Gen.java revision 3348:080e6e093a70
1/* 2 * Copyright (c) 1999, 2016, 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 com.sun.tools.javac.util.*; 29import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition; 30import com.sun.tools.javac.util.List; 31import com.sun.tools.javac.code.*; 32import com.sun.tools.javac.code.Attribute.TypeCompound; 33import com.sun.tools.javac.code.Symbol.VarSymbol; 34import com.sun.tools.javac.comp.*; 35import com.sun.tools.javac.tree.*; 36 37import com.sun.tools.javac.code.Symbol.*; 38import com.sun.tools.javac.code.Type.*; 39import com.sun.tools.javac.jvm.Code.*; 40import com.sun.tools.javac.jvm.Items.*; 41import com.sun.tools.javac.tree.EndPosTable; 42import com.sun.tools.javac.tree.JCTree.*; 43 44import static com.sun.tools.javac.code.Flags.*; 45import static com.sun.tools.javac.code.Kinds.Kind.*; 46import static com.sun.tools.javac.code.TypeTag.*; 47import static com.sun.tools.javac.jvm.ByteCodes.*; 48import static com.sun.tools.javac.jvm.CRTFlags.*; 49import static com.sun.tools.javac.main.Option.*; 50import static com.sun.tools.javac.tree.JCTree.Tag.*; 51 52/** This pass maps flat Java (i.e. without inner classes) to bytecodes. 53 * 54 * <p><b>This is NOT part of any supported API. 55 * If you write code that depends on this, you do so at your own risk. 56 * This code and its internal interfaces are subject to change or 57 * deletion without notice.</b> 58 */ 59public class Gen extends JCTree.Visitor { 60 protected static final Context.Key<Gen> genKey = new Context.Key<>(); 61 62 private final Log log; 63 private final Symtab syms; 64 private final Check chk; 65 private final Resolve rs; 66 private final TreeMaker make; 67 private final Names names; 68 private final Target target; 69 private Name accessDollar; 70 private final Types types; 71 private final Lower lower; 72 private final Flow flow; 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 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 flow = Flow.instance(context); 116 lower = Lower.instance(context); 117 118 Options options = Options.instance(context); 119 lineDebugInfo = 120 options.isUnset(G_CUSTOM) || 121 options.isSet(G_CUSTOM, "lines"); 122 varDebugInfo = 123 options.isUnset(G_CUSTOM) 124 ? options.isSet(G) 125 : options.isSet(G_CUSTOM, "vars"); 126 genCrt = options.isSet(XJCOV); 127 debugCode = options.isSet("debugcode"); 128 allowBetterNullChecks = target.hasObjects(); 129 pool = new Pool(types); 130 131 // ignore cldc because we cannot have both stackmap formats 132 this.stackMap = StackMapFormat.JSR202; 133 annotate = Annotate.instance(context); 134 } 135 136 /** Switches 137 */ 138 private final boolean lineDebugInfo; 139 private final boolean varDebugInfo; 140 private final boolean genCrt; 141 private final boolean debugCode; 142 private final boolean allowBetterNullChecks; 143 144 /** Code buffer, set by genMethod. 145 */ 146 private Code code; 147 148 /** Items structure, set by genMethod. 149 */ 150 private Items items; 151 152 /** Environment for symbol lookup, set by genClass 153 */ 154 private Env<AttrContext> attrEnv; 155 156 /** The top level tree. 157 */ 158 private JCCompilationUnit toplevel; 159 160 /** The number of code-gen errors in this class. 161 */ 162 private int nerrs = 0; 163 164 /** An object containing mappings of syntax trees to their 165 * ending source positions. 166 */ 167 EndPosTable endPosTable; 168 169 /** Generate code to load an integer constant. 170 * @param n The integer to be loaded. 171 */ 172 void loadIntConst(int n) { 173 items.makeImmediateItem(syms.intType, n).load(); 174 } 175 176 /** The opcode that loads a zero constant of a given type code. 177 * @param tc The given type code (@see ByteCode). 178 */ 179 public static int zero(int tc) { 180 switch(tc) { 181 case INTcode: case BYTEcode: case SHORTcode: case CHARcode: 182 return iconst_0; 183 case LONGcode: 184 return lconst_0; 185 case FLOATcode: 186 return fconst_0; 187 case DOUBLEcode: 188 return dconst_0; 189 default: 190 throw new AssertionError("zero"); 191 } 192 } 193 194 /** The opcode that loads a one constant of a given type code. 195 * @param tc The given type code (@see ByteCode). 196 */ 197 public static int one(int tc) { 198 return zero(tc) + 1; 199 } 200 201 /** Generate code to load -1 of the given type code (either int or long). 202 * @param tc The given type code (@see ByteCode). 203 */ 204 void emitMinusOne(int tc) { 205 if (tc == LONGcode) { 206 items.makeImmediateItem(syms.longType, Long.valueOf(-1)).load(); 207 } else { 208 code.emitop0(iconst_m1); 209 } 210 } 211 212 /** Construct a symbol to reflect the qualifying type that should 213 * appear in the byte code as per JLS 13.1. 214 * 215 * For {@literal target >= 1.2}: Clone a method with the qualifier as owner (except 216 * for those cases where we need to work around VM bugs). 217 * 218 * For {@literal target <= 1.1}: If qualified variable or method is defined in a 219 * non-accessible class, clone it with the qualifier class as owner. 220 * 221 * @param sym The accessed symbol 222 * @param site The qualifier's type. 223 */ 224 Symbol binaryQualifier(Symbol sym, Type site) { 225 226 if (site.hasTag(ARRAY)) { 227 if (sym == syms.lengthVar || 228 sym.owner != syms.arrayClass) 229 return sym; 230 // array clone can be qualified by the array type in later targets 231 Symbol qualifier = new ClassSymbol(Flags.PUBLIC, site.tsym.name, 232 site, syms.noSymbol); 233 return sym.clone(qualifier); 234 } 235 236 if (sym.owner == site.tsym || 237 (sym.flags() & (STATIC | SYNTHETIC)) == (STATIC | SYNTHETIC)) { 238 return sym; 239 } 240 241 // leave alone methods inherited from Object 242 // JLS 13.1. 243 if (sym.owner == syms.objectType.tsym) 244 return sym; 245 246 return sym.clone(site.tsym); 247 } 248 249 /** Insert a reference to given type in the constant pool, 250 * checking for an array with too many dimensions; 251 * return the reference's index. 252 * @param type The type for which a reference is inserted. 253 */ 254 int makeRef(DiagnosticPosition pos, Type type) { 255 checkDimension(pos, type); 256 if (type.isAnnotated()) { 257 return pool.put((Object)type); 258 } else { 259 return pool.put(type.hasTag(CLASS) ? (Object)type.tsym : (Object)type); 260 } 261 } 262 263 /** Check if the given type is an array with too many dimensions. 264 */ 265 private void checkDimension(DiagnosticPosition pos, Type t) { 266 switch (t.getTag()) { 267 case METHOD: 268 checkDimension(pos, t.getReturnType()); 269 for (List<Type> args = t.getParameterTypes(); args.nonEmpty(); args = args.tail) 270 checkDimension(pos, args.head); 271 break; 272 case ARRAY: 273 if (types.dimensions(t) > ClassFile.MAX_DIMENSIONS) { 274 log.error(pos, "limit.dimensions"); 275 nerrs++; 276 } 277 break; 278 default: 279 break; 280 } 281 } 282 283 /** Create a tempory variable. 284 * @param type The variable's type. 285 */ 286 LocalItem makeTemp(Type type) { 287 VarSymbol v = new VarSymbol(Flags.SYNTHETIC, 288 names.empty, 289 type, 290 env.enclMethod.sym); 291 code.newLocal(v); 292 return items.makeLocalItem(v); 293 } 294 295 /** Generate code to call a non-private method or constructor. 296 * @param pos Position to be used for error reporting. 297 * @param site The type of which the method is a member. 298 * @param name The method's name. 299 * @param argtypes The method's argument types. 300 * @param isStatic A flag that indicates whether we call a 301 * static or instance method. 302 */ 303 void callMethod(DiagnosticPosition pos, 304 Type site, Name name, List<Type> argtypes, 305 boolean isStatic) { 306 Symbol msym = rs. 307 resolveInternalMethod(pos, attrEnv, site, name, argtypes, null); 308 if (isStatic) items.makeStaticItem(msym).invoke(); 309 else items.makeMemberItem(msym, name == names.init).invoke(); 310 } 311 312 /** Is the given method definition an access method 313 * resulting from a qualified super? This is signified by an odd 314 * access code. 315 */ 316 private boolean isAccessSuper(JCMethodDecl enclMethod) { 317 return 318 (enclMethod.mods.flags & SYNTHETIC) != 0 && 319 isOddAccessName(enclMethod.name); 320 } 321 322 /** Does given name start with "access$" and end in an odd digit? 323 */ 324 private boolean isOddAccessName(Name name) { 325 return 326 name.startsWith(accessDollar) && 327 (name.getByteAt(name.getByteLength() - 1) & 1) == 1; 328 } 329 330/* ************************************************************************ 331 * Non-local exits 332 *************************************************************************/ 333 334 /** Generate code to invoke the finalizer associated with given 335 * environment. 336 * Any calls to finalizers are appended to the environments `cont' chain. 337 * Mark beginning of gap in catch all range for finalizer. 338 */ 339 void genFinalizer(Env<GenContext> env) { 340 if (code.isAlive() && env.info.finalize != null) 341 env.info.finalize.gen(); 342 } 343 344 /** Generate code to call all finalizers of structures aborted by 345 * a non-local 346 * exit. Return target environment of the non-local exit. 347 * @param target The tree representing the structure that's aborted 348 * @param env The environment current at the non-local exit. 349 */ 350 Env<GenContext> unwind(JCTree target, Env<GenContext> env) { 351 Env<GenContext> env1 = env; 352 while (true) { 353 genFinalizer(env1); 354 if (env1.tree == target) break; 355 env1 = env1.next; 356 } 357 return env1; 358 } 359 360 /** Mark end of gap in catch-all range for finalizer. 361 * @param env the environment which might contain the finalizer 362 * (if it does, env.info.gaps != null). 363 */ 364 void endFinalizerGap(Env<GenContext> env) { 365 if (env.info.gaps != null && env.info.gaps.length() % 2 == 1) 366 env.info.gaps.append(code.curCP()); 367 } 368 369 /** Mark end of all gaps in catch-all ranges for finalizers of environments 370 * lying between, and including to two environments. 371 * @param from the most deeply nested environment to mark 372 * @param to the least deeply nested environment to mark 373 */ 374 void endFinalizerGaps(Env<GenContext> from, Env<GenContext> to) { 375 Env<GenContext> last = null; 376 while (last != to) { 377 endFinalizerGap(from); 378 last = from; 379 from = from.next; 380 } 381 } 382 383 /** Do any of the structures aborted by a non-local exit have 384 * finalizers that require an empty stack? 385 * @param target The tree representing the structure that's aborted 386 * @param env The environment current at the non-local exit. 387 */ 388 boolean hasFinally(JCTree target, Env<GenContext> env) { 389 while (env.tree != target) { 390 if (env.tree.hasTag(TRY) && env.info.finalize.hasFinalizer()) 391 return true; 392 env = env.next; 393 } 394 return false; 395 } 396 397/* ************************************************************************ 398 * Normalizing class-members. 399 *************************************************************************/ 400 401 /** Distribute member initializer code into constructors and {@code <clinit>} 402 * method. 403 * @param defs The list of class member declarations. 404 * @param c The enclosing class. 405 */ 406 List<JCTree> normalizeDefs(List<JCTree> defs, ClassSymbol c) { 407 ListBuffer<JCStatement> initCode = new ListBuffer<>(); 408 ListBuffer<Attribute.TypeCompound> initTAs = new ListBuffer<>(); 409 ListBuffer<JCStatement> clinitCode = new ListBuffer<>(); 410 ListBuffer<Attribute.TypeCompound> clinitTAs = new ListBuffer<>(); 411 ListBuffer<JCTree> methodDefs = new ListBuffer<>(); 412 // Sort definitions into three listbuffers: 413 // - initCode for instance initializers 414 // - clinitCode for class initializers 415 // - methodDefs for method definitions 416 for (List<JCTree> l = defs; l.nonEmpty(); l = l.tail) { 417 JCTree def = l.head; 418 switch (def.getTag()) { 419 case BLOCK: 420 JCBlock block = (JCBlock)def; 421 if ((block.flags & STATIC) != 0) 422 clinitCode.append(block); 423 else if ((block.flags & SYNTHETIC) == 0) 424 initCode.append(block); 425 break; 426 case METHODDEF: 427 methodDefs.append(def); 428 break; 429 case VARDEF: 430 JCVariableDecl vdef = (JCVariableDecl) def; 431 VarSymbol sym = vdef.sym; 432 checkDimension(vdef.pos(), sym.type); 433 if (vdef.init != null) { 434 if ((sym.flags() & STATIC) == 0) { 435 // Always initialize instance variables. 436 JCStatement init = make.at(vdef.pos()). 437 Assignment(sym, vdef.init); 438 initCode.append(init); 439 endPosTable.replaceTree(vdef, init); 440 initTAs.addAll(getAndRemoveNonFieldTAs(sym)); 441 } else if (sym.getConstValue() == null) { 442 // Initialize class (static) variables only if 443 // they are not compile-time constants. 444 JCStatement init = make.at(vdef.pos). 445 Assignment(sym, vdef.init); 446 clinitCode.append(init); 447 endPosTable.replaceTree(vdef, init); 448 clinitTAs.addAll(getAndRemoveNonFieldTAs(sym)); 449 } else { 450 checkStringConstant(vdef.init.pos(), sym.getConstValue()); 451 /* if the init contains a reference to an external class, add it to the 452 * constant's pool 453 */ 454 vdef.init.accept(classReferenceVisitor); 455 } 456 } 457 break; 458 default: 459 Assert.error(); 460 } 461 } 462 // Insert any instance initializers into all constructors. 463 if (initCode.length() != 0) { 464 List<JCStatement> inits = initCode.toList(); 465 initTAs.addAll(c.getInitTypeAttributes()); 466 List<Attribute.TypeCompound> initTAlist = initTAs.toList(); 467 for (JCTree t : methodDefs) { 468 normalizeMethod((JCMethodDecl)t, inits, initTAlist); 469 } 470 } 471 // If there are class initializers, create a <clinit> method 472 // that contains them as its body. 473 if (clinitCode.length() != 0) { 474 MethodSymbol clinit = new MethodSymbol( 475 STATIC | (c.flags() & STRICTFP), 476 names.clinit, 477 new MethodType( 478 List.<Type>nil(), syms.voidType, 479 List.<Type>nil(), syms.methodClass), 480 c); 481 c.members().enter(clinit); 482 List<JCStatement> clinitStats = clinitCode.toList(); 483 JCBlock block = make.at(clinitStats.head.pos()).Block(0, clinitStats); 484 block.endpos = TreeInfo.endPos(clinitStats.last()); 485 methodDefs.append(make.MethodDef(clinit, block)); 486 487 if (!clinitTAs.isEmpty()) 488 clinit.appendUniqueTypeAttributes(clinitTAs.toList()); 489 if (!c.getClassInitTypeAttributes().isEmpty()) 490 clinit.appendUniqueTypeAttributes(c.getClassInitTypeAttributes()); 491 } 492 // Return all method definitions. 493 return methodDefs.toList(); 494 } 495 496 private List<Attribute.TypeCompound> getAndRemoveNonFieldTAs(VarSymbol sym) { 497 List<TypeCompound> tas = sym.getRawTypeAttributes(); 498 ListBuffer<Attribute.TypeCompound> fieldTAs = new ListBuffer<>(); 499 ListBuffer<Attribute.TypeCompound> nonfieldTAs = new ListBuffer<>(); 500 for (TypeCompound ta : tas) { 501 Assert.check(ta.getPosition().type != TargetType.UNKNOWN); 502 if (ta.getPosition().type == TargetType.FIELD) { 503 fieldTAs.add(ta); 504 } else { 505 nonfieldTAs.add(ta); 506 } 507 } 508 sym.setTypeAttributes(fieldTAs.toList()); 509 return nonfieldTAs.toList(); 510 } 511 512 /** Check a constant value and report if it is a string that is 513 * too large. 514 */ 515 private void checkStringConstant(DiagnosticPosition pos, Object constValue) { 516 if (nerrs != 0 || // only complain about a long string once 517 constValue == null || 518 !(constValue instanceof String) || 519 ((String)constValue).length() < Pool.MAX_STRING_LENGTH) 520 return; 521 log.error(pos, "limit.string"); 522 nerrs++; 523 } 524 525 /** Insert instance initializer code into initial constructor. 526 * @param md The tree potentially representing a 527 * constructor's definition. 528 * @param initCode The list of instance initializer statements. 529 * @param initTAs Type annotations from the initializer expression. 530 */ 531 void normalizeMethod(JCMethodDecl md, List<JCStatement> initCode, List<TypeCompound> initTAs) { 532 if (md.name == names.init && TreeInfo.isInitialConstructor(md)) { 533 // We are seeing a constructor that does not call another 534 // constructor of the same class. 535 List<JCStatement> stats = md.body.stats; 536 ListBuffer<JCStatement> newstats = new ListBuffer<>(); 537 538 if (stats.nonEmpty()) { 539 // Copy initializers of synthetic variables generated in 540 // the translation of inner classes. 541 while (TreeInfo.isSyntheticInit(stats.head)) { 542 newstats.append(stats.head); 543 stats = stats.tail; 544 } 545 // Copy superclass constructor call 546 newstats.append(stats.head); 547 stats = stats.tail; 548 // Copy remaining synthetic initializers. 549 while (stats.nonEmpty() && 550 TreeInfo.isSyntheticInit(stats.head)) { 551 newstats.append(stats.head); 552 stats = stats.tail; 553 } 554 // Now insert the initializer code. 555 newstats.appendList(initCode); 556 // And copy all remaining statements. 557 while (stats.nonEmpty()) { 558 newstats.append(stats.head); 559 stats = stats.tail; 560 } 561 } 562 md.body.stats = newstats.toList(); 563 if (md.body.endpos == Position.NOPOS) 564 md.body.endpos = TreeInfo.endPos(md.body.stats.last()); 565 566 md.sym.appendUniqueTypeAttributes(initTAs); 567 } 568 } 569 570/* ************************************************************************ 571 * Traversal methods 572 *************************************************************************/ 573 574 /** Visitor argument: The current environment. 575 */ 576 Env<GenContext> env; 577 578 /** Visitor argument: The expected type (prototype). 579 */ 580 Type pt; 581 582 /** Visitor result: The item representing the computed value. 583 */ 584 Item result; 585 586 /** Visitor method: generate code for a definition, catching and reporting 587 * any completion failures. 588 * @param tree The definition to be visited. 589 * @param env The environment current at the definition. 590 */ 591 public void genDef(JCTree tree, Env<GenContext> env) { 592 Env<GenContext> prevEnv = this.env; 593 try { 594 this.env = env; 595 tree.accept(this); 596 } catch (CompletionFailure ex) { 597 chk.completionError(tree.pos(), ex); 598 } finally { 599 this.env = prevEnv; 600 } 601 } 602 603 /** Derived visitor method: check whether CharacterRangeTable 604 * should be emitted, if so, put a new entry into CRTable 605 * and call method to generate bytecode. 606 * If not, just call method to generate bytecode. 607 * @see #genStat(JCTree, Env) 608 * 609 * @param tree The tree to be visited. 610 * @param env The environment to use. 611 * @param crtFlags The CharacterRangeTable flags 612 * indicating type of the entry. 613 */ 614 public void genStat(JCTree tree, Env<GenContext> env, int crtFlags) { 615 if (!genCrt) { 616 genStat(tree, env); 617 return; 618 } 619 int startpc = code.curCP(); 620 genStat(tree, env); 621 if (tree.hasTag(Tag.BLOCK)) crtFlags |= CRT_BLOCK; 622 code.crt.put(tree, crtFlags, startpc, code.curCP()); 623 } 624 625 /** Derived visitor method: generate code for a statement. 626 */ 627 public void genStat(JCTree tree, Env<GenContext> env) { 628 if (code.isAlive()) { 629 code.statBegin(tree.pos); 630 genDef(tree, env); 631 } else if (env.info.isSwitch && tree.hasTag(VARDEF)) { 632 // variables whose declarations are in a switch 633 // can be used even if the decl is unreachable. 634 code.newLocal(((JCVariableDecl) tree).sym); 635 } 636 } 637 638 /** Derived visitor method: check whether CharacterRangeTable 639 * should be emitted, if so, put a new entry into CRTable 640 * and call method to generate bytecode. 641 * If not, just call method to generate bytecode. 642 * @see #genStats(List, Env) 643 * 644 * @param trees The list of trees to be visited. 645 * @param env The environment to use. 646 * @param crtFlags The CharacterRangeTable flags 647 * indicating type of the entry. 648 */ 649 public void genStats(List<JCStatement> trees, Env<GenContext> env, int crtFlags) { 650 if (!genCrt) { 651 genStats(trees, env); 652 return; 653 } 654 if (trees.length() == 1) { // mark one statement with the flags 655 genStat(trees.head, env, crtFlags | CRT_STATEMENT); 656 } else { 657 int startpc = code.curCP(); 658 genStats(trees, env); 659 code.crt.put(trees, crtFlags, startpc, code.curCP()); 660 } 661 } 662 663 /** Derived visitor method: generate code for a list of statements. 664 */ 665 public void genStats(List<? extends JCTree> trees, Env<GenContext> env) { 666 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail) 667 genStat(l.head, env, CRT_STATEMENT); 668 } 669 670 /** Derived visitor method: check whether CharacterRangeTable 671 * should be emitted, if so, put a new entry into CRTable 672 * and call method to generate bytecode. 673 * If not, just call method to generate bytecode. 674 * @see #genCond(JCTree,boolean) 675 * 676 * @param tree The tree to be visited. 677 * @param crtFlags The CharacterRangeTable flags 678 * indicating type of the entry. 679 */ 680 public CondItem genCond(JCTree tree, int crtFlags) { 681 if (!genCrt) return genCond(tree, false); 682 int startpc = code.curCP(); 683 CondItem item = genCond(tree, (crtFlags & CRT_FLOW_CONTROLLER) != 0); 684 code.crt.put(tree, crtFlags, startpc, code.curCP()); 685 return item; 686 } 687 688 /** Derived visitor method: generate code for a boolean 689 * expression in a control-flow context. 690 * @param _tree The expression to be visited. 691 * @param markBranches The flag to indicate that the condition is 692 * a flow controller so produced conditions 693 * should contain a proper tree to generate 694 * CharacterRangeTable branches for them. 695 */ 696 public CondItem genCond(JCTree _tree, boolean markBranches) { 697 JCTree inner_tree = TreeInfo.skipParens(_tree); 698 if (inner_tree.hasTag(CONDEXPR)) { 699 JCConditional tree = (JCConditional)inner_tree; 700 CondItem cond = genCond(tree.cond, CRT_FLOW_CONTROLLER); 701 if (cond.isTrue()) { 702 code.resolve(cond.trueJumps); 703 CondItem result = genCond(tree.truepart, CRT_FLOW_TARGET); 704 if (markBranches) result.tree = tree.truepart; 705 return result; 706 } 707 if (cond.isFalse()) { 708 code.resolve(cond.falseJumps); 709 CondItem result = genCond(tree.falsepart, CRT_FLOW_TARGET); 710 if (markBranches) result.tree = tree.falsepart; 711 return result; 712 } 713 Chain secondJumps = cond.jumpFalse(); 714 code.resolve(cond.trueJumps); 715 CondItem first = genCond(tree.truepart, CRT_FLOW_TARGET); 716 if (markBranches) first.tree = tree.truepart; 717 Chain falseJumps = first.jumpFalse(); 718 code.resolve(first.trueJumps); 719 Chain trueJumps = code.branch(goto_); 720 code.resolve(secondJumps); 721 CondItem second = genCond(tree.falsepart, CRT_FLOW_TARGET); 722 CondItem result = items.makeCondItem(second.opcode, 723 Code.mergeChains(trueJumps, second.trueJumps), 724 Code.mergeChains(falseJumps, second.falseJumps)); 725 if (markBranches) result.tree = tree.falsepart; 726 return result; 727 } else { 728 CondItem result = genExpr(_tree, syms.booleanType).mkCond(); 729 if (markBranches) result.tree = _tree; 730 return result; 731 } 732 } 733 734 public Code getCode() { 735 return code; 736 } 737 738 public Items getItems() { 739 return items; 740 } 741 742 public Env<AttrContext> getAttrEnv() { 743 return attrEnv; 744 } 745 746 /** Visitor class for expressions which might be constant expressions. 747 * This class is a subset of TreeScanner. Intended to visit trees pruned by 748 * Lower as long as constant expressions looking for references to any 749 * ClassSymbol. Any such reference will be added to the constant pool so 750 * automated tools can detect class dependencies better. 751 */ 752 class ClassReferenceVisitor extends JCTree.Visitor { 753 754 @Override 755 public void visitTree(JCTree tree) {} 756 757 @Override 758 public void visitBinary(JCBinary tree) { 759 tree.lhs.accept(this); 760 tree.rhs.accept(this); 761 } 762 763 @Override 764 public void visitSelect(JCFieldAccess tree) { 765 if (tree.selected.type.hasTag(CLASS)) { 766 makeRef(tree.selected.pos(), tree.selected.type); 767 } 768 } 769 770 @Override 771 public void visitIdent(JCIdent tree) { 772 if (tree.sym.owner instanceof ClassSymbol) { 773 pool.put(tree.sym.owner); 774 } 775 } 776 777 @Override 778 public void visitConditional(JCConditional tree) { 779 tree.cond.accept(this); 780 tree.truepart.accept(this); 781 tree.falsepart.accept(this); 782 } 783 784 @Override 785 public void visitUnary(JCUnary tree) { 786 tree.arg.accept(this); 787 } 788 789 @Override 790 public void visitParens(JCParens tree) { 791 tree.expr.accept(this); 792 } 793 794 @Override 795 public void visitTypeCast(JCTypeCast tree) { 796 tree.expr.accept(this); 797 } 798 } 799 800 private ClassReferenceVisitor classReferenceVisitor = new ClassReferenceVisitor(); 801 802 /** Visitor method: generate code for an expression, catching and reporting 803 * any completion failures. 804 * @param tree The expression to be visited. 805 * @param pt The expression's expected type (proto-type). 806 */ 807 public Item genExpr(JCTree tree, Type pt) { 808 Type prevPt = this.pt; 809 try { 810 if (tree.type.constValue() != null) { 811 // Short circuit any expressions which are constants 812 tree.accept(classReferenceVisitor); 813 checkStringConstant(tree.pos(), tree.type.constValue()); 814 result = items.makeImmediateItem(tree.type, tree.type.constValue()); 815 } else { 816 this.pt = pt; 817 tree.accept(this); 818 } 819 return result.coerce(pt); 820 } catch (CompletionFailure ex) { 821 chk.completionError(tree.pos(), ex); 822 code.state.stacksize = 1; 823 return items.makeStackItem(pt); 824 } finally { 825 this.pt = prevPt; 826 } 827 } 828 829 /** Derived visitor method: generate code for a list of method arguments. 830 * @param trees The argument expressions to be visited. 831 * @param pts The expression's expected types (i.e. the formal parameter 832 * types of the invoked method). 833 */ 834 public void genArgs(List<JCExpression> trees, List<Type> pts) { 835 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail) { 836 genExpr(l.head, pts.head).load(); 837 pts = pts.tail; 838 } 839 // require lists be of same length 840 Assert.check(pts.isEmpty()); 841 } 842 843/* ************************************************************************ 844 * Visitor methods for statements and definitions 845 *************************************************************************/ 846 847 /** Thrown when the byte code size exceeds limit. 848 */ 849 public static class CodeSizeOverflow extends RuntimeException { 850 private static final long serialVersionUID = 0; 851 public CodeSizeOverflow() {} 852 } 853 854 public void visitMethodDef(JCMethodDecl tree) { 855 // Create a new local environment that points pack at method 856 // definition. 857 Env<GenContext> localEnv = env.dup(tree); 858 localEnv.enclMethod = tree; 859 // The expected type of every return statement in this method 860 // is the method's return type. 861 this.pt = tree.sym.erasure(types).getReturnType(); 862 863 checkDimension(tree.pos(), tree.sym.erasure(types)); 864 genMethod(tree, localEnv, false); 865 } 866//where 867 /** Generate code for a method. 868 * @param tree The tree representing the method definition. 869 * @param env The environment current for the method body. 870 * @param fatcode A flag that indicates whether all jumps are 871 * within 32K. We first invoke this method under 872 * the assumption that fatcode == false, i.e. all 873 * jumps are within 32K. If this fails, fatcode 874 * is set to true and we try again. 875 */ 876 void genMethod(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) { 877 MethodSymbol meth = tree.sym; 878 int extras = 0; 879 // Count up extra parameters 880 if (meth.isConstructor()) { 881 extras++; 882 if (meth.enclClass().isInner() && 883 !meth.enclClass().isStatic()) { 884 extras++; 885 } 886 } else if ((tree.mods.flags & STATIC) == 0) { 887 extras++; 888 } 889 // System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG 890 if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes()) + extras > 891 ClassFile.MAX_PARAMETERS) { 892 log.error(tree.pos(), "limit.parameters"); 893 nerrs++; 894 } 895 896 else if (tree.body != null) { 897 // Create a new code structure and initialize it. 898 int startpcCrt = initCode(tree, env, fatcode); 899 900 try { 901 genStat(tree.body, env); 902 } catch (CodeSizeOverflow e) { 903 // Failed due to code limit, try again with jsr/ret 904 startpcCrt = initCode(tree, env, fatcode); 905 genStat(tree.body, env); 906 } 907 908 if (code.state.stacksize != 0) { 909 log.error(tree.body.pos(), "stack.sim.error", tree); 910 throw new AssertionError(); 911 } 912 913 // If last statement could complete normally, insert a 914 // return at the end. 915 if (code.isAlive()) { 916 code.statBegin(TreeInfo.endPos(tree.body)); 917 if (env.enclMethod == null || 918 env.enclMethod.sym.type.getReturnType().hasTag(VOID)) { 919 code.emitop0(return_); 920 } else { 921 // sometime dead code seems alive (4415991); 922 // generate a small loop instead 923 int startpc = code.entryPoint(); 924 CondItem c = items.makeCondItem(goto_); 925 code.resolve(c.jumpTrue(), startpc); 926 } 927 } 928 if (genCrt) 929 code.crt.put(tree.body, 930 CRT_BLOCK, 931 startpcCrt, 932 code.curCP()); 933 934 code.endScopes(0); 935 936 // If we exceeded limits, panic 937 if (code.checkLimits(tree.pos(), log)) { 938 nerrs++; 939 return; 940 } 941 942 // If we generated short code but got a long jump, do it again 943 // with fatCode = true. 944 if (!fatcode && code.fatcode) genMethod(tree, env, true); 945 946 // Clean up 947 if(stackMap == StackMapFormat.JSR202) { 948 code.lastFrame = null; 949 code.frameBeforeLast = null; 950 } 951 952 // Compress exception table 953 code.compressCatchTable(); 954 955 // Fill in type annotation positions for exception parameters 956 code.fillExceptionParameterPositions(); 957 } 958 } 959 960 private int initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) { 961 MethodSymbol meth = tree.sym; 962 963 // Create a new code structure. 964 meth.code = code = new Code(meth, 965 fatcode, 966 lineDebugInfo ? toplevel.lineMap : null, 967 varDebugInfo, 968 stackMap, 969 debugCode, 970 genCrt ? new CRTable(tree, env.toplevel.endPositions) 971 : null, 972 syms, 973 types, 974 pool); 975 items = new Items(pool, code, syms, types); 976 if (code.debugCode) { 977 System.err.println(meth + " for body " + tree); 978 } 979 980 // If method is not static, create a new local variable address 981 // for `this'. 982 if ((tree.mods.flags & STATIC) == 0) { 983 Type selfType = meth.owner.type; 984 if (meth.isConstructor() && selfType != syms.objectType) 985 selfType = UninitializedType.uninitializedThis(selfType); 986 code.setDefined( 987 code.newLocal( 988 new VarSymbol(FINAL, names._this, selfType, meth.owner))); 989 } 990 991 // Mark all parameters as defined from the beginning of 992 // the method. 993 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) { 994 checkDimension(l.head.pos(), l.head.sym.type); 995 code.setDefined(code.newLocal(l.head.sym)); 996 } 997 998 // Get ready to generate code for method body. 999 int startpcCrt = genCrt ? code.curCP() : 0; 1000 code.entryPoint(); 1001 1002 // Suppress initial stackmap 1003 code.pendingStackMap = false; 1004 1005 return startpcCrt; 1006 } 1007 1008 public void visitVarDef(JCVariableDecl tree) { 1009 VarSymbol v = tree.sym; 1010 code.newLocal(v); 1011 if (tree.init != null) { 1012 checkStringConstant(tree.init.pos(), v.getConstValue()); 1013 if (v.getConstValue() == null || varDebugInfo) { 1014 Assert.check(letExprDepth != 0 || code.state.stacksize == 0); 1015 genExpr(tree.init, v.erasure(types)).load(); 1016 items.makeLocalItem(v).store(); 1017 Assert.check(letExprDepth != 0 || code.state.stacksize == 0); 1018 } 1019 } 1020 checkDimension(tree.pos(), v.type); 1021 } 1022 1023 public void visitSkip(JCSkip tree) { 1024 } 1025 1026 public void visitBlock(JCBlock tree) { 1027 int limit = code.nextreg; 1028 Env<GenContext> localEnv = env.dup(tree, new GenContext()); 1029 genStats(tree.stats, localEnv); 1030 // End the scope of all block-local variables in variable info. 1031 if (!env.tree.hasTag(METHODDEF)) { 1032 code.statBegin(tree.endpos); 1033 code.endScopes(limit); 1034 code.pendingStatPos = Position.NOPOS; 1035 } 1036 } 1037 1038 public void visitDoLoop(JCDoWhileLoop tree) { 1039 genLoop(tree, tree.body, tree.cond, List.<JCExpressionStatement>nil(), false); 1040 } 1041 1042 public void visitWhileLoop(JCWhileLoop tree) { 1043 genLoop(tree, tree.body, tree.cond, List.<JCExpressionStatement>nil(), true); 1044 } 1045 1046 public void visitForLoop(JCForLoop tree) { 1047 int limit = code.nextreg; 1048 genStats(tree.init, env); 1049 genLoop(tree, tree.body, tree.cond, tree.step, true); 1050 code.endScopes(limit); 1051 } 1052 //where 1053 /** Generate code for a loop. 1054 * @param loop The tree representing the loop. 1055 * @param body The loop's body. 1056 * @param cond The loop's controling condition. 1057 * @param step "Step" statements to be inserted at end of 1058 * each iteration. 1059 * @param testFirst True if the loop test belongs before the body. 1060 */ 1061 private void genLoop(JCStatement loop, 1062 JCStatement body, 1063 JCExpression cond, 1064 List<JCExpressionStatement> step, 1065 boolean testFirst) { 1066 Env<GenContext> loopEnv = env.dup(loop, new GenContext()); 1067 int startpc = code.entryPoint(); 1068 if (testFirst) { //while or for loop 1069 CondItem c; 1070 if (cond != null) { 1071 code.statBegin(cond.pos); 1072 Assert.check(code.state.stacksize == 0); 1073 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER); 1074 } else { 1075 c = items.makeCondItem(goto_); 1076 } 1077 Chain loopDone = c.jumpFalse(); 1078 code.resolve(c.trueJumps); 1079 Assert.check(code.state.stacksize == 0); 1080 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET); 1081 code.resolve(loopEnv.info.cont); 1082 genStats(step, loopEnv); 1083 code.resolve(code.branch(goto_), startpc); 1084 code.resolve(loopDone); 1085 } else { 1086 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET); 1087 code.resolve(loopEnv.info.cont); 1088 genStats(step, loopEnv); 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 Chain exit = loopEnv.info.exit; 1102 if (exit != null) { 1103 code.resolve(exit); 1104 exit.state.defined.excludeFrom(code.nextreg); 1105 } 1106 } 1107 1108 public void visitForeachLoop(JCEnhancedForLoop tree) { 1109 throw new AssertionError(); // should have been removed by Lower. 1110 } 1111 1112 public void visitLabelled(JCLabeledStatement tree) { 1113 Env<GenContext> localEnv = env.dup(tree, new GenContext()); 1114 genStat(tree.body, localEnv, CRT_STATEMENT); 1115 Chain exit = localEnv.info.exit; 1116 if (exit != null) { 1117 code.resolve(exit); 1118 exit.state.defined.excludeFrom(code.nextreg); 1119 } 1120 } 1121 1122 public void visitSwitch(JCSwitch tree) { 1123 int limit = code.nextreg; 1124 Assert.check(!tree.selector.type.hasTag(CLASS)); 1125 int startpcCrt = genCrt ? code.curCP() : 0; 1126 Assert.check(code.state.stacksize == 0); 1127 Item sel = genExpr(tree.selector, syms.intType); 1128 List<JCCase> cases = tree.cases; 1129 if (cases.isEmpty()) { 1130 // We are seeing: switch <sel> {} 1131 sel.load().drop(); 1132 if (genCrt) 1133 code.crt.put(TreeInfo.skipParens(tree.selector), 1134 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP()); 1135 } else { 1136 // We are seeing a nonempty switch. 1137 sel.load(); 1138 if (genCrt) 1139 code.crt.put(TreeInfo.skipParens(tree.selector), 1140 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP()); 1141 Env<GenContext> switchEnv = env.dup(tree, new GenContext()); 1142 switchEnv.info.isSwitch = true; 1143 1144 // Compute number of labels and minimum and maximum label values. 1145 // For each case, store its label in an array. 1146 int lo = Integer.MAX_VALUE; // minimum label. 1147 int hi = Integer.MIN_VALUE; // maximum label. 1148 int nlabels = 0; // number of labels. 1149 1150 int[] labels = new int[cases.length()]; // the label array. 1151 int defaultIndex = -1; // the index of the default clause. 1152 1153 List<JCCase> l = cases; 1154 for (int i = 0; i < labels.length; i++) { 1155 if (l.head.pat != null) { 1156 int val = ((Number)l.head.pat.type.constValue()).intValue(); 1157 labels[i] = val; 1158 if (val < lo) lo = val; 1159 if (hi < val) hi = val; 1160 nlabels++; 1161 } else { 1162 Assert.check(defaultIndex == -1); 1163 defaultIndex = i; 1164 } 1165 l = l.tail; 1166 } 1167 1168 // Determine whether to issue a tableswitch or a lookupswitch 1169 // instruction. 1170 long table_space_cost = 4 + ((long) hi - lo + 1); // words 1171 long table_time_cost = 3; // comparisons 1172 long lookup_space_cost = 3 + 2 * (long) nlabels; 1173 long lookup_time_cost = nlabels; 1174 int opcode = 1175 nlabels > 0 && 1176 table_space_cost + 3 * table_time_cost <= 1177 lookup_space_cost + 3 * lookup_time_cost 1178 ? 1179 tableswitch : lookupswitch; 1180 1181 int startpc = code.curCP(); // the position of the selector operation 1182 code.emitop0(opcode); 1183 code.align(4); 1184 int tableBase = code.curCP(); // the start of the jump table 1185 int[] offsets = null; // a table of offsets for a lookupswitch 1186 code.emit4(-1); // leave space for default offset 1187 if (opcode == tableswitch) { 1188 code.emit4(lo); // minimum label 1189 code.emit4(hi); // maximum label 1190 for (long i = lo; i <= hi; i++) { // leave space for jump table 1191 code.emit4(-1); 1192 } 1193 } else { 1194 code.emit4(nlabels); // number of labels 1195 for (int i = 0; i < nlabels; i++) { 1196 code.emit4(-1); code.emit4(-1); // leave space for lookup table 1197 } 1198 offsets = new int[labels.length]; 1199 } 1200 Code.State stateSwitch = code.state.dup(); 1201 code.markDead(); 1202 1203 // For each case do: 1204 l = cases; 1205 for (int i = 0; i < labels.length; i++) { 1206 JCCase c = l.head; 1207 l = l.tail; 1208 1209 int pc = code.entryPoint(stateSwitch); 1210 // Insert offset directly into code or else into the 1211 // offsets table. 1212 if (i != defaultIndex) { 1213 if (opcode == tableswitch) { 1214 code.put4( 1215 tableBase + 4 * (labels[i] - lo + 3), 1216 pc - startpc); 1217 } else { 1218 offsets[i] = pc - startpc; 1219 } 1220 } else { 1221 code.put4(tableBase, pc - startpc); 1222 } 1223 1224 // Generate code for the statements in this case. 1225 genStats(c.stats, switchEnv, CRT_FLOW_TARGET); 1226 } 1227 1228 // Resolve all breaks. 1229 Chain exit = switchEnv.info.exit; 1230 if (exit != null) { 1231 code.resolve(exit); 1232 exit.state.defined.excludeFrom(code.nextreg); 1233 } 1234 1235 // If we have not set the default offset, we do so now. 1236 if (code.get4(tableBase) == -1) { 1237 code.put4(tableBase, code.entryPoint(stateSwitch) - startpc); 1238 } 1239 1240 if (opcode == tableswitch) { 1241 // Let any unfilled slots point to the default case. 1242 int defaultOffset = code.get4(tableBase); 1243 for (long i = lo; i <= hi; i++) { 1244 int t = (int)(tableBase + 4 * (i - lo + 3)); 1245 if (code.get4(t) == -1) 1246 code.put4(t, defaultOffset); 1247 } 1248 } else { 1249 // Sort non-default offsets and copy into lookup table. 1250 if (defaultIndex >= 0) 1251 for (int i = defaultIndex; i < labels.length - 1; i++) { 1252 labels[i] = labels[i+1]; 1253 offsets[i] = offsets[i+1]; 1254 } 1255 if (nlabels > 0) 1256 qsort2(labels, offsets, 0, nlabels - 1); 1257 for (int i = 0; i < nlabels; i++) { 1258 int caseidx = tableBase + 8 * (i + 1); 1259 code.put4(caseidx, labels[i]); 1260 code.put4(caseidx + 4, offsets[i]); 1261 } 1262 } 1263 } 1264 code.endScopes(limit); 1265 } 1266//where 1267 /** Sort (int) arrays of keys and values 1268 */ 1269 static void qsort2(int[] keys, int[] values, int lo, int hi) { 1270 int i = lo; 1271 int j = hi; 1272 int pivot = keys[(i+j)/2]; 1273 do { 1274 while (keys[i] < pivot) i++; 1275 while (pivot < keys[j]) j--; 1276 if (i <= j) { 1277 int temp1 = keys[i]; 1278 keys[i] = keys[j]; 1279 keys[j] = temp1; 1280 int temp2 = values[i]; 1281 values[i] = values[j]; 1282 values[j] = temp2; 1283 i++; 1284 j--; 1285 } 1286 } while (i <= j); 1287 if (lo < j) qsort2(keys, values, lo, j); 1288 if (i < hi) qsort2(keys, values, i, hi); 1289 } 1290 1291 public void visitSynchronized(JCSynchronized tree) { 1292 int limit = code.nextreg; 1293 // Generate code to evaluate lock and save in temporary variable. 1294 final LocalItem lockVar = makeTemp(syms.objectType); 1295 Assert.check(code.state.stacksize == 0); 1296 genExpr(tree.lock, tree.lock.type).load().duplicate(); 1297 lockVar.store(); 1298 1299 // Generate code to enter monitor. 1300 code.emitop0(monitorenter); 1301 code.state.lock(lockVar.reg); 1302 1303 // Generate code for a try statement with given body, no catch clauses 1304 // in a new environment with the "exit-monitor" operation as finalizer. 1305 final Env<GenContext> syncEnv = env.dup(tree, new GenContext()); 1306 syncEnv.info.finalize = new GenFinalizer() { 1307 void gen() { 1308 genLast(); 1309 Assert.check(syncEnv.info.gaps.length() % 2 == 0); 1310 syncEnv.info.gaps.append(code.curCP()); 1311 } 1312 void genLast() { 1313 if (code.isAlive()) { 1314 lockVar.load(); 1315 code.emitop0(monitorexit); 1316 code.state.unlock(lockVar.reg); 1317 } 1318 } 1319 }; 1320 syncEnv.info.gaps = new ListBuffer<>(); 1321 genTry(tree.body, List.<JCCatch>nil(), syncEnv); 1322 code.endScopes(limit); 1323 } 1324 1325 public void visitTry(final JCTry tree) { 1326 // Generate code for a try statement with given body and catch clauses, 1327 // in a new environment which calls the finally block if there is one. 1328 final Env<GenContext> tryEnv = env.dup(tree, new GenContext()); 1329 final Env<GenContext> oldEnv = env; 1330 tryEnv.info.finalize = new GenFinalizer() { 1331 void gen() { 1332 Assert.check(tryEnv.info.gaps.length() % 2 == 0); 1333 tryEnv.info.gaps.append(code.curCP()); 1334 genLast(); 1335 } 1336 void genLast() { 1337 if (tree.finalizer != null) 1338 genStat(tree.finalizer, oldEnv, CRT_BLOCK); 1339 } 1340 boolean hasFinalizer() { 1341 return tree.finalizer != null; 1342 } 1343 }; 1344 tryEnv.info.gaps = new ListBuffer<>(); 1345 genTry(tree.body, tree.catchers, tryEnv); 1346 } 1347 //where 1348 /** Generate code for a try or synchronized statement 1349 * @param body The body of the try or synchronized statement. 1350 * @param catchers The lis of catch clauses. 1351 * @param env the environment current for the body. 1352 */ 1353 void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) { 1354 int limit = code.nextreg; 1355 int startpc = code.curCP(); 1356 Code.State stateTry = code.state.dup(); 1357 genStat(body, env, CRT_BLOCK); 1358 int endpc = code.curCP(); 1359 boolean hasFinalizer = 1360 env.info.finalize != null && 1361 env.info.finalize.hasFinalizer(); 1362 List<Integer> gaps = env.info.gaps.toList(); 1363 code.statBegin(TreeInfo.endPos(body)); 1364 genFinalizer(env); 1365 code.statBegin(TreeInfo.endPos(env.tree)); 1366 Chain exitChain = code.branch(goto_); 1367 endFinalizerGap(env); 1368 if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) { 1369 // start off with exception on stack 1370 code.entryPoint(stateTry, l.head.param.sym.type); 1371 genCatch(l.head, env, startpc, endpc, gaps); 1372 genFinalizer(env); 1373 if (hasFinalizer || l.tail.nonEmpty()) { 1374 code.statBegin(TreeInfo.endPos(env.tree)); 1375 exitChain = Code.mergeChains(exitChain, 1376 code.branch(goto_)); 1377 } 1378 endFinalizerGap(env); 1379 } 1380 if (hasFinalizer) { 1381 // Create a new register segement to avoid allocating 1382 // the same variables in finalizers and other statements. 1383 code.newRegSegment(); 1384 1385 // Add a catch-all clause. 1386 1387 // start off with exception on stack 1388 int catchallpc = code.entryPoint(stateTry, syms.throwableType); 1389 1390 // Register all exception ranges for catch all clause. 1391 // The range of the catch all clause is from the beginning 1392 // of the try or synchronized block until the present 1393 // code pointer excluding all gaps in the current 1394 // environment's GenContext. 1395 int startseg = startpc; 1396 while (env.info.gaps.nonEmpty()) { 1397 int endseg = env.info.gaps.next().intValue(); 1398 registerCatch(body.pos(), startseg, endseg, 1399 catchallpc, 0); 1400 startseg = env.info.gaps.next().intValue(); 1401 } 1402 code.statBegin(TreeInfo.finalizerPos(env.tree)); 1403 code.markStatBegin(); 1404 1405 Item excVar = makeTemp(syms.throwableType); 1406 excVar.store(); 1407 genFinalizer(env); 1408 excVar.load(); 1409 registerCatch(body.pos(), startseg, 1410 env.info.gaps.next().intValue(), 1411 catchallpc, 0); 1412 code.emitop0(athrow); 1413 code.markDead(); 1414 1415 // If there are jsr's to this finalizer, ... 1416 if (env.info.cont != null) { 1417 // Resolve all jsr's. 1418 code.resolve(env.info.cont); 1419 1420 // Mark statement line number 1421 code.statBegin(TreeInfo.finalizerPos(env.tree)); 1422 code.markStatBegin(); 1423 1424 // Save return address. 1425 LocalItem retVar = makeTemp(syms.throwableType); 1426 retVar.store(); 1427 1428 // Generate finalizer code. 1429 env.info.finalize.genLast(); 1430 1431 // Return. 1432 code.emitop1w(ret, retVar.reg); 1433 code.markDead(); 1434 } 1435 } 1436 // Resolve all breaks. 1437 code.resolve(exitChain); 1438 1439 code.endScopes(limit); 1440 } 1441 1442 /** Generate code for a catch clause. 1443 * @param tree The catch clause. 1444 * @param env The environment current in the enclosing try. 1445 * @param startpc Start pc of try-block. 1446 * @param endpc End pc of try-block. 1447 */ 1448 void genCatch(JCCatch tree, 1449 Env<GenContext> env, 1450 int startpc, int endpc, 1451 List<Integer> gaps) { 1452 if (startpc != endpc) { 1453 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypeExprs 1454 = catchTypesWithAnnotations(tree); 1455 while (gaps.nonEmpty()) { 1456 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) { 1457 JCExpression subCatch = subCatch1.snd; 1458 int catchType = makeRef(tree.pos(), subCatch.type); 1459 int end = gaps.head.intValue(); 1460 registerCatch(tree.pos(), 1461 startpc, end, code.curCP(), 1462 catchType); 1463 for (Attribute.TypeCompound tc : subCatch1.fst) { 1464 tc.position.setCatchInfo(catchType, startpc); 1465 } 1466 } 1467 gaps = gaps.tail; 1468 startpc = gaps.head.intValue(); 1469 gaps = gaps.tail; 1470 } 1471 if (startpc < endpc) { 1472 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) { 1473 JCExpression subCatch = subCatch1.snd; 1474 int catchType = makeRef(tree.pos(), subCatch.type); 1475 registerCatch(tree.pos(), 1476 startpc, endpc, code.curCP(), 1477 catchType); 1478 for (Attribute.TypeCompound tc : subCatch1.fst) { 1479 tc.position.setCatchInfo(catchType, startpc); 1480 } 1481 } 1482 } 1483 VarSymbol exparam = tree.param.sym; 1484 code.statBegin(tree.pos); 1485 code.markStatBegin(); 1486 int limit = code.nextreg; 1487 code.newLocal(exparam); 1488 items.makeLocalItem(exparam).store(); 1489 code.statBegin(TreeInfo.firstStatPos(tree.body)); 1490 genStat(tree.body, env, CRT_BLOCK); 1491 code.endScopes(limit); 1492 code.statBegin(TreeInfo.endPos(tree.body)); 1493 } 1494 } 1495 // where 1496 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotations(JCCatch tree) { 1497 return TreeInfo.isMultiCatch(tree) ? 1498 catchTypesWithAnnotationsFromMulticatch((JCTypeUnion)tree.param.vartype, tree.param.sym.getRawTypeAttributes()) : 1499 List.of(new Pair<>(tree.param.sym.getRawTypeAttributes(), tree.param.vartype)); 1500 } 1501 // where 1502 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotationsFromMulticatch(JCTypeUnion tree, List<TypeCompound> first) { 1503 List<JCExpression> alts = tree.alternatives; 1504 List<Pair<List<TypeCompound>, JCExpression>> res = List.of(new Pair<>(first, alts.head)); 1505 alts = alts.tail; 1506 1507 while(alts != null && alts.head != null) { 1508 JCExpression alt = alts.head; 1509 if (alt instanceof JCAnnotatedType) { 1510 JCAnnotatedType a = (JCAnnotatedType)alt; 1511 res = res.prepend(new Pair<>(annotate.fromAnnotations(a.annotations), alt)); 1512 } else { 1513 res = res.prepend(new Pair<>(List.nil(), alt)); 1514 } 1515 alts = alts.tail; 1516 } 1517 return res.reverse(); 1518 } 1519 1520 /** Register a catch clause in the "Exceptions" code-attribute. 1521 */ 1522 void registerCatch(DiagnosticPosition pos, 1523 int startpc, int endpc, 1524 int handler_pc, int catch_type) { 1525 char startpc1 = (char)startpc; 1526 char endpc1 = (char)endpc; 1527 char handler_pc1 = (char)handler_pc; 1528 if (startpc1 == startpc && 1529 endpc1 == endpc && 1530 handler_pc1 == handler_pc) { 1531 code.addCatch(startpc1, endpc1, handler_pc1, 1532 (char)catch_type); 1533 } else { 1534 log.error(pos, "limit.code.too.large.for.try.stmt"); 1535 nerrs++; 1536 } 1537 } 1538 1539 public void visitIf(JCIf tree) { 1540 int limit = code.nextreg; 1541 Chain thenExit = null; 1542 Assert.check(code.state.stacksize == 0); 1543 CondItem c = genCond(TreeInfo.skipParens(tree.cond), 1544 CRT_FLOW_CONTROLLER); 1545 Chain elseChain = c.jumpFalse(); 1546 Assert.check(code.state.stacksize == 0); 1547 if (!c.isFalse()) { 1548 code.resolve(c.trueJumps); 1549 genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET); 1550 thenExit = code.branch(goto_); 1551 } 1552 if (elseChain != null) { 1553 code.resolve(elseChain); 1554 if (tree.elsepart != null) { 1555 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET); 1556 } 1557 } 1558 code.resolve(thenExit); 1559 code.endScopes(limit); 1560 Assert.check(code.state.stacksize == 0); 1561 } 1562 1563 public void visitExec(JCExpressionStatement tree) { 1564 // Optimize x++ to ++x and x-- to --x. 1565 JCExpression e = tree.expr; 1566 switch (e.getTag()) { 1567 case POSTINC: 1568 ((JCUnary) e).setTag(PREINC); 1569 break; 1570 case POSTDEC: 1571 ((JCUnary) e).setTag(PREDEC); 1572 break; 1573 } 1574 Assert.check(code.state.stacksize == 0); 1575 genExpr(tree.expr, tree.expr.type).drop(); 1576 Assert.check(code.state.stacksize == 0); 1577 } 1578 1579 public void visitBreak(JCBreak tree) { 1580 Env<GenContext> targetEnv = unwind(tree.target, env); 1581 Assert.check(code.state.stacksize == 0); 1582 targetEnv.info.addExit(code.branch(goto_)); 1583 endFinalizerGaps(env, targetEnv); 1584 } 1585 1586 public void visitContinue(JCContinue tree) { 1587 Env<GenContext> targetEnv = unwind(tree.target, env); 1588 Assert.check(code.state.stacksize == 0); 1589 targetEnv.info.addCont(code.branch(goto_)); 1590 endFinalizerGaps(env, targetEnv); 1591 } 1592 1593 public void visitReturn(JCReturn tree) { 1594 int limit = code.nextreg; 1595 final Env<GenContext> targetEnv; 1596 1597 /* Save and then restore the location of the return in case a finally 1598 * is expanded (with unwind()) in the middle of our bytecodes. 1599 */ 1600 int tmpPos = code.pendingStatPos; 1601 if (tree.expr != null) { 1602 Assert.check(code.state.stacksize == 0); 1603 Item r = genExpr(tree.expr, pt).load(); 1604 if (hasFinally(env.enclMethod, env)) { 1605 r = makeTemp(pt); 1606 r.store(); 1607 } 1608 targetEnv = unwind(env.enclMethod, env); 1609 code.pendingStatPos = tmpPos; 1610 r.load(); 1611 code.emitop0(ireturn + Code.truncate(Code.typecode(pt))); 1612 } else { 1613 targetEnv = unwind(env.enclMethod, env); 1614 code.pendingStatPos = tmpPos; 1615 code.emitop0(return_); 1616 } 1617 endFinalizerGaps(env, targetEnv); 1618 code.endScopes(limit); 1619 } 1620 1621 public void visitThrow(JCThrow tree) { 1622 Assert.check(code.state.stacksize == 0); 1623 genExpr(tree.expr, tree.expr.type).load(); 1624 code.emitop0(athrow); 1625 Assert.check(code.state.stacksize == 0); 1626 } 1627 1628/* ************************************************************************ 1629 * Visitor methods for expressions 1630 *************************************************************************/ 1631 1632 public void visitApply(JCMethodInvocation tree) { 1633 setTypeAnnotationPositions(tree.pos); 1634 // Generate code for method. 1635 Item m = genExpr(tree.meth, methodType); 1636 // Generate code for all arguments, where the expected types are 1637 // the parameters of the method's external type (that is, any implicit 1638 // outer instance of a super(...) call appears as first parameter). 1639 MethodSymbol msym = (MethodSymbol)TreeInfo.symbol(tree.meth); 1640 genArgs(tree.args, 1641 msym.externalType(types).getParameterTypes()); 1642 if (!msym.isDynamic()) { 1643 code.statBegin(tree.pos); 1644 } 1645 result = m.invoke(); 1646 } 1647 1648 public void visitConditional(JCConditional tree) { 1649 Chain thenExit = null; 1650 CondItem c = genCond(tree.cond, CRT_FLOW_CONTROLLER); 1651 Chain elseChain = c.jumpFalse(); 1652 if (!c.isFalse()) { 1653 code.resolve(c.trueJumps); 1654 int startpc = genCrt ? code.curCP() : 0; 1655 code.statBegin(tree.truepart.pos); 1656 genExpr(tree.truepart, pt).load(); 1657 code.state.forceStackTop(tree.type); 1658 if (genCrt) code.crt.put(tree.truepart, CRT_FLOW_TARGET, 1659 startpc, code.curCP()); 1660 thenExit = code.branch(goto_); 1661 } 1662 if (elseChain != null) { 1663 code.resolve(elseChain); 1664 int startpc = genCrt ? code.curCP() : 0; 1665 code.statBegin(tree.falsepart.pos); 1666 genExpr(tree.falsepart, pt).load(); 1667 code.state.forceStackTop(tree.type); 1668 if (genCrt) code.crt.put(tree.falsepart, CRT_FLOW_TARGET, 1669 startpc, code.curCP()); 1670 } 1671 code.resolve(thenExit); 1672 result = items.makeStackItem(pt); 1673 } 1674 1675 private void setTypeAnnotationPositions(int treePos) { 1676 MethodSymbol meth = code.meth; 1677 boolean initOrClinit = code.meth.getKind() == javax.lang.model.element.ElementKind.CONSTRUCTOR 1678 || code.meth.getKind() == javax.lang.model.element.ElementKind.STATIC_INIT; 1679 1680 for (Attribute.TypeCompound ta : meth.getRawTypeAttributes()) { 1681 if (ta.hasUnknownPosition()) 1682 ta.tryFixPosition(); 1683 1684 if (ta.position.matchesPos(treePos)) 1685 ta.position.updatePosOffset(code.cp); 1686 } 1687 1688 if (!initOrClinit) 1689 return; 1690 1691 for (Attribute.TypeCompound ta : meth.owner.getRawTypeAttributes()) { 1692 if (ta.hasUnknownPosition()) 1693 ta.tryFixPosition(); 1694 1695 if (ta.position.matchesPos(treePos)) 1696 ta.position.updatePosOffset(code.cp); 1697 } 1698 1699 ClassSymbol clazz = meth.enclClass(); 1700 for (Symbol s : new com.sun.tools.javac.model.FilteredMemberList(clazz.members())) { 1701 if (!s.getKind().isField()) 1702 continue; 1703 1704 for (Attribute.TypeCompound ta : s.getRawTypeAttributes()) { 1705 if (ta.hasUnknownPosition()) 1706 ta.tryFixPosition(); 1707 1708 if (ta.position.matchesPos(treePos)) 1709 ta.position.updatePosOffset(code.cp); 1710 } 1711 } 1712 } 1713 1714 public void visitNewClass(JCNewClass tree) { 1715 // Enclosing instances or anonymous classes should have been eliminated 1716 // by now. 1717 Assert.check(tree.encl == null && tree.def == null); 1718 setTypeAnnotationPositions(tree.pos); 1719 1720 code.emitop2(new_, makeRef(tree.pos(), tree.type)); 1721 code.emitop0(dup); 1722 1723 // Generate code for all arguments, where the expected types are 1724 // the parameters of the constructor's external type (that is, 1725 // any implicit outer instance appears as first parameter). 1726 genArgs(tree.args, tree.constructor.externalType(types).getParameterTypes()); 1727 1728 items.makeMemberItem(tree.constructor, true).invoke(); 1729 result = items.makeStackItem(tree.type); 1730 } 1731 1732 public void visitNewArray(JCNewArray tree) { 1733 setTypeAnnotationPositions(tree.pos); 1734 1735 if (tree.elems != null) { 1736 Type elemtype = types.elemtype(tree.type); 1737 loadIntConst(tree.elems.length()); 1738 Item arr = makeNewArray(tree.pos(), tree.type, 1); 1739 int i = 0; 1740 for (List<JCExpression> l = tree.elems; l.nonEmpty(); l = l.tail) { 1741 arr.duplicate(); 1742 loadIntConst(i); 1743 i++; 1744 genExpr(l.head, elemtype).load(); 1745 items.makeIndexedItem(elemtype).store(); 1746 } 1747 result = arr; 1748 } else { 1749 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) { 1750 genExpr(l.head, syms.intType).load(); 1751 } 1752 result = makeNewArray(tree.pos(), tree.type, tree.dims.length()); 1753 } 1754 } 1755//where 1756 /** Generate code to create an array with given element type and number 1757 * of dimensions. 1758 */ 1759 Item makeNewArray(DiagnosticPosition pos, Type type, int ndims) { 1760 Type elemtype = types.elemtype(type); 1761 if (types.dimensions(type) > ClassFile.MAX_DIMENSIONS) { 1762 log.error(pos, "limit.dimensions"); 1763 nerrs++; 1764 } 1765 int elemcode = Code.arraycode(elemtype); 1766 if (elemcode == 0 || (elemcode == 1 && ndims == 1)) { 1767 code.emitAnewarray(makeRef(pos, elemtype), type); 1768 } else if (elemcode == 1) { 1769 code.emitMultianewarray(ndims, makeRef(pos, type), type); 1770 } else { 1771 code.emitNewarray(elemcode, type); 1772 } 1773 return items.makeStackItem(type); 1774 } 1775 1776 public void visitParens(JCParens tree) { 1777 result = genExpr(tree.expr, tree.expr.type); 1778 } 1779 1780 public void visitAssign(JCAssign tree) { 1781 Item l = genExpr(tree.lhs, tree.lhs.type); 1782 genExpr(tree.rhs, tree.lhs.type).load(); 1783 if (tree.rhs.type.hasTag(BOT)) { 1784 /* This is just a case of widening reference conversion that per 5.1.5 simply calls 1785 for "regarding a reference as having some other type in a manner that can be proved 1786 correct at compile time." 1787 */ 1788 code.state.forceStackTop(tree.lhs.type); 1789 } 1790 result = items.makeAssignItem(l); 1791 } 1792 1793 public void visitAssignop(JCAssignOp tree) { 1794 OperatorSymbol operator = (OperatorSymbol) tree.operator; 1795 Item l; 1796 if (operator.opcode == string_add) { 1797 l = concat.makeConcat(tree); 1798 } else { 1799 // Generate code for first expression 1800 l = genExpr(tree.lhs, tree.lhs.type); 1801 1802 // If we have an increment of -32768 to +32767 of a local 1803 // int variable we can use an incr instruction instead of 1804 // proceeding further. 1805 if ((tree.hasTag(PLUS_ASG) || tree.hasTag(MINUS_ASG)) && 1806 l instanceof LocalItem && 1807 tree.lhs.type.getTag().isSubRangeOf(INT) && 1808 tree.rhs.type.getTag().isSubRangeOf(INT) && 1809 tree.rhs.type.constValue() != null) { 1810 int ival = ((Number) tree.rhs.type.constValue()).intValue(); 1811 if (tree.hasTag(MINUS_ASG)) ival = -ival; 1812 ((LocalItem)l).incr(ival); 1813 result = l; 1814 return; 1815 } 1816 // Otherwise, duplicate expression, load one copy 1817 // and complete binary operation. 1818 l.duplicate(); 1819 l.coerce(operator.type.getParameterTypes().head).load(); 1820 completeBinop(tree.lhs, tree.rhs, operator).coerce(tree.lhs.type); 1821 } 1822 result = items.makeAssignItem(l); 1823 } 1824 1825 public void visitUnary(JCUnary tree) { 1826 OperatorSymbol operator = (OperatorSymbol)tree.operator; 1827 if (tree.hasTag(NOT)) { 1828 CondItem od = genCond(tree.arg, false); 1829 result = od.negate(); 1830 } else { 1831 Item od = genExpr(tree.arg, operator.type.getParameterTypes().head); 1832 switch (tree.getTag()) { 1833 case POS: 1834 result = od.load(); 1835 break; 1836 case NEG: 1837 result = od.load(); 1838 code.emitop0(operator.opcode); 1839 break; 1840 case COMPL: 1841 result = od.load(); 1842 emitMinusOne(od.typecode); 1843 code.emitop0(operator.opcode); 1844 break; 1845 case PREINC: case PREDEC: 1846 od.duplicate(); 1847 if (od instanceof LocalItem && 1848 (operator.opcode == iadd || operator.opcode == isub)) { 1849 ((LocalItem)od).incr(tree.hasTag(PREINC) ? 1 : -1); 1850 result = od; 1851 } else { 1852 od.load(); 1853 code.emitop0(one(od.typecode)); 1854 code.emitop0(operator.opcode); 1855 // Perform narrowing primitive conversion if byte, 1856 // char, or short. Fix for 4304655. 1857 if (od.typecode != INTcode && 1858 Code.truncate(od.typecode) == INTcode) 1859 code.emitop0(int2byte + od.typecode - BYTEcode); 1860 result = items.makeAssignItem(od); 1861 } 1862 break; 1863 case POSTINC: case POSTDEC: 1864 od.duplicate(); 1865 if (od instanceof LocalItem && 1866 (operator.opcode == iadd || operator.opcode == isub)) { 1867 Item res = od.load(); 1868 ((LocalItem)od).incr(tree.hasTag(POSTINC) ? 1 : -1); 1869 result = res; 1870 } else { 1871 Item res = od.load(); 1872 od.stash(od.typecode); 1873 code.emitop0(one(od.typecode)); 1874 code.emitop0(operator.opcode); 1875 // Perform narrowing primitive conversion if byte, 1876 // char, or short. Fix for 4304655. 1877 if (od.typecode != INTcode && 1878 Code.truncate(od.typecode) == INTcode) 1879 code.emitop0(int2byte + od.typecode - BYTEcode); 1880 od.store(); 1881 result = res; 1882 } 1883 break; 1884 case NULLCHK: 1885 result = od.load(); 1886 code.emitop0(dup); 1887 genNullCheck(tree.pos()); 1888 break; 1889 default: 1890 Assert.error(); 1891 } 1892 } 1893 } 1894 1895 /** Generate a null check from the object value at stack top. */ 1896 private void genNullCheck(DiagnosticPosition pos) { 1897 if (allowBetterNullChecks) { 1898 callMethod(pos, syms.objectsType, names.requireNonNull, 1899 List.of(syms.objectType), true); 1900 } else { 1901 callMethod(pos, syms.objectType, names.getClass, 1902 List.<Type>nil(), false); 1903 } 1904 code.emitop0(pop); 1905 } 1906 1907 public void visitBinary(JCBinary tree) { 1908 OperatorSymbol operator = (OperatorSymbol)tree.operator; 1909 if (operator.opcode == string_add) { 1910 result = concat.makeConcat(tree); 1911 } else if (tree.hasTag(AND)) { 1912 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER); 1913 if (!lcond.isFalse()) { 1914 Chain falseJumps = lcond.jumpFalse(); 1915 code.resolve(lcond.trueJumps); 1916 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET); 1917 result = items. 1918 makeCondItem(rcond.opcode, 1919 rcond.trueJumps, 1920 Code.mergeChains(falseJumps, 1921 rcond.falseJumps)); 1922 } else { 1923 result = lcond; 1924 } 1925 } else if (tree.hasTag(OR)) { 1926 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER); 1927 if (!lcond.isTrue()) { 1928 Chain trueJumps = lcond.jumpTrue(); 1929 code.resolve(lcond.falseJumps); 1930 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET); 1931 result = items. 1932 makeCondItem(rcond.opcode, 1933 Code.mergeChains(trueJumps, rcond.trueJumps), 1934 rcond.falseJumps); 1935 } else { 1936 result = lcond; 1937 } 1938 } else { 1939 Item od = genExpr(tree.lhs, operator.type.getParameterTypes().head); 1940 od.load(); 1941 result = completeBinop(tree.lhs, tree.rhs, operator); 1942 } 1943 } 1944 1945 1946 /** Complete generating code for operation, with left operand 1947 * already on stack. 1948 * @param lhs The tree representing the left operand. 1949 * @param rhs The tree representing the right operand. 1950 * @param operator The operator symbol. 1951 */ 1952 Item completeBinop(JCTree lhs, JCTree rhs, OperatorSymbol operator) { 1953 MethodType optype = (MethodType)operator.type; 1954 int opcode = operator.opcode; 1955 if (opcode >= if_icmpeq && opcode <= if_icmple && 1956 rhs.type.constValue() instanceof Number && 1957 ((Number) rhs.type.constValue()).intValue() == 0) { 1958 opcode = opcode + (ifeq - if_icmpeq); 1959 } else if (opcode >= if_acmpeq && opcode <= if_acmpne && 1960 TreeInfo.isNull(rhs)) { 1961 opcode = opcode + (if_acmp_null - if_acmpeq); 1962 } else { 1963 // The expected type of the right operand is 1964 // the second parameter type of the operator, except for 1965 // shifts with long shiftcount, where we convert the opcode 1966 // to a short shift and the expected type to int. 1967 Type rtype = operator.erasure(types).getParameterTypes().tail.head; 1968 if (opcode >= ishll && opcode <= lushrl) { 1969 opcode = opcode + (ishl - ishll); 1970 rtype = syms.intType; 1971 } 1972 // Generate code for right operand and load. 1973 genExpr(rhs, rtype).load(); 1974 // If there are two consecutive opcode instructions, 1975 // emit the first now. 1976 if (opcode >= (1 << preShift)) { 1977 code.emitop0(opcode >> preShift); 1978 opcode = opcode & 0xFF; 1979 } 1980 } 1981 if (opcode >= ifeq && opcode <= if_acmpne || 1982 opcode == if_acmp_null || opcode == if_acmp_nonnull) { 1983 return items.makeCondItem(opcode); 1984 } else { 1985 code.emitop0(opcode); 1986 return items.makeStackItem(optype.restype); 1987 } 1988 } 1989 1990 public void visitTypeCast(JCTypeCast tree) { 1991 result = genExpr(tree.expr, tree.clazz.type).load(); 1992 setTypeAnnotationPositions(tree.pos); 1993 // Additional code is only needed if we cast to a reference type 1994 // which is not statically a supertype of the expression's type. 1995 // For basic types, the coerce(...) in genExpr(...) will do 1996 // the conversion. 1997 if (!tree.clazz.type.isPrimitive() && 1998 !types.isSameType(tree.expr.type, tree.clazz.type) && 1999 types.asSuper(tree.expr.type, tree.clazz.type.tsym) == null) { 2000 code.emitop2(checkcast, makeRef(tree.pos(), tree.clazz.type)); 2001 } 2002 } 2003 2004 public void visitWildcard(JCWildcard tree) { 2005 throw new AssertionError(this.getClass().getName()); 2006 } 2007 2008 public void visitTypeTest(JCInstanceOf tree) { 2009 genExpr(tree.expr, tree.expr.type).load(); 2010 setTypeAnnotationPositions(tree.pos); 2011 code.emitop2(instanceof_, makeRef(tree.pos(), tree.clazz.type)); 2012 result = items.makeStackItem(syms.booleanType); 2013 } 2014 2015 public void visitIndexed(JCArrayAccess tree) { 2016 genExpr(tree.indexed, tree.indexed.type).load(); 2017 genExpr(tree.index, syms.intType).load(); 2018 result = items.makeIndexedItem(tree.type); 2019 } 2020 2021 public void visitIdent(JCIdent tree) { 2022 Symbol sym = tree.sym; 2023 if (tree.name == names._this || tree.name == names._super) { 2024 Item res = tree.name == names._this 2025 ? items.makeThisItem() 2026 : items.makeSuperItem(); 2027 if (sym.kind == MTH) { 2028 // Generate code to address the constructor. 2029 res.load(); 2030 res = items.makeMemberItem(sym, true); 2031 } 2032 result = res; 2033 } else if (sym.kind == VAR && sym.owner.kind == MTH) { 2034 result = items.makeLocalItem((VarSymbol)sym); 2035 } else if (isInvokeDynamic(sym)) { 2036 result = items.makeDynamicItem(sym); 2037 } else if ((sym.flags() & STATIC) != 0) { 2038 if (!isAccessSuper(env.enclMethod)) 2039 sym = binaryQualifier(sym, env.enclClass.type); 2040 result = items.makeStaticItem(sym); 2041 } else { 2042 items.makeThisItem().load(); 2043 sym = binaryQualifier(sym, env.enclClass.type); 2044 result = items.makeMemberItem(sym, (sym.flags() & PRIVATE) != 0); 2045 } 2046 } 2047 2048 public void visitSelect(JCFieldAccess tree) { 2049 Symbol sym = tree.sym; 2050 2051 if (tree.name == names._class) { 2052 code.emitLdc(makeRef(tree.pos(), tree.selected.type)); 2053 result = items.makeStackItem(pt); 2054 return; 2055 } 2056 2057 Symbol ssym = TreeInfo.symbol(tree.selected); 2058 2059 // Are we selecting via super? 2060 boolean selectSuper = 2061 ssym != null && (ssym.kind == TYP || ssym.name == names._super); 2062 2063 // Are we accessing a member of the superclass in an access method 2064 // resulting from a qualified super? 2065 boolean accessSuper = isAccessSuper(env.enclMethod); 2066 2067 Item base = (selectSuper) 2068 ? items.makeSuperItem() 2069 : genExpr(tree.selected, tree.selected.type); 2070 2071 if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) { 2072 // We are seeing a variable that is constant but its selecting 2073 // expression is not. 2074 if ((sym.flags() & STATIC) != 0) { 2075 if (!selectSuper && (ssym == null || ssym.kind != TYP)) 2076 base = base.load(); 2077 base.drop(); 2078 } else { 2079 base.load(); 2080 genNullCheck(tree.selected.pos()); 2081 } 2082 result = items. 2083 makeImmediateItem(sym.type, ((VarSymbol) sym).getConstValue()); 2084 } else { 2085 if (isInvokeDynamic(sym)) { 2086 result = items.makeDynamicItem(sym); 2087 return; 2088 } else { 2089 sym = binaryQualifier(sym, tree.selected.type); 2090 } 2091 if ((sym.flags() & STATIC) != 0) { 2092 if (!selectSuper && (ssym == null || ssym.kind != TYP)) 2093 base = base.load(); 2094 base.drop(); 2095 result = items.makeStaticItem(sym); 2096 } else { 2097 base.load(); 2098 if (sym == syms.lengthVar) { 2099 code.emitop0(arraylength); 2100 result = items.makeStackItem(syms.intType); 2101 } else { 2102 result = items. 2103 makeMemberItem(sym, 2104 (sym.flags() & PRIVATE) != 0 || 2105 selectSuper || accessSuper); 2106 } 2107 } 2108 } 2109 } 2110 2111 public boolean isInvokeDynamic(Symbol sym) { 2112 return sym.kind == MTH && ((MethodSymbol)sym).isDynamic(); 2113 } 2114 2115 public void visitLiteral(JCLiteral tree) { 2116 if (tree.type.hasTag(BOT)) { 2117 code.emitop0(aconst_null); 2118 result = items.makeStackItem(tree.type); 2119 } 2120 else 2121 result = items.makeImmediateItem(tree.type, tree.value); 2122 } 2123 2124 public void visitLetExpr(LetExpr tree) { 2125 letExprDepth++; 2126 int limit = code.nextreg; 2127 genStats(tree.defs, env); 2128 result = genExpr(tree.expr, tree.expr.type).load(); 2129 code.endScopes(limit); 2130 letExprDepth--; 2131 } 2132 2133 private void generateReferencesToPrunedTree(ClassSymbol classSymbol, Pool pool) { 2134 List<JCTree> prunedInfo = lower.prunedTree.get(classSymbol); 2135 if (prunedInfo != null) { 2136 for (JCTree prunedTree: prunedInfo) { 2137 prunedTree.accept(classReferenceVisitor); 2138 } 2139 } 2140 } 2141 2142/* ************************************************************************ 2143 * main method 2144 *************************************************************************/ 2145 2146 /** Generate code for a class definition. 2147 * @param env The attribution environment that belongs to the 2148 * outermost class containing this class definition. 2149 * We need this for resolving some additional symbols. 2150 * @param cdef The tree representing the class definition. 2151 * @return True if code is generated with no errors. 2152 */ 2153 public boolean genClass(Env<AttrContext> env, JCClassDecl cdef) { 2154 try { 2155 attrEnv = env; 2156 ClassSymbol c = cdef.sym; 2157 this.toplevel = env.toplevel; 2158 this.endPosTable = toplevel.endPositions; 2159 c.pool = pool; 2160 pool.reset(); 2161 /* method normalizeDefs() can add references to external classes into the constant pool 2162 */ 2163 cdef.defs = normalizeDefs(cdef.defs, c); 2164 generateReferencesToPrunedTree(c, pool); 2165 Env<GenContext> localEnv = new Env<>(cdef, new GenContext()); 2166 localEnv.toplevel = env.toplevel; 2167 localEnv.enclClass = cdef; 2168 2169 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) { 2170 genDef(l.head, localEnv); 2171 } 2172 if (pool.numEntries() > Pool.MAX_ENTRIES) { 2173 log.error(cdef.pos(), "limit.pool"); 2174 nerrs++; 2175 } 2176 if (nerrs != 0) { 2177 // if errors, discard code 2178 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) { 2179 if (l.head.hasTag(METHODDEF)) 2180 ((JCMethodDecl) l.head).sym.code = null; 2181 } 2182 } 2183 cdef.defs = List.nil(); // discard trees 2184 return nerrs == 0; 2185 } finally { 2186 // note: this method does NOT support recursion. 2187 attrEnv = null; 2188 this.env = null; 2189 toplevel = null; 2190 endPosTable = null; 2191 nerrs = 0; 2192 } 2193 } 2194 2195/* ************************************************************************ 2196 * Auxiliary classes 2197 *************************************************************************/ 2198 2199 /** An abstract class for finalizer generation. 2200 */ 2201 abstract class GenFinalizer { 2202 /** Generate code to clean up when unwinding. */ 2203 abstract void gen(); 2204 2205 /** Generate code to clean up at last. */ 2206 abstract void genLast(); 2207 2208 /** Does this finalizer have some nontrivial cleanup to perform? */ 2209 boolean hasFinalizer() { return true; } 2210 } 2211 2212 /** code generation contexts, 2213 * to be used as type parameter for environments. 2214 */ 2215 static class GenContext { 2216 2217 /** A chain for all unresolved jumps that exit the current environment. 2218 */ 2219 Chain exit = null; 2220 2221 /** A chain for all unresolved jumps that continue in the 2222 * current environment. 2223 */ 2224 Chain cont = null; 2225 2226 /** A closure that generates the finalizer of the current environment. 2227 * Only set for Synchronized and Try contexts. 2228 */ 2229 GenFinalizer finalize = null; 2230 2231 /** Is this a switch statement? If so, allocate registers 2232 * even when the variable declaration is unreachable. 2233 */ 2234 boolean isSwitch = false; 2235 2236 /** A list buffer containing all gaps in the finalizer range, 2237 * where a catch all exception should not apply. 2238 */ 2239 ListBuffer<Integer> gaps = null; 2240 2241 /** Add given chain to exit chain. 2242 */ 2243 void addExit(Chain c) { 2244 exit = Code.mergeChains(c, exit); 2245 } 2246 2247 /** Add given chain to cont chain. 2248 */ 2249 void addCont(Chain c) { 2250 cont = Code.mergeChains(c, cont); 2251 } 2252 } 2253 2254} 2255