1 /* 2 * Copyright (c) 1999, 2021, 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 java.util.HashMap; 29 import java.util.Map; 30 import java.util.Set; 31 32 import com.sun.tools.javac.jvm.PoolConstant.LoadableConstant; 33 import com.sun.tools.javac.tree.TreeInfo.PosKind; 34 import com.sun.tools.javac.util.*; 35 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition; 36 import com.sun.tools.javac.util.List; 37 import com.sun.tools.javac.code.*; 38 import com.sun.tools.javac.code.Attribute.TypeCompound; 39 import com.sun.tools.javac.code.Symbol.VarSymbol; 40 import com.sun.tools.javac.comp.*; 41 import com.sun.tools.javac.tree.*; 42 43 import com.sun.tools.javac.code.Symbol.*; 44 import com.sun.tools.javac.code.Type.*; 45 import com.sun.tools.javac.jvm.Code.*; 46 import com.sun.tools.javac.jvm.Items.*; 47 import com.sun.tools.javac.resources.CompilerProperties.Errors; 48 import com.sun.tools.javac.tree.EndPosTable; 49 import com.sun.tools.javac.tree.JCTree.*; 50 51 import static com.sun.tools.javac.code.Flags.*; 52 import static com.sun.tools.javac.code.Kinds.Kind.*; 53 import static com.sun.tools.javac.code.TypeTag.*; 54 import static com.sun.tools.javac.jvm.ByteCodes.*; 55 import static com.sun.tools.javac.jvm.CRTFlags.*; 56 import static com.sun.tools.javac.main.Option.*; 57 import static com.sun.tools.javac.tree.JCTree.Tag.*; 58 59 /** This pass maps flat Java (i.e. without inner classes) to bytecodes. 60 * 61 * <p><b>This is NOT part of any supported API. 62 * If you write code that depends on this, you do so at your own risk. 63 * This code and its internal interfaces are subject to change or 64 * deletion without notice.</b> 65 */ 66 public class Gen extends JCTree.Visitor { 67 protected static final Context.Key<Gen> genKey = new Context.Key<>(); 68 69 private final Log log; 70 private final Symtab syms; 71 private final Check chk; 72 private final Resolve rs; 73 private final TreeMaker make; 74 private final Names names; 75 private final Target target; 76 private final String accessDollar; 77 private final Types types; 78 private final Lower lower; 79 private final Annotate annotate; 80 private final StringConcat concat; 81 82 /** Format of stackmap tables to be generated. */ 83 private final Code.StackMapFormat stackMap; 84 85 /** A type that serves as the expected type for all method expressions. 86 */ 87 private final Type methodType; 88 89 public static Gen instance(Context context) { 90 Gen instance = context.get(genKey); 91 if (instance == null) 92 instance = new Gen(context); 93 return instance; 94 } 95 96 /** Constant pool writer, set by genClass. 97 */ 98 final PoolWriter poolWriter; 99 100 @SuppressWarnings("this-escape") 101 protected Gen(Context context) { 102 context.put(genKey, this); 103 104 names = Names.instance(context); 105 log = Log.instance(context); 106 syms = Symtab.instance(context); 107 chk = Check.instance(context); 108 rs = Resolve.instance(context); 109 make = TreeMaker.instance(context); 110 target = Target.instance(context); 111 types = Types.instance(context); 112 concat = StringConcat.instance(context); 113 114 methodType = new MethodType(null, null, null, syms.methodClass); 115 accessDollar = "access" + target.syntheticNameChar(); 116 lower = Lower.instance(context); 117 118 Options options = Options.instance(context); 119 lineDebugInfo = 120 options.isUnset(G_CUSTOM) || 121 options.isSet(G_CUSTOM, "lines"); 122 varDebugInfo = 123 options.isUnset(G_CUSTOM) 124 ? options.isSet(G) 125 : options.isSet(G_CUSTOM, "vars"); 126 genCrt = options.isSet(XJCOV); 127 debugCode = options.isSet("debug.code"); 128 disableVirtualizedPrivateInvoke = options.isSet("disableVirtualizedPrivateInvoke"); 129 poolWriter = new PoolWriter(types, names); 130 131 // ignore cldc because we cannot have both stackmap formats 132 this.stackMap = StackMapFormat.JSR202; 133 annotate = Annotate.instance(context); 134 qualifiedSymbolCache = new HashMap<>(); 135 } 136 137 /** Switches 138 */ 139 private final boolean lineDebugInfo; 140 private final boolean varDebugInfo; 141 private final boolean genCrt; 142 private final boolean debugCode; 143 private boolean disableVirtualizedPrivateInvoke; 144 145 /** Code buffer, set by genMethod. 146 */ 147 private Code code; 148 149 /** Items structure, set by genMethod. 150 */ 151 private Items items; 152 153 /** Environment for symbol lookup, set by genClass 154 */ 155 private Env<AttrContext> attrEnv; 156 157 /** The top level tree. 158 */ 159 private JCCompilationUnit toplevel; 160 161 /** The number of code-gen errors in this class. 162 */ 163 private int nerrs = 0; 164 165 /** An object containing mappings of syntax trees to their 166 * ending source positions. 167 */ 168 EndPosTable endPosTable; 169 170 boolean inCondSwitchExpression; 171 Chain switchExpressionTrueChain; 172 Chain switchExpressionFalseChain; 173 List<LocalItem> stackBeforeSwitchExpression; 174 LocalItem switchResult; 175 Set<JCMethodInvocation> invocationsWithPatternMatchingCatch = Set.of(); 176 ListBuffer<int[]> patternMatchingInvocationRanges; 177 178 /** Cache the symbol to reflect the qualifying type. 179 * key: corresponding type 180 * value: qualified symbol 181 */ 182 Map<Type, Symbol> qualifiedSymbolCache; 183 184 /** Generate code to load an integer constant. 185 * @param n The integer to be loaded. 186 */ 187 void loadIntConst(int n) { 188 items.makeImmediateItem(syms.intType, n).load(); 189 } 190 191 /** The opcode that loads a zero constant of a given type code. 192 * @param tc The given type code (@see ByteCode). 193 */ 194 public static int zero(int tc) { 195 switch(tc) { 196 case INTcode: case BYTEcode: case SHORTcode: case CHARcode: 197 return iconst_0; 198 case LONGcode: 199 return lconst_0; 200 case FLOATcode: 201 return fconst_0; 202 case DOUBLEcode: 203 return dconst_0; 204 default: 205 throw new AssertionError("zero"); 206 } 207 } 208 209 /** The opcode that loads a one constant of a given type code. 210 * @param tc The given type code (@see ByteCode). 211 */ 212 public static int one(int tc) { 213 return zero(tc) + 1; 214 } 215 216 /** Generate code to load -1 of the given type code (either int or long). 217 * @param tc The given type code (@see ByteCode). 218 */ 219 void emitMinusOne(int tc) { 220 if (tc == LONGcode) { 221 items.makeImmediateItem(syms.longType, Long.valueOf(-1)).load(); 222 } else { 223 code.emitop0(iconst_m1); 224 } 225 } 226 227 /** Construct a symbol to reflect the qualifying type that should 228 * appear in the byte code as per JLS 13.1. 229 * 230 * For {@literal target >= 1.2}: Clone a method with the qualifier as owner (except 231 * for those cases where we need to work around VM bugs). 232 * 233 * For {@literal target <= 1.1}: If qualified variable or method is defined in a 234 * non-accessible class, clone it with the qualifier class as owner. 235 * 236 * @param sym The accessed symbol 237 * @param site The qualifier's type. 238 */ 239 Symbol binaryQualifier(Symbol sym, Type site) { 240 241 if (site.hasTag(ARRAY)) { 242 if (sym == syms.lengthVar || 243 sym.owner != syms.arrayClass) 244 return sym; 245 // array clone can be qualified by the array type in later targets 246 Symbol qualifier; 247 if ((qualifier = qualifiedSymbolCache.get(site)) == null) { 248 qualifier = new ClassSymbol(Flags.PUBLIC, site.tsym.name, site, syms.noSymbol); 249 qualifiedSymbolCache.put(site, qualifier); 250 } 251 return sym.clone(qualifier); 252 } 253 254 if (sym.owner == site.tsym || 255 (sym.flags() & (STATIC | SYNTHETIC)) == (STATIC | SYNTHETIC)) { 256 return sym; 257 } 258 259 // leave alone methods inherited from Object 260 // JLS 13.1. 261 if (sym.owner == syms.objectType.tsym) 262 return sym; 263 264 return sym.clone(site.tsym); 265 } 266 267 /** Insert a reference to given type in the constant pool, 268 * checking for an array with too many dimensions; 269 * return the reference's index. 270 * @param type The type for which a reference is inserted. 271 */ 272 int makeRef(DiagnosticPosition pos, Type type) { 273 return poolWriter.putClass(checkDimension(pos, type)); 274 } 275 276 /** Check if the given type is an array with too many dimensions. 277 */ 278 private Type checkDimension(DiagnosticPosition pos, Type t) { 279 checkDimensionInternal(pos, t); 280 return t; 281 } 282 283 private void checkDimensionInternal(DiagnosticPosition pos, Type t) { 284 switch (t.getTag()) { 285 case METHOD: 286 checkDimension(pos, t.getReturnType()); 287 for (List<Type> args = t.getParameterTypes(); args.nonEmpty(); args = args.tail) 288 checkDimension(pos, args.head); 289 break; 290 case ARRAY: 291 if (types.dimensions(t) > ClassFile.MAX_DIMENSIONS) { 292 log.error(pos, Errors.LimitDimensions); 293 nerrs++; 294 } 295 break; 296 default: 297 break; 298 } 299 } 300 301 /** Create a temporary variable. 302 * @param type The variable's type. 303 */ 304 LocalItem makeTemp(Type type) { 305 VarSymbol v = new VarSymbol(Flags.SYNTHETIC, 306 names.empty, 307 type, 308 env.enclMethod.sym); 309 code.newLocal(v); 310 return items.makeLocalItem(v); 311 } 312 313 /** Generate code to call a non-private method or constructor. 314 * @param pos Position to be used for error reporting. 315 * @param site The type of which the method is a member. 316 * @param name The method's name. 317 * @param argtypes The method's argument types. 318 * @param isStatic A flag that indicates whether we call a 319 * static or instance method. 320 */ 321 void callMethod(DiagnosticPosition pos, 322 Type site, Name name, List<Type> argtypes, 323 boolean isStatic) { 324 Symbol msym = rs. 325 resolveInternalMethod(pos, attrEnv, site, name, argtypes, null); 326 if (isStatic) items.makeStaticItem(msym).invoke(); 327 else items.makeMemberItem(msym, name == names.init).invoke(); 328 } 329 330 /** Is the given method definition an access method 331 * resulting from a qualified super? This is signified by an odd 332 * access code. 333 */ 334 private boolean isAccessSuper(JCMethodDecl enclMethod) { 335 return 336 (enclMethod.mods.flags & SYNTHETIC) != 0 && 337 isOddAccessName(enclMethod.name); 338 } 339 340 /** Does given name start with "access$" and end in an odd digit? 341 */ 342 private boolean isOddAccessName(Name name) { 343 final String string = name.toString(); 344 return 345 string.startsWith(accessDollar) && 346 (string.charAt(string.length() - 1) & 1) != 0; 347 } 348 349 /* ************************************************************************ 350 * Non-local exits 351 *************************************************************************/ 352 353 /** Generate code to invoke the finalizer associated with given 354 * environment. 355 * Any calls to finalizers are appended to the environments `cont' chain. 356 * Mark beginning of gap in catch all range for finalizer. 357 */ 358 void genFinalizer(Env<GenContext> env) { 359 if (code.isAlive() && env.info.finalize != null) 360 env.info.finalize.gen(); 361 } 362 363 /** Generate code to call all finalizers of structures aborted by 364 * a non-local 365 * exit. Return target environment of the non-local exit. 366 * @param target The tree representing the structure that's aborted 367 * @param env The environment current at the non-local exit. 368 */ 369 Env<GenContext> unwind(JCTree target, Env<GenContext> env) { 370 Env<GenContext> env1 = env; 371 while (true) { 372 genFinalizer(env1); 373 if (env1.tree == target) break; 374 env1 = env1.next; 375 } 376 return env1; 377 } 378 379 /** Mark end of gap in catch-all range for finalizer. 380 * @param env the environment which might contain the finalizer 381 * (if it does, env.info.gaps != null). 382 */ 383 void endFinalizerGap(Env<GenContext> env) { 384 if (env.info.gaps != null && env.info.gaps.length() % 2 == 1) 385 env.info.gaps.append(code.curCP()); 386 } 387 388 /** Mark end of all gaps in catch-all ranges for finalizers of environments 389 * lying between, and including to two environments. 390 * @param from the most deeply nested environment to mark 391 * @param to the least deeply nested environment to mark 392 */ 393 void endFinalizerGaps(Env<GenContext> from, Env<GenContext> to) { 394 Env<GenContext> last = null; 395 while (last != to) { 396 endFinalizerGap(from); 397 last = from; 398 from = from.next; 399 } 400 } 401 402 /** Do any of the structures aborted by a non-local exit have 403 * finalizers that require an empty stack? 404 * @param target The tree representing the structure that's aborted 405 * @param env The environment current at the non-local exit. 406 */ 407 boolean hasFinally(JCTree target, Env<GenContext> env) { 408 while (env.tree != target) { 409 if (env.tree.hasTag(TRY) && env.info.finalize.hasFinalizer()) 410 return true; 411 env = env.next; 412 } 413 return false; 414 } 415 416 /* ************************************************************************ 417 * Normalizing class-members. 418 *************************************************************************/ 419 420 /** Distribute member initializer code into constructors and {@code <clinit>} 421 * method. 422 * @param defs The list of class member declarations. 423 * @param c The enclosing class. 424 */ 425 List<JCTree> normalizeDefs(List<JCTree> defs, ClassSymbol c) { 426 ListBuffer<JCStatement> initCode = new ListBuffer<>(); 427 ListBuffer<Attribute.TypeCompound> initTAs = new ListBuffer<>(); 428 ListBuffer<JCStatement> clinitCode = new ListBuffer<>(); 429 ListBuffer<Attribute.TypeCompound> clinitTAs = new ListBuffer<>(); 430 ListBuffer<JCTree> methodDefs = new ListBuffer<>(); 431 // Sort definitions into three listbuffers: 432 // - initCode for instance initializers 433 // - clinitCode for class initializers 434 // - methodDefs for method definitions 435 for (List<JCTree> l = defs; l.nonEmpty(); l = l.tail) { 436 JCTree def = l.head; 437 switch (def.getTag()) { 438 case BLOCK: 439 JCBlock block = (JCBlock)def; 440 if ((block.flags & STATIC) != 0) 441 clinitCode.append(block); 442 else if ((block.flags & SYNTHETIC) == 0) 443 initCode.append(block); 444 break; 445 case METHODDEF: 446 methodDefs.append(def); 447 break; 448 case VARDEF: 449 JCVariableDecl vdef = (JCVariableDecl) def; 450 VarSymbol sym = vdef.sym; 451 checkDimension(vdef.pos(), sym.type); 452 if (vdef.init != null) { 453 if ((sym.flags() & STATIC) == 0) { 454 // Always initialize instance variables. 455 JCStatement init = make.at(vdef.pos()). 456 Assignment(sym, vdef.init); 457 initCode.append(init); 458 endPosTable.replaceTree(vdef, init); 459 initTAs.addAll(getAndRemoveNonFieldTAs(sym)); 460 } else if (sym.getConstValue() == null) { 461 // Initialize class (static) variables only if 462 // they are not compile-time constants. 463 JCStatement init = make.at(vdef.pos). 464 Assignment(sym, vdef.init); 465 clinitCode.append(init); 466 endPosTable.replaceTree(vdef, init); 467 clinitTAs.addAll(getAndRemoveNonFieldTAs(sym)); 468 } else { 469 checkStringConstant(vdef.init.pos(), sym.getConstValue()); 470 /* if the init contains a reference to an external class, add it to the 471 * constant's pool 472 */ 473 vdef.init.accept(classReferenceVisitor); 474 } 475 } 476 break; 477 default: 478 Assert.error(); 479 } 480 } 481 // Insert any instance initializers into all constructors. 482 if (initCode.length() != 0) { 483 List<JCStatement> inits = initCode.toList(); 484 initTAs.addAll(c.getInitTypeAttributes()); 485 List<Attribute.TypeCompound> initTAlist = initTAs.toList(); 486 for (JCTree t : methodDefs) { 487 normalizeMethod((JCMethodDecl)t, inits, initTAlist); 488 } 489 } 490 // If there are class initializers, create a <clinit> method 491 // that contains them as its body. 492 if (clinitCode.length() != 0) { 493 MethodSymbol clinit = new MethodSymbol( 494 STATIC | (c.flags() & STRICTFP), 495 names.clinit, 496 new MethodType( 497 List.nil(), syms.voidType, 498 List.nil(), syms.methodClass), 499 c); 500 c.members().enter(clinit); 501 List<JCStatement> clinitStats = clinitCode.toList(); 502 JCBlock block = make.at(clinitStats.head.pos()).Block(0, clinitStats); 503 block.endpos = TreeInfo.endPos(clinitStats.last()); 504 methodDefs.append(make.MethodDef(clinit, block)); 505 506 if (!clinitTAs.isEmpty()) 507 clinit.appendUniqueTypeAttributes(clinitTAs.toList()); 508 if (!c.getClassInitTypeAttributes().isEmpty()) 509 clinit.appendUniqueTypeAttributes(c.getClassInitTypeAttributes()); 510 } 511 // Return all method definitions. 512 return methodDefs.toList(); 513 } 514 515 private List<Attribute.TypeCompound> getAndRemoveNonFieldTAs(VarSymbol sym) { 516 List<TypeCompound> tas = sym.getRawTypeAttributes(); 517 ListBuffer<Attribute.TypeCompound> fieldTAs = new ListBuffer<>(); 518 ListBuffer<Attribute.TypeCompound> nonfieldTAs = new ListBuffer<>(); 519 for (TypeCompound ta : tas) { 520 Assert.check(ta.getPosition().type != TargetType.UNKNOWN); 521 if (ta.getPosition().type == TargetType.FIELD) { 522 fieldTAs.add(ta); 523 } else { 524 nonfieldTAs.add(ta); 525 } 526 } 527 sym.setTypeAttributes(fieldTAs.toList()); 528 return nonfieldTAs.toList(); 529 } 530 531 /** Check a constant value and report if it is a string that is 532 * too large. 533 */ 534 private void checkStringConstant(DiagnosticPosition pos, Object constValue) { 535 if (nerrs != 0 || // only complain about a long string once 536 constValue == null || 537 !(constValue instanceof String str) || 538 str.length() < PoolWriter.MAX_STRING_LENGTH) 539 return; 540 log.error(pos, Errors.LimitString); 541 nerrs++; 542 } 543 544 /** Insert instance initializer code into constructors prior to the super() call. 545 * @param md The tree potentially representing a 546 * constructor's definition. 547 * @param initCode The list of instance initializer statements. 548 * @param initTAs Type annotations from the initializer expression. 549 */ 550 void normalizeMethod(JCMethodDecl md, List<JCStatement> initCode, List<TypeCompound> initTAs) { 551 if (TreeInfo.isConstructor(md) && TreeInfo.hasConstructorCall(md, names._super)) { 552 // We are seeing a constructor that has a super() call. 553 // Find the super() invocation and append the given initializer code. 554 TreeInfo.mapSuperCalls(md.body, supercall -> make.Block(0, initCode.prepend(supercall))); 555 556 if (md.body.endpos == Position.NOPOS) 557 md.body.endpos = TreeInfo.endPos(md.body.stats.last()); 558 559 md.sym.appendUniqueTypeAttributes(initTAs); 560 } 561 } 562 563 /* ************************************************************************ 564 * Traversal methods 565 *************************************************************************/ 566 567 /** Visitor argument: The current environment. 568 */ 569 Env<GenContext> env; 570 571 /** Visitor argument: The expected type (prototype). 572 */ 573 Type pt; 574 575 /** Visitor result: The item representing the computed value. 576 */ 577 Item result; 578 579 /** Visitor method: generate code for a definition, catching and reporting 580 * any completion failures. 581 * @param tree The definition to be visited. 582 * @param env The environment current at the definition. 583 */ 584 public void genDef(JCTree tree, Env<GenContext> env) { 585 Env<GenContext> prevEnv = this.env; 586 try { 587 this.env = env; 588 tree.accept(this); 589 } catch (CompletionFailure ex) { 590 chk.completionError(tree.pos(), ex); 591 } finally { 592 this.env = prevEnv; 593 } 594 } 595 596 /** Derived visitor method: check whether CharacterRangeTable 597 * should be emitted, if so, put a new entry into CRTable 598 * and call method to generate bytecode. 599 * If not, just call method to generate bytecode. 600 * @see #genStat(JCTree, Env) 601 * 602 * @param tree The tree to be visited. 603 * @param env The environment to use. 604 * @param crtFlags The CharacterRangeTable flags 605 * indicating type of the entry. 606 */ 607 public void genStat(JCTree tree, Env<GenContext> env, int crtFlags) { 608 if (!genCrt) { 609 genStat(tree, env); 610 return; 611 } 612 int startpc = code.curCP(); 613 genStat(tree, env); 614 if (tree.hasTag(Tag.BLOCK)) crtFlags |= CRT_BLOCK; 615 code.crt.put(tree, crtFlags, startpc, code.curCP()); 616 } 617 618 /** Derived visitor method: generate code for a statement. 619 */ 620 public void genStat(JCTree tree, Env<GenContext> env) { 621 if (code.isAlive()) { 622 code.statBegin(tree.pos); 623 genDef(tree, env); 624 } else if (env.info.isSwitch && tree.hasTag(VARDEF)) { 625 // variables whose declarations are in a switch 626 // can be used even if the decl is unreachable. 627 code.newLocal(((JCVariableDecl) tree).sym); 628 } 629 } 630 631 /** Derived visitor method: check whether CharacterRangeTable 632 * should be emitted, if so, put a new entry into CRTable 633 * and call method to generate bytecode. 634 * If not, just call method to generate bytecode. 635 * @see #genStats(List, Env) 636 * 637 * @param trees The list of trees to be visited. 638 * @param env The environment to use. 639 * @param crtFlags The CharacterRangeTable flags 640 * indicating type of the entry. 641 */ 642 public void genStats(List<JCStatement> trees, Env<GenContext> env, int crtFlags) { 643 if (!genCrt) { 644 genStats(trees, env); 645 return; 646 } 647 if (trees.length() == 1) { // mark one statement with the flags 648 genStat(trees.head, env, crtFlags | CRT_STATEMENT); 649 } else { 650 int startpc = code.curCP(); 651 genStats(trees, env); 652 code.crt.put(trees, crtFlags, startpc, code.curCP()); 653 } 654 } 655 656 /** Derived visitor method: generate code for a list of statements. 657 */ 658 public void genStats(List<? extends JCTree> trees, Env<GenContext> env) { 659 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail) 660 genStat(l.head, env, CRT_STATEMENT); 661 } 662 663 /** Derived visitor method: check whether CharacterRangeTable 664 * should be emitted, if so, put a new entry into CRTable 665 * and call method to generate bytecode. 666 * If not, just call method to generate bytecode. 667 * @see #genCond(JCTree,boolean) 668 * 669 * @param tree The tree to be visited. 670 * @param crtFlags The CharacterRangeTable flags 671 * indicating type of the entry. 672 */ 673 public CondItem genCond(JCTree tree, int crtFlags) { 674 if (!genCrt) return genCond(tree, false); 675 int startpc = code.curCP(); 676 CondItem item = genCond(tree, (crtFlags & CRT_FLOW_CONTROLLER) != 0); 677 code.crt.put(tree, crtFlags, startpc, code.curCP()); 678 return item; 679 } 680 681 /** Derived visitor method: generate code for a boolean 682 * expression in a control-flow context. 683 * @param _tree The expression to be visited. 684 * @param markBranches The flag to indicate that the condition is 685 * a flow controller so produced conditions 686 * should contain a proper tree to generate 687 * CharacterRangeTable branches for them. 688 */ 689 public CondItem genCond(JCTree _tree, boolean markBranches) { 690 JCTree inner_tree = TreeInfo.skipParens(_tree); 691 if (inner_tree.hasTag(CONDEXPR)) { 692 JCConditional tree = (JCConditional)inner_tree; 693 CondItem cond = genCond(tree.cond, CRT_FLOW_CONTROLLER); 694 if (cond.isTrue()) { 695 code.resolve(cond.trueJumps); 696 CondItem result = genCond(tree.truepart, CRT_FLOW_TARGET); 697 if (markBranches) result.tree = tree.truepart; 698 return result; 699 } 700 if (cond.isFalse()) { 701 code.resolve(cond.falseJumps); 702 CondItem result = genCond(tree.falsepart, CRT_FLOW_TARGET); 703 if (markBranches) result.tree = tree.falsepart; 704 return result; 705 } 706 Chain secondJumps = cond.jumpFalse(); 707 code.resolve(cond.trueJumps); 708 CondItem first = genCond(tree.truepart, CRT_FLOW_TARGET); 709 if (markBranches) first.tree = tree.truepart; 710 Chain falseJumps = first.jumpFalse(); 711 code.resolve(first.trueJumps); 712 Chain trueJumps = code.branch(goto_); 713 code.resolve(secondJumps); 714 CondItem second = genCond(tree.falsepart, CRT_FLOW_TARGET); 715 CondItem result = items.makeCondItem(second.opcode, 716 Code.mergeChains(trueJumps, second.trueJumps), 717 Code.mergeChains(falseJumps, second.falseJumps)); 718 if (markBranches) result.tree = tree.falsepart; 719 return result; 720 } else if (inner_tree.hasTag(SWITCH_EXPRESSION)) { 721 code.resolvePending(); 722 723 boolean prevInCondSwitchExpression = inCondSwitchExpression; 724 Chain prevSwitchExpressionTrueChain = switchExpressionTrueChain; 725 Chain prevSwitchExpressionFalseChain = switchExpressionFalseChain; 726 try { 727 inCondSwitchExpression = true; 728 switchExpressionTrueChain = null; 729 switchExpressionFalseChain = null; 730 try { 731 doHandleSwitchExpression((JCSwitchExpression) inner_tree); 732 } catch (CompletionFailure ex) { 733 chk.completionError(_tree.pos(), ex); 734 code.state.stacksize = 1; 735 } 736 CondItem result = items.makeCondItem(goto_, 737 switchExpressionTrueChain, 738 switchExpressionFalseChain); 739 if (markBranches) result.tree = _tree; 740 return result; 741 } finally { 742 inCondSwitchExpression = prevInCondSwitchExpression; 743 switchExpressionTrueChain = prevSwitchExpressionTrueChain; 744 switchExpressionFalseChain = prevSwitchExpressionFalseChain; 745 } 746 } else if (inner_tree.hasTag(LETEXPR) && ((LetExpr) inner_tree).needsCond) { 747 code.resolvePending(); 748 749 LetExpr tree = (LetExpr) inner_tree; 750 int limit = code.nextreg; 751 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize); 752 try { 753 genStats(tree.defs, env); 754 } finally { 755 code.setLetExprStackPos(prevLetExprStart); 756 } 757 CondItem result = genCond(tree.expr, markBranches); 758 code.endScopes(limit); 759 return result; 760 } else { 761 CondItem result = genExpr(_tree, syms.booleanType).mkCond(); 762 if (markBranches) result.tree = _tree; 763 return result; 764 } 765 } 766 767 public Code getCode() { 768 return code; 769 } 770 771 public Items getItems() { 772 return items; 773 } 774 775 public Env<AttrContext> getAttrEnv() { 776 return attrEnv; 777 } 778 779 /** Visitor class for expressions which might be constant expressions. 780 * This class is a subset of TreeScanner. Intended to visit trees pruned by 781 * Lower as long as constant expressions looking for references to any 782 * ClassSymbol. Any such reference will be added to the constant pool so 783 * automated tools can detect class dependencies better. 784 */ 785 class ClassReferenceVisitor extends JCTree.Visitor { 786 787 @Override 788 public void visitTree(JCTree tree) {} 789 790 @Override 791 public void visitBinary(JCBinary tree) { 792 tree.lhs.accept(this); 793 tree.rhs.accept(this); 794 } 795 796 @Override 797 public void visitSelect(JCFieldAccess tree) { 798 if (tree.selected.type.hasTag(CLASS)) { 799 makeRef(tree.selected.pos(), tree.selected.type); 800 } 801 } 802 803 @Override 804 public void visitIdent(JCIdent tree) { 805 if (tree.sym.owner instanceof ClassSymbol classSymbol) { 806 poolWriter.putClass(classSymbol); 807 } 808 } 809 810 @Override 811 public void visitConditional(JCConditional tree) { 812 tree.cond.accept(this); 813 tree.truepart.accept(this); 814 tree.falsepart.accept(this); 815 } 816 817 @Override 818 public void visitUnary(JCUnary tree) { 819 tree.arg.accept(this); 820 } 821 822 @Override 823 public void visitParens(JCParens tree) { 824 tree.expr.accept(this); 825 } 826 827 @Override 828 public void visitTypeCast(JCTypeCast tree) { 829 tree.expr.accept(this); 830 } 831 } 832 833 private ClassReferenceVisitor classReferenceVisitor = new ClassReferenceVisitor(); 834 835 /** Visitor method: generate code for an expression, catching and reporting 836 * any completion failures. 837 * @param tree The expression to be visited. 838 * @param pt The expression's expected type (proto-type). 839 */ 840 public Item genExpr(JCTree tree, Type pt) { 841 if (!code.isAlive()) { 842 return items.makeStackItem(pt); 843 } 844 845 Type prevPt = this.pt; 846 try { 847 if (tree.type.constValue() != null) { 848 // Short circuit any expressions which are constants 849 tree.accept(classReferenceVisitor); 850 checkStringConstant(tree.pos(), tree.type.constValue()); 851 Symbol sym = TreeInfo.symbol(tree); 852 if (sym != null && isConstantDynamic(sym)) { 853 result = items.makeDynamicItem(sym); 854 } else { 855 result = items.makeImmediateItem(tree.type, tree.type.constValue()); 856 } 857 } else { 858 this.pt = pt; 859 tree.accept(this); 860 } 861 return result.coerce(pt); 862 } catch (CompletionFailure ex) { 863 chk.completionError(tree.pos(), ex); 864 code.state.stacksize = 1; 865 return items.makeStackItem(pt); 866 } finally { 867 this.pt = prevPt; 868 } 869 } 870 871 public boolean isConstantDynamic(Symbol sym) { 872 return sym.kind == VAR && 873 sym instanceof DynamicVarSymbol dynamicVarSymbol && 874 dynamicVarSymbol.isDynamic(); 875 } 876 877 /** Derived visitor method: generate code for a list of method arguments. 878 * @param trees The argument expressions to be visited. 879 * @param pts The expression's expected types (i.e. the formal parameter 880 * types of the invoked method). 881 */ 882 public void genArgs(List<JCExpression> trees, List<Type> pts) { 883 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail) { 884 genExpr(l.head, pts.head).load(); 885 pts = pts.tail; 886 } 887 // require lists be of same length 888 Assert.check(pts.isEmpty()); 889 } 890 891 /* ************************************************************************ 892 * Visitor methods for statements and definitions 893 *************************************************************************/ 894 895 /** Thrown when the byte code size exceeds limit. 896 */ 897 public static class CodeSizeOverflow extends RuntimeException { 898 private static final long serialVersionUID = 0; 899 public CodeSizeOverflow() {} 900 } 901 902 public void visitMethodDef(JCMethodDecl tree) { 903 // Create a new local environment that points pack at method 904 // definition. 905 Env<GenContext> localEnv = env.dup(tree); 906 localEnv.enclMethod = tree; 907 // The expected type of every return statement in this method 908 // is the method's return type. 909 this.pt = tree.sym.erasure(types).getReturnType(); 910 911 checkDimension(tree.pos(), tree.sym.erasure(types)); 912 genMethod(tree, localEnv, false); 913 } 914 //where 915 /** Generate code for a method. 916 * @param tree The tree representing the method definition. 917 * @param env The environment current for the method body. 918 * @param fatcode A flag that indicates whether all jumps are 919 * within 32K. We first invoke this method under 920 * the assumption that fatcode == false, i.e. all 921 * jumps are within 32K. If this fails, fatcode 922 * is set to true and we try again. 923 */ 924 void genMethod(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) { 925 MethodSymbol meth = tree.sym; 926 int extras = 0; 927 // Count up extra parameters 928 if (meth.isConstructor()) { 929 extras++; 930 if (meth.enclClass().isInner() && 931 !meth.enclClass().isStatic()) { 932 extras++; 933 } 934 } else if ((tree.mods.flags & STATIC) == 0) { 935 extras++; 936 } 937 // System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG 938 if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes()) + extras > 939 ClassFile.MAX_PARAMETERS) { 940 log.error(tree.pos(), Errors.LimitParameters); 941 nerrs++; 942 } 943 944 else if (tree.body != null) { 945 // Create a new code structure and initialize it. 946 int startpcCrt = initCode(tree, env, fatcode); 947 948 try { 949 genStat(tree.body, env); 950 } catch (CodeSizeOverflow e) { 951 // Failed due to code limit, try again with jsr/ret 952 startpcCrt = initCode(tree, env, fatcode); 953 genStat(tree.body, env); 954 } 955 956 if (code.state.stacksize != 0) { 957 log.error(tree.body.pos(), Errors.StackSimError(tree.sym)); 958 throw new AssertionError(); 959 } 960 961 // If last statement could complete normally, insert a 962 // return at the end. 963 if (code.isAlive()) { 964 code.statBegin(TreeInfo.endPos(tree.body)); 965 if (env.enclMethod == null || 966 env.enclMethod.sym.type.getReturnType().hasTag(VOID)) { 967 code.emitop0(return_); 968 } else { 969 // sometime dead code seems alive (4415991); 970 // generate a small loop instead 971 int startpc = code.entryPoint(); 972 CondItem c = items.makeCondItem(goto_); 973 code.resolve(c.jumpTrue(), startpc); 974 } 975 } 976 if (genCrt) 977 code.crt.put(tree.body, 978 CRT_BLOCK, 979 startpcCrt, 980 code.curCP()); 981 982 code.endScopes(0); 983 984 // If we exceeded limits, panic 985 if (code.checkLimits(tree.pos(), log)) { 986 nerrs++; 987 return; 988 } 989 990 // If we generated short code but got a long jump, do it again 991 // with fatCode = true. 992 if (!fatcode && code.fatcode) genMethod(tree, env, true); 993 994 // Clean up 995 if(stackMap == StackMapFormat.JSR202) { 996 code.lastFrame = null; 997 code.frameBeforeLast = null; 998 } 999 1000 // Compress exception table 1001 code.compressCatchTable(); 1002 1003 // Fill in type annotation positions for exception parameters 1004 code.fillExceptionParameterPositions(); 1005 } 1006 } 1007 1008 private int initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) { 1009 MethodSymbol meth = tree.sym; 1010 1011 // Create a new code structure. 1012 meth.code = code = new Code(meth, 1013 fatcode, 1014 lineDebugInfo ? toplevel.lineMap : null, 1015 varDebugInfo, 1016 stackMap, 1017 debugCode, 1018 genCrt ? new CRTable(tree, env.toplevel.endPositions) 1019 : null, 1020 syms, 1021 types, 1022 poolWriter); 1023 items = new Items(poolWriter, code, syms, types); 1024 if (code.debugCode) { 1025 System.err.println(meth + " for body " + tree); 1026 } 1027 1028 // If method is not static, create a new local variable address 1029 // for `this'. 1030 if ((tree.mods.flags & STATIC) == 0) { 1031 Type selfType = meth.owner.type; 1032 if (meth.isConstructor() && selfType != syms.objectType) 1033 selfType = UninitializedType.uninitializedThis(selfType); 1034 code.setDefined( 1035 code.newLocal( 1036 new VarSymbol(FINAL, names._this, selfType, meth.owner))); 1037 } 1038 1039 // Mark all parameters as defined from the beginning of 1040 // the method. 1041 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) { 1042 checkDimension(l.head.pos(), l.head.sym.type); 1043 code.setDefined(code.newLocal(l.head.sym)); 1044 } 1045 1046 // Get ready to generate code for method body. 1047 int startpcCrt = genCrt ? code.curCP() : 0; 1048 code.entryPoint(); 1049 1050 // Suppress initial stackmap 1051 code.pendingStackMap = false; 1052 1053 return startpcCrt; 1054 } 1055 1056 public void visitVarDef(JCVariableDecl tree) { 1057 VarSymbol v = tree.sym; 1058 if (tree.init != null) { 1059 checkStringConstant(tree.init.pos(), v.getConstValue()); 1060 if (v.getConstValue() == null || varDebugInfo) { 1061 Assert.check(code.isStatementStart()); 1062 code.newLocal(v); 1063 genExpr(tree.init, v.erasure(types)).load(); 1064 items.makeLocalItem(v).store(); 1065 Assert.check(code.isStatementStart()); 1066 } 1067 } else { 1068 code.newLocal(v); 1069 } 1070 checkDimension(tree.pos(), v.type); 1071 } 1072 1073 public void visitSkip(JCSkip tree) { 1074 } 1075 1076 public void visitBlock(JCBlock tree) { 1077 if (tree.patternMatchingCatch != null) { 1078 Set<JCMethodInvocation> prevInvocationsWithPatternMatchingCatch = invocationsWithPatternMatchingCatch; 1079 ListBuffer<int[]> prevRanges = patternMatchingInvocationRanges; 1080 State startState = code.state.dup(); 1081 try { 1082 invocationsWithPatternMatchingCatch = tree.patternMatchingCatch.calls2Handle(); 1083 patternMatchingInvocationRanges = new ListBuffer<>(); 1084 doVisitBlock(tree); 1085 } finally { 1086 Chain skipCatch = code.branch(goto_); 1087 JCCatch handler = tree.patternMatchingCatch.handler(); 1088 code.entryPoint(startState, handler.param.sym.type); 1089 genPatternMatchingCatch(handler, env, patternMatchingInvocationRanges.toList()); 1090 code.resolve(skipCatch); 1091 invocationsWithPatternMatchingCatch = prevInvocationsWithPatternMatchingCatch; 1092 patternMatchingInvocationRanges = prevRanges; 1093 } 1094 } else { 1095 doVisitBlock(tree); 1096 } 1097 } 1098 1099 private void doVisitBlock(JCBlock tree) { 1100 int limit = code.nextreg; 1101 Env<GenContext> localEnv = env.dup(tree, new GenContext()); 1102 genStats(tree.stats, localEnv); 1103 // End the scope of all block-local variables in variable info. 1104 if (!env.tree.hasTag(METHODDEF)) { 1105 code.statBegin(tree.endpos); 1106 code.endScopes(limit); 1107 code.pendingStatPos = Position.NOPOS; 1108 } 1109 } 1110 1111 public void visitDoLoop(JCDoWhileLoop tree) { 1112 genLoop(tree, tree.body, tree.cond, List.nil(), false); 1113 } 1114 1115 public void visitWhileLoop(JCWhileLoop tree) { 1116 genLoop(tree, tree.body, tree.cond, List.nil(), true); 1117 } 1118 1119 public void visitForLoop(JCForLoop tree) { 1120 int limit = code.nextreg; 1121 genStats(tree.init, env); 1122 genLoop(tree, tree.body, tree.cond, tree.step, true); 1123 code.endScopes(limit); 1124 } 1125 //where 1126 /** Generate code for a loop. 1127 * @param loop The tree representing the loop. 1128 * @param body The loop's body. 1129 * @param cond The loop's controlling condition. 1130 * @param step "Step" statements to be inserted at end of 1131 * each iteration. 1132 * @param testFirst True if the loop test belongs before the body. 1133 */ 1134 private void genLoop(JCStatement loop, 1135 JCStatement body, 1136 JCExpression cond, 1137 List<JCExpressionStatement> step, 1138 boolean testFirst) { 1139 Env<GenContext> loopEnv = env.dup(loop, new GenContext()); 1140 int startpc = code.entryPoint(); 1141 if (testFirst) { //while or for loop 1142 CondItem c; 1143 if (cond != null) { 1144 code.statBegin(cond.pos); 1145 Assert.check(code.isStatementStart()); 1146 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER); 1147 } else { 1148 c = items.makeCondItem(goto_); 1149 } 1150 Chain loopDone = c.jumpFalse(); 1151 code.resolve(c.trueJumps); 1152 Assert.check(code.isStatementStart()); 1153 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET); 1154 code.resolve(loopEnv.info.cont); 1155 genStats(step, loopEnv); 1156 code.resolve(code.branch(goto_), startpc); 1157 code.resolve(loopDone); 1158 } else { 1159 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET); 1160 code.resolve(loopEnv.info.cont); 1161 genStats(step, loopEnv); 1162 if (code.isAlive()) { 1163 CondItem c; 1164 if (cond != null) { 1165 code.statBegin(cond.pos); 1166 Assert.check(code.isStatementStart()); 1167 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER); 1168 } else { 1169 c = items.makeCondItem(goto_); 1170 } 1171 code.resolve(c.jumpTrue(), startpc); 1172 Assert.check(code.isStatementStart()); 1173 code.resolve(c.falseJumps); 1174 } 1175 } 1176 Chain exit = loopEnv.info.exit; 1177 if (exit != null) { 1178 code.resolve(exit); 1179 exit.state.defined.excludeFrom(code.nextreg); 1180 } 1181 } 1182 1183 public void visitForeachLoop(JCEnhancedForLoop tree) { 1184 throw new AssertionError(); // should have been removed by Lower. 1185 } 1186 1187 public void visitLabelled(JCLabeledStatement tree) { 1188 Env<GenContext> localEnv = env.dup(tree, new GenContext()); 1189 genStat(tree.body, localEnv, CRT_STATEMENT); 1190 Chain exit = localEnv.info.exit; 1191 if (exit != null) { 1192 code.resolve(exit); 1193 exit.state.defined.excludeFrom(code.nextreg); 1194 } 1195 } 1196 1197 public void visitSwitch(JCSwitch tree) { 1198 handleSwitch(tree, tree.selector, tree.cases, tree.patternSwitch); 1199 } 1200 1201 @Override 1202 public void visitSwitchExpression(JCSwitchExpression tree) { 1203 code.resolvePending(); 1204 boolean prevInCondSwitchExpression = inCondSwitchExpression; 1205 try { 1206 inCondSwitchExpression = false; 1207 doHandleSwitchExpression(tree); 1208 } finally { 1209 inCondSwitchExpression = prevInCondSwitchExpression; 1210 } 1211 result = items.makeStackItem(pt); 1212 } 1213 1214 private void doHandleSwitchExpression(JCSwitchExpression tree) { 1215 List<LocalItem> prevStackBeforeSwitchExpression = stackBeforeSwitchExpression; 1216 LocalItem prevSwitchResult = switchResult; 1217 int limit = code.nextreg; 1218 try { 1219 stackBeforeSwitchExpression = List.nil(); 1220 switchResult = null; 1221 if (hasTry(tree)) { 1222 //if the switch expression contains try-catch, the catch handlers need to have 1223 //an empty stack. So stash whole stack to local variables, and restore it before 1224 //breaks: 1225 while (code.state.stacksize > 0) { 1226 Type type = code.state.peek(); 1227 Name varName = names.fromString(target.syntheticNameChar() + 1228 "stack" + 1229 target.syntheticNameChar() + 1230 tree.pos + 1231 target.syntheticNameChar() + 1232 code.state.stacksize); 1233 VarSymbol var = new VarSymbol(Flags.SYNTHETIC, varName, type, 1234 this.env.enclMethod.sym); 1235 LocalItem item = items.new LocalItem(type, code.newLocal(var)); 1236 stackBeforeSwitchExpression = stackBeforeSwitchExpression.prepend(item); 1237 item.store(); 1238 } 1239 switchResult = makeTemp(tree.type); 1240 } 1241 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize); 1242 try { 1243 handleSwitch(tree, tree.selector, tree.cases, tree.patternSwitch); 1244 } finally { 1245 code.setLetExprStackPos(prevLetExprStart); 1246 } 1247 } finally { 1248 stackBeforeSwitchExpression = prevStackBeforeSwitchExpression; 1249 switchResult = prevSwitchResult; 1250 code.endScopes(limit); 1251 } 1252 } 1253 //where: 1254 private boolean hasTry(JCSwitchExpression tree) { 1255 class HasTryScanner extends TreeScanner { 1256 private boolean hasTry; 1257 1258 @Override 1259 public void visitTry(JCTry tree) { 1260 hasTry = true; 1261 } 1262 1263 @Override 1264 public void visitSynchronized(JCSynchronized tree) { 1265 hasTry = true; 1266 } 1267 1268 @Override 1269 public void visitClassDef(JCClassDecl tree) { 1270 } 1271 1272 @Override 1273 public void visitLambda(JCLambda tree) { 1274 } 1275 }; 1276 1277 HasTryScanner hasTryScanner = new HasTryScanner(); 1278 1279 hasTryScanner.scan(tree); 1280 return hasTryScanner.hasTry; 1281 } 1282 1283 private void handleSwitch(JCTree swtch, JCExpression selector, List<JCCase> cases, 1284 boolean patternSwitch) { 1285 int limit = code.nextreg; 1286 Assert.check(!selector.type.hasTag(CLASS)); 1287 int switchStart = patternSwitch ? code.entryPoint() : -1; 1288 int startpcCrt = genCrt ? code.curCP() : 0; 1289 Assert.check(code.isStatementStart()); 1290 Item sel = genExpr(selector, syms.intType); 1291 if (cases.isEmpty()) { 1292 // We are seeing: switch <sel> {} 1293 sel.load().drop(); 1294 if (genCrt) 1295 code.crt.put(TreeInfo.skipParens(selector), 1296 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP()); 1297 } else { 1298 // We are seeing a nonempty switch. 1299 sel.load(); 1300 if (genCrt) 1301 code.crt.put(TreeInfo.skipParens(selector), 1302 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP()); 1303 Env<GenContext> switchEnv = env.dup(swtch, new GenContext()); 1304 switchEnv.info.isSwitch = true; 1305 1306 // Compute number of labels and minimum and maximum label values. 1307 // For each case, store its label in an array. 1308 int lo = Integer.MAX_VALUE; // minimum label. 1309 int hi = Integer.MIN_VALUE; // maximum label. 1310 int nlabels = 0; // number of labels. 1311 1312 int[] labels = new int[cases.length()]; // the label array. 1313 int defaultIndex = -1; // the index of the default clause. 1314 1315 List<JCCase> l = cases; 1316 for (int i = 0; i < labels.length; i++) { 1317 if (l.head.labels.head instanceof JCConstantCaseLabel constLabel) { 1318 Assert.check(l.head.labels.size() == 1); 1319 int val = ((Number) constLabel.expr.type.constValue()).intValue(); 1320 labels[i] = val; 1321 if (val < lo) lo = val; 1322 if (hi < val) hi = val; 1323 nlabels++; 1324 } else { 1325 Assert.check(defaultIndex == -1); 1326 defaultIndex = i; 1327 } 1328 l = l.tail; 1329 } 1330 1331 // Determine whether to issue a tableswitch or a lookupswitch 1332 // instruction. 1333 long table_space_cost = 4 + ((long) hi - lo + 1); // words 1334 long table_time_cost = 3; // comparisons 1335 long lookup_space_cost = 3 + 2 * (long) nlabels; 1336 long lookup_time_cost = nlabels; 1337 int opcode = 1338 nlabels > 0 && 1339 table_space_cost + 3 * table_time_cost <= 1340 lookup_space_cost + 3 * lookup_time_cost 1341 ? 1342 tableswitch : lookupswitch; 1343 1344 int startpc = code.curCP(); // the position of the selector operation 1345 code.emitop0(opcode); 1346 code.align(4); 1347 int tableBase = code.curCP(); // the start of the jump table 1348 int[] offsets = null; // a table of offsets for a lookupswitch 1349 code.emit4(-1); // leave space for default offset 1350 if (opcode == tableswitch) { 1351 code.emit4(lo); // minimum label 1352 code.emit4(hi); // maximum label 1353 for (long i = lo; i <= hi; i++) { // leave space for jump table 1354 code.emit4(-1); 1355 } 1356 } else { 1357 code.emit4(nlabels); // number of labels 1358 for (int i = 0; i < nlabels; i++) { 1359 code.emit4(-1); code.emit4(-1); // leave space for lookup table 1360 } 1361 offsets = new int[labels.length]; 1362 } 1363 Code.State stateSwitch = code.state.dup(); 1364 code.markDead(); 1365 1366 // For each case do: 1367 l = cases; 1368 for (int i = 0; i < labels.length; i++) { 1369 JCCase c = l.head; 1370 l = l.tail; 1371 1372 int pc = code.entryPoint(stateSwitch); 1373 // Insert offset directly into code or else into the 1374 // offsets table. 1375 if (i != defaultIndex) { 1376 if (opcode == tableswitch) { 1377 code.put4( 1378 tableBase + 4 * (labels[i] - lo + 3), 1379 pc - startpc); 1380 } else { 1381 offsets[i] = pc - startpc; 1382 } 1383 } else { 1384 code.put4(tableBase, pc - startpc); 1385 } 1386 1387 // Generate code for the statements in this case. 1388 genStats(c.stats, switchEnv, CRT_FLOW_TARGET); 1389 } 1390 1391 if (switchEnv.info.cont != null) { 1392 Assert.check(patternSwitch); 1393 code.resolve(switchEnv.info.cont, switchStart); 1394 } 1395 1396 // Resolve all breaks. 1397 Chain exit = switchEnv.info.exit; 1398 if (exit != null) { 1399 code.resolve(exit); 1400 exit.state.defined.excludeFrom(limit); 1401 } 1402 1403 // If we have not set the default offset, we do so now. 1404 if (code.get4(tableBase) == -1) { 1405 code.put4(tableBase, code.entryPoint(stateSwitch) - startpc); 1406 } 1407 1408 if (opcode == tableswitch) { 1409 // Let any unfilled slots point to the default case. 1410 int defaultOffset = code.get4(tableBase); 1411 for (long i = lo; i <= hi; i++) { 1412 int t = (int)(tableBase + 4 * (i - lo + 3)); 1413 if (code.get4(t) == -1) 1414 code.put4(t, defaultOffset); 1415 } 1416 } else { 1417 // Sort non-default offsets and copy into lookup table. 1418 if (defaultIndex >= 0) 1419 for (int i = defaultIndex; i < labels.length - 1; i++) { 1420 labels[i] = labels[i+1]; 1421 offsets[i] = offsets[i+1]; 1422 } 1423 if (nlabels > 0) 1424 qsort2(labels, offsets, 0, nlabels - 1); 1425 for (int i = 0; i < nlabels; i++) { 1426 int caseidx = tableBase + 8 * (i + 1); 1427 code.put4(caseidx, labels[i]); 1428 code.put4(caseidx + 4, offsets[i]); 1429 } 1430 } 1431 1432 if (swtch instanceof JCSwitchExpression) { 1433 // Emit line position for the end of a switch expression 1434 code.statBegin(TreeInfo.endPos(swtch)); 1435 } 1436 } 1437 code.endScopes(limit); 1438 } 1439 //where 1440 /** Sort (int) arrays of keys and values 1441 */ 1442 static void qsort2(int[] keys, int[] values, int lo, int hi) { 1443 int i = lo; 1444 int j = hi; 1445 int pivot = keys[(i+j)/2]; 1446 do { 1447 while (keys[i] < pivot) i++; 1448 while (pivot < keys[j]) j--; 1449 if (i <= j) { 1450 int temp1 = keys[i]; 1451 keys[i] = keys[j]; 1452 keys[j] = temp1; 1453 int temp2 = values[i]; 1454 values[i] = values[j]; 1455 values[j] = temp2; 1456 i++; 1457 j--; 1458 } 1459 } while (i <= j); 1460 if (lo < j) qsort2(keys, values, lo, j); 1461 if (i < hi) qsort2(keys, values, i, hi); 1462 } 1463 1464 public void visitSynchronized(JCSynchronized tree) { 1465 int limit = code.nextreg; 1466 // Generate code to evaluate lock and save in temporary variable. 1467 final LocalItem lockVar = makeTemp(syms.objectType); 1468 Assert.check(code.isStatementStart()); 1469 genExpr(tree.lock, tree.lock.type).load().duplicate(); 1470 lockVar.store(); 1471 1472 // Generate code to enter monitor. 1473 code.emitop0(monitorenter); 1474 code.state.lock(lockVar.reg); 1475 1476 // Generate code for a try statement with given body, no catch clauses 1477 // in a new environment with the "exit-monitor" operation as finalizer. 1478 final Env<GenContext> syncEnv = env.dup(tree, new GenContext()); 1479 syncEnv.info.finalize = new GenFinalizer() { 1480 void gen() { 1481 genLast(); 1482 Assert.check(syncEnv.info.gaps.length() % 2 == 0); 1483 syncEnv.info.gaps.append(code.curCP()); 1484 } 1485 void genLast() { 1486 if (code.isAlive()) { 1487 lockVar.load(); 1488 code.emitop0(monitorexit); 1489 code.state.unlock(lockVar.reg); 1490 } 1491 } 1492 }; 1493 syncEnv.info.gaps = new ListBuffer<>(); 1494 genTry(tree.body, List.nil(), syncEnv); 1495 code.endScopes(limit); 1496 } 1497 1498 public void visitTry(final JCTry tree) { 1499 // Generate code for a try statement with given body and catch clauses, 1500 // in a new environment which calls the finally block if there is one. 1501 final Env<GenContext> tryEnv = env.dup(tree, new GenContext()); 1502 final Env<GenContext> oldEnv = env; 1503 tryEnv.info.finalize = new GenFinalizer() { 1504 void gen() { 1505 Assert.check(tryEnv.info.gaps.length() % 2 == 0); 1506 tryEnv.info.gaps.append(code.curCP()); 1507 genLast(); 1508 } 1509 void genLast() { 1510 if (tree.finalizer != null) 1511 genStat(tree.finalizer, oldEnv, CRT_BLOCK); 1512 } 1513 boolean hasFinalizer() { 1514 return tree.finalizer != null; 1515 } 1516 1517 @Override 1518 void afterBody() { 1519 if (tree.finalizer != null && (tree.finalizer.flags & BODY_ONLY_FINALIZE) != 0) { 1520 //for body-only finally, remove the GenFinalizer after try body 1521 //so that the finally is not generated to catch bodies: 1522 tryEnv.info.finalize = null; 1523 } 1524 } 1525 1526 }; 1527 tryEnv.info.gaps = new ListBuffer<>(); 1528 genTry(tree.body, tree.catchers, tryEnv); 1529 } 1530 //where 1531 /** Generate code for a try or synchronized statement 1532 * @param body The body of the try or synchronized statement. 1533 * @param catchers The list of catch clauses. 1534 * @param env The current environment of the body. 1535 */ 1536 void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) { 1537 int limit = code.nextreg; 1538 int startpc = code.curCP(); 1539 Code.State stateTry = code.state.dup(); 1540 genStat(body, env, CRT_BLOCK); 1541 int endpc = code.curCP(); 1542 List<Integer> gaps = env.info.gaps.toList(); 1543 code.statBegin(TreeInfo.endPos(body)); 1544 genFinalizer(env); 1545 code.statBegin(TreeInfo.endPos(env.tree)); 1546 Chain exitChain; 1547 boolean actualTry = env.tree.hasTag(TRY); 1548 if (startpc == endpc && actualTry) { 1549 exitChain = code.branch(dontgoto); 1550 } else { 1551 exitChain = code.branch(goto_); 1552 } 1553 endFinalizerGap(env); 1554 env.info.finalize.afterBody(); 1555 boolean hasFinalizer = 1556 env.info.finalize != null && 1557 env.info.finalize.hasFinalizer(); 1558 if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) { 1559 // start off with exception on stack 1560 code.entryPoint(stateTry, l.head.param.sym.type); 1561 genCatch(l.head, env, startpc, endpc, gaps); 1562 genFinalizer(env); 1563 if (hasFinalizer || l.tail.nonEmpty()) { 1564 code.statBegin(TreeInfo.endPos(env.tree)); 1565 exitChain = Code.mergeChains(exitChain, 1566 code.branch(goto_)); 1567 } 1568 endFinalizerGap(env); 1569 } 1570 if (hasFinalizer && (startpc != endpc || !actualTry)) { 1571 // Create a new register segment to avoid allocating 1572 // the same variables in finalizers and other statements. 1573 code.newRegSegment(); 1574 1575 // Add a catch-all clause. 1576 1577 // start off with exception on stack 1578 int catchallpc = code.entryPoint(stateTry, syms.throwableType); 1579 1580 // Register all exception ranges for catch all clause. 1581 // The range of the catch all clause is from the beginning 1582 // of the try or synchronized block until the present 1583 // code pointer excluding all gaps in the current 1584 // environment's GenContext. 1585 int startseg = startpc; 1586 while (env.info.gaps.nonEmpty()) { 1587 int endseg = env.info.gaps.next().intValue(); 1588 registerCatch(body.pos(), startseg, endseg, 1589 catchallpc, 0); 1590 startseg = env.info.gaps.next().intValue(); 1591 } 1592 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS)); 1593 code.markStatBegin(); 1594 1595 Item excVar = makeTemp(syms.throwableType); 1596 excVar.store(); 1597 genFinalizer(env); 1598 code.resolvePending(); 1599 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.END_POS)); 1600 code.markStatBegin(); 1601 1602 excVar.load(); 1603 registerCatch(body.pos(), startseg, 1604 env.info.gaps.next().intValue(), 1605 catchallpc, 0); 1606 code.emitop0(athrow); 1607 code.markDead(); 1608 1609 // If there are jsr's to this finalizer, ... 1610 if (env.info.cont != null) { 1611 // Resolve all jsr's. 1612 code.resolve(env.info.cont); 1613 1614 // Mark statement line number 1615 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS)); 1616 code.markStatBegin(); 1617 1618 // Save return address. 1619 LocalItem retVar = makeTemp(syms.throwableType); 1620 retVar.store(); 1621 1622 // Generate finalizer code. 1623 env.info.finalize.genLast(); 1624 1625 // Return. 1626 code.emitop1w(ret, retVar.reg); 1627 code.markDead(); 1628 } 1629 } 1630 // Resolve all breaks. 1631 code.resolve(exitChain); 1632 1633 code.endScopes(limit); 1634 } 1635 1636 /** Generate code for a catch clause. 1637 * @param tree The catch clause. 1638 * @param env The environment current in the enclosing try. 1639 * @param startpc Start pc of try-block. 1640 * @param endpc End pc of try-block. 1641 */ 1642 void genCatch(JCCatch tree, 1643 Env<GenContext> env, 1644 int startpc, int endpc, 1645 List<Integer> gaps) { 1646 if (startpc != endpc) { 1647 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypeExprs 1648 = catchTypesWithAnnotations(tree); 1649 while (gaps.nonEmpty()) { 1650 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) { 1651 JCExpression subCatch = subCatch1.snd; 1652 int catchType = makeRef(tree.pos(), subCatch.type); 1653 int end = gaps.head.intValue(); 1654 registerCatch(tree.pos(), 1655 startpc, end, code.curCP(), 1656 catchType); 1657 for (Attribute.TypeCompound tc : subCatch1.fst) { 1658 tc.position.setCatchInfo(catchType, startpc); 1659 } 1660 } 1661 gaps = gaps.tail; 1662 startpc = gaps.head.intValue(); 1663 gaps = gaps.tail; 1664 } 1665 if (startpc < endpc) { 1666 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) { 1667 JCExpression subCatch = subCatch1.snd; 1668 int catchType = makeRef(tree.pos(), subCatch.type); 1669 registerCatch(tree.pos(), 1670 startpc, endpc, code.curCP(), 1671 catchType); 1672 for (Attribute.TypeCompound tc : subCatch1.fst) { 1673 tc.position.setCatchInfo(catchType, startpc); 1674 } 1675 } 1676 } 1677 genCatchBlock(tree, env); 1678 } 1679 } 1680 void genPatternMatchingCatch(JCCatch tree, 1681 Env<GenContext> env, 1682 List<int[]> ranges) { 1683 for (int[] range : ranges) { 1684 JCExpression subCatch = tree.param.vartype; 1685 int catchType = makeRef(tree.pos(), subCatch.type); 1686 registerCatch(tree.pos(), 1687 range[0], range[1], code.curCP(), 1688 catchType); 1689 } 1690 genCatchBlock(tree, env); 1691 } 1692 void genCatchBlock(JCCatch tree, Env<GenContext> env) { 1693 VarSymbol exparam = tree.param.sym; 1694 code.statBegin(tree.pos); 1695 code.markStatBegin(); 1696 int limit = code.nextreg; 1697 code.newLocal(exparam); 1698 items.makeLocalItem(exparam).store(); 1699 code.statBegin(TreeInfo.firstStatPos(tree.body)); 1700 genStat(tree.body, env, CRT_BLOCK); 1701 code.endScopes(limit); 1702 code.statBegin(TreeInfo.endPos(tree.body)); 1703 } 1704 // where 1705 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotations(JCCatch tree) { 1706 return TreeInfo.isMultiCatch(tree) ? 1707 catchTypesWithAnnotationsFromMulticatch((JCTypeUnion)tree.param.vartype, tree.param.sym.getRawTypeAttributes()) : 1708 List.of(new Pair<>(tree.param.sym.getRawTypeAttributes(), tree.param.vartype)); 1709 } 1710 // where 1711 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotationsFromMulticatch(JCTypeUnion tree, List<TypeCompound> first) { 1712 List<JCExpression> alts = tree.alternatives; 1713 List<Pair<List<TypeCompound>, JCExpression>> res = List.of(new Pair<>(first, alts.head)); 1714 alts = alts.tail; 1715 1716 while(alts != null && alts.head != null) { 1717 JCExpression alt = alts.head; 1718 if (alt instanceof JCAnnotatedType annotatedType) { 1719 res = res.prepend(new Pair<>(annotate.fromAnnotations(annotatedType.annotations), alt)); 1720 } else { 1721 res = res.prepend(new Pair<>(List.nil(), alt)); 1722 } 1723 alts = alts.tail; 1724 } 1725 return res.reverse(); 1726 } 1727 1728 /** Register a catch clause in the "Exceptions" code-attribute. 1729 */ 1730 void registerCatch(DiagnosticPosition pos, 1731 int startpc, int endpc, 1732 int handler_pc, int catch_type) { 1733 char startpc1 = (char)startpc; 1734 char endpc1 = (char)endpc; 1735 char handler_pc1 = (char)handler_pc; 1736 if (startpc1 == startpc && 1737 endpc1 == endpc && 1738 handler_pc1 == handler_pc) { 1739 code.addCatch(startpc1, endpc1, handler_pc1, 1740 (char)catch_type); 1741 } else { 1742 log.error(pos, Errors.LimitCodeTooLargeForTryStmt); 1743 nerrs++; 1744 } 1745 } 1746 1747 public void visitIf(JCIf tree) { 1748 int limit = code.nextreg; 1749 Chain thenExit = null; 1750 Assert.check(code.isStatementStart()); 1751 CondItem c = genCond(TreeInfo.skipParens(tree.cond), 1752 CRT_FLOW_CONTROLLER); 1753 Chain elseChain = c.jumpFalse(); 1754 Assert.check(code.isStatementStart()); 1755 if (!c.isFalse()) { 1756 code.resolve(c.trueJumps); 1757 genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET); 1758 thenExit = code.branch(goto_); 1759 } 1760 if (elseChain != null) { 1761 code.resolve(elseChain); 1762 if (tree.elsepart != null) { 1763 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET); 1764 } 1765 } 1766 code.resolve(thenExit); 1767 code.endScopes(limit); 1768 Assert.check(code.isStatementStart()); 1769 } 1770 1771 public void visitExec(JCExpressionStatement tree) { 1772 // Optimize x++ to ++x and x-- to --x. 1773 JCExpression e = tree.expr; 1774 switch (e.getTag()) { 1775 case POSTINC: 1776 ((JCUnary) e).setTag(PREINC); 1777 break; 1778 case POSTDEC: 1779 ((JCUnary) e).setTag(PREDEC); 1780 break; 1781 } 1782 Assert.check(code.isStatementStart()); 1783 genExpr(tree.expr, tree.expr.type).drop(); 1784 Assert.check(code.isStatementStart()); 1785 } 1786 1787 public void visitBreak(JCBreak tree) { 1788 Assert.check(code.isStatementStart()); 1789 final Env<GenContext> targetEnv = unwindBreak(tree.target); 1790 targetEnv.info.addExit(code.branch(goto_)); 1791 endFinalizerGaps(env, targetEnv); 1792 } 1793 1794 public void visitYield(JCYield tree) { 1795 Assert.check(code.isStatementStart()); 1796 final Env<GenContext> targetEnv; 1797 if (inCondSwitchExpression) { 1798 CondItem value = genCond(tree.value, CRT_FLOW_TARGET); 1799 Chain falseJumps = value.jumpFalse(); 1800 1801 code.resolve(value.trueJumps); 1802 Env<GenContext> localEnv = unwindBreak(tree.target); 1803 reloadStackBeforeSwitchExpr(); 1804 Chain trueJumps = code.branch(goto_); 1805 1806 endFinalizerGaps(env, localEnv); 1807 1808 code.resolve(falseJumps); 1809 targetEnv = unwindBreak(tree.target); 1810 reloadStackBeforeSwitchExpr(); 1811 falseJumps = code.branch(goto_); 1812 1813 if (switchExpressionTrueChain == null) { 1814 switchExpressionTrueChain = trueJumps; 1815 } else { 1816 switchExpressionTrueChain = 1817 Code.mergeChains(switchExpressionTrueChain, trueJumps); 1818 } 1819 if (switchExpressionFalseChain == null) { 1820 switchExpressionFalseChain = falseJumps; 1821 } else { 1822 switchExpressionFalseChain = 1823 Code.mergeChains(switchExpressionFalseChain, falseJumps); 1824 } 1825 } else { 1826 genExpr(tree.value, pt).load(); 1827 if (switchResult != null) 1828 switchResult.store(); 1829 1830 targetEnv = unwindBreak(tree.target); 1831 1832 if (code.isAlive()) { 1833 reloadStackBeforeSwitchExpr(); 1834 if (switchResult != null) 1835 switchResult.load(); 1836 1837 code.state.forceStackTop(tree.target.type); 1838 targetEnv.info.addExit(code.branch(goto_)); 1839 code.markDead(); 1840 } 1841 } 1842 endFinalizerGaps(env, targetEnv); 1843 } 1844 //where: 1845 /** As side-effect, might mark code as dead disabling any further emission. 1846 */ 1847 private Env<GenContext> unwindBreak(JCTree target) { 1848 int tmpPos = code.pendingStatPos; 1849 Env<GenContext> targetEnv = unwind(target, env); 1850 code.pendingStatPos = tmpPos; 1851 return targetEnv; 1852 } 1853 1854 private void reloadStackBeforeSwitchExpr() { 1855 for (LocalItem li : stackBeforeSwitchExpression) 1856 li.load(); 1857 } 1858 1859 public void visitContinue(JCContinue tree) { 1860 int tmpPos = code.pendingStatPos; 1861 Env<GenContext> targetEnv = unwind(tree.target, env); 1862 code.pendingStatPos = tmpPos; 1863 Assert.check(code.isStatementStart()); 1864 targetEnv.info.addCont(code.branch(goto_)); 1865 endFinalizerGaps(env, targetEnv); 1866 } 1867 1868 public void visitReturn(JCReturn tree) { 1869 int limit = code.nextreg; 1870 final Env<GenContext> targetEnv; 1871 1872 /* Save and then restore the location of the return in case a finally 1873 * is expanded (with unwind()) in the middle of our bytecodes. 1874 */ 1875 int tmpPos = code.pendingStatPos; 1876 if (tree.expr != null) { 1877 Assert.check(code.isStatementStart()); 1878 Item r = genExpr(tree.expr, pt).load(); 1879 if (hasFinally(env.enclMethod, env)) { 1880 r = makeTemp(pt); 1881 r.store(); 1882 } 1883 targetEnv = unwind(env.enclMethod, env); 1884 code.pendingStatPos = tmpPos; 1885 r.load(); 1886 code.emitop0(ireturn + Code.truncate(Code.typecode(pt))); 1887 } else { 1888 targetEnv = unwind(env.enclMethod, env); 1889 code.pendingStatPos = tmpPos; 1890 code.emitop0(return_); 1891 } 1892 endFinalizerGaps(env, targetEnv); 1893 code.endScopes(limit); 1894 } 1895 1896 public void visitThrow(JCThrow tree) { 1897 Assert.check(code.isStatementStart()); 1898 genExpr(tree.expr, tree.expr.type).load(); 1899 code.emitop0(athrow); 1900 Assert.check(code.isStatementStart()); 1901 } 1902 1903 /* ************************************************************************ 1904 * Visitor methods for expressions 1905 *************************************************************************/ 1906 1907 public void visitApply(JCMethodInvocation tree) { 1908 setTypeAnnotationPositions(tree.pos); 1909 // Generate code for method. 1910 Item m = genExpr(tree.meth, methodType); 1911 // Generate code for all arguments, where the expected types are 1912 // the parameters of the method's external type (that is, any implicit 1913 // outer instance of a super(...) call appears as first parameter). 1914 MethodSymbol msym = (MethodSymbol)TreeInfo.symbol(tree.meth); 1915 genArgs(tree.args, 1916 msym.externalType(types).getParameterTypes()); 1917 if (!msym.isDynamic()) { 1918 code.statBegin(tree.pos); 1919 } 1920 if (invocationsWithPatternMatchingCatch.contains(tree)) { 1921 int start = code.curCP(); 1922 result = m.invoke(); 1923 patternMatchingInvocationRanges.add(new int[] {start, code.curCP()}); 1924 } else { 1925 result = m.invoke(); 1926 } 1927 } 1928 1929 public void visitConditional(JCConditional tree) { 1930 Chain thenExit = null; 1931 code.statBegin(tree.cond.pos); 1932 CondItem c = genCond(tree.cond, CRT_FLOW_CONTROLLER); 1933 Chain elseChain = c.jumpFalse(); 1934 if (!c.isFalse()) { 1935 code.resolve(c.trueJumps); 1936 int startpc = genCrt ? code.curCP() : 0; 1937 code.statBegin(tree.truepart.pos); 1938 genExpr(tree.truepart, pt).load(); 1939 code.state.forceStackTop(tree.type); 1940 if (genCrt) code.crt.put(tree.truepart, CRT_FLOW_TARGET, 1941 startpc, code.curCP()); 1942 thenExit = code.branch(goto_); 1943 } 1944 if (elseChain != null) { 1945 code.resolve(elseChain); 1946 int startpc = genCrt ? code.curCP() : 0; 1947 code.statBegin(tree.falsepart.pos); 1948 genExpr(tree.falsepart, pt).load(); 1949 code.state.forceStackTop(tree.type); 1950 if (genCrt) code.crt.put(tree.falsepart, CRT_FLOW_TARGET, 1951 startpc, code.curCP()); 1952 } 1953 code.resolve(thenExit); 1954 result = items.makeStackItem(pt); 1955 } 1956 1957 private void setTypeAnnotationPositions(int treePos) { 1958 MethodSymbol meth = code.meth; 1959 boolean initOrClinit = code.meth.getKind() == javax.lang.model.element.ElementKind.CONSTRUCTOR 1960 || code.meth.getKind() == javax.lang.model.element.ElementKind.STATIC_INIT; 1961 1962 for (Attribute.TypeCompound ta : meth.getRawTypeAttributes()) { 1963 if (ta.hasUnknownPosition()) 1964 ta.tryFixPosition(); 1965 1966 if (ta.position.matchesPos(treePos)) 1967 ta.position.updatePosOffset(code.cp); 1968 } 1969 1970 if (!initOrClinit) 1971 return; 1972 1973 for (Attribute.TypeCompound ta : meth.owner.getRawTypeAttributes()) { 1974 if (ta.hasUnknownPosition()) 1975 ta.tryFixPosition(); 1976 1977 if (ta.position.matchesPos(treePos)) 1978 ta.position.updatePosOffset(code.cp); 1979 } 1980 1981 ClassSymbol clazz = meth.enclClass(); 1982 for (Symbol s : new com.sun.tools.javac.model.FilteredMemberList(clazz.members())) { 1983 if (!s.getKind().isField()) 1984 continue; 1985 1986 for (Attribute.TypeCompound ta : s.getRawTypeAttributes()) { 1987 if (ta.hasUnknownPosition()) 1988 ta.tryFixPosition(); 1989 1990 if (ta.position.matchesPos(treePos)) 1991 ta.position.updatePosOffset(code.cp); 1992 } 1993 } 1994 } 1995 1996 public void visitNewClass(JCNewClass tree) { 1997 // Enclosing instances or anonymous classes should have been eliminated 1998 // by now. 1999 Assert.check(tree.encl == null && tree.def == null); 2000 setTypeAnnotationPositions(tree.pos); 2001 2002 code.emitop2(new_, checkDimension(tree.pos(), tree.type), PoolWriter::putClass); 2003 code.emitop0(dup); 2004 2005 // Generate code for all arguments, where the expected types are 2006 // the parameters of the constructor's external type (that is, 2007 // any implicit outer instance appears as first parameter). 2008 genArgs(tree.args, tree.constructor.externalType(types).getParameterTypes()); 2009 2010 items.makeMemberItem(tree.constructor, true).invoke(); 2011 result = items.makeStackItem(tree.type); 2012 } 2013 2014 public void visitNewArray(JCNewArray tree) { 2015 setTypeAnnotationPositions(tree.pos); 2016 2017 if (tree.elems != null) { 2018 Type elemtype = types.elemtype(tree.type); 2019 loadIntConst(tree.elems.length()); 2020 Item arr = makeNewArray(tree.pos(), tree.type, 1); 2021 int i = 0; 2022 for (List<JCExpression> l = tree.elems; l.nonEmpty(); l = l.tail) { 2023 arr.duplicate(); 2024 loadIntConst(i); 2025 i++; 2026 genExpr(l.head, elemtype).load(); 2027 items.makeIndexedItem(elemtype).store(); 2028 } 2029 result = arr; 2030 } else { 2031 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) { 2032 genExpr(l.head, syms.intType).load(); 2033 } 2034 result = makeNewArray(tree.pos(), tree.type, tree.dims.length()); 2035 } 2036 } 2037 //where 2038 /** Generate code to create an array with given element type and number 2039 * of dimensions. 2040 */ 2041 Item makeNewArray(DiagnosticPosition pos, Type type, int ndims) { 2042 Type elemtype = types.elemtype(type); 2043 if (types.dimensions(type) > ClassFile.MAX_DIMENSIONS) { 2044 log.error(pos, Errors.LimitDimensions); 2045 nerrs++; 2046 } 2047 int elemcode = Code.arraycode(elemtype); 2048 if (elemcode == 0 || (elemcode == 1 && ndims == 1)) { 2049 code.emitAnewarray(makeRef(pos, elemtype), type); 2050 } else if (elemcode == 1) { 2051 code.emitMultianewarray(ndims, makeRef(pos, type), type); 2052 } else { 2053 code.emitNewarray(elemcode, type); 2054 } 2055 return items.makeStackItem(type); 2056 } 2057 2058 public void visitParens(JCParens tree) { 2059 result = genExpr(tree.expr, tree.expr.type); 2060 } 2061 2062 public void visitAssign(JCAssign tree) { 2063 Item l = genExpr(tree.lhs, tree.lhs.type); 2064 genExpr(tree.rhs, tree.lhs.type).load(); 2065 if (tree.rhs.type.hasTag(BOT)) { 2066 /* This is just a case of widening reference conversion that per 5.1.5 simply calls 2067 for "regarding a reference as having some other type in a manner that can be proved 2068 correct at compile time." 2069 */ 2070 code.state.forceStackTop(tree.lhs.type); 2071 } 2072 result = items.makeAssignItem(l); 2073 } 2074 2075 public void visitAssignop(JCAssignOp tree) { 2076 OperatorSymbol operator = tree.operator; 2077 Item l; 2078 if (operator.opcode == string_add) { 2079 l = concat.makeConcat(tree); 2080 } else { 2081 // Generate code for first expression 2082 l = genExpr(tree.lhs, tree.lhs.type); 2083 2084 // If we have an increment of -32768 to +32767 of a local 2085 // int variable we can use an incr instruction instead of 2086 // proceeding further. 2087 if ((tree.hasTag(PLUS_ASG) || tree.hasTag(MINUS_ASG)) && 2088 l instanceof LocalItem localItem && 2089 tree.lhs.type.getTag().isSubRangeOf(INT) && 2090 tree.rhs.type.getTag().isSubRangeOf(INT) && 2091 tree.rhs.type.constValue() != null) { 2092 int ival = ((Number) tree.rhs.type.constValue()).intValue(); 2093 if (tree.hasTag(MINUS_ASG)) ival = -ival; 2094 localItem.incr(ival); 2095 result = l; 2096 return; 2097 } 2098 // Otherwise, duplicate expression, load one copy 2099 // and complete binary operation. 2100 l.duplicate(); 2101 l.coerce(operator.type.getParameterTypes().head).load(); 2102 completeBinop(tree.lhs, tree.rhs, operator).coerce(tree.lhs.type); 2103 } 2104 result = items.makeAssignItem(l); 2105 } 2106 2107 public void visitUnary(JCUnary tree) { 2108 OperatorSymbol operator = tree.operator; 2109 if (tree.hasTag(NOT)) { 2110 CondItem od = genCond(tree.arg, false); 2111 result = od.negate(); 2112 } else { 2113 Item od = genExpr(tree.arg, operator.type.getParameterTypes().head); 2114 switch (tree.getTag()) { 2115 case POS: 2116 result = od.load(); 2117 break; 2118 case NEG: 2119 result = od.load(); 2120 code.emitop0(operator.opcode); 2121 break; 2122 case COMPL: 2123 result = od.load(); 2124 emitMinusOne(od.typecode); 2125 code.emitop0(operator.opcode); 2126 break; 2127 case PREINC: case PREDEC: 2128 od.duplicate(); 2129 if (od instanceof LocalItem localItem && 2130 (operator.opcode == iadd || operator.opcode == isub)) { 2131 localItem.incr(tree.hasTag(PREINC) ? 1 : -1); 2132 result = od; 2133 } else { 2134 od.load(); 2135 code.emitop0(one(od.typecode)); 2136 code.emitop0(operator.opcode); 2137 // Perform narrowing primitive conversion if byte, 2138 // char, or short. Fix for 4304655. 2139 if (od.typecode != INTcode && 2140 Code.truncate(od.typecode) == INTcode) 2141 code.emitop0(int2byte + od.typecode - BYTEcode); 2142 result = items.makeAssignItem(od); 2143 } 2144 break; 2145 case POSTINC: case POSTDEC: 2146 od.duplicate(); 2147 if (od instanceof LocalItem localItem && 2148 (operator.opcode == iadd || operator.opcode == isub)) { 2149 Item res = od.load(); 2150 localItem.incr(tree.hasTag(POSTINC) ? 1 : -1); 2151 result = res; 2152 } else { 2153 Item res = od.load(); 2154 od.stash(od.typecode); 2155 code.emitop0(one(od.typecode)); 2156 code.emitop0(operator.opcode); 2157 // Perform narrowing primitive conversion if byte, 2158 // char, or short. Fix for 4304655. 2159 if (od.typecode != INTcode && 2160 Code.truncate(od.typecode) == INTcode) 2161 code.emitop0(int2byte + od.typecode - BYTEcode); 2162 od.store(); 2163 result = res; 2164 } 2165 break; 2166 case NULLCHK: 2167 result = od.load(); 2168 code.emitop0(dup); 2169 genNullCheck(tree); 2170 break; 2171 default: 2172 Assert.error(); 2173 } 2174 } 2175 } 2176 2177 /** Generate a null check from the object value at stack top. */ 2178 private void genNullCheck(JCTree tree) { 2179 code.statBegin(tree.pos); 2180 callMethod(tree.pos(), syms.objectsType, names.requireNonNull, 2181 List.of(syms.objectType), true); 2182 code.emitop0(pop); 2183 } 2184 2185 public void visitBinary(JCBinary tree) { 2186 OperatorSymbol operator = tree.operator; 2187 if (operator.opcode == string_add) { 2188 result = concat.makeConcat(tree); 2189 } else if (tree.hasTag(AND)) { 2190 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER); 2191 if (!lcond.isFalse()) { 2192 Chain falseJumps = lcond.jumpFalse(); 2193 code.resolve(lcond.trueJumps); 2194 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET); 2195 result = items. 2196 makeCondItem(rcond.opcode, 2197 rcond.trueJumps, 2198 Code.mergeChains(falseJumps, 2199 rcond.falseJumps)); 2200 } else { 2201 result = lcond; 2202 } 2203 } else if (tree.hasTag(OR)) { 2204 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER); 2205 if (!lcond.isTrue()) { 2206 Chain trueJumps = lcond.jumpTrue(); 2207 code.resolve(lcond.falseJumps); 2208 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET); 2209 result = items. 2210 makeCondItem(rcond.opcode, 2211 Code.mergeChains(trueJumps, rcond.trueJumps), 2212 rcond.falseJumps); 2213 } else { 2214 result = lcond; 2215 } 2216 } else { 2217 Item od = genExpr(tree.lhs, operator.type.getParameterTypes().head); 2218 od.load(); 2219 result = completeBinop(tree.lhs, tree.rhs, operator); 2220 } 2221 } 2222 2223 2224 /** Complete generating code for operation, with left operand 2225 * already on stack. 2226 * @param lhs The tree representing the left operand. 2227 * @param rhs The tree representing the right operand. 2228 * @param operator The operator symbol. 2229 */ 2230 Item completeBinop(JCTree lhs, JCTree rhs, OperatorSymbol operator) { 2231 MethodType optype = (MethodType)operator.type; 2232 int opcode = operator.opcode; 2233 if (opcode >= if_icmpeq && opcode <= if_icmple && 2234 rhs.type.constValue() instanceof Number number && 2235 number.intValue() == 0) { 2236 opcode = opcode + (ifeq - if_icmpeq); 2237 } else if (opcode >= if_acmpeq && opcode <= if_acmpne && 2238 TreeInfo.isNull(rhs)) { 2239 opcode = opcode + (if_acmp_null - if_acmpeq); 2240 } else { 2241 // The expected type of the right operand is 2242 // the second parameter type of the operator, except for 2243 // shifts with long shiftcount, where we convert the opcode 2244 // to a short shift and the expected type to int. 2245 Type rtype = operator.erasure(types).getParameterTypes().tail.head; 2246 if (opcode >= ishll && opcode <= lushrl) { 2247 opcode = opcode + (ishl - ishll); 2248 rtype = syms.intType; 2249 } 2250 // Generate code for right operand and load. 2251 genExpr(rhs, rtype).load(); 2252 // If there are two consecutive opcode instructions, 2253 // emit the first now. 2254 if (opcode >= (1 << preShift)) { 2255 code.emitop0(opcode >> preShift); 2256 opcode = opcode & 0xFF; 2257 } 2258 } 2259 if (opcode >= ifeq && opcode <= if_acmpne || 2260 opcode == if_acmp_null || opcode == if_acmp_nonnull) { 2261 return items.makeCondItem(opcode); 2262 } else { 2263 code.emitop0(opcode); 2264 return items.makeStackItem(optype.restype); 2265 } 2266 } 2267 2268 public void visitTypeCast(JCTypeCast tree) { 2269 result = genExpr(tree.expr, tree.clazz.type).load(); 2270 setTypeAnnotationPositions(tree.pos); 2271 // Additional code is only needed if we cast to a reference type 2272 // which is not statically a supertype of the expression's type. 2273 // For basic types, the coerce(...) in genExpr(...) will do 2274 // the conversion. 2275 if (!tree.clazz.type.isPrimitive() && 2276 !types.isSameType(tree.expr.type, tree.clazz.type) && 2277 types.asSuper(tree.expr.type, tree.clazz.type.tsym) == null) { 2278 code.emitop2(checkcast, checkDimension(tree.pos(), tree.clazz.type), PoolWriter::putClass); 2279 } 2280 } 2281 2282 public void visitWildcard(JCWildcard tree) { 2283 throw new AssertionError(this.getClass().getName()); 2284 } 2285 2286 public void visitTypeTest(JCInstanceOf tree) { 2287 genExpr(tree.expr, tree.expr.type).load(); 2288 setTypeAnnotationPositions(tree.pos); 2289 code.emitop2(instanceof_, makeRef(tree.pos(), tree.pattern.type)); 2290 result = items.makeStackItem(syms.booleanType); 2291 } 2292 2293 public void visitIndexed(JCArrayAccess tree) { 2294 genExpr(tree.indexed, tree.indexed.type).load(); 2295 genExpr(tree.index, syms.intType).load(); 2296 result = items.makeIndexedItem(tree.type); 2297 } 2298 2299 public void visitIdent(JCIdent tree) { 2300 Symbol sym = tree.sym; 2301 if (tree.name == names._this || tree.name == names._super) { 2302 Item res = tree.name == names._this 2303 ? items.makeThisItem() 2304 : items.makeSuperItem(); 2305 if (sym.kind == MTH) { 2306 // Generate code to address the constructor. 2307 res.load(); 2308 res = items.makeMemberItem(sym, true); 2309 } 2310 result = res; 2311 } else if (isInvokeDynamic(sym) || isConstantDynamic(sym)) { 2312 if (isConstantDynamic(sym)) { 2313 setTypeAnnotationPositions(tree.pos); 2314 } 2315 result = items.makeDynamicItem(sym); 2316 } else if (sym.kind == VAR && (sym.owner.kind == MTH || sym.owner.kind == VAR)) { 2317 result = items.makeLocalItem((VarSymbol)sym); 2318 } else if ((sym.flags() & STATIC) != 0) { 2319 if (!isAccessSuper(env.enclMethod)) 2320 sym = binaryQualifier(sym, env.enclClass.type); 2321 result = items.makeStaticItem(sym); 2322 } else { 2323 items.makeThisItem().load(); 2324 sym = binaryQualifier(sym, env.enclClass.type); 2325 result = items.makeMemberItem(sym, nonVirtualForPrivateAccess(sym)); 2326 } 2327 } 2328 2329 //where 2330 private boolean nonVirtualForPrivateAccess(Symbol sym) { 2331 boolean useVirtual = target.hasVirtualPrivateInvoke() && 2332 !disableVirtualizedPrivateInvoke; 2333 return !useVirtual && ((sym.flags() & PRIVATE) != 0); 2334 } 2335 2336 public void visitSelect(JCFieldAccess tree) { 2337 Symbol sym = tree.sym; 2338 2339 if (tree.name == names._class) { 2340 code.emitLdc((LoadableConstant)checkDimension(tree.pos(), tree.selected.type)); 2341 result = items.makeStackItem(pt); 2342 return; 2343 } 2344 2345 Symbol ssym = TreeInfo.symbol(tree.selected); 2346 2347 // Are we selecting via super? 2348 boolean selectSuper = 2349 ssym != null && (ssym.kind == TYP || ssym.name == names._super); 2350 2351 // Are we accessing a member of the superclass in an access method 2352 // resulting from a qualified super? 2353 boolean accessSuper = isAccessSuper(env.enclMethod); 2354 2355 Item base = (selectSuper) 2356 ? items.makeSuperItem() 2357 : genExpr(tree.selected, tree.selected.type); 2358 2359 if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) { 2360 // We are seeing a variable that is constant but its selecting 2361 // expression is not. 2362 if ((sym.flags() & STATIC) != 0) { 2363 if (!selectSuper && (ssym == null || ssym.kind != TYP)) 2364 base = base.load(); 2365 base.drop(); 2366 } else { 2367 base.load(); 2368 genNullCheck(tree.selected); 2369 } 2370 result = items. 2371 makeImmediateItem(sym.type, ((VarSymbol) sym).getConstValue()); 2372 } else { 2373 if (isInvokeDynamic(sym)) { 2374 result = items.makeDynamicItem(sym); 2375 return; 2376 } else { 2377 sym = binaryQualifier(sym, tree.selected.type); 2378 } 2379 if ((sym.flags() & STATIC) != 0) { 2380 if (!selectSuper && (ssym == null || ssym.kind != TYP)) 2381 base = base.load(); 2382 base.drop(); 2383 result = items.makeStaticItem(sym); 2384 } else { 2385 base.load(); 2386 if (sym == syms.lengthVar) { 2387 code.emitop0(arraylength); 2388 result = items.makeStackItem(syms.intType); 2389 } else { 2390 result = items. 2391 makeMemberItem(sym, 2392 nonVirtualForPrivateAccess(sym) || 2393 selectSuper || accessSuper); 2394 } 2395 } 2396 } 2397 } 2398 2399 public boolean isInvokeDynamic(Symbol sym) { 2400 return sym.kind == MTH && ((MethodSymbol)sym).isDynamic(); 2401 } 2402 2403 public void visitLiteral(JCLiteral tree) { 2404 if (tree.type.hasTag(BOT)) { 2405 code.emitop0(aconst_null); 2406 result = items.makeStackItem(tree.type); 2407 } 2408 else 2409 result = items.makeImmediateItem(tree.type, tree.value); 2410 } 2411 2412 public void visitLetExpr(LetExpr tree) { 2413 code.resolvePending(); 2414 2415 int limit = code.nextreg; 2416 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize); 2417 try { 2418 genStats(tree.defs, env); 2419 } finally { 2420 code.setLetExprStackPos(prevLetExprStart); 2421 } 2422 result = genExpr(tree.expr, tree.expr.type).load(); 2423 code.endScopes(limit); 2424 } 2425 2426 private void generateReferencesToPrunedTree(ClassSymbol classSymbol) { 2427 List<JCTree> prunedInfo = lower.prunedTree.get(classSymbol); 2428 if (prunedInfo != null) { 2429 for (JCTree prunedTree: prunedInfo) { 2430 prunedTree.accept(classReferenceVisitor); 2431 } 2432 } 2433 } 2434 2435 /* ************************************************************************ 2436 * main method 2437 *************************************************************************/ 2438 2439 /** Generate code for a class definition. 2440 * @param env The attribution environment that belongs to the 2441 * outermost class containing this class definition. 2442 * We need this for resolving some additional symbols. 2443 * @param cdef The tree representing the class definition. 2444 * @return True if code is generated with no errors. 2445 */ 2446 public boolean genClass(Env<AttrContext> env, JCClassDecl cdef) { 2447 try { 2448 attrEnv = env; 2449 ClassSymbol c = cdef.sym; 2450 this.toplevel = env.toplevel; 2451 this.endPosTable = toplevel.endPositions; 2452 /* method normalizeDefs() can add references to external classes into the constant pool 2453 */ 2454 cdef.defs = normalizeDefs(cdef.defs, c); 2455 generateReferencesToPrunedTree(c); 2456 Env<GenContext> localEnv = new Env<>(cdef, new GenContext()); 2457 localEnv.toplevel = env.toplevel; 2458 localEnv.enclClass = cdef; 2459 2460 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) { 2461 genDef(l.head, localEnv); 2462 } 2463 if (poolWriter.size() > PoolWriter.MAX_ENTRIES) { 2464 log.error(cdef.pos(), Errors.LimitPool); 2465 nerrs++; 2466 } 2467 if (nerrs != 0) { 2468 // if errors, discard code 2469 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) { 2470 if (l.head.hasTag(METHODDEF)) 2471 ((JCMethodDecl) l.head).sym.code = null; 2472 } 2473 } 2474 cdef.defs = List.nil(); // discard trees 2475 return nerrs == 0; 2476 } finally { 2477 // note: this method does NOT support recursion. 2478 attrEnv = null; 2479 this.env = null; 2480 toplevel = null; 2481 endPosTable = null; 2482 nerrs = 0; 2483 qualifiedSymbolCache.clear(); 2484 } 2485 } 2486 2487 /* ************************************************************************ 2488 * Auxiliary classes 2489 *************************************************************************/ 2490 2491 /** An abstract class for finalizer generation. 2492 */ 2493 abstract class GenFinalizer { 2494 /** Generate code to clean up when unwinding. */ 2495 abstract void gen(); 2496 2497 /** Generate code to clean up at last. */ 2498 abstract void genLast(); 2499 2500 /** Does this finalizer have some nontrivial cleanup to perform? */ 2501 boolean hasFinalizer() { return true; } 2502 2503 /** Should be invoked after the try's body has been visited. */ 2504 void afterBody() {} 2505 } 2506 2507 /** code generation contexts, 2508 * to be used as type parameter for environments. 2509 */ 2510 static class GenContext { 2511 2512 /** A chain for all unresolved jumps that exit the current environment. 2513 */ 2514 Chain exit = null; 2515 2516 /** A chain for all unresolved jumps that continue in the 2517 * current environment. 2518 */ 2519 Chain cont = null; 2520 2521 /** A closure that generates the finalizer of the current environment. 2522 * Only set for Synchronized and Try contexts. 2523 */ 2524 GenFinalizer finalize = null; 2525 2526 /** Is this a switch statement? If so, allocate registers 2527 * even when the variable declaration is unreachable. 2528 */ 2529 boolean isSwitch = false; 2530 2531 /** A list buffer containing all gaps in the finalizer range, 2532 * where a catch all exception should not apply. 2533 */ 2534 ListBuffer<Integer> gaps = null; 2535 2536 /** Add given chain to exit chain. 2537 */ 2538 void addExit(Chain c) { 2539 exit = Code.mergeChains(c, exit); 2540 } 2541 2542 /** Add given chain to cont chain. 2543 */ 2544 void addCont(Chain c) { 2545 cont = Code.mergeChains(c, cont); 2546 } 2547 } 2548 2549 }