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 @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.bracePos = 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.bracePos == Position.NOPOS)
557 md.body.bracePos = 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.
939 // Count up extra parameters
940 if (meth.isConstructor()) {
941 extras++;
942 if (meth.enclClass().isInner() &&
943 !meth.enclClass().isStatic()) {
944 extras++;
945 }
946 } else if ((tree.mods.flags & STATIC) == 0) {
947 extras++;
948 }
949 // System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG
950 if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes()) + extras >
951 ClassFile.MAX_PARAMETERS) {
952 log.error(tree.pos(), Errors.LimitParameters);
953 nerrs++;
954 }
955
956 else if (tree.body != null) {
957 // Create a new code structure and initialize it.
958 int startpcCrt = initCode(tree, env, fatcode);
959
960 try {
961 genStat(tree.body, env);
962 } catch (CodeSizeOverflow e) {
963 // Failed due to code limit, try again with jsr/ret
964 startpcCrt = initCode(tree, env, fatcode);
965 genStat(tree.body, env);
966 }
967
968 if (code.state.stacksize != 0) {
969 log.error(tree.body.pos(), Errors.StackSimError(tree.sym));
970 throw new AssertionError();
971 }
972
973 // If last statement could complete normally, insert a
974 // return at the end.
975 if (code.isAlive()) {
976 code.statBegin(TreeInfo.endPos(tree.body));
977 if (env.enclMethod == null ||
978 env.enclMethod.sym.type.getReturnType().hasTag(VOID)) {
979 code.emitop0(return_);
980 } else {
981 // sometime dead code seems alive (4415991);
982 // generate a small loop instead
983 int startpc = code.entryPoint();
984 CondItem c = items.makeCondItem(goto_);
985 code.resolve(c.jumpTrue(), startpc);
1014
1015 // Fill in type annotation positions for exception parameters
1016 code.fillExceptionParameterPositions();
1017 }
1018 }
1019
1020 private int initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
1021 MethodSymbol meth = tree.sym;
1022
1023 // Create a new code structure.
1024 meth.code = code = new Code(meth,
1025 fatcode,
1026 lineDebugInfo ? toplevel.lineMap : null,
1027 varDebugInfo,
1028 stackMap,
1029 debugCode,
1030 genCrt ? new CRTable(tree, env.toplevel.endPositions)
1031 : null,
1032 syms,
1033 types,
1034 poolWriter);
1035 items = new Items(poolWriter, code, syms, types);
1036 if (code.debugCode) {
1037 System.err.println(meth + " for body " + tree);
1038 }
1039
1040 // If method is not static, create a new local variable address
1041 // for `this'.
1042 if ((tree.mods.flags & STATIC) == 0) {
1043 Type selfType = meth.owner.type;
1044 if (meth.isConstructor() && selfType != syms.objectType)
1045 selfType = UninitializedType.uninitializedThis(selfType);
1046 code.setDefined(
1047 code.newLocal(
1048 new VarSymbol(FINAL, names._this, selfType, meth.owner)));
1049 }
1050
1051 // Mark all parameters as defined from the beginning of
1052 // the method.
1053 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
1054 checkDimension(l.head.pos(), l.head.sym.type);
1150 public void visitForLoop(JCForLoop tree) {
1151 int limit = code.nextreg;
1152 genStats(tree.init, env);
1153 genLoop(tree, tree.body, tree.cond, tree.step, true);
1154 code.endScopes(limit);
1155 }
1156 //where
1157 /** Generate code for a loop.
1158 * @param loop The tree representing the loop.
1159 * @param body The loop's body.
1160 * @param cond The loop's controlling condition.
1161 * @param step "Step" statements to be inserted at end of
1162 * each iteration.
1163 * @param testFirst True if the loop test belongs before the body.
1164 */
1165 private void genLoop(JCStatement loop,
1166 JCStatement body,
1167 JCExpression cond,
1168 List<JCExpressionStatement> step,
1169 boolean testFirst) {
1170 Env<GenContext> loopEnv = env.dup(loop, new GenContext());
1171 int startpc = code.entryPoint();
1172 if (testFirst) { //while or for loop
1173 CondItem c;
1174 if (cond != null) {
1175 code.statBegin(cond.pos);
1176 Assert.check(code.isStatementStart());
1177 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1178 } else {
1179 c = items.makeCondItem(goto_);
1180 }
1181 Chain loopDone = c.jumpFalse();
1182 code.resolve(c.trueJumps);
1183 Assert.check(code.isStatementStart());
1184 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1185 code.resolve(loopEnv.info.cont);
1186 genStats(step, loopEnv);
1187 code.resolve(code.branch(goto_), startpc);
1188 code.resolve(loopDone);
1189 } else {
1208 }
1209
1210 public void visitForeachLoop(JCEnhancedForLoop tree) {
1211 throw new AssertionError(); // should have been removed by Lower.
1212 }
1213
1214 public void visitLabelled(JCLabeledStatement tree) {
1215 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1216 genStat(tree.body, localEnv, CRT_STATEMENT);
1217 code.resolve(localEnv.info.exit);
1218 }
1219
1220 public void visitSwitch(JCSwitch tree) {
1221 handleSwitch(tree, tree.selector, tree.cases, tree.patternSwitch);
1222 }
1223
1224 @Override
1225 public void visitSwitchExpression(JCSwitchExpression tree) {
1226 code.resolvePending();
1227 boolean prevInCondSwitchExpression = inCondSwitchExpression;
1228 try {
1229 inCondSwitchExpression = false;
1230 doHandleSwitchExpression(tree);
1231 } finally {
1232 inCondSwitchExpression = prevInCondSwitchExpression;
1233 }
1234 result = items.makeStackItem(pt);
1235 }
1236
1237 private void doHandleSwitchExpression(JCSwitchExpression tree) {
1238 List<LocalItem> prevStackBeforeSwitchExpression = stackBeforeSwitchExpression;
1239 LocalItem prevSwitchResult = switchResult;
1240 int limit = code.nextreg;
1241 try {
1242 stackBeforeSwitchExpression = List.nil();
1243 switchResult = null;
1244 if (hasTry(tree)) {
1245 //if the switch expression contains try-catch, the catch handlers need to have
1246 //an empty stack. So stash whole stack to local variables, and restore it before
1247 //breaks:
1248 while (code.state.stacksize > 0) {
1249 Type type = code.state.peek();
1250 Name varName = names.fromString(target.syntheticNameChar() +
1251 "stack" +
1252 target.syntheticNameChar() +
1288 hasTry = true;
1289 }
1290
1291 @Override
1292 public void visitClassDef(JCClassDecl tree) {
1293 }
1294
1295 @Override
1296 public void visitLambda(JCLambda tree) {
1297 }
1298 };
1299
1300 HasTryScanner hasTryScanner = new HasTryScanner();
1301
1302 hasTryScanner.scan(tree);
1303 return hasTryScanner.hasTry;
1304 }
1305
1306 private void handleSwitch(JCTree swtch, JCExpression selector, List<JCCase> cases,
1307 boolean patternSwitch) {
1308 int limit = code.nextreg;
1309 Assert.check(!selector.type.hasTag(CLASS));
1310 int switchStart = patternSwitch ? code.entryPoint() : -1;
1311 int startpcCrt = genCrt ? code.curCP() : 0;
1312 Assert.check(code.isStatementStart());
1313 Item sel = genExpr(selector, syms.intType);
1314 if (cases.isEmpty()) {
1315 // We are seeing: switch <sel> {}
1316 sel.load().drop();
1317 if (genCrt)
1318 code.crt.put(TreeInfo.skipParens(selector),
1319 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1320 } else {
1321 // We are seeing a nonempty switch.
1322 sel.load();
1323 if (genCrt)
1324 code.crt.put(TreeInfo.skipParens(selector),
1325 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1326 Env<GenContext> switchEnv = env.dup(swtch, new GenContext());
1327 switchEnv.info.isSwitch = true;
1328
1329 // Compute number of labels and minimum and maximum label values.
1330 // For each case, store its label in an array.
1331 int lo = Integer.MAX_VALUE; // minimum label.
1332 int hi = Integer.MIN_VALUE; // maximum label.
1333 int nlabels = 0; // number of labels.
1334
1335 int[] labels = new int[cases.length()]; // the label array.
1336 int defaultIndex = -1; // the index of the default clause.
1337
1338 List<JCCase> l = cases;
1339 for (int i = 0; i < labels.length; i++) {
1340 if (l.head.labels.head instanceof JCConstantCaseLabel constLabel) {
1341 Assert.check(l.head.labels.size() == 1);
1342 int val = ((Number) constLabel.expr.type.constValue()).intValue();
1343 labels[i] = val;
1344 if (val < lo) lo = val;
1345 if (hi < val) hi = val;
1346 nlabels++;
1347 } else {
1348 Assert.check(defaultIndex == -1);
1349 defaultIndex = i;
1350 }
1351 l = l.tail;
1352 }
1353
1354 // Determine whether to issue a tableswitch or a lookupswitch
1355 // instruction.
1356 long table_space_cost = 4 + ((long) hi - lo + 1); // words
1357 long table_time_cost = 3; // comparisons
1358 long lookup_space_cost = 3 + 2 * (long) nlabels;
1359 long lookup_time_cost = nlabels;
1360 int opcode =
1361 nlabels > 0 &&
1362 table_space_cost + 3 * table_time_cost <=
1363 lookup_space_cost + 3 * lookup_time_cost
1364 ?
1365 tableswitch : lookupswitch;
1366
1367 int startpc = code.curCP(); // the position of the selector operation
1368 code.emitop0(opcode);
1369 code.align(4);
1370 int tableBase = code.curCP(); // the start of the jump table
1371 int[] offsets = null; // a table of offsets for a lookupswitch
1372 code.emit4(-1); // leave space for default offset
1373 if (opcode == tableswitch) {
1374 code.emit4(lo); // minimum label
1375 code.emit4(hi); // maximum label
1376 for (long i = lo; i <= hi; i++) { // leave space for jump table
1377 code.emit4(-1);
1378 }
1379 } else {
1380 code.emit4(nlabels); // number of labels
1381 for (int i = 0; i < nlabels; i++) {
1382 code.emit4(-1); code.emit4(-1); // leave space for lookup table
1383 }
1384 offsets = new int[labels.length];
1385 }
1386 Code.State stateSwitch = code.state.dup();
1387 code.markDead();
1388
1389 // For each case do:
1390 l = cases;
1391 for (int i = 0; i < labels.length; i++) {
1392 JCCase c = l.head;
1393 l = l.tail;
1394
1395 int pc = code.entryPoint(stateSwitch);
1396 // Insert offset directly into code or else into the
1397 // offsets table.
1398 if (i != defaultIndex) {
1399 if (opcode == tableswitch) {
1400 code.put4(
1401 tableBase + 4 * (labels[i] - lo + 3),
1402 pc - startpc);
1403 } else {
1404 offsets[i] = pc - startpc;
1405 }
1406 } else {
1407 code.put4(tableBase, pc - startpc);
1408 }
1409
1410 // Generate code for the statements in this case.
1411 genStats(c.stats, switchEnv, CRT_FLOW_TARGET);
1412 }
1413
1414 if (switchEnv.info.cont != null) {
1415 Assert.check(patternSwitch);
1416 code.resolve(switchEnv.info.cont, switchStart);
1417 }
1418
1419 // Resolve all breaks.
1420 code.resolve(switchEnv.info.exit);
1421
1422 // If we have not set the default offset, we do so now.
1432 if (code.get4(t) == -1)
1433 code.put4(t, defaultOffset);
1434 }
1435 } else {
1436 // Sort non-default offsets and copy into lookup table.
1437 if (defaultIndex >= 0)
1438 for (int i = defaultIndex; i < labels.length - 1; i++) {
1439 labels[i] = labels[i+1];
1440 offsets[i] = offsets[i+1];
1441 }
1442 if (nlabels > 0)
1443 qsort2(labels, offsets, 0, nlabels - 1);
1444 for (int i = 0; i < nlabels; i++) {
1445 int caseidx = tableBase + 8 * (i + 1);
1446 code.put4(caseidx, labels[i]);
1447 code.put4(caseidx + 4, offsets[i]);
1448 }
1449 }
1450
1451 if (swtch instanceof JCSwitchExpression) {
1452 // Emit line position for the end of a switch expression
1453 code.statBegin(TreeInfo.endPos(swtch));
1454 }
1455 }
1456 code.endScopes(limit);
1457 }
1458 //where
1459 /** Sort (int) arrays of keys and values
1460 */
1461 static void qsort2(int[] keys, int[] values, int lo, int hi) {
1462 int i = lo;
1463 int j = hi;
1464 int pivot = keys[(i+j)/2];
1465 do {
1466 while (keys[i] < pivot) i++;
1467 while (pivot < keys[j]) j--;
1468 if (i <= j) {
1469 int temp1 = keys[i];
1470 keys[i] = keys[j];
1471 keys[j] = temp1;
1472 int temp2 = values[i];
1473 values[i] = values[j];
1536 @Override
1537 void afterBody() {
1538 if (tree.finalizer != null && (tree.finalizer.flags & BODY_ONLY_FINALIZE) != 0) {
1539 //for body-only finally, remove the GenFinalizer after try body
1540 //so that the finally is not generated to catch bodies:
1541 tryEnv.info.finalize = null;
1542 }
1543 }
1544
1545 };
1546 tryEnv.info.gaps = new ListBuffer<>();
1547 genTry(tree.body, tree.catchers, tryEnv);
1548 }
1549 //where
1550 /** Generate code for a try or synchronized statement
1551 * @param body The body of the try or synchronized statement.
1552 * @param catchers The list of catch clauses.
1553 * @param env The current environment of the body.
1554 */
1555 void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) {
1556 int limit = code.nextreg;
1557 int startpc = code.curCP();
1558 Code.State stateTry = code.state.dup();
1559 genStat(body, env, CRT_BLOCK);
1560 int endpc = code.curCP();
1561 List<Integer> gaps = env.info.gaps.toList();
1562 code.statBegin(TreeInfo.endPos(body));
1563 genFinalizer(env);
1564 code.statBegin(TreeInfo.endPos(env.tree));
1565 Chain exitChain;
1566 boolean actualTry = env.tree.hasTag(TRY);
1567 if (startpc == endpc && actualTry) {
1568 exitChain = code.branch(dontgoto);
1569 } else {
1570 exitChain = code.branch(goto_);
1571 }
1572 endFinalizerGap(env);
1573 env.info.finalize.afterBody();
1574 boolean hasFinalizer =
1575 env.info.finalize != null &&
1576 env.info.finalize.hasFinalizer();
1577 if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) {
1578 // start off with exception on stack
1579 code.entryPoint(stateTry, l.head.param.sym.type);
1580 genCatch(l.head, env, startpc, endpc, gaps);
1581 genFinalizer(env);
1582 if (hasFinalizer || l.tail.nonEmpty()) {
1583 code.statBegin(TreeInfo.endPos(env.tree));
1584 exitChain = Code.mergeChains(exitChain,
1585 code.branch(goto_));
1586 }
1587 endFinalizerGap(env);
1588 }
1589 if (hasFinalizer && (startpc != endpc || !actualTry)) {
1590 // Create a new register segment to avoid allocating
1591 // the same variables in finalizers and other statements.
1592 code.newRegSegment();
1593
1594 // Add a catch-all clause.
1595
1596 // start off with exception on stack
1597 int catchallpc = code.entryPoint(stateTry, syms.throwableType);
1598
1599 // Register all exception ranges for catch all clause.
1600 // The range of the catch all clause is from the beginning
1601 // of the try or synchronized block until the present
1602 // code pointer excluding all gaps in the current
1603 // environment's GenContext.
1604 int startseg = startpc;
1605 while (env.info.gaps.nonEmpty()) {
1606 int endseg = env.info.gaps.next().intValue();
1607 registerCatch(body.pos(), startseg, endseg,
1608 catchallpc, 0);
1609 startseg = env.info.gaps.next().intValue();
1610 }
1611 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1612 code.markStatBegin();
1613
1614 Item excVar = makeTemp(syms.throwableType);
1615 excVar.store();
1616 genFinalizer(env);
1617 code.resolvePending();
1618 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.END_POS));
1619 code.markStatBegin();
1620
1621 excVar.load();
1622 registerCatch(body.pos(), startseg,
1623 env.info.gaps.next().intValue(),
1624 catchallpc, 0);
1625 code.emitop0(athrow);
1626 code.markDead();
1627
1628 // If there are jsr's to this finalizer, ...
1629 if (env.info.cont != null) {
1630 // Resolve all jsr's.
1631 code.resolve(env.info.cont);
1632
1633 // Mark statement line number
1634 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1635 code.markStatBegin();
1636
1637 // Save return address.
1638 LocalItem retVar = makeTemp(syms.throwableType);
1639 retVar.store();
1640
1641 // Generate finalizer code.
1642 env.info.finalize.genLast();
1643
1644 // Return.
1747 /** Register a catch clause in the "Exceptions" code-attribute.
1748 */
1749 void registerCatch(DiagnosticPosition pos,
1750 int startpc, int endpc,
1751 int handler_pc, int catch_type) {
1752 char startpc1 = (char)startpc;
1753 char endpc1 = (char)endpc;
1754 char handler_pc1 = (char)handler_pc;
1755 if (startpc1 == startpc &&
1756 endpc1 == endpc &&
1757 handler_pc1 == handler_pc) {
1758 code.addCatch(startpc1, endpc1, handler_pc1,
1759 (char)catch_type);
1760 } else {
1761 log.error(pos, Errors.LimitCodeTooLargeForTryStmt);
1762 nerrs++;
1763 }
1764 }
1765
1766 public void visitIf(JCIf tree) {
1767 int limit = code.nextreg;
1768 Chain thenExit = null;
1769 Assert.check(code.isStatementStart());
1770 CondItem c = genCond(TreeInfo.skipParens(tree.cond),
1771 CRT_FLOW_CONTROLLER);
1772 Chain elseChain = c.jumpFalse();
1773 Assert.check(code.isStatementStart());
1774 if (!c.isFalse()) {
1775 code.resolve(c.trueJumps);
1776 genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET);
1777 thenExit = code.branch(goto_);
1778 }
1779 if (elseChain != null) {
1780 code.resolve(elseChain);
1781 if (tree.elsepart != null) {
1782 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET);
1783 }
1784 }
1785 code.resolve(thenExit);
1786 code.endScopes(limit);
1787 Assert.check(code.isStatementStart());
1788 }
1789
1790 public void visitExec(JCExpressionStatement tree) {
1791 // Optimize x++ to ++x and x-- to --x.
2075 nerrs++;
2076 }
2077 int elemcode = Code.arraycode(elemtype);
2078 if (elemcode == 0 || (elemcode == 1 && ndims == 1)) {
2079 code.emitAnewarray(makeRef(pos, elemtype), type);
2080 } else if (elemcode == 1) {
2081 code.emitMultianewarray(ndims, makeRef(pos, type), type);
2082 } else {
2083 code.emitNewarray(elemcode, type);
2084 }
2085 return items.makeStackItem(type);
2086 }
2087
2088 public void visitParens(JCParens tree) {
2089 result = genExpr(tree.expr, tree.expr.type);
2090 }
2091
2092 public void visitAssign(JCAssign tree) {
2093 Item l = genExpr(tree.lhs, tree.lhs.type);
2094 genExpr(tree.rhs, tree.lhs.type).load();
2095 if (tree.rhs.type.hasTag(BOT)) {
2096 /* This is just a case of widening reference conversion that per 5.1.5 simply calls
2097 for "regarding a reference as having some other type in a manner that can be proved
2098 correct at compile time."
2099 */
2100 code.state.forceStackTop(tree.lhs.type);
2101 }
2102 result = items.makeAssignItem(l);
2103 }
2104
2105 public void visitAssignop(JCAssignOp tree) {
2106 OperatorSymbol operator = tree.operator;
2107 Item l;
2108 if (operator.opcode == string_add) {
2109 l = concat.makeConcat(tree);
2110 } else {
2111 // Generate code for first expression
2112 l = genExpr(tree.lhs, tree.lhs.type);
2113
2114 // If we have an increment of -32768 to +32767 of a local
2353 items.makeThisItem().load();
2354 sym = binaryQualifier(sym, env.enclClass.type);
2355 result = items.makeMemberItem(sym, nonVirtualForPrivateAccess(sym));
2356 }
2357 }
2358
2359 //where
2360 private boolean nonVirtualForPrivateAccess(Symbol sym) {
2361 boolean useVirtual = target.hasVirtualPrivateInvoke() &&
2362 !disableVirtualizedPrivateInvoke;
2363 return !useVirtual && ((sym.flags() & PRIVATE) != 0);
2364 }
2365
2366 public void visitSelect(JCFieldAccess tree) {
2367 Symbol sym = tree.sym;
2368
2369 if (tree.name == names._class) {
2370 code.emitLdc((LoadableConstant)checkDimension(tree.pos(), tree.selected.type));
2371 result = items.makeStackItem(pt);
2372 return;
2373 }
2374
2375 Symbol ssym = TreeInfo.symbol(tree.selected);
2376
2377 // Are we selecting via super?
2378 boolean selectSuper =
2379 ssym != null && (ssym.kind == TYP || ssym.name == names._super);
2380
2381 // Are we accessing a member of the superclass in an access method
2382 // resulting from a qualified super?
2383 boolean accessSuper = isAccessSuper(env.enclMethod);
2384
2385 Item base = (selectSuper)
2386 ? items.makeSuperItem()
2387 : genExpr(tree.selected, tree.selected.type);
2388
2389 if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) {
2390 // We are seeing a variable that is constant but its selecting
2391 // expression is not.
2392 if ((sym.flags() & STATIC) != 0) {
2393 if (!selectSuper && (ssym == null || ssym.kind != TYP))
|
61 * <p><b>This is NOT part of any supported API.
62 * If you write code that depends on this, you do so at your own risk.
63 * This code and its internal interfaces are subject to change or
64 * deletion without notice.</b>
65 */
66 public class Gen extends JCTree.Visitor {
67 protected static final Context.Key<Gen> genKey = new Context.Key<>();
68
69 private final Log log;
70 private final Symtab syms;
71 private final Check chk;
72 private final Resolve rs;
73 private final TreeMaker make;
74 private final Names names;
75 private final Target target;
76 private final String accessDollar;
77 private final Types types;
78 private final Lower lower;
79 private final Annotate annotate;
80 private final StringConcat concat;
81 private final LocalProxyVarsGen localProxyVarsGen;
82
83 /** Format of stackmap tables to be generated. */
84 private final Code.StackMapFormat stackMap;
85
86 /** A type that serves as the expected type for all method expressions.
87 */
88 private final Type methodType;
89
90 public static Gen instance(Context context) {
91 Gen instance = context.get(genKey);
92 if (instance == null)
93 instance = new Gen(context);
94 return instance;
95 }
96
97 /** Constant pool writer, set by genClass.
98 */
99 final PoolWriter poolWriter;
100
101 private final UnsetFieldsInfo unsetFieldsInfo;
102
103 @SuppressWarnings("this-escape")
104 protected Gen(Context context) {
105 context.put(genKey, this);
106
107 names = Names.instance(context);
108 log = Log.instance(context);
109 syms = Symtab.instance(context);
110 chk = Check.instance(context);
111 rs = Resolve.instance(context);
112 make = TreeMaker.instance(context);
113 target = Target.instance(context);
114 types = Types.instance(context);
115 concat = StringConcat.instance(context);
116 localProxyVarsGen = LocalProxyVarsGen.instance(context);
117
118 methodType = new MethodType(null, null, null, syms.methodClass);
119 accessDollar = "access" + target.syntheticNameChar();
120 lower = Lower.instance(context);
121
122 Options options = Options.instance(context);
123 lineDebugInfo =
124 options.isUnset(G_CUSTOM) ||
125 options.isSet(G_CUSTOM, "lines");
126 varDebugInfo =
127 options.isUnset(G_CUSTOM)
128 ? options.isSet(G)
129 : options.isSet(G_CUSTOM, "vars");
130 genCrt = options.isSet(XJCOV);
131 debugCode = options.isSet("debug.code");
132 disableVirtualizedPrivateInvoke = options.isSet("disableVirtualizedPrivateInvoke");
133 poolWriter = new PoolWriter(types, names);
134 unsetFieldsInfo = UnsetFieldsInfo.instance(context);
135
136 // ignore cldc because we cannot have both stackmap formats
137 this.stackMap = StackMapFormat.JSR202;
138 annotate = Annotate.instance(context);
139 qualifiedSymbolCache = new HashMap<>();
140 Preview preview = Preview.instance(context);
141 Source source = Source.instance(context);
142 allowValueClasses = (!preview.isPreview(Source.Feature.VALUE_CLASSES) || preview.isEnabled()) &&
143 Source.Feature.VALUE_CLASSES.allowedInSource(source);
144 }
145
146 /** Switches
147 */
148 private final boolean lineDebugInfo;
149 private final boolean varDebugInfo;
150 private final boolean genCrt;
151 private final boolean debugCode;
152 private boolean disableVirtualizedPrivateInvoke;
153 private final boolean allowValueClasses;
154
155 /** Code buffer, set by genMethod.
156 */
157 private Code code;
158
159 /** Items structure, set by genMethod.
160 */
161 private Items items;
162
163 /** Environment for symbol lookup, set by genClass
164 */
165 private Env<AttrContext> attrEnv;
166
167 /** The top level tree.
168 */
169 private JCCompilationUnit toplevel;
170
171 /** The number of code-gen errors in this class.
172 */
173 private int nerrs = 0;
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());
546
547 /** Check a constant value and report if it is a string that is
548 * too large.
549 */
550 private void checkStringConstant(DiagnosticPosition pos, Object constValue) {
551 if (nerrs != 0 || // only complain about a long string once
552 constValue == null ||
553 !(constValue instanceof String str) ||
554 str.length() < PoolWriter.MAX_STRING_LENGTH)
555 return;
556 log.error(pos, Errors.LimitString);
557 nerrs++;
558 }
559
560 /** Insert instance initializer code into constructors prior to the super() call.
561 * @param md The tree potentially representing a
562 * constructor's definition.
563 * @param initCode The list of instance initializer statements.
564 * @param initTAs Type annotations from the initializer expression.
565 */
566 void normalizeMethod(JCMethodDecl md, List<JCStatement> initCode, List<JCStatement> initBlocks, List<TypeCompound> initTAs) {
567 Set<Symbol> fieldsWithInits;
568 List<JCStatement> inits;
569 if ((fieldsWithInits = localProxyVarsGen.initializersAlreadyInConst.get(md)) != null) {
570 ListBuffer<JCStatement> newInitCode = new ListBuffer<>();
571 for (JCStatement init : initCode) {
572 Symbol sym = ((JCIdent)((JCAssign)((JCExpressionStatement)init).expr).lhs).sym;
573 if (!fieldsWithInits.contains(sym)) {
574 newInitCode.add(init);
575 }
576 }
577 inits = newInitCode.toList();
578 localProxyVarsGen.initializersAlreadyInConst.remove(md);
579 } else {
580 inits = initCode;
581 }
582 if (TreeInfo.isConstructor(md) && TreeInfo.hasConstructorCall(md, names._super)) {
583 // We are seeing a constructor that has a super() call.
584 // Find the super() invocation and append the given initializer code.
585 if (allowValueClasses & (md.sym.owner.isValueClass() || md.sym.owner.hasStrict() || ((md.sym.owner.flags_field & RECORD) != 0))) {
586 rewriteInitializersIfNeeded(md, inits);
587 md.body.stats = inits.appendList(md.body.stats);
588 TreeInfo.mapSuperCalls(md.body, supercall -> make.Block(0, initBlocks.prepend(supercall)));
589 } else {
590 TreeInfo.mapSuperCalls(md.body, supercall -> make.Block(0, inits.prepend(supercall)));
591 }
592
593 if (md.body.bracePos == Position.NOPOS)
594 md.body.bracePos = TreeInfo.endPos(md.body.stats.last());
595
596 md.sym.appendUniqueTypeAttributes(initTAs);
597 }
598 }
599
600 void rewriteInitializersIfNeeded(JCMethodDecl md, List<JCStatement> initCode) {
601 if (lower.initializerOuterThis.containsKey(md.sym.owner)) {
602 InitializerVisitor initializerVisitor = new InitializerVisitor(md, lower.initializerOuterThis.get(md.sym.owner));
603 for (JCStatement init : initCode) {
604 initializerVisitor.scan(init);
605 }
606 }
607 }
608
609 public static class InitializerVisitor extends TreeScanner {
610 JCMethodDecl md;
611 Set<JCExpression> exprSet;
612
613 public InitializerVisitor(JCMethodDecl md, Set<JCExpression> exprSet) {
614 this.md = md;
615 this.exprSet = exprSet;
616 }
617
618 @Override
619 public void visitTree(JCTree tree) {}
620
621 @Override
622 public void visitIdent(JCIdent tree) {
623 if (exprSet.contains(tree)) {
624 for (JCVariableDecl param: md.params) {
625 if (param.name == tree.name &&
626 ((param.sym.flags_field & (MANDATED | NOOUTERTHIS)) == (MANDATED | NOOUTERTHIS))) {
627 tree.sym = param.sym;
628 }
629 }
630 }
631 }
632 }
633
634 /* ************************************************************************
635 * Traversal methods
636 *************************************************************************/
637
638 /** Visitor argument: The current environment.
639 */
640 Env<GenContext> env;
641
642 /** Visitor argument: The expected type (prototype).
643 */
644 Type pt;
645
646 /** Visitor result: The item representing the computed value.
647 */
648 Item result;
649
650 /** Visitor method: generate code for a definition, catching and reporting
651 * any completion failures.
652 * @param tree The definition to be visited.
653 * @param env The environment current at the definition.
1010 // Count up extra parameters
1011 if (meth.isConstructor()) {
1012 extras++;
1013 if (meth.enclClass().isInner() &&
1014 !meth.enclClass().isStatic()) {
1015 extras++;
1016 }
1017 } else if ((tree.mods.flags & STATIC) == 0) {
1018 extras++;
1019 }
1020 // System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG
1021 if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes()) + extras >
1022 ClassFile.MAX_PARAMETERS) {
1023 log.error(tree.pos(), Errors.LimitParameters);
1024 nerrs++;
1025 }
1026
1027 else if (tree.body != null) {
1028 // Create a new code structure and initialize it.
1029 int startpcCrt = initCode(tree, env, fatcode);
1030 Set<VarSymbol> prevUnsetFields = code.currentUnsetFields;
1031 if (meth.isConstructor()) {
1032 code.currentUnsetFields = unsetFieldsInfo.getUnsetFields(env.enclClass.sym, tree.body);
1033 code.initialUnsetFields = unsetFieldsInfo.getUnsetFields(env.enclClass.sym, tree.body);
1034 }
1035
1036 try {
1037 genStat(tree.body, env);
1038 } catch (CodeSizeOverflow e) {
1039 // Failed due to code limit, try again with jsr/ret
1040 startpcCrt = initCode(tree, env, fatcode);
1041 genStat(tree.body, env);
1042 } finally {
1043 code.currentUnsetFields = prevUnsetFields;
1044 }
1045
1046 if (code.state.stacksize != 0) {
1047 log.error(tree.body.pos(), Errors.StackSimError(tree.sym));
1048 throw new AssertionError();
1049 }
1050
1051 // If last statement could complete normally, insert a
1052 // return at the end.
1053 if (code.isAlive()) {
1054 code.statBegin(TreeInfo.endPos(tree.body));
1055 if (env.enclMethod == null ||
1056 env.enclMethod.sym.type.getReturnType().hasTag(VOID)) {
1057 code.emitop0(return_);
1058 } else {
1059 // sometime dead code seems alive (4415991);
1060 // generate a small loop instead
1061 int startpc = code.entryPoint();
1062 CondItem c = items.makeCondItem(goto_);
1063 code.resolve(c.jumpTrue(), startpc);
1092
1093 // Fill in type annotation positions for exception parameters
1094 code.fillExceptionParameterPositions();
1095 }
1096 }
1097
1098 private int initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
1099 MethodSymbol meth = tree.sym;
1100
1101 // Create a new code structure.
1102 meth.code = code = new Code(meth,
1103 fatcode,
1104 lineDebugInfo ? toplevel.lineMap : null,
1105 varDebugInfo,
1106 stackMap,
1107 debugCode,
1108 genCrt ? new CRTable(tree, env.toplevel.endPositions)
1109 : null,
1110 syms,
1111 types,
1112 poolWriter,
1113 allowValueClasses);
1114 items = new Items(poolWriter, code, syms, types);
1115 if (code.debugCode) {
1116 System.err.println(meth + " for body " + tree);
1117 }
1118
1119 // If method is not static, create a new local variable address
1120 // for `this'.
1121 if ((tree.mods.flags & STATIC) == 0) {
1122 Type selfType = meth.owner.type;
1123 if (meth.isConstructor() && selfType != syms.objectType)
1124 selfType = UninitializedType.uninitializedThis(selfType);
1125 code.setDefined(
1126 code.newLocal(
1127 new VarSymbol(FINAL, names._this, selfType, meth.owner)));
1128 }
1129
1130 // Mark all parameters as defined from the beginning of
1131 // the method.
1132 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
1133 checkDimension(l.head.pos(), l.head.sym.type);
1229 public void visitForLoop(JCForLoop tree) {
1230 int limit = code.nextreg;
1231 genStats(tree.init, env);
1232 genLoop(tree, tree.body, tree.cond, tree.step, true);
1233 code.endScopes(limit);
1234 }
1235 //where
1236 /** Generate code for a loop.
1237 * @param loop The tree representing the loop.
1238 * @param body The loop's body.
1239 * @param cond The loop's controlling condition.
1240 * @param step "Step" statements to be inserted at end of
1241 * each iteration.
1242 * @param testFirst True if the loop test belongs before the body.
1243 */
1244 private void genLoop(JCStatement loop,
1245 JCStatement body,
1246 JCExpression cond,
1247 List<JCExpressionStatement> step,
1248 boolean testFirst) {
1249 Set<VarSymbol> prevCodeUnsetFields = code.currentUnsetFields;
1250 try {
1251 genLoopHelper(loop, body, cond, step, testFirst);
1252 } finally {
1253 code.currentUnsetFields = prevCodeUnsetFields;
1254 }
1255 }
1256
1257 private void genLoopHelper(JCStatement loop,
1258 JCStatement body,
1259 JCExpression cond,
1260 List<JCExpressionStatement> step,
1261 boolean testFirst) {
1262 Env<GenContext> loopEnv = env.dup(loop, new GenContext());
1263 int startpc = code.entryPoint();
1264 if (testFirst) { //while or for loop
1265 CondItem c;
1266 if (cond != null) {
1267 code.statBegin(cond.pos);
1268 Assert.check(code.isStatementStart());
1269 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1270 } else {
1271 c = items.makeCondItem(goto_);
1272 }
1273 Chain loopDone = c.jumpFalse();
1274 code.resolve(c.trueJumps);
1275 Assert.check(code.isStatementStart());
1276 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1277 code.resolve(loopEnv.info.cont);
1278 genStats(step, loopEnv);
1279 code.resolve(code.branch(goto_), startpc);
1280 code.resolve(loopDone);
1281 } else {
1300 }
1301
1302 public void visitForeachLoop(JCEnhancedForLoop tree) {
1303 throw new AssertionError(); // should have been removed by Lower.
1304 }
1305
1306 public void visitLabelled(JCLabeledStatement tree) {
1307 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1308 genStat(tree.body, localEnv, CRT_STATEMENT);
1309 code.resolve(localEnv.info.exit);
1310 }
1311
1312 public void visitSwitch(JCSwitch tree) {
1313 handleSwitch(tree, tree.selector, tree.cases, tree.patternSwitch);
1314 }
1315
1316 @Override
1317 public void visitSwitchExpression(JCSwitchExpression tree) {
1318 code.resolvePending();
1319 boolean prevInCondSwitchExpression = inCondSwitchExpression;
1320 Set<VarSymbol> prevCodeUnsetFields = code.currentUnsetFields;
1321 try {
1322 inCondSwitchExpression = false;
1323 doHandleSwitchExpression(tree);
1324 } finally {
1325 inCondSwitchExpression = prevInCondSwitchExpression;
1326 code.currentUnsetFields = prevCodeUnsetFields;
1327 }
1328 result = items.makeStackItem(pt);
1329 }
1330
1331 private void doHandleSwitchExpression(JCSwitchExpression tree) {
1332 List<LocalItem> prevStackBeforeSwitchExpression = stackBeforeSwitchExpression;
1333 LocalItem prevSwitchResult = switchResult;
1334 int limit = code.nextreg;
1335 try {
1336 stackBeforeSwitchExpression = List.nil();
1337 switchResult = null;
1338 if (hasTry(tree)) {
1339 //if the switch expression contains try-catch, the catch handlers need to have
1340 //an empty stack. So stash whole stack to local variables, and restore it before
1341 //breaks:
1342 while (code.state.stacksize > 0) {
1343 Type type = code.state.peek();
1344 Name varName = names.fromString(target.syntheticNameChar() +
1345 "stack" +
1346 target.syntheticNameChar() +
1382 hasTry = true;
1383 }
1384
1385 @Override
1386 public void visitClassDef(JCClassDecl tree) {
1387 }
1388
1389 @Override
1390 public void visitLambda(JCLambda tree) {
1391 }
1392 };
1393
1394 HasTryScanner hasTryScanner = new HasTryScanner();
1395
1396 hasTryScanner.scan(tree);
1397 return hasTryScanner.hasTry;
1398 }
1399
1400 private void handleSwitch(JCTree swtch, JCExpression selector, List<JCCase> cases,
1401 boolean patternSwitch) {
1402 Set<VarSymbol> prevCodeUnsetFields = code.currentUnsetFields;
1403 try {
1404 handleSwitchHelper(swtch, selector, cases, patternSwitch);
1405 } finally {
1406 code.currentUnsetFields = prevCodeUnsetFields;
1407 }
1408 }
1409
1410 void handleSwitchHelper(JCTree swtch, JCExpression selector, List<JCCase> cases,
1411 boolean patternSwitch) {
1412 int limit = code.nextreg;
1413 Assert.check(!selector.type.hasTag(CLASS));
1414 int switchStart = patternSwitch ? code.entryPoint() : -1;
1415 int startpcCrt = genCrt ? code.curCP() : 0;
1416 Assert.check(code.isStatementStart());
1417 Item sel = genExpr(selector, syms.intType);
1418 if (cases.isEmpty()) {
1419 // We are seeing: switch <sel> {}
1420 sel.load().drop();
1421 if (genCrt)
1422 code.crt.put(TreeInfo.skipParens(selector),
1423 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1424 } else {
1425 // We are seeing a nonempty switch.
1426 sel.load();
1427 if (genCrt)
1428 code.crt.put(TreeInfo.skipParens(selector),
1429 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1430 Env<GenContext> switchEnv = env.dup(swtch, new GenContext());
1431 switchEnv.info.isSwitch = true;
1432
1433 // Compute number of labels and minimum and maximum label values.
1434 // For each case, store its label in an array.
1435 int lo = Integer.MAX_VALUE; // minimum label.
1436 int hi = Integer.MIN_VALUE; // maximum label.
1437 int nlabels = 0; // number of labels.
1438
1439 int[] labels = new int[cases.length()]; // the label array.
1440 int defaultIndex = -1; // the index of the default clause.
1441
1442 List<JCCase> l = cases;
1443 for (int i = 0; i < labels.length; i++) {
1444 if (l.head.labels.head instanceof JCConstantCaseLabel constLabel) {
1445 Assert.check(l.head.labels.size() == 1);
1446 int val = ((Number) constLabel.expr.type.constValue()).intValue();
1447 labels[i] = val;
1448 if (val < lo) lo = val;
1449 if (hi < val) hi = val;
1450 nlabels++;
1451 } else {
1452 Assert.check(defaultIndex == -1);
1453 defaultIndex = i;
1454 }
1455 l = l.tail;
1456 }
1457
1458 // Determine whether to issue a tableswitch or a lookupswitch
1459 // instruction.
1460 long table_space_cost = 4 + ((long) hi - lo + 1); // words
1461 long table_time_cost = 3; // comparisons
1462 long lookup_space_cost = 3 + 2 * (long) nlabels;
1463 long lookup_time_cost = nlabels;
1464 int opcode =
1465 nlabels > 0 &&
1466 table_space_cost + 3 * table_time_cost <=
1467 lookup_space_cost + 3 * lookup_time_cost
1468 ?
1469 tableswitch : lookupswitch;
1470
1471 int startpc = code.curCP(); // the position of the selector operation
1472 code.emitop0(opcode);
1473 code.align(4);
1474 int tableBase = code.curCP(); // the start of the jump table
1475 int[] offsets = null; // a table of offsets for a lookupswitch
1476 code.emit4(-1); // leave space for default offset
1477 if (opcode == tableswitch) {
1478 code.emit4(lo); // minimum label
1479 code.emit4(hi); // maximum label
1480 for (long i = lo; i <= hi; i++) { // leave space for jump table
1481 code.emit4(-1);
1482 }
1483 } else {
1484 code.emit4(nlabels); // number of labels
1485 for (int i = 0; i < nlabels; i++) {
1486 code.emit4(-1); code.emit4(-1); // leave space for lookup table
1487 }
1488 offsets = new int[labels.length];
1489 }
1490 Code.State stateSwitch = code.state.dup();
1491 code.markDead();
1492
1493 // For each case do:
1494 l = cases;
1495 for (int i = 0; i < labels.length; i++) {
1496 JCCase c = l.head;
1497 l = l.tail;
1498
1499 int pc = code.entryPoint(stateSwitch);
1500 // Insert offset directly into code or else into the
1501 // offsets table.
1502 if (i != defaultIndex) {
1503 if (opcode == tableswitch) {
1504 code.put4(
1505 tableBase + 4 * (labels[i] - lo + 3),
1506 pc - startpc);
1507 } else {
1508 offsets[i] = pc - startpc;
1509 }
1510 } else {
1511 code.put4(tableBase, pc - startpc);
1512 }
1513
1514 // Generate code for the statements in this case.
1515 genStats(c.stats, switchEnv, CRT_FLOW_TARGET);
1516 }
1517
1518 if (switchEnv.info.cont != null) {
1519 Assert.check(patternSwitch);
1520 code.resolve(switchEnv.info.cont, switchStart);
1521 }
1522
1523 // Resolve all breaks.
1524 code.resolve(switchEnv.info.exit);
1525
1526 // If we have not set the default offset, we do so now.
1536 if (code.get4(t) == -1)
1537 code.put4(t, defaultOffset);
1538 }
1539 } else {
1540 // Sort non-default offsets and copy into lookup table.
1541 if (defaultIndex >= 0)
1542 for (int i = defaultIndex; i < labels.length - 1; i++) {
1543 labels[i] = labels[i+1];
1544 offsets[i] = offsets[i+1];
1545 }
1546 if (nlabels > 0)
1547 qsort2(labels, offsets, 0, nlabels - 1);
1548 for (int i = 0; i < nlabels; i++) {
1549 int caseidx = tableBase + 8 * (i + 1);
1550 code.put4(caseidx, labels[i]);
1551 code.put4(caseidx + 4, offsets[i]);
1552 }
1553 }
1554
1555 if (swtch instanceof JCSwitchExpression) {
1556 // Emit line position for the end of a switch expression
1557 code.statBegin(TreeInfo.endPos(swtch));
1558 }
1559 }
1560 code.endScopes(limit);
1561 }
1562 //where
1563 /** Sort (int) arrays of keys and values
1564 */
1565 static void qsort2(int[] keys, int[] values, int lo, int hi) {
1566 int i = lo;
1567 int j = hi;
1568 int pivot = keys[(i+j)/2];
1569 do {
1570 while (keys[i] < pivot) i++;
1571 while (pivot < keys[j]) j--;
1572 if (i <= j) {
1573 int temp1 = keys[i];
1574 keys[i] = keys[j];
1575 keys[j] = temp1;
1576 int temp2 = values[i];
1577 values[i] = values[j];
1640 @Override
1641 void afterBody() {
1642 if (tree.finalizer != null && (tree.finalizer.flags & BODY_ONLY_FINALIZE) != 0) {
1643 //for body-only finally, remove the GenFinalizer after try body
1644 //so that the finally is not generated to catch bodies:
1645 tryEnv.info.finalize = null;
1646 }
1647 }
1648
1649 };
1650 tryEnv.info.gaps = new ListBuffer<>();
1651 genTry(tree.body, tree.catchers, tryEnv);
1652 }
1653 //where
1654 /** Generate code for a try or synchronized statement
1655 * @param body The body of the try or synchronized statement.
1656 * @param catchers The list of catch clauses.
1657 * @param env The current environment of the body.
1658 */
1659 void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) {
1660 Set<VarSymbol> prevCodeUnsetFields = code.currentUnsetFields;
1661 try {
1662 genTryHelper(body, catchers, env);
1663 } finally {
1664 code.currentUnsetFields = prevCodeUnsetFields;
1665 }
1666 }
1667
1668 void genTryHelper(JCTree body, List<JCCatch> catchers, Env<GenContext> env) {
1669 int limit = code.nextreg;
1670 int startpc = code.curCP();
1671 Code.State stateTry = code.state.dup();
1672 genStat(body, env, CRT_BLOCK);
1673 int endpc = code.curCP();
1674 List<Integer> gaps = env.info.gaps.toList();
1675 code.statBegin(TreeInfo.endPos(body));
1676 genFinalizer(env);
1677 code.statBegin(TreeInfo.endPos(env.tree));
1678 Chain exitChain;
1679 boolean actualTry = env.tree.hasTag(TRY);
1680 if (startpc == endpc && actualTry) {
1681 exitChain = code.branch(dontgoto);
1682 } else {
1683 exitChain = code.branch(goto_);
1684 }
1685 endFinalizerGap(env);
1686 env.info.finalize.afterBody();
1687 boolean hasFinalizer =
1688 env.info.finalize != null &&
1689 env.info.finalize.hasFinalizer();
1690 if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) {
1691 // start off with exception on stack
1692 code.entryPoint(stateTry, l.head.param.sym.type);
1693 genCatch(l.head, env, startpc, endpc, gaps);
1694 genFinalizer(env);
1695 if (hasFinalizer || l.tail.nonEmpty()) {
1696 code.statBegin(TreeInfo.endPos(env.tree));
1697 exitChain = Code.mergeChains(exitChain,
1698 code.branch(goto_));
1699 }
1700 endFinalizerGap(env);
1701 }
1702 if (hasFinalizer && (startpc != endpc || !actualTry)) {
1703 // Create a new register segment to avoid allocating
1704 // the same variables in finalizers and other statements.
1705 code.newRegSegment();
1706
1707 // Add a catch-all clause.
1708
1709 // start off with exception on stack
1710 int catchallpc = code.entryPoint(stateTry, syms.throwableType);
1711
1712 // Register all exception ranges for catch all clause.
1713 // The range of the catch all clause is from the beginning
1714 // of the try or synchronized block until the present
1715 // code pointer excluding all gaps in the current
1716 // environment's GenContext.
1717 int startseg = startpc;
1718 while (env.info.gaps.nonEmpty()) {
1719 int endseg = env.info.gaps.next().intValue();
1720 registerCatch(body.pos(), startseg, endseg,
1721 catchallpc, 0);
1722 startseg = env.info.gaps.next().intValue();
1723 }
1724 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1725 code.markStatBegin();
1726
1727 Item excVar = makeTemp(syms.throwableType);
1728 excVar.store();
1729 genFinalizer(env);
1730 code.resolvePending();
1731 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.END_POS));
1732 code.markStatBegin();
1733
1734 excVar.load();
1735 registerCatch(body.pos(), startseg,
1736 env.info.gaps.next().intValue(),
1737 catchallpc, 0);
1738 code.emitop0(athrow);
1739 code.markDead();
1740
1741 // If there are jsr's to this finalizer, ...
1742 if (env.info.cont != null) {
1743 // Resolve all jsr's.
1744 code.resolve(env.info.cont);
1745
1746 // Mark statement line number
1747 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1748 code.markStatBegin();
1749
1750 // Save return address.
1751 LocalItem retVar = makeTemp(syms.throwableType);
1752 retVar.store();
1753
1754 // Generate finalizer code.
1755 env.info.finalize.genLast();
1756
1757 // Return.
1860 /** Register a catch clause in the "Exceptions" code-attribute.
1861 */
1862 void registerCatch(DiagnosticPosition pos,
1863 int startpc, int endpc,
1864 int handler_pc, int catch_type) {
1865 char startpc1 = (char)startpc;
1866 char endpc1 = (char)endpc;
1867 char handler_pc1 = (char)handler_pc;
1868 if (startpc1 == startpc &&
1869 endpc1 == endpc &&
1870 handler_pc1 == handler_pc) {
1871 code.addCatch(startpc1, endpc1, handler_pc1,
1872 (char)catch_type);
1873 } else {
1874 log.error(pos, Errors.LimitCodeTooLargeForTryStmt);
1875 nerrs++;
1876 }
1877 }
1878
1879 public void visitIf(JCIf tree) {
1880 Set<VarSymbol> prevCodeUnsetFields = code.currentUnsetFields;
1881 try {
1882 visitIfHelper(tree);
1883 } finally {
1884 code.currentUnsetFields = prevCodeUnsetFields;
1885 }
1886 }
1887
1888 public void visitIfHelper(JCIf tree) {
1889 int limit = code.nextreg;
1890 Chain thenExit = null;
1891 Assert.check(code.isStatementStart());
1892 CondItem c = genCond(TreeInfo.skipParens(tree.cond),
1893 CRT_FLOW_CONTROLLER);
1894 Chain elseChain = c.jumpFalse();
1895 Assert.check(code.isStatementStart());
1896 if (!c.isFalse()) {
1897 code.resolve(c.trueJumps);
1898 genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET);
1899 thenExit = code.branch(goto_);
1900 }
1901 if (elseChain != null) {
1902 code.resolve(elseChain);
1903 if (tree.elsepart != null) {
1904 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET);
1905 }
1906 }
1907 code.resolve(thenExit);
1908 code.endScopes(limit);
1909 Assert.check(code.isStatementStart());
1910 }
1911
1912 public void visitExec(JCExpressionStatement tree) {
1913 // Optimize x++ to ++x and x-- to --x.
2197 nerrs++;
2198 }
2199 int elemcode = Code.arraycode(elemtype);
2200 if (elemcode == 0 || (elemcode == 1 && ndims == 1)) {
2201 code.emitAnewarray(makeRef(pos, elemtype), type);
2202 } else if (elemcode == 1) {
2203 code.emitMultianewarray(ndims, makeRef(pos, type), type);
2204 } else {
2205 code.emitNewarray(elemcode, type);
2206 }
2207 return items.makeStackItem(type);
2208 }
2209
2210 public void visitParens(JCParens tree) {
2211 result = genExpr(tree.expr, tree.expr.type);
2212 }
2213
2214 public void visitAssign(JCAssign tree) {
2215 Item l = genExpr(tree.lhs, tree.lhs.type);
2216 genExpr(tree.rhs, tree.lhs.type).load();
2217 Set<VarSymbol> tmpUnsetSymbols = unsetFieldsInfo.getUnsetFields(env.enclClass.sym, tree);
2218 code.currentUnsetFields = tmpUnsetSymbols != null ? tmpUnsetSymbols : code.currentUnsetFields;
2219 if (tree.rhs.type.hasTag(BOT)) {
2220 /* This is just a case of widening reference conversion that per 5.1.5 simply calls
2221 for "regarding a reference as having some other type in a manner that can be proved
2222 correct at compile time."
2223 */
2224 code.state.forceStackTop(tree.lhs.type);
2225 }
2226 result = items.makeAssignItem(l);
2227 }
2228
2229 public void visitAssignop(JCAssignOp tree) {
2230 OperatorSymbol operator = tree.operator;
2231 Item l;
2232 if (operator.opcode == string_add) {
2233 l = concat.makeConcat(tree);
2234 } else {
2235 // Generate code for first expression
2236 l = genExpr(tree.lhs, tree.lhs.type);
2237
2238 // If we have an increment of -32768 to +32767 of a local
2477 items.makeThisItem().load();
2478 sym = binaryQualifier(sym, env.enclClass.type);
2479 result = items.makeMemberItem(sym, nonVirtualForPrivateAccess(sym));
2480 }
2481 }
2482
2483 //where
2484 private boolean nonVirtualForPrivateAccess(Symbol sym) {
2485 boolean useVirtual = target.hasVirtualPrivateInvoke() &&
2486 !disableVirtualizedPrivateInvoke;
2487 return !useVirtual && ((sym.flags() & PRIVATE) != 0);
2488 }
2489
2490 public void visitSelect(JCFieldAccess tree) {
2491 Symbol sym = tree.sym;
2492
2493 if (tree.name == names._class) {
2494 code.emitLdc((LoadableConstant)checkDimension(tree.pos(), tree.selected.type));
2495 result = items.makeStackItem(pt);
2496 return;
2497 }
2498
2499 Symbol ssym = TreeInfo.symbol(tree.selected);
2500
2501 // Are we selecting via super?
2502 boolean selectSuper =
2503 ssym != null && (ssym.kind == TYP || ssym.name == names._super);
2504
2505 // Are we accessing a member of the superclass in an access method
2506 // resulting from a qualified super?
2507 boolean accessSuper = isAccessSuper(env.enclMethod);
2508
2509 Item base = (selectSuper)
2510 ? items.makeSuperItem()
2511 : genExpr(tree.selected, tree.selected.type);
2512
2513 if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) {
2514 // We are seeing a variable that is constant but its selecting
2515 // expression is not.
2516 if ((sym.flags() & STATIC) != 0) {
2517 if (!selectSuper && (ssym == null || ssym.kind != TYP))
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