Gen.java revision 4177:f52e81f886fb
155682Smarkm/* 2178825Sdfr * Copyright (c) 1999, 2017, Oracle and/or its affiliates. All rights reserved. 355682Smarkm * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 455682Smarkm * 555682Smarkm * This code is free software; you can redistribute it and/or modify it 655682Smarkm * under the terms of the GNU General Public License version 2 only, as 755682Smarkm * published by the Free Software Foundation. Oracle designates this 855682Smarkm * particular file as subject to the "Classpath" exception as provided 955682Smarkm * by Oracle in the LICENSE file that accompanied this code. 10127808Snectar * 1155682Smarkm * This code is distributed in the hope that it will be useful, but WITHOUT 12178825Sdfr * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 1355682Smarkm * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 1455682Smarkm * version 2 for more details (a copy is included in the LICENSE file that 15178825Sdfr * accompanied this code). 1655682Smarkm * 17178825Sdfr * You should have received a copy of the GNU General Public License version 1855682Smarkm * 2 along with this work; if not, write to the Free Software Foundation, 19178825Sdfr * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 2055682Smarkm * 21178825Sdfr * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 2255682Smarkm * or visit www.oracle.com if you need additional information or have any 2355682Smarkm * questions. 24178825Sdfr */ 2572445Sassar 2672445Sassarpackage com.sun.tools.javac.jvm; 27178825Sdfr 2855682Smarkmimport com.sun.tools.javac.tree.TreeInfo.PosKind; 29178825Sdfrimport com.sun.tools.javac.util.*; 3055682Smarkmimport com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition; 3155682Smarkmimport com.sun.tools.javac.util.List; 32178825Sdfrimport com.sun.tools.javac.code.*; 3372445Sassarimport com.sun.tools.javac.code.Attribute.TypeCompound; 34178825Sdfrimport com.sun.tools.javac.code.Symbol.VarSymbol; 3555682Smarkmimport com.sun.tools.javac.comp.*; 3655682Smarkmimport com.sun.tools.javac.tree.*; 3755682Smarkm 3855682Smarkmimport com.sun.tools.javac.code.Symbol.*; 3955682Smarkmimport com.sun.tools.javac.code.Type.*; 4072445Sassarimport com.sun.tools.javac.jvm.Code.*; 4172445Sassarimport com.sun.tools.javac.jvm.Items.*; 4272445Sassarimport com.sun.tools.javac.tree.EndPosTable; 43178825Sdfrimport com.sun.tools.javac.tree.JCTree.*; 44178825Sdfr 4555682Smarkmimport static com.sun.tools.javac.code.Flags.*; 4672445Sassarimport static com.sun.tools.javac.code.Kinds.Kind.*; 4772445Sassarimport static com.sun.tools.javac.code.TypeTag.*; 4872445Sassarimport static com.sun.tools.javac.jvm.ByteCodes.*; 4955682Smarkmimport static com.sun.tools.javac.jvm.CRTFlags.*; 5055682Smarkmimport static com.sun.tools.javac.main.Option.*; 5155682Smarkmimport static com.sun.tools.javac.tree.JCTree.Tag.*; 5255682Smarkm 53102644Snectar/** This pass maps flat Java (i.e. without inner classes) to bytecodes. 54102644Snectar * 55102644Snectar * <p><b>This is NOT part of any supported API. 56102644Snectar * If you write code that depends on this, you do so at your own risk. 57102644Snectar * This code and its internal interfaces are subject to change or 58102644Snectar * deletion without notice.</b> 59102644Snectar */ 60102644Snectarpublic class Gen extends JCTree.Visitor { 6155682Smarkm protected static final Context.Key<Gen> genKey = new Context.Key<>(); 62102644Snectar 63 private final Log log; 64 private final Symtab syms; 65 private final Check chk; 66 private final Resolve rs; 67 private final TreeMaker make; 68 private final Names names; 69 private final Target target; 70 private final Name accessDollar; 71 private final Types types; 72 private final Lower lower; 73 private final Annotate annotate; 74 private final StringConcat concat; 75 76 /** Format of stackmap tables to be generated. */ 77 private final Code.StackMapFormat stackMap; 78 79 /** A type that serves as the expected type for all method expressions. 80 */ 81 private final Type methodType; 82 83 /** 84 * Are we presently traversing a let expression ? Yes if depth != 0 85 */ 86 private int letExprDepth; 87 88 public static Gen instance(Context context) { 89 Gen instance = context.get(genKey); 90 if (instance == null) 91 instance = new Gen(context); 92 return instance; 93 } 94 95 /** Constant pool, reset by genClass. 96 */ 97 private final Pool pool; 98 99 protected Gen(Context context) { 100 context.put(genKey, this); 101 102 names = Names.instance(context); 103 log = Log.instance(context); 104 syms = Symtab.instance(context); 105 chk = Check.instance(context); 106 rs = Resolve.instance(context); 107 make = TreeMaker.instance(context); 108 target = Target.instance(context); 109 types = Types.instance(context); 110 concat = StringConcat.instance(context); 111 112 methodType = new MethodType(null, null, null, syms.methodClass); 113 accessDollar = names. 114 fromString("access" + target.syntheticNameChar()); 115 lower = Lower.instance(context); 116 117 Options options = Options.instance(context); 118 lineDebugInfo = 119 options.isUnset(G_CUSTOM) || 120 options.isSet(G_CUSTOM, "lines"); 121 varDebugInfo = 122 options.isUnset(G_CUSTOM) 123 ? options.isSet(G) 124 : options.isSet(G_CUSTOM, "vars"); 125 genCrt = options.isSet(XJCOV); 126 debugCode = options.isSet("debug.code"); 127 allowBetterNullChecks = target.hasObjects(); 128 pool = new Pool(types); 129 130 // ignore cldc because we cannot have both stackmap formats 131 this.stackMap = StackMapFormat.JSR202; 132 annotate = Annotate.instance(context); 133 } 134 135 /** Switches 136 */ 137 private final boolean lineDebugInfo; 138 private final boolean varDebugInfo; 139 private final boolean genCrt; 140 private final boolean debugCode; 141 private final boolean allowBetterNullChecks; 142 143 /** Code buffer, set by genMethod. 144 */ 145 private Code code; 146 147 /** Items structure, set by genMethod. 148 */ 149 private Items items; 150 151 /** Environment for symbol lookup, set by genClass 152 */ 153 private Env<AttrContext> attrEnv; 154 155 /** The top level tree. 156 */ 157 private JCCompilationUnit toplevel; 158 159 /** The number of code-gen errors in this class. 160 */ 161 private int nerrs = 0; 162 163 /** An object containing mappings of syntax trees to their 164 * ending source positions. 165 */ 166 EndPosTable endPosTable; 167 168 /** Generate code to load an integer constant. 169 * @param n The integer to be loaded. 170 */ 171 void loadIntConst(int n) { 172 items.makeImmediateItem(syms.intType, n).load(); 173 } 174 175 /** The opcode that loads a zero constant of a given type code. 176 * @param tc The given type code (@see ByteCode). 177 */ 178 public static int zero(int tc) { 179 switch(tc) { 180 case INTcode: case BYTEcode: case SHORTcode: case CHARcode: 181 return iconst_0; 182 case LONGcode: 183 return lconst_0; 184 case FLOATcode: 185 return fconst_0; 186 case DOUBLEcode: 187 return dconst_0; 188 default: 189 throw new AssertionError("zero"); 190 } 191 } 192 193 /** The opcode that loads a one constant of a given type code. 194 * @param tc The given type code (@see ByteCode). 195 */ 196 public static int one(int tc) { 197 return zero(tc) + 1; 198 } 199 200 /** Generate code to load -1 of the given type code (either int or long). 201 * @param tc The given type code (@see ByteCode). 202 */ 203 void emitMinusOne(int tc) { 204 if (tc == LONGcode) { 205 items.makeImmediateItem(syms.longType, Long.valueOf(-1)).load(); 206 } else { 207 code.emitop0(iconst_m1); 208 } 209 } 210 211 /** Construct a symbol to reflect the qualifying type that should 212 * appear in the byte code as per JLS 13.1. 213 * 214 * For {@literal target >= 1.2}: Clone a method with the qualifier as owner (except 215 * for those cases where we need to work around VM bugs). 216 * 217 * For {@literal target <= 1.1}: If qualified variable or method is defined in a 218 * non-accessible class, clone it with the qualifier class as owner. 219 * 220 * @param sym The accessed symbol 221 * @param site The qualifier's type. 222 */ 223 Symbol binaryQualifier(Symbol sym, Type site) { 224 225 if (site.hasTag(ARRAY)) { 226 if (sym == syms.lengthVar || 227 sym.owner != syms.arrayClass) 228 return sym; 229 // array clone can be qualified by the array type in later targets 230 Symbol qualifier = new ClassSymbol(Flags.PUBLIC, site.tsym.name, 231 site, syms.noSymbol); 232 return sym.clone(qualifier); 233 } 234 235 if (sym.owner == site.tsym || 236 (sym.flags() & (STATIC | SYNTHETIC)) == (STATIC | SYNTHETIC)) { 237 return sym; 238 } 239 240 // leave alone methods inherited from Object 241 // JLS 13.1. 242 if (sym.owner == syms.objectType.tsym) 243 return sym; 244 245 return sym.clone(site.tsym); 246 } 247 248 /** Insert a reference to given type in the constant pool, 249 * checking for an array with too many dimensions; 250 * return the reference's index. 251 * @param type The type for which a reference is inserted. 252 */ 253 int makeRef(DiagnosticPosition pos, Type type) { 254 checkDimension(pos, type); 255 if (type.isAnnotated()) { 256 return pool.put((Object)type); 257 } else { 258 return pool.put(type.hasTag(CLASS) ? (Object)type.tsym : (Object)type); 259 } 260 } 261 262 /** Check if the given type is an array with too many dimensions. 263 */ 264 private void checkDimension(DiagnosticPosition pos, Type t) { 265 switch (t.getTag()) { 266 case METHOD: 267 checkDimension(pos, t.getReturnType()); 268 for (List<Type> args = t.getParameterTypes(); args.nonEmpty(); args = args.tail) 269 checkDimension(pos, args.head); 270 break; 271 case ARRAY: 272 if (types.dimensions(t) > ClassFile.MAX_DIMENSIONS) { 273 log.error(pos, "limit.dimensions"); 274 nerrs++; 275 } 276 break; 277 default: 278 break; 279 } 280 } 281 282 /** Create a tempory variable. 283 * @param type The variable's type. 284 */ 285 LocalItem makeTemp(Type type) { 286 VarSymbol v = new VarSymbol(Flags.SYNTHETIC, 287 names.empty, 288 type, 289 env.enclMethod.sym); 290 code.newLocal(v); 291 return items.makeLocalItem(v); 292 } 293 294 /** Generate code to call a non-private method or constructor. 295 * @param pos Position to be used for error reporting. 296 * @param site The type of which the method is a member. 297 * @param name The method's name. 298 * @param argtypes The method's argument types. 299 * @param isStatic A flag that indicates whether we call a 300 * static or instance method. 301 */ 302 void callMethod(DiagnosticPosition pos, 303 Type site, Name name, List<Type> argtypes, 304 boolean isStatic) { 305 Symbol msym = rs. 306 resolveInternalMethod(pos, attrEnv, site, name, argtypes, null); 307 if (isStatic) items.makeStaticItem(msym).invoke(); 308 else items.makeMemberItem(msym, name == names.init).invoke(); 309 } 310 311 /** Is the given method definition an access method 312 * resulting from a qualified super? This is signified by an odd 313 * access code. 314 */ 315 private boolean isAccessSuper(JCMethodDecl enclMethod) { 316 return 317 (enclMethod.mods.flags & SYNTHETIC) != 0 && 318 isOddAccessName(enclMethod.name); 319 } 320 321 /** Does given name start with "access$" and end in an odd digit? 322 */ 323 private boolean isOddAccessName(Name name) { 324 return 325 name.startsWith(accessDollar) && 326 (name.getByteAt(name.getByteLength() - 1) & 1) == 1; 327 } 328 329/* ************************************************************************ 330 * Non-local exits 331 *************************************************************************/ 332 333 /** Generate code to invoke the finalizer associated with given 334 * environment. 335 * Any calls to finalizers are appended to the environments `cont' chain. 336 * Mark beginning of gap in catch all range for finalizer. 337 */ 338 void genFinalizer(Env<GenContext> env) { 339 if (code.isAlive() && env.info.finalize != null) 340 env.info.finalize.gen(); 341 } 342 343 /** Generate code to call all finalizers of structures aborted by 344 * a non-local 345 * exit. Return target environment of the non-local exit. 346 * @param target The tree representing the structure that's aborted 347 * @param env The environment current at the non-local exit. 348 */ 349 Env<GenContext> unwind(JCTree target, Env<GenContext> env) { 350 Env<GenContext> env1 = env; 351 while (true) { 352 genFinalizer(env1); 353 if (env1.tree == target) break; 354 env1 = env1.next; 355 } 356 return env1; 357 } 358 359 /** Mark end of gap in catch-all range for finalizer. 360 * @param env the environment which might contain the finalizer 361 * (if it does, env.info.gaps != null). 362 */ 363 void endFinalizerGap(Env<GenContext> env) { 364 if (env.info.gaps != null && env.info.gaps.length() % 2 == 1) 365 env.info.gaps.append(code.curCP()); 366 } 367 368 /** Mark end of all gaps in catch-all ranges for finalizers of environments 369 * lying between, and including to two environments. 370 * @param from the most deeply nested environment to mark 371 * @param to the least deeply nested environment to mark 372 */ 373 void endFinalizerGaps(Env<GenContext> from, Env<GenContext> to) { 374 Env<GenContext> last = null; 375 while (last != to) { 376 endFinalizerGap(from); 377 last = from; 378 from = from.next; 379 } 380 } 381 382 /** Do any of the structures aborted by a non-local exit have 383 * finalizers that require an empty stack? 384 * @param target The tree representing the structure that's aborted 385 * @param env The environment current at the non-local exit. 386 */ 387 boolean hasFinally(JCTree target, Env<GenContext> env) { 388 while (env.tree != target) { 389 if (env.tree.hasTag(TRY) && env.info.finalize.hasFinalizer()) 390 return true; 391 env = env.next; 392 } 393 return false; 394 } 395 396/* ************************************************************************ 397 * Normalizing class-members. 398 *************************************************************************/ 399 400 /** Distribute member initializer code into constructors and {@code <clinit>} 401 * method. 402 * @param defs The list of class member declarations. 403 * @param c The enclosing class. 404 */ 405 List<JCTree> normalizeDefs(List<JCTree> defs, ClassSymbol c) { 406 ListBuffer<JCStatement> initCode = new ListBuffer<>(); 407 ListBuffer<Attribute.TypeCompound> initTAs = new ListBuffer<>(); 408 ListBuffer<JCStatement> clinitCode = new ListBuffer<>(); 409 ListBuffer<Attribute.TypeCompound> clinitTAs = new ListBuffer<>(); 410 ListBuffer<JCTree> methodDefs = new ListBuffer<>(); 411 // Sort definitions into three listbuffers: 412 // - initCode for instance initializers 413 // - clinitCode for class initializers 414 // - methodDefs for method definitions 415 for (List<JCTree> l = defs; l.nonEmpty(); l = l.tail) { 416 JCTree def = l.head; 417 switch (def.getTag()) { 418 case BLOCK: 419 JCBlock block = (JCBlock)def; 420 if ((block.flags & STATIC) != 0) 421 clinitCode.append(block); 422 else if ((block.flags & SYNTHETIC) == 0) 423 initCode.append(block); 424 break; 425 case METHODDEF: 426 methodDefs.append(def); 427 break; 428 case VARDEF: 429 JCVariableDecl vdef = (JCVariableDecl) def; 430 VarSymbol sym = vdef.sym; 431 checkDimension(vdef.pos(), sym.type); 432 if (vdef.init != null) { 433 if ((sym.flags() & STATIC) == 0) { 434 // Always initialize instance variables. 435 JCStatement init = make.at(vdef.pos()). 436 Assignment(sym, vdef.init); 437 initCode.append(init); 438 endPosTable.replaceTree(vdef, init); 439 initTAs.addAll(getAndRemoveNonFieldTAs(sym)); 440 } else if (sym.getConstValue() == null) { 441 // Initialize class (static) variables only if 442 // they are not compile-time constants. 443 JCStatement init = make.at(vdef.pos). 444 Assignment(sym, vdef.init); 445 clinitCode.append(init); 446 endPosTable.replaceTree(vdef, init); 447 clinitTAs.addAll(getAndRemoveNonFieldTAs(sym)); 448 } else { 449 checkStringConstant(vdef.init.pos(), sym.getConstValue()); 450 /* if the init contains a reference to an external class, add it to the 451 * constant's pool 452 */ 453 vdef.init.accept(classReferenceVisitor); 454 } 455 } 456 break; 457 default: 458 Assert.error(); 459 } 460 } 461 // Insert any instance initializers into all constructors. 462 if (initCode.length() != 0) { 463 List<JCStatement> inits = initCode.toList(); 464 initTAs.addAll(c.getInitTypeAttributes()); 465 List<Attribute.TypeCompound> initTAlist = initTAs.toList(); 466 for (JCTree t : methodDefs) { 467 normalizeMethod((JCMethodDecl)t, inits, initTAlist); 468 } 469 } 470 // If there are class initializers, create a <clinit> method 471 // that contains them as its body. 472 if (clinitCode.length() != 0) { 473 MethodSymbol clinit = new MethodSymbol( 474 STATIC | (c.flags() & STRICTFP), 475 names.clinit, 476 new MethodType( 477 List.nil(), syms.voidType, 478 List.nil(), syms.methodClass), 479 c); 480 c.members().enter(clinit); 481 List<JCStatement> clinitStats = clinitCode.toList(); 482 JCBlock block = make.at(clinitStats.head.pos()).Block(0, clinitStats); 483 block.endpos = TreeInfo.endPos(clinitStats.last()); 484 methodDefs.append(make.MethodDef(clinit, block)); 485 486 if (!clinitTAs.isEmpty()) 487 clinit.appendUniqueTypeAttributes(clinitTAs.toList()); 488 if (!c.getClassInitTypeAttributes().isEmpty()) 489 clinit.appendUniqueTypeAttributes(c.getClassInitTypeAttributes()); 490 } 491 // Return all method definitions. 492 return methodDefs.toList(); 493 } 494 495 private List<Attribute.TypeCompound> getAndRemoveNonFieldTAs(VarSymbol sym) { 496 List<TypeCompound> tas = sym.getRawTypeAttributes(); 497 ListBuffer<Attribute.TypeCompound> fieldTAs = new ListBuffer<>(); 498 ListBuffer<Attribute.TypeCompound> nonfieldTAs = new ListBuffer<>(); 499 for (TypeCompound ta : tas) { 500 Assert.check(ta.getPosition().type != TargetType.UNKNOWN); 501 if (ta.getPosition().type == TargetType.FIELD) { 502 fieldTAs.add(ta); 503 } else { 504 nonfieldTAs.add(ta); 505 } 506 } 507 sym.setTypeAttributes(fieldTAs.toList()); 508 return nonfieldTAs.toList(); 509 } 510 511 /** Check a constant value and report if it is a string that is 512 * too large. 513 */ 514 private void checkStringConstant(DiagnosticPosition pos, Object constValue) { 515 if (nerrs != 0 || // only complain about a long string once 516 constValue == null || 517 !(constValue instanceof String) || 518 ((String)constValue).length() < Pool.MAX_STRING_LENGTH) 519 return; 520 log.error(pos, "limit.string"); 521 nerrs++; 522 } 523 524 /** Insert instance initializer code into initial constructor. 525 * @param md The tree potentially representing a 526 * constructor's definition. 527 * @param initCode The list of instance initializer statements. 528 * @param initTAs Type annotations from the initializer expression. 529 */ 530 void normalizeMethod(JCMethodDecl md, List<JCStatement> initCode, List<TypeCompound> initTAs) { 531 if (md.name == names.init && TreeInfo.isInitialConstructor(md)) { 532 // We are seeing a constructor that does not call another 533 // constructor of the same class. 534 List<JCStatement> stats = md.body.stats; 535 ListBuffer<JCStatement> newstats = new ListBuffer<>(); 536 537 if (stats.nonEmpty()) { 538 // Copy initializers of synthetic variables generated in 539 // the translation of inner classes. 540 while (TreeInfo.isSyntheticInit(stats.head)) { 541 newstats.append(stats.head); 542 stats = stats.tail; 543 } 544 // Copy superclass constructor call 545 newstats.append(stats.head); 546 stats = stats.tail; 547 // Copy remaining synthetic initializers. 548 while (stats.nonEmpty() && 549 TreeInfo.isSyntheticInit(stats.head)) { 550 newstats.append(stats.head); 551 stats = stats.tail; 552 } 553 // Now insert the initializer code. 554 newstats.appendList(initCode); 555 // And copy all remaining statements. 556 while (stats.nonEmpty()) { 557 newstats.append(stats.head); 558 stats = stats.tail; 559 } 560 } 561 md.body.stats = newstats.toList(); 562 if (md.body.endpos == Position.NOPOS) 563 md.body.endpos = TreeInfo.endPos(md.body.stats.last()); 564 565 md.sym.appendUniqueTypeAttributes(initTAs); 566 } 567 } 568 569/* ************************************************************************ 570 * Traversal methods 571 *************************************************************************/ 572 573 /** Visitor argument: The current environment. 574 */ 575 Env<GenContext> env; 576 577 /** Visitor argument: The expected type (prototype). 578 */ 579 Type pt; 580 581 /** Visitor result: The item representing the computed value. 582 */ 583 Item result; 584 585 /** Visitor method: generate code for a definition, catching and reporting 586 * any completion failures. 587 * @param tree The definition to be visited. 588 * @param env The environment current at the definition. 589 */ 590 public void genDef(JCTree tree, Env<GenContext> env) { 591 Env<GenContext> prevEnv = this.env; 592 try { 593 this.env = env; 594 tree.accept(this); 595 } catch (CompletionFailure ex) { 596 chk.completionError(tree.pos(), ex); 597 } finally { 598 this.env = prevEnv; 599 } 600 } 601 602 /** Derived visitor method: check whether CharacterRangeTable 603 * should be emitted, if so, put a new entry into CRTable 604 * and call method to generate bytecode. 605 * If not, just call method to generate bytecode. 606 * @see #genStat(JCTree, Env) 607 * 608 * @param tree The tree to be visited. 609 * @param env The environment to use. 610 * @param crtFlags The CharacterRangeTable flags 611 * indicating type of the entry. 612 */ 613 public void genStat(JCTree tree, Env<GenContext> env, int crtFlags) { 614 if (!genCrt) { 615 genStat(tree, env); 616 return; 617 } 618 int startpc = code.curCP(); 619 genStat(tree, env); 620 if (tree.hasTag(Tag.BLOCK)) crtFlags |= CRT_BLOCK; 621 code.crt.put(tree, crtFlags, startpc, code.curCP()); 622 } 623 624 /** Derived visitor method: generate code for a statement. 625 */ 626 public void genStat(JCTree tree, Env<GenContext> env) { 627 if (code.isAlive()) { 628 code.statBegin(tree.pos); 629 genDef(tree, env); 630 } else if (env.info.isSwitch && tree.hasTag(VARDEF)) { 631 // variables whose declarations are in a switch 632 // can be used even if the decl is unreachable. 633 code.newLocal(((JCVariableDecl) tree).sym); 634 } 635 } 636 637 /** Derived visitor method: check whether CharacterRangeTable 638 * should be emitted, if so, put a new entry into CRTable 639 * and call method to generate bytecode. 640 * If not, just call method to generate bytecode. 641 * @see #genStats(List, Env) 642 * 643 * @param trees The list of trees to be visited. 644 * @param env The environment to use. 645 * @param crtFlags The CharacterRangeTable flags 646 * indicating type of the entry. 647 */ 648 public void genStats(List<JCStatement> trees, Env<GenContext> env, int crtFlags) { 649 if (!genCrt) { 650 genStats(trees, env); 651 return; 652 } 653 if (trees.length() == 1) { // mark one statement with the flags 654 genStat(trees.head, env, crtFlags | CRT_STATEMENT); 655 } else { 656 int startpc = code.curCP(); 657 genStats(trees, env); 658 code.crt.put(trees, crtFlags, startpc, code.curCP()); 659 } 660 } 661 662 /** Derived visitor method: generate code for a list of statements. 663 */ 664 public void genStats(List<? extends JCTree> trees, Env<GenContext> env) { 665 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail) 666 genStat(l.head, env, CRT_STATEMENT); 667 } 668 669 /** Derived visitor method: check whether CharacterRangeTable 670 * should be emitted, if so, put a new entry into CRTable 671 * and call method to generate bytecode. 672 * If not, just call method to generate bytecode. 673 * @see #genCond(JCTree,boolean) 674 * 675 * @param tree The tree to be visited. 676 * @param crtFlags The CharacterRangeTable flags 677 * indicating type of the entry. 678 */ 679 public CondItem genCond(JCTree tree, int crtFlags) { 680 if (!genCrt) return genCond(tree, false); 681 int startpc = code.curCP(); 682 CondItem item = genCond(tree, (crtFlags & CRT_FLOW_CONTROLLER) != 0); 683 code.crt.put(tree, crtFlags, startpc, code.curCP()); 684 return item; 685 } 686 687 /** Derived visitor method: generate code for a boolean 688 * expression in a control-flow context. 689 * @param _tree The expression to be visited. 690 * @param markBranches The flag to indicate that the condition is 691 * a flow controller so produced conditions 692 * should contain a proper tree to generate 693 * CharacterRangeTable branches for them. 694 */ 695 public CondItem genCond(JCTree _tree, boolean markBranches) { 696 JCTree inner_tree = TreeInfo.skipParens(_tree); 697 if (inner_tree.hasTag(CONDEXPR)) { 698 JCConditional tree = (JCConditional)inner_tree; 699 CondItem cond = genCond(tree.cond, CRT_FLOW_CONTROLLER); 700 if (cond.isTrue()) { 701 code.resolve(cond.trueJumps); 702 CondItem result = genCond(tree.truepart, CRT_FLOW_TARGET); 703 if (markBranches) result.tree = tree.truepart; 704 return result; 705 } 706 if (cond.isFalse()) { 707 code.resolve(cond.falseJumps); 708 CondItem result = genCond(tree.falsepart, CRT_FLOW_TARGET); 709 if (markBranches) result.tree = tree.falsepart; 710 return result; 711 } 712 Chain secondJumps = cond.jumpFalse(); 713 code.resolve(cond.trueJumps); 714 CondItem first = genCond(tree.truepart, CRT_FLOW_TARGET); 715 if (markBranches) first.tree = tree.truepart; 716 Chain falseJumps = first.jumpFalse(); 717 code.resolve(first.trueJumps); 718 Chain trueJumps = code.branch(goto_); 719 code.resolve(secondJumps); 720 CondItem second = genCond(tree.falsepart, CRT_FLOW_TARGET); 721 CondItem result = items.makeCondItem(second.opcode, 722 Code.mergeChains(trueJumps, second.trueJumps), 723 Code.mergeChains(falseJumps, second.falseJumps)); 724 if (markBranches) result.tree = tree.falsepart; 725 return result; 726 } else { 727 CondItem result = genExpr(_tree, syms.booleanType).mkCond(); 728 if (markBranches) result.tree = _tree; 729 return result; 730 } 731 } 732 733 public Code getCode() { 734 return code; 735 } 736 737 public Items getItems() { 738 return items; 739 } 740 741 public Env<AttrContext> getAttrEnv() { 742 return attrEnv; 743 } 744 745 /** Visitor class for expressions which might be constant expressions. 746 * This class is a subset of TreeScanner. Intended to visit trees pruned by 747 * Lower as long as constant expressions looking for references to any 748 * ClassSymbol. Any such reference will be added to the constant pool so 749 * automated tools can detect class dependencies better. 750 */ 751 class ClassReferenceVisitor extends JCTree.Visitor { 752 753 @Override 754 public void visitTree(JCTree tree) {} 755 756 @Override 757 public void visitBinary(JCBinary tree) { 758 tree.lhs.accept(this); 759 tree.rhs.accept(this); 760 } 761 762 @Override 763 public void visitSelect(JCFieldAccess tree) { 764 if (tree.selected.type.hasTag(CLASS)) { 765 makeRef(tree.selected.pos(), tree.selected.type); 766 } 767 } 768 769 @Override 770 public void visitIdent(JCIdent tree) { 771 if (tree.sym.owner instanceof ClassSymbol) { 772 pool.put(tree.sym.owner); 773 } 774 } 775 776 @Override 777 public void visitConditional(JCConditional tree) { 778 tree.cond.accept(this); 779 tree.truepart.accept(this); 780 tree.falsepart.accept(this); 781 } 782 783 @Override 784 public void visitUnary(JCUnary tree) { 785 tree.arg.accept(this); 786 } 787 788 @Override 789 public void visitParens(JCParens tree) { 790 tree.expr.accept(this); 791 } 792 793 @Override 794 public void visitTypeCast(JCTypeCast tree) { 795 tree.expr.accept(this); 796 } 797 } 798 799 private ClassReferenceVisitor classReferenceVisitor = new ClassReferenceVisitor(); 800 801 /** Visitor method: generate code for an expression, catching and reporting 802 * any completion failures. 803 * @param tree The expression to be visited. 804 * @param pt The expression's expected type (proto-type). 805 */ 806 public Item genExpr(JCTree tree, Type pt) { 807 Type prevPt = this.pt; 808 try { 809 if (tree.type.constValue() != null) { 810 // Short circuit any expressions which are constants 811 tree.accept(classReferenceVisitor); 812 checkStringConstant(tree.pos(), tree.type.constValue()); 813 result = items.makeImmediateItem(tree.type, tree.type.constValue()); 814 } else { 815 this.pt = pt; 816 tree.accept(this); 817 } 818 return result.coerce(pt); 819 } catch (CompletionFailure ex) { 820 chk.completionError(tree.pos(), ex); 821 code.state.stacksize = 1; 822 return items.makeStackItem(pt); 823 } finally { 824 this.pt = prevPt; 825 } 826 } 827 828 /** Derived visitor method: generate code for a list of method arguments. 829 * @param trees The argument expressions to be visited. 830 * @param pts The expression's expected types (i.e. the formal parameter 831 * types of the invoked method). 832 */ 833 public void genArgs(List<JCExpression> trees, List<Type> pts) { 834 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail) { 835 genExpr(l.head, pts.head).load(); 836 pts = pts.tail; 837 } 838 // require lists be of same length 839 Assert.check(pts.isEmpty()); 840 } 841 842/* ************************************************************************ 843 * Visitor methods for statements and definitions 844 *************************************************************************/ 845 846 /** Thrown when the byte code size exceeds limit. 847 */ 848 public static class CodeSizeOverflow extends RuntimeException { 849 private static final long serialVersionUID = 0; 850 public CodeSizeOverflow() {} 851 } 852 853 public void visitMethodDef(JCMethodDecl tree) { 854 // Create a new local environment that points pack at method 855 // definition. 856 Env<GenContext> localEnv = env.dup(tree); 857 localEnv.enclMethod = tree; 858 // The expected type of every return statement in this method 859 // is the method's return type. 860 this.pt = tree.sym.erasure(types).getReturnType(); 861 862 checkDimension(tree.pos(), tree.sym.erasure(types)); 863 genMethod(tree, localEnv, false); 864 } 865//where 866 /** Generate code for a method. 867 * @param tree The tree representing the method definition. 868 * @param env The environment current for the method body. 869 * @param fatcode A flag that indicates whether all jumps are 870 * within 32K. We first invoke this method under 871 * the assumption that fatcode == false, i.e. all 872 * jumps are within 32K. If this fails, fatcode 873 * is set to true and we try again. 874 */ 875 void genMethod(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) { 876 MethodSymbol meth = tree.sym; 877 int extras = 0; 878 // Count up extra parameters 879 if (meth.isConstructor()) { 880 extras++; 881 if (meth.enclClass().isInner() && 882 !meth.enclClass().isStatic()) { 883 extras++; 884 } 885 } else if ((tree.mods.flags & STATIC) == 0) { 886 extras++; 887 } 888 // System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG 889 if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes()) + extras > 890 ClassFile.MAX_PARAMETERS) { 891 log.error(tree.pos(), "limit.parameters"); 892 nerrs++; 893 } 894 895 else if (tree.body != null) { 896 // Create a new code structure and initialize it. 897 int startpcCrt = initCode(tree, env, fatcode); 898 899 try { 900 genStat(tree.body, env); 901 } catch (CodeSizeOverflow e) { 902 // Failed due to code limit, try again with jsr/ret 903 startpcCrt = initCode(tree, env, fatcode); 904 genStat(tree.body, env); 905 } 906 907 if (code.state.stacksize != 0) { 908 log.error(tree.body.pos(), "stack.sim.error", tree); 909 throw new AssertionError(); 910 } 911 912 // If last statement could complete normally, insert a 913 // return at the end. 914 if (code.isAlive()) { 915 code.statBegin(TreeInfo.endPos(tree.body)); 916 if (env.enclMethod == null || 917 env.enclMethod.sym.type.getReturnType().hasTag(VOID)) { 918 code.emitop0(return_); 919 } else { 920 // sometime dead code seems alive (4415991); 921 // generate a small loop instead 922 int startpc = code.entryPoint(); 923 CondItem c = items.makeCondItem(goto_); 924 code.resolve(c.jumpTrue(), startpc); 925 } 926 } 927 if (genCrt) 928 code.crt.put(tree.body, 929 CRT_BLOCK, 930 startpcCrt, 931 code.curCP()); 932 933 code.endScopes(0); 934 935 // If we exceeded limits, panic 936 if (code.checkLimits(tree.pos(), log)) { 937 nerrs++; 938 return; 939 } 940 941 // If we generated short code but got a long jump, do it again 942 // with fatCode = true. 943 if (!fatcode && code.fatcode) genMethod(tree, env, true); 944 945 // Clean up 946 if(stackMap == StackMapFormat.JSR202) { 947 code.lastFrame = null; 948 code.frameBeforeLast = null; 949 } 950 951 // Compress exception table 952 code.compressCatchTable(); 953 954 // Fill in type annotation positions for exception parameters 955 code.fillExceptionParameterPositions(); 956 } 957 } 958 959 private int initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) { 960 MethodSymbol meth = tree.sym; 961 962 // Create a new code structure. 963 meth.code = code = new Code(meth, 964 fatcode, 965 lineDebugInfo ? toplevel.lineMap : null, 966 varDebugInfo, 967 stackMap, 968 debugCode, 969 genCrt ? new CRTable(tree, env.toplevel.endPositions) 970 : null, 971 syms, 972 types, 973 pool); 974 items = new Items(pool, code, syms, types); 975 if (code.debugCode) { 976 System.err.println(meth + " for body " + tree); 977 } 978 979 // If method is not static, create a new local variable address 980 // for `this'. 981 if ((tree.mods.flags & STATIC) == 0) { 982 Type selfType = meth.owner.type; 983 if (meth.isConstructor() && selfType != syms.objectType) 984 selfType = UninitializedType.uninitializedThis(selfType); 985 code.setDefined( 986 code.newLocal( 987 new VarSymbol(FINAL, names._this, selfType, meth.owner))); 988 } 989 990 // Mark all parameters as defined from the beginning of 991 // the method. 992 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) { 993 checkDimension(l.head.pos(), l.head.sym.type); 994 code.setDefined(code.newLocal(l.head.sym)); 995 } 996 997 // Get ready to generate code for method body. 998 int startpcCrt = genCrt ? code.curCP() : 0; 999 code.entryPoint(); 1000 1001 // Suppress initial stackmap 1002 code.pendingStackMap = false; 1003 1004 return startpcCrt; 1005 } 1006 1007 public void visitVarDef(JCVariableDecl tree) { 1008 VarSymbol v = tree.sym; 1009 code.newLocal(v); 1010 if (tree.init != null) { 1011 checkStringConstant(tree.init.pos(), v.getConstValue()); 1012 if (v.getConstValue() == null || varDebugInfo) { 1013 Assert.check(letExprDepth != 0 || code.state.stacksize == 0); 1014 genExpr(tree.init, v.erasure(types)).load(); 1015 items.makeLocalItem(v).store(); 1016 Assert.check(letExprDepth != 0 || code.state.stacksize == 0); 1017 } 1018 } 1019 checkDimension(tree.pos(), v.type); 1020 } 1021 1022 public void visitSkip(JCSkip tree) { 1023 } 1024 1025 public void visitBlock(JCBlock tree) { 1026 int limit = code.nextreg; 1027 Env<GenContext> localEnv = env.dup(tree, new GenContext()); 1028 genStats(tree.stats, localEnv); 1029 // End the scope of all block-local variables in variable info. 1030 if (!env.tree.hasTag(METHODDEF)) { 1031 code.statBegin(tree.endpos); 1032 code.endScopes(limit); 1033 code.pendingStatPos = Position.NOPOS; 1034 } 1035 } 1036 1037 public void visitDoLoop(JCDoWhileLoop tree) { 1038 genLoop(tree, tree.body, tree.cond, List.nil(), false); 1039 } 1040 1041 public void visitWhileLoop(JCWhileLoop tree) { 1042 genLoop(tree, tree.body, tree.cond, List.nil(), true); 1043 } 1044 1045 public void visitForLoop(JCForLoop tree) { 1046 int limit = code.nextreg; 1047 genStats(tree.init, env); 1048 genLoop(tree, tree.body, tree.cond, tree.step, true); 1049 code.endScopes(limit); 1050 } 1051 //where 1052 /** Generate code for a loop. 1053 * @param loop The tree representing the loop. 1054 * @param body The loop's body. 1055 * @param cond The loop's controling condition. 1056 * @param step "Step" statements to be inserted at end of 1057 * each iteration. 1058 * @param testFirst True if the loop test belongs before the body. 1059 */ 1060 private void genLoop(JCStatement loop, 1061 JCStatement body, 1062 JCExpression cond, 1063 List<JCExpressionStatement> step, 1064 boolean testFirst) { 1065 Env<GenContext> loopEnv = env.dup(loop, new GenContext()); 1066 int startpc = code.entryPoint(); 1067 if (testFirst) { //while or for loop 1068 CondItem c; 1069 if (cond != null) { 1070 code.statBegin(cond.pos); 1071 Assert.check(code.state.stacksize == 0); 1072 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER); 1073 } else { 1074 c = items.makeCondItem(goto_); 1075 } 1076 Chain loopDone = c.jumpFalse(); 1077 code.resolve(c.trueJumps); 1078 Assert.check(code.state.stacksize == 0); 1079 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET); 1080 code.resolve(loopEnv.info.cont); 1081 genStats(step, loopEnv); 1082 code.resolve(code.branch(goto_), startpc); 1083 code.resolve(loopDone); 1084 } else { 1085 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET); 1086 code.resolve(loopEnv.info.cont); 1087 genStats(step, loopEnv); 1088 if (code.isAlive()) { 1089 CondItem c; 1090 if (cond != null) { 1091 code.statBegin(cond.pos); 1092 Assert.check(code.state.stacksize == 0); 1093 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER); 1094 } else { 1095 c = items.makeCondItem(goto_); 1096 } 1097 code.resolve(c.jumpTrue(), startpc); 1098 Assert.check(code.state.stacksize == 0); 1099 code.resolve(c.falseJumps); 1100 } 1101 } 1102 Chain exit = loopEnv.info.exit; 1103 if (exit != null) { 1104 code.resolve(exit); 1105 exit.state.defined.excludeFrom(code.nextreg); 1106 } 1107 } 1108 1109 public void visitForeachLoop(JCEnhancedForLoop tree) { 1110 throw new AssertionError(); // should have been removed by Lower. 1111 } 1112 1113 public void visitLabelled(JCLabeledStatement tree) { 1114 Env<GenContext> localEnv = env.dup(tree, new GenContext()); 1115 genStat(tree.body, localEnv, CRT_STATEMENT); 1116 Chain exit = localEnv.info.exit; 1117 if (exit != null) { 1118 code.resolve(exit); 1119 exit.state.defined.excludeFrom(code.nextreg); 1120 } 1121 } 1122 1123 public void visitSwitch(JCSwitch tree) { 1124 int limit = code.nextreg; 1125 Assert.check(!tree.selector.type.hasTag(CLASS)); 1126 int startpcCrt = genCrt ? code.curCP() : 0; 1127 Assert.check(code.state.stacksize == 0); 1128 Item sel = genExpr(tree.selector, syms.intType); 1129 List<JCCase> cases = tree.cases; 1130 if (cases.isEmpty()) { 1131 // We are seeing: switch <sel> {} 1132 sel.load().drop(); 1133 if (genCrt) 1134 code.crt.put(TreeInfo.skipParens(tree.selector), 1135 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP()); 1136 } else { 1137 // We are seeing a nonempty switch. 1138 sel.load(); 1139 if (genCrt) 1140 code.crt.put(TreeInfo.skipParens(tree.selector), 1141 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP()); 1142 Env<GenContext> switchEnv = env.dup(tree, new GenContext()); 1143 switchEnv.info.isSwitch = true; 1144 1145 // Compute number of labels and minimum and maximum label values. 1146 // For each case, store its label in an array. 1147 int lo = Integer.MAX_VALUE; // minimum label. 1148 int hi = Integer.MIN_VALUE; // maximum label. 1149 int nlabels = 0; // number of labels. 1150 1151 int[] labels = new int[cases.length()]; // the label array. 1152 int defaultIndex = -1; // the index of the default clause. 1153 1154 List<JCCase> l = cases; 1155 for (int i = 0; i < labels.length; i++) { 1156 if (l.head.pat != null) { 1157 int val = ((Number)l.head.pat.type.constValue()).intValue(); 1158 labels[i] = val; 1159 if (val < lo) lo = val; 1160 if (hi < val) hi = val; 1161 nlabels++; 1162 } else { 1163 Assert.check(defaultIndex == -1); 1164 defaultIndex = i; 1165 } 1166 l = l.tail; 1167 } 1168 1169 // Determine whether to issue a tableswitch or a lookupswitch 1170 // instruction. 1171 long table_space_cost = 4 + ((long) hi - lo + 1); // words 1172 long table_time_cost = 3; // comparisons 1173 long lookup_space_cost = 3 + 2 * (long) nlabels; 1174 long lookup_time_cost = nlabels; 1175 int opcode = 1176 nlabels > 0 && 1177 table_space_cost + 3 * table_time_cost <= 1178 lookup_space_cost + 3 * lookup_time_cost 1179 ? 1180 tableswitch : lookupswitch; 1181 1182 int startpc = code.curCP(); // the position of the selector operation 1183 code.emitop0(opcode); 1184 code.align(4); 1185 int tableBase = code.curCP(); // the start of the jump table 1186 int[] offsets = null; // a table of offsets for a lookupswitch 1187 code.emit4(-1); // leave space for default offset 1188 if (opcode == tableswitch) { 1189 code.emit4(lo); // minimum label 1190 code.emit4(hi); // maximum label 1191 for (long i = lo; i <= hi; i++) { // leave space for jump table 1192 code.emit4(-1); 1193 } 1194 } else { 1195 code.emit4(nlabels); // number of labels 1196 for (int i = 0; i < nlabels; i++) { 1197 code.emit4(-1); code.emit4(-1); // leave space for lookup table 1198 } 1199 offsets = new int[labels.length]; 1200 } 1201 Code.State stateSwitch = code.state.dup(); 1202 code.markDead(); 1203 1204 // For each case do: 1205 l = cases; 1206 for (int i = 0; i < labels.length; i++) { 1207 JCCase c = l.head; 1208 l = l.tail; 1209 1210 int pc = code.entryPoint(stateSwitch); 1211 // Insert offset directly into code or else into the 1212 // offsets table. 1213 if (i != defaultIndex) { 1214 if (opcode == tableswitch) { 1215 code.put4( 1216 tableBase + 4 * (labels[i] - lo + 3), 1217 pc - startpc); 1218 } else { 1219 offsets[i] = pc - startpc; 1220 } 1221 } else { 1222 code.put4(tableBase, pc - startpc); 1223 } 1224 1225 // Generate code for the statements in this case. 1226 genStats(c.stats, switchEnv, CRT_FLOW_TARGET); 1227 } 1228 1229 // Resolve all breaks. 1230 Chain exit = switchEnv.info.exit; 1231 if (exit != null) { 1232 code.resolve(exit); 1233 exit.state.defined.excludeFrom(limit); 1234 } 1235 1236 // If we have not set the default offset, we do so now. 1237 if (code.get4(tableBase) == -1) { 1238 code.put4(tableBase, code.entryPoint(stateSwitch) - startpc); 1239 } 1240 1241 if (opcode == tableswitch) { 1242 // Let any unfilled slots point to the default case. 1243 int defaultOffset = code.get4(tableBase); 1244 for (long i = lo; i <= hi; i++) { 1245 int t = (int)(tableBase + 4 * (i - lo + 3)); 1246 if (code.get4(t) == -1) 1247 code.put4(t, defaultOffset); 1248 } 1249 } else { 1250 // Sort non-default offsets and copy into lookup table. 1251 if (defaultIndex >= 0) 1252 for (int i = defaultIndex; i < labels.length - 1; i++) { 1253 labels[i] = labels[i+1]; 1254 offsets[i] = offsets[i+1]; 1255 } 1256 if (nlabels > 0) 1257 qsort2(labels, offsets, 0, nlabels - 1); 1258 for (int i = 0; i < nlabels; i++) { 1259 int caseidx = tableBase + 8 * (i + 1); 1260 code.put4(caseidx, labels[i]); 1261 code.put4(caseidx + 4, offsets[i]); 1262 } 1263 } 1264 } 1265 code.endScopes(limit); 1266 } 1267//where 1268 /** Sort (int) arrays of keys and values 1269 */ 1270 static void qsort2(int[] keys, int[] values, int lo, int hi) { 1271 int i = lo; 1272 int j = hi; 1273 int pivot = keys[(i+j)/2]; 1274 do { 1275 while (keys[i] < pivot) i++; 1276 while (pivot < keys[j]) j--; 1277 if (i <= j) { 1278 int temp1 = keys[i]; 1279 keys[i] = keys[j]; 1280 keys[j] = temp1; 1281 int temp2 = values[i]; 1282 values[i] = values[j]; 1283 values[j] = temp2; 1284 i++; 1285 j--; 1286 } 1287 } while (i <= j); 1288 if (lo < j) qsort2(keys, values, lo, j); 1289 if (i < hi) qsort2(keys, values, i, hi); 1290 } 1291 1292 public void visitSynchronized(JCSynchronized tree) { 1293 int limit = code.nextreg; 1294 // Generate code to evaluate lock and save in temporary variable. 1295 final LocalItem lockVar = makeTemp(syms.objectType); 1296 Assert.check(code.state.stacksize == 0); 1297 genExpr(tree.lock, tree.lock.type).load().duplicate(); 1298 lockVar.store(); 1299 1300 // Generate code to enter monitor. 1301 code.emitop0(monitorenter); 1302 code.state.lock(lockVar.reg); 1303 1304 // Generate code for a try statement with given body, no catch clauses 1305 // in a new environment with the "exit-monitor" operation as finalizer. 1306 final Env<GenContext> syncEnv = env.dup(tree, new GenContext()); 1307 syncEnv.info.finalize = new GenFinalizer() { 1308 void gen() { 1309 genLast(); 1310 Assert.check(syncEnv.info.gaps.length() % 2 == 0); 1311 syncEnv.info.gaps.append(code.curCP()); 1312 } 1313 void genLast() { 1314 if (code.isAlive()) { 1315 lockVar.load(); 1316 code.emitop0(monitorexit); 1317 code.state.unlock(lockVar.reg); 1318 } 1319 } 1320 }; 1321 syncEnv.info.gaps = new ListBuffer<>(); 1322 genTry(tree.body, List.nil(), syncEnv); 1323 code.endScopes(limit); 1324 } 1325 1326 public void visitTry(final JCTry tree) { 1327 // Generate code for a try statement with given body and catch clauses, 1328 // in a new environment which calls the finally block if there is one. 1329 final Env<GenContext> tryEnv = env.dup(tree, new GenContext()); 1330 final Env<GenContext> oldEnv = env; 1331 tryEnv.info.finalize = new GenFinalizer() { 1332 void gen() { 1333 Assert.check(tryEnv.info.gaps.length() % 2 == 0); 1334 tryEnv.info.gaps.append(code.curCP()); 1335 genLast(); 1336 } 1337 void genLast() { 1338 if (tree.finalizer != null) 1339 genStat(tree.finalizer, oldEnv, CRT_BLOCK); 1340 } 1341 boolean hasFinalizer() { 1342 return tree.finalizer != null; 1343 } 1344 }; 1345 tryEnv.info.gaps = new ListBuffer<>(); 1346 genTry(tree.body, tree.catchers, tryEnv); 1347 } 1348 //where 1349 /** Generate code for a try or synchronized statement 1350 * @param body The body of the try or synchronized statement. 1351 * @param catchers The lis of catch clauses. 1352 * @param env the environment current for the body. 1353 */ 1354 void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) { 1355 int limit = code.nextreg; 1356 int startpc = code.curCP(); 1357 Code.State stateTry = code.state.dup(); 1358 genStat(body, env, CRT_BLOCK); 1359 int endpc = code.curCP(); 1360 boolean hasFinalizer = 1361 env.info.finalize != null && 1362 env.info.finalize.hasFinalizer(); 1363 List<Integer> gaps = env.info.gaps.toList(); 1364 code.statBegin(TreeInfo.endPos(body)); 1365 genFinalizer(env); 1366 code.statBegin(TreeInfo.endPos(env.tree)); 1367 Chain exitChain = code.branch(goto_); 1368 endFinalizerGap(env); 1369 if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) { 1370 // start off with exception on stack 1371 code.entryPoint(stateTry, l.head.param.sym.type); 1372 genCatch(l.head, env, startpc, endpc, gaps); 1373 genFinalizer(env); 1374 if (hasFinalizer || l.tail.nonEmpty()) { 1375 code.statBegin(TreeInfo.endPos(env.tree)); 1376 exitChain = Code.mergeChains(exitChain, 1377 code.branch(goto_)); 1378 } 1379 endFinalizerGap(env); 1380 } 1381 if (hasFinalizer) { 1382 // Create a new register segement to avoid allocating 1383 // the same variables in finalizers and other statements. 1384 code.newRegSegment(); 1385 1386 // Add a catch-all clause. 1387 1388 // start off with exception on stack 1389 int catchallpc = code.entryPoint(stateTry, syms.throwableType); 1390 1391 // Register all exception ranges for catch all clause. 1392 // The range of the catch all clause is from the beginning 1393 // of the try or synchronized block until the present 1394 // code pointer excluding all gaps in the current 1395 // environment's GenContext. 1396 int startseg = startpc; 1397 while (env.info.gaps.nonEmpty()) { 1398 int endseg = env.info.gaps.next().intValue(); 1399 registerCatch(body.pos(), startseg, endseg, 1400 catchallpc, 0); 1401 startseg = env.info.gaps.next().intValue(); 1402 } 1403 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS)); 1404 code.markStatBegin(); 1405 1406 Item excVar = makeTemp(syms.throwableType); 1407 excVar.store(); 1408 genFinalizer(env); 1409 code.resolvePending(); 1410 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.END_POS)); 1411 code.markStatBegin(); 1412 1413 excVar.load(); 1414 registerCatch(body.pos(), startseg, 1415 env.info.gaps.next().intValue(), 1416 catchallpc, 0); 1417 code.emitop0(athrow); 1418 code.markDead(); 1419 1420 // If there are jsr's to this finalizer, ... 1421 if (env.info.cont != null) { 1422 // Resolve all jsr's. 1423 code.resolve(env.info.cont); 1424 1425 // Mark statement line number 1426 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS)); 1427 code.markStatBegin(); 1428 1429 // Save return address. 1430 LocalItem retVar = makeTemp(syms.throwableType); 1431 retVar.store(); 1432 1433 // Generate finalizer code. 1434 env.info.finalize.genLast(); 1435 1436 // Return. 1437 code.emitop1w(ret, retVar.reg); 1438 code.markDead(); 1439 } 1440 } 1441 // Resolve all breaks. 1442 code.resolve(exitChain); 1443 1444 code.endScopes(limit); 1445 } 1446 1447 /** Generate code for a catch clause. 1448 * @param tree The catch clause. 1449 * @param env The environment current in the enclosing try. 1450 * @param startpc Start pc of try-block. 1451 * @param endpc End pc of try-block. 1452 */ 1453 void genCatch(JCCatch tree, 1454 Env<GenContext> env, 1455 int startpc, int endpc, 1456 List<Integer> gaps) { 1457 if (startpc != endpc) { 1458 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypeExprs 1459 = catchTypesWithAnnotations(tree); 1460 while (gaps.nonEmpty()) { 1461 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) { 1462 JCExpression subCatch = subCatch1.snd; 1463 int catchType = makeRef(tree.pos(), subCatch.type); 1464 int end = gaps.head.intValue(); 1465 registerCatch(tree.pos(), 1466 startpc, end, code.curCP(), 1467 catchType); 1468 for (Attribute.TypeCompound tc : subCatch1.fst) { 1469 tc.position.setCatchInfo(catchType, startpc); 1470 } 1471 } 1472 gaps = gaps.tail; 1473 startpc = gaps.head.intValue(); 1474 gaps = gaps.tail; 1475 } 1476 if (startpc < endpc) { 1477 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) { 1478 JCExpression subCatch = subCatch1.snd; 1479 int catchType = makeRef(tree.pos(), subCatch.type); 1480 registerCatch(tree.pos(), 1481 startpc, endpc, code.curCP(), 1482 catchType); 1483 for (Attribute.TypeCompound tc : subCatch1.fst) { 1484 tc.position.setCatchInfo(catchType, startpc); 1485 } 1486 } 1487 } 1488 VarSymbol exparam = tree.param.sym; 1489 code.statBegin(tree.pos); 1490 code.markStatBegin(); 1491 int limit = code.nextreg; 1492 code.newLocal(exparam); 1493 items.makeLocalItem(exparam).store(); 1494 code.statBegin(TreeInfo.firstStatPos(tree.body)); 1495 genStat(tree.body, env, CRT_BLOCK); 1496 code.endScopes(limit); 1497 code.statBegin(TreeInfo.endPos(tree.body)); 1498 } 1499 } 1500 // where 1501 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotations(JCCatch tree) { 1502 return TreeInfo.isMultiCatch(tree) ? 1503 catchTypesWithAnnotationsFromMulticatch((JCTypeUnion)tree.param.vartype, tree.param.sym.getRawTypeAttributes()) : 1504 List.of(new Pair<>(tree.param.sym.getRawTypeAttributes(), tree.param.vartype)); 1505 } 1506 // where 1507 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotationsFromMulticatch(JCTypeUnion tree, List<TypeCompound> first) { 1508 List<JCExpression> alts = tree.alternatives; 1509 List<Pair<List<TypeCompound>, JCExpression>> res = List.of(new Pair<>(first, alts.head)); 1510 alts = alts.tail; 1511 1512 while(alts != null && alts.head != null) { 1513 JCExpression alt = alts.head; 1514 if (alt instanceof JCAnnotatedType) { 1515 JCAnnotatedType a = (JCAnnotatedType)alt; 1516 res = res.prepend(new Pair<>(annotate.fromAnnotations(a.annotations), alt)); 1517 } else { 1518 res = res.prepend(new Pair<>(List.nil(), alt)); 1519 } 1520 alts = alts.tail; 1521 } 1522 return res.reverse(); 1523 } 1524 1525 /** Register a catch clause in the "Exceptions" code-attribute. 1526 */ 1527 void registerCatch(DiagnosticPosition pos, 1528 int startpc, int endpc, 1529 int handler_pc, int catch_type) { 1530 char startpc1 = (char)startpc; 1531 char endpc1 = (char)endpc; 1532 char handler_pc1 = (char)handler_pc; 1533 if (startpc1 == startpc && 1534 endpc1 == endpc && 1535 handler_pc1 == handler_pc) { 1536 code.addCatch(startpc1, endpc1, handler_pc1, 1537 (char)catch_type); 1538 } else { 1539 log.error(pos, "limit.code.too.large.for.try.stmt"); 1540 nerrs++; 1541 } 1542 } 1543 1544 public void visitIf(JCIf tree) { 1545 int limit = code.nextreg; 1546 Chain thenExit = null; 1547 Assert.check(code.state.stacksize == 0); 1548 CondItem c = genCond(TreeInfo.skipParens(tree.cond), 1549 CRT_FLOW_CONTROLLER); 1550 Chain elseChain = c.jumpFalse(); 1551 Assert.check(code.state.stacksize == 0); 1552 if (!c.isFalse()) { 1553 code.resolve(c.trueJumps); 1554 genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET); 1555 thenExit = code.branch(goto_); 1556 } 1557 if (elseChain != null) { 1558 code.resolve(elseChain); 1559 if (tree.elsepart != null) { 1560 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET); 1561 } 1562 } 1563 code.resolve(thenExit); 1564 code.endScopes(limit); 1565 Assert.check(code.state.stacksize == 0); 1566 } 1567 1568 public void visitExec(JCExpressionStatement tree) { 1569 // Optimize x++ to ++x and x-- to --x. 1570 JCExpression e = tree.expr; 1571 switch (e.getTag()) { 1572 case POSTINC: 1573 ((JCUnary) e).setTag(PREINC); 1574 break; 1575 case POSTDEC: 1576 ((JCUnary) e).setTag(PREDEC); 1577 break; 1578 } 1579 Assert.check(code.state.stacksize == 0); 1580 genExpr(tree.expr, tree.expr.type).drop(); 1581 Assert.check(code.state.stacksize == 0); 1582 } 1583 1584 public void visitBreak(JCBreak tree) { 1585 int tmpPos = code.pendingStatPos; 1586 Env<GenContext> targetEnv = unwind(tree.target, env); 1587 code.pendingStatPos = tmpPos; 1588 Assert.check(code.state.stacksize == 0); 1589 targetEnv.info.addExit(code.branch(goto_)); 1590 endFinalizerGaps(env, targetEnv); 1591 } 1592 1593 public void visitContinue(JCContinue tree) { 1594 int tmpPos = code.pendingStatPos; 1595 Env<GenContext> targetEnv = unwind(tree.target, env); 1596 code.pendingStatPos = tmpPos; 1597 Assert.check(code.state.stacksize == 0); 1598 targetEnv.info.addCont(code.branch(goto_)); 1599 endFinalizerGaps(env, targetEnv); 1600 } 1601 1602 public void visitReturn(JCReturn tree) { 1603 int limit = code.nextreg; 1604 final Env<GenContext> targetEnv; 1605 1606 /* Save and then restore the location of the return in case a finally 1607 * is expanded (with unwind()) in the middle of our bytecodes. 1608 */ 1609 int tmpPos = code.pendingStatPos; 1610 if (tree.expr != null) { 1611 Assert.check(code.state.stacksize == 0); 1612 Item r = genExpr(tree.expr, pt).load(); 1613 if (hasFinally(env.enclMethod, env)) { 1614 r = makeTemp(pt); 1615 r.store(); 1616 } 1617 targetEnv = unwind(env.enclMethod, env); 1618 code.pendingStatPos = tmpPos; 1619 r.load(); 1620 code.emitop0(ireturn + Code.truncate(Code.typecode(pt))); 1621 } else { 1622 targetEnv = unwind(env.enclMethod, env); 1623 code.pendingStatPos = tmpPos; 1624 code.emitop0(return_); 1625 } 1626 endFinalizerGaps(env, targetEnv); 1627 code.endScopes(limit); 1628 } 1629 1630 public void visitThrow(JCThrow tree) { 1631 Assert.check(code.state.stacksize == 0); 1632 genExpr(tree.expr, tree.expr.type).load(); 1633 code.emitop0(athrow); 1634 Assert.check(code.state.stacksize == 0); 1635 } 1636 1637/* ************************************************************************ 1638 * Visitor methods for expressions 1639 *************************************************************************/ 1640 1641 public void visitApply(JCMethodInvocation tree) { 1642 setTypeAnnotationPositions(tree.pos); 1643 // Generate code for method. 1644 Item m = genExpr(tree.meth, methodType); 1645 // Generate code for all arguments, where the expected types are 1646 // the parameters of the method's external type (that is, any implicit 1647 // outer instance of a super(...) call appears as first parameter). 1648 MethodSymbol msym = (MethodSymbol)TreeInfo.symbol(tree.meth); 1649 genArgs(tree.args, 1650 msym.externalType(types).getParameterTypes()); 1651 if (!msym.isDynamic()) { 1652 code.statBegin(tree.pos); 1653 } 1654 result = m.invoke(); 1655 } 1656 1657 public void visitConditional(JCConditional tree) { 1658 Chain thenExit = null; 1659 code.statBegin(tree.cond.pos); 1660 CondItem c = genCond(tree.cond, CRT_FLOW_CONTROLLER); 1661 Chain elseChain = c.jumpFalse(); 1662 if (!c.isFalse()) { 1663 code.resolve(c.trueJumps); 1664 int startpc = genCrt ? code.curCP() : 0; 1665 code.statBegin(tree.truepart.pos); 1666 genExpr(tree.truepart, pt).load(); 1667 code.state.forceStackTop(tree.type); 1668 if (genCrt) code.crt.put(tree.truepart, CRT_FLOW_TARGET, 1669 startpc, code.curCP()); 1670 thenExit = code.branch(goto_); 1671 } 1672 if (elseChain != null) { 1673 code.resolve(elseChain); 1674 int startpc = genCrt ? code.curCP() : 0; 1675 code.statBegin(tree.falsepart.pos); 1676 genExpr(tree.falsepart, pt).load(); 1677 code.state.forceStackTop(tree.type); 1678 if (genCrt) code.crt.put(tree.falsepart, CRT_FLOW_TARGET, 1679 startpc, code.curCP()); 1680 } 1681 code.resolve(thenExit); 1682 result = items.makeStackItem(pt); 1683 } 1684 1685 private void setTypeAnnotationPositions(int treePos) { 1686 MethodSymbol meth = code.meth; 1687 boolean initOrClinit = code.meth.getKind() == javax.lang.model.element.ElementKind.CONSTRUCTOR 1688 || code.meth.getKind() == javax.lang.model.element.ElementKind.STATIC_INIT; 1689 1690 for (Attribute.TypeCompound ta : meth.getRawTypeAttributes()) { 1691 if (ta.hasUnknownPosition()) 1692 ta.tryFixPosition(); 1693 1694 if (ta.position.matchesPos(treePos)) 1695 ta.position.updatePosOffset(code.cp); 1696 } 1697 1698 if (!initOrClinit) 1699 return; 1700 1701 for (Attribute.TypeCompound ta : meth.owner.getRawTypeAttributes()) { 1702 if (ta.hasUnknownPosition()) 1703 ta.tryFixPosition(); 1704 1705 if (ta.position.matchesPos(treePos)) 1706 ta.position.updatePosOffset(code.cp); 1707 } 1708 1709 ClassSymbol clazz = meth.enclClass(); 1710 for (Symbol s : new com.sun.tools.javac.model.FilteredMemberList(clazz.members())) { 1711 if (!s.getKind().isField()) 1712 continue; 1713 1714 for (Attribute.TypeCompound ta : s.getRawTypeAttributes()) { 1715 if (ta.hasUnknownPosition()) 1716 ta.tryFixPosition(); 1717 1718 if (ta.position.matchesPos(treePos)) 1719 ta.position.updatePosOffset(code.cp); 1720 } 1721 } 1722 } 1723 1724 public void visitNewClass(JCNewClass tree) { 1725 // Enclosing instances or anonymous classes should have been eliminated 1726 // by now. 1727 Assert.check(tree.encl == null && tree.def == null); 1728 setTypeAnnotationPositions(tree.pos); 1729 1730 code.emitop2(new_, makeRef(tree.pos(), tree.type)); 1731 code.emitop0(dup); 1732 1733 // Generate code for all arguments, where the expected types are 1734 // the parameters of the constructor's external type (that is, 1735 // any implicit outer instance appears as first parameter). 1736 genArgs(tree.args, tree.constructor.externalType(types).getParameterTypes()); 1737 1738 items.makeMemberItem(tree.constructor, true).invoke(); 1739 result = items.makeStackItem(tree.type); 1740 } 1741 1742 public void visitNewArray(JCNewArray tree) { 1743 setTypeAnnotationPositions(tree.pos); 1744 1745 if (tree.elems != null) { 1746 Type elemtype = types.elemtype(tree.type); 1747 loadIntConst(tree.elems.length()); 1748 Item arr = makeNewArray(tree.pos(), tree.type, 1); 1749 int i = 0; 1750 for (List<JCExpression> l = tree.elems; l.nonEmpty(); l = l.tail) { 1751 arr.duplicate(); 1752 loadIntConst(i); 1753 i++; 1754 genExpr(l.head, elemtype).load(); 1755 items.makeIndexedItem(elemtype).store(); 1756 } 1757 result = arr; 1758 } else { 1759 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) { 1760 genExpr(l.head, syms.intType).load(); 1761 } 1762 result = makeNewArray(tree.pos(), tree.type, tree.dims.length()); 1763 } 1764 } 1765//where 1766 /** Generate code to create an array with given element type and number 1767 * of dimensions. 1768 */ 1769 Item makeNewArray(DiagnosticPosition pos, Type type, int ndims) { 1770 Type elemtype = types.elemtype(type); 1771 if (types.dimensions(type) > ClassFile.MAX_DIMENSIONS) { 1772 log.error(pos, "limit.dimensions"); 1773 nerrs++; 1774 } 1775 int elemcode = Code.arraycode(elemtype); 1776 if (elemcode == 0 || (elemcode == 1 && ndims == 1)) { 1777 code.emitAnewarray(makeRef(pos, elemtype), type); 1778 } else if (elemcode == 1) { 1779 code.emitMultianewarray(ndims, makeRef(pos, type), type); 1780 } else { 1781 code.emitNewarray(elemcode, type); 1782 } 1783 return items.makeStackItem(type); 1784 } 1785 1786 public void visitParens(JCParens tree) { 1787 result = genExpr(tree.expr, tree.expr.type); 1788 } 1789 1790 public void visitAssign(JCAssign tree) { 1791 Item l = genExpr(tree.lhs, tree.lhs.type); 1792 genExpr(tree.rhs, tree.lhs.type).load(); 1793 if (tree.rhs.type.hasTag(BOT)) { 1794 /* This is just a case of widening reference conversion that per 5.1.5 simply calls 1795 for "regarding a reference as having some other type in a manner that can be proved 1796 correct at compile time." 1797 */ 1798 code.state.forceStackTop(tree.lhs.type); 1799 } 1800 result = items.makeAssignItem(l); 1801 } 1802 1803 public void visitAssignop(JCAssignOp tree) { 1804 OperatorSymbol operator = tree.operator; 1805 Item l; 1806 if (operator.opcode == string_add) { 1807 l = concat.makeConcat(tree); 1808 } else { 1809 // Generate code for first expression 1810 l = genExpr(tree.lhs, tree.lhs.type); 1811 1812 // If we have an increment of -32768 to +32767 of a local 1813 // int variable we can use an incr instruction instead of 1814 // proceeding further. 1815 if ((tree.hasTag(PLUS_ASG) || tree.hasTag(MINUS_ASG)) && 1816 l instanceof LocalItem && 1817 tree.lhs.type.getTag().isSubRangeOf(INT) && 1818 tree.rhs.type.getTag().isSubRangeOf(INT) && 1819 tree.rhs.type.constValue() != null) { 1820 int ival = ((Number) tree.rhs.type.constValue()).intValue(); 1821 if (tree.hasTag(MINUS_ASG)) ival = -ival; 1822 ((LocalItem)l).incr(ival); 1823 result = l; 1824 return; 1825 } 1826 // Otherwise, duplicate expression, load one copy 1827 // and complete binary operation. 1828 l.duplicate(); 1829 l.coerce(operator.type.getParameterTypes().head).load(); 1830 completeBinop(tree.lhs, tree.rhs, operator).coerce(tree.lhs.type); 1831 } 1832 result = items.makeAssignItem(l); 1833 } 1834 1835 public void visitUnary(JCUnary tree) { 1836 OperatorSymbol operator = tree.operator; 1837 if (tree.hasTag(NOT)) { 1838 CondItem od = genCond(tree.arg, false); 1839 result = od.negate(); 1840 } else { 1841 Item od = genExpr(tree.arg, operator.type.getParameterTypes().head); 1842 switch (tree.getTag()) { 1843 case POS: 1844 result = od.load(); 1845 break; 1846 case NEG: 1847 result = od.load(); 1848 code.emitop0(operator.opcode); 1849 break; 1850 case COMPL: 1851 result = od.load(); 1852 emitMinusOne(od.typecode); 1853 code.emitop0(operator.opcode); 1854 break; 1855 case PREINC: case PREDEC: 1856 od.duplicate(); 1857 if (od instanceof LocalItem && 1858 (operator.opcode == iadd || operator.opcode == isub)) { 1859 ((LocalItem)od).incr(tree.hasTag(PREINC) ? 1 : -1); 1860 result = od; 1861 } else { 1862 od.load(); 1863 code.emitop0(one(od.typecode)); 1864 code.emitop0(operator.opcode); 1865 // Perform narrowing primitive conversion if byte, 1866 // char, or short. Fix for 4304655. 1867 if (od.typecode != INTcode && 1868 Code.truncate(od.typecode) == INTcode) 1869 code.emitop0(int2byte + od.typecode - BYTEcode); 1870 result = items.makeAssignItem(od); 1871 } 1872 break; 1873 case POSTINC: case POSTDEC: 1874 od.duplicate(); 1875 if (od instanceof LocalItem && 1876 (operator.opcode == iadd || operator.opcode == isub)) { 1877 Item res = od.load(); 1878 ((LocalItem)od).incr(tree.hasTag(POSTINC) ? 1 : -1); 1879 result = res; 1880 } else { 1881 Item res = od.load(); 1882 od.stash(od.typecode); 1883 code.emitop0(one(od.typecode)); 1884 code.emitop0(operator.opcode); 1885 // Perform narrowing primitive conversion if byte, 1886 // char, or short. Fix for 4304655. 1887 if (od.typecode != INTcode && 1888 Code.truncate(od.typecode) == INTcode) 1889 code.emitop0(int2byte + od.typecode - BYTEcode); 1890 od.store(); 1891 result = res; 1892 } 1893 break; 1894 case NULLCHK: 1895 result = od.load(); 1896 code.emitop0(dup); 1897 genNullCheck(tree.pos()); 1898 break; 1899 default: 1900 Assert.error(); 1901 } 1902 } 1903 } 1904 1905 /** Generate a null check from the object value at stack top. */ 1906 private void genNullCheck(DiagnosticPosition pos) { 1907 if (allowBetterNullChecks) { 1908 callMethod(pos, syms.objectsType, names.requireNonNull, 1909 List.of(syms.objectType), true); 1910 } else { 1911 callMethod(pos, syms.objectType, names.getClass, 1912 List.nil(), false); 1913 } 1914 code.emitop0(pop); 1915 } 1916 1917 public void visitBinary(JCBinary tree) { 1918 OperatorSymbol operator = tree.operator; 1919 if (operator.opcode == string_add) { 1920 result = concat.makeConcat(tree); 1921 } else if (tree.hasTag(AND)) { 1922 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER); 1923 if (!lcond.isFalse()) { 1924 Chain falseJumps = lcond.jumpFalse(); 1925 code.resolve(lcond.trueJumps); 1926 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET); 1927 result = items. 1928 makeCondItem(rcond.opcode, 1929 rcond.trueJumps, 1930 Code.mergeChains(falseJumps, 1931 rcond.falseJumps)); 1932 } else { 1933 result = lcond; 1934 } 1935 } else if (tree.hasTag(OR)) { 1936 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER); 1937 if (!lcond.isTrue()) { 1938 Chain trueJumps = lcond.jumpTrue(); 1939 code.resolve(lcond.falseJumps); 1940 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET); 1941 result = items. 1942 makeCondItem(rcond.opcode, 1943 Code.mergeChains(trueJumps, rcond.trueJumps), 1944 rcond.falseJumps); 1945 } else { 1946 result = lcond; 1947 } 1948 } else { 1949 Item od = genExpr(tree.lhs, operator.type.getParameterTypes().head); 1950 od.load(); 1951 result = completeBinop(tree.lhs, tree.rhs, operator); 1952 } 1953 } 1954 1955 1956 /** Complete generating code for operation, with left operand 1957 * already on stack. 1958 * @param lhs The tree representing the left operand. 1959 * @param rhs The tree representing the right operand. 1960 * @param operator The operator symbol. 1961 */ 1962 Item completeBinop(JCTree lhs, JCTree rhs, OperatorSymbol operator) { 1963 MethodType optype = (MethodType)operator.type; 1964 int opcode = operator.opcode; 1965 if (opcode >= if_icmpeq && opcode <= if_icmple && 1966 rhs.type.constValue() instanceof Number && 1967 ((Number) rhs.type.constValue()).intValue() == 0) { 1968 opcode = opcode + (ifeq - if_icmpeq); 1969 } else if (opcode >= if_acmpeq && opcode <= if_acmpne && 1970 TreeInfo.isNull(rhs)) { 1971 opcode = opcode + (if_acmp_null - if_acmpeq); 1972 } else { 1973 // The expected type of the right operand is 1974 // the second parameter type of the operator, except for 1975 // shifts with long shiftcount, where we convert the opcode 1976 // to a short shift and the expected type to int. 1977 Type rtype = operator.erasure(types).getParameterTypes().tail.head; 1978 if (opcode >= ishll && opcode <= lushrl) { 1979 opcode = opcode + (ishl - ishll); 1980 rtype = syms.intType; 1981 } 1982 // Generate code for right operand and load. 1983 genExpr(rhs, rtype).load(); 1984 // If there are two consecutive opcode instructions, 1985 // emit the first now. 1986 if (opcode >= (1 << preShift)) { 1987 code.emitop0(opcode >> preShift); 1988 opcode = opcode & 0xFF; 1989 } 1990 } 1991 if (opcode >= ifeq && opcode <= if_acmpne || 1992 opcode == if_acmp_null || opcode == if_acmp_nonnull) { 1993 return items.makeCondItem(opcode); 1994 } else { 1995 code.emitop0(opcode); 1996 return items.makeStackItem(optype.restype); 1997 } 1998 } 1999 2000 public void visitTypeCast(JCTypeCast tree) { 2001 result = genExpr(tree.expr, tree.clazz.type).load(); 2002 setTypeAnnotationPositions(tree.pos); 2003 // Additional code is only needed if we cast to a reference type 2004 // which is not statically a supertype of the expression's type. 2005 // For basic types, the coerce(...) in genExpr(...) will do 2006 // the conversion. 2007 if (!tree.clazz.type.isPrimitive() && 2008 !types.isSameType(tree.expr.type, tree.clazz.type) && 2009 types.asSuper(tree.expr.type, tree.clazz.type.tsym) == null) { 2010 code.emitop2(checkcast, makeRef(tree.pos(), tree.clazz.type)); 2011 } 2012 } 2013 2014 public void visitWildcard(JCWildcard tree) { 2015 throw new AssertionError(this.getClass().getName()); 2016 } 2017 2018 public void visitTypeTest(JCInstanceOf tree) { 2019 genExpr(tree.expr, tree.expr.type).load(); 2020 setTypeAnnotationPositions(tree.pos); 2021 code.emitop2(instanceof_, makeRef(tree.pos(), tree.clazz.type)); 2022 result = items.makeStackItem(syms.booleanType); 2023 } 2024 2025 public void visitIndexed(JCArrayAccess tree) { 2026 genExpr(tree.indexed, tree.indexed.type).load(); 2027 genExpr(tree.index, syms.intType).load(); 2028 result = items.makeIndexedItem(tree.type); 2029 } 2030 2031 public void visitIdent(JCIdent tree) { 2032 Symbol sym = tree.sym; 2033 if (tree.name == names._this || tree.name == names._super) { 2034 Item res = tree.name == names._this 2035 ? items.makeThisItem() 2036 : items.makeSuperItem(); 2037 if (sym.kind == MTH) { 2038 // Generate code to address the constructor. 2039 res.load(); 2040 res = items.makeMemberItem(sym, true); 2041 } 2042 result = res; 2043 } else if (sym.kind == VAR && sym.owner.kind == MTH) { 2044 result = items.makeLocalItem((VarSymbol)sym); 2045 } else if (isInvokeDynamic(sym)) { 2046 result = items.makeDynamicItem(sym); 2047 } else if ((sym.flags() & STATIC) != 0) { 2048 if (!isAccessSuper(env.enclMethod)) 2049 sym = binaryQualifier(sym, env.enclClass.type); 2050 result = items.makeStaticItem(sym); 2051 } else { 2052 items.makeThisItem().load(); 2053 sym = binaryQualifier(sym, env.enclClass.type); 2054 result = items.makeMemberItem(sym, (sym.flags() & PRIVATE) != 0); 2055 } 2056 } 2057 2058 public void visitSelect(JCFieldAccess tree) { 2059 Symbol sym = tree.sym; 2060 2061 if (tree.name == names._class) { 2062 code.emitLdc(makeRef(tree.pos(), tree.selected.type)); 2063 result = items.makeStackItem(pt); 2064 return; 2065 } 2066 2067 Symbol ssym = TreeInfo.symbol(tree.selected); 2068 2069 // Are we selecting via super? 2070 boolean selectSuper = 2071 ssym != null && (ssym.kind == TYP || ssym.name == names._super); 2072 2073 // Are we accessing a member of the superclass in an access method 2074 // resulting from a qualified super? 2075 boolean accessSuper = isAccessSuper(env.enclMethod); 2076 2077 Item base = (selectSuper) 2078 ? items.makeSuperItem() 2079 : genExpr(tree.selected, tree.selected.type); 2080 2081 if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) { 2082 // We are seeing a variable that is constant but its selecting 2083 // expression is not. 2084 if ((sym.flags() & STATIC) != 0) { 2085 if (!selectSuper && (ssym == null || ssym.kind != TYP)) 2086 base = base.load(); 2087 base.drop(); 2088 } else { 2089 base.load(); 2090 genNullCheck(tree.selected.pos()); 2091 } 2092 result = items. 2093 makeImmediateItem(sym.type, ((VarSymbol) sym).getConstValue()); 2094 } else { 2095 if (isInvokeDynamic(sym)) { 2096 result = items.makeDynamicItem(sym); 2097 return; 2098 } else { 2099 sym = binaryQualifier(sym, tree.selected.type); 2100 } 2101 if ((sym.flags() & STATIC) != 0) { 2102 if (!selectSuper && (ssym == null || ssym.kind != TYP)) 2103 base = base.load(); 2104 base.drop(); 2105 result = items.makeStaticItem(sym); 2106 } else { 2107 base.load(); 2108 if (sym == syms.lengthVar) { 2109 code.emitop0(arraylength); 2110 result = items.makeStackItem(syms.intType); 2111 } else { 2112 result = items. 2113 makeMemberItem(sym, 2114 (sym.flags() & PRIVATE) != 0 || 2115 selectSuper || accessSuper); 2116 } 2117 } 2118 } 2119 } 2120 2121 public boolean isInvokeDynamic(Symbol sym) { 2122 return sym.kind == MTH && ((MethodSymbol)sym).isDynamic(); 2123 } 2124 2125 public void visitLiteral(JCLiteral tree) { 2126 if (tree.type.hasTag(BOT)) { 2127 code.emitop0(aconst_null); 2128 result = items.makeStackItem(tree.type); 2129 } 2130 else 2131 result = items.makeImmediateItem(tree.type, tree.value); 2132 } 2133 2134 public void visitLetExpr(LetExpr tree) { 2135 letExprDepth++; 2136 int limit = code.nextreg; 2137 genStats(tree.defs, env); 2138 result = genExpr(tree.expr, tree.expr.type).load(); 2139 code.endScopes(limit); 2140 letExprDepth--; 2141 } 2142 2143 private void generateReferencesToPrunedTree(ClassSymbol classSymbol, Pool pool) { 2144 List<JCTree> prunedInfo = lower.prunedTree.get(classSymbol); 2145 if (prunedInfo != null) { 2146 for (JCTree prunedTree: prunedInfo) { 2147 prunedTree.accept(classReferenceVisitor); 2148 } 2149 } 2150 } 2151 2152/* ************************************************************************ 2153 * main method 2154 *************************************************************************/ 2155 2156 /** Generate code for a class definition. 2157 * @param env The attribution environment that belongs to the 2158 * outermost class containing this class definition. 2159 * We need this for resolving some additional symbols. 2160 * @param cdef The tree representing the class definition. 2161 * @return True if code is generated with no errors. 2162 */ 2163 public boolean genClass(Env<AttrContext> env, JCClassDecl cdef) { 2164 try { 2165 attrEnv = env; 2166 ClassSymbol c = cdef.sym; 2167 this.toplevel = env.toplevel; 2168 this.endPosTable = toplevel.endPositions; 2169 c.pool = pool; 2170 pool.reset(); 2171 /* method normalizeDefs() can add references to external classes into the constant pool 2172 */ 2173 cdef.defs = normalizeDefs(cdef.defs, c); 2174 generateReferencesToPrunedTree(c, pool); 2175 Env<GenContext> localEnv = new Env<>(cdef, new GenContext()); 2176 localEnv.toplevel = env.toplevel; 2177 localEnv.enclClass = cdef; 2178 2179 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) { 2180 genDef(l.head, localEnv); 2181 } 2182 if (pool.numEntries() > Pool.MAX_ENTRIES) { 2183 log.error(cdef.pos(), "limit.pool"); 2184 nerrs++; 2185 } 2186 if (nerrs != 0) { 2187 // if errors, discard code 2188 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) { 2189 if (l.head.hasTag(METHODDEF)) 2190 ((JCMethodDecl) l.head).sym.code = null; 2191 } 2192 } 2193 cdef.defs = List.nil(); // discard trees 2194 return nerrs == 0; 2195 } finally { 2196 // note: this method does NOT support recursion. 2197 attrEnv = null; 2198 this.env = null; 2199 toplevel = null; 2200 endPosTable = null; 2201 nerrs = 0; 2202 } 2203 } 2204 2205/* ************************************************************************ 2206 * Auxiliary classes 2207 *************************************************************************/ 2208 2209 /** An abstract class for finalizer generation. 2210 */ 2211 abstract class GenFinalizer { 2212 /** Generate code to clean up when unwinding. */ 2213 abstract void gen(); 2214 2215 /** Generate code to clean up at last. */ 2216 abstract void genLast(); 2217 2218 /** Does this finalizer have some nontrivial cleanup to perform? */ 2219 boolean hasFinalizer() { return true; } 2220 } 2221 2222 /** code generation contexts, 2223 * to be used as type parameter for environments. 2224 */ 2225 static class GenContext { 2226 2227 /** A chain for all unresolved jumps that exit the current environment. 2228 */ 2229 Chain exit = null; 2230 2231 /** A chain for all unresolved jumps that continue in the 2232 * current environment. 2233 */ 2234 Chain cont = null; 2235 2236 /** A closure that generates the finalizer of the current environment. 2237 * Only set for Synchronized and Try contexts. 2238 */ 2239 GenFinalizer finalize = null; 2240 2241 /** Is this a switch statement? If so, allocate registers 2242 * even when the variable declaration is unreachable. 2243 */ 2244 boolean isSwitch = false; 2245 2246 /** A list buffer containing all gaps in the finalizer range, 2247 * where a catch all exception should not apply. 2248 */ 2249 ListBuffer<Integer> gaps = null; 2250 2251 /** Add given chain to exit chain. 2252 */ 2253 void addExit(Chain c) { 2254 exit = Code.mergeChains(c, exit); 2255 } 2256 2257 /** Add given chain to cont chain. 2258 */ 2259 void addCont(Chain c) { 2260 cont = Code.mergeChains(c, cont); 2261 } 2262 } 2263 2264} 2265