1 /*
2 * Copyright (c) 1999, 2026, 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.JCTree.*;
49
50 import static com.sun.tools.javac.code.Flags.*;
51 import static com.sun.tools.javac.code.Kinds.Kind.*;
52 import static com.sun.tools.javac.code.TypeTag.*;
53 import static com.sun.tools.javac.jvm.ByteCodes.*;
54 import static com.sun.tools.javac.jvm.CRTFlags.*;
55 import static com.sun.tools.javac.main.Option.*;
56 import static com.sun.tools.javac.tree.JCTree.Tag.*;
57
58 /** This pass maps flat Java (i.e. without inner classes) to bytecodes.
59 *
60 * <p><b>This is NOT part of any supported API.
61 * If you write code that depends on this, you do so at your own risk.
62 * This code and its internal interfaces are subject to change or
63 * deletion without notice.</b>
64 */
65 public class Gen extends JCTree.Visitor {
66 protected static final Context.Key<Gen> genKey = new Context.Key<>();
67
68 private final Log log;
69 private final Symtab syms;
70 private final Check chk;
71 private final Resolve rs;
72 private final TreeMaker make;
73 private final Names names;
74 private final Target target;
75 private final String accessDollar;
76 private final Types types;
77 private final Lower lower;
78 private final Annotate annotate;
79 private final StringConcat concat;
80 private final LocalProxyVarsGen localProxyVarsGen;
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 localProxyVarsGen = LocalProxyVarsGen.instance(context);
114
115 methodType = new MethodType(null, null, null, syms.methodClass);
116 accessDollar = "access" + target.syntheticNameChar();
117 lower = Lower.instance(context);
118
119 Options options = Options.instance(context);
120 lineDebugInfo =
121 options.isUnset(G_CUSTOM) ||
122 options.isSet(G_CUSTOM, "lines");
123 varDebugInfo =
124 options.isUnset(G_CUSTOM)
125 ? options.isSet(G)
126 : options.isSet(G_CUSTOM, "vars");
127 genCrt = options.isSet(XJCOV);
128 debugCode = options.isSet("debug.code");
129 disableVirtualizedPrivateInvoke = options.isSet("disableVirtualizedPrivateInvoke");
130 poolWriter = new PoolWriter(types, names);
131
132 // ignore cldc because we cannot have both stackmap formats
133 this.stackMap = StackMapFormat.JSR202;
134 annotate = Annotate.instance(context);
135 qualifiedSymbolCache = new HashMap<>();
136 Preview preview = Preview.instance(context);
137 Source source = Source.instance(context);
138 allowValueClasses = preview.isEnabled() && Source.Feature.VALUE_CLASSES.allowedInSource(source);
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 private final boolean allowValueClasses;
149
150 /** Code buffer, set by genMethod.
151 */
152 private Code code;
153
154 /** Items structure, set by genMethod.
155 */
156 private Items items;
157
158 /** Environment for symbol lookup, set by genClass
159 */
160 private Env<AttrContext> attrEnv;
161
162 /** The top level tree.
163 */
164 private JCCompilationUnit toplevel;
165
166 /** The number of code-gen errors in this class.
167 */
168 private int nerrs = 0;
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 classDecl The class declaration to normalize.
423 */
424 List<JCTree> normalizeDefs(JCClassDecl classDecl) {
425 ListBuffer<JCStatement> initCode = new ListBuffer<>();
426 // only used for value classes
427 ListBuffer<JCStatement> initBlocks = new ListBuffer<>();
428 ListBuffer<Attribute.TypeCompound> initTAs = new ListBuffer<>();
429 ListBuffer<JCStatement> clinitCode = new ListBuffer<>();
430 ListBuffer<Attribute.TypeCompound> clinitTAs = new ListBuffer<>();
431 ListBuffer<JCTree> methodDefs = new ListBuffer<>();
432 // Sort definitions into three listbuffers:
433 // - initCode for instance initializers
434 // - clinitCode for class initializers
435 // - methodDefs for method definitions
436 for (List<JCTree> l = classDecl.defs; l.nonEmpty(); l = l.tail) {
437 JCTree def = l.head;
438 switch (def.getTag()) {
439 case BLOCK:
440 JCBlock block = (JCBlock)def;
441 if ((block.flags & STATIC) != 0)
442 clinitCode.append(block);
443 else if ((block.flags & SYNTHETIC) == 0) {
444 if (classDecl.sym.isValueClass()) {
445 initBlocks.append(block);
446 } else {
447 initCode.append(block);
448 }
449 }
450 break;
451 case METHODDEF:
452 methodDefs.append(def);
453 break;
454 case VARDEF:
455 JCVariableDecl vdef = (JCVariableDecl) def;
456 VarSymbol sym = vdef.sym;
457 checkDimension(vdef.pos(), sym.type);
458 if (vdef.init != null) {
459 if ((sym.flags() & STATIC) == 0) {
460 // Always initialize instance variables.
461 JCStatement init = make.at(vdef.pos()).
462 Assignment(sym, vdef.init);
463 initCode.append(init);
464 init.endpos = vdef.endpos;
465 initTAs.addAll(getAndRemoveNonFieldTAs(sym));
466 } else if (sym.getConstValue() == null) {
467 // Initialize class (static) variables only if
468 // they are not compile-time constants.
469 JCStatement init = make.at(vdef.pos).
470 Assignment(sym, vdef.init);
471 clinitCode.append(init);
472 init.endpos = vdef.endpos;
473 clinitTAs.addAll(getAndRemoveNonFieldTAs(sym));
474 } else {
475 checkStringConstant(vdef.init.pos(), sym.getConstValue());
476 /* if the init contains a reference to an external class, add it to the
477 * constant's pool
478 */
479 vdef.init.accept(classReferenceVisitor);
480 }
481 }
482 break;
483 default:
484 Assert.error();
485 }
486 }
487 // Insert any instance initializers into all constructors.
488 List<TypeCompound> initTAlist = List.nil();
489 if (initCode.nonEmpty() || initBlocks.nonEmpty()) {
490 initTAs.addAll(classDecl.sym.getInitTypeAttributes());
491 initTAlist = initTAs.toList();
492 }
493 for (JCTree t : methodDefs) {
494 normalizeMethod((JCMethodDecl)t, initCode.toList(), initBlocks.toList(), initTAlist);
495 }
496 localProxyVarsGen.allFieldNormalized(classDecl.sym);
497 // If there are class initializers, create a <clinit> method
498 // that contains them as its body.
499 if (clinitCode.length() != 0) {
500 MethodSymbol clinit = new MethodSymbol(
501 STATIC | (classDecl.sym.flags() & STRICTFP),
502 names.clinit,
503 new MethodType(
504 List.nil(), syms.voidType,
505 List.nil(), syms.methodClass),
506 classDecl.sym);
507 classDecl.sym.members().enter(clinit);
508 List<JCStatement> clinitStats = clinitCode.toList();
509 JCBlock block = make.at(clinitStats.head.pos()).Block(0, clinitStats);
510 block.bracePos = TreeInfo.endPos(clinitStats.last());
511 methodDefs.append(make.MethodDef(clinit, block));
512
513 if (!clinitTAs.isEmpty())
514 clinit.appendUniqueTypeAttributes(clinitTAs.toList());
515 if (!classDecl.sym.getClassInitTypeAttributes().isEmpty())
516 clinit.appendUniqueTypeAttributes(classDecl.sym.getClassInitTypeAttributes());
517 }
518 // Return all method definitions.
519 return methodDefs.toList();
520 }
521
522 private List<Attribute.TypeCompound> getAndRemoveNonFieldTAs(VarSymbol sym) {
523 List<TypeCompound> tas = sym.getRawTypeAttributes();
524 ListBuffer<Attribute.TypeCompound> fieldTAs = new ListBuffer<>();
525 ListBuffer<Attribute.TypeCompound> nonfieldTAs = new ListBuffer<>();
526 for (TypeCompound ta : tas) {
527 Assert.check(ta.getPosition().type != TargetType.UNKNOWN);
528 if (ta.getPosition().type == TargetType.FIELD) {
529 fieldTAs.add(ta);
530 } else {
531 nonfieldTAs.add(ta);
532 }
533 }
534 sym.setTypeAttributes(fieldTAs.toList());
535 return nonfieldTAs.toList();
536 }
537
538 /** Check a constant value and report if it is a string that is
539 * too large.
540 */
541 private void checkStringConstant(DiagnosticPosition pos, Object constValue) {
542 if (nerrs != 0 || // only complain about a long string once
543 constValue == null ||
544 !(constValue instanceof String str) ||
545 str.length() < PoolWriter.MAX_STRING_LENGTH)
546 return;
547 log.error(pos, Errors.LimitString);
548 nerrs++;
549 }
550
551 /** Insert instance initializer code into constructors prior to the super() call.
552 * @param md The tree potentially representing a
553 * constructor's definition.
554 * @param initCode The list of instance initializer statements.
555 * @param initTAs Type annotations from the initializer expression.
556 */
557 void normalizeMethod(JCMethodDecl md, List<JCStatement> initCode, List<JCStatement> initBlocks, List<TypeCompound> initTAs) {
558 if (TreeInfo.isConstructor(md) && TreeInfo.hasConstructorCall(md, names._super)) {
559 // We are seeing a constructor that has a super() call.
560 // Find the super() invocation and append the given initializer code.
561 if (initCode.nonEmpty() || initBlocks.nonEmpty()) {
562 if (allowValueClasses &&
563 (md.sym.owner.isValueClass() || ((md.sym.owner.flags_field & RECORD) != 0))) {
564 rewriteEarlyInitializersIfNeeded(md, initCode);
565 md.body.stats = initCode.appendList(md.body.stats);
566 TreeInfo.mapSuperCalls(md.body, supercall -> make.Block(0, initBlocks.prepend(supercall)));
567 } else {
568 TreeInfo.mapSuperCalls(md.body, supercall -> make.Block(0, initCode.prepend(supercall)));
569 }
570 md.sym.appendUniqueTypeAttributes(initTAs);
571 }
572
573 localProxyVarsGen.patchConstructor(md, make);
574
575 if (md.body.bracePos == Position.NOPOS)
576 md.body.bracePos = TreeInfo.endPos(md.body.stats.last());
577 }
578 }
579
580 /**
581 * Some early field initializer might contain references to synthetic Lower symbols,
582 * such as 'this$0' or local var proxies. Since these are effectively "early reads",
583 * we need to replace such reference with a reference to the corresponding
584 * (synthetic) constructor parameter.
585 */
586 void rewriteEarlyInitializersIfNeeded(JCMethodDecl md, List<JCStatement> initCode) {
587 class EarlyInitializerVisitor extends TreeScanner {
588 @Override
589 public void visitIdent(JCIdent tree) {
590 if ((tree.sym.flags() & OUTER_THIS_FIELD) != 0) {
591 tree.sym = md.sym.extraParams.head;
592 } else if ((tree.sym.flags() & LOCAL_CAPTURE_FIELD) != 0) {
593 Symbol capturedSym = tree.sym.baseSymbol();
594 tree.sym = md.sym.capturedLocals.stream()
595 .filter(l -> l.baseSymbol() == capturedSym)
596 .findAny().orElseThrow();
597 }
598 }
599 }
600 if (md.sym.capturedLocals.nonEmpty() || md.sym.extraParams.nonEmpty()) {
601 EarlyInitializerVisitor initializerVisitor = new EarlyInitializerVisitor();
602 for (JCStatement init : initCode) {
603 initializerVisitor.scan(init);
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
796 if (tree.needsLineNumberTableEntry) {
797 code.statBegin(tree.pos);
798 }
799
800 int limit = code.nextreg;
801 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
802 try {
803 genStats(tree.defs, env);
804 } finally {
805 code.setLetExprStackPos(prevLetExprStart);
806 }
807 CondItem result = genCond(tree.expr, markBranches);
808 code.endScopes(limit);
809 //make sure variables defined in the let expression are not included
810 //in the defined variables for jumps that go outside of this let
811 //expression:
812 undefineVariablesInChain(result.falseJumps, limit);
813 undefineVariablesInChain(result.trueJumps, limit);
814 return result;
815 } else {
816 CondItem result = genExpr(_tree, syms.booleanType).mkCond();
817 if (markBranches) result.tree = _tree;
818 return result;
819 }
820 }
821 //where:
822 private void undefineVariablesInChain(Chain toClear, int limit) {
823 while (toClear != null) {
824 toClear.state.defined.excludeFrom(limit);
825 toClear = toClear.next;
826 }
827 }
828
829 public Code getCode() {
830 return code;
831 }
832
833 public Items getItems() {
834 return items;
835 }
836
837 public Env<AttrContext> getAttrEnv() {
838 return attrEnv;
839 }
840
841 /** Visitor class for expressions which might be constant expressions.
842 * This class is a subset of TreeScanner. Intended to visit trees pruned by
843 * Lower as long as constant expressions looking for references to any
844 * ClassSymbol. Any such reference will be added to the constant pool so
845 * automated tools can detect class dependencies better.
846 */
847 class ClassReferenceVisitor extends JCTree.Visitor {
848
849 @Override
850 public void visitTree(JCTree tree) {}
851
852 @Override
853 public void visitBinary(JCBinary tree) {
854 tree.lhs.accept(this);
855 tree.rhs.accept(this);
856 }
857
858 @Override
859 public void visitSelect(JCFieldAccess tree) {
860 if (tree.selected.type.hasTag(CLASS)) {
861 makeRef(tree.selected.pos(), tree.selected.type);
862 }
863 }
864
865 @Override
866 public void visitIdent(JCIdent tree) {
867 if (tree.sym.owner instanceof ClassSymbol classSymbol) {
868 poolWriter.putClass(classSymbol);
869 }
870 }
871
872 @Override
873 public void visitConditional(JCConditional tree) {
874 tree.cond.accept(this);
875 tree.truepart.accept(this);
876 tree.falsepart.accept(this);
877 }
878
879 @Override
880 public void visitUnary(JCUnary tree) {
881 tree.arg.accept(this);
882 }
883
884 @Override
885 public void visitParens(JCParens tree) {
886 tree.expr.accept(this);
887 }
888
889 @Override
890 public void visitTypeCast(JCTypeCast tree) {
891 tree.expr.accept(this);
892 }
893 }
894
895 private ClassReferenceVisitor classReferenceVisitor = new ClassReferenceVisitor();
896
897 /** Visitor method: generate code for an expression, catching and reporting
898 * any completion failures.
899 * @param tree The expression to be visited.
900 * @param pt The expression's expected type (proto-type).
901 */
902 public Item genExpr(JCTree tree, Type pt) {
903 if (!code.isAlive()) {
904 return items.makeStackItem(pt);
905 }
906
907 Type prevPt = this.pt;
908 try {
909 if (tree.type.constValue() != null) {
910 // Short circuit any expressions which are constants
911 tree.accept(classReferenceVisitor);
912 checkStringConstant(tree.pos(), tree.type.constValue());
913 Symbol sym = TreeInfo.symbol(tree);
914 if (sym != null && isConstantDynamic(sym)) {
915 result = items.makeDynamicItem(sym);
916 } else {
917 result = items.makeImmediateItem(tree.type, tree.type.constValue());
918 }
919 } else {
920 this.pt = pt;
921 tree.accept(this);
922 }
923 return result.coerce(pt);
924 } catch (CompletionFailure ex) {
925 chk.completionError(tree.pos(), ex);
926 code.state.stacksize = 1;
927 return items.makeStackItem(pt);
928 } finally {
929 this.pt = prevPt;
930 }
931 }
932
933 public boolean isConstantDynamic(Symbol sym) {
934 return sym.kind == VAR &&
935 sym instanceof DynamicVarSymbol dynamicVarSymbol &&
936 dynamicVarSymbol.isDynamic();
937 }
938
939 /** Derived visitor method: generate code for a list of method arguments.
940 * @param trees The argument expressions to be visited.
941 * @param pts The expression's expected types (i.e. the formal parameter
942 * types of the invoked method).
943 */
944 public void genArgs(List<JCExpression> trees, List<Type> pts) {
945 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail) {
946 genExpr(l.head, pts.head).load();
947 pts = pts.tail;
948 }
949 // require lists be of same length
950 Assert.check(pts.isEmpty());
951 }
952
953 /* ************************************************************************
954 * Visitor methods for statements and definitions
955 *************************************************************************/
956
957 public void visitMethodDef(JCMethodDecl tree) {
958 // Create a new local environment that points pack at method
959 // definition.
960 Env<GenContext> localEnv = env.dup(tree);
961 localEnv.enclMethod = tree;
962 // The expected type of every return statement in this method
963 // is the method's return type.
964 this.pt = tree.sym.erasure(types).getReturnType();
965
966 checkDimension(tree.pos(), tree.sym.erasure(types));
967 genMethod(tree, localEnv, false);
968 }
969 //where
970 /** Generate code for a method.
971 * @param tree The tree representing the method definition.
972 * @param env The environment current for the method body.
973 * @param fatcode A flag that indicates whether all jumps are
974 * within 32K. We first invoke this method under
975 * the assumption that fatcode == false, i.e. all
976 * jumps are within 32K. If this fails, fatcode
977 * is set to true and we try again.
978 */
979 void genMethod(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
980 MethodSymbol meth = tree.sym;
981 int extras = 0;
982 // Count up extra parameters
983 if (meth.isConstructor()) {
984 extras++;
985 if (meth.enclClass().isInner() &&
986 !meth.enclClass().isStatic()) {
987 extras++;
988 }
989 } else if ((tree.mods.flags & STATIC) == 0) {
990 extras++;
991 }
992 // System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG
993 if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes()) + extras >
994 ClassFile.MAX_PARAMETERS) {
995 log.error(tree.pos(), Errors.LimitParameters);
996 nerrs++;
997 }
998
999 else if (tree.body != null) {
1000 // Create a new code structure and initialize it.
1001 int startpcCrt = initCode(tree, env, fatcode);
1002
1003 genStat(tree.body, env);
1004
1005 if (code.state.stacksize != 0) {
1006 log.error(tree.body.pos(), Errors.StackSimError(tree.sym));
1007 throw new AssertionError();
1008 }
1009
1010 // If last statement could complete normally, insert a
1011 // return at the end.
1012 if (code.isAlive()) {
1013 code.statBegin(TreeInfo.endPos(tree.body));
1014 if (env.enclMethod == null ||
1015 env.enclMethod.sym.type.getReturnType().hasTag(VOID)) {
1016 code.emitop0(return_);
1017 } else {
1018 // sometime dead code seems alive (4415991);
1019 // generate a small loop instead
1020 int startpc = code.entryPoint();
1021 CondItem c = items.makeCondItem(goto_);
1022 code.resolve(c.jumpTrue(), startpc);
1023 }
1024 }
1025 if (genCrt)
1026 code.crt.put(tree.body,
1027 CRT_BLOCK,
1028 startpcCrt,
1029 code.curCP());
1030
1031 code.endScopes(0);
1032
1033 // If we exceeded limits, panic
1034 if (code.checkLimits(tree.pos(), log)) {
1035 nerrs++;
1036 return;
1037 }
1038
1039 // If we generated short code but got a long jump, do it again
1040 // with fatCode = true.
1041 if (!fatcode && code.fatcode) genMethod(tree, env, true);
1042
1043 // Clean up
1044 if(stackMap == StackMapFormat.JSR202) {
1045 code.lastFrame = null;
1046 code.frameBeforeLast = null;
1047 }
1048
1049 // Compress exception table
1050 code.compressCatchTable();
1051
1052 // Fill in type annotation positions for exception parameters
1053 code.fillExceptionParameterPositions();
1054 }
1055 }
1056
1057 private int initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
1058 MethodSymbol meth = tree.sym;
1059
1060 // Create a new code structure.
1061 meth.code = code = new Code(meth,
1062 fatcode,
1063 lineDebugInfo ? toplevel.lineMap : null,
1064 varDebugInfo,
1065 stackMap,
1066 debugCode,
1067 genCrt ? new CRTable(tree) : null,
1068 syms,
1069 types,
1070 poolWriter,
1071 allowValueClasses);
1072 items = new Items(poolWriter, code, syms, types);
1073 if (code.debugCode) {
1074 System.err.println(meth + " for body " + tree);
1075 }
1076
1077 // If method is not static, create a new local variable address
1078 // for `this'.
1079 if ((tree.mods.flags & STATIC) == 0) {
1080 Type selfType = meth.owner.type;
1081 if (meth.isConstructor() && selfType != syms.objectType)
1082 selfType = UninitializedType.uninitializedThis(selfType);
1083 code.setDefined(
1084 code.newLocal(
1085 new VarSymbol(FINAL, names._this, selfType, meth.owner)));
1086 }
1087
1088 // Mark all parameters as defined from the beginning of
1089 // the method.
1090 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
1091 checkDimension(l.head.pos(), l.head.sym.type);
1092 code.setDefined(code.newLocal(l.head.sym));
1093 }
1094
1095 if (allowValueClasses && meth.isConstructor()) {
1096 code.initUnsetStrictFields(env.enclClass.sym);
1097 }
1098
1099 // Get ready to generate code for method body.
1100 int startpcCrt = genCrt ? code.curCP() : 0;
1101 code.entryPoint();
1102
1103 // Suppress initial stackmap
1104 code.pendingStackMap = false;
1105
1106 return startpcCrt;
1107 }
1108
1109 public void visitVarDef(JCVariableDecl tree) {
1110 VarSymbol v = tree.sym;
1111 if (tree.init != null) {
1112 checkStringConstant(tree.init.pos(), v.getConstValue());
1113 if (v.getConstValue() == null || varDebugInfo) {
1114 Assert.check(code.isStatementStart());
1115 code.newLocal(v);
1116 genExpr(tree.init, v.erasure(types)).load();
1117 items.makeLocalItem(v).store();
1118 Assert.check(code.isStatementStart());
1119 }
1120 } else {
1121 code.newLocal(v);
1122 }
1123 checkDimension(tree.pos(), v.type);
1124 }
1125
1126 public void visitSkip(JCSkip tree) {
1127 }
1128
1129 public void visitBlock(JCBlock tree) {
1130 /* this method is heavily invoked, as expected, for deeply nested blocks, if blocks doesn't happen to have
1131 * patterns there will be an unnecessary tax on memory consumption every time this method is executed, for this
1132 * reason we have created helper methods and here at a higher level we just discriminate depending on the
1133 * presence, or not, of patterns in a given block
1134 */
1135 if (tree.patternMatchingCatch != null) {
1136 visitBlockWithPatterns(tree);
1137 } else {
1138 internalVisitBlock(tree);
1139 }
1140 }
1141
1142 private void visitBlockWithPatterns(JCBlock tree) {
1143 PatternMatchingCatchConfiguration prevConfiguration = patternMatchingCatchConfiguration;
1144 try {
1145 patternMatchingCatchConfiguration =
1146 new PatternMatchingCatchConfiguration(tree.patternMatchingCatch.calls2Handle(),
1147 new ListBuffer<int[]>(),
1148 tree.patternMatchingCatch.handler(),
1149 code.state.dup());
1150 internalVisitBlock(tree);
1151 } finally {
1152 generatePatternMatchingCatch(env);
1153 patternMatchingCatchConfiguration = prevConfiguration;
1154 }
1155 }
1156
1157 private void generatePatternMatchingCatch(Env<GenContext> env) {
1158 if (patternMatchingCatchConfiguration.handler != null &&
1159 !patternMatchingCatchConfiguration.ranges.isEmpty()) {
1160 Chain skipCatch = code.branch(goto_);
1161 JCCatch handler = patternMatchingCatchConfiguration.handler();
1162 code.entryPoint(patternMatchingCatchConfiguration.startState(),
1163 handler.param.sym.type);
1164 genPatternMatchingCatch(handler,
1165 env,
1166 patternMatchingCatchConfiguration.ranges.toList());
1167 code.resolve(skipCatch);
1168 }
1169 }
1170
1171 private void internalVisitBlock(JCBlock tree) {
1172 int limit = code.nextreg;
1173 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1174 genStats(tree.stats, localEnv);
1175 // End the scope of all block-local variables in variable info.
1176 if (!env.tree.hasTag(METHODDEF)) {
1177 code.statBegin(tree.bracePos);
1178 code.endScopes(limit);
1179 code.pendingStatPos = Position.NOPOS;
1180 }
1181 }
1182
1183 public void visitDoLoop(JCDoWhileLoop tree) {
1184 genLoop(tree, tree.body, tree.cond, List.nil(), false);
1185 }
1186
1187 public void visitWhileLoop(JCWhileLoop tree) {
1188 genLoop(tree, tree.body, tree.cond, List.nil(), true);
1189 }
1190
1191 public void visitForLoop(JCForLoop tree) {
1192 int limit = code.nextreg;
1193 genStats(tree.init, env);
1194 genLoop(tree, tree.body, tree.cond, tree.step, true);
1195 code.endScopes(limit);
1196 }
1197 //where
1198 /** Generate code for a loop.
1199 * @param loop The tree representing the loop.
1200 * @param body The loop's body.
1201 * @param cond The loop's controlling condition.
1202 * @param step "Step" statements to be inserted at end of
1203 * each iteration.
1204 * @param testFirst True if the loop test belongs before the body.
1205 */
1206 private void genLoop(JCStatement loop,
1207 JCStatement body,
1208 JCExpression cond,
1209 List<JCExpressionStatement> step,
1210 boolean testFirst) {
1211 genLoopHelper(loop, body, cond, step, testFirst);
1212 }
1213
1214 private void genLoopHelper(JCStatement loop,
1215 JCStatement body,
1216 JCExpression cond,
1217 List<JCExpressionStatement> step,
1218 boolean testFirst) {
1219 Env<GenContext> loopEnv = env.dup(loop, new GenContext());
1220 int startpc = code.entryPoint();
1221 if (testFirst) { //while or for loop
1222 CondItem c;
1223 if (cond != null) {
1224 code.statBegin(cond.pos);
1225 Assert.check(code.isStatementStart());
1226 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1227 } else {
1228 c = items.makeCondItem(goto_);
1229 }
1230 Chain loopDone = c.jumpFalse();
1231 code.resolve(c.trueJumps);
1232 Assert.check(code.isStatementStart());
1233 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1234 code.resolve(loopEnv.info.cont);
1235 genStats(step, loopEnv);
1236 code.resolve(code.branch(goto_), startpc);
1237 code.resolve(loopDone);
1238 } else {
1239 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1240 code.resolve(loopEnv.info.cont);
1241 genStats(step, loopEnv);
1242 if (code.isAlive()) {
1243 CondItem c;
1244 if (cond != null) {
1245 code.statBegin(cond.pos);
1246 Assert.check(code.isStatementStart());
1247 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1248 } else {
1249 c = items.makeCondItem(goto_);
1250 }
1251 code.resolve(c.jumpTrue(), startpc);
1252 Assert.check(code.isStatementStart());
1253 code.resolve(c.falseJumps);
1254 }
1255 }
1256 code.resolve(loopEnv.info.exit);
1257 }
1258
1259 public void visitForeachLoop(JCEnhancedForLoop tree) {
1260 throw new AssertionError(); // should have been removed by Lower.
1261 }
1262
1263 public void visitLabelled(JCLabeledStatement tree) {
1264 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1265 genStat(tree.body, localEnv, CRT_STATEMENT);
1266 code.resolve(localEnv.info.exit);
1267 }
1268
1269 public void visitSwitch(JCSwitch tree) {
1270 handleSwitch(tree, tree.selector, tree.cases, tree.patternSwitch);
1271 }
1272
1273 @Override
1274 public void visitSwitchExpression(JCSwitchExpression tree) {
1275 code.resolvePending();
1276 boolean prevInCondSwitchExpression = inCondSwitchExpression;
1277 try {
1278 inCondSwitchExpression = false;
1279 doHandleSwitchExpression(tree);
1280 } finally {
1281 inCondSwitchExpression = prevInCondSwitchExpression;
1282 }
1283 result = items.makeStackItem(pt);
1284 }
1285
1286 private void doHandleSwitchExpression(JCSwitchExpression tree) {
1287 List<LocalItem> prevStackBeforeSwitchExpression = stackBeforeSwitchExpression;
1288 LocalItem prevSwitchResult = switchResult;
1289 int limit = code.nextreg;
1290 try {
1291 stackBeforeSwitchExpression = List.nil();
1292 switchResult = null;
1293 if (hasTry(tree)) {
1294 //if the switch expression contains try-catch, the catch handlers need to have
1295 //an empty stack. So stash whole stack to local variables, and restore it before
1296 //breaks:
1297 while (code.state.stacksize > 0) {
1298 Type type = code.state.peek();
1299 Name varName = names.fromString(target.syntheticNameChar() +
1300 "stack" +
1301 target.syntheticNameChar() +
1302 tree.pos +
1303 target.syntheticNameChar() +
1304 code.state.stacksize);
1305 VarSymbol var = new VarSymbol(Flags.SYNTHETIC, varName, type,
1306 this.env.enclMethod.sym);
1307 LocalItem item = items.new LocalItem(type, code.newLocal(var));
1308 stackBeforeSwitchExpression = stackBeforeSwitchExpression.prepend(item);
1309 item.store();
1310 }
1311 switchResult = makeTemp(tree.type);
1312 }
1313 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
1314 try {
1315 handleSwitch(tree, tree.selector, tree.cases, tree.patternSwitch);
1316 } finally {
1317 code.setLetExprStackPos(prevLetExprStart);
1318 }
1319 } finally {
1320 stackBeforeSwitchExpression = prevStackBeforeSwitchExpression;
1321 switchResult = prevSwitchResult;
1322 code.endScopes(limit);
1323 }
1324 }
1325 //where:
1326 private boolean hasTry(JCSwitchExpression tree) {
1327 class HasTryScanner extends TreeScanner {
1328 private boolean hasTry;
1329
1330 @Override
1331 public void visitTry(JCTry tree) {
1332 hasTry = true;
1333 }
1334
1335 @Override
1336 public void visitSynchronized(JCSynchronized tree) {
1337 hasTry = true;
1338 }
1339
1340 @Override
1341 public void visitClassDef(JCClassDecl tree) {
1342 }
1343
1344 @Override
1345 public void visitLambda(JCLambda tree) {
1346 }
1347 };
1348
1349 HasTryScanner hasTryScanner = new HasTryScanner();
1350
1351 hasTryScanner.scan(tree);
1352 return hasTryScanner.hasTry;
1353 }
1354
1355 private void handleSwitch(JCTree swtch, JCExpression selector, List<JCCase> cases,
1356 boolean patternSwitch) {
1357 handleSwitchHelper(swtch, selector, cases, patternSwitch);
1358 }
1359
1360 void handleSwitchHelper(JCTree swtch, JCExpression selector, List<JCCase> cases,
1361 boolean patternSwitch) {
1362 int limit = code.nextreg;
1363 Assert.check(!selector.type.hasTag(CLASS));
1364 int switchStart = patternSwitch ? code.entryPoint() : -1;
1365 int startpcCrt = genCrt ? code.curCP() : 0;
1366 Assert.check(code.isStatementStart());
1367 Item sel = genExpr(selector, syms.intType);
1368 if (cases.isEmpty()) {
1369 // We are seeing: switch <sel> {}
1370 sel.load().drop();
1371 if (genCrt)
1372 code.crt.put(TreeInfo.skipParens(selector),
1373 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1374 } else {
1375 // We are seeing a nonempty switch.
1376 sel.load();
1377 if (genCrt)
1378 code.crt.put(TreeInfo.skipParens(selector),
1379 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1380 Env<GenContext> switchEnv = env.dup(swtch, new GenContext());
1381 switchEnv.info.isSwitch = true;
1382
1383 // Compute number of labels and minimum and maximum label values.
1384 // For each case, store its label in an array.
1385 int lo = Integer.MAX_VALUE; // minimum label.
1386 int hi = Integer.MIN_VALUE; // maximum label.
1387 int nlabels = 0; // number of labels.
1388
1389 int[] labels = new int[cases.length()]; // the label array.
1390 int defaultIndex = -1; // the index of the default clause.
1391
1392 List<JCCase> l = cases;
1393 for (int i = 0; i < labels.length; i++) {
1394 if (l.head.labels.head instanceof JCConstantCaseLabel constLabel) {
1395 Assert.check(l.head.labels.size() == 1);
1396 int val = ((Number) constLabel.expr.type.constValue()).intValue();
1397 labels[i] = val;
1398 if (val < lo) lo = val;
1399 if (hi < val) hi = val;
1400 nlabels++;
1401 } else {
1402 Assert.check(defaultIndex == -1);
1403 defaultIndex = i;
1404 }
1405 l = l.tail;
1406 }
1407
1408 // Determine whether to issue a tableswitch or a lookupswitch
1409 // instruction.
1410 long table_space_cost = 4 + ((long) hi - lo + 1); // words
1411 long table_time_cost = 3; // comparisons
1412 long lookup_space_cost = 3 + 2 * (long) nlabels;
1413 long lookup_time_cost = nlabels;
1414 int opcode =
1415 nlabels > 0 &&
1416 table_space_cost + 3 * table_time_cost <=
1417 lookup_space_cost + 3 * lookup_time_cost
1418 ?
1419 tableswitch : lookupswitch;
1420
1421 int startpc = code.curCP(); // the position of the selector operation
1422 code.emitop0(opcode);
1423 code.align(4);
1424 int tableBase = code.curCP(); // the start of the jump table
1425 int[] offsets = null; // a table of offsets for a lookupswitch
1426 code.emit4(-1); // leave space for default offset
1427 if (opcode == tableswitch) {
1428 code.emit4(lo); // minimum label
1429 code.emit4(hi); // maximum label
1430 for (long i = lo; i <= hi; i++) { // leave space for jump table
1431 code.emit4(-1);
1432 }
1433 } else {
1434 code.emit4(nlabels); // number of labels
1435 for (int i = 0; i < nlabels; i++) {
1436 code.emit4(-1); code.emit4(-1); // leave space for lookup table
1437 }
1438 offsets = new int[labels.length];
1439 }
1440 Code.State stateSwitch = code.state.dup();
1441 code.markDead();
1442
1443 // For each case do:
1444 l = cases;
1445 for (int i = 0; i < labels.length; i++) {
1446 JCCase c = l.head;
1447 l = l.tail;
1448
1449 int pc = code.entryPoint(stateSwitch);
1450 // Insert offset directly into code or else into the
1451 // offsets table.
1452 if (i != defaultIndex) {
1453 if (opcode == tableswitch) {
1454 code.put4(
1455 tableBase + 4 * (labels[i] - lo + 3),
1456 pc - startpc);
1457 } else {
1458 offsets[i] = pc - startpc;
1459 }
1460 } else {
1461 code.put4(tableBase, pc - startpc);
1462 }
1463
1464 // Generate code for the statements in this case.
1465 genStats(c.stats, switchEnv, CRT_FLOW_TARGET);
1466 }
1467
1468 if (switchEnv.info.cont != null) {
1469 Assert.check(patternSwitch);
1470 code.resolve(switchEnv.info.cont, switchStart);
1471 }
1472
1473 // Resolve all breaks.
1474 code.resolve(switchEnv.info.exit);
1475
1476 // If we have not set the default offset, we do so now.
1477 if (code.get4(tableBase) == -1) {
1478 code.put4(tableBase, code.entryPoint(stateSwitch) - startpc);
1479 }
1480
1481 if (opcode == tableswitch) {
1482 // Let any unfilled slots point to the default case.
1483 int defaultOffset = code.get4(tableBase);
1484 for (long i = lo; i <= hi; i++) {
1485 int t = (int)(tableBase + 4 * (i - lo + 3));
1486 if (code.get4(t) == -1)
1487 code.put4(t, defaultOffset);
1488 }
1489 } else {
1490 // Sort non-default offsets and copy into lookup table.
1491 if (defaultIndex >= 0)
1492 for (int i = defaultIndex; i < labels.length - 1; i++) {
1493 labels[i] = labels[i+1];
1494 offsets[i] = offsets[i+1];
1495 }
1496 if (nlabels > 0)
1497 qsort2(labels, offsets, 0, nlabels - 1);
1498 for (int i = 0; i < nlabels; i++) {
1499 int caseidx = tableBase + 8 * (i + 1);
1500 code.put4(caseidx, labels[i]);
1501 code.put4(caseidx + 4, offsets[i]);
1502 }
1503 }
1504
1505 if (swtch instanceof JCSwitchExpression) {
1506 // Emit line position for the end of a switch expression
1507 code.statBegin(TreeInfo.endPos(swtch));
1508 }
1509 }
1510 code.endScopes(limit);
1511 }
1512 //where
1513 /** Sort (int) arrays of keys and values
1514 */
1515 static void qsort2(int[] keys, int[] values, int lo, int hi) {
1516 int i = lo;
1517 int j = hi;
1518 int pivot = keys[(i+j)/2];
1519 do {
1520 while (keys[i] < pivot) i++;
1521 while (pivot < keys[j]) j--;
1522 if (i <= j) {
1523 int temp1 = keys[i];
1524 keys[i] = keys[j];
1525 keys[j] = temp1;
1526 int temp2 = values[i];
1527 values[i] = values[j];
1528 values[j] = temp2;
1529 i++;
1530 j--;
1531 }
1532 } while (i <= j);
1533 if (lo < j) qsort2(keys, values, lo, j);
1534 if (i < hi) qsort2(keys, values, i, hi);
1535 }
1536
1537 public void visitSynchronized(JCSynchronized tree) {
1538 int limit = code.nextreg;
1539 // Generate code to evaluate lock and save in temporary variable.
1540 final LocalItem lockVar = makeTemp(syms.objectType);
1541 Assert.check(code.isStatementStart());
1542 genExpr(tree.lock, tree.lock.type).load().duplicate();
1543 lockVar.store();
1544
1545 // Generate code to enter monitor.
1546 code.emitop0(monitorenter);
1547 code.state.lock(lockVar.reg);
1548
1549 // Generate code for a try statement with given body, no catch clauses
1550 // in a new environment with the "exit-monitor" operation as finalizer.
1551 final Env<GenContext> syncEnv = env.dup(tree, new GenContext());
1552 syncEnv.info.finalize = new GenFinalizer() {
1553 void gen() {
1554 genLast();
1555 Assert.check(syncEnv.info.gaps.length() % 2 == 0);
1556 syncEnv.info.gaps.append(code.curCP());
1557 }
1558 void genLast() {
1559 if (code.isAlive()) {
1560 lockVar.load();
1561 code.emitop0(monitorexit);
1562 code.state.unlock(lockVar.reg);
1563 }
1564 }
1565 };
1566 syncEnv.info.gaps = new ListBuffer<>();
1567 genTry(tree.body, List.nil(), syncEnv);
1568 code.endScopes(limit);
1569 }
1570
1571 public void visitTry(final JCTry tree) {
1572 // Generate code for a try statement with given body and catch clauses,
1573 // in a new environment which calls the finally block if there is one.
1574 final Env<GenContext> tryEnv = env.dup(tree, new GenContext());
1575 final Env<GenContext> oldEnv = env;
1576 tryEnv.info.finalize = new GenFinalizer() {
1577 void gen() {
1578 Assert.check(tryEnv.info.gaps.length() % 2 == 0);
1579 tryEnv.info.gaps.append(code.curCP());
1580 genLast();
1581 }
1582 void genLast() {
1583 if (tree.finalizer != null)
1584 genStat(tree.finalizer, oldEnv, CRT_BLOCK);
1585 }
1586 boolean hasFinalizer() {
1587 return tree.finalizer != null;
1588 }
1589
1590 @Override
1591 void afterBody() {
1592 if (tree.finalizer != null && (tree.finalizer.flags & BODY_ONLY_FINALIZE) != 0) {
1593 //for body-only finally, remove the GenFinalizer after try body
1594 //so that the finally is not generated to catch bodies:
1595 tryEnv.info.finalize = null;
1596 }
1597 }
1598
1599 };
1600 tryEnv.info.gaps = new ListBuffer<>();
1601 genTry(tree.body, tree.catchers, tryEnv);
1602 }
1603 //where
1604 /** Generate code for a try or synchronized statement
1605 * @param body The body of the try or synchronized statement.
1606 * @param catchers The list of catch clauses.
1607 * @param env The current environment of the body.
1608 */
1609 void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) {
1610 genTryHelper(body, catchers, env);
1611 }
1612
1613 void genTryHelper(JCTree body, List<JCCatch> catchers, Env<GenContext> env) {
1614 int limit = code.nextreg;
1615 int startpc = code.curCP();
1616 Code.State stateTry = code.state.dup();
1617 genStat(body, env, CRT_BLOCK);
1618 int endpc = code.curCP();
1619 List<Integer> gaps = env.info.gaps.toList();
1620 code.statBegin(TreeInfo.endPos(body));
1621 genFinalizer(env);
1622 code.statBegin(TreeInfo.endPos(env.tree));
1623 Chain exitChain;
1624 boolean actualTry = env.tree.hasTag(TRY);
1625 if (startpc == endpc && actualTry) {
1626 exitChain = code.branch(dontgoto);
1627 } else {
1628 exitChain = code.branch(goto_);
1629 }
1630 endFinalizerGap(env);
1631 env.info.finalize.afterBody();
1632 boolean hasFinalizer =
1633 env.info.finalize != null &&
1634 env.info.finalize.hasFinalizer();
1635 if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) {
1636 // start off with exception on stack
1637 code.entryPoint(stateTry, l.head.param.sym.type);
1638 genCatch(l.head, env, startpc, endpc, gaps);
1639 genFinalizer(env);
1640 if (hasFinalizer || l.tail.nonEmpty()) {
1641 code.statBegin(TreeInfo.endPos(env.tree));
1642 exitChain = Code.mergeChains(exitChain,
1643 code.branch(goto_));
1644 }
1645 endFinalizerGap(env);
1646 }
1647 if (hasFinalizer && (startpc != endpc || !actualTry)) {
1648 // Create a new register segment to avoid allocating
1649 // the same variables in finalizers and other statements.
1650 code.newRegSegment();
1651
1652 // Add a catch-all clause.
1653
1654 // start off with exception on stack
1655 int catchallpc = code.entryPoint(stateTry, syms.throwableType);
1656
1657 // Register all exception ranges for catch all clause.
1658 // The range of the catch all clause is from the beginning
1659 // of the try or synchronized block until the present
1660 // code pointer excluding all gaps in the current
1661 // environment's GenContext.
1662 int startseg = startpc;
1663 while (env.info.gaps.nonEmpty()) {
1664 int endseg = env.info.gaps.next().intValue();
1665 registerCatch(body.pos(), startseg, endseg,
1666 catchallpc, 0);
1667 startseg = env.info.gaps.next().intValue();
1668 }
1669 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1670 code.markStatBegin();
1671
1672 Item excVar = makeTemp(syms.throwableType);
1673 excVar.store();
1674 genFinalizer(env);
1675 code.resolvePending();
1676 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.END_POS));
1677 code.markStatBegin();
1678
1679 excVar.load();
1680 registerCatch(body.pos(), startseg,
1681 env.info.gaps.next().intValue(),
1682 catchallpc, 0);
1683 code.emitop0(athrow);
1684 code.markDead();
1685
1686 // If there are jsr's to this finalizer, ...
1687 if (env.info.cont != null) {
1688 // Resolve all jsr's.
1689 code.resolve(env.info.cont);
1690
1691 // Mark statement line number
1692 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1693 code.markStatBegin();
1694
1695 // Save return address.
1696 LocalItem retVar = makeTemp(syms.throwableType);
1697 retVar.store();
1698
1699 // Generate finalizer code.
1700 env.info.finalize.genLast();
1701
1702 // Return.
1703 code.emitop1w(ret, retVar.reg);
1704 code.markDead();
1705 }
1706 }
1707 // Resolve all breaks.
1708 code.resolve(exitChain);
1709
1710 code.endScopes(limit);
1711 }
1712
1713 /** Generate code for a catch clause.
1714 * @param tree The catch clause.
1715 * @param env The environment current in the enclosing try.
1716 * @param startpc Start pc of try-block.
1717 * @param endpc End pc of try-block.
1718 */
1719 void genCatch(JCCatch tree,
1720 Env<GenContext> env,
1721 int startpc, int endpc,
1722 List<Integer> gaps) {
1723 if (startpc != endpc) {
1724 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypeExprs
1725 = catchTypesWithAnnotations(tree);
1726 while (gaps.nonEmpty()) {
1727 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) {
1728 JCExpression subCatch = subCatch1.snd;
1729 int catchType = makeRef(tree.pos(), subCatch.type);
1730 int end = gaps.head.intValue();
1731 registerCatch(tree.pos(),
1732 startpc, end, code.curCP(),
1733 catchType);
1734 for (Attribute.TypeCompound tc : subCatch1.fst) {
1735 tc.position.setCatchInfo(catchType, startpc);
1736 }
1737 }
1738 gaps = gaps.tail;
1739 startpc = gaps.head.intValue();
1740 gaps = gaps.tail;
1741 }
1742 if (startpc < endpc) {
1743 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) {
1744 JCExpression subCatch = subCatch1.snd;
1745 int catchType = makeRef(tree.pos(), subCatch.type);
1746 registerCatch(tree.pos(),
1747 startpc, endpc, code.curCP(),
1748 catchType);
1749 for (Attribute.TypeCompound tc : subCatch1.fst) {
1750 tc.position.setCatchInfo(catchType, startpc);
1751 }
1752 }
1753 }
1754 genCatchBlock(tree, env);
1755 }
1756 }
1757 void genPatternMatchingCatch(JCCatch tree,
1758 Env<GenContext> env,
1759 List<int[]> ranges) {
1760 for (int[] range : ranges) {
1761 JCExpression subCatch = tree.param.vartype;
1762 int catchType = makeRef(tree.pos(), subCatch.type);
1763 registerCatch(tree.pos(),
1764 range[0], range[1], code.curCP(),
1765 catchType);
1766 }
1767 genCatchBlock(tree, env);
1768 }
1769 void genCatchBlock(JCCatch tree, Env<GenContext> env) {
1770 VarSymbol exparam = tree.param.sym;
1771 code.statBegin(tree.pos);
1772 code.markStatBegin();
1773 int limit = code.nextreg;
1774 code.newLocal(exparam);
1775 items.makeLocalItem(exparam).store();
1776 code.statBegin(TreeInfo.firstStatPos(tree.body));
1777 genStat(tree.body, env, CRT_BLOCK);
1778 code.endScopes(limit);
1779 code.statBegin(TreeInfo.endPos(tree.body));
1780 }
1781 // where
1782 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotations(JCCatch tree) {
1783 return TreeInfo.isMultiCatch(tree) ?
1784 catchTypesWithAnnotationsFromMulticatch((JCTypeUnion)tree.param.vartype, tree.param.sym.getRawTypeAttributes()) :
1785 List.of(new Pair<>(tree.param.sym.getRawTypeAttributes(), tree.param.vartype));
1786 }
1787 // where
1788 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotationsFromMulticatch(JCTypeUnion tree, List<TypeCompound> first) {
1789 List<JCExpression> alts = tree.alternatives;
1790 List<Pair<List<TypeCompound>, JCExpression>> res = List.of(new Pair<>(first, alts.head));
1791 alts = alts.tail;
1792
1793 while(alts != null && alts.head != null) {
1794 JCExpression alt = alts.head;
1795 if (alt instanceof JCAnnotatedType annotatedType) {
1796 res = res.prepend(new Pair<>(annotate.fromAnnotations(annotatedType.annotations), alt));
1797 } else {
1798 res = res.prepend(new Pair<>(List.nil(), alt));
1799 }
1800 alts = alts.tail;
1801 }
1802 return res.reverse();
1803 }
1804
1805 /** Register a catch clause in the "Exceptions" code-attribute.
1806 */
1807 void registerCatch(DiagnosticPosition pos,
1808 int startpc, int endpc,
1809 int handler_pc, int catch_type) {
1810 char startpc1 = (char)startpc;
1811 char endpc1 = (char)endpc;
1812 char handler_pc1 = (char)handler_pc;
1813 if (startpc1 == startpc &&
1814 endpc1 == endpc &&
1815 handler_pc1 == handler_pc) {
1816 code.addCatch(startpc1, endpc1, handler_pc1,
1817 (char)catch_type);
1818 } else {
1819 log.error(pos, Errors.LimitCodeTooLargeForTryStmt);
1820 nerrs++;
1821 }
1822 }
1823
1824 public void visitIf(JCIf tree) {
1825 visitIfHelper(tree);
1826 }
1827
1828 public void visitIfHelper(JCIf tree) {
1829 int limit = code.nextreg;
1830 Chain thenExit = null;
1831 Assert.check(code.isStatementStart());
1832 CondItem c = genCond(TreeInfo.skipParens(tree.cond),
1833 CRT_FLOW_CONTROLLER);
1834 Chain elseChain = c.jumpFalse();
1835 Assert.check(code.isStatementStart());
1836 if (!c.isFalse()) {
1837 code.resolve(c.trueJumps);
1838 genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET);
1839 thenExit = code.branch(goto_);
1840 }
1841 if (elseChain != null) {
1842 code.resolve(elseChain);
1843 if (tree.elsepart != null) {
1844 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET);
1845 }
1846 }
1847 code.resolve(thenExit);
1848 code.endScopes(limit);
1849 Assert.check(code.isStatementStart());
1850 }
1851
1852 public void visitExec(JCExpressionStatement tree) {
1853 // Optimize x++ to ++x and x-- to --x.
1854 JCExpression e = tree.expr;
1855 switch (e.getTag()) {
1856 case POSTINC:
1857 ((JCUnary) e).setTag(PREINC);
1858 break;
1859 case POSTDEC:
1860 ((JCUnary) e).setTag(PREDEC);
1861 break;
1862 }
1863 Assert.check(code.isStatementStart());
1864 genExpr(tree.expr, tree.expr.type).drop();
1865 Assert.check(code.isStatementStart());
1866 }
1867
1868 public void visitBreak(JCBreak tree) {
1869 Assert.check(code.isStatementStart());
1870 final Env<GenContext> targetEnv = unwindBreak(tree.target);
1871 targetEnv.info.addExit(code.branch(goto_));
1872 endFinalizerGaps(env, targetEnv);
1873 }
1874
1875 public void visitYield(JCYield tree) {
1876 Assert.check(code.isStatementStart());
1877 final Env<GenContext> targetEnv;
1878 if (inCondSwitchExpression) {
1879 CondItem value = genCond(tree.value, CRT_FLOW_TARGET);
1880 Chain falseJumps = value.jumpFalse();
1881
1882 code.resolve(value.trueJumps);
1883 Env<GenContext> localEnv = unwindBreak(tree.target);
1884 reloadStackBeforeSwitchExpr();
1885 Chain trueJumps = code.branch(goto_);
1886
1887 endFinalizerGaps(env, localEnv);
1888
1889 code.resolve(falseJumps);
1890 targetEnv = unwindBreak(tree.target);
1891 reloadStackBeforeSwitchExpr();
1892 falseJumps = code.branch(goto_);
1893
1894 if (switchExpressionTrueChain == null) {
1895 switchExpressionTrueChain = trueJumps;
1896 } else {
1897 switchExpressionTrueChain =
1898 Code.mergeChains(switchExpressionTrueChain, trueJumps);
1899 }
1900 if (switchExpressionFalseChain == null) {
1901 switchExpressionFalseChain = falseJumps;
1902 } else {
1903 switchExpressionFalseChain =
1904 Code.mergeChains(switchExpressionFalseChain, falseJumps);
1905 }
1906 } else {
1907 genExpr(tree.value, pt).load();
1908 if (switchResult != null)
1909 switchResult.store();
1910
1911 targetEnv = unwindBreak(tree.target);
1912
1913 if (code.isAlive()) {
1914 reloadStackBeforeSwitchExpr();
1915 if (switchResult != null)
1916 switchResult.load();
1917
1918 targetEnv.info.addExit(code.branch(goto_));
1919 code.markDead();
1920 }
1921 }
1922 endFinalizerGaps(env, targetEnv);
1923 }
1924 //where:
1925 /** As side-effect, might mark code as dead disabling any further emission.
1926 */
1927 private Env<GenContext> unwindBreak(JCTree target) {
1928 int tmpPos = code.pendingStatPos;
1929 Env<GenContext> targetEnv = unwind(target, env);
1930 code.pendingStatPos = tmpPos;
1931 return targetEnv;
1932 }
1933
1934 private void reloadStackBeforeSwitchExpr() {
1935 for (LocalItem li : stackBeforeSwitchExpression)
1936 li.load();
1937 }
1938
1939 public void visitContinue(JCContinue tree) {
1940 int tmpPos = code.pendingStatPos;
1941 Env<GenContext> targetEnv = unwind(tree.target, env);
1942 code.pendingStatPos = tmpPos;
1943 Assert.check(code.isStatementStart());
1944 targetEnv.info.addCont(code.branch(goto_));
1945 endFinalizerGaps(env, targetEnv);
1946 }
1947
1948 public void visitReturn(JCReturn tree) {
1949 int limit = code.nextreg;
1950 final Env<GenContext> targetEnv;
1951
1952 /* Save and then restore the location of the return in case a finally
1953 * is expanded (with unwind()) in the middle of our bytecodes.
1954 */
1955 int tmpPos = code.pendingStatPos;
1956 if (tree.expr != null) {
1957 Assert.check(code.isStatementStart());
1958 Item r = genExpr(tree.expr, pt).load();
1959 if (hasFinally(env.enclMethod, env)) {
1960 r = makeTemp(pt);
1961 r.store();
1962 }
1963 targetEnv = unwind(env.enclMethod, env);
1964 code.pendingStatPos = tmpPos;
1965 r.load();
1966 code.emitop0(ireturn + Code.truncate(Code.typecode(pt)));
1967 } else {
1968 targetEnv = unwind(env.enclMethod, env);
1969 code.pendingStatPos = tmpPos;
1970 code.emitop0(return_);
1971 }
1972 endFinalizerGaps(env, targetEnv);
1973 code.endScopes(limit);
1974 }
1975
1976 public void visitThrow(JCThrow tree) {
1977 Assert.check(code.isStatementStart());
1978 genExpr(tree.expr, tree.expr.type).load();
1979 code.emitop0(athrow);
1980 Assert.check(code.isStatementStart());
1981 }
1982
1983 /* ************************************************************************
1984 * Visitor methods for expressions
1985 *************************************************************************/
1986
1987 public void visitApply(JCMethodInvocation tree) {
1988 setTypeAnnotationPositions(tree.pos);
1989 // Generate code for method.
1990 Item m = genExpr(tree.meth, methodType);
1991 // Generate code for all arguments, where the expected types are
1992 // the parameters of the method's external type (that is, any implicit
1993 // outer instance of a super(...) call appears as first parameter).
1994 MethodSymbol msym = (MethodSymbol)TreeInfo.symbol(tree.meth);
1995 genArgs(tree.args,
1996 msym.externalType(types).getParameterTypes());
1997 if (!msym.isDynamic()) {
1998 code.statBegin(tree.pos);
1999 }
2000 if (patternMatchingCatchConfiguration.invocations().contains(tree)) {
2001 int start = code.curCP();
2002 result = m.invoke();
2003 patternMatchingCatchConfiguration.ranges().add(new int[] {start, code.curCP()});
2004 } else {
2005 if (msym.isConstructor() && TreeInfo.isConstructorCall(tree)) {
2006 //if this is a this(...) or super(...) call, there is a pending
2007 //"uninitialized this" before this call. One catch handler cannot
2008 //handle exceptions that may come from places with "uninitialized this"
2009 //and (initialized) this, hence generate one set of handlers here
2010 //for the "uninitialized this" case, and another set of handlers
2011 //will be generated at the end of the method for the initialized this,
2012 //if needed:
2013 generatePatternMatchingCatch(env);
2014 result = m.invoke();
2015 patternMatchingCatchConfiguration =
2016 patternMatchingCatchConfiguration.restart(code.state.dup());
2017 } else {
2018 result = m.invoke();
2019 }
2020 }
2021 }
2022
2023 public void visitConditional(JCConditional tree) {
2024 Chain thenExit = null;
2025 code.statBegin(tree.cond.pos);
2026 CondItem c = genCond(tree.cond, CRT_FLOW_CONTROLLER);
2027 Chain elseChain = c.jumpFalse();
2028 if (!c.isFalse()) {
2029 code.resolve(c.trueJumps);
2030 int startpc = genCrt ? code.curCP() : 0;
2031 code.statBegin(tree.truepart.pos);
2032 genExpr(tree.truepart, pt).load();
2033 if (genCrt) code.crt.put(tree.truepart, CRT_FLOW_TARGET,
2034 startpc, code.curCP());
2035 thenExit = code.branch(goto_);
2036 }
2037 if (elseChain != null) {
2038 code.resolve(elseChain);
2039 int startpc = genCrt ? code.curCP() : 0;
2040 code.statBegin(tree.falsepart.pos);
2041 genExpr(tree.falsepart, pt).load();
2042 if (genCrt) code.crt.put(tree.falsepart, CRT_FLOW_TARGET,
2043 startpc, code.curCP());
2044 }
2045 code.resolve(thenExit);
2046 result = items.makeStackItem(pt);
2047 }
2048
2049 private void setTypeAnnotationPositions(int treePos) {
2050 MethodSymbol meth = code.meth;
2051 boolean initOrClinit = code.meth.getKind() == javax.lang.model.element.ElementKind.CONSTRUCTOR
2052 || code.meth.getKind() == javax.lang.model.element.ElementKind.STATIC_INIT;
2053
2054 for (Attribute.TypeCompound ta : meth.getRawTypeAttributes()) {
2055 if (ta.hasUnknownPosition())
2056 ta.tryFixPosition();
2057
2058 if (ta.position.matchesPos(treePos))
2059 ta.position.updatePosOffset(code.cp);
2060 }
2061
2062 if (!initOrClinit)
2063 return;
2064
2065 for (Attribute.TypeCompound ta : meth.owner.getRawTypeAttributes()) {
2066 if (ta.hasUnknownPosition())
2067 ta.tryFixPosition();
2068
2069 if (ta.position.matchesPos(treePos))
2070 ta.position.updatePosOffset(code.cp);
2071 }
2072
2073 ClassSymbol clazz = meth.enclClass();
2074 for (Symbol s : new com.sun.tools.javac.model.FilteredMemberList(clazz.members())) {
2075 if (!s.getKind().isField())
2076 continue;
2077
2078 for (Attribute.TypeCompound ta : s.getRawTypeAttributes()) {
2079 if (ta.hasUnknownPosition())
2080 ta.tryFixPosition();
2081
2082 if (ta.position.matchesPos(treePos))
2083 ta.position.updatePosOffset(code.cp);
2084 }
2085 }
2086 }
2087
2088 public void visitNewClass(JCNewClass tree) {
2089 // Enclosing instances or anonymous classes should have been eliminated
2090 // by now.
2091 Assert.check(tree.encl == null && tree.def == null);
2092 setTypeAnnotationPositions(tree.pos);
2093
2094 code.emitop2(new_, checkDimension(tree.pos(), tree.type), PoolWriter::putClass);
2095 code.emitop0(dup);
2096
2097 // Generate code for all arguments, where the expected types are
2098 // the parameters of the constructor's external type (that is,
2099 // any implicit outer instance appears as first parameter).
2100 genArgs(tree.args, tree.constructor.externalType(types).getParameterTypes());
2101
2102 items.makeMemberItem(tree.constructor, true).invoke();
2103 result = items.makeStackItem(tree.type);
2104 }
2105
2106 public void visitNewArray(JCNewArray tree) {
2107 setTypeAnnotationPositions(tree.pos);
2108
2109 if (tree.elems != null) {
2110 Type elemtype = types.elemtype(tree.type);
2111 loadIntConst(tree.elems.length());
2112 Item arr = makeNewArray(tree.pos(), tree.type, 1);
2113 int i = 0;
2114 for (List<JCExpression> l = tree.elems; l.nonEmpty(); l = l.tail) {
2115 arr.duplicate();
2116 loadIntConst(i);
2117 i++;
2118 genExpr(l.head, elemtype).load();
2119 items.makeIndexedItem(elemtype).store();
2120 }
2121 result = arr;
2122 } else {
2123 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
2124 genExpr(l.head, syms.intType).load();
2125 }
2126 result = makeNewArray(tree.pos(), tree.type, tree.dims.length());
2127 }
2128 }
2129 //where
2130 /** Generate code to create an array with given element type and number
2131 * of dimensions.
2132 */
2133 Item makeNewArray(DiagnosticPosition pos, Type type, int ndims) {
2134 Type elemtype = types.elemtype(type);
2135 if (types.dimensions(type) > ClassFile.MAX_DIMENSIONS) {
2136 log.error(pos, Errors.LimitDimensions);
2137 nerrs++;
2138 }
2139 int elemcode = Code.arraycode(elemtype);
2140 if (elemcode == 0 || (elemcode == 1 && ndims == 1)) {
2141 code.emitAnewarray(makeRef(pos, elemtype), type);
2142 } else if (elemcode == 1) {
2143 code.emitMultianewarray(ndims, makeRef(pos, type), type);
2144 } else {
2145 code.emitNewarray(elemcode, type);
2146 }
2147 return items.makeStackItem(type);
2148 }
2149
2150 public void visitParens(JCParens tree) {
2151 result = genExpr(tree.expr, tree.expr.type);
2152 }
2153
2154 public void visitAssign(JCAssign tree) {
2155 Item l = genExpr(tree.lhs, tree.lhs.type);
2156 genExpr(tree.rhs, tree.lhs.type).load();
2157 if (tree.rhs.type.hasTag(BOT)) {
2158 /* This is just a case of widening reference conversion that per 5.1.5 simply calls
2159 for "regarding a reference as having some other type in a manner that can be proved
2160 correct at compile time."
2161 */
2162 code.state.forceStackTop(tree.lhs.type);
2163 }
2164 result = items.makeAssignItem(l);
2165 }
2166
2167 public void visitAssignop(JCAssignOp tree) {
2168 OperatorSymbol operator = tree.operator;
2169 Item l;
2170 if (operator.opcode == string_add) {
2171 l = concat.makeConcat(tree);
2172 } else {
2173 // Generate code for first expression
2174 l = genExpr(tree.lhs, tree.lhs.type);
2175
2176 // If we have an increment of -32768 to +32767 of a local
2177 // int variable we can use an incr instruction instead of
2178 // proceeding further.
2179 if ((tree.hasTag(PLUS_ASG) || tree.hasTag(MINUS_ASG)) &&
2180 l instanceof LocalItem localItem &&
2181 tree.lhs.type.getTag().isSubRangeOf(INT) &&
2182 tree.rhs.type.getTag().isSubRangeOf(INT) &&
2183 tree.rhs.type.constValue() != null) {
2184 int ival = ((Number) tree.rhs.type.constValue()).intValue();
2185 if (tree.hasTag(MINUS_ASG)) ival = -ival;
2186 localItem.incr(ival);
2187 result = l;
2188 return;
2189 }
2190 // Otherwise, duplicate expression, load one copy
2191 // and complete binary operation.
2192 l.duplicate();
2193 l.coerce(operator.type.getParameterTypes().head).load();
2194 completeBinop(tree.lhs, tree.rhs, operator).coerce(tree.lhs.type);
2195 }
2196 result = items.makeAssignItem(l);
2197 }
2198
2199 public void visitUnary(JCUnary tree) {
2200 OperatorSymbol operator = tree.operator;
2201 if (tree.hasTag(NOT)) {
2202 CondItem od = genCond(tree.arg, false);
2203 result = od.negate();
2204 } else {
2205 Item od = genExpr(tree.arg, operator.type.getParameterTypes().head);
2206 switch (tree.getTag()) {
2207 case POS:
2208 result = od.load();
2209 break;
2210 case NEG:
2211 result = od.load();
2212 code.emitop0(operator.opcode);
2213 break;
2214 case COMPL:
2215 result = od.load();
2216 emitMinusOne(od.typecode);
2217 code.emitop0(operator.opcode);
2218 break;
2219 case PREINC: case PREDEC:
2220 od.duplicate();
2221 if (od instanceof LocalItem localItem &&
2222 (operator.opcode == iadd || operator.opcode == isub)) {
2223 localItem.incr(tree.hasTag(PREINC) ? 1 : -1);
2224 result = od;
2225 } else {
2226 od.load();
2227 code.emitop0(one(od.typecode));
2228 code.emitop0(operator.opcode);
2229 // Perform narrowing primitive conversion if byte,
2230 // char, or short. Fix for 4304655.
2231 if (od.typecode != INTcode &&
2232 Code.truncate(od.typecode) == INTcode)
2233 code.emitop0(int2byte + od.typecode - BYTEcode);
2234 result = items.makeAssignItem(od);
2235 }
2236 break;
2237 case POSTINC: case POSTDEC:
2238 od.duplicate();
2239 if (od instanceof LocalItem localItem &&
2240 (operator.opcode == iadd || operator.opcode == isub)) {
2241 Item res = od.load();
2242 localItem.incr(tree.hasTag(POSTINC) ? 1 : -1);
2243 result = res;
2244 } else {
2245 Item res = od.load();
2246 od.stash(od.typecode);
2247 code.emitop0(one(od.typecode));
2248 code.emitop0(operator.opcode);
2249 // Perform narrowing primitive conversion if byte,
2250 // char, or short. Fix for 4304655.
2251 if (od.typecode != INTcode &&
2252 Code.truncate(od.typecode) == INTcode)
2253 code.emitop0(int2byte + od.typecode - BYTEcode);
2254 od.store();
2255 result = res;
2256 }
2257 break;
2258 case NULLCHK:
2259 result = od.load();
2260 code.emitop0(dup);
2261 genNullCheck(tree);
2262 break;
2263 default:
2264 Assert.error();
2265 }
2266 }
2267 }
2268
2269 /** Generate a null check from the object value at stack top. */
2270 private void genNullCheck(JCTree tree) {
2271 code.statBegin(tree.pos);
2272 callMethod(tree.pos(), syms.objectsType, names.requireNonNull,
2273 List.of(syms.objectType), true);
2274 code.emitop0(pop);
2275 }
2276
2277 public void visitBinary(JCBinary tree) {
2278 OperatorSymbol operator = tree.operator;
2279 if (operator.opcode == string_add) {
2280 result = concat.makeConcat(tree);
2281 } else if (tree.hasTag(AND)) {
2282 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2283 if (!lcond.isFalse()) {
2284 Chain falseJumps = lcond.jumpFalse();
2285 code.resolve(lcond.trueJumps);
2286 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2287 result = items.
2288 makeCondItem(rcond.opcode,
2289 rcond.trueJumps,
2290 Code.mergeChains(falseJumps,
2291 rcond.falseJumps));
2292 } else {
2293 result = lcond;
2294 }
2295 } else if (tree.hasTag(OR)) {
2296 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2297 if (!lcond.isTrue()) {
2298 Chain trueJumps = lcond.jumpTrue();
2299 code.resolve(lcond.falseJumps);
2300 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2301 result = items.
2302 makeCondItem(rcond.opcode,
2303 Code.mergeChains(trueJumps, rcond.trueJumps),
2304 rcond.falseJumps);
2305 } else {
2306 result = lcond;
2307 }
2308 } else {
2309 Item od = genExpr(tree.lhs, operator.type.getParameterTypes().head);
2310 od.load();
2311 result = completeBinop(tree.lhs, tree.rhs, operator);
2312 }
2313 }
2314
2315
2316 /** Complete generating code for operation, with left operand
2317 * already on stack.
2318 * @param lhs The tree representing the left operand.
2319 * @param rhs The tree representing the right operand.
2320 * @param operator The operator symbol.
2321 */
2322 Item completeBinop(JCTree lhs, JCTree rhs, OperatorSymbol operator) {
2323 MethodType optype = (MethodType)operator.type;
2324 int opcode = operator.opcode;
2325 if (opcode >= if_icmpeq && opcode <= if_icmple &&
2326 rhs.type.constValue() instanceof Number number &&
2327 number.intValue() == 0) {
2328 opcode = opcode + (ifeq - if_icmpeq);
2329 } else if (opcode >= if_acmpeq && opcode <= if_acmpne &&
2330 TreeInfo.isNull(rhs)) {
2331 opcode = opcode + (if_acmp_null - if_acmpeq);
2332 } else {
2333 // The expected type of the right operand is
2334 // the second parameter type of the operator, except for
2335 // shifts with long shiftcount, where we convert the opcode
2336 // to a short shift and the expected type to int.
2337 Type rtype = operator.erasure(types).getParameterTypes().tail.head;
2338 if (opcode >= ishll && opcode <= lushrl) {
2339 opcode = opcode + (ishl - ishll);
2340 rtype = syms.intType;
2341 }
2342 // Generate code for right operand and load.
2343 genExpr(rhs, rtype).load();
2344 // If there are two consecutive opcode instructions,
2345 // emit the first now.
2346 if (opcode >= (1 << preShift)) {
2347 code.emitop0(opcode >> preShift);
2348 opcode = opcode & 0xFF;
2349 }
2350 }
2351 if (opcode >= ifeq && opcode <= if_acmpne ||
2352 opcode == if_acmp_null || opcode == if_acmp_nonnull) {
2353 return items.makeCondItem(opcode);
2354 } else {
2355 code.emitop0(opcode);
2356 return items.makeStackItem(optype.restype);
2357 }
2358 }
2359
2360 public void visitTypeCast(JCTypeCast tree) {
2361 result = genExpr(tree.expr, tree.clazz.type).load();
2362 setTypeAnnotationPositions(tree.pos);
2363 // Additional code is only needed if we cast to a reference type
2364 // which is not statically a supertype of the expression's type.
2365 // For basic types, the coerce(...) in genExpr(...) will do
2366 // the conversion.
2367 if (!tree.clazz.type.isPrimitive() &&
2368 !types.isSameType(tree.expr.type, tree.clazz.type) &&
2369 types.asSuper(tree.expr.type, tree.clazz.type.tsym) == null) {
2370 code.emitop2(checkcast, checkDimension(tree.pos(), tree.clazz.type), PoolWriter::putClass);
2371 }
2372 }
2373
2374 public void visitWildcard(JCWildcard tree) {
2375 throw new AssertionError(this.getClass().getName());
2376 }
2377
2378 public void visitTypeTest(JCInstanceOf tree) {
2379 genExpr(tree.expr, tree.expr.type).load();
2380 setTypeAnnotationPositions(tree.pos);
2381 code.emitop2(instanceof_, makeRef(tree.pos(), tree.pattern.type));
2382 result = items.makeStackItem(syms.booleanType);
2383 }
2384
2385 public void visitIndexed(JCArrayAccess tree) {
2386 genExpr(tree.indexed, tree.indexed.type).load();
2387 genExpr(tree.index, syms.intType).load();
2388 result = items.makeIndexedItem(tree.type);
2389 }
2390
2391 public void visitIdent(JCIdent tree) {
2392 Symbol sym = tree.sym;
2393 if (tree.name == names._this || tree.name == names._super) {
2394 Item res = tree.name == names._this
2395 ? items.makeThisItem()
2396 : items.makeSuperItem();
2397 if (sym.kind == MTH) {
2398 // Generate code to address the constructor.
2399 res.load();
2400 res = items.makeMemberItem(sym, true);
2401 }
2402 result = res;
2403 } else if (isInvokeDynamic(sym) || isConstantDynamic(sym)) {
2404 if (isConstantDynamic(sym)) {
2405 setTypeAnnotationPositions(tree.pos);
2406 }
2407 result = items.makeDynamicItem(sym);
2408 } else if (sym.kind == VAR && (sym.owner.kind == MTH || sym.owner.kind == VAR)) {
2409 result = items.makeLocalItem((VarSymbol)sym);
2410 } else if ((sym.flags() & STATIC) != 0) {
2411 if (!isAccessSuper(env.enclMethod))
2412 sym = binaryQualifier(sym, env.enclClass.type);
2413 result = items.makeStaticItem(sym);
2414 } else {
2415 items.makeThisItem().load();
2416 sym = binaryQualifier(sym, env.enclClass.type);
2417 result = items.makeMemberItem(sym, nonVirtualForPrivateAccess(sym));
2418 }
2419 }
2420
2421 //where
2422 private boolean nonVirtualForPrivateAccess(Symbol sym) {
2423 boolean useVirtual = target.hasVirtualPrivateInvoke() &&
2424 !disableVirtualizedPrivateInvoke;
2425 return !useVirtual && ((sym.flags() & PRIVATE) != 0);
2426 }
2427
2428 public void visitSelect(JCFieldAccess tree) {
2429 Symbol sym = tree.sym;
2430
2431 if (tree.name == names._class) {
2432 code.emitLdc((LoadableConstant)checkDimension(tree.pos(), tree.selected.type));
2433 result = items.makeStackItem(pt);
2434 return;
2435 }
2436
2437 Symbol ssym = TreeInfo.symbol(tree.selected);
2438
2439 // Are we selecting via super?
2440 boolean selectSuper =
2441 ssym != null && (ssym.kind == TYP || ssym.name == names._super);
2442
2443 // Are we accessing a member of the superclass in an access method
2444 // resulting from a qualified super?
2445 boolean accessSuper = isAccessSuper(env.enclMethod);
2446
2447 Item base = (selectSuper)
2448 ? items.makeSuperItem()
2449 : genExpr(tree.selected, tree.selected.type);
2450
2451 if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) {
2452 // We are seeing a variable that is constant but its selecting
2453 // expression is not.
2454 if ((sym.flags() & STATIC) != 0) {
2455 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2456 base = base.load();
2457 base.drop();
2458 } else {
2459 base.load();
2460 genNullCheck(tree.selected);
2461 }
2462 result = items.
2463 makeImmediateItem(sym.type, ((VarSymbol) sym).getConstValue());
2464 } else {
2465 if (isInvokeDynamic(sym)) {
2466 result = items.makeDynamicItem(sym);
2467 return;
2468 } else {
2469 sym = binaryQualifier(sym, tree.selected.type);
2470 }
2471 if ((sym.flags() & STATIC) != 0) {
2472 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2473 base = base.load();
2474 base.drop();
2475 result = items.makeStaticItem(sym);
2476 } else {
2477 base.load();
2478 if (sym == syms.lengthVar) {
2479 code.emitop0(arraylength);
2480 result = items.makeStackItem(syms.intType);
2481 } else {
2482 result = items.
2483 makeMemberItem(sym,
2484 nonVirtualForPrivateAccess(sym) ||
2485 selectSuper || accessSuper);
2486 }
2487 }
2488 }
2489 }
2490
2491 public boolean isInvokeDynamic(Symbol sym) {
2492 return sym.kind == MTH && ((MethodSymbol)sym).isDynamic();
2493 }
2494
2495 public void visitLiteral(JCLiteral tree) {
2496 if (tree.type.hasTag(BOT)) {
2497 code.emitop0(aconst_null);
2498 result = items.makeStackItem(tree.type);
2499 }
2500 else
2501 result = items.makeImmediateItem(tree.type, tree.value);
2502 }
2503
2504 public void visitLetExpr(LetExpr tree) {
2505 code.resolvePending();
2506
2507 if (tree.needsLineNumberTableEntry) {
2508 code.statBegin(tree.pos);
2509 }
2510
2511 int limit = code.nextreg;
2512 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
2513 try {
2514 genStats(tree.defs, env);
2515 } finally {
2516 code.setLetExprStackPos(prevLetExprStart);
2517 }
2518 result = genExpr(tree.expr, tree.expr.type).load();
2519 code.endScopes(limit);
2520 }
2521
2522 private void generateReferencesToPrunedTree(ClassSymbol classSymbol) {
2523 List<JCTree> prunedInfo = lower.prunedTree.get(classSymbol);
2524 if (prunedInfo != null) {
2525 for (JCTree prunedTree: prunedInfo) {
2526 prunedTree.accept(classReferenceVisitor);
2527 }
2528 }
2529 }
2530
2531 /* ************************************************************************
2532 * main method
2533 *************************************************************************/
2534
2535 /** Generate code for a class definition.
2536 * @param env The attribution environment that belongs to the
2537 * outermost class containing this class definition.
2538 * We need this for resolving some additional symbols.
2539 * @param cdef The tree representing the class definition.
2540 * @return True if code is generated with no errors.
2541 */
2542 public boolean genClass(Env<AttrContext> env, JCClassDecl cdef) {
2543 try {
2544 attrEnv = env;
2545 ClassSymbol c = cdef.sym;
2546 this.toplevel = env.toplevel;
2547 /* method normalizeDefs() can add references to external classes into the constant pool
2548 */
2549 cdef.defs = normalizeDefs(cdef);
2550 generateReferencesToPrunedTree(c);
2551 Env<GenContext> localEnv = new Env<>(cdef, new GenContext());
2552 localEnv.toplevel = env.toplevel;
2553 localEnv.enclClass = cdef;
2554
2555 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2556 genDef(l.head, localEnv);
2557 }
2558 if (poolWriter.size() > PoolWriter.MAX_ENTRIES) {
2559 log.error(cdef.pos(), Errors.LimitPool);
2560 nerrs++;
2561 }
2562 if (nerrs != 0) {
2563 // if errors, discard code
2564 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2565 if (l.head.hasTag(METHODDEF))
2566 ((JCMethodDecl) l.head).sym.code = null;
2567 }
2568 }
2569 cdef.defs = List.nil(); // discard trees
2570 return nerrs == 0;
2571 } finally {
2572 // note: this method does NOT support recursion.
2573 attrEnv = null;
2574 this.env = null;
2575 toplevel = null;
2576 nerrs = 0;
2577 qualifiedSymbolCache.clear();
2578 }
2579 }
2580
2581 /* ************************************************************************
2582 * Auxiliary classes
2583 *************************************************************************/
2584
2585 /** An abstract class for finalizer generation.
2586 */
2587 abstract class GenFinalizer {
2588 /** Generate code to clean up when unwinding. */
2589 abstract void gen();
2590
2591 /** Generate code to clean up at last. */
2592 abstract void genLast();
2593
2594 /** Does this finalizer have some nontrivial cleanup to perform? */
2595 boolean hasFinalizer() { return true; }
2596
2597 /** Should be invoked after the try's body has been visited. */
2598 void afterBody() {}
2599 }
2600
2601 /** code generation contexts,
2602 * to be used as type parameter for environments.
2603 */
2604 final class GenContext {
2605
2606 /**
2607 * The top defined local variables for exit or continue branches to merge into.
2608 * It may contain uninitialized variables to be initialized by branched code,
2609 * so we cannot use Code.State.defined bits.
2610 */
2611 final int limit;
2612
2613 /** A chain for all unresolved jumps that exit the current environment.
2614 */
2615 Chain exit = null;
2616
2617 /** A chain for all unresolved jumps that continue in the
2618 * current environment.
2619 */
2620 Chain cont = null;
2621
2622 /** A closure that generates the finalizer of the current environment.
2623 * Only set for Synchronized and Try contexts.
2624 */
2625 GenFinalizer finalize = null;
2626
2627 /** Is this a switch statement? If so, allocate registers
2628 * even when the variable declaration is unreachable.
2629 */
2630 boolean isSwitch = false;
2631
2632 /** A list buffer containing all gaps in the finalizer range,
2633 * where a catch all exception should not apply.
2634 */
2635 ListBuffer<Integer> gaps = null;
2636
2637 GenContext() {
2638 var code = Gen.this.code;
2639 this.limit = code == null ? 0 : code.nextreg;
2640 }
2641
2642 /** Add given chain to exit chain.
2643 */
2644 void addExit(Chain c) {
2645 if (c != null) {
2646 c.state.defined.excludeFrom(limit);
2647 }
2648 exit = Code.mergeChains(c, exit);
2649 }
2650
2651 /** Add given chain to cont chain.
2652 */
2653 void addCont(Chain c) {
2654 if (c != null) {
2655 c.state.defined.excludeFrom(limit);
2656 }
2657 cont = Code.mergeChains(c, cont);
2658 }
2659 }
2660
2661 record PatternMatchingCatchConfiguration(Set<JCMethodInvocation> invocations,
2662 ListBuffer<int[]> ranges,
2663 JCCatch handler,
2664 State startState) {
2665 public PatternMatchingCatchConfiguration restart(State newState) {
2666 return new PatternMatchingCatchConfiguration(invocations(),
2667 new ListBuffer<int[]>(),
2668 handler(),
2669 newState);
2670 }
2671 }
2672 }