1 /* 2 * Copyright (c) 1999, 2019, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package com.sun.tools.javac.jvm; 27 28 import com.sun.tools.javac.jvm.PoolConstant.LoadableConstant; 29 import com.sun.tools.javac.tree.TreeInfo.PosKind; 30 import com.sun.tools.javac.util.*; 31 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition; 32 import com.sun.tools.javac.util.List; 33 import com.sun.tools.javac.code.*; 34 import com.sun.tools.javac.code.Attribute.TypeCompound; 35 import com.sun.tools.javac.code.Symbol.VarSymbol; 36 import com.sun.tools.javac.comp.*; 37 import com.sun.tools.javac.tree.*; 38 39 import com.sun.tools.javac.code.Symbol.*; 40 import com.sun.tools.javac.code.Type.*; 41 import com.sun.tools.javac.jvm.Code.*; 42 import com.sun.tools.javac.jvm.Items.*; 43 import com.sun.tools.javac.resources.CompilerProperties.Errors; 44 import com.sun.tools.javac.tree.EndPosTable; 45 import com.sun.tools.javac.tree.JCTree.*; 46 47 import static com.sun.tools.javac.code.Flags.*; 48 import static com.sun.tools.javac.code.Kinds.Kind.*; 49 import static com.sun.tools.javac.code.TypeTag.*; 50 import static com.sun.tools.javac.jvm.ByteCodes.*; 51 import static com.sun.tools.javac.jvm.CRTFlags.*; 52 import static com.sun.tools.javac.main.Option.*; 53 import static com.sun.tools.javac.tree.JCTree.Tag.*; 54 55 /** This pass maps flat Java (i.e. without inner classes) to bytecodes. 56 * 57 * <p><b>This is NOT part of any supported API. 58 * If you write code that depends on this, you do so at your own risk. 59 * This code and its internal interfaces are subject to change or 60 * deletion without notice.</b> 61 */ 62 public class Gen extends JCTree.Visitor { 63 protected static final Context.Key<Gen> genKey = new Context.Key<>(); 64 65 private final Log log; 66 private final Symtab syms; 67 private final Check chk; 68 private final Resolve rs; 69 private final TreeMaker make; 70 private final Names names; 71 private final Target target; 72 private final Name accessDollar; 73 private final Types types; 74 private final Lower lower; 75 private final Annotate annotate; 76 private final StringConcat concat; 77 78 /** Format of stackmap tables to be generated. */ 79 private final Code.StackMapFormat stackMap; 80 81 /** A type that serves as the expected type for all method expressions. 82 */ 83 private final Type methodType; 84 85 public static Gen instance(Context context) { 86 Gen instance = context.get(genKey); 87 if (instance == null) 88 instance = new Gen(context); 89 return instance; 90 } 91 92 /** Constant pool writer, set by genClass. 93 */ 94 final PoolWriter poolWriter; 95 96 protected Gen(Context context) { 97 context.put(genKey, this); 98 99 names = Names.instance(context); 100 log = Log.instance(context); 101 syms = Symtab.instance(context); 102 chk = Check.instance(context); 103 rs = Resolve.instance(context); 104 make = TreeMaker.instance(context); 105 target = Target.instance(context); 106 types = Types.instance(context); 107 concat = StringConcat.instance(context); 108 109 methodType = new MethodType(null, null, null, syms.methodClass); 110 accessDollar = names. 111 fromString("access" + target.syntheticNameChar()); 112 lower = Lower.instance(context); 113 114 Options options = Options.instance(context); 115 lineDebugInfo = 116 options.isUnset(G_CUSTOM) || 117 options.isSet(G_CUSTOM, "lines"); 118 varDebugInfo = 119 options.isUnset(G_CUSTOM) 120 ? options.isSet(G) 121 : options.isSet(G_CUSTOM, "vars"); 122 genCrt = options.isSet(XJCOV); 123 debugCode = options.isSet("debug.code"); 124 disableVirtualizedPrivateInvoke = options.isSet("disableVirtualizedPrivateInvoke"); 125 poolWriter = new PoolWriter(types, names); 126 127 // ignore cldc because we cannot have both stackmap formats 128 this.stackMap = StackMapFormat.JSR202; 129 annotate = Annotate.instance(context); 130 } 131 132 /** Switches 133 */ 134 private final boolean lineDebugInfo; 135 private final boolean varDebugInfo; 136 private final boolean genCrt; 137 private final boolean debugCode; 138 private boolean disableVirtualizedPrivateInvoke; 139 140 /** Code buffer, set by genMethod. 141 */ 142 private Code code; 143 144 /** Items structure, set by genMethod. 145 */ 146 private Items items; 147 148 /** Environment for symbol lookup, set by genClass 149 */ 150 private Env<AttrContext> attrEnv; 151 152 /** The top level tree. 153 */ 154 private JCCompilationUnit toplevel; 155 156 /** The number of code-gen errors in this class. 157 */ 158 private int nerrs = 0; 159 160 /** An object containing mappings of syntax trees to their 161 * ending source positions. 162 */ 163 EndPosTable endPosTable; 164 165 boolean inCondSwitchExpression; 166 Chain switchExpressionTrueChain; 167 Chain switchExpressionFalseChain; 168 List<LocalItem> stackBeforeSwitchExpression; 169 LocalItem switchResult; 170 171 /** Generate code to load an integer constant. 172 * @param n The integer to be loaded. 173 */ 174 void loadIntConst(int n) { 175 items.makeImmediateItem(syms.intType, n).load(); 176 } 177 178 /** The opcode that loads a zero constant of a given type code. 179 * @param tc The given type code (@see ByteCode). 180 */ 181 public static int zero(int tc) { 182 switch(tc) { 183 case INTcode: case BYTEcode: case SHORTcode: case CHARcode: 184 return iconst_0; 185 case LONGcode: 186 return lconst_0; 187 case FLOATcode: 188 return fconst_0; 189 case DOUBLEcode: 190 return dconst_0; 191 default: 192 throw new AssertionError("zero"); 193 } 194 } 195 196 /** The opcode that loads a one constant of a given type code. 197 * @param tc The given type code (@see ByteCode). 198 */ 199 public static int one(int tc) { 200 return zero(tc) + 1; 201 } 202 203 /** Generate code to load -1 of the given type code (either int or long). 204 * @param tc The given type code (@see ByteCode). 205 */ 206 void emitMinusOne(int tc) { 207 if (tc == LONGcode) { 208 items.makeImmediateItem(syms.longType, Long.valueOf(-1)).load(); 209 } else { 210 code.emitop0(iconst_m1); 211 } 212 } 213 214 /** Construct a symbol to reflect the qualifying type that should 215 * appear in the byte code as per JLS 13.1. 216 * 217 * For {@literal target >= 1.2}: Clone a method with the qualifier as owner (except 218 * for those cases where we need to work around VM bugs). 219 * 220 * For {@literal target <= 1.1}: If qualified variable or method is defined in a 221 * non-accessible class, clone it with the qualifier class as owner. 222 * 223 * @param sym The accessed symbol 224 * @param site The qualifier's type. 225 */ 226 Symbol binaryQualifier(Symbol sym, Type site) { 227 228 if (site.hasTag(ARRAY)) { 229 if (sym == syms.lengthVar || 230 sym.owner != syms.arrayClass) 231 return sym; 232 // array clone can be qualified by the array type in later targets 233 Symbol qualifier = new ClassSymbol(Flags.PUBLIC, site.tsym.name, 234 site, syms.noSymbol); 235 return sym.clone(qualifier); 236 } 237 238 if (sym.owner == site.tsym || 239 (sym.flags() & (STATIC | SYNTHETIC)) == (STATIC | SYNTHETIC)) { 240 return sym; 241 } 242 243 // leave alone methods inherited from Object 244 // JLS 13.1. 245 if (sym.owner == syms.objectType.tsym) 246 return sym; 247 248 return sym.clone(site.tsym); 249 } 250 251 /** Insert a reference to given type in the constant pool, 252 * checking for an array with too many dimensions; 253 * return the reference's index. 254 * @param type The type for which a reference is inserted. 255 */ 256 int makeRef(DiagnosticPosition pos, Type type) { 257 return poolWriter.putClass(checkDimension(pos, type)); 258 } 259 260 /** Check if the given type is an array with too many dimensions. 261 */ 262 private Type checkDimension(DiagnosticPosition pos, Type t) { 263 checkDimensionInternal(pos, t); 264 return t; 265 } 266 267 private void checkDimensionInternal(DiagnosticPosition pos, Type t) { 268 switch (t.getTag()) { 269 case METHOD: 270 checkDimension(pos, t.getReturnType()); 271 for (List<Type> args = t.getParameterTypes(); args.nonEmpty(); args = args.tail) 272 checkDimension(pos, args.head); 273 break; 274 case ARRAY: 275 if (types.dimensions(t) > ClassFile.MAX_DIMENSIONS) { 276 log.error(pos, Errors.LimitDimensions); 277 nerrs++; 278 } 279 break; 280 default: 281 break; 282 } 283 } 284 285 /** Create a temporary variable. 286 * @param type The variable's type. 287 */ 288 LocalItem makeTemp(Type type) { 289 VarSymbol v = new VarSymbol(Flags.SYNTHETIC, 290 names.empty, 291 type, 292 env.enclMethod.sym); 293 code.newLocal(v); 294 return items.makeLocalItem(v); 295 } 296 297 /** Generate code to call a non-private method or constructor. 298 * @param pos Position to be used for error reporting. 299 * @param site The type of which the method is a member. 300 * @param name The method's name. 301 * @param argtypes The method's argument types. 302 * @param isStatic A flag that indicates whether we call a 303 * static or instance method. 304 */ 305 void callMethod(DiagnosticPosition pos, 306 Type site, Name name, List<Type> argtypes, 307 boolean isStatic) { 308 Symbol msym = rs. 309 resolveInternalMethod(pos, attrEnv, site, name, argtypes, null); 310 if (isStatic) items.makeStaticItem(msym).invoke(); 311 else items.makeMemberItem(msym, name == names.init).invoke(); 312 } 313 314 /** Is the given method definition an access method 315 * resulting from a qualified super? This is signified by an odd 316 * access code. 317 */ 318 private boolean isAccessSuper(JCMethodDecl enclMethod) { 319 return 320 (enclMethod.mods.flags & SYNTHETIC) != 0 && 321 isOddAccessName(enclMethod.name); 322 } 323 324 /** Does given name start with "access$" and end in an odd digit? 325 */ 326 private boolean isOddAccessName(Name name) { 327 return 328 name.startsWith(accessDollar) && 329 (name.getByteAt(name.getByteLength() - 1) & 1) == 1; 330 } 331 332 /* ************************************************************************ 333 * Non-local exits 334 *************************************************************************/ 335 336 /** Generate code to invoke the finalizer associated with given 337 * environment. 338 * Any calls to finalizers are appended to the environments `cont' chain. 339 * Mark beginning of gap in catch all range for finalizer. 340 */ 341 void genFinalizer(Env<GenContext> env) { 342 if (code.isAlive() && env.info.finalize != null) 343 env.info.finalize.gen(); 344 } 345 346 /** Generate code to call all finalizers of structures aborted by 347 * a non-local 348 * exit. Return target environment of the non-local exit. 349 * @param target The tree representing the structure that's aborted 350 * @param env The environment current at the non-local exit. 351 */ 352 Env<GenContext> unwind(JCTree target, Env<GenContext> env) { 353 Env<GenContext> env1 = env; 354 while (true) { 355 genFinalizer(env1); 356 if (env1.tree == target) break; 357 env1 = env1.next; 358 } 359 return env1; 360 } 361 362 /** Mark end of gap in catch-all range for finalizer. 363 * @param env the environment which might contain the finalizer 364 * (if it does, env.info.gaps != null). 365 */ 366 void endFinalizerGap(Env<GenContext> env) { 367 if (env.info.gaps != null && env.info.gaps.length() % 2 == 1) 368 env.info.gaps.append(code.curCP()); 369 } 370 371 /** Mark end of all gaps in catch-all ranges for finalizers of environments 372 * lying between, and including to two environments. 373 * @param from the most deeply nested environment to mark 374 * @param to the least deeply nested environment to mark 375 */ 376 void endFinalizerGaps(Env<GenContext> from, Env<GenContext> to) { 377 Env<GenContext> last = null; 378 while (last != to) { 379 endFinalizerGap(from); 380 last = from; 381 from = from.next; 382 } 383 } 384 385 /** Do any of the structures aborted by a non-local exit have 386 * finalizers that require an empty stack? 387 * @param target The tree representing the structure that's aborted 388 * @param env The environment current at the non-local exit. 389 */ 390 boolean hasFinally(JCTree target, Env<GenContext> env) { 391 while (env.tree != target) { 392 if (env.tree.hasTag(TRY) && env.info.finalize.hasFinalizer()) 393 return true; 394 env = env.next; 395 } 396 return false; 397 } 398 399 /* ************************************************************************ 400 * Normalizing class-members. 401 *************************************************************************/ 402 403 /** Distribute member initializer code into constructors and {@code <clinit>} 404 * method. 405 * @param defs The list of class member declarations. 406 * @param c The enclosing class. 407 */ 408 List<JCTree> normalizeDefs(List<JCTree> defs, ClassSymbol c) { 409 ListBuffer<JCStatement> initCode = new ListBuffer<>(); 410 ListBuffer<Attribute.TypeCompound> initTAs = new ListBuffer<>(); 411 ListBuffer<JCStatement> clinitCode = new ListBuffer<>(); 412 ListBuffer<Attribute.TypeCompound> clinitTAs = new ListBuffer<>(); 413 ListBuffer<JCTree> methodDefs = new ListBuffer<>(); 414 // Sort definitions into three listbuffers: 415 // - initCode for instance initializers 416 // - clinitCode for class initializers 417 // - methodDefs for method definitions 418 for (List<JCTree> l = defs; l.nonEmpty(); l = l.tail) { 419 JCTree def = l.head; 420 switch (def.getTag()) { 421 case BLOCK: 422 JCBlock block = (JCBlock)def; 423 if ((block.flags & STATIC) != 0) 424 clinitCode.append(block); 425 else if ((block.flags & SYNTHETIC) == 0) 426 initCode.append(block); 427 break; 428 case METHODDEF: 429 methodDefs.append(def); 430 break; 431 case VARDEF: 432 JCVariableDecl vdef = (JCVariableDecl) def; 433 VarSymbol sym = vdef.sym; 434 checkDimension(vdef.pos(), sym.type); 435 if (vdef.init != null) { 436 if ((sym.flags() & STATIC) == 0) { 437 // Always initialize instance variables. 438 JCStatement init = make.at(vdef.pos()). 439 Assignment(sym, vdef.init); 440 initCode.append(init); 441 endPosTable.replaceTree(vdef, init); 442 initTAs.addAll(getAndRemoveNonFieldTAs(sym)); 443 } else if (sym.getConstValue() == null) { 444 // Initialize class (static) variables only if 445 // they are not compile-time constants. 446 JCStatement init = make.at(vdef.pos). 447 Assignment(sym, vdef.init); 448 clinitCode.append(init); 449 endPosTable.replaceTree(vdef, init); 450 clinitTAs.addAll(getAndRemoveNonFieldTAs(sym)); 451 } else { 452 checkStringConstant(vdef.init.pos(), sym.getConstValue()); 453 /* if the init contains a reference to an external class, add it to the 454 * constant's pool 455 */ 456 vdef.init.accept(classReferenceVisitor); 457 } 458 } 459 break; 460 default: 461 Assert.error(); 462 } 463 } 464 // Insert any instance initializers into all constructors. 465 if (initCode.length() != 0) { 466 List<JCStatement> inits = initCode.toList(); 467 initTAs.addAll(c.getInitTypeAttributes()); 468 List<Attribute.TypeCompound> initTAlist = initTAs.toList(); 469 for (JCTree t : methodDefs) { 470 normalizeMethod((JCMethodDecl)t, inits, initTAlist); 471 } 472 } 473 // If there are class initializers, create a <clinit> method 474 // that contains them as its body. 475 if (clinitCode.length() != 0) { 476 MethodSymbol clinit = new MethodSymbol( 477 STATIC | (c.flags() & STRICTFP), 478 names.clinit, 479 new MethodType( 480 List.nil(), syms.voidType, 481 List.nil(), syms.methodClass), 482 c); 483 c.members().enter(clinit); 484 List<JCStatement> clinitStats = clinitCode.toList(); 485 JCBlock block = make.at(clinitStats.head.pos()).Block(0, clinitStats); 486 block.endpos = TreeInfo.endPos(clinitStats.last()); 487 methodDefs.append(make.MethodDef(clinit, block)); 488 489 if (!clinitTAs.isEmpty()) 490 clinit.appendUniqueTypeAttributes(clinitTAs.toList()); 491 if (!c.getClassInitTypeAttributes().isEmpty()) 492 clinit.appendUniqueTypeAttributes(c.getClassInitTypeAttributes()); 493 } 494 // Return all method definitions. 495 return methodDefs.toList(); 496 } 497 498 private List<Attribute.TypeCompound> getAndRemoveNonFieldTAs(VarSymbol sym) { 499 List<TypeCompound> tas = sym.getRawTypeAttributes(); 500 ListBuffer<Attribute.TypeCompound> fieldTAs = new ListBuffer<>(); 501 ListBuffer<Attribute.TypeCompound> nonfieldTAs = new ListBuffer<>(); 502 for (TypeCompound ta : tas) { 503 Assert.check(ta.getPosition().type != TargetType.UNKNOWN); 504 if (ta.getPosition().type == TargetType.FIELD) { 505 fieldTAs.add(ta); 506 } else { 507 nonfieldTAs.add(ta); 508 } 509 } 510 sym.setTypeAttributes(fieldTAs.toList()); 511 return nonfieldTAs.toList(); 512 } 513 514 /** Check a constant value and report if it is a string that is 515 * too large. 516 */ 517 private void checkStringConstant(DiagnosticPosition pos, Object constValue) { 518 if (nerrs != 0 || // only complain about a long string once 519 constValue == null || 520 !(constValue instanceof String) || 521 ((String)constValue).length() < PoolWriter.MAX_STRING_LENGTH) 522 return; 523 log.error(pos, Errors.LimitString); 524 nerrs++; 525 } 526 527 /** Insert instance initializer code into initial constructor. 528 * @param md The tree potentially representing a 529 * constructor's definition. 530 * @param initCode The list of instance initializer statements. 531 * @param initTAs Type annotations from the initializer expression. 532 */ 533 void normalizeMethod(JCMethodDecl md, List<JCStatement> initCode, List<TypeCompound> initTAs) { 534 if (md.name == names.init && TreeInfo.isInitialConstructor(md)) { 535 // We are seeing a constructor that does not call another 536 // constructor of the same class. 537 List<JCStatement> stats = md.body.stats; 538 ListBuffer<JCStatement> newstats = new ListBuffer<>(); 539 540 if (stats.nonEmpty()) { 541 // Copy initializers of synthetic variables generated in 542 // the translation of inner classes. 543 while (TreeInfo.isSyntheticInit(stats.head)) { 544 newstats.append(stats.head); 545 stats = stats.tail; 546 } 547 // Copy superclass constructor call 548 newstats.append(stats.head); 549 stats = stats.tail; 550 // Copy remaining synthetic initializers. 551 while (stats.nonEmpty() && 552 TreeInfo.isSyntheticInit(stats.head)) { 553 newstats.append(stats.head); 554 stats = stats.tail; 555 } 556 // Now insert the initializer code. 557 newstats.appendList(initCode); 558 // And copy all remaining statements. 559 while (stats.nonEmpty()) { 560 newstats.append(stats.head); 561 stats = stats.tail; 562 } 563 } 564 md.body.stats = newstats.toList(); 565 if (md.body.endpos == Position.NOPOS) 566 md.body.endpos = TreeInfo.endPos(md.body.stats.last()); 567 568 md.sym.appendUniqueTypeAttributes(initTAs); 569 } 570 } 571 572 /* ************************************************************************ 573 * Traversal methods 574 *************************************************************************/ 575 576 /** Visitor argument: The current environment. 577 */ 578 Env<GenContext> env; 579 580 /** Visitor argument: The expected type (prototype). 581 */ 582 Type pt; 583 584 /** Visitor result: The item representing the computed value. 585 */ 586 Item result; 587 588 /** Visitor method: generate code for a definition, catching and reporting 589 * any completion failures. 590 * @param tree The definition to be visited. 591 * @param env The environment current at the definition. 592 */ 593 public void genDef(JCTree tree, Env<GenContext> env) { 594 Env<GenContext> prevEnv = this.env; 595 try { 596 this.env = env; 597 tree.accept(this); 598 } catch (CompletionFailure ex) { 599 chk.completionError(tree.pos(), ex); 600 } finally { 601 this.env = prevEnv; 602 } 603 } 604 605 /** Derived visitor method: check whether CharacterRangeTable 606 * should be emitted, if so, put a new entry into CRTable 607 * and call method to generate bytecode. 608 * If not, just call method to generate bytecode. 609 * @see #genStat(JCTree, Env) 610 * 611 * @param tree The tree to be visited. 612 * @param env The environment to use. 613 * @param crtFlags The CharacterRangeTable flags 614 * indicating type of the entry. 615 */ 616 public void genStat(JCTree tree, Env<GenContext> env, int crtFlags) { 617 if (!genCrt) { 618 genStat(tree, env); 619 return; 620 } 621 int startpc = code.curCP(); 622 genStat(tree, env); 623 if (tree.hasTag(Tag.BLOCK)) crtFlags |= CRT_BLOCK; 624 code.crt.put(tree, crtFlags, startpc, code.curCP()); 625 } 626 627 /** Derived visitor method: generate code for a statement. 628 */ 629 public void genStat(JCTree tree, Env<GenContext> env) { 630 if (code.isAlive()) { 631 code.statBegin(tree.pos); 632 genDef(tree, env); 633 } else if (env.info.isSwitch && tree.hasTag(VARDEF)) { 634 // variables whose declarations are in a switch 635 // can be used even if the decl is unreachable. 636 code.newLocal(((JCVariableDecl) tree).sym); 637 } 638 } 639 640 /** Derived visitor method: check whether CharacterRangeTable 641 * should be emitted, if so, put a new entry into CRTable 642 * and call method to generate bytecode. 643 * If not, just call method to generate bytecode. 644 * @see #genStats(List, Env) 645 * 646 * @param trees The list of trees to be visited. 647 * @param env The environment to use. 648 * @param crtFlags The CharacterRangeTable flags 649 * indicating type of the entry. 650 */ 651 public void genStats(List<JCStatement> trees, Env<GenContext> env, int crtFlags) { 652 if (!genCrt) { 653 genStats(trees, env); 654 return; 655 } 656 if (trees.length() == 1) { // mark one statement with the flags 657 genStat(trees.head, env, crtFlags | CRT_STATEMENT); 658 } else { 659 int startpc = code.curCP(); 660 genStats(trees, env); 661 code.crt.put(trees, crtFlags, startpc, code.curCP()); 662 } 663 } 664 665 /** Derived visitor method: generate code for a list of statements. 666 */ 667 public void genStats(List<? extends JCTree> trees, Env<GenContext> env) { 668 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail) 669 genStat(l.head, env, CRT_STATEMENT); 670 } 671 672 /** Derived visitor method: check whether CharacterRangeTable 673 * should be emitted, if so, put a new entry into CRTable 674 * and call method to generate bytecode. 675 * If not, just call method to generate bytecode. 676 * @see #genCond(JCTree,boolean) 677 * 678 * @param tree The tree to be visited. 679 * @param crtFlags The CharacterRangeTable flags 680 * indicating type of the entry. 681 */ 682 public CondItem genCond(JCTree tree, int crtFlags) { 683 if (!genCrt) return genCond(tree, false); 684 int startpc = code.curCP(); 685 CondItem item = genCond(tree, (crtFlags & CRT_FLOW_CONTROLLER) != 0); 686 code.crt.put(tree, crtFlags, startpc, code.curCP()); 687 return item; 688 } 689 690 /** Derived visitor method: generate code for a boolean 691 * expression in a control-flow context. 692 * @param _tree The expression to be visited. 693 * @param markBranches The flag to indicate that the condition is 694 * a flow controller so produced conditions 695 * should contain a proper tree to generate 696 * CharacterRangeTable branches for them. 697 */ 698 public CondItem genCond(JCTree _tree, boolean markBranches) { 699 JCTree inner_tree = TreeInfo.skipParens(_tree); 700 if (inner_tree.hasTag(CONDEXPR)) { 701 JCConditional tree = (JCConditional)inner_tree; 702 CondItem cond = genCond(tree.cond, CRT_FLOW_CONTROLLER); 703 if (cond.isTrue()) { 704 code.resolve(cond.trueJumps); 705 CondItem result = genCond(tree.truepart, CRT_FLOW_TARGET); 706 if (markBranches) result.tree = tree.truepart; 707 return result; 708 } 709 if (cond.isFalse()) { 710 code.resolve(cond.falseJumps); 711 CondItem result = genCond(tree.falsepart, CRT_FLOW_TARGET); 712 if (markBranches) result.tree = tree.falsepart; 713 return result; 714 } 715 Chain secondJumps = cond.jumpFalse(); 716 code.resolve(cond.trueJumps); 717 CondItem first = genCond(tree.truepart, CRT_FLOW_TARGET); 718 if (markBranches) first.tree = tree.truepart; 719 Chain falseJumps = first.jumpFalse(); 720 code.resolve(first.trueJumps); 721 Chain trueJumps = code.branch(goto_); 722 code.resolve(secondJumps); 723 CondItem second = genCond(tree.falsepart, CRT_FLOW_TARGET); 724 CondItem result = items.makeCondItem(second.opcode, 725 Code.mergeChains(trueJumps, second.trueJumps), 726 Code.mergeChains(falseJumps, second.falseJumps)); 727 if (markBranches) result.tree = tree.falsepart; 728 return result; 729 } else if (inner_tree.hasTag(SWITCH_EXPRESSION)) { 730 code.resolvePending(); 731 732 boolean prevInCondSwitchExpression = inCondSwitchExpression; 733 Chain prevSwitchExpressionTrueChain = switchExpressionTrueChain; 734 Chain prevSwitchExpressionFalseChain = switchExpressionFalseChain; 735 try { 736 inCondSwitchExpression = true; 737 switchExpressionTrueChain = null; 738 switchExpressionFalseChain = null; 739 try { 740 doHandleSwitchExpression((JCSwitchExpression) inner_tree); 741 } catch (CompletionFailure ex) { 742 chk.completionError(_tree.pos(), ex); 743 code.state.stacksize = 1; 744 } 745 CondItem result = items.makeCondItem(goto_, 746 switchExpressionTrueChain, 747 switchExpressionFalseChain); 748 if (markBranches) result.tree = _tree; 749 return result; 750 } finally { 751 inCondSwitchExpression = prevInCondSwitchExpression; 752 switchExpressionTrueChain = prevSwitchExpressionTrueChain; 753 switchExpressionFalseChain = prevSwitchExpressionFalseChain; 754 } 755 } else if (inner_tree.hasTag(LETEXPR) && ((LetExpr) inner_tree).needsCond) { 756 code.resolvePending(); 757 758 LetExpr tree = (LetExpr) inner_tree; 759 int limit = code.nextreg; 760 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize); 761 try { 762 genStats(tree.defs, env); 763 } finally { 764 code.setLetExprStackPos(prevLetExprStart); 765 } 766 CondItem result = genCond(tree.expr, markBranches); 767 code.endScopes(limit); 768 return result; 769 } else { 770 CondItem result = genExpr(_tree, syms.booleanType).mkCond(); 771 if (markBranches) result.tree = _tree; 772 return result; 773 } 774 } 775 776 public Code getCode() { 777 return code; 778 } 779 780 public Items getItems() { 781 return items; 782 } 783 784 public Env<AttrContext> getAttrEnv() { 785 return attrEnv; 786 } 787 788 /** Visitor class for expressions which might be constant expressions. 789 * This class is a subset of TreeScanner. Intended to visit trees pruned by 790 * Lower as long as constant expressions looking for references to any 791 * ClassSymbol. Any such reference will be added to the constant pool so 792 * automated tools can detect class dependencies better. 793 */ 794 class ClassReferenceVisitor extends JCTree.Visitor { 795 796 @Override 797 public void visitTree(JCTree tree) {} 798 799 @Override 800 public void visitBinary(JCBinary tree) { 801 tree.lhs.accept(this); 802 tree.rhs.accept(this); 803 } 804 805 @Override 806 public void visitSelect(JCFieldAccess tree) { 807 if (tree.selected.type.hasTag(CLASS)) { 808 makeRef(tree.selected.pos(), tree.selected.type); 809 } 810 } 811 812 @Override 813 public void visitIdent(JCIdent tree) { 814 if (tree.sym.owner instanceof ClassSymbol) { 815 poolWriter.putClass((ClassSymbol)tree.sym.owner); 816 } 817 } 818 819 @Override 820 public void visitConditional(JCConditional tree) { 821 tree.cond.accept(this); 822 tree.truepart.accept(this); 823 tree.falsepart.accept(this); 824 } 825 826 @Override 827 public void visitUnary(JCUnary tree) { 828 tree.arg.accept(this); 829 } 830 831 @Override 832 public void visitParens(JCParens tree) { 833 tree.expr.accept(this); 834 } 835 836 @Override 837 public void visitTypeCast(JCTypeCast tree) { 838 tree.expr.accept(this); 839 } 840 } 841 842 private ClassReferenceVisitor classReferenceVisitor = new ClassReferenceVisitor(); 843 844 /** Visitor method: generate code for an expression, catching and reporting 845 * any completion failures. 846 * @param tree The expression to be visited. 847 * @param pt The expression's expected type (proto-type). 848 */ 849 public Item genExpr(JCTree tree, Type pt) { 850 Type prevPt = this.pt; 851 try { 852 if (tree.type.constValue() != null) { 853 // Short circuit any expressions which are constants 854 tree.accept(classReferenceVisitor); 855 checkStringConstant(tree.pos(), tree.type.constValue()); 856 Symbol sym = TreeInfo.symbol(tree); 857 if (sym != null && isConstantDynamic(sym)) { 858 result = items.makeDynamicItem(sym); 859 } else { 860 result = items.makeImmediateItem(tree.type, tree.type.constValue()); 861 } 862 } else { 863 this.pt = pt; 864 tree.accept(this); 865 } 866 return result.coerce(pt); 867 } catch (CompletionFailure ex) { 868 chk.completionError(tree.pos(), ex); 869 code.state.stacksize = 1; 870 return items.makeStackItem(pt); 871 } finally { 872 this.pt = prevPt; 873 } 874 } 875 876 public boolean isConstantDynamic(Symbol sym) { 877 return sym.kind == VAR && 878 sym instanceof DynamicVarSymbol && 879 ((DynamicVarSymbol)sym).isDynamic(); 880 } 881 882 /** Derived visitor method: generate code for a list of method arguments. 883 * @param trees The argument expressions to be visited. 884 * @param pts The expression's expected types (i.e. the formal parameter 885 * types of the invoked method). 886 */ 887 public void genArgs(List<JCExpression> trees, List<Type> pts) { 888 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail) { 889 genExpr(l.head, pts.head).load(); 890 pts = pts.tail; 891 } 892 // require lists be of same length 893 Assert.check(pts.isEmpty()); 894 } 895 896 /* ************************************************************************ 897 * Visitor methods for statements and definitions 898 *************************************************************************/ 899 900 /** Thrown when the byte code size exceeds limit. 901 */ 902 public static class CodeSizeOverflow extends RuntimeException { 903 private static final long serialVersionUID = 0; 904 public CodeSizeOverflow() {} 905 } 906 907 public void visitMethodDef(JCMethodDecl tree) { 908 // Create a new local environment that points pack at method 909 // definition. 910 Env<GenContext> localEnv = env.dup(tree); 911 localEnv.enclMethod = tree; 912 // The expected type of every return statement in this method 913 // is the method's return type. 914 this.pt = tree.sym.erasure(types).getReturnType(); 915 916 checkDimension(tree.pos(), tree.sym.erasure(types)); 917 genMethod(tree, localEnv, false); 918 } 919 //where 920 /** Generate code for a method. 921 * @param tree The tree representing the method definition. 922 * @param env The environment current for the method body. 923 * @param fatcode A flag that indicates whether all jumps are 924 * within 32K. We first invoke this method under 925 * the assumption that fatcode == false, i.e. all 926 * jumps are within 32K. If this fails, fatcode 927 * is set to true and we try again. 928 */ 929 void genMethod(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) { 930 MethodSymbol meth = tree.sym; 931 int extras = 0; 932 // Count up extra parameters 933 if (meth.isConstructor()) { 934 extras++; 935 if (meth.enclClass().isInner() && 936 !meth.enclClass().isStatic()) { 937 extras++; 938 } 939 } else if ((tree.mods.flags & STATIC) == 0) { 940 extras++; 941 } 942 // System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG 943 if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes()) + extras > 944 ClassFile.MAX_PARAMETERS) { 945 log.error(tree.pos(), Errors.LimitParameters); 946 nerrs++; 947 } 948 949 else if (tree.body != null) { 950 // Create a new code structure and initialize it. 951 int startpcCrt = initCode(tree, env, fatcode); 952 953 try { 954 genStat(tree.body, env); 955 } catch (CodeSizeOverflow e) { 956 // Failed due to code limit, try again with jsr/ret 957 startpcCrt = initCode(tree, env, fatcode); 958 genStat(tree.body, env); 959 } 960 961 if (code.state.stacksize != 0) { 962 log.error(tree.body.pos(), Errors.StackSimError(tree.sym)); 963 throw new AssertionError(); 964 } 965 966 // If last statement could complete normally, insert a 967 // return at the end. 968 if (code.isAlive()) { 969 code.statBegin(TreeInfo.endPos(tree.body)); 970 if (env.enclMethod == null || 971 env.enclMethod.sym.type.getReturnType().hasTag(VOID)) { 972 code.emitop0(return_); 973 } else { 974 // sometime dead code seems alive (4415991); 975 // generate a small loop instead 976 int startpc = code.entryPoint(); 977 CondItem c = items.makeCondItem(goto_); 978 code.resolve(c.jumpTrue(), startpc); 979 } 980 } 981 if (genCrt) 982 code.crt.put(tree.body, 983 CRT_BLOCK, 984 startpcCrt, 985 code.curCP()); 986 987 code.endScopes(0); 988 989 // If we exceeded limits, panic 990 if (code.checkLimits(tree.pos(), log)) { 991 nerrs++; 992 return; 993 } 994 995 // If we generated short code but got a long jump, do it again 996 // with fatCode = true. 997 if (!fatcode && code.fatcode) genMethod(tree, env, true); 998 999 // Clean up 1000 if(stackMap == StackMapFormat.JSR202) { 1001 code.lastFrame = null; 1002 code.frameBeforeLast = null; 1003 } 1004 1005 // Compress exception table 1006 code.compressCatchTable(); 1007 1008 // Fill in type annotation positions for exception parameters 1009 code.fillExceptionParameterPositions(); 1010 } 1011 } 1012 1013 private int initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) { 1014 MethodSymbol meth = tree.sym; 1015 1016 // Create a new code structure. 1017 meth.code = code = new Code(meth, 1018 fatcode, 1019 lineDebugInfo ? toplevel.lineMap : null, 1020 varDebugInfo, 1021 stackMap, 1022 debugCode, 1023 genCrt ? new CRTable(tree, env.toplevel.endPositions) 1024 : null, 1025 syms, 1026 types, 1027 poolWriter); 1028 items = new Items(poolWriter, code, syms, types); 1029 if (code.debugCode) { 1030 System.err.println(meth + " for body " + tree); 1031 } 1032 1033 // If method is not static, create a new local variable address 1034 // for `this'. 1035 if ((tree.mods.flags & STATIC) == 0) { 1036 Type selfType = meth.owner.type; 1037 if (meth.isConstructor() && selfType != syms.objectType) 1038 selfType = UninitializedType.uninitializedThis(selfType); 1039 code.setDefined( 1040 code.newLocal( 1041 new VarSymbol(FINAL, names._this, selfType, meth.owner))); 1042 } 1043 1044 // Mark all parameters as defined from the beginning of 1045 // the method. 1046 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) { 1047 checkDimension(l.head.pos(), l.head.sym.type); 1048 code.setDefined(code.newLocal(l.head.sym)); 1049 } 1050 1051 // Get ready to generate code for method body. 1052 int startpcCrt = genCrt ? code.curCP() : 0; 1053 code.entryPoint(); 1054 1055 // Suppress initial stackmap 1056 code.pendingStackMap = false; 1057 1058 return startpcCrt; 1059 } 1060 1061 public void visitVarDef(JCVariableDecl tree) { 1062 VarSymbol v = tree.sym; 1063 if (tree.init != null) { 1064 checkStringConstant(tree.init.pos(), v.getConstValue()); 1065 if (v.getConstValue() == null || varDebugInfo) { 1066 Assert.check(code.isStatementStart()); 1067 code.newLocal(v); 1068 genExpr(tree.init, v.erasure(types)).load(); 1069 items.makeLocalItem(v).store(); 1070 Assert.check(code.isStatementStart()); 1071 } 1072 } else { 1073 code.newLocal(v); 1074 } 1075 checkDimension(tree.pos(), v.type); 1076 } 1077 1078 public void visitSkip(JCSkip tree) { 1079 } 1080 1081 public void visitBlock(JCBlock tree) { 1082 int limit = code.nextreg; 1083 Env<GenContext> localEnv = env.dup(tree, new GenContext()); 1084 genStats(tree.stats, localEnv); 1085 // End the scope of all block-local variables in variable info. 1086 if (!env.tree.hasTag(METHODDEF)) { 1087 code.statBegin(tree.endpos); 1088 code.endScopes(limit); 1089 code.pendingStatPos = Position.NOPOS; 1090 } 1091 } 1092 1093 public void visitDoLoop(JCDoWhileLoop tree) { 1094 genLoop(tree, tree.body, tree.cond, List.nil(), false); 1095 } 1096 1097 public void visitWhileLoop(JCWhileLoop tree) { 1098 genLoop(tree, tree.body, tree.cond, List.nil(), true); 1099 } 1100 1101 public void visitForLoop(JCForLoop tree) { 1102 int limit = code.nextreg; 1103 genStats(tree.init, env); 1104 genLoop(tree, tree.body, tree.cond, tree.step, true); 1105 code.endScopes(limit); 1106 } 1107 //where 1108 /** Generate code for a loop. 1109 * @param loop The tree representing the loop. 1110 * @param body The loop's body. 1111 * @param cond The loop's controlling condition. 1112 * @param step "Step" statements to be inserted at end of 1113 * each iteration. 1114 * @param testFirst True if the loop test belongs before the body. 1115 */ 1116 private void genLoop(JCStatement loop, 1117 JCStatement body, 1118 JCExpression cond, 1119 List<JCExpressionStatement> step, 1120 boolean testFirst) { 1121 Env<GenContext> loopEnv = env.dup(loop, new GenContext()); 1122 int startpc = code.entryPoint(); 1123 if (testFirst) { //while or for loop 1124 CondItem c; 1125 if (cond != null) { 1126 code.statBegin(cond.pos); 1127 Assert.check(code.isStatementStart()); 1128 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER); 1129 } else { 1130 c = items.makeCondItem(goto_); 1131 } 1132 Chain loopDone = c.jumpFalse(); 1133 code.resolve(c.trueJumps); 1134 Assert.check(code.isStatementStart()); 1135 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET); 1136 code.resolve(loopEnv.info.cont); 1137 genStats(step, loopEnv); 1138 code.resolve(code.branch(goto_), startpc); 1139 code.resolve(loopDone); 1140 } else { 1141 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET); 1142 code.resolve(loopEnv.info.cont); 1143 genStats(step, loopEnv); 1144 if (code.isAlive()) { 1145 CondItem c; 1146 if (cond != null) { 1147 code.statBegin(cond.pos); 1148 Assert.check(code.isStatementStart()); 1149 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER); 1150 } else { 1151 c = items.makeCondItem(goto_); 1152 } 1153 code.resolve(c.jumpTrue(), startpc); 1154 Assert.check(code.isStatementStart()); 1155 code.resolve(c.falseJumps); 1156 } 1157 } 1158 Chain exit = loopEnv.info.exit; 1159 if (exit != null) { 1160 code.resolve(exit); 1161 exit.state.defined.excludeFrom(code.nextreg); 1162 } 1163 } 1164 1165 public void visitForeachLoop(JCEnhancedForLoop tree) { 1166 throw new AssertionError(); // should have been removed by Lower. 1167 } 1168 1169 public void visitLabelled(JCLabeledStatement tree) { 1170 Env<GenContext> localEnv = env.dup(tree, new GenContext()); 1171 genStat(tree.body, localEnv, CRT_STATEMENT); 1172 Chain exit = localEnv.info.exit; 1173 if (exit != null) { 1174 code.resolve(exit); 1175 exit.state.defined.excludeFrom(code.nextreg); 1176 } 1177 } 1178 1179 public void visitSwitch(JCSwitch tree) { 1180 handleSwitch(tree, tree.selector, tree.cases); 1181 } 1182 1183 @Override 1184 public void visitSwitchExpression(JCSwitchExpression tree) { 1185 code.resolvePending(); 1186 boolean prevInCondSwitchExpression = inCondSwitchExpression; 1187 try { 1188 inCondSwitchExpression = false; 1189 doHandleSwitchExpression(tree); 1190 } finally { 1191 inCondSwitchExpression = prevInCondSwitchExpression; 1192 } 1193 result = items.makeStackItem(pt); 1194 } 1195 1196 private void doHandleSwitchExpression(JCSwitchExpression tree) { 1197 List<LocalItem> prevStackBeforeSwitchExpression = stackBeforeSwitchExpression; 1198 LocalItem prevSwitchResult = switchResult; 1199 int limit = code.nextreg; 1200 try { 1201 stackBeforeSwitchExpression = List.nil(); 1202 switchResult = null; 1203 if (hasTry(tree)) { 1204 //if the switch expression contains try-catch, the catch handlers need to have 1205 //an empty stack. So stash whole stack to local variables, and restore it before 1206 //breaks: 1207 while (code.state.stacksize > 0) { 1208 Type type = code.state.peek(); 1209 Name varName = names.fromString(target.syntheticNameChar() + 1210 "stack" + 1211 target.syntheticNameChar() + 1212 tree.pos + 1213 target.syntheticNameChar() + 1214 code.state.stacksize); 1215 VarSymbol var = new VarSymbol(Flags.SYNTHETIC, varName, type, 1216 this.env.enclMethod.sym); 1217 LocalItem item = items.new LocalItem(type, code.newLocal(var)); 1218 stackBeforeSwitchExpression = stackBeforeSwitchExpression.prepend(item); 1219 item.store(); 1220 } 1221 switchResult = makeTemp(tree.type); 1222 } 1223 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize); 1224 try { 1225 handleSwitch(tree, tree.selector, tree.cases); 1226 } finally { 1227 code.setLetExprStackPos(prevLetExprStart); 1228 } 1229 } finally { 1230 stackBeforeSwitchExpression = prevStackBeforeSwitchExpression; 1231 switchResult = prevSwitchResult; 1232 code.endScopes(limit); 1233 } 1234 } 1235 //where: 1236 private boolean hasTry(JCSwitchExpression tree) { 1237 boolean[] hasTry = new boolean[1]; 1238 new TreeScanner() { 1239 @Override 1240 public void visitTry(JCTry tree) { 1241 hasTry[0] = true; 1242 } 1243 1244 @Override 1245 public void visitClassDef(JCClassDecl tree) { 1246 } 1247 1248 @Override 1249 public void visitLambda(JCLambda tree) { 1250 } 1251 }.scan(tree); 1252 return hasTry[0]; 1253 } 1254 1255 private void handleSwitch(JCTree swtch, JCExpression selector, List<JCCase> cases) { 1256 int limit = code.nextreg; 1257 Assert.check(!selector.type.hasTag(CLASS)); 1258 int startpcCrt = genCrt ? code.curCP() : 0; 1259 Assert.check(code.isStatementStart()); 1260 Item sel = genExpr(selector, syms.intType); 1261 if (cases.isEmpty()) { 1262 // We are seeing: switch <sel> {} 1263 sel.load().drop(); 1264 if (genCrt) 1265 code.crt.put(TreeInfo.skipParens(selector), 1266 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP()); 1267 } else { 1268 // We are seeing a nonempty switch. 1269 sel.load(); 1270 if (genCrt) 1271 code.crt.put(TreeInfo.skipParens(selector), 1272 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP()); 1273 Env<GenContext> switchEnv = env.dup(swtch, new GenContext()); 1274 switchEnv.info.isSwitch = true; 1275 1276 // Compute number of labels and minimum and maximum label values. 1277 // For each case, store its label in an array. 1278 int lo = Integer.MAX_VALUE; // minimum label. 1279 int hi = Integer.MIN_VALUE; // maximum label. 1280 int nlabels = 0; // number of labels. 1281 1282 int[] labels = new int[cases.length()]; // the label array. 1283 int defaultIndex = -1; // the index of the default clause. 1284 1285 List<JCCase> l = cases; 1286 for (int i = 0; i < labels.length; i++) { 1287 if (l.head.pats.nonEmpty()) { 1288 Assert.check(l.head.pats.size() == 1); 1289 int val = ((Number)l.head.pats.head.type.constValue()).intValue(); 1290 labels[i] = val; 1291 if (val < lo) lo = val; 1292 if (hi < val) hi = val; 1293 nlabels++; 1294 } else { 1295 Assert.check(defaultIndex == -1); 1296 defaultIndex = i; 1297 } 1298 l = l.tail; 1299 } 1300 1301 // Determine whether to issue a tableswitch or a lookupswitch 1302 // instruction. 1303 long table_space_cost = 4 + ((long) hi - lo + 1); // words 1304 long table_time_cost = 3; // comparisons 1305 long lookup_space_cost = 3 + 2 * (long) nlabels; 1306 long lookup_time_cost = nlabels; 1307 int opcode = 1308 nlabels > 0 && 1309 table_space_cost + 3 * table_time_cost <= 1310 lookup_space_cost + 3 * lookup_time_cost 1311 ? 1312 tableswitch : lookupswitch; 1313 1314 int startpc = code.curCP(); // the position of the selector operation 1315 code.emitop0(opcode); 1316 code.align(4); 1317 int tableBase = code.curCP(); // the start of the jump table 1318 int[] offsets = null; // a table of offsets for a lookupswitch 1319 code.emit4(-1); // leave space for default offset 1320 if (opcode == tableswitch) { 1321 code.emit4(lo); // minimum label 1322 code.emit4(hi); // maximum label 1323 for (long i = lo; i <= hi; i++) { // leave space for jump table 1324 code.emit4(-1); 1325 } 1326 } else { 1327 code.emit4(nlabels); // number of labels 1328 for (int i = 0; i < nlabels; i++) { 1329 code.emit4(-1); code.emit4(-1); // leave space for lookup table 1330 } 1331 offsets = new int[labels.length]; 1332 } 1333 Code.State stateSwitch = code.state.dup(); 1334 code.markDead(); 1335 1336 // For each case do: 1337 l = cases; 1338 for (int i = 0; i < labels.length; i++) { 1339 JCCase c = l.head; 1340 l = l.tail; 1341 1342 int pc = code.entryPoint(stateSwitch); 1343 // Insert offset directly into code or else into the 1344 // offsets table. 1345 if (i != defaultIndex) { 1346 if (opcode == tableswitch) { 1347 code.put4( 1348 tableBase + 4 * (labels[i] - lo + 3), 1349 pc - startpc); 1350 } else { 1351 offsets[i] = pc - startpc; 1352 } 1353 } else { 1354 code.put4(tableBase, pc - startpc); 1355 } 1356 1357 // Generate code for the statements in this case. 1358 genStats(c.stats, switchEnv, CRT_FLOW_TARGET); 1359 } 1360 1361 // Resolve all breaks. 1362 Chain exit = switchEnv.info.exit; 1363 if (exit != null) { 1364 code.resolve(exit); 1365 exit.state.defined.excludeFrom(limit); 1366 } 1367 1368 // If we have not set the default offset, we do so now. 1369 if (code.get4(tableBase) == -1) { 1370 code.put4(tableBase, code.entryPoint(stateSwitch) - startpc); 1371 } 1372 1373 if (opcode == tableswitch) { 1374 // Let any unfilled slots point to the default case. 1375 int defaultOffset = code.get4(tableBase); 1376 for (long i = lo; i <= hi; i++) { 1377 int t = (int)(tableBase + 4 * (i - lo + 3)); 1378 if (code.get4(t) == -1) 1379 code.put4(t, defaultOffset); 1380 } 1381 } else { 1382 // Sort non-default offsets and copy into lookup table. 1383 if (defaultIndex >= 0) 1384 for (int i = defaultIndex; i < labels.length - 1; i++) { 1385 labels[i] = labels[i+1]; 1386 offsets[i] = offsets[i+1]; 1387 } 1388 if (nlabels > 0) 1389 qsort2(labels, offsets, 0, nlabels - 1); 1390 for (int i = 0; i < nlabels; i++) { 1391 int caseidx = tableBase + 8 * (i + 1); 1392 code.put4(caseidx, labels[i]); 1393 code.put4(caseidx + 4, offsets[i]); 1394 } 1395 } 1396 } 1397 code.endScopes(limit); 1398 } 1399 //where 1400 /** Sort (int) arrays of keys and values 1401 */ 1402 static void qsort2(int[] keys, int[] values, int lo, int hi) { 1403 int i = lo; 1404 int j = hi; 1405 int pivot = keys[(i+j)/2]; 1406 do { 1407 while (keys[i] < pivot) i++; 1408 while (pivot < keys[j]) j--; 1409 if (i <= j) { 1410 int temp1 = keys[i]; 1411 keys[i] = keys[j]; 1412 keys[j] = temp1; 1413 int temp2 = values[i]; 1414 values[i] = values[j]; 1415 values[j] = temp2; 1416 i++; 1417 j--; 1418 } 1419 } while (i <= j); 1420 if (lo < j) qsort2(keys, values, lo, j); 1421 if (i < hi) qsort2(keys, values, i, hi); 1422 } 1423 1424 public void visitSynchronized(JCSynchronized tree) { 1425 int limit = code.nextreg; 1426 // Generate code to evaluate lock and save in temporary variable. 1427 final LocalItem lockVar = makeTemp(syms.objectType); 1428 Assert.check(code.isStatementStart()); 1429 genExpr(tree.lock, tree.lock.type).load().duplicate(); 1430 lockVar.store(); 1431 1432 // Generate code to enter monitor. 1433 code.emitop0(monitorenter); 1434 code.state.lock(lockVar.reg); 1435 1436 // Generate code for a try statement with given body, no catch clauses 1437 // in a new environment with the "exit-monitor" operation as finalizer. 1438 final Env<GenContext> syncEnv = env.dup(tree, new GenContext()); 1439 syncEnv.info.finalize = new GenFinalizer() { 1440 void gen() { 1441 genLast(); 1442 Assert.check(syncEnv.info.gaps.length() % 2 == 0); 1443 syncEnv.info.gaps.append(code.curCP()); 1444 } 1445 void genLast() { 1446 if (code.isAlive()) { 1447 lockVar.load(); 1448 code.emitop0(monitorexit); 1449 code.state.unlock(lockVar.reg); 1450 } 1451 } 1452 }; 1453 syncEnv.info.gaps = new ListBuffer<>(); 1454 genTry(tree.body, List.nil(), syncEnv); 1455 code.endScopes(limit); 1456 } 1457 1458 public void visitTry(final JCTry tree) { 1459 // Generate code for a try statement with given body and catch clauses, 1460 // in a new environment which calls the finally block if there is one. 1461 final Env<GenContext> tryEnv = env.dup(tree, new GenContext()); 1462 final Env<GenContext> oldEnv = env; 1463 tryEnv.info.finalize = new GenFinalizer() { 1464 void gen() { 1465 Assert.check(tryEnv.info.gaps.length() % 2 == 0); 1466 tryEnv.info.gaps.append(code.curCP()); 1467 genLast(); 1468 } 1469 void genLast() { 1470 if (tree.finalizer != null) 1471 genStat(tree.finalizer, oldEnv, CRT_BLOCK); 1472 } 1473 boolean hasFinalizer() { 1474 return tree.finalizer != null; 1475 } 1476 1477 @Override 1478 void afterBody() { 1479 if (tree.finalizer != null && (tree.finalizer.flags & BODY_ONLY_FINALIZE) != 0) { 1480 //for body-only finally, remove the GenFinalizer after try body 1481 //so that the finally is not generated to catch bodies: 1482 tryEnv.info.finalize = null; 1483 } 1484 } 1485 1486 }; 1487 tryEnv.info.gaps = new ListBuffer<>(); 1488 genTry(tree.body, tree.catchers, tryEnv); 1489 } 1490 //where 1491 /** Generate code for a try or synchronized statement 1492 * @param body The body of the try or synchronized statement. 1493 * @param catchers The lis of catch clauses. 1494 * @param env the environment current for the body. 1495 */ 1496 void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) { 1497 int limit = code.nextreg; 1498 int startpc = code.curCP(); 1499 Code.State stateTry = code.state.dup(); 1500 genStat(body, env, CRT_BLOCK); 1501 int endpc = code.curCP(); 1502 List<Integer> gaps = env.info.gaps.toList(); 1503 code.statBegin(TreeInfo.endPos(body)); 1504 genFinalizer(env); 1505 code.statBegin(TreeInfo.endPos(env.tree)); 1506 Chain exitChain = code.branch(goto_); 1507 endFinalizerGap(env); 1508 env.info.finalize.afterBody(); 1509 boolean hasFinalizer = 1510 env.info.finalize != null && 1511 env.info.finalize.hasFinalizer(); 1512 if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) { 1513 // start off with exception on stack 1514 code.entryPoint(stateTry, l.head.param.sym.type); 1515 genCatch(l.head, env, startpc, endpc, gaps); 1516 genFinalizer(env); 1517 if (hasFinalizer || l.tail.nonEmpty()) { 1518 code.statBegin(TreeInfo.endPos(env.tree)); 1519 exitChain = Code.mergeChains(exitChain, 1520 code.branch(goto_)); 1521 } 1522 endFinalizerGap(env); 1523 } 1524 if (hasFinalizer) { 1525 // Create a new register segment to avoid allocating 1526 // the same variables in finalizers and other statements. 1527 code.newRegSegment(); 1528 1529 // Add a catch-all clause. 1530 1531 // start off with exception on stack 1532 int catchallpc = code.entryPoint(stateTry, syms.throwableType); 1533 1534 // Register all exception ranges for catch all clause. 1535 // The range of the catch all clause is from the beginning 1536 // of the try or synchronized block until the present 1537 // code pointer excluding all gaps in the current 1538 // environment's GenContext. 1539 int startseg = startpc; 1540 while (env.info.gaps.nonEmpty()) { 1541 int endseg = env.info.gaps.next().intValue(); 1542 registerCatch(body.pos(), startseg, endseg, 1543 catchallpc, 0); 1544 startseg = env.info.gaps.next().intValue(); 1545 } 1546 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS)); 1547 code.markStatBegin(); 1548 1549 Item excVar = makeTemp(syms.throwableType); 1550 excVar.store(); 1551 genFinalizer(env); 1552 code.resolvePending(); 1553 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.END_POS)); 1554 code.markStatBegin(); 1555 1556 excVar.load(); 1557 registerCatch(body.pos(), startseg, 1558 env.info.gaps.next().intValue(), 1559 catchallpc, 0); 1560 code.emitop0(athrow); 1561 code.markDead(); 1562 1563 // If there are jsr's to this finalizer, ... 1564 if (env.info.cont != null) { 1565 // Resolve all jsr's. 1566 code.resolve(env.info.cont); 1567 1568 // Mark statement line number 1569 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS)); 1570 code.markStatBegin(); 1571 1572 // Save return address. 1573 LocalItem retVar = makeTemp(syms.throwableType); 1574 retVar.store(); 1575 1576 // Generate finalizer code. 1577 env.info.finalize.genLast(); 1578 1579 // Return. 1580 code.emitop1w(ret, retVar.reg); 1581 code.markDead(); 1582 } 1583 } 1584 // Resolve all breaks. 1585 code.resolve(exitChain); 1586 1587 code.endScopes(limit); 1588 } 1589 1590 /** Generate code for a catch clause. 1591 * @param tree The catch clause. 1592 * @param env The environment current in the enclosing try. 1593 * @param startpc Start pc of try-block. 1594 * @param endpc End pc of try-block. 1595 */ 1596 void genCatch(JCCatch tree, 1597 Env<GenContext> env, 1598 int startpc, int endpc, 1599 List<Integer> gaps) { 1600 if (startpc != endpc) { 1601 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypeExprs 1602 = catchTypesWithAnnotations(tree); 1603 while (gaps.nonEmpty()) { 1604 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) { 1605 JCExpression subCatch = subCatch1.snd; 1606 int catchType = makeRef(tree.pos(), subCatch.type); 1607 int end = gaps.head.intValue(); 1608 registerCatch(tree.pos(), 1609 startpc, end, code.curCP(), 1610 catchType); 1611 for (Attribute.TypeCompound tc : subCatch1.fst) { 1612 tc.position.setCatchInfo(catchType, startpc); 1613 } 1614 } 1615 gaps = gaps.tail; 1616 startpc = gaps.head.intValue(); 1617 gaps = gaps.tail; 1618 } 1619 if (startpc < endpc) { 1620 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) { 1621 JCExpression subCatch = subCatch1.snd; 1622 int catchType = makeRef(tree.pos(), subCatch.type); 1623 registerCatch(tree.pos(), 1624 startpc, endpc, code.curCP(), 1625 catchType); 1626 for (Attribute.TypeCompound tc : subCatch1.fst) { 1627 tc.position.setCatchInfo(catchType, startpc); 1628 } 1629 } 1630 } 1631 VarSymbol exparam = tree.param.sym; 1632 code.statBegin(tree.pos); 1633 code.markStatBegin(); 1634 int limit = code.nextreg; 1635 code.newLocal(exparam); 1636 items.makeLocalItem(exparam).store(); 1637 code.statBegin(TreeInfo.firstStatPos(tree.body)); 1638 genStat(tree.body, env, CRT_BLOCK); 1639 code.endScopes(limit); 1640 code.statBegin(TreeInfo.endPos(tree.body)); 1641 } 1642 } 1643 // where 1644 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotations(JCCatch tree) { 1645 return TreeInfo.isMultiCatch(tree) ? 1646 catchTypesWithAnnotationsFromMulticatch((JCTypeUnion)tree.param.vartype, tree.param.sym.getRawTypeAttributes()) : 1647 List.of(new Pair<>(tree.param.sym.getRawTypeAttributes(), tree.param.vartype)); 1648 } 1649 // where 1650 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotationsFromMulticatch(JCTypeUnion tree, List<TypeCompound> first) { 1651 List<JCExpression> alts = tree.alternatives; 1652 List<Pair<List<TypeCompound>, JCExpression>> res = List.of(new Pair<>(first, alts.head)); 1653 alts = alts.tail; 1654 1655 while(alts != null && alts.head != null) { 1656 JCExpression alt = alts.head; 1657 if (alt instanceof JCAnnotatedType) { 1658 JCAnnotatedType a = (JCAnnotatedType)alt; 1659 res = res.prepend(new Pair<>(annotate.fromAnnotations(a.annotations), alt)); 1660 } else { 1661 res = res.prepend(new Pair<>(List.nil(), alt)); 1662 } 1663 alts = alts.tail; 1664 } 1665 return res.reverse(); 1666 } 1667 1668 /** Register a catch clause in the "Exceptions" code-attribute. 1669 */ 1670 void registerCatch(DiagnosticPosition pos, 1671 int startpc, int endpc, 1672 int handler_pc, int catch_type) { 1673 char startpc1 = (char)startpc; 1674 char endpc1 = (char)endpc; 1675 char handler_pc1 = (char)handler_pc; 1676 if (startpc1 == startpc && 1677 endpc1 == endpc && 1678 handler_pc1 == handler_pc) { 1679 code.addCatch(startpc1, endpc1, handler_pc1, 1680 (char)catch_type); 1681 } else { 1682 log.error(pos, Errors.LimitCodeTooLargeForTryStmt); 1683 nerrs++; 1684 } 1685 } 1686 1687 public void visitIf(JCIf tree) { 1688 int limit = code.nextreg; 1689 Chain thenExit = null; 1690 Assert.check(code.isStatementStart()); 1691 CondItem c = genCond(TreeInfo.skipParens(tree.cond), 1692 CRT_FLOW_CONTROLLER); 1693 Chain elseChain = c.jumpFalse(); 1694 Assert.check(code.isStatementStart()); 1695 if (!c.isFalse()) { 1696 code.resolve(c.trueJumps); 1697 genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET); 1698 thenExit = code.branch(goto_); 1699 } 1700 if (elseChain != null) { 1701 code.resolve(elseChain); 1702 if (tree.elsepart != null) { 1703 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET); 1704 } 1705 } 1706 code.resolve(thenExit); 1707 code.endScopes(limit); 1708 Assert.check(code.isStatementStart()); 1709 } 1710 1711 public void visitExec(JCExpressionStatement tree) { 1712 // Optimize x++ to ++x and x-- to --x. 1713 JCExpression e = tree.expr; 1714 switch (e.getTag()) { 1715 case POSTINC: 1716 ((JCUnary) e).setTag(PREINC); 1717 break; 1718 case POSTDEC: 1719 ((JCUnary) e).setTag(PREDEC); 1720 break; 1721 } 1722 Assert.check(code.isStatementStart()); 1723 genExpr(tree.expr, tree.expr.type).drop(); 1724 Assert.check(code.isStatementStart()); 1725 } 1726 1727 public void visitBreak(JCBreak tree) { 1728 Assert.check(code.isStatementStart()); 1729 final Env<GenContext> targetEnv = unwindBreak(tree.target); 1730 targetEnv.info.addExit(code.branch(goto_)); 1731 endFinalizerGaps(env, targetEnv); 1732 } 1733 1734 public void visitYield(JCYield tree) { 1735 Assert.check(code.isStatementStart()); 1736 final Env<GenContext> targetEnv; 1737 if (inCondSwitchExpression) { 1738 CondItem value = genCond(tree.value, CRT_FLOW_TARGET); 1739 Chain falseJumps = value.jumpFalse(); 1740 1741 code.resolve(value.trueJumps); 1742 Env<GenContext> localEnv = unwindBreak(tree.target); 1743 reloadStackBeforeSwitchExpr(); 1744 Chain trueJumps = code.branch(goto_); 1745 1746 endFinalizerGaps(env, localEnv); 1747 1748 code.resolve(falseJumps); 1749 targetEnv = unwindBreak(tree.target); 1750 reloadStackBeforeSwitchExpr(); 1751 falseJumps = code.branch(goto_); 1752 1753 if (switchExpressionTrueChain == null) { 1754 switchExpressionTrueChain = trueJumps; 1755 } else { 1756 switchExpressionTrueChain = 1757 Code.mergeChains(switchExpressionTrueChain, trueJumps); 1758 } 1759 if (switchExpressionFalseChain == null) { 1760 switchExpressionFalseChain = falseJumps; 1761 } else { 1762 switchExpressionFalseChain = 1763 Code.mergeChains(switchExpressionFalseChain, falseJumps); 1764 } 1765 } else { 1766 genExpr(tree.value, pt).load(); 1767 if (switchResult != null) 1768 switchResult.store(); 1769 1770 targetEnv = unwindBreak(tree.target); 1771 1772 if (code.isAlive()) { 1773 reloadStackBeforeSwitchExpr(); 1774 if (switchResult != null) 1775 switchResult.load(); 1776 1777 code.state.forceStackTop(tree.target.type); 1778 targetEnv.info.addExit(code.branch(goto_)); 1779 code.markDead(); 1780 } 1781 } 1782 endFinalizerGaps(env, targetEnv); 1783 } 1784 //where: 1785 /** As side-effect, might mark code as dead disabling any further emission. 1786 */ 1787 private Env<GenContext> unwindBreak(JCTree target) { 1788 int tmpPos = code.pendingStatPos; 1789 Env<GenContext> targetEnv = unwind(target, env); 1790 code.pendingStatPos = tmpPos; 1791 return targetEnv; 1792 } 1793 1794 private void reloadStackBeforeSwitchExpr() { 1795 for (LocalItem li : stackBeforeSwitchExpression) 1796 li.load(); 1797 } 1798 1799 public void visitContinue(JCContinue tree) { 1800 int tmpPos = code.pendingStatPos; 1801 Env<GenContext> targetEnv = unwind(tree.target, env); 1802 code.pendingStatPos = tmpPos; 1803 Assert.check(code.isStatementStart()); 1804 targetEnv.info.addCont(code.branch(goto_)); 1805 endFinalizerGaps(env, targetEnv); 1806 } 1807 1808 public void visitReturn(JCReturn tree) { 1809 int limit = code.nextreg; 1810 final Env<GenContext> targetEnv; 1811 1812 /* Save and then restore the location of the return in case a finally 1813 * is expanded (with unwind()) in the middle of our bytecodes. 1814 */ 1815 int tmpPos = code.pendingStatPos; 1816 if (tree.expr != null) { 1817 Assert.check(code.isStatementStart()); 1818 Item r = genExpr(tree.expr, pt).load(); 1819 if (hasFinally(env.enclMethod, env)) { 1820 r = makeTemp(pt); 1821 r.store(); 1822 } 1823 targetEnv = unwind(env.enclMethod, env); 1824 code.pendingStatPos = tmpPos; 1825 r.load(); 1826 code.emitop0(ireturn + Code.truncate(Code.typecode(pt))); 1827 } else { 1828 targetEnv = unwind(env.enclMethod, env); 1829 code.pendingStatPos = tmpPos; 1830 code.emitop0(return_); 1831 } 1832 endFinalizerGaps(env, targetEnv); 1833 code.endScopes(limit); 1834 } 1835 1836 public void visitThrow(JCThrow tree) { 1837 Assert.check(code.isStatementStart()); 1838 genExpr(tree.expr, tree.expr.type).load(); 1839 code.emitop0(athrow); 1840 Assert.check(code.isStatementStart()); 1841 } 1842 1843 /* ************************************************************************ 1844 * Visitor methods for expressions 1845 *************************************************************************/ 1846 1847 public void visitApply(JCMethodInvocation tree) { 1848 setTypeAnnotationPositions(tree.pos); 1849 // Generate code for method. 1850 Item m = genExpr(tree.meth, methodType); 1851 // Generate code for all arguments, where the expected types are 1852 // the parameters of the method's external type (that is, any implicit 1853 // outer instance of a super(...) call appears as first parameter). 1854 MethodSymbol msym = (MethodSymbol)TreeInfo.symbol(tree.meth); 1855 genArgs(tree.args, 1856 msym.externalType(types).getParameterTypes()); 1857 if (!msym.isDynamic()) { 1858 code.statBegin(tree.pos); 1859 } 1860 result = m.invoke(); 1861 } 1862 1863 public void visitConditional(JCConditional tree) { 1864 Chain thenExit = null; 1865 code.statBegin(tree.cond.pos); 1866 CondItem c = genCond(tree.cond, CRT_FLOW_CONTROLLER); 1867 Chain elseChain = c.jumpFalse(); 1868 if (!c.isFalse()) { 1869 code.resolve(c.trueJumps); 1870 int startpc = genCrt ? code.curCP() : 0; 1871 code.statBegin(tree.truepart.pos); 1872 genExpr(tree.truepart, pt).load(); 1873 code.state.forceStackTop(tree.type); 1874 if (genCrt) code.crt.put(tree.truepart, CRT_FLOW_TARGET, 1875 startpc, code.curCP()); 1876 thenExit = code.branch(goto_); 1877 } 1878 if (elseChain != null) { 1879 code.resolve(elseChain); 1880 int startpc = genCrt ? code.curCP() : 0; 1881 code.statBegin(tree.falsepart.pos); 1882 genExpr(tree.falsepart, pt).load(); 1883 code.state.forceStackTop(tree.type); 1884 if (genCrt) code.crt.put(tree.falsepart, CRT_FLOW_TARGET, 1885 startpc, code.curCP()); 1886 } 1887 code.resolve(thenExit); 1888 result = items.makeStackItem(pt); 1889 } 1890 1891 private void setTypeAnnotationPositions(int treePos) { 1892 MethodSymbol meth = code.meth; 1893 boolean initOrClinit = code.meth.getKind() == javax.lang.model.element.ElementKind.CONSTRUCTOR 1894 || code.meth.getKind() == javax.lang.model.element.ElementKind.STATIC_INIT; 1895 1896 for (Attribute.TypeCompound ta : meth.getRawTypeAttributes()) { 1897 if (ta.hasUnknownPosition()) 1898 ta.tryFixPosition(); 1899 1900 if (ta.position.matchesPos(treePos)) 1901 ta.position.updatePosOffset(code.cp); 1902 } 1903 1904 if (!initOrClinit) 1905 return; 1906 1907 for (Attribute.TypeCompound ta : meth.owner.getRawTypeAttributes()) { 1908 if (ta.hasUnknownPosition()) 1909 ta.tryFixPosition(); 1910 1911 if (ta.position.matchesPos(treePos)) 1912 ta.position.updatePosOffset(code.cp); 1913 } 1914 1915 ClassSymbol clazz = meth.enclClass(); 1916 for (Symbol s : new com.sun.tools.javac.model.FilteredMemberList(clazz.members())) { 1917 if (!s.getKind().isField()) 1918 continue; 1919 1920 for (Attribute.TypeCompound ta : s.getRawTypeAttributes()) { 1921 if (ta.hasUnknownPosition()) 1922 ta.tryFixPosition(); 1923 1924 if (ta.position.matchesPos(treePos)) 1925 ta.position.updatePosOffset(code.cp); 1926 } 1927 } 1928 } 1929 1930 public void visitNewClass(JCNewClass tree) { 1931 // Enclosing instances or anonymous classes should have been eliminated 1932 // by now. 1933 Assert.check(tree.encl == null && tree.def == null); 1934 setTypeAnnotationPositions(tree.pos); 1935 1936 code.emitop2(new_, checkDimension(tree.pos(), tree.type), PoolWriter::putClass); 1937 code.emitop0(dup); 1938 1939 // Generate code for all arguments, where the expected types are 1940 // the parameters of the constructor's external type (that is, 1941 // any implicit outer instance appears as first parameter). 1942 genArgs(tree.args, tree.constructor.externalType(types).getParameterTypes()); 1943 1944 items.makeMemberItem(tree.constructor, true).invoke(); 1945 result = items.makeStackItem(tree.type); 1946 } 1947 1948 public void visitNewArray(JCNewArray tree) { 1949 setTypeAnnotationPositions(tree.pos); 1950 1951 if (tree.elems != null) { 1952 Type elemtype = types.elemtype(tree.type); 1953 loadIntConst(tree.elems.length()); 1954 Item arr = makeNewArray(tree.pos(), tree.type, 1); 1955 int i = 0; 1956 for (List<JCExpression> l = tree.elems; l.nonEmpty(); l = l.tail) { 1957 arr.duplicate(); 1958 loadIntConst(i); 1959 i++; 1960 genExpr(l.head, elemtype).load(); 1961 items.makeIndexedItem(elemtype).store(); 1962 } 1963 result = arr; 1964 } else { 1965 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) { 1966 genExpr(l.head, syms.intType).load(); 1967 } 1968 result = makeNewArray(tree.pos(), tree.type, tree.dims.length()); 1969 } 1970 } 1971 //where 1972 /** Generate code to create an array with given element type and number 1973 * of dimensions. 1974 */ 1975 Item makeNewArray(DiagnosticPosition pos, Type type, int ndims) { 1976 Type elemtype = types.elemtype(type); 1977 if (types.dimensions(type) > ClassFile.MAX_DIMENSIONS) { 1978 log.error(pos, Errors.LimitDimensions); 1979 nerrs++; 1980 } 1981 int elemcode = Code.arraycode(elemtype); 1982 if (elemcode == 0 || (elemcode == 1 && ndims == 1)) { 1983 code.emitAnewarray(makeRef(pos, elemtype), type); 1984 } else if (elemcode == 1) { 1985 code.emitMultianewarray(ndims, makeRef(pos, type), type); 1986 } else { 1987 code.emitNewarray(elemcode, type); 1988 } 1989 return items.makeStackItem(type); 1990 } 1991 1992 public void visitParens(JCParens tree) { 1993 result = genExpr(tree.expr, tree.expr.type); 1994 } 1995 1996 public void visitAssign(JCAssign tree) { 1997 Item l = genExpr(tree.lhs, tree.lhs.type); 1998 genExpr(tree.rhs, tree.lhs.type).load(); 1999 if (tree.rhs.type.hasTag(BOT)) { 2000 /* This is just a case of widening reference conversion that per 5.1.5 simply calls 2001 for "regarding a reference as having some other type in a manner that can be proved 2002 correct at compile time." 2003 */ 2004 code.state.forceStackTop(tree.lhs.type); 2005 } 2006 result = items.makeAssignItem(l); 2007 } 2008 2009 public void visitAssignop(JCAssignOp tree) { 2010 OperatorSymbol operator = tree.operator; 2011 Item l; 2012 if (operator.opcode == string_add) { 2013 l = concat.makeConcat(tree); 2014 } else { 2015 // Generate code for first expression 2016 l = genExpr(tree.lhs, tree.lhs.type); 2017 2018 // If we have an increment of -32768 to +32767 of a local 2019 // int variable we can use an incr instruction instead of 2020 // proceeding further. 2021 if ((tree.hasTag(PLUS_ASG) || tree.hasTag(MINUS_ASG)) && 2022 l instanceof LocalItem && 2023 tree.lhs.type.getTag().isSubRangeOf(INT) && 2024 tree.rhs.type.getTag().isSubRangeOf(INT) && 2025 tree.rhs.type.constValue() != null) { 2026 int ival = ((Number) tree.rhs.type.constValue()).intValue(); 2027 if (tree.hasTag(MINUS_ASG)) ival = -ival; 2028 ((LocalItem)l).incr(ival); 2029 result = l; 2030 return; 2031 } 2032 // Otherwise, duplicate expression, load one copy 2033 // and complete binary operation. 2034 l.duplicate(); 2035 l.coerce(operator.type.getParameterTypes().head).load(); 2036 completeBinop(tree.lhs, tree.rhs, operator).coerce(tree.lhs.type); 2037 } 2038 result = items.makeAssignItem(l); 2039 } 2040 2041 public void visitUnary(JCUnary tree) { 2042 OperatorSymbol operator = tree.operator; 2043 if (tree.hasTag(NOT)) { 2044 CondItem od = genCond(tree.arg, false); 2045 result = od.negate(); 2046 } else { 2047 Item od = genExpr(tree.arg, operator.type.getParameterTypes().head); 2048 switch (tree.getTag()) { 2049 case POS: 2050 result = od.load(); 2051 break; 2052 case NEG: 2053 result = od.load(); 2054 code.emitop0(operator.opcode); 2055 break; 2056 case COMPL: 2057 result = od.load(); 2058 emitMinusOne(od.typecode); 2059 code.emitop0(operator.opcode); 2060 break; 2061 case PREINC: case PREDEC: 2062 od.duplicate(); 2063 if (od instanceof LocalItem && 2064 (operator.opcode == iadd || operator.opcode == isub)) { 2065 ((LocalItem)od).incr(tree.hasTag(PREINC) ? 1 : -1); 2066 result = od; 2067 } else { 2068 od.load(); 2069 code.emitop0(one(od.typecode)); 2070 code.emitop0(operator.opcode); 2071 // Perform narrowing primitive conversion if byte, 2072 // char, or short. Fix for 4304655. 2073 if (od.typecode != INTcode && 2074 Code.truncate(od.typecode) == INTcode) 2075 code.emitop0(int2byte + od.typecode - BYTEcode); 2076 result = items.makeAssignItem(od); 2077 } 2078 break; 2079 case POSTINC: case POSTDEC: 2080 od.duplicate(); 2081 if (od instanceof LocalItem && 2082 (operator.opcode == iadd || operator.opcode == isub)) { 2083 Item res = od.load(); 2084 ((LocalItem)od).incr(tree.hasTag(POSTINC) ? 1 : -1); 2085 result = res; 2086 } else { 2087 Item res = od.load(); 2088 od.stash(od.typecode); 2089 code.emitop0(one(od.typecode)); 2090 code.emitop0(operator.opcode); 2091 // Perform narrowing primitive conversion if byte, 2092 // char, or short. Fix for 4304655. 2093 if (od.typecode != INTcode && 2094 Code.truncate(od.typecode) == INTcode) 2095 code.emitop0(int2byte + od.typecode - BYTEcode); 2096 od.store(); 2097 result = res; 2098 } 2099 break; 2100 case NULLCHK: 2101 result = od.load(); 2102 code.emitop0(dup); 2103 genNullCheck(tree); 2104 break; 2105 default: 2106 Assert.error(); 2107 } 2108 } 2109 } 2110 2111 /** Generate a null check from the object value at stack top. */ 2112 private void genNullCheck(JCTree tree) { 2113 code.statBegin(tree.pos); 2114 callMethod(tree.pos(), syms.objectsType, names.requireNonNull, 2115 List.of(syms.objectType), true); 2116 code.emitop0(pop); 2117 } 2118 2119 public void visitBinary(JCBinary tree) { 2120 OperatorSymbol operator = tree.operator; 2121 if (operator.opcode == string_add) { 2122 result = concat.makeConcat(tree); 2123 } else if (tree.hasTag(AND)) { 2124 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER); 2125 if (!lcond.isFalse()) { 2126 Chain falseJumps = lcond.jumpFalse(); 2127 code.resolve(lcond.trueJumps); 2128 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET); 2129 result = items. 2130 makeCondItem(rcond.opcode, 2131 rcond.trueJumps, 2132 Code.mergeChains(falseJumps, 2133 rcond.falseJumps)); 2134 } else { 2135 result = lcond; 2136 } 2137 } else if (tree.hasTag(OR)) { 2138 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER); 2139 if (!lcond.isTrue()) { 2140 Chain trueJumps = lcond.jumpTrue(); 2141 code.resolve(lcond.falseJumps); 2142 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET); 2143 result = items. 2144 makeCondItem(rcond.opcode, 2145 Code.mergeChains(trueJumps, rcond.trueJumps), 2146 rcond.falseJumps); 2147 } else { 2148 result = lcond; 2149 } 2150 } else { 2151 Item od = genExpr(tree.lhs, operator.type.getParameterTypes().head); 2152 od.load(); 2153 result = completeBinop(tree.lhs, tree.rhs, operator); 2154 } 2155 } 2156 2157 2158 /** Complete generating code for operation, with left operand 2159 * already on stack. 2160 * @param lhs The tree representing the left operand. 2161 * @param rhs The tree representing the right operand. 2162 * @param operator The operator symbol. 2163 */ 2164 Item completeBinop(JCTree lhs, JCTree rhs, OperatorSymbol operator) { 2165 MethodType optype = (MethodType)operator.type; 2166 int opcode = operator.opcode; 2167 if (opcode >= if_icmpeq && opcode <= if_icmple && 2168 rhs.type.constValue() instanceof Number && 2169 ((Number) rhs.type.constValue()).intValue() == 0) { 2170 opcode = opcode + (ifeq - if_icmpeq); 2171 } else if (opcode >= if_acmpeq && opcode <= if_acmpne && 2172 TreeInfo.isNull(rhs)) { 2173 opcode = opcode + (if_acmp_null - if_acmpeq); 2174 } else { 2175 // The expected type of the right operand is 2176 // the second parameter type of the operator, except for 2177 // shifts with long shiftcount, where we convert the opcode 2178 // to a short shift and the expected type to int. 2179 Type rtype = operator.erasure(types).getParameterTypes().tail.head; 2180 if (opcode >= ishll && opcode <= lushrl) { 2181 opcode = opcode + (ishl - ishll); 2182 rtype = syms.intType; 2183 } 2184 // Generate code for right operand and load. 2185 genExpr(rhs, rtype).load(); 2186 // If there are two consecutive opcode instructions, 2187 // emit the first now. 2188 if (opcode >= (1 << preShift)) { 2189 code.emitop0(opcode >> preShift); 2190 opcode = opcode & 0xFF; 2191 } 2192 } 2193 if (opcode >= ifeq && opcode <= if_acmpne || 2194 opcode == if_acmp_null || opcode == if_acmp_nonnull) { 2195 return items.makeCondItem(opcode); 2196 } else { 2197 code.emitop0(opcode); 2198 return items.makeStackItem(optype.restype); 2199 } 2200 } 2201 2202 public void visitTypeCast(JCTypeCast tree) { 2203 result = genExpr(tree.expr, tree.clazz.type).load(); 2204 setTypeAnnotationPositions(tree.pos); 2205 // Additional code is only needed if we cast to a reference type 2206 // which is not statically a supertype of the expression's type. 2207 // For basic types, the coerce(...) in genExpr(...) will do 2208 // the conversion. 2209 if (!tree.clazz.type.isPrimitive() && 2210 !types.isSameType(tree.expr.type, tree.clazz.type) && 2211 types.asSuper(tree.expr.type, tree.clazz.type.tsym) == null) { 2212 code.emitop2(checkcast, checkDimension(tree.pos(), tree.clazz.type), PoolWriter::putClass); 2213 } 2214 } 2215 2216 public void visitWildcard(JCWildcard tree) { 2217 throw new AssertionError(this.getClass().getName()); 2218 } 2219 2220 public void visitTypeTest(JCInstanceOf tree) { 2221 genExpr(tree.expr, tree.expr.type).load(); 2222 setTypeAnnotationPositions(tree.pos); 2223 code.emitop2(instanceof_, makeRef(tree.pos(), tree.pattern.type)); 2224 result = items.makeStackItem(syms.booleanType); 2225 } 2226 2227 public void visitIndexed(JCArrayAccess tree) { 2228 genExpr(tree.indexed, tree.indexed.type).load(); 2229 genExpr(tree.index, syms.intType).load(); 2230 result = items.makeIndexedItem(tree.type); 2231 } 2232 2233 public void visitIdent(JCIdent tree) { 2234 Symbol sym = tree.sym; 2235 if (tree.name == names._this || tree.name == names._super) { 2236 Item res = tree.name == names._this 2237 ? items.makeThisItem() 2238 : items.makeSuperItem(); 2239 if (sym.kind == MTH) { 2240 // Generate code to address the constructor. 2241 res.load(); 2242 res = items.makeMemberItem(sym, true); 2243 } 2244 result = res; 2245 } else if (isInvokeDynamic(sym) || isConstantDynamic(sym)) { 2246 if (isConstantDynamic(sym)) { 2247 setTypeAnnotationPositions(tree.pos); 2248 } 2249 result = items.makeDynamicItem(sym); 2250 } else if (sym.kind == VAR && (sym.owner.kind == MTH || sym.owner.kind == VAR)) { 2251 result = items.makeLocalItem((VarSymbol)sym); 2252 } else if ((sym.flags() & STATIC) != 0) { 2253 if (!isAccessSuper(env.enclMethod)) 2254 sym = binaryQualifier(sym, env.enclClass.type); 2255 result = items.makeStaticItem(sym); 2256 } else { 2257 items.makeThisItem().load(); 2258 sym = binaryQualifier(sym, env.enclClass.type); 2259 result = items.makeMemberItem(sym, nonVirtualForPrivateAccess(sym)); 2260 } 2261 } 2262 2263 //where 2264 private boolean nonVirtualForPrivateAccess(Symbol sym) { 2265 boolean useVirtual = target.hasVirtualPrivateInvoke() && 2266 !disableVirtualizedPrivateInvoke; 2267 return !useVirtual && ((sym.flags() & PRIVATE) != 0); 2268 } 2269 2270 public void visitSelect(JCFieldAccess tree) { 2271 Symbol sym = tree.sym; 2272 2273 if (tree.name == names._class) { 2274 code.emitLdc((LoadableConstant)checkDimension(tree.pos(), tree.selected.type)); 2275 result = items.makeStackItem(pt); 2276 return; 2277 } 2278 2279 Symbol ssym = TreeInfo.symbol(tree.selected); 2280 2281 // Are we selecting via super? 2282 boolean selectSuper = 2283 ssym != null && (ssym.kind == TYP || ssym.name == names._super); 2284 2285 // Are we accessing a member of the superclass in an access method 2286 // resulting from a qualified super? 2287 boolean accessSuper = isAccessSuper(env.enclMethod); 2288 2289 Item base = (selectSuper) 2290 ? items.makeSuperItem() 2291 : genExpr(tree.selected, tree.selected.type); 2292 2293 if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) { 2294 // We are seeing a variable that is constant but its selecting 2295 // expression is not. 2296 if ((sym.flags() & STATIC) != 0) { 2297 if (!selectSuper && (ssym == null || ssym.kind != TYP)) 2298 base = base.load(); 2299 base.drop(); 2300 } else { 2301 base.load(); 2302 genNullCheck(tree.selected); 2303 } 2304 result = items. 2305 makeImmediateItem(sym.type, ((VarSymbol) sym).getConstValue()); 2306 } else { 2307 if (isInvokeDynamic(sym)) { 2308 result = items.makeDynamicItem(sym); 2309 return; 2310 } else { 2311 sym = binaryQualifier(sym, tree.selected.type); 2312 } 2313 if ((sym.flags() & STATIC) != 0) { 2314 if (!selectSuper && (ssym == null || ssym.kind != TYP)) 2315 base = base.load(); 2316 base.drop(); 2317 result = items.makeStaticItem(sym); 2318 } else { 2319 base.load(); 2320 if (sym == syms.lengthVar) { 2321 code.emitop0(arraylength); 2322 result = items.makeStackItem(syms.intType); 2323 } else { 2324 result = items. 2325 makeMemberItem(sym, 2326 nonVirtualForPrivateAccess(sym) || 2327 selectSuper || accessSuper); 2328 } 2329 } 2330 } 2331 } 2332 2333 public boolean isInvokeDynamic(Symbol sym) { 2334 return sym.kind == MTH && ((MethodSymbol)sym).isDynamic(); 2335 } 2336 2337 public void visitLiteral(JCLiteral tree) { 2338 if (tree.type.hasTag(BOT)) { 2339 code.emitop0(aconst_null); 2340 result = items.makeStackItem(tree.type); 2341 } 2342 else 2343 result = items.makeImmediateItem(tree.type, tree.value); 2344 } 2345 2346 public void visitLetExpr(LetExpr tree) { 2347 code.resolvePending(); 2348 2349 int limit = code.nextreg; 2350 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize); 2351 try { 2352 genStats(tree.defs, env); 2353 } finally { 2354 code.setLetExprStackPos(prevLetExprStart); 2355 } 2356 result = genExpr(tree.expr, tree.expr.type).load(); 2357 code.endScopes(limit); 2358 } 2359 2360 private void generateReferencesToPrunedTree(ClassSymbol classSymbol) { 2361 List<JCTree> prunedInfo = lower.prunedTree.get(classSymbol); 2362 if (prunedInfo != null) { 2363 for (JCTree prunedTree: prunedInfo) { 2364 prunedTree.accept(classReferenceVisitor); 2365 } 2366 } 2367 } 2368 2369 /* ************************************************************************ 2370 * main method 2371 *************************************************************************/ 2372 2373 /** Generate code for a class definition. 2374 * @param env The attribution environment that belongs to the 2375 * outermost class containing this class definition. 2376 * We need this for resolving some additional symbols. 2377 * @param cdef The tree representing the class definition. 2378 * @return True if code is generated with no errors. 2379 */ 2380 public boolean genClass(Env<AttrContext> env, JCClassDecl cdef) { 2381 try { 2382 attrEnv = env; 2383 ClassSymbol c = cdef.sym; 2384 this.toplevel = env.toplevel; 2385 this.endPosTable = toplevel.endPositions; 2386 /* method normalizeDefs() can add references to external classes into the constant pool 2387 */ 2388 cdef.defs = normalizeDefs(cdef.defs, c); 2389 generateReferencesToPrunedTree(c); 2390 Env<GenContext> localEnv = new Env<>(cdef, new GenContext()); 2391 localEnv.toplevel = env.toplevel; 2392 localEnv.enclClass = cdef; 2393 2394 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) { 2395 genDef(l.head, localEnv); 2396 } 2397 if (poolWriter.size() > PoolWriter.MAX_ENTRIES) { 2398 log.error(cdef.pos(), Errors.LimitPool); 2399 nerrs++; 2400 } 2401 if (nerrs != 0) { 2402 // if errors, discard code 2403 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) { 2404 if (l.head.hasTag(METHODDEF)) 2405 ((JCMethodDecl) l.head).sym.code = null; 2406 } 2407 } 2408 cdef.defs = List.nil(); // discard trees 2409 return nerrs == 0; 2410 } finally { 2411 // note: this method does NOT support recursion. 2412 attrEnv = null; 2413 this.env = null; 2414 toplevel = null; 2415 endPosTable = null; 2416 nerrs = 0; 2417 } 2418 } 2419 2420 /* ************************************************************************ 2421 * Auxiliary classes 2422 *************************************************************************/ 2423 2424 /** An abstract class for finalizer generation. 2425 */ 2426 abstract class GenFinalizer { 2427 /** Generate code to clean up when unwinding. */ 2428 abstract void gen(); 2429 2430 /** Generate code to clean up at last. */ 2431 abstract void genLast(); 2432 2433 /** Does this finalizer have some nontrivial cleanup to perform? */ 2434 boolean hasFinalizer() { return true; } 2435 2436 /** Should be invoked after the try's body has been visited. */ 2437 void afterBody() {} 2438 } 2439 2440 /** code generation contexts, 2441 * to be used as type parameter for environments. 2442 */ 2443 static class GenContext { 2444 2445 /** A chain for all unresolved jumps that exit the current environment. 2446 */ 2447 Chain exit = null; 2448 2449 /** A chain for all unresolved jumps that continue in the 2450 * current environment. 2451 */ 2452 Chain cont = null; 2453 2454 /** A closure that generates the finalizer of the current environment. 2455 * Only set for Synchronized and Try contexts. 2456 */ 2457 GenFinalizer finalize = null; 2458 2459 /** Is this a switch statement? If so, allocate registers 2460 * even when the variable declaration is unreachable. 2461 */ 2462 boolean isSwitch = false; 2463 2464 /** A list buffer containing all gaps in the finalizer range, 2465 * where a catch all exception should not apply. 2466 */ 2467 ListBuffer<Integer> gaps = null; 2468 2469 /** Add given chain to exit chain. 2470 */ 2471 void addExit(Chain c) { 2472 exit = Code.mergeChains(c, exit); 2473 } 2474 2475 /** Add given chain to cont chain. 2476 */ 2477 void addCont(Chain c) { 2478 cont = Code.mergeChains(c, cont); 2479 } 2480 } 2481 2482 }