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