Gen.java revision 2877:62e285806e83
1/* 2 * Copyright (c) 1999, 2015, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26package com.sun.tools.javac.jvm; 27 28import java.util.*; 29 30import com.sun.tools.javac.util.*; 31import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition; 32import com.sun.tools.javac.util.List; 33import com.sun.tools.javac.code.*; 34import com.sun.tools.javac.code.Attribute.TypeCompound; 35import com.sun.tools.javac.code.Symbol.VarSymbol; 36import com.sun.tools.javac.comp.*; 37import com.sun.tools.javac.tree.*; 38 39import com.sun.tools.javac.code.Symbol.*; 40import com.sun.tools.javac.code.Type.*; 41import com.sun.tools.javac.jvm.Code.*; 42import com.sun.tools.javac.jvm.Items.*; 43import com.sun.tools.javac.tree.EndPosTable; 44import com.sun.tools.javac.tree.JCTree.*; 45 46import static com.sun.tools.javac.code.Flags.*; 47import static com.sun.tools.javac.code.Kinds.Kind.*; 48import static com.sun.tools.javac.code.Scope.LookupKind.NON_RECURSIVE; 49import static com.sun.tools.javac.code.TypeTag.*; 50import static com.sun.tools.javac.jvm.ByteCodes.*; 51import static com.sun.tools.javac.jvm.CRTFlags.*; 52import static com.sun.tools.javac.main.Option.*; 53import static com.sun.tools.javac.tree.JCTree.Tag.*; 54 55/** This pass maps flat Java (i.e. without inner classes) to bytecodes. 56 * 57 * <p><b>This is NOT part of any supported API. 58 * If you write code that depends on this, you do so at your own risk. 59 * This code and its internal interfaces are subject to change or 60 * deletion without notice.</b> 61 */ 62public class Gen extends JCTree.Visitor { 63 protected static final Context.Key<Gen> genKey = new Context.Key<>(); 64 65 private final Log log; 66 private final Symtab syms; 67 private final Check chk; 68 private final Resolve rs; 69 private final TreeMaker make; 70 private final Names names; 71 private final Target target; 72 private final Type stringBufferType; 73 private final Map<Type,Symbol> stringBufferAppend; 74 private Name accessDollar; 75 private final Types types; 76 private final Lower lower; 77 private final Flow flow; 78 private final Annotate annotate; 79 80 /** Format of stackmap tables to be generated. */ 81 private final Code.StackMapFormat stackMap; 82 83 /** A type that serves as the expected type for all method expressions. 84 */ 85 private final Type methodType; 86 87 public static Gen instance(Context context) { 88 Gen instance = context.get(genKey); 89 if (instance == null) 90 instance = new Gen(context); 91 return instance; 92 } 93 94 /** Constant pool, reset by genClass. 95 */ 96 private Pool pool; 97 98 protected Gen(Context context) { 99 context.put(genKey, this); 100 101 names = Names.instance(context); 102 log = Log.instance(context); 103 syms = Symtab.instance(context); 104 chk = Check.instance(context); 105 rs = Resolve.instance(context); 106 make = TreeMaker.instance(context); 107 target = Target.instance(context); 108 types = Types.instance(context); 109 methodType = new MethodType(null, null, null, syms.methodClass); 110 stringBufferType = syms.stringBuilderType; 111 stringBufferAppend = new HashMap<>(); 112 accessDollar = names. 113 fromString("access" + target.syntheticNameChar()); 114 flow = Flow.instance(context); 115 lower = Lower.instance(context); 116 117 Options options = Options.instance(context); 118 lineDebugInfo = 119 options.isUnset(G_CUSTOM) || 120 options.isSet(G_CUSTOM, "lines"); 121 varDebugInfo = 122 options.isUnset(G_CUSTOM) 123 ? options.isSet(G) 124 : options.isSet(G_CUSTOM, "vars"); 125 genCrt = options.isSet(XJCOV); 126 debugCode = options.isSet("debugcode"); 127 allowInvokedynamic = target.hasInvokedynamic() || options.isSet("invokedynamic"); 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; 133 134 // by default, avoid jsr's for simple finalizers 135 int setjsrlimit = 50; 136 String jsrlimitString = options.get("jsrlimit"); 137 if (jsrlimitString != null) { 138 try { 139 setjsrlimit = Integer.parseInt(jsrlimitString); 140 } catch (NumberFormatException ex) { 141 // ignore ill-formed numbers for jsrlimit 142 } 143 } 144 this.jsrlimit = setjsrlimit; 145 this.useJsrLocally = false; // reset in visitTry 146 annotate = Annotate.instance(context); 147 } 148 149 /** Switches 150 */ 151 private final boolean lineDebugInfo; 152 private final boolean varDebugInfo; 153 private final boolean genCrt; 154 private final boolean debugCode; 155 private final boolean allowInvokedynamic; 156 private final boolean allowBetterNullChecks; 157 158 /** Default limit of (approximate) size of finalizer to inline. 159 * Zero means always use jsr. 100 or greater means never use 160 * jsr. 161 */ 162 private final int jsrlimit; 163 164 /** True if jsr is used. 165 */ 166 private boolean useJsrLocally; 167 168 /** Code buffer, set by genMethod. 169 */ 170 private Code code; 171 172 /** Items structure, set by genMethod. 173 */ 174 private Items items; 175 176 /** Environment for symbol lookup, set by genClass 177 */ 178 private Env<AttrContext> attrEnv; 179 180 /** The top level tree. 181 */ 182 private JCCompilationUnit toplevel; 183 184 /** The number of code-gen errors in this class. 185 */ 186 private int nerrs = 0; 187 188 /** An object containing mappings of syntax trees to their 189 * ending source positions. 190 */ 191 EndPosTable endPosTable; 192 193 /** Generate code to load an integer constant. 194 * @param n The integer to be loaded. 195 */ 196 void loadIntConst(int n) { 197 items.makeImmediateItem(syms.intType, n).load(); 198 } 199 200 /** The opcode that loads a zero constant of a given type code. 201 * @param tc The given type code (@see ByteCode). 202 */ 203 public static int zero(int tc) { 204 switch(tc) { 205 case INTcode: case BYTEcode: case SHORTcode: case CHARcode: 206 return iconst_0; 207 case LONGcode: 208 return lconst_0; 209 case FLOATcode: 210 return fconst_0; 211 case DOUBLEcode: 212 return dconst_0; 213 default: 214 throw new AssertionError("zero"); 215 } 216 } 217 218 /** The opcode that loads a one constant of a given type code. 219 * @param tc The given type code (@see ByteCode). 220 */ 221 public static int one(int tc) { 222 return zero(tc) + 1; 223 } 224 225 /** Generate code to load -1 of the given type code (either int or long). 226 * @param tc The given type code (@see ByteCode). 227 */ 228 void emitMinusOne(int tc) { 229 if (tc == LONGcode) { 230 items.makeImmediateItem(syms.longType, new Long(-1)).load(); 231 } else { 232 code.emitop0(iconst_m1); 233 } 234 } 235 236 /** Construct a symbol to reflect the qualifying type that should 237 * appear in the byte code as per JLS 13.1. 238 * 239 * For {@literal target >= 1.2}: Clone a method with the qualifier as owner (except 240 * for those cases where we need to work around VM bugs). 241 * 242 * For {@literal target <= 1.1}: If qualified variable or method is defined in a 243 * non-accessible class, clone it with the qualifier class as owner. 244 * 245 * @param sym The accessed symbol 246 * @param site The qualifier's type. 247 */ 248 Symbol binaryQualifier(Symbol sym, Type site) { 249 250 if (site.hasTag(ARRAY)) { 251 if (sym == syms.lengthVar || 252 sym.owner != syms.arrayClass) 253 return sym; 254 // array clone can be qualified by the array type in later targets 255 Symbol qualifier = new ClassSymbol(Flags.PUBLIC, site.tsym.name, 256 site, syms.noSymbol); 257 return sym.clone(qualifier); 258 } 259 260 if (sym.owner == site.tsym || 261 (sym.flags() & (STATIC | SYNTHETIC)) == (STATIC | SYNTHETIC)) { 262 return sym; 263 } 264 265 // leave alone methods inherited from Object 266 // JLS 13.1. 267 if (sym.owner == syms.objectType.tsym) 268 return sym; 269 270 return sym.clone(site.tsym); 271 } 272 273 /** Insert a reference to given type in the constant pool, 274 * checking for an array with too many dimensions; 275 * return the reference's index. 276 * @param type The type for which a reference is inserted. 277 */ 278 int makeRef(DiagnosticPosition pos, Type type) { 279 checkDimension(pos, type); 280 if (type.isAnnotated()) { 281 return pool.put((Object)type); 282 } else { 283 return pool.put(type.hasTag(CLASS) ? (Object)type.tsym : (Object)type); 284 } 285 } 286 287 /** Check if the given type is an array with too many dimensions. 288 */ 289 private void checkDimension(DiagnosticPosition pos, Type t) { 290 switch (t.getTag()) { 291 case METHOD: 292 checkDimension(pos, t.getReturnType()); 293 for (List<Type> args = t.getParameterTypes(); args.nonEmpty(); args = args.tail) 294 checkDimension(pos, args.head); 295 break; 296 case ARRAY: 297 if (types.dimensions(t) > ClassFile.MAX_DIMENSIONS) { 298 log.error(pos, "limit.dimensions"); 299 nerrs++; 300 } 301 break; 302 default: 303 break; 304 } 305 } 306 307 /** Create a tempory variable. 308 * @param type The variable's type. 309 */ 310 LocalItem makeTemp(Type type) { 311 VarSymbol v = new VarSymbol(Flags.SYNTHETIC, 312 names.empty, 313 type, 314 env.enclMethod.sym); 315 code.newLocal(v); 316 return items.makeLocalItem(v); 317 } 318 319 /** Generate code to call a non-private method or constructor. 320 * @param pos Position to be used for error reporting. 321 * @param site The type of which the method is a member. 322 * @param name The method's name. 323 * @param argtypes The method's argument types. 324 * @param isStatic A flag that indicates whether we call a 325 * static or instance method. 326 */ 327 void callMethod(DiagnosticPosition pos, 328 Type site, Name name, List<Type> argtypes, 329 boolean isStatic) { 330 Symbol msym = rs. 331 resolveInternalMethod(pos, attrEnv, site, name, argtypes, null); 332 if (isStatic) items.makeStaticItem(msym).invoke(); 333 else items.makeMemberItem(msym, name == names.init).invoke(); 334 } 335 336 /** Is the given method definition an access method 337 * resulting from a qualified super? This is signified by an odd 338 * access code. 339 */ 340 private boolean isAccessSuper(JCMethodDecl enclMethod) { 341 return 342 (enclMethod.mods.flags & SYNTHETIC) != 0 && 343 isOddAccessName(enclMethod.name); 344 } 345 346 /** Does given name start with "access$" and end in an odd digit? 347 */ 348 private boolean isOddAccessName(Name name) { 349 return 350 name.startsWith(accessDollar) && 351 (name.getByteAt(name.getByteLength() - 1) & 1) == 1; 352 } 353 354/* ************************************************************************ 355 * Non-local exits 356 *************************************************************************/ 357 358 /** Generate code to invoke the finalizer associated with given 359 * environment. 360 * Any calls to finalizers are appended to the environments `cont' chain. 361 * Mark beginning of gap in catch all range for finalizer. 362 */ 363 void genFinalizer(Env<GenContext> env) { 364 if (code.isAlive() && env.info.finalize != null) 365 env.info.finalize.gen(); 366 } 367 368 /** Generate code to call all finalizers of structures aborted by 369 * a non-local 370 * exit. Return target environment of the non-local exit. 371 * @param target The tree representing the structure that's aborted 372 * @param env The environment current at the non-local exit. 373 */ 374 Env<GenContext> unwind(JCTree target, Env<GenContext> env) { 375 Env<GenContext> env1 = env; 376 while (true) { 377 genFinalizer(env1); 378 if (env1.tree == target) break; 379 env1 = env1.next; 380 } 381 return env1; 382 } 383 384 /** Mark end of gap in catch-all range for finalizer. 385 * @param env the environment which might contain the finalizer 386 * (if it does, env.info.gaps != null). 387 */ 388 void endFinalizerGap(Env<GenContext> env) { 389 if (env.info.gaps != null && env.info.gaps.length() % 2 == 1) 390 env.info.gaps.append(code.curCP()); 391 } 392 393 /** Mark end of all gaps in catch-all ranges for finalizers of environments 394 * lying between, and including to two environments. 395 * @param from the most deeply nested environment to mark 396 * @param to the least deeply nested environment to mark 397 */ 398 void endFinalizerGaps(Env<GenContext> from, Env<GenContext> to) { 399 Env<GenContext> last = null; 400 while (last != to) { 401 endFinalizerGap(from); 402 last = from; 403 from = from.next; 404 } 405 } 406 407 /** Do any of the structures aborted by a non-local exit have 408 * finalizers that require an empty stack? 409 * @param target The tree representing the structure that's aborted 410 * @param env The environment current at the non-local exit. 411 */ 412 boolean hasFinally(JCTree target, Env<GenContext> env) { 413 while (env.tree != target) { 414 if (env.tree.hasTag(TRY) && env.info.finalize.hasFinalizer()) 415 return true; 416 env = env.next; 417 } 418 return false; 419 } 420 421/* ************************************************************************ 422 * Normalizing class-members. 423 *************************************************************************/ 424 425 /** Distribute member initializer code into constructors and {@code <clinit>} 426 * method. 427 * @param defs The list of class member declarations. 428 * @param c The enclosing class. 429 */ 430 List<JCTree> normalizeDefs(List<JCTree> defs, ClassSymbol c) { 431 ListBuffer<JCStatement> initCode = new ListBuffer<>(); 432 ListBuffer<Attribute.TypeCompound> initTAs = new ListBuffer<>(); 433 ListBuffer<JCStatement> clinitCode = new ListBuffer<>(); 434 ListBuffer<Attribute.TypeCompound> clinitTAs = new ListBuffer<>(); 435 ListBuffer<JCTree> methodDefs = new ListBuffer<>(); 436 // Sort definitions into three listbuffers: 437 // - initCode for instance initializers 438 // - clinitCode for class initializers 439 // - methodDefs for method definitions 440 for (List<JCTree> l = defs; l.nonEmpty(); l = l.tail) { 441 JCTree def = l.head; 442 switch (def.getTag()) { 443 case BLOCK: 444 JCBlock block = (JCBlock)def; 445 if ((block.flags & STATIC) != 0) 446 clinitCode.append(block); 447 else if ((block.flags & SYNTHETIC) == 0) 448 initCode.append(block); 449 break; 450 case METHODDEF: 451 methodDefs.append(def); 452 break; 453 case VARDEF: 454 JCVariableDecl vdef = (JCVariableDecl) def; 455 VarSymbol sym = vdef.sym; 456 checkDimension(vdef.pos(), sym.type); 457 if (vdef.init != null) { 458 if ((sym.flags() & STATIC) == 0) { 459 // Always initialize instance variables. 460 JCStatement init = make.at(vdef.pos()). 461 Assignment(sym, vdef.init); 462 initCode.append(init); 463 endPosTable.replaceTree(vdef, init); 464 initTAs.addAll(getAndRemoveNonFieldTAs(sym)); 465 } else if (sym.getConstValue() == null) { 466 // Initialize class (static) variables only if 467 // they are not compile-time constants. 468 JCStatement init = make.at(vdef.pos). 469 Assignment(sym, vdef.init); 470 clinitCode.append(init); 471 endPosTable.replaceTree(vdef, init); 472 clinitTAs.addAll(getAndRemoveNonFieldTAs(sym)); 473 } else { 474 checkStringConstant(vdef.init.pos(), sym.getConstValue()); 475 } 476 } 477 break; 478 default: 479 Assert.error(); 480 } 481 } 482 // Insert any instance initializers into all constructors. 483 if (initCode.length() != 0) { 484 List<JCStatement> inits = initCode.toList(); 485 initTAs.addAll(c.getInitTypeAttributes()); 486 List<Attribute.TypeCompound> initTAlist = initTAs.toList(); 487 for (JCTree t : methodDefs) { 488 normalizeMethod((JCMethodDecl)t, inits, initTAlist); 489 } 490 } 491 // If there are class initializers, create a <clinit> method 492 // that contains them as its body. 493 if (clinitCode.length() != 0) { 494 MethodSymbol clinit = new MethodSymbol( 495 STATIC | (c.flags() & STRICTFP), 496 names.clinit, 497 new MethodType( 498 List.<Type>nil(), syms.voidType, 499 List.<Type>nil(), syms.methodClass), 500 c); 501 c.members().enter(clinit); 502 List<JCStatement> clinitStats = clinitCode.toList(); 503 JCBlock block = make.at(clinitStats.head.pos()).Block(0, clinitStats); 504 block.endpos = TreeInfo.endPos(clinitStats.last()); 505 methodDefs.append(make.MethodDef(clinit, block)); 506 507 if (!clinitTAs.isEmpty()) 508 clinit.appendUniqueTypeAttributes(clinitTAs.toList()); 509 if (!c.getClassInitTypeAttributes().isEmpty()) 510 clinit.appendUniqueTypeAttributes(c.getClassInitTypeAttributes()); 511 } 512 // Return all method definitions. 513 return methodDefs.toList(); 514 } 515 516 private List<Attribute.TypeCompound> getAndRemoveNonFieldTAs(VarSymbol sym) { 517 List<TypeCompound> tas = sym.getRawTypeAttributes(); 518 ListBuffer<Attribute.TypeCompound> fieldTAs = new ListBuffer<>(); 519 ListBuffer<Attribute.TypeCompound> nonfieldTAs = new ListBuffer<>(); 520 for (TypeCompound ta : tas) { 521 Assert.check(ta.getPosition().type != TargetType.UNKNOWN); 522 if (ta.getPosition().type == TargetType.FIELD) { 523 fieldTAs.add(ta); 524 } else { 525 nonfieldTAs.add(ta); 526 } 527 } 528 sym.setTypeAttributes(fieldTAs.toList()); 529 return nonfieldTAs.toList(); 530 } 531 532 /** Check a constant value and report if it is a string that is 533 * too large. 534 */ 535 private void checkStringConstant(DiagnosticPosition pos, Object constValue) { 536 if (nerrs != 0 || // only complain about a long string once 537 constValue == null || 538 !(constValue instanceof String) || 539 ((String)constValue).length() < Pool.MAX_STRING_LENGTH) 540 return; 541 log.error(pos, "limit.string"); 542 nerrs++; 543 } 544 545 /** Insert instance initializer code into initial constructor. 546 * @param md The tree potentially representing a 547 * constructor's definition. 548 * @param initCode The list of instance initializer statements. 549 * @param initTAs Type annotations from the initializer expression. 550 */ 551 void normalizeMethod(JCMethodDecl md, List<JCStatement> initCode, List<TypeCompound> initTAs) { 552 if (md.name == names.init && TreeInfo.isInitialConstructor(md)) { 553 // We are seeing a constructor that does not call another 554 // constructor of the same class. 555 List<JCStatement> stats = md.body.stats; 556 ListBuffer<JCStatement> newstats = new ListBuffer<>(); 557 558 if (stats.nonEmpty()) { 559 // Copy initializers of synthetic variables generated in 560 // the translation of inner classes. 561 while (TreeInfo.isSyntheticInit(stats.head)) { 562 newstats.append(stats.head); 563 stats = stats.tail; 564 } 565 // Copy superclass constructor call 566 newstats.append(stats.head); 567 stats = stats.tail; 568 // Copy remaining synthetic initializers. 569 while (stats.nonEmpty() && 570 TreeInfo.isSyntheticInit(stats.head)) { 571 newstats.append(stats.head); 572 stats = stats.tail; 573 } 574 // Now insert the initializer code. 575 newstats.appendList(initCode); 576 // And copy all remaining statements. 577 while (stats.nonEmpty()) { 578 newstats.append(stats.head); 579 stats = stats.tail; 580 } 581 } 582 md.body.stats = newstats.toList(); 583 if (md.body.endpos == Position.NOPOS) 584 md.body.endpos = TreeInfo.endPos(md.body.stats.last()); 585 586 md.sym.appendUniqueTypeAttributes(initTAs); 587 } 588 } 589 590/* ************************************************************************ 591 * Traversal methods 592 *************************************************************************/ 593 594 /** Visitor argument: The current environment. 595 */ 596 Env<GenContext> env; 597 598 /** Visitor argument: The expected type (prototype). 599 */ 600 Type pt; 601 602 /** Visitor result: The item representing the computed value. 603 */ 604 Item result; 605 606 /** Visitor method: generate code for a definition, catching and reporting 607 * any completion failures. 608 * @param tree The definition to be visited. 609 * @param env The environment current at the definition. 610 */ 611 public void genDef(JCTree tree, Env<GenContext> env) { 612 Env<GenContext> prevEnv = this.env; 613 try { 614 this.env = env; 615 tree.accept(this); 616 } catch (CompletionFailure ex) { 617 chk.completionError(tree.pos(), ex); 618 } finally { 619 this.env = prevEnv; 620 } 621 } 622 623 /** Derived visitor method: check whether CharacterRangeTable 624 * should be emitted, if so, put a new entry into CRTable 625 * and call method to generate bytecode. 626 * If not, just call method to generate bytecode. 627 * @see #genStat(JCTree, Env) 628 * 629 * @param tree The tree to be visited. 630 * @param env The environment to use. 631 * @param crtFlags The CharacterRangeTable flags 632 * indicating type of the entry. 633 */ 634 public void genStat(JCTree tree, Env<GenContext> env, int crtFlags) { 635 if (!genCrt) { 636 genStat(tree, env); 637 return; 638 } 639 int startpc = code.curCP(); 640 genStat(tree, env); 641 if (tree.hasTag(Tag.BLOCK)) crtFlags |= CRT_BLOCK; 642 code.crt.put(tree, crtFlags, startpc, code.curCP()); 643 } 644 645 /** Derived visitor method: generate code for a statement. 646 */ 647 public void genStat(JCTree tree, Env<GenContext> env) { 648 if (code.isAlive()) { 649 code.statBegin(tree.pos); 650 genDef(tree, env); 651 } else if (env.info.isSwitch && tree.hasTag(VARDEF)) { 652 // variables whose declarations are in a switch 653 // can be used even if the decl is unreachable. 654 code.newLocal(((JCVariableDecl) tree).sym); 655 } 656 } 657 658 /** Derived visitor method: check whether CharacterRangeTable 659 * should be emitted, if so, put a new entry into CRTable 660 * and call method to generate bytecode. 661 * If not, just call method to generate bytecode. 662 * @see #genStats(List, Env) 663 * 664 * @param trees The list of trees to be visited. 665 * @param env The environment to use. 666 * @param crtFlags The CharacterRangeTable flags 667 * indicating type of the entry. 668 */ 669 public void genStats(List<JCStatement> trees, Env<GenContext> env, int crtFlags) { 670 if (!genCrt) { 671 genStats(trees, env); 672 return; 673 } 674 if (trees.length() == 1) { // mark one statement with the flags 675 genStat(trees.head, env, crtFlags | CRT_STATEMENT); 676 } else { 677 int startpc = code.curCP(); 678 genStats(trees, env); 679 code.crt.put(trees, crtFlags, startpc, code.curCP()); 680 } 681 } 682 683 /** Derived visitor method: generate code for a list of statements. 684 */ 685 public void genStats(List<? extends JCTree> trees, Env<GenContext> env) { 686 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail) 687 genStat(l.head, env, CRT_STATEMENT); 688 } 689 690 /** Derived visitor method: check whether CharacterRangeTable 691 * should be emitted, if so, put a new entry into CRTable 692 * and call method to generate bytecode. 693 * If not, just call method to generate bytecode. 694 * @see #genCond(JCTree,boolean) 695 * 696 * @param tree The tree to be visited. 697 * @param crtFlags The CharacterRangeTable flags 698 * indicating type of the entry. 699 */ 700 public CondItem genCond(JCTree tree, int crtFlags) { 701 if (!genCrt) return genCond(tree, false); 702 int startpc = code.curCP(); 703 CondItem item = genCond(tree, (crtFlags & CRT_FLOW_CONTROLLER) != 0); 704 code.crt.put(tree, crtFlags, startpc, code.curCP()); 705 return item; 706 } 707 708 /** Derived visitor method: generate code for a boolean 709 * expression in a control-flow context. 710 * @param _tree The expression to be visited. 711 * @param markBranches The flag to indicate that the condition is 712 * a flow controller so produced conditions 713 * should contain a proper tree to generate 714 * CharacterRangeTable branches for them. 715 */ 716 public CondItem genCond(JCTree _tree, boolean markBranches) { 717 JCTree inner_tree = TreeInfo.skipParens(_tree); 718 if (inner_tree.hasTag(CONDEXPR)) { 719 JCConditional tree = (JCConditional)inner_tree; 720 CondItem cond = genCond(tree.cond, CRT_FLOW_CONTROLLER); 721 if (cond.isTrue()) { 722 code.resolve(cond.trueJumps); 723 CondItem result = genCond(tree.truepart, CRT_FLOW_TARGET); 724 if (markBranches) result.tree = tree.truepart; 725 return result; 726 } 727 if (cond.isFalse()) { 728 code.resolve(cond.falseJumps); 729 CondItem result = genCond(tree.falsepart, CRT_FLOW_TARGET); 730 if (markBranches) result.tree = tree.falsepart; 731 return result; 732 } 733 Chain secondJumps = cond.jumpFalse(); 734 code.resolve(cond.trueJumps); 735 CondItem first = genCond(tree.truepart, CRT_FLOW_TARGET); 736 if (markBranches) first.tree = tree.truepart; 737 Chain falseJumps = first.jumpFalse(); 738 code.resolve(first.trueJumps); 739 Chain trueJumps = code.branch(goto_); 740 code.resolve(secondJumps); 741 CondItem second = genCond(tree.falsepart, CRT_FLOW_TARGET); 742 CondItem result = items.makeCondItem(second.opcode, 743 Code.mergeChains(trueJumps, second.trueJumps), 744 Code.mergeChains(falseJumps, second.falseJumps)); 745 if (markBranches) result.tree = tree.falsepart; 746 return result; 747 } else { 748 CondItem result = genExpr(_tree, syms.booleanType).mkCond(); 749 if (markBranches) result.tree = _tree; 750 return result; 751 } 752 } 753 754 /** Visitor class for expressions which might be constant expressions. 755 * This class is a subset of TreeScanner. Intended to visit trees pruned by 756 * Lower as long as constant expressions looking for references to any 757 * ClassSymbol. Any such reference will be added to the constant pool so 758 * automated tools can detect class dependencies better. 759 */ 760 class ClassReferenceVisitor extends JCTree.Visitor { 761 762 @Override 763 public void visitTree(JCTree tree) {} 764 765 @Override 766 public void visitBinary(JCBinary tree) { 767 tree.lhs.accept(this); 768 tree.rhs.accept(this); 769 } 770 771 @Override 772 public void visitSelect(JCFieldAccess tree) { 773 if (tree.selected.type.hasTag(CLASS)) { 774 makeRef(tree.selected.pos(), tree.selected.type); 775 } 776 } 777 778 @Override 779 public void visitIdent(JCIdent tree) { 780 if (tree.sym.owner instanceof ClassSymbol) { 781 pool.put(tree.sym.owner); 782 } 783 } 784 785 @Override 786 public void visitConditional(JCConditional tree) { 787 tree.cond.accept(this); 788 tree.truepart.accept(this); 789 tree.falsepart.accept(this); 790 } 791 792 @Override 793 public void visitUnary(JCUnary tree) { 794 tree.arg.accept(this); 795 } 796 797 @Override 798 public void visitParens(JCParens tree) { 799 tree.expr.accept(this); 800 } 801 802 @Override 803 public void visitTypeCast(JCTypeCast tree) { 804 tree.expr.accept(this); 805 } 806 } 807 808 private ClassReferenceVisitor classReferenceVisitor = new ClassReferenceVisitor(); 809 810 /** Visitor method: generate code for an expression, catching and reporting 811 * any completion failures. 812 * @param tree The expression to be visited. 813 * @param pt The expression's expected type (proto-type). 814 */ 815 public Item genExpr(JCTree tree, Type pt) { 816 Type prevPt = this.pt; 817 try { 818 if (tree.type.constValue() != null) { 819 // Short circuit any expressions which are constants 820 tree.accept(classReferenceVisitor); 821 checkStringConstant(tree.pos(), tree.type.constValue()); 822 result = items.makeImmediateItem(tree.type, tree.type.constValue()); 823 } else { 824 this.pt = pt; 825 tree.accept(this); 826 } 827 return result.coerce(pt); 828 } catch (CompletionFailure ex) { 829 chk.completionError(tree.pos(), ex); 830 code.state.stacksize = 1; 831 return items.makeStackItem(pt); 832 } finally { 833 this.pt = prevPt; 834 } 835 } 836 837 /** Derived visitor method: generate code for a list of method arguments. 838 * @param trees The argument expressions to be visited. 839 * @param pts The expression's expected types (i.e. the formal parameter 840 * types of the invoked method). 841 */ 842 public void genArgs(List<JCExpression> trees, List<Type> pts) { 843 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail) { 844 genExpr(l.head, pts.head).load(); 845 pts = pts.tail; 846 } 847 // require lists be of same length 848 Assert.check(pts.isEmpty()); 849 } 850 851/* ************************************************************************ 852 * Visitor methods for statements and definitions 853 *************************************************************************/ 854 855 /** Thrown when the byte code size exceeds limit. 856 */ 857 public static class CodeSizeOverflow extends RuntimeException { 858 private static final long serialVersionUID = 0; 859 public CodeSizeOverflow() {} 860 } 861 862 public void visitMethodDef(JCMethodDecl tree) { 863 // Create a new local environment that points pack at method 864 // definition. 865 Env<GenContext> localEnv = env.dup(tree); 866 localEnv.enclMethod = tree; 867 // The expected type of every return statement in this method 868 // is the method's return type. 869 this.pt = tree.sym.erasure(types).getReturnType(); 870 871 checkDimension(tree.pos(), tree.sym.erasure(types)); 872 genMethod(tree, localEnv, false); 873 } 874//where 875 /** Generate code for a method. 876 * @param tree The tree representing the method definition. 877 * @param env The environment current for the method body. 878 * @param fatcode A flag that indicates whether all jumps are 879 * within 32K. We first invoke this method under 880 * the assumption that fatcode == false, i.e. all 881 * jumps are within 32K. If this fails, fatcode 882 * is set to true and we try again. 883 */ 884 void genMethod(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) { 885 MethodSymbol meth = tree.sym; 886 int extras = 0; 887 // Count up extra parameters 888 if (meth.isConstructor()) { 889 extras++; 890 if (meth.enclClass().isInner() && 891 !meth.enclClass().isStatic()) { 892 extras++; 893 } 894 } else if ((tree.mods.flags & STATIC) == 0) { 895 extras++; 896 } 897 // System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG 898 if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes()) + extras > 899 ClassFile.MAX_PARAMETERS) { 900 log.error(tree.pos(), "limit.parameters"); 901 nerrs++; 902 } 903 904 else if (tree.body != null) { 905 // Create a new code structure and initialize it. 906 int startpcCrt = initCode(tree, env, fatcode); 907 908 try { 909 genStat(tree.body, env); 910 } catch (CodeSizeOverflow e) { 911 // Failed due to code limit, try again with jsr/ret 912 startpcCrt = initCode(tree, env, fatcode); 913 genStat(tree.body, env); 914 } 915 916 if (code.state.stacksize != 0) { 917 log.error(tree.body.pos(), "stack.sim.error", tree); 918 throw new AssertionError(); 919 } 920 921 // If last statement could complete normally, insert a 922 // return at the end. 923 if (code.isAlive()) { 924 code.statBegin(TreeInfo.endPos(tree.body)); 925 if (env.enclMethod == null || 926 env.enclMethod.sym.type.getReturnType().hasTag(VOID)) { 927 code.emitop0(return_); 928 } else { 929 // sometime dead code seems alive (4415991); 930 // generate a small loop instead 931 int startpc = code.entryPoint(); 932 CondItem c = items.makeCondItem(goto_); 933 code.resolve(c.jumpTrue(), startpc); 934 } 935 } 936 if (genCrt) 937 code.crt.put(tree.body, 938 CRT_BLOCK, 939 startpcCrt, 940 code.curCP()); 941 942 code.endScopes(0); 943 944 // If we exceeded limits, panic 945 if (code.checkLimits(tree.pos(), log)) { 946 nerrs++; 947 return; 948 } 949 950 // If we generated short code but got a long jump, do it again 951 // with fatCode = true. 952 if (!fatcode && code.fatcode) genMethod(tree, env, true); 953 954 // Clean up 955 if(stackMap == StackMapFormat.JSR202) { 956 code.lastFrame = null; 957 code.frameBeforeLast = null; 958 } 959 960 // Compress exception table 961 code.compressCatchTable(); 962 963 // Fill in type annotation positions for exception parameters 964 code.fillExceptionParameterPositions(); 965 } 966 } 967 968 private int initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) { 969 MethodSymbol meth = tree.sym; 970 971 // Create a new code structure. 972 meth.code = code = new Code(meth, 973 fatcode, 974 lineDebugInfo ? toplevel.lineMap : null, 975 varDebugInfo, 976 stackMap, 977 debugCode, 978 genCrt ? new CRTable(tree, env.toplevel.endPositions) 979 : null, 980 syms, 981 types, 982 pool); 983 items = new Items(pool, code, syms, types); 984 if (code.debugCode) { 985 System.err.println(meth + " for body " + tree); 986 } 987 988 // If method is not static, create a new local variable address 989 // for `this'. 990 if ((tree.mods.flags & STATIC) == 0) { 991 Type selfType = meth.owner.type; 992 if (meth.isConstructor() && selfType != syms.objectType) 993 selfType = UninitializedType.uninitializedThis(selfType); 994 code.setDefined( 995 code.newLocal( 996 new VarSymbol(FINAL, names._this, selfType, meth.owner))); 997 } 998 999 // Mark all parameters as defined from the beginning of 1000 // the method. 1001 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) { 1002 checkDimension(l.head.pos(), l.head.sym.type); 1003 code.setDefined(code.newLocal(l.head.sym)); 1004 } 1005 1006 // Get ready to generate code for method body. 1007 int startpcCrt = genCrt ? code.curCP() : 0; 1008 code.entryPoint(); 1009 1010 // Suppress initial stackmap 1011 code.pendingStackMap = false; 1012 1013 return startpcCrt; 1014 } 1015 1016 public void visitVarDef(JCVariableDecl tree) { 1017 VarSymbol v = tree.sym; 1018 code.newLocal(v); 1019 if (tree.init != null) { 1020 checkStringConstant(tree.init.pos(), v.getConstValue()); 1021 if (v.getConstValue() == null || varDebugInfo) { 1022 genExpr(tree.init, v.erasure(types)).load(); 1023 items.makeLocalItem(v).store(); 1024 } 1025 } 1026 checkDimension(tree.pos(), v.type); 1027 } 1028 1029 public void visitSkip(JCSkip tree) { 1030 } 1031 1032 public void visitBlock(JCBlock tree) { 1033 int limit = code.nextreg; 1034 Env<GenContext> localEnv = env.dup(tree, new GenContext()); 1035 genStats(tree.stats, localEnv); 1036 // End the scope of all block-local variables in variable info. 1037 if (!env.tree.hasTag(METHODDEF)) { 1038 code.statBegin(tree.endpos); 1039 code.endScopes(limit); 1040 code.pendingStatPos = Position.NOPOS; 1041 } 1042 } 1043 1044 public void visitDoLoop(JCDoWhileLoop tree) { 1045 genLoop(tree, tree.body, tree.cond, List.<JCExpressionStatement>nil(), false); 1046 } 1047 1048 public void visitWhileLoop(JCWhileLoop tree) { 1049 genLoop(tree, tree.body, tree.cond, List.<JCExpressionStatement>nil(), true); 1050 } 1051 1052 public void visitForLoop(JCForLoop tree) { 1053 int limit = code.nextreg; 1054 genStats(tree.init, env); 1055 genLoop(tree, tree.body, tree.cond, tree.step, true); 1056 code.endScopes(limit); 1057 } 1058 //where 1059 /** Generate code for a loop. 1060 * @param loop The tree representing the loop. 1061 * @param body The loop's body. 1062 * @param cond The loop's controling condition. 1063 * @param step "Step" statements to be inserted at end of 1064 * each iteration. 1065 * @param testFirst True if the loop test belongs before the body. 1066 */ 1067 private void genLoop(JCStatement loop, 1068 JCStatement body, 1069 JCExpression cond, 1070 List<JCExpressionStatement> step, 1071 boolean testFirst) { 1072 Env<GenContext> loopEnv = env.dup(loop, new GenContext()); 1073 int startpc = code.entryPoint(); 1074 if (testFirst) { //while or for loop 1075 CondItem c; 1076 if (cond != null) { 1077 code.statBegin(cond.pos); 1078 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER); 1079 } else { 1080 c = items.makeCondItem(goto_); 1081 } 1082 Chain loopDone = c.jumpFalse(); 1083 code.resolve(c.trueJumps); 1084 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET); 1085 code.resolve(loopEnv.info.cont); 1086 genStats(step, loopEnv); 1087 code.resolve(code.branch(goto_), startpc); 1088 code.resolve(loopDone); 1089 } else { 1090 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET); 1091 code.resolve(loopEnv.info.cont); 1092 genStats(step, loopEnv); 1093 CondItem c; 1094 if (cond != null) { 1095 code.statBegin(cond.pos); 1096 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER); 1097 } else { 1098 c = items.makeCondItem(goto_); 1099 } 1100 code.resolve(c.jumpTrue(), startpc); 1101 code.resolve(c.falseJumps); 1102 } 1103 Chain exit = loopEnv.info.exit; 1104 if (exit != null) { 1105 code.resolve(exit); 1106 exit.state.defined.excludeFrom(code.nextreg); 1107 } 1108 } 1109 1110 public void visitForeachLoop(JCEnhancedForLoop tree) { 1111 throw new AssertionError(); // should have been removed by Lower. 1112 } 1113 1114 public void visitLabelled(JCLabeledStatement tree) { 1115 Env<GenContext> localEnv = env.dup(tree, new GenContext()); 1116 genStat(tree.body, localEnv, CRT_STATEMENT); 1117 Chain exit = localEnv.info.exit; 1118 if (exit != null) { 1119 code.resolve(exit); 1120 exit.state.defined.excludeFrom(code.nextreg); 1121 } 1122 } 1123 1124 public void visitSwitch(JCSwitch tree) { 1125 int limit = code.nextreg; 1126 Assert.check(!tree.selector.type.hasTag(CLASS)); 1127 int startpcCrt = genCrt ? code.curCP() : 0; 1128 Item sel = genExpr(tree.selector, syms.intType); 1129 List<JCCase> cases = tree.cases; 1130 if (cases.isEmpty()) { 1131 // We are seeing: switch <sel> {} 1132 sel.load().drop(); 1133 if (genCrt) 1134 code.crt.put(TreeInfo.skipParens(tree.selector), 1135 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP()); 1136 } else { 1137 // We are seeing a nonempty switch. 1138 sel.load(); 1139 if (genCrt) 1140 code.crt.put(TreeInfo.skipParens(tree.selector), 1141 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP()); 1142 Env<GenContext> switchEnv = env.dup(tree, new GenContext()); 1143 switchEnv.info.isSwitch = true; 1144 1145 // Compute number of labels and minimum and maximum label values. 1146 // For each case, store its label in an array. 1147 int lo = Integer.MAX_VALUE; // minimum label. 1148 int hi = Integer.MIN_VALUE; // maximum label. 1149 int nlabels = 0; // number of labels. 1150 1151 int[] labels = new int[cases.length()]; // the label array. 1152 int defaultIndex = -1; // the index of the default clause. 1153 1154 List<JCCase> l = cases; 1155 for (int i = 0; i < labels.length; i++) { 1156 if (l.head.pat != null) { 1157 int val = ((Number)l.head.pat.type.constValue()).intValue(); 1158 labels[i] = val; 1159 if (val < lo) lo = val; 1160 if (hi < val) hi = val; 1161 nlabels++; 1162 } else { 1163 Assert.check(defaultIndex == -1); 1164 defaultIndex = i; 1165 } 1166 l = l.tail; 1167 } 1168 1169 // Determine whether to issue a tableswitch or a lookupswitch 1170 // instruction. 1171 long table_space_cost = 4 + ((long) hi - lo + 1); // words 1172 long table_time_cost = 3; // comparisons 1173 long lookup_space_cost = 3 + 2 * (long) nlabels; 1174 long lookup_time_cost = nlabels; 1175 int opcode = 1176 nlabels > 0 && 1177 table_space_cost + 3 * table_time_cost <= 1178 lookup_space_cost + 3 * lookup_time_cost 1179 ? 1180 tableswitch : lookupswitch; 1181 1182 int startpc = code.curCP(); // the position of the selector operation 1183 code.emitop0(opcode); 1184 code.align(4); 1185 int tableBase = code.curCP(); // the start of the jump table 1186 int[] offsets = null; // a table of offsets for a lookupswitch 1187 code.emit4(-1); // leave space for default offset 1188 if (opcode == tableswitch) { 1189 code.emit4(lo); // minimum label 1190 code.emit4(hi); // maximum label 1191 for (long i = lo; i <= hi; i++) { // leave space for jump table 1192 code.emit4(-1); 1193 } 1194 } else { 1195 code.emit4(nlabels); // number of labels 1196 for (int i = 0; i < nlabels; i++) { 1197 code.emit4(-1); code.emit4(-1); // leave space for lookup table 1198 } 1199 offsets = new int[labels.length]; 1200 } 1201 Code.State stateSwitch = code.state.dup(); 1202 code.markDead(); 1203 1204 // For each case do: 1205 l = cases; 1206 for (int i = 0; i < labels.length; i++) { 1207 JCCase c = l.head; 1208 l = l.tail; 1209 1210 int pc = code.entryPoint(stateSwitch); 1211 // Insert offset directly into code or else into the 1212 // offsets table. 1213 if (i != defaultIndex) { 1214 if (opcode == tableswitch) { 1215 code.put4( 1216 tableBase + 4 * (labels[i] - lo + 3), 1217 pc - startpc); 1218 } else { 1219 offsets[i] = pc - startpc; 1220 } 1221 } else { 1222 code.put4(tableBase, pc - startpc); 1223 } 1224 1225 // Generate code for the statements in this case. 1226 genStats(c.stats, switchEnv, CRT_FLOW_TARGET); 1227 } 1228 1229 // Resolve all breaks. 1230 Chain exit = switchEnv.info.exit; 1231 if (exit != null) { 1232 code.resolve(exit); 1233 exit.state.defined.excludeFrom(code.nextreg); 1234 } 1235 1236 // If we have not set the default offset, we do so now. 1237 if (code.get4(tableBase) == -1) { 1238 code.put4(tableBase, code.entryPoint(stateSwitch) - startpc); 1239 } 1240 1241 if (opcode == tableswitch) { 1242 // Let any unfilled slots point to the default case. 1243 int defaultOffset = code.get4(tableBase); 1244 for (long i = lo; i <= hi; i++) { 1245 int t = (int)(tableBase + 4 * (i - lo + 3)); 1246 if (code.get4(t) == -1) 1247 code.put4(t, defaultOffset); 1248 } 1249 } else { 1250 // Sort non-default offsets and copy into lookup table. 1251 if (defaultIndex >= 0) 1252 for (int i = defaultIndex; i < labels.length - 1; i++) { 1253 labels[i] = labels[i+1]; 1254 offsets[i] = offsets[i+1]; 1255 } 1256 if (nlabels > 0) 1257 qsort2(labels, offsets, 0, nlabels - 1); 1258 for (int i = 0; i < nlabels; i++) { 1259 int caseidx = tableBase + 8 * (i + 1); 1260 code.put4(caseidx, labels[i]); 1261 code.put4(caseidx + 4, offsets[i]); 1262 } 1263 } 1264 } 1265 code.endScopes(limit); 1266 } 1267//where 1268 /** Sort (int) arrays of keys and values 1269 */ 1270 static void qsort2(int[] keys, int[] values, int lo, int hi) { 1271 int i = lo; 1272 int j = hi; 1273 int pivot = keys[(i+j)/2]; 1274 do { 1275 while (keys[i] < pivot) i++; 1276 while (pivot < keys[j]) j--; 1277 if (i <= j) { 1278 int temp1 = keys[i]; 1279 keys[i] = keys[j]; 1280 keys[j] = temp1; 1281 int temp2 = values[i]; 1282 values[i] = values[j]; 1283 values[j] = temp2; 1284 i++; 1285 j--; 1286 } 1287 } while (i <= j); 1288 if (lo < j) qsort2(keys, values, lo, j); 1289 if (i < hi) qsort2(keys, values, i, hi); 1290 } 1291 1292 public void visitSynchronized(JCSynchronized tree) { 1293 int limit = code.nextreg; 1294 // Generate code to evaluate lock and save in temporary variable. 1295 final LocalItem lockVar = makeTemp(syms.objectType); 1296 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 if (!useJsrLocally) { 1331 useJsrLocally = 1332 (stackMap == StackMapFormat.NONE) && 1333 (jsrlimit <= 0 || 1334 jsrlimit < 100 && 1335 estimateCodeComplexity(tree.finalizer)>jsrlimit); 1336 } 1337 tryEnv.info.finalize = new GenFinalizer() { 1338 void gen() { 1339 if (useJsrLocally) { 1340 if (tree.finalizer != null) { 1341 Code.State jsrState = code.state.dup(); 1342 jsrState.push(Code.jsrReturnValue); 1343 tryEnv.info.cont = 1344 new Chain(code.emitJump(jsr), 1345 tryEnv.info.cont, 1346 jsrState); 1347 } 1348 Assert.check(tryEnv.info.gaps.length() % 2 == 0); 1349 tryEnv.info.gaps.append(code.curCP()); 1350 } else { 1351 Assert.check(tryEnv.info.gaps.length() % 2 == 0); 1352 tryEnv.info.gaps.append(code.curCP()); 1353 genLast(); 1354 } 1355 } 1356 void genLast() { 1357 if (tree.finalizer != null) 1358 genStat(tree.finalizer, oldEnv, CRT_BLOCK); 1359 } 1360 boolean hasFinalizer() { 1361 return tree.finalizer != null; 1362 } 1363 }; 1364 tryEnv.info.gaps = new ListBuffer<>(); 1365 genTry(tree.body, tree.catchers, tryEnv); 1366 } 1367 //where 1368 /** Generate code for a try or synchronized statement 1369 * @param body The body of the try or synchronized statement. 1370 * @param catchers The lis of catch clauses. 1371 * @param env the environment current for the body. 1372 */ 1373 void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) { 1374 int limit = code.nextreg; 1375 int startpc = code.curCP(); 1376 Code.State stateTry = code.state.dup(); 1377 genStat(body, env, CRT_BLOCK); 1378 int endpc = code.curCP(); 1379 boolean hasFinalizer = 1380 env.info.finalize != null && 1381 env.info.finalize.hasFinalizer(); 1382 List<Integer> gaps = env.info.gaps.toList(); 1383 code.statBegin(TreeInfo.endPos(body)); 1384 genFinalizer(env); 1385 code.statBegin(TreeInfo.endPos(env.tree)); 1386 Chain exitChain = code.branch(goto_); 1387 endFinalizerGap(env); 1388 if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) { 1389 // start off with exception on stack 1390 code.entryPoint(stateTry, l.head.param.sym.type); 1391 genCatch(l.head, env, startpc, endpc, gaps); 1392 genFinalizer(env); 1393 if (hasFinalizer || l.tail.nonEmpty()) { 1394 code.statBegin(TreeInfo.endPos(env.tree)); 1395 exitChain = Code.mergeChains(exitChain, 1396 code.branch(goto_)); 1397 } 1398 endFinalizerGap(env); 1399 } 1400 if (hasFinalizer) { 1401 // Create a new register segement to avoid allocating 1402 // the same variables in finalizers and other statements. 1403 code.newRegSegment(); 1404 1405 // Add a catch-all clause. 1406 1407 // start off with exception on stack 1408 int catchallpc = code.entryPoint(stateTry, syms.throwableType); 1409 1410 // Register all exception ranges for catch all clause. 1411 // The range of the catch all clause is from the beginning 1412 // of the try or synchronized block until the present 1413 // code pointer excluding all gaps in the current 1414 // environment's GenContext. 1415 int startseg = startpc; 1416 while (env.info.gaps.nonEmpty()) { 1417 int endseg = env.info.gaps.next().intValue(); 1418 registerCatch(body.pos(), startseg, endseg, 1419 catchallpc, 0); 1420 startseg = env.info.gaps.next().intValue(); 1421 } 1422 code.statBegin(TreeInfo.finalizerPos(env.tree)); 1423 code.markStatBegin(); 1424 1425 Item excVar = makeTemp(syms.throwableType); 1426 excVar.store(); 1427 genFinalizer(env); 1428 excVar.load(); 1429 registerCatch(body.pos(), startseg, 1430 env.info.gaps.next().intValue(), 1431 catchallpc, 0); 1432 code.emitop0(athrow); 1433 code.markDead(); 1434 1435 // If there are jsr's to this finalizer, ... 1436 if (env.info.cont != null) { 1437 // Resolve all jsr's. 1438 code.resolve(env.info.cont); 1439 1440 // Mark statement line number 1441 code.statBegin(TreeInfo.finalizerPos(env.tree)); 1442 code.markStatBegin(); 1443 1444 // Save return address. 1445 LocalItem retVar = makeTemp(syms.throwableType); 1446 retVar.store(); 1447 1448 // Generate finalizer code. 1449 env.info.finalize.genLast(); 1450 1451 // Return. 1452 code.emitop1w(ret, retVar.reg); 1453 code.markDead(); 1454 } 1455 } 1456 // Resolve all breaks. 1457 code.resolve(exitChain); 1458 1459 code.endScopes(limit); 1460 } 1461 1462 /** Generate code for a catch clause. 1463 * @param tree The catch clause. 1464 * @param env The environment current in the enclosing try. 1465 * @param startpc Start pc of try-block. 1466 * @param endpc End pc of try-block. 1467 */ 1468 void genCatch(JCCatch tree, 1469 Env<GenContext> env, 1470 int startpc, int endpc, 1471 List<Integer> gaps) { 1472 if (startpc != endpc) { 1473 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypeExprs 1474 = catchTypesWithAnnotations(tree); 1475 while (gaps.nonEmpty()) { 1476 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) { 1477 JCExpression subCatch = subCatch1.snd; 1478 int catchType = makeRef(tree.pos(), subCatch.type); 1479 int end = gaps.head.intValue(); 1480 registerCatch(tree.pos(), 1481 startpc, end, code.curCP(), 1482 catchType); 1483 for (Attribute.TypeCompound tc : subCatch1.fst) { 1484 tc.position.setCatchInfo(catchType, startpc); 1485 } 1486 } 1487 gaps = gaps.tail; 1488 startpc = gaps.head.intValue(); 1489 gaps = gaps.tail; 1490 } 1491 if (startpc < endpc) { 1492 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) { 1493 JCExpression subCatch = subCatch1.snd; 1494 int catchType = makeRef(tree.pos(), subCatch.type); 1495 registerCatch(tree.pos(), 1496 startpc, endpc, code.curCP(), 1497 catchType); 1498 for (Attribute.TypeCompound tc : subCatch1.fst) { 1499 tc.position.setCatchInfo(catchType, startpc); 1500 } 1501 } 1502 } 1503 VarSymbol exparam = tree.param.sym; 1504 code.statBegin(tree.pos); 1505 code.markStatBegin(); 1506 int limit = code.nextreg; 1507 code.newLocal(exparam); 1508 items.makeLocalItem(exparam).store(); 1509 code.statBegin(TreeInfo.firstStatPos(tree.body)); 1510 genStat(tree.body, env, CRT_BLOCK); 1511 code.endScopes(limit); 1512 code.statBegin(TreeInfo.endPos(tree.body)); 1513 } 1514 } 1515 // where 1516 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotations(JCCatch tree) { 1517 return TreeInfo.isMultiCatch(tree) ? 1518 catchTypesWithAnnotationsFromMulticatch((JCTypeUnion)tree.param.vartype, tree.param.sym.getRawTypeAttributes()) : 1519 List.of(new Pair<>(tree.param.sym.getRawTypeAttributes(), tree.param.vartype)); 1520 } 1521 // where 1522 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotationsFromMulticatch(JCTypeUnion tree, List<TypeCompound> first) { 1523 List<JCExpression> alts = tree.alternatives; 1524 List<Pair<List<TypeCompound>, JCExpression>> res = List.of(new Pair<>(first, alts.head)); 1525 alts = alts.tail; 1526 1527 while(alts != null && alts.head != null) { 1528 JCExpression alt = alts.head; 1529 if (alt instanceof JCAnnotatedType) { 1530 JCAnnotatedType a = (JCAnnotatedType)alt; 1531 res = res.prepend(new Pair<>(annotate.fromAnnotations(a.annotations), alt)); 1532 } else { 1533 res = res.prepend(new Pair<>(List.nil(), alt)); 1534 } 1535 alts = alts.tail; 1536 } 1537 return res.reverse(); 1538 } 1539 1540 /** Register a catch clause in the "Exceptions" code-attribute. 1541 */ 1542 void registerCatch(DiagnosticPosition pos, 1543 int startpc, int endpc, 1544 int handler_pc, int catch_type) { 1545 char startpc1 = (char)startpc; 1546 char endpc1 = (char)endpc; 1547 char handler_pc1 = (char)handler_pc; 1548 if (startpc1 == startpc && 1549 endpc1 == endpc && 1550 handler_pc1 == handler_pc) { 1551 code.addCatch(startpc1, endpc1, handler_pc1, 1552 (char)catch_type); 1553 } else { 1554 log.error(pos, "limit.code.too.large.for.try.stmt"); 1555 nerrs++; 1556 } 1557 } 1558 1559 /** Very roughly estimate the number of instructions needed for 1560 * the given tree. 1561 */ 1562 int estimateCodeComplexity(JCTree tree) { 1563 if (tree == null) return 0; 1564 class ComplexityScanner extends TreeScanner { 1565 int complexity = 0; 1566 public void scan(JCTree tree) { 1567 if (complexity > jsrlimit) return; 1568 super.scan(tree); 1569 } 1570 public void visitClassDef(JCClassDecl tree) {} 1571 public void visitDoLoop(JCDoWhileLoop tree) 1572 { super.visitDoLoop(tree); complexity++; } 1573 public void visitWhileLoop(JCWhileLoop tree) 1574 { super.visitWhileLoop(tree); complexity++; } 1575 public void visitForLoop(JCForLoop tree) 1576 { super.visitForLoop(tree); complexity++; } 1577 public void visitSwitch(JCSwitch tree) 1578 { super.visitSwitch(tree); complexity+=5; } 1579 public void visitCase(JCCase tree) 1580 { super.visitCase(tree); complexity++; } 1581 public void visitSynchronized(JCSynchronized tree) 1582 { super.visitSynchronized(tree); complexity+=6; } 1583 public void visitTry(JCTry tree) 1584 { super.visitTry(tree); 1585 if (tree.finalizer != null) complexity+=6; } 1586 public void visitCatch(JCCatch tree) 1587 { super.visitCatch(tree); complexity+=2; } 1588 public void visitConditional(JCConditional tree) 1589 { super.visitConditional(tree); complexity+=2; } 1590 public void visitIf(JCIf tree) 1591 { super.visitIf(tree); complexity+=2; } 1592 // note: for break, continue, and return we don't take unwind() into account. 1593 public void visitBreak(JCBreak tree) 1594 { super.visitBreak(tree); complexity+=1; } 1595 public void visitContinue(JCContinue tree) 1596 { super.visitContinue(tree); complexity+=1; } 1597 public void visitReturn(JCReturn tree) 1598 { super.visitReturn(tree); complexity+=1; } 1599 public void visitThrow(JCThrow tree) 1600 { super.visitThrow(tree); complexity+=1; } 1601 public void visitAssert(JCAssert tree) 1602 { super.visitAssert(tree); complexity+=5; } 1603 public void visitApply(JCMethodInvocation tree) 1604 { super.visitApply(tree); complexity+=2; } 1605 public void visitNewClass(JCNewClass tree) 1606 { scan(tree.encl); scan(tree.args); complexity+=2; } 1607 public void visitNewArray(JCNewArray tree) 1608 { super.visitNewArray(tree); complexity+=5; } 1609 public void visitAssign(JCAssign tree) 1610 { super.visitAssign(tree); complexity+=1; } 1611 public void visitAssignop(JCAssignOp tree) 1612 { super.visitAssignop(tree); complexity+=2; } 1613 public void visitUnary(JCUnary tree) 1614 { complexity+=1; 1615 if (tree.type.constValue() == null) super.visitUnary(tree); } 1616 public void visitBinary(JCBinary tree) 1617 { complexity+=1; 1618 if (tree.type.constValue() == null) super.visitBinary(tree); } 1619 public void visitTypeTest(JCInstanceOf tree) 1620 { super.visitTypeTest(tree); complexity+=1; } 1621 public void visitIndexed(JCArrayAccess tree) 1622 { super.visitIndexed(tree); complexity+=1; } 1623 public void visitSelect(JCFieldAccess tree) 1624 { super.visitSelect(tree); 1625 if (tree.sym.kind == VAR) complexity+=1; } 1626 public void visitIdent(JCIdent tree) { 1627 if (tree.sym.kind == VAR) { 1628 complexity+=1; 1629 if (tree.type.constValue() == null && 1630 tree.sym.owner.kind == TYP) 1631 complexity+=1; 1632 } 1633 } 1634 public void visitLiteral(JCLiteral tree) 1635 { complexity+=1; } 1636 public void visitTree(JCTree tree) {} 1637 public void visitWildcard(JCWildcard tree) { 1638 throw new AssertionError(this.getClass().getName()); 1639 } 1640 } 1641 ComplexityScanner scanner = new ComplexityScanner(); 1642 tree.accept(scanner); 1643 return scanner.complexity; 1644 } 1645 1646 public void visitIf(JCIf tree) { 1647 int limit = code.nextreg; 1648 Chain thenExit = null; 1649 CondItem c = genCond(TreeInfo.skipParens(tree.cond), 1650 CRT_FLOW_CONTROLLER); 1651 Chain elseChain = c.jumpFalse(); 1652 if (!c.isFalse()) { 1653 code.resolve(c.trueJumps); 1654 genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET); 1655 thenExit = code.branch(goto_); 1656 } 1657 if (elseChain != null) { 1658 code.resolve(elseChain); 1659 if (tree.elsepart != null) { 1660 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET); 1661 } 1662 } 1663 code.resolve(thenExit); 1664 code.endScopes(limit); 1665 } 1666 1667 public void visitExec(JCExpressionStatement tree) { 1668 // Optimize x++ to ++x and x-- to --x. 1669 JCExpression e = tree.expr; 1670 switch (e.getTag()) { 1671 case POSTINC: 1672 ((JCUnary) e).setTag(PREINC); 1673 break; 1674 case POSTDEC: 1675 ((JCUnary) e).setTag(PREDEC); 1676 break; 1677 } 1678 genExpr(tree.expr, tree.expr.type).drop(); 1679 } 1680 1681 public void visitBreak(JCBreak tree) { 1682 Env<GenContext> targetEnv = unwind(tree.target, env); 1683 Assert.check(code.state.stacksize == 0); 1684 targetEnv.info.addExit(code.branch(goto_)); 1685 endFinalizerGaps(env, targetEnv); 1686 } 1687 1688 public void visitContinue(JCContinue tree) { 1689 Env<GenContext> targetEnv = unwind(tree.target, env); 1690 Assert.check(code.state.stacksize == 0); 1691 targetEnv.info.addCont(code.branch(goto_)); 1692 endFinalizerGaps(env, targetEnv); 1693 } 1694 1695 public void visitReturn(JCReturn tree) { 1696 int limit = code.nextreg; 1697 final Env<GenContext> targetEnv; 1698 if (tree.expr != null) { 1699 Item r = genExpr(tree.expr, pt).load(); 1700 if (hasFinally(env.enclMethod, env)) { 1701 r = makeTemp(pt); 1702 r.store(); 1703 } 1704 targetEnv = unwind(env.enclMethod, env); 1705 r.load(); 1706 code.emitop0(ireturn + Code.truncate(Code.typecode(pt))); 1707 } else { 1708 /* If we have a statement like: 1709 * 1710 * return; 1711 * 1712 * we need to store the code.pendingStatPos value before generating 1713 * the finalizer. 1714 */ 1715 int tmpPos = code.pendingStatPos; 1716 targetEnv = unwind(env.enclMethod, env); 1717 code.pendingStatPos = tmpPos; 1718 code.emitop0(return_); 1719 } 1720 endFinalizerGaps(env, targetEnv); 1721 code.endScopes(limit); 1722 } 1723 1724 public void visitThrow(JCThrow tree) { 1725 genExpr(tree.expr, tree.expr.type).load(); 1726 code.emitop0(athrow); 1727 } 1728 1729/* ************************************************************************ 1730 * Visitor methods for expressions 1731 *************************************************************************/ 1732 1733 public void visitApply(JCMethodInvocation tree) { 1734 setTypeAnnotationPositions(tree.pos); 1735 // Generate code for method. 1736 Item m = genExpr(tree.meth, methodType); 1737 // Generate code for all arguments, where the expected types are 1738 // the parameters of the method's external type (that is, any implicit 1739 // outer instance of a super(...) call appears as first parameter). 1740 MethodSymbol msym = (MethodSymbol)TreeInfo.symbol(tree.meth); 1741 genArgs(tree.args, 1742 msym.externalType(types).getParameterTypes()); 1743 if (!msym.isDynamic()) { 1744 code.statBegin(tree.pos); 1745 } 1746 result = m.invoke(); 1747 } 1748 1749 public void visitConditional(JCConditional tree) { 1750 Chain thenExit = null; 1751 CondItem c = genCond(tree.cond, CRT_FLOW_CONTROLLER); 1752 Chain elseChain = c.jumpFalse(); 1753 if (!c.isFalse()) { 1754 code.resolve(c.trueJumps); 1755 int startpc = genCrt ? code.curCP() : 0; 1756 code.statBegin(tree.truepart.pos); 1757 genExpr(tree.truepart, pt).load(); 1758 code.state.forceStackTop(tree.type); 1759 if (genCrt) code.crt.put(tree.truepart, CRT_FLOW_TARGET, 1760 startpc, code.curCP()); 1761 thenExit = code.branch(goto_); 1762 } 1763 if (elseChain != null) { 1764 code.resolve(elseChain); 1765 int startpc = genCrt ? code.curCP() : 0; 1766 code.statBegin(tree.falsepart.pos); 1767 genExpr(tree.falsepart, pt).load(); 1768 code.state.forceStackTop(tree.type); 1769 if (genCrt) code.crt.put(tree.falsepart, CRT_FLOW_TARGET, 1770 startpc, code.curCP()); 1771 } 1772 code.resolve(thenExit); 1773 result = items.makeStackItem(pt); 1774 } 1775 1776 private void setTypeAnnotationPositions(int treePos) { 1777 MethodSymbol meth = code.meth; 1778 boolean initOrClinit = code.meth.getKind() == javax.lang.model.element.ElementKind.CONSTRUCTOR 1779 || code.meth.getKind() == javax.lang.model.element.ElementKind.STATIC_INIT; 1780 1781 for (Attribute.TypeCompound ta : meth.getRawTypeAttributes()) { 1782 if (ta.hasUnknownPosition()) 1783 ta.tryFixPosition(); 1784 1785 if (ta.position.matchesPos(treePos)) 1786 ta.position.updatePosOffset(code.cp); 1787 } 1788 1789 if (!initOrClinit) 1790 return; 1791 1792 for (Attribute.TypeCompound ta : meth.owner.getRawTypeAttributes()) { 1793 if (ta.hasUnknownPosition()) 1794 ta.tryFixPosition(); 1795 1796 if (ta.position.matchesPos(treePos)) 1797 ta.position.updatePosOffset(code.cp); 1798 } 1799 1800 ClassSymbol clazz = meth.enclClass(); 1801 for (Symbol s : new com.sun.tools.javac.model.FilteredMemberList(clazz.members())) { 1802 if (!s.getKind().isField()) 1803 continue; 1804 1805 for (Attribute.TypeCompound ta : s.getRawTypeAttributes()) { 1806 if (ta.hasUnknownPosition()) 1807 ta.tryFixPosition(); 1808 1809 if (ta.position.matchesPos(treePos)) 1810 ta.position.updatePosOffset(code.cp); 1811 } 1812 } 1813 } 1814 1815 public void visitNewClass(JCNewClass tree) { 1816 // Enclosing instances or anonymous classes should have been eliminated 1817 // by now. 1818 Assert.check(tree.encl == null && tree.def == null); 1819 setTypeAnnotationPositions(tree.pos); 1820 1821 code.emitop2(new_, makeRef(tree.pos(), tree.type)); 1822 code.emitop0(dup); 1823 1824 // Generate code for all arguments, where the expected types are 1825 // the parameters of the constructor's external type (that is, 1826 // any implicit outer instance appears as first parameter). 1827 genArgs(tree.args, tree.constructor.externalType(types).getParameterTypes()); 1828 1829 items.makeMemberItem(tree.constructor, true).invoke(); 1830 result = items.makeStackItem(tree.type); 1831 } 1832 1833 public void visitNewArray(JCNewArray tree) { 1834 setTypeAnnotationPositions(tree.pos); 1835 1836 if (tree.elems != null) { 1837 Type elemtype = types.elemtype(tree.type); 1838 loadIntConst(tree.elems.length()); 1839 Item arr = makeNewArray(tree.pos(), tree.type, 1); 1840 int i = 0; 1841 for (List<JCExpression> l = tree.elems; l.nonEmpty(); l = l.tail) { 1842 arr.duplicate(); 1843 loadIntConst(i); 1844 i++; 1845 genExpr(l.head, elemtype).load(); 1846 items.makeIndexedItem(elemtype).store(); 1847 } 1848 result = arr; 1849 } else { 1850 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) { 1851 genExpr(l.head, syms.intType).load(); 1852 } 1853 result = makeNewArray(tree.pos(), tree.type, tree.dims.length()); 1854 } 1855 } 1856//where 1857 /** Generate code to create an array with given element type and number 1858 * of dimensions. 1859 */ 1860 Item makeNewArray(DiagnosticPosition pos, Type type, int ndims) { 1861 Type elemtype = types.elemtype(type); 1862 if (types.dimensions(type) > ClassFile.MAX_DIMENSIONS) { 1863 log.error(pos, "limit.dimensions"); 1864 nerrs++; 1865 } 1866 int elemcode = Code.arraycode(elemtype); 1867 if (elemcode == 0 || (elemcode == 1 && ndims == 1)) { 1868 code.emitAnewarray(makeRef(pos, elemtype), type); 1869 } else if (elemcode == 1) { 1870 code.emitMultianewarray(ndims, makeRef(pos, type), type); 1871 } else { 1872 code.emitNewarray(elemcode, type); 1873 } 1874 return items.makeStackItem(type); 1875 } 1876 1877 public void visitParens(JCParens tree) { 1878 result = genExpr(tree.expr, tree.expr.type); 1879 } 1880 1881 public void visitAssign(JCAssign tree) { 1882 Item l = genExpr(tree.lhs, tree.lhs.type); 1883 genExpr(tree.rhs, tree.lhs.type).load(); 1884 if (tree.rhs.type.hasTag(BOT)) { 1885 /* This is just a case of widening reference conversion that per 5.1.5 simply calls 1886 for "regarding a reference as having some other type in a manner that can be proved 1887 correct at compile time." 1888 */ 1889 code.state.forceStackTop(tree.lhs.type); 1890 } 1891 result = items.makeAssignItem(l); 1892 } 1893 1894 public void visitAssignop(JCAssignOp tree) { 1895 OperatorSymbol operator = (OperatorSymbol) tree.operator; 1896 Item l; 1897 if (operator.opcode == string_add) { 1898 // Generate code to make a string buffer 1899 makeStringBuffer(tree.pos()); 1900 1901 // Generate code for first string, possibly save one 1902 // copy under buffer 1903 l = genExpr(tree.lhs, tree.lhs.type); 1904 if (l.width() > 0) { 1905 code.emitop0(dup_x1 + 3 * (l.width() - 1)); 1906 } 1907 1908 // Load first string and append to buffer. 1909 l.load(); 1910 appendString(tree.lhs); 1911 1912 // Append all other strings to buffer. 1913 appendStrings(tree.rhs); 1914 1915 // Convert buffer to string. 1916 bufferToString(tree.pos()); 1917 } else { 1918 // Generate code for first expression 1919 l = genExpr(tree.lhs, tree.lhs.type); 1920 1921 // If we have an increment of -32768 to +32767 of a local 1922 // int variable we can use an incr instruction instead of 1923 // proceeding further. 1924 if ((tree.hasTag(PLUS_ASG) || tree.hasTag(MINUS_ASG)) && 1925 l instanceof LocalItem && 1926 tree.lhs.type.getTag().isSubRangeOf(INT) && 1927 tree.rhs.type.getTag().isSubRangeOf(INT) && 1928 tree.rhs.type.constValue() != null) { 1929 int ival = ((Number) tree.rhs.type.constValue()).intValue(); 1930 if (tree.hasTag(MINUS_ASG)) ival = -ival; 1931 ((LocalItem)l).incr(ival); 1932 result = l; 1933 return; 1934 } 1935 // Otherwise, duplicate expression, load one copy 1936 // and complete binary operation. 1937 l.duplicate(); 1938 l.coerce(operator.type.getParameterTypes().head).load(); 1939 completeBinop(tree.lhs, tree.rhs, operator).coerce(tree.lhs.type); 1940 } 1941 result = items.makeAssignItem(l); 1942 } 1943 1944 public void visitUnary(JCUnary tree) { 1945 OperatorSymbol operator = (OperatorSymbol)tree.operator; 1946 if (tree.hasTag(NOT)) { 1947 CondItem od = genCond(tree.arg, false); 1948 result = od.negate(); 1949 } else { 1950 Item od = genExpr(tree.arg, operator.type.getParameterTypes().head); 1951 switch (tree.getTag()) { 1952 case POS: 1953 result = od.load(); 1954 break; 1955 case NEG: 1956 result = od.load(); 1957 code.emitop0(operator.opcode); 1958 break; 1959 case COMPL: 1960 result = od.load(); 1961 emitMinusOne(od.typecode); 1962 code.emitop0(operator.opcode); 1963 break; 1964 case PREINC: case PREDEC: 1965 od.duplicate(); 1966 if (od instanceof LocalItem && 1967 (operator.opcode == iadd || operator.opcode == isub)) { 1968 ((LocalItem)od).incr(tree.hasTag(PREINC) ? 1 : -1); 1969 result = od; 1970 } else { 1971 od.load(); 1972 code.emitop0(one(od.typecode)); 1973 code.emitop0(operator.opcode); 1974 // Perform narrowing primitive conversion if byte, 1975 // char, or short. Fix for 4304655. 1976 if (od.typecode != INTcode && 1977 Code.truncate(od.typecode) == INTcode) 1978 code.emitop0(int2byte + od.typecode - BYTEcode); 1979 result = items.makeAssignItem(od); 1980 } 1981 break; 1982 case POSTINC: case POSTDEC: 1983 od.duplicate(); 1984 if (od instanceof LocalItem && 1985 (operator.opcode == iadd || operator.opcode == isub)) { 1986 Item res = od.load(); 1987 ((LocalItem)od).incr(tree.hasTag(POSTINC) ? 1 : -1); 1988 result = res; 1989 } else { 1990 Item res = od.load(); 1991 od.stash(od.typecode); 1992 code.emitop0(one(od.typecode)); 1993 code.emitop0(operator.opcode); 1994 // Perform narrowing primitive conversion if byte, 1995 // char, or short. Fix for 4304655. 1996 if (od.typecode != INTcode && 1997 Code.truncate(od.typecode) == INTcode) 1998 code.emitop0(int2byte + od.typecode - BYTEcode); 1999 od.store(); 2000 result = res; 2001 } 2002 break; 2003 case NULLCHK: 2004 result = od.load(); 2005 code.emitop0(dup); 2006 genNullCheck(tree.pos()); 2007 break; 2008 default: 2009 Assert.error(); 2010 } 2011 } 2012 } 2013 2014 /** Generate a null check from the object value at stack top. */ 2015 private void genNullCheck(DiagnosticPosition pos) { 2016 if (allowBetterNullChecks) { 2017 callMethod(pos, syms.objectsType, names.requireNonNull, 2018 List.of(syms.objectType), true); 2019 } else { 2020 callMethod(pos, syms.objectType, names.getClass, 2021 List.<Type>nil(), false); 2022 } 2023 code.emitop0(pop); 2024 } 2025 2026 public void visitBinary(JCBinary tree) { 2027 OperatorSymbol operator = (OperatorSymbol)tree.operator; 2028 if (operator.opcode == string_add) { 2029 // Create a string buffer. 2030 makeStringBuffer(tree.pos()); 2031 // Append all strings to buffer. 2032 appendStrings(tree); 2033 // Convert buffer to string. 2034 bufferToString(tree.pos()); 2035 result = items.makeStackItem(syms.stringType); 2036 } else if (tree.hasTag(AND)) { 2037 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER); 2038 if (!lcond.isFalse()) { 2039 Chain falseJumps = lcond.jumpFalse(); 2040 code.resolve(lcond.trueJumps); 2041 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET); 2042 result = items. 2043 makeCondItem(rcond.opcode, 2044 rcond.trueJumps, 2045 Code.mergeChains(falseJumps, 2046 rcond.falseJumps)); 2047 } else { 2048 result = lcond; 2049 } 2050 } else if (tree.hasTag(OR)) { 2051 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER); 2052 if (!lcond.isTrue()) { 2053 Chain trueJumps = lcond.jumpTrue(); 2054 code.resolve(lcond.falseJumps); 2055 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET); 2056 result = items. 2057 makeCondItem(rcond.opcode, 2058 Code.mergeChains(trueJumps, rcond.trueJumps), 2059 rcond.falseJumps); 2060 } else { 2061 result = lcond; 2062 } 2063 } else { 2064 Item od = genExpr(tree.lhs, operator.type.getParameterTypes().head); 2065 od.load(); 2066 result = completeBinop(tree.lhs, tree.rhs, operator); 2067 } 2068 } 2069//where 2070 /** Make a new string buffer. 2071 */ 2072 void makeStringBuffer(DiagnosticPosition pos) { 2073 code.emitop2(new_, makeRef(pos, stringBufferType)); 2074 code.emitop0(dup); 2075 callMethod( 2076 pos, stringBufferType, names.init, List.<Type>nil(), false); 2077 } 2078 2079 /** Append value (on tos) to string buffer (on tos - 1). 2080 */ 2081 void appendString(JCTree tree) { 2082 Type t = tree.type.baseType(); 2083 if (!t.isPrimitive() && t.tsym != syms.stringType.tsym) { 2084 t = syms.objectType; 2085 } 2086 items.makeMemberItem(getStringBufferAppend(tree, t), false).invoke(); 2087 } 2088 Symbol getStringBufferAppend(JCTree tree, Type t) { 2089 Assert.checkNull(t.constValue()); 2090 Symbol method = stringBufferAppend.get(t); 2091 if (method == null) { 2092 method = rs.resolveInternalMethod(tree.pos(), 2093 attrEnv, 2094 stringBufferType, 2095 names.append, 2096 List.of(t), 2097 null); 2098 stringBufferAppend.put(t, method); 2099 } 2100 return method; 2101 } 2102 2103 /** Add all strings in tree to string buffer. 2104 */ 2105 void appendStrings(JCTree tree) { 2106 tree = TreeInfo.skipParens(tree); 2107 if (tree.hasTag(PLUS) && tree.type.constValue() == null) { 2108 JCBinary op = (JCBinary) tree; 2109 if (op.operator.kind == MTH && 2110 ((OperatorSymbol) op.operator).opcode == string_add) { 2111 appendStrings(op.lhs); 2112 appendStrings(op.rhs); 2113 return; 2114 } 2115 } 2116 genExpr(tree, tree.type).load(); 2117 appendString(tree); 2118 } 2119 2120 /** Convert string buffer on tos to string. 2121 */ 2122 void bufferToString(DiagnosticPosition pos) { 2123 callMethod( 2124 pos, 2125 stringBufferType, 2126 names.toString, 2127 List.<Type>nil(), 2128 false); 2129 } 2130 2131 /** Complete generating code for operation, with left operand 2132 * already on stack. 2133 * @param lhs The tree representing the left operand. 2134 * @param rhs The tree representing the right operand. 2135 * @param operator The operator symbol. 2136 */ 2137 Item completeBinop(JCTree lhs, JCTree rhs, OperatorSymbol operator) { 2138 MethodType optype = (MethodType)operator.type; 2139 int opcode = operator.opcode; 2140 if (opcode >= if_icmpeq && opcode <= if_icmple && 2141 rhs.type.constValue() instanceof Number && 2142 ((Number) rhs.type.constValue()).intValue() == 0) { 2143 opcode = opcode + (ifeq - if_icmpeq); 2144 } else if (opcode >= if_acmpeq && opcode <= if_acmpne && 2145 TreeInfo.isNull(rhs)) { 2146 opcode = opcode + (if_acmp_null - if_acmpeq); 2147 } else { 2148 // The expected type of the right operand is 2149 // the second parameter type of the operator, except for 2150 // shifts with long shiftcount, where we convert the opcode 2151 // to a short shift and the expected type to int. 2152 Type rtype = operator.erasure(types).getParameterTypes().tail.head; 2153 if (opcode >= ishll && opcode <= lushrl) { 2154 opcode = opcode + (ishl - ishll); 2155 rtype = syms.intType; 2156 } 2157 // Generate code for right operand and load. 2158 genExpr(rhs, rtype).load(); 2159 // If there are two consecutive opcode instructions, 2160 // emit the first now. 2161 if (opcode >= (1 << preShift)) { 2162 code.emitop0(opcode >> preShift); 2163 opcode = opcode & 0xFF; 2164 } 2165 } 2166 if (opcode >= ifeq && opcode <= if_acmpne || 2167 opcode == if_acmp_null || opcode == if_acmp_nonnull) { 2168 return items.makeCondItem(opcode); 2169 } else { 2170 code.emitop0(opcode); 2171 return items.makeStackItem(optype.restype); 2172 } 2173 } 2174 2175 public void visitTypeCast(JCTypeCast tree) { 2176 setTypeAnnotationPositions(tree.pos); 2177 result = genExpr(tree.expr, tree.clazz.type).load(); 2178 // Additional code is only needed if we cast to a reference type 2179 // which is not statically a supertype of the expression's type. 2180 // For basic types, the coerce(...) in genExpr(...) will do 2181 // the conversion. 2182 if (!tree.clazz.type.isPrimitive() && 2183 !types.isSameType(tree.expr.type, tree.clazz.type) && 2184 types.asSuper(tree.expr.type, tree.clazz.type.tsym) == null) { 2185 code.emitop2(checkcast, makeRef(tree.pos(), tree.clazz.type)); 2186 } 2187 } 2188 2189 public void visitWildcard(JCWildcard tree) { 2190 throw new AssertionError(this.getClass().getName()); 2191 } 2192 2193 public void visitTypeTest(JCInstanceOf tree) { 2194 setTypeAnnotationPositions(tree.pos); 2195 genExpr(tree.expr, tree.expr.type).load(); 2196 code.emitop2(instanceof_, makeRef(tree.pos(), tree.clazz.type)); 2197 result = items.makeStackItem(syms.booleanType); 2198 } 2199 2200 public void visitIndexed(JCArrayAccess tree) { 2201 genExpr(tree.indexed, tree.indexed.type).load(); 2202 genExpr(tree.index, syms.intType).load(); 2203 result = items.makeIndexedItem(tree.type); 2204 } 2205 2206 public void visitIdent(JCIdent tree) { 2207 Symbol sym = tree.sym; 2208 if (tree.name == names._this || tree.name == names._super) { 2209 Item res = tree.name == names._this 2210 ? items.makeThisItem() 2211 : items.makeSuperItem(); 2212 if (sym.kind == MTH) { 2213 // Generate code to address the constructor. 2214 res.load(); 2215 res = items.makeMemberItem(sym, true); 2216 } 2217 result = res; 2218 } else if (sym.kind == VAR && sym.owner.kind == MTH) { 2219 result = items.makeLocalItem((VarSymbol)sym); 2220 } else if (isInvokeDynamic(sym)) { 2221 result = items.makeDynamicItem(sym); 2222 } else if ((sym.flags() & STATIC) != 0) { 2223 if (!isAccessSuper(env.enclMethod)) 2224 sym = binaryQualifier(sym, env.enclClass.type); 2225 result = items.makeStaticItem(sym); 2226 } else { 2227 items.makeThisItem().load(); 2228 sym = binaryQualifier(sym, env.enclClass.type); 2229 result = items.makeMemberItem(sym, (sym.flags() & PRIVATE) != 0); 2230 } 2231 } 2232 2233 public void visitSelect(JCFieldAccess tree) { 2234 Symbol sym = tree.sym; 2235 2236 if (tree.name == names._class) { 2237 code.emitLdc(makeRef(tree.pos(), tree.selected.type)); 2238 result = items.makeStackItem(pt); 2239 return; 2240 } 2241 2242 Symbol ssym = TreeInfo.symbol(tree.selected); 2243 2244 // Are we selecting via super? 2245 boolean selectSuper = 2246 ssym != null && (ssym.kind == TYP || ssym.name == names._super); 2247 2248 // Are we accessing a member of the superclass in an access method 2249 // resulting from a qualified super? 2250 boolean accessSuper = isAccessSuper(env.enclMethod); 2251 2252 Item base = (selectSuper) 2253 ? items.makeSuperItem() 2254 : genExpr(tree.selected, tree.selected.type); 2255 2256 if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) { 2257 // We are seeing a variable that is constant but its selecting 2258 // expression is not. 2259 if ((sym.flags() & STATIC) != 0) { 2260 if (!selectSuper && (ssym == null || ssym.kind != TYP)) 2261 base = base.load(); 2262 base.drop(); 2263 } else { 2264 base.load(); 2265 genNullCheck(tree.selected.pos()); 2266 } 2267 result = items. 2268 makeImmediateItem(sym.type, ((VarSymbol) sym).getConstValue()); 2269 } else { 2270 if (isInvokeDynamic(sym)) { 2271 result = items.makeDynamicItem(sym); 2272 return; 2273 } else { 2274 sym = binaryQualifier(sym, tree.selected.type); 2275 } 2276 if ((sym.flags() & STATIC) != 0) { 2277 if (!selectSuper && (ssym == null || ssym.kind != TYP)) 2278 base = base.load(); 2279 base.drop(); 2280 result = items.makeStaticItem(sym); 2281 } else { 2282 base.load(); 2283 if (sym == syms.lengthVar) { 2284 code.emitop0(arraylength); 2285 result = items.makeStackItem(syms.intType); 2286 } else { 2287 result = items. 2288 makeMemberItem(sym, 2289 (sym.flags() & PRIVATE) != 0 || 2290 selectSuper || accessSuper); 2291 } 2292 } 2293 } 2294 } 2295 2296 public boolean isInvokeDynamic(Symbol sym) { 2297 return sym.kind == MTH && ((MethodSymbol)sym).isDynamic(); 2298 } 2299 2300 public void visitLiteral(JCLiteral tree) { 2301 if (tree.type.hasTag(BOT)) { 2302 code.emitop0(aconst_null); 2303 result = items.makeStackItem(tree.type); 2304 } 2305 else 2306 result = items.makeImmediateItem(tree.type, tree.value); 2307 } 2308 2309 public void visitLetExpr(LetExpr tree) { 2310 int limit = code.nextreg; 2311 genStats(tree.defs, env); 2312 result = genExpr(tree.expr, tree.expr.type).load(); 2313 code.endScopes(limit); 2314 } 2315 2316 private void generateReferencesToPrunedTree(ClassSymbol classSymbol, Pool pool) { 2317 List<JCTree> prunedInfo = lower.prunedTree.get(classSymbol); 2318 if (prunedInfo != null) { 2319 for (JCTree prunedTree: prunedInfo) { 2320 prunedTree.accept(classReferenceVisitor); 2321 } 2322 } 2323 } 2324 2325/* ************************************************************************ 2326 * main method 2327 *************************************************************************/ 2328 2329 /** Generate code for a class definition. 2330 * @param env The attribution environment that belongs to the 2331 * outermost class containing this class definition. 2332 * We need this for resolving some additional symbols. 2333 * @param cdef The tree representing the class definition. 2334 * @return True if code is generated with no errors. 2335 */ 2336 public boolean genClass(Env<AttrContext> env, JCClassDecl cdef) { 2337 try { 2338 attrEnv = env; 2339 ClassSymbol c = cdef.sym; 2340 this.toplevel = env.toplevel; 2341 this.endPosTable = toplevel.endPositions; 2342 cdef.defs = normalizeDefs(cdef.defs, c); 2343 c.pool = pool; 2344 pool.reset(); 2345 generateReferencesToPrunedTree(c, pool); 2346 Env<GenContext> localEnv = new Env<>(cdef, new GenContext()); 2347 localEnv.toplevel = env.toplevel; 2348 localEnv.enclClass = cdef; 2349 2350 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) { 2351 genDef(l.head, localEnv); 2352 } 2353 if (pool.numEntries() > Pool.MAX_ENTRIES) { 2354 log.error(cdef.pos(), "limit.pool"); 2355 nerrs++; 2356 } 2357 if (nerrs != 0) { 2358 // if errors, discard code 2359 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) { 2360 if (l.head.hasTag(METHODDEF)) 2361 ((JCMethodDecl) l.head).sym.code = null; 2362 } 2363 } 2364 cdef.defs = List.nil(); // discard trees 2365 return nerrs == 0; 2366 } finally { 2367 // note: this method does NOT support recursion. 2368 attrEnv = null; 2369 this.env = null; 2370 toplevel = null; 2371 endPosTable = null; 2372 nerrs = 0; 2373 } 2374 } 2375 2376/* ************************************************************************ 2377 * Auxiliary classes 2378 *************************************************************************/ 2379 2380 /** An abstract class for finalizer generation. 2381 */ 2382 abstract class GenFinalizer { 2383 /** Generate code to clean up when unwinding. */ 2384 abstract void gen(); 2385 2386 /** Generate code to clean up at last. */ 2387 abstract void genLast(); 2388 2389 /** Does this finalizer have some nontrivial cleanup to perform? */ 2390 boolean hasFinalizer() { return true; } 2391 } 2392 2393 /** code generation contexts, 2394 * to be used as type parameter for environments. 2395 */ 2396 static class GenContext { 2397 2398 /** A chain for all unresolved jumps that exit the current environment. 2399 */ 2400 Chain exit = null; 2401 2402 /** A chain for all unresolved jumps that continue in the 2403 * current environment. 2404 */ 2405 Chain cont = null; 2406 2407 /** A closure that generates the finalizer of the current environment. 2408 * Only set for Synchronized and Try contexts. 2409 */ 2410 GenFinalizer finalize = null; 2411 2412 /** Is this a switch statement? If so, allocate registers 2413 * even when the variable declaration is unreachable. 2414 */ 2415 boolean isSwitch = false; 2416 2417 /** A list buffer containing all gaps in the finalizer range, 2418 * where a catch all exception should not apply. 2419 */ 2420 ListBuffer<Integer> gaps = null; 2421 2422 /** Add given chain to exit chain. 2423 */ 2424 void addExit(Chain c) { 2425 exit = Code.mergeChains(c, exit); 2426 } 2427 2428 /** Add given chain to cont chain. 2429 */ 2430 void addCont(Chain c) { 2431 cont = Code.mergeChains(c, cont); 2432 } 2433 } 2434 2435} 2436