean nonVirtualForPrivateAccess(Symbol sym) {
2409 boolean useVirtual = target.hasVirtualPrivateInvoke() &&
2410 !disableVirtualizedPrivateInvoke;
2411 return !useVirtual && ((sym.flags() & PRIVATE) != 0);
2412 }
2413
2414 public void visitSelect(JCFieldAccess tree) {
2415 Symbol sym = tree.sym;
2416
2417 if (tree.name == names._class) {
2418 code.emitLdc((LoadableConstant)checkDimension(tree.pos(), tree.selected.type));
2419 result = items.makeStackItem(pt);
2420 return;
2421 }
2422
2423 Symbol ssym = TreeInfo.symbol(tree.selected);
2424
2425 // Are we selecting via super?
2426 boolean selectSuper =
2427 ssym != null && (ssym.kind == TYP || ssym.name == names._super);
2428
2429 // Are we accessing a member of the superclass in an access method
2430 // resulting from a qualified super?
2431 boolean accessSuper = isAccessSuper(env.enclMethod);
2432
2433 Item base = (selectSuper)
2434 ? items.makeSuperItem()
2435 : genExpr(tree.selected, tree.selected.type);
2436
2437 if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) {
2438 // We are seeing a variable that is constant but its selecting
2439 // expression is not.
2440 if ((sym.flags() & STATIC) != 0) {
2441 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2442 base = base.load();
2443 base.drop();
2444 } else {
2445 base.load();
2446 genNullCheck(tree.selected);
2447 }
2448 result = items.
2449 makeImmediateItem(sym.type, ((VarSymbol) sym).getConstValue());
2450 } else {
2451 if (isInvokeDynamic(sym)) {
2452 result = items.makeDynamicItem(sym);
2453 return;
2454 } else {
2455 sym = binaryQualifier(sym, tree.selected.type);
2456 }
2457 if ((sym.flags() & STATIC) != 0) {
2458 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2459 base = base.load();
2460 base.drop();
2461 result = items.makeStaticItem(sym);
2462 } else {
2463 base.load();
2464 if (sym == syms.lengthVar) {
2465 code.emitop0(arraylength);
2466 result = items.makeStackItem(syms.intType);
2467 } else {
2468 result = items.
2469 makeMemberItem(sym,
2470 nonVirtualForPrivateAccess(sym) ||
2471 selectSuper || accessSuper);
2472 }
2473 }
2474 }
2475 }
2476
2477 public boolean isInvokeDynamic(Symbol sym) {
2478 return sym.kind == MTH && ((MethodSymbol)sym).isDynamic();
2479 }
2480
2481 public void visitLiteral(JCLiteral tree) {
2482 if (tree.type.hasTag(BOT)) {
2483 code.emitop0(aconst_null);
2484 result = items.makeStackItem(tree.type);
2485 }
2486 else
2487 result = items.makeImmediateItem(tree.type, tree.value);
2488 }
2489
2490 public void visitLetExpr(LetExpr tree) {
2491 code.resolvePending();
2492
2493 int limit = code.nextreg;
2494 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
2495 try {
2496 genStats(tree.defs, env);
2497 } finally {
2498 code.setLetExprStackPos(prevLetExprStart);
2499 }
2500 result = genExpr(tree.expr, tree.expr.type).load();
2501 code.endScopes(limit);
2502 }
2503
2504 private void generateReferencesToPrunedTree(ClassSymbol classSymbol) {
2505 List<JCTree> prunedInfo = lower.prunedTree.get(classSymbol);
2506 if (prunedInfo != null) {
2507 for (JCTree prunedTree: prunedInfo) {
2508 prunedTree.accept(classReferenceVisitor);
2509 }
2510 }
2511 }
2512
2513 /* ************************************************************************
2514 * main method
2515 *************************************************************************/
2516
2517 /** Generate code for a class definition.
2518 * @param env The attribution environment that belongs to the
2519 * outermost class containing this class definition.
2520 * We need this for resolving some additional symbols.
2521 * @param cdef The tree representing the class definition.
2522 * @return True if code is generated with no errors.
2523 */
2524 public boolean genClass(Env<AttrContext> env, JCClassDecl cdef) {
2525 try {
2526 attrEnv = env;
2527 ClassSymbol c = cdef.sym;
2528 this.toplevel = env.toplevel;
2529 this.endPosTable = toplevel.endPositions;
2530 /* method normalizeDefs() can add references to external classes into the constant pool
2531 */
2532 cdef.defs = normalizeDefs(cdef.defs, c);
2533 generateReferencesToPrunedTree(c);
2534 Env<GenContext> localEnv = new Env<>(cdef, new GenContext());
2535 localEnv.toplevel = env.toplevel;
2536 localEnv.enclClass = cdef;
2537
2538 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2539 genDef(l.head, localEnv);
2540 }
2541 if (poolWriter.size() > PoolWriter.MAX_ENTRIES) {
2542 log.error(cdef.pos(), Errors.LimitPool);
2543 nerrs++;
2544 }
2545 if (nerrs != 0) {
2546 // if errors, discard code
2547 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2548 if (l.head.hasTag(METHODDEF))
2549 ((JCMethodDecl) l.head).sym.code = null;
2550 }
2551 }
2552 cdef.defs = List.nil(); // discard trees
2553 return nerrs == 0;
2554 } finally {
2555 // note: this method does NOT support recursion.
2556 attrEnv = null;
2557 this.env = null;
2558 toplevel = null;
2559 endPosTable = null;
2560 nerrs = 0;
2561 qualifiedSymbolCache.clear();
2562 }
2563 }
2564
2565 /* ************************************************************************
2566 * Auxiliary classes
2567 *************************************************************************/
2568
2569 /** An abstract class for finalizer generation.
2570 */
2571 abstract class GenFinalizer {
2572 /** Generate code to clean up when unwinding. */
2573 abstract void gen();
2574
2575 /** Generate code to clean up at last. */
2576 abstract void genLast();
2577
2578 /** Does this finalizer have some nontrivial cleanup to perform? */
2579 boolean hasFinalizer() { return true; }
2580
2581 /** Should be invoked after the try's body has been visited. */
2582 void afterBody() {}
2583 }
2584
2585 /** code generation contexts,
2586 * to be used as type parameter for environments.
2587 */
2588 static class GenContext {
2589
2590 /** A chain for all unresolved jumps that exit the current environment.
2591 */
2592 Chain exit = null;
2593
2594 /** A chain for all unresolved jumps that continue in the
2595 * current environment.
2596 */
2597 Chain cont = null;
2598
2599 /** A closure that generates the finalizer of the current environment.
2600 * Only set for Synchronized and Try contexts.
2601 */
2602 GenFinalizer finalize = null;
2603
2604 /** Is this a switch statement? If so, allocate registers
2605 * even when the variable declaration is unreachable.
2606 */
2607 boolean isSwitch = false;
2608
2609 /** A list buffer containing all gaps in the finalizer range,
2610 * where a catch all exception should not apply.
2611 */
2612 ListBuffer<Integer> gaps = null;
2613
2614 /** Add given chain to exit chain.
2615 */
2616 void addExit(Chain c) {
2617 exit = Code.mergeChains(c, exit);
2618 }
2619
2620 /** Add given chain to cont chain.
2621 */
2622 void addCont(Chain c) {
2623 cont = Code.mergeChains(c, cont);
2624 }
2625 }
2626
2627 record PatternMatchingCatchConfiguration(Set<JCMethodInvocation> invocations,
2628 ListBuffer<int[]> ranges,
2629 JCCatch handler,
2630 State startState) {
2631 public PatternMatchingCatchConfiguration restart(State newState) {
2632 return new PatternMatchingCatchConfiguration(invocations(),
2633 new ListBuffer<int[]>(),
2634 handler(),
2635 newState);
2636 }
2637 }
2638 }