1 /* 2 * Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package com.sun.tools.javac.jvm; 27 28 import com.sun.tools.javac.tree.TreeInfo.PosKind; 29 import com.sun.tools.javac.util.*; 30 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition; 31 import com.sun.tools.javac.util.List; 32 import com.sun.tools.javac.code.*; 33 import com.sun.tools.javac.code.Attribute.TypeCompound; 34 import com.sun.tools.javac.code.Symbol.VarSymbol; 35 import com.sun.tools.javac.comp.*; 36 import com.sun.tools.javac.tree.*; 37 38 import com.sun.tools.javac.code.Symbol.*; 39 import com.sun.tools.javac.code.Type.*; 40 import com.sun.tools.javac.jvm.Code.*; 41 import com.sun.tools.javac.jvm.Items.*; 42 import com.sun.tools.javac.resources.CompilerProperties.Errors; 43 import com.sun.tools.javac.tree.EndPosTable; 44 import com.sun.tools.javac.tree.JCTree.*; 45 46 import static com.sun.tools.javac.code.Flags.*; 47 import static com.sun.tools.javac.code.Kinds.Kind.*; 48 import static com.sun.tools.javac.code.TypeTag.*; 49 import static com.sun.tools.javac.jvm.ByteCodes.*; 50 import static com.sun.tools.javac.jvm.CRTFlags.*; 51 import static com.sun.tools.javac.main.Option.*; 52 import static com.sun.tools.javac.tree.JCTree.Tag.*; 53 54 /** This pass maps flat Java (i.e. without inner classes) to bytecodes. 55 * 56 * <p><b>This is NOT part of any supported API. 57 * If you write code that depends on this, you do so at your own risk. 58 * This code and its internal interfaces are subject to change or 59 * deletion without notice.</b> 60 */ 61 public class Gen extends JCTree.Visitor { 62 protected static final Context.Key<Gen> genKey = new Context.Key<>(); 63 64 private final Log log; 65 private final Symtab syms; 66 private final Check chk; 67 private final Resolve rs; 68 private final TreeMaker make; 69 private final Names names; 70 private final Target target; 71 private final Name accessDollar; 72 private final Types types; 73 private final Lower lower; 74 private final Annotate annotate; 75 private final StringConcat concat; 76 77 /** Format of stackmap tables to be generated. */ 78 private final Code.StackMapFormat stackMap; 79 80 /** A type that serves as the expected type for all method expressions. 81 */ 82 private final Type methodType; 83 instance(Context context)84 public static Gen instance(Context context) { 85 Gen instance = context.get(genKey); 86 if (instance == null) 87 instance = new Gen(context); 88 return instance; 89 } 90 91 /** Constant pool, reset by genClass. 92 */ 93 private final Pool pool; 94 Gen(Context context)95 protected Gen(Context context) { 96 context.put(genKey, this); 97 98 names = Names.instance(context); 99 log = Log.instance(context); 100 syms = Symtab.instance(context); 101 chk = Check.instance(context); 102 rs = Resolve.instance(context); 103 make = TreeMaker.instance(context); 104 target = Target.instance(context); 105 types = Types.instance(context); 106 concat = StringConcat.instance(context); 107 108 methodType = new MethodType(null, null, null, syms.methodClass); 109 accessDollar = names. 110 fromString("access" + target.syntheticNameChar()); 111 lower = Lower.instance(context); 112 113 Options options = Options.instance(context); 114 lineDebugInfo = 115 options.isUnset(G_CUSTOM) || 116 options.isSet(G_CUSTOM, "lines"); 117 varDebugInfo = 118 options.isUnset(G_CUSTOM) 119 ? options.isSet(G) 120 : options.isSet(G_CUSTOM, "vars"); 121 genCrt = options.isSet(XJCOV); 122 debugCode = options.isSet("debug.code"); 123 disableVirtualizedPrivateInvoke = options.isSet("disableVirtualizedPrivateInvoke"); 124 pool = new Pool(types); 125 126 // ignore cldc because we cannot have both stackmap formats 127 this.stackMap = StackMapFormat.JSR202; 128 annotate = Annotate.instance(context); 129 } 130 131 /** Switches 132 */ 133 private final boolean lineDebugInfo; 134 private final boolean varDebugInfo; 135 private final boolean genCrt; 136 private final boolean debugCode; 137 private boolean disableVirtualizedPrivateInvoke; 138 139 /** Code buffer, set by genMethod. 140 */ 141 private Code code; 142 143 /** Items structure, set by genMethod. 144 */ 145 private Items items; 146 147 /** Environment for symbol lookup, set by genClass 148 */ 149 private Env<AttrContext> attrEnv; 150 151 /** The top level tree. 152 */ 153 private JCCompilationUnit toplevel; 154 155 /** The number of code-gen errors in this class. 156 */ 157 private int nerrs = 0; 158 159 /** An object containing mappings of syntax trees to their 160 * ending source positions. 161 */ 162 EndPosTable endPosTable; 163 164 boolean inCondSwitchExpression; 165 Chain switchExpressionTrueChain; 166 Chain switchExpressionFalseChain; 167 List<LocalItem> stackBeforeSwitchExpression; 168 169 /** Generate code to load an integer constant. 170 * @param n The integer to be loaded. 171 */ loadIntConst(int n)172 void loadIntConst(int n) { 173 items.makeImmediateItem(syms.intType, n).load(); 174 } 175 176 /** The opcode that loads a zero constant of a given type code. 177 * @param tc The given type code (@see ByteCode). 178 */ zero(int tc)179 public static int zero(int tc) { 180 switch(tc) { 181 case INTcode: case BYTEcode: case SHORTcode: case CHARcode: 182 return iconst_0; 183 case LONGcode: 184 return lconst_0; 185 case FLOATcode: 186 return fconst_0; 187 case DOUBLEcode: 188 return dconst_0; 189 default: 190 throw new AssertionError("zero"); 191 } 192 } 193 194 /** The opcode that loads a one constant of a given type code. 195 * @param tc The given type code (@see ByteCode). 196 */ one(int tc)197 public static int one(int tc) { 198 return zero(tc) + 1; 199 } 200 201 /** Generate code to load -1 of the given type code (either int or long). 202 * @param tc The given type code (@see ByteCode). 203 */ emitMinusOne(int tc)204 void emitMinusOne(int tc) { 205 if (tc == LONGcode) { 206 items.makeImmediateItem(syms.longType, Long.valueOf(-1)).load(); 207 } else { 208 code.emitop0(iconst_m1); 209 } 210 } 211 212 /** Construct a symbol to reflect the qualifying type that should 213 * appear in the byte code as per JLS 13.1. 214 * 215 * For {@literal target >= 1.2}: Clone a method with the qualifier as owner (except 216 * for those cases where we need to work around VM bugs). 217 * 218 * For {@literal target <= 1.1}: If qualified variable or method is defined in a 219 * non-accessible class, clone it with the qualifier class as owner. 220 * 221 * @param sym The accessed symbol 222 * @param site The qualifier's type. 223 */ binaryQualifier(Symbol sym, Type site)224 Symbol binaryQualifier(Symbol sym, Type site) { 225 226 if (site.hasTag(ARRAY)) { 227 if (sym == syms.lengthVar || 228 sym.owner != syms.arrayClass) 229 return sym; 230 // array clone can be qualified by the array type in later targets 231 Symbol qualifier = new ClassSymbol(Flags.PUBLIC, site.tsym.name, 232 site, syms.noSymbol); 233 return sym.clone(qualifier); 234 } 235 236 if (sym.owner == site.tsym || 237 (sym.flags() & (STATIC | SYNTHETIC)) == (STATIC | SYNTHETIC)) { 238 return sym; 239 } 240 241 // leave alone methods inherited from Object 242 // JLS 13.1. 243 if (sym.owner == syms.objectType.tsym) 244 return sym; 245 246 return sym.clone(site.tsym); 247 } 248 249 /** Insert a reference to given type in the constant pool, 250 * checking for an array with too many dimensions; 251 * return the reference's index. 252 * @param type The type for which a reference is inserted. 253 */ makeRef(DiagnosticPosition pos, Type type)254 int makeRef(DiagnosticPosition pos, Type type) { 255 checkDimension(pos, type); 256 if (type.isAnnotated()) { 257 return pool.put((Object)type); 258 } else { 259 return pool.put(type.hasTag(CLASS) ? (Object)type.tsym : (Object)type); 260 } 261 } 262 263 /** Check if the given type is an array with too many dimensions. 264 */ checkDimension(DiagnosticPosition pos, Type t)265 private void checkDimension(DiagnosticPosition pos, Type t) { 266 switch (t.getTag()) { 267 case METHOD: 268 checkDimension(pos, t.getReturnType()); 269 for (List<Type> args = t.getParameterTypes(); args.nonEmpty(); args = args.tail) 270 checkDimension(pos, args.head); 271 break; 272 case ARRAY: 273 if (types.dimensions(t) > ClassFile.MAX_DIMENSIONS) { 274 log.error(pos, Errors.LimitDimensions); 275 nerrs++; 276 } 277 break; 278 default: 279 break; 280 } 281 } 282 283 /** Create a tempory variable. 284 * @param type The variable's type. 285 */ makeTemp(Type type)286 LocalItem makeTemp(Type type) { 287 VarSymbol v = new VarSymbol(Flags.SYNTHETIC, 288 names.empty, 289 type, 290 env.enclMethod.sym); 291 code.newLocal(v); 292 return items.makeLocalItem(v); 293 } 294 295 /** Generate code to call a non-private method or constructor. 296 * @param pos Position to be used for error reporting. 297 * @param site The type of which the method is a member. 298 * @param name The method's name. 299 * @param argtypes The method's argument types. 300 * @param isStatic A flag that indicates whether we call a 301 * static or instance method. 302 */ callMethod(DiagnosticPosition pos, Type site, Name name, List<Type> argtypes, boolean isStatic)303 void callMethod(DiagnosticPosition pos, 304 Type site, Name name, List<Type> argtypes, 305 boolean isStatic) { 306 Symbol msym = rs. 307 resolveInternalMethod(pos, attrEnv, site, name, argtypes, null); 308 if (isStatic) items.makeStaticItem(msym).invoke(); 309 else items.makeMemberItem(msym, name == names.init).invoke(); 310 } 311 312 /** Is the given method definition an access method 313 * resulting from a qualified super? This is signified by an odd 314 * access code. 315 */ isAccessSuper(JCMethodDecl enclMethod)316 private boolean isAccessSuper(JCMethodDecl enclMethod) { 317 return 318 (enclMethod.mods.flags & SYNTHETIC) != 0 && 319 isOddAccessName(enclMethod.name); 320 } 321 322 /** Does given name start with "access$" and end in an odd digit? 323 */ isOddAccessName(Name name)324 private boolean isOddAccessName(Name name) { 325 return 326 name.startsWith(accessDollar) && 327 (name.getByteAt(name.getByteLength() - 1) & 1) == 1; 328 } 329 330 /* ************************************************************************ 331 * Non-local exits 332 *************************************************************************/ 333 334 /** Generate code to invoke the finalizer associated with given 335 * environment. 336 * Any calls to finalizers are appended to the environments `cont' chain. 337 * Mark beginning of gap in catch all range for finalizer. 338 */ genFinalizer(Env<GenContext> env)339 void genFinalizer(Env<GenContext> env) { 340 if (code.isAlive() && env.info.finalize != null) 341 env.info.finalize.gen(); 342 } 343 344 /** Generate code to call all finalizers of structures aborted by 345 * a non-local 346 * exit. Return target environment of the non-local exit. 347 * @param target The tree representing the structure that's aborted 348 * @param env The environment current at the non-local exit. 349 */ unwind(JCTree target, Env<GenContext> env)350 Env<GenContext> unwind(JCTree target, Env<GenContext> env) { 351 Env<GenContext> env1 = env; 352 while (true) { 353 genFinalizer(env1); 354 if (env1.tree == target) break; 355 env1 = env1.next; 356 } 357 return env1; 358 } 359 360 /** Mark end of gap in catch-all range for finalizer. 361 * @param env the environment which might contain the finalizer 362 * (if it does, env.info.gaps != null). 363 */ endFinalizerGap(Env<GenContext> env)364 void endFinalizerGap(Env<GenContext> env) { 365 if (env.info.gaps != null && env.info.gaps.length() % 2 == 1) 366 env.info.gaps.append(code.curCP()); 367 } 368 369 /** Mark end of all gaps in catch-all ranges for finalizers of environments 370 * lying between, and including to two environments. 371 * @param from the most deeply nested environment to mark 372 * @param to the least deeply nested environment to mark 373 */ endFinalizerGaps(Env<GenContext> from, Env<GenContext> to)374 void endFinalizerGaps(Env<GenContext> from, Env<GenContext> to) { 375 Env<GenContext> last = null; 376 while (last != to) { 377 endFinalizerGap(from); 378 last = from; 379 from = from.next; 380 } 381 } 382 383 /** Do any of the structures aborted by a non-local exit have 384 * finalizers that require an empty stack? 385 * @param target The tree representing the structure that's aborted 386 * @param env The environment current at the non-local exit. 387 */ hasFinally(JCTree target, Env<GenContext> env)388 boolean hasFinally(JCTree target, Env<GenContext> env) { 389 while (env.tree != target) { 390 if (env.tree.hasTag(TRY) && env.info.finalize.hasFinalizer()) 391 return true; 392 env = env.next; 393 } 394 return false; 395 } 396 397 /* ************************************************************************ 398 * Normalizing class-members. 399 *************************************************************************/ 400 401 /** Distribute member initializer code into constructors and {@code <clinit>} 402 * method. 403 * @param defs The list of class member declarations. 404 * @param c The enclosing class. 405 */ normalizeDefs(List<JCTree> defs, ClassSymbol c)406 List<JCTree> normalizeDefs(List<JCTree> defs, ClassSymbol c) { 407 ListBuffer<JCStatement> initCode = new ListBuffer<>(); 408 ListBuffer<Attribute.TypeCompound> initTAs = new ListBuffer<>(); 409 ListBuffer<JCStatement> clinitCode = new ListBuffer<>(); 410 ListBuffer<Attribute.TypeCompound> clinitTAs = new ListBuffer<>(); 411 ListBuffer<JCTree> methodDefs = new ListBuffer<>(); 412 // Sort definitions into three listbuffers: 413 // - initCode for instance initializers 414 // - clinitCode for class initializers 415 // - methodDefs for method definitions 416 for (List<JCTree> l = defs; l.nonEmpty(); l = l.tail) { 417 JCTree def = l.head; 418 switch (def.getTag()) { 419 case BLOCK: 420 JCBlock block = (JCBlock)def; 421 if ((block.flags & STATIC) != 0) 422 clinitCode.append(block); 423 else if ((block.flags & SYNTHETIC) == 0) 424 initCode.append(block); 425 break; 426 case METHODDEF: 427 methodDefs.append(def); 428 break; 429 case VARDEF: 430 JCVariableDecl vdef = (JCVariableDecl) def; 431 VarSymbol sym = vdef.sym; 432 checkDimension(vdef.pos(), sym.type); 433 if (vdef.init != null) { 434 if ((sym.flags() & STATIC) == 0) { 435 // Always initialize instance variables. 436 JCStatement init = make.at(vdef.pos()). 437 Assignment(sym, vdef.init); 438 initCode.append(init); 439 endPosTable.replaceTree(vdef, init); 440 initTAs.addAll(getAndRemoveNonFieldTAs(sym)); 441 } else if (sym.getConstValue() == null) { 442 // Initialize class (static) variables only if 443 // they are not compile-time constants. 444 JCStatement init = make.at(vdef.pos). 445 Assignment(sym, vdef.init); 446 clinitCode.append(init); 447 endPosTable.replaceTree(vdef, init); 448 clinitTAs.addAll(getAndRemoveNonFieldTAs(sym)); 449 } else { 450 checkStringConstant(vdef.init.pos(), sym.getConstValue()); 451 /* if the init contains a reference to an external class, add it to the 452 * constant's pool 453 */ 454 vdef.init.accept(classReferenceVisitor); 455 } 456 } 457 break; 458 default: 459 Assert.error(); 460 } 461 } 462 // Insert any instance initializers into all constructors. 463 if (initCode.length() != 0) { 464 List<JCStatement> inits = initCode.toList(); 465 initTAs.addAll(c.getInitTypeAttributes()); 466 List<Attribute.TypeCompound> initTAlist = initTAs.toList(); 467 for (JCTree t : methodDefs) { 468 normalizeMethod((JCMethodDecl)t, inits, initTAlist); 469 } 470 } 471 // If there are class initializers, create a <clinit> method 472 // that contains them as its body. 473 if (clinitCode.length() != 0) { 474 MethodSymbol clinit = new MethodSymbol( 475 STATIC | (c.flags() & STRICTFP), 476 names.clinit, 477 new MethodType( 478 List.nil(), syms.voidType, 479 List.nil(), syms.methodClass), 480 c); 481 c.members().enter(clinit); 482 List<JCStatement> clinitStats = clinitCode.toList(); 483 JCBlock block = make.at(clinitStats.head.pos()).Block(0, clinitStats); 484 block.endpos = TreeInfo.endPos(clinitStats.last()); 485 methodDefs.append(make.MethodDef(clinit, block)); 486 487 if (!clinitTAs.isEmpty()) 488 clinit.appendUniqueTypeAttributes(clinitTAs.toList()); 489 if (!c.getClassInitTypeAttributes().isEmpty()) 490 clinit.appendUniqueTypeAttributes(c.getClassInitTypeAttributes()); 491 } 492 // Return all method definitions. 493 return methodDefs.toList(); 494 } 495 getAndRemoveNonFieldTAs(VarSymbol sym)496 private List<Attribute.TypeCompound> getAndRemoveNonFieldTAs(VarSymbol sym) { 497 List<TypeCompound> tas = sym.getRawTypeAttributes(); 498 ListBuffer<Attribute.TypeCompound> fieldTAs = new ListBuffer<>(); 499 ListBuffer<Attribute.TypeCompound> nonfieldTAs = new ListBuffer<>(); 500 for (TypeCompound ta : tas) { 501 Assert.check(ta.getPosition().type != TargetType.UNKNOWN); 502 if (ta.getPosition().type == TargetType.FIELD) { 503 fieldTAs.add(ta); 504 } else { 505 nonfieldTAs.add(ta); 506 } 507 } 508 sym.setTypeAttributes(fieldTAs.toList()); 509 return nonfieldTAs.toList(); 510 } 511 512 /** Check a constant value and report if it is a string that is 513 * too large. 514 */ checkStringConstant(DiagnosticPosition pos, Object constValue)515 private void checkStringConstant(DiagnosticPosition pos, Object constValue) { 516 if (nerrs != 0 || // only complain about a long string once 517 constValue == null || 518 !(constValue instanceof String) || 519 ((String)constValue).length() < Pool.MAX_STRING_LENGTH) 520 return; 521 log.error(pos, Errors.LimitString); 522 nerrs++; 523 } 524 525 /** Insert instance initializer code into initial constructor. 526 * @param md The tree potentially representing a 527 * constructor's definition. 528 * @param initCode The list of instance initializer statements. 529 * @param initTAs Type annotations from the initializer expression. 530 */ normalizeMethod(JCMethodDecl md, List<JCStatement> initCode, List<TypeCompound> initTAs)531 void normalizeMethod(JCMethodDecl md, List<JCStatement> initCode, List<TypeCompound> initTAs) { 532 if (md.name == names.init && TreeInfo.isInitialConstructor(md)) { 533 // We are seeing a constructor that does not call another 534 // constructor of the same class. 535 List<JCStatement> stats = md.body.stats; 536 ListBuffer<JCStatement> newstats = new ListBuffer<>(); 537 538 if (stats.nonEmpty()) { 539 // Copy initializers of synthetic variables generated in 540 // the translation of inner classes. 541 while (TreeInfo.isSyntheticInit(stats.head)) { 542 newstats.append(stats.head); 543 stats = stats.tail; 544 } 545 // Copy superclass constructor call 546 newstats.append(stats.head); 547 stats = stats.tail; 548 // Copy remaining synthetic initializers. 549 while (stats.nonEmpty() && 550 TreeInfo.isSyntheticInit(stats.head)) { 551 newstats.append(stats.head); 552 stats = stats.tail; 553 } 554 // Now insert the initializer code. 555 newstats.appendList(initCode); 556 // And copy all remaining statements. 557 while (stats.nonEmpty()) { 558 newstats.append(stats.head); 559 stats = stats.tail; 560 } 561 } 562 md.body.stats = newstats.toList(); 563 if (md.body.endpos == Position.NOPOS) 564 md.body.endpos = TreeInfo.endPos(md.body.stats.last()); 565 566 md.sym.appendUniqueTypeAttributes(initTAs); 567 } 568 } 569 570 /* ************************************************************************ 571 * Traversal methods 572 *************************************************************************/ 573 574 /** Visitor argument: The current environment. 575 */ 576 Env<GenContext> env; 577 578 /** Visitor argument: The expected type (prototype). 579 */ 580 Type pt; 581 582 /** Visitor result: The item representing the computed value. 583 */ 584 Item result; 585 586 /** Visitor method: generate code for a definition, catching and reporting 587 * any completion failures. 588 * @param tree The definition to be visited. 589 * @param env The environment current at the definition. 590 */ genDef(JCTree tree, Env<GenContext> env)591 public void genDef(JCTree tree, Env<GenContext> env) { 592 Env<GenContext> prevEnv = this.env; 593 try { 594 this.env = env; 595 tree.accept(this); 596 } catch (CompletionFailure ex) { 597 chk.completionError(tree.pos(), ex); 598 } finally { 599 this.env = prevEnv; 600 } 601 } 602 603 /** Derived visitor method: check whether CharacterRangeTable 604 * should be emitted, if so, put a new entry into CRTable 605 * and call method to generate bytecode. 606 * If not, just call method to generate bytecode. 607 * @see #genStat(JCTree, Env) 608 * 609 * @param tree The tree to be visited. 610 * @param env The environment to use. 611 * @param crtFlags The CharacterRangeTable flags 612 * indicating type of the entry. 613 */ genStat(JCTree tree, Env<GenContext> env, int crtFlags)614 public void genStat(JCTree tree, Env<GenContext> env, int crtFlags) { 615 if (!genCrt) { 616 genStat(tree, env); 617 return; 618 } 619 int startpc = code.curCP(); 620 genStat(tree, env); 621 if (tree.hasTag(Tag.BLOCK)) crtFlags |= CRT_BLOCK; 622 code.crt.put(tree, crtFlags, startpc, code.curCP()); 623 } 624 625 /** Derived visitor method: generate code for a statement. 626 */ genStat(JCTree tree, Env<GenContext> env)627 public void genStat(JCTree tree, Env<GenContext> env) { 628 if (code.isAlive()) { 629 code.statBegin(tree.pos); 630 genDef(tree, env); 631 } else if (env.info.isSwitch && tree.hasTag(VARDEF)) { 632 // variables whose declarations are in a switch 633 // can be used even if the decl is unreachable. 634 code.newLocal(((JCVariableDecl) tree).sym); 635 } 636 } 637 638 /** Derived visitor method: check whether CharacterRangeTable 639 * should be emitted, if so, put a new entry into CRTable 640 * and call method to generate bytecode. 641 * If not, just call method to generate bytecode. 642 * @see #genStats(List, Env) 643 * 644 * @param trees The list of trees to be visited. 645 * @param env The environment to use. 646 * @param crtFlags The CharacterRangeTable flags 647 * indicating type of the entry. 648 */ genStats(List<JCStatement> trees, Env<GenContext> env, int crtFlags)649 public void genStats(List<JCStatement> trees, Env<GenContext> env, int crtFlags) { 650 if (!genCrt) { 651 genStats(trees, env); 652 return; 653 } 654 if (trees.length() == 1) { // mark one statement with the flags 655 genStat(trees.head, env, crtFlags | CRT_STATEMENT); 656 } else { 657 int startpc = code.curCP(); 658 genStats(trees, env); 659 code.crt.put(trees, crtFlags, startpc, code.curCP()); 660 } 661 } 662 663 /** Derived visitor method: generate code for a list of statements. 664 */ genStats(List<? extends JCTree> trees, Env<GenContext> env)665 public void genStats(List<? extends JCTree> trees, Env<GenContext> env) { 666 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail) 667 genStat(l.head, env, CRT_STATEMENT); 668 } 669 670 /** Derived visitor method: check whether CharacterRangeTable 671 * should be emitted, if so, put a new entry into CRTable 672 * and call method to generate bytecode. 673 * If not, just call method to generate bytecode. 674 * @see #genCond(JCTree,boolean) 675 * 676 * @param tree The tree to be visited. 677 * @param crtFlags The CharacterRangeTable flags 678 * indicating type of the entry. 679 */ genCond(JCTree tree, int crtFlags)680 public CondItem genCond(JCTree tree, int crtFlags) { 681 if (!genCrt) return genCond(tree, false); 682 int startpc = code.curCP(); 683 CondItem item = genCond(tree, (crtFlags & CRT_FLOW_CONTROLLER) != 0); 684 code.crt.put(tree, crtFlags, startpc, code.curCP()); 685 return item; 686 } 687 688 /** Derived visitor method: generate code for a boolean 689 * expression in a control-flow context. 690 * @param _tree The expression to be visited. 691 * @param markBranches The flag to indicate that the condition is 692 * a flow controller so produced conditions 693 * should contain a proper tree to generate 694 * CharacterRangeTable branches for them. 695 */ genCond(JCTree _tree, boolean markBranches)696 public CondItem genCond(JCTree _tree, boolean markBranches) { 697 JCTree inner_tree = TreeInfo.skipParens(_tree); 698 if (inner_tree.hasTag(CONDEXPR)) { 699 JCConditional tree = (JCConditional)inner_tree; 700 CondItem cond = genCond(tree.cond, CRT_FLOW_CONTROLLER); 701 if (cond.isTrue()) { 702 code.resolve(cond.trueJumps); 703 CondItem result = genCond(tree.truepart, CRT_FLOW_TARGET); 704 if (markBranches) result.tree = tree.truepart; 705 return result; 706 } 707 if (cond.isFalse()) { 708 code.resolve(cond.falseJumps); 709 CondItem result = genCond(tree.falsepart, CRT_FLOW_TARGET); 710 if (markBranches) result.tree = tree.falsepart; 711 return result; 712 } 713 Chain secondJumps = cond.jumpFalse(); 714 code.resolve(cond.trueJumps); 715 CondItem first = genCond(tree.truepart, CRT_FLOW_TARGET); 716 if (markBranches) first.tree = tree.truepart; 717 Chain falseJumps = first.jumpFalse(); 718 code.resolve(first.trueJumps); 719 Chain trueJumps = code.branch(goto_); 720 code.resolve(secondJumps); 721 CondItem second = genCond(tree.falsepart, CRT_FLOW_TARGET); 722 CondItem result = items.makeCondItem(second.opcode, 723 Code.mergeChains(trueJumps, second.trueJumps), 724 Code.mergeChains(falseJumps, second.falseJumps)); 725 if (markBranches) result.tree = tree.falsepart; 726 return result; 727 } else if (inner_tree.hasTag(SWITCH_EXPRESSION)) { 728 boolean prevInCondSwitchExpression = inCondSwitchExpression; 729 Chain prevSwitchExpressionTrueChain = switchExpressionTrueChain; 730 Chain prevSwitchExpressionFalseChain = switchExpressionFalseChain; 731 try { 732 inCondSwitchExpression = true; 733 switchExpressionTrueChain = null; 734 switchExpressionFalseChain = null; 735 try { 736 doHandleSwitchExpression((JCSwitchExpression) inner_tree); 737 } catch (CompletionFailure ex) { 738 chk.completionError(_tree.pos(), ex); 739 code.state.stacksize = 1; 740 } 741 CondItem result = items.makeCondItem(goto_, 742 switchExpressionTrueChain, 743 switchExpressionFalseChain); 744 if (markBranches) result.tree = _tree; 745 return result; 746 } finally { 747 inCondSwitchExpression = prevInCondSwitchExpression; 748 switchExpressionTrueChain = prevSwitchExpressionTrueChain; 749 switchExpressionFalseChain = prevSwitchExpressionFalseChain; 750 } 751 } else if (inner_tree.hasTag(LETEXPR) && ((LetExpr) inner_tree).needsCond) { 752 LetExpr tree = (LetExpr) inner_tree; 753 int limit = code.nextreg; 754 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize); 755 try { 756 genStats(tree.defs, env); 757 } finally { 758 code.setLetExprStackPos(prevLetExprStart); 759 } 760 CondItem result = genCond(tree.expr, markBranches); 761 code.endScopes(limit); 762 return result; 763 } else { 764 CondItem result = genExpr(_tree, syms.booleanType).mkCond(); 765 if (markBranches) result.tree = _tree; 766 return result; 767 } 768 } 769 getCode()770 public Code getCode() { 771 return code; 772 } 773 getItems()774 public Items getItems() { 775 return items; 776 } 777 getAttrEnv()778 public Env<AttrContext> getAttrEnv() { 779 return attrEnv; 780 } 781 782 /** Visitor class for expressions which might be constant expressions. 783 * This class is a subset of TreeScanner. Intended to visit trees pruned by 784 * Lower as long as constant expressions looking for references to any 785 * ClassSymbol. Any such reference will be added to the constant pool so 786 * automated tools can detect class dependencies better. 787 */ 788 class ClassReferenceVisitor extends JCTree.Visitor { 789 790 @Override visitTree(JCTree tree)791 public void visitTree(JCTree tree) {} 792 793 @Override visitBinary(JCBinary tree)794 public void visitBinary(JCBinary tree) { 795 tree.lhs.accept(this); 796 tree.rhs.accept(this); 797 } 798 799 @Override visitSelect(JCFieldAccess tree)800 public void visitSelect(JCFieldAccess tree) { 801 if (tree.selected.type.hasTag(CLASS)) { 802 makeRef(tree.selected.pos(), tree.selected.type); 803 } 804 } 805 806 @Override visitIdent(JCIdent tree)807 public void visitIdent(JCIdent tree) { 808 if (tree.sym.owner instanceof ClassSymbol) { 809 pool.put(tree.sym.owner); 810 } 811 } 812 813 @Override visitConditional(JCConditional tree)814 public void visitConditional(JCConditional tree) { 815 tree.cond.accept(this); 816 tree.truepart.accept(this); 817 tree.falsepart.accept(this); 818 } 819 820 @Override visitUnary(JCUnary tree)821 public void visitUnary(JCUnary tree) { 822 tree.arg.accept(this); 823 } 824 825 @Override visitParens(JCParens tree)826 public void visitParens(JCParens tree) { 827 tree.expr.accept(this); 828 } 829 830 @Override visitTypeCast(JCTypeCast tree)831 public void visitTypeCast(JCTypeCast tree) { 832 tree.expr.accept(this); 833 } 834 } 835 836 private ClassReferenceVisitor classReferenceVisitor = new ClassReferenceVisitor(); 837 838 /** Visitor method: generate code for an expression, catching and reporting 839 * any completion failures. 840 * @param tree The expression to be visited. 841 * @param pt The expression's expected type (proto-type). 842 */ genExpr(JCTree tree, Type pt)843 public Item genExpr(JCTree tree, Type pt) { 844 Type prevPt = this.pt; 845 try { 846 if (tree.type.constValue() != null) { 847 // Short circuit any expressions which are constants 848 tree.accept(classReferenceVisitor); 849 checkStringConstant(tree.pos(), tree.type.constValue()); 850 result = items.makeImmediateItem(tree.type, tree.type.constValue()); 851 } else { 852 this.pt = pt; 853 tree.accept(this); 854 } 855 return result.coerce(pt); 856 } catch (CompletionFailure ex) { 857 chk.completionError(tree.pos(), ex); 858 code.state.stacksize = 1; 859 return items.makeStackItem(pt); 860 } finally { 861 this.pt = prevPt; 862 } 863 } 864 865 /** Derived visitor method: generate code for a list of method arguments. 866 * @param trees The argument expressions to be visited. 867 * @param pts The expression's expected types (i.e. the formal parameter 868 * types of the invoked method). 869 */ genArgs(List<JCExpression> trees, List<Type> pts)870 public void genArgs(List<JCExpression> trees, List<Type> pts) { 871 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail) { 872 genExpr(l.head, pts.head).load(); 873 pts = pts.tail; 874 } 875 // require lists be of same length 876 Assert.check(pts.isEmpty()); 877 } 878 879 /* ************************************************************************ 880 * Visitor methods for statements and definitions 881 *************************************************************************/ 882 883 /** Thrown when the byte code size exceeds limit. 884 */ 885 public static class CodeSizeOverflow extends RuntimeException { 886 private static final long serialVersionUID = 0; CodeSizeOverflow()887 public CodeSizeOverflow() {} 888 } 889 visitMethodDef(JCMethodDecl tree)890 public void visitMethodDef(JCMethodDecl tree) { 891 // Create a new local environment that points pack at method 892 // definition. 893 Env<GenContext> localEnv = env.dup(tree); 894 localEnv.enclMethod = tree; 895 // The expected type of every return statement in this method 896 // is the method's return type. 897 this.pt = tree.sym.erasure(types).getReturnType(); 898 899 checkDimension(tree.pos(), tree.sym.erasure(types)); 900 genMethod(tree, localEnv, false); 901 } 902 //where 903 /** Generate code for a method. 904 * @param tree The tree representing the method definition. 905 * @param env The environment current for the method body. 906 * @param fatcode A flag that indicates whether all jumps are 907 * within 32K. We first invoke this method under 908 * the assumption that fatcode == false, i.e. all 909 * jumps are within 32K. If this fails, fatcode 910 * is set to true and we try again. 911 */ genMethod(JCMethodDecl tree, Env<GenContext> env, boolean fatcode)912 void genMethod(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) { 913 MethodSymbol meth = tree.sym; 914 int extras = 0; 915 // Count up extra parameters 916 if (meth.isConstructor()) { 917 extras++; 918 if (meth.enclClass().isInner() && 919 !meth.enclClass().isStatic()) { 920 extras++; 921 } 922 } else if ((tree.mods.flags & STATIC) == 0) { 923 extras++; 924 } 925 // System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG 926 if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes()) + extras > 927 ClassFile.MAX_PARAMETERS) { 928 log.error(tree.pos(), Errors.LimitParameters); 929 nerrs++; 930 } 931 932 else if (tree.body != null) { 933 // Create a new code structure and initialize it. 934 int startpcCrt = initCode(tree, env, fatcode); 935 936 try { 937 genStat(tree.body, env); 938 } catch (CodeSizeOverflow e) { 939 // Failed due to code limit, try again with jsr/ret 940 startpcCrt = initCode(tree, env, fatcode); 941 genStat(tree.body, env); 942 } 943 944 if (code.state.stacksize != 0) { 945 log.error(tree.body.pos(), Errors.StackSimError(tree.sym)); 946 throw new AssertionError(); 947 } 948 949 // If last statement could complete normally, insert a 950 // return at the end. 951 if (code.isAlive()) { 952 code.statBegin(TreeInfo.endPos(tree.body)); 953 if (env.enclMethod == null || 954 env.enclMethod.sym.type.getReturnType().hasTag(VOID)) { 955 code.emitop0(return_); 956 } else { 957 // sometime dead code seems alive (4415991); 958 // generate a small loop instead 959 int startpc = code.entryPoint(); 960 CondItem c = items.makeCondItem(goto_); 961 code.resolve(c.jumpTrue(), startpc); 962 } 963 } 964 if (genCrt) 965 code.crt.put(tree.body, 966 CRT_BLOCK, 967 startpcCrt, 968 code.curCP()); 969 970 code.endScopes(0); 971 972 // If we exceeded limits, panic 973 if (code.checkLimits(tree.pos(), log)) { 974 nerrs++; 975 return; 976 } 977 978 // If we generated short code but got a long jump, do it again 979 // with fatCode = true. 980 if (!fatcode && code.fatcode) genMethod(tree, env, true); 981 982 // Clean up 983 if(stackMap == StackMapFormat.JSR202) { 984 code.lastFrame = null; 985 code.frameBeforeLast = null; 986 } 987 988 // Compress exception table 989 code.compressCatchTable(); 990 991 // Fill in type annotation positions for exception parameters 992 code.fillExceptionParameterPositions(); 993 } 994 } 995 initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode)996 private int initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) { 997 MethodSymbol meth = tree.sym; 998 999 // Create a new code structure. 1000 meth.code = code = new Code(meth, 1001 fatcode, 1002 lineDebugInfo ? toplevel.lineMap : null, 1003 varDebugInfo, 1004 stackMap, 1005 debugCode, 1006 genCrt ? new CRTable(tree, env.toplevel.endPositions) 1007 : null, 1008 syms, 1009 types, 1010 pool); 1011 items = new Items(pool, code, syms, types); 1012 if (code.debugCode) { 1013 System.err.println(meth + " for body " + tree); 1014 } 1015 1016 // If method is not static, create a new local variable address 1017 // for `this'. 1018 if ((tree.mods.flags & STATIC) == 0) { 1019 Type selfType = meth.owner.type; 1020 if (meth.isConstructor() && selfType != syms.objectType) 1021 selfType = UninitializedType.uninitializedThis(selfType); 1022 code.setDefined( 1023 code.newLocal( 1024 new VarSymbol(FINAL, names._this, selfType, meth.owner))); 1025 } 1026 1027 // Mark all parameters as defined from the beginning of 1028 // the method. 1029 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) { 1030 checkDimension(l.head.pos(), l.head.sym.type); 1031 code.setDefined(code.newLocal(l.head.sym)); 1032 } 1033 1034 // Get ready to generate code for method body. 1035 int startpcCrt = genCrt ? code.curCP() : 0; 1036 code.entryPoint(); 1037 1038 // Suppress initial stackmap 1039 code.pendingStackMap = false; 1040 1041 return startpcCrt; 1042 } 1043 visitVarDef(JCVariableDecl tree)1044 public void visitVarDef(JCVariableDecl tree) { 1045 VarSymbol v = tree.sym; 1046 if (tree.init != null) { 1047 checkStringConstant(tree.init.pos(), v.getConstValue()); 1048 if (v.getConstValue() == null || varDebugInfo) { 1049 Assert.check(code.isStatementStart()); 1050 code.newLocal(v); 1051 genExpr(tree.init, v.erasure(types)).load(); 1052 items.makeLocalItem(v).store(); 1053 Assert.check(code.isStatementStart()); 1054 } 1055 } else { 1056 code.newLocal(v); 1057 } 1058 checkDimension(tree.pos(), v.type); 1059 } 1060 visitSkip(JCSkip tree)1061 public void visitSkip(JCSkip tree) { 1062 } 1063 visitBlock(JCBlock tree)1064 public void visitBlock(JCBlock tree) { 1065 int limit = code.nextreg; 1066 Env<GenContext> localEnv = env.dup(tree, new GenContext()); 1067 genStats(tree.stats, localEnv); 1068 // End the scope of all block-local variables in variable info. 1069 if (!env.tree.hasTag(METHODDEF)) { 1070 code.statBegin(tree.endpos); 1071 code.endScopes(limit); 1072 code.pendingStatPos = Position.NOPOS; 1073 } 1074 } 1075 visitDoLoop(JCDoWhileLoop tree)1076 public void visitDoLoop(JCDoWhileLoop tree) { 1077 genLoop(tree, tree.body, tree.cond, List.nil(), false); 1078 } 1079 visitWhileLoop(JCWhileLoop tree)1080 public void visitWhileLoop(JCWhileLoop tree) { 1081 genLoop(tree, tree.body, tree.cond, List.nil(), true); 1082 } 1083 visitForLoop(JCForLoop tree)1084 public void visitForLoop(JCForLoop tree) { 1085 int limit = code.nextreg; 1086 genStats(tree.init, env); 1087 genLoop(tree, tree.body, tree.cond, tree.step, true); 1088 code.endScopes(limit); 1089 } 1090 //where 1091 /** Generate code for a loop. 1092 * @param loop The tree representing the loop. 1093 * @param body The loop's body. 1094 * @param cond The loop's controling condition. 1095 * @param step "Step" statements to be inserted at end of 1096 * each iteration. 1097 * @param testFirst True if the loop test belongs before the body. 1098 */ genLoop(JCStatement loop, JCStatement body, JCExpression cond, List<JCExpressionStatement> step, boolean testFirst)1099 private void genLoop(JCStatement loop, 1100 JCStatement body, 1101 JCExpression cond, 1102 List<JCExpressionStatement> step, 1103 boolean testFirst) { 1104 Env<GenContext> loopEnv = env.dup(loop, new GenContext()); 1105 int startpc = code.entryPoint(); 1106 if (testFirst) { //while or for loop 1107 CondItem c; 1108 if (cond != null) { 1109 code.statBegin(cond.pos); 1110 Assert.check(code.isStatementStart()); 1111 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER); 1112 } else { 1113 c = items.makeCondItem(goto_); 1114 } 1115 Chain loopDone = c.jumpFalse(); 1116 code.resolve(c.trueJumps); 1117 Assert.check(code.isStatementStart()); 1118 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET); 1119 code.resolve(loopEnv.info.cont); 1120 genStats(step, loopEnv); 1121 code.resolve(code.branch(goto_), startpc); 1122 code.resolve(loopDone); 1123 } else { 1124 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET); 1125 code.resolve(loopEnv.info.cont); 1126 genStats(step, loopEnv); 1127 if (code.isAlive()) { 1128 CondItem c; 1129 if (cond != null) { 1130 code.statBegin(cond.pos); 1131 Assert.check(code.isStatementStart()); 1132 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER); 1133 } else { 1134 c = items.makeCondItem(goto_); 1135 } 1136 code.resolve(c.jumpTrue(), startpc); 1137 Assert.check(code.isStatementStart()); 1138 code.resolve(c.falseJumps); 1139 } 1140 } 1141 Chain exit = loopEnv.info.exit; 1142 if (exit != null) { 1143 code.resolve(exit); 1144 exit.state.defined.excludeFrom(code.nextreg); 1145 } 1146 } 1147 visitForeachLoop(JCEnhancedForLoop tree)1148 public void visitForeachLoop(JCEnhancedForLoop tree) { 1149 throw new AssertionError(); // should have been removed by Lower. 1150 } 1151 visitLabelled(JCLabeledStatement tree)1152 public void visitLabelled(JCLabeledStatement tree) { 1153 Env<GenContext> localEnv = env.dup(tree, new GenContext()); 1154 genStat(tree.body, localEnv, CRT_STATEMENT); 1155 Chain exit = localEnv.info.exit; 1156 if (exit != null) { 1157 code.resolve(exit); 1158 exit.state.defined.excludeFrom(code.nextreg); 1159 } 1160 } 1161 visitSwitch(JCSwitch tree)1162 public void visitSwitch(JCSwitch tree) { 1163 handleSwitch(tree, tree.selector, tree.cases); 1164 } 1165 1166 @Override visitSwitchExpression(JCSwitchExpression tree)1167 public void visitSwitchExpression(JCSwitchExpression tree) { 1168 code.resolvePending(); 1169 boolean prevInCondSwitchExpression = inCondSwitchExpression; 1170 try { 1171 inCondSwitchExpression = false; 1172 doHandleSwitchExpression(tree); 1173 } finally { 1174 inCondSwitchExpression = prevInCondSwitchExpression; 1175 } 1176 result = items.makeStackItem(pt); 1177 } 1178 doHandleSwitchExpression(JCSwitchExpression tree)1179 private void doHandleSwitchExpression(JCSwitchExpression tree) { 1180 List<LocalItem> prevStackBeforeSwitchExpression = stackBeforeSwitchExpression; 1181 int limit = code.nextreg; 1182 try { 1183 stackBeforeSwitchExpression = List.nil(); 1184 if (hasTry(tree)) { 1185 //if the switch expression contains try-catch, the catch handlers need to have 1186 //an empty stack. So stash whole stack to local variables, and restore it before 1187 //breaks: 1188 while (code.state.stacksize > 0) { 1189 Type type = code.state.peek(); 1190 Name varName = names.fromString(target.syntheticNameChar() + 1191 "stack" + 1192 target.syntheticNameChar() + 1193 tree.pos + 1194 target.syntheticNameChar() + 1195 code.state.stacksize); 1196 VarSymbol var = new VarSymbol(Flags.SYNTHETIC, varName, type, 1197 this.env.enclMethod.sym); 1198 LocalItem item = items.new LocalItem(type, code.newLocal(var)); 1199 stackBeforeSwitchExpression = stackBeforeSwitchExpression.prepend(item); 1200 item.store(); 1201 } 1202 } 1203 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize); 1204 try { 1205 handleSwitch(tree, tree.selector, tree.cases); 1206 } finally { 1207 code.setLetExprStackPos(prevLetExprStart); 1208 } 1209 } finally { 1210 stackBeforeSwitchExpression = prevStackBeforeSwitchExpression; 1211 code.endScopes(limit); 1212 } 1213 } 1214 //where: hasTry(JCSwitchExpression tree)1215 private boolean hasTry(JCSwitchExpression tree) { 1216 boolean[] hasTry = new boolean[1]; 1217 new TreeScanner() { 1218 @Override 1219 public void visitTry(JCTry tree) { 1220 hasTry[0] = true; 1221 } 1222 1223 @Override 1224 public void visitClassDef(JCClassDecl tree) { 1225 } 1226 1227 @Override 1228 public void visitLambda(JCLambda tree) { 1229 } 1230 }.scan(tree); 1231 return hasTry[0]; 1232 } 1233 handleSwitch(JCTree swtch, JCExpression selector, List<JCCase> cases)1234 private void handleSwitch(JCTree swtch, JCExpression selector, List<JCCase> cases) { 1235 int limit = code.nextreg; 1236 Assert.check(!selector.type.hasTag(CLASS)); 1237 int startpcCrt = genCrt ? code.curCP() : 0; 1238 Assert.check(code.isStatementStart()); 1239 Item sel = genExpr(selector, syms.intType); 1240 if (cases.isEmpty()) { 1241 // We are seeing: switch <sel> {} 1242 sel.load().drop(); 1243 if (genCrt) 1244 code.crt.put(TreeInfo.skipParens(selector), 1245 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP()); 1246 } else { 1247 // We are seeing a nonempty switch. 1248 sel.load(); 1249 if (genCrt) 1250 code.crt.put(TreeInfo.skipParens(selector), 1251 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP()); 1252 Env<GenContext> switchEnv = env.dup(swtch, new GenContext()); 1253 switchEnv.info.isSwitch = true; 1254 1255 // Compute number of labels and minimum and maximum label values. 1256 // For each case, store its label in an array. 1257 int lo = Integer.MAX_VALUE; // minimum label. 1258 int hi = Integer.MIN_VALUE; // maximum label. 1259 int nlabels = 0; // number of labels. 1260 1261 int[] labels = new int[cases.length()]; // the label array. 1262 int defaultIndex = -1; // the index of the default clause. 1263 1264 List<JCCase> l = cases; 1265 for (int i = 0; i < labels.length; i++) { 1266 if (l.head.pats.nonEmpty()) { 1267 Assert.check(l.head.pats.size() == 1); 1268 int val = ((Number)l.head.pats.head.type.constValue()).intValue(); 1269 labels[i] = val; 1270 if (val < lo) lo = val; 1271 if (hi < val) hi = val; 1272 nlabels++; 1273 } else { 1274 Assert.check(defaultIndex == -1); 1275 defaultIndex = i; 1276 } 1277 l = l.tail; 1278 } 1279 1280 // Determine whether to issue a tableswitch or a lookupswitch 1281 // instruction. 1282 long table_space_cost = 4 + ((long) hi - lo + 1); // words 1283 long table_time_cost = 3; // comparisons 1284 long lookup_space_cost = 3 + 2 * (long) nlabels; 1285 long lookup_time_cost = nlabels; 1286 int opcode = 1287 nlabels > 0 && 1288 table_space_cost + 3 * table_time_cost <= 1289 lookup_space_cost + 3 * lookup_time_cost 1290 ? 1291 tableswitch : lookupswitch; 1292 1293 int startpc = code.curCP(); // the position of the selector operation 1294 code.emitop0(opcode); 1295 code.align(4); 1296 int tableBase = code.curCP(); // the start of the jump table 1297 int[] offsets = null; // a table of offsets for a lookupswitch 1298 code.emit4(-1); // leave space for default offset 1299 if (opcode == tableswitch) { 1300 code.emit4(lo); // minimum label 1301 code.emit4(hi); // maximum label 1302 for (long i = lo; i <= hi; i++) { // leave space for jump table 1303 code.emit4(-1); 1304 } 1305 } else { 1306 code.emit4(nlabels); // number of labels 1307 for (int i = 0; i < nlabels; i++) { 1308 code.emit4(-1); code.emit4(-1); // leave space for lookup table 1309 } 1310 offsets = new int[labels.length]; 1311 } 1312 Code.State stateSwitch = code.state.dup(); 1313 code.markDead(); 1314 1315 // For each case do: 1316 l = cases; 1317 for (int i = 0; i < labels.length; i++) { 1318 JCCase c = l.head; 1319 l = l.tail; 1320 1321 int pc = code.entryPoint(stateSwitch); 1322 // Insert offset directly into code or else into the 1323 // offsets table. 1324 if (i != defaultIndex) { 1325 if (opcode == tableswitch) { 1326 code.put4( 1327 tableBase + 4 * (labels[i] - lo + 3), 1328 pc - startpc); 1329 } else { 1330 offsets[i] = pc - startpc; 1331 } 1332 } else { 1333 code.put4(tableBase, pc - startpc); 1334 } 1335 1336 // Generate code for the statements in this case. 1337 genStats(c.stats, switchEnv, CRT_FLOW_TARGET); 1338 } 1339 1340 // Resolve all breaks. 1341 Chain exit = switchEnv.info.exit; 1342 if (exit != null) { 1343 code.resolve(exit); 1344 exit.state.defined.excludeFrom(limit); 1345 } 1346 1347 // If we have not set the default offset, we do so now. 1348 if (code.get4(tableBase) == -1) { 1349 code.put4(tableBase, code.entryPoint(stateSwitch) - startpc); 1350 } 1351 1352 if (opcode == tableswitch) { 1353 // Let any unfilled slots point to the default case. 1354 int defaultOffset = code.get4(tableBase); 1355 for (long i = lo; i <= hi; i++) { 1356 int t = (int)(tableBase + 4 * (i - lo + 3)); 1357 if (code.get4(t) == -1) 1358 code.put4(t, defaultOffset); 1359 } 1360 } else { 1361 // Sort non-default offsets and copy into lookup table. 1362 if (defaultIndex >= 0) 1363 for (int i = defaultIndex; i < labels.length - 1; i++) { 1364 labels[i] = labels[i+1]; 1365 offsets[i] = offsets[i+1]; 1366 } 1367 if (nlabels > 0) 1368 qsort2(labels, offsets, 0, nlabels - 1); 1369 for (int i = 0; i < nlabels; i++) { 1370 int caseidx = tableBase + 8 * (i + 1); 1371 code.put4(caseidx, labels[i]); 1372 code.put4(caseidx + 4, offsets[i]); 1373 } 1374 } 1375 } 1376 code.endScopes(limit); 1377 } 1378 //where 1379 /** Sort (int) arrays of keys and values 1380 */ qsort2(int[] keys, int[] values, int lo, int hi)1381 static void qsort2(int[] keys, int[] values, int lo, int hi) { 1382 int i = lo; 1383 int j = hi; 1384 int pivot = keys[(i+j)/2]; 1385 do { 1386 while (keys[i] < pivot) i++; 1387 while (pivot < keys[j]) j--; 1388 if (i <= j) { 1389 int temp1 = keys[i]; 1390 keys[i] = keys[j]; 1391 keys[j] = temp1; 1392 int temp2 = values[i]; 1393 values[i] = values[j]; 1394 values[j] = temp2; 1395 i++; 1396 j--; 1397 } 1398 } while (i <= j); 1399 if (lo < j) qsort2(keys, values, lo, j); 1400 if (i < hi) qsort2(keys, values, i, hi); 1401 } 1402 visitSynchronized(JCSynchronized tree)1403 public void visitSynchronized(JCSynchronized tree) { 1404 int limit = code.nextreg; 1405 // Generate code to evaluate lock and save in temporary variable. 1406 final LocalItem lockVar = makeTemp(syms.objectType); 1407 Assert.check(code.isStatementStart()); 1408 genExpr(tree.lock, tree.lock.type).load().duplicate(); 1409 lockVar.store(); 1410 1411 // Generate code to enter monitor. 1412 code.emitop0(monitorenter); 1413 code.state.lock(lockVar.reg); 1414 1415 // Generate code for a try statement with given body, no catch clauses 1416 // in a new environment with the "exit-monitor" operation as finalizer. 1417 final Env<GenContext> syncEnv = env.dup(tree, new GenContext()); 1418 syncEnv.info.finalize = new GenFinalizer() { 1419 void gen() { 1420 genLast(); 1421 Assert.check(syncEnv.info.gaps.length() % 2 == 0); 1422 syncEnv.info.gaps.append(code.curCP()); 1423 } 1424 void genLast() { 1425 if (code.isAlive()) { 1426 lockVar.load(); 1427 code.emitop0(monitorexit); 1428 code.state.unlock(lockVar.reg); 1429 } 1430 } 1431 }; 1432 syncEnv.info.gaps = new ListBuffer<>(); 1433 genTry(tree.body, List.nil(), syncEnv); 1434 code.endScopes(limit); 1435 } 1436 visitTry(final JCTry tree)1437 public void visitTry(final JCTry tree) { 1438 // Generate code for a try statement with given body and catch clauses, 1439 // in a new environment which calls the finally block if there is one. 1440 final Env<GenContext> tryEnv = env.dup(tree, new GenContext()); 1441 final Env<GenContext> oldEnv = env; 1442 tryEnv.info.finalize = new GenFinalizer() { 1443 void gen() { 1444 Assert.check(tryEnv.info.gaps.length() % 2 == 0); 1445 tryEnv.info.gaps.append(code.curCP()); 1446 genLast(); 1447 } 1448 void genLast() { 1449 if (tree.finalizer != null) 1450 genStat(tree.finalizer, oldEnv, CRT_BLOCK); 1451 } 1452 boolean hasFinalizer() { 1453 return tree.finalizer != null; 1454 } 1455 1456 @Override 1457 void afterBody() { 1458 if (tree.finalizer != null && (tree.finalizer.flags & BODY_ONLY_FINALIZE) != 0) { 1459 //for body-only finally, remove the GenFinalizer after try body 1460 //so that the finally is not generated to catch bodies: 1461 tryEnv.info.finalize = null; 1462 } 1463 } 1464 1465 }; 1466 tryEnv.info.gaps = new ListBuffer<>(); 1467 genTry(tree.body, tree.catchers, tryEnv); 1468 } 1469 //where 1470 /** Generate code for a try or synchronized statement 1471 * @param body The body of the try or synchronized statement. 1472 * @param catchers The lis of catch clauses. 1473 * @param env the environment current for the body. 1474 */ genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env)1475 void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) { 1476 int limit = code.nextreg; 1477 int startpc = code.curCP(); 1478 Code.State stateTry = code.state.dup(); 1479 genStat(body, env, CRT_BLOCK); 1480 int endpc = code.curCP(); 1481 List<Integer> gaps = env.info.gaps.toList(); 1482 code.statBegin(TreeInfo.endPos(body)); 1483 genFinalizer(env); 1484 code.statBegin(TreeInfo.endPos(env.tree)); 1485 Chain exitChain = code.branch(goto_); 1486 endFinalizerGap(env); 1487 env.info.finalize.afterBody(); 1488 boolean hasFinalizer = 1489 env.info.finalize != null && 1490 env.info.finalize.hasFinalizer(); 1491 if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) { 1492 // start off with exception on stack 1493 code.entryPoint(stateTry, l.head.param.sym.type); 1494 genCatch(l.head, env, startpc, endpc, gaps); 1495 genFinalizer(env); 1496 if (hasFinalizer || l.tail.nonEmpty()) { 1497 code.statBegin(TreeInfo.endPos(env.tree)); 1498 exitChain = Code.mergeChains(exitChain, 1499 code.branch(goto_)); 1500 } 1501 endFinalizerGap(env); 1502 } 1503 if (hasFinalizer) { 1504 // Create a new register segement to avoid allocating 1505 // the same variables in finalizers and other statements. 1506 code.newRegSegment(); 1507 1508 // Add a catch-all clause. 1509 1510 // start off with exception on stack 1511 int catchallpc = code.entryPoint(stateTry, syms.throwableType); 1512 1513 // Register all exception ranges for catch all clause. 1514 // The range of the catch all clause is from the beginning 1515 // of the try or synchronized block until the present 1516 // code pointer excluding all gaps in the current 1517 // environment's GenContext. 1518 int startseg = startpc; 1519 while (env.info.gaps.nonEmpty()) { 1520 int endseg = env.info.gaps.next().intValue(); 1521 registerCatch(body.pos(), startseg, endseg, 1522 catchallpc, 0); 1523 startseg = env.info.gaps.next().intValue(); 1524 } 1525 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS)); 1526 code.markStatBegin(); 1527 1528 Item excVar = makeTemp(syms.throwableType); 1529 excVar.store(); 1530 genFinalizer(env); 1531 code.resolvePending(); 1532 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.END_POS)); 1533 code.markStatBegin(); 1534 1535 excVar.load(); 1536 registerCatch(body.pos(), startseg, 1537 env.info.gaps.next().intValue(), 1538 catchallpc, 0); 1539 code.emitop0(athrow); 1540 code.markDead(); 1541 1542 // If there are jsr's to this finalizer, ... 1543 if (env.info.cont != null) { 1544 // Resolve all jsr's. 1545 code.resolve(env.info.cont); 1546 1547 // Mark statement line number 1548 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS)); 1549 code.markStatBegin(); 1550 1551 // Save return address. 1552 LocalItem retVar = makeTemp(syms.throwableType); 1553 retVar.store(); 1554 1555 // Generate finalizer code. 1556 env.info.finalize.genLast(); 1557 1558 // Return. 1559 code.emitop1w(ret, retVar.reg); 1560 code.markDead(); 1561 } 1562 } 1563 // Resolve all breaks. 1564 code.resolve(exitChain); 1565 1566 code.endScopes(limit); 1567 } 1568 1569 /** Generate code for a catch clause. 1570 * @param tree The catch clause. 1571 * @param env The environment current in the enclosing try. 1572 * @param startpc Start pc of try-block. 1573 * @param endpc End pc of try-block. 1574 */ genCatch(JCCatch tree, Env<GenContext> env, int startpc, int endpc, List<Integer> gaps)1575 void genCatch(JCCatch tree, 1576 Env<GenContext> env, 1577 int startpc, int endpc, 1578 List<Integer> gaps) { 1579 if (startpc != endpc) { 1580 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypeExprs 1581 = catchTypesWithAnnotations(tree); 1582 while (gaps.nonEmpty()) { 1583 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) { 1584 JCExpression subCatch = subCatch1.snd; 1585 int catchType = makeRef(tree.pos(), subCatch.type); 1586 int end = gaps.head.intValue(); 1587 registerCatch(tree.pos(), 1588 startpc, end, code.curCP(), 1589 catchType); 1590 for (Attribute.TypeCompound tc : subCatch1.fst) { 1591 tc.position.setCatchInfo(catchType, startpc); 1592 } 1593 } 1594 gaps = gaps.tail; 1595 startpc = gaps.head.intValue(); 1596 gaps = gaps.tail; 1597 } 1598 if (startpc < endpc) { 1599 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) { 1600 JCExpression subCatch = subCatch1.snd; 1601 int catchType = makeRef(tree.pos(), subCatch.type); 1602 registerCatch(tree.pos(), 1603 startpc, endpc, code.curCP(), 1604 catchType); 1605 for (Attribute.TypeCompound tc : subCatch1.fst) { 1606 tc.position.setCatchInfo(catchType, startpc); 1607 } 1608 } 1609 } 1610 VarSymbol exparam = tree.param.sym; 1611 code.statBegin(tree.pos); 1612 code.markStatBegin(); 1613 int limit = code.nextreg; 1614 code.newLocal(exparam); 1615 items.makeLocalItem(exparam).store(); 1616 code.statBegin(TreeInfo.firstStatPos(tree.body)); 1617 genStat(tree.body, env, CRT_BLOCK); 1618 code.endScopes(limit); 1619 code.statBegin(TreeInfo.endPos(tree.body)); 1620 } 1621 } 1622 // where catchTypesWithAnnotations(JCCatch tree)1623 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotations(JCCatch tree) { 1624 return TreeInfo.isMultiCatch(tree) ? 1625 catchTypesWithAnnotationsFromMulticatch((JCTypeUnion)tree.param.vartype, tree.param.sym.getRawTypeAttributes()) : 1626 List.of(new Pair<>(tree.param.sym.getRawTypeAttributes(), tree.param.vartype)); 1627 } 1628 // where catchTypesWithAnnotationsFromMulticatch(JCTypeUnion tree, List<TypeCompound> first)1629 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotationsFromMulticatch(JCTypeUnion tree, List<TypeCompound> first) { 1630 List<JCExpression> alts = tree.alternatives; 1631 List<Pair<List<TypeCompound>, JCExpression>> res = List.of(new Pair<>(first, alts.head)); 1632 alts = alts.tail; 1633 1634 while(alts != null && alts.head != null) { 1635 JCExpression alt = alts.head; 1636 if (alt instanceof JCAnnotatedType) { 1637 JCAnnotatedType a = (JCAnnotatedType)alt; 1638 res = res.prepend(new Pair<>(annotate.fromAnnotations(a.annotations), alt)); 1639 } else { 1640 res = res.prepend(new Pair<>(List.nil(), alt)); 1641 } 1642 alts = alts.tail; 1643 } 1644 return res.reverse(); 1645 } 1646 1647 /** Register a catch clause in the "Exceptions" code-attribute. 1648 */ registerCatch(DiagnosticPosition pos, int startpc, int endpc, int handler_pc, int catch_type)1649 void registerCatch(DiagnosticPosition pos, 1650 int startpc, int endpc, 1651 int handler_pc, int catch_type) { 1652 char startpc1 = (char)startpc; 1653 char endpc1 = (char)endpc; 1654 char handler_pc1 = (char)handler_pc; 1655 if (startpc1 == startpc && 1656 endpc1 == endpc && 1657 handler_pc1 == handler_pc) { 1658 code.addCatch(startpc1, endpc1, handler_pc1, 1659 (char)catch_type); 1660 } else { 1661 log.error(pos, Errors.LimitCodeTooLargeForTryStmt); 1662 nerrs++; 1663 } 1664 } 1665 visitIf(JCIf tree)1666 public void visitIf(JCIf tree) { 1667 int limit = code.nextreg; 1668 Chain thenExit = null; 1669 Assert.check(code.isStatementStart()); 1670 CondItem c = genCond(TreeInfo.skipParens(tree.cond), 1671 CRT_FLOW_CONTROLLER); 1672 Chain elseChain = c.jumpFalse(); 1673 Assert.check(code.isStatementStart()); 1674 if (!c.isFalse()) { 1675 code.resolve(c.trueJumps); 1676 genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET); 1677 thenExit = code.branch(goto_); 1678 } 1679 if (elseChain != null) { 1680 code.resolve(elseChain); 1681 if (tree.elsepart != null) { 1682 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET); 1683 } 1684 } 1685 code.resolve(thenExit); 1686 code.endScopes(limit); 1687 Assert.check(code.isStatementStart()); 1688 } 1689 visitExec(JCExpressionStatement tree)1690 public void visitExec(JCExpressionStatement tree) { 1691 // Optimize x++ to ++x and x-- to --x. 1692 JCExpression e = tree.expr; 1693 switch (e.getTag()) { 1694 case POSTINC: 1695 ((JCUnary) e).setTag(PREINC); 1696 break; 1697 case POSTDEC: 1698 ((JCUnary) e).setTag(PREDEC); 1699 break; 1700 } 1701 Assert.check(code.isStatementStart()); 1702 genExpr(tree.expr, tree.expr.type).drop(); 1703 Assert.check(code.isStatementStart()); 1704 } 1705 visitBreak(JCBreak tree)1706 public void visitBreak(JCBreak tree) { 1707 Assert.check(code.isStatementStart()); 1708 final Env<GenContext> targetEnv; 1709 if (tree.isValueBreak()) { 1710 //restore stack as it was before the switch expression: 1711 for (LocalItem li : stackBeforeSwitchExpression) { 1712 li.load(); 1713 } 1714 if (inCondSwitchExpression) { 1715 CondItem value = genCond(tree.value, CRT_FLOW_TARGET); 1716 Chain falseJumps = value.jumpFalse(); 1717 targetEnv = unwindBreak(tree); 1718 code.resolve(value.trueJumps); 1719 Chain trueJumps = code.branch(goto_); 1720 if (switchExpressionTrueChain == null) { 1721 switchExpressionTrueChain = trueJumps; 1722 } else { 1723 switchExpressionTrueChain = 1724 Code.mergeChains(switchExpressionTrueChain, trueJumps); 1725 } 1726 if (switchExpressionFalseChain == null) { 1727 switchExpressionFalseChain = falseJumps; 1728 } else { 1729 switchExpressionFalseChain = 1730 Code.mergeChains(switchExpressionFalseChain, falseJumps); 1731 } 1732 } else { 1733 genExpr(tree.value, pt).load(); 1734 code.state.forceStackTop(tree.target.type); 1735 targetEnv = unwindBreak(tree); 1736 targetEnv.info.addExit(code.branch(goto_)); 1737 } 1738 } else { 1739 targetEnv = unwindBreak(tree); 1740 targetEnv.info.addExit(code.branch(goto_)); 1741 } 1742 endFinalizerGaps(env, targetEnv); 1743 } 1744 //where: unwindBreak(JCBreak tree)1745 private Env<GenContext> unwindBreak(JCBreak tree) { 1746 int tmpPos = code.pendingStatPos; 1747 Env<GenContext> targetEnv = unwind(tree.target, env); 1748 code.pendingStatPos = tmpPos; 1749 return targetEnv; 1750 } 1751 visitContinue(JCContinue tree)1752 public void visitContinue(JCContinue tree) { 1753 int tmpPos = code.pendingStatPos; 1754 Env<GenContext> targetEnv = unwind(tree.target, env); 1755 code.pendingStatPos = tmpPos; 1756 Assert.check(code.isStatementStart()); 1757 targetEnv.info.addCont(code.branch(goto_)); 1758 endFinalizerGaps(env, targetEnv); 1759 } 1760 visitReturn(JCReturn tree)1761 public void visitReturn(JCReturn tree) { 1762 int limit = code.nextreg; 1763 final Env<GenContext> targetEnv; 1764 1765 /* Save and then restore the location of the return in case a finally 1766 * is expanded (with unwind()) in the middle of our bytecodes. 1767 */ 1768 int tmpPos = code.pendingStatPos; 1769 if (tree.expr != null) { 1770 Assert.check(code.isStatementStart()); 1771 Item r = genExpr(tree.expr, pt).load(); 1772 if (hasFinally(env.enclMethod, env)) { 1773 r = makeTemp(pt); 1774 r.store(); 1775 } 1776 targetEnv = unwind(env.enclMethod, env); 1777 code.pendingStatPos = tmpPos; 1778 r.load(); 1779 code.emitop0(ireturn + Code.truncate(Code.typecode(pt))); 1780 } else { 1781 targetEnv = unwind(env.enclMethod, env); 1782 code.pendingStatPos = tmpPos; 1783 code.emitop0(return_); 1784 } 1785 endFinalizerGaps(env, targetEnv); 1786 code.endScopes(limit); 1787 } 1788 visitThrow(JCThrow tree)1789 public void visitThrow(JCThrow tree) { 1790 Assert.check(code.isStatementStart()); 1791 genExpr(tree.expr, tree.expr.type).load(); 1792 code.emitop0(athrow); 1793 Assert.check(code.isStatementStart()); 1794 } 1795 1796 /* ************************************************************************ 1797 * Visitor methods for expressions 1798 *************************************************************************/ 1799 visitApply(JCMethodInvocation tree)1800 public void visitApply(JCMethodInvocation tree) { 1801 setTypeAnnotationPositions(tree.pos); 1802 // Generate code for method. 1803 Item m = genExpr(tree.meth, methodType); 1804 // Generate code for all arguments, where the expected types are 1805 // the parameters of the method's external type (that is, any implicit 1806 // outer instance of a super(...) call appears as first parameter). 1807 MethodSymbol msym = (MethodSymbol)TreeInfo.symbol(tree.meth); 1808 genArgs(tree.args, 1809 msym.externalType(types).getParameterTypes()); 1810 if (!msym.isDynamic()) { 1811 code.statBegin(tree.pos); 1812 } 1813 result = m.invoke(); 1814 } 1815 visitConditional(JCConditional tree)1816 public void visitConditional(JCConditional tree) { 1817 Chain thenExit = null; 1818 code.statBegin(tree.cond.pos); 1819 CondItem c = genCond(tree.cond, CRT_FLOW_CONTROLLER); 1820 Chain elseChain = c.jumpFalse(); 1821 if (!c.isFalse()) { 1822 code.resolve(c.trueJumps); 1823 int startpc = genCrt ? code.curCP() : 0; 1824 code.statBegin(tree.truepart.pos); 1825 genExpr(tree.truepart, pt).load(); 1826 code.state.forceStackTop(tree.type); 1827 if (genCrt) code.crt.put(tree.truepart, CRT_FLOW_TARGET, 1828 startpc, code.curCP()); 1829 thenExit = code.branch(goto_); 1830 } 1831 if (elseChain != null) { 1832 code.resolve(elseChain); 1833 int startpc = genCrt ? code.curCP() : 0; 1834 code.statBegin(tree.falsepart.pos); 1835 genExpr(tree.falsepart, pt).load(); 1836 code.state.forceStackTop(tree.type); 1837 if (genCrt) code.crt.put(tree.falsepart, CRT_FLOW_TARGET, 1838 startpc, code.curCP()); 1839 } 1840 code.resolve(thenExit); 1841 result = items.makeStackItem(pt); 1842 } 1843 setTypeAnnotationPositions(int treePos)1844 private void setTypeAnnotationPositions(int treePos) { 1845 MethodSymbol meth = code.meth; 1846 boolean initOrClinit = code.meth.getKind() == javax.lang.model.element.ElementKind.CONSTRUCTOR 1847 || code.meth.getKind() == javax.lang.model.element.ElementKind.STATIC_INIT; 1848 1849 for (Attribute.TypeCompound ta : meth.getRawTypeAttributes()) { 1850 if (ta.hasUnknownPosition()) 1851 ta.tryFixPosition(); 1852 1853 if (ta.position.matchesPos(treePos)) 1854 ta.position.updatePosOffset(code.cp); 1855 } 1856 1857 if (!initOrClinit) 1858 return; 1859 1860 for (Attribute.TypeCompound ta : meth.owner.getRawTypeAttributes()) { 1861 if (ta.hasUnknownPosition()) 1862 ta.tryFixPosition(); 1863 1864 if (ta.position.matchesPos(treePos)) 1865 ta.position.updatePosOffset(code.cp); 1866 } 1867 1868 ClassSymbol clazz = meth.enclClass(); 1869 for (Symbol s : new com.sun.tools.javac.model.FilteredMemberList(clazz.members())) { 1870 if (!s.getKind().isField()) 1871 continue; 1872 1873 for (Attribute.TypeCompound ta : s.getRawTypeAttributes()) { 1874 if (ta.hasUnknownPosition()) 1875 ta.tryFixPosition(); 1876 1877 if (ta.position.matchesPos(treePos)) 1878 ta.position.updatePosOffset(code.cp); 1879 } 1880 } 1881 } 1882 visitNewClass(JCNewClass tree)1883 public void visitNewClass(JCNewClass tree) { 1884 // Enclosing instances or anonymous classes should have been eliminated 1885 // by now. 1886 Assert.check(tree.encl == null && tree.def == null); 1887 setTypeAnnotationPositions(tree.pos); 1888 1889 code.emitop2(new_, makeRef(tree.pos(), tree.type)); 1890 code.emitop0(dup); 1891 1892 // Generate code for all arguments, where the expected types are 1893 // the parameters of the constructor's external type (that is, 1894 // any implicit outer instance appears as first parameter). 1895 genArgs(tree.args, tree.constructor.externalType(types).getParameterTypes()); 1896 1897 items.makeMemberItem(tree.constructor, true).invoke(); 1898 result = items.makeStackItem(tree.type); 1899 } 1900 visitNewArray(JCNewArray tree)1901 public void visitNewArray(JCNewArray tree) { 1902 setTypeAnnotationPositions(tree.pos); 1903 1904 if (tree.elems != null) { 1905 Type elemtype = types.elemtype(tree.type); 1906 loadIntConst(tree.elems.length()); 1907 Item arr = makeNewArray(tree.pos(), tree.type, 1); 1908 int i = 0; 1909 for (List<JCExpression> l = tree.elems; l.nonEmpty(); l = l.tail) { 1910 arr.duplicate(); 1911 loadIntConst(i); 1912 i++; 1913 genExpr(l.head, elemtype).load(); 1914 items.makeIndexedItem(elemtype).store(); 1915 } 1916 result = arr; 1917 } else { 1918 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) { 1919 genExpr(l.head, syms.intType).load(); 1920 } 1921 result = makeNewArray(tree.pos(), tree.type, tree.dims.length()); 1922 } 1923 } 1924 //where 1925 /** Generate code to create an array with given element type and number 1926 * of dimensions. 1927 */ makeNewArray(DiagnosticPosition pos, Type type, int ndims)1928 Item makeNewArray(DiagnosticPosition pos, Type type, int ndims) { 1929 Type elemtype = types.elemtype(type); 1930 if (types.dimensions(type) > ClassFile.MAX_DIMENSIONS) { 1931 log.error(pos, Errors.LimitDimensions); 1932 nerrs++; 1933 } 1934 int elemcode = Code.arraycode(elemtype); 1935 if (elemcode == 0 || (elemcode == 1 && ndims == 1)) { 1936 code.emitAnewarray(makeRef(pos, elemtype), type); 1937 } else if (elemcode == 1) { 1938 code.emitMultianewarray(ndims, makeRef(pos, type), type); 1939 } else { 1940 code.emitNewarray(elemcode, type); 1941 } 1942 return items.makeStackItem(type); 1943 } 1944 visitParens(JCParens tree)1945 public void visitParens(JCParens tree) { 1946 result = genExpr(tree.expr, tree.expr.type); 1947 } 1948 visitAssign(JCAssign tree)1949 public void visitAssign(JCAssign tree) { 1950 Item l = genExpr(tree.lhs, tree.lhs.type); 1951 genExpr(tree.rhs, tree.lhs.type).load(); 1952 if (tree.rhs.type.hasTag(BOT)) { 1953 /* This is just a case of widening reference conversion that per 5.1.5 simply calls 1954 for "regarding a reference as having some other type in a manner that can be proved 1955 correct at compile time." 1956 */ 1957 code.state.forceStackTop(tree.lhs.type); 1958 } 1959 result = items.makeAssignItem(l); 1960 } 1961 visitAssignop(JCAssignOp tree)1962 public void visitAssignop(JCAssignOp tree) { 1963 OperatorSymbol operator = tree.operator; 1964 Item l; 1965 if (operator.opcode == string_add) { 1966 l = concat.makeConcat(tree); 1967 } else { 1968 // Generate code for first expression 1969 l = genExpr(tree.lhs, tree.lhs.type); 1970 1971 // If we have an increment of -32768 to +32767 of a local 1972 // int variable we can use an incr instruction instead of 1973 // proceeding further. 1974 if ((tree.hasTag(PLUS_ASG) || tree.hasTag(MINUS_ASG)) && 1975 l instanceof LocalItem && 1976 tree.lhs.type.getTag().isSubRangeOf(INT) && 1977 tree.rhs.type.getTag().isSubRangeOf(INT) && 1978 tree.rhs.type.constValue() != null) { 1979 int ival = ((Number) tree.rhs.type.constValue()).intValue(); 1980 if (tree.hasTag(MINUS_ASG)) ival = -ival; 1981 ((LocalItem)l).incr(ival); 1982 result = l; 1983 return; 1984 } 1985 // Otherwise, duplicate expression, load one copy 1986 // and complete binary operation. 1987 l.duplicate(); 1988 l.coerce(operator.type.getParameterTypes().head).load(); 1989 completeBinop(tree.lhs, tree.rhs, operator).coerce(tree.lhs.type); 1990 } 1991 result = items.makeAssignItem(l); 1992 } 1993 visitUnary(JCUnary tree)1994 public void visitUnary(JCUnary tree) { 1995 OperatorSymbol operator = tree.operator; 1996 if (tree.hasTag(NOT)) { 1997 CondItem od = genCond(tree.arg, false); 1998 result = od.negate(); 1999 } else { 2000 Item od = genExpr(tree.arg, operator.type.getParameterTypes().head); 2001 switch (tree.getTag()) { 2002 case POS: 2003 result = od.load(); 2004 break; 2005 case NEG: 2006 result = od.load(); 2007 code.emitop0(operator.opcode); 2008 break; 2009 case COMPL: 2010 result = od.load(); 2011 emitMinusOne(od.typecode); 2012 code.emitop0(operator.opcode); 2013 break; 2014 case PREINC: case PREDEC: 2015 od.duplicate(); 2016 if (od instanceof LocalItem && 2017 (operator.opcode == iadd || operator.opcode == isub)) { 2018 ((LocalItem)od).incr(tree.hasTag(PREINC) ? 1 : -1); 2019 result = od; 2020 } else { 2021 od.load(); 2022 code.emitop0(one(od.typecode)); 2023 code.emitop0(operator.opcode); 2024 // Perform narrowing primitive conversion if byte, 2025 // char, or short. Fix for 4304655. 2026 if (od.typecode != INTcode && 2027 Code.truncate(od.typecode) == INTcode) 2028 code.emitop0(int2byte + od.typecode - BYTEcode); 2029 result = items.makeAssignItem(od); 2030 } 2031 break; 2032 case POSTINC: case POSTDEC: 2033 od.duplicate(); 2034 if (od instanceof LocalItem && 2035 (operator.opcode == iadd || operator.opcode == isub)) { 2036 Item res = od.load(); 2037 ((LocalItem)od).incr(tree.hasTag(POSTINC) ? 1 : -1); 2038 result = res; 2039 } else { 2040 Item res = od.load(); 2041 od.stash(od.typecode); 2042 code.emitop0(one(od.typecode)); 2043 code.emitop0(operator.opcode); 2044 // Perform narrowing primitive conversion if byte, 2045 // char, or short. Fix for 4304655. 2046 if (od.typecode != INTcode && 2047 Code.truncate(od.typecode) == INTcode) 2048 code.emitop0(int2byte + od.typecode - BYTEcode); 2049 od.store(); 2050 result = res; 2051 } 2052 break; 2053 case NULLCHK: 2054 result = od.load(); 2055 code.emitop0(dup); 2056 genNullCheck(tree); 2057 break; 2058 default: 2059 Assert.error(); 2060 } 2061 } 2062 } 2063 2064 /** Generate a null check from the object value at stack top. */ genNullCheck(JCTree tree)2065 private void genNullCheck(JCTree tree) { 2066 code.statBegin(tree.pos); 2067 callMethod(tree.pos(), syms.objectsType, names.requireNonNull, 2068 List.of(syms.objectType), true); 2069 code.emitop0(pop); 2070 } 2071 visitBinary(JCBinary tree)2072 public void visitBinary(JCBinary tree) { 2073 OperatorSymbol operator = tree.operator; 2074 if (operator.opcode == string_add) { 2075 result = concat.makeConcat(tree); 2076 } else if (tree.hasTag(AND)) { 2077 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER); 2078 if (!lcond.isFalse()) { 2079 Chain falseJumps = lcond.jumpFalse(); 2080 code.resolve(lcond.trueJumps); 2081 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET); 2082 result = items. 2083 makeCondItem(rcond.opcode, 2084 rcond.trueJumps, 2085 Code.mergeChains(falseJumps, 2086 rcond.falseJumps)); 2087 } else { 2088 result = lcond; 2089 } 2090 } else if (tree.hasTag(OR)) { 2091 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER); 2092 if (!lcond.isTrue()) { 2093 Chain trueJumps = lcond.jumpTrue(); 2094 code.resolve(lcond.falseJumps); 2095 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET); 2096 result = items. 2097 makeCondItem(rcond.opcode, 2098 Code.mergeChains(trueJumps, rcond.trueJumps), 2099 rcond.falseJumps); 2100 } else { 2101 result = lcond; 2102 } 2103 } else { 2104 Item od = genExpr(tree.lhs, operator.type.getParameterTypes().head); 2105 od.load(); 2106 result = completeBinop(tree.lhs, tree.rhs, operator); 2107 } 2108 } 2109 2110 2111 /** Complete generating code for operation, with left operand 2112 * already on stack. 2113 * @param lhs The tree representing the left operand. 2114 * @param rhs The tree representing the right operand. 2115 * @param operator The operator symbol. 2116 */ completeBinop(JCTree lhs, JCTree rhs, OperatorSymbol operator)2117 Item completeBinop(JCTree lhs, JCTree rhs, OperatorSymbol operator) { 2118 MethodType optype = (MethodType)operator.type; 2119 int opcode = operator.opcode; 2120 if (opcode >= if_icmpeq && opcode <= if_icmple && 2121 rhs.type.constValue() instanceof Number && 2122 ((Number) rhs.type.constValue()).intValue() == 0) { 2123 opcode = opcode + (ifeq - if_icmpeq); 2124 } else if (opcode >= if_acmpeq && opcode <= if_acmpne && 2125 TreeInfo.isNull(rhs)) { 2126 opcode = opcode + (if_acmp_null - if_acmpeq); 2127 } else { 2128 // The expected type of the right operand is 2129 // the second parameter type of the operator, except for 2130 // shifts with long shiftcount, where we convert the opcode 2131 // to a short shift and the expected type to int. 2132 Type rtype = operator.erasure(types).getParameterTypes().tail.head; 2133 if (opcode >= ishll && opcode <= lushrl) { 2134 opcode = opcode + (ishl - ishll); 2135 rtype = syms.intType; 2136 } 2137 // Generate code for right operand and load. 2138 genExpr(rhs, rtype).load(); 2139 // If there are two consecutive opcode instructions, 2140 // emit the first now. 2141 if (opcode >= (1 << preShift)) { 2142 code.emitop0(opcode >> preShift); 2143 opcode = opcode & 0xFF; 2144 } 2145 } 2146 if (opcode >= ifeq && opcode <= if_acmpne || 2147 opcode == if_acmp_null || opcode == if_acmp_nonnull) { 2148 return items.makeCondItem(opcode); 2149 } else { 2150 code.emitop0(opcode); 2151 return items.makeStackItem(optype.restype); 2152 } 2153 } 2154 visitTypeCast(JCTypeCast tree)2155 public void visitTypeCast(JCTypeCast tree) { 2156 result = genExpr(tree.expr, tree.clazz.type).load(); 2157 setTypeAnnotationPositions(tree.pos); 2158 // Additional code is only needed if we cast to a reference type 2159 // which is not statically a supertype of the expression's type. 2160 // For basic types, the coerce(...) in genExpr(...) will do 2161 // the conversion. 2162 if (!tree.clazz.type.isPrimitive() && 2163 !types.isSameType(tree.expr.type, tree.clazz.type) && 2164 types.asSuper(tree.expr.type, tree.clazz.type.tsym) == null) { 2165 code.emitop2(checkcast, makeRef(tree.pos(), tree.clazz.type)); 2166 } 2167 } 2168 visitWildcard(JCWildcard tree)2169 public void visitWildcard(JCWildcard tree) { 2170 throw new AssertionError(this.getClass().getName()); 2171 } 2172 visitTypeTest(JCInstanceOf tree)2173 public void visitTypeTest(JCInstanceOf tree) { 2174 genExpr(tree.expr, tree.expr.type).load(); 2175 setTypeAnnotationPositions(tree.pos); 2176 code.emitop2(instanceof_, makeRef(tree.pos(), tree.clazz.type)); 2177 result = items.makeStackItem(syms.booleanType); 2178 } 2179 visitIndexed(JCArrayAccess tree)2180 public void visitIndexed(JCArrayAccess tree) { 2181 genExpr(tree.indexed, tree.indexed.type).load(); 2182 genExpr(tree.index, syms.intType).load(); 2183 result = items.makeIndexedItem(tree.type); 2184 } 2185 visitIdent(JCIdent tree)2186 public void visitIdent(JCIdent tree) { 2187 Symbol sym = tree.sym; 2188 if (tree.name == names._this || tree.name == names._super) { 2189 Item res = tree.name == names._this 2190 ? items.makeThisItem() 2191 : items.makeSuperItem(); 2192 if (sym.kind == MTH) { 2193 // Generate code to address the constructor. 2194 res.load(); 2195 res = items.makeMemberItem(sym, true); 2196 } 2197 result = res; 2198 } else if (sym.kind == VAR && (sym.owner.kind == MTH || sym.owner.kind == VAR)) { 2199 result = items.makeLocalItem((VarSymbol)sym); 2200 } else if (isInvokeDynamic(sym)) { 2201 result = items.makeDynamicItem(sym); 2202 } else if ((sym.flags() & STATIC) != 0) { 2203 if (!isAccessSuper(env.enclMethod)) 2204 sym = binaryQualifier(sym, env.enclClass.type); 2205 result = items.makeStaticItem(sym); 2206 } else { 2207 items.makeThisItem().load(); 2208 sym = binaryQualifier(sym, env.enclClass.type); 2209 result = items.makeMemberItem(sym, nonVirtualForPrivateAccess(sym)); 2210 } 2211 } 2212 2213 //where nonVirtualForPrivateAccess(Symbol sym)2214 private boolean nonVirtualForPrivateAccess(Symbol sym) { 2215 boolean useVirtual = target.hasVirtualPrivateInvoke() && 2216 !disableVirtualizedPrivateInvoke; 2217 return !useVirtual && ((sym.flags() & PRIVATE) != 0); 2218 } 2219 visitSelect(JCFieldAccess tree)2220 public void visitSelect(JCFieldAccess tree) { 2221 Symbol sym = tree.sym; 2222 2223 if (tree.name == names._class) { 2224 code.emitLdc(makeRef(tree.pos(), tree.selected.type)); 2225 result = items.makeStackItem(pt); 2226 return; 2227 } 2228 2229 Symbol ssym = TreeInfo.symbol(tree.selected); 2230 2231 // Are we selecting via super? 2232 boolean selectSuper = 2233 ssym != null && (ssym.kind == TYP || ssym.name == names._super); 2234 2235 // Are we accessing a member of the superclass in an access method 2236 // resulting from a qualified super? 2237 boolean accessSuper = isAccessSuper(env.enclMethod); 2238 2239 Item base = (selectSuper) 2240 ? items.makeSuperItem() 2241 : genExpr(tree.selected, tree.selected.type); 2242 2243 if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) { 2244 // We are seeing a variable that is constant but its selecting 2245 // expression is not. 2246 if ((sym.flags() & STATIC) != 0) { 2247 if (!selectSuper && (ssym == null || ssym.kind != TYP)) 2248 base = base.load(); 2249 base.drop(); 2250 } else { 2251 base.load(); 2252 genNullCheck(tree.selected); 2253 } 2254 result = items. 2255 makeImmediateItem(sym.type, ((VarSymbol) sym).getConstValue()); 2256 } else { 2257 if (isInvokeDynamic(sym)) { 2258 result = items.makeDynamicItem(sym); 2259 return; 2260 } else { 2261 sym = binaryQualifier(sym, tree.selected.type); 2262 } 2263 if ((sym.flags() & STATIC) != 0) { 2264 if (!selectSuper && (ssym == null || ssym.kind != TYP)) 2265 base = base.load(); 2266 base.drop(); 2267 result = items.makeStaticItem(sym); 2268 } else { 2269 base.load(); 2270 if (sym == syms.lengthVar) { 2271 code.emitop0(arraylength); 2272 result = items.makeStackItem(syms.intType); 2273 } else { 2274 result = items. 2275 makeMemberItem(sym, 2276 nonVirtualForPrivateAccess(sym) || 2277 selectSuper || accessSuper); 2278 } 2279 } 2280 } 2281 } 2282 isInvokeDynamic(Symbol sym)2283 public boolean isInvokeDynamic(Symbol sym) { 2284 return sym.kind == MTH && ((MethodSymbol)sym).isDynamic(); 2285 } 2286 visitLiteral(JCLiteral tree)2287 public void visitLiteral(JCLiteral tree) { 2288 if (tree.type.hasTag(BOT)) { 2289 code.emitop0(aconst_null); 2290 result = items.makeStackItem(tree.type); 2291 } 2292 else 2293 result = items.makeImmediateItem(tree.type, tree.value); 2294 } 2295 visitLetExpr(LetExpr tree)2296 public void visitLetExpr(LetExpr tree) { 2297 int limit = code.nextreg; 2298 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize); 2299 try { 2300 genStats(tree.defs, env); 2301 } finally { 2302 code.setLetExprStackPos(prevLetExprStart); 2303 } 2304 result = genExpr(tree.expr, tree.expr.type).load(); 2305 code.endScopes(limit); 2306 } 2307 generateReferencesToPrunedTree(ClassSymbol classSymbol, Pool pool)2308 private void generateReferencesToPrunedTree(ClassSymbol classSymbol, Pool pool) { 2309 List<JCTree> prunedInfo = lower.prunedTree.get(classSymbol); 2310 if (prunedInfo != null) { 2311 for (JCTree prunedTree: prunedInfo) { 2312 prunedTree.accept(classReferenceVisitor); 2313 } 2314 } 2315 } 2316 2317 /* ************************************************************************ 2318 * main method 2319 *************************************************************************/ 2320 2321 /** Generate code for a class definition. 2322 * @param env The attribution environment that belongs to the 2323 * outermost class containing this class definition. 2324 * We need this for resolving some additional symbols. 2325 * @param cdef The tree representing the class definition. 2326 * @return True if code is generated with no errors. 2327 */ genClass(Env<AttrContext> env, JCClassDecl cdef)2328 public boolean genClass(Env<AttrContext> env, JCClassDecl cdef) { 2329 try { 2330 attrEnv = env; 2331 ClassSymbol c = cdef.sym; 2332 this.toplevel = env.toplevel; 2333 this.endPosTable = toplevel.endPositions; 2334 c.pool = pool; 2335 pool.reset(); 2336 /* method normalizeDefs() can add references to external classes into the constant pool 2337 */ 2338 cdef.defs = normalizeDefs(cdef.defs, c); 2339 generateReferencesToPrunedTree(c, pool); 2340 Env<GenContext> localEnv = new Env<>(cdef, new GenContext()); 2341 localEnv.toplevel = env.toplevel; 2342 localEnv.enclClass = cdef; 2343 2344 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) { 2345 genDef(l.head, localEnv); 2346 } 2347 if (pool.numEntries() > Pool.MAX_ENTRIES) { 2348 log.error(cdef.pos(), Errors.LimitPool); 2349 nerrs++; 2350 } 2351 if (nerrs != 0) { 2352 // if errors, discard code 2353 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) { 2354 if (l.head.hasTag(METHODDEF)) 2355 ((JCMethodDecl) l.head).sym.code = null; 2356 } 2357 } 2358 cdef.defs = List.nil(); // discard trees 2359 return nerrs == 0; 2360 } finally { 2361 // note: this method does NOT support recursion. 2362 attrEnv = null; 2363 this.env = null; 2364 toplevel = null; 2365 endPosTable = null; 2366 nerrs = 0; 2367 } 2368 } 2369 2370 /* ************************************************************************ 2371 * Auxiliary classes 2372 *************************************************************************/ 2373 2374 /** An abstract class for finalizer generation. 2375 */ 2376 abstract class GenFinalizer { 2377 /** Generate code to clean up when unwinding. */ gen()2378 abstract void gen(); 2379 2380 /** Generate code to clean up at last. */ genLast()2381 abstract void genLast(); 2382 2383 /** Does this finalizer have some nontrivial cleanup to perform? */ hasFinalizer()2384 boolean hasFinalizer() { return true; } 2385 2386 /** Should be invoked after the try's body has been visited. */ afterBody()2387 void afterBody() {} 2388 } 2389 2390 /** code generation contexts, 2391 * to be used as type parameter for environments. 2392 */ 2393 static class GenContext { 2394 2395 /** A chain for all unresolved jumps that exit the current environment. 2396 */ 2397 Chain exit = null; 2398 2399 /** A chain for all unresolved jumps that continue in the 2400 * current environment. 2401 */ 2402 Chain cont = null; 2403 2404 /** A closure that generates the finalizer of the current environment. 2405 * Only set for Synchronized and Try contexts. 2406 */ 2407 GenFinalizer finalize = null; 2408 2409 /** Is this a switch statement? If so, allocate registers 2410 * even when the variable declaration is unreachable. 2411 */ 2412 boolean isSwitch = false; 2413 2414 /** A list buffer containing all gaps in the finalizer range, 2415 * where a catch all exception should not apply. 2416 */ 2417 ListBuffer<Integer> gaps = null; 2418 2419 /** Add given chain to exit chain. 2420 */ addExit(Chain c)2421 void addExit(Chain c) { 2422 exit = Code.mergeChains(c, exit); 2423 } 2424 2425 /** Add given chain to cont chain. 2426 */ addCont(Chain c)2427 void addCont(Chain c) { 2428 cont = Code.mergeChains(c, cont); 2429 } 2430 } 2431 2432 } 2433