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 Preview preview = Preview.instance(context);
139 Source source = Source.instance(context);
140 allowValueClasses = (!preview.isPreview(Source.Feature.VALUE_CLASSES) || preview.isEnabled()) &&
141 Source.Feature.VALUE_CLASSES.allowedInSource(source);
142 }
143
144 /** Switches
145 */
146 private final boolean lineDebugInfo;
147 private final boolean varDebugInfo;
148 private final boolean genCrt;
149 private final boolean debugCode;
150 private boolean disableVirtualizedPrivateInvoke;
151 private final boolean allowValueClasses;
152
153 /** Code buffer, set by genMethod.
154 */
155 private Code code;
156
157 /** Items structure, set by genMethod.
158 */
159 private Items items;
160
161 /** Environment for symbol lookup, set by genClass
162 */
163 private Env<AttrContext> attrEnv;
164
165 /** The top level tree.
166 */
167 private JCCompilationUnit toplevel;
168
169 /** The number of code-gen errors in this class.
170 */
171 private int nerrs = 0;
172
173 /** An object containing mappings of syntax trees to their
174 * ending source positions.
175 */
176 EndPosTable endPosTable;
177
178 boolean inCondSwitchExpression;
179 Chain switchExpressionTrueChain;
180 Chain switchExpressionFalseChain;
181 List<LocalItem> stackBeforeSwitchExpression;
182 LocalItem switchResult;
183 PatternMatchingCatchConfiguration patternMatchingCatchConfiguration =
184 new PatternMatchingCatchConfiguration(Set.of(), null, null, null);
185
186 /** Cache the symbol to reflect the qualifying type.
187 * key: corresponding type
188 * value: qualified symbol
189 */
190 Map<Type, Symbol> qualifiedSymbolCache;
191
192 /** Generate code to load an integer constant.
193 * @param n The integer to be loaded.
194 */
195 void loadIntConst(int n) {
196 items.makeImmediateItem(syms.intType, n).load();
197 }
198
199 /** The opcode that loads a zero constant of a given type code.
200 * @param tc The given type code (@see ByteCode).
201 */
202 public static int zero(int tc) {
203 switch(tc) {
204 case INTcode: case BYTEcode: case SHORTcode: case CHARcode:
205 return iconst_0;
206 case LONGcode:
207 return lconst_0;
208 case FLOATcode:
209 return fconst_0;
210 case DOUBLEcode:
211 return dconst_0;
212 default:
213 throw new AssertionError("zero");
214 }
215 }
216
217 /** The opcode that loads a one constant of a given type code.
218 * @param tc The given type code (@see ByteCode).
219 */
220 public static int one(int tc) {
221 return zero(tc) + 1;
222 }
223
224 /** Generate code to load -1 of the given type code (either int or long).
225 * @param tc The given type code (@see ByteCode).
226 */
227 void emitMinusOne(int tc) {
228 if (tc == LONGcode) {
229 items.makeImmediateItem(syms.longType, Long.valueOf(-1)).load();
230 } else {
231 code.emitop0(iconst_m1);
232 }
233 }
234
235 /** Construct a symbol to reflect the qualifying type that should
236 * appear in the byte code as per JLS 13.1.
237 *
238 * For {@literal target >= 1.2}: Clone a method with the qualifier as owner (except
239 * for those cases where we need to work around VM bugs).
240 *
241 * For {@literal target <= 1.1}: If qualified variable or method is defined in a
242 * non-accessible class, clone it with the qualifier class as owner.
243 *
244 * @param sym The accessed symbol
245 * @param site The qualifier's type.
246 */
247 Symbol binaryQualifier(Symbol sym, Type site) {
248
249 if (site.hasTag(ARRAY)) {
250 if (sym == syms.lengthVar ||
251 sym.owner != syms.arrayClass)
252 return sym;
253 // array clone can be qualified by the array type in later targets
254 Symbol qualifier;
255 if ((qualifier = qualifiedSymbolCache.get(site)) == null) {
256 qualifier = new ClassSymbol(Flags.PUBLIC, site.tsym.name, site, syms.noSymbol);
257 qualifiedSymbolCache.put(site, qualifier);
258 }
259 return sym.clone(qualifier);
260 }
261
262 if (sym.owner == site.tsym ||
263 (sym.flags() & (STATIC | SYNTHETIC)) == (STATIC | SYNTHETIC)) {
264 return sym;
265 }
266
267 // leave alone methods inherited from Object
268 // JLS 13.1.
269 if (sym.owner == syms.objectType.tsym)
270 return sym;
271
272 return sym.clone(site.tsym);
273 }
274
275 /** Insert a reference to given type in the constant pool,
276 * checking for an array with too many dimensions;
277 * return the reference's index.
278 * @param type The type for which a reference is inserted.
279 */
280 int makeRef(DiagnosticPosition pos, Type type) {
281 return poolWriter.putClass(checkDimension(pos, type));
282 }
283
284 /** Check if the given type is an array with too many dimensions.
285 */
286 private Type checkDimension(DiagnosticPosition pos, Type t) {
287 checkDimensionInternal(pos, t);
288 return t;
289 }
290
291 private void checkDimensionInternal(DiagnosticPosition pos, Type t) {
292 switch (t.getTag()) {
293 case METHOD:
294 checkDimension(pos, t.getReturnType());
295 for (List<Type> args = t.getParameterTypes(); args.nonEmpty(); args = args.tail)
296 checkDimension(pos, args.head);
297 break;
298 case ARRAY:
299 if (types.dimensions(t) > ClassFile.MAX_DIMENSIONS) {
300 log.error(pos, Errors.LimitDimensions);
301 nerrs++;
302 }
303 break;
304 default:
305 break;
306 }
307 }
308
309 /** Create a temporary variable.
310 * @param type The variable's type.
311 */
312 LocalItem makeTemp(Type type) {
313 VarSymbol v = new VarSymbol(Flags.SYNTHETIC,
314 names.empty,
315 type,
316 env.enclMethod.sym);
317 code.newLocal(v);
318 return items.makeLocalItem(v);
319 }
320
321 /** Generate code to call a non-private method or constructor.
322 * @param pos Position to be used for error reporting.
323 * @param site The type of which the method is a member.
324 * @param name The method's name.
325 * @param argtypes The method's argument types.
326 * @param isStatic A flag that indicates whether we call a
327 * static or instance method.
328 */
329 void callMethod(DiagnosticPosition pos,
330 Type site, Name name, List<Type> argtypes,
331 boolean isStatic) {
332 Symbol msym = rs.
333 resolveInternalMethod(pos, attrEnv, site, name, argtypes, null);
334 if (isStatic) items.makeStaticItem(msym).invoke();
335 else items.makeMemberItem(msym, name == names.init).invoke();
336 }
337
338 /** Is the given method definition an access method
339 * resulting from a qualified super? This is signified by an odd
340 * access code.
341 */
342 private boolean isAccessSuper(JCMethodDecl enclMethod) {
343 return
344 (enclMethod.mods.flags & SYNTHETIC) != 0 &&
345 isOddAccessName(enclMethod.name);
346 }
347
348 /** Does given name start with "access$" and end in an odd digit?
349 */
350 private boolean isOddAccessName(Name name) {
351 final String string = name.toString();
352 return
353 string.startsWith(accessDollar) &&
354 (string.charAt(string.length() - 1) & 1) != 0;
355 }
356
357 /* ************************************************************************
358 * Non-local exits
359 *************************************************************************/
360
361 /** Generate code to invoke the finalizer associated with given
362 * environment.
363 * Any calls to finalizers are appended to the environments `cont' chain.
364 * Mark beginning of gap in catch all range for finalizer.
365 */
366 void genFinalizer(Env<GenContext> env) {
367 if (code.isAlive() && env.info.finalize != null)
368 env.info.finalize.gen();
369 }
370
371 /** Generate code to call all finalizers of structures aborted by
372 * a non-local
373 * exit. Return target environment of the non-local exit.
374 * @param target The tree representing the structure that's aborted
375 * @param env The environment current at the non-local exit.
376 */
377 Env<GenContext> unwind(JCTree target, Env<GenContext> env) {
378 Env<GenContext> env1 = env;
379 while (true) {
380 genFinalizer(env1);
381 if (env1.tree == target) break;
382 env1 = env1.next;
383 }
384 return env1;
385 }
386
387 /** Mark end of gap in catch-all range for finalizer.
388 * @param env the environment which might contain the finalizer
389 * (if it does, env.info.gaps != null).
390 */
391 void endFinalizerGap(Env<GenContext> env) {
392 if (env.info.gaps != null && env.info.gaps.length() % 2 == 1)
393 env.info.gaps.append(code.curCP());
394 }
395
396 /** Mark end of all gaps in catch-all ranges for finalizers of environments
397 * lying between, and including to two environments.
398 * @param from the most deeply nested environment to mark
399 * @param to the least deeply nested environment to mark
400 */
401 void endFinalizerGaps(Env<GenContext> from, Env<GenContext> to) {
402 Env<GenContext> last = null;
403 while (last != to) {
404 endFinalizerGap(from);
405 last = from;
406 from = from.next;
407 }
408 }
409
410 /** Do any of the structures aborted by a non-local exit have
411 * finalizers that require an empty stack?
412 * @param target The tree representing the structure that's aborted
413 * @param env The environment current at the non-local exit.
414 */
415 boolean hasFinally(JCTree target, Env<GenContext> env) {
416 while (env.tree != target) {
417 if (env.tree.hasTag(TRY) && env.info.finalize.hasFinalizer())
418 return true;
419 env = env.next;
420 }
421 return false;
422 }
423
424 /* ************************************************************************
425 * Normalizing class-members.
426 *************************************************************************/
427
428 /** Distribute member initializer code into constructors and {@code <clinit>}
429 * method.
430 * @param defs The list of class member declarations.
431 * @param c The enclosing class.
432 */
433 List<JCTree> normalizeDefs(List<JCTree> defs, ClassSymbol c) {
434 ListBuffer<JCStatement> initCode = new ListBuffer<>();
435 // only used for value classes
436 ListBuffer<JCStatement> initBlocks = new ListBuffer<>();
437 ListBuffer<Attribute.TypeCompound> initTAs = new ListBuffer<>();
438 ListBuffer<JCStatement> clinitCode = new ListBuffer<>();
439 ListBuffer<Attribute.TypeCompound> clinitTAs = new ListBuffer<>();
440 ListBuffer<JCTree> methodDefs = new ListBuffer<>();
441 // Sort definitions into three listbuffers:
442 // - initCode for instance initializers
443 // - clinitCode for class initializers
444 // - methodDefs for method definitions
445 for (List<JCTree> l = defs; l.nonEmpty(); l = l.tail) {
446 JCTree def = l.head;
447 switch (def.getTag()) {
448 case BLOCK:
449 JCBlock block = (JCBlock)def;
450 if ((block.flags & STATIC) != 0)
451 clinitCode.append(block);
452 else if ((block.flags & SYNTHETIC) == 0) {
453 if (c.isValueClass() || c.hasStrict()) {
454 initBlocks.append(block);
455 } else {
456 initCode.append(block);
457 }
458 }
459 break;
460 case METHODDEF:
461 methodDefs.append(def);
462 break;
463 case VARDEF:
464 JCVariableDecl vdef = (JCVariableDecl) def;
465 VarSymbol sym = vdef.sym;
466 checkDimension(vdef.pos(), sym.type);
467 if (vdef.init != null) {
468 if ((sym.flags() & STATIC) == 0) {
469 // Always initialize instance variables.
470 JCStatement init = make.at(vdef.pos()).
471 Assignment(sym, vdef.init);
472 initCode.append(init);
473 endPosTable.replaceTree(vdef, init);
474 initTAs.addAll(getAndRemoveNonFieldTAs(sym));
475 } else if (sym.getConstValue() == null) {
476 // Initialize class (static) variables only if
477 // they are not compile-time constants.
478 JCStatement init = make.at(vdef.pos).
479 Assignment(sym, vdef.init);
480 clinitCode.append(init);
481 endPosTable.replaceTree(vdef, init);
482 clinitTAs.addAll(getAndRemoveNonFieldTAs(sym));
483 } else {
484 checkStringConstant(vdef.init.pos(), sym.getConstValue());
485 /* if the init contains a reference to an external class, add it to the
486 * constant's pool
487 */
488 vdef.init.accept(classReferenceVisitor);
489 }
490 }
491 break;
492 default:
493 Assert.error();
494 }
495 }
496 // Insert any instance initializers into all constructors.
497 if (initCode.length() != 0 || initBlocks.length() != 0) {
498 initTAs.addAll(c.getInitTypeAttributes());
499 List<Attribute.TypeCompound> initTAlist = initTAs.toList();
500 for (JCTree t : methodDefs) {
501 normalizeMethod((JCMethodDecl)t, initCode.toList(), initBlocks.toList(), initTAlist);
502 }
503 }
504 // If there are class initializers, create a <clinit> method
505 // that contains them as its body.
506 if (clinitCode.length() != 0) {
507 MethodSymbol clinit = new MethodSymbol(
508 STATIC | (c.flags() & STRICTFP),
509 names.clinit,
510 new MethodType(
511 List.nil(), syms.voidType,
512 List.nil(), syms.methodClass),
513 c);
514 c.members().enter(clinit);
515 List<JCStatement> clinitStats = clinitCode.toList();
516 JCBlock block = make.at(clinitStats.head.pos()).Block(0, clinitStats);
517 block.bracePos = TreeInfo.endPos(clinitStats.last());
518 methodDefs.append(make.MethodDef(clinit, block));
519
520 if (!clinitTAs.isEmpty())
521 clinit.appendUniqueTypeAttributes(clinitTAs.toList());
522 if (!c.getClassInitTypeAttributes().isEmpty())
523 clinit.appendUniqueTypeAttributes(c.getClassInitTypeAttributes());
524 }
525 // Return all method definitions.
526 return methodDefs.toList();
527 }
528
529 private List<Attribute.TypeCompound> getAndRemoveNonFieldTAs(VarSymbol sym) {
530 List<TypeCompound> tas = sym.getRawTypeAttributes();
531 ListBuffer<Attribute.TypeCompound> fieldTAs = new ListBuffer<>();
532 ListBuffer<Attribute.TypeCompound> nonfieldTAs = new ListBuffer<>();
533 for (TypeCompound ta : tas) {
534 Assert.check(ta.getPosition().type != TargetType.UNKNOWN);
535 if (ta.getPosition().type == TargetType.FIELD) {
536 fieldTAs.add(ta);
537 } else {
538 nonfieldTAs.add(ta);
539 }
540 }
541 sym.setTypeAttributes(fieldTAs.toList());
542 return nonfieldTAs.toList();
543 }
544
545 /** Check a constant value and report if it is a string that is
546 * too large.
547 */
548 private void checkStringConstant(DiagnosticPosition pos, Object constValue) {
549 if (nerrs != 0 || // only complain about a long string once
550 constValue == null ||
551 !(constValue instanceof String str) ||
552 str.length() < PoolWriter.MAX_STRING_LENGTH)
553 return;
554 log.error(pos, Errors.LimitString);
555 nerrs++;
556 }
557
558 /** Insert instance initializer code into constructors prior to the super() call.
559 * @param md The tree potentially representing a
560 * constructor's definition.
561 * @param initCode The list of instance initializer statements.
562 * @param initTAs Type annotations from the initializer expression.
563 */
564 void normalizeMethod(JCMethodDecl md, List<JCStatement> initCode, List<JCStatement> initBlocks, List<TypeCompound> initTAs) {
565 if (TreeInfo.isConstructor(md) && TreeInfo.hasConstructorCall(md, names._super)) {
566 // We are seeing a constructor that has a super() call.
567 // Find the super() invocation and append the given initializer code.
568 if (allowValueClasses & (md.sym.owner.isValueClass() || md.sym.owner.hasStrict() || ((md.sym.owner.flags_field & RECORD) != 0))) {
569 rewriteInitializersIfNeeded(md, initCode);
570 md.body.stats = initCode.appendList(md.body.stats);
571 TreeInfo.mapSuperCalls(md.body, supercall -> make.Block(0, initBlocks.prepend(supercall)));
572 } else {
573 TreeInfo.mapSuperCalls(md.body, supercall -> make.Block(0, initCode.prepend(supercall)));
574 }
575
576 if (md.body.bracePos == Position.NOPOS)
577 md.body.bracePos = TreeInfo.endPos(md.body.stats.last());
578
579 md.sym.appendUniqueTypeAttributes(initTAs);
580 }
581 }
582
583 void rewriteInitializersIfNeeded(JCMethodDecl md, List<JCStatement> initCode) {
584 if (lower.initializerOuterThis.containsKey(md.sym.owner)) {
585 InitializerVisitor initializerVisitor = new InitializerVisitor(md, lower.initializerOuterThis.get(md.sym.owner));
586 for (JCStatement init : initCode) {
587 initializerVisitor.scan(init);
588 }
589 }
590 }
591
592 public static class InitializerVisitor extends TreeScanner {
593 JCMethodDecl md;
594 Set<JCExpression> exprSet;
595
596 public InitializerVisitor(JCMethodDecl md, Set<JCExpression> exprSet) {
597 this.md = md;
598 this.exprSet = exprSet;
599 }
600
601 @Override
602 public void visitTree(JCTree tree) {}
603
604 @Override
605 public void visitIdent(JCIdent tree) {
606 if (exprSet.contains(tree)) {
607 for (JCVariableDecl param: md.params) {
608 if (param.name == tree.name &&
609 ((param.sym.flags_field & (MANDATED | NOOUTERTHIS)) == (MANDATED | NOOUTERTHIS))) {
610 tree.sym = param.sym;
611 }
612 }
613 }
614 }
615 }
616
617 /* ************************************************************************
618 * Traversal methods
619 *************************************************************************/
620
621 /** Visitor argument: The current environment.
622 */
623 Env<GenContext> env;
624
625 /** Visitor argument: The expected type (prototype).
626 */
627 Type pt;
628
629 /** Visitor result: The item representing the computed value.
630 */
631 Item result;
632
633 /** Visitor method: generate code for a definition, catching and reporting
634 * any completion failures.
635 * @param tree The definition to be visited.
636 * @param env The environment current at the definition.
637 */
638 public void genDef(JCTree tree, Env<GenContext> env) {
639 Env<GenContext> prevEnv = this.env;
640 try {
641 this.env = env;
642 tree.accept(this);
643 } catch (CompletionFailure ex) {
644 chk.completionError(tree.pos(), ex);
645 } finally {
646 this.env = prevEnv;
647 }
648 }
649
650 /** Derived visitor method: check whether CharacterRangeTable
651 * should be emitted, if so, put a new entry into CRTable
652 * and call method to generate bytecode.
653 * If not, just call method to generate bytecode.
654 * @see #genStat(JCTree, Env)
655 *
656 * @param tree The tree to be visited.
657 * @param env The environment to use.
658 * @param crtFlags The CharacterRangeTable flags
659 * indicating type of the entry.
660 */
661 public void genStat(JCTree tree, Env<GenContext> env, int crtFlags) {
662 if (!genCrt) {
663 genStat(tree, env);
664 return;
665 }
666 int startpc = code.curCP();
667 genStat(tree, env);
668 if (tree.hasTag(Tag.BLOCK)) crtFlags |= CRT_BLOCK;
669 code.crt.put(tree, crtFlags, startpc, code.curCP());
670 }
671
672 /** Derived visitor method: generate code for a statement.
673 */
674 public void genStat(JCTree tree, Env<GenContext> env) {
675 if (code.isAlive()) {
676 code.statBegin(tree.pos);
677 genDef(tree, env);
678 } else if (env.info.isSwitch && tree.hasTag(VARDEF)) {
679 // variables whose declarations are in a switch
680 // can be used even if the decl is unreachable.
681 code.newLocal(((JCVariableDecl) tree).sym);
682 }
683 }
684
685 /** Derived visitor method: check whether CharacterRangeTable
686 * should be emitted, if so, put a new entry into CRTable
687 * and call method to generate bytecode.
688 * If not, just call method to generate bytecode.
689 * @see #genStats(List, Env)
690 *
691 * @param trees The list of trees to be visited.
692 * @param env The environment to use.
693 * @param crtFlags The CharacterRangeTable flags
694 * indicating type of the entry.
695 */
696 public void genStats(List<JCStatement> trees, Env<GenContext> env, int crtFlags) {
697 if (!genCrt) {
698 genStats(trees, env);
699 return;
700 }
701 if (trees.length() == 1) { // mark one statement with the flags
702 genStat(trees.head, env, crtFlags | CRT_STATEMENT);
703 } else {
704 int startpc = code.curCP();
705 genStats(trees, env);
706 code.crt.put(trees, crtFlags, startpc, code.curCP());
707 }
708 }
709
710 /** Derived visitor method: generate code for a list of statements.
711 */
712 public void genStats(List<? extends JCTree> trees, Env<GenContext> env) {
713 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
714 genStat(l.head, env, CRT_STATEMENT);
715 }
716
717 /** Derived visitor method: check whether CharacterRangeTable
718 * should be emitted, if so, put a new entry into CRTable
719 * and call method to generate bytecode.
720 * If not, just call method to generate bytecode.
721 * @see #genCond(JCTree,boolean)
722 *
723 * @param tree The tree to be visited.
724 * @param crtFlags The CharacterRangeTable flags
725 * indicating type of the entry.
726 */
727 public CondItem genCond(JCTree tree, int crtFlags) {
728 if (!genCrt) return genCond(tree, false);
729 int startpc = code.curCP();
730 CondItem item = genCond(tree, (crtFlags & CRT_FLOW_CONTROLLER) != 0);
731 code.crt.put(tree, crtFlags, startpc, code.curCP());
732 return item;
733 }
734
735 /** Derived visitor method: generate code for a boolean
736 * expression in a control-flow context.
737 * @param _tree The expression to be visited.
738 * @param markBranches The flag to indicate that the condition is
739 * a flow controller so produced conditions
740 * should contain a proper tree to generate
741 * CharacterRangeTable branches for them.
742 */
743 public CondItem genCond(JCTree _tree, boolean markBranches) {
744 JCTree inner_tree = TreeInfo.skipParens(_tree);
745 if (inner_tree.hasTag(CONDEXPR)) {
746 JCConditional tree = (JCConditional)inner_tree;
747 CondItem cond = genCond(tree.cond, CRT_FLOW_CONTROLLER);
748 if (cond.isTrue()) {
749 code.resolve(cond.trueJumps);
750 CondItem result = genCond(tree.truepart, CRT_FLOW_TARGET);
751 if (markBranches) result.tree = tree.truepart;
752 return result;
753 }
754 if (cond.isFalse()) {
755 code.resolve(cond.falseJumps);
756 CondItem result = genCond(tree.falsepart, CRT_FLOW_TARGET);
757 if (markBranches) result.tree = tree.falsepart;
758 return result;
759 }
760 Chain secondJumps = cond.jumpFalse();
761 code.resolve(cond.trueJumps);
762 CondItem first = genCond(tree.truepart, CRT_FLOW_TARGET);
763 if (markBranches) first.tree = tree.truepart;
764 Chain falseJumps = first.jumpFalse();
765 code.resolve(first.trueJumps);
766 Chain trueJumps = code.branch(goto_);
767 code.resolve(secondJumps);
768 CondItem second = genCond(tree.falsepart, CRT_FLOW_TARGET);
769 CondItem result = items.makeCondItem(second.opcode,
770 Code.mergeChains(trueJumps, second.trueJumps),
771 Code.mergeChains(falseJumps, second.falseJumps));
772 if (markBranches) result.tree = tree.falsepart;
773 return result;
774 } else if (inner_tree.hasTag(SWITCH_EXPRESSION)) {
775 code.resolvePending();
776
777 boolean prevInCondSwitchExpression = inCondSwitchExpression;
778 Chain prevSwitchExpressionTrueChain = switchExpressionTrueChain;
779 Chain prevSwitchExpressionFalseChain = switchExpressionFalseChain;
780 try {
781 inCondSwitchExpression = true;
782 switchExpressionTrueChain = null;
783 switchExpressionFalseChain = null;
784 try {
785 doHandleSwitchExpression((JCSwitchExpression) inner_tree);
786 } catch (CompletionFailure ex) {
787 chk.completionError(_tree.pos(), ex);
788 code.state.stacksize = 1;
789 }
790 CondItem result = items.makeCondItem(goto_,
791 switchExpressionTrueChain,
792 switchExpressionFalseChain);
793 if (markBranches) result.tree = _tree;
794 return result;
795 } finally {
796 inCondSwitchExpression = prevInCondSwitchExpression;
797 switchExpressionTrueChain = prevSwitchExpressionTrueChain;
798 switchExpressionFalseChain = prevSwitchExpressionFalseChain;
799 }
800 } else if (inner_tree.hasTag(LETEXPR) && ((LetExpr) inner_tree).needsCond) {
801 code.resolvePending();
802
803 LetExpr tree = (LetExpr) inner_tree;
804 int limit = code.nextreg;
805 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
806 try {
807 genStats(tree.defs, env);
808 } finally {
809 code.setLetExprStackPos(prevLetExprStart);
810 }
811 CondItem result = genCond(tree.expr, markBranches);
812 code.endScopes(limit);
813 //make sure variables defined in the let expression are not included
814 //in the defined variables for jumps that go outside of this let
815 //expression:
816 undefineVariablesInChain(result.falseJumps, limit);
817 undefineVariablesInChain(result.trueJumps, limit);
818 return result;
819 } else {
820 CondItem result = genExpr(_tree, syms.booleanType).mkCond();
821 if (markBranches) result.tree = _tree;
822 return result;
823 }
824 }
825 //where:
826 private void undefineVariablesInChain(Chain toClear, int limit) {
827 while (toClear != null) {
828 toClear.state.defined.excludeFrom(limit);
829 toClear = toClear.next;
830 }
831 }
832
833 public Code getCode() {
834 return code;
835 }
836
837 public Items getItems() {
838 return items;
839 }
840
841 public Env<AttrContext> getAttrEnv() {
842 return attrEnv;
843 }
844
845 /** Visitor class for expressions which might be constant expressions.
846 * This class is a subset of TreeScanner. Intended to visit trees pruned by
847 * Lower as long as constant expressions looking for references to any
848 * ClassSymbol. Any such reference will be added to the constant pool so
849 * automated tools can detect class dependencies better.
850 */
851 class ClassReferenceVisitor extends JCTree.Visitor {
852
853 @Override
854 public void visitTree(JCTree tree) {}
855
856 @Override
857 public void visitBinary(JCBinary tree) {
858 tree.lhs.accept(this);
859 tree.rhs.accept(this);
860 }
861
862 @Override
863 public void visitSelect(JCFieldAccess tree) {
864 if (tree.selected.type.hasTag(CLASS)) {
865 makeRef(tree.selected.pos(), tree.selected.type);
866 }
867 }
868
869 @Override
870 public void visitIdent(JCIdent tree) {
871 if (tree.sym.owner instanceof ClassSymbol classSymbol) {
872 poolWriter.putClass(classSymbol);
873 }
874 }
875
876 @Override
877 public void visitConditional(JCConditional tree) {
878 tree.cond.accept(this);
879 tree.truepart.accept(this);
880 tree.falsepart.accept(this);
881 }
882
883 @Override
884 public void visitUnary(JCUnary tree) {
885 tree.arg.accept(this);
886 }
887
888 @Override
889 public void visitParens(JCParens tree) {
890 tree.expr.accept(this);
891 }
892
893 @Override
894 public void visitTypeCast(JCTypeCast tree) {
895 tree.expr.accept(this);
896 }
897 }
898
899 private ClassReferenceVisitor classReferenceVisitor = new ClassReferenceVisitor();
900
901 /** Visitor method: generate code for an expression, catching and reporting
902 * any completion failures.
903 * @param tree The expression to be visited.
904 * @param pt The expression's expected type (proto-type).
905 */
906 public Item genExpr(JCTree tree, Type pt) {
907 if (!code.isAlive()) {
908 return items.makeStackItem(pt);
909 }
910
911 Type prevPt = this.pt;
912 try {
913 if (tree.type.constValue() != null) {
914 // Short circuit any expressions which are constants
915 tree.accept(classReferenceVisitor);
916 checkStringConstant(tree.pos(), tree.type.constValue());
917 Symbol sym = TreeInfo.symbol(tree);
918 if (sym != null && isConstantDynamic(sym)) {
919 result = items.makeDynamicItem(sym);
920 } else {
921 result = items.makeImmediateItem(tree.type, tree.type.constValue());
922 }
923 } else {
924 this.pt = pt;
925 tree.accept(this);
926 }
927 return result.coerce(pt);
928 } catch (CompletionFailure ex) {
929 chk.completionError(tree.pos(), ex);
930 code.state.stacksize = 1;
931 return items.makeStackItem(pt);
932 } finally {
933 this.pt = prevPt;
934 }
935 }
936
937 public boolean isConstantDynamic(Symbol sym) {
938 return sym.kind == VAR &&
939 sym instanceof DynamicVarSymbol dynamicVarSymbol &&
940 dynamicVarSymbol.isDynamic();
941 }
942
943 /** Derived visitor method: generate code for a list of method arguments.
944 * @param trees The argument expressions to be visited.
945 * @param pts The expression's expected types (i.e. the formal parameter
946 * types of the invoked method).
947 */
948 public void genArgs(List<JCExpression> trees, List<Type> pts) {
949 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail) {
950 genExpr(l.head, pts.head).load();
951 pts = pts.tail;
952 }
953 // require lists be of same length
954 Assert.check(pts.isEmpty());
955 }
956
957 /* ************************************************************************
958 * Visitor methods for statements and definitions
959 *************************************************************************/
960
961 /** Thrown when the byte code size exceeds limit.
962 */
963 public static class CodeSizeOverflow extends RuntimeException {
964 private static final long serialVersionUID = 0;
965 public CodeSizeOverflow() {}
966 }
967
968 public void visitMethodDef(JCMethodDecl tree) {
969 // Create a new local environment that points pack at method
970 // definition.
971 Env<GenContext> localEnv = env.dup(tree);
972 localEnv.enclMethod = tree;
973 // The expected type of every return statement in this method
974 // is the method's return type.
975 this.pt = tree.sym.erasure(types).getReturnType();
976
977 checkDimension(tree.pos(), tree.sym.erasure(types));
978 genMethod(tree, localEnv, false);
979 }
980 //where
981 /** Generate code for a method.
982 * @param tree The tree representing the method definition.
983 * @param env The environment current for the method body.
984 * @param fatcode A flag that indicates whether all jumps are
985 * within 32K. We first invoke this method under
986 * the assumption that fatcode == false, i.e. all
987 * jumps are within 32K. If this fails, fatcode
988 * is set to true and we try again.
989 */
990 void genMethod(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
991 MethodSymbol meth = tree.sym;
992 int extras = 0;
993 // Count up extra parameters
994 if (meth.isConstructor()) {
995 extras++;
996 if (meth.enclClass().isInner() &&
997 !meth.enclClass().isStatic()) {
998 extras++;
999 }
1000 } else if ((tree.mods.flags & STATIC) == 0) {
1001 extras++;
1002 }
1003 // System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG
1004 if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes()) + extras >
1005 ClassFile.MAX_PARAMETERS) {
1006 log.error(tree.pos(), Errors.LimitParameters);
1007 nerrs++;
1008 }
1009
1010 else if (tree.body != null) {
1011 // Create a new code structure and initialize it.
1012 int startpcCrt = initCode(tree, env, fatcode);
1013 Set<VarSymbol> prevUnsetFields = code.currentUnsetFields;
1014 if (meth.isConstructor()) {
1015 code.currentUnsetFields = unsetFieldsInfo.getUnsetFields(env.enclClass.sym, tree.body);
1016 code.initialUnsetFields = unsetFieldsInfo.getUnsetFields(env.enclClass.sym, tree.body);
1017 }
1018
1019 try {
1020 genStat(tree.body, env);
1021 } catch (CodeSizeOverflow e) {
1022 // Failed due to code limit, try again with jsr/ret
1023 startpcCrt = initCode(tree, env, fatcode);
1024 genStat(tree.body, env);
1025 } finally {
1026 code.currentUnsetFields = prevUnsetFields;
1027 }
1028
1029 if (code.state.stacksize != 0) {
1030 log.error(tree.body.pos(), Errors.StackSimError(tree.sym));
1031 throw new AssertionError();
1032 }
1033
1034 // If last statement could complete normally, insert a
1035 // return at the end.
1036 if (code.isAlive()) {
1037 code.statBegin(TreeInfo.endPos(tree.body));
1038 if (env.enclMethod == null ||
1039 env.enclMethod.sym.type.getReturnType().hasTag(VOID)) {
1040 code.emitop0(return_);
1041 } else {
1042 // sometime dead code seems alive (4415991);
1043 // generate a small loop instead
1044 int startpc = code.entryPoint();
1045 CondItem c = items.makeCondItem(goto_);
1046 code.resolve(c.jumpTrue(), startpc);
1047 }
1048 }
1049 if (genCrt)
1050 code.crt.put(tree.body,
1051 CRT_BLOCK,
1052 startpcCrt,
1053 code.curCP());
1054
1055 code.endScopes(0);
1056
1057 // If we exceeded limits, panic
1058 if (code.checkLimits(tree.pos(), log)) {
1059 nerrs++;
1060 return;
1061 }
1062
1063 // If we generated short code but got a long jump, do it again
1064 // with fatCode = true.
1065 if (!fatcode && code.fatcode) genMethod(tree, env, true);
1066
1067 // Clean up
1068 if(stackMap == StackMapFormat.JSR202) {
1069 code.lastFrame = null;
1070 code.frameBeforeLast = null;
1071 }
1072
1073 // Compress exception table
1074 code.compressCatchTable();
1075
1076 // Fill in type annotation positions for exception parameters
1077 code.fillExceptionParameterPositions();
1078 }
1079 }
1080
1081 private int initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
1082 MethodSymbol meth = tree.sym;
1083
1084 // Create a new code structure.
1085 meth.code = code = new Code(meth,
1086 fatcode,
1087 lineDebugInfo ? toplevel.lineMap : null,
1088 varDebugInfo,
1089 stackMap,
1090 debugCode,
1091 genCrt ? new CRTable(tree, env.toplevel.endPositions)
1092 : null,
1093 syms,
1094 types,
1095 poolWriter,
1096 allowValueClasses);
1097 items = new Items(poolWriter, code, syms, types);
1098 if (code.debugCode) {
1099 System.err.println(meth + " for body " + tree);
1100 }
1101
1102 // If method is not static, create a new local variable address
1103 // for `this'.
1104 if ((tree.mods.flags & STATIC) == 0) {
1105 Type selfType = meth.owner.type;
1106 if (meth.isConstructor() && selfType != syms.objectType)
1107 selfType = UninitializedType.uninitializedThis(selfType);
1108 code.setDefined(
1109 code.newLocal(
1110 new VarSymbol(FINAL, names._this, selfType, meth.owner)));
1111 }
1112
1113 // Mark all parameters as defined from the beginning of
1114 // the method.
1115 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
1116 checkDimension(l.head.pos(), l.head.sym.type);
1117 code.setDefined(code.newLocal(l.head.sym));
1118 }
1119
1120 // Get ready to generate code for method body.
1121 int startpcCrt = genCrt ? code.curCP() : 0;
1122 code.entryPoint();
1123
1124 // Suppress initial stackmap
1125 code.pendingStackMap = false;
1126
1127 return startpcCrt;
1128 }
1129
1130 public void visitVarDef(JCVariableDecl tree) {
1131 VarSymbol v = tree.sym;
1132 if (tree.init != null) {
1133 checkStringConstant(tree.init.pos(), v.getConstValue());
1134 if (v.getConstValue() == null || varDebugInfo) {
1135 Assert.check(code.isStatementStart());
1136 code.newLocal(v);
1137 genExpr(tree.init, v.erasure(types)).load();
1138 items.makeLocalItem(v).store();
1139 Assert.check(code.isStatementStart());
1140 }
1141 } else {
1142 code.newLocal(v);
1143 }
1144 checkDimension(tree.pos(), v.type);
1145 }
1146
1147 public void visitSkip(JCSkip tree) {
1148 }
1149
1150 public void visitBlock(JCBlock tree) {
1151 /* this method is heavily invoked, as expected, for deeply nested blocks, if blocks doesn't happen to have
1152 * patterns there will be an unnecessary tax on memory consumption every time this method is executed, for this
1153 * reason we have created helper methods and here at a higher level we just discriminate depending on the
1154 * presence, or not, of patterns in a given block
1155 */
1156 if (tree.patternMatchingCatch != null) {
1157 visitBlockWithPatterns(tree);
1158 } else {
1159 internalVisitBlock(tree);
1160 }
1161 }
1162
1163 private void visitBlockWithPatterns(JCBlock tree) {
1164 PatternMatchingCatchConfiguration prevConfiguration = patternMatchingCatchConfiguration;
1165 try {
1166 patternMatchingCatchConfiguration =
1167 new PatternMatchingCatchConfiguration(tree.patternMatchingCatch.calls2Handle(),
1168 new ListBuffer<int[]>(),
1169 tree.patternMatchingCatch.handler(),
1170 code.state.dup());
1171 internalVisitBlock(tree);
1172 } finally {
1173 generatePatternMatchingCatch(env);
1174 patternMatchingCatchConfiguration = prevConfiguration;
1175 }
1176 }
1177
1178 private void generatePatternMatchingCatch(Env<GenContext> env) {
1179 if (patternMatchingCatchConfiguration.handler != null &&
1180 !patternMatchingCatchConfiguration.ranges.isEmpty()) {
1181 Chain skipCatch = code.branch(goto_);
1182 JCCatch handler = patternMatchingCatchConfiguration.handler();
1183 code.entryPoint(patternMatchingCatchConfiguration.startState(),
1184 handler.param.sym.type);
1185 genPatternMatchingCatch(handler,
1186 env,
1187 patternMatchingCatchConfiguration.ranges.toList());
1188 code.resolve(skipCatch);
1189 }
1190 }
1191
1192 private void internalVisitBlock(JCBlock tree) {
1193 int limit = code.nextreg;
1194 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1195 genStats(tree.stats, localEnv);
1196 // End the scope of all block-local variables in variable info.
1197 if (!env.tree.hasTag(METHODDEF)) {
1198 code.statBegin(tree.bracePos);
1199 code.endScopes(limit);
1200 code.pendingStatPos = Position.NOPOS;
1201 }
1202 }
1203
1204 public void visitDoLoop(JCDoWhileLoop tree) {
1205 genLoop(tree, tree.body, tree.cond, List.nil(), false);
1206 }
1207
1208 public void visitWhileLoop(JCWhileLoop tree) {
1209 genLoop(tree, tree.body, tree.cond, List.nil(), true);
1210 }
1211
1212 public void visitForLoop(JCForLoop tree) {
1213 int limit = code.nextreg;
1214 genStats(tree.init, env);
1215 genLoop(tree, tree.body, tree.cond, tree.step, true);
1216 code.endScopes(limit);
1217 }
1218 //where
1219 /** Generate code for a loop.
1220 * @param loop The tree representing the loop.
1221 * @param body The loop's body.
1222 * @param cond The loop's controlling condition.
1223 * @param step "Step" statements to be inserted at end of
1224 * each iteration.
1225 * @param testFirst True if the loop test belongs before the body.
1226 */
1227 private void genLoop(JCStatement loop,
1228 JCStatement body,
1229 JCExpression cond,
1230 List<JCExpressionStatement> step,
1231 boolean testFirst) {
1232 Set<VarSymbol> prevCodeUnsetFields = code.currentUnsetFields;
1233 try {
1234 genLoopHelper(loop, body, cond, step, testFirst);
1235 } finally {
1236 code.currentUnsetFields = prevCodeUnsetFields;
1237 }
1238 }
1239
1240 private void genLoopHelper(JCStatement loop,
1241 JCStatement body,
1242 JCExpression cond,
1243 List<JCExpressionStatement> step,
1244 boolean testFirst) {
1245 Env<GenContext> loopEnv = env.dup(loop, new GenContext());
1246 int startpc = code.entryPoint();
1247 if (testFirst) { //while or for loop
1248 CondItem c;
1249 if (cond != null) {
1250 code.statBegin(cond.pos);
1251 Assert.check(code.isStatementStart());
1252 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1253 } else {
1254 c = items.makeCondItem(goto_);
1255 }
1256 Chain loopDone = c.jumpFalse();
1257 code.resolve(c.trueJumps);
1258 Assert.check(code.isStatementStart());
1259 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1260 code.resolve(loopEnv.info.cont);
1261 genStats(step, loopEnv);
1262 code.resolve(code.branch(goto_), startpc);
1263 code.resolve(loopDone);
1264 } else {
1265 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1266 code.resolve(loopEnv.info.cont);
1267 genStats(step, loopEnv);
1268 if (code.isAlive()) {
1269 CondItem c;
1270 if (cond != null) {
1271 code.statBegin(cond.pos);
1272 Assert.check(code.isStatementStart());
1273 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1274 } else {
1275 c = items.makeCondItem(goto_);
1276 }
1277 code.resolve(c.jumpTrue(), startpc);
1278 Assert.check(code.isStatementStart());
1279 code.resolve(c.falseJumps);
1280 }
1281 }
1282 code.resolve(loopEnv.info.exit);
1283 }
1284
1285 public void visitForeachLoop(JCEnhancedForLoop tree) {
1286 throw new AssertionError(); // should have been removed by Lower.
1287 }
1288
1289 public void visitLabelled(JCLabeledStatement tree) {
1290 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1291 genStat(tree.body, localEnv, CRT_STATEMENT);
1292 code.resolve(localEnv.info.exit);
1293 }
1294
1295 public void visitSwitch(JCSwitch tree) {
1296 handleSwitch(tree, tree.selector, tree.cases, tree.patternSwitch);
1297 }
1298
1299 @Override
1300 public void visitSwitchExpression(JCSwitchExpression tree) {
1301 code.resolvePending();
1302 boolean prevInCondSwitchExpression = inCondSwitchExpression;
1303 Set<VarSymbol> prevCodeUnsetFields = code.currentUnsetFields;
1304 try {
1305 inCondSwitchExpression = false;
1306 doHandleSwitchExpression(tree);
1307 } finally {
1308 inCondSwitchExpression = prevInCondSwitchExpression;
1309 code.currentUnsetFields = prevCodeUnsetFields;
1310 }
1311 result = items.makeStackItem(pt);
1312 }
1313
1314 private void doHandleSwitchExpression(JCSwitchExpression tree) {
1315 List<LocalItem> prevStackBeforeSwitchExpression = stackBeforeSwitchExpression;
1316 LocalItem prevSwitchResult = switchResult;
1317 int limit = code.nextreg;
1318 try {
1319 stackBeforeSwitchExpression = List.nil();
1320 switchResult = null;
1321 if (hasTry(tree)) {
1322 //if the switch expression contains try-catch, the catch handlers need to have
1323 //an empty stack. So stash whole stack to local variables, and restore it before
1324 //breaks:
1325 while (code.state.stacksize > 0) {
1326 Type type = code.state.peek();
1327 Name varName = names.fromString(target.syntheticNameChar() +
1328 "stack" +
1329 target.syntheticNameChar() +
1330 tree.pos +
1331 target.syntheticNameChar() +
1332 code.state.stacksize);
1333 VarSymbol var = new VarSymbol(Flags.SYNTHETIC, varName, type,
1334 this.env.enclMethod.sym);
1335 LocalItem item = items.new LocalItem(type, code.newLocal(var));
1336 stackBeforeSwitchExpression = stackBeforeSwitchExpression.prepend(item);
1337 item.store();
1338 }
1339 switchResult = makeTemp(tree.type);
1340 }
1341 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
1342 try {
1343 handleSwitch(tree, tree.selector, tree.cases, tree.patternSwitch);
1344 } finally {
1345 code.setLetExprStackPos(prevLetExprStart);
1346 }
1347 } finally {
1348 stackBeforeSwitchExpression = prevStackBeforeSwitchExpression;
1349 switchResult = prevSwitchResult;
1350 code.endScopes(limit);
1351 }
1352 }
1353 //where:
1354 private boolean hasTry(JCSwitchExpression tree) {
1355 class HasTryScanner extends TreeScanner {
1356 private boolean hasTry;
1357
1358 @Override
1359 public void visitTry(JCTry tree) {
1360 hasTry = true;
1361 }
1362
1363 @Override
1364 public void visitSynchronized(JCSynchronized tree) {
1365 hasTry = true;
1366 }
1367
1368 @Override
1369 public void visitClassDef(JCClassDecl tree) {
1370 }
1371
1372 @Override
1373 public void visitLambda(JCLambda tree) {
1374 }
1375 };
1376
1377 HasTryScanner hasTryScanner = new HasTryScanner();
1378
1379 hasTryScanner.scan(tree);
1380 return hasTryScanner.hasTry;
1381 }
1382
1383 private void handleSwitch(JCTree swtch, JCExpression selector, List<JCCase> cases,
1384 boolean patternSwitch) {
1385 Set<VarSymbol> prevCodeUnsetFields = code.currentUnsetFields;
1386 try {
1387 handleSwitchHelper(swtch, selector, cases, patternSwitch);
1388 } finally {
1389 code.currentUnsetFields = prevCodeUnsetFields;
1390 }
1391 }
1392
1393 void handleSwitchHelper(JCTree swtch, JCExpression selector, List<JCCase> cases,
1394 boolean patternSwitch) {
1395 int limit = code.nextreg;
1396 Assert.check(!selector.type.hasTag(CLASS));
1397 int switchStart = patternSwitch ? code.entryPoint() : -1;
1398 int startpcCrt = genCrt ? code.curCP() : 0;
1399 Assert.check(code.isStatementStart());
1400 Item sel = genExpr(selector, syms.intType);
1401 if (cases.isEmpty()) {
1402 // We are seeing: switch <sel> {}
1403 sel.load().drop();
1404 if (genCrt)
1405 code.crt.put(TreeInfo.skipParens(selector),
1406 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1407 } else {
1408 // We are seeing a nonempty switch.
1409 sel.load();
1410 if (genCrt)
1411 code.crt.put(TreeInfo.skipParens(selector),
1412 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1413 Env<GenContext> switchEnv = env.dup(swtch, new GenContext());
1414 switchEnv.info.isSwitch = true;
1415
1416 // Compute number of labels and minimum and maximum label values.
1417 // For each case, store its label in an array.
1418 int lo = Integer.MAX_VALUE; // minimum label.
1419 int hi = Integer.MIN_VALUE; // maximum label.
1420 int nlabels = 0; // number of labels.
1421
1422 int[] labels = new int[cases.length()]; // the label array.
1423 int defaultIndex = -1; // the index of the default clause.
1424
1425 List<JCCase> l = cases;
1426 for (int i = 0; i < labels.length; i++) {
1427 if (l.head.labels.head instanceof JCConstantCaseLabel constLabel) {
1428 Assert.check(l.head.labels.size() == 1);
1429 int val = ((Number) constLabel.expr.type.constValue()).intValue();
1430 labels[i] = val;
1431 if (val < lo) lo = val;
1432 if (hi < val) hi = val;
1433 nlabels++;
1434 } else {
1435 Assert.check(defaultIndex == -1);
1436 defaultIndex = i;
1437 }
1438 l = l.tail;
1439 }
1440
1441 // Determine whether to issue a tableswitch or a lookupswitch
1442 // instruction.
1443 long table_space_cost = 4 + ((long) hi - lo + 1); // words
1444 long table_time_cost = 3; // comparisons
1445 long lookup_space_cost = 3 + 2 * (long) nlabels;
1446 long lookup_time_cost = nlabels;
1447 int opcode =
1448 nlabels > 0 &&
1449 table_space_cost + 3 * table_time_cost <=
1450 lookup_space_cost + 3 * lookup_time_cost
1451 ?
1452 tableswitch : lookupswitch;
1453
1454 int startpc = code.curCP(); // the position of the selector operation
1455 code.emitop0(opcode);
1456 code.align(4);
1457 int tableBase = code.curCP(); // the start of the jump table
1458 int[] offsets = null; // a table of offsets for a lookupswitch
1459 code.emit4(-1); // leave space for default offset
1460 if (opcode == tableswitch) {
1461 code.emit4(lo); // minimum label
1462 code.emit4(hi); // maximum label
1463 for (long i = lo; i <= hi; i++) { // leave space for jump table
1464 code.emit4(-1);
1465 }
1466 } else {
1467 code.emit4(nlabels); // number of labels
1468 for (int i = 0; i < nlabels; i++) {
1469 code.emit4(-1); code.emit4(-1); // leave space for lookup table
1470 }
1471 offsets = new int[labels.length];
1472 }
1473 Code.State stateSwitch = code.state.dup();
1474 code.markDead();
1475
1476 // For each case do:
1477 l = cases;
1478 for (int i = 0; i < labels.length; i++) {
1479 JCCase c = l.head;
1480 l = l.tail;
1481
1482 int pc = code.entryPoint(stateSwitch);
1483 // Insert offset directly into code or else into the
1484 // offsets table.
1485 if (i != defaultIndex) {
1486 if (opcode == tableswitch) {
1487 code.put4(
1488 tableBase + 4 * (labels[i] - lo + 3),
1489 pc - startpc);
1490 } else {
1491 offsets[i] = pc - startpc;
1492 }
1493 } else {
1494 code.put4(tableBase, pc - startpc);
1495 }
1496
1497 // Generate code for the statements in this case.
1498 genStats(c.stats, switchEnv, CRT_FLOW_TARGET);
1499 }
1500
1501 if (switchEnv.info.cont != null) {
1502 Assert.check(patternSwitch);
1503 code.resolve(switchEnv.info.cont, switchStart);
1504 }
1505
1506 // Resolve all breaks.
1507 code.resolve(switchEnv.info.exit);
1508
1509 // If we have not set the default offset, we do so now.
1510 if (code.get4(tableBase) == -1) {
1511 code.put4(tableBase, code.entryPoint(stateSwitch) - startpc);
1512 }
1513
1514 if (opcode == tableswitch) {
1515 // Let any unfilled slots point to the default case.
1516 int defaultOffset = code.get4(tableBase);
1517 for (long i = lo; i <= hi; i++) {
1518 int t = (int)(tableBase + 4 * (i - lo + 3));
1519 if (code.get4(t) == -1)
1520 code.put4(t, defaultOffset);
1521 }
1522 } else {
1523 // Sort non-default offsets and copy into lookup table.
1524 if (defaultIndex >= 0)
1525 for (int i = defaultIndex; i < labels.length - 1; i++) {
1526 labels[i] = labels[i+1];
1527 offsets[i] = offsets[i+1];
1528 }
1529 if (nlabels > 0)
1530 qsort2(labels, offsets, 0, nlabels - 1);
1531 for (int i = 0; i < nlabels; i++) {
1532 int caseidx = tableBase + 8 * (i + 1);
1533 code.put4(caseidx, labels[i]);
1534 code.put4(caseidx + 4, offsets[i]);
1535 }
1536 }
1537
1538 if (swtch instanceof JCSwitchExpression) {
1539 // Emit line position for the end of a switch expression
1540 code.statBegin(TreeInfo.endPos(swtch));
1541 }
1542 }
1543 code.endScopes(limit);
1544 }
1545 //where
1546 /** Sort (int) arrays of keys and values
1547 */
1548 static void qsort2(int[] keys, int[] values, int lo, int hi) {
1549 int i = lo;
1550 int j = hi;
1551 int pivot = keys[(i+j)/2];
1552 do {
1553 while (keys[i] < pivot) i++;
1554 while (pivot < keys[j]) j--;
1555 if (i <= j) {
1556 int temp1 = keys[i];
1557 keys[i] = keys[j];
1558 keys[j] = temp1;
1559 int temp2 = values[i];
1560 values[i] = values[j];
1561 values[j] = temp2;
1562 i++;
1563 j--;
1564 }
1565 } while (i <= j);
1566 if (lo < j) qsort2(keys, values, lo, j);
1567 if (i < hi) qsort2(keys, values, i, hi);
1568 }
1569
1570 public void visitSynchronized(JCSynchronized tree) {
1571 int limit = code.nextreg;
1572 // Generate code to evaluate lock and save in temporary variable.
1573 final LocalItem lockVar = makeTemp(syms.objectType);
1574 Assert.check(code.isStatementStart());
1575 genExpr(tree.lock, tree.lock.type).load().duplicate();
1576 lockVar.store();
1577
1578 // Generate code to enter monitor.
1579 code.emitop0(monitorenter);
1580 code.state.lock(lockVar.reg);
1581
1582 // Generate code for a try statement with given body, no catch clauses
1583 // in a new environment with the "exit-monitor" operation as finalizer.
1584 final Env<GenContext> syncEnv = env.dup(tree, new GenContext());
1585 syncEnv.info.finalize = new GenFinalizer() {
1586 void gen() {
1587 genLast();
1588 Assert.check(syncEnv.info.gaps.length() % 2 == 0);
1589 syncEnv.info.gaps.append(code.curCP());
1590 }
1591 void genLast() {
1592 if (code.isAlive()) {
1593 lockVar.load();
1594 code.emitop0(monitorexit);
1595 code.state.unlock(lockVar.reg);
1596 }
1597 }
1598 };
1599 syncEnv.info.gaps = new ListBuffer<>();
1600 genTry(tree.body, List.nil(), syncEnv);
1601 code.endScopes(limit);
1602 }
1603
1604 public void visitTry(final JCTry tree) {
1605 // Generate code for a try statement with given body and catch clauses,
1606 // in a new environment which calls the finally block if there is one.
1607 final Env<GenContext> tryEnv = env.dup(tree, new GenContext());
1608 final Env<GenContext> oldEnv = env;
1609 tryEnv.info.finalize = new GenFinalizer() {
1610 void gen() {
1611 Assert.check(tryEnv.info.gaps.length() % 2 == 0);
1612 tryEnv.info.gaps.append(code.curCP());
1613 genLast();
1614 }
1615 void genLast() {
1616 if (tree.finalizer != null)
1617 genStat(tree.finalizer, oldEnv, CRT_BLOCK);
1618 }
1619 boolean hasFinalizer() {
1620 return tree.finalizer != null;
1621 }
1622
1623 @Override
1624 void afterBody() {
1625 if (tree.finalizer != null && (tree.finalizer.flags & BODY_ONLY_FINALIZE) != 0) {
1626 //for body-only finally, remove the GenFinalizer after try body
1627 //so that the finally is not generated to catch bodies:
1628 tryEnv.info.finalize = null;
1629 }
1630 }
1631
1632 };
1633 tryEnv.info.gaps = new ListBuffer<>();
1634 genTry(tree.body, tree.catchers, tryEnv);
1635 }
1636 //where
1637 /** Generate code for a try or synchronized statement
1638 * @param body The body of the try or synchronized statement.
1639 * @param catchers The list of catch clauses.
1640 * @param env The current environment of the body.
1641 */
1642 void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) {
1643 Set<VarSymbol> prevCodeUnsetFields = code.currentUnsetFields;
1644 try {
1645 genTryHelper(body, catchers, env);
1646 } finally {
1647 code.currentUnsetFields = prevCodeUnsetFields;
1648 }
1649 }
1650
1651 void genTryHelper(JCTree body, List<JCCatch> catchers, Env<GenContext> env) {
1652 int limit = code.nextreg;
1653 int startpc = code.curCP();
1654 Code.State stateTry = code.state.dup();
1655 genStat(body, env, CRT_BLOCK);
1656 int endpc = code.curCP();
1657 List<Integer> gaps = env.info.gaps.toList();
1658 code.statBegin(TreeInfo.endPos(body));
1659 genFinalizer(env);
1660 code.statBegin(TreeInfo.endPos(env.tree));
1661 Chain exitChain;
1662 boolean actualTry = env.tree.hasTag(TRY);
1663 if (startpc == endpc && actualTry) {
1664 exitChain = code.branch(dontgoto);
1665 } else {
1666 exitChain = code.branch(goto_);
1667 }
1668 endFinalizerGap(env);
1669 env.info.finalize.afterBody();
1670 boolean hasFinalizer =
1671 env.info.finalize != null &&
1672 env.info.finalize.hasFinalizer();
1673 if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) {
1674 // start off with exception on stack
1675 code.entryPoint(stateTry, l.head.param.sym.type);
1676 genCatch(l.head, env, startpc, endpc, gaps);
1677 genFinalizer(env);
1678 if (hasFinalizer || l.tail.nonEmpty()) {
1679 code.statBegin(TreeInfo.endPos(env.tree));
1680 exitChain = Code.mergeChains(exitChain,
1681 code.branch(goto_));
1682 }
1683 endFinalizerGap(env);
1684 }
1685 if (hasFinalizer && (startpc != endpc || !actualTry)) {
1686 // Create a new register segment to avoid allocating
1687 // the same variables in finalizers and other statements.
1688 code.newRegSegment();
1689
1690 // Add a catch-all clause.
1691
1692 // start off with exception on stack
1693 int catchallpc = code.entryPoint(stateTry, syms.throwableType);
1694
1695 // Register all exception ranges for catch all clause.
1696 // The range of the catch all clause is from the beginning
1697 // of the try or synchronized block until the present
1698 // code pointer excluding all gaps in the current
1699 // environment's GenContext.
1700 int startseg = startpc;
1701 while (env.info.gaps.nonEmpty()) {
1702 int endseg = env.info.gaps.next().intValue();
1703 registerCatch(body.pos(), startseg, endseg,
1704 catchallpc, 0);
1705 startseg = env.info.gaps.next().intValue();
1706 }
1707 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1708 code.markStatBegin();
1709
1710 Item excVar = makeTemp(syms.throwableType);
1711 excVar.store();
1712 genFinalizer(env);
1713 code.resolvePending();
1714 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.END_POS));
1715 code.markStatBegin();
1716
1717 excVar.load();
1718 registerCatch(body.pos(), startseg,
1719 env.info.gaps.next().intValue(),
1720 catchallpc, 0);
1721 code.emitop0(athrow);
1722 code.markDead();
1723
1724 // If there are jsr's to this finalizer, ...
1725 if (env.info.cont != null) {
1726 // Resolve all jsr's.
1727 code.resolve(env.info.cont);
1728
1729 // Mark statement line number
1730 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1731 code.markStatBegin();
1732
1733 // Save return address.
1734 LocalItem retVar = makeTemp(syms.throwableType);
1735 retVar.store();
1736
1737 // Generate finalizer code.
1738 env.info.finalize.genLast();
1739
1740 // Return.
1741 code.emitop1w(ret, retVar.reg);
1742 code.markDead();
1743 }
1744 }
1745 // Resolve all breaks.
1746 code.resolve(exitChain);
1747
1748 code.endScopes(limit);
1749 }
1750
1751 /** Generate code for a catch clause.
1752 * @param tree The catch clause.
1753 * @param env The environment current in the enclosing try.
1754 * @param startpc Start pc of try-block.
1755 * @param endpc End pc of try-block.
1756 */
1757 void genCatch(JCCatch tree,
1758 Env<GenContext> env,
1759 int startpc, int endpc,
1760 List<Integer> gaps) {
1761 if (startpc != endpc) {
1762 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypeExprs
1763 = catchTypesWithAnnotations(tree);
1764 while (gaps.nonEmpty()) {
1765 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) {
1766 JCExpression subCatch = subCatch1.snd;
1767 int catchType = makeRef(tree.pos(), subCatch.type);
1768 int end = gaps.head.intValue();
1769 registerCatch(tree.pos(),
1770 startpc, end, code.curCP(),
1771 catchType);
1772 for (Attribute.TypeCompound tc : subCatch1.fst) {
1773 tc.position.setCatchInfo(catchType, startpc);
1774 }
1775 }
1776 gaps = gaps.tail;
1777 startpc = gaps.head.intValue();
1778 gaps = gaps.tail;
1779 }
1780 if (startpc < endpc) {
1781 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) {
1782 JCExpression subCatch = subCatch1.snd;
1783 int catchType = makeRef(tree.pos(), subCatch.type);
1784 registerCatch(tree.pos(),
1785 startpc, endpc, code.curCP(),
1786 catchType);
1787 for (Attribute.TypeCompound tc : subCatch1.fst) {
1788 tc.position.setCatchInfo(catchType, startpc);
1789 }
1790 }
1791 }
1792 genCatchBlock(tree, env);
1793 }
1794 }
1795 void genPatternMatchingCatch(JCCatch tree,
1796 Env<GenContext> env,
1797 List<int[]> ranges) {
1798 for (int[] range : ranges) {
1799 JCExpression subCatch = tree.param.vartype;
1800 int catchType = makeRef(tree.pos(), subCatch.type);
1801 registerCatch(tree.pos(),
1802 range[0], range[1], code.curCP(),
1803 catchType);
1804 }
1805 genCatchBlock(tree, env);
1806 }
1807 void genCatchBlock(JCCatch tree, Env<GenContext> env) {
1808 VarSymbol exparam = tree.param.sym;
1809 code.statBegin(tree.pos);
1810 code.markStatBegin();
1811 int limit = code.nextreg;
1812 code.newLocal(exparam);
1813 items.makeLocalItem(exparam).store();
1814 code.statBegin(TreeInfo.firstStatPos(tree.body));
1815 genStat(tree.body, env, CRT_BLOCK);
1816 code.endScopes(limit);
1817 code.statBegin(TreeInfo.endPos(tree.body));
1818 }
1819 // where
1820 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotations(JCCatch tree) {
1821 return TreeInfo.isMultiCatch(tree) ?
1822 catchTypesWithAnnotationsFromMulticatch((JCTypeUnion)tree.param.vartype, tree.param.sym.getRawTypeAttributes()) :
1823 List.of(new Pair<>(tree.param.sym.getRawTypeAttributes(), tree.param.vartype));
1824 }
1825 // where
1826 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotationsFromMulticatch(JCTypeUnion tree, List<TypeCompound> first) {
1827 List<JCExpression> alts = tree.alternatives;
1828 List<Pair<List<TypeCompound>, JCExpression>> res = List.of(new Pair<>(first, alts.head));
1829 alts = alts.tail;
1830
1831 while(alts != null && alts.head != null) {
1832 JCExpression alt = alts.head;
1833 if (alt instanceof JCAnnotatedType annotatedType) {
1834 res = res.prepend(new Pair<>(annotate.fromAnnotations(annotatedType.annotations), alt));
1835 } else {
1836 res = res.prepend(new Pair<>(List.nil(), alt));
1837 }
1838 alts = alts.tail;
1839 }
1840 return res.reverse();
1841 }
1842
1843 /** Register a catch clause in the "Exceptions" code-attribute.
1844 */
1845 void registerCatch(DiagnosticPosition pos,
1846 int startpc, int endpc,
1847 int handler_pc, int catch_type) {
1848 char startpc1 = (char)startpc;
1849 char endpc1 = (char)endpc;
1850 char handler_pc1 = (char)handler_pc;
1851 if (startpc1 == startpc &&
1852 endpc1 == endpc &&
1853 handler_pc1 == handler_pc) {
1854 code.addCatch(startpc1, endpc1, handler_pc1,
1855 (char)catch_type);
1856 } else {
1857 log.error(pos, Errors.LimitCodeTooLargeForTryStmt);
1858 nerrs++;
1859 }
1860 }
1861
1862 public void visitIf(JCIf tree) {
1863 Set<VarSymbol> prevCodeUnsetFields = code.currentUnsetFields;
1864 try {
1865 visitIfHelper(tree);
1866 } finally {
1867 code.currentUnsetFields = prevCodeUnsetFields;
1868 }
1869 }
1870
1871 public void visitIfHelper(JCIf tree) {
1872 int limit = code.nextreg;
1873 Chain thenExit = null;
1874 Assert.check(code.isStatementStart());
1875 CondItem c = genCond(TreeInfo.skipParens(tree.cond),
1876 CRT_FLOW_CONTROLLER);
1877 Chain elseChain = c.jumpFalse();
1878 Assert.check(code.isStatementStart());
1879 if (!c.isFalse()) {
1880 code.resolve(c.trueJumps);
1881 genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET);
1882 thenExit = code.branch(goto_);
1883 }
1884 if (elseChain != null) {
1885 code.resolve(elseChain);
1886 if (tree.elsepart != null) {
1887 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET);
1888 }
1889 }
1890 code.resolve(thenExit);
1891 code.endScopes(limit);
1892 Assert.check(code.isStatementStart());
1893 }
1894
1895 public void visitExec(JCExpressionStatement tree) {
1896 // Optimize x++ to ++x and x-- to --x.
1897 JCExpression e = tree.expr;
1898 switch (e.getTag()) {
1899 case POSTINC:
1900 ((JCUnary) e).setTag(PREINC);
1901 break;
1902 case POSTDEC:
1903 ((JCUnary) e).setTag(PREDEC);
1904 break;
1905 }
1906 Assert.check(code.isStatementStart());
1907 genExpr(tree.expr, tree.expr.type).drop();
1908 Assert.check(code.isStatementStart());
1909 }
1910
1911 public void visitBreak(JCBreak tree) {
1912 Assert.check(code.isStatementStart());
1913 final Env<GenContext> targetEnv = unwindBreak(tree.target);
1914 targetEnv.info.addExit(code.branch(goto_));
1915 endFinalizerGaps(env, targetEnv);
1916 }
1917
1918 public void visitYield(JCYield tree) {
1919 Assert.check(code.isStatementStart());
1920 final Env<GenContext> targetEnv;
1921 if (inCondSwitchExpression) {
1922 CondItem value = genCond(tree.value, CRT_FLOW_TARGET);
1923 Chain falseJumps = value.jumpFalse();
1924
1925 code.resolve(value.trueJumps);
1926 Env<GenContext> localEnv = unwindBreak(tree.target);
1927 reloadStackBeforeSwitchExpr();
1928 Chain trueJumps = code.branch(goto_);
1929
1930 endFinalizerGaps(env, localEnv);
1931
1932 code.resolve(falseJumps);
1933 targetEnv = unwindBreak(tree.target);
1934 reloadStackBeforeSwitchExpr();
1935 falseJumps = code.branch(goto_);
1936
1937 if (switchExpressionTrueChain == null) {
1938 switchExpressionTrueChain = trueJumps;
1939 } else {
1940 switchExpressionTrueChain =
1941 Code.mergeChains(switchExpressionTrueChain, trueJumps);
1942 }
1943 if (switchExpressionFalseChain == null) {
1944 switchExpressionFalseChain = falseJumps;
1945 } else {
1946 switchExpressionFalseChain =
1947 Code.mergeChains(switchExpressionFalseChain, falseJumps);
1948 }
1949 } else {
1950 genExpr(tree.value, pt).load();
1951 if (switchResult != null)
1952 switchResult.store();
1953
1954 targetEnv = unwindBreak(tree.target);
1955
1956 if (code.isAlive()) {
1957 reloadStackBeforeSwitchExpr();
1958 if (switchResult != null)
1959 switchResult.load();
1960
1961 targetEnv.info.addExit(code.branch(goto_));
1962 code.markDead();
1963 }
1964 }
1965 endFinalizerGaps(env, targetEnv);
1966 }
1967 //where:
1968 /** As side-effect, might mark code as dead disabling any further emission.
1969 */
1970 private Env<GenContext> unwindBreak(JCTree target) {
1971 int tmpPos = code.pendingStatPos;
1972 Env<GenContext> targetEnv = unwind(target, env);
1973 code.pendingStatPos = tmpPos;
1974 return targetEnv;
1975 }
1976
1977 private void reloadStackBeforeSwitchExpr() {
1978 for (LocalItem li : stackBeforeSwitchExpression)
1979 li.load();
1980 }
1981
1982 public void visitContinue(JCContinue tree) {
1983 int tmpPos = code.pendingStatPos;
1984 Env<GenContext> targetEnv = unwind(tree.target, env);
1985 code.pendingStatPos = tmpPos;
1986 Assert.check(code.isStatementStart());
1987 targetEnv.info.addCont(code.branch(goto_));
1988 endFinalizerGaps(env, targetEnv);
1989 }
1990
1991 public void visitReturn(JCReturn tree) {
1992 int limit = code.nextreg;
1993 final Env<GenContext> targetEnv;
1994
1995 /* Save and then restore the location of the return in case a finally
1996 * is expanded (with unwind()) in the middle of our bytecodes.
1997 */
1998 int tmpPos = code.pendingStatPos;
1999 if (tree.expr != null) {
2000 Assert.check(code.isStatementStart());
2001 Item r = genExpr(tree.expr, pt).load();
2002 if (hasFinally(env.enclMethod, env)) {
2003 r = makeTemp(pt);
2004 r.store();
2005 }
2006 targetEnv = unwind(env.enclMethod, env);
2007 code.pendingStatPos = tmpPos;
2008 r.load();
2009 code.emitop0(ireturn + Code.truncate(Code.typecode(pt)));
2010 } else {
2011 targetEnv = unwind(env.enclMethod, env);
2012 code.pendingStatPos = tmpPos;
2013 code.emitop0(return_);
2014 }
2015 endFinalizerGaps(env, targetEnv);
2016 code.endScopes(limit);
2017 }
2018
2019 public void visitThrow(JCThrow tree) {
2020 Assert.check(code.isStatementStart());
2021 genExpr(tree.expr, tree.expr.type).load();
2022 code.emitop0(athrow);
2023 Assert.check(code.isStatementStart());
2024 }
2025
2026 /* ************************************************************************
2027 * Visitor methods for expressions
2028 *************************************************************************/
2029
2030 public void visitApply(JCMethodInvocation tree) {
2031 setTypeAnnotationPositions(tree.pos);
2032 // Generate code for method.
2033 Item m = genExpr(tree.meth, methodType);
2034 // Generate code for all arguments, where the expected types are
2035 // the parameters of the method's external type (that is, any implicit
2036 // outer instance of a super(...) call appears as first parameter).
2037 MethodSymbol msym = (MethodSymbol)TreeInfo.symbol(tree.meth);
2038 genArgs(tree.args,
2039 msym.externalType(types).getParameterTypes());
2040 if (!msym.isDynamic()) {
2041 code.statBegin(tree.pos);
2042 }
2043 if (patternMatchingCatchConfiguration.invocations().contains(tree)) {
2044 int start = code.curCP();
2045 result = m.invoke();
2046 patternMatchingCatchConfiguration.ranges().add(new int[] {start, code.curCP()});
2047 } else {
2048 if (msym.isConstructor() && TreeInfo.isConstructorCall(tree)) {
2049 //if this is a this(...) or super(...) call, there is a pending
2050 //"uninitialized this" before this call. One catch handler cannot
2051 //handle exceptions that may come from places with "uninitialized this"
2052 //and (initialized) this, hence generate one set of handlers here
2053 //for the "uninitialized this" case, and another set of handlers
2054 //will be generated at the end of the method for the initialized this,
2055 //if needed:
2056 generatePatternMatchingCatch(env);
2057 result = m.invoke();
2058 patternMatchingCatchConfiguration =
2059 patternMatchingCatchConfiguration.restart(code.state.dup());
2060 } else {
2061 result = m.invoke();
2062 }
2063 }
2064 }
2065
2066 public void visitConditional(JCConditional tree) {
2067 Chain thenExit = null;
2068 code.statBegin(tree.cond.pos);
2069 CondItem c = genCond(tree.cond, CRT_FLOW_CONTROLLER);
2070 Chain elseChain = c.jumpFalse();
2071 if (!c.isFalse()) {
2072 code.resolve(c.trueJumps);
2073 int startpc = genCrt ? code.curCP() : 0;
2074 code.statBegin(tree.truepart.pos);
2075 genExpr(tree.truepart, pt).load();
2076 if (genCrt) code.crt.put(tree.truepart, CRT_FLOW_TARGET,
2077 startpc, code.curCP());
2078 thenExit = code.branch(goto_);
2079 }
2080 if (elseChain != null) {
2081 code.resolve(elseChain);
2082 int startpc = genCrt ? code.curCP() : 0;
2083 code.statBegin(tree.falsepart.pos);
2084 genExpr(tree.falsepart, pt).load();
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 final class GenContext {
2648
2649 /**
2650 * The top defined local variables for exit or continue branches to merge into.
2651 * It may contain uninitialized variables to be initialized by branched code,
2652 * so we cannot use Code.State.defined bits.
2653 */
2654 final int limit;
2655
2656 /** A chain for all unresolved jumps that exit the current environment.
2657 */
2658 Chain exit = null;
2659
2660 /** A chain for all unresolved jumps that continue in the
2661 * current environment.
2662 */
2663 Chain cont = null;
2664
2665 /** A closure that generates the finalizer of the current environment.
2666 * Only set for Synchronized and Try contexts.
2667 */
2668 GenFinalizer finalize = null;
2669
2670 /** Is this a switch statement? If so, allocate registers
2671 * even when the variable declaration is unreachable.
2672 */
2673 boolean isSwitch = false;
2674
2675 /** A list buffer containing all gaps in the finalizer range,
2676 * where a catch all exception should not apply.
2677 */
2678 ListBuffer<Integer> gaps = null;
2679
2680 GenContext() {
2681 var code = Gen.this.code;
2682 this.limit = code == null ? 0 : code.nextreg;
2683 }
2684
2685 /** Add given chain to exit chain.
2686 */
2687 void addExit(Chain c) {
2688 if (c != null) {
2689 c.state.defined.excludeFrom(limit);
2690 }
2691 exit = Code.mergeChains(c, exit);
2692 }
2693
2694 /** Add given chain to cont chain.
2695 */
2696 void addCont(Chain c) {
2697 if (c != null) {
2698 c.state.defined.excludeFrom(limit);
2699 }
2700 cont = Code.mergeChains(c, cont);
2701 }
2702 }
2703
2704 record PatternMatchingCatchConfiguration(Set<JCMethodInvocation> invocations,
2705 ListBuffer<int[]> ranges,
2706 JCCatch handler,
2707 State startState) {
2708 public PatternMatchingCatchConfiguration restart(State newState) {
2709 return new PatternMatchingCatchConfiguration(invocations(),
2710 new ListBuffer<int[]>(),
2711 handler(),
2712 newState);
2713 }
2714 }
2715 }