Gen.java revision 2628:8df25ec8c930
1/* 2 * Copyright (c) 1999, 2014, 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 26package com.sun.tools.javac.jvm; 27 28import java.util.*; 29 30import com.sun.tools.javac.util.*; 31import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition; 32import com.sun.tools.javac.util.List; 33import com.sun.tools.javac.code.*; 34import com.sun.tools.javac.code.Attribute.TypeCompound; 35import com.sun.tools.javac.code.Symbol.VarSymbol; 36import com.sun.tools.javac.comp.*; 37import com.sun.tools.javac.tree.*; 38 39import com.sun.tools.javac.code.Symbol.*; 40import com.sun.tools.javac.code.Type.*; 41import com.sun.tools.javac.jvm.Code.*; 42import com.sun.tools.javac.jvm.Items.*; 43import com.sun.tools.javac.tree.EndPosTable; 44import com.sun.tools.javac.tree.JCTree.*; 45 46import static com.sun.tools.javac.code.Flags.*; 47import static com.sun.tools.javac.code.Kinds.*; 48import static com.sun.tools.javac.code.Scope.LookupKind.NON_RECURSIVE; 49import static com.sun.tools.javac.code.TypeTag.*; 50import static com.sun.tools.javac.jvm.ByteCodes.*; 51import static com.sun.tools.javac.jvm.CRTFlags.*; 52import static com.sun.tools.javac.main.Option.*; 53import 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 */ 62public 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 Type stringBufferType; 73 private final Map<Type,Symbol> stringBufferAppend; 74 private Name accessDollar; 75 private final Types types; 76 private final Lower lower; 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, reset by genClass. 93 */ 94 private Pool pool; 95 96 /** LVTRanges info. 97 */ 98 private LVTRanges lvtRanges; 99 100 protected Gen(Context context) { 101 context.put(genKey, this); 102 103 names = Names.instance(context); 104 log = Log.instance(context); 105 syms = Symtab.instance(context); 106 chk = Check.instance(context); 107 rs = Resolve.instance(context); 108 make = TreeMaker.instance(context); 109 target = Target.instance(context); 110 types = Types.instance(context); 111 methodType = new MethodType(null, null, null, syms.methodClass); 112 stringBufferType = syms.stringBuilderType; 113 stringBufferAppend = new HashMap<>(); 114 accessDollar = names. 115 fromString("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 if (varDebugInfo) { 127 lvtRanges = LVTRanges.instance(context); 128 } 129 genCrt = options.isSet(XJCOV); 130 debugCode = options.isSet("debugcode"); 131 allowInvokedynamic = target.hasInvokedynamic() || options.isSet("invokedynamic"); 132 pool = new Pool(types); 133 134 // ignore cldc because we cannot have both stackmap formats 135 this.stackMap = StackMapFormat.JSR202; 136 137 // by default, avoid jsr's for simple finalizers 138 int setjsrlimit = 50; 139 String jsrlimitString = options.get("jsrlimit"); 140 if (jsrlimitString != null) { 141 try { 142 setjsrlimit = Integer.parseInt(jsrlimitString); 143 } catch (NumberFormatException ex) { 144 // ignore ill-formed numbers for jsrlimit 145 } 146 } 147 this.jsrlimit = setjsrlimit; 148 this.useJsrLocally = false; // reset in visitTry 149 } 150 151 /** Switches 152 */ 153 private final boolean lineDebugInfo; 154 private final boolean varDebugInfo; 155 private final boolean genCrt; 156 private final boolean debugCode; 157 private final boolean allowInvokedynamic; 158 159 /** Default limit of (approximate) size of finalizer to inline. 160 * Zero means always use jsr. 100 or greater means never use 161 * jsr. 162 */ 163 private final int jsrlimit; 164 165 /** True if jsr is used. 166 */ 167 private boolean useJsrLocally; 168 169 /** Code buffer, set by genMethod. 170 */ 171 private Code code; 172 173 /** Items structure, set by genMethod. 174 */ 175 private Items items; 176 177 /** Environment for symbol lookup, set by genClass 178 */ 179 private Env<AttrContext> attrEnv; 180 181 /** The top level tree. 182 */ 183 private JCCompilationUnit toplevel; 184 185 /** The number of code-gen errors in this class. 186 */ 187 private int nerrs = 0; 188 189 /** An object containing mappings of syntax trees to their 190 * ending source positions. 191 */ 192 EndPosTable endPosTable; 193 194 /** Generate code to load an integer constant. 195 * @param n The integer to be loaded. 196 */ 197 void loadIntConst(int n) { 198 items.makeImmediateItem(syms.intType, n).load(); 199 } 200 201 /** The opcode that loads a zero constant of a given type code. 202 * @param tc The given type code (@see ByteCode). 203 */ 204 public static int zero(int tc) { 205 switch(tc) { 206 case INTcode: case BYTEcode: case SHORTcode: case CHARcode: 207 return iconst_0; 208 case LONGcode: 209 return lconst_0; 210 case FLOATcode: 211 return fconst_0; 212 case DOUBLEcode: 213 return dconst_0; 214 default: 215 throw new AssertionError("zero"); 216 } 217 } 218 219 /** The opcode that loads a one constant of a given type code. 220 * @param tc The given type code (@see ByteCode). 221 */ 222 public static int one(int tc) { 223 return zero(tc) + 1; 224 } 225 226 /** Generate code to load -1 of the given type code (either int or long). 227 * @param tc The given type code (@see ByteCode). 228 */ 229 void emitMinusOne(int tc) { 230 if (tc == LONGcode) { 231 items.makeImmediateItem(syms.longType, new Long(-1)).load(); 232 } else { 233 code.emitop0(iconst_m1); 234 } 235 } 236 237 /** Construct a symbol to reflect the qualifying type that should 238 * appear in the byte code as per JLS 13.1. 239 * 240 * For {@literal target >= 1.2}: Clone a method with the qualifier as owner (except 241 * for those cases where we need to work around VM bugs). 242 * 243 * For {@literal target <= 1.1}: If qualified variable or method is defined in a 244 * non-accessible class, clone it with the qualifier class as owner. 245 * 246 * @param sym The accessed symbol 247 * @param site The qualifier's type. 248 */ 249 Symbol binaryQualifier(Symbol sym, Type site) { 250 251 if (site.hasTag(ARRAY)) { 252 if (sym == syms.lengthVar || 253 sym.owner != syms.arrayClass) 254 return sym; 255 // array clone can be qualified by the array type in later targets 256 Symbol qualifier = new ClassSymbol(Flags.PUBLIC, site.tsym.name, 257 site, syms.noSymbol); 258 return sym.clone(qualifier); 259 } 260 261 if (sym.owner == site.tsym || 262 (sym.flags() & (STATIC | SYNTHETIC)) == (STATIC | SYNTHETIC)) { 263 return sym; 264 } 265 266 // leave alone methods inherited from Object 267 // JLS 13.1. 268 if (sym.owner == syms.objectType.tsym) 269 return sym; 270 271 return sym.clone(site.tsym); 272 } 273 274 /** Insert a reference to given type in the constant pool, 275 * checking for an array with too many dimensions; 276 * return the reference's index. 277 * @param type The type for which a reference is inserted. 278 */ 279 int makeRef(DiagnosticPosition pos, Type type) { 280 checkDimension(pos, type); 281 if (type.isAnnotated()) { 282 return pool.put((Object)type); 283 } else { 284 return pool.put(type.hasTag(CLASS) ? (Object)type.tsym : (Object)type); 285 } 286 } 287 288 /** Check if the given type is an array with too many dimensions. 289 */ 290 private void checkDimension(DiagnosticPosition pos, Type t) { 291 switch (t.getTag()) { 292 case METHOD: 293 checkDimension(pos, t.getReturnType()); 294 for (List<Type> args = t.getParameterTypes(); args.nonEmpty(); args = args.tail) 295 checkDimension(pos, args.head); 296 break; 297 case ARRAY: 298 if (types.dimensions(t) > ClassFile.MAX_DIMENSIONS) { 299 log.error(pos, "limit.dimensions"); 300 nerrs++; 301 } 302 break; 303 default: 304 break; 305 } 306 } 307 308 /** Create a tempory variable. 309 * @param type The variable's type. 310 */ 311 LocalItem makeTemp(Type type) { 312 VarSymbol v = new VarSymbol(Flags.SYNTHETIC, 313 names.empty, 314 type, 315 env.enclMethod.sym); 316 code.newLocal(v); 317 return items.makeLocalItem(v); 318 } 319 320 /** Generate code to call a non-private method or constructor. 321 * @param pos Position to be used for error reporting. 322 * @param site The type of which the method is a member. 323 * @param name The method's name. 324 * @param argtypes The method's argument types. 325 * @param isStatic A flag that indicates whether we call a 326 * static or instance method. 327 */ 328 void callMethod(DiagnosticPosition pos, 329 Type site, Name name, List<Type> argtypes, 330 boolean isStatic) { 331 Symbol msym = rs. 332 resolveInternalMethod(pos, attrEnv, site, name, argtypes, null); 333 if (isStatic) items.makeStaticItem(msym).invoke(); 334 else items.makeMemberItem(msym, name == names.init).invoke(); 335 } 336 337 /** Is the given method definition an access method 338 * resulting from a qualified super? This is signified by an odd 339 * access code. 340 */ 341 private boolean isAccessSuper(JCMethodDecl enclMethod) { 342 return 343 (enclMethod.mods.flags & SYNTHETIC) != 0 && 344 isOddAccessName(enclMethod.name); 345 } 346 347 /** Does given name start with "access$" and end in an odd digit? 348 */ 349 private boolean isOddAccessName(Name name) { 350 return 351 name.startsWith(accessDollar) && 352 (name.getByteAt(name.getByteLength() - 1) & 1) == 1; 353 } 354 355/* ************************************************************************ 356 * Non-local exits 357 *************************************************************************/ 358 359 /** Generate code to invoke the finalizer associated with given 360 * environment. 361 * Any calls to finalizers are appended to the environments `cont' chain. 362 * Mark beginning of gap in catch all range for finalizer. 363 */ 364 void genFinalizer(Env<GenContext> env) { 365 if (code.isAlive() && env.info.finalize != null) 366 env.info.finalize.gen(); 367 } 368 369 /** Generate code to call all finalizers of structures aborted by 370 * a non-local 371 * exit. Return target environment of the non-local exit. 372 * @param target The tree representing the structure that's aborted 373 * @param env The environment current at the non-local exit. 374 */ 375 Env<GenContext> unwind(JCTree target, Env<GenContext> env) { 376 Env<GenContext> env1 = env; 377 while (true) { 378 genFinalizer(env1); 379 if (env1.tree == target) break; 380 env1 = env1.next; 381 } 382 return env1; 383 } 384 385 /** Mark end of gap in catch-all range for finalizer. 386 * @param env the environment which might contain the finalizer 387 * (if it does, env.info.gaps != null). 388 */ 389 void endFinalizerGap(Env<GenContext> env) { 390 if (env.info.gaps != null && env.info.gaps.length() % 2 == 1) 391 env.info.gaps.append(code.curCP()); 392 } 393 394 /** Mark end of all gaps in catch-all ranges for finalizers of environments 395 * lying between, and including to two environments. 396 * @param from the most deeply nested environment to mark 397 * @param to the least deeply nested environment to mark 398 */ 399 void endFinalizerGaps(Env<GenContext> from, Env<GenContext> to) { 400 Env<GenContext> last = null; 401 while (last != to) { 402 endFinalizerGap(from); 403 last = from; 404 from = from.next; 405 } 406 } 407 408 /** Do any of the structures aborted by a non-local exit have 409 * finalizers that require an empty stack? 410 * @param target The tree representing the structure that's aborted 411 * @param env The environment current at the non-local exit. 412 */ 413 boolean hasFinally(JCTree target, Env<GenContext> env) { 414 while (env.tree != target) { 415 if (env.tree.hasTag(TRY) && env.info.finalize.hasFinalizer()) 416 return true; 417 env = env.next; 418 } 419 return false; 420 } 421 422/* ************************************************************************ 423 * Normalizing class-members. 424 *************************************************************************/ 425 426 /** Distribute member initializer code into constructors and {@code <clinit>} 427 * method. 428 * @param defs The list of class member declarations. 429 * @param c The enclosing class. 430 */ 431 List<JCTree> normalizeDefs(List<JCTree> defs, ClassSymbol c) { 432 ListBuffer<JCStatement> initCode = new ListBuffer<>(); 433 ListBuffer<Attribute.TypeCompound> initTAs = new ListBuffer<>(); 434 ListBuffer<JCStatement> clinitCode = new ListBuffer<>(); 435 ListBuffer<Attribute.TypeCompound> clinitTAs = new ListBuffer<>(); 436 ListBuffer<JCTree> methodDefs = new ListBuffer<>(); 437 // Sort definitions into three listbuffers: 438 // - initCode for instance initializers 439 // - clinitCode for class initializers 440 // - methodDefs for method definitions 441 for (List<JCTree> l = defs; l.nonEmpty(); l = l.tail) { 442 JCTree def = l.head; 443 switch (def.getTag()) { 444 case BLOCK: 445 JCBlock block = (JCBlock)def; 446 if ((block.flags & STATIC) != 0) 447 clinitCode.append(block); 448 else 449 initCode.append(block); 450 break; 451 case METHODDEF: 452 methodDefs.append(def); 453 break; 454 case VARDEF: 455 JCVariableDecl vdef = (JCVariableDecl) def; 456 VarSymbol sym = vdef.sym; 457 checkDimension(vdef.pos(), sym.type); 458 if (vdef.init != null) { 459 if ((sym.flags() & STATIC) == 0) { 460 // Always initialize instance variables. 461 JCStatement init = make.at(vdef.pos()). 462 Assignment(sym, vdef.init); 463 initCode.append(init); 464 endPosTable.replaceTree(vdef, init); 465 initTAs.addAll(getAndRemoveNonFieldTAs(sym)); 466 } else if (sym.getConstValue() == null) { 467 // Initialize class (static) variables only if 468 // they are not compile-time constants. 469 JCStatement init = make.at(vdef.pos). 470 Assignment(sym, vdef.init); 471 clinitCode.append(init); 472 endPosTable.replaceTree(vdef, init); 473 clinitTAs.addAll(getAndRemoveNonFieldTAs(sym)); 474 } else { 475 checkStringConstant(vdef.init.pos(), sym.getConstValue()); 476 } 477 } 478 break; 479 default: 480 Assert.error(); 481 } 482 } 483 // Insert any instance initializers into all constructors. 484 if (initCode.length() != 0) { 485 List<JCStatement> inits = initCode.toList(); 486 initTAs.addAll(c.getInitTypeAttributes()); 487 List<Attribute.TypeCompound> initTAlist = initTAs.toList(); 488 for (JCTree t : methodDefs) { 489 normalizeMethod((JCMethodDecl)t, inits, initTAlist); 490 } 491 } 492 // If there are class initializers, create a <clinit> method 493 // that contains them as its body. 494 if (clinitCode.length() != 0) { 495 MethodSymbol clinit = new MethodSymbol( 496 STATIC | (c.flags() & STRICTFP), 497 names.clinit, 498 new MethodType( 499 List.<Type>nil(), syms.voidType, 500 List.<Type>nil(), syms.methodClass), 501 c); 502 c.members().enter(clinit); 503 List<JCStatement> clinitStats = clinitCode.toList(); 504 JCBlock block = make.at(clinitStats.head.pos()).Block(0, clinitStats); 505 block.endpos = TreeInfo.endPos(clinitStats.last()); 506 methodDefs.append(make.MethodDef(clinit, block)); 507 508 if (!clinitTAs.isEmpty()) 509 clinit.appendUniqueTypeAttributes(clinitTAs.toList()); 510 if (!c.getClassInitTypeAttributes().isEmpty()) 511 clinit.appendUniqueTypeAttributes(c.getClassInitTypeAttributes()); 512 } 513 // Return all method definitions. 514 return methodDefs.toList(); 515 } 516 517 private List<Attribute.TypeCompound> getAndRemoveNonFieldTAs(VarSymbol sym) { 518 List<TypeCompound> tas = sym.getRawTypeAttributes(); 519 ListBuffer<Attribute.TypeCompound> fieldTAs = new ListBuffer<>(); 520 ListBuffer<Attribute.TypeCompound> nonfieldTAs = new ListBuffer<>(); 521 for (TypeCompound ta : tas) { 522 Assert.check(ta.getPosition().type != TargetType.UNKNOWN); 523 if (ta.getPosition().type == TargetType.FIELD) { 524 fieldTAs.add(ta); 525 } else { 526 nonfieldTAs.add(ta); 527 } 528 } 529 sym.setTypeAttributes(fieldTAs.toList()); 530 return nonfieldTAs.toList(); 531 } 532 533 /** Check a constant value and report if it is a string that is 534 * too large. 535 */ 536 private void checkStringConstant(DiagnosticPosition pos, Object constValue) { 537 if (nerrs != 0 || // only complain about a long string once 538 constValue == null || 539 !(constValue instanceof String) || 540 ((String)constValue).length() < Pool.MAX_STRING_LENGTH) 541 return; 542 log.error(pos, "limit.string"); 543 nerrs++; 544 } 545 546 /** Insert instance initializer code into initial constructor. 547 * @param md The tree potentially representing a 548 * constructor's definition. 549 * @param initCode The list of instance initializer statements. 550 * @param initTAs Type annotations from the initializer expression. 551 */ 552 void normalizeMethod(JCMethodDecl md, List<JCStatement> initCode, List<TypeCompound> initTAs) { 553 if (md.name == names.init && TreeInfo.isInitialConstructor(md)) { 554 // We are seeing a constructor that does not call another 555 // constructor of the same class. 556 List<JCStatement> stats = md.body.stats; 557 ListBuffer<JCStatement> newstats = new ListBuffer<>(); 558 559 if (stats.nonEmpty()) { 560 // Copy initializers of synthetic variables generated in 561 // the translation of inner classes. 562 while (TreeInfo.isSyntheticInit(stats.head)) { 563 newstats.append(stats.head); 564 stats = stats.tail; 565 } 566 // Copy superclass constructor call 567 newstats.append(stats.head); 568 stats = stats.tail; 569 // Copy remaining synthetic initializers. 570 while (stats.nonEmpty() && 571 TreeInfo.isSyntheticInit(stats.head)) { 572 newstats.append(stats.head); 573 stats = stats.tail; 574 } 575 // Now insert the initializer code. 576 newstats.appendList(initCode); 577 // And copy all remaining statements. 578 while (stats.nonEmpty()) { 579 newstats.append(stats.head); 580 stats = stats.tail; 581 } 582 } 583 md.body.stats = newstats.toList(); 584 if (md.body.endpos == Position.NOPOS) 585 md.body.endpos = TreeInfo.endPos(md.body.stats.last()); 586 587 md.sym.appendUniqueTypeAttributes(initTAs); 588 } 589 } 590 591/* ************************************************************************ 592 * Traversal methods 593 *************************************************************************/ 594 595 /** Visitor argument: The current environment. 596 */ 597 Env<GenContext> env; 598 599 /** Visitor argument: The expected type (prototype). 600 */ 601 Type pt; 602 603 /** Visitor result: The item representing the computed value. 604 */ 605 Item result; 606 607 /** Visitor method: generate code for a definition, catching and reporting 608 * any completion failures. 609 * @param tree The definition to be visited. 610 * @param env The environment current at the definition. 611 */ 612 public void genDef(JCTree tree, Env<GenContext> env) { 613 Env<GenContext> prevEnv = this.env; 614 try { 615 this.env = env; 616 tree.accept(this); 617 } catch (CompletionFailure ex) { 618 chk.completionError(tree.pos(), ex); 619 } finally { 620 this.env = prevEnv; 621 } 622 } 623 624 /** Derived visitor method: check whether CharacterRangeTable 625 * should be emitted, if so, put a new entry into CRTable 626 * and call method to generate bytecode. 627 * If not, just call method to generate bytecode. 628 * @see #genStat(JCTree, Env) 629 * 630 * @param tree The tree to be visited. 631 * @param env The environment to use. 632 * @param crtFlags The CharacterRangeTable flags 633 * indicating type of the entry. 634 */ 635 public void genStat(JCTree tree, Env<GenContext> env, int crtFlags) { 636 if (!genCrt) { 637 genStat(tree, env); 638 return; 639 } 640 int startpc = code.curCP(); 641 genStat(tree, env); 642 if (tree.hasTag(Tag.BLOCK)) crtFlags |= CRT_BLOCK; 643 code.crt.put(tree, crtFlags, startpc, code.curCP()); 644 } 645 646 /** Derived visitor method: generate code for a statement. 647 */ 648 public void genStat(JCTree tree, Env<GenContext> env) { 649 if (code.isAlive()) { 650 code.statBegin(tree.pos); 651 genDef(tree, env); 652 } else if (env.info.isSwitch && tree.hasTag(VARDEF)) { 653 // variables whose declarations are in a switch 654 // can be used even if the decl is unreachable. 655 code.newLocal(((JCVariableDecl) tree).sym); 656 } 657 } 658 659 /** Derived visitor method: check whether CharacterRangeTable 660 * should be emitted, if so, put a new entry into CRTable 661 * and call method to generate bytecode. 662 * If not, just call method to generate bytecode. 663 * @see #genStats(List, Env) 664 * 665 * @param trees The list of trees to be visited. 666 * @param env The environment to use. 667 * @param crtFlags The CharacterRangeTable flags 668 * indicating type of the entry. 669 */ 670 public void genStats(List<JCStatement> trees, Env<GenContext> env, int crtFlags) { 671 if (!genCrt) { 672 genStats(trees, env); 673 return; 674 } 675 if (trees.length() == 1) { // mark one statement with the flags 676 genStat(trees.head, env, crtFlags | CRT_STATEMENT); 677 } else { 678 int startpc = code.curCP(); 679 genStats(trees, env); 680 code.crt.put(trees, crtFlags, startpc, code.curCP()); 681 } 682 } 683 684 /** Derived visitor method: generate code for a list of statements. 685 */ 686 public void genStats(List<? extends JCTree> trees, Env<GenContext> env) { 687 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail) 688 genStat(l.head, env, CRT_STATEMENT); 689 } 690 691 /** Derived visitor method: check whether CharacterRangeTable 692 * should be emitted, if so, put a new entry into CRTable 693 * and call method to generate bytecode. 694 * If not, just call method to generate bytecode. 695 * @see #genCond(JCTree,boolean) 696 * 697 * @param tree The tree to be visited. 698 * @param crtFlags The CharacterRangeTable flags 699 * indicating type of the entry. 700 */ 701 public CondItem genCond(JCTree tree, int crtFlags) { 702 if (!genCrt) return genCond(tree, false); 703 int startpc = code.curCP(); 704 CondItem item = genCond(tree, (crtFlags & CRT_FLOW_CONTROLLER) != 0); 705 code.crt.put(tree, crtFlags, startpc, code.curCP()); 706 return item; 707 } 708 709 /** Derived visitor method: generate code for a boolean 710 * expression in a control-flow context. 711 * @param _tree The expression to be visited. 712 * @param markBranches The flag to indicate that the condition is 713 * a flow controller so produced conditions 714 * should contain a proper tree to generate 715 * CharacterRangeTable branches for them. 716 */ 717 public CondItem genCond(JCTree _tree, boolean markBranches) { 718 JCTree inner_tree = TreeInfo.skipParens(_tree); 719 if (inner_tree.hasTag(CONDEXPR)) { 720 JCConditional tree = (JCConditional)inner_tree; 721 CondItem cond = genCond(tree.cond, CRT_FLOW_CONTROLLER); 722 if (cond.isTrue()) { 723 code.resolve(cond.trueJumps); 724 CondItem result = genCond(tree.truepart, CRT_FLOW_TARGET); 725 if (markBranches) result.tree = tree.truepart; 726 return result; 727 } 728 if (cond.isFalse()) { 729 code.resolve(cond.falseJumps); 730 CondItem result = genCond(tree.falsepart, CRT_FLOW_TARGET); 731 if (markBranches) result.tree = tree.falsepart; 732 return result; 733 } 734 Chain secondJumps = cond.jumpFalse(); 735 code.resolve(cond.trueJumps); 736 CondItem first = genCond(tree.truepart, CRT_FLOW_TARGET); 737 if (markBranches) first.tree = tree.truepart; 738 Chain falseJumps = first.jumpFalse(); 739 code.resolve(first.trueJumps); 740 Chain trueJumps = code.branch(goto_); 741 code.resolve(secondJumps); 742 CondItem second = genCond(tree.falsepart, CRT_FLOW_TARGET); 743 CondItem result = items.makeCondItem(second.opcode, 744 Code.mergeChains(trueJumps, second.trueJumps), 745 Code.mergeChains(falseJumps, second.falseJumps)); 746 if (markBranches) result.tree = tree.falsepart; 747 return result; 748 } else { 749 CondItem result = genExpr(_tree, syms.booleanType).mkCond(); 750 if (markBranches) result.tree = _tree; 751 return result; 752 } 753 } 754 755 /** Visitor class for expressions which might be constant expressions. 756 * This class is a subset of TreeScanner. Intended to visit trees pruned by 757 * Lower as long as constant expressions looking for references to any 758 * ClassSymbol. Any such reference will be added to the constant pool so 759 * automated tools can detect class dependencies better. 760 */ 761 class ClassReferenceVisitor extends JCTree.Visitor { 762 763 @Override 764 public void visitTree(JCTree tree) {} 765 766 @Override 767 public void visitBinary(JCBinary tree) { 768 tree.lhs.accept(this); 769 tree.rhs.accept(this); 770 } 771 772 @Override 773 public void visitSelect(JCFieldAccess tree) { 774 if (tree.selected.type.hasTag(CLASS)) { 775 makeRef(tree.selected.pos(), tree.selected.type); 776 } 777 } 778 779 @Override 780 public void visitIdent(JCIdent tree) { 781 if (tree.sym.owner instanceof ClassSymbol) { 782 pool.put(tree.sym.owner); 783 } 784 } 785 786 @Override 787 public void visitConditional(JCConditional tree) { 788 tree.cond.accept(this); 789 tree.truepart.accept(this); 790 tree.falsepart.accept(this); 791 } 792 793 @Override 794 public void visitUnary(JCUnary tree) { 795 tree.arg.accept(this); 796 } 797 798 @Override 799 public void visitParens(JCParens tree) { 800 tree.expr.accept(this); 801 } 802 803 @Override 804 public void visitTypeCast(JCTypeCast tree) { 805 tree.expr.accept(this); 806 } 807 } 808 809 private ClassReferenceVisitor classReferenceVisitor = new ClassReferenceVisitor(); 810 811 /** Visitor method: generate code for an expression, catching and reporting 812 * any completion failures. 813 * @param tree The expression to be visited. 814 * @param pt The expression's expected type (proto-type). 815 */ 816 public Item genExpr(JCTree tree, Type pt) { 817 Type prevPt = this.pt; 818 try { 819 if (tree.type.constValue() != null) { 820 // Short circuit any expressions which are constants 821 tree.accept(classReferenceVisitor); 822 checkStringConstant(tree.pos(), tree.type.constValue()); 823 result = items.makeImmediateItem(tree.type, tree.type.constValue()); 824 } else { 825 this.pt = pt; 826 tree.accept(this); 827 } 828 return result.coerce(pt); 829 } catch (CompletionFailure ex) { 830 chk.completionError(tree.pos(), ex); 831 code.state.stacksize = 1; 832 return items.makeStackItem(pt); 833 } finally { 834 this.pt = prevPt; 835 } 836 } 837 838 /** Derived visitor method: generate code for a list of method arguments. 839 * @param trees The argument expressions to be visited. 840 * @param pts The expression's expected types (i.e. the formal parameter 841 * types of the invoked method). 842 */ 843 public void genArgs(List<JCExpression> trees, List<Type> pts) { 844 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail) { 845 genExpr(l.head, pts.head).load(); 846 pts = pts.tail; 847 } 848 // require lists be of same length 849 Assert.check(pts.isEmpty()); 850 } 851 852/* ************************************************************************ 853 * Visitor methods for statements and definitions 854 *************************************************************************/ 855 856 /** Thrown when the byte code size exceeds limit. 857 */ 858 public static class CodeSizeOverflow extends RuntimeException { 859 private static final long serialVersionUID = 0; 860 public CodeSizeOverflow() {} 861 } 862 863 public void visitMethodDef(JCMethodDecl tree) { 864 // Create a new local environment that points pack at method 865 // definition. 866 Env<GenContext> localEnv = env.dup(tree); 867 localEnv.enclMethod = tree; 868 // The expected type of every return statement in this method 869 // is the method's return type. 870 this.pt = tree.sym.erasure(types).getReturnType(); 871 872 checkDimension(tree.pos(), tree.sym.erasure(types)); 873 genMethod(tree, localEnv, false); 874 } 875//where 876 /** Generate code for a method. 877 * @param tree The tree representing the method definition. 878 * @param env The environment current for the method body. 879 * @param fatcode A flag that indicates whether all jumps are 880 * within 32K. We first invoke this method under 881 * the assumption that fatcode == false, i.e. all 882 * jumps are within 32K. If this fails, fatcode 883 * is set to true and we try again. 884 */ 885 void genMethod(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) { 886 MethodSymbol meth = tree.sym; 887 int extras = 0; 888 // Count up extra parameters 889 if (meth.isConstructor()) { 890 extras++; 891 if (meth.enclClass().isInner() && 892 !meth.enclClass().isStatic()) { 893 extras++; 894 } 895 } else if ((tree.mods.flags & STATIC) == 0) { 896 extras++; 897 } 898 // System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG 899 if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes()) + extras > 900 ClassFile.MAX_PARAMETERS) { 901 log.error(tree.pos(), "limit.parameters"); 902 nerrs++; 903 } 904 905 else if (tree.body != null) { 906 // Create a new code structure and initialize it. 907 int startpcCrt = initCode(tree, env, fatcode); 908 909 try { 910 genStat(tree.body, env); 911 } catch (CodeSizeOverflow e) { 912 // Failed due to code limit, try again with jsr/ret 913 startpcCrt = initCode(tree, env, fatcode); 914 genStat(tree.body, env); 915 } 916 917 if (code.state.stacksize != 0) { 918 log.error(tree.body.pos(), "stack.sim.error", tree); 919 throw new AssertionError(); 920 } 921 922 // If last statement could complete normally, insert a 923 // return at the end. 924 if (code.isAlive()) { 925 code.statBegin(TreeInfo.endPos(tree.body)); 926 if (env.enclMethod == null || 927 env.enclMethod.sym.type.getReturnType().hasTag(VOID)) { 928 code.emitop0(return_); 929 } else { 930 // sometime dead code seems alive (4415991); 931 // generate a small loop instead 932 int startpc = code.entryPoint(); 933 CondItem c = items.makeCondItem(goto_); 934 code.resolve(c.jumpTrue(), startpc); 935 } 936 } 937 if (genCrt) 938 code.crt.put(tree.body, 939 CRT_BLOCK, 940 startpcCrt, 941 code.curCP()); 942 943 code.endScopes(0); 944 945 // If we exceeded limits, panic 946 if (code.checkLimits(tree.pos(), log)) { 947 nerrs++; 948 return; 949 } 950 951 // If we generated short code but got a long jump, do it again 952 // with fatCode = true. 953 if (!fatcode && code.fatcode) genMethod(tree, env, true); 954 955 // Clean up 956 if(stackMap == StackMapFormat.JSR202) { 957 code.lastFrame = null; 958 code.frameBeforeLast = null; 959 } 960 961 // Compress exception table 962 code.compressCatchTable(); 963 964 // Fill in type annotation positions for exception parameters 965 code.fillExceptionParameterPositions(); 966 } 967 } 968 969 private int initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) { 970 MethodSymbol meth = tree.sym; 971 972 // Create a new code structure. 973 meth.code = code = new Code(meth, 974 fatcode, 975 lineDebugInfo ? toplevel.lineMap : null, 976 varDebugInfo, 977 stackMap, 978 debugCode, 979 genCrt ? new CRTable(tree, env.toplevel.endPositions) 980 : null, 981 syms, 982 types, 983 pool, 984 varDebugInfo ? lvtRanges : null); 985 items = new Items(pool, code, syms, types); 986 if (code.debugCode) { 987 System.err.println(meth + " for body " + tree); 988 } 989 990 // If method is not static, create a new local variable address 991 // for `this'. 992 if ((tree.mods.flags & STATIC) == 0) { 993 Type selfType = meth.owner.type; 994 if (meth.isConstructor() && selfType != syms.objectType) 995 selfType = UninitializedType.uninitializedThis(selfType); 996 code.setDefined( 997 code.newLocal( 998 new VarSymbol(FINAL, names._this, selfType, meth.owner))); 999 } 1000 1001 // Mark all parameters as defined from the beginning of 1002 // the method. 1003 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) { 1004 checkDimension(l.head.pos(), l.head.sym.type); 1005 code.setDefined(code.newLocal(l.head.sym)); 1006 } 1007 1008 // Get ready to generate code for method body. 1009 int startpcCrt = genCrt ? code.curCP() : 0; 1010 code.entryPoint(); 1011 1012 // Suppress initial stackmap 1013 code.pendingStackMap = false; 1014 1015 return startpcCrt; 1016 } 1017 1018 public void visitVarDef(JCVariableDecl tree) { 1019 VarSymbol v = tree.sym; 1020 code.newLocal(v); 1021 if (tree.init != null) { 1022 checkStringConstant(tree.init.pos(), v.getConstValue()); 1023 if (v.getConstValue() == null || varDebugInfo) { 1024 genExpr(tree.init, v.erasure(types)).load(); 1025 items.makeLocalItem(v).store(); 1026 } 1027 } 1028 checkDimension(tree.pos(), v.type); 1029 } 1030 1031 public void visitSkip(JCSkip tree) { 1032 } 1033 1034 public void visitBlock(JCBlock tree) { 1035 int limit = code.nextreg; 1036 Env<GenContext> localEnv = env.dup(tree, new GenContext()); 1037 genStats(tree.stats, localEnv); 1038 // End the scope of all block-local variables in variable info. 1039 if (!env.tree.hasTag(METHODDEF)) { 1040 code.statBegin(tree.endpos); 1041 code.endScopes(limit); 1042 code.pendingStatPos = Position.NOPOS; 1043 } 1044 } 1045 1046 public void visitDoLoop(JCDoWhileLoop tree) { 1047 genLoop(tree, tree.body, tree.cond, List.<JCExpressionStatement>nil(), false); 1048 } 1049 1050 public void visitWhileLoop(JCWhileLoop tree) { 1051 genLoop(tree, tree.body, tree.cond, List.<JCExpressionStatement>nil(), true); 1052 } 1053 1054 public void visitForLoop(JCForLoop tree) { 1055 int limit = code.nextreg; 1056 genStats(tree.init, env); 1057 genLoop(tree, tree.body, tree.cond, tree.step, true); 1058 code.endScopes(limit); 1059 } 1060 //where 1061 /** Generate code for a loop. 1062 * @param loop The tree representing the loop. 1063 * @param body The loop's body. 1064 * @param cond The loop's controling condition. 1065 * @param step "Step" statements to be inserted at end of 1066 * each iteration. 1067 * @param testFirst True if the loop test belongs before the body. 1068 */ 1069 private void genLoop(JCStatement loop, 1070 JCStatement body, 1071 JCExpression cond, 1072 List<JCExpressionStatement> step, 1073 boolean testFirst) { 1074 Env<GenContext> loopEnv = env.dup(loop, new GenContext()); 1075 int startpc = code.entryPoint(); 1076 if (testFirst) { //while or for loop 1077 CondItem c; 1078 if (cond != null) { 1079 code.statBegin(cond.pos); 1080 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER); 1081 } else { 1082 c = items.makeCondItem(goto_); 1083 } 1084 Chain loopDone = c.jumpFalse(); 1085 code.resolve(c.trueJumps); 1086 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET); 1087 if (varDebugInfo) { 1088 checkLoopLocalVarRangeEnding(loop, body, 1089 LoopLocalVarRangeEndingPoint.BEFORE_STEPS); 1090 } 1091 code.resolve(loopEnv.info.cont); 1092 genStats(step, loopEnv); 1093 if (varDebugInfo) { 1094 checkLoopLocalVarRangeEnding(loop, body, 1095 LoopLocalVarRangeEndingPoint.AFTER_STEPS); 1096 } 1097 code.resolve(code.branch(goto_), startpc); 1098 code.resolve(loopDone); 1099 } else { 1100 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET); 1101 if (varDebugInfo) { 1102 checkLoopLocalVarRangeEnding(loop, body, 1103 LoopLocalVarRangeEndingPoint.BEFORE_STEPS); 1104 } 1105 code.resolve(loopEnv.info.cont); 1106 genStats(step, loopEnv); 1107 if (varDebugInfo) { 1108 checkLoopLocalVarRangeEnding(loop, body, 1109 LoopLocalVarRangeEndingPoint.AFTER_STEPS); 1110 } 1111 CondItem c; 1112 if (cond != null) { 1113 code.statBegin(cond.pos); 1114 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER); 1115 } else { 1116 c = items.makeCondItem(goto_); 1117 } 1118 code.resolve(c.jumpTrue(), startpc); 1119 code.resolve(c.falseJumps); 1120 } 1121 code.resolve(loopEnv.info.exit); 1122 if (loopEnv.info.exit != null) { 1123 loopEnv.info.exit.state.defined.excludeFrom(code.nextreg); 1124 } 1125 } 1126 1127 private enum LoopLocalVarRangeEndingPoint { 1128 BEFORE_STEPS, 1129 AFTER_STEPS, 1130 } 1131 1132 /** 1133 * Checks whether we have reached an alive range ending point for local 1134 * variables after a loop. 1135 * 1136 * Local variables alive range ending point for loops varies depending 1137 * on the loop type. The range can be closed before or after the code 1138 * for the steps sentences has been generated. 1139 * 1140 * - While loops has no steps so in that case the range is closed just 1141 * after the body of the loop. 1142 * 1143 * - For-like loops may have steps so as long as the steps sentences 1144 * can possibly contain non-synthetic local variables, the alive range 1145 * for local variables must be closed after the steps in this case. 1146 */ 1147 private void checkLoopLocalVarRangeEnding(JCTree loop, JCTree body, 1148 LoopLocalVarRangeEndingPoint endingPoint) { 1149 if (varDebugInfo && lvtRanges.containsKey(code.meth, body)) { 1150 switch (endingPoint) { 1151 case BEFORE_STEPS: 1152 if (!loop.hasTag(FORLOOP)) { 1153 code.closeAliveRanges(body); 1154 } 1155 break; 1156 case AFTER_STEPS: 1157 if (loop.hasTag(FORLOOP)) { 1158 code.closeAliveRanges(body); 1159 } 1160 break; 1161 } 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 code.resolve(localEnv.info.exit); 1173 } 1174 1175 public void visitSwitch(JCSwitch tree) { 1176 int limit = code.nextreg; 1177 Assert.check(!tree.selector.type.hasTag(CLASS)); 1178 int startpcCrt = genCrt ? code.curCP() : 0; 1179 Item sel = genExpr(tree.selector, syms.intType); 1180 List<JCCase> cases = tree.cases; 1181 if (cases.isEmpty()) { 1182 // We are seeing: switch <sel> {} 1183 sel.load().drop(); 1184 if (genCrt) 1185 code.crt.put(TreeInfo.skipParens(tree.selector), 1186 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP()); 1187 } else { 1188 // We are seeing a nonempty switch. 1189 sel.load(); 1190 if (genCrt) 1191 code.crt.put(TreeInfo.skipParens(tree.selector), 1192 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP()); 1193 Env<GenContext> switchEnv = env.dup(tree, new GenContext()); 1194 switchEnv.info.isSwitch = true; 1195 1196 // Compute number of labels and minimum and maximum label values. 1197 // For each case, store its label in an array. 1198 int lo = Integer.MAX_VALUE; // minimum label. 1199 int hi = Integer.MIN_VALUE; // maximum label. 1200 int nlabels = 0; // number of labels. 1201 1202 int[] labels = new int[cases.length()]; // the label array. 1203 int defaultIndex = -1; // the index of the default clause. 1204 1205 List<JCCase> l = cases; 1206 for (int i = 0; i < labels.length; i++) { 1207 if (l.head.pat != null) { 1208 int val = ((Number)l.head.pat.type.constValue()).intValue(); 1209 labels[i] = val; 1210 if (val < lo) lo = val; 1211 if (hi < val) hi = val; 1212 nlabels++; 1213 } else { 1214 Assert.check(defaultIndex == -1); 1215 defaultIndex = i; 1216 } 1217 l = l.tail; 1218 } 1219 1220 // Determine whether to issue a tableswitch or a lookupswitch 1221 // instruction. 1222 long table_space_cost = 4 + ((long) hi - lo + 1); // words 1223 long table_time_cost = 3; // comparisons 1224 long lookup_space_cost = 3 + 2 * (long) nlabels; 1225 long lookup_time_cost = nlabels; 1226 int opcode = 1227 nlabels > 0 && 1228 table_space_cost + 3 * table_time_cost <= 1229 lookup_space_cost + 3 * lookup_time_cost 1230 ? 1231 tableswitch : lookupswitch; 1232 1233 int startpc = code.curCP(); // the position of the selector operation 1234 code.emitop0(opcode); 1235 code.align(4); 1236 int tableBase = code.curCP(); // the start of the jump table 1237 int[] offsets = null; // a table of offsets for a lookupswitch 1238 code.emit4(-1); // leave space for default offset 1239 if (opcode == tableswitch) { 1240 code.emit4(lo); // minimum label 1241 code.emit4(hi); // maximum label 1242 for (long i = lo; i <= hi; i++) { // leave space for jump table 1243 code.emit4(-1); 1244 } 1245 } else { 1246 code.emit4(nlabels); // number of labels 1247 for (int i = 0; i < nlabels; i++) { 1248 code.emit4(-1); code.emit4(-1); // leave space for lookup table 1249 } 1250 offsets = new int[labels.length]; 1251 } 1252 Code.State stateSwitch = code.state.dup(); 1253 code.markDead(); 1254 1255 // For each case do: 1256 l = cases; 1257 for (int i = 0; i < labels.length; i++) { 1258 JCCase c = l.head; 1259 l = l.tail; 1260 1261 int pc = code.entryPoint(stateSwitch); 1262 // Insert offset directly into code or else into the 1263 // offsets table. 1264 if (i != defaultIndex) { 1265 if (opcode == tableswitch) { 1266 code.put4( 1267 tableBase + 4 * (labels[i] - lo + 3), 1268 pc - startpc); 1269 } else { 1270 offsets[i] = pc - startpc; 1271 } 1272 } else { 1273 code.put4(tableBase, pc - startpc); 1274 } 1275 1276 // Generate code for the statements in this case. 1277 genStats(c.stats, switchEnv, CRT_FLOW_TARGET); 1278 if (varDebugInfo && lvtRanges.containsKey(code.meth, c.stats.last())) { 1279 code.closeAliveRanges(c.stats.last()); 1280 } 1281 } 1282 1283 // Resolve all breaks. 1284 code.resolve(switchEnv.info.exit); 1285 1286 // If we have not set the default offset, we do so now. 1287 if (code.get4(tableBase) == -1) { 1288 code.put4(tableBase, code.entryPoint(stateSwitch) - startpc); 1289 } 1290 1291 if (opcode == tableswitch) { 1292 // Let any unfilled slots point to the default case. 1293 int defaultOffset = code.get4(tableBase); 1294 for (long i = lo; i <= hi; i++) { 1295 int t = (int)(tableBase + 4 * (i - lo + 3)); 1296 if (code.get4(t) == -1) 1297 code.put4(t, defaultOffset); 1298 } 1299 } else { 1300 // Sort non-default offsets and copy into lookup table. 1301 if (defaultIndex >= 0) 1302 for (int i = defaultIndex; i < labels.length - 1; i++) { 1303 labels[i] = labels[i+1]; 1304 offsets[i] = offsets[i+1]; 1305 } 1306 if (nlabels > 0) 1307 qsort2(labels, offsets, 0, nlabels - 1); 1308 for (int i = 0; i < nlabels; i++) { 1309 int caseidx = tableBase + 8 * (i + 1); 1310 code.put4(caseidx, labels[i]); 1311 code.put4(caseidx + 4, offsets[i]); 1312 } 1313 } 1314 } 1315 code.endScopes(limit); 1316 } 1317//where 1318 /** Sort (int) arrays of keys and values 1319 */ 1320 static void qsort2(int[] keys, int[] values, int lo, int hi) { 1321 int i = lo; 1322 int j = hi; 1323 int pivot = keys[(i+j)/2]; 1324 do { 1325 while (keys[i] < pivot) i++; 1326 while (pivot < keys[j]) j--; 1327 if (i <= j) { 1328 int temp1 = keys[i]; 1329 keys[i] = keys[j]; 1330 keys[j] = temp1; 1331 int temp2 = values[i]; 1332 values[i] = values[j]; 1333 values[j] = temp2; 1334 i++; 1335 j--; 1336 } 1337 } while (i <= j); 1338 if (lo < j) qsort2(keys, values, lo, j); 1339 if (i < hi) qsort2(keys, values, i, hi); 1340 } 1341 1342 public void visitSynchronized(JCSynchronized tree) { 1343 int limit = code.nextreg; 1344 // Generate code to evaluate lock and save in temporary variable. 1345 final LocalItem lockVar = makeTemp(syms.objectType); 1346 genExpr(tree.lock, tree.lock.type).load().duplicate(); 1347 lockVar.store(); 1348 1349 // Generate code to enter monitor. 1350 code.emitop0(monitorenter); 1351 code.state.lock(lockVar.reg); 1352 1353 // Generate code for a try statement with given body, no catch clauses 1354 // in a new environment with the "exit-monitor" operation as finalizer. 1355 final Env<GenContext> syncEnv = env.dup(tree, new GenContext()); 1356 syncEnv.info.finalize = new GenFinalizer() { 1357 void gen() { 1358 genLast(); 1359 Assert.check(syncEnv.info.gaps.length() % 2 == 0); 1360 syncEnv.info.gaps.append(code.curCP()); 1361 } 1362 void genLast() { 1363 if (code.isAlive()) { 1364 lockVar.load(); 1365 code.emitop0(monitorexit); 1366 code.state.unlock(lockVar.reg); 1367 } 1368 } 1369 }; 1370 syncEnv.info.gaps = new ListBuffer<>(); 1371 genTry(tree.body, List.<JCCatch>nil(), syncEnv); 1372 code.endScopes(limit); 1373 } 1374 1375 public void visitTry(final JCTry tree) { 1376 // Generate code for a try statement with given body and catch clauses, 1377 // in a new environment which calls the finally block if there is one. 1378 final Env<GenContext> tryEnv = env.dup(tree, new GenContext()); 1379 final Env<GenContext> oldEnv = env; 1380 if (!useJsrLocally) { 1381 useJsrLocally = 1382 (stackMap == StackMapFormat.NONE) && 1383 (jsrlimit <= 0 || 1384 jsrlimit < 100 && 1385 estimateCodeComplexity(tree.finalizer)>jsrlimit); 1386 } 1387 tryEnv.info.finalize = new GenFinalizer() { 1388 void gen() { 1389 if (useJsrLocally) { 1390 if (tree.finalizer != null) { 1391 Code.State jsrState = code.state.dup(); 1392 jsrState.push(Code.jsrReturnValue); 1393 tryEnv.info.cont = 1394 new Chain(code.emitJump(jsr), 1395 tryEnv.info.cont, 1396 jsrState); 1397 } 1398 Assert.check(tryEnv.info.gaps.length() % 2 == 0); 1399 tryEnv.info.gaps.append(code.curCP()); 1400 } else { 1401 Assert.check(tryEnv.info.gaps.length() % 2 == 0); 1402 tryEnv.info.gaps.append(code.curCP()); 1403 genLast(); 1404 } 1405 } 1406 void genLast() { 1407 if (tree.finalizer != null) 1408 genStat(tree.finalizer, oldEnv, CRT_BLOCK); 1409 } 1410 boolean hasFinalizer() { 1411 return tree.finalizer != null; 1412 } 1413 }; 1414 tryEnv.info.gaps = new ListBuffer<>(); 1415 genTry(tree.body, tree.catchers, tryEnv); 1416 } 1417 //where 1418 /** Generate code for a try or synchronized statement 1419 * @param body The body of the try or synchronized statement. 1420 * @param catchers The lis of catch clauses. 1421 * @param env the environment current for the body. 1422 */ 1423 void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) { 1424 int limit = code.nextreg; 1425 int startpc = code.curCP(); 1426 Code.State stateTry = code.state.dup(); 1427 genStat(body, env, CRT_BLOCK); 1428 int endpc = code.curCP(); 1429 boolean hasFinalizer = 1430 env.info.finalize != null && 1431 env.info.finalize.hasFinalizer(); 1432 List<Integer> gaps = env.info.gaps.toList(); 1433 code.statBegin(TreeInfo.endPos(body)); 1434 genFinalizer(env); 1435 code.statBegin(TreeInfo.endPos(env.tree)); 1436 Chain exitChain = code.branch(goto_); 1437 if (varDebugInfo && lvtRanges.containsKey(code.meth, body)) { 1438 code.closeAliveRanges(body); 1439 } 1440 endFinalizerGap(env); 1441 if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) { 1442 // start off with exception on stack 1443 code.entryPoint(stateTry, l.head.param.sym.type); 1444 genCatch(l.head, env, startpc, endpc, gaps); 1445 genFinalizer(env); 1446 if (hasFinalizer || l.tail.nonEmpty()) { 1447 code.statBegin(TreeInfo.endPos(env.tree)); 1448 exitChain = Code.mergeChains(exitChain, 1449 code.branch(goto_)); 1450 } 1451 endFinalizerGap(env); 1452 } 1453 if (hasFinalizer) { 1454 // Create a new register segement to avoid allocating 1455 // the same variables in finalizers and other statements. 1456 code.newRegSegment(); 1457 1458 // Add a catch-all clause. 1459 1460 // start off with exception on stack 1461 int catchallpc = code.entryPoint(stateTry, syms.throwableType); 1462 1463 // Register all exception ranges for catch all clause. 1464 // The range of the catch all clause is from the beginning 1465 // of the try or synchronized block until the present 1466 // code pointer excluding all gaps in the current 1467 // environment's GenContext. 1468 int startseg = startpc; 1469 while (env.info.gaps.nonEmpty()) { 1470 int endseg = env.info.gaps.next().intValue(); 1471 registerCatch(body.pos(), startseg, endseg, 1472 catchallpc, 0); 1473 startseg = env.info.gaps.next().intValue(); 1474 } 1475 code.statBegin(TreeInfo.finalizerPos(env.tree)); 1476 code.markStatBegin(); 1477 1478 Item excVar = makeTemp(syms.throwableType); 1479 excVar.store(); 1480 genFinalizer(env); 1481 excVar.load(); 1482 registerCatch(body.pos(), startseg, 1483 env.info.gaps.next().intValue(), 1484 catchallpc, 0); 1485 code.emitop0(athrow); 1486 code.markDead(); 1487 1488 // If there are jsr's to this finalizer, ... 1489 if (env.info.cont != null) { 1490 // Resolve all jsr's. 1491 code.resolve(env.info.cont); 1492 1493 // Mark statement line number 1494 code.statBegin(TreeInfo.finalizerPos(env.tree)); 1495 code.markStatBegin(); 1496 1497 // Save return address. 1498 LocalItem retVar = makeTemp(syms.throwableType); 1499 retVar.store(); 1500 1501 // Generate finalizer code. 1502 env.info.finalize.genLast(); 1503 1504 // Return. 1505 code.emitop1w(ret, retVar.reg); 1506 code.markDead(); 1507 } 1508 } 1509 // Resolve all breaks. 1510 code.resolve(exitChain); 1511 1512 code.endScopes(limit); 1513 } 1514 1515 /** Generate code for a catch clause. 1516 * @param tree The catch clause. 1517 * @param env The environment current in the enclosing try. 1518 * @param startpc Start pc of try-block. 1519 * @param endpc End pc of try-block. 1520 */ 1521 void genCatch(JCCatch tree, 1522 Env<GenContext> env, 1523 int startpc, int endpc, 1524 List<Integer> gaps) { 1525 if (startpc != endpc) { 1526 List<JCExpression> subClauses = TreeInfo.isMultiCatch(tree) ? 1527 ((JCTypeUnion)tree.param.vartype).alternatives : 1528 List.of(tree.param.vartype); 1529 while (gaps.nonEmpty()) { 1530 for (JCExpression subCatch : subClauses) { 1531 int catchType = makeRef(tree.pos(), subCatch.type); 1532 int end = gaps.head.intValue(); 1533 registerCatch(tree.pos(), 1534 startpc, end, code.curCP(), 1535 catchType); 1536 if (subCatch.type.isAnnotated()) { 1537 for (Attribute.TypeCompound tc : 1538 subCatch.type.getAnnotationMirrors()) { 1539 tc.position.setCatchInfo(catchType, startpc); 1540 } 1541 } 1542 } 1543 gaps = gaps.tail; 1544 startpc = gaps.head.intValue(); 1545 gaps = gaps.tail; 1546 } 1547 if (startpc < endpc) { 1548 for (JCExpression subCatch : subClauses) { 1549 int catchType = makeRef(tree.pos(), subCatch.type); 1550 registerCatch(tree.pos(), 1551 startpc, endpc, code.curCP(), 1552 catchType); 1553 if (subCatch.type.isAnnotated()) { 1554 for (Attribute.TypeCompound tc : 1555 subCatch.type.getAnnotationMirrors()) { 1556 tc.position.setCatchInfo(catchType, startpc); 1557 } 1558 } 1559 } 1560 } 1561 VarSymbol exparam = tree.param.sym; 1562 code.statBegin(tree.pos); 1563 code.markStatBegin(); 1564 int limit = code.nextreg; 1565 int exlocal = code.newLocal(exparam); 1566 items.makeLocalItem(exparam).store(); 1567 code.statBegin(TreeInfo.firstStatPos(tree.body)); 1568 genStat(tree.body, env, CRT_BLOCK); 1569 code.endScopes(limit); 1570 code.statBegin(TreeInfo.endPos(tree.body)); 1571 } 1572 } 1573 1574 /** Register a catch clause in the "Exceptions" code-attribute. 1575 */ 1576 void registerCatch(DiagnosticPosition pos, 1577 int startpc, int endpc, 1578 int handler_pc, int catch_type) { 1579 char startpc1 = (char)startpc; 1580 char endpc1 = (char)endpc; 1581 char handler_pc1 = (char)handler_pc; 1582 if (startpc1 == startpc && 1583 endpc1 == endpc && 1584 handler_pc1 == handler_pc) { 1585 code.addCatch(startpc1, endpc1, handler_pc1, 1586 (char)catch_type); 1587 } else { 1588 log.error(pos, "limit.code.too.large.for.try.stmt"); 1589 nerrs++; 1590 } 1591 } 1592 1593 /** Very roughly estimate the number of instructions needed for 1594 * the given tree. 1595 */ 1596 int estimateCodeComplexity(JCTree tree) { 1597 if (tree == null) return 0; 1598 class ComplexityScanner extends TreeScanner { 1599 int complexity = 0; 1600 public void scan(JCTree tree) { 1601 if (complexity > jsrlimit) return; 1602 super.scan(tree); 1603 } 1604 public void visitClassDef(JCClassDecl tree) {} 1605 public void visitDoLoop(JCDoWhileLoop tree) 1606 { super.visitDoLoop(tree); complexity++; } 1607 public void visitWhileLoop(JCWhileLoop tree) 1608 { super.visitWhileLoop(tree); complexity++; } 1609 public void visitForLoop(JCForLoop tree) 1610 { super.visitForLoop(tree); complexity++; } 1611 public void visitSwitch(JCSwitch tree) 1612 { super.visitSwitch(tree); complexity+=5; } 1613 public void visitCase(JCCase tree) 1614 { super.visitCase(tree); complexity++; } 1615 public void visitSynchronized(JCSynchronized tree) 1616 { super.visitSynchronized(tree); complexity+=6; } 1617 public void visitTry(JCTry tree) 1618 { super.visitTry(tree); 1619 if (tree.finalizer != null) complexity+=6; } 1620 public void visitCatch(JCCatch tree) 1621 { super.visitCatch(tree); complexity+=2; } 1622 public void visitConditional(JCConditional tree) 1623 { super.visitConditional(tree); complexity+=2; } 1624 public void visitIf(JCIf tree) 1625 { super.visitIf(tree); complexity+=2; } 1626 // note: for break, continue, and return we don't take unwind() into account. 1627 public void visitBreak(JCBreak tree) 1628 { super.visitBreak(tree); complexity+=1; } 1629 public void visitContinue(JCContinue tree) 1630 { super.visitContinue(tree); complexity+=1; } 1631 public void visitReturn(JCReturn tree) 1632 { super.visitReturn(tree); complexity+=1; } 1633 public void visitThrow(JCThrow tree) 1634 { super.visitThrow(tree); complexity+=1; } 1635 public void visitAssert(JCAssert tree) 1636 { super.visitAssert(tree); complexity+=5; } 1637 public void visitApply(JCMethodInvocation tree) 1638 { super.visitApply(tree); complexity+=2; } 1639 public void visitNewClass(JCNewClass tree) 1640 { scan(tree.encl); scan(tree.args); complexity+=2; } 1641 public void visitNewArray(JCNewArray tree) 1642 { super.visitNewArray(tree); complexity+=5; } 1643 public void visitAssign(JCAssign tree) 1644 { super.visitAssign(tree); complexity+=1; } 1645 public void visitAssignop(JCAssignOp tree) 1646 { super.visitAssignop(tree); complexity+=2; } 1647 public void visitUnary(JCUnary tree) 1648 { complexity+=1; 1649 if (tree.type.constValue() == null) super.visitUnary(tree); } 1650 public void visitBinary(JCBinary tree) 1651 { complexity+=1; 1652 if (tree.type.constValue() == null) super.visitBinary(tree); } 1653 public void visitTypeTest(JCInstanceOf tree) 1654 { super.visitTypeTest(tree); complexity+=1; } 1655 public void visitIndexed(JCArrayAccess tree) 1656 { super.visitIndexed(tree); complexity+=1; } 1657 public void visitSelect(JCFieldAccess tree) 1658 { super.visitSelect(tree); 1659 if (tree.sym.kind == VAR) complexity+=1; } 1660 public void visitIdent(JCIdent tree) { 1661 if (tree.sym.kind == VAR) { 1662 complexity+=1; 1663 if (tree.type.constValue() == null && 1664 tree.sym.owner.kind == TYP) 1665 complexity+=1; 1666 } 1667 } 1668 public void visitLiteral(JCLiteral tree) 1669 { complexity+=1; } 1670 public void visitTree(JCTree tree) {} 1671 public void visitWildcard(JCWildcard tree) { 1672 throw new AssertionError(this.getClass().getName()); 1673 } 1674 } 1675 ComplexityScanner scanner = new ComplexityScanner(); 1676 tree.accept(scanner); 1677 return scanner.complexity; 1678 } 1679 1680 public void visitIf(JCIf tree) { 1681 int limit = code.nextreg; 1682 Chain thenExit = null; 1683 CondItem c = genCond(TreeInfo.skipParens(tree.cond), 1684 CRT_FLOW_CONTROLLER); 1685 Chain elseChain = c.jumpFalse(); 1686 if (!c.isFalse()) { 1687 code.resolve(c.trueJumps); 1688 genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET); 1689 thenExit = code.branch(goto_); 1690 if (varDebugInfo && lvtRanges.containsKey(code.meth, tree.thenpart)) { 1691 code.closeAliveRanges(tree.thenpart, code.cp); 1692 } 1693 } 1694 if (elseChain != null) { 1695 code.resolve(elseChain); 1696 if (tree.elsepart != null) { 1697 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET); 1698 if (varDebugInfo && lvtRanges.containsKey(code.meth, tree.elsepart)) { 1699 code.closeAliveRanges(tree.elsepart); 1700 } 1701 } 1702 } 1703 code.resolve(thenExit); 1704 code.endScopes(limit); 1705 } 1706 1707 public void visitExec(JCExpressionStatement tree) { 1708 // Optimize x++ to ++x and x-- to --x. 1709 JCExpression e = tree.expr; 1710 switch (e.getTag()) { 1711 case POSTINC: 1712 ((JCUnary) e).setTag(PREINC); 1713 break; 1714 case POSTDEC: 1715 ((JCUnary) e).setTag(PREDEC); 1716 break; 1717 } 1718 genExpr(tree.expr, tree.expr.type).drop(); 1719 } 1720 1721 public void visitBreak(JCBreak tree) { 1722 Env<GenContext> targetEnv = unwind(tree.target, env); 1723 Assert.check(code.state.stacksize == 0); 1724 targetEnv.info.addExit(code.branch(goto_)); 1725 endFinalizerGaps(env, targetEnv); 1726 } 1727 1728 public void visitContinue(JCContinue tree) { 1729 Env<GenContext> targetEnv = unwind(tree.target, env); 1730 Assert.check(code.state.stacksize == 0); 1731 targetEnv.info.addCont(code.branch(goto_)); 1732 endFinalizerGaps(env, targetEnv); 1733 } 1734 1735 public void visitReturn(JCReturn tree) { 1736 int limit = code.nextreg; 1737 final Env<GenContext> targetEnv; 1738 if (tree.expr != null) { 1739 Item r = genExpr(tree.expr, pt).load(); 1740 if (hasFinally(env.enclMethod, env)) { 1741 r = makeTemp(pt); 1742 r.store(); 1743 } 1744 targetEnv = unwind(env.enclMethod, env); 1745 r.load(); 1746 code.emitop0(ireturn + Code.truncate(Code.typecode(pt))); 1747 } else { 1748 /* If we have a statement like: 1749 * 1750 * return; 1751 * 1752 * we need to store the code.pendingStatPos value before generating 1753 * the finalizer. 1754 */ 1755 int tmpPos = code.pendingStatPos; 1756 targetEnv = unwind(env.enclMethod, env); 1757 code.pendingStatPos = tmpPos; 1758 code.emitop0(return_); 1759 } 1760 endFinalizerGaps(env, targetEnv); 1761 code.endScopes(limit); 1762 } 1763 1764 public void visitThrow(JCThrow tree) { 1765 genExpr(tree.expr, tree.expr.type).load(); 1766 code.emitop0(athrow); 1767 } 1768 1769/* ************************************************************************ 1770 * Visitor methods for expressions 1771 *************************************************************************/ 1772 1773 public void visitApply(JCMethodInvocation tree) { 1774 setTypeAnnotationPositions(tree.pos); 1775 // Generate code for method. 1776 Item m = genExpr(tree.meth, methodType); 1777 // Generate code for all arguments, where the expected types are 1778 // the parameters of the method's external type (that is, any implicit 1779 // outer instance of a super(...) call appears as first parameter). 1780 MethodSymbol msym = (MethodSymbol)TreeInfo.symbol(tree.meth); 1781 genArgs(tree.args, 1782 msym.externalType(types).getParameterTypes()); 1783 if (!msym.isDynamic()) { 1784 code.statBegin(tree.pos); 1785 } 1786 result = m.invoke(); 1787 } 1788 1789 public void visitConditional(JCConditional tree) { 1790 Chain thenExit = null; 1791 CondItem c = genCond(tree.cond, CRT_FLOW_CONTROLLER); 1792 Chain elseChain = c.jumpFalse(); 1793 if (!c.isFalse()) { 1794 code.resolve(c.trueJumps); 1795 int startpc = genCrt ? code.curCP() : 0; 1796 code.statBegin(tree.truepart.pos); 1797 genExpr(tree.truepart, pt).load(); 1798 code.state.forceStackTop(tree.type); 1799 if (genCrt) code.crt.put(tree.truepart, CRT_FLOW_TARGET, 1800 startpc, code.curCP()); 1801 thenExit = code.branch(goto_); 1802 } 1803 if (elseChain != null) { 1804 code.resolve(elseChain); 1805 int startpc = genCrt ? code.curCP() : 0; 1806 code.statBegin(tree.falsepart.pos); 1807 genExpr(tree.falsepart, pt).load(); 1808 code.state.forceStackTop(tree.type); 1809 if (genCrt) code.crt.put(tree.falsepart, CRT_FLOW_TARGET, 1810 startpc, code.curCP()); 1811 } 1812 code.resolve(thenExit); 1813 result = items.makeStackItem(pt); 1814 } 1815 1816 private void setTypeAnnotationPositions(int treePos) { 1817 MethodSymbol meth = code.meth; 1818 boolean initOrClinit = code.meth.getKind() == javax.lang.model.element.ElementKind.CONSTRUCTOR 1819 || code.meth.getKind() == javax.lang.model.element.ElementKind.STATIC_INIT; 1820 1821 for (Attribute.TypeCompound ta : meth.getRawTypeAttributes()) { 1822 if (ta.hasUnknownPosition()) 1823 ta.tryFixPosition(); 1824 1825 if (ta.position.matchesPos(treePos)) 1826 ta.position.updatePosOffset(code.cp); 1827 } 1828 1829 if (!initOrClinit) 1830 return; 1831 1832 for (Attribute.TypeCompound ta : meth.owner.getRawTypeAttributes()) { 1833 if (ta.hasUnknownPosition()) 1834 ta.tryFixPosition(); 1835 1836 if (ta.position.matchesPos(treePos)) 1837 ta.position.updatePosOffset(code.cp); 1838 } 1839 1840 ClassSymbol clazz = meth.enclClass(); 1841 for (Symbol s : new com.sun.tools.javac.model.FilteredMemberList(clazz.members())) { 1842 if (!s.getKind().isField()) 1843 continue; 1844 1845 for (Attribute.TypeCompound ta : s.getRawTypeAttributes()) { 1846 if (ta.hasUnknownPosition()) 1847 ta.tryFixPosition(); 1848 1849 if (ta.position.matchesPos(treePos)) 1850 ta.position.updatePosOffset(code.cp); 1851 } 1852 } 1853 } 1854 1855 public void visitNewClass(JCNewClass tree) { 1856 // Enclosing instances or anonymous classes should have been eliminated 1857 // by now. 1858 Assert.check(tree.encl == null && tree.def == null); 1859 setTypeAnnotationPositions(tree.pos); 1860 1861 code.emitop2(new_, makeRef(tree.pos(), tree.type)); 1862 code.emitop0(dup); 1863 1864 // Generate code for all arguments, where the expected types are 1865 // the parameters of the constructor's external type (that is, 1866 // any implicit outer instance appears as first parameter). 1867 genArgs(tree.args, tree.constructor.externalType(types).getParameterTypes()); 1868 1869 items.makeMemberItem(tree.constructor, true).invoke(); 1870 result = items.makeStackItem(tree.type); 1871 } 1872 1873 public void visitNewArray(JCNewArray tree) { 1874 setTypeAnnotationPositions(tree.pos); 1875 1876 if (tree.elems != null) { 1877 Type elemtype = types.elemtype(tree.type); 1878 loadIntConst(tree.elems.length()); 1879 Item arr = makeNewArray(tree.pos(), tree.type, 1); 1880 int i = 0; 1881 for (List<JCExpression> l = tree.elems; l.nonEmpty(); l = l.tail) { 1882 arr.duplicate(); 1883 loadIntConst(i); 1884 i++; 1885 genExpr(l.head, elemtype).load(); 1886 items.makeIndexedItem(elemtype).store(); 1887 } 1888 result = arr; 1889 } else { 1890 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) { 1891 genExpr(l.head, syms.intType).load(); 1892 } 1893 result = makeNewArray(tree.pos(), tree.type, tree.dims.length()); 1894 } 1895 } 1896//where 1897 /** Generate code to create an array with given element type and number 1898 * of dimensions. 1899 */ 1900 Item makeNewArray(DiagnosticPosition pos, Type type, int ndims) { 1901 Type elemtype = types.elemtype(type); 1902 if (types.dimensions(type) > ClassFile.MAX_DIMENSIONS) { 1903 log.error(pos, "limit.dimensions"); 1904 nerrs++; 1905 } 1906 int elemcode = Code.arraycode(elemtype); 1907 if (elemcode == 0 || (elemcode == 1 && ndims == 1)) { 1908 code.emitAnewarray(makeRef(pos, elemtype), type); 1909 } else if (elemcode == 1) { 1910 code.emitMultianewarray(ndims, makeRef(pos, type), type); 1911 } else { 1912 code.emitNewarray(elemcode, type); 1913 } 1914 return items.makeStackItem(type); 1915 } 1916 1917 public void visitParens(JCParens tree) { 1918 result = genExpr(tree.expr, tree.expr.type); 1919 } 1920 1921 public void visitAssign(JCAssign tree) { 1922 Item l = genExpr(tree.lhs, tree.lhs.type); 1923 genExpr(tree.rhs, tree.lhs.type).load(); 1924 result = items.makeAssignItem(l); 1925 } 1926 1927 public void visitAssignop(JCAssignOp tree) { 1928 OperatorSymbol operator = (OperatorSymbol) tree.operator; 1929 Item l; 1930 if (operator.opcode == string_add) { 1931 // Generate code to make a string buffer 1932 makeStringBuffer(tree.pos()); 1933 1934 // Generate code for first string, possibly save one 1935 // copy under buffer 1936 l = genExpr(tree.lhs, tree.lhs.type); 1937 if (l.width() > 0) { 1938 code.emitop0(dup_x1 + 3 * (l.width() - 1)); 1939 } 1940 1941 // Load first string and append to buffer. 1942 l.load(); 1943 appendString(tree.lhs); 1944 1945 // Append all other strings to buffer. 1946 appendStrings(tree.rhs); 1947 1948 // Convert buffer to string. 1949 bufferToString(tree.pos()); 1950 } else { 1951 // Generate code for first expression 1952 l = genExpr(tree.lhs, tree.lhs.type); 1953 1954 // If we have an increment of -32768 to +32767 of a local 1955 // int variable we can use an incr instruction instead of 1956 // proceeding further. 1957 if ((tree.hasTag(PLUS_ASG) || tree.hasTag(MINUS_ASG)) && 1958 l instanceof LocalItem && 1959 tree.lhs.type.getTag().isSubRangeOf(INT) && 1960 tree.rhs.type.getTag().isSubRangeOf(INT) && 1961 tree.rhs.type.constValue() != null) { 1962 int ival = ((Number) tree.rhs.type.constValue()).intValue(); 1963 if (tree.hasTag(MINUS_ASG)) ival = -ival; 1964 ((LocalItem)l).incr(ival); 1965 result = l; 1966 return; 1967 } 1968 // Otherwise, duplicate expression, load one copy 1969 // and complete binary operation. 1970 l.duplicate(); 1971 l.coerce(operator.type.getParameterTypes().head).load(); 1972 completeBinop(tree.lhs, tree.rhs, operator).coerce(tree.lhs.type); 1973 } 1974 result = items.makeAssignItem(l); 1975 } 1976 1977 public void visitUnary(JCUnary tree) { 1978 OperatorSymbol operator = (OperatorSymbol)tree.operator; 1979 if (tree.hasTag(NOT)) { 1980 CondItem od = genCond(tree.arg, false); 1981 result = od.negate(); 1982 } else { 1983 Item od = genExpr(tree.arg, operator.type.getParameterTypes().head); 1984 switch (tree.getTag()) { 1985 case POS: 1986 result = od.load(); 1987 break; 1988 case NEG: 1989 result = od.load(); 1990 code.emitop0(operator.opcode); 1991 break; 1992 case COMPL: 1993 result = od.load(); 1994 emitMinusOne(od.typecode); 1995 code.emitop0(operator.opcode); 1996 break; 1997 case PREINC: case PREDEC: 1998 od.duplicate(); 1999 if (od instanceof LocalItem && 2000 (operator.opcode == iadd || operator.opcode == isub)) { 2001 ((LocalItem)od).incr(tree.hasTag(PREINC) ? 1 : -1); 2002 result = od; 2003 } else { 2004 od.load(); 2005 code.emitop0(one(od.typecode)); 2006 code.emitop0(operator.opcode); 2007 // Perform narrowing primitive conversion if byte, 2008 // char, or short. Fix for 4304655. 2009 if (od.typecode != INTcode && 2010 Code.truncate(od.typecode) == INTcode) 2011 code.emitop0(int2byte + od.typecode - BYTEcode); 2012 result = items.makeAssignItem(od); 2013 } 2014 break; 2015 case POSTINC: case POSTDEC: 2016 od.duplicate(); 2017 if (od instanceof LocalItem && 2018 (operator.opcode == iadd || operator.opcode == isub)) { 2019 Item res = od.load(); 2020 ((LocalItem)od).incr(tree.hasTag(POSTINC) ? 1 : -1); 2021 result = res; 2022 } else { 2023 Item res = od.load(); 2024 od.stash(od.typecode); 2025 code.emitop0(one(od.typecode)); 2026 code.emitop0(operator.opcode); 2027 // Perform narrowing primitive conversion if byte, 2028 // char, or short. Fix for 4304655. 2029 if (od.typecode != INTcode && 2030 Code.truncate(od.typecode) == INTcode) 2031 code.emitop0(int2byte + od.typecode - BYTEcode); 2032 od.store(); 2033 result = res; 2034 } 2035 break; 2036 case NULLCHK: 2037 result = od.load(); 2038 code.emitop0(dup); 2039 genNullCheck(tree.pos()); 2040 break; 2041 default: 2042 Assert.error(); 2043 } 2044 } 2045 } 2046 2047 /** Generate a null check from the object value at stack top. */ 2048 private void genNullCheck(DiagnosticPosition pos) { 2049 callMethod(pos, syms.objectType, names.getClass, 2050 List.<Type>nil(), false); 2051 code.emitop0(pop); 2052 } 2053 2054 public void visitBinary(JCBinary tree) { 2055 OperatorSymbol operator = (OperatorSymbol)tree.operator; 2056 if (operator.opcode == string_add) { 2057 // Create a string buffer. 2058 makeStringBuffer(tree.pos()); 2059 // Append all strings to buffer. 2060 appendStrings(tree); 2061 // Convert buffer to string. 2062 bufferToString(tree.pos()); 2063 result = items.makeStackItem(syms.stringType); 2064 } else if (tree.hasTag(AND)) { 2065 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER); 2066 if (!lcond.isFalse()) { 2067 Chain falseJumps = lcond.jumpFalse(); 2068 code.resolve(lcond.trueJumps); 2069 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET); 2070 result = items. 2071 makeCondItem(rcond.opcode, 2072 rcond.trueJumps, 2073 Code.mergeChains(falseJumps, 2074 rcond.falseJumps)); 2075 } else { 2076 result = lcond; 2077 } 2078 } else if (tree.hasTag(OR)) { 2079 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER); 2080 if (!lcond.isTrue()) { 2081 Chain trueJumps = lcond.jumpTrue(); 2082 code.resolve(lcond.falseJumps); 2083 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET); 2084 result = items. 2085 makeCondItem(rcond.opcode, 2086 Code.mergeChains(trueJumps, rcond.trueJumps), 2087 rcond.falseJumps); 2088 } else { 2089 result = lcond; 2090 } 2091 } else { 2092 Item od = genExpr(tree.lhs, operator.type.getParameterTypes().head); 2093 od.load(); 2094 result = completeBinop(tree.lhs, tree.rhs, operator); 2095 } 2096 } 2097//where 2098 /** Make a new string buffer. 2099 */ 2100 void makeStringBuffer(DiagnosticPosition pos) { 2101 code.emitop2(new_, makeRef(pos, stringBufferType)); 2102 code.emitop0(dup); 2103 callMethod( 2104 pos, stringBufferType, names.init, List.<Type>nil(), false); 2105 } 2106 2107 /** Append value (on tos) to string buffer (on tos - 1). 2108 */ 2109 void appendString(JCTree tree) { 2110 Type t = tree.type.baseType(); 2111 if (!t.isPrimitive() && t.tsym != syms.stringType.tsym) { 2112 t = syms.objectType; 2113 } 2114 items.makeMemberItem(getStringBufferAppend(tree, t), false).invoke(); 2115 } 2116 Symbol getStringBufferAppend(JCTree tree, Type t) { 2117 Assert.checkNull(t.constValue()); 2118 Symbol method = stringBufferAppend.get(t); 2119 if (method == null) { 2120 method = rs.resolveInternalMethod(tree.pos(), 2121 attrEnv, 2122 stringBufferType, 2123 names.append, 2124 List.of(t), 2125 null); 2126 stringBufferAppend.put(t, method); 2127 } 2128 return method; 2129 } 2130 2131 /** Add all strings in tree to string buffer. 2132 */ 2133 void appendStrings(JCTree tree) { 2134 tree = TreeInfo.skipParens(tree); 2135 if (tree.hasTag(PLUS) && tree.type.constValue() == null) { 2136 JCBinary op = (JCBinary) tree; 2137 if (op.operator.kind == MTH && 2138 ((OperatorSymbol) op.operator).opcode == string_add) { 2139 appendStrings(op.lhs); 2140 appendStrings(op.rhs); 2141 return; 2142 } 2143 } 2144 genExpr(tree, tree.type).load(); 2145 appendString(tree); 2146 } 2147 2148 /** Convert string buffer on tos to string. 2149 */ 2150 void bufferToString(DiagnosticPosition pos) { 2151 callMethod( 2152 pos, 2153 stringBufferType, 2154 names.toString, 2155 List.<Type>nil(), 2156 false); 2157 } 2158 2159 /** Complete generating code for operation, with left operand 2160 * already on stack. 2161 * @param lhs The tree representing the left operand. 2162 * @param rhs The tree representing the right operand. 2163 * @param operator The operator symbol. 2164 */ 2165 Item completeBinop(JCTree lhs, JCTree rhs, OperatorSymbol operator) { 2166 MethodType optype = (MethodType)operator.type; 2167 int opcode = operator.opcode; 2168 if (opcode >= if_icmpeq && opcode <= if_icmple && 2169 rhs.type.constValue() instanceof Number && 2170 ((Number) rhs.type.constValue()).intValue() == 0) { 2171 opcode = opcode + (ifeq - if_icmpeq); 2172 } else if (opcode >= if_acmpeq && opcode <= if_acmpne && 2173 TreeInfo.isNull(rhs)) { 2174 opcode = opcode + (if_acmp_null - if_acmpeq); 2175 } else { 2176 // The expected type of the right operand is 2177 // the second parameter type of the operator, except for 2178 // shifts with long shiftcount, where we convert the opcode 2179 // to a short shift and the expected type to int. 2180 Type rtype = operator.erasure(types).getParameterTypes().tail.head; 2181 if (opcode >= ishll && opcode <= lushrl) { 2182 opcode = opcode + (ishl - ishll); 2183 rtype = syms.intType; 2184 } 2185 // Generate code for right operand and load. 2186 genExpr(rhs, rtype).load(); 2187 // If there are two consecutive opcode instructions, 2188 // emit the first now. 2189 if (opcode >= (1 << preShift)) { 2190 code.emitop0(opcode >> preShift); 2191 opcode = opcode & 0xFF; 2192 } 2193 } 2194 if (opcode >= ifeq && opcode <= if_acmpne || 2195 opcode == if_acmp_null || opcode == if_acmp_nonnull) { 2196 return items.makeCondItem(opcode); 2197 } else { 2198 code.emitop0(opcode); 2199 return items.makeStackItem(optype.restype); 2200 } 2201 } 2202 2203 public void visitTypeCast(JCTypeCast tree) { 2204 setTypeAnnotationPositions(tree.pos); 2205 result = genExpr(tree.expr, tree.clazz.type).load(); 2206 // Additional code is only needed if we cast to a reference type 2207 // which is not statically a supertype of the expression's type. 2208 // For basic types, the coerce(...) in genExpr(...) will do 2209 // the conversion. 2210 if (!tree.clazz.type.isPrimitive() && 2211 types.asSuper(tree.expr.type, tree.clazz.type.tsym) == null) { 2212 code.emitop2(checkcast, makeRef(tree.pos(), tree.clazz.type)); 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 setTypeAnnotationPositions(tree.pos); 2222 genExpr(tree.expr, tree.expr.type).load(); 2223 code.emitop2(instanceof_, makeRef(tree.pos(), tree.clazz.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 (sym.kind == VAR && sym.owner.kind == MTH) { 2246 result = items.makeLocalItem((VarSymbol)sym); 2247 } else if (isInvokeDynamic(sym)) { 2248 result = items.makeDynamicItem(sym); 2249 } else if ((sym.flags() & STATIC) != 0) { 2250 if (!isAccessSuper(env.enclMethod)) 2251 sym = binaryQualifier(sym, env.enclClass.type); 2252 result = items.makeStaticItem(sym); 2253 } else { 2254 items.makeThisItem().load(); 2255 sym = binaryQualifier(sym, env.enclClass.type); 2256 result = items.makeMemberItem(sym, (sym.flags() & PRIVATE) != 0); 2257 } 2258 } 2259 2260 public void visitSelect(JCFieldAccess tree) { 2261 Symbol sym = tree.sym; 2262 2263 if (tree.name == names._class) { 2264 code.emitLdc(makeRef(tree.pos(), tree.selected.type)); 2265 result = items.makeStackItem(pt); 2266 return; 2267 } 2268 2269 Symbol ssym = TreeInfo.symbol(tree.selected); 2270 2271 // Are we selecting via super? 2272 boolean selectSuper = 2273 ssym != null && (ssym.kind == TYP || ssym.name == names._super); 2274 2275 // Are we accessing a member of the superclass in an access method 2276 // resulting from a qualified super? 2277 boolean accessSuper = isAccessSuper(env.enclMethod); 2278 2279 Item base = (selectSuper) 2280 ? items.makeSuperItem() 2281 : genExpr(tree.selected, tree.selected.type); 2282 2283 if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) { 2284 // We are seeing a variable that is constant but its selecting 2285 // expression is not. 2286 if ((sym.flags() & STATIC) != 0) { 2287 if (!selectSuper && (ssym == null || ssym.kind != TYP)) 2288 base = base.load(); 2289 base.drop(); 2290 } else { 2291 base.load(); 2292 genNullCheck(tree.selected.pos()); 2293 } 2294 result = items. 2295 makeImmediateItem(sym.type, ((VarSymbol) sym).getConstValue()); 2296 } else { 2297 if (isInvokeDynamic(sym)) { 2298 result = items.makeDynamicItem(sym); 2299 return; 2300 } else { 2301 sym = binaryQualifier(sym, tree.selected.type); 2302 } 2303 if ((sym.flags() & STATIC) != 0) { 2304 if (!selectSuper && (ssym == null || ssym.kind != TYP)) 2305 base = base.load(); 2306 base.drop(); 2307 result = items.makeStaticItem(sym); 2308 } else { 2309 base.load(); 2310 if (sym == syms.lengthVar) { 2311 code.emitop0(arraylength); 2312 result = items.makeStackItem(syms.intType); 2313 } else { 2314 result = items. 2315 makeMemberItem(sym, 2316 (sym.flags() & PRIVATE) != 0 || 2317 selectSuper || accessSuper); 2318 } 2319 } 2320 } 2321 } 2322 2323 public boolean isInvokeDynamic(Symbol sym) { 2324 return sym.kind == MTH && ((MethodSymbol)sym).isDynamic(); 2325 } 2326 2327 public void visitLiteral(JCLiteral tree) { 2328 if (tree.type.hasTag(BOT)) { 2329 code.emitop0(aconst_null); 2330 if (types.dimensions(pt) > 1) { 2331 code.emitop2(checkcast, makeRef(tree.pos(), pt)); 2332 result = items.makeStackItem(pt); 2333 } else { 2334 result = items.makeStackItem(tree.type); 2335 } 2336 } 2337 else 2338 result = items.makeImmediateItem(tree.type, tree.value); 2339 } 2340 2341 public void visitLetExpr(LetExpr tree) { 2342 int limit = code.nextreg; 2343 genStats(tree.defs, env); 2344 result = genExpr(tree.expr, tree.expr.type).load(); 2345 code.endScopes(limit); 2346 } 2347 2348 private void generateReferencesToPrunedTree(ClassSymbol classSymbol, Pool pool) { 2349 List<JCTree> prunedInfo = lower.prunedTree.get(classSymbol); 2350 if (prunedInfo != null) { 2351 for (JCTree prunedTree: prunedInfo) { 2352 prunedTree.accept(classReferenceVisitor); 2353 } 2354 } 2355 } 2356 2357/* ************************************************************************ 2358 * main method 2359 *************************************************************************/ 2360 2361 /** Generate code for a class definition. 2362 * @param env The attribution environment that belongs to the 2363 * outermost class containing this class definition. 2364 * We need this for resolving some additional symbols. 2365 * @param cdef The tree representing the class definition. 2366 * @return True if code is generated with no errors. 2367 */ 2368 public boolean genClass(Env<AttrContext> env, JCClassDecl cdef) { 2369 try { 2370 attrEnv = env; 2371 ClassSymbol c = cdef.sym; 2372 this.toplevel = env.toplevel; 2373 this.endPosTable = toplevel.endPositions; 2374 cdef.defs = normalizeDefs(cdef.defs, c); 2375 c.pool = pool; 2376 pool.reset(); 2377 generateReferencesToPrunedTree(c, pool); 2378 Env<GenContext> localEnv = new Env<>(cdef, new GenContext()); 2379 localEnv.toplevel = env.toplevel; 2380 localEnv.enclClass = cdef; 2381 2382 /* We must not analyze synthetic methods 2383 */ 2384 if (varDebugInfo && (cdef.sym.flags() & SYNTHETIC) == 0) { 2385 try { 2386 LVTAssignAnalyzer lvtAssignAnalyzer = LVTAssignAnalyzer.make( 2387 lvtRanges, syms, names); 2388 lvtAssignAnalyzer.analyzeTree(localEnv); 2389 } catch (Throwable e) { 2390 throw e; 2391 } 2392 } 2393 2394 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) { 2395 genDef(l.head, localEnv); 2396 } 2397 if (pool.numEntries() > Pool.MAX_ENTRIES) { 2398 log.error(cdef.pos(), "limit.pool"); 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 2437 /** code generation contexts, 2438 * to be used as type parameter for environments. 2439 */ 2440 static class GenContext { 2441 2442 /** A chain for all unresolved jumps that exit the current environment. 2443 */ 2444 Chain exit = null; 2445 2446 /** A chain for all unresolved jumps that continue in the 2447 * current environment. 2448 */ 2449 Chain cont = null; 2450 2451 /** A closure that generates the finalizer of the current environment. 2452 * Only set for Synchronized and Try contexts. 2453 */ 2454 GenFinalizer finalize = null; 2455 2456 /** Is this a switch statement? If so, allocate registers 2457 * even when the variable declaration is unreachable. 2458 */ 2459 boolean isSwitch = false; 2460 2461 /** A list buffer containing all gaps in the finalizer range, 2462 * where a catch all exception should not apply. 2463 */ 2464 ListBuffer<Integer> gaps = null; 2465 2466 /** Add given chain to exit chain. 2467 */ 2468 void addExit(Chain c) { 2469 exit = Code.mergeChains(c, exit); 2470 } 2471 2472 /** Add given chain to cont chain. 2473 */ 2474 void addCont(Chain c) { 2475 cont = Code.mergeChains(c, cont); 2476 } 2477 } 2478 2479 static class LVTAssignAnalyzer 2480 extends Flow.AbstractAssignAnalyzer<LVTAssignAnalyzer.LVTAssignPendingExit> { 2481 2482 final LVTBits lvtInits; 2483 final LVTRanges lvtRanges; 2484 2485 /* This class is anchored to a context dependent tree. The tree can 2486 * vary inside the same instruction for example in the switch instruction 2487 * the same FlowBits instance can be anchored to the whole tree, or 2488 * to a given case. The aim is to always anchor the bits to the tree 2489 * capable of closing a DA range. 2490 */ 2491 static class LVTBits extends Bits { 2492 2493 enum BitsOpKind { 2494 INIT, 2495 CLEAR, 2496 INCL_BIT, 2497 EXCL_BIT, 2498 ASSIGN, 2499 AND_SET, 2500 OR_SET, 2501 DIFF_SET, 2502 XOR_SET, 2503 INCL_RANGE, 2504 EXCL_RANGE, 2505 } 2506 2507 JCTree currentTree; 2508 LVTAssignAnalyzer analyzer; 2509 private int[] oldBits = null; 2510 BitsState stateBeforeOp; 2511 2512 LVTBits() { 2513 super(false); 2514 } 2515 2516 LVTBits(int[] bits, BitsState initState) { 2517 super(bits, initState); 2518 } 2519 2520 @Override 2521 public void clear() { 2522 generalOp(null, -1, BitsOpKind.CLEAR); 2523 } 2524 2525 @Override 2526 protected void internalReset() { 2527 super.internalReset(); 2528 oldBits = null; 2529 } 2530 2531 @Override 2532 public Bits assign(Bits someBits) { 2533 // bits can be null 2534 oldBits = bits; 2535 stateBeforeOp = currentState; 2536 super.assign(someBits); 2537 changed(); 2538 return this; 2539 } 2540 2541 @Override 2542 public void excludeFrom(int start) { 2543 generalOp(null, start, BitsOpKind.EXCL_RANGE); 2544 } 2545 2546 @Override 2547 public void excl(int x) { 2548 Assert.check(x >= 0); 2549 generalOp(null, x, BitsOpKind.EXCL_BIT); 2550 } 2551 2552 @Override 2553 public Bits andSet(Bits xs) { 2554 return generalOp(xs, -1, BitsOpKind.AND_SET); 2555 } 2556 2557 @Override 2558 public Bits orSet(Bits xs) { 2559 return generalOp(xs, -1, BitsOpKind.OR_SET); 2560 } 2561 2562 @Override 2563 public Bits diffSet(Bits xs) { 2564 return generalOp(xs, -1, BitsOpKind.DIFF_SET); 2565 } 2566 2567 @Override 2568 public Bits xorSet(Bits xs) { 2569 return generalOp(xs, -1, BitsOpKind.XOR_SET); 2570 } 2571 2572 private Bits generalOp(Bits xs, int i, BitsOpKind opKind) { 2573 Assert.check(currentState != BitsState.UNKNOWN); 2574 oldBits = dupBits(); 2575 stateBeforeOp = currentState; 2576 switch (opKind) { 2577 case AND_SET: 2578 super.andSet(xs); 2579 break; 2580 case OR_SET: 2581 super.orSet(xs); 2582 break; 2583 case XOR_SET: 2584 super.xorSet(xs); 2585 break; 2586 case DIFF_SET: 2587 super.diffSet(xs); 2588 break; 2589 case CLEAR: 2590 super.clear(); 2591 break; 2592 case EXCL_BIT: 2593 super.excl(i); 2594 break; 2595 case EXCL_RANGE: 2596 super.excludeFrom(i); 2597 break; 2598 } 2599 changed(); 2600 return this; 2601 } 2602 2603 /* The tree we need to anchor the bits instance to. 2604 */ 2605 LVTBits at(JCTree tree) { 2606 this.currentTree = tree; 2607 return this; 2608 } 2609 2610 /* If the instance should be changed but the tree is not a closing 2611 * tree then a reset is needed or the former tree can mistakingly be 2612 * used. 2613 */ 2614 LVTBits resetTree() { 2615 this.currentTree = null; 2616 return this; 2617 } 2618 2619 /** This method will be called after any operation that causes a change to 2620 * the bits. Subclasses can thus override it in order to extract information 2621 * from the changes produced to the bits by the given operation. 2622 */ 2623 public void changed() { 2624 if (currentTree != null && 2625 stateBeforeOp != BitsState.UNKNOWN && 2626 trackTree(currentTree)) { 2627 List<VarSymbol> locals = 2628 analyzer.lvtRanges 2629 .getVars(analyzer.currentMethod, currentTree); 2630 locals = locals != null ? 2631 locals : List.<VarSymbol>nil(); 2632 for (JCVariableDecl vardecl : analyzer.vardecls) { 2633 //once the first is null, the rest will be so. 2634 if (vardecl == null) { 2635 break; 2636 } 2637 if (trackVar(vardecl.sym) && bitChanged(vardecl.sym.adr)) { 2638 locals = locals.prepend(vardecl.sym); 2639 } 2640 } 2641 if (!locals.isEmpty()) { 2642 analyzer.lvtRanges.setEntry(analyzer.currentMethod, 2643 currentTree, locals); 2644 } 2645 } 2646 } 2647 2648 boolean bitChanged(int x) { 2649 boolean isMemberOfBits = isMember(x); 2650 int[] tmp = bits; 2651 bits = oldBits; 2652 boolean isMemberOfOldBits = isMember(x); 2653 bits = tmp; 2654 return (!isMemberOfBits && isMemberOfOldBits); 2655 } 2656 2657 boolean trackVar(VarSymbol var) { 2658 return (var.owner.kind == MTH && 2659 (var.flags() & PARAMETER) == 0 && 2660 analyzer.trackable(var)); 2661 } 2662 2663 boolean trackTree(JCTree tree) { 2664 switch (tree.getTag()) { 2665 // of course a method closes the alive range of a local variable. 2666 case METHODDEF: 2667 // for while loops we want only the body 2668 case WHILELOOP: 2669 return false; 2670 } 2671 return true; 2672 } 2673 2674 } 2675 2676 public class LVTAssignPendingExit extends Flow.AssignAnalyzer.AssignPendingExit { 2677 2678 LVTAssignPendingExit(JCTree tree, final Bits inits, final Bits uninits) { 2679 super(tree, inits, uninits); 2680 } 2681 2682 @Override 2683 public void resolveJump(JCTree tree) { 2684 lvtInits.at(tree); 2685 super.resolveJump(tree); 2686 } 2687 } 2688 2689 private LVTAssignAnalyzer(LVTRanges lvtRanges, Symtab syms, Names names) { 2690 super(new LVTBits(), syms, names, false); 2691 lvtInits = (LVTBits)inits; 2692 this.lvtRanges = lvtRanges; 2693 } 2694 2695 public static LVTAssignAnalyzer make(LVTRanges lvtRanges, Symtab syms, Names names) { 2696 LVTAssignAnalyzer result = new LVTAssignAnalyzer(lvtRanges, syms, names); 2697 result.lvtInits.analyzer = result; 2698 return result; 2699 } 2700 2701 @Override 2702 protected void markDead(JCTree tree) { 2703 lvtInits.at(tree).inclRange(returnadr, nextadr); 2704 super.markDead(tree); 2705 } 2706 2707 @Override 2708 protected void merge(JCTree tree) { 2709 lvtInits.at(tree); 2710 super.merge(tree); 2711 } 2712 2713 boolean isSyntheticOrMandated(Symbol sym) { 2714 return (sym.flags() & (SYNTHETIC | MANDATED)) != 0; 2715 } 2716 2717 @Override 2718 protected boolean trackable(VarSymbol sym) { 2719 if (isSyntheticOrMandated(sym)) { 2720 //fast check to avoid tracking synthetic or mandated variables 2721 return false; 2722 } 2723 return super.trackable(sym); 2724 } 2725 2726 @Override 2727 protected void initParam(JCVariableDecl def) { 2728 if (!isSyntheticOrMandated(def.sym)) { 2729 super.initParam(def); 2730 } 2731 } 2732 2733 @Override 2734 protected void assignToInits(JCTree tree, Bits bits) { 2735 lvtInits.at(tree); 2736 lvtInits.assign(bits); 2737 } 2738 2739 @Override 2740 protected void andSetInits(JCTree tree, Bits bits) { 2741 lvtInits.at(tree); 2742 lvtInits.andSet(bits); 2743 } 2744 2745 @Override 2746 protected void orSetInits(JCTree tree, Bits bits) { 2747 lvtInits.at(tree); 2748 lvtInits.orSet(bits); 2749 } 2750 2751 @Override 2752 protected void exclVarFromInits(JCTree tree, int adr) { 2753 lvtInits.at(tree); 2754 lvtInits.excl(adr); 2755 } 2756 2757 @Override 2758 protected LVTAssignPendingExit createNewPendingExit(JCTree tree, Bits inits, Bits uninits) { 2759 return new LVTAssignPendingExit(tree, inits, uninits); 2760 } 2761 2762 MethodSymbol currentMethod; 2763 2764 @Override 2765 public void visitMethodDef(JCMethodDecl tree) { 2766 if ((tree.sym.flags() & (SYNTHETIC | GENERATEDCONSTR)) != 0 2767 && (tree.sym.flags() & LAMBDA_METHOD) == 0) { 2768 return; 2769 } 2770 if (tree.name.equals(names.clinit)) { 2771 return; 2772 } 2773 boolean enumClass = (tree.sym.owner.flags() & ENUM) != 0; 2774 if (enumClass && 2775 (tree.name.equals(names.valueOf) || 2776 tree.name.equals(names.values) || 2777 tree.name.equals(names.init))) { 2778 return; 2779 } 2780 currentMethod = tree.sym; 2781 2782 super.visitMethodDef(tree); 2783 } 2784 2785 } 2786 2787} 2788