1 /*
2 * Copyright (c) 1999, 2025, 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 private final UnsetFieldsInfo unsetFieldsInfo;
101
102 @SuppressWarnings("this-escape")
103 protected Gen(Context context) {
104 context.put(genKey, this);
105
106 names = Names.instance(context);
107 log = Log.instance(context);
108 syms = Symtab.instance(context);
109 chk = Check.instance(context);
110 rs = Resolve.instance(context);
111 make = TreeMaker.instance(context);
112 target = Target.instance(context);
113 types = Types.instance(context);
114 concat = StringConcat.instance(context);
115
116 methodType = new MethodType(null, null, null, syms.methodClass);
117 accessDollar = "access" + target.syntheticNameChar();
118 lower = Lower.instance(context);
119
120 Options options = Options.instance(context);
121 lineDebugInfo =
122 options.isUnset(G_CUSTOM) ||
123 options.isSet(G_CUSTOM, "lines");
124 varDebugInfo =
125 options.isUnset(G_CUSTOM)
126 ? options.isSet(G)
127 : options.isSet(G_CUSTOM, "vars");
128 genCrt = options.isSet(XJCOV);
129 debugCode = options.isSet("debug.code");
130 disableVirtualizedPrivateInvoke = options.isSet("disableVirtualizedPrivateInvoke");
131 poolWriter = new PoolWriter(types, names);
132 unsetFieldsInfo = UnsetFieldsInfo.instance(context);
133
134 // ignore cldc because we cannot have both stackmap formats
135 this.stackMap = StackMapFormat.JSR202;
136 annotate = Annotate.instance(context);
137 qualifiedSymbolCache = new HashMap<>();
138 generateAssertUnsetFieldsFrame = options.isSet("generateAssertUnsetFieldsFrame");
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 boolean generateAssertUnsetFieldsFrame;
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 /** An object containing mappings of syntax trees to their
171 * ending source positions.
172 */
173 EndPosTable endPosTable;
174
175 boolean inCondSwitchExpression;
176 Chain switchExpressionTrueChain;
177 Chain switchExpressionFalseChain;
178 List<LocalItem> stackBeforeSwitchExpression;
179 LocalItem switchResult;
180 PatternMatchingCatchConfiguration patternMatchingCatchConfiguration =
181 new PatternMatchingCatchConfiguration(Set.of(), null, null, null);
182
183 /** Cache the symbol to reflect the qualifying type.
184 * key: corresponding type
185 * value: qualified symbol
186 */
187 Map<Type, Symbol> qualifiedSymbolCache;
188
189 /** Generate code to load an integer constant.
190 * @param n The integer to be loaded.
191 */
192 void loadIntConst(int n) {
193 items.makeImmediateItem(syms.intType, n).load();
194 }
195
196 /** The opcode that loads a zero constant of a given type code.
197 * @param tc The given type code (@see ByteCode).
198 */
199 public static int zero(int tc) {
200 switch(tc) {
201 case INTcode: case BYTEcode: case SHORTcode: case CHARcode:
202 return iconst_0;
203 case LONGcode:
204 return lconst_0;
205 case FLOATcode:
206 return fconst_0;
207 case DOUBLEcode:
208 return dconst_0;
209 default:
210 throw new AssertionError("zero");
211 }
212 }
213
214 /** The opcode that loads a one constant of a given type code.
215 * @param tc The given type code (@see ByteCode).
216 */
217 public static int one(int tc) {
218 return zero(tc) + 1;
219 }
220
221 /** Generate code to load -1 of the given type code (either int or long).
222 * @param tc The given type code (@see ByteCode).
223 */
224 void emitMinusOne(int tc) {
225 if (tc == LONGcode) {
226 items.makeImmediateItem(syms.longType, Long.valueOf(-1)).load();
227 } else {
228 code.emitop0(iconst_m1);
229 }
230 }
231
232 /** Construct a symbol to reflect the qualifying type that should
233 * appear in the byte code as per JLS 13.1.
234 *
235 * For {@literal target >= 1.2}: Clone a method with the qualifier as owner (except
236 * for those cases where we need to work around VM bugs).
237 *
238 * For {@literal target <= 1.1}: If qualified variable or method is defined in a
239 * non-accessible class, clone it with the qualifier class as owner.
240 *
241 * @param sym The accessed symbol
242 * @param site The qualifier's type.
243 */
244 Symbol binaryQualifier(Symbol sym, Type site) {
245
246 if (site.hasTag(ARRAY)) {
247 if (sym == syms.lengthVar ||
248 sym.owner != syms.arrayClass)
249 return sym;
250 // array clone can be qualified by the array type in later targets
251 Symbol qualifier;
252 if ((qualifier = qualifiedSymbolCache.get(site)) == null) {
253 qualifier = new ClassSymbol(Flags.PUBLIC, site.tsym.name, site, syms.noSymbol);
254 qualifiedSymbolCache.put(site, qualifier);
255 }
256 return sym.clone(qualifier);
257 }
258
259 if (sym.owner == site.tsym ||
260 (sym.flags() & (STATIC | SYNTHETIC)) == (STATIC | SYNTHETIC)) {
261 return sym;
262 }
263
264 // leave alone methods inherited from Object
265 // JLS 13.1.
266 if (sym.owner == syms.objectType.tsym)
267 return sym;
268
269 return sym.clone(site.tsym);
270 }
271
272 /** Insert a reference to given type in the constant pool,
273 * checking for an array with too many dimensions;
274 * return the reference's index.
275 * @param type The type for which a reference is inserted.
276 */
277 int makeRef(DiagnosticPosition pos, Type type) {
278 return poolWriter.putClass(checkDimension(pos, type));
279 }
280
281 /** Check if the given type is an array with too many dimensions.
282 */
283 private Type checkDimension(DiagnosticPosition pos, Type t) {
284 checkDimensionInternal(pos, t);
285 return t;
286 }
287
288 private void checkDimensionInternal(DiagnosticPosition pos, Type t) {
289 switch (t.getTag()) {
290 case METHOD:
291 checkDimension(pos, t.getReturnType());
292 for (List<Type> args = t.getParameterTypes(); args.nonEmpty(); args = args.tail)
293 checkDimension(pos, args.head);
294 break;
295 case ARRAY:
296 if (types.dimensions(t) > ClassFile.MAX_DIMENSIONS) {
297 log.error(pos, Errors.LimitDimensions);
298 nerrs++;
299 }
300 break;
301 default:
302 break;
303 }
304 }
305
306 /** Create a temporary variable.
307 * @param type The variable's type.
308 */
309 LocalItem makeTemp(Type type) {
310 VarSymbol v = new VarSymbol(Flags.SYNTHETIC,
311 names.empty,
312 type,
313 env.enclMethod.sym);
314 code.newLocal(v);
315 return items.makeLocalItem(v);
316 }
317
318 /** Generate code to call a non-private method or constructor.
319 * @param pos Position to be used for error reporting.
320 * @param site The type of which the method is a member.
321 * @param name The method's name.
322 * @param argtypes The method's argument types.
323 * @param isStatic A flag that indicates whether we call a
324 * static or instance method.
325 */
326 void callMethod(DiagnosticPosition pos,
327 Type site, Name name, List<Type> argtypes,
328 boolean isStatic) {
329 Symbol msym = rs.
330 resolveInternalMethod(pos, attrEnv, site, name, argtypes, null);
331 if (isStatic) items.makeStaticItem(msym).invoke();
332 else items.makeMemberItem(msym, name == names.init).invoke();
333 }
334
335 /** Is the given method definition an access method
336 * resulting from a qualified super? This is signified by an odd
337 * access code.
338 */
339 private boolean isAccessSuper(JCMethodDecl enclMethod) {
340 return
341 (enclMethod.mods.flags & SYNTHETIC) != 0 &&
342 isOddAccessName(enclMethod.name);
343 }
344
345 /** Does given name start with "access$" and end in an odd digit?
346 */
347 private boolean isOddAccessName(Name name) {
348 final String string = name.toString();
349 return
350 string.startsWith(accessDollar) &&
351 (string.charAt(string.length() - 1) & 1) != 0;
352 }
353
354 /* ************************************************************************
355 * Non-local exits
356 *************************************************************************/
357
358 /** Generate code to invoke the finalizer associated with given
359 * environment.
360 * Any calls to finalizers are appended to the environments `cont' chain.
361 * Mark beginning of gap in catch all range for finalizer.
362 */
363 void genFinalizer(Env<GenContext> env) {
364 if (code.isAlive() && env.info.finalize != null)
365 env.info.finalize.gen();
366 }
367
368 /** Generate code to call all finalizers of structures aborted by
369 * a non-local
370 * exit. Return target environment of the non-local exit.
371 * @param target The tree representing the structure that's aborted
372 * @param env The environment current at the non-local exit.
373 */
374 Env<GenContext> unwind(JCTree target, Env<GenContext> env) {
375 Env<GenContext> env1 = env;
376 while (true) {
377 genFinalizer(env1);
378 if (env1.tree == target) break;
379 env1 = env1.next;
380 }
381 return env1;
382 }
383
384 /** Mark end of gap in catch-all range for finalizer.
385 * @param env the environment which might contain the finalizer
386 * (if it does, env.info.gaps != null).
387 */
388 void endFinalizerGap(Env<GenContext> env) {
389 if (env.info.gaps != null && env.info.gaps.length() % 2 == 1)
390 env.info.gaps.append(code.curCP());
391 }
392
393 /** Mark end of all gaps in catch-all ranges for finalizers of environments
394 * lying between, and including to two environments.
395 * @param from the most deeply nested environment to mark
396 * @param to the least deeply nested environment to mark
397 */
398 void endFinalizerGaps(Env<GenContext> from, Env<GenContext> to) {
399 Env<GenContext> last = null;
400 while (last != to) {
401 endFinalizerGap(from);
402 last = from;
403 from = from.next;
404 }
405 }
406
407 /** Do any of the structures aborted by a non-local exit have
408 * finalizers that require an empty stack?
409 * @param target The tree representing the structure that's aborted
410 * @param env The environment current at the non-local exit.
411 */
412 boolean hasFinally(JCTree target, Env<GenContext> env) {
413 while (env.tree != target) {
414 if (env.tree.hasTag(TRY) && env.info.finalize.hasFinalizer())
415 return true;
416 env = env.next;
417 }
418 return false;
419 }
420
421 /* ************************************************************************
422 * Normalizing class-members.
423 *************************************************************************/
424
425 /** Distribute member initializer code into constructors and {@code <clinit>}
426 * method.
427 * @param defs The list of class member declarations.
428 * @param c The enclosing class.
429 */
430 List<JCTree> normalizeDefs(List<JCTree> defs, ClassSymbol c) {
431 ListBuffer<JCStatement> initCode = new ListBuffer<>();
432 // only used for value classes
433 ListBuffer<JCStatement> initBlocks = new ListBuffer<>();
434 ListBuffer<Attribute.TypeCompound> initTAs = new ListBuffer<>();
435 ListBuffer<JCStatement> clinitCode = new ListBuffer<>();
436 ListBuffer<Attribute.TypeCompound> clinitTAs = new ListBuffer<>();
437 ListBuffer<JCTree> methodDefs = new ListBuffer<>();
438 // Sort definitions into three listbuffers:
439 // - initCode for instance initializers
440 // - clinitCode for class initializers
441 // - methodDefs for method definitions
442 for (List<JCTree> l = defs; l.nonEmpty(); l = l.tail) {
443 JCTree def = l.head;
444 switch (def.getTag()) {
445 case BLOCK:
446 JCBlock block = (JCBlock)def;
447 if ((block.flags & STATIC) != 0)
448 clinitCode.append(block);
449 else if ((block.flags & SYNTHETIC) == 0) {
450 if (c.isValueClass() || c.hasStrict()) {
451 initBlocks.append(block);
452 } else {
453 initCode.append(block);
454 }
455 }
456 break;
457 case METHODDEF:
458 methodDefs.append(def);
459 break;
460 case VARDEF:
461 JCVariableDecl vdef = (JCVariableDecl) def;
462 VarSymbol sym = vdef.sym;
463 checkDimension(vdef.pos(), sym.type);
464 if (vdef.init != null) {
465 if ((sym.flags() & STATIC) == 0) {
466 // Always initialize instance variables.
467 JCStatement init = make.at(vdef.pos()).
468 Assignment(sym, vdef.init);
469 initCode.append(init);
470 endPosTable.replaceTree(vdef, init);
471 initTAs.addAll(getAndRemoveNonFieldTAs(sym));
472 } else if (sym.getConstValue() == null) {
473 // Initialize class (static) variables only if
474 // they are not compile-time constants.
475 JCStatement init = make.at(vdef.pos).
476 Assignment(sym, vdef.init);
477 clinitCode.append(init);
478 endPosTable.replaceTree(vdef, init);
479 clinitTAs.addAll(getAndRemoveNonFieldTAs(sym));
480 } else {
481 checkStringConstant(vdef.init.pos(), sym.getConstValue());
482 /* if the init contains a reference to an external class, add it to the
483 * constant's pool
484 */
485 vdef.init.accept(classReferenceVisitor);
486 }
487 }
488 break;
489 default:
490 Assert.error();
491 }
492 }
493 // Insert any instance initializers into all constructors.
494 if (initCode.length() != 0 || initBlocks.length() != 0) {
495 initTAs.addAll(c.getInitTypeAttributes());
496 List<Attribute.TypeCompound> initTAlist = initTAs.toList();
497 for (JCTree t : methodDefs) {
498 normalizeMethod((JCMethodDecl)t, initCode.toList(), initBlocks.toList(), initTAlist);
499 }
500 }
501 // If there are class initializers, create a <clinit> method
502 // that contains them as its body.
503 if (clinitCode.length() != 0) {
504 MethodSymbol clinit = new MethodSymbol(
505 STATIC | (c.flags() & STRICTFP),
506 names.clinit,
507 new MethodType(
508 List.nil(), syms.voidType,
509 List.nil(), syms.methodClass),
510 c);
511 c.members().enter(clinit);
512 List<JCStatement> clinitStats = clinitCode.toList();
513 JCBlock block = make.at(clinitStats.head.pos()).Block(0, clinitStats);
514 block.endpos = TreeInfo.endPos(clinitStats.last());
515 methodDefs.append(make.MethodDef(clinit, block));
516
517 if (!clinitTAs.isEmpty())
518 clinit.appendUniqueTypeAttributes(clinitTAs.toList());
519 if (!c.getClassInitTypeAttributes().isEmpty())
520 clinit.appendUniqueTypeAttributes(c.getClassInitTypeAttributes());
521 }
522 // Return all method definitions.
523 return methodDefs.toList();
524 }
525
526 private List<Attribute.TypeCompound> getAndRemoveNonFieldTAs(VarSymbol sym) {
527 List<TypeCompound> tas = sym.getRawTypeAttributes();
528 ListBuffer<Attribute.TypeCompound> fieldTAs = new ListBuffer<>();
529 ListBuffer<Attribute.TypeCompound> nonfieldTAs = new ListBuffer<>();
530 for (TypeCompound ta : tas) {
531 Assert.check(ta.getPosition().type != TargetType.UNKNOWN);
532 if (ta.getPosition().type == TargetType.FIELD) {
533 fieldTAs.add(ta);
534 } else {
535 nonfieldTAs.add(ta);
536 }
537 }
538 sym.setTypeAttributes(fieldTAs.toList());
539 return nonfieldTAs.toList();
540 }
541
542 /** Check a constant value and report if it is a string that is
543 * too large.
544 */
545 private void checkStringConstant(DiagnosticPosition pos, Object constValue) {
546 if (nerrs != 0 || // only complain about a long string once
547 constValue == null ||
548 !(constValue instanceof String str) ||
549 str.length() < PoolWriter.MAX_STRING_LENGTH)
550 return;
551 log.error(pos, Errors.LimitString);
552 nerrs++;
553 }
554
555 /** Insert instance initializer code into constructors prior to the super() call.
556 * @param md The tree potentially representing a
557 * constructor's definition.
558 * @param initCode The list of instance initializer statements.
559 * @param initTAs Type annotations from the initializer expression.
560 */
561 void normalizeMethod(JCMethodDecl md, List<JCStatement> initCode, List<JCStatement> initBlocks, List<TypeCompound> initTAs) {
562 if (TreeInfo.isConstructor(md) && TreeInfo.hasConstructorCall(md, names._super)) {
563 // We are seeing a constructor that has a super() call.
564 // Find the super() invocation and append the given initializer code.
565 if (md.sym.owner.isValueClass() || md.sym.owner.hasStrict()) {
566 rewriteInitializersIfNeeded(md, initCode);
567 md.body.stats = initCode.appendList(md.body.stats);
568 TreeInfo.mapSuperCalls(md.body, supercall -> make.Block(0, initBlocks.prepend(supercall)));
569 } else {
570 TreeInfo.mapSuperCalls(md.body, supercall -> make.Block(0, initCode.prepend(supercall)));
571 }
572
573 if (md.body.endpos == Position.NOPOS)
574 md.body.endpos = TreeInfo.endPos(md.body.stats.last());
575
576 md.sym.appendUniqueTypeAttributes(initTAs);
577 }
578 }
579
580 void rewriteInitializersIfNeeded(JCMethodDecl md, List<JCStatement> initCode) {
581 if (lower.initializerOuterThis.containsKey(md.sym.owner)) {
582 InitializerVisitor initializerVisitor = new InitializerVisitor(md, lower.initializerOuterThis.get(md.sym.owner));
583 for (JCStatement init : initCode) {
584 initializerVisitor.scan(init);
585 }
586 }
587 }
588
589 public static class InitializerVisitor extends TreeScanner {
590 JCMethodDecl md;
591 Set<JCExpression> exprSet;
592
593 public InitializerVisitor(JCMethodDecl md, Set<JCExpression> exprSet) {
594 this.md = md;
595 this.exprSet = exprSet;
596 }
597
598 @Override
599 public void visitTree(JCTree tree) {}
600
601 @Override
602 public void visitIdent(JCIdent tree) {
603 if (exprSet.contains(tree)) {
604 for (JCVariableDecl param: md.params) {
605 if (param.name == tree.name &&
606 ((param.sym.flags_field & (MANDATED | NOOUTERTHIS)) == (MANDATED | NOOUTERTHIS))) {
607 tree.sym = param.sym;
608 }
609 }
610 }
611 }
612 }
613
614 /* ************************************************************************
615 * Traversal methods
616 *************************************************************************/
617
618 /** Visitor argument: The current environment.
619 */
620 Env<GenContext> env;
621
622 /** Visitor argument: The expected type (prototype).
623 */
624 Type pt;
625
626 /** Visitor result: The item representing the computed value.
627 */
628 Item result;
629
630 /** Visitor method: generate code for a definition, catching and reporting
631 * any completion failures.
632 * @param tree The definition to be visited.
633 * @param env The environment current at the definition.
634 */
635 public void genDef(JCTree tree, Env<GenContext> env) {
636 Env<GenContext> prevEnv = this.env;
637 try {
638 this.env = env;
639 tree.accept(this);
640 } catch (CompletionFailure ex) {
641 chk.completionError(tree.pos(), ex);
642 } finally {
643 this.env = prevEnv;
644 }
645 }
646
647 /** Derived visitor method: check whether CharacterRangeTable
648 * should be emitted, if so, put a new entry into CRTable
649 * and call method to generate bytecode.
650 * If not, just call method to generate bytecode.
651 * @see #genStat(JCTree, Env)
652 *
653 * @param tree The tree to be visited.
654 * @param env The environment to use.
655 * @param crtFlags The CharacterRangeTable flags
656 * indicating type of the entry.
657 */
658 public void genStat(JCTree tree, Env<GenContext> env, int crtFlags) {
659 if (!genCrt) {
660 genStat(tree, env);
661 return;
662 }
663 int startpc = code.curCP();
664 genStat(tree, env);
665 if (tree.hasTag(Tag.BLOCK)) crtFlags |= CRT_BLOCK;
666 code.crt.put(tree, crtFlags, startpc, code.curCP());
667 }
668
669 /** Derived visitor method: generate code for a statement.
670 */
671 public void genStat(JCTree tree, Env<GenContext> env) {
672 if (code.isAlive()) {
673 code.statBegin(tree.pos);
674 genDef(tree, env);
675 } else if (env.info.isSwitch && tree.hasTag(VARDEF)) {
676 // variables whose declarations are in a switch
677 // can be used even if the decl is unreachable.
678 code.newLocal(((JCVariableDecl) tree).sym);
679 }
680 }
681
682 /** Derived visitor method: check whether CharacterRangeTable
683 * should be emitted, if so, put a new entry into CRTable
684 * and call method to generate bytecode.
685 * If not, just call method to generate bytecode.
686 * @see #genStats(List, Env)
687 *
688 * @param trees The list of trees to be visited.
689 * @param env The environment to use.
690 * @param crtFlags The CharacterRangeTable flags
691 * indicating type of the entry.
692 */
693 public void genStats(List<JCStatement> trees, Env<GenContext> env, int crtFlags) {
694 if (!genCrt) {
695 genStats(trees, env);
696 return;
697 }
698 if (trees.length() == 1) { // mark one statement with the flags
699 genStat(trees.head, env, crtFlags | CRT_STATEMENT);
700 } else {
701 int startpc = code.curCP();
702 genStats(trees, env);
703 code.crt.put(trees, crtFlags, startpc, code.curCP());
704 }
705 }
706
707 /** Derived visitor method: generate code for a list of statements.
708 */
709 public void genStats(List<? extends JCTree> trees, Env<GenContext> env) {
710 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
711 genStat(l.head, env, CRT_STATEMENT);
712 }
713
714 /** Derived visitor method: check whether CharacterRangeTable
715 * should be emitted, if so, put a new entry into CRTable
716 * and call method to generate bytecode.
717 * If not, just call method to generate bytecode.
718 * @see #genCond(JCTree,boolean)
719 *
720 * @param tree The tree to be visited.
721 * @param crtFlags The CharacterRangeTable flags
722 * indicating type of the entry.
723 */
724 public CondItem genCond(JCTree tree, int crtFlags) {
725 if (!genCrt) return genCond(tree, false);
726 int startpc = code.curCP();
727 CondItem item = genCond(tree, (crtFlags & CRT_FLOW_CONTROLLER) != 0);
728 code.crt.put(tree, crtFlags, startpc, code.curCP());
729 return item;
730 }
731
732 /** Derived visitor method: generate code for a boolean
733 * expression in a control-flow context.
734 * @param _tree The expression to be visited.
735 * @param markBranches The flag to indicate that the condition is
736 * a flow controller so produced conditions
737 * should contain a proper tree to generate
738 * CharacterRangeTable branches for them.
739 */
740 public CondItem genCond(JCTree _tree, boolean markBranches) {
741 JCTree inner_tree = TreeInfo.skipParens(_tree);
742 if (inner_tree.hasTag(CONDEXPR)) {
743 JCConditional tree = (JCConditional)inner_tree;
744 CondItem cond = genCond(tree.cond, CRT_FLOW_CONTROLLER);
745 if (cond.isTrue()) {
746 code.resolve(cond.trueJumps);
747 CondItem result = genCond(tree.truepart, CRT_FLOW_TARGET);
748 if (markBranches) result.tree = tree.truepart;
749 return result;
750 }
751 if (cond.isFalse()) {
752 code.resolve(cond.falseJumps);
753 CondItem result = genCond(tree.falsepart, CRT_FLOW_TARGET);
754 if (markBranches) result.tree = tree.falsepart;
755 return result;
756 }
757 Chain secondJumps = cond.jumpFalse();
758 code.resolve(cond.trueJumps);
759 CondItem first = genCond(tree.truepart, CRT_FLOW_TARGET);
760 if (markBranches) first.tree = tree.truepart;
761 Chain falseJumps = first.jumpFalse();
762 code.resolve(first.trueJumps);
763 Chain trueJumps = code.branch(goto_);
764 code.resolve(secondJumps);
765 CondItem second = genCond(tree.falsepart, CRT_FLOW_TARGET);
766 CondItem result = items.makeCondItem(second.opcode,
767 Code.mergeChains(trueJumps, second.trueJumps),
768 Code.mergeChains(falseJumps, second.falseJumps));
769 if (markBranches) result.tree = tree.falsepart;
770 return result;
771 } else if (inner_tree.hasTag(SWITCH_EXPRESSION)) {
772 code.resolvePending();
773
774 boolean prevInCondSwitchExpression = inCondSwitchExpression;
775 Chain prevSwitchExpressionTrueChain = switchExpressionTrueChain;
776 Chain prevSwitchExpressionFalseChain = switchExpressionFalseChain;
777 try {
778 inCondSwitchExpression = true;
779 switchExpressionTrueChain = null;
780 switchExpressionFalseChain = null;
781 try {
782 doHandleSwitchExpression((JCSwitchExpression) inner_tree);
783 } catch (CompletionFailure ex) {
784 chk.completionError(_tree.pos(), ex);
785 code.state.stacksize = 1;
786 }
787 CondItem result = items.makeCondItem(goto_,
788 switchExpressionTrueChain,
789 switchExpressionFalseChain);
790 if (markBranches) result.tree = _tree;
791 return result;
792 } finally {
793 inCondSwitchExpression = prevInCondSwitchExpression;
794 switchExpressionTrueChain = prevSwitchExpressionTrueChain;
795 switchExpressionFalseChain = prevSwitchExpressionFalseChain;
796 }
797 } else if (inner_tree.hasTag(LETEXPR) && ((LetExpr) inner_tree).needsCond) {
798 code.resolvePending();
799
800 LetExpr tree = (LetExpr) inner_tree;
801 int limit = code.nextreg;
802 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
803 try {
804 genStats(tree.defs, env);
805 } finally {
806 code.setLetExprStackPos(prevLetExprStart);
807 }
808 CondItem result = genCond(tree.expr, markBranches);
809 code.endScopes(limit);
810 return result;
811 } else {
812 CondItem result = genExpr(_tree, syms.booleanType).mkCond();
813 if (markBranches) result.tree = _tree;
814 return result;
815 }
816 }
817
818 public Code getCode() {
819 return code;
820 }
821
822 public Items getItems() {
823 return items;
824 }
825
826 public Env<AttrContext> getAttrEnv() {
827 return attrEnv;
828 }
829
830 /** Visitor class for expressions which might be constant expressions.
831 * This class is a subset of TreeScanner. Intended to visit trees pruned by
832 * Lower as long as constant expressions looking for references to any
833 * ClassSymbol. Any such reference will be added to the constant pool so
834 * automated tools can detect class dependencies better.
835 */
836 class ClassReferenceVisitor extends JCTree.Visitor {
837
838 @Override
839 public void visitTree(JCTree tree) {}
840
841 @Override
842 public void visitBinary(JCBinary tree) {
843 tree.lhs.accept(this);
844 tree.rhs.accept(this);
845 }
846
847 @Override
848 public void visitSelect(JCFieldAccess tree) {
849 if (tree.selected.type.hasTag(CLASS)) {
850 makeRef(tree.selected.pos(), tree.selected.type);
851 }
852 }
853
854 @Override
855 public void visitIdent(JCIdent tree) {
856 if (tree.sym.owner instanceof ClassSymbol classSymbol) {
857 poolWriter.putClass(classSymbol);
858 }
859 }
860
861 @Override
862 public void visitConditional(JCConditional tree) {
863 tree.cond.accept(this);
864 tree.truepart.accept(this);
865 tree.falsepart.accept(this);
866 }
867
868 @Override
869 public void visitUnary(JCUnary tree) {
870 tree.arg.accept(this);
871 }
872
873 @Override
874 public void visitParens(JCParens tree) {
875 tree.expr.accept(this);
876 }
877
878 @Override
879 public void visitTypeCast(JCTypeCast tree) {
880 tree.expr.accept(this);
881 }
882 }
883
884 private ClassReferenceVisitor classReferenceVisitor = new ClassReferenceVisitor();
885
886 /** Visitor method: generate code for an expression, catching and reporting
887 * any completion failures.
888 * @param tree The expression to be visited.
889 * @param pt The expression's expected type (proto-type).
890 */
891 public Item genExpr(JCTree tree, Type pt) {
892 if (!code.isAlive()) {
893 return items.makeStackItem(pt);
894 }
895
896 Type prevPt = this.pt;
897 try {
898 if (tree.type.constValue() != null) {
899 // Short circuit any expressions which are constants
900 tree.accept(classReferenceVisitor);
901 checkStringConstant(tree.pos(), tree.type.constValue());
902 Symbol sym = TreeInfo.symbol(tree);
903 if (sym != null && isConstantDynamic(sym)) {
904 result = items.makeDynamicItem(sym);
905 } else {
906 result = items.makeImmediateItem(tree.type, tree.type.constValue());
907 }
908 } else {
909 this.pt = pt;
910 tree.accept(this);
911 }
912 return result.coerce(pt);
913 } catch (CompletionFailure ex) {
914 chk.completionError(tree.pos(), ex);
915 code.state.stacksize = 1;
916 return items.makeStackItem(pt);
917 } finally {
918 this.pt = prevPt;
919 }
920 }
921
922 public boolean isConstantDynamic(Symbol sym) {
923 return sym.kind == VAR &&
924 sym instanceof DynamicVarSymbol dynamicVarSymbol &&
925 dynamicVarSymbol.isDynamic();
926 }
927
928 /** Derived visitor method: generate code for a list of method arguments.
929 * @param trees The argument expressions to be visited.
930 * @param pts The expression's expected types (i.e. the formal parameter
931 * types of the invoked method).
932 */
933 public void genArgs(List<JCExpression> trees, List<Type> pts) {
934 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail) {
935 genExpr(l.head, pts.head).load();
936 pts = pts.tail;
937 }
938 // require lists be of same length
939 Assert.check(pts.isEmpty());
940 }
941
942 /* ************************************************************************
943 * Visitor methods for statements and definitions
944 *************************************************************************/
945
946 /** Thrown when the byte code size exceeds limit.
947 */
948 public static class CodeSizeOverflow extends RuntimeException {
949 private static final long serialVersionUID = 0;
950 public CodeSizeOverflow() {}
951 }
952
953 public void visitMethodDef(JCMethodDecl tree) {
954 // Create a new local environment that points pack at method
955 // definition.
956 Env<GenContext> localEnv = env.dup(tree);
957 localEnv.enclMethod = tree;
958 // The expected type of every return statement in this method
959 // is the method's return type.
960 this.pt = tree.sym.erasure(types).getReturnType();
961
962 checkDimension(tree.pos(), tree.sym.erasure(types));
963 genMethod(tree, localEnv, false);
964 }
965 //where
966 /** Generate code for a method.
967 * @param tree The tree representing the method definition.
968 * @param env The environment current for the method body.
969 * @param fatcode A flag that indicates whether all jumps are
970 * within 32K. We first invoke this method under
971 * the assumption that fatcode == false, i.e. all
972 * jumps are within 32K. If this fails, fatcode
973 * is set to true and we try again.
974 */
975 void genMethod(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
976 MethodSymbol meth = tree.sym;
977 int extras = 0;
978 // Count up extra parameters
979 if (meth.isConstructor()) {
980 extras++;
981 if (meth.enclClass().isInner() &&
982 !meth.enclClass().isStatic()) {
983 extras++;
984 }
985 } else if ((tree.mods.flags & STATIC) == 0) {
986 extras++;
987 }
988 // System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG
989 if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes()) + extras >
990 ClassFile.MAX_PARAMETERS) {
991 log.error(tree.pos(), Errors.LimitParameters);
992 nerrs++;
993 }
994
995 else if (tree.body != null) {
996 // Create a new code structure and initialize it.
997 int startpcCrt = initCode(tree, env, fatcode);
998 Set<VarSymbol> prevUnsetFields = code.currentUnsetFields;
999 if (meth.isConstructor()) {
1000 code.currentUnsetFields = unsetFieldsInfo.getUnsetFields(env.enclClass.sym, tree.body);
1001 code.initialUnsetFields = unsetFieldsInfo.getUnsetFields(env.enclClass.sym, tree.body);
1002 }
1003
1004 try {
1005 genStat(tree.body, env);
1006 } catch (CodeSizeOverflow e) {
1007 // Failed due to code limit, try again with jsr/ret
1008 startpcCrt = initCode(tree, env, fatcode);
1009 genStat(tree.body, env);
1010 } finally {
1011 code.currentUnsetFields = prevUnsetFields;
1012 }
1013
1014 if (code.state.stacksize != 0) {
1015 log.error(tree.body.pos(), Errors.StackSimError(tree.sym));
1016 throw new AssertionError();
1017 }
1018
1019 // If last statement could complete normally, insert a
1020 // return at the end.
1021 if (code.isAlive()) {
1022 code.statBegin(TreeInfo.endPos(tree.body));
1023 if (env.enclMethod == null ||
1024 env.enclMethod.sym.type.getReturnType().hasTag(VOID)) {
1025 code.emitop0(return_);
1026 } else {
1027 // sometime dead code seems alive (4415991);
1028 // generate a small loop instead
1029 int startpc = code.entryPoint();
1030 CondItem c = items.makeCondItem(goto_);
1031 code.resolve(c.jumpTrue(), startpc);
1032 }
1033 }
1034 if (genCrt)
1035 code.crt.put(tree.body,
1036 CRT_BLOCK,
1037 startpcCrt,
1038 code.curCP());
1039
1040 code.endScopes(0);
1041
1042 // If we exceeded limits, panic
1043 if (code.checkLimits(tree.pos(), log)) {
1044 nerrs++;
1045 return;
1046 }
1047
1048 // If we generated short code but got a long jump, do it again
1049 // with fatCode = true.
1050 if (!fatcode && code.fatcode) genMethod(tree, env, true);
1051
1052 // Clean up
1053 if(stackMap == StackMapFormat.JSR202) {
1054 code.lastFrame = null;
1055 code.frameBeforeLast = null;
1056 }
1057
1058 // Compress exception table
1059 code.compressCatchTable();
1060
1061 // Fill in type annotation positions for exception parameters
1062 code.fillExceptionParameterPositions();
1063 }
1064 }
1065
1066 private int initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
1067 MethodSymbol meth = tree.sym;
1068
1069 // Create a new code structure.
1070 meth.code = code = new Code(meth,
1071 fatcode,
1072 lineDebugInfo ? toplevel.lineMap : null,
1073 varDebugInfo,
1074 stackMap,
1075 debugCode,
1076 genCrt ? new CRTable(tree, env.toplevel.endPositions)
1077 : null,
1078 syms,
1079 types,
1080 poolWriter,
1081 generateAssertUnsetFieldsFrame);
1082 items = new Items(poolWriter, code, syms, types);
1083 if (code.debugCode) {
1084 System.err.println(meth + " for body " + tree);
1085 }
1086
1087 // If method is not static, create a new local variable address
1088 // for `this'.
1089 if ((tree.mods.flags & STATIC) == 0) {
1090 Type selfType = meth.owner.type;
1091 if (meth.isConstructor() && selfType != syms.objectType)
1092 selfType = UninitializedType.uninitializedThis(selfType);
1093 code.setDefined(
1094 code.newLocal(
1095 new VarSymbol(FINAL, names._this, selfType, meth.owner)));
1096 }
1097
1098 // Mark all parameters as defined from the beginning of
1099 // the method.
1100 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
1101 checkDimension(l.head.pos(), l.head.sym.type);
1102 code.setDefined(code.newLocal(l.head.sym));
1103 }
1104
1105 // Get ready to generate code for method body.
1106 int startpcCrt = genCrt ? code.curCP() : 0;
1107 code.entryPoint();
1108
1109 // Suppress initial stackmap
1110 code.pendingStackMap = false;
1111
1112 return startpcCrt;
1113 }
1114
1115 public void visitVarDef(JCVariableDecl tree) {
1116 VarSymbol v = tree.sym;
1117 if (tree.init != null) {
1118 checkStringConstant(tree.init.pos(), v.getConstValue());
1119 if (v.getConstValue() == null || varDebugInfo) {
1120 Assert.check(code.isStatementStart());
1121 code.newLocal(v);
1122 genExpr(tree.init, v.erasure(types)).load();
1123 items.makeLocalItem(v).store();
1124 Assert.check(code.isStatementStart());
1125 }
1126 } else {
1127 code.newLocal(v);
1128 }
1129 checkDimension(tree.pos(), v.type);
1130 }
1131
1132 public void visitSkip(JCSkip tree) {
1133 }
1134
1135 public void visitBlock(JCBlock tree) {
1136 /* this method is heavily invoked, as expected, for deeply nested blocks, if blocks doesn't happen to have
1137 * patterns there will be an unnecessary tax on memory consumption every time this method is executed, for this
1138 * reason we have created helper methods and here at a higher level we just discriminate depending on the
1139 * presence, or not, of patterns in a given block
1140 */
1141 if (tree.patternMatchingCatch != null) {
1142 visitBlockWithPatterns(tree);
1143 } else {
1144 internalVisitBlock(tree);
1145 }
1146 }
1147
1148 private void visitBlockWithPatterns(JCBlock tree) {
1149 PatternMatchingCatchConfiguration prevConfiguration = patternMatchingCatchConfiguration;
1150 try {
1151 patternMatchingCatchConfiguration =
1152 new PatternMatchingCatchConfiguration(tree.patternMatchingCatch.calls2Handle(),
1153 new ListBuffer<int[]>(),
1154 tree.patternMatchingCatch.handler(),
1155 code.state.dup());
1156 internalVisitBlock(tree);
1157 } finally {
1158 generatePatternMatchingCatch(env);
1159 patternMatchingCatchConfiguration = prevConfiguration;
1160 }
1161 }
1162
1163 private void generatePatternMatchingCatch(Env<GenContext> env) {
1164 if (patternMatchingCatchConfiguration.handler != null &&
1165 !patternMatchingCatchConfiguration.ranges.isEmpty()) {
1166 Chain skipCatch = code.branch(goto_);
1167 JCCatch handler = patternMatchingCatchConfiguration.handler();
1168 code.entryPoint(patternMatchingCatchConfiguration.startState(),
1169 handler.param.sym.type);
1170 genPatternMatchingCatch(handler,
1171 env,
1172 patternMatchingCatchConfiguration.ranges.toList());
1173 code.resolve(skipCatch);
1174 }
1175 }
1176
1177 private void internalVisitBlock(JCBlock tree) {
1178 int limit = code.nextreg;
1179 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1180 genStats(tree.stats, localEnv);
1181 // End the scope of all block-local variables in variable info.
1182 if (!env.tree.hasTag(METHODDEF)) {
1183 code.statBegin(tree.endpos);
1184 code.endScopes(limit);
1185 code.pendingStatPos = Position.NOPOS;
1186 }
1187 }
1188
1189 public void visitDoLoop(JCDoWhileLoop tree) {
1190 genLoop(tree, tree.body, tree.cond, List.nil(), false);
1191 }
1192
1193 public void visitWhileLoop(JCWhileLoop tree) {
1194 genLoop(tree, tree.body, tree.cond, List.nil(), true);
1195 }
1196
1197 public void visitForLoop(JCForLoop tree) {
1198 int limit = code.nextreg;
1199 genStats(tree.init, env);
1200 genLoop(tree, tree.body, tree.cond, tree.step, true);
1201 code.endScopes(limit);
1202 }
1203 //where
1204 /** Generate code for a loop.
1205 * @param loop The tree representing the loop.
1206 * @param body The loop's body.
1207 * @param cond The loop's controlling condition.
1208 * @param step "Step" statements to be inserted at end of
1209 * each iteration.
1210 * @param testFirst True if the loop test belongs before the body.
1211 */
1212 private void genLoop(JCStatement loop,
1213 JCStatement body,
1214 JCExpression cond,
1215 List<JCExpressionStatement> step,
1216 boolean testFirst) {
1217 Set<VarSymbol> prevCodeUnsetFields = code.currentUnsetFields;
1218 try {
1219 genLoopHelper(loop, body, cond, step, testFirst);
1220 } finally {
1221 code.currentUnsetFields = prevCodeUnsetFields;
1222 }
1223 }
1224
1225 private void genLoopHelper(JCStatement loop,
1226 JCStatement body,
1227 JCExpression cond,
1228 List<JCExpressionStatement> step,
1229 boolean testFirst) {
1230 Env<GenContext> loopEnv = env.dup(loop, new GenContext());
1231 int startpc = code.entryPoint();
1232 if (testFirst) { //while or for loop
1233 CondItem c;
1234 if (cond != null) {
1235 code.statBegin(cond.pos);
1236 Assert.check(code.isStatementStart());
1237 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1238 } else {
1239 c = items.makeCondItem(goto_);
1240 }
1241 Chain loopDone = c.jumpFalse();
1242 code.resolve(c.trueJumps);
1243 Assert.check(code.isStatementStart());
1244 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1245 code.resolve(loopEnv.info.cont);
1246 genStats(step, loopEnv);
1247 code.resolve(code.branch(goto_), startpc);
1248 code.resolve(loopDone);
1249 } else {
1250 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1251 code.resolve(loopEnv.info.cont);
1252 genStats(step, loopEnv);
1253 if (code.isAlive()) {
1254 CondItem c;
1255 if (cond != null) {
1256 code.statBegin(cond.pos);
1257 Assert.check(code.isStatementStart());
1258 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1259 } else {
1260 c = items.makeCondItem(goto_);
1261 }
1262 code.resolve(c.jumpTrue(), startpc);
1263 Assert.check(code.isStatementStart());
1264 code.resolve(c.falseJumps);
1265 }
1266 }
1267 Chain exit = loopEnv.info.exit;
1268 if (exit != null) {
1269 code.resolve(exit);
1270 exit.state.defined.excludeFrom(code.nextreg);
1271 }
1272 }
1273
1274 public void visitForeachLoop(JCEnhancedForLoop tree) {
1275 throw new AssertionError(); // should have been removed by Lower.
1276 }
1277
1278 public void visitLabelled(JCLabeledStatement tree) {
1279 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1280 genStat(tree.body, localEnv, CRT_STATEMENT);
1281 Chain exit = localEnv.info.exit;
1282 if (exit != null) {
1283 code.resolve(exit);
1284 exit.state.defined.excludeFrom(code.nextreg);
1285 }
1286 }
1287
1288 public void visitSwitch(JCSwitch tree) {
1289 handleSwitch(tree, tree.selector, tree.cases, tree.patternSwitch);
1290 }
1291
1292 @Override
1293 public void visitSwitchExpression(JCSwitchExpression tree) {
1294 code.resolvePending();
1295 boolean prevInCondSwitchExpression = inCondSwitchExpression;
1296 Set<VarSymbol> prevCodeUnsetFields = code.currentUnsetFields;
1297 try {
1298 inCondSwitchExpression = false;
1299 doHandleSwitchExpression(tree);
1300 } finally {
1301 inCondSwitchExpression = prevInCondSwitchExpression;
1302 code.currentUnsetFields = prevCodeUnsetFields;
1303 }
1304 result = items.makeStackItem(pt);
1305 }
1306
1307 private void doHandleSwitchExpression(JCSwitchExpression tree) {
1308 List<LocalItem> prevStackBeforeSwitchExpression = stackBeforeSwitchExpression;
1309 LocalItem prevSwitchResult = switchResult;
1310 int limit = code.nextreg;
1311 try {
1312 stackBeforeSwitchExpression = List.nil();
1313 switchResult = null;
1314 if (hasTry(tree)) {
1315 //if the switch expression contains try-catch, the catch handlers need to have
1316 //an empty stack. So stash whole stack to local variables, and restore it before
1317 //breaks:
1318 while (code.state.stacksize > 0) {
1319 Type type = code.state.peek();
1320 Name varName = names.fromString(target.syntheticNameChar() +
1321 "stack" +
1322 target.syntheticNameChar() +
1323 tree.pos +
1324 target.syntheticNameChar() +
1325 code.state.stacksize);
1326 VarSymbol var = new VarSymbol(Flags.SYNTHETIC, varName, type,
1327 this.env.enclMethod.sym);
1328 LocalItem item = items.new LocalItem(type, code.newLocal(var));
1329 stackBeforeSwitchExpression = stackBeforeSwitchExpression.prepend(item);
1330 item.store();
1331 }
1332 switchResult = makeTemp(tree.type);
1333 }
1334 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
1335 try {
1336 handleSwitch(tree, tree.selector, tree.cases, tree.patternSwitch);
1337 } finally {
1338 code.setLetExprStackPos(prevLetExprStart);
1339 }
1340 } finally {
1341 stackBeforeSwitchExpression = prevStackBeforeSwitchExpression;
1342 switchResult = prevSwitchResult;
1343 code.endScopes(limit);
1344 }
1345 }
1346 //where:
1347 private boolean hasTry(JCSwitchExpression tree) {
1348 class HasTryScanner extends TreeScanner {
1349 private boolean hasTry;
1350
1351 @Override
1352 public void visitTry(JCTry tree) {
1353 hasTry = true;
1354 }
1355
1356 @Override
1357 public void visitSynchronized(JCSynchronized tree) {
1358 hasTry = true;
1359 }
1360
1361 @Override
1362 public void visitClassDef(JCClassDecl tree) {
1363 }
1364
1365 @Override
1366 public void visitLambda(JCLambda tree) {
1367 }
1368 };
1369
1370 HasTryScanner hasTryScanner = new HasTryScanner();
1371
1372 hasTryScanner.scan(tree);
1373 return hasTryScanner.hasTry;
1374 }
1375
1376 private void handleSwitch(JCTree swtch, JCExpression selector, List<JCCase> cases,
1377 boolean patternSwitch) {
1378 Set<VarSymbol> prevCodeUnsetFields = code.currentUnsetFields;
1379 try {
1380 handleSwitchHelper(swtch, selector, cases, patternSwitch);
1381 } finally {
1382 code.currentUnsetFields = prevCodeUnsetFields;
1383 }
1384 }
1385
1386 void handleSwitchHelper(JCTree swtch, JCExpression selector, List<JCCase> cases,
1387 boolean patternSwitch) {
1388 int limit = code.nextreg;
1389 Assert.check(!selector.type.hasTag(CLASS));
1390 int switchStart = patternSwitch ? code.entryPoint() : -1;
1391 int startpcCrt = genCrt ? code.curCP() : 0;
1392 Assert.check(code.isStatementStart());
1393 Item sel = genExpr(selector, syms.intType);
1394 if (cases.isEmpty()) {
1395 // We are seeing: switch <sel> {}
1396 sel.load().drop();
1397 if (genCrt)
1398 code.crt.put(TreeInfo.skipParens(selector),
1399 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1400 } else {
1401 // We are seeing a nonempty switch.
1402 sel.load();
1403 if (genCrt)
1404 code.crt.put(TreeInfo.skipParens(selector),
1405 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1406 Env<GenContext> switchEnv = env.dup(swtch, new GenContext());
1407 switchEnv.info.isSwitch = true;
1408
1409 // Compute number of labels and minimum and maximum label values.
1410 // For each case, store its label in an array.
1411 int lo = Integer.MAX_VALUE; // minimum label.
1412 int hi = Integer.MIN_VALUE; // maximum label.
1413 int nlabels = 0; // number of labels.
1414
1415 int[] labels = new int[cases.length()]; // the label array.
1416 int defaultIndex = -1; // the index of the default clause.
1417
1418 List<JCCase> l = cases;
1419 for (int i = 0; i < labels.length; i++) {
1420 if (l.head.labels.head instanceof JCConstantCaseLabel constLabel) {
1421 Assert.check(l.head.labels.size() == 1);
1422 int val = ((Number) constLabel.expr.type.constValue()).intValue();
1423 labels[i] = val;
1424 if (val < lo) lo = val;
1425 if (hi < val) hi = val;
1426 nlabels++;
1427 } else {
1428 Assert.check(defaultIndex == -1);
1429 defaultIndex = i;
1430 }
1431 l = l.tail;
1432 }
1433
1434 // Determine whether to issue a tableswitch or a lookupswitch
1435 // instruction.
1436 long table_space_cost = 4 + ((long) hi - lo + 1); // words
1437 long table_time_cost = 3; // comparisons
1438 long lookup_space_cost = 3 + 2 * (long) nlabels;
1439 long lookup_time_cost = nlabels;
1440 int opcode =
1441 nlabels > 0 &&
1442 table_space_cost + 3 * table_time_cost <=
1443 lookup_space_cost + 3 * lookup_time_cost
1444 ?
1445 tableswitch : lookupswitch;
1446
1447 int startpc = code.curCP(); // the position of the selector operation
1448 code.emitop0(opcode);
1449 code.align(4);
1450 int tableBase = code.curCP(); // the start of the jump table
1451 int[] offsets = null; // a table of offsets for a lookupswitch
1452 code.emit4(-1); // leave space for default offset
1453 if (opcode == tableswitch) {
1454 code.emit4(lo); // minimum label
1455 code.emit4(hi); // maximum label
1456 for (long i = lo; i <= hi; i++) { // leave space for jump table
1457 code.emit4(-1);
1458 }
1459 } else {
1460 code.emit4(nlabels); // number of labels
1461 for (int i = 0; i < nlabels; i++) {
1462 code.emit4(-1); code.emit4(-1); // leave space for lookup table
1463 }
1464 offsets = new int[labels.length];
1465 }
1466 Code.State stateSwitch = code.state.dup();
1467 code.markDead();
1468
1469 // For each case do:
1470 l = cases;
1471 for (int i = 0; i < labels.length; i++) {
1472 JCCase c = l.head;
1473 l = l.tail;
1474
1475 int pc = code.entryPoint(stateSwitch);
1476 // Insert offset directly into code or else into the
1477 // offsets table.
1478 if (i != defaultIndex) {
1479 if (opcode == tableswitch) {
1480 code.put4(
1481 tableBase + 4 * (labels[i] - lo + 3),
1482 pc - startpc);
1483 } else {
1484 offsets[i] = pc - startpc;
1485 }
1486 } else {
1487 code.put4(tableBase, pc - startpc);
1488 }
1489
1490 // Generate code for the statements in this case.
1491 genStats(c.stats, switchEnv, CRT_FLOW_TARGET);
1492 }
1493
1494 if (switchEnv.info.cont != null) {
1495 Assert.check(patternSwitch);
1496 code.resolve(switchEnv.info.cont, switchStart);
1497 }
1498
1499 // Resolve all breaks.
1500 Chain exit = switchEnv.info.exit;
1501 if (exit != null) {
1502 code.resolve(exit);
1503 exit.state.defined.excludeFrom(limit);
1504 }
1505
1506 // If we have not set the default offset, we do so now.
1507 if (code.get4(tableBase) == -1) {
1508 code.put4(tableBase, code.entryPoint(stateSwitch) - startpc);
1509 }
1510
1511 if (opcode == tableswitch) {
1512 // Let any unfilled slots point to the default case.
1513 int defaultOffset = code.get4(tableBase);
1514 for (long i = lo; i <= hi; i++) {
1515 int t = (int)(tableBase + 4 * (i - lo + 3));
1516 if (code.get4(t) == -1)
1517 code.put4(t, defaultOffset);
1518 }
1519 } else {
1520 // Sort non-default offsets and copy into lookup table.
1521 if (defaultIndex >= 0)
1522 for (int i = defaultIndex; i < labels.length - 1; i++) {
1523 labels[i] = labels[i+1];
1524 offsets[i] = offsets[i+1];
1525 }
1526 if (nlabels > 0)
1527 qsort2(labels, offsets, 0, nlabels - 1);
1528 for (int i = 0; i < nlabels; i++) {
1529 int caseidx = tableBase + 8 * (i + 1);
1530 code.put4(caseidx, labels[i]);
1531 code.put4(caseidx + 4, offsets[i]);
1532 }
1533 }
1534
1535 if (swtch instanceof JCSwitchExpression) {
1536 // Emit line position for the end of a switch expression
1537 code.statBegin(TreeInfo.endPos(swtch));
1538 }
1539 }
1540 code.endScopes(limit);
1541 }
1542 //where
1543 /** Sort (int) arrays of keys and values
1544 */
1545 static void qsort2(int[] keys, int[] values, int lo, int hi) {
1546 int i = lo;
1547 int j = hi;
1548 int pivot = keys[(i+j)/2];
1549 do {
1550 while (keys[i] < pivot) i++;
1551 while (pivot < keys[j]) j--;
1552 if (i <= j) {
1553 int temp1 = keys[i];
1554 keys[i] = keys[j];
1555 keys[j] = temp1;
1556 int temp2 = values[i];
1557 values[i] = values[j];
1558 values[j] = temp2;
1559 i++;
1560 j--;
1561 }
1562 } while (i <= j);
1563 if (lo < j) qsort2(keys, values, lo, j);
1564 if (i < hi) qsort2(keys, values, i, hi);
1565 }
1566
1567 public void visitSynchronized(JCSynchronized tree) {
1568 int limit = code.nextreg;
1569 // Generate code to evaluate lock and save in temporary variable.
1570 final LocalItem lockVar = makeTemp(syms.objectType);
1571 Assert.check(code.isStatementStart());
1572 genExpr(tree.lock, tree.lock.type).load().duplicate();
1573 lockVar.store();
1574
1575 // Generate code to enter monitor.
1576 code.emitop0(monitorenter);
1577 code.state.lock(lockVar.reg);
1578
1579 // Generate code for a try statement with given body, no catch clauses
1580 // in a new environment with the "exit-monitor" operation as finalizer.
1581 final Env<GenContext> syncEnv = env.dup(tree, new GenContext());
1582 syncEnv.info.finalize = new GenFinalizer() {
1583 void gen() {
1584 genLast();
1585 Assert.check(syncEnv.info.gaps.length() % 2 == 0);
1586 syncEnv.info.gaps.append(code.curCP());
1587 }
1588 void genLast() {
1589 if (code.isAlive()) {
1590 lockVar.load();
1591 code.emitop0(monitorexit);
1592 code.state.unlock(lockVar.reg);
1593 }
1594 }
1595 };
1596 syncEnv.info.gaps = new ListBuffer<>();
1597 genTry(tree.body, List.nil(), syncEnv);
1598 code.endScopes(limit);
1599 }
1600
1601 public void visitTry(final JCTry tree) {
1602 // Generate code for a try statement with given body and catch clauses,
1603 // in a new environment which calls the finally block if there is one.
1604 final Env<GenContext> tryEnv = env.dup(tree, new GenContext());
1605 final Env<GenContext> oldEnv = env;
1606 tryEnv.info.finalize = new GenFinalizer() {
1607 void gen() {
1608 Assert.check(tryEnv.info.gaps.length() % 2 == 0);
1609 tryEnv.info.gaps.append(code.curCP());
1610 genLast();
1611 }
1612 void genLast() {
1613 if (tree.finalizer != null)
1614 genStat(tree.finalizer, oldEnv, CRT_BLOCK);
1615 }
1616 boolean hasFinalizer() {
1617 return tree.finalizer != null;
1618 }
1619
1620 @Override
1621 void afterBody() {
1622 if (tree.finalizer != null && (tree.finalizer.flags & BODY_ONLY_FINALIZE) != 0) {
1623 //for body-only finally, remove the GenFinalizer after try body
1624 //so that the finally is not generated to catch bodies:
1625 tryEnv.info.finalize = null;
1626 }
1627 }
1628
1629 };
1630 tryEnv.info.gaps = new ListBuffer<>();
1631 genTry(tree.body, tree.catchers, tryEnv);
1632 }
1633 //where
1634 /** Generate code for a try or synchronized statement
1635 * @param body The body of the try or synchronized statement.
1636 * @param catchers The list of catch clauses.
1637 * @param env The current environment of the body.
1638 */
1639 void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) {
1640 Set<VarSymbol> prevCodeUnsetFields = code.currentUnsetFields;
1641 try {
1642 genTryHelper(body, catchers, env);
1643 } finally {
1644 code.currentUnsetFields = prevCodeUnsetFields;
1645 }
1646 }
1647
1648 void genTryHelper(JCTree body, List<JCCatch> catchers, Env<GenContext> env) {
1649 int limit = code.nextreg;
1650 int startpc = code.curCP();
1651 Code.State stateTry = code.state.dup();
1652 genStat(body, env, CRT_BLOCK);
1653 int endpc = code.curCP();
1654 List<Integer> gaps = env.info.gaps.toList();
1655 code.statBegin(TreeInfo.endPos(body));
1656 genFinalizer(env);
1657 code.statBegin(TreeInfo.endPos(env.tree));
1658 Chain exitChain;
1659 boolean actualTry = env.tree.hasTag(TRY);
1660 if (startpc == endpc && actualTry) {
1661 exitChain = code.branch(dontgoto);
1662 } else {
1663 exitChain = code.branch(goto_);
1664 }
1665 endFinalizerGap(env);
1666 env.info.finalize.afterBody();
1667 boolean hasFinalizer =
1668 env.info.finalize != null &&
1669 env.info.finalize.hasFinalizer();
1670 if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) {
1671 // start off with exception on stack
1672 code.entryPoint(stateTry, l.head.param.sym.type);
1673 genCatch(l.head, env, startpc, endpc, gaps);
1674 genFinalizer(env);
1675 if (hasFinalizer || l.tail.nonEmpty()) {
1676 code.statBegin(TreeInfo.endPos(env.tree));
1677 exitChain = Code.mergeChains(exitChain,
1678 code.branch(goto_));
1679 }
1680 endFinalizerGap(env);
1681 }
1682 if (hasFinalizer && (startpc != endpc || !actualTry)) {
1683 // Create a new register segment to avoid allocating
1684 // the same variables in finalizers and other statements.
1685 code.newRegSegment();
1686
1687 // Add a catch-all clause.
1688
1689 // start off with exception on stack
1690 int catchallpc = code.entryPoint(stateTry, syms.throwableType);
1691
1692 // Register all exception ranges for catch all clause.
1693 // The range of the catch all clause is from the beginning
1694 // of the try or synchronized block until the present
1695 // code pointer excluding all gaps in the current
1696 // environment's GenContext.
1697 int startseg = startpc;
1698 while (env.info.gaps.nonEmpty()) {
1699 int endseg = env.info.gaps.next().intValue();
1700 registerCatch(body.pos(), startseg, endseg,
1701 catchallpc, 0);
1702 startseg = env.info.gaps.next().intValue();
1703 }
1704 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1705 code.markStatBegin();
1706
1707 Item excVar = makeTemp(syms.throwableType);
1708 excVar.store();
1709 genFinalizer(env);
1710 code.resolvePending();
1711 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.END_POS));
1712 code.markStatBegin();
1713
1714 excVar.load();
1715 registerCatch(body.pos(), startseg,
1716 env.info.gaps.next().intValue(),
1717 catchallpc, 0);
1718 code.emitop0(athrow);
1719 code.markDead();
1720
1721 // If there are jsr's to this finalizer, ...
1722 if (env.info.cont != null) {
1723 // Resolve all jsr's.
1724 code.resolve(env.info.cont);
1725
1726 // Mark statement line number
1727 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1728 code.markStatBegin();
1729
1730 // Save return address.
1731 LocalItem retVar = makeTemp(syms.throwableType);
1732 retVar.store();
1733
1734 // Generate finalizer code.
1735 env.info.finalize.genLast();
1736
1737 // Return.
1738 code.emitop1w(ret, retVar.reg);
1739 code.markDead();
1740 }
1741 }
1742 // Resolve all breaks.
1743 code.resolve(exitChain);
1744
1745 code.endScopes(limit);
1746 }
1747
1748 /** Generate code for a catch clause.
1749 * @param tree The catch clause.
1750 * @param env The environment current in the enclosing try.
1751 * @param startpc Start pc of try-block.
1752 * @param endpc End pc of try-block.
1753 */
1754 void genCatch(JCCatch tree,
1755 Env<GenContext> env,
1756 int startpc, int endpc,
1757 List<Integer> gaps) {
1758 if (startpc != endpc) {
1759 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypeExprs
1760 = catchTypesWithAnnotations(tree);
1761 while (gaps.nonEmpty()) {
1762 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) {
1763 JCExpression subCatch = subCatch1.snd;
1764 int catchType = makeRef(tree.pos(), subCatch.type);
1765 int end = gaps.head.intValue();
1766 registerCatch(tree.pos(),
1767 startpc, end, code.curCP(),
1768 catchType);
1769 for (Attribute.TypeCompound tc : subCatch1.fst) {
1770 tc.position.setCatchInfo(catchType, startpc);
1771 }
1772 }
1773 gaps = gaps.tail;
1774 startpc = gaps.head.intValue();
1775 gaps = gaps.tail;
1776 }
1777 if (startpc < endpc) {
1778 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) {
1779 JCExpression subCatch = subCatch1.snd;
1780 int catchType = makeRef(tree.pos(), subCatch.type);
1781 registerCatch(tree.pos(),
1782 startpc, endpc, code.curCP(),
1783 catchType);
1784 for (Attribute.TypeCompound tc : subCatch1.fst) {
1785 tc.position.setCatchInfo(catchType, startpc);
1786 }
1787 }
1788 }
1789 genCatchBlock(tree, env);
1790 }
1791 }
1792 void genPatternMatchingCatch(JCCatch tree,
1793 Env<GenContext> env,
1794 List<int[]> ranges) {
1795 for (int[] range : ranges) {
1796 JCExpression subCatch = tree.param.vartype;
1797 int catchType = makeRef(tree.pos(), subCatch.type);
1798 registerCatch(tree.pos(),
1799 range[0], range[1], code.curCP(),
1800 catchType);
1801 }
1802 genCatchBlock(tree, env);
1803 }
1804 void genCatchBlock(JCCatch tree, Env<GenContext> env) {
1805 VarSymbol exparam = tree.param.sym;
1806 code.statBegin(tree.pos);
1807 code.markStatBegin();
1808 int limit = code.nextreg;
1809 code.newLocal(exparam);
1810 items.makeLocalItem(exparam).store();
1811 code.statBegin(TreeInfo.firstStatPos(tree.body));
1812 genStat(tree.body, env, CRT_BLOCK);
1813 code.endScopes(limit);
1814 code.statBegin(TreeInfo.endPos(tree.body));
1815 }
1816 // where
1817 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotations(JCCatch tree) {
1818 return TreeInfo.isMultiCatch(tree) ?
1819 catchTypesWithAnnotationsFromMulticatch((JCTypeUnion)tree.param.vartype, tree.param.sym.getRawTypeAttributes()) :
1820 List.of(new Pair<>(tree.param.sym.getRawTypeAttributes(), tree.param.vartype));
1821 }
1822 // where
1823 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotationsFromMulticatch(JCTypeUnion tree, List<TypeCompound> first) {
1824 List<JCExpression> alts = tree.alternatives;
1825 List<Pair<List<TypeCompound>, JCExpression>> res = List.of(new Pair<>(first, alts.head));
1826 alts = alts.tail;
1827
1828 while(alts != null && alts.head != null) {
1829 JCExpression alt = alts.head;
1830 if (alt instanceof JCAnnotatedType annotatedType) {
1831 res = res.prepend(new Pair<>(annotate.fromAnnotations(annotatedType.annotations), alt));
1832 } else {
1833 res = res.prepend(new Pair<>(List.nil(), alt));
1834 }
1835 alts = alts.tail;
1836 }
1837 return res.reverse();
1838 }
1839
1840 /** Register a catch clause in the "Exceptions" code-attribute.
1841 */
1842 void registerCatch(DiagnosticPosition pos,
1843 int startpc, int endpc,
1844 int handler_pc, int catch_type) {
1845 char startpc1 = (char)startpc;
1846 char endpc1 = (char)endpc;
1847 char handler_pc1 = (char)handler_pc;
1848 if (startpc1 == startpc &&
1849 endpc1 == endpc &&
1850 handler_pc1 == handler_pc) {
1851 code.addCatch(startpc1, endpc1, handler_pc1,
1852 (char)catch_type);
1853 } else {
1854 log.error(pos, Errors.LimitCodeTooLargeForTryStmt);
1855 nerrs++;
1856 }
1857 }
1858
1859 public void visitIf(JCIf tree) {
1860 Set<VarSymbol> prevCodeUnsetFields = code.currentUnsetFields;
1861 try {
1862 visitIfHelper(tree);
1863 } finally {
1864 code.currentUnsetFields = prevCodeUnsetFields;
1865 }
1866 }
1867
1868 public void visitIfHelper(JCIf tree) {
1869 int limit = code.nextreg;
1870 Chain thenExit = null;
1871 Assert.check(code.isStatementStart());
1872 CondItem c = genCond(TreeInfo.skipParens(tree.cond),
1873 CRT_FLOW_CONTROLLER);
1874 Chain elseChain = c.jumpFalse();
1875 Assert.check(code.isStatementStart());
1876 if (!c.isFalse()) {
1877 code.resolve(c.trueJumps);
1878 genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET);
1879 thenExit = code.branch(goto_);
1880 }
1881 if (elseChain != null) {
1882 code.resolve(elseChain);
1883 if (tree.elsepart != null) {
1884 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET);
1885 }
1886 }
1887 code.resolve(thenExit);
1888 code.endScopes(limit);
1889 Assert.check(code.isStatementStart());
1890 }
1891
1892 public void visitExec(JCExpressionStatement tree) {
1893 // Optimize x++ to ++x and x-- to --x.
1894 JCExpression e = tree.expr;
1895 switch (e.getTag()) {
1896 case POSTINC:
1897 ((JCUnary) e).setTag(PREINC);
1898 break;
1899 case POSTDEC:
1900 ((JCUnary) e).setTag(PREDEC);
1901 break;
1902 }
1903 Assert.check(code.isStatementStart());
1904 genExpr(tree.expr, tree.expr.type).drop();
1905 Assert.check(code.isStatementStart());
1906 }
1907
1908 public void visitBreak(JCBreak tree) {
1909 Assert.check(code.isStatementStart());
1910 final Env<GenContext> targetEnv = unwindBreak(tree.target);
1911 targetEnv.info.addExit(code.branch(goto_));
1912 endFinalizerGaps(env, targetEnv);
1913 }
1914
1915 public void visitYield(JCYield tree) {
1916 Assert.check(code.isStatementStart());
1917 final Env<GenContext> targetEnv;
1918 if (inCondSwitchExpression) {
1919 CondItem value = genCond(tree.value, CRT_FLOW_TARGET);
1920 Chain falseJumps = value.jumpFalse();
1921
1922 code.resolve(value.trueJumps);
1923 Env<GenContext> localEnv = unwindBreak(tree.target);
1924 reloadStackBeforeSwitchExpr();
1925 Chain trueJumps = code.branch(goto_);
1926
1927 endFinalizerGaps(env, localEnv);
1928
1929 code.resolve(falseJumps);
1930 targetEnv = unwindBreak(tree.target);
1931 reloadStackBeforeSwitchExpr();
1932 falseJumps = code.branch(goto_);
1933
1934 if (switchExpressionTrueChain == null) {
1935 switchExpressionTrueChain = trueJumps;
1936 } else {
1937 switchExpressionTrueChain =
1938 Code.mergeChains(switchExpressionTrueChain, trueJumps);
1939 }
1940 if (switchExpressionFalseChain == null) {
1941 switchExpressionFalseChain = falseJumps;
1942 } else {
1943 switchExpressionFalseChain =
1944 Code.mergeChains(switchExpressionFalseChain, falseJumps);
1945 }
1946 } else {
1947 genExpr(tree.value, pt).load();
1948 if (switchResult != null)
1949 switchResult.store();
1950
1951 targetEnv = unwindBreak(tree.target);
1952
1953 if (code.isAlive()) {
1954 reloadStackBeforeSwitchExpr();
1955 if (switchResult != null)
1956 switchResult.load();
1957
1958 code.state.forceStackTop(tree.target.type);
1959 targetEnv.info.addExit(code.branch(goto_));
1960 code.markDead();
1961 }
1962 }
1963 endFinalizerGaps(env, targetEnv);
1964 }
1965 //where:
1966 /** As side-effect, might mark code as dead disabling any further emission.
1967 */
1968 private Env<GenContext> unwindBreak(JCTree target) {
1969 int tmpPos = code.pendingStatPos;
1970 Env<GenContext> targetEnv = unwind(target, env);
1971 code.pendingStatPos = tmpPos;
1972 return targetEnv;
1973 }
1974
1975 private void reloadStackBeforeSwitchExpr() {
1976 for (LocalItem li : stackBeforeSwitchExpression)
1977 li.load();
1978 }
1979
1980 public void visitContinue(JCContinue tree) {
1981 int tmpPos = code.pendingStatPos;
1982 Env<GenContext> targetEnv = unwind(tree.target, env);
1983 code.pendingStatPos = tmpPos;
1984 Assert.check(code.isStatementStart());
1985 targetEnv.info.addCont(code.branch(goto_));
1986 endFinalizerGaps(env, targetEnv);
1987 }
1988
1989 public void visitReturn(JCReturn tree) {
1990 int limit = code.nextreg;
1991 final Env<GenContext> targetEnv;
1992
1993 /* Save and then restore the location of the return in case a finally
1994 * is expanded (with unwind()) in the middle of our bytecodes.
1995 */
1996 int tmpPos = code.pendingStatPos;
1997 if (tree.expr != null) {
1998 Assert.check(code.isStatementStart());
1999 Item r = genExpr(tree.expr, pt).load();
2000 if (hasFinally(env.enclMethod, env)) {
2001 r = makeTemp(pt);
2002 r.store();
2003 }
2004 targetEnv = unwind(env.enclMethod, env);
2005 code.pendingStatPos = tmpPos;
2006 r.load();
2007 code.emitop0(ireturn + Code.truncate(Code.typecode(pt)));
2008 } else {
2009 targetEnv = unwind(env.enclMethod, env);
2010 code.pendingStatPos = tmpPos;
2011 code.emitop0(return_);
2012 }
2013 endFinalizerGaps(env, targetEnv);
2014 code.endScopes(limit);
2015 }
2016
2017 public void visitThrow(JCThrow tree) {
2018 Assert.check(code.isStatementStart());
2019 genExpr(tree.expr, tree.expr.type).load();
2020 code.emitop0(athrow);
2021 Assert.check(code.isStatementStart());
2022 }
2023
2024 /* ************************************************************************
2025 * Visitor methods for expressions
2026 *************************************************************************/
2027
2028 public void visitApply(JCMethodInvocation tree) {
2029 setTypeAnnotationPositions(tree.pos);
2030 // Generate code for method.
2031 Item m = genExpr(tree.meth, methodType);
2032 // Generate code for all arguments, where the expected types are
2033 // the parameters of the method's external type (that is, any implicit
2034 // outer instance of a super(...) call appears as first parameter).
2035 MethodSymbol msym = (MethodSymbol)TreeInfo.symbol(tree.meth);
2036 genArgs(tree.args,
2037 msym.externalType(types).getParameterTypes());
2038 if (!msym.isDynamic()) {
2039 code.statBegin(tree.pos);
2040 }
2041 if (patternMatchingCatchConfiguration.invocations().contains(tree)) {
2042 int start = code.curCP();
2043 result = m.invoke();
2044 patternMatchingCatchConfiguration.ranges().add(new int[] {start, code.curCP()});
2045 } else {
2046 if (msym.isConstructor() && TreeInfo.isConstructorCall(tree)) {
2047 //if this is a this(...) or super(...) call, there is a pending
2048 //"uninitialized this" before this call. One catch handler cannot
2049 //handle exceptions that may come from places with "uninitialized this"
2050 //and (initialized) this, hence generate one set of handlers here
2051 //for the "uninitialized this" case, and another set of handlers
2052 //will be generated at the end of the method for the initialized this,
2053 //if needed:
2054 generatePatternMatchingCatch(env);
2055 result = m.invoke();
2056 patternMatchingCatchConfiguration =
2057 patternMatchingCatchConfiguration.restart(code.state.dup());
2058 } else {
2059 result = m.invoke();
2060 }
2061 }
2062 }
2063
2064 public void visitConditional(JCConditional tree) {
2065 Chain thenExit = null;
2066 code.statBegin(tree.cond.pos);
2067 CondItem c = genCond(tree.cond, CRT_FLOW_CONTROLLER);
2068 Chain elseChain = c.jumpFalse();
2069 if (!c.isFalse()) {
2070 code.resolve(c.trueJumps);
2071 int startpc = genCrt ? code.curCP() : 0;
2072 code.statBegin(tree.truepart.pos);
2073 genExpr(tree.truepart, pt).load();
2074 code.state.forceStackTop(tree.type);
2075 if (genCrt) code.crt.put(tree.truepart, CRT_FLOW_TARGET,
2076 startpc, code.curCP());
2077 thenExit = code.branch(goto_);
2078 }
2079 if (elseChain != null) {
2080 code.resolve(elseChain);
2081 int startpc = genCrt ? code.curCP() : 0;
2082 code.statBegin(tree.falsepart.pos);
2083 genExpr(tree.falsepart, pt).load();
2084 code.state.forceStackTop(tree.type);
2085 if (genCrt) code.crt.put(tree.falsepart, CRT_FLOW_TARGET,
2086 startpc, code.curCP());
2087 }
2088 code.resolve(thenExit);
2089 result = items.makeStackItem(pt);
2090 }
2091
2092 private void setTypeAnnotationPositions(int treePos) {
2093 MethodSymbol meth = code.meth;
2094 boolean initOrClinit = code.meth.getKind() == javax.lang.model.element.ElementKind.CONSTRUCTOR
2095 || code.meth.getKind() == javax.lang.model.element.ElementKind.STATIC_INIT;
2096
2097 for (Attribute.TypeCompound ta : meth.getRawTypeAttributes()) {
2098 if (ta.hasUnknownPosition())
2099 ta.tryFixPosition();
2100
2101 if (ta.position.matchesPos(treePos))
2102 ta.position.updatePosOffset(code.cp);
2103 }
2104
2105 if (!initOrClinit)
2106 return;
2107
2108 for (Attribute.TypeCompound ta : meth.owner.getRawTypeAttributes()) {
2109 if (ta.hasUnknownPosition())
2110 ta.tryFixPosition();
2111
2112 if (ta.position.matchesPos(treePos))
2113 ta.position.updatePosOffset(code.cp);
2114 }
2115
2116 ClassSymbol clazz = meth.enclClass();
2117 for (Symbol s : new com.sun.tools.javac.model.FilteredMemberList(clazz.members())) {
2118 if (!s.getKind().isField())
2119 continue;
2120
2121 for (Attribute.TypeCompound ta : s.getRawTypeAttributes()) {
2122 if (ta.hasUnknownPosition())
2123 ta.tryFixPosition();
2124
2125 if (ta.position.matchesPos(treePos))
2126 ta.position.updatePosOffset(code.cp);
2127 }
2128 }
2129 }
2130
2131 public void visitNewClass(JCNewClass tree) {
2132 // Enclosing instances or anonymous classes should have been eliminated
2133 // by now.
2134 Assert.check(tree.encl == null && tree.def == null);
2135 setTypeAnnotationPositions(tree.pos);
2136
2137 code.emitop2(new_, checkDimension(tree.pos(), tree.type), PoolWriter::putClass);
2138 code.emitop0(dup);
2139
2140 // Generate code for all arguments, where the expected types are
2141 // the parameters of the constructor's external type (that is,
2142 // any implicit outer instance appears as first parameter).
2143 genArgs(tree.args, tree.constructor.externalType(types).getParameterTypes());
2144
2145 items.makeMemberItem(tree.constructor, true).invoke();
2146 result = items.makeStackItem(tree.type);
2147 }
2148
2149 public void visitNewArray(JCNewArray tree) {
2150 setTypeAnnotationPositions(tree.pos);
2151
2152 if (tree.elems != null) {
2153 Type elemtype = types.elemtype(tree.type);
2154 loadIntConst(tree.elems.length());
2155 Item arr = makeNewArray(tree.pos(), tree.type, 1);
2156 int i = 0;
2157 for (List<JCExpression> l = tree.elems; l.nonEmpty(); l = l.tail) {
2158 arr.duplicate();
2159 loadIntConst(i);
2160 i++;
2161 genExpr(l.head, elemtype).load();
2162 items.makeIndexedItem(elemtype).store();
2163 }
2164 result = arr;
2165 } else {
2166 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
2167 genExpr(l.head, syms.intType).load();
2168 }
2169 result = makeNewArray(tree.pos(), tree.type, tree.dims.length());
2170 }
2171 }
2172 //where
2173 /** Generate code to create an array with given element type and number
2174 * of dimensions.
2175 */
2176 Item makeNewArray(DiagnosticPosition pos, Type type, int ndims) {
2177 Type elemtype = types.elemtype(type);
2178 if (types.dimensions(type) > ClassFile.MAX_DIMENSIONS) {
2179 log.error(pos, Errors.LimitDimensions);
2180 nerrs++;
2181 }
2182 int elemcode = Code.arraycode(elemtype);
2183 if (elemcode == 0 || (elemcode == 1 && ndims == 1)) {
2184 code.emitAnewarray(makeRef(pos, elemtype), type);
2185 } else if (elemcode == 1) {
2186 code.emitMultianewarray(ndims, makeRef(pos, type), type);
2187 } else {
2188 code.emitNewarray(elemcode, type);
2189 }
2190 return items.makeStackItem(type);
2191 }
2192
2193 public void visitParens(JCParens tree) {
2194 result = genExpr(tree.expr, tree.expr.type);
2195 }
2196
2197 public void visitAssign(JCAssign tree) {
2198 Item l = genExpr(tree.lhs, tree.lhs.type);
2199 genExpr(tree.rhs, tree.lhs.type).load();
2200 Set<VarSymbol> tmpUnsetSymbols = unsetFieldsInfo.getUnsetFields(env.enclClass.sym, tree);
2201 code.currentUnsetFields = tmpUnsetSymbols != null ? tmpUnsetSymbols : code.currentUnsetFields;
2202 if (tree.rhs.type.hasTag(BOT)) {
2203 /* This is just a case of widening reference conversion that per 5.1.5 simply calls
2204 for "regarding a reference as having some other type in a manner that can be proved
2205 correct at compile time."
2206 */
2207 code.state.forceStackTop(tree.lhs.type);
2208 }
2209 result = items.makeAssignItem(l);
2210 }
2211
2212 public void visitAssignop(JCAssignOp tree) {
2213 OperatorSymbol operator = tree.operator;
2214 Item l;
2215 if (operator.opcode == string_add) {
2216 l = concat.makeConcat(tree);
2217 } else {
2218 // Generate code for first expression
2219 l = genExpr(tree.lhs, tree.lhs.type);
2220
2221 // If we have an increment of -32768 to +32767 of a local
2222 // int variable we can use an incr instruction instead of
2223 // proceeding further.
2224 if ((tree.hasTag(PLUS_ASG) || tree.hasTag(MINUS_ASG)) &&
2225 l instanceof LocalItem localItem &&
2226 tree.lhs.type.getTag().isSubRangeOf(INT) &&
2227 tree.rhs.type.getTag().isSubRangeOf(INT) &&
2228 tree.rhs.type.constValue() != null) {
2229 int ival = ((Number) tree.rhs.type.constValue()).intValue();
2230 if (tree.hasTag(MINUS_ASG)) ival = -ival;
2231 localItem.incr(ival);
2232 result = l;
2233 return;
2234 }
2235 // Otherwise, duplicate expression, load one copy
2236 // and complete binary operation.
2237 l.duplicate();
2238 l.coerce(operator.type.getParameterTypes().head).load();
2239 completeBinop(tree.lhs, tree.rhs, operator).coerce(tree.lhs.type);
2240 }
2241 result = items.makeAssignItem(l);
2242 }
2243
2244 public void visitUnary(JCUnary tree) {
2245 OperatorSymbol operator = tree.operator;
2246 if (tree.hasTag(NOT)) {
2247 CondItem od = genCond(tree.arg, false);
2248 result = od.negate();
2249 } else {
2250 Item od = genExpr(tree.arg, operator.type.getParameterTypes().head);
2251 switch (tree.getTag()) {
2252 case POS:
2253 result = od.load();
2254 break;
2255 case NEG:
2256 result = od.load();
2257 code.emitop0(operator.opcode);
2258 break;
2259 case COMPL:
2260 result = od.load();
2261 emitMinusOne(od.typecode);
2262 code.emitop0(operator.opcode);
2263 break;
2264 case PREINC: case PREDEC:
2265 od.duplicate();
2266 if (od instanceof LocalItem localItem &&
2267 (operator.opcode == iadd || operator.opcode == isub)) {
2268 localItem.incr(tree.hasTag(PREINC) ? 1 : -1);
2269 result = od;
2270 } else {
2271 od.load();
2272 code.emitop0(one(od.typecode));
2273 code.emitop0(operator.opcode);
2274 // Perform narrowing primitive conversion if byte,
2275 // char, or short. Fix for 4304655.
2276 if (od.typecode != INTcode &&
2277 Code.truncate(od.typecode) == INTcode)
2278 code.emitop0(int2byte + od.typecode - BYTEcode);
2279 result = items.makeAssignItem(od);
2280 }
2281 break;
2282 case POSTINC: case POSTDEC:
2283 od.duplicate();
2284 if (od instanceof LocalItem localItem &&
2285 (operator.opcode == iadd || operator.opcode == isub)) {
2286 Item res = od.load();
2287 localItem.incr(tree.hasTag(POSTINC) ? 1 : -1);
2288 result = res;
2289 } else {
2290 Item res = od.load();
2291 od.stash(od.typecode);
2292 code.emitop0(one(od.typecode));
2293 code.emitop0(operator.opcode);
2294 // Perform narrowing primitive conversion if byte,
2295 // char, or short. Fix for 4304655.
2296 if (od.typecode != INTcode &&
2297 Code.truncate(od.typecode) == INTcode)
2298 code.emitop0(int2byte + od.typecode - BYTEcode);
2299 od.store();
2300 result = res;
2301 }
2302 break;
2303 case NULLCHK:
2304 result = od.load();
2305 code.emitop0(dup);
2306 genNullCheck(tree);
2307 break;
2308 default:
2309 Assert.error();
2310 }
2311 }
2312 }
2313
2314 /** Generate a null check from the object value at stack top. */
2315 private void genNullCheck(JCTree tree) {
2316 code.statBegin(tree.pos);
2317 callMethod(tree.pos(), syms.objectsType, names.requireNonNull,
2318 List.of(syms.objectType), true);
2319 code.emitop0(pop);
2320 }
2321
2322 public void visitBinary(JCBinary tree) {
2323 OperatorSymbol operator = tree.operator;
2324 if (operator.opcode == string_add) {
2325 result = concat.makeConcat(tree);
2326 } else if (tree.hasTag(AND)) {
2327 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2328 if (!lcond.isFalse()) {
2329 Chain falseJumps = lcond.jumpFalse();
2330 code.resolve(lcond.trueJumps);
2331 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2332 result = items.
2333 makeCondItem(rcond.opcode,
2334 rcond.trueJumps,
2335 Code.mergeChains(falseJumps,
2336 rcond.falseJumps));
2337 } else {
2338 result = lcond;
2339 }
2340 } else if (tree.hasTag(OR)) {
2341 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2342 if (!lcond.isTrue()) {
2343 Chain trueJumps = lcond.jumpTrue();
2344 code.resolve(lcond.falseJumps);
2345 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2346 result = items.
2347 makeCondItem(rcond.opcode,
2348 Code.mergeChains(trueJumps, rcond.trueJumps),
2349 rcond.falseJumps);
2350 } else {
2351 result = lcond;
2352 }
2353 } else {
2354 Item od = genExpr(tree.lhs, operator.type.getParameterTypes().head);
2355 od.load();
2356 result = completeBinop(tree.lhs, tree.rhs, operator);
2357 }
2358 }
2359
2360
2361 /** Complete generating code for operation, with left operand
2362 * already on stack.
2363 * @param lhs The tree representing the left operand.
2364 * @param rhs The tree representing the right operand.
2365 * @param operator The operator symbol.
2366 */
2367 Item completeBinop(JCTree lhs, JCTree rhs, OperatorSymbol operator) {
2368 MethodType optype = (MethodType)operator.type;
2369 int opcode = operator.opcode;
2370 if (opcode >= if_icmpeq && opcode <= if_icmple &&
2371 rhs.type.constValue() instanceof Number number &&
2372 number.intValue() == 0) {
2373 opcode = opcode + (ifeq - if_icmpeq);
2374 } else if (opcode >= if_acmpeq && opcode <= if_acmpne &&
2375 TreeInfo.isNull(rhs)) {
2376 opcode = opcode + (if_acmp_null - if_acmpeq);
2377 } else {
2378 // The expected type of the right operand is
2379 // the second parameter type of the operator, except for
2380 // shifts with long shiftcount, where we convert the opcode
2381 // to a short shift and the expected type to int.
2382 Type rtype = operator.erasure(types).getParameterTypes().tail.head;
2383 if (opcode >= ishll && opcode <= lushrl) {
2384 opcode = opcode + (ishl - ishll);
2385 rtype = syms.intType;
2386 }
2387 // Generate code for right operand and load.
2388 genExpr(rhs, rtype).load();
2389 // If there are two consecutive opcode instructions,
2390 // emit the first now.
2391 if (opcode >= (1 << preShift)) {
2392 code.emitop0(opcode >> preShift);
2393 opcode = opcode & 0xFF;
2394 }
2395 }
2396 if (opcode >= ifeq && opcode <= if_acmpne ||
2397 opcode == if_acmp_null || opcode == if_acmp_nonnull) {
2398 return items.makeCondItem(opcode);
2399 } else {
2400 code.emitop0(opcode);
2401 return items.makeStackItem(optype.restype);
2402 }
2403 }
2404
2405 public void visitTypeCast(JCTypeCast tree) {
2406 result = genExpr(tree.expr, tree.clazz.type).load();
2407 setTypeAnnotationPositions(tree.pos);
2408 // Additional code is only needed if we cast to a reference type
2409 // which is not statically a supertype of the expression's type.
2410 // For basic types, the coerce(...) in genExpr(...) will do
2411 // the conversion.
2412 if (!tree.clazz.type.isPrimitive() &&
2413 !types.isSameType(tree.expr.type, tree.clazz.type) &&
2414 types.asSuper(tree.expr.type, tree.clazz.type.tsym) == null) {
2415 code.emitop2(checkcast, checkDimension(tree.pos(), tree.clazz.type), PoolWriter::putClass);
2416 }
2417 }
2418
2419 public void visitWildcard(JCWildcard tree) {
2420 throw new AssertionError(this.getClass().getName());
2421 }
2422
2423 public void visitTypeTest(JCInstanceOf tree) {
2424 genExpr(tree.expr, tree.expr.type).load();
2425 setTypeAnnotationPositions(tree.pos);
2426 code.emitop2(instanceof_, makeRef(tree.pos(), tree.pattern.type));
2427 result = items.makeStackItem(syms.booleanType);
2428 }
2429
2430 public void visitIndexed(JCArrayAccess tree) {
2431 genExpr(tree.indexed, tree.indexed.type).load();
2432 genExpr(tree.index, syms.intType).load();
2433 result = items.makeIndexedItem(tree.type);
2434 }
2435
2436 public void visitIdent(JCIdent tree) {
2437 Symbol sym = tree.sym;
2438 if (tree.name == names._this || tree.name == names._super) {
2439 Item res = tree.name == names._this
2440 ? items.makeThisItem()
2441 : items.makeSuperItem();
2442 if (sym.kind == MTH) {
2443 // Generate code to address the constructor.
2444 res.load();
2445 res = items.makeMemberItem(sym, true);
2446 }
2447 result = res;
2448 } else if (isInvokeDynamic(sym) || isConstantDynamic(sym)) {
2449 if (isConstantDynamic(sym)) {
2450 setTypeAnnotationPositions(tree.pos);
2451 }
2452 result = items.makeDynamicItem(sym);
2453 } else if (sym.kind == VAR && (sym.owner.kind == MTH || sym.owner.kind == VAR)) {
2454 result = items.makeLocalItem((VarSymbol)sym);
2455 } else if ((sym.flags() & STATIC) != 0) {
2456 if (!isAccessSuper(env.enclMethod))
2457 sym = binaryQualifier(sym, env.enclClass.type);
2458 result = items.makeStaticItem(sym);
2459 } else {
2460 items.makeThisItem().load();
2461 sym = binaryQualifier(sym, env.enclClass.type);
2462 result = items.makeMemberItem(sym, nonVirtualForPrivateAccess(sym));
2463 }
2464 }
2465
2466 //where
2467 private boolean nonVirtualForPrivateAccess(Symbol sym) {
2468 boolean useVirtual = target.hasVirtualPrivateInvoke() &&
2469 !disableVirtualizedPrivateInvoke;
2470 return !useVirtual && ((sym.flags() & PRIVATE) != 0);
2471 }
2472
2473 public void visitSelect(JCFieldAccess tree) {
2474 Symbol sym = tree.sym;
2475
2476 if (tree.name == names._class) {
2477 code.emitLdc((LoadableConstant)checkDimension(tree.pos(), tree.selected.type));
2478 result = items.makeStackItem(pt);
2479 return;
2480 }
2481
2482 Symbol ssym = TreeInfo.symbol(tree.selected);
2483
2484 // Are we selecting via super?
2485 boolean selectSuper =
2486 ssym != null && (ssym.kind == TYP || ssym.name == names._super);
2487
2488 // Are we accessing a member of the superclass in an access method
2489 // resulting from a qualified super?
2490 boolean accessSuper = isAccessSuper(env.enclMethod);
2491
2492 Item base = (selectSuper)
2493 ? items.makeSuperItem()
2494 : genExpr(tree.selected, tree.selected.type);
2495
2496 if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) {
2497 // We are seeing a variable that is constant but its selecting
2498 // expression is not.
2499 if ((sym.flags() & STATIC) != 0) {
2500 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2501 base = base.load();
2502 base.drop();
2503 } else {
2504 base.load();
2505 genNullCheck(tree.selected);
2506 }
2507 result = items.
2508 makeImmediateItem(sym.type, ((VarSymbol) sym).getConstValue());
2509 } else {
2510 if (isInvokeDynamic(sym)) {
2511 result = items.makeDynamicItem(sym);
2512 return;
2513 } else {
2514 sym = binaryQualifier(sym, tree.selected.type);
2515 }
2516 if ((sym.flags() & STATIC) != 0) {
2517 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2518 base = base.load();
2519 base.drop();
2520 result = items.makeStaticItem(sym);
2521 } else {
2522 base.load();
2523 if (sym == syms.lengthVar) {
2524 code.emitop0(arraylength);
2525 result = items.makeStackItem(syms.intType);
2526 } else {
2527 result = items.
2528 makeMemberItem(sym,
2529 nonVirtualForPrivateAccess(sym) ||
2530 selectSuper || accessSuper);
2531 }
2532 }
2533 }
2534 }
2535
2536 public boolean isInvokeDynamic(Symbol sym) {
2537 return sym.kind == MTH && ((MethodSymbol)sym).isDynamic();
2538 }
2539
2540 public void visitLiteral(JCLiteral tree) {
2541 if (tree.type.hasTag(BOT)) {
2542 code.emitop0(aconst_null);
2543 result = items.makeStackItem(tree.type);
2544 }
2545 else
2546 result = items.makeImmediateItem(tree.type, tree.value);
2547 }
2548
2549 public void visitLetExpr(LetExpr tree) {
2550 code.resolvePending();
2551
2552 int limit = code.nextreg;
2553 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
2554 try {
2555 genStats(tree.defs, env);
2556 } finally {
2557 code.setLetExprStackPos(prevLetExprStart);
2558 }
2559 result = genExpr(tree.expr, tree.expr.type).load();
2560 code.endScopes(limit);
2561 }
2562
2563 private void generateReferencesToPrunedTree(ClassSymbol classSymbol) {
2564 List<JCTree> prunedInfo = lower.prunedTree.get(classSymbol);
2565 if (prunedInfo != null) {
2566 for (JCTree prunedTree: prunedInfo) {
2567 prunedTree.accept(classReferenceVisitor);
2568 }
2569 }
2570 }
2571
2572 /* ************************************************************************
2573 * main method
2574 *************************************************************************/
2575
2576 /** Generate code for a class definition.
2577 * @param env The attribution environment that belongs to the
2578 * outermost class containing this class definition.
2579 * We need this for resolving some additional symbols.
2580 * @param cdef The tree representing the class definition.
2581 * @return True if code is generated with no errors.
2582 */
2583 public boolean genClass(Env<AttrContext> env, JCClassDecl cdef) {
2584 try {
2585 attrEnv = env;
2586 ClassSymbol c = cdef.sym;
2587 this.toplevel = env.toplevel;
2588 this.endPosTable = toplevel.endPositions;
2589 /* method normalizeDefs() can add references to external classes into the constant pool
2590 */
2591 cdef.defs = normalizeDefs(cdef.defs, c);
2592 generateReferencesToPrunedTree(c);
2593 Env<GenContext> localEnv = new Env<>(cdef, new GenContext());
2594 localEnv.toplevel = env.toplevel;
2595 localEnv.enclClass = cdef;
2596
2597 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2598 genDef(l.head, localEnv);
2599 }
2600 if (poolWriter.size() > PoolWriter.MAX_ENTRIES) {
2601 log.error(cdef.pos(), Errors.LimitPool);
2602 nerrs++;
2603 }
2604 if (nerrs != 0) {
2605 // if errors, discard code
2606 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2607 if (l.head.hasTag(METHODDEF))
2608 ((JCMethodDecl) l.head).sym.code = null;
2609 }
2610 }
2611 cdef.defs = List.nil(); // discard trees
2612 return nerrs == 0;
2613 } finally {
2614 // note: this method does NOT support recursion.
2615 attrEnv = null;
2616 this.env = null;
2617 toplevel = null;
2618 endPosTable = null;
2619 nerrs = 0;
2620 qualifiedSymbolCache.clear();
2621 }
2622 }
2623
2624 /* ************************************************************************
2625 * Auxiliary classes
2626 *************************************************************************/
2627
2628 /** An abstract class for finalizer generation.
2629 */
2630 abstract class GenFinalizer {
2631 /** Generate code to clean up when unwinding. */
2632 abstract void gen();
2633
2634 /** Generate code to clean up at last. */
2635 abstract void genLast();
2636
2637 /** Does this finalizer have some nontrivial cleanup to perform? */
2638 boolean hasFinalizer() { return true; }
2639
2640 /** Should be invoked after the try's body has been visited. */
2641 void afterBody() {}
2642 }
2643
2644 /** code generation contexts,
2645 * to be used as type parameter for environments.
2646 */
2647 static class GenContext {
2648
2649 /** A chain for all unresolved jumps that exit the current environment.
2650 */
2651 Chain exit = null;
2652
2653 /** A chain for all unresolved jumps that continue in the
2654 * current environment.
2655 */
2656 Chain cont = null;
2657
2658 /** A closure that generates the finalizer of the current environment.
2659 * Only set for Synchronized and Try contexts.
2660 */
2661 GenFinalizer finalize = null;
2662
2663 /** Is this a switch statement? If so, allocate registers
2664 * even when the variable declaration is unreachable.
2665 */
2666 boolean isSwitch = false;
2667
2668 /** A list buffer containing all gaps in the finalizer range,
2669 * where a catch all exception should not apply.
2670 */
2671 ListBuffer<Integer> gaps = null;
2672
2673 /** Add given chain to exit chain.
2674 */
2675 void addExit(Chain c) {
2676 exit = Code.mergeChains(c, exit);
2677 }
2678
2679 /** Add given chain to cont chain.
2680 */
2681 void addCont(Chain c) {
2682 cont = Code.mergeChains(c, cont);
2683 }
2684 }
2685
2686 record PatternMatchingCatchConfiguration(Set<JCMethodInvocation> invocations,
2687 ListBuffer<int[]> ranges,
2688 JCCatch handler,
2689 State startState) {
2690 public PatternMatchingCatchConfiguration restart(State newState) {
2691 return new PatternMatchingCatchConfiguration(invocations(),
2692 new ListBuffer<int[]>(),
2693 handler(),
2694 newState);
2695 }
2696 }
2697 }