1 /*
2 * Copyright (c) 1999, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package com.sun.tools.javac.jvm;
27
28 import java.util.HashMap;
29 import java.util.Map;
30 import java.util.Set;
31
32 import com.sun.tools.javac.jvm.PoolConstant.LoadableConstant;
33 import com.sun.tools.javac.tree.TreeInfo.PosKind;
34 import com.sun.tools.javac.util.*;
35 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
36 import com.sun.tools.javac.util.List;
37 import com.sun.tools.javac.code.*;
38 import com.sun.tools.javac.code.Attribute.TypeCompound;
39 import com.sun.tools.javac.code.Symbol.VarSymbol;
40 import com.sun.tools.javac.comp.*;
41 import com.sun.tools.javac.tree.*;
42
43 import com.sun.tools.javac.code.Symbol.*;
44 import com.sun.tools.javac.code.Type.*;
45 import com.sun.tools.javac.jvm.Code.*;
46 import com.sun.tools.javac.jvm.Items.*;
47 import com.sun.tools.javac.resources.CompilerProperties.Errors;
48 import com.sun.tools.javac.tree.EndPosTable;
49 import com.sun.tools.javac.tree.JCTree.*;
50
51 import static com.sun.tools.javac.code.Flags.*;
52 import static com.sun.tools.javac.code.Kinds.Kind.*;
53 import static com.sun.tools.javac.code.TypeTag.*;
54 import static com.sun.tools.javac.jvm.ByteCodes.*;
55 import static com.sun.tools.javac.jvm.CRTFlags.*;
56 import static com.sun.tools.javac.main.Option.*;
57 import static com.sun.tools.javac.tree.JCTree.Tag.*;
58
59 /** This pass maps flat Java (i.e. without inner classes) to bytecodes.
60 *
61 * <p><b>This is NOT part of any supported API.
62 * If you write code that depends on this, you do so at your own risk.
63 * This code and its internal interfaces are subject to change or
64 * deletion without notice.</b>
65 */
66 public class Gen extends JCTree.Visitor {
67 protected static final Context.Key<Gen> genKey = new Context.Key<>();
68
69 private final Log log;
70 private final Symtab syms;
71 private final Check chk;
72 private final Resolve rs;
73 private final TreeMaker make;
74 private final Names names;
75 private final Target target;
76 private final String accessDollar;
77 private final Types types;
78 private final Lower lower;
79 private final Annotate annotate;
80 private final StringConcat concat;
81
82 /** Format of stackmap tables to be generated. */
83 private final Code.StackMapFormat stackMap;
84
85 /** A type that serves as the expected type for all method expressions.
86 */
87 private final Type methodType;
88
89 public static Gen instance(Context context) {
90 Gen instance = context.get(genKey);
91 if (instance == null)
92 instance = new Gen(context);
93 return instance;
94 }
95
96 /** Constant pool writer, set by genClass.
97 */
98 final PoolWriter poolWriter;
99
100 private final UnsetFieldsInfo unsetFieldsInfo;
101
102 @SuppressWarnings("this-escape")
103 protected Gen(Context context) {
104 context.put(genKey, this);
105
106 names = Names.instance(context);
107 log = Log.instance(context);
108 syms = Symtab.instance(context);
109 chk = Check.instance(context);
110 rs = Resolve.instance(context);
111 make = TreeMaker.instance(context);
112 target = Target.instance(context);
113 types = Types.instance(context);
114 concat = StringConcat.instance(context);
115
116 methodType = new MethodType(null, null, null, syms.methodClass);
117 accessDollar = "access" + target.syntheticNameChar();
118 lower = Lower.instance(context);
119
120 Options options = Options.instance(context);
121 lineDebugInfo =
122 options.isUnset(G_CUSTOM) ||
123 options.isSet(G_CUSTOM, "lines");
124 varDebugInfo =
125 options.isUnset(G_CUSTOM)
126 ? options.isSet(G)
127 : options.isSet(G_CUSTOM, "vars");
128 genCrt = options.isSet(XJCOV);
129 debugCode = options.isSet("debug.code");
130 disableVirtualizedPrivateInvoke = options.isSet("disableVirtualizedPrivateInvoke");
131 poolWriter = new PoolWriter(types, names);
132 unsetFieldsInfo = UnsetFieldsInfo.instance(context);
133
134 // ignore cldc because we cannot have both stackmap formats
135 this.stackMap = StackMapFormat.JSR202;
136 annotate = Annotate.instance(context);
137 qualifiedSymbolCache = new HashMap<>();
138 generateEarlyLarvalFrame = options.isSet("generateEarlyLarvalFrame");
139 Preview preview = Preview.instance(context);
140 Source source = Source.instance(context);
141 allowValueClasses = (!preview.isPreview(Source.Feature.VALUE_CLASSES) || preview.isEnabled()) &&
142 Source.Feature.VALUE_CLASSES.allowedInSource(source);
143 }
144
145 /** Switches
146 */
147 private final boolean lineDebugInfo;
148 private final boolean varDebugInfo;
149 private final boolean genCrt;
150 private final boolean debugCode;
151 private boolean disableVirtualizedPrivateInvoke;
152 private boolean generateEarlyLarvalFrame;
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 if (TreeInfo.isConstructor(md) && TreeInfo.hasConstructorCall(md, names._super)) {
568 // We are seeing a constructor that has a super() call.
569 // Find the super() invocation and append the given initializer code.
570 if (allowValueClasses & (md.sym.owner.isValueClass() || md.sym.owner.hasStrict() || ((md.sym.owner.flags_field & RECORD) != 0))) {
571 rewriteInitializersIfNeeded(md, initCode);
572 md.body.stats = initCode.appendList(md.body.stats);
573 TreeInfo.mapSuperCalls(md.body, supercall -> make.Block(0, initBlocks.prepend(supercall)));
574 } else {
575 TreeInfo.mapSuperCalls(md.body, supercall -> make.Block(0, initCode.prepend(supercall)));
576 }
577
578 if (md.body.bracePos == Position.NOPOS)
579 md.body.bracePos = TreeInfo.endPos(md.body.stats.last());
580
581 md.sym.appendUniqueTypeAttributes(initTAs);
582 }
583 }
584
585 void rewriteInitializersIfNeeded(JCMethodDecl md, List<JCStatement> initCode) {
586 if (lower.initializerOuterThis.containsKey(md.sym.owner)) {
587 InitializerVisitor initializerVisitor = new InitializerVisitor(md, lower.initializerOuterThis.get(md.sym.owner));
588 for (JCStatement init : initCode) {
589 initializerVisitor.scan(init);
590 }
591 }
592 }
593
594 public static class InitializerVisitor extends TreeScanner {
595 JCMethodDecl md;
596 Set<JCExpression> exprSet;
597
598 public InitializerVisitor(JCMethodDecl md, Set<JCExpression> exprSet) {
599 this.md = md;
600 this.exprSet = exprSet;
601 }
602
603 @Override
604 public void visitTree(JCTree tree) {}
605
606 @Override
607 public void visitIdent(JCIdent tree) {
608 if (exprSet.contains(tree)) {
609 for (JCVariableDecl param: md.params) {
610 if (param.name == tree.name &&
611 ((param.sym.flags_field & (MANDATED | NOOUTERTHIS)) == (MANDATED | NOOUTERTHIS))) {
612 tree.sym = param.sym;
613 }
614 }
615 }
616 }
617 }
618
619 /* ************************************************************************
620 * Traversal methods
621 *************************************************************************/
622
623 /** Visitor argument: The current environment.
624 */
625 Env<GenContext> env;
626
627 /** Visitor argument: The expected type (prototype).
628 */
629 Type pt;
630
631 /** Visitor result: The item representing the computed value.
632 */
633 Item result;
634
635 /** Visitor method: generate code for a definition, catching and reporting
636 * any completion failures.
637 * @param tree The definition to be visited.
638 * @param env The environment current at the definition.
639 */
640 public void genDef(JCTree tree, Env<GenContext> env) {
641 Env<GenContext> prevEnv = this.env;
642 try {
643 this.env = env;
644 tree.accept(this);
645 } catch (CompletionFailure ex) {
646 chk.completionError(tree.pos(), ex);
647 } finally {
648 this.env = prevEnv;
649 }
650 }
651
652 /** Derived visitor method: check whether CharacterRangeTable
653 * should be emitted, if so, put a new entry into CRTable
654 * and call method to generate bytecode.
655 * If not, just call method to generate bytecode.
656 * @see #genStat(JCTree, Env)
657 *
658 * @param tree The tree to be visited.
659 * @param env The environment to use.
660 * @param crtFlags The CharacterRangeTable flags
661 * indicating type of the entry.
662 */
663 public void genStat(JCTree tree, Env<GenContext> env, int crtFlags) {
664 if (!genCrt) {
665 genStat(tree, env);
666 return;
667 }
668 int startpc = code.curCP();
669 genStat(tree, env);
670 if (tree.hasTag(Tag.BLOCK)) crtFlags |= CRT_BLOCK;
671 code.crt.put(tree, crtFlags, startpc, code.curCP());
672 }
673
674 /** Derived visitor method: generate code for a statement.
675 */
676 public void genStat(JCTree tree, Env<GenContext> env) {
677 if (code.isAlive()) {
678 code.statBegin(tree.pos);
679 genDef(tree, env);
680 } else if (env.info.isSwitch && tree.hasTag(VARDEF)) {
681 // variables whose declarations are in a switch
682 // can be used even if the decl is unreachable.
683 code.newLocal(((JCVariableDecl) tree).sym);
684 }
685 }
686
687 /** Derived visitor method: check whether CharacterRangeTable
688 * should be emitted, if so, put a new entry into CRTable
689 * and call method to generate bytecode.
690 * If not, just call method to generate bytecode.
691 * @see #genStats(List, Env)
692 *
693 * @param trees The list of trees to be visited.
694 * @param env The environment to use.
695 * @param crtFlags The CharacterRangeTable flags
696 * indicating type of the entry.
697 */
698 public void genStats(List<JCStatement> trees, Env<GenContext> env, int crtFlags) {
699 if (!genCrt) {
700 genStats(trees, env);
701 return;
702 }
703 if (trees.length() == 1) { // mark one statement with the flags
704 genStat(trees.head, env, crtFlags | CRT_STATEMENT);
705 } else {
706 int startpc = code.curCP();
707 genStats(trees, env);
708 code.crt.put(trees, crtFlags, startpc, code.curCP());
709 }
710 }
711
712 /** Derived visitor method: generate code for a list of statements.
713 */
714 public void genStats(List<? extends JCTree> trees, Env<GenContext> env) {
715 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
716 genStat(l.head, env, CRT_STATEMENT);
717 }
718
719 /** Derived visitor method: check whether CharacterRangeTable
720 * should be emitted, if so, put a new entry into CRTable
721 * and call method to generate bytecode.
722 * If not, just call method to generate bytecode.
723 * @see #genCond(JCTree,boolean)
724 *
725 * @param tree The tree to be visited.
726 * @param crtFlags The CharacterRangeTable flags
727 * indicating type of the entry.
728 */
729 public CondItem genCond(JCTree tree, int crtFlags) {
730 if (!genCrt) return genCond(tree, false);
731 int startpc = code.curCP();
732 CondItem item = genCond(tree, (crtFlags & CRT_FLOW_CONTROLLER) != 0);
733 code.crt.put(tree, crtFlags, startpc, code.curCP());
734 return item;
735 }
736
737 /** Derived visitor method: generate code for a boolean
738 * expression in a control-flow context.
739 * @param _tree The expression to be visited.
740 * @param markBranches The flag to indicate that the condition is
741 * a flow controller so produced conditions
742 * should contain a proper tree to generate
743 * CharacterRangeTable branches for them.
744 */
745 public CondItem genCond(JCTree _tree, boolean markBranches) {
746 JCTree inner_tree = TreeInfo.skipParens(_tree);
747 if (inner_tree.hasTag(CONDEXPR)) {
748 JCConditional tree = (JCConditional)inner_tree;
749 CondItem cond = genCond(tree.cond, CRT_FLOW_CONTROLLER);
750 if (cond.isTrue()) {
751 code.resolve(cond.trueJumps);
752 CondItem result = genCond(tree.truepart, CRT_FLOW_TARGET);
753 if (markBranches) result.tree = tree.truepart;
754 return result;
755 }
756 if (cond.isFalse()) {
757 code.resolve(cond.falseJumps);
758 CondItem result = genCond(tree.falsepart, CRT_FLOW_TARGET);
759 if (markBranches) result.tree = tree.falsepart;
760 return result;
761 }
762 Chain secondJumps = cond.jumpFalse();
763 code.resolve(cond.trueJumps);
764 CondItem first = genCond(tree.truepart, CRT_FLOW_TARGET);
765 if (markBranches) first.tree = tree.truepart;
766 Chain falseJumps = first.jumpFalse();
767 code.resolve(first.trueJumps);
768 Chain trueJumps = code.branch(goto_);
769 code.resolve(secondJumps);
770 CondItem second = genCond(tree.falsepart, CRT_FLOW_TARGET);
771 CondItem result = items.makeCondItem(second.opcode,
772 Code.mergeChains(trueJumps, second.trueJumps),
773 Code.mergeChains(falseJumps, second.falseJumps));
774 if (markBranches) result.tree = tree.falsepart;
775 return result;
776 } else if (inner_tree.hasTag(SWITCH_EXPRESSION)) {
777 code.resolvePending();
778
779 boolean prevInCondSwitchExpression = inCondSwitchExpression;
780 Chain prevSwitchExpressionTrueChain = switchExpressionTrueChain;
781 Chain prevSwitchExpressionFalseChain = switchExpressionFalseChain;
782 try {
783 inCondSwitchExpression = true;
784 switchExpressionTrueChain = null;
785 switchExpressionFalseChain = null;
786 try {
787 doHandleSwitchExpression((JCSwitchExpression) inner_tree);
788 } catch (CompletionFailure ex) {
789 chk.completionError(_tree.pos(), ex);
790 code.state.stacksize = 1;
791 }
792 CondItem result = items.makeCondItem(goto_,
793 switchExpressionTrueChain,
794 switchExpressionFalseChain);
795 if (markBranches) result.tree = _tree;
796 return result;
797 } finally {
798 inCondSwitchExpression = prevInCondSwitchExpression;
799 switchExpressionTrueChain = prevSwitchExpressionTrueChain;
800 switchExpressionFalseChain = prevSwitchExpressionFalseChain;
801 }
802 } else if (inner_tree.hasTag(LETEXPR) && ((LetExpr) inner_tree).needsCond) {
803 code.resolvePending();
804
805 LetExpr tree = (LetExpr) inner_tree;
806 int limit = code.nextreg;
807 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
808 try {
809 genStats(tree.defs, env);
810 } finally {
811 code.setLetExprStackPos(prevLetExprStart);
812 }
813 CondItem result = genCond(tree.expr, markBranches);
814 code.endScopes(limit);
815 //make sure variables defined in the let expression are not included
816 //in the defined variables for jumps that go outside of this let
817 //expression:
818 undefineVariablesInChain(result.falseJumps, limit);
819 undefineVariablesInChain(result.trueJumps, limit);
820 return result;
821 } else {
822 CondItem result = genExpr(_tree, syms.booleanType).mkCond();
823 if (markBranches) result.tree = _tree;
824 return result;
825 }
826 }
827 //where:
828 private void undefineVariablesInChain(Chain toClear, int limit) {
829 while (toClear != null) {
830 toClear.state.defined.excludeFrom(limit);
831 toClear = toClear.next;
832 }
833 }
834
835 public Code getCode() {
836 return code;
837 }
838
839 public Items getItems() {
840 return items;
841 }
842
843 public Env<AttrContext> getAttrEnv() {
844 return attrEnv;
845 }
846
847 /** Visitor class for expressions which might be constant expressions.
848 * This class is a subset of TreeScanner. Intended to visit trees pruned by
849 * Lower as long as constant expressions looking for references to any
850 * ClassSymbol. Any such reference will be added to the constant pool so
851 * automated tools can detect class dependencies better.
852 */
853 class ClassReferenceVisitor extends JCTree.Visitor {
854
855 @Override
856 public void visitTree(JCTree tree) {}
857
858 @Override
859 public void visitBinary(JCBinary tree) {
860 tree.lhs.accept(this);
861 tree.rhs.accept(this);
862 }
863
864 @Override
865 public void visitSelect(JCFieldAccess tree) {
866 if (tree.selected.type.hasTag(CLASS)) {
867 makeRef(tree.selected.pos(), tree.selected.type);
868 }
869 }
870
871 @Override
872 public void visitIdent(JCIdent tree) {
873 if (tree.sym.owner instanceof ClassSymbol classSymbol) {
874 poolWriter.putClass(classSymbol);
875 }
876 }
877
878 @Override
879 public void visitConditional(JCConditional tree) {
880 tree.cond.accept(this);
881 tree.truepart.accept(this);
882 tree.falsepart.accept(this);
883 }
884
885 @Override
886 public void visitUnary(JCUnary tree) {
887 tree.arg.accept(this);
888 }
889
890 @Override
891 public void visitParens(JCParens tree) {
892 tree.expr.accept(this);
893 }
894
895 @Override
896 public void visitTypeCast(JCTypeCast tree) {
897 tree.expr.accept(this);
898 }
899 }
900
901 private ClassReferenceVisitor classReferenceVisitor = new ClassReferenceVisitor();
902
903 /** Visitor method: generate code for an expression, catching and reporting
904 * any completion failures.
905 * @param tree The expression to be visited.
906 * @param pt The expression's expected type (proto-type).
907 */
908 public Item genExpr(JCTree tree, Type pt) {
909 if (!code.isAlive()) {
910 return items.makeStackItem(pt);
911 }
912
913 Type prevPt = this.pt;
914 try {
915 if (tree.type.constValue() != null) {
916 // Short circuit any expressions which are constants
917 tree.accept(classReferenceVisitor);
918 checkStringConstant(tree.pos(), tree.type.constValue());
919 Symbol sym = TreeInfo.symbol(tree);
920 if (sym != null && isConstantDynamic(sym)) {
921 result = items.makeDynamicItem(sym);
922 } else {
923 result = items.makeImmediateItem(tree.type, tree.type.constValue());
924 }
925 } else {
926 this.pt = pt;
927 tree.accept(this);
928 }
929 return result.coerce(pt);
930 } catch (CompletionFailure ex) {
931 chk.completionError(tree.pos(), ex);
932 code.state.stacksize = 1;
933 return items.makeStackItem(pt);
934 } finally {
935 this.pt = prevPt;
936 }
937 }
938
939 public boolean isConstantDynamic(Symbol sym) {
940 return sym.kind == VAR &&
941 sym instanceof DynamicVarSymbol dynamicVarSymbol &&
942 dynamicVarSymbol.isDynamic();
943 }
944
945 /** Derived visitor method: generate code for a list of method arguments.
946 * @param trees The argument expressions to be visited.
947 * @param pts The expression's expected types (i.e. the formal parameter
948 * types of the invoked method).
949 */
950 public void genArgs(List<JCExpression> trees, List<Type> pts) {
951 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail) {
952 genExpr(l.head, pts.head).load();
953 pts = pts.tail;
954 }
955 // require lists be of same length
956 Assert.check(pts.isEmpty());
957 }
958
959 /* ************************************************************************
960 * Visitor methods for statements and definitions
961 *************************************************************************/
962
963 /** Thrown when the byte code size exceeds limit.
964 */
965 public static class CodeSizeOverflow extends RuntimeException {
966 private static final long serialVersionUID = 0;
967 public CodeSizeOverflow() {}
968 }
969
970 public void visitMethodDef(JCMethodDecl tree) {
971 // Create a new local environment that points pack at method
972 // definition.
973 Env<GenContext> localEnv = env.dup(tree);
974 localEnv.enclMethod = tree;
975 // The expected type of every return statement in this method
976 // is the method's return type.
977 this.pt = tree.sym.erasure(types).getReturnType();
978
979 checkDimension(tree.pos(), tree.sym.erasure(types));
980 genMethod(tree, localEnv, false);
981 }
982 //where
983 /** Generate code for a method.
984 * @param tree The tree representing the method definition.
985 * @param env The environment current for the method body.
986 * @param fatcode A flag that indicates whether all jumps are
987 * within 32K. We first invoke this method under
988 * the assumption that fatcode == false, i.e. all
989 * jumps are within 32K. If this fails, fatcode
990 * is set to true and we try again.
991 */
992 void genMethod(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
993 MethodSymbol meth = tree.sym;
994 int extras = 0;
995 // Count up extra parameters
996 if (meth.isConstructor()) {
997 extras++;
998 if (meth.enclClass().isInner() &&
999 !meth.enclClass().isStatic()) {
1000 extras++;
1001 }
1002 } else if ((tree.mods.flags & STATIC) == 0) {
1003 extras++;
1004 }
1005 // System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG
1006 if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes()) + extras >
1007 ClassFile.MAX_PARAMETERS) {
1008 log.error(tree.pos(), Errors.LimitParameters);
1009 nerrs++;
1010 }
1011
1012 else if (tree.body != null) {
1013 // Create a new code structure and initialize it.
1014 int startpcCrt = initCode(tree, env, fatcode);
1015 Set<VarSymbol> prevUnsetFields = code.currentUnsetFields;
1016 if (meth.isConstructor()) {
1017 code.currentUnsetFields = unsetFieldsInfo.getUnsetFields(env.enclClass.sym, tree.body);
1018 code.initialUnsetFields = unsetFieldsInfo.getUnsetFields(env.enclClass.sym, tree.body);
1019 }
1020
1021 try {
1022 genStat(tree.body, env);
1023 } catch (CodeSizeOverflow e) {
1024 // Failed due to code limit, try again with jsr/ret
1025 startpcCrt = initCode(tree, env, fatcode);
1026 genStat(tree.body, env);
1027 } finally {
1028 code.currentUnsetFields = prevUnsetFields;
1029 }
1030
1031 if (code.state.stacksize != 0) {
1032 log.error(tree.body.pos(), Errors.StackSimError(tree.sym));
1033 throw new AssertionError();
1034 }
1035
1036 // If last statement could complete normally, insert a
1037 // return at the end.
1038 if (code.isAlive()) {
1039 code.statBegin(TreeInfo.endPos(tree.body));
1040 if (env.enclMethod == null ||
1041 env.enclMethod.sym.type.getReturnType().hasTag(VOID)) {
1042 code.emitop0(return_);
1043 } else {
1044 // sometime dead code seems alive (4415991);
1045 // generate a small loop instead
1046 int startpc = code.entryPoint();
1047 CondItem c = items.makeCondItem(goto_);
1048 code.resolve(c.jumpTrue(), startpc);
1049 }
1050 }
1051 if (genCrt)
1052 code.crt.put(tree.body,
1053 CRT_BLOCK,
1054 startpcCrt,
1055 code.curCP());
1056
1057 code.endScopes(0);
1058
1059 // If we exceeded limits, panic
1060 if (code.checkLimits(tree.pos(), log)) {
1061 nerrs++;
1062 return;
1063 }
1064
1065 // If we generated short code but got a long jump, do it again
1066 // with fatCode = true.
1067 if (!fatcode && code.fatcode) genMethod(tree, env, true);
1068
1069 // Clean up
1070 if(stackMap == StackMapFormat.JSR202) {
1071 code.lastFrame = null;
1072 code.frameBeforeLast = null;
1073 }
1074
1075 // Compress exception table
1076 code.compressCatchTable();
1077
1078 // Fill in type annotation positions for exception parameters
1079 code.fillExceptionParameterPositions();
1080 }
1081 }
1082
1083 private int initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
1084 MethodSymbol meth = tree.sym;
1085
1086 // Create a new code structure.
1087 meth.code = code = new Code(meth,
1088 fatcode,
1089 lineDebugInfo ? toplevel.lineMap : null,
1090 varDebugInfo,
1091 stackMap,
1092 debugCode,
1093 genCrt ? new CRTable(tree, env.toplevel.endPositions)
1094 : null,
1095 syms,
1096 types,
1097 poolWriter,
1098 generateEarlyLarvalFrame);
1099 items = new Items(poolWriter, code, syms, types);
1100 if (code.debugCode) {
1101 System.err.println(meth + " for body " + tree);
1102 }
1103
1104 // If method is not static, create a new local variable address
1105 // for `this'.
1106 if ((tree.mods.flags & STATIC) == 0) {
1107 Type selfType = meth.owner.type;
1108 if (meth.isConstructor() && selfType != syms.objectType)
1109 selfType = UninitializedType.uninitializedThis(selfType);
1110 code.setDefined(
1111 code.newLocal(
1112 new VarSymbol(FINAL, names._this, selfType, meth.owner)));
1113 }
1114
1115 // Mark all parameters as defined from the beginning of
1116 // the method.
1117 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
1118 checkDimension(l.head.pos(), l.head.sym.type);
1119 code.setDefined(code.newLocal(l.head.sym));
1120 }
1121
1122 // Get ready to generate code for method body.
1123 int startpcCrt = genCrt ? code.curCP() : 0;
1124 code.entryPoint();
1125
1126 // Suppress initial stackmap
1127 code.pendingStackMap = false;
1128
1129 return startpcCrt;
1130 }
1131
1132 public void visitVarDef(JCVariableDecl tree) {
1133 VarSymbol v = tree.sym;
1134 if (tree.init != null) {
1135 checkStringConstant(tree.init.pos(), v.getConstValue());
1136 if (v.getConstValue() == null || varDebugInfo) {
1137 Assert.check(code.isStatementStart());
1138 code.newLocal(v);
1139 genExpr(tree.init, v.erasure(types)).load();
1140 items.makeLocalItem(v).store();
1141 Assert.check(code.isStatementStart());
1142 }
1143 } else {
1144 code.newLocal(v);
1145 }
1146 checkDimension(tree.pos(), v.type);
1147 }
1148
1149 public void visitSkip(JCSkip tree) {
1150 }
1151
1152 public void visitBlock(JCBlock tree) {
1153 /* this method is heavily invoked, as expected, for deeply nested blocks, if blocks doesn't happen to have
1154 * patterns there will be an unnecessary tax on memory consumption every time this method is executed, for this
1155 * reason we have created helper methods and here at a higher level we just discriminate depending on the
1156 * presence, or not, of patterns in a given block
1157 */
1158 if (tree.patternMatchingCatch != null) {
1159 visitBlockWithPatterns(tree);
1160 } else {
1161 internalVisitBlock(tree);
1162 }
1163 }
1164
1165 private void visitBlockWithPatterns(JCBlock tree) {
1166 PatternMatchingCatchConfiguration prevConfiguration = patternMatchingCatchConfiguration;
1167 try {
1168 patternMatchingCatchConfiguration =
1169 new PatternMatchingCatchConfiguration(tree.patternMatchingCatch.calls2Handle(),
1170 new ListBuffer<int[]>(),
1171 tree.patternMatchingCatch.handler(),
1172 code.state.dup());
1173 internalVisitBlock(tree);
1174 } finally {
1175 generatePatternMatchingCatch(env);
1176 patternMatchingCatchConfiguration = prevConfiguration;
1177 }
1178 }
1179
1180 private void generatePatternMatchingCatch(Env<GenContext> env) {
1181 if (patternMatchingCatchConfiguration.handler != null &&
1182 !patternMatchingCatchConfiguration.ranges.isEmpty()) {
1183 Chain skipCatch = code.branch(goto_);
1184 JCCatch handler = patternMatchingCatchConfiguration.handler();
1185 code.entryPoint(patternMatchingCatchConfiguration.startState(),
1186 handler.param.sym.type);
1187 genPatternMatchingCatch(handler,
1188 env,
1189 patternMatchingCatchConfiguration.ranges.toList());
1190 code.resolve(skipCatch);
1191 }
1192 }
1193
1194 private void internalVisitBlock(JCBlock tree) {
1195 int limit = code.nextreg;
1196 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1197 genStats(tree.stats, localEnv);
1198 // End the scope of all block-local variables in variable info.
1199 if (!env.tree.hasTag(METHODDEF)) {
1200 code.statBegin(tree.bracePos);
1201 code.endScopes(limit);
1202 code.pendingStatPos = Position.NOPOS;
1203 }
1204 }
1205
1206 public void visitDoLoop(JCDoWhileLoop tree) {
1207 genLoop(tree, tree.body, tree.cond, List.nil(), false);
1208 }
1209
1210 public void visitWhileLoop(JCWhileLoop tree) {
1211 genLoop(tree, tree.body, tree.cond, List.nil(), true);
1212 }
1213
1214 public void visitForLoop(JCForLoop tree) {
1215 int limit = code.nextreg;
1216 genStats(tree.init, env);
1217 genLoop(tree, tree.body, tree.cond, tree.step, true);
1218 code.endScopes(limit);
1219 }
1220 //where
1221 /** Generate code for a loop.
1222 * @param loop The tree representing the loop.
1223 * @param body The loop's body.
1224 * @param cond The loop's controlling condition.
1225 * @param step "Step" statements to be inserted at end of
1226 * each iteration.
1227 * @param testFirst True if the loop test belongs before the body.
1228 */
1229 private void genLoop(JCStatement loop,
1230 JCStatement body,
1231 JCExpression cond,
1232 List<JCExpressionStatement> step,
1233 boolean testFirst) {
1234 Set<VarSymbol> prevCodeUnsetFields = code.currentUnsetFields;
1235 try {
1236 genLoopHelper(loop, body, cond, step, testFirst);
1237 } finally {
1238 code.currentUnsetFields = prevCodeUnsetFields;
1239 }
1240 }
1241
1242 private void genLoopHelper(JCStatement loop,
1243 JCStatement body,
1244 JCExpression cond,
1245 List<JCExpressionStatement> step,
1246 boolean testFirst) {
1247 Env<GenContext> loopEnv = env.dup(loop, new GenContext());
1248 int startpc = code.entryPoint();
1249 if (testFirst) { //while or for loop
1250 CondItem c;
1251 if (cond != null) {
1252 code.statBegin(cond.pos);
1253 Assert.check(code.isStatementStart());
1254 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1255 } else {
1256 c = items.makeCondItem(goto_);
1257 }
1258 Chain loopDone = c.jumpFalse();
1259 code.resolve(c.trueJumps);
1260 Assert.check(code.isStatementStart());
1261 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1262 code.resolve(loopEnv.info.cont);
1263 genStats(step, loopEnv);
1264 code.resolve(code.branch(goto_), startpc);
1265 code.resolve(loopDone);
1266 } else {
1267 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1268 code.resolve(loopEnv.info.cont);
1269 genStats(step, loopEnv);
1270 if (code.isAlive()) {
1271 CondItem c;
1272 if (cond != null) {
1273 code.statBegin(cond.pos);
1274 Assert.check(code.isStatementStart());
1275 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1276 } else {
1277 c = items.makeCondItem(goto_);
1278 }
1279 code.resolve(c.jumpTrue(), startpc);
1280 Assert.check(code.isStatementStart());
1281 code.resolve(c.falseJumps);
1282 }
1283 }
1284 code.resolve(loopEnv.info.exit);
1285 }
1286
1287 public void visitForeachLoop(JCEnhancedForLoop tree) {
1288 throw new AssertionError(); // should have been removed by Lower.
1289 }
1290
1291 public void visitLabelled(JCLabeledStatement tree) {
1292 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1293 genStat(tree.body, localEnv, CRT_STATEMENT);
1294 code.resolve(localEnv.info.exit);
1295 }
1296
1297 public void visitSwitch(JCSwitch tree) {
1298 handleSwitch(tree, tree.selector, tree.cases, tree.patternSwitch);
1299 }
1300
1301 @Override
1302 public void visitSwitchExpression(JCSwitchExpression tree) {
1303 code.resolvePending();
1304 boolean prevInCondSwitchExpression = inCondSwitchExpression;
1305 Set<VarSymbol> prevCodeUnsetFields = code.currentUnsetFields;
1306 try {
1307 inCondSwitchExpression = false;
1308 doHandleSwitchExpression(tree);
1309 } finally {
1310 inCondSwitchExpression = prevInCondSwitchExpression;
1311 code.currentUnsetFields = prevCodeUnsetFields;
1312 }
1313 result = items.makeStackItem(pt);
1314 }
1315
1316 private void doHandleSwitchExpression(JCSwitchExpression tree) {
1317 List<LocalItem> prevStackBeforeSwitchExpression = stackBeforeSwitchExpression;
1318 LocalItem prevSwitchResult = switchResult;
1319 int limit = code.nextreg;
1320 try {
1321 stackBeforeSwitchExpression = List.nil();
1322 switchResult = null;
1323 if (hasTry(tree)) {
1324 //if the switch expression contains try-catch, the catch handlers need to have
1325 //an empty stack. So stash whole stack to local variables, and restore it before
1326 //breaks:
1327 while (code.state.stacksize > 0) {
1328 Type type = code.state.peek();
1329 Name varName = names.fromString(target.syntheticNameChar() +
1330 "stack" +
1331 target.syntheticNameChar() +
1332 tree.pos +
1333 target.syntheticNameChar() +
1334 code.state.stacksize);
1335 VarSymbol var = new VarSymbol(Flags.SYNTHETIC, varName, type,
1336 this.env.enclMethod.sym);
1337 LocalItem item = items.new LocalItem(type, code.newLocal(var));
1338 stackBeforeSwitchExpression = stackBeforeSwitchExpression.prepend(item);
1339 item.store();
1340 }
1341 switchResult = makeTemp(tree.type);
1342 }
1343 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
1344 try {
1345 handleSwitch(tree, tree.selector, tree.cases, tree.patternSwitch);
1346 } finally {
1347 code.setLetExprStackPos(prevLetExprStart);
1348 }
1349 } finally {
1350 stackBeforeSwitchExpression = prevStackBeforeSwitchExpression;
1351 switchResult = prevSwitchResult;
1352 code.endScopes(limit);
1353 }
1354 }
1355 //where:
1356 private boolean hasTry(JCSwitchExpression tree) {
1357 class HasTryScanner extends TreeScanner {
1358 private boolean hasTry;
1359
1360 @Override
1361 public void visitTry(JCTry tree) {
1362 hasTry = true;
1363 }
1364
1365 @Override
1366 public void visitSynchronized(JCSynchronized tree) {
1367 hasTry = true;
1368 }
1369
1370 @Override
1371 public void visitClassDef(JCClassDecl tree) {
1372 }
1373
1374 @Override
1375 public void visitLambda(JCLambda tree) {
1376 }
1377 };
1378
1379 HasTryScanner hasTryScanner = new HasTryScanner();
1380
1381 hasTryScanner.scan(tree);
1382 return hasTryScanner.hasTry;
1383 }
1384
1385 private void handleSwitch(JCTree swtch, JCExpression selector, List<JCCase> cases,
1386 boolean patternSwitch) {
1387 Set<VarSymbol> prevCodeUnsetFields = code.currentUnsetFields;
1388 try {
1389 handleSwitchHelper(swtch, selector, cases, patternSwitch);
1390 } finally {
1391 code.currentUnsetFields = prevCodeUnsetFields;
1392 }
1393 }
1394
1395 void handleSwitchHelper(JCTree swtch, JCExpression selector, List<JCCase> cases,
1396 boolean patternSwitch) {
1397 int limit = code.nextreg;
1398 Assert.check(!selector.type.hasTag(CLASS));
1399 int switchStart = patternSwitch ? code.entryPoint() : -1;
1400 int startpcCrt = genCrt ? code.curCP() : 0;
1401 Assert.check(code.isStatementStart());
1402 Item sel = genExpr(selector, syms.intType);
1403 if (cases.isEmpty()) {
1404 // We are seeing: switch <sel> {}
1405 sel.load().drop();
1406 if (genCrt)
1407 code.crt.put(TreeInfo.skipParens(selector),
1408 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1409 } else {
1410 // We are seeing a nonempty switch.
1411 sel.load();
1412 if (genCrt)
1413 code.crt.put(TreeInfo.skipParens(selector),
1414 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1415 Env<GenContext> switchEnv = env.dup(swtch, new GenContext());
1416 switchEnv.info.isSwitch = true;
1417
1418 // Compute number of labels and minimum and maximum label values.
1419 // For each case, store its label in an array.
1420 int lo = Integer.MAX_VALUE; // minimum label.
1421 int hi = Integer.MIN_VALUE; // maximum label.
1422 int nlabels = 0; // number of labels.
1423
1424 int[] labels = new int[cases.length()]; // the label array.
1425 int defaultIndex = -1; // the index of the default clause.
1426
1427 List<JCCase> l = cases;
1428 for (int i = 0; i < labels.length; i++) {
1429 if (l.head.labels.head instanceof JCConstantCaseLabel constLabel) {
1430 Assert.check(l.head.labels.size() == 1);
1431 int val = ((Number) constLabel.expr.type.constValue()).intValue();
1432 labels[i] = val;
1433 if (val < lo) lo = val;
1434 if (hi < val) hi = val;
1435 nlabels++;
1436 } else {
1437 Assert.check(defaultIndex == -1);
1438 defaultIndex = i;
1439 }
1440 l = l.tail;
1441 }
1442
1443 // Determine whether to issue a tableswitch or a lookupswitch
1444 // instruction.
1445 long table_space_cost = 4 + ((long) hi - lo + 1); // words
1446 long table_time_cost = 3; // comparisons
1447 long lookup_space_cost = 3 + 2 * (long) nlabels;
1448 long lookup_time_cost = nlabels;
1449 int opcode =
1450 nlabels > 0 &&
1451 table_space_cost + 3 * table_time_cost <=
1452 lookup_space_cost + 3 * lookup_time_cost
1453 ?
1454 tableswitch : lookupswitch;
1455
1456 int startpc = code.curCP(); // the position of the selector operation
1457 code.emitop0(opcode);
1458 code.align(4);
1459 int tableBase = code.curCP(); // the start of the jump table
1460 int[] offsets = null; // a table of offsets for a lookupswitch
1461 code.emit4(-1); // leave space for default offset
1462 if (opcode == tableswitch) {
1463 code.emit4(lo); // minimum label
1464 code.emit4(hi); // maximum label
1465 for (long i = lo; i <= hi; i++) { // leave space for jump table
1466 code.emit4(-1);
1467 }
1468 } else {
1469 code.emit4(nlabels); // number of labels
1470 for (int i = 0; i < nlabels; i++) {
1471 code.emit4(-1); code.emit4(-1); // leave space for lookup table
1472 }
1473 offsets = new int[labels.length];
1474 }
1475 Code.State stateSwitch = code.state.dup();
1476 code.markDead();
1477
1478 // For each case do:
1479 l = cases;
1480 for (int i = 0; i < labels.length; i++) {
1481 JCCase c = l.head;
1482 l = l.tail;
1483
1484 int pc = code.entryPoint(stateSwitch);
1485 // Insert offset directly into code or else into the
1486 // offsets table.
1487 if (i != defaultIndex) {
1488 if (opcode == tableswitch) {
1489 code.put4(
1490 tableBase + 4 * (labels[i] - lo + 3),
1491 pc - startpc);
1492 } else {
1493 offsets[i] = pc - startpc;
1494 }
1495 } else {
1496 code.put4(tableBase, pc - startpc);
1497 }
1498
1499 // Generate code for the statements in this case.
1500 genStats(c.stats, switchEnv, CRT_FLOW_TARGET);
1501 }
1502
1503 if (switchEnv.info.cont != null) {
1504 Assert.check(patternSwitch);
1505 code.resolve(switchEnv.info.cont, switchStart);
1506 }
1507
1508 // Resolve all breaks.
1509 code.resolve(switchEnv.info.exit);
1510
1511 // If we have not set the default offset, we do so now.
1512 if (code.get4(tableBase) == -1) {
1513 code.put4(tableBase, code.entryPoint(stateSwitch) - startpc);
1514 }
1515
1516 if (opcode == tableswitch) {
1517 // Let any unfilled slots point to the default case.
1518 int defaultOffset = code.get4(tableBase);
1519 for (long i = lo; i <= hi; i++) {
1520 int t = (int)(tableBase + 4 * (i - lo + 3));
1521 if (code.get4(t) == -1)
1522 code.put4(t, defaultOffset);
1523 }
1524 } else {
1525 // Sort non-default offsets and copy into lookup table.
1526 if (defaultIndex >= 0)
1527 for (int i = defaultIndex; i < labels.length - 1; i++) {
1528 labels[i] = labels[i+1];
1529 offsets[i] = offsets[i+1];
1530 }
1531 if (nlabels > 0)
1532 qsort2(labels, offsets, 0, nlabels - 1);
1533 for (int i = 0; i < nlabels; i++) {
1534 int caseidx = tableBase + 8 * (i + 1);
1535 code.put4(caseidx, labels[i]);
1536 code.put4(caseidx + 4, offsets[i]);
1537 }
1538 }
1539
1540 if (swtch instanceof JCSwitchExpression) {
1541 // Emit line position for the end of a switch expression
1542 code.statBegin(TreeInfo.endPos(swtch));
1543 }
1544 }
1545 code.endScopes(limit);
1546 }
1547 //where
1548 /** Sort (int) arrays of keys and values
1549 */
1550 static void qsort2(int[] keys, int[] values, int lo, int hi) {
1551 int i = lo;
1552 int j = hi;
1553 int pivot = keys[(i+j)/2];
1554 do {
1555 while (keys[i] < pivot) i++;
1556 while (pivot < keys[j]) j--;
1557 if (i <= j) {
1558 int temp1 = keys[i];
1559 keys[i] = keys[j];
1560 keys[j] = temp1;
1561 int temp2 = values[i];
1562 values[i] = values[j];
1563 values[j] = temp2;
1564 i++;
1565 j--;
1566 }
1567 } while (i <= j);
1568 if (lo < j) qsort2(keys, values, lo, j);
1569 if (i < hi) qsort2(keys, values, i, hi);
1570 }
1571
1572 public void visitSynchronized(JCSynchronized tree) {
1573 int limit = code.nextreg;
1574 // Generate code to evaluate lock and save in temporary variable.
1575 final LocalItem lockVar = makeTemp(syms.objectType);
1576 Assert.check(code.isStatementStart());
1577 genExpr(tree.lock, tree.lock.type).load().duplicate();
1578 lockVar.store();
1579
1580 // Generate code to enter monitor.
1581 code.emitop0(monitorenter);
1582 code.state.lock(lockVar.reg);
1583
1584 // Generate code for a try statement with given body, no catch clauses
1585 // in a new environment with the "exit-monitor" operation as finalizer.
1586 final Env<GenContext> syncEnv = env.dup(tree, new GenContext());
1587 syncEnv.info.finalize = new GenFinalizer() {
1588 void gen() {
1589 genLast();
1590 Assert.check(syncEnv.info.gaps.length() % 2 == 0);
1591 syncEnv.info.gaps.append(code.curCP());
1592 }
1593 void genLast() {
1594 if (code.isAlive()) {
1595 lockVar.load();
1596 code.emitop0(monitorexit);
1597 code.state.unlock(lockVar.reg);
1598 }
1599 }
1600 };
1601 syncEnv.info.gaps = new ListBuffer<>();
1602 genTry(tree.body, List.nil(), syncEnv);
1603 code.endScopes(limit);
1604 }
1605
1606 public void visitTry(final JCTry tree) {
1607 // Generate code for a try statement with given body and catch clauses,
1608 // in a new environment which calls the finally block if there is one.
1609 final Env<GenContext> tryEnv = env.dup(tree, new GenContext());
1610 final Env<GenContext> oldEnv = env;
1611 tryEnv.info.finalize = new GenFinalizer() {
1612 void gen() {
1613 Assert.check(tryEnv.info.gaps.length() % 2 == 0);
1614 tryEnv.info.gaps.append(code.curCP());
1615 genLast();
1616 }
1617 void genLast() {
1618 if (tree.finalizer != null)
1619 genStat(tree.finalizer, oldEnv, CRT_BLOCK);
1620 }
1621 boolean hasFinalizer() {
1622 return tree.finalizer != null;
1623 }
1624
1625 @Override
1626 void afterBody() {
1627 if (tree.finalizer != null && (tree.finalizer.flags & BODY_ONLY_FINALIZE) != 0) {
1628 //for body-only finally, remove the GenFinalizer after try body
1629 //so that the finally is not generated to catch bodies:
1630 tryEnv.info.finalize = null;
1631 }
1632 }
1633
1634 };
1635 tryEnv.info.gaps = new ListBuffer<>();
1636 genTry(tree.body, tree.catchers, tryEnv);
1637 }
1638 //where
1639 /** Generate code for a try or synchronized statement
1640 * @param body The body of the try or synchronized statement.
1641 * @param catchers The list of catch clauses.
1642 * @param env The current environment of the body.
1643 */
1644 void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) {
1645 Set<VarSymbol> prevCodeUnsetFields = code.currentUnsetFields;
1646 try {
1647 genTryHelper(body, catchers, env);
1648 } finally {
1649 code.currentUnsetFields = prevCodeUnsetFields;
1650 }
1651 }
1652
1653 void genTryHelper(JCTree body, List<JCCatch> catchers, Env<GenContext> env) {
1654 int limit = code.nextreg;
1655 int startpc = code.curCP();
1656 Code.State stateTry = code.state.dup();
1657 genStat(body, env, CRT_BLOCK);
1658 int endpc = code.curCP();
1659 List<Integer> gaps = env.info.gaps.toList();
1660 code.statBegin(TreeInfo.endPos(body));
1661 genFinalizer(env);
1662 code.statBegin(TreeInfo.endPos(env.tree));
1663 Chain exitChain;
1664 boolean actualTry = env.tree.hasTag(TRY);
1665 if (startpc == endpc && actualTry) {
1666 exitChain = code.branch(dontgoto);
1667 } else {
1668 exitChain = code.branch(goto_);
1669 }
1670 endFinalizerGap(env);
1671 env.info.finalize.afterBody();
1672 boolean hasFinalizer =
1673 env.info.finalize != null &&
1674 env.info.finalize.hasFinalizer();
1675 if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) {
1676 // start off with exception on stack
1677 code.entryPoint(stateTry, l.head.param.sym.type);
1678 genCatch(l.head, env, startpc, endpc, gaps);
1679 genFinalizer(env);
1680 if (hasFinalizer || l.tail.nonEmpty()) {
1681 code.statBegin(TreeInfo.endPos(env.tree));
1682 exitChain = Code.mergeChains(exitChain,
1683 code.branch(goto_));
1684 }
1685 endFinalizerGap(env);
1686 }
1687 if (hasFinalizer && (startpc != endpc || !actualTry)) {
1688 // Create a new register segment to avoid allocating
1689 // the same variables in finalizers and other statements.
1690 code.newRegSegment();
1691
1692 // Add a catch-all clause.
1693
1694 // start off with exception on stack
1695 int catchallpc = code.entryPoint(stateTry, syms.throwableType);
1696
1697 // Register all exception ranges for catch all clause.
1698 // The range of the catch all clause is from the beginning
1699 // of the try or synchronized block until the present
1700 // code pointer excluding all gaps in the current
1701 // environment's GenContext.
1702 int startseg = startpc;
1703 while (env.info.gaps.nonEmpty()) {
1704 int endseg = env.info.gaps.next().intValue();
1705 registerCatch(body.pos(), startseg, endseg,
1706 catchallpc, 0);
1707 startseg = env.info.gaps.next().intValue();
1708 }
1709 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1710 code.markStatBegin();
1711
1712 Item excVar = makeTemp(syms.throwableType);
1713 excVar.store();
1714 genFinalizer(env);
1715 code.resolvePending();
1716 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.END_POS));
1717 code.markStatBegin();
1718
1719 excVar.load();
1720 registerCatch(body.pos(), startseg,
1721 env.info.gaps.next().intValue(),
1722 catchallpc, 0);
1723 code.emitop0(athrow);
1724 code.markDead();
1725
1726 // If there are jsr's to this finalizer, ...
1727 if (env.info.cont != null) {
1728 // Resolve all jsr's.
1729 code.resolve(env.info.cont);
1730
1731 // Mark statement line number
1732 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1733 code.markStatBegin();
1734
1735 // Save return address.
1736 LocalItem retVar = makeTemp(syms.throwableType);
1737 retVar.store();
1738
1739 // Generate finalizer code.
1740 env.info.finalize.genLast();
1741
1742 // Return.
1743 code.emitop1w(ret, retVar.reg);
1744 code.markDead();
1745 }
1746 }
1747 // Resolve all breaks.
1748 code.resolve(exitChain);
1749
1750 code.endScopes(limit);
1751 }
1752
1753 /** Generate code for a catch clause.
1754 * @param tree The catch clause.
1755 * @param env The environment current in the enclosing try.
1756 * @param startpc Start pc of try-block.
1757 * @param endpc End pc of try-block.
1758 */
1759 void genCatch(JCCatch tree,
1760 Env<GenContext> env,
1761 int startpc, int endpc,
1762 List<Integer> gaps) {
1763 if (startpc != endpc) {
1764 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypeExprs
1765 = catchTypesWithAnnotations(tree);
1766 while (gaps.nonEmpty()) {
1767 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) {
1768 JCExpression subCatch = subCatch1.snd;
1769 int catchType = makeRef(tree.pos(), subCatch.type);
1770 int end = gaps.head.intValue();
1771 registerCatch(tree.pos(),
1772 startpc, end, code.curCP(),
1773 catchType);
1774 for (Attribute.TypeCompound tc : subCatch1.fst) {
1775 tc.position.setCatchInfo(catchType, startpc);
1776 }
1777 }
1778 gaps = gaps.tail;
1779 startpc = gaps.head.intValue();
1780 gaps = gaps.tail;
1781 }
1782 if (startpc < endpc) {
1783 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) {
1784 JCExpression subCatch = subCatch1.snd;
1785 int catchType = makeRef(tree.pos(), subCatch.type);
1786 registerCatch(tree.pos(),
1787 startpc, endpc, code.curCP(),
1788 catchType);
1789 for (Attribute.TypeCompound tc : subCatch1.fst) {
1790 tc.position.setCatchInfo(catchType, startpc);
1791 }
1792 }
1793 }
1794 genCatchBlock(tree, env);
1795 }
1796 }
1797 void genPatternMatchingCatch(JCCatch tree,
1798 Env<GenContext> env,
1799 List<int[]> ranges) {
1800 for (int[] range : ranges) {
1801 JCExpression subCatch = tree.param.vartype;
1802 int catchType = makeRef(tree.pos(), subCatch.type);
1803 registerCatch(tree.pos(),
1804 range[0], range[1], code.curCP(),
1805 catchType);
1806 }
1807 genCatchBlock(tree, env);
1808 }
1809 void genCatchBlock(JCCatch tree, Env<GenContext> env) {
1810 VarSymbol exparam = tree.param.sym;
1811 code.statBegin(tree.pos);
1812 code.markStatBegin();
1813 int limit = code.nextreg;
1814 code.newLocal(exparam);
1815 items.makeLocalItem(exparam).store();
1816 code.statBegin(TreeInfo.firstStatPos(tree.body));
1817 genStat(tree.body, env, CRT_BLOCK);
1818 code.endScopes(limit);
1819 code.statBegin(TreeInfo.endPos(tree.body));
1820 }
1821 // where
1822 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotations(JCCatch tree) {
1823 return TreeInfo.isMultiCatch(tree) ?
1824 catchTypesWithAnnotationsFromMulticatch((JCTypeUnion)tree.param.vartype, tree.param.sym.getRawTypeAttributes()) :
1825 List.of(new Pair<>(tree.param.sym.getRawTypeAttributes(), tree.param.vartype));
1826 }
1827 // where
1828 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotationsFromMulticatch(JCTypeUnion tree, List<TypeCompound> first) {
1829 List<JCExpression> alts = tree.alternatives;
1830 List<Pair<List<TypeCompound>, JCExpression>> res = List.of(new Pair<>(first, alts.head));
1831 alts = alts.tail;
1832
1833 while(alts != null && alts.head != null) {
1834 JCExpression alt = alts.head;
1835 if (alt instanceof JCAnnotatedType annotatedType) {
1836 res = res.prepend(new Pair<>(annotate.fromAnnotations(annotatedType.annotations), alt));
1837 } else {
1838 res = res.prepend(new Pair<>(List.nil(), alt));
1839 }
1840 alts = alts.tail;
1841 }
1842 return res.reverse();
1843 }
1844
1845 /** Register a catch clause in the "Exceptions" code-attribute.
1846 */
1847 void registerCatch(DiagnosticPosition pos,
1848 int startpc, int endpc,
1849 int handler_pc, int catch_type) {
1850 char startpc1 = (char)startpc;
1851 char endpc1 = (char)endpc;
1852 char handler_pc1 = (char)handler_pc;
1853 if (startpc1 == startpc &&
1854 endpc1 == endpc &&
1855 handler_pc1 == handler_pc) {
1856 code.addCatch(startpc1, endpc1, handler_pc1,
1857 (char)catch_type);
1858 } else {
1859 log.error(pos, Errors.LimitCodeTooLargeForTryStmt);
1860 nerrs++;
1861 }
1862 }
1863
1864 public void visitIf(JCIf tree) {
1865 Set<VarSymbol> prevCodeUnsetFields = code.currentUnsetFields;
1866 try {
1867 visitIfHelper(tree);
1868 } finally {
1869 code.currentUnsetFields = prevCodeUnsetFields;
1870 }
1871 }
1872
1873 public void visitIfHelper(JCIf tree) {
1874 int limit = code.nextreg;
1875 Chain thenExit = null;
1876 Assert.check(code.isStatementStart());
1877 CondItem c = genCond(TreeInfo.skipParens(tree.cond),
1878 CRT_FLOW_CONTROLLER);
1879 Chain elseChain = c.jumpFalse();
1880 Assert.check(code.isStatementStart());
1881 if (!c.isFalse()) {
1882 code.resolve(c.trueJumps);
1883 genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET);
1884 thenExit = code.branch(goto_);
1885 }
1886 if (elseChain != null) {
1887 code.resolve(elseChain);
1888 if (tree.elsepart != null) {
1889 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET);
1890 }
1891 }
1892 code.resolve(thenExit);
1893 code.endScopes(limit);
1894 Assert.check(code.isStatementStart());
1895 }
1896
1897 public void visitExec(JCExpressionStatement tree) {
1898 // Optimize x++ to ++x and x-- to --x.
1899 JCExpression e = tree.expr;
1900 switch (e.getTag()) {
1901 case POSTINC:
1902 ((JCUnary) e).setTag(PREINC);
1903 break;
1904 case POSTDEC:
1905 ((JCUnary) e).setTag(PREDEC);
1906 break;
1907 }
1908 Assert.check(code.isStatementStart());
1909 genExpr(tree.expr, tree.expr.type).drop();
1910 Assert.check(code.isStatementStart());
1911 }
1912
1913 public void visitBreak(JCBreak tree) {
1914 Assert.check(code.isStatementStart());
1915 final Env<GenContext> targetEnv = unwindBreak(tree.target);
1916 targetEnv.info.addExit(code.branch(goto_));
1917 endFinalizerGaps(env, targetEnv);
1918 }
1919
1920 public void visitYield(JCYield tree) {
1921 Assert.check(code.isStatementStart());
1922 final Env<GenContext> targetEnv;
1923 if (inCondSwitchExpression) {
1924 CondItem value = genCond(tree.value, CRT_FLOW_TARGET);
1925 Chain falseJumps = value.jumpFalse();
1926
1927 code.resolve(value.trueJumps);
1928 Env<GenContext> localEnv = unwindBreak(tree.target);
1929 reloadStackBeforeSwitchExpr();
1930 Chain trueJumps = code.branch(goto_);
1931
1932 endFinalizerGaps(env, localEnv);
1933
1934 code.resolve(falseJumps);
1935 targetEnv = unwindBreak(tree.target);
1936 reloadStackBeforeSwitchExpr();
1937 falseJumps = code.branch(goto_);
1938
1939 if (switchExpressionTrueChain == null) {
1940 switchExpressionTrueChain = trueJumps;
1941 } else {
1942 switchExpressionTrueChain =
1943 Code.mergeChains(switchExpressionTrueChain, trueJumps);
1944 }
1945 if (switchExpressionFalseChain == null) {
1946 switchExpressionFalseChain = falseJumps;
1947 } else {
1948 switchExpressionFalseChain =
1949 Code.mergeChains(switchExpressionFalseChain, falseJumps);
1950 }
1951 } else {
1952 genExpr(tree.value, pt).load();
1953 if (switchResult != null)
1954 switchResult.store();
1955
1956 targetEnv = unwindBreak(tree.target);
1957
1958 if (code.isAlive()) {
1959 reloadStackBeforeSwitchExpr();
1960 if (switchResult != null)
1961 switchResult.load();
1962
1963 targetEnv.info.addExit(code.branch(goto_));
1964 code.markDead();
1965 }
1966 }
1967 endFinalizerGaps(env, targetEnv);
1968 }
1969 //where:
1970 /** As side-effect, might mark code as dead disabling any further emission.
1971 */
1972 private Env<GenContext> unwindBreak(JCTree target) {
1973 int tmpPos = code.pendingStatPos;
1974 Env<GenContext> targetEnv = unwind(target, env);
1975 code.pendingStatPos = tmpPos;
1976 return targetEnv;
1977 }
1978
1979 private void reloadStackBeforeSwitchExpr() {
1980 for (LocalItem li : stackBeforeSwitchExpression)
1981 li.load();
1982 }
1983
1984 public void visitContinue(JCContinue tree) {
1985 int tmpPos = code.pendingStatPos;
1986 Env<GenContext> targetEnv = unwind(tree.target, env);
1987 code.pendingStatPos = tmpPos;
1988 Assert.check(code.isStatementStart());
1989 targetEnv.info.addCont(code.branch(goto_));
1990 endFinalizerGaps(env, targetEnv);
1991 }
1992
1993 public void visitReturn(JCReturn tree) {
1994 int limit = code.nextreg;
1995 final Env<GenContext> targetEnv;
1996
1997 /* Save and then restore the location of the return in case a finally
1998 * is expanded (with unwind()) in the middle of our bytecodes.
1999 */
2000 int tmpPos = code.pendingStatPos;
2001 if (tree.expr != null) {
2002 Assert.check(code.isStatementStart());
2003 Item r = genExpr(tree.expr, pt).load();
2004 if (hasFinally(env.enclMethod, env)) {
2005 r = makeTemp(pt);
2006 r.store();
2007 }
2008 targetEnv = unwind(env.enclMethod, env);
2009 code.pendingStatPos = tmpPos;
2010 r.load();
2011 code.emitop0(ireturn + Code.truncate(Code.typecode(pt)));
2012 } else {
2013 targetEnv = unwind(env.enclMethod, env);
2014 code.pendingStatPos = tmpPos;
2015 code.emitop0(return_);
2016 }
2017 endFinalizerGaps(env, targetEnv);
2018 code.endScopes(limit);
2019 }
2020
2021 public void visitThrow(JCThrow tree) {
2022 Assert.check(code.isStatementStart());
2023 genExpr(tree.expr, tree.expr.type).load();
2024 code.emitop0(athrow);
2025 Assert.check(code.isStatementStart());
2026 }
2027
2028 /* ************************************************************************
2029 * Visitor methods for expressions
2030 *************************************************************************/
2031
2032 public void visitApply(JCMethodInvocation tree) {
2033 setTypeAnnotationPositions(tree.pos);
2034 // Generate code for method.
2035 Item m = genExpr(tree.meth, methodType);
2036 // Generate code for all arguments, where the expected types are
2037 // the parameters of the method's external type (that is, any implicit
2038 // outer instance of a super(...) call appears as first parameter).
2039 MethodSymbol msym = (MethodSymbol)TreeInfo.symbol(tree.meth);
2040 genArgs(tree.args,
2041 msym.externalType(types).getParameterTypes());
2042 if (!msym.isDynamic()) {
2043 code.statBegin(tree.pos);
2044 }
2045 if (patternMatchingCatchConfiguration.invocations().contains(tree)) {
2046 int start = code.curCP();
2047 result = m.invoke();
2048 patternMatchingCatchConfiguration.ranges().add(new int[] {start, code.curCP()});
2049 } else {
2050 if (msym.isConstructor() && TreeInfo.isConstructorCall(tree)) {
2051 //if this is a this(...) or super(...) call, there is a pending
2052 //"uninitialized this" before this call. One catch handler cannot
2053 //handle exceptions that may come from places with "uninitialized this"
2054 //and (initialized) this, hence generate one set of handlers here
2055 //for the "uninitialized this" case, and another set of handlers
2056 //will be generated at the end of the method for the initialized this,
2057 //if needed:
2058 generatePatternMatchingCatch(env);
2059 result = m.invoke();
2060 patternMatchingCatchConfiguration =
2061 patternMatchingCatchConfiguration.restart(code.state.dup());
2062 } else {
2063 result = m.invoke();
2064 }
2065 }
2066 }
2067
2068 public void visitConditional(JCConditional tree) {
2069 Chain thenExit = null;
2070 code.statBegin(tree.cond.pos);
2071 CondItem c = genCond(tree.cond, CRT_FLOW_CONTROLLER);
2072 Chain elseChain = c.jumpFalse();
2073 if (!c.isFalse()) {
2074 code.resolve(c.trueJumps);
2075 int startpc = genCrt ? code.curCP() : 0;
2076 code.statBegin(tree.truepart.pos);
2077 genExpr(tree.truepart, pt).load();
2078 if (genCrt) code.crt.put(tree.truepart, CRT_FLOW_TARGET,
2079 startpc, code.curCP());
2080 thenExit = code.branch(goto_);
2081 }
2082 if (elseChain != null) {
2083 code.resolve(elseChain);
2084 int startpc = genCrt ? code.curCP() : 0;
2085 code.statBegin(tree.falsepart.pos);
2086 genExpr(tree.falsepart, pt).load();
2087 if (genCrt) code.crt.put(tree.falsepart, CRT_FLOW_TARGET,
2088 startpc, code.curCP());
2089 }
2090 code.resolve(thenExit);
2091 result = items.makeStackItem(pt);
2092 }
2093
2094 private void setTypeAnnotationPositions(int treePos) {
2095 MethodSymbol meth = code.meth;
2096 boolean initOrClinit = code.meth.getKind() == javax.lang.model.element.ElementKind.CONSTRUCTOR
2097 || code.meth.getKind() == javax.lang.model.element.ElementKind.STATIC_INIT;
2098
2099 for (Attribute.TypeCompound ta : meth.getRawTypeAttributes()) {
2100 if (ta.hasUnknownPosition())
2101 ta.tryFixPosition();
2102
2103 if (ta.position.matchesPos(treePos))
2104 ta.position.updatePosOffset(code.cp);
2105 }
2106
2107 if (!initOrClinit)
2108 return;
2109
2110 for (Attribute.TypeCompound ta : meth.owner.getRawTypeAttributes()) {
2111 if (ta.hasUnknownPosition())
2112 ta.tryFixPosition();
2113
2114 if (ta.position.matchesPos(treePos))
2115 ta.position.updatePosOffset(code.cp);
2116 }
2117
2118 ClassSymbol clazz = meth.enclClass();
2119 for (Symbol s : new com.sun.tools.javac.model.FilteredMemberList(clazz.members())) {
2120 if (!s.getKind().isField())
2121 continue;
2122
2123 for (Attribute.TypeCompound ta : s.getRawTypeAttributes()) {
2124 if (ta.hasUnknownPosition())
2125 ta.tryFixPosition();
2126
2127 if (ta.position.matchesPos(treePos))
2128 ta.position.updatePosOffset(code.cp);
2129 }
2130 }
2131 }
2132
2133 public void visitNewClass(JCNewClass tree) {
2134 // Enclosing instances or anonymous classes should have been eliminated
2135 // by now.
2136 Assert.check(tree.encl == null && tree.def == null);
2137 setTypeAnnotationPositions(tree.pos);
2138
2139 code.emitop2(new_, checkDimension(tree.pos(), tree.type), PoolWriter::putClass);
2140 code.emitop0(dup);
2141
2142 // Generate code for all arguments, where the expected types are
2143 // the parameters of the constructor's external type (that is,
2144 // any implicit outer instance appears as first parameter).
2145 genArgs(tree.args, tree.constructor.externalType(types).getParameterTypes());
2146
2147 items.makeMemberItem(tree.constructor, true).invoke();
2148 result = items.makeStackItem(tree.type);
2149 }
2150
2151 public void visitNewArray(JCNewArray tree) {
2152 setTypeAnnotationPositions(tree.pos);
2153
2154 if (tree.elems != null) {
2155 Type elemtype = types.elemtype(tree.type);
2156 loadIntConst(tree.elems.length());
2157 Item arr = makeNewArray(tree.pos(), tree.type, 1);
2158 int i = 0;
2159 for (List<JCExpression> l = tree.elems; l.nonEmpty(); l = l.tail) {
2160 arr.duplicate();
2161 loadIntConst(i);
2162 i++;
2163 genExpr(l.head, elemtype).load();
2164 items.makeIndexedItem(elemtype).store();
2165 }
2166 result = arr;
2167 } else {
2168 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
2169 genExpr(l.head, syms.intType).load();
2170 }
2171 result = makeNewArray(tree.pos(), tree.type, tree.dims.length());
2172 }
2173 }
2174 //where
2175 /** Generate code to create an array with given element type and number
2176 * of dimensions.
2177 */
2178 Item makeNewArray(DiagnosticPosition pos, Type type, int ndims) {
2179 Type elemtype = types.elemtype(type);
2180 if (types.dimensions(type) > ClassFile.MAX_DIMENSIONS) {
2181 log.error(pos, Errors.LimitDimensions);
2182 nerrs++;
2183 }
2184 int elemcode = Code.arraycode(elemtype);
2185 if (elemcode == 0 || (elemcode == 1 && ndims == 1)) {
2186 code.emitAnewarray(makeRef(pos, elemtype), type);
2187 } else if (elemcode == 1) {
2188 code.emitMultianewarray(ndims, makeRef(pos, type), type);
2189 } else {
2190 code.emitNewarray(elemcode, type);
2191 }
2192 return items.makeStackItem(type);
2193 }
2194
2195 public void visitParens(JCParens tree) {
2196 result = genExpr(tree.expr, tree.expr.type);
2197 }
2198
2199 public void visitAssign(JCAssign tree) {
2200 Item l = genExpr(tree.lhs, tree.lhs.type);
2201 genExpr(tree.rhs, tree.lhs.type).load();
2202 Set<VarSymbol> tmpUnsetSymbols = unsetFieldsInfo.getUnsetFields(env.enclClass.sym, tree);
2203 code.currentUnsetFields = tmpUnsetSymbols != null ? tmpUnsetSymbols : code.currentUnsetFields;
2204 if (tree.rhs.type.hasTag(BOT)) {
2205 /* This is just a case of widening reference conversion that per 5.1.5 simply calls
2206 for "regarding a reference as having some other type in a manner that can be proved
2207 correct at compile time."
2208 */
2209 code.state.forceStackTop(tree.lhs.type);
2210 }
2211 result = items.makeAssignItem(l);
2212 }
2213
2214 public void visitAssignop(JCAssignOp tree) {
2215 OperatorSymbol operator = tree.operator;
2216 Item l;
2217 if (operator.opcode == string_add) {
2218 l = concat.makeConcat(tree);
2219 } else {
2220 // Generate code for first expression
2221 l = genExpr(tree.lhs, tree.lhs.type);
2222
2223 // If we have an increment of -32768 to +32767 of a local
2224 // int variable we can use an incr instruction instead of
2225 // proceeding further.
2226 if ((tree.hasTag(PLUS_ASG) || tree.hasTag(MINUS_ASG)) &&
2227 l instanceof LocalItem localItem &&
2228 tree.lhs.type.getTag().isSubRangeOf(INT) &&
2229 tree.rhs.type.getTag().isSubRangeOf(INT) &&
2230 tree.rhs.type.constValue() != null) {
2231 int ival = ((Number) tree.rhs.type.constValue()).intValue();
2232 if (tree.hasTag(MINUS_ASG)) ival = -ival;
2233 localItem.incr(ival);
2234 result = l;
2235 return;
2236 }
2237 // Otherwise, duplicate expression, load one copy
2238 // and complete binary operation.
2239 l.duplicate();
2240 l.coerce(operator.type.getParameterTypes().head).load();
2241 completeBinop(tree.lhs, tree.rhs, operator).coerce(tree.lhs.type);
2242 }
2243 result = items.makeAssignItem(l);
2244 }
2245
2246 public void visitUnary(JCUnary tree) {
2247 OperatorSymbol operator = tree.operator;
2248 if (tree.hasTag(NOT)) {
2249 CondItem od = genCond(tree.arg, false);
2250 result = od.negate();
2251 } else {
2252 Item od = genExpr(tree.arg, operator.type.getParameterTypes().head);
2253 switch (tree.getTag()) {
2254 case POS:
2255 result = od.load();
2256 break;
2257 case NEG:
2258 result = od.load();
2259 code.emitop0(operator.opcode);
2260 break;
2261 case COMPL:
2262 result = od.load();
2263 emitMinusOne(od.typecode);
2264 code.emitop0(operator.opcode);
2265 break;
2266 case PREINC: case PREDEC:
2267 od.duplicate();
2268 if (od instanceof LocalItem localItem &&
2269 (operator.opcode == iadd || operator.opcode == isub)) {
2270 localItem.incr(tree.hasTag(PREINC) ? 1 : -1);
2271 result = od;
2272 } else {
2273 od.load();
2274 code.emitop0(one(od.typecode));
2275 code.emitop0(operator.opcode);
2276 // Perform narrowing primitive conversion if byte,
2277 // char, or short. Fix for 4304655.
2278 if (od.typecode != INTcode &&
2279 Code.truncate(od.typecode) == INTcode)
2280 code.emitop0(int2byte + od.typecode - BYTEcode);
2281 result = items.makeAssignItem(od);
2282 }
2283 break;
2284 case POSTINC: case POSTDEC:
2285 od.duplicate();
2286 if (od instanceof LocalItem localItem &&
2287 (operator.opcode == iadd || operator.opcode == isub)) {
2288 Item res = od.load();
2289 localItem.incr(tree.hasTag(POSTINC) ? 1 : -1);
2290 result = res;
2291 } else {
2292 Item res = od.load();
2293 od.stash(od.typecode);
2294 code.emitop0(one(od.typecode));
2295 code.emitop0(operator.opcode);
2296 // Perform narrowing primitive conversion if byte,
2297 // char, or short. Fix for 4304655.
2298 if (od.typecode != INTcode &&
2299 Code.truncate(od.typecode) == INTcode)
2300 code.emitop0(int2byte + od.typecode - BYTEcode);
2301 od.store();
2302 result = res;
2303 }
2304 break;
2305 case NULLCHK:
2306 result = od.load();
2307 code.emitop0(dup);
2308 genNullCheck(tree);
2309 break;
2310 default:
2311 Assert.error();
2312 }
2313 }
2314 }
2315
2316 /** Generate a null check from the object value at stack top. */
2317 private void genNullCheck(JCTree tree) {
2318 code.statBegin(tree.pos);
2319 callMethod(tree.pos(), syms.objectsType, names.requireNonNull,
2320 List.of(syms.objectType), true);
2321 code.emitop0(pop);
2322 }
2323
2324 public void visitBinary(JCBinary tree) {
2325 OperatorSymbol operator = tree.operator;
2326 if (operator.opcode == string_add) {
2327 result = concat.makeConcat(tree);
2328 } else if (tree.hasTag(AND)) {
2329 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2330 if (!lcond.isFalse()) {
2331 Chain falseJumps = lcond.jumpFalse();
2332 code.resolve(lcond.trueJumps);
2333 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2334 result = items.
2335 makeCondItem(rcond.opcode,
2336 rcond.trueJumps,
2337 Code.mergeChains(falseJumps,
2338 rcond.falseJumps));
2339 } else {
2340 result = lcond;
2341 }
2342 } else if (tree.hasTag(OR)) {
2343 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2344 if (!lcond.isTrue()) {
2345 Chain trueJumps = lcond.jumpTrue();
2346 code.resolve(lcond.falseJumps);
2347 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2348 result = items.
2349 makeCondItem(rcond.opcode,
2350 Code.mergeChains(trueJumps, rcond.trueJumps),
2351 rcond.falseJumps);
2352 } else {
2353 result = lcond;
2354 }
2355 } else {
2356 Item od = genExpr(tree.lhs, operator.type.getParameterTypes().head);
2357 od.load();
2358 result = completeBinop(tree.lhs, tree.rhs, operator);
2359 }
2360 }
2361
2362
2363 /** Complete generating code for operation, with left operand
2364 * already on stack.
2365 * @param lhs The tree representing the left operand.
2366 * @param rhs The tree representing the right operand.
2367 * @param operator The operator symbol.
2368 */
2369 Item completeBinop(JCTree lhs, JCTree rhs, OperatorSymbol operator) {
2370 MethodType optype = (MethodType)operator.type;
2371 int opcode = operator.opcode;
2372 if (opcode >= if_icmpeq && opcode <= if_icmple &&
2373 rhs.type.constValue() instanceof Number number &&
2374 number.intValue() == 0) {
2375 opcode = opcode + (ifeq - if_icmpeq);
2376 } else if (opcode >= if_acmpeq && opcode <= if_acmpne &&
2377 TreeInfo.isNull(rhs)) {
2378 opcode = opcode + (if_acmp_null - if_acmpeq);
2379 } else {
2380 // The expected type of the right operand is
2381 // the second parameter type of the operator, except for
2382 // shifts with long shiftcount, where we convert the opcode
2383 // to a short shift and the expected type to int.
2384 Type rtype = operator.erasure(types).getParameterTypes().tail.head;
2385 if (opcode >= ishll && opcode <= lushrl) {
2386 opcode = opcode + (ishl - ishll);
2387 rtype = syms.intType;
2388 }
2389 // Generate code for right operand and load.
2390 genExpr(rhs, rtype).load();
2391 // If there are two consecutive opcode instructions,
2392 // emit the first now.
2393 if (opcode >= (1 << preShift)) {
2394 code.emitop0(opcode >> preShift);
2395 opcode = opcode & 0xFF;
2396 }
2397 }
2398 if (opcode >= ifeq && opcode <= if_acmpne ||
2399 opcode == if_acmp_null || opcode == if_acmp_nonnull) {
2400 return items.makeCondItem(opcode);
2401 } else {
2402 code.emitop0(opcode);
2403 return items.makeStackItem(optype.restype);
2404 }
2405 }
2406
2407 public void visitTypeCast(JCTypeCast tree) {
2408 result = genExpr(tree.expr, tree.clazz.type).load();
2409 setTypeAnnotationPositions(tree.pos);
2410 // Additional code is only needed if we cast to a reference type
2411 // which is not statically a supertype of the expression's type.
2412 // For basic types, the coerce(...) in genExpr(...) will do
2413 // the conversion.
2414 if (!tree.clazz.type.isPrimitive() &&
2415 !types.isSameType(tree.expr.type, tree.clazz.type) &&
2416 types.asSuper(tree.expr.type, tree.clazz.type.tsym) == null) {
2417 code.emitop2(checkcast, checkDimension(tree.pos(), tree.clazz.type), PoolWriter::putClass);
2418 }
2419 }
2420
2421 public void visitWildcard(JCWildcard tree) {
2422 throw new AssertionError(this.getClass().getName());
2423 }
2424
2425 public void visitTypeTest(JCInstanceOf tree) {
2426 genExpr(tree.expr, tree.expr.type).load();
2427 setTypeAnnotationPositions(tree.pos);
2428 code.emitop2(instanceof_, makeRef(tree.pos(), tree.pattern.type));
2429 result = items.makeStackItem(syms.booleanType);
2430 }
2431
2432 public void visitIndexed(JCArrayAccess tree) {
2433 genExpr(tree.indexed, tree.indexed.type).load();
2434 genExpr(tree.index, syms.intType).load();
2435 result = items.makeIndexedItem(tree.type);
2436 }
2437
2438 public void visitIdent(JCIdent tree) {
2439 Symbol sym = tree.sym;
2440 if (tree.name == names._this || tree.name == names._super) {
2441 Item res = tree.name == names._this
2442 ? items.makeThisItem()
2443 : items.makeSuperItem();
2444 if (sym.kind == MTH) {
2445 // Generate code to address the constructor.
2446 res.load();
2447 res = items.makeMemberItem(sym, true);
2448 }
2449 result = res;
2450 } else if (isInvokeDynamic(sym) || isConstantDynamic(sym)) {
2451 if (isConstantDynamic(sym)) {
2452 setTypeAnnotationPositions(tree.pos);
2453 }
2454 result = items.makeDynamicItem(sym);
2455 } else if (sym.kind == VAR && (sym.owner.kind == MTH || sym.owner.kind == VAR)) {
2456 result = items.makeLocalItem((VarSymbol)sym);
2457 } else if ((sym.flags() & STATIC) != 0) {
2458 if (!isAccessSuper(env.enclMethod))
2459 sym = binaryQualifier(sym, env.enclClass.type);
2460 result = items.makeStaticItem(sym);
2461 } else {
2462 items.makeThisItem().load();
2463 sym = binaryQualifier(sym, env.enclClass.type);
2464 result = items.makeMemberItem(sym, nonVirtualForPrivateAccess(sym));
2465 }
2466 }
2467
2468 //where
2469 private boolean nonVirtualForPrivateAccess(Symbol sym) {
2470 boolean useVirtual = target.hasVirtualPrivateInvoke() &&
2471 !disableVirtualizedPrivateInvoke;
2472 return !useVirtual && ((sym.flags() & PRIVATE) != 0);
2473 }
2474
2475 public void visitSelect(JCFieldAccess tree) {
2476 Symbol sym = tree.sym;
2477
2478 if (tree.name == names._class) {
2479 code.emitLdc((LoadableConstant)checkDimension(tree.pos(), tree.selected.type));
2480 result = items.makeStackItem(pt);
2481 return;
2482 }
2483
2484 Symbol ssym = TreeInfo.symbol(tree.selected);
2485
2486 // Are we selecting via super?
2487 boolean selectSuper =
2488 ssym != null && (ssym.kind == TYP || ssym.name == names._super);
2489
2490 // Are we accessing a member of the superclass in an access method
2491 // resulting from a qualified super?
2492 boolean accessSuper = isAccessSuper(env.enclMethod);
2493
2494 Item base = (selectSuper)
2495 ? items.makeSuperItem()
2496 : genExpr(tree.selected, tree.selected.type);
2497
2498 if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) {
2499 // We are seeing a variable that is constant but its selecting
2500 // expression is not.
2501 if ((sym.flags() & STATIC) != 0) {
2502 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2503 base = base.load();
2504 base.drop();
2505 } else {
2506 base.load();
2507 genNullCheck(tree.selected);
2508 }
2509 result = items.
2510 makeImmediateItem(sym.type, ((VarSymbol) sym).getConstValue());
2511 } else {
2512 if (isInvokeDynamic(sym)) {
2513 result = items.makeDynamicItem(sym);
2514 return;
2515 } else {
2516 sym = binaryQualifier(sym, tree.selected.type);
2517 }
2518 if ((sym.flags() & STATIC) != 0) {
2519 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2520 base = base.load();
2521 base.drop();
2522 result = items.makeStaticItem(sym);
2523 } else {
2524 base.load();
2525 if (sym == syms.lengthVar) {
2526 code.emitop0(arraylength);
2527 result = items.makeStackItem(syms.intType);
2528 } else {
2529 result = items.
2530 makeMemberItem(sym,
2531 nonVirtualForPrivateAccess(sym) ||
2532 selectSuper || accessSuper);
2533 }
2534 }
2535 }
2536 }
2537
2538 public boolean isInvokeDynamic(Symbol sym) {
2539 return sym.kind == MTH && ((MethodSymbol)sym).isDynamic();
2540 }
2541
2542 public void visitLiteral(JCLiteral tree) {
2543 if (tree.type.hasTag(BOT)) {
2544 code.emitop0(aconst_null);
2545 result = items.makeStackItem(tree.type);
2546 }
2547 else
2548 result = items.makeImmediateItem(tree.type, tree.value);
2549 }
2550
2551 public void visitLetExpr(LetExpr tree) {
2552 code.resolvePending();
2553
2554 int limit = code.nextreg;
2555 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
2556 try {
2557 genStats(tree.defs, env);
2558 } finally {
2559 code.setLetExprStackPos(prevLetExprStart);
2560 }
2561 result = genExpr(tree.expr, tree.expr.type).load();
2562 code.endScopes(limit);
2563 }
2564
2565 private void generateReferencesToPrunedTree(ClassSymbol classSymbol) {
2566 List<JCTree> prunedInfo = lower.prunedTree.get(classSymbol);
2567 if (prunedInfo != null) {
2568 for (JCTree prunedTree: prunedInfo) {
2569 prunedTree.accept(classReferenceVisitor);
2570 }
2571 }
2572 }
2573
2574 /* ************************************************************************
2575 * main method
2576 *************************************************************************/
2577
2578 /** Generate code for a class definition.
2579 * @param env The attribution environment that belongs to the
2580 * outermost class containing this class definition.
2581 * We need this for resolving some additional symbols.
2582 * @param cdef The tree representing the class definition.
2583 * @return True if code is generated with no errors.
2584 */
2585 public boolean genClass(Env<AttrContext> env, JCClassDecl cdef) {
2586 try {
2587 attrEnv = env;
2588 ClassSymbol c = cdef.sym;
2589 this.toplevel = env.toplevel;
2590 this.endPosTable = toplevel.endPositions;
2591 /* method normalizeDefs() can add references to external classes into the constant pool
2592 */
2593 cdef.defs = normalizeDefs(cdef.defs, c);
2594 generateReferencesToPrunedTree(c);
2595 Env<GenContext> localEnv = new Env<>(cdef, new GenContext());
2596 localEnv.toplevel = env.toplevel;
2597 localEnv.enclClass = cdef;
2598
2599 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2600 genDef(l.head, localEnv);
2601 }
2602 if (poolWriter.size() > PoolWriter.MAX_ENTRIES) {
2603 log.error(cdef.pos(), Errors.LimitPool);
2604 nerrs++;
2605 }
2606 if (nerrs != 0) {
2607 // if errors, discard code
2608 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2609 if (l.head.hasTag(METHODDEF))
2610 ((JCMethodDecl) l.head).sym.code = null;
2611 }
2612 }
2613 cdef.defs = List.nil(); // discard trees
2614 return nerrs == 0;
2615 } finally {
2616 // note: this method does NOT support recursion.
2617 attrEnv = null;
2618 this.env = null;
2619 toplevel = null;
2620 endPosTable = null;
2621 nerrs = 0;
2622 qualifiedSymbolCache.clear();
2623 }
2624 }
2625
2626 /* ************************************************************************
2627 * Auxiliary classes
2628 *************************************************************************/
2629
2630 /** An abstract class for finalizer generation.
2631 */
2632 abstract class GenFinalizer {
2633 /** Generate code to clean up when unwinding. */
2634 abstract void gen();
2635
2636 /** Generate code to clean up at last. */
2637 abstract void genLast();
2638
2639 /** Does this finalizer have some nontrivial cleanup to perform? */
2640 boolean hasFinalizer() { return true; }
2641
2642 /** Should be invoked after the try's body has been visited. */
2643 void afterBody() {}
2644 }
2645
2646 /** code generation contexts,
2647 * to be used as type parameter for environments.
2648 */
2649 final class GenContext {
2650
2651 /**
2652 * The top defined local variables for exit or continue branches to merge into.
2653 * It may contain uninitialized variables to be initialized by branched code,
2654 * so we cannot use Code.State.defined bits.
2655 */
2656 final int limit;
2657
2658 /** A chain for all unresolved jumps that exit the current environment.
2659 */
2660 Chain exit = null;
2661
2662 /** A chain for all unresolved jumps that continue in the
2663 * current environment.
2664 */
2665 Chain cont = null;
2666
2667 /** A closure that generates the finalizer of the current environment.
2668 * Only set for Synchronized and Try contexts.
2669 */
2670 GenFinalizer finalize = null;
2671
2672 /** Is this a switch statement? If so, allocate registers
2673 * even when the variable declaration is unreachable.
2674 */
2675 boolean isSwitch = false;
2676
2677 /** A list buffer containing all gaps in the finalizer range,
2678 * where a catch all exception should not apply.
2679 */
2680 ListBuffer<Integer> gaps = null;
2681
2682 GenContext() {
2683 var code = Gen.this.code;
2684 this.limit = code == null ? 0 : code.nextreg;
2685 }
2686
2687 /** Add given chain to exit chain.
2688 */
2689 void addExit(Chain c) {
2690 if (c != null) {
2691 c.state.defined.excludeFrom(limit);
2692 }
2693 exit = Code.mergeChains(c, exit);
2694 }
2695
2696 /** Add given chain to cont chain.
2697 */
2698 void addCont(Chain c) {
2699 if (c != null) {
2700 c.state.defined.excludeFrom(limit);
2701 }
2702 cont = Code.mergeChains(c, cont);
2703 }
2704 }
2705
2706 record PatternMatchingCatchConfiguration(Set<JCMethodInvocation> invocations,
2707 ListBuffer<int[]> ranges,
2708 JCCatch handler,
2709 State startState) {
2710 public PatternMatchingCatchConfiguration restart(State newState) {
2711 return new PatternMatchingCatchConfiguration(invocations(),
2712 new ListBuffer<int[]>(),
2713 handler(),
2714 newState);
2715 }
2716 }
2717 }