Gen.java revision 3225:3a9a4b5eabe4
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 Map<Type,Symbol> stringBufferAppend; 73 private Name accessDollar; 74 private final Types types; 75 private final Lower lower; 76 private final Flow flow; 77 private final Annotate annotate; 78 79 /** Format of stackmap tables to be generated. */ 80 private final Code.StackMapFormat stackMap; 81 82 /** A type that serves as the expected type for all method expressions. 83 */ 84 private final Type methodType; 85 86 public static Gen instance(Context context) { 87 Gen instance = context.get(genKey); 88 if (instance == null) 89 instance = new Gen(context); 90 return instance; 91 } 92 93 /** Constant pool, reset by genClass. 94 */ 95 private Pool pool; 96 97 protected Gen(Context context) { 98 context.put(genKey, this); 99 100 names = Names.instance(context); 101 log = Log.instance(context); 102 syms = Symtab.instance(context); 103 chk = Check.instance(context); 104 rs = Resolve.instance(context); 105 make = TreeMaker.instance(context); 106 target = Target.instance(context); 107 types = Types.instance(context); 108 methodType = new MethodType(null, null, null, syms.methodClass); 109 stringBufferAppend = new HashMap<>(); 110 accessDollar = names. 111 fromString("access" + target.syntheticNameChar()); 112 flow = Flow.instance(context); 113 lower = Lower.instance(context); 114 115 Options options = Options.instance(context); 116 lineDebugInfo = 117 options.isUnset(G_CUSTOM) || 118 options.isSet(G_CUSTOM, "lines"); 119 varDebugInfo = 120 options.isUnset(G_CUSTOM) 121 ? options.isSet(G) 122 : options.isSet(G_CUSTOM, "vars"); 123 genCrt = options.isSet(XJCOV); 124 debugCode = options.isSet("debugcode"); 125 allowInvokedynamic = target.hasInvokedynamic() || options.isSet("invokedynamic"); 126 allowBetterNullChecks = target.hasObjects(); 127 pool = new Pool(types); 128 129 // ignore cldc because we cannot have both stackmap formats 130 this.stackMap = StackMapFormat.JSR202; 131 132 // by default, avoid jsr's for simple finalizers 133 int setjsrlimit = 50; 134 String jsrlimitString = options.get("jsrlimit"); 135 if (jsrlimitString != null) { 136 try { 137 setjsrlimit = Integer.parseInt(jsrlimitString); 138 } catch (NumberFormatException ex) { 139 // ignore ill-formed numbers for jsrlimit 140 } 141 } 142 this.jsrlimit = setjsrlimit; 143 this.useJsrLocally = false; // reset in visitTry 144 annotate = Annotate.instance(context); 145 } 146 147 /** Switches 148 */ 149 private final boolean lineDebugInfo; 150 private final boolean varDebugInfo; 151 private final boolean genCrt; 152 private final boolean debugCode; 153 private final boolean allowInvokedynamic; 154 private final boolean allowBetterNullChecks; 155 156 /** Default limit of (approximate) size of finalizer to inline. 157 * Zero means always use jsr. 100 or greater means never use 158 * jsr. 159 */ 160 private final int jsrlimit; 161 162 /** True if jsr is used. 163 */ 164 private boolean useJsrLocally; 165 166 /** Code buffer, set by genMethod. 167 */ 168 private Code code; 169 170 /** Items structure, set by genMethod. 171 */ 172 private Items items; 173 174 /** Environment for symbol lookup, set by genClass 175 */ 176 private Env<AttrContext> attrEnv; 177 178 /** The top level tree. 179 */ 180 private JCCompilationUnit toplevel; 181 182 /** The number of code-gen errors in this class. 183 */ 184 private int nerrs = 0; 185 186 /** An object containing mappings of syntax trees to their 187 * ending source positions. 188 */ 189 EndPosTable endPosTable; 190 191 /** Generate code to load an integer constant. 192 * @param n The integer to be loaded. 193 */ 194 void loadIntConst(int n) { 195 items.makeImmediateItem(syms.intType, n).load(); 196 } 197 198 /** The opcode that loads a zero constant of a given type code. 199 * @param tc The given type code (@see ByteCode). 200 */ 201 public static int zero(int tc) { 202 switch(tc) { 203 case INTcode: case BYTEcode: case SHORTcode: case CHARcode: 204 return iconst_0; 205 case LONGcode: 206 return lconst_0; 207 case FLOATcode: 208 return fconst_0; 209 case DOUBLEcode: 210 return dconst_0; 211 default: 212 throw new AssertionError("zero"); 213 } 214 } 215 216 /** The opcode that loads a one constant of a given type code. 217 * @param tc The given type code (@see ByteCode). 218 */ 219 public static int one(int tc) { 220 return zero(tc) + 1; 221 } 222 223 /** Generate code to load -1 of the given type code (either int or long). 224 * @param tc The given type code (@see ByteCode). 225 */ 226 void emitMinusOne(int tc) { 227 if (tc == LONGcode) { 228 items.makeImmediateItem(syms.longType, new Long(-1)).load(); 229 } else { 230 code.emitop0(iconst_m1); 231 } 232 } 233 234 /** Construct a symbol to reflect the qualifying type that should 235 * appear in the byte code as per JLS 13.1. 236 * 237 * For {@literal target >= 1.2}: Clone a method with the qualifier as owner (except 238 * for those cases where we need to work around VM bugs). 239 * 240 * For {@literal target <= 1.1}: If qualified variable or method is defined in a 241 * non-accessible class, clone it with the qualifier class as owner. 242 * 243 * @param sym The accessed symbol 244 * @param site The qualifier's type. 245 */ 246 Symbol binaryQualifier(Symbol sym, Type site) { 247 248 if (site.hasTag(ARRAY)) { 249 if (sym == syms.lengthVar || 250 sym.owner != syms.arrayClass) 251 return sym; 252 // array clone can be qualified by the array type in later targets 253 Symbol qualifier = new ClassSymbol(Flags.PUBLIC, site.tsym.name, 254 site, syms.noSymbol); 255 return sym.clone(qualifier); 256 } 257 258 if (sym.owner == site.tsym || 259 (sym.flags() & (STATIC | SYNTHETIC)) == (STATIC | SYNTHETIC)) { 260 return sym; 261 } 262 263 // leave alone methods inherited from Object 264 // JLS 13.1. 265 if (sym.owner == syms.objectType.tsym) 266 return sym; 267 268 return sym.clone(site.tsym); 269 } 270 271 /** Insert a reference to given type in the constant pool, 272 * checking for an array with too many dimensions; 273 * return the reference's index. 274 * @param type The type for which a reference is inserted. 275 */ 276 int makeRef(DiagnosticPosition pos, Type type) { 277 checkDimension(pos, type); 278 if (type.isAnnotated()) { 279 return pool.put((Object)type); 280 } else { 281 return pool.put(type.hasTag(CLASS) ? (Object)type.tsym : (Object)type); 282 } 283 } 284 285 /** Check if the given type is an array with too many dimensions. 286 */ 287 private void checkDimension(DiagnosticPosition pos, Type t) { 288 switch (t.getTag()) { 289 case METHOD: 290 checkDimension(pos, t.getReturnType()); 291 for (List<Type> args = t.getParameterTypes(); args.nonEmpty(); args = args.tail) 292 checkDimension(pos, args.head); 293 break; 294 case ARRAY: 295 if (types.dimensions(t) > ClassFile.MAX_DIMENSIONS) { 296 log.error(pos, "limit.dimensions"); 297 nerrs++; 298 } 299 break; 300 default: 301 break; 302 } 303 } 304 305 /** Create a tempory variable. 306 * @param type The variable's type. 307 */ 308 LocalItem makeTemp(Type type) { 309 VarSymbol v = new VarSymbol(Flags.SYNTHETIC, 310 names.empty, 311 type, 312 env.enclMethod.sym); 313 code.newLocal(v); 314 return items.makeLocalItem(v); 315 } 316 317 /** Generate code to call a non-private method or constructor. 318 * @param pos Position to be used for error reporting. 319 * @param site The type of which the method is a member. 320 * @param name The method's name. 321 * @param argtypes The method's argument types. 322 * @param isStatic A flag that indicates whether we call a 323 * static or instance method. 324 */ 325 void callMethod(DiagnosticPosition pos, 326 Type site, Name name, List<Type> argtypes, 327 boolean isStatic) { 328 Symbol msym = rs. 329 resolveInternalMethod(pos, attrEnv, site, name, argtypes, null); 330 if (isStatic) items.makeStaticItem(msym).invoke(); 331 else items.makeMemberItem(msym, name == names.init).invoke(); 332 } 333 334 /** Is the given method definition an access method 335 * resulting from a qualified super? This is signified by an odd 336 * access code. 337 */ 338 private boolean isAccessSuper(JCMethodDecl enclMethod) { 339 return 340 (enclMethod.mods.flags & SYNTHETIC) != 0 && 341 isOddAccessName(enclMethod.name); 342 } 343 344 /** Does given name start with "access$" and end in an odd digit? 345 */ 346 private boolean isOddAccessName(Name name) { 347 return 348 name.startsWith(accessDollar) && 349 (name.getByteAt(name.getByteLength() - 1) & 1) == 1; 350 } 351 352/* ************************************************************************ 353 * Non-local exits 354 *************************************************************************/ 355 356 /** Generate code to invoke the finalizer associated with given 357 * environment. 358 * Any calls to finalizers are appended to the environments `cont' chain. 359 * Mark beginning of gap in catch all range for finalizer. 360 */ 361 void genFinalizer(Env<GenContext> env) { 362 if (code.isAlive() && env.info.finalize != null) 363 env.info.finalize.gen(); 364 } 365 366 /** Generate code to call all finalizers of structures aborted by 367 * a non-local 368 * exit. Return target environment of the non-local exit. 369 * @param target The tree representing the structure that's aborted 370 * @param env The environment current at the non-local exit. 371 */ 372 Env<GenContext> unwind(JCTree target, Env<GenContext> env) { 373 Env<GenContext> env1 = env; 374 while (true) { 375 genFinalizer(env1); 376 if (env1.tree == target) break; 377 env1 = env1.next; 378 } 379 return env1; 380 } 381 382 /** Mark end of gap in catch-all range for finalizer. 383 * @param env the environment which might contain the finalizer 384 * (if it does, env.info.gaps != null). 385 */ 386 void endFinalizerGap(Env<GenContext> env) { 387 if (env.info.gaps != null && env.info.gaps.length() % 2 == 1) 388 env.info.gaps.append(code.curCP()); 389 } 390 391 /** Mark end of all gaps in catch-all ranges for finalizers of environments 392 * lying between, and including to two environments. 393 * @param from the most deeply nested environment to mark 394 * @param to the least deeply nested environment to mark 395 */ 396 void endFinalizerGaps(Env<GenContext> from, Env<GenContext> to) { 397 Env<GenContext> last = null; 398 while (last != to) { 399 endFinalizerGap(from); 400 last = from; 401 from = from.next; 402 } 403 } 404 405 /** Do any of the structures aborted by a non-local exit have 406 * finalizers that require an empty stack? 407 * @param target The tree representing the structure that's aborted 408 * @param env The environment current at the non-local exit. 409 */ 410 boolean hasFinally(JCTree target, Env<GenContext> env) { 411 while (env.tree != target) { 412 if (env.tree.hasTag(TRY) && env.info.finalize.hasFinalizer()) 413 return true; 414 env = env.next; 415 } 416 return false; 417 } 418 419/* ************************************************************************ 420 * Normalizing class-members. 421 *************************************************************************/ 422 423 /** Distribute member initializer code into constructors and {@code <clinit>} 424 * method. 425 * @param defs The list of class member declarations. 426 * @param c The enclosing class. 427 */ 428 List<JCTree> normalizeDefs(List<JCTree> defs, ClassSymbol c) { 429 ListBuffer<JCStatement> initCode = new ListBuffer<>(); 430 ListBuffer<Attribute.TypeCompound> initTAs = new ListBuffer<>(); 431 ListBuffer<JCStatement> clinitCode = new ListBuffer<>(); 432 ListBuffer<Attribute.TypeCompound> clinitTAs = new ListBuffer<>(); 433 ListBuffer<JCTree> methodDefs = new ListBuffer<>(); 434 // Sort definitions into three listbuffers: 435 // - initCode for instance initializers 436 // - clinitCode for class initializers 437 // - methodDefs for method definitions 438 for (List<JCTree> l = defs; l.nonEmpty(); l = l.tail) { 439 JCTree def = l.head; 440 switch (def.getTag()) { 441 case BLOCK: 442 JCBlock block = (JCBlock)def; 443 if ((block.flags & STATIC) != 0) 444 clinitCode.append(block); 445 else if ((block.flags & SYNTHETIC) == 0) 446 initCode.append(block); 447 break; 448 case METHODDEF: 449 methodDefs.append(def); 450 break; 451 case VARDEF: 452 JCVariableDecl vdef = (JCVariableDecl) def; 453 VarSymbol sym = vdef.sym; 454 checkDimension(vdef.pos(), sym.type); 455 if (vdef.init != null) { 456 if ((sym.flags() & STATIC) == 0) { 457 // Always initialize instance variables. 458 JCStatement init = make.at(vdef.pos()). 459 Assignment(sym, vdef.init); 460 initCode.append(init); 461 endPosTable.replaceTree(vdef, init); 462 initTAs.addAll(getAndRemoveNonFieldTAs(sym)); 463 } else if (sym.getConstValue() == null) { 464 // Initialize class (static) variables only if 465 // they are not compile-time constants. 466 JCStatement init = make.at(vdef.pos). 467 Assignment(sym, vdef.init); 468 clinitCode.append(init); 469 endPosTable.replaceTree(vdef, init); 470 clinitTAs.addAll(getAndRemoveNonFieldTAs(sym)); 471 } else { 472 checkStringConstant(vdef.init.pos(), sym.getConstValue()); 473 /* if the init contains a reference to an external class, add it to the 474 * constant's pool 475 */ 476 vdef.init.accept(classReferenceVisitor); 477 } 478 } 479 break; 480 default: 481 Assert.error(); 482 } 483 } 484 // Insert any instance initializers into all constructors. 485 if (initCode.length() != 0) { 486 List<JCStatement> inits = initCode.toList(); 487 initTAs.addAll(c.getInitTypeAttributes()); 488 List<Attribute.TypeCompound> initTAlist = initTAs.toList(); 489 for (JCTree t : methodDefs) { 490 normalizeMethod((JCMethodDecl)t, inits, initTAlist); 491 } 492 } 493 // If there are class initializers, create a <clinit> method 494 // that contains them as its body. 495 if (clinitCode.length() != 0) { 496 MethodSymbol clinit = new MethodSymbol( 497 STATIC | (c.flags() & STRICTFP), 498 names.clinit, 499 new MethodType( 500 List.<Type>nil(), syms.voidType, 501 List.<Type>nil(), syms.methodClass), 502 c); 503 c.members().enter(clinit); 504 List<JCStatement> clinitStats = clinitCode.toList(); 505 JCBlock block = make.at(clinitStats.head.pos()).Block(0, clinitStats); 506 block.endpos = TreeInfo.endPos(clinitStats.last()); 507 methodDefs.append(make.MethodDef(clinit, block)); 508 509 if (!clinitTAs.isEmpty()) 510 clinit.appendUniqueTypeAttributes(clinitTAs.toList()); 511 if (!c.getClassInitTypeAttributes().isEmpty()) 512 clinit.appendUniqueTypeAttributes(c.getClassInitTypeAttributes()); 513 } 514 // Return all method definitions. 515 return methodDefs.toList(); 516 } 517 518 private List<Attribute.TypeCompound> getAndRemoveNonFieldTAs(VarSymbol sym) { 519 List<TypeCompound> tas = sym.getRawTypeAttributes(); 520 ListBuffer<Attribute.TypeCompound> fieldTAs = new ListBuffer<>(); 521 ListBuffer<Attribute.TypeCompound> nonfieldTAs = new ListBuffer<>(); 522 for (TypeCompound ta : tas) { 523 Assert.check(ta.getPosition().type != TargetType.UNKNOWN); 524 if (ta.getPosition().type == TargetType.FIELD) { 525 fieldTAs.add(ta); 526 } else { 527 nonfieldTAs.add(ta); 528 } 529 } 530 sym.setTypeAttributes(fieldTAs.toList()); 531 return nonfieldTAs.toList(); 532 } 533 534 /** Check a constant value and report if it is a string that is 535 * too large. 536 */ 537 private void checkStringConstant(DiagnosticPosition pos, Object constValue) { 538 if (nerrs != 0 || // only complain about a long string once 539 constValue == null || 540 !(constValue instanceof String) || 541 ((String)constValue).length() < Pool.MAX_STRING_LENGTH) 542 return; 543 log.error(pos, "limit.string"); 544 nerrs++; 545 } 546 547 /** Insert instance initializer code into initial constructor. 548 * @param md The tree potentially representing a 549 * constructor's definition. 550 * @param initCode The list of instance initializer statements. 551 * @param initTAs Type annotations from the initializer expression. 552 */ 553 void normalizeMethod(JCMethodDecl md, List<JCStatement> initCode, List<TypeCompound> initTAs) { 554 if (md.name == names.init && TreeInfo.isInitialConstructor(md)) { 555 // We are seeing a constructor that does not call another 556 // constructor of the same class. 557 List<JCStatement> stats = md.body.stats; 558 ListBuffer<JCStatement> newstats = new ListBuffer<>(); 559 560 if (stats.nonEmpty()) { 561 // Copy initializers of synthetic variables generated in 562 // the translation of inner classes. 563 while (TreeInfo.isSyntheticInit(stats.head)) { 564 newstats.append(stats.head); 565 stats = stats.tail; 566 } 567 // Copy superclass constructor call 568 newstats.append(stats.head); 569 stats = stats.tail; 570 // Copy remaining synthetic initializers. 571 while (stats.nonEmpty() && 572 TreeInfo.isSyntheticInit(stats.head)) { 573 newstats.append(stats.head); 574 stats = stats.tail; 575 } 576 // Now insert the initializer code. 577 newstats.appendList(initCode); 578 // And copy all remaining statements. 579 while (stats.nonEmpty()) { 580 newstats.append(stats.head); 581 stats = stats.tail; 582 } 583 } 584 md.body.stats = newstats.toList(); 585 if (md.body.endpos == Position.NOPOS) 586 md.body.endpos = TreeInfo.endPos(md.body.stats.last()); 587 588 md.sym.appendUniqueTypeAttributes(initTAs); 589 } 590 } 591 592/* ************************************************************************ 593 * Traversal methods 594 *************************************************************************/ 595 596 /** Visitor argument: The current environment. 597 */ 598 Env<GenContext> env; 599 600 /** Visitor argument: The expected type (prototype). 601 */ 602 Type pt; 603 604 /** Visitor result: The item representing the computed value. 605 */ 606 Item result; 607 608 /** Visitor method: generate code for a definition, catching and reporting 609 * any completion failures. 610 * @param tree The definition to be visited. 611 * @param env The environment current at the definition. 612 */ 613 public void genDef(JCTree tree, Env<GenContext> env) { 614 Env<GenContext> prevEnv = this.env; 615 try { 616 this.env = env; 617 tree.accept(this); 618 } catch (CompletionFailure ex) { 619 chk.completionError(tree.pos(), ex); 620 } finally { 621 this.env = prevEnv; 622 } 623 } 624 625 /** Derived visitor method: check whether CharacterRangeTable 626 * should be emitted, if so, put a new entry into CRTable 627 * and call method to generate bytecode. 628 * If not, just call method to generate bytecode. 629 * @see #genStat(JCTree, Env) 630 * 631 * @param tree The tree to be visited. 632 * @param env The environment to use. 633 * @param crtFlags The CharacterRangeTable flags 634 * indicating type of the entry. 635 */ 636 public void genStat(JCTree tree, Env<GenContext> env, int crtFlags) { 637 if (!genCrt) { 638 genStat(tree, env); 639 return; 640 } 641 int startpc = code.curCP(); 642 genStat(tree, env); 643 if (tree.hasTag(Tag.BLOCK)) crtFlags |= CRT_BLOCK; 644 code.crt.put(tree, crtFlags, startpc, code.curCP()); 645 } 646 647 /** Derived visitor method: generate code for a statement. 648 */ 649 public void genStat(JCTree tree, Env<GenContext> env) { 650 if (code.isAlive()) { 651 code.statBegin(tree.pos); 652 genDef(tree, env); 653 } else if (env.info.isSwitch && tree.hasTag(VARDEF)) { 654 // variables whose declarations are in a switch 655 // can be used even if the decl is unreachable. 656 code.newLocal(((JCVariableDecl) tree).sym); 657 } 658 } 659 660 /** Derived visitor method: check whether CharacterRangeTable 661 * should be emitted, if so, put a new entry into CRTable 662 * and call method to generate bytecode. 663 * If not, just call method to generate bytecode. 664 * @see #genStats(List, Env) 665 * 666 * @param trees The list of trees to be visited. 667 * @param env The environment to use. 668 * @param crtFlags The CharacterRangeTable flags 669 * indicating type of the entry. 670 */ 671 public void genStats(List<JCStatement> trees, Env<GenContext> env, int crtFlags) { 672 if (!genCrt) { 673 genStats(trees, env); 674 return; 675 } 676 if (trees.length() == 1) { // mark one statement with the flags 677 genStat(trees.head, env, crtFlags | CRT_STATEMENT); 678 } else { 679 int startpc = code.curCP(); 680 genStats(trees, env); 681 code.crt.put(trees, crtFlags, startpc, code.curCP()); 682 } 683 } 684 685 /** Derived visitor method: generate code for a list of statements. 686 */ 687 public void genStats(List<? extends JCTree> trees, Env<GenContext> env) { 688 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail) 689 genStat(l.head, env, CRT_STATEMENT); 690 } 691 692 /** Derived visitor method: check whether CharacterRangeTable 693 * should be emitted, if so, put a new entry into CRTable 694 * and call method to generate bytecode. 695 * If not, just call method to generate bytecode. 696 * @see #genCond(JCTree,boolean) 697 * 698 * @param tree The tree to be visited. 699 * @param crtFlags The CharacterRangeTable flags 700 * indicating type of the entry. 701 */ 702 public CondItem genCond(JCTree tree, int crtFlags) { 703 if (!genCrt) return genCond(tree, false); 704 int startpc = code.curCP(); 705 CondItem item = genCond(tree, (crtFlags & CRT_FLOW_CONTROLLER) != 0); 706 code.crt.put(tree, crtFlags, startpc, code.curCP()); 707 return item; 708 } 709 710 /** Derived visitor method: generate code for a boolean 711 * expression in a control-flow context. 712 * @param _tree The expression to be visited. 713 * @param markBranches The flag to indicate that the condition is 714 * a flow controller so produced conditions 715 * should contain a proper tree to generate 716 * CharacterRangeTable branches for them. 717 */ 718 public CondItem genCond(JCTree _tree, boolean markBranches) { 719 JCTree inner_tree = TreeInfo.skipParens(_tree); 720 if (inner_tree.hasTag(CONDEXPR)) { 721 JCConditional tree = (JCConditional)inner_tree; 722 CondItem cond = genCond(tree.cond, CRT_FLOW_CONTROLLER); 723 if (cond.isTrue()) { 724 code.resolve(cond.trueJumps); 725 CondItem result = genCond(tree.truepart, CRT_FLOW_TARGET); 726 if (markBranches) result.tree = tree.truepart; 727 return result; 728 } 729 if (cond.isFalse()) { 730 code.resolve(cond.falseJumps); 731 CondItem result = genCond(tree.falsepart, CRT_FLOW_TARGET); 732 if (markBranches) result.tree = tree.falsepart; 733 return result; 734 } 735 Chain secondJumps = cond.jumpFalse(); 736 code.resolve(cond.trueJumps); 737 CondItem first = genCond(tree.truepart, CRT_FLOW_TARGET); 738 if (markBranches) first.tree = tree.truepart; 739 Chain falseJumps = first.jumpFalse(); 740 code.resolve(first.trueJumps); 741 Chain trueJumps = code.branch(goto_); 742 code.resolve(secondJumps); 743 CondItem second = genCond(tree.falsepart, CRT_FLOW_TARGET); 744 CondItem result = items.makeCondItem(second.opcode, 745 Code.mergeChains(trueJumps, second.trueJumps), 746 Code.mergeChains(falseJumps, second.falseJumps)); 747 if (markBranches) result.tree = tree.falsepart; 748 return result; 749 } else { 750 CondItem result = genExpr(_tree, syms.booleanType).mkCond(); 751 if (markBranches) result.tree = _tree; 752 return result; 753 } 754 } 755 756 /** Visitor class for expressions which might be constant expressions. 757 * This class is a subset of TreeScanner. Intended to visit trees pruned by 758 * Lower as long as constant expressions looking for references to any 759 * ClassSymbol. Any such reference will be added to the constant pool so 760 * automated tools can detect class dependencies better. 761 */ 762 class ClassReferenceVisitor extends JCTree.Visitor { 763 764 @Override 765 public void visitTree(JCTree tree) {} 766 767 @Override 768 public void visitBinary(JCBinary tree) { 769 tree.lhs.accept(this); 770 tree.rhs.accept(this); 771 } 772 773 @Override 774 public void visitSelect(JCFieldAccess tree) { 775 if (tree.selected.type.hasTag(CLASS)) { 776 makeRef(tree.selected.pos(), tree.selected.type); 777 } 778 } 779 780 @Override 781 public void visitIdent(JCIdent tree) { 782 if (tree.sym.owner instanceof ClassSymbol) { 783 pool.put(tree.sym.owner); 784 } 785 } 786 787 @Override 788 public void visitConditional(JCConditional tree) { 789 tree.cond.accept(this); 790 tree.truepart.accept(this); 791 tree.falsepart.accept(this); 792 } 793 794 @Override 795 public void visitUnary(JCUnary tree) { 796 tree.arg.accept(this); 797 } 798 799 @Override 800 public void visitParens(JCParens tree) { 801 tree.expr.accept(this); 802 } 803 804 @Override 805 public void visitTypeCast(JCTypeCast tree) { 806 tree.expr.accept(this); 807 } 808 } 809 810 private ClassReferenceVisitor classReferenceVisitor = new ClassReferenceVisitor(); 811 812 /** Visitor method: generate code for an expression, catching and reporting 813 * any completion failures. 814 * @param tree The expression to be visited. 815 * @param pt The expression's expected type (proto-type). 816 */ 817 public Item genExpr(JCTree tree, Type pt) { 818 Type prevPt = this.pt; 819 try { 820 if (tree.type.constValue() != null) { 821 // Short circuit any expressions which are constants 822 tree.accept(classReferenceVisitor); 823 checkStringConstant(tree.pos(), tree.type.constValue()); 824 result = items.makeImmediateItem(tree.type, tree.type.constValue()); 825 } else { 826 this.pt = pt; 827 tree.accept(this); 828 } 829 return result.coerce(pt); 830 } catch (CompletionFailure ex) { 831 chk.completionError(tree.pos(), ex); 832 code.state.stacksize = 1; 833 return items.makeStackItem(pt); 834 } finally { 835 this.pt = prevPt; 836 } 837 } 838 839 /** Derived visitor method: generate code for a list of method arguments. 840 * @param trees The argument expressions to be visited. 841 * @param pts The expression's expected types (i.e. the formal parameter 842 * types of the invoked method). 843 */ 844 public void genArgs(List<JCExpression> trees, List<Type> pts) { 845 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail) { 846 genExpr(l.head, pts.head).load(); 847 pts = pts.tail; 848 } 849 // require lists be of same length 850 Assert.check(pts.isEmpty()); 851 } 852 853/* ************************************************************************ 854 * Visitor methods for statements and definitions 855 *************************************************************************/ 856 857 /** Thrown when the byte code size exceeds limit. 858 */ 859 public static class CodeSizeOverflow extends RuntimeException { 860 private static final long serialVersionUID = 0; 861 public CodeSizeOverflow() {} 862 } 863 864 public void visitMethodDef(JCMethodDecl tree) { 865 // Create a new local environment that points pack at method 866 // definition. 867 Env<GenContext> localEnv = env.dup(tree); 868 localEnv.enclMethod = tree; 869 // The expected type of every return statement in this method 870 // is the method's return type. 871 this.pt = tree.sym.erasure(types).getReturnType(); 872 873 checkDimension(tree.pos(), tree.sym.erasure(types)); 874 genMethod(tree, localEnv, false); 875 } 876//where 877 /** Generate code for a method. 878 * @param tree The tree representing the method definition. 879 * @param env The environment current for the method body. 880 * @param fatcode A flag that indicates whether all jumps are 881 * within 32K. We first invoke this method under 882 * the assumption that fatcode == false, i.e. all 883 * jumps are within 32K. If this fails, fatcode 884 * is set to true and we try again. 885 */ 886 void genMethod(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) { 887 MethodSymbol meth = tree.sym; 888 int extras = 0; 889 // Count up extra parameters 890 if (meth.isConstructor()) { 891 extras++; 892 if (meth.enclClass().isInner() && 893 !meth.enclClass().isStatic()) { 894 extras++; 895 } 896 } else if ((tree.mods.flags & STATIC) == 0) { 897 extras++; 898 } 899 // System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG 900 if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes()) + extras > 901 ClassFile.MAX_PARAMETERS) { 902 log.error(tree.pos(), "limit.parameters"); 903 nerrs++; 904 } 905 906 else if (tree.body != null) { 907 // Create a new code structure and initialize it. 908 int startpcCrt = initCode(tree, env, fatcode); 909 910 try { 911 genStat(tree.body, env); 912 } catch (CodeSizeOverflow e) { 913 // Failed due to code limit, try again with jsr/ret 914 startpcCrt = initCode(tree, env, fatcode); 915 genStat(tree.body, env); 916 } 917 918 if (code.state.stacksize != 0) { 919 log.error(tree.body.pos(), "stack.sim.error", tree); 920 throw new AssertionError(); 921 } 922 923 // If last statement could complete normally, insert a 924 // return at the end. 925 if (code.isAlive()) { 926 code.statBegin(TreeInfo.endPos(tree.body)); 927 if (env.enclMethod == null || 928 env.enclMethod.sym.type.getReturnType().hasTag(VOID)) { 929 code.emitop0(return_); 930 } else { 931 // sometime dead code seems alive (4415991); 932 // generate a small loop instead 933 int startpc = code.entryPoint(); 934 CondItem c = items.makeCondItem(goto_); 935 code.resolve(c.jumpTrue(), startpc); 936 } 937 } 938 if (genCrt) 939 code.crt.put(tree.body, 940 CRT_BLOCK, 941 startpcCrt, 942 code.curCP()); 943 944 code.endScopes(0); 945 946 // If we exceeded limits, panic 947 if (code.checkLimits(tree.pos(), log)) { 948 nerrs++; 949 return; 950 } 951 952 // If we generated short code but got a long jump, do it again 953 // with fatCode = true. 954 if (!fatcode && code.fatcode) genMethod(tree, env, true); 955 956 // Clean up 957 if(stackMap == StackMapFormat.JSR202) { 958 code.lastFrame = null; 959 code.frameBeforeLast = null; 960 } 961 962 // Compress exception table 963 code.compressCatchTable(); 964 965 // Fill in type annotation positions for exception parameters 966 code.fillExceptionParameterPositions(); 967 } 968 } 969 970 private int initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) { 971 MethodSymbol meth = tree.sym; 972 973 // Create a new code structure. 974 meth.code = code = new Code(meth, 975 fatcode, 976 lineDebugInfo ? toplevel.lineMap : null, 977 varDebugInfo, 978 stackMap, 979 debugCode, 980 genCrt ? new CRTable(tree, env.toplevel.endPositions) 981 : null, 982 syms, 983 types, 984 pool); 985 items = new Items(pool, code, syms, types); 986 if (code.debugCode) { 987 System.err.println(meth + " for body " + tree); 988 } 989 990 // If method is not static, create a new local variable address 991 // for `this'. 992 if ((tree.mods.flags & STATIC) == 0) { 993 Type selfType = meth.owner.type; 994 if (meth.isConstructor() && selfType != syms.objectType) 995 selfType = UninitializedType.uninitializedThis(selfType); 996 code.setDefined( 997 code.newLocal( 998 new VarSymbol(FINAL, names._this, selfType, meth.owner))); 999 } 1000 1001 // Mark all parameters as defined from the beginning of 1002 // the method. 1003 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) { 1004 checkDimension(l.head.pos(), l.head.sym.type); 1005 code.setDefined(code.newLocal(l.head.sym)); 1006 } 1007 1008 // Get ready to generate code for method body. 1009 int startpcCrt = genCrt ? code.curCP() : 0; 1010 code.entryPoint(); 1011 1012 // Suppress initial stackmap 1013 code.pendingStackMap = false; 1014 1015 return startpcCrt; 1016 } 1017 1018 public void visitVarDef(JCVariableDecl tree) { 1019 VarSymbol v = tree.sym; 1020 code.newLocal(v); 1021 if (tree.init != null) { 1022 checkStringConstant(tree.init.pos(), v.getConstValue()); 1023 if (v.getConstValue() == null || varDebugInfo) { 1024 genExpr(tree.init, v.erasure(types)).load(); 1025 items.makeLocalItem(v).store(); 1026 } 1027 } 1028 checkDimension(tree.pos(), v.type); 1029 } 1030 1031 public void visitSkip(JCSkip tree) { 1032 } 1033 1034 public void visitBlock(JCBlock tree) { 1035 int limit = code.nextreg; 1036 Env<GenContext> localEnv = env.dup(tree, new GenContext()); 1037 genStats(tree.stats, localEnv); 1038 // End the scope of all block-local variables in variable info. 1039 if (!env.tree.hasTag(METHODDEF)) { 1040 code.statBegin(tree.endpos); 1041 code.endScopes(limit); 1042 code.pendingStatPos = Position.NOPOS; 1043 } 1044 } 1045 1046 public void visitDoLoop(JCDoWhileLoop tree) { 1047 genLoop(tree, tree.body, tree.cond, List.<JCExpressionStatement>nil(), false); 1048 } 1049 1050 public void visitWhileLoop(JCWhileLoop tree) { 1051 genLoop(tree, tree.body, tree.cond, List.<JCExpressionStatement>nil(), true); 1052 } 1053 1054 public void visitForLoop(JCForLoop tree) { 1055 int limit = code.nextreg; 1056 genStats(tree.init, env); 1057 genLoop(tree, tree.body, tree.cond, tree.step, true); 1058 code.endScopes(limit); 1059 } 1060 //where 1061 /** Generate code for a loop. 1062 * @param loop The tree representing the loop. 1063 * @param body The loop's body. 1064 * @param cond The loop's controling condition. 1065 * @param step "Step" statements to be inserted at end of 1066 * each iteration. 1067 * @param testFirst True if the loop test belongs before the body. 1068 */ 1069 private void genLoop(JCStatement loop, 1070 JCStatement body, 1071 JCExpression cond, 1072 List<JCExpressionStatement> step, 1073 boolean testFirst) { 1074 Env<GenContext> loopEnv = env.dup(loop, new GenContext()); 1075 int startpc = code.entryPoint(); 1076 if (testFirst) { //while or for loop 1077 CondItem c; 1078 if (cond != null) { 1079 code.statBegin(cond.pos); 1080 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER); 1081 } else { 1082 c = items.makeCondItem(goto_); 1083 } 1084 Chain loopDone = c.jumpFalse(); 1085 code.resolve(c.trueJumps); 1086 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET); 1087 code.resolve(loopEnv.info.cont); 1088 genStats(step, loopEnv); 1089 code.resolve(code.branch(goto_), startpc); 1090 code.resolve(loopDone); 1091 } else { 1092 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET); 1093 code.resolve(loopEnv.info.cont); 1094 genStats(step, loopEnv); 1095 CondItem c; 1096 if (cond != null) { 1097 code.statBegin(cond.pos); 1098 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER); 1099 } else { 1100 c = items.makeCondItem(goto_); 1101 } 1102 code.resolve(c.jumpTrue(), startpc); 1103 code.resolve(c.falseJumps); 1104 } 1105 Chain exit = loopEnv.info.exit; 1106 if (exit != null) { 1107 code.resolve(exit); 1108 exit.state.defined.excludeFrom(code.nextreg); 1109 } 1110 } 1111 1112 public void visitForeachLoop(JCEnhancedForLoop tree) { 1113 throw new AssertionError(); // should have been removed by Lower. 1114 } 1115 1116 public void visitLabelled(JCLabeledStatement tree) { 1117 Env<GenContext> localEnv = env.dup(tree, new GenContext()); 1118 genStat(tree.body, localEnv, CRT_STATEMENT); 1119 Chain exit = localEnv.info.exit; 1120 if (exit != null) { 1121 code.resolve(exit); 1122 exit.state.defined.excludeFrom(code.nextreg); 1123 } 1124 } 1125 1126 public void visitSwitch(JCSwitch tree) { 1127 int limit = code.nextreg; 1128 Assert.check(!tree.selector.type.hasTag(CLASS)); 1129 int startpcCrt = genCrt ? code.curCP() : 0; 1130 Item sel = genExpr(tree.selector, syms.intType); 1131 List<JCCase> cases = tree.cases; 1132 if (cases.isEmpty()) { 1133 // We are seeing: switch <sel> {} 1134 sel.load().drop(); 1135 if (genCrt) 1136 code.crt.put(TreeInfo.skipParens(tree.selector), 1137 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP()); 1138 } else { 1139 // We are seeing a nonempty switch. 1140 sel.load(); 1141 if (genCrt) 1142 code.crt.put(TreeInfo.skipParens(tree.selector), 1143 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP()); 1144 Env<GenContext> switchEnv = env.dup(tree, new GenContext()); 1145 switchEnv.info.isSwitch = true; 1146 1147 // Compute number of labels and minimum and maximum label values. 1148 // For each case, store its label in an array. 1149 int lo = Integer.MAX_VALUE; // minimum label. 1150 int hi = Integer.MIN_VALUE; // maximum label. 1151 int nlabels = 0; // number of labels. 1152 1153 int[] labels = new int[cases.length()]; // the label array. 1154 int defaultIndex = -1; // the index of the default clause. 1155 1156 List<JCCase> l = cases; 1157 for (int i = 0; i < labels.length; i++) { 1158 if (l.head.pat != null) { 1159 int val = ((Number)l.head.pat.type.constValue()).intValue(); 1160 labels[i] = val; 1161 if (val < lo) lo = val; 1162 if (hi < val) hi = val; 1163 nlabels++; 1164 } else { 1165 Assert.check(defaultIndex == -1); 1166 defaultIndex = i; 1167 } 1168 l = l.tail; 1169 } 1170 1171 // Determine whether to issue a tableswitch or a lookupswitch 1172 // instruction. 1173 long table_space_cost = 4 + ((long) hi - lo + 1); // words 1174 long table_time_cost = 3; // comparisons 1175 long lookup_space_cost = 3 + 2 * (long) nlabels; 1176 long lookup_time_cost = nlabels; 1177 int opcode = 1178 nlabels > 0 && 1179 table_space_cost + 3 * table_time_cost <= 1180 lookup_space_cost + 3 * lookup_time_cost 1181 ? 1182 tableswitch : lookupswitch; 1183 1184 int startpc = code.curCP(); // the position of the selector operation 1185 code.emitop0(opcode); 1186 code.align(4); 1187 int tableBase = code.curCP(); // the start of the jump table 1188 int[] offsets = null; // a table of offsets for a lookupswitch 1189 code.emit4(-1); // leave space for default offset 1190 if (opcode == tableswitch) { 1191 code.emit4(lo); // minimum label 1192 code.emit4(hi); // maximum label 1193 for (long i = lo; i <= hi; i++) { // leave space for jump table 1194 code.emit4(-1); 1195 } 1196 } else { 1197 code.emit4(nlabels); // number of labels 1198 for (int i = 0; i < nlabels; i++) { 1199 code.emit4(-1); code.emit4(-1); // leave space for lookup table 1200 } 1201 offsets = new int[labels.length]; 1202 } 1203 Code.State stateSwitch = code.state.dup(); 1204 code.markDead(); 1205 1206 // For each case do: 1207 l = cases; 1208 for (int i = 0; i < labels.length; i++) { 1209 JCCase c = l.head; 1210 l = l.tail; 1211 1212 int pc = code.entryPoint(stateSwitch); 1213 // Insert offset directly into code or else into the 1214 // offsets table. 1215 if (i != defaultIndex) { 1216 if (opcode == tableswitch) { 1217 code.put4( 1218 tableBase + 4 * (labels[i] - lo + 3), 1219 pc - startpc); 1220 } else { 1221 offsets[i] = pc - startpc; 1222 } 1223 } else { 1224 code.put4(tableBase, pc - startpc); 1225 } 1226 1227 // Generate code for the statements in this case. 1228 genStats(c.stats, switchEnv, CRT_FLOW_TARGET); 1229 } 1230 1231 // Resolve all breaks. 1232 Chain exit = switchEnv.info.exit; 1233 if (exit != null) { 1234 code.resolve(exit); 1235 exit.state.defined.excludeFrom(code.nextreg); 1236 } 1237 1238 // If we have not set the default offset, we do so now. 1239 if (code.get4(tableBase) == -1) { 1240 code.put4(tableBase, code.entryPoint(stateSwitch) - startpc); 1241 } 1242 1243 if (opcode == tableswitch) { 1244 // Let any unfilled slots point to the default case. 1245 int defaultOffset = code.get4(tableBase); 1246 for (long i = lo; i <= hi; i++) { 1247 int t = (int)(tableBase + 4 * (i - lo + 3)); 1248 if (code.get4(t) == -1) 1249 code.put4(t, defaultOffset); 1250 } 1251 } else { 1252 // Sort non-default offsets and copy into lookup table. 1253 if (defaultIndex >= 0) 1254 for (int i = defaultIndex; i < labels.length - 1; i++) { 1255 labels[i] = labels[i+1]; 1256 offsets[i] = offsets[i+1]; 1257 } 1258 if (nlabels > 0) 1259 qsort2(labels, offsets, 0, nlabels - 1); 1260 for (int i = 0; i < nlabels; i++) { 1261 int caseidx = tableBase + 8 * (i + 1); 1262 code.put4(caseidx, labels[i]); 1263 code.put4(caseidx + 4, offsets[i]); 1264 } 1265 } 1266 } 1267 code.endScopes(limit); 1268 } 1269//where 1270 /** Sort (int) arrays of keys and values 1271 */ 1272 static void qsort2(int[] keys, int[] values, int lo, int hi) { 1273 int i = lo; 1274 int j = hi; 1275 int pivot = keys[(i+j)/2]; 1276 do { 1277 while (keys[i] < pivot) i++; 1278 while (pivot < keys[j]) j--; 1279 if (i <= j) { 1280 int temp1 = keys[i]; 1281 keys[i] = keys[j]; 1282 keys[j] = temp1; 1283 int temp2 = values[i]; 1284 values[i] = values[j]; 1285 values[j] = temp2; 1286 i++; 1287 j--; 1288 } 1289 } while (i <= j); 1290 if (lo < j) qsort2(keys, values, lo, j); 1291 if (i < hi) qsort2(keys, values, i, hi); 1292 } 1293 1294 public void visitSynchronized(JCSynchronized tree) { 1295 int limit = code.nextreg; 1296 // Generate code to evaluate lock and save in temporary variable. 1297 final LocalItem lockVar = makeTemp(syms.objectType); 1298 genExpr(tree.lock, tree.lock.type).load().duplicate(); 1299 lockVar.store(); 1300 1301 // Generate code to enter monitor. 1302 code.emitop0(monitorenter); 1303 code.state.lock(lockVar.reg); 1304 1305 // Generate code for a try statement with given body, no catch clauses 1306 // in a new environment with the "exit-monitor" operation as finalizer. 1307 final Env<GenContext> syncEnv = env.dup(tree, new GenContext()); 1308 syncEnv.info.finalize = new GenFinalizer() { 1309 void gen() { 1310 genLast(); 1311 Assert.check(syncEnv.info.gaps.length() % 2 == 0); 1312 syncEnv.info.gaps.append(code.curCP()); 1313 } 1314 void genLast() { 1315 if (code.isAlive()) { 1316 lockVar.load(); 1317 code.emitop0(monitorexit); 1318 code.state.unlock(lockVar.reg); 1319 } 1320 } 1321 }; 1322 syncEnv.info.gaps = new ListBuffer<>(); 1323 genTry(tree.body, List.<JCCatch>nil(), syncEnv); 1324 code.endScopes(limit); 1325 } 1326 1327 public void visitTry(final JCTry tree) { 1328 // Generate code for a try statement with given body and catch clauses, 1329 // in a new environment which calls the finally block if there is one. 1330 final Env<GenContext> tryEnv = env.dup(tree, new GenContext()); 1331 final Env<GenContext> oldEnv = env; 1332 if (!useJsrLocally) { 1333 useJsrLocally = 1334 (stackMap == StackMapFormat.NONE) && 1335 (jsrlimit <= 0 || 1336 jsrlimit < 100 && 1337 estimateCodeComplexity(tree.finalizer)>jsrlimit); 1338 } 1339 tryEnv.info.finalize = new GenFinalizer() { 1340 void gen() { 1341 if (useJsrLocally) { 1342 if (tree.finalizer != null) { 1343 Code.State jsrState = code.state.dup(); 1344 jsrState.push(Code.jsrReturnValue); 1345 tryEnv.info.cont = 1346 new Chain(code.emitJump(jsr), 1347 tryEnv.info.cont, 1348 jsrState); 1349 } 1350 Assert.check(tryEnv.info.gaps.length() % 2 == 0); 1351 tryEnv.info.gaps.append(code.curCP()); 1352 } else { 1353 Assert.check(tryEnv.info.gaps.length() % 2 == 0); 1354 tryEnv.info.gaps.append(code.curCP()); 1355 genLast(); 1356 } 1357 } 1358 void genLast() { 1359 if (tree.finalizer != null) 1360 genStat(tree.finalizer, oldEnv, CRT_BLOCK); 1361 } 1362 boolean hasFinalizer() { 1363 return tree.finalizer != null; 1364 } 1365 }; 1366 tryEnv.info.gaps = new ListBuffer<>(); 1367 genTry(tree.body, tree.catchers, tryEnv); 1368 } 1369 //where 1370 /** Generate code for a try or synchronized statement 1371 * @param body The body of the try or synchronized statement. 1372 * @param catchers The lis of catch clauses. 1373 * @param env the environment current for the body. 1374 */ 1375 void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) { 1376 int limit = code.nextreg; 1377 int startpc = code.curCP(); 1378 Code.State stateTry = code.state.dup(); 1379 genStat(body, env, CRT_BLOCK); 1380 int endpc = code.curCP(); 1381 boolean hasFinalizer = 1382 env.info.finalize != null && 1383 env.info.finalize.hasFinalizer(); 1384 List<Integer> gaps = env.info.gaps.toList(); 1385 code.statBegin(TreeInfo.endPos(body)); 1386 genFinalizer(env); 1387 code.statBegin(TreeInfo.endPos(env.tree)); 1388 Chain exitChain = code.branch(goto_); 1389 endFinalizerGap(env); 1390 if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) { 1391 // start off with exception on stack 1392 code.entryPoint(stateTry, l.head.param.sym.type); 1393 genCatch(l.head, env, startpc, endpc, gaps); 1394 genFinalizer(env); 1395 if (hasFinalizer || l.tail.nonEmpty()) { 1396 code.statBegin(TreeInfo.endPos(env.tree)); 1397 exitChain = Code.mergeChains(exitChain, 1398 code.branch(goto_)); 1399 } 1400 endFinalizerGap(env); 1401 } 1402 if (hasFinalizer) { 1403 // Create a new register segement to avoid allocating 1404 // the same variables in finalizers and other statements. 1405 code.newRegSegment(); 1406 1407 // Add a catch-all clause. 1408 1409 // start off with exception on stack 1410 int catchallpc = code.entryPoint(stateTry, syms.throwableType); 1411 1412 // Register all exception ranges for catch all clause. 1413 // The range of the catch all clause is from the beginning 1414 // of the try or synchronized block until the present 1415 // code pointer excluding all gaps in the current 1416 // environment's GenContext. 1417 int startseg = startpc; 1418 while (env.info.gaps.nonEmpty()) { 1419 int endseg = env.info.gaps.next().intValue(); 1420 registerCatch(body.pos(), startseg, endseg, 1421 catchallpc, 0); 1422 startseg = env.info.gaps.next().intValue(); 1423 } 1424 code.statBegin(TreeInfo.finalizerPos(env.tree)); 1425 code.markStatBegin(); 1426 1427 Item excVar = makeTemp(syms.throwableType); 1428 excVar.store(); 1429 genFinalizer(env); 1430 excVar.load(); 1431 registerCatch(body.pos(), startseg, 1432 env.info.gaps.next().intValue(), 1433 catchallpc, 0); 1434 code.emitop0(athrow); 1435 code.markDead(); 1436 1437 // If there are jsr's to this finalizer, ... 1438 if (env.info.cont != null) { 1439 // Resolve all jsr's. 1440 code.resolve(env.info.cont); 1441 1442 // Mark statement line number 1443 code.statBegin(TreeInfo.finalizerPos(env.tree)); 1444 code.markStatBegin(); 1445 1446 // Save return address. 1447 LocalItem retVar = makeTemp(syms.throwableType); 1448 retVar.store(); 1449 1450 // Generate finalizer code. 1451 env.info.finalize.genLast(); 1452 1453 // Return. 1454 code.emitop1w(ret, retVar.reg); 1455 code.markDead(); 1456 } 1457 } 1458 // Resolve all breaks. 1459 code.resolve(exitChain); 1460 1461 code.endScopes(limit); 1462 } 1463 1464 /** Generate code for a catch clause. 1465 * @param tree The catch clause. 1466 * @param env The environment current in the enclosing try. 1467 * @param startpc Start pc of try-block. 1468 * @param endpc End pc of try-block. 1469 */ 1470 void genCatch(JCCatch tree, 1471 Env<GenContext> env, 1472 int startpc, int endpc, 1473 List<Integer> gaps) { 1474 if (startpc != endpc) { 1475 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypeExprs 1476 = catchTypesWithAnnotations(tree); 1477 while (gaps.nonEmpty()) { 1478 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) { 1479 JCExpression subCatch = subCatch1.snd; 1480 int catchType = makeRef(tree.pos(), subCatch.type); 1481 int end = gaps.head.intValue(); 1482 registerCatch(tree.pos(), 1483 startpc, end, code.curCP(), 1484 catchType); 1485 for (Attribute.TypeCompound tc : subCatch1.fst) { 1486 tc.position.setCatchInfo(catchType, startpc); 1487 } 1488 } 1489 gaps = gaps.tail; 1490 startpc = gaps.head.intValue(); 1491 gaps = gaps.tail; 1492 } 1493 if (startpc < endpc) { 1494 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) { 1495 JCExpression subCatch = subCatch1.snd; 1496 int catchType = makeRef(tree.pos(), subCatch.type); 1497 registerCatch(tree.pos(), 1498 startpc, endpc, code.curCP(), 1499 catchType); 1500 for (Attribute.TypeCompound tc : subCatch1.fst) { 1501 tc.position.setCatchInfo(catchType, startpc); 1502 } 1503 } 1504 } 1505 VarSymbol exparam = tree.param.sym; 1506 code.statBegin(tree.pos); 1507 code.markStatBegin(); 1508 int limit = code.nextreg; 1509 code.newLocal(exparam); 1510 items.makeLocalItem(exparam).store(); 1511 code.statBegin(TreeInfo.firstStatPos(tree.body)); 1512 genStat(tree.body, env, CRT_BLOCK); 1513 code.endScopes(limit); 1514 code.statBegin(TreeInfo.endPos(tree.body)); 1515 } 1516 } 1517 // where 1518 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotations(JCCatch tree) { 1519 return TreeInfo.isMultiCatch(tree) ? 1520 catchTypesWithAnnotationsFromMulticatch((JCTypeUnion)tree.param.vartype, tree.param.sym.getRawTypeAttributes()) : 1521 List.of(new Pair<>(tree.param.sym.getRawTypeAttributes(), tree.param.vartype)); 1522 } 1523 // where 1524 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotationsFromMulticatch(JCTypeUnion tree, List<TypeCompound> first) { 1525 List<JCExpression> alts = tree.alternatives; 1526 List<Pair<List<TypeCompound>, JCExpression>> res = List.of(new Pair<>(first, alts.head)); 1527 alts = alts.tail; 1528 1529 while(alts != null && alts.head != null) { 1530 JCExpression alt = alts.head; 1531 if (alt instanceof JCAnnotatedType) { 1532 JCAnnotatedType a = (JCAnnotatedType)alt; 1533 res = res.prepend(new Pair<>(annotate.fromAnnotations(a.annotations), alt)); 1534 } else { 1535 res = res.prepend(new Pair<>(List.nil(), alt)); 1536 } 1537 alts = alts.tail; 1538 } 1539 return res.reverse(); 1540 } 1541 1542 /** Register a catch clause in the "Exceptions" code-attribute. 1543 */ 1544 void registerCatch(DiagnosticPosition pos, 1545 int startpc, int endpc, 1546 int handler_pc, int catch_type) { 1547 char startpc1 = (char)startpc; 1548 char endpc1 = (char)endpc; 1549 char handler_pc1 = (char)handler_pc; 1550 if (startpc1 == startpc && 1551 endpc1 == endpc && 1552 handler_pc1 == handler_pc) { 1553 code.addCatch(startpc1, endpc1, handler_pc1, 1554 (char)catch_type); 1555 } else { 1556 log.error(pos, "limit.code.too.large.for.try.stmt"); 1557 nerrs++; 1558 } 1559 } 1560 1561 /** Very roughly estimate the number of instructions needed for 1562 * the given tree. 1563 */ 1564 int estimateCodeComplexity(JCTree tree) { 1565 if (tree == null) return 0; 1566 class ComplexityScanner extends TreeScanner { 1567 int complexity = 0; 1568 public void scan(JCTree tree) { 1569 if (complexity > jsrlimit) return; 1570 super.scan(tree); 1571 } 1572 public void visitClassDef(JCClassDecl tree) {} 1573 public void visitDoLoop(JCDoWhileLoop tree) 1574 { super.visitDoLoop(tree); complexity++; } 1575 public void visitWhileLoop(JCWhileLoop tree) 1576 { super.visitWhileLoop(tree); complexity++; } 1577 public void visitForLoop(JCForLoop tree) 1578 { super.visitForLoop(tree); complexity++; } 1579 public void visitSwitch(JCSwitch tree) 1580 { super.visitSwitch(tree); complexity+=5; } 1581 public void visitCase(JCCase tree) 1582 { super.visitCase(tree); complexity++; } 1583 public void visitSynchronized(JCSynchronized tree) 1584 { super.visitSynchronized(tree); complexity+=6; } 1585 public void visitTry(JCTry tree) 1586 { super.visitTry(tree); 1587 if (tree.finalizer != null) complexity+=6; } 1588 public void visitCatch(JCCatch tree) 1589 { super.visitCatch(tree); complexity+=2; } 1590 public void visitConditional(JCConditional tree) 1591 { super.visitConditional(tree); complexity+=2; } 1592 public void visitIf(JCIf tree) 1593 { super.visitIf(tree); complexity+=2; } 1594 // note: for break, continue, and return we don't take unwind() into account. 1595 public void visitBreak(JCBreak tree) 1596 { super.visitBreak(tree); complexity+=1; } 1597 public void visitContinue(JCContinue tree) 1598 { super.visitContinue(tree); complexity+=1; } 1599 public void visitReturn(JCReturn tree) 1600 { super.visitReturn(tree); complexity+=1; } 1601 public void visitThrow(JCThrow tree) 1602 { super.visitThrow(tree); complexity+=1; } 1603 public void visitAssert(JCAssert tree) 1604 { super.visitAssert(tree); complexity+=5; } 1605 public void visitApply(JCMethodInvocation tree) 1606 { super.visitApply(tree); complexity+=2; } 1607 public void visitNewClass(JCNewClass tree) 1608 { scan(tree.encl); scan(tree.args); complexity+=2; } 1609 public void visitNewArray(JCNewArray tree) 1610 { super.visitNewArray(tree); complexity+=5; } 1611 public void visitAssign(JCAssign tree) 1612 { super.visitAssign(tree); complexity+=1; } 1613 public void visitAssignop(JCAssignOp tree) 1614 { super.visitAssignop(tree); complexity+=2; } 1615 public void visitUnary(JCUnary tree) 1616 { complexity+=1; 1617 if (tree.type.constValue() == null) super.visitUnary(tree); } 1618 public void visitBinary(JCBinary tree) 1619 { complexity+=1; 1620 if (tree.type.constValue() == null) super.visitBinary(tree); } 1621 public void visitTypeTest(JCInstanceOf tree) 1622 { super.visitTypeTest(tree); complexity+=1; } 1623 public void visitIndexed(JCArrayAccess tree) 1624 { super.visitIndexed(tree); complexity+=1; } 1625 public void visitSelect(JCFieldAccess tree) 1626 { super.visitSelect(tree); 1627 if (tree.sym.kind == VAR) complexity+=1; } 1628 public void visitIdent(JCIdent tree) { 1629 if (tree.sym.kind == VAR) { 1630 complexity+=1; 1631 if (tree.type.constValue() == null && 1632 tree.sym.owner.kind == TYP) 1633 complexity+=1; 1634 } 1635 } 1636 public void visitLiteral(JCLiteral tree) 1637 { complexity+=1; } 1638 public void visitTree(JCTree tree) {} 1639 public void visitWildcard(JCWildcard tree) { 1640 throw new AssertionError(this.getClass().getName()); 1641 } 1642 } 1643 ComplexityScanner scanner = new ComplexityScanner(); 1644 tree.accept(scanner); 1645 return scanner.complexity; 1646 } 1647 1648 public void visitIf(JCIf tree) { 1649 int limit = code.nextreg; 1650 Chain thenExit = null; 1651 CondItem c = genCond(TreeInfo.skipParens(tree.cond), 1652 CRT_FLOW_CONTROLLER); 1653 Chain elseChain = c.jumpFalse(); 1654 if (!c.isFalse()) { 1655 code.resolve(c.trueJumps); 1656 genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET); 1657 thenExit = code.branch(goto_); 1658 } 1659 if (elseChain != null) { 1660 code.resolve(elseChain); 1661 if (tree.elsepart != null) { 1662 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET); 1663 } 1664 } 1665 code.resolve(thenExit); 1666 code.endScopes(limit); 1667 } 1668 1669 public void visitExec(JCExpressionStatement tree) { 1670 // Optimize x++ to ++x and x-- to --x. 1671 JCExpression e = tree.expr; 1672 switch (e.getTag()) { 1673 case POSTINC: 1674 ((JCUnary) e).setTag(PREINC); 1675 break; 1676 case POSTDEC: 1677 ((JCUnary) e).setTag(PREDEC); 1678 break; 1679 } 1680 genExpr(tree.expr, tree.expr.type).drop(); 1681 } 1682 1683 public void visitBreak(JCBreak tree) { 1684 Env<GenContext> targetEnv = unwind(tree.target, env); 1685 Assert.check(code.state.stacksize == 0); 1686 targetEnv.info.addExit(code.branch(goto_)); 1687 endFinalizerGaps(env, targetEnv); 1688 } 1689 1690 public void visitContinue(JCContinue tree) { 1691 Env<GenContext> targetEnv = unwind(tree.target, env); 1692 Assert.check(code.state.stacksize == 0); 1693 targetEnv.info.addCont(code.branch(goto_)); 1694 endFinalizerGaps(env, targetEnv); 1695 } 1696 1697 public void visitReturn(JCReturn tree) { 1698 int limit = code.nextreg; 1699 final Env<GenContext> targetEnv; 1700 1701 /* Save and then restore the location of the return in case a finally 1702 * is expanded (with unwind()) in the middle of our bytecodes. 1703 */ 1704 int tmpPos = code.pendingStatPos; 1705 if (tree.expr != null) { 1706 Item r = genExpr(tree.expr, pt).load(); 1707 if (hasFinally(env.enclMethod, env)) { 1708 r = makeTemp(pt); 1709 r.store(); 1710 } 1711 targetEnv = unwind(env.enclMethod, env); 1712 code.pendingStatPos = tmpPos; 1713 r.load(); 1714 code.emitop0(ireturn + Code.truncate(Code.typecode(pt))); 1715 } else { 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, syms.stringBuilderType)); 2074 code.emitop0(dup); 2075 callMethod( 2076 pos, syms.stringBuilderType, 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 syms.stringBuilderType, 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 syms.stringBuilderType, 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 result = genExpr(tree.expr, tree.clazz.type).load(); 2177 setTypeAnnotationPositions(tree.pos); 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 genExpr(tree.expr, tree.expr.type).load(); 2195 setTypeAnnotationPositions(tree.pos); 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 c.pool = pool; 2343 pool.reset(); 2344 /* method normalizeDefs() can add references to external classes into the constant pool 2345 */ 2346 cdef.defs = normalizeDefs(cdef.defs, c); 2347 generateReferencesToPrunedTree(c, pool); 2348 Env<GenContext> localEnv = new Env<>(cdef, new GenContext()); 2349 localEnv.toplevel = env.toplevel; 2350 localEnv.enclClass = cdef; 2351 2352 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) { 2353 genDef(l.head, localEnv); 2354 } 2355 if (pool.numEntries() > Pool.MAX_ENTRIES) { 2356 log.error(cdef.pos(), "limit.pool"); 2357 nerrs++; 2358 } 2359 if (nerrs != 0) { 2360 // if errors, discard code 2361 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) { 2362 if (l.head.hasTag(METHODDEF)) 2363 ((JCMethodDecl) l.head).sym.code = null; 2364 } 2365 } 2366 cdef.defs = List.nil(); // discard trees 2367 return nerrs == 0; 2368 } finally { 2369 // note: this method does NOT support recursion. 2370 attrEnv = null; 2371 this.env = null; 2372 toplevel = null; 2373 endPosTable = null; 2374 nerrs = 0; 2375 } 2376 } 2377 2378/* ************************************************************************ 2379 * Auxiliary classes 2380 *************************************************************************/ 2381 2382 /** An abstract class for finalizer generation. 2383 */ 2384 abstract class GenFinalizer { 2385 /** Generate code to clean up when unwinding. */ 2386 abstract void gen(); 2387 2388 /** Generate code to clean up at last. */ 2389 abstract void genLast(); 2390 2391 /** Does this finalizer have some nontrivial cleanup to perform? */ 2392 boolean hasFinalizer() { return true; } 2393 } 2394 2395 /** code generation contexts, 2396 * to be used as type parameter for environments. 2397 */ 2398 static class GenContext { 2399 2400 /** A chain for all unresolved jumps that exit the current environment. 2401 */ 2402 Chain exit = null; 2403 2404 /** A chain for all unresolved jumps that continue in the 2405 * current environment. 2406 */ 2407 Chain cont = null; 2408 2409 /** A closure that generates the finalizer of the current environment. 2410 * Only set for Synchronized and Try contexts. 2411 */ 2412 GenFinalizer finalize = null; 2413 2414 /** Is this a switch statement? If so, allocate registers 2415 * even when the variable declaration is unreachable. 2416 */ 2417 boolean isSwitch = false; 2418 2419 /** A list buffer containing all gaps in the finalizer range, 2420 * where a catch all exception should not apply. 2421 */ 2422 ListBuffer<Integer> gaps = null; 2423 2424 /** Add given chain to exit chain. 2425 */ 2426 void addExit(Chain c) { 2427 exit = Code.mergeChains(c, exit); 2428 } 2429 2430 /** Add given chain to cont chain. 2431 */ 2432 void addCont(Chain c) { 2433 cont = Code.mergeChains(c, cont); 2434 } 2435 } 2436 2437} 2438