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src/jdk.compiler/share/classes/com/sun/tools/javac/jvm/Gen.java

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  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     @SuppressWarnings("this-escape")
 101     protected Gen(Context context) {
 102         context.put(genKey, this);
 103 
 104         names = Names.instance(context);
 105         log = Log.instance(context);
 106         syms = Symtab.instance(context);
 107         chk = Check.instance(context);
 108         rs = Resolve.instance(context);
 109         make = TreeMaker.instance(context);
 110         target = Target.instance(context);
 111         types = Types.instance(context);
 112         concat = StringConcat.instance(context);
 113 
 114         methodType = new MethodType(null, null, null, syms.methodClass);
 115         accessDollar = "access" + target.syntheticNameChar();
 116         lower = Lower.instance(context);
 117 
 118         Options options = Options.instance(context);
 119         lineDebugInfo =
 120             options.isUnset(G_CUSTOM) ||
 121             options.isSet(G_CUSTOM, "lines");
 122         varDebugInfo =
 123             options.isUnset(G_CUSTOM)
 124             ? options.isSet(G)
 125             : options.isSet(G_CUSTOM, "vars");
 126         genCrt = options.isSet(XJCOV);
 127         debugCode = options.isSet("debug.code");
 128         disableVirtualizedPrivateInvoke = options.isSet("disableVirtualizedPrivateInvoke");
 129         poolWriter = new PoolWriter(types, names);

 130 
 131         // ignore cldc because we cannot have both stackmap formats
 132         this.stackMap = StackMapFormat.JSR202;
 133         annotate = Annotate.instance(context);
 134         qualifiedSymbolCache = new HashMap<>();





 135     }
 136 
 137     /** Switches
 138      */
 139     private final boolean lineDebugInfo;
 140     private final boolean varDebugInfo;
 141     private final boolean genCrt;
 142     private final boolean debugCode;
 143     private boolean disableVirtualizedPrivateInvoke;


 144 
 145     /** Code buffer, set by genMethod.
 146      */
 147     private Code code;
 148 
 149     /** Items structure, set by genMethod.
 150      */
 151     private Items items;
 152 
 153     /** Environment for symbol lookup, set by genClass
 154      */
 155     private Env<AttrContext> attrEnv;
 156 
 157     /** The top level tree.
 158      */
 159     private JCCompilationUnit toplevel;
 160 
 161     /** The number of code-gen errors in this class.
 162      */
 163     private int nerrs = 0;

 407     boolean hasFinally(JCTree target, Env<GenContext> env) {
 408         while (env.tree != target) {
 409             if (env.tree.hasTag(TRY) && env.info.finalize.hasFinalizer())
 410                 return true;
 411             env = env.next;
 412         }
 413         return false;
 414     }
 415 
 416 /* ************************************************************************
 417  * Normalizing class-members.
 418  *************************************************************************/
 419 
 420     /** Distribute member initializer code into constructors and {@code <clinit>}
 421      *  method.
 422      *  @param defs         The list of class member declarations.
 423      *  @param c            The enclosing class.
 424      */
 425     List<JCTree> normalizeDefs(List<JCTree> defs, ClassSymbol c) {
 426         ListBuffer<JCStatement> initCode = new ListBuffer<>();


 427         ListBuffer<Attribute.TypeCompound> initTAs = new ListBuffer<>();
 428         ListBuffer<JCStatement> clinitCode = new ListBuffer<>();
 429         ListBuffer<Attribute.TypeCompound> clinitTAs = new ListBuffer<>();
 430         ListBuffer<JCTree> methodDefs = new ListBuffer<>();
 431         // Sort definitions into three listbuffers:
 432         //  - initCode for instance initializers
 433         //  - clinitCode for class initializers
 434         //  - methodDefs for method definitions
 435         for (List<JCTree> l = defs; l.nonEmpty(); l = l.tail) {
 436             JCTree def = l.head;
 437             switch (def.getTag()) {
 438             case BLOCK:
 439                 JCBlock block = (JCBlock)def;
 440                 if ((block.flags & STATIC) != 0)
 441                     clinitCode.append(block);
 442                 else if ((block.flags & SYNTHETIC) == 0)
 443                     initCode.append(block);





 444                 break;
 445             case METHODDEF:
 446                 methodDefs.append(def);
 447                 break;
 448             case VARDEF:
 449                 JCVariableDecl vdef = (JCVariableDecl) def;
 450                 VarSymbol sym = vdef.sym;
 451                 checkDimension(vdef.pos(), sym.type);
 452                 if (vdef.init != null) {
 453                     if ((sym.flags() & STATIC) == 0) {
 454                         // Always initialize instance variables.
 455                         JCStatement init = make.at(vdef.pos()).
 456                             Assignment(sym, vdef.init);
 457                         initCode.append(init);
 458                         endPosTable.replaceTree(vdef, init);
 459                         initTAs.addAll(getAndRemoveNonFieldTAs(sym));
 460                     } else if (sym.getConstValue() == null) {
 461                         // Initialize class (static) variables only if
 462                         // they are not compile-time constants.
 463                         JCStatement init = make.at(vdef.pos).
 464                             Assignment(sym, vdef.init);
 465                         clinitCode.append(init);
 466                         endPosTable.replaceTree(vdef, init);
 467                         clinitTAs.addAll(getAndRemoveNonFieldTAs(sym));
 468                     } else {
 469                         checkStringConstant(vdef.init.pos(), sym.getConstValue());
 470                         /* if the init contains a reference to an external class, add it to the
 471                          * constant's pool
 472                          */
 473                         vdef.init.accept(classReferenceVisitor);
 474                     }
 475                 }
 476                 break;
 477             default:
 478                 Assert.error();
 479             }
 480         }
 481         // Insert any instance initializers into all constructors.
 482         if (initCode.length() != 0) {
 483             List<JCStatement> inits = initCode.toList();
 484             initTAs.addAll(c.getInitTypeAttributes());
 485             List<Attribute.TypeCompound> initTAlist = initTAs.toList();
 486             for (JCTree t : methodDefs) {
 487                 normalizeMethod((JCMethodDecl)t, inits, initTAlist);
 488             }
 489         }
 490         // If there are class initializers, create a <clinit> method
 491         // that contains them as its body.
 492         if (clinitCode.length() != 0) {
 493             MethodSymbol clinit = new MethodSymbol(
 494                 STATIC | (c.flags() & STRICTFP),
 495                 names.clinit,
 496                 new MethodType(
 497                     List.nil(), syms.voidType,
 498                     List.nil(), syms.methodClass),
 499                 c);
 500             c.members().enter(clinit);
 501             List<JCStatement> clinitStats = clinitCode.toList();
 502             JCBlock block = make.at(clinitStats.head.pos()).Block(0, clinitStats);
 503             block.endpos = TreeInfo.endPos(clinitStats.last());
 504             methodDefs.append(make.MethodDef(clinit, block));
 505 
 506             if (!clinitTAs.isEmpty())
 507                 clinit.appendUniqueTypeAttributes(clinitTAs.toList());

 530 
 531     /** Check a constant value and report if it is a string that is
 532      *  too large.
 533      */
 534     private void checkStringConstant(DiagnosticPosition pos, Object constValue) {
 535         if (nerrs != 0 || // only complain about a long string once
 536             constValue == null ||
 537             !(constValue instanceof String str) ||
 538             str.length() < PoolWriter.MAX_STRING_LENGTH)
 539             return;
 540         log.error(pos, Errors.LimitString);
 541         nerrs++;
 542     }
 543 
 544     /** Insert instance initializer code into constructors prior to the super() call.
 545      *  @param md        The tree potentially representing a
 546      *                   constructor's definition.
 547      *  @param initCode  The list of instance initializer statements.
 548      *  @param initTAs  Type annotations from the initializer expression.
 549      */
 550     void normalizeMethod(JCMethodDecl md, List<JCStatement> initCode, List<TypeCompound> initTAs) {
 551         if (TreeInfo.isConstructor(md) && TreeInfo.hasConstructorCall(md, names._super)) {
 552             // We are seeing a constructor that has a super() call.
 553             // Find the super() invocation and append the given initializer code.
 554             TreeInfo.mapSuperCalls(md.body, supercall -> make.Block(0, initCode.prepend(supercall)));






 555 
 556             if (md.body.endpos == Position.NOPOS)
 557                 md.body.endpos = TreeInfo.endPos(md.body.stats.last());
 558 
 559             md.sym.appendUniqueTypeAttributes(initTAs);
 560         }
 561     }
 562 


































 563 /* ************************************************************************
 564  * Traversal methods
 565  *************************************************************************/
 566 
 567     /** Visitor argument: The current environment.
 568      */
 569     Env<GenContext> env;
 570 
 571     /** Visitor argument: The expected type (prototype).
 572      */
 573     Type pt;
 574 
 575     /** Visitor result: The item representing the computed value.
 576      */
 577     Item result;
 578 
 579     /** Visitor method: generate code for a definition, catching and reporting
 580      *  any completion failures.
 581      *  @param tree    The definition to be visited.
 582      *  @param env     The environment current at the definition.

 927             // Count up extra parameters
 928             if (meth.isConstructor()) {
 929                 extras++;
 930                 if (meth.enclClass().isInner() &&
 931                     !meth.enclClass().isStatic()) {
 932                     extras++;
 933                 }
 934             } else if ((tree.mods.flags & STATIC) == 0) {
 935                 extras++;
 936             }
 937             //      System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG
 938             if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes()) + extras >
 939                 ClassFile.MAX_PARAMETERS) {
 940                 log.error(tree.pos(), Errors.LimitParameters);
 941                 nerrs++;
 942             }
 943 
 944             else if (tree.body != null) {
 945                 // Create a new code structure and initialize it.
 946                 int startpcCrt = initCode(tree, env, fatcode);





 947 
 948                 try {
 949                     genStat(tree.body, env);
 950                 } catch (CodeSizeOverflow e) {
 951                     // Failed due to code limit, try again with jsr/ret
 952                     startpcCrt = initCode(tree, env, fatcode);
 953                     genStat(tree.body, env);


 954                 }
 955 
 956                 if (code.state.stacksize != 0) {
 957                     log.error(tree.body.pos(), Errors.StackSimError(tree.sym));
 958                     throw new AssertionError();
 959                 }
 960 
 961                 // If last statement could complete normally, insert a
 962                 // return at the end.
 963                 if (code.isAlive()) {
 964                     code.statBegin(TreeInfo.endPos(tree.body));
 965                     if (env.enclMethod == null ||
 966                         env.enclMethod.sym.type.getReturnType().hasTag(VOID)) {
 967                         code.emitop0(return_);
 968                     } else {
 969                         // sometime dead code seems alive (4415991);
 970                         // generate a small loop instead
 971                         int startpc = code.entryPoint();
 972                         CondItem c = items.makeCondItem(goto_);
 973                         code.resolve(c.jumpTrue(), startpc);

1002 
1003                 // Fill in type annotation positions for exception parameters
1004                 code.fillExceptionParameterPositions();
1005             }
1006         }
1007 
1008         private int initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
1009             MethodSymbol meth = tree.sym;
1010 
1011             // Create a new code structure.
1012             meth.code = code = new Code(meth,
1013                                         fatcode,
1014                                         lineDebugInfo ? toplevel.lineMap : null,
1015                                         varDebugInfo,
1016                                         stackMap,
1017                                         debugCode,
1018                                         genCrt ? new CRTable(tree, env.toplevel.endPositions)
1019                                                : null,
1020                                         syms,
1021                                         types,
1022                                         poolWriter);

1023             items = new Items(poolWriter, code, syms, types);
1024             if (code.debugCode) {
1025                 System.err.println(meth + " for body " + tree);
1026             }
1027 
1028             // If method is not static, create a new local variable address
1029             // for `this'.
1030             if ((tree.mods.flags & STATIC) == 0) {
1031                 Type selfType = meth.owner.type;
1032                 if (meth.isConstructor() && selfType != syms.objectType)
1033                     selfType = UninitializedType.uninitializedThis(selfType);
1034                 code.setDefined(
1035                         code.newLocal(
1036                             new VarSymbol(FINAL, names._this, selfType, meth.owner)));
1037             }
1038 
1039             // Mark all parameters as defined from the beginning of
1040             // the method.
1041             for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
1042                 checkDimension(l.head.pos(), l.head.sym.type);

1138     public void visitForLoop(JCForLoop tree) {
1139         int limit = code.nextreg;
1140         genStats(tree.init, env);
1141         genLoop(tree, tree.body, tree.cond, tree.step, true);
1142         code.endScopes(limit);
1143     }
1144     //where
1145         /** Generate code for a loop.
1146          *  @param loop       The tree representing the loop.
1147          *  @param body       The loop's body.
1148          *  @param cond       The loop's controlling condition.
1149          *  @param step       "Step" statements to be inserted at end of
1150          *                    each iteration.
1151          *  @param testFirst  True if the loop test belongs before the body.
1152          */
1153         private void genLoop(JCStatement loop,
1154                              JCStatement body,
1155                              JCExpression cond,
1156                              List<JCExpressionStatement> step,
1157                              boolean testFirst) {













1158             Env<GenContext> loopEnv = env.dup(loop, new GenContext());
1159             int startpc = code.entryPoint();
1160             if (testFirst) { //while or for loop
1161                 CondItem c;
1162                 if (cond != null) {
1163                     code.statBegin(cond.pos);
1164                     Assert.check(code.isStatementStart());
1165                     c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1166                 } else {
1167                     c = items.makeCondItem(goto_);
1168                 }
1169                 Chain loopDone = c.jumpFalse();
1170                 code.resolve(c.trueJumps);
1171                 Assert.check(code.isStatementStart());
1172                 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1173                 code.resolve(loopEnv.info.cont);
1174                 genStats(step, loopEnv);
1175                 code.resolve(code.branch(goto_), startpc);
1176                 code.resolve(loopDone);
1177             } else {

1196         }
1197 
1198     public void visitForeachLoop(JCEnhancedForLoop tree) {
1199         throw new AssertionError(); // should have been removed by Lower.
1200     }
1201 
1202     public void visitLabelled(JCLabeledStatement tree) {
1203         Env<GenContext> localEnv = env.dup(tree, new GenContext());
1204         genStat(tree.body, localEnv, CRT_STATEMENT);
1205         code.resolve(localEnv.info.exit);
1206     }
1207 
1208     public void visitSwitch(JCSwitch tree) {
1209         handleSwitch(tree, tree.selector, tree.cases, tree.patternSwitch);
1210     }
1211 
1212     @Override
1213     public void visitSwitchExpression(JCSwitchExpression tree) {
1214         code.resolvePending();
1215         boolean prevInCondSwitchExpression = inCondSwitchExpression;

1216         try {
1217             inCondSwitchExpression = false;
1218             doHandleSwitchExpression(tree);
1219         } finally {
1220             inCondSwitchExpression = prevInCondSwitchExpression;

1221         }
1222         result = items.makeStackItem(pt);
1223     }
1224 
1225     private void doHandleSwitchExpression(JCSwitchExpression tree) {
1226         List<LocalItem> prevStackBeforeSwitchExpression = stackBeforeSwitchExpression;
1227         LocalItem prevSwitchResult = switchResult;
1228         int limit = code.nextreg;
1229         try {
1230             stackBeforeSwitchExpression = List.nil();
1231             switchResult = null;
1232             if (hasTry(tree)) {
1233                 //if the switch expression contains try-catch, the catch handlers need to have
1234                 //an empty stack. So stash whole stack to local variables, and restore it before
1235                 //breaks:
1236                 while (code.state.stacksize > 0) {
1237                     Type type = code.state.peek();
1238                     Name varName = names.fromString(target.syntheticNameChar() +
1239                                                     "stack" +
1240                                                     target.syntheticNameChar() +

1276                     hasTry = true;
1277                 }
1278 
1279                 @Override
1280                 public void visitClassDef(JCClassDecl tree) {
1281                 }
1282 
1283                 @Override
1284                 public void visitLambda(JCLambda tree) {
1285                 }
1286             };
1287 
1288             HasTryScanner hasTryScanner = new HasTryScanner();
1289 
1290             hasTryScanner.scan(tree);
1291             return hasTryScanner.hasTry;
1292         }
1293 
1294     private void handleSwitch(JCTree swtch, JCExpression selector, List<JCCase> cases,
1295                               boolean patternSwitch) {










1296         int limit = code.nextreg;
1297         Assert.check(!selector.type.hasTag(CLASS));
1298         int switchStart = patternSwitch ? code.entryPoint() : -1;
1299         int startpcCrt = genCrt ? code.curCP() : 0;
1300         Assert.check(code.isStatementStart());
1301         Item sel = genExpr(selector, syms.intType);
1302         if (cases.isEmpty()) {
1303             // We are seeing:  switch <sel> {}
1304             sel.load().drop();
1305             if (genCrt)
1306                 code.crt.put(TreeInfo.skipParens(selector),
1307                              CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1308         } else {
1309             // We are seeing a nonempty switch.
1310             sel.load();
1311             if (genCrt)
1312                 code.crt.put(TreeInfo.skipParens(selector),
1313                              CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1314             Env<GenContext> switchEnv = env.dup(swtch, new GenContext());
1315             switchEnv.info.isSwitch = true;
1316 
1317             // Compute number of labels and minimum and maximum label values.
1318             // For each case, store its label in an array.
1319             int lo = Integer.MAX_VALUE;  // minimum label.
1320             int hi = Integer.MIN_VALUE;  // maximum label.
1321             int nlabels = 0;               // number of labels.
1322 
1323             int[] labels = new int[cases.length()];  // the label array.
1324             int defaultIndex = -1;     // the index of the default clause.
1325 
1326             List<JCCase> l = cases;
1327             for (int i = 0; i < labels.length; i++) {
1328                 if (l.head.labels.head instanceof JCConstantCaseLabel constLabel) {
1329                     Assert.check(l.head.labels.size() == 1);
1330                     int val = ((Number) constLabel.expr.type.constValue()).intValue();
1331                     labels[i] = val;
1332                     if (val < lo) lo = val;
1333                     if (hi < val) hi = val;
1334                     nlabels++;
1335                 } else {
1336                     Assert.check(defaultIndex == -1);
1337                     defaultIndex = i;
1338                 }
1339                 l = l.tail;
1340             }
1341 
1342             // Determine whether to issue a tableswitch or a lookupswitch
1343             // instruction.
1344             long table_space_cost = 4 + ((long) hi - lo + 1); // words
1345             long table_time_cost = 3; // comparisons
1346             long lookup_space_cost = 3 + 2 * (long) nlabels;
1347             long lookup_time_cost = nlabels;
1348             int opcode =
1349                 nlabels > 0 &&
1350                 table_space_cost + 3 * table_time_cost <=
1351                 lookup_space_cost + 3 * lookup_time_cost
1352                 ?
1353                 tableswitch : lookupswitch;
1354 
1355             int startpc = code.curCP();    // the position of the selector operation
1356             code.emitop0(opcode);
1357             code.align(4);
1358             int tableBase = code.curCP();  // the start of the jump table
1359             int[] offsets = null;          // a table of offsets for a lookupswitch
1360             code.emit4(-1);                // leave space for default offset
1361             if (opcode == tableswitch) {
1362                 code.emit4(lo);            // minimum label
1363                 code.emit4(hi);            // maximum label
1364                 for (long i = lo; i <= hi; i++) {  // leave space for jump table
1365                     code.emit4(-1);
1366                 }
1367             } else {
1368                 code.emit4(nlabels);    // number of labels
1369                 for (int i = 0; i < nlabels; i++) {
1370                     code.emit4(-1); code.emit4(-1); // leave space for lookup table
1371                 }
1372                 offsets = new int[labels.length];
1373             }
1374             Code.State stateSwitch = code.state.dup();
1375             code.markDead();
1376 
1377             // For each case do:
1378             l = cases;
1379             for (int i = 0; i < labels.length; i++) {
1380                 JCCase c = l.head;
1381                 l = l.tail;
1382 
1383                 int pc = code.entryPoint(stateSwitch);
1384                 // Insert offset directly into code or else into the
1385                 // offsets table.
1386                 if (i != defaultIndex) {
1387                     if (opcode == tableswitch) {
1388                         code.put4(
1389                             tableBase + 4 * (labels[i] - lo + 3),
1390                             pc - startpc);
1391                     } else {
1392                         offsets[i] = pc - startpc;
1393                     }
1394                 } else {
1395                     code.put4(tableBase, pc - startpc);
1396                 }
1397 
1398                 // Generate code for the statements in this case.
1399                 genStats(c.stats, switchEnv, CRT_FLOW_TARGET);
1400             }
1401 
1402             if (switchEnv.info.cont != null) {
1403                 Assert.check(patternSwitch);
1404                 code.resolve(switchEnv.info.cont, switchStart);
1405             }
1406 
1407             // Resolve all breaks.
1408             code.resolve(switchEnv.info.exit);
1409 
1410             // If we have not set the default offset, we do so now.

1420                     if (code.get4(t) == -1)
1421                         code.put4(t, defaultOffset);
1422                 }
1423             } else {
1424                 // Sort non-default offsets and copy into lookup table.
1425                 if (defaultIndex >= 0)
1426                     for (int i = defaultIndex; i < labels.length - 1; i++) {
1427                         labels[i] = labels[i+1];
1428                         offsets[i] = offsets[i+1];
1429                     }
1430                 if (nlabels > 0)
1431                     qsort2(labels, offsets, 0, nlabels - 1);
1432                 for (int i = 0; i < nlabels; i++) {
1433                     int caseidx = tableBase + 8 * (i + 1);
1434                     code.put4(caseidx, labels[i]);
1435                     code.put4(caseidx + 4, offsets[i]);
1436                 }
1437             }
1438 
1439             if (swtch instanceof JCSwitchExpression) {
1440                  // Emit line position for the end of a switch expression
1441                  code.statBegin(TreeInfo.endPos(swtch));
1442             }
1443         }
1444         code.endScopes(limit);
1445     }
1446 //where
1447         /** Sort (int) arrays of keys and values
1448          */
1449        static void qsort2(int[] keys, int[] values, int lo, int hi) {
1450             int i = lo;
1451             int j = hi;
1452             int pivot = keys[(i+j)/2];
1453             do {
1454                 while (keys[i] < pivot) i++;
1455                 while (pivot < keys[j]) j--;
1456                 if (i <= j) {
1457                     int temp1 = keys[i];
1458                     keys[i] = keys[j];
1459                     keys[j] = temp1;
1460                     int temp2 = values[i];
1461                     values[i] = values[j];

1524             @Override
1525             void afterBody() {
1526                 if (tree.finalizer != null && (tree.finalizer.flags & BODY_ONLY_FINALIZE) != 0) {
1527                     //for body-only finally, remove the GenFinalizer after try body
1528                     //so that the finally is not generated to catch bodies:
1529                     tryEnv.info.finalize = null;
1530                 }
1531             }
1532 
1533         };
1534         tryEnv.info.gaps = new ListBuffer<>();
1535         genTry(tree.body, tree.catchers, tryEnv);
1536     }
1537     //where
1538         /** Generate code for a try or synchronized statement
1539          *  @param body      The body of the try or synchronized statement.
1540          *  @param catchers  The list of catch clauses.
1541          *  @param env       The current environment of the body.
1542          */
1543         void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) {









1544             int limit = code.nextreg;
1545             int startpc = code.curCP();
1546             Code.State stateTry = code.state.dup();
1547             genStat(body, env, CRT_BLOCK);
1548             int endpc = code.curCP();
1549             List<Integer> gaps = env.info.gaps.toList();
1550             code.statBegin(TreeInfo.endPos(body));
1551             genFinalizer(env);
1552             code.statBegin(TreeInfo.endPos(env.tree));
1553             Chain exitChain;
1554             boolean actualTry = env.tree.hasTag(TRY);
1555             if (startpc == endpc && actualTry) {
1556                 exitChain = code.branch(dontgoto);
1557             } else {
1558                 exitChain = code.branch(goto_);
1559             }
1560             endFinalizerGap(env);
1561             env.info.finalize.afterBody();
1562             boolean hasFinalizer =
1563                 env.info.finalize != null &&
1564                 env.info.finalize.hasFinalizer();
1565             if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) {
1566                 // start off with exception on stack
1567                 code.entryPoint(stateTry, l.head.param.sym.type);
1568                 genCatch(l.head, env, startpc, endpc, gaps);
1569                 genFinalizer(env);
1570                 if (hasFinalizer || l.tail.nonEmpty()) {
1571                     code.statBegin(TreeInfo.endPos(env.tree));
1572                     exitChain = Code.mergeChains(exitChain,
1573                                                  code.branch(goto_));
1574                 }
1575                 endFinalizerGap(env);
1576             }
1577             if (hasFinalizer && (startpc != endpc || !actualTry)) {
1578                 // Create a new register segment to avoid allocating
1579                 // the same variables in finalizers and other statements.
1580                 code.newRegSegment();
1581 
1582                 // Add a catch-all clause.
1583 
1584                 // start off with exception on stack
1585                 int catchallpc = code.entryPoint(stateTry, syms.throwableType);
1586 
1587                 // Register all exception ranges for catch all clause.
1588                 // The range of the catch all clause is from the beginning
1589                 // of the try or synchronized block until the present
1590                 // code pointer excluding all gaps in the current
1591                 // environment's GenContext.
1592                 int startseg = startpc;
1593                 while (env.info.gaps.nonEmpty()) {
1594                     int endseg = env.info.gaps.next().intValue();
1595                     registerCatch(body.pos(), startseg, endseg,
1596                                   catchallpc, 0);
1597                     startseg = env.info.gaps.next().intValue();
1598                 }
1599                 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1600                 code.markStatBegin();
1601 
1602                 Item excVar = makeTemp(syms.throwableType);
1603                 excVar.store();
1604                 genFinalizer(env);
1605                 code.resolvePending();
1606                 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.END_POS));
1607                 code.markStatBegin();
1608 
1609                 excVar.load();
1610                 registerCatch(body.pos(), startseg,
1611                               env.info.gaps.next().intValue(),
1612                               catchallpc, 0);
1613                 code.emitop0(athrow);
1614                 code.markDead();
1615 
1616                 // If there are jsr's to this finalizer, ...
1617                 if (env.info.cont != null) {
1618                     // Resolve all jsr's.
1619                     code.resolve(env.info.cont);
1620 
1621                     // Mark statement line number
1622                     code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1623                     code.markStatBegin();
1624 
1625                     // Save return address.
1626                     LocalItem retVar = makeTemp(syms.throwableType);
1627                     retVar.store();
1628 
1629                     // Generate finalizer code.
1630                     env.info.finalize.genLast();
1631 
1632                     // Return.

1735         /** Register a catch clause in the "Exceptions" code-attribute.
1736          */
1737         void registerCatch(DiagnosticPosition pos,
1738                            int startpc, int endpc,
1739                            int handler_pc, int catch_type) {
1740             char startpc1 = (char)startpc;
1741             char endpc1 = (char)endpc;
1742             char handler_pc1 = (char)handler_pc;
1743             if (startpc1 == startpc &&
1744                 endpc1 == endpc &&
1745                 handler_pc1 == handler_pc) {
1746                 code.addCatch(startpc1, endpc1, handler_pc1,
1747                               (char)catch_type);
1748             } else {
1749                 log.error(pos, Errors.LimitCodeTooLargeForTryStmt);
1750                 nerrs++;
1751             }
1752         }
1753 
1754     public void visitIf(JCIf tree) {









1755         int limit = code.nextreg;
1756         Chain thenExit = null;
1757         Assert.check(code.isStatementStart());
1758         CondItem c = genCond(TreeInfo.skipParens(tree.cond),
1759                              CRT_FLOW_CONTROLLER);
1760         Chain elseChain = c.jumpFalse();
1761         Assert.check(code.isStatementStart());
1762         if (!c.isFalse()) {
1763             code.resolve(c.trueJumps);
1764             genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET);
1765             thenExit = code.branch(goto_);
1766         }
1767         if (elseChain != null) {
1768             code.resolve(elseChain);
1769             if (tree.elsepart != null) {
1770                 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET);
1771             }
1772         }
1773         code.resolve(thenExit);
1774         code.endScopes(limit);
1775         Assert.check(code.isStatementStart());
1776     }
1777 
1778     public void visitExec(JCExpressionStatement tree) {
1779         // Optimize x++ to ++x and x-- to --x.

2063                 nerrs++;
2064             }
2065             int elemcode = Code.arraycode(elemtype);
2066             if (elemcode == 0 || (elemcode == 1 && ndims == 1)) {
2067                 code.emitAnewarray(makeRef(pos, elemtype), type);
2068             } else if (elemcode == 1) {
2069                 code.emitMultianewarray(ndims, makeRef(pos, type), type);
2070             } else {
2071                 code.emitNewarray(elemcode, type);
2072             }
2073             return items.makeStackItem(type);
2074         }
2075 
2076     public void visitParens(JCParens tree) {
2077         result = genExpr(tree.expr, tree.expr.type);
2078     }
2079 
2080     public void visitAssign(JCAssign tree) {
2081         Item l = genExpr(tree.lhs, tree.lhs.type);
2082         genExpr(tree.rhs, tree.lhs.type).load();


2083         if (tree.rhs.type.hasTag(BOT)) {
2084             /* This is just a case of widening reference conversion that per 5.1.5 simply calls
2085                for "regarding a reference as having some other type in a manner that can be proved
2086                correct at compile time."
2087             */
2088             code.state.forceStackTop(tree.lhs.type);
2089         }
2090         result = items.makeAssignItem(l);
2091     }
2092 
2093     public void visitAssignop(JCAssignOp tree) {
2094         OperatorSymbol operator = tree.operator;
2095         Item l;
2096         if (operator.opcode == string_add) {
2097             l = concat.makeConcat(tree);
2098         } else {
2099             // Generate code for first expression
2100             l = genExpr(tree.lhs, tree.lhs.type);
2101 
2102             // If we have an increment of -32768 to +32767 of a local

2341             items.makeThisItem().load();
2342             sym = binaryQualifier(sym, env.enclClass.type);
2343             result = items.makeMemberItem(sym, nonVirtualForPrivateAccess(sym));
2344         }
2345     }
2346 
2347     //where
2348     private boolean nonVirtualForPrivateAccess(Symbol sym) {
2349         boolean useVirtual = target.hasVirtualPrivateInvoke() &&
2350                              !disableVirtualizedPrivateInvoke;
2351         return !useVirtual && ((sym.flags() & PRIVATE) != 0);
2352     }
2353 
2354     public void visitSelect(JCFieldAccess tree) {
2355         Symbol sym = tree.sym;
2356 
2357         if (tree.name == names._class) {
2358             code.emitLdc((LoadableConstant)checkDimension(tree.pos(), tree.selected.type));
2359             result = items.makeStackItem(pt);
2360             return;
2361        }
2362 
2363         Symbol ssym = TreeInfo.symbol(tree.selected);
2364 
2365         // Are we selecting via super?
2366         boolean selectSuper =
2367             ssym != null && (ssym.kind == TYP || ssym.name == names._super);
2368 
2369         // Are we accessing a member of the superclass in an access method
2370         // resulting from a qualified super?
2371         boolean accessSuper = isAccessSuper(env.enclMethod);
2372 
2373         Item base = (selectSuper)
2374             ? items.makeSuperItem()
2375             : genExpr(tree.selected, tree.selected.type);
2376 
2377         if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) {
2378             // We are seeing a variable that is constant but its selecting
2379             // expression is not.
2380             if ((sym.flags() & STATIC) != 0) {
2381                 if (!selectSuper && (ssym == null || ssym.kind != TYP))

  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;

 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.endpos = TreeInfo.endPos(clinitStats.last());
 520             methodDefs.append(make.MethodDef(clinit, block));
 521 
 522             if (!clinitTAs.isEmpty())
 523                 clinit.appendUniqueTypeAttributes(clinitTAs.toList());

 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.endpos == Position.NOPOS)
 579                 md.body.endpos = 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.

 983             // Count up extra parameters
 984             if (meth.isConstructor()) {
 985                 extras++;
 986                 if (meth.enclClass().isInner() &&
 987                     !meth.enclClass().isStatic()) {
 988                     extras++;
 989                 }
 990             } else if ((tree.mods.flags & STATIC) == 0) {
 991                 extras++;
 992             }
 993             //      System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG
 994             if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes()) + extras >
 995                 ClassFile.MAX_PARAMETERS) {
 996                 log.error(tree.pos(), Errors.LimitParameters);
 997                 nerrs++;
 998             }
 999 
1000             else if (tree.body != null) {
1001                 // Create a new code structure and initialize it.
1002                 int startpcCrt = initCode(tree, env, fatcode);
1003                 Set<VarSymbol> prevUnsetFields = code.currentUnsetFields;
1004                 if (meth.isConstructor()) {
1005                     code.currentUnsetFields = unsetFieldsInfo.getUnsetFields(env.enclClass.sym, tree.body);
1006                     code.initialUnsetFields = unsetFieldsInfo.getUnsetFields(env.enclClass.sym, tree.body);
1007                 }
1008 
1009                 try {
1010                     genStat(tree.body, env);
1011                 } catch (CodeSizeOverflow e) {
1012                     // Failed due to code limit, try again with jsr/ret
1013                     startpcCrt = initCode(tree, env, fatcode);
1014                     genStat(tree.body, env);
1015                 } finally {
1016                     code.currentUnsetFields = prevUnsetFields;
1017                 }
1018 
1019                 if (code.state.stacksize != 0) {
1020                     log.error(tree.body.pos(), Errors.StackSimError(tree.sym));
1021                     throw new AssertionError();
1022                 }
1023 
1024                 // If last statement could complete normally, insert a
1025                 // return at the end.
1026                 if (code.isAlive()) {
1027                     code.statBegin(TreeInfo.endPos(tree.body));
1028                     if (env.enclMethod == null ||
1029                         env.enclMethod.sym.type.getReturnType().hasTag(VOID)) {
1030                         code.emitop0(return_);
1031                     } else {
1032                         // sometime dead code seems alive (4415991);
1033                         // generate a small loop instead
1034                         int startpc = code.entryPoint();
1035                         CondItem c = items.makeCondItem(goto_);
1036                         code.resolve(c.jumpTrue(), startpc);

1065 
1066                 // Fill in type annotation positions for exception parameters
1067                 code.fillExceptionParameterPositions();
1068             }
1069         }
1070 
1071         private int initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
1072             MethodSymbol meth = tree.sym;
1073 
1074             // Create a new code structure.
1075             meth.code = code = new Code(meth,
1076                                         fatcode,
1077                                         lineDebugInfo ? toplevel.lineMap : null,
1078                                         varDebugInfo,
1079                                         stackMap,
1080                                         debugCode,
1081                                         genCrt ? new CRTable(tree, env.toplevel.endPositions)
1082                                                : null,
1083                                         syms,
1084                                         types,
1085                                         poolWriter,
1086                                         generateEarlyLarvalFrame);
1087             items = new Items(poolWriter, code, syms, types);
1088             if (code.debugCode) {
1089                 System.err.println(meth + " for body " + tree);
1090             }
1091 
1092             // If method is not static, create a new local variable address
1093             // for `this'.
1094             if ((tree.mods.flags & STATIC) == 0) {
1095                 Type selfType = meth.owner.type;
1096                 if (meth.isConstructor() && selfType != syms.objectType)
1097                     selfType = UninitializedType.uninitializedThis(selfType);
1098                 code.setDefined(
1099                         code.newLocal(
1100                             new VarSymbol(FINAL, names._this, selfType, meth.owner)));
1101             }
1102 
1103             // Mark all parameters as defined from the beginning of
1104             // the method.
1105             for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
1106                 checkDimension(l.head.pos(), l.head.sym.type);

1202     public void visitForLoop(JCForLoop tree) {
1203         int limit = code.nextreg;
1204         genStats(tree.init, env);
1205         genLoop(tree, tree.body, tree.cond, tree.step, true);
1206         code.endScopes(limit);
1207     }
1208     //where
1209         /** Generate code for a loop.
1210          *  @param loop       The tree representing the loop.
1211          *  @param body       The loop's body.
1212          *  @param cond       The loop's controlling condition.
1213          *  @param step       "Step" statements to be inserted at end of
1214          *                    each iteration.
1215          *  @param testFirst  True if the loop test belongs before the body.
1216          */
1217         private void genLoop(JCStatement loop,
1218                              JCStatement body,
1219                              JCExpression cond,
1220                              List<JCExpressionStatement> step,
1221                              boolean testFirst) {
1222             Set<VarSymbol> prevCodeUnsetFields = code.currentUnsetFields;
1223             try {
1224                 genLoopHelper(loop, body, cond, step, testFirst);
1225             } finally {
1226                 code.currentUnsetFields = prevCodeUnsetFields;
1227             }
1228         }
1229 
1230         private void genLoopHelper(JCStatement loop,
1231                              JCStatement body,
1232                              JCExpression cond,
1233                              List<JCExpressionStatement> step,
1234                              boolean testFirst) {
1235             Env<GenContext> loopEnv = env.dup(loop, new GenContext());
1236             int startpc = code.entryPoint();
1237             if (testFirst) { //while or for loop
1238                 CondItem c;
1239                 if (cond != null) {
1240                     code.statBegin(cond.pos);
1241                     Assert.check(code.isStatementStart());
1242                     c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1243                 } else {
1244                     c = items.makeCondItem(goto_);
1245                 }
1246                 Chain loopDone = c.jumpFalse();
1247                 code.resolve(c.trueJumps);
1248                 Assert.check(code.isStatementStart());
1249                 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1250                 code.resolve(loopEnv.info.cont);
1251                 genStats(step, loopEnv);
1252                 code.resolve(code.branch(goto_), startpc);
1253                 code.resolve(loopDone);
1254             } else {

1273         }
1274 
1275     public void visitForeachLoop(JCEnhancedForLoop tree) {
1276         throw new AssertionError(); // should have been removed by Lower.
1277     }
1278 
1279     public void visitLabelled(JCLabeledStatement tree) {
1280         Env<GenContext> localEnv = env.dup(tree, new GenContext());
1281         genStat(tree.body, localEnv, CRT_STATEMENT);
1282         code.resolve(localEnv.info.exit);
1283     }
1284 
1285     public void visitSwitch(JCSwitch tree) {
1286         handleSwitch(tree, tree.selector, tree.cases, tree.patternSwitch);
1287     }
1288 
1289     @Override
1290     public void visitSwitchExpression(JCSwitchExpression tree) {
1291         code.resolvePending();
1292         boolean prevInCondSwitchExpression = inCondSwitchExpression;
1293         Set<VarSymbol> prevCodeUnsetFields = code.currentUnsetFields;
1294         try {
1295             inCondSwitchExpression = false;
1296             doHandleSwitchExpression(tree);
1297         } finally {
1298             inCondSwitchExpression = prevInCondSwitchExpression;
1299             code.currentUnsetFields = prevCodeUnsetFields;
1300         }
1301         result = items.makeStackItem(pt);
1302     }
1303 
1304     private void doHandleSwitchExpression(JCSwitchExpression tree) {
1305         List<LocalItem> prevStackBeforeSwitchExpression = stackBeforeSwitchExpression;
1306         LocalItem prevSwitchResult = switchResult;
1307         int limit = code.nextreg;
1308         try {
1309             stackBeforeSwitchExpression = List.nil();
1310             switchResult = null;
1311             if (hasTry(tree)) {
1312                 //if the switch expression contains try-catch, the catch handlers need to have
1313                 //an empty stack. So stash whole stack to local variables, and restore it before
1314                 //breaks:
1315                 while (code.state.stacksize > 0) {
1316                     Type type = code.state.peek();
1317                     Name varName = names.fromString(target.syntheticNameChar() +
1318                                                     "stack" +
1319                                                     target.syntheticNameChar() +

1355                     hasTry = true;
1356                 }
1357 
1358                 @Override
1359                 public void visitClassDef(JCClassDecl tree) {
1360                 }
1361 
1362                 @Override
1363                 public void visitLambda(JCLambda tree) {
1364                 }
1365             };
1366 
1367             HasTryScanner hasTryScanner = new HasTryScanner();
1368 
1369             hasTryScanner.scan(tree);
1370             return hasTryScanner.hasTry;
1371         }
1372 
1373     private void handleSwitch(JCTree swtch, JCExpression selector, List<JCCase> cases,
1374                               boolean patternSwitch) {
1375         Set<VarSymbol> prevCodeUnsetFields = code.currentUnsetFields;
1376         try {
1377             handleSwitchHelper(swtch, selector, cases, patternSwitch);
1378         } finally {
1379             code.currentUnsetFields = prevCodeUnsetFields;
1380         }
1381     }
1382 
1383     void handleSwitchHelper(JCTree swtch, JCExpression selector, List<JCCase> cases,
1384                       boolean patternSwitch) {
1385         int limit = code.nextreg;
1386         Assert.check(!selector.type.hasTag(CLASS));
1387         int switchStart = patternSwitch ? code.entryPoint() : -1;
1388         int startpcCrt = genCrt ? code.curCP() : 0;
1389         Assert.check(code.isStatementStart());
1390         Item sel = genExpr(selector, syms.intType);
1391         if (cases.isEmpty()) {
1392             // We are seeing:  switch <sel> {}
1393             sel.load().drop();
1394             if (genCrt)
1395                 code.crt.put(TreeInfo.skipParens(selector),
1396                         CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1397         } else {
1398             // We are seeing a nonempty switch.
1399             sel.load();
1400             if (genCrt)
1401                 code.crt.put(TreeInfo.skipParens(selector),
1402                         CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1403             Env<GenContext> switchEnv = env.dup(swtch, new GenContext());
1404             switchEnv.info.isSwitch = true;
1405 
1406             // Compute number of labels and minimum and maximum label values.
1407             // For each case, store its label in an array.
1408             int lo = Integer.MAX_VALUE;  // minimum label.
1409             int hi = Integer.MIN_VALUE;  // maximum label.
1410             int nlabels = 0;               // number of labels.
1411 
1412             int[] labels = new int[cases.length()];  // the label array.
1413             int defaultIndex = -1;     // the index of the default clause.
1414 
1415             List<JCCase> l = cases;
1416             for (int i = 0; i < labels.length; i++) {
1417                 if (l.head.labels.head instanceof JCConstantCaseLabel constLabel) {
1418                     Assert.check(l.head.labels.size() == 1);
1419                     int val = ((Number) constLabel.expr.type.constValue()).intValue();
1420                     labels[i] = val;
1421                     if (val < lo) lo = val;
1422                     if (hi < val) hi = val;
1423                     nlabels++;
1424                 } else {
1425                     Assert.check(defaultIndex == -1);
1426                     defaultIndex = i;
1427                 }
1428                 l = l.tail;
1429             }
1430 
1431             // Determine whether to issue a tableswitch or a lookupswitch
1432             // instruction.
1433             long table_space_cost = 4 + ((long) hi - lo + 1); // words
1434             long table_time_cost = 3; // comparisons
1435             long lookup_space_cost = 3 + 2 * (long) nlabels;
1436             long lookup_time_cost = nlabels;
1437             int opcode =
1438                     nlabels > 0 &&
1439                             table_space_cost + 3 * table_time_cost <=
1440                                     lookup_space_cost + 3 * lookup_time_cost
1441                             ?
1442                             tableswitch : lookupswitch;
1443 
1444             int startpc = code.curCP();    // the position of the selector operation
1445             code.emitop0(opcode);
1446             code.align(4);
1447             int tableBase = code.curCP();  // the start of the jump table
1448             int[] offsets = null;          // a table of offsets for a lookupswitch
1449             code.emit4(-1);                // leave space for default offset
1450             if (opcode == tableswitch) {
1451                 code.emit4(lo);            // minimum label
1452                 code.emit4(hi);            // maximum label
1453                 for (long i = lo; i <= hi; i++) {  // leave space for jump table
1454                     code.emit4(-1);
1455                 }
1456             } else {
1457                 code.emit4(nlabels);    // number of labels
1458                 for (int i = 0; i < nlabels; i++) {
1459                     code.emit4(-1); code.emit4(-1); // leave space for lookup table
1460                 }
1461                 offsets = new int[labels.length];
1462             }
1463             Code.State stateSwitch = code.state.dup();
1464             code.markDead();
1465 
1466             // For each case do:
1467             l = cases;
1468             for (int i = 0; i < labels.length; i++) {
1469                 JCCase c = l.head;
1470                 l = l.tail;
1471 
1472                 int pc = code.entryPoint(stateSwitch);
1473                 // Insert offset directly into code or else into the
1474                 // offsets table.
1475                 if (i != defaultIndex) {
1476                     if (opcode == tableswitch) {
1477                         code.put4(
1478                                 tableBase + 4 * (labels[i] - lo + 3),
1479                                 pc - startpc);
1480                     } else {
1481                         offsets[i] = pc - startpc;
1482                     }
1483                 } else {
1484                     code.put4(tableBase, pc - startpc);
1485                 }
1486 
1487                 // Generate code for the statements in this case.
1488                 genStats(c.stats, switchEnv, CRT_FLOW_TARGET);
1489             }
1490 
1491             if (switchEnv.info.cont != null) {
1492                 Assert.check(patternSwitch);
1493                 code.resolve(switchEnv.info.cont, switchStart);
1494             }
1495 
1496             // Resolve all breaks.
1497             code.resolve(switchEnv.info.exit);
1498 
1499             // If we have not set the default offset, we do so now.

1509                     if (code.get4(t) == -1)
1510                         code.put4(t, defaultOffset);
1511                 }
1512             } else {
1513                 // Sort non-default offsets and copy into lookup table.
1514                 if (defaultIndex >= 0)
1515                     for (int i = defaultIndex; i < labels.length - 1; i++) {
1516                         labels[i] = labels[i+1];
1517                         offsets[i] = offsets[i+1];
1518                     }
1519                 if (nlabels > 0)
1520                     qsort2(labels, offsets, 0, nlabels - 1);
1521                 for (int i = 0; i < nlabels; i++) {
1522                     int caseidx = tableBase + 8 * (i + 1);
1523                     code.put4(caseidx, labels[i]);
1524                     code.put4(caseidx + 4, offsets[i]);
1525                 }
1526             }
1527 
1528             if (swtch instanceof JCSwitchExpression) {
1529                 // Emit line position for the end of a switch expression
1530                 code.statBegin(TreeInfo.endPos(swtch));
1531             }
1532         }
1533         code.endScopes(limit);
1534     }
1535 //where
1536         /** Sort (int) arrays of keys and values
1537          */
1538        static void qsort2(int[] keys, int[] values, int lo, int hi) {
1539             int i = lo;
1540             int j = hi;
1541             int pivot = keys[(i+j)/2];
1542             do {
1543                 while (keys[i] < pivot) i++;
1544                 while (pivot < keys[j]) j--;
1545                 if (i <= j) {
1546                     int temp1 = keys[i];
1547                     keys[i] = keys[j];
1548                     keys[j] = temp1;
1549                     int temp2 = values[i];
1550                     values[i] = values[j];

1613             @Override
1614             void afterBody() {
1615                 if (tree.finalizer != null && (tree.finalizer.flags & BODY_ONLY_FINALIZE) != 0) {
1616                     //for body-only finally, remove the GenFinalizer after try body
1617                     //so that the finally is not generated to catch bodies:
1618                     tryEnv.info.finalize = null;
1619                 }
1620             }
1621 
1622         };
1623         tryEnv.info.gaps = new ListBuffer<>();
1624         genTry(tree.body, tree.catchers, tryEnv);
1625     }
1626     //where
1627         /** Generate code for a try or synchronized statement
1628          *  @param body      The body of the try or synchronized statement.
1629          *  @param catchers  The list of catch clauses.
1630          *  @param env       The current environment of the body.
1631          */
1632         void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) {
1633             Set<VarSymbol> prevCodeUnsetFields = code.currentUnsetFields;
1634             try {
1635                 genTryHelper(body, catchers, env);
1636             } finally {
1637                 code.currentUnsetFields = prevCodeUnsetFields;
1638             }
1639         }
1640 
1641         void genTryHelper(JCTree body, List<JCCatch> catchers, Env<GenContext> env) {
1642             int limit = code.nextreg;
1643             int startpc = code.curCP();
1644             Code.State stateTry = code.state.dup();
1645             genStat(body, env, CRT_BLOCK);
1646             int endpc = code.curCP();
1647             List<Integer> gaps = env.info.gaps.toList();
1648             code.statBegin(TreeInfo.endPos(body));
1649             genFinalizer(env);
1650             code.statBegin(TreeInfo.endPos(env.tree));
1651             Chain exitChain;
1652             boolean actualTry = env.tree.hasTag(TRY);
1653             if (startpc == endpc && actualTry) {
1654                 exitChain = code.branch(dontgoto);
1655             } else {
1656                 exitChain = code.branch(goto_);
1657             }
1658             endFinalizerGap(env);
1659             env.info.finalize.afterBody();
1660             boolean hasFinalizer =
1661                     env.info.finalize != null &&
1662                             env.info.finalize.hasFinalizer();
1663             if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) {
1664                 // start off with exception on stack
1665                 code.entryPoint(stateTry, l.head.param.sym.type);
1666                 genCatch(l.head, env, startpc, endpc, gaps);
1667                 genFinalizer(env);
1668                 if (hasFinalizer || l.tail.nonEmpty()) {
1669                     code.statBegin(TreeInfo.endPos(env.tree));
1670                     exitChain = Code.mergeChains(exitChain,
1671                             code.branch(goto_));
1672                 }
1673                 endFinalizerGap(env);
1674             }
1675             if (hasFinalizer && (startpc != endpc || !actualTry)) {
1676                 // Create a new register segment to avoid allocating
1677                 // the same variables in finalizers and other statements.
1678                 code.newRegSegment();
1679 
1680                 // Add a catch-all clause.
1681 
1682                 // start off with exception on stack
1683                 int catchallpc = code.entryPoint(stateTry, syms.throwableType);
1684 
1685                 // Register all exception ranges for catch all clause.
1686                 // The range of the catch all clause is from the beginning
1687                 // of the try or synchronized block until the present
1688                 // code pointer excluding all gaps in the current
1689                 // environment's GenContext.
1690                 int startseg = startpc;
1691                 while (env.info.gaps.nonEmpty()) {
1692                     int endseg = env.info.gaps.next().intValue();
1693                     registerCatch(body.pos(), startseg, endseg,
1694                             catchallpc, 0);
1695                     startseg = env.info.gaps.next().intValue();
1696                 }
1697                 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1698                 code.markStatBegin();
1699 
1700                 Item excVar = makeTemp(syms.throwableType);
1701                 excVar.store();
1702                 genFinalizer(env);
1703                 code.resolvePending();
1704                 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.END_POS));
1705                 code.markStatBegin();
1706 
1707                 excVar.load();
1708                 registerCatch(body.pos(), startseg,
1709                         env.info.gaps.next().intValue(),
1710                         catchallpc, 0);
1711                 code.emitop0(athrow);
1712                 code.markDead();
1713 
1714                 // If there are jsr's to this finalizer, ...
1715                 if (env.info.cont != null) {
1716                     // Resolve all jsr's.
1717                     code.resolve(env.info.cont);
1718 
1719                     // Mark statement line number
1720                     code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1721                     code.markStatBegin();
1722 
1723                     // Save return address.
1724                     LocalItem retVar = makeTemp(syms.throwableType);
1725                     retVar.store();
1726 
1727                     // Generate finalizer code.
1728                     env.info.finalize.genLast();
1729 
1730                     // Return.

1833         /** Register a catch clause in the "Exceptions" code-attribute.
1834          */
1835         void registerCatch(DiagnosticPosition pos,
1836                            int startpc, int endpc,
1837                            int handler_pc, int catch_type) {
1838             char startpc1 = (char)startpc;
1839             char endpc1 = (char)endpc;
1840             char handler_pc1 = (char)handler_pc;
1841             if (startpc1 == startpc &&
1842                 endpc1 == endpc &&
1843                 handler_pc1 == handler_pc) {
1844                 code.addCatch(startpc1, endpc1, handler_pc1,
1845                               (char)catch_type);
1846             } else {
1847                 log.error(pos, Errors.LimitCodeTooLargeForTryStmt);
1848                 nerrs++;
1849             }
1850         }
1851 
1852     public void visitIf(JCIf tree) {
1853         Set<VarSymbol> prevCodeUnsetFields = code.currentUnsetFields;
1854         try {
1855             visitIfHelper(tree);
1856         } finally {
1857             code.currentUnsetFields = prevCodeUnsetFields;
1858         }
1859     }
1860 
1861     public void visitIfHelper(JCIf tree) {
1862         int limit = code.nextreg;
1863         Chain thenExit = null;
1864         Assert.check(code.isStatementStart());
1865         CondItem c = genCond(TreeInfo.skipParens(tree.cond),
1866                 CRT_FLOW_CONTROLLER);
1867         Chain elseChain = c.jumpFalse();
1868         Assert.check(code.isStatementStart());
1869         if (!c.isFalse()) {
1870             code.resolve(c.trueJumps);
1871             genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET);
1872             thenExit = code.branch(goto_);
1873         }
1874         if (elseChain != null) {
1875             code.resolve(elseChain);
1876             if (tree.elsepart != null) {
1877                 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET);
1878             }
1879         }
1880         code.resolve(thenExit);
1881         code.endScopes(limit);
1882         Assert.check(code.isStatementStart());
1883     }
1884 
1885     public void visitExec(JCExpressionStatement tree) {
1886         // Optimize x++ to ++x and x-- to --x.

2170                 nerrs++;
2171             }
2172             int elemcode = Code.arraycode(elemtype);
2173             if (elemcode == 0 || (elemcode == 1 && ndims == 1)) {
2174                 code.emitAnewarray(makeRef(pos, elemtype), type);
2175             } else if (elemcode == 1) {
2176                 code.emitMultianewarray(ndims, makeRef(pos, type), type);
2177             } else {
2178                 code.emitNewarray(elemcode, type);
2179             }
2180             return items.makeStackItem(type);
2181         }
2182 
2183     public void visitParens(JCParens tree) {
2184         result = genExpr(tree.expr, tree.expr.type);
2185     }
2186 
2187     public void visitAssign(JCAssign tree) {
2188         Item l = genExpr(tree.lhs, tree.lhs.type);
2189         genExpr(tree.rhs, tree.lhs.type).load();
2190         Set<VarSymbol> tmpUnsetSymbols = unsetFieldsInfo.getUnsetFields(env.enclClass.sym, tree);
2191         code.currentUnsetFields = tmpUnsetSymbols != null ? tmpUnsetSymbols : code.currentUnsetFields;
2192         if (tree.rhs.type.hasTag(BOT)) {
2193             /* This is just a case of widening reference conversion that per 5.1.5 simply calls
2194                for "regarding a reference as having some other type in a manner that can be proved
2195                correct at compile time."
2196             */
2197             code.state.forceStackTop(tree.lhs.type);
2198         }
2199         result = items.makeAssignItem(l);
2200     }
2201 
2202     public void visitAssignop(JCAssignOp tree) {
2203         OperatorSymbol operator = tree.operator;
2204         Item l;
2205         if (operator.opcode == string_add) {
2206             l = concat.makeConcat(tree);
2207         } else {
2208             // Generate code for first expression
2209             l = genExpr(tree.lhs, tree.lhs.type);
2210 
2211             // If we have an increment of -32768 to +32767 of a local

2450             items.makeThisItem().load();
2451             sym = binaryQualifier(sym, env.enclClass.type);
2452             result = items.makeMemberItem(sym, nonVirtualForPrivateAccess(sym));
2453         }
2454     }
2455 
2456     //where
2457     private boolean nonVirtualForPrivateAccess(Symbol sym) {
2458         boolean useVirtual = target.hasVirtualPrivateInvoke() &&
2459                              !disableVirtualizedPrivateInvoke;
2460         return !useVirtual && ((sym.flags() & PRIVATE) != 0);
2461     }
2462 
2463     public void visitSelect(JCFieldAccess tree) {
2464         Symbol sym = tree.sym;
2465 
2466         if (tree.name == names._class) {
2467             code.emitLdc((LoadableConstant)checkDimension(tree.pos(), tree.selected.type));
2468             result = items.makeStackItem(pt);
2469             return;
2470         }
2471 
2472         Symbol ssym = TreeInfo.symbol(tree.selected);
2473 
2474         // Are we selecting via super?
2475         boolean selectSuper =
2476             ssym != null && (ssym.kind == TYP || ssym.name == names._super);
2477 
2478         // Are we accessing a member of the superclass in an access method
2479         // resulting from a qualified super?
2480         boolean accessSuper = isAccessSuper(env.enclMethod);
2481 
2482         Item base = (selectSuper)
2483             ? items.makeSuperItem()
2484             : genExpr(tree.selected, tree.selected.type);
2485 
2486         if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) {
2487             // We are seeing a variable that is constant but its selecting
2488             // expression is not.
2489             if ((sym.flags() & STATIC) != 0) {
2490                 if (!selectSuper && (ssym == null || ssym.kind != TYP))
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