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 private final LocalProxyVarsGen localProxyVarsGen;
82
83 /** Format of stackmap tables to be generated. */
84 private final Code.StackMapFormat stackMap;
85
86 /** A type that serves as the expected type for all method expressions.
87 */
88 private final Type methodType;
89
90 public static Gen instance(Context context) {
91 Gen instance = context.get(genKey);
92 if (instance == null)
93 instance = new Gen(context);
94 return instance;
95 }
96
97 /** Constant pool writer, set by genClass.
98 */
99 final PoolWriter poolWriter;
100
101 private final UnsetFieldsInfo unsetFieldsInfo;
102
103 @SuppressWarnings("this-escape")
104 protected Gen(Context context) {
105 context.put(genKey, this);
106
107 names = Names.instance(context);
108 log = Log.instance(context);
109 syms = Symtab.instance(context);
110 chk = Check.instance(context);
111 rs = Resolve.instance(context);
112 make = TreeMaker.instance(context);
113 target = Target.instance(context);
114 types = Types.instance(context);
115 concat = StringConcat.instance(context);
116 localProxyVarsGen = LocalProxyVarsGen.instance(context);
117
118 methodType = new MethodType(null, null, null, syms.methodClass);
119 accessDollar = "access" + target.syntheticNameChar();
120 lower = Lower.instance(context);
121
122 Options options = Options.instance(context);
123 lineDebugInfo =
124 options.isUnset(G_CUSTOM) ||
125 options.isSet(G_CUSTOM, "lines");
126 varDebugInfo =
127 options.isUnset(G_CUSTOM)
128 ? options.isSet(G)
129 : options.isSet(G_CUSTOM, "vars");
130 genCrt = options.isSet(XJCOV);
131 debugCode = options.isSet("debug.code");
132 disableVirtualizedPrivateInvoke = options.isSet("disableVirtualizedPrivateInvoke");
133 poolWriter = new PoolWriter(types, names);
134 unsetFieldsInfo = UnsetFieldsInfo.instance(context);
135
136 // ignore cldc because we cannot have both stackmap formats
137 this.stackMap = StackMapFormat.JSR202;
138 annotate = Annotate.instance(context);
139 qualifiedSymbolCache = new HashMap<>();
140 Preview preview = Preview.instance(context);
141 Source source = Source.instance(context);
142 allowValueClasses = (!preview.isPreview(Source.Feature.VALUE_CLASSES) || preview.isEnabled()) &&
143 Source.Feature.VALUE_CLASSES.allowedInSource(source);
144 }
145
146 /** Switches
147 */
148 private final boolean lineDebugInfo;
149 private final boolean varDebugInfo;
150 private final boolean genCrt;
151 private final boolean debugCode;
152 private boolean disableVirtualizedPrivateInvoke;
153 private final boolean allowValueClasses;
154
155 /** Code buffer, set by genMethod.
156 */
157 private Code code;
158
159 /** Items structure, set by genMethod.
160 */
161 private Items items;
162
163 /** Environment for symbol lookup, set by genClass
164 */
165 private Env<AttrContext> attrEnv;
166
167 /** The top level tree.
168 */
169 private JCCompilationUnit toplevel;
170
171 /** The number of code-gen errors in this class.
172 */
173 private int nerrs = 0;
174
175 /** An object containing mappings of syntax trees to their
176 * ending source positions.
177 */
178 EndPosTable endPosTable;
179
180 boolean inCondSwitchExpression;
181 Chain switchExpressionTrueChain;
182 Chain switchExpressionFalseChain;
183 List<LocalItem> stackBeforeSwitchExpression;
184 LocalItem switchResult;
185 PatternMatchingCatchConfiguration patternMatchingCatchConfiguration =
186 new PatternMatchingCatchConfiguration(Set.of(), null, null, null);
187
188 /** Cache the symbol to reflect the qualifying type.
189 * key: corresponding type
190 * value: qualified symbol
191 */
192 Map<Type, Symbol> qualifiedSymbolCache;
193
194 /** Generate code to load an integer constant.
195 * @param n The integer to be loaded.
196 */
197 void loadIntConst(int n) {
198 items.makeImmediateItem(syms.intType, n).load();
199 }
200
201 /** The opcode that loads a zero constant of a given type code.
202 * @param tc The given type code (@see ByteCode).
203 */
204 public static int zero(int tc) {
205 switch(tc) {
206 case INTcode: case BYTEcode: case SHORTcode: case CHARcode:
207 return iconst_0;
208 case LONGcode:
209 return lconst_0;
210 case FLOATcode:
211 return fconst_0;
212 case DOUBLEcode:
213 return dconst_0;
214 default:
215 throw new AssertionError("zero");
216 }
217 }
218
219 /** The opcode that loads a one constant of a given type code.
220 * @param tc The given type code (@see ByteCode).
221 */
222 public static int one(int tc) {
223 return zero(tc) + 1;
224 }
225
226 /** Generate code to load -1 of the given type code (either int or long).
227 * @param tc The given type code (@see ByteCode).
228 */
229 void emitMinusOne(int tc) {
230 if (tc == LONGcode) {
231 items.makeImmediateItem(syms.longType, Long.valueOf(-1)).load();
232 } else {
233 code.emitop0(iconst_m1);
234 }
235 }
236
237 /** Construct a symbol to reflect the qualifying type that should
238 * appear in the byte code as per JLS 13.1.
239 *
240 * For {@literal target >= 1.2}: Clone a method with the qualifier as owner (except
241 * for those cases where we need to work around VM bugs).
242 *
243 * For {@literal target <= 1.1}: If qualified variable or method is defined in a
244 * non-accessible class, clone it with the qualifier class as owner.
245 *
246 * @param sym The accessed symbol
247 * @param site The qualifier's type.
248 */
249 Symbol binaryQualifier(Symbol sym, Type site) {
250
251 if (site.hasTag(ARRAY)) {
252 if (sym == syms.lengthVar ||
253 sym.owner != syms.arrayClass)
254 return sym;
255 // array clone can be qualified by the array type in later targets
256 Symbol qualifier;
257 if ((qualifier = qualifiedSymbolCache.get(site)) == null) {
258 qualifier = new ClassSymbol(Flags.PUBLIC, site.tsym.name, site, syms.noSymbol);
259 qualifiedSymbolCache.put(site, qualifier);
260 }
261 return sym.clone(qualifier);
262 }
263
264 if (sym.owner == site.tsym ||
265 (sym.flags() & (STATIC | SYNTHETIC)) == (STATIC | SYNTHETIC)) {
266 return sym;
267 }
268
269 // leave alone methods inherited from Object
270 // JLS 13.1.
271 if (sym.owner == syms.objectType.tsym)
272 return sym;
273
274 return sym.clone(site.tsym);
275 }
276
277 /** Insert a reference to given type in the constant pool,
278 * checking for an array with too many dimensions;
279 * return the reference's index.
280 * @param type The type for which a reference is inserted.
281 */
282 int makeRef(DiagnosticPosition pos, Type type) {
283 return poolWriter.putClass(checkDimension(pos, type));
284 }
285
286 /** Check if the given type is an array with too many dimensions.
287 */
288 private Type checkDimension(DiagnosticPosition pos, Type t) {
289 checkDimensionInternal(pos, t);
290 return t;
291 }
292
293 private void checkDimensionInternal(DiagnosticPosition pos, Type t) {
294 switch (t.getTag()) {
295 case METHOD:
296 checkDimension(pos, t.getReturnType());
297 for (List<Type> args = t.getParameterTypes(); args.nonEmpty(); args = args.tail)
298 checkDimension(pos, args.head);
299 break;
300 case ARRAY:
301 if (types.dimensions(t) > ClassFile.MAX_DIMENSIONS) {
302 log.error(pos, Errors.LimitDimensions);
303 nerrs++;
304 }
305 break;
306 default:
307 break;
308 }
309 }
310
311 /** Create a temporary variable.
312 * @param type The variable's type.
313 */
314 LocalItem makeTemp(Type type) {
315 VarSymbol v = new VarSymbol(Flags.SYNTHETIC,
316 names.empty,
317 type,
318 env.enclMethod.sym);
319 code.newLocal(v);
320 return items.makeLocalItem(v);
321 }
322
323 /** Generate code to call a non-private method or constructor.
324 * @param pos Position to be used for error reporting.
325 * @param site The type of which the method is a member.
326 * @param name The method's name.
327 * @param argtypes The method's argument types.
328 * @param isStatic A flag that indicates whether we call a
329 * static or instance method.
330 */
331 void callMethod(DiagnosticPosition pos,
332 Type site, Name name, List<Type> argtypes,
333 boolean isStatic) {
334 Symbol msym = rs.
335 resolveInternalMethod(pos, attrEnv, site, name, argtypes, null);
336 if (isStatic) items.makeStaticItem(msym).invoke();
337 else items.makeMemberItem(msym, name == names.init).invoke();
338 }
339
340 /** Is the given method definition an access method
341 * resulting from a qualified super? This is signified by an odd
342 * access code.
343 */
344 private boolean isAccessSuper(JCMethodDecl enclMethod) {
345 return
346 (enclMethod.mods.flags & SYNTHETIC) != 0 &&
347 isOddAccessName(enclMethod.name);
348 }
349
350 /** Does given name start with "access$" and end in an odd digit?
351 */
352 private boolean isOddAccessName(Name name) {
353 final String string = name.toString();
354 return
355 string.startsWith(accessDollar) &&
356 (string.charAt(string.length() - 1) & 1) != 0;
357 }
358
359 /* ************************************************************************
360 * Non-local exits
361 *************************************************************************/
362
363 /** Generate code to invoke the finalizer associated with given
364 * environment.
365 * Any calls to finalizers are appended to the environments `cont' chain.
366 * Mark beginning of gap in catch all range for finalizer.
367 */
368 void genFinalizer(Env<GenContext> env) {
369 if (code.isAlive() && env.info.finalize != null)
370 env.info.finalize.gen();
371 }
372
373 /** Generate code to call all finalizers of structures aborted by
374 * a non-local
375 * exit. Return target environment of the non-local exit.
376 * @param target The tree representing the structure that's aborted
377 * @param env The environment current at the non-local exit.
378 */
379 Env<GenContext> unwind(JCTree target, Env<GenContext> env) {
380 Env<GenContext> env1 = env;
381 while (true) {
382 genFinalizer(env1);
383 if (env1.tree == target) break;
384 env1 = env1.next;
385 }
386 return env1;
387 }
388
389 /** Mark end of gap in catch-all range for finalizer.
390 * @param env the environment which might contain the finalizer
391 * (if it does, env.info.gaps != null).
392 */
393 void endFinalizerGap(Env<GenContext> env) {
394 if (env.info.gaps != null && env.info.gaps.length() % 2 == 1)
395 env.info.gaps.append(code.curCP());
396 }
397
398 /** Mark end of all gaps in catch-all ranges for finalizers of environments
399 * lying between, and including to two environments.
400 * @param from the most deeply nested environment to mark
401 * @param to the least deeply nested environment to mark
402 */
403 void endFinalizerGaps(Env<GenContext> from, Env<GenContext> to) {
404 Env<GenContext> last = null;
405 while (last != to) {
406 endFinalizerGap(from);
407 last = from;
408 from = from.next;
409 }
410 }
411
412 /** Do any of the structures aborted by a non-local exit have
413 * finalizers that require an empty stack?
414 * @param target The tree representing the structure that's aborted
415 * @param env The environment current at the non-local exit.
416 */
417 boolean hasFinally(JCTree target, Env<GenContext> env) {
418 while (env.tree != target) {
419 if (env.tree.hasTag(TRY) && env.info.finalize.hasFinalizer())
420 return true;
421 env = env.next;
422 }
423 return false;
424 }
425
426 /* ************************************************************************
427 * Normalizing class-members.
428 *************************************************************************/
429
430 /** Distribute member initializer code into constructors and {@code <clinit>}
431 * method.
432 * @param defs The list of class member declarations.
433 * @param c The enclosing class.
434 */
435 List<JCTree> normalizeDefs(List<JCTree> defs, ClassSymbol c) {
436 ListBuffer<JCStatement> initCode = new ListBuffer<>();
437 // only used for value classes
438 ListBuffer<JCStatement> initBlocks = new ListBuffer<>();
439 ListBuffer<Attribute.TypeCompound> initTAs = new ListBuffer<>();
440 ListBuffer<JCStatement> clinitCode = new ListBuffer<>();
441 ListBuffer<Attribute.TypeCompound> clinitTAs = new ListBuffer<>();
442 ListBuffer<JCTree> methodDefs = new ListBuffer<>();
443 // Sort definitions into three listbuffers:
444 // - initCode for instance initializers
445 // - clinitCode for class initializers
446 // - methodDefs for method definitions
447 for (List<JCTree> l = defs; l.nonEmpty(); l = l.tail) {
448 JCTree def = l.head;
449 switch (def.getTag()) {
450 case BLOCK:
451 JCBlock block = (JCBlock)def;
452 if ((block.flags & STATIC) != 0)
453 clinitCode.append(block);
454 else if ((block.flags & SYNTHETIC) == 0) {
455 if (c.isValueClass() || c.hasStrict()) {
456 initBlocks.append(block);
457 } else {
458 initCode.append(block);
459 }
460 }
461 break;
462 case METHODDEF:
463 methodDefs.append(def);
464 break;
465 case VARDEF:
466 JCVariableDecl vdef = (JCVariableDecl) def;
467 VarSymbol sym = vdef.sym;
468 checkDimension(vdef.pos(), sym.type);
469 if (vdef.init != null) {
470 if ((sym.flags() & STATIC) == 0) {
471 // Always initialize instance variables.
472 JCStatement init = make.at(vdef.pos()).
473 Assignment(sym, vdef.init);
474 initCode.append(init);
475 endPosTable.replaceTree(vdef, init);
476 initTAs.addAll(getAndRemoveNonFieldTAs(sym));
477 } else if (sym.getConstValue() == null) {
478 // Initialize class (static) variables only if
479 // they are not compile-time constants.
480 JCStatement init = make.at(vdef.pos).
481 Assignment(sym, vdef.init);
482 clinitCode.append(init);
483 endPosTable.replaceTree(vdef, init);
484 clinitTAs.addAll(getAndRemoveNonFieldTAs(sym));
485 } else {
486 checkStringConstant(vdef.init.pos(), sym.getConstValue());
487 /* if the init contains a reference to an external class, add it to the
488 * constant's pool
489 */
490 vdef.init.accept(classReferenceVisitor);
491 }
492 }
493 break;
494 default:
495 Assert.error();
496 }
497 }
498 // Insert any instance initializers into all constructors.
499 if (initCode.length() != 0 || initBlocks.length() != 0) {
500 initTAs.addAll(c.getInitTypeAttributes());
501 List<Attribute.TypeCompound> initTAlist = initTAs.toList();
502 for (JCTree t : methodDefs) {
503 normalizeMethod((JCMethodDecl)t, initCode.toList(), initBlocks.toList(), initTAlist);
504 }
505 }
506 // If there are class initializers, create a <clinit> method
507 // that contains them as its body.
508 if (clinitCode.length() != 0) {
509 MethodSymbol clinit = new MethodSymbol(
510 STATIC | (c.flags() & STRICTFP),
511 names.clinit,
512 new MethodType(
513 List.nil(), syms.voidType,
514 List.nil(), syms.methodClass),
515 c);
516 c.members().enter(clinit);
517 List<JCStatement> clinitStats = clinitCode.toList();
518 JCBlock block = make.at(clinitStats.head.pos()).Block(0, clinitStats);
519 block.bracePos = TreeInfo.endPos(clinitStats.last());
520 methodDefs.append(make.MethodDef(clinit, block));
521
522 if (!clinitTAs.isEmpty())
523 clinit.appendUniqueTypeAttributes(clinitTAs.toList());
524 if (!c.getClassInitTypeAttributes().isEmpty())
525 clinit.appendUniqueTypeAttributes(c.getClassInitTypeAttributes());
526 }
527 // Return all method definitions.
528 return methodDefs.toList();
529 }
530
531 private List<Attribute.TypeCompound> getAndRemoveNonFieldTAs(VarSymbol sym) {
532 List<TypeCompound> tas = sym.getRawTypeAttributes();
533 ListBuffer<Attribute.TypeCompound> fieldTAs = new ListBuffer<>();
534 ListBuffer<Attribute.TypeCompound> nonfieldTAs = new ListBuffer<>();
535 for (TypeCompound ta : tas) {
536 Assert.check(ta.getPosition().type != TargetType.UNKNOWN);
537 if (ta.getPosition().type == TargetType.FIELD) {
538 fieldTAs.add(ta);
539 } else {
540 nonfieldTAs.add(ta);
541 }
542 }
543 sym.setTypeAttributes(fieldTAs.toList());
544 return nonfieldTAs.toList();
545 }
546
547 /** Check a constant value and report if it is a string that is
548 * too large.
549 */
550 private void checkStringConstant(DiagnosticPosition pos, Object constValue) {
551 if (nerrs != 0 || // only complain about a long string once
552 constValue == null ||
553 !(constValue instanceof String str) ||
554 str.length() < PoolWriter.MAX_STRING_LENGTH)
555 return;
556 log.error(pos, Errors.LimitString);
557 nerrs++;
558 }
559
560 /** Insert instance initializer code into constructors prior to the super() call.
561 * @param md The tree potentially representing a
562 * constructor's definition.
563 * @param initCode The list of instance initializer statements.
564 * @param initTAs Type annotations from the initializer expression.
565 */
566 void normalizeMethod(JCMethodDecl md, List<JCStatement> initCode, List<JCStatement> initBlocks, List<TypeCompound> initTAs) {
567 Set<Symbol> fieldsWithInits;
568 List<JCStatement> inits;
569 if ((fieldsWithInits = localProxyVarsGen.initializersAlreadyInConst.get(md)) != null) {
570 ListBuffer<JCStatement> newInitCode = new ListBuffer<>();
571 for (JCStatement init : initCode) {
572 Symbol sym = ((JCIdent)((JCAssign)((JCExpressionStatement)init).expr).lhs).sym;
573 if (!fieldsWithInits.contains(sym)) {
574 newInitCode.add(init);
575 }
576 }
577 inits = newInitCode.toList();
578 localProxyVarsGen.initializersAlreadyInConst.remove(md);
579 } else {
580 inits = initCode;
581 }
582 if (TreeInfo.isConstructor(md) && TreeInfo.hasConstructorCall(md, names._super)) {
583 // We are seeing a constructor that has a super() call.
584 // Find the super() invocation and append the given initializer code.
585 if (allowValueClasses & (md.sym.owner.isValueClass() || md.sym.owner.hasStrict() || ((md.sym.owner.flags_field & RECORD) != 0))) {
586 rewriteInitializersIfNeeded(md, inits);
587 md.body.stats = inits.appendList(md.body.stats);
588 TreeInfo.mapSuperCalls(md.body, supercall -> make.Block(0, initBlocks.prepend(supercall)));
589 } else {
590 TreeInfo.mapSuperCalls(md.body, supercall -> make.Block(0, inits.prepend(supercall)));
591 }
592
593 if (md.body.bracePos == Position.NOPOS)
594 md.body.bracePos = TreeInfo.endPos(md.body.stats.last());
595
596 md.sym.appendUniqueTypeAttributes(initTAs);
597 }
598 }
599
600 void rewriteInitializersIfNeeded(JCMethodDecl md, List<JCStatement> initCode) {
601 if (lower.initializerOuterThis.containsKey(md.sym.owner)) {
602 InitializerVisitor initializerVisitor = new InitializerVisitor(md, lower.initializerOuterThis.get(md.sym.owner));
603 for (JCStatement init : initCode) {
604 initializerVisitor.scan(init);
605 }
606 }
607 }
608
609 public static class InitializerVisitor extends TreeScanner {
610 JCMethodDecl md;
611 Set<JCExpression> exprSet;
612
613 public InitializerVisitor(JCMethodDecl md, Set<JCExpression> exprSet) {
614 this.md = md;
615 this.exprSet = exprSet;
616 }
617
618 @Override
619 public void visitTree(JCTree tree) {}
620
621 @Override
622 public void visitIdent(JCIdent tree) {
623 if (exprSet.contains(tree)) {
624 for (JCVariableDecl param: md.params) {
625 if (param.name == tree.name &&
626 ((param.sym.flags_field & (MANDATED | NOOUTERTHIS)) == (MANDATED | NOOUTERTHIS))) {
627 tree.sym = param.sym;
628 }
629 }
630 }
631 }
632 }
633
634 /* ************************************************************************
635 * Traversal methods
636 *************************************************************************/
637
638 /** Visitor argument: The current environment.
639 */
640 Env<GenContext> env;
641
642 /** Visitor argument: The expected type (prototype).
643 */
644 Type pt;
645
646 /** Visitor result: The item representing the computed value.
647 */
648 Item result;
649
650 /** Visitor method: generate code for a definition, catching and reporting
651 * any completion failures.
652 * @param tree The definition to be visited.
653 * @param env The environment current at the definition.
654 */
655 public void genDef(JCTree tree, Env<GenContext> env) {
656 Env<GenContext> prevEnv = this.env;
657 try {
658 this.env = env;
659 tree.accept(this);
660 } catch (CompletionFailure ex) {
661 chk.completionError(tree.pos(), ex);
662 } finally {
663 this.env = prevEnv;
664 }
665 }
666
667 /** Derived visitor method: check whether CharacterRangeTable
668 * should be emitted, if so, put a new entry into CRTable
669 * and call method to generate bytecode.
670 * If not, just call method to generate bytecode.
671 * @see #genStat(JCTree, Env)
672 *
673 * @param tree The tree to be visited.
674 * @param env The environment to use.
675 * @param crtFlags The CharacterRangeTable flags
676 * indicating type of the entry.
677 */
678 public void genStat(JCTree tree, Env<GenContext> env, int crtFlags) {
679 if (!genCrt) {
680 genStat(tree, env);
681 return;
682 }
683 int startpc = code.curCP();
684 genStat(tree, env);
685 if (tree.hasTag(Tag.BLOCK)) crtFlags |= CRT_BLOCK;
686 code.crt.put(tree, crtFlags, startpc, code.curCP());
687 }
688
689 /** Derived visitor method: generate code for a statement.
690 */
691 public void genStat(JCTree tree, Env<GenContext> env) {
692 if (code.isAlive()) {
693 code.statBegin(tree.pos);
694 genDef(tree, env);
695 } else if (env.info.isSwitch && tree.hasTag(VARDEF)) {
696 // variables whose declarations are in a switch
697 // can be used even if the decl is unreachable.
698 code.newLocal(((JCVariableDecl) tree).sym);
699 }
700 }
701
702 /** Derived visitor method: check whether CharacterRangeTable
703 * should be emitted, if so, put a new entry into CRTable
704 * and call method to generate bytecode.
705 * If not, just call method to generate bytecode.
706 * @see #genStats(List, Env)
707 *
708 * @param trees The list of trees to be visited.
709 * @param env The environment to use.
710 * @param crtFlags The CharacterRangeTable flags
711 * indicating type of the entry.
712 */
713 public void genStats(List<JCStatement> trees, Env<GenContext> env, int crtFlags) {
714 if (!genCrt) {
715 genStats(trees, env);
716 return;
717 }
718 if (trees.length() == 1) { // mark one statement with the flags
719 genStat(trees.head, env, crtFlags | CRT_STATEMENT);
720 } else {
721 int startpc = code.curCP();
722 genStats(trees, env);
723 code.crt.put(trees, crtFlags, startpc, code.curCP());
724 }
725 }
726
727 /** Derived visitor method: generate code for a list of statements.
728 */
729 public void genStats(List<? extends JCTree> trees, Env<GenContext> env) {
730 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
731 genStat(l.head, env, CRT_STATEMENT);
732 }
733
734 /** Derived visitor method: check whether CharacterRangeTable
735 * should be emitted, if so, put a new entry into CRTable
736 * and call method to generate bytecode.
737 * If not, just call method to generate bytecode.
738 * @see #genCond(JCTree,boolean)
739 *
740 * @param tree The tree to be visited.
741 * @param crtFlags The CharacterRangeTable flags
742 * indicating type of the entry.
743 */
744 public CondItem genCond(JCTree tree, int crtFlags) {
745 if (!genCrt) return genCond(tree, false);
746 int startpc = code.curCP();
747 CondItem item = genCond(tree, (crtFlags & CRT_FLOW_CONTROLLER) != 0);
748 code.crt.put(tree, crtFlags, startpc, code.curCP());
749 return item;
750 }
751
752 /** Derived visitor method: generate code for a boolean
753 * expression in a control-flow context.
754 * @param _tree The expression to be visited.
755 * @param markBranches The flag to indicate that the condition is
756 * a flow controller so produced conditions
757 * should contain a proper tree to generate
758 * CharacterRangeTable branches for them.
759 */
760 public CondItem genCond(JCTree _tree, boolean markBranches) {
761 JCTree inner_tree = TreeInfo.skipParens(_tree);
762 if (inner_tree.hasTag(CONDEXPR)) {
763 JCConditional tree = (JCConditional)inner_tree;
764 CondItem cond = genCond(tree.cond, CRT_FLOW_CONTROLLER);
765 if (cond.isTrue()) {
766 code.resolve(cond.trueJumps);
767 CondItem result = genCond(tree.truepart, CRT_FLOW_TARGET);
768 if (markBranches) result.tree = tree.truepart;
769 return result;
770 }
771 if (cond.isFalse()) {
772 code.resolve(cond.falseJumps);
773 CondItem result = genCond(tree.falsepart, CRT_FLOW_TARGET);
774 if (markBranches) result.tree = tree.falsepart;
775 return result;
776 }
777 Chain secondJumps = cond.jumpFalse();
778 code.resolve(cond.trueJumps);
779 CondItem first = genCond(tree.truepart, CRT_FLOW_TARGET);
780 if (markBranches) first.tree = tree.truepart;
781 Chain falseJumps = first.jumpFalse();
782 code.resolve(first.trueJumps);
783 Chain trueJumps = code.branch(goto_);
784 code.resolve(secondJumps);
785 CondItem second = genCond(tree.falsepart, CRT_FLOW_TARGET);
786 CondItem result = items.makeCondItem(second.opcode,
787 Code.mergeChains(trueJumps, second.trueJumps),
788 Code.mergeChains(falseJumps, second.falseJumps));
789 if (markBranches) result.tree = tree.falsepart;
790 return result;
791 } else if (inner_tree.hasTag(SWITCH_EXPRESSION)) {
792 code.resolvePending();
793
794 boolean prevInCondSwitchExpression = inCondSwitchExpression;
795 Chain prevSwitchExpressionTrueChain = switchExpressionTrueChain;
796 Chain prevSwitchExpressionFalseChain = switchExpressionFalseChain;
797 try {
798 inCondSwitchExpression = true;
799 switchExpressionTrueChain = null;
800 switchExpressionFalseChain = null;
801 try {
802 doHandleSwitchExpression((JCSwitchExpression) inner_tree);
803 } catch (CompletionFailure ex) {
804 chk.completionError(_tree.pos(), ex);
805 code.state.stacksize = 1;
806 }
807 CondItem result = items.makeCondItem(goto_,
808 switchExpressionTrueChain,
809 switchExpressionFalseChain);
810 if (markBranches) result.tree = _tree;
811 return result;
812 } finally {
813 inCondSwitchExpression = prevInCondSwitchExpression;
814 switchExpressionTrueChain = prevSwitchExpressionTrueChain;
815 switchExpressionFalseChain = prevSwitchExpressionFalseChain;
816 }
817 } else if (inner_tree.hasTag(LETEXPR) && ((LetExpr) inner_tree).needsCond) {
818 code.resolvePending();
819
820 LetExpr tree = (LetExpr) inner_tree;
821 int limit = code.nextreg;
822 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
823 try {
824 genStats(tree.defs, env);
825 } finally {
826 code.setLetExprStackPos(prevLetExprStart);
827 }
828 CondItem result = genCond(tree.expr, markBranches);
829 code.endScopes(limit);
830 //make sure variables defined in the let expression are not included
831 //in the defined variables for jumps that go outside of this let
832 //expression:
833 undefineVariablesInChain(result.falseJumps, limit);
834 undefineVariablesInChain(result.trueJumps, limit);
835 return result;
836 } else {
837 CondItem result = genExpr(_tree, syms.booleanType).mkCond();
838 if (markBranches) result.tree = _tree;
839 return result;
840 }
841 }
842 //where:
843 private void undefineVariablesInChain(Chain toClear, int limit) {
844 while (toClear != null) {
845 toClear.state.defined.excludeFrom(limit);
846 toClear = toClear.next;
847 }
848 }
849
850 public Code getCode() {
851 return code;
852 }
853
854 public Items getItems() {
855 return items;
856 }
857
858 public Env<AttrContext> getAttrEnv() {
859 return attrEnv;
860 }
861
862 /** Visitor class for expressions which might be constant expressions.
863 * This class is a subset of TreeScanner. Intended to visit trees pruned by
864 * Lower as long as constant expressions looking for references to any
865 * ClassSymbol. Any such reference will be added to the constant pool so
866 * automated tools can detect class dependencies better.
867 */
868 class ClassReferenceVisitor extends JCTree.Visitor {
869
870 @Override
871 public void visitTree(JCTree tree) {}
872
873 @Override
874 public void visitBinary(JCBinary tree) {
875 tree.lhs.accept(this);
876 tree.rhs.accept(this);
877 }
878
879 @Override
880 public void visitSelect(JCFieldAccess tree) {
881 if (tree.selected.type.hasTag(CLASS)) {
882 makeRef(tree.selected.pos(), tree.selected.type);
883 }
884 }
885
886 @Override
887 public void visitIdent(JCIdent tree) {
888 if (tree.sym.owner instanceof ClassSymbol classSymbol) {
889 poolWriter.putClass(classSymbol);
890 }
891 }
892
893 @Override
894 public void visitConditional(JCConditional tree) {
895 tree.cond.accept(this);
896 tree.truepart.accept(this);
897 tree.falsepart.accept(this);
898 }
899
900 @Override
901 public void visitUnary(JCUnary tree) {
902 tree.arg.accept(this);
903 }
904
905 @Override
906 public void visitParens(JCParens tree) {
907 tree.expr.accept(this);
908 }
909
910 @Override
911 public void visitTypeCast(JCTypeCast tree) {
912 tree.expr.accept(this);
913 }
914 }
915
916 private ClassReferenceVisitor classReferenceVisitor = new ClassReferenceVisitor();
917
918 /** Visitor method: generate code for an expression, catching and reporting
919 * any completion failures.
920 * @param tree The expression to be visited.
921 * @param pt The expression's expected type (proto-type).
922 */
923 public Item genExpr(JCTree tree, Type pt) {
924 if (!code.isAlive()) {
925 return items.makeStackItem(pt);
926 }
927
928 Type prevPt = this.pt;
929 try {
930 if (tree.type.constValue() != null) {
931 // Short circuit any expressions which are constants
932 tree.accept(classReferenceVisitor);
933 checkStringConstant(tree.pos(), tree.type.constValue());
934 Symbol sym = TreeInfo.symbol(tree);
935 if (sym != null && isConstantDynamic(sym)) {
936 result = items.makeDynamicItem(sym);
937 } else {
938 result = items.makeImmediateItem(tree.type, tree.type.constValue());
939 }
940 } else {
941 this.pt = pt;
942 tree.accept(this);
943 }
944 return result.coerce(pt);
945 } catch (CompletionFailure ex) {
946 chk.completionError(tree.pos(), ex);
947 code.state.stacksize = 1;
948 return items.makeStackItem(pt);
949 } finally {
950 this.pt = prevPt;
951 }
952 }
953
954 public boolean isConstantDynamic(Symbol sym) {
955 return sym.kind == VAR &&
956 sym instanceof DynamicVarSymbol dynamicVarSymbol &&
957 dynamicVarSymbol.isDynamic();
958 }
959
960 /** Derived visitor method: generate code for a list of method arguments.
961 * @param trees The argument expressions to be visited.
962 * @param pts The expression's expected types (i.e. the formal parameter
963 * types of the invoked method).
964 */
965 public void genArgs(List<JCExpression> trees, List<Type> pts) {
966 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail) {
967 genExpr(l.head, pts.head).load();
968 pts = pts.tail;
969 }
970 // require lists be of same length
971 Assert.check(pts.isEmpty());
972 }
973
974 /* ************************************************************************
975 * Visitor methods for statements and definitions
976 *************************************************************************/
977
978 /** Thrown when the byte code size exceeds limit.
979 */
980 public static class CodeSizeOverflow extends RuntimeException {
981 private static final long serialVersionUID = 0;
982 public CodeSizeOverflow() {}
983 }
984
985 public void visitMethodDef(JCMethodDecl tree) {
986 // Create a new local environment that points pack at method
987 // definition.
988 Env<GenContext> localEnv = env.dup(tree);
989 localEnv.enclMethod = tree;
990 // The expected type of every return statement in this method
991 // is the method's return type.
992 this.pt = tree.sym.erasure(types).getReturnType();
993
994 checkDimension(tree.pos(), tree.sym.erasure(types));
995 genMethod(tree, localEnv, false);
996 }
997 //where
998 /** Generate code for a method.
999 * @param tree The tree representing the method definition.
1000 * @param env The environment current for the method body.
1001 * @param fatcode A flag that indicates whether all jumps are
1002 * within 32K. We first invoke this method under
1003 * the assumption that fatcode == false, i.e. all
1004 * jumps are within 32K. If this fails, fatcode
1005 * is set to true and we try again.
1006 */
1007 void genMethod(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
1008 MethodSymbol meth = tree.sym;
1009 int extras = 0;
1010 // Count up extra parameters
1011 if (meth.isConstructor()) {
1012 extras++;
1013 if (meth.enclClass().isInner() &&
1014 !meth.enclClass().isStatic()) {
1015 extras++;
1016 }
1017 } else if ((tree.mods.flags & STATIC) == 0) {
1018 extras++;
1019 }
1020 // System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG
1021 if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes()) + extras >
1022 ClassFile.MAX_PARAMETERS) {
1023 log.error(tree.pos(), Errors.LimitParameters);
1024 nerrs++;
1025 }
1026
1027 else if (tree.body != null) {
1028 // Create a new code structure and initialize it.
1029 int startpcCrt = initCode(tree, env, fatcode);
1030 Set<VarSymbol> prevUnsetFields = code.currentUnsetFields;
1031 if (meth.isConstructor()) {
1032 code.currentUnsetFields = unsetFieldsInfo.getUnsetFields(env.enclClass.sym, tree.body);
1033 code.initialUnsetFields = unsetFieldsInfo.getUnsetFields(env.enclClass.sym, tree.body);
1034 }
1035
1036 try {
1037 genStat(tree.body, env);
1038 } catch (CodeSizeOverflow e) {
1039 // Failed due to code limit, try again with jsr/ret
1040 startpcCrt = initCode(tree, env, fatcode);
1041 genStat(tree.body, env);
1042 } finally {
1043 code.currentUnsetFields = prevUnsetFields;
1044 }
1045
1046 if (code.state.stacksize != 0) {
1047 log.error(tree.body.pos(), Errors.StackSimError(tree.sym));
1048 throw new AssertionError();
1049 }
1050
1051 // If last statement could complete normally, insert a
1052 // return at the end.
1053 if (code.isAlive()) {
1054 code.statBegin(TreeInfo.endPos(tree.body));
1055 if (env.enclMethod == null ||
1056 env.enclMethod.sym.type.getReturnType().hasTag(VOID)) {
1057 code.emitop0(return_);
1058 } else {
1059 // sometime dead code seems alive (4415991);
1060 // generate a small loop instead
1061 int startpc = code.entryPoint();
1062 CondItem c = items.makeCondItem(goto_);
1063 code.resolve(c.jumpTrue(), startpc);
1064 }
1065 }
1066 if (genCrt)
1067 code.crt.put(tree.body,
1068 CRT_BLOCK,
1069 startpcCrt,
1070 code.curCP());
1071
1072 code.endScopes(0);
1073
1074 // If we exceeded limits, panic
1075 if (code.checkLimits(tree.pos(), log)) {
1076 nerrs++;
1077 return;
1078 }
1079
1080 // If we generated short code but got a long jump, do it again
1081 // with fatCode = true.
1082 if (!fatcode && code.fatcode) genMethod(tree, env, true);
1083
1084 // Clean up
1085 if(stackMap == StackMapFormat.JSR202) {
1086 code.lastFrame = null;
1087 code.frameBeforeLast = null;
1088 }
1089
1090 // Compress exception table
1091 code.compressCatchTable();
1092
1093 // Fill in type annotation positions for exception parameters
1094 code.fillExceptionParameterPositions();
1095 }
1096 }
1097
1098 private int initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
1099 MethodSymbol meth = tree.sym;
1100
1101 // Create a new code structure.
1102 meth.code = code = new Code(meth,
1103 fatcode,
1104 lineDebugInfo ? toplevel.lineMap : null,
1105 varDebugInfo,
1106 stackMap,
1107 debugCode,
1108 genCrt ? new CRTable(tree, env.toplevel.endPositions)
1109 : null,
1110 syms,
1111 types,
1112 poolWriter,
1113 allowValueClasses);
1114 items = new Items(poolWriter, code, syms, types);
1115 if (code.debugCode) {
1116 System.err.println(meth + " for body " + tree);
1117 }
1118
1119 // If method is not static, create a new local variable address
1120 // for `this'.
1121 if ((tree.mods.flags & STATIC) == 0) {
1122 Type selfType = meth.owner.type;
1123 if (meth.isConstructor() && selfType != syms.objectType)
1124 selfType = UninitializedType.uninitializedThis(selfType);
1125 code.setDefined(
1126 code.newLocal(
1127 new VarSymbol(FINAL, names._this, selfType, meth.owner)));
1128 }
1129
1130 // Mark all parameters as defined from the beginning of
1131 // the method.
1132 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
1133 checkDimension(l.head.pos(), l.head.sym.type);
1134 code.setDefined(code.newLocal(l.head.sym));
1135 }
1136
1137 // Get ready to generate code for method body.
1138 int startpcCrt = genCrt ? code.curCP() : 0;
1139 code.entryPoint();
1140
1141 // Suppress initial stackmap
1142 code.pendingStackMap = false;
1143
1144 return startpcCrt;
1145 }
1146
1147 public void visitVarDef(JCVariableDecl tree) {
1148 VarSymbol v = tree.sym;
1149 if (tree.init != null) {
1150 checkStringConstant(tree.init.pos(), v.getConstValue());
1151 if (v.getConstValue() == null || varDebugInfo) {
1152 Assert.check(code.isStatementStart());
1153 code.newLocal(v);
1154 genExpr(tree.init, v.erasure(types)).load();
1155 items.makeLocalItem(v).store();
1156 Assert.check(code.isStatementStart());
1157 }
1158 } else {
1159 code.newLocal(v);
1160 }
1161 checkDimension(tree.pos(), v.type);
1162 }
1163
1164 public void visitSkip(JCSkip tree) {
1165 }
1166
1167 public void visitBlock(JCBlock tree) {
1168 /* this method is heavily invoked, as expected, for deeply nested blocks, if blocks doesn't happen to have
1169 * patterns there will be an unnecessary tax on memory consumption every time this method is executed, for this
1170 * reason we have created helper methods and here at a higher level we just discriminate depending on the
1171 * presence, or not, of patterns in a given block
1172 */
1173 if (tree.patternMatchingCatch != null) {
1174 visitBlockWithPatterns(tree);
1175 } else {
1176 internalVisitBlock(tree);
1177 }
1178 }
1179
1180 private void visitBlockWithPatterns(JCBlock tree) {
1181 PatternMatchingCatchConfiguration prevConfiguration = patternMatchingCatchConfiguration;
1182 try {
1183 patternMatchingCatchConfiguration =
1184 new PatternMatchingCatchConfiguration(tree.patternMatchingCatch.calls2Handle(),
1185 new ListBuffer<int[]>(),
1186 tree.patternMatchingCatch.handler(),
1187 code.state.dup());
1188 internalVisitBlock(tree);
1189 } finally {
1190 generatePatternMatchingCatch(env);
1191 patternMatchingCatchConfiguration = prevConfiguration;
1192 }
1193 }
1194
1195 private void generatePatternMatchingCatch(Env<GenContext> env) {
1196 if (patternMatchingCatchConfiguration.handler != null &&
1197 !patternMatchingCatchConfiguration.ranges.isEmpty()) {
1198 Chain skipCatch = code.branch(goto_);
1199 JCCatch handler = patternMatchingCatchConfiguration.handler();
1200 code.entryPoint(patternMatchingCatchConfiguration.startState(),
1201 handler.param.sym.type);
1202 genPatternMatchingCatch(handler,
1203 env,
1204 patternMatchingCatchConfiguration.ranges.toList());
1205 code.resolve(skipCatch);
1206 }
1207 }
1208
1209 private void internalVisitBlock(JCBlock tree) {
1210 int limit = code.nextreg;
1211 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1212 genStats(tree.stats, localEnv);
1213 // End the scope of all block-local variables in variable info.
1214 if (!env.tree.hasTag(METHODDEF)) {
1215 code.statBegin(tree.bracePos);
1216 code.endScopes(limit);
1217 code.pendingStatPos = Position.NOPOS;
1218 }
1219 }
1220
1221 public void visitDoLoop(JCDoWhileLoop tree) {
1222 genLoop(tree, tree.body, tree.cond, List.nil(), false);
1223 }
1224
1225 public void visitWhileLoop(JCWhileLoop tree) {
1226 genLoop(tree, tree.body, tree.cond, List.nil(), true);
1227 }
1228
1229 public void visitForLoop(JCForLoop tree) {
1230 int limit = code.nextreg;
1231 genStats(tree.init, env);
1232 genLoop(tree, tree.body, tree.cond, tree.step, true);
1233 code.endScopes(limit);
1234 }
1235 //where
1236 /** Generate code for a loop.
1237 * @param loop The tree representing the loop.
1238 * @param body The loop's body.
1239 * @param cond The loop's controlling condition.
1240 * @param step "Step" statements to be inserted at end of
1241 * each iteration.
1242 * @param testFirst True if the loop test belongs before the body.
1243 */
1244 private void genLoop(JCStatement loop,
1245 JCStatement body,
1246 JCExpression cond,
1247 List<JCExpressionStatement> step,
1248 boolean testFirst) {
1249 Set<VarSymbol> prevCodeUnsetFields = code.currentUnsetFields;
1250 try {
1251 genLoopHelper(loop, body, cond, step, testFirst);
1252 } finally {
1253 code.currentUnsetFields = prevCodeUnsetFields;
1254 }
1255 }
1256
1257 private void genLoopHelper(JCStatement loop,
1258 JCStatement body,
1259 JCExpression cond,
1260 List<JCExpressionStatement> step,
1261 boolean testFirst) {
1262 Env<GenContext> loopEnv = env.dup(loop, new GenContext());
1263 int startpc = code.entryPoint();
1264 if (testFirst) { //while or for loop
1265 CondItem c;
1266 if (cond != null) {
1267 code.statBegin(cond.pos);
1268 Assert.check(code.isStatementStart());
1269 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1270 } else {
1271 c = items.makeCondItem(goto_);
1272 }
1273 Chain loopDone = c.jumpFalse();
1274 code.resolve(c.trueJumps);
1275 Assert.check(code.isStatementStart());
1276 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1277 code.resolve(loopEnv.info.cont);
1278 genStats(step, loopEnv);
1279 code.resolve(code.branch(goto_), startpc);
1280 code.resolve(loopDone);
1281 } else {
1282 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1283 code.resolve(loopEnv.info.cont);
1284 genStats(step, loopEnv);
1285 if (code.isAlive()) {
1286 CondItem c;
1287 if (cond != null) {
1288 code.statBegin(cond.pos);
1289 Assert.check(code.isStatementStart());
1290 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1291 } else {
1292 c = items.makeCondItem(goto_);
1293 }
1294 code.resolve(c.jumpTrue(), startpc);
1295 Assert.check(code.isStatementStart());
1296 code.resolve(c.falseJumps);
1297 }
1298 }
1299 code.resolve(loopEnv.info.exit);
1300 }
1301
1302 public void visitForeachLoop(JCEnhancedForLoop tree) {
1303 throw new AssertionError(); // should have been removed by Lower.
1304 }
1305
1306 public void visitLabelled(JCLabeledStatement tree) {
1307 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1308 genStat(tree.body, localEnv, CRT_STATEMENT);
1309 code.resolve(localEnv.info.exit);
1310 }
1311
1312 public void visitSwitch(JCSwitch tree) {
1313 handleSwitch(tree, tree.selector, tree.cases, tree.patternSwitch);
1314 }
1315
1316 @Override
1317 public void visitSwitchExpression(JCSwitchExpression tree) {
1318 code.resolvePending();
1319 boolean prevInCondSwitchExpression = inCondSwitchExpression;
1320 Set<VarSymbol> prevCodeUnsetFields = code.currentUnsetFields;
1321 try {
1322 inCondSwitchExpression = false;
1323 doHandleSwitchExpression(tree);
1324 } finally {
1325 inCondSwitchExpression = prevInCondSwitchExpression;
1326 code.currentUnsetFields = prevCodeUnsetFields;
1327 }
1328 result = items.makeStackItem(pt);
1329 }
1330
1331 private void doHandleSwitchExpression(JCSwitchExpression tree) {
1332 List<LocalItem> prevStackBeforeSwitchExpression = stackBeforeSwitchExpression;
1333 LocalItem prevSwitchResult = switchResult;
1334 int limit = code.nextreg;
1335 try {
1336 stackBeforeSwitchExpression = List.nil();
1337 switchResult = null;
1338 if (hasTry(tree)) {
1339 //if the switch expression contains try-catch, the catch handlers need to have
1340 //an empty stack. So stash whole stack to local variables, and restore it before
1341 //breaks:
1342 while (code.state.stacksize > 0) {
1343 Type type = code.state.peek();
1344 Name varName = names.fromString(target.syntheticNameChar() +
1345 "stack" +
1346 target.syntheticNameChar() +
1347 tree.pos +
1348 target.syntheticNameChar() +
1349 code.state.stacksize);
1350 VarSymbol var = new VarSymbol(Flags.SYNTHETIC, varName, type,
1351 this.env.enclMethod.sym);
1352 LocalItem item = items.new LocalItem(type, code.newLocal(var));
1353 stackBeforeSwitchExpression = stackBeforeSwitchExpression.prepend(item);
1354 item.store();
1355 }
1356 switchResult = makeTemp(tree.type);
1357 }
1358 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
1359 try {
1360 handleSwitch(tree, tree.selector, tree.cases, tree.patternSwitch);
1361 } finally {
1362 code.setLetExprStackPos(prevLetExprStart);
1363 }
1364 } finally {
1365 stackBeforeSwitchExpression = prevStackBeforeSwitchExpression;
1366 switchResult = prevSwitchResult;
1367 code.endScopes(limit);
1368 }
1369 }
1370 //where:
1371 private boolean hasTry(JCSwitchExpression tree) {
1372 class HasTryScanner extends TreeScanner {
1373 private boolean hasTry;
1374
1375 @Override
1376 public void visitTry(JCTry tree) {
1377 hasTry = true;
1378 }
1379
1380 @Override
1381 public void visitSynchronized(JCSynchronized tree) {
1382 hasTry = true;
1383 }
1384
1385 @Override
1386 public void visitClassDef(JCClassDecl tree) {
1387 }
1388
1389 @Override
1390 public void visitLambda(JCLambda tree) {
1391 }
1392 };
1393
1394 HasTryScanner hasTryScanner = new HasTryScanner();
1395
1396 hasTryScanner.scan(tree);
1397 return hasTryScanner.hasTry;
1398 }
1399
1400 private void handleSwitch(JCTree swtch, JCExpression selector, List<JCCase> cases,
1401 boolean patternSwitch) {
1402 Set<VarSymbol> prevCodeUnsetFields = code.currentUnsetFields;
1403 try {
1404 handleSwitchHelper(swtch, selector, cases, patternSwitch);
1405 } finally {
1406 code.currentUnsetFields = prevCodeUnsetFields;
1407 }
1408 }
1409
1410 void handleSwitchHelper(JCTree swtch, JCExpression selector, List<JCCase> cases,
1411 boolean patternSwitch) {
1412 int limit = code.nextreg;
1413 Assert.check(!selector.type.hasTag(CLASS));
1414 int switchStart = patternSwitch ? code.entryPoint() : -1;
1415 int startpcCrt = genCrt ? code.curCP() : 0;
1416 Assert.check(code.isStatementStart());
1417 Item sel = genExpr(selector, syms.intType);
1418 if (cases.isEmpty()) {
1419 // We are seeing: switch <sel> {}
1420 sel.load().drop();
1421 if (genCrt)
1422 code.crt.put(TreeInfo.skipParens(selector),
1423 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1424 } else {
1425 // We are seeing a nonempty switch.
1426 sel.load();
1427 if (genCrt)
1428 code.crt.put(TreeInfo.skipParens(selector),
1429 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1430 Env<GenContext> switchEnv = env.dup(swtch, new GenContext());
1431 switchEnv.info.isSwitch = true;
1432
1433 // Compute number of labels and minimum and maximum label values.
1434 // For each case, store its label in an array.
1435 int lo = Integer.MAX_VALUE; // minimum label.
1436 int hi = Integer.MIN_VALUE; // maximum label.
1437 int nlabels = 0; // number of labels.
1438
1439 int[] labels = new int[cases.length()]; // the label array.
1440 int defaultIndex = -1; // the index of the default clause.
1441
1442 List<JCCase> l = cases;
1443 for (int i = 0; i < labels.length; i++) {
1444 if (l.head.labels.head instanceof JCConstantCaseLabel constLabel) {
1445 Assert.check(l.head.labels.size() == 1);
1446 int val = ((Number) constLabel.expr.type.constValue()).intValue();
1447 labels[i] = val;
1448 if (val < lo) lo = val;
1449 if (hi < val) hi = val;
1450 nlabels++;
1451 } else {
1452 Assert.check(defaultIndex == -1);
1453 defaultIndex = i;
1454 }
1455 l = l.tail;
1456 }
1457
1458 // Determine whether to issue a tableswitch or a lookupswitch
1459 // instruction.
1460 long table_space_cost = 4 + ((long) hi - lo + 1); // words
1461 long table_time_cost = 3; // comparisons
1462 long lookup_space_cost = 3 + 2 * (long) nlabels;
1463 long lookup_time_cost = nlabels;
1464 int opcode =
1465 nlabels > 0 &&
1466 table_space_cost + 3 * table_time_cost <=
1467 lookup_space_cost + 3 * lookup_time_cost
1468 ?
1469 tableswitch : lookupswitch;
1470
1471 int startpc = code.curCP(); // the position of the selector operation
1472 code.emitop0(opcode);
1473 code.align(4);
1474 int tableBase = code.curCP(); // the start of the jump table
1475 int[] offsets = null; // a table of offsets for a lookupswitch
1476 code.emit4(-1); // leave space for default offset
1477 if (opcode == tableswitch) {
1478 code.emit4(lo); // minimum label
1479 code.emit4(hi); // maximum label
1480 for (long i = lo; i <= hi; i++) { // leave space for jump table
1481 code.emit4(-1);
1482 }
1483 } else {
1484 code.emit4(nlabels); // number of labels
1485 for (int i = 0; i < nlabels; i++) {
1486 code.emit4(-1); code.emit4(-1); // leave space for lookup table
1487 }
1488 offsets = new int[labels.length];
1489 }
1490 Code.State stateSwitch = code.state.dup();
1491 code.markDead();
1492
1493 // For each case do:
1494 l = cases;
1495 for (int i = 0; i < labels.length; i++) {
1496 JCCase c = l.head;
1497 l = l.tail;
1498
1499 int pc = code.entryPoint(stateSwitch);
1500 // Insert offset directly into code or else into the
1501 // offsets table.
1502 if (i != defaultIndex) {
1503 if (opcode == tableswitch) {
1504 code.put4(
1505 tableBase + 4 * (labels[i] - lo + 3),
1506 pc - startpc);
1507 } else {
1508 offsets[i] = pc - startpc;
1509 }
1510 } else {
1511 code.put4(tableBase, pc - startpc);
1512 }
1513
1514 // Generate code for the statements in this case.
1515 genStats(c.stats, switchEnv, CRT_FLOW_TARGET);
1516 }
1517
1518 if (switchEnv.info.cont != null) {
1519 Assert.check(patternSwitch);
1520 code.resolve(switchEnv.info.cont, switchStart);
1521 }
1522
1523 // Resolve all breaks.
1524 code.resolve(switchEnv.info.exit);
1525
1526 // If we have not set the default offset, we do so now.
1527 if (code.get4(tableBase) == -1) {
1528 code.put4(tableBase, code.entryPoint(stateSwitch) - startpc);
1529 }
1530
1531 if (opcode == tableswitch) {
1532 // Let any unfilled slots point to the default case.
1533 int defaultOffset = code.get4(tableBase);
1534 for (long i = lo; i <= hi; i++) {
1535 int t = (int)(tableBase + 4 * (i - lo + 3));
1536 if (code.get4(t) == -1)
1537 code.put4(t, defaultOffset);
1538 }
1539 } else {
1540 // Sort non-default offsets and copy into lookup table.
1541 if (defaultIndex >= 0)
1542 for (int i = defaultIndex; i < labels.length - 1; i++) {
1543 labels[i] = labels[i+1];
1544 offsets[i] = offsets[i+1];
1545 }
1546 if (nlabels > 0)
1547 qsort2(labels, offsets, 0, nlabels - 1);
1548 for (int i = 0; i < nlabels; i++) {
1549 int caseidx = tableBase + 8 * (i + 1);
1550 code.put4(caseidx, labels[i]);
1551 code.put4(caseidx + 4, offsets[i]);
1552 }
1553 }
1554
1555 if (swtch instanceof JCSwitchExpression) {
1556 // Emit line position for the end of a switch expression
1557 code.statBegin(TreeInfo.endPos(swtch));
1558 }
1559 }
1560 code.endScopes(limit);
1561 }
1562 //where
1563 /** Sort (int) arrays of keys and values
1564 */
1565 static void qsort2(int[] keys, int[] values, int lo, int hi) {
1566 int i = lo;
1567 int j = hi;
1568 int pivot = keys[(i+j)/2];
1569 do {
1570 while (keys[i] < pivot) i++;
1571 while (pivot < keys[j]) j--;
1572 if (i <= j) {
1573 int temp1 = keys[i];
1574 keys[i] = keys[j];
1575 keys[j] = temp1;
1576 int temp2 = values[i];
1577 values[i] = values[j];
1578 values[j] = temp2;
1579 i++;
1580 j--;
1581 }
1582 } while (i <= j);
1583 if (lo < j) qsort2(keys, values, lo, j);
1584 if (i < hi) qsort2(keys, values, i, hi);
1585 }
1586
1587 public void visitSynchronized(JCSynchronized tree) {
1588 int limit = code.nextreg;
1589 // Generate code to evaluate lock and save in temporary variable.
1590 final LocalItem lockVar = makeTemp(syms.objectType);
1591 Assert.check(code.isStatementStart());
1592 genExpr(tree.lock, tree.lock.type).load().duplicate();
1593 lockVar.store();
1594
1595 // Generate code to enter monitor.
1596 code.emitop0(monitorenter);
1597 code.state.lock(lockVar.reg);
1598
1599 // Generate code for a try statement with given body, no catch clauses
1600 // in a new environment with the "exit-monitor" operation as finalizer.
1601 final Env<GenContext> syncEnv = env.dup(tree, new GenContext());
1602 syncEnv.info.finalize = new GenFinalizer() {
1603 void gen() {
1604 genLast();
1605 Assert.check(syncEnv.info.gaps.length() % 2 == 0);
1606 syncEnv.info.gaps.append(code.curCP());
1607 }
1608 void genLast() {
1609 if (code.isAlive()) {
1610 lockVar.load();
1611 code.emitop0(monitorexit);
1612 code.state.unlock(lockVar.reg);
1613 }
1614 }
1615 };
1616 syncEnv.info.gaps = new ListBuffer<>();
1617 genTry(tree.body, List.nil(), syncEnv);
1618 code.endScopes(limit);
1619 }
1620
1621 public void visitTry(final JCTry tree) {
1622 // Generate code for a try statement with given body and catch clauses,
1623 // in a new environment which calls the finally block if there is one.
1624 final Env<GenContext> tryEnv = env.dup(tree, new GenContext());
1625 final Env<GenContext> oldEnv = env;
1626 tryEnv.info.finalize = new GenFinalizer() {
1627 void gen() {
1628 Assert.check(tryEnv.info.gaps.length() % 2 == 0);
1629 tryEnv.info.gaps.append(code.curCP());
1630 genLast();
1631 }
1632 void genLast() {
1633 if (tree.finalizer != null)
1634 genStat(tree.finalizer, oldEnv, CRT_BLOCK);
1635 }
1636 boolean hasFinalizer() {
1637 return tree.finalizer != null;
1638 }
1639
1640 @Override
1641 void afterBody() {
1642 if (tree.finalizer != null && (tree.finalizer.flags & BODY_ONLY_FINALIZE) != 0) {
1643 //for body-only finally, remove the GenFinalizer after try body
1644 //so that the finally is not generated to catch bodies:
1645 tryEnv.info.finalize = null;
1646 }
1647 }
1648
1649 };
1650 tryEnv.info.gaps = new ListBuffer<>();
1651 genTry(tree.body, tree.catchers, tryEnv);
1652 }
1653 //where
1654 /** Generate code for a try or synchronized statement
1655 * @param body The body of the try or synchronized statement.
1656 * @param catchers The list of catch clauses.
1657 * @param env The current environment of the body.
1658 */
1659 void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) {
1660 Set<VarSymbol> prevCodeUnsetFields = code.currentUnsetFields;
1661 try {
1662 genTryHelper(body, catchers, env);
1663 } finally {
1664 code.currentUnsetFields = prevCodeUnsetFields;
1665 }
1666 }
1667
1668 void genTryHelper(JCTree body, List<JCCatch> catchers, Env<GenContext> env) {
1669 int limit = code.nextreg;
1670 int startpc = code.curCP();
1671 Code.State stateTry = code.state.dup();
1672 genStat(body, env, CRT_BLOCK);
1673 int endpc = code.curCP();
1674 List<Integer> gaps = env.info.gaps.toList();
1675 code.statBegin(TreeInfo.endPos(body));
1676 genFinalizer(env);
1677 code.statBegin(TreeInfo.endPos(env.tree));
1678 Chain exitChain;
1679 boolean actualTry = env.tree.hasTag(TRY);
1680 if (startpc == endpc && actualTry) {
1681 exitChain = code.branch(dontgoto);
1682 } else {
1683 exitChain = code.branch(goto_);
1684 }
1685 endFinalizerGap(env);
1686 env.info.finalize.afterBody();
1687 boolean hasFinalizer =
1688 env.info.finalize != null &&
1689 env.info.finalize.hasFinalizer();
1690 if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) {
1691 // start off with exception on stack
1692 code.entryPoint(stateTry, l.head.param.sym.type);
1693 genCatch(l.head, env, startpc, endpc, gaps);
1694 genFinalizer(env);
1695 if (hasFinalizer || l.tail.nonEmpty()) {
1696 code.statBegin(TreeInfo.endPos(env.tree));
1697 exitChain = Code.mergeChains(exitChain,
1698 code.branch(goto_));
1699 }
1700 endFinalizerGap(env);
1701 }
1702 if (hasFinalizer && (startpc != endpc || !actualTry)) {
1703 // Create a new register segment to avoid allocating
1704 // the same variables in finalizers and other statements.
1705 code.newRegSegment();
1706
1707 // Add a catch-all clause.
1708
1709 // start off with exception on stack
1710 int catchallpc = code.entryPoint(stateTry, syms.throwableType);
1711
1712 // Register all exception ranges for catch all clause.
1713 // The range of the catch all clause is from the beginning
1714 // of the try or synchronized block until the present
1715 // code pointer excluding all gaps in the current
1716 // environment's GenContext.
1717 int startseg = startpc;
1718 while (env.info.gaps.nonEmpty()) {
1719 int endseg = env.info.gaps.next().intValue();
1720 registerCatch(body.pos(), startseg, endseg,
1721 catchallpc, 0);
1722 startseg = env.info.gaps.next().intValue();
1723 }
1724 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1725 code.markStatBegin();
1726
1727 Item excVar = makeTemp(syms.throwableType);
1728 excVar.store();
1729 genFinalizer(env);
1730 code.resolvePending();
1731 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.END_POS));
1732 code.markStatBegin();
1733
1734 excVar.load();
1735 registerCatch(body.pos(), startseg,
1736 env.info.gaps.next().intValue(),
1737 catchallpc, 0);
1738 code.emitop0(athrow);
1739 code.markDead();
1740
1741 // If there are jsr's to this finalizer, ...
1742 if (env.info.cont != null) {
1743 // Resolve all jsr's.
1744 code.resolve(env.info.cont);
1745
1746 // Mark statement line number
1747 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1748 code.markStatBegin();
1749
1750 // Save return address.
1751 LocalItem retVar = makeTemp(syms.throwableType);
1752 retVar.store();
1753
1754 // Generate finalizer code.
1755 env.info.finalize.genLast();
1756
1757 // Return.
1758 code.emitop1w(ret, retVar.reg);
1759 code.markDead();
1760 }
1761 }
1762 // Resolve all breaks.
1763 code.resolve(exitChain);
1764
1765 code.endScopes(limit);
1766 }
1767
1768 /** Generate code for a catch clause.
1769 * @param tree The catch clause.
1770 * @param env The environment current in the enclosing try.
1771 * @param startpc Start pc of try-block.
1772 * @param endpc End pc of try-block.
1773 */
1774 void genCatch(JCCatch tree,
1775 Env<GenContext> env,
1776 int startpc, int endpc,
1777 List<Integer> gaps) {
1778 if (startpc != endpc) {
1779 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypeExprs
1780 = catchTypesWithAnnotations(tree);
1781 while (gaps.nonEmpty()) {
1782 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) {
1783 JCExpression subCatch = subCatch1.snd;
1784 int catchType = makeRef(tree.pos(), subCatch.type);
1785 int end = gaps.head.intValue();
1786 registerCatch(tree.pos(),
1787 startpc, end, code.curCP(),
1788 catchType);
1789 for (Attribute.TypeCompound tc : subCatch1.fst) {
1790 tc.position.setCatchInfo(catchType, startpc);
1791 }
1792 }
1793 gaps = gaps.tail;
1794 startpc = gaps.head.intValue();
1795 gaps = gaps.tail;
1796 }
1797 if (startpc < endpc) {
1798 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) {
1799 JCExpression subCatch = subCatch1.snd;
1800 int catchType = makeRef(tree.pos(), subCatch.type);
1801 registerCatch(tree.pos(),
1802 startpc, endpc, code.curCP(),
1803 catchType);
1804 for (Attribute.TypeCompound tc : subCatch1.fst) {
1805 tc.position.setCatchInfo(catchType, startpc);
1806 }
1807 }
1808 }
1809 genCatchBlock(tree, env);
1810 }
1811 }
1812 void genPatternMatchingCatch(JCCatch tree,
1813 Env<GenContext> env,
1814 List<int[]> ranges) {
1815 for (int[] range : ranges) {
1816 JCExpression subCatch = tree.param.vartype;
1817 int catchType = makeRef(tree.pos(), subCatch.type);
1818 registerCatch(tree.pos(),
1819 range[0], range[1], code.curCP(),
1820 catchType);
1821 }
1822 genCatchBlock(tree, env);
1823 }
1824 void genCatchBlock(JCCatch tree, Env<GenContext> env) {
1825 VarSymbol exparam = tree.param.sym;
1826 code.statBegin(tree.pos);
1827 code.markStatBegin();
1828 int limit = code.nextreg;
1829 code.newLocal(exparam);
1830 items.makeLocalItem(exparam).store();
1831 code.statBegin(TreeInfo.firstStatPos(tree.body));
1832 genStat(tree.body, env, CRT_BLOCK);
1833 code.endScopes(limit);
1834 code.statBegin(TreeInfo.endPos(tree.body));
1835 }
1836 // where
1837 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotations(JCCatch tree) {
1838 return TreeInfo.isMultiCatch(tree) ?
1839 catchTypesWithAnnotationsFromMulticatch((JCTypeUnion)tree.param.vartype, tree.param.sym.getRawTypeAttributes()) :
1840 List.of(new Pair<>(tree.param.sym.getRawTypeAttributes(), tree.param.vartype));
1841 }
1842 // where
1843 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotationsFromMulticatch(JCTypeUnion tree, List<TypeCompound> first) {
1844 List<JCExpression> alts = tree.alternatives;
1845 List<Pair<List<TypeCompound>, JCExpression>> res = List.of(new Pair<>(first, alts.head));
1846 alts = alts.tail;
1847
1848 while(alts != null && alts.head != null) {
1849 JCExpression alt = alts.head;
1850 if (alt instanceof JCAnnotatedType annotatedType) {
1851 res = res.prepend(new Pair<>(annotate.fromAnnotations(annotatedType.annotations), alt));
1852 } else {
1853 res = res.prepend(new Pair<>(List.nil(), alt));
1854 }
1855 alts = alts.tail;
1856 }
1857 return res.reverse();
1858 }
1859
1860 /** Register a catch clause in the "Exceptions" code-attribute.
1861 */
1862 void registerCatch(DiagnosticPosition pos,
1863 int startpc, int endpc,
1864 int handler_pc, int catch_type) {
1865 char startpc1 = (char)startpc;
1866 char endpc1 = (char)endpc;
1867 char handler_pc1 = (char)handler_pc;
1868 if (startpc1 == startpc &&
1869 endpc1 == endpc &&
1870 handler_pc1 == handler_pc) {
1871 code.addCatch(startpc1, endpc1, handler_pc1,
1872 (char)catch_type);
1873 } else {
1874 log.error(pos, Errors.LimitCodeTooLargeForTryStmt);
1875 nerrs++;
1876 }
1877 }
1878
1879 public void visitIf(JCIf tree) {
1880 Set<VarSymbol> prevCodeUnsetFields = code.currentUnsetFields;
1881 try {
1882 visitIfHelper(tree);
1883 } finally {
1884 code.currentUnsetFields = prevCodeUnsetFields;
1885 }
1886 }
1887
1888 public void visitIfHelper(JCIf tree) {
1889 int limit = code.nextreg;
1890 Chain thenExit = null;
1891 Assert.check(code.isStatementStart());
1892 CondItem c = genCond(TreeInfo.skipParens(tree.cond),
1893 CRT_FLOW_CONTROLLER);
1894 Chain elseChain = c.jumpFalse();
1895 Assert.check(code.isStatementStart());
1896 if (!c.isFalse()) {
1897 code.resolve(c.trueJumps);
1898 genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET);
1899 thenExit = code.branch(goto_);
1900 }
1901 if (elseChain != null) {
1902 code.resolve(elseChain);
1903 if (tree.elsepart != null) {
1904 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET);
1905 }
1906 }
1907 code.resolve(thenExit);
1908 code.endScopes(limit);
1909 Assert.check(code.isStatementStart());
1910 }
1911
1912 public void visitExec(JCExpressionStatement tree) {
1913 // Optimize x++ to ++x and x-- to --x.
1914 JCExpression e = tree.expr;
1915 switch (e.getTag()) {
1916 case POSTINC:
1917 ((JCUnary) e).setTag(PREINC);
1918 break;
1919 case POSTDEC:
1920 ((JCUnary) e).setTag(PREDEC);
1921 break;
1922 }
1923 Assert.check(code.isStatementStart());
1924 genExpr(tree.expr, tree.expr.type).drop();
1925 Assert.check(code.isStatementStart());
1926 }
1927
1928 public void visitBreak(JCBreak tree) {
1929 Assert.check(code.isStatementStart());
1930 final Env<GenContext> targetEnv = unwindBreak(tree.target);
1931 targetEnv.info.addExit(code.branch(goto_));
1932 endFinalizerGaps(env, targetEnv);
1933 }
1934
1935 public void visitYield(JCYield tree) {
1936 Assert.check(code.isStatementStart());
1937 final Env<GenContext> targetEnv;
1938 if (inCondSwitchExpression) {
1939 CondItem value = genCond(tree.value, CRT_FLOW_TARGET);
1940 Chain falseJumps = value.jumpFalse();
1941
1942 code.resolve(value.trueJumps);
1943 Env<GenContext> localEnv = unwindBreak(tree.target);
1944 reloadStackBeforeSwitchExpr();
1945 Chain trueJumps = code.branch(goto_);
1946
1947 endFinalizerGaps(env, localEnv);
1948
1949 code.resolve(falseJumps);
1950 targetEnv = unwindBreak(tree.target);
1951 reloadStackBeforeSwitchExpr();
1952 falseJumps = code.branch(goto_);
1953
1954 if (switchExpressionTrueChain == null) {
1955 switchExpressionTrueChain = trueJumps;
1956 } else {
1957 switchExpressionTrueChain =
1958 Code.mergeChains(switchExpressionTrueChain, trueJumps);
1959 }
1960 if (switchExpressionFalseChain == null) {
1961 switchExpressionFalseChain = falseJumps;
1962 } else {
1963 switchExpressionFalseChain =
1964 Code.mergeChains(switchExpressionFalseChain, falseJumps);
1965 }
1966 } else {
1967 genExpr(tree.value, pt).load();
1968 if (switchResult != null)
1969 switchResult.store();
1970
1971 targetEnv = unwindBreak(tree.target);
1972
1973 if (code.isAlive()) {
1974 reloadStackBeforeSwitchExpr();
1975 if (switchResult != null)
1976 switchResult.load();
1977
1978 targetEnv.info.addExit(code.branch(goto_));
1979 code.markDead();
1980 }
1981 }
1982 endFinalizerGaps(env, targetEnv);
1983 }
1984 //where:
1985 /** As side-effect, might mark code as dead disabling any further emission.
1986 */
1987 private Env<GenContext> unwindBreak(JCTree target) {
1988 int tmpPos = code.pendingStatPos;
1989 Env<GenContext> targetEnv = unwind(target, env);
1990 code.pendingStatPos = tmpPos;
1991 return targetEnv;
1992 }
1993
1994 private void reloadStackBeforeSwitchExpr() {
1995 for (LocalItem li : stackBeforeSwitchExpression)
1996 li.load();
1997 }
1998
1999 public void visitContinue(JCContinue tree) {
2000 int tmpPos = code.pendingStatPos;
2001 Env<GenContext> targetEnv = unwind(tree.target, env);
2002 code.pendingStatPos = tmpPos;
2003 Assert.check(code.isStatementStart());
2004 targetEnv.info.addCont(code.branch(goto_));
2005 endFinalizerGaps(env, targetEnv);
2006 }
2007
2008 public void visitReturn(JCReturn tree) {
2009 int limit = code.nextreg;
2010 final Env<GenContext> targetEnv;
2011
2012 /* Save and then restore the location of the return in case a finally
2013 * is expanded (with unwind()) in the middle of our bytecodes.
2014 */
2015 int tmpPos = code.pendingStatPos;
2016 if (tree.expr != null) {
2017 Assert.check(code.isStatementStart());
2018 Item r = genExpr(tree.expr, pt).load();
2019 if (hasFinally(env.enclMethod, env)) {
2020 r = makeTemp(pt);
2021 r.store();
2022 }
2023 targetEnv = unwind(env.enclMethod, env);
2024 code.pendingStatPos = tmpPos;
2025 r.load();
2026 code.emitop0(ireturn + Code.truncate(Code.typecode(pt)));
2027 } else {
2028 targetEnv = unwind(env.enclMethod, env);
2029 code.pendingStatPos = tmpPos;
2030 code.emitop0(return_);
2031 }
2032 endFinalizerGaps(env, targetEnv);
2033 code.endScopes(limit);
2034 }
2035
2036 public void visitThrow(JCThrow tree) {
2037 Assert.check(code.isStatementStart());
2038 genExpr(tree.expr, tree.expr.type).load();
2039 code.emitop0(athrow);
2040 Assert.check(code.isStatementStart());
2041 }
2042
2043 /* ************************************************************************
2044 * Visitor methods for expressions
2045 *************************************************************************/
2046
2047 public void visitApply(JCMethodInvocation tree) {
2048 setTypeAnnotationPositions(tree.pos);
2049 // Generate code for method.
2050 Item m = genExpr(tree.meth, methodType);
2051 // Generate code for all arguments, where the expected types are
2052 // the parameters of the method's external type (that is, any implicit
2053 // outer instance of a super(...) call appears as first parameter).
2054 MethodSymbol msym = (MethodSymbol)TreeInfo.symbol(tree.meth);
2055 genArgs(tree.args,
2056 msym.externalType(types).getParameterTypes());
2057 if (!msym.isDynamic()) {
2058 code.statBegin(tree.pos);
2059 }
2060 if (patternMatchingCatchConfiguration.invocations().contains(tree)) {
2061 int start = code.curCP();
2062 result = m.invoke();
2063 patternMatchingCatchConfiguration.ranges().add(new int[] {start, code.curCP()});
2064 } else {
2065 if (msym.isConstructor() && TreeInfo.isConstructorCall(tree)) {
2066 //if this is a this(...) or super(...) call, there is a pending
2067 //"uninitialized this" before this call. One catch handler cannot
2068 //handle exceptions that may come from places with "uninitialized this"
2069 //and (initialized) this, hence generate one set of handlers here
2070 //for the "uninitialized this" case, and another set of handlers
2071 //will be generated at the end of the method for the initialized this,
2072 //if needed:
2073 generatePatternMatchingCatch(env);
2074 result = m.invoke();
2075 patternMatchingCatchConfiguration =
2076 patternMatchingCatchConfiguration.restart(code.state.dup());
2077 } else {
2078 result = m.invoke();
2079 }
2080 }
2081 }
2082
2083 public void visitConditional(JCConditional tree) {
2084 Chain thenExit = null;
2085 code.statBegin(tree.cond.pos);
2086 CondItem c = genCond(tree.cond, CRT_FLOW_CONTROLLER);
2087 Chain elseChain = c.jumpFalse();
2088 if (!c.isFalse()) {
2089 code.resolve(c.trueJumps);
2090 int startpc = genCrt ? code.curCP() : 0;
2091 code.statBegin(tree.truepart.pos);
2092 genExpr(tree.truepart, pt).load();
2093 if (genCrt) code.crt.put(tree.truepart, CRT_FLOW_TARGET,
2094 startpc, code.curCP());
2095 thenExit = code.branch(goto_);
2096 }
2097 if (elseChain != null) {
2098 code.resolve(elseChain);
2099 int startpc = genCrt ? code.curCP() : 0;
2100 code.statBegin(tree.falsepart.pos);
2101 genExpr(tree.falsepart, pt).load();
2102 if (genCrt) code.crt.put(tree.falsepart, CRT_FLOW_TARGET,
2103 startpc, code.curCP());
2104 }
2105 code.resolve(thenExit);
2106 result = items.makeStackItem(pt);
2107 }
2108
2109 private void setTypeAnnotationPositions(int treePos) {
2110 MethodSymbol meth = code.meth;
2111 boolean initOrClinit = code.meth.getKind() == javax.lang.model.element.ElementKind.CONSTRUCTOR
2112 || code.meth.getKind() == javax.lang.model.element.ElementKind.STATIC_INIT;
2113
2114 for (Attribute.TypeCompound ta : meth.getRawTypeAttributes()) {
2115 if (ta.hasUnknownPosition())
2116 ta.tryFixPosition();
2117
2118 if (ta.position.matchesPos(treePos))
2119 ta.position.updatePosOffset(code.cp);
2120 }
2121
2122 if (!initOrClinit)
2123 return;
2124
2125 for (Attribute.TypeCompound ta : meth.owner.getRawTypeAttributes()) {
2126 if (ta.hasUnknownPosition())
2127 ta.tryFixPosition();
2128
2129 if (ta.position.matchesPos(treePos))
2130 ta.position.updatePosOffset(code.cp);
2131 }
2132
2133 ClassSymbol clazz = meth.enclClass();
2134 for (Symbol s : new com.sun.tools.javac.model.FilteredMemberList(clazz.members())) {
2135 if (!s.getKind().isField())
2136 continue;
2137
2138 for (Attribute.TypeCompound ta : s.getRawTypeAttributes()) {
2139 if (ta.hasUnknownPosition())
2140 ta.tryFixPosition();
2141
2142 if (ta.position.matchesPos(treePos))
2143 ta.position.updatePosOffset(code.cp);
2144 }
2145 }
2146 }
2147
2148 public void visitNewClass(JCNewClass tree) {
2149 // Enclosing instances or anonymous classes should have been eliminated
2150 // by now.
2151 Assert.check(tree.encl == null && tree.def == null);
2152 setTypeAnnotationPositions(tree.pos);
2153
2154 code.emitop2(new_, checkDimension(tree.pos(), tree.type), PoolWriter::putClass);
2155 code.emitop0(dup);
2156
2157 // Generate code for all arguments, where the expected types are
2158 // the parameters of the constructor's external type (that is,
2159 // any implicit outer instance appears as first parameter).
2160 genArgs(tree.args, tree.constructor.externalType(types).getParameterTypes());
2161
2162 items.makeMemberItem(tree.constructor, true).invoke();
2163 result = items.makeStackItem(tree.type);
2164 }
2165
2166 public void visitNewArray(JCNewArray tree) {
2167 setTypeAnnotationPositions(tree.pos);
2168
2169 if (tree.elems != null) {
2170 Type elemtype = types.elemtype(tree.type);
2171 loadIntConst(tree.elems.length());
2172 Item arr = makeNewArray(tree.pos(), tree.type, 1);
2173 int i = 0;
2174 for (List<JCExpression> l = tree.elems; l.nonEmpty(); l = l.tail) {
2175 arr.duplicate();
2176 loadIntConst(i);
2177 i++;
2178 genExpr(l.head, elemtype).load();
2179 items.makeIndexedItem(elemtype).store();
2180 }
2181 result = arr;
2182 } else {
2183 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
2184 genExpr(l.head, syms.intType).load();
2185 }
2186 result = makeNewArray(tree.pos(), tree.type, tree.dims.length());
2187 }
2188 }
2189 //where
2190 /** Generate code to create an array with given element type and number
2191 * of dimensions.
2192 */
2193 Item makeNewArray(DiagnosticPosition pos, Type type, int ndims) {
2194 Type elemtype = types.elemtype(type);
2195 if (types.dimensions(type) > ClassFile.MAX_DIMENSIONS) {
2196 log.error(pos, Errors.LimitDimensions);
2197 nerrs++;
2198 }
2199 int elemcode = Code.arraycode(elemtype);
2200 if (elemcode == 0 || (elemcode == 1 && ndims == 1)) {
2201 code.emitAnewarray(makeRef(pos, elemtype), type);
2202 } else if (elemcode == 1) {
2203 code.emitMultianewarray(ndims, makeRef(pos, type), type);
2204 } else {
2205 code.emitNewarray(elemcode, type);
2206 }
2207 return items.makeStackItem(type);
2208 }
2209
2210 public void visitParens(JCParens tree) {
2211 result = genExpr(tree.expr, tree.expr.type);
2212 }
2213
2214 public void visitAssign(JCAssign tree) {
2215 Item l = genExpr(tree.lhs, tree.lhs.type);
2216 genExpr(tree.rhs, tree.lhs.type).load();
2217 Set<VarSymbol> tmpUnsetSymbols = unsetFieldsInfo.getUnsetFields(env.enclClass.sym, tree);
2218 code.currentUnsetFields = tmpUnsetSymbols != null ? tmpUnsetSymbols : code.currentUnsetFields;
2219 if (tree.rhs.type.hasTag(BOT)) {
2220 /* This is just a case of widening reference conversion that per 5.1.5 simply calls
2221 for "regarding a reference as having some other type in a manner that can be proved
2222 correct at compile time."
2223 */
2224 code.state.forceStackTop(tree.lhs.type);
2225 }
2226 result = items.makeAssignItem(l);
2227 }
2228
2229 public void visitAssignop(JCAssignOp tree) {
2230 OperatorSymbol operator = tree.operator;
2231 Item l;
2232 if (operator.opcode == string_add) {
2233 l = concat.makeConcat(tree);
2234 } else {
2235 // Generate code for first expression
2236 l = genExpr(tree.lhs, tree.lhs.type);
2237
2238 // If we have an increment of -32768 to +32767 of a local
2239 // int variable we can use an incr instruction instead of
2240 // proceeding further.
2241 if ((tree.hasTag(PLUS_ASG) || tree.hasTag(MINUS_ASG)) &&
2242 l instanceof LocalItem localItem &&
2243 tree.lhs.type.getTag().isSubRangeOf(INT) &&
2244 tree.rhs.type.getTag().isSubRangeOf(INT) &&
2245 tree.rhs.type.constValue() != null) {
2246 int ival = ((Number) tree.rhs.type.constValue()).intValue();
2247 if (tree.hasTag(MINUS_ASG)) ival = -ival;
2248 localItem.incr(ival);
2249 result = l;
2250 return;
2251 }
2252 // Otherwise, duplicate expression, load one copy
2253 // and complete binary operation.
2254 l.duplicate();
2255 l.coerce(operator.type.getParameterTypes().head).load();
2256 completeBinop(tree.lhs, tree.rhs, operator).coerce(tree.lhs.type);
2257 }
2258 result = items.makeAssignItem(l);
2259 }
2260
2261 public void visitUnary(JCUnary tree) {
2262 OperatorSymbol operator = tree.operator;
2263 if (tree.hasTag(NOT)) {
2264 CondItem od = genCond(tree.arg, false);
2265 result = od.negate();
2266 } else {
2267 Item od = genExpr(tree.arg, operator.type.getParameterTypes().head);
2268 switch (tree.getTag()) {
2269 case POS:
2270 result = od.load();
2271 break;
2272 case NEG:
2273 result = od.load();
2274 code.emitop0(operator.opcode);
2275 break;
2276 case COMPL:
2277 result = od.load();
2278 emitMinusOne(od.typecode);
2279 code.emitop0(operator.opcode);
2280 break;
2281 case PREINC: case PREDEC:
2282 od.duplicate();
2283 if (od instanceof LocalItem localItem &&
2284 (operator.opcode == iadd || operator.opcode == isub)) {
2285 localItem.incr(tree.hasTag(PREINC) ? 1 : -1);
2286 result = od;
2287 } else {
2288 od.load();
2289 code.emitop0(one(od.typecode));
2290 code.emitop0(operator.opcode);
2291 // Perform narrowing primitive conversion if byte,
2292 // char, or short. Fix for 4304655.
2293 if (od.typecode != INTcode &&
2294 Code.truncate(od.typecode) == INTcode)
2295 code.emitop0(int2byte + od.typecode - BYTEcode);
2296 result = items.makeAssignItem(od);
2297 }
2298 break;
2299 case POSTINC: case POSTDEC:
2300 od.duplicate();
2301 if (od instanceof LocalItem localItem &&
2302 (operator.opcode == iadd || operator.opcode == isub)) {
2303 Item res = od.load();
2304 localItem.incr(tree.hasTag(POSTINC) ? 1 : -1);
2305 result = res;
2306 } else {
2307 Item res = od.load();
2308 od.stash(od.typecode);
2309 code.emitop0(one(od.typecode));
2310 code.emitop0(operator.opcode);
2311 // Perform narrowing primitive conversion if byte,
2312 // char, or short. Fix for 4304655.
2313 if (od.typecode != INTcode &&
2314 Code.truncate(od.typecode) == INTcode)
2315 code.emitop0(int2byte + od.typecode - BYTEcode);
2316 od.store();
2317 result = res;
2318 }
2319 break;
2320 case NULLCHK:
2321 result = od.load();
2322 code.emitop0(dup);
2323 genNullCheck(tree);
2324 break;
2325 default:
2326 Assert.error();
2327 }
2328 }
2329 }
2330
2331 /** Generate a null check from the object value at stack top. */
2332 private void genNullCheck(JCTree tree) {
2333 code.statBegin(tree.pos);
2334 callMethod(tree.pos(), syms.objectsType, names.requireNonNull,
2335 List.of(syms.objectType), true);
2336 code.emitop0(pop);
2337 }
2338
2339 public void visitBinary(JCBinary tree) {
2340 OperatorSymbol operator = tree.operator;
2341 if (operator.opcode == string_add) {
2342 result = concat.makeConcat(tree);
2343 } else if (tree.hasTag(AND)) {
2344 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2345 if (!lcond.isFalse()) {
2346 Chain falseJumps = lcond.jumpFalse();
2347 code.resolve(lcond.trueJumps);
2348 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2349 result = items.
2350 makeCondItem(rcond.opcode,
2351 rcond.trueJumps,
2352 Code.mergeChains(falseJumps,
2353 rcond.falseJumps));
2354 } else {
2355 result = lcond;
2356 }
2357 } else if (tree.hasTag(OR)) {
2358 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2359 if (!lcond.isTrue()) {
2360 Chain trueJumps = lcond.jumpTrue();
2361 code.resolve(lcond.falseJumps);
2362 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2363 result = items.
2364 makeCondItem(rcond.opcode,
2365 Code.mergeChains(trueJumps, rcond.trueJumps),
2366 rcond.falseJumps);
2367 } else {
2368 result = lcond;
2369 }
2370 } else {
2371 Item od = genExpr(tree.lhs, operator.type.getParameterTypes().head);
2372 od.load();
2373 result = completeBinop(tree.lhs, tree.rhs, operator);
2374 }
2375 }
2376
2377
2378 /** Complete generating code for operation, with left operand
2379 * already on stack.
2380 * @param lhs The tree representing the left operand.
2381 * @param rhs The tree representing the right operand.
2382 * @param operator The operator symbol.
2383 */
2384 Item completeBinop(JCTree lhs, JCTree rhs, OperatorSymbol operator) {
2385 MethodType optype = (MethodType)operator.type;
2386 int opcode = operator.opcode;
2387 if (opcode >= if_icmpeq && opcode <= if_icmple &&
2388 rhs.type.constValue() instanceof Number number &&
2389 number.intValue() == 0) {
2390 opcode = opcode + (ifeq - if_icmpeq);
2391 } else if (opcode >= if_acmpeq && opcode <= if_acmpne &&
2392 TreeInfo.isNull(rhs)) {
2393 opcode = opcode + (if_acmp_null - if_acmpeq);
2394 } else {
2395 // The expected type of the right operand is
2396 // the second parameter type of the operator, except for
2397 // shifts with long shiftcount, where we convert the opcode
2398 // to a short shift and the expected type to int.
2399 Type rtype = operator.erasure(types).getParameterTypes().tail.head;
2400 if (opcode >= ishll && opcode <= lushrl) {
2401 opcode = opcode + (ishl - ishll);
2402 rtype = syms.intType;
2403 }
2404 // Generate code for right operand and load.
2405 genExpr(rhs, rtype).load();
2406 // If there are two consecutive opcode instructions,
2407 // emit the first now.
2408 if (opcode >= (1 << preShift)) {
2409 code.emitop0(opcode >> preShift);
2410 opcode = opcode & 0xFF;
2411 }
2412 }
2413 if (opcode >= ifeq && opcode <= if_acmpne ||
2414 opcode == if_acmp_null || opcode == if_acmp_nonnull) {
2415 return items.makeCondItem(opcode);
2416 } else {
2417 code.emitop0(opcode);
2418 return items.makeStackItem(optype.restype);
2419 }
2420 }
2421
2422 public void visitTypeCast(JCTypeCast tree) {
2423 result = genExpr(tree.expr, tree.clazz.type).load();
2424 setTypeAnnotationPositions(tree.pos);
2425 // Additional code is only needed if we cast to a reference type
2426 // which is not statically a supertype of the expression's type.
2427 // For basic types, the coerce(...) in genExpr(...) will do
2428 // the conversion.
2429 if (!tree.clazz.type.isPrimitive() &&
2430 !types.isSameType(tree.expr.type, tree.clazz.type) &&
2431 types.asSuper(tree.expr.type, tree.clazz.type.tsym) == null) {
2432 code.emitop2(checkcast, checkDimension(tree.pos(), tree.clazz.type), PoolWriter::putClass);
2433 }
2434 }
2435
2436 public void visitWildcard(JCWildcard tree) {
2437 throw new AssertionError(this.getClass().getName());
2438 }
2439
2440 public void visitTypeTest(JCInstanceOf tree) {
2441 genExpr(tree.expr, tree.expr.type).load();
2442 setTypeAnnotationPositions(tree.pos);
2443 code.emitop2(instanceof_, makeRef(tree.pos(), tree.pattern.type));
2444 result = items.makeStackItem(syms.booleanType);
2445 }
2446
2447 public void visitIndexed(JCArrayAccess tree) {
2448 genExpr(tree.indexed, tree.indexed.type).load();
2449 genExpr(tree.index, syms.intType).load();
2450 result = items.makeIndexedItem(tree.type);
2451 }
2452
2453 public void visitIdent(JCIdent tree) {
2454 Symbol sym = tree.sym;
2455 if (tree.name == names._this || tree.name == names._super) {
2456 Item res = tree.name == names._this
2457 ? items.makeThisItem()
2458 : items.makeSuperItem();
2459 if (sym.kind == MTH) {
2460 // Generate code to address the constructor.
2461 res.load();
2462 res = items.makeMemberItem(sym, true);
2463 }
2464 result = res;
2465 } else if (isInvokeDynamic(sym) || isConstantDynamic(sym)) {
2466 if (isConstantDynamic(sym)) {
2467 setTypeAnnotationPositions(tree.pos);
2468 }
2469 result = items.makeDynamicItem(sym);
2470 } else if (sym.kind == VAR && (sym.owner.kind == MTH || sym.owner.kind == VAR)) {
2471 result = items.makeLocalItem((VarSymbol)sym);
2472 } else if ((sym.flags() & STATIC) != 0) {
2473 if (!isAccessSuper(env.enclMethod))
2474 sym = binaryQualifier(sym, env.enclClass.type);
2475 result = items.makeStaticItem(sym);
2476 } else {
2477 items.makeThisItem().load();
2478 sym = binaryQualifier(sym, env.enclClass.type);
2479 result = items.makeMemberItem(sym, nonVirtualForPrivateAccess(sym));
2480 }
2481 }
2482
2483 //where
2484 private boolean nonVirtualForPrivateAccess(Symbol sym) {
2485 boolean useVirtual = target.hasVirtualPrivateInvoke() &&
2486 !disableVirtualizedPrivateInvoke;
2487 return !useVirtual && ((sym.flags() & PRIVATE) != 0);
2488 }
2489
2490 public void visitSelect(JCFieldAccess tree) {
2491 Symbol sym = tree.sym;
2492
2493 if (tree.name == names._class) {
2494 code.emitLdc((LoadableConstant)checkDimension(tree.pos(), tree.selected.type));
2495 result = items.makeStackItem(pt);
2496 return;
2497 }
2498
2499 Symbol ssym = TreeInfo.symbol(tree.selected);
2500
2501 // Are we selecting via super?
2502 boolean selectSuper =
2503 ssym != null && (ssym.kind == TYP || ssym.name == names._super);
2504
2505 // Are we accessing a member of the superclass in an access method
2506 // resulting from a qualified super?
2507 boolean accessSuper = isAccessSuper(env.enclMethod);
2508
2509 Item base = (selectSuper)
2510 ? items.makeSuperItem()
2511 : genExpr(tree.selected, tree.selected.type);
2512
2513 if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) {
2514 // We are seeing a variable that is constant but its selecting
2515 // expression is not.
2516 if ((sym.flags() & STATIC) != 0) {
2517 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2518 base = base.load();
2519 base.drop();
2520 } else {
2521 base.load();
2522 genNullCheck(tree.selected);
2523 }
2524 result = items.
2525 makeImmediateItem(sym.type, ((VarSymbol) sym).getConstValue());
2526 } else {
2527 if (isInvokeDynamic(sym)) {
2528 result = items.makeDynamicItem(sym);
2529 return;
2530 } else {
2531 sym = binaryQualifier(sym, tree.selected.type);
2532 }
2533 if ((sym.flags() & STATIC) != 0) {
2534 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2535 base = base.load();
2536 base.drop();
2537 result = items.makeStaticItem(sym);
2538 } else {
2539 base.load();
2540 if (sym == syms.lengthVar) {
2541 code.emitop0(arraylength);
2542 result = items.makeStackItem(syms.intType);
2543 } else {
2544 result = items.
2545 makeMemberItem(sym,
2546 nonVirtualForPrivateAccess(sym) ||
2547 selectSuper || accessSuper);
2548 }
2549 }
2550 }
2551 }
2552
2553 public boolean isInvokeDynamic(Symbol sym) {
2554 return sym.kind == MTH && ((MethodSymbol)sym).isDynamic();
2555 }
2556
2557 public void visitLiteral(JCLiteral tree) {
2558 if (tree.type.hasTag(BOT)) {
2559 code.emitop0(aconst_null);
2560 result = items.makeStackItem(tree.type);
2561 }
2562 else
2563 result = items.makeImmediateItem(tree.type, tree.value);
2564 }
2565
2566 public void visitLetExpr(LetExpr tree) {
2567 code.resolvePending();
2568
2569 int limit = code.nextreg;
2570 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
2571 try {
2572 genStats(tree.defs, env);
2573 } finally {
2574 code.setLetExprStackPos(prevLetExprStart);
2575 }
2576 result = genExpr(tree.expr, tree.expr.type).load();
2577 code.endScopes(limit);
2578 }
2579
2580 private void generateReferencesToPrunedTree(ClassSymbol classSymbol) {
2581 List<JCTree> prunedInfo = lower.prunedTree.get(classSymbol);
2582 if (prunedInfo != null) {
2583 for (JCTree prunedTree: prunedInfo) {
2584 prunedTree.accept(classReferenceVisitor);
2585 }
2586 }
2587 }
2588
2589 /* ************************************************************************
2590 * main method
2591 *************************************************************************/
2592
2593 /** Generate code for a class definition.
2594 * @param env The attribution environment that belongs to the
2595 * outermost class containing this class definition.
2596 * We need this for resolving some additional symbols.
2597 * @param cdef The tree representing the class definition.
2598 * @return True if code is generated with no errors.
2599 */
2600 public boolean genClass(Env<AttrContext> env, JCClassDecl cdef) {
2601 try {
2602 attrEnv = env;
2603 ClassSymbol c = cdef.sym;
2604 this.toplevel = env.toplevel;
2605 this.endPosTable = toplevel.endPositions;
2606 /* method normalizeDefs() can add references to external classes into the constant pool
2607 */
2608 cdef.defs = normalizeDefs(cdef.defs, c);
2609 generateReferencesToPrunedTree(c);
2610 Env<GenContext> localEnv = new Env<>(cdef, new GenContext());
2611 localEnv.toplevel = env.toplevel;
2612 localEnv.enclClass = cdef;
2613
2614 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2615 genDef(l.head, localEnv);
2616 }
2617 if (poolWriter.size() > PoolWriter.MAX_ENTRIES) {
2618 log.error(cdef.pos(), Errors.LimitPool);
2619 nerrs++;
2620 }
2621 if (nerrs != 0) {
2622 // if errors, discard code
2623 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2624 if (l.head.hasTag(METHODDEF))
2625 ((JCMethodDecl) l.head).sym.code = null;
2626 }
2627 }
2628 cdef.defs = List.nil(); // discard trees
2629 return nerrs == 0;
2630 } finally {
2631 // note: this method does NOT support recursion.
2632 attrEnv = null;
2633 this.env = null;
2634 toplevel = null;
2635 endPosTable = null;
2636 nerrs = 0;
2637 qualifiedSymbolCache.clear();
2638 }
2639 }
2640
2641 /* ************************************************************************
2642 * Auxiliary classes
2643 *************************************************************************/
2644
2645 /** An abstract class for finalizer generation.
2646 */
2647 abstract class GenFinalizer {
2648 /** Generate code to clean up when unwinding. */
2649 abstract void gen();
2650
2651 /** Generate code to clean up at last. */
2652 abstract void genLast();
2653
2654 /** Does this finalizer have some nontrivial cleanup to perform? */
2655 boolean hasFinalizer() { return true; }
2656
2657 /** Should be invoked after the try's body has been visited. */
2658 void afterBody() {}
2659 }
2660
2661 /** code generation contexts,
2662 * to be used as type parameter for environments.
2663 */
2664 final class GenContext {
2665
2666 /**
2667 * The top defined local variables for exit or continue branches to merge into.
2668 * It may contain uninitialized variables to be initialized by branched code,
2669 * so we cannot use Code.State.defined bits.
2670 */
2671 final int limit;
2672
2673 /** A chain for all unresolved jumps that exit the current environment.
2674 */
2675 Chain exit = null;
2676
2677 /** A chain for all unresolved jumps that continue in the
2678 * current environment.
2679 */
2680 Chain cont = null;
2681
2682 /** A closure that generates the finalizer of the current environment.
2683 * Only set for Synchronized and Try contexts.
2684 */
2685 GenFinalizer finalize = null;
2686
2687 /** Is this a switch statement? If so, allocate registers
2688 * even when the variable declaration is unreachable.
2689 */
2690 boolean isSwitch = false;
2691
2692 /** A list buffer containing all gaps in the finalizer range,
2693 * where a catch all exception should not apply.
2694 */
2695 ListBuffer<Integer> gaps = null;
2696
2697 GenContext() {
2698 var code = Gen.this.code;
2699 this.limit = code == null ? 0 : code.nextreg;
2700 }
2701
2702 /** Add given chain to exit chain.
2703 */
2704 void addExit(Chain c) {
2705 if (c != null) {
2706 c.state.defined.excludeFrom(limit);
2707 }
2708 exit = Code.mergeChains(c, exit);
2709 }
2710
2711 /** Add given chain to cont chain.
2712 */
2713 void addCont(Chain c) {
2714 if (c != null) {
2715 c.state.defined.excludeFrom(limit);
2716 }
2717 cont = Code.mergeChains(c, cont);
2718 }
2719 }
2720
2721 record PatternMatchingCatchConfiguration(Set<JCMethodInvocation> invocations,
2722 ListBuffer<int[]> ranges,
2723 JCCatch handler,
2724 State startState) {
2725 public PatternMatchingCatchConfiguration restart(State newState) {
2726 return new PatternMatchingCatchConfiguration(invocations(),
2727 new ListBuffer<int[]>(),
2728 handler(),
2729 newState);
2730 }
2731 }
2732 }