1 /* 2 * Copyright (c) 2012, 2015, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package java.lang.invoke; 27 28 import java.io.*; 29 import java.util.*; 30 import java.lang.reflect.Modifier; 31 32 import jdk.internal.org.objectweb.asm.*; 33 34 import static java.lang.invoke.LambdaForm.*; 35 import static java.lang.invoke.LambdaForm.BasicType.*; 36 import static java.lang.invoke.MethodHandleStatics.*; 37 import static java.lang.invoke.MethodHandleNatives.Constants.*; 38 39 import sun.invoke.util.VerifyAccess; 40 import sun.invoke.util.VerifyType; 41 import sun.invoke.util.Wrapper; 42 import sun.reflect.misc.ReflectUtil; 43 44 /** 45 * Code generation backend for LambdaForm. 46 * <p> 47 * @author John Rose, JSR 292 EG 48 */ 49 class InvokerBytecodeGenerator { 50 /** Define class names for convenience. */ 51 private static final String MH = "java/lang/invoke/MethodHandle"; 52 private static final String MHI = "java/lang/invoke/MethodHandleImpl"; 53 private static final String LF = "java/lang/invoke/LambdaForm"; 54 private static final String LFN = "java/lang/invoke/LambdaForm$Name"; 55 private static final String CLS = "java/lang/Class"; 56 private static final String OBJ = "java/lang/Object"; 57 private static final String OBJARY = "[Ljava/lang/Object;"; 58 59 private static final String LF_SIG = "L" + LF + ";"; 60 private static final String LFN_SIG = "L" + LFN + ";"; 61 private static final String LL_SIG = "(L" + OBJ + ";)L" + OBJ + ";"; 62 private static final String LLV_SIG = "(L" + OBJ + ";L" + OBJ + ";)V"; 63 64 /** Name of its super class*/ 65 private static final String superName = OBJ; 66 67 /** Name of new class */ 68 private final String className; 69 70 /** Name of the source file (for stack trace printing). */ 71 private final String sourceFile; 72 73 private final LambdaForm lambdaForm; 74 private final String invokerName; 75 private final MethodType invokerType; 76 77 /** Info about local variables in compiled lambda form */ 78 private final int[] localsMap; // index 79 private final Class<?>[] localClasses; // type 80 81 /** ASM bytecode generation. */ 82 private ClassWriter cw; 83 private MethodVisitor mv; 84 85 private static final MemberName.Factory MEMBERNAME_FACTORY = MemberName.getFactory(); 86 private static final Class<?> HOST_CLASS = LambdaForm.class; 87 88 /** Main constructor; other constructors delegate to this one. */ 89 private InvokerBytecodeGenerator(LambdaForm lambdaForm, int localsMapSize, 90 String className, String invokerName, MethodType invokerType) { 91 if (invokerName.contains(".")) { 92 int p = invokerName.indexOf('.'); 93 className = invokerName.substring(0, p); 94 invokerName = invokerName.substring(p+1); 95 } 96 if (DUMP_CLASS_FILES) { 97 className = makeDumpableClassName(className); 98 } 99 this.className = LF + "$" + className; 100 this.sourceFile = "LambdaForm$" + className; 101 this.lambdaForm = lambdaForm; 102 this.invokerName = invokerName; 103 this.invokerType = invokerType; 104 this.localsMap = new int[localsMapSize+1]; 105 // last entry of localsMap is count of allocated local slots 106 this.localClasses = new Class<?>[localsMapSize+1]; 107 } 108 109 /** For generating LambdaForm interpreter entry points. */ 110 private InvokerBytecodeGenerator(String className, String invokerName, MethodType invokerType) { 111 this(null, invokerType.parameterCount(), 112 className, invokerName, invokerType); 113 // Create an array to map name indexes to locals indexes. 114 for (int i = 0; i < localsMap.length; i++) { 115 localsMap[i] = invokerType.parameterSlotCount() - invokerType.parameterSlotDepth(i); 116 } 117 } 118 119 /** For generating customized code for a single LambdaForm. */ 120 private InvokerBytecodeGenerator(String className, LambdaForm form, MethodType invokerType) { 121 this(form, form.names.length, 122 className, form.debugName, invokerType); 123 // Create an array to map name indexes to locals indexes. 124 Name[] names = form.names; 125 for (int i = 0, index = 0; i < localsMap.length; i++) { 126 localsMap[i] = index; 127 if (i < names.length) { 128 BasicType type = names[i].type(); 129 index += type.basicTypeSlots(); 130 } 131 } 132 } 133 134 135 /** instance counters for dumped classes */ 136 private static final HashMap<String,Integer> DUMP_CLASS_FILES_COUNTERS; 137 /** debugging flag for saving generated class files */ 138 private static final File DUMP_CLASS_FILES_DIR; 139 140 static { 141 if (DUMP_CLASS_FILES) { 142 DUMP_CLASS_FILES_COUNTERS = new HashMap<>(); 143 try { 144 File dumpDir = new File("DUMP_CLASS_FILES"); 145 if (!dumpDir.exists()) { 146 dumpDir.mkdirs(); 147 } 148 DUMP_CLASS_FILES_DIR = dumpDir; 149 System.out.println("Dumping class files to "+DUMP_CLASS_FILES_DIR+"/..."); 150 } catch (Exception e) { 151 throw newInternalError(e); 152 } 153 } else { 154 DUMP_CLASS_FILES_COUNTERS = null; 155 DUMP_CLASS_FILES_DIR = null; 156 } 157 } 158 159 static void maybeDump(final String className, final byte[] classFile) { 160 if (DUMP_CLASS_FILES) { 161 java.security.AccessController.doPrivileged( 162 new java.security.PrivilegedAction<>() { 163 public Void run() { 164 try { 165 String dumpName = className; 166 //dumpName = dumpName.replace('/', '-'); 167 File dumpFile = new File(DUMP_CLASS_FILES_DIR, dumpName+".class"); 168 System.out.println("dump: " + dumpFile); 169 dumpFile.getParentFile().mkdirs(); 170 FileOutputStream file = new FileOutputStream(dumpFile); 171 file.write(classFile); 172 file.close(); 173 return null; 174 } catch (IOException ex) { 175 throw newInternalError(ex); 176 } 177 } 178 }); 179 } 180 181 } 182 183 private static String makeDumpableClassName(String className) { 184 Integer ctr; 185 synchronized (DUMP_CLASS_FILES_COUNTERS) { 186 ctr = DUMP_CLASS_FILES_COUNTERS.get(className); 187 if (ctr == null) ctr = 0; 188 DUMP_CLASS_FILES_COUNTERS.put(className, ctr+1); 189 } 190 String sfx = ctr.toString(); 191 while (sfx.length() < 3) 192 sfx = "0"+sfx; 193 className += sfx; 194 return className; 195 } 196 197 class CpPatch { 198 final int index; 199 final String placeholder; 200 final Object value; 201 CpPatch(int index, String placeholder, Object value) { 202 this.index = index; 203 this.placeholder = placeholder; 204 this.value = value; 205 } 206 public String toString() { 207 return "CpPatch/index="+index+",placeholder="+placeholder+",value="+value; 208 } 209 } 210 211 Map<Object, CpPatch> cpPatches = new HashMap<>(); 212 213 int cph = 0; // for counting constant placeholders 214 215 String constantPlaceholder(Object arg) { 216 String cpPlaceholder = "CONSTANT_PLACEHOLDER_" + cph++; 217 if (DUMP_CLASS_FILES) cpPlaceholder += " <<" + debugString(arg) + ">>"; // debugging aid 218 if (cpPatches.containsKey(cpPlaceholder)) { 219 throw new InternalError("observed CP placeholder twice: " + cpPlaceholder); 220 } 221 // insert placeholder in CP and remember the patch 222 int index = cw.newConst((Object) cpPlaceholder); // TODO check if already in the constant pool 223 cpPatches.put(cpPlaceholder, new CpPatch(index, cpPlaceholder, arg)); 224 return cpPlaceholder; 225 } 226 227 Object[] cpPatches(byte[] classFile) { 228 int size = getConstantPoolSize(classFile); 229 Object[] res = new Object[size]; 230 for (CpPatch p : cpPatches.values()) { 231 if (p.index >= size) 232 throw new InternalError("in cpool["+size+"]: "+p+"\n"+Arrays.toString(Arrays.copyOf(classFile, 20))); 233 res[p.index] = p.value; 234 } 235 return res; 236 } 237 238 private static String debugString(Object arg) { 239 if (arg instanceof MethodHandle) { 240 MethodHandle mh = (MethodHandle) arg; 241 MemberName member = mh.internalMemberName(); 242 if (member != null) 243 return member.toString(); 244 return mh.debugString(); 245 } 246 return arg.toString(); 247 } 248 249 /** 250 * Extract the number of constant pool entries from a given class file. 251 * 252 * @param classFile the bytes of the class file in question. 253 * @return the number of entries in the constant pool. 254 */ 255 private static int getConstantPoolSize(byte[] classFile) { 256 // The first few bytes: 257 // u4 magic; 258 // u2 minor_version; 259 // u2 major_version; 260 // u2 constant_pool_count; 261 return ((classFile[8] & 0xFF) << 8) | (classFile[9] & 0xFF); 262 } 263 264 /** 265 * Extract the MemberName of a newly-defined method. 266 */ 267 private MemberName loadMethod(byte[] classFile) { 268 Class<?> invokerClass = loadAndInitializeInvokerClass(classFile, cpPatches(classFile)); 269 return resolveInvokerMember(invokerClass, invokerName, invokerType); 270 } 271 272 /** 273 * Define a given class as anonymous class in the runtime system. 274 */ 275 private static Class<?> loadAndInitializeInvokerClass(byte[] classBytes, Object[] patches) { 276 Class<?> invokerClass = UNSAFE.defineAnonymousClass(HOST_CLASS, classBytes, patches); 277 UNSAFE.ensureClassInitialized(invokerClass); // Make sure the class is initialized; VM might complain. 278 return invokerClass; 279 } 280 281 private static MemberName resolveInvokerMember(Class<?> invokerClass, String name, MethodType type) { 282 MemberName member = new MemberName(invokerClass, name, type, REF_invokeStatic); 283 //System.out.println("resolveInvokerMember => "+member); 284 //for (Method m : invokerClass.getDeclaredMethods()) System.out.println(" "+m); 285 try { 286 member = MEMBERNAME_FACTORY.resolveOrFail(REF_invokeStatic, member, HOST_CLASS, ReflectiveOperationException.class); 287 } catch (ReflectiveOperationException e) { 288 throw newInternalError(e); 289 } 290 //System.out.println("resolveInvokerMember => "+member); 291 return member; 292 } 293 294 /** 295 * Set up class file generation. 296 */ 297 private void classFilePrologue() { 298 final int NOT_ACC_PUBLIC = 0; // not ACC_PUBLIC 299 cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES); 300 cw.visit(Opcodes.V1_8, NOT_ACC_PUBLIC + Opcodes.ACC_FINAL + Opcodes.ACC_SUPER, className, null, superName, null); 301 cw.visitSource(sourceFile, null); 302 303 String invokerDesc = invokerType.toMethodDescriptorString(); 304 mv = cw.visitMethod(Opcodes.ACC_STATIC, invokerName, invokerDesc, null, null); 305 } 306 307 /** 308 * Tear down class file generation. 309 */ 310 private void classFileEpilogue() { 311 mv.visitMaxs(0, 0); 312 mv.visitEnd(); 313 } 314 315 /* 316 * Low-level emit helpers. 317 */ 318 private void emitConst(Object con) { 319 if (con == null) { 320 mv.visitInsn(Opcodes.ACONST_NULL); 321 return; 322 } 323 if (con instanceof Integer) { 324 emitIconstInsn((int) con); 325 return; 326 } 327 if (con instanceof Byte) { 328 emitIconstInsn((byte)con); 329 return; 330 } 331 if (con instanceof Short) { 332 emitIconstInsn((short)con); 333 return; 334 } 335 if (con instanceof Character) { 336 emitIconstInsn((char)con); 337 return; 338 } 339 if (con instanceof Long) { 340 long x = (long) con; 341 short sx = (short)x; 342 if (x == sx) { 343 if (sx >= 0 && sx <= 1) { 344 mv.visitInsn(Opcodes.LCONST_0 + (int) sx); 345 } else { 346 emitIconstInsn((int) x); 347 mv.visitInsn(Opcodes.I2L); 348 } 349 return; 350 } 351 } 352 if (con instanceof Float) { 353 float x = (float) con; 354 short sx = (short)x; 355 if (x == sx) { 356 if (sx >= 0 && sx <= 2) { 357 mv.visitInsn(Opcodes.FCONST_0 + (int) sx); 358 } else { 359 emitIconstInsn((int) x); 360 mv.visitInsn(Opcodes.I2F); 361 } 362 return; 363 } 364 } 365 if (con instanceof Double) { 366 double x = (double) con; 367 short sx = (short)x; 368 if (x == sx) { 369 if (sx >= 0 && sx <= 1) { 370 mv.visitInsn(Opcodes.DCONST_0 + (int) sx); 371 } else { 372 emitIconstInsn((int) x); 373 mv.visitInsn(Opcodes.I2D); 374 } 375 return; 376 } 377 } 378 if (con instanceof Boolean) { 379 emitIconstInsn((boolean) con ? 1 : 0); 380 return; 381 } 382 // fall through: 383 mv.visitLdcInsn(con); 384 } 385 386 private void emitIconstInsn(final int cst) { 387 if (cst >= -1 && cst <= 5) { 388 mv.visitInsn(Opcodes.ICONST_0 + cst); 389 } else if (cst >= Byte.MIN_VALUE && cst <= Byte.MAX_VALUE) { 390 mv.visitIntInsn(Opcodes.BIPUSH, cst); 391 } else if (cst >= Short.MIN_VALUE && cst <= Short.MAX_VALUE) { 392 mv.visitIntInsn(Opcodes.SIPUSH, cst); 393 } else { 394 mv.visitLdcInsn(cst); 395 } 396 } 397 398 /* 399 * NOTE: These load/store methods use the localsMap to find the correct index! 400 */ 401 private void emitLoadInsn(BasicType type, int index) { 402 int opcode = loadInsnOpcode(type); 403 mv.visitVarInsn(opcode, localsMap[index]); 404 } 405 406 private int loadInsnOpcode(BasicType type) throws InternalError { 407 switch (type) { 408 case I_TYPE: return Opcodes.ILOAD; 409 case J_TYPE: return Opcodes.LLOAD; 410 case F_TYPE: return Opcodes.FLOAD; 411 case D_TYPE: return Opcodes.DLOAD; 412 case L_TYPE: return Opcodes.ALOAD; 413 default: 414 throw new InternalError("unknown type: " + type); 415 } 416 } 417 private void emitAloadInsn(int index) { 418 emitLoadInsn(L_TYPE, index); 419 } 420 421 private void emitStoreInsn(BasicType type, int index) { 422 int opcode = storeInsnOpcode(type); 423 mv.visitVarInsn(opcode, localsMap[index]); 424 } 425 426 private int storeInsnOpcode(BasicType type) throws InternalError { 427 switch (type) { 428 case I_TYPE: return Opcodes.ISTORE; 429 case J_TYPE: return Opcodes.LSTORE; 430 case F_TYPE: return Opcodes.FSTORE; 431 case D_TYPE: return Opcodes.DSTORE; 432 case L_TYPE: return Opcodes.ASTORE; 433 default: 434 throw new InternalError("unknown type: " + type); 435 } 436 } 437 private void emitAstoreInsn(int index) { 438 emitStoreInsn(L_TYPE, index); 439 } 440 441 private byte arrayTypeCode(Wrapper elementType) { 442 switch (elementType) { 443 case BOOLEAN: return Opcodes.T_BOOLEAN; 444 case BYTE: return Opcodes.T_BYTE; 445 case CHAR: return Opcodes.T_CHAR; 446 case SHORT: return Opcodes.T_SHORT; 447 case INT: return Opcodes.T_INT; 448 case LONG: return Opcodes.T_LONG; 449 case FLOAT: return Opcodes.T_FLOAT; 450 case DOUBLE: return Opcodes.T_DOUBLE; 451 case OBJECT: return 0; // in place of Opcodes.T_OBJECT 452 default: throw new InternalError(); 453 } 454 } 455 456 private int arrayInsnOpcode(byte tcode, int aaop) throws InternalError { 457 assert(aaop == Opcodes.AASTORE || aaop == Opcodes.AALOAD); 458 int xas; 459 switch (tcode) { 460 case Opcodes.T_BOOLEAN: xas = Opcodes.BASTORE; break; 461 case Opcodes.T_BYTE: xas = Opcodes.BASTORE; break; 462 case Opcodes.T_CHAR: xas = Opcodes.CASTORE; break; 463 case Opcodes.T_SHORT: xas = Opcodes.SASTORE; break; 464 case Opcodes.T_INT: xas = Opcodes.IASTORE; break; 465 case Opcodes.T_LONG: xas = Opcodes.LASTORE; break; 466 case Opcodes.T_FLOAT: xas = Opcodes.FASTORE; break; 467 case Opcodes.T_DOUBLE: xas = Opcodes.DASTORE; break; 468 case 0: xas = Opcodes.AASTORE; break; 469 default: throw new InternalError(); 470 } 471 return xas - Opcodes.AASTORE + aaop; 472 } 473 474 /** 475 * Emit a boxing call. 476 * 477 * @param wrapper primitive type class to box. 478 */ 479 private void emitBoxing(Wrapper wrapper) { 480 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName(); 481 String name = "valueOf"; 482 String desc = "(" + wrapper.basicTypeChar() + ")L" + owner + ";"; 483 mv.visitMethodInsn(Opcodes.INVOKESTATIC, owner, name, desc, false); 484 } 485 486 /** 487 * Emit an unboxing call (plus preceding checkcast). 488 * 489 * @param wrapper wrapper type class to unbox. 490 */ 491 private void emitUnboxing(Wrapper wrapper) { 492 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName(); 493 String name = wrapper.primitiveSimpleName() + "Value"; 494 String desc = "()" + wrapper.basicTypeChar(); 495 emitReferenceCast(wrapper.wrapperType(), null); 496 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, owner, name, desc, false); 497 } 498 499 /** 500 * Emit an implicit conversion for an argument which must be of the given pclass. 501 * This is usually a no-op, except when pclass is a subword type or a reference other than Object or an interface. 502 * 503 * @param ptype type of value present on stack 504 * @param pclass type of value required on stack 505 * @param arg compile-time representation of value on stack (Node, constant) or null if none 506 */ 507 private void emitImplicitConversion(BasicType ptype, Class<?> pclass, Object arg) { 508 assert(basicType(pclass) == ptype); // boxing/unboxing handled by caller 509 if (pclass == ptype.basicTypeClass() && ptype != L_TYPE) 510 return; // nothing to do 511 switch (ptype) { 512 case L_TYPE: 513 if (VerifyType.isNullConversion(Object.class, pclass, false)) { 514 if (PROFILE_LEVEL > 0) 515 emitReferenceCast(Object.class, arg); 516 return; 517 } 518 emitReferenceCast(pclass, arg); 519 return; 520 case I_TYPE: 521 if (!VerifyType.isNullConversion(int.class, pclass, false)) 522 emitPrimCast(ptype.basicTypeWrapper(), Wrapper.forPrimitiveType(pclass)); 523 return; 524 } 525 throw newInternalError("bad implicit conversion: tc="+ptype+": "+pclass); 526 } 527 528 /** Update localClasses type map. Return true if the information is already present. */ 529 private boolean assertStaticType(Class<?> cls, Name n) { 530 int local = n.index(); 531 Class<?> aclass = localClasses[local]; 532 if (aclass != null && (aclass == cls || cls.isAssignableFrom(aclass))) { 533 return true; // type info is already present 534 } else if (aclass == null || aclass.isAssignableFrom(cls)) { 535 localClasses[local] = cls; // type info can be improved 536 } 537 return false; 538 } 539 540 private void emitReferenceCast(Class<?> cls, Object arg) { 541 Name writeBack = null; // local to write back result 542 if (arg instanceof Name) { 543 Name n = (Name) arg; 544 if (assertStaticType(cls, n)) 545 return; // this cast was already performed 546 if (lambdaForm.useCount(n) > 1) { 547 // This guy gets used more than once. 548 writeBack = n; 549 } 550 } 551 if (isStaticallyNameable(cls)) { 552 String sig = getInternalName(cls); 553 mv.visitTypeInsn(Opcodes.CHECKCAST, sig); 554 } else { 555 mv.visitLdcInsn(constantPlaceholder(cls)); 556 mv.visitTypeInsn(Opcodes.CHECKCAST, CLS); 557 mv.visitInsn(Opcodes.SWAP); 558 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, CLS, "cast", LL_SIG, false); 559 if (Object[].class.isAssignableFrom(cls)) 560 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJARY); 561 else if (PROFILE_LEVEL > 0) 562 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJ); 563 } 564 if (writeBack != null) { 565 mv.visitInsn(Opcodes.DUP); 566 emitAstoreInsn(writeBack.index()); 567 } 568 } 569 570 /** 571 * Emits an actual return instruction conforming to the given return type. 572 */ 573 private void emitReturnInsn(BasicType type) { 574 int opcode; 575 switch (type) { 576 case I_TYPE: opcode = Opcodes.IRETURN; break; 577 case J_TYPE: opcode = Opcodes.LRETURN; break; 578 case F_TYPE: opcode = Opcodes.FRETURN; break; 579 case D_TYPE: opcode = Opcodes.DRETURN; break; 580 case L_TYPE: opcode = Opcodes.ARETURN; break; 581 case V_TYPE: opcode = Opcodes.RETURN; break; 582 default: 583 throw new InternalError("unknown return type: " + type); 584 } 585 mv.visitInsn(opcode); 586 } 587 588 private static String getInternalName(Class<?> c) { 589 if (c == Object.class) return OBJ; 590 else if (c == Object[].class) return OBJARY; 591 else if (c == Class.class) return CLS; 592 else if (c == MethodHandle.class) return MH; 593 assert(VerifyAccess.isTypeVisible(c, Object.class)) : c.getName(); 594 return c.getName().replace('.', '/'); 595 } 596 597 /** 598 * Generate customized bytecode for a given LambdaForm. 599 */ 600 static MemberName generateCustomizedCode(LambdaForm form, MethodType invokerType) { 601 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("MH", form, invokerType); 602 return g.loadMethod(g.generateCustomizedCodeBytes()); 603 } 604 605 /** Generates code to check that actual receiver and LambdaForm matches */ 606 private boolean checkActualReceiver() { 607 // Expects MethodHandle on the stack and actual receiver MethodHandle in slot #0 608 mv.visitInsn(Opcodes.DUP); 609 mv.visitVarInsn(Opcodes.ALOAD, localsMap[0]); 610 mv.visitMethodInsn(Opcodes.INVOKESTATIC, MHI, "assertSame", LLV_SIG, false); 611 return true; 612 } 613 614 static String className(String cn) { 615 assert checkClassName(cn): "Class not found: " + cn; 616 return cn; 617 } 618 619 static boolean checkClassName(String cn) { 620 Type tp = Type.getType(cn); 621 // additional sanity so only valid "L;" descriptors work 622 if (tp.getSort() != Type.OBJECT) { 623 return false; 624 } 625 try { 626 Class<?> c = Class.forName(tp.getClassName(), false, null); 627 return true; 628 } catch (ClassNotFoundException e) { 629 return false; 630 } 631 } 632 633 static final String LF_HIDDEN_SIG = className("Ljava/lang/invoke/LambdaForm$Hidden;"); 634 static final String LF_COMPILED_SIG = className("Ljava/lang/invoke/LambdaForm$Compiled;"); 635 static final String FORCEINLINE_SIG = className("Ljdk/internal/vm/annotation/ForceInline;"); 636 static final String DONTINLINE_SIG = className("Ljdk/internal/vm/annotation/DontInline;"); 637 static final String INJECTEDPROFILE_SIG = className("Ljava/lang/invoke/InjectedProfile;"); 638 639 /** 640 * Generate an invoker method for the passed {@link LambdaForm}. 641 */ 642 private byte[] generateCustomizedCodeBytes() { 643 classFilePrologue(); 644 645 // Suppress this method in backtraces displayed to the user. 646 mv.visitAnnotation(LF_HIDDEN_SIG, true); 647 648 // Mark this method as a compiled LambdaForm 649 mv.visitAnnotation(LF_COMPILED_SIG, true); 650 651 if (lambdaForm.forceInline) { 652 // Force inlining of this invoker method. 653 mv.visitAnnotation(FORCEINLINE_SIG, true); 654 } else { 655 mv.visitAnnotation(DONTINLINE_SIG, true); 656 } 657 658 if (lambdaForm.customized != null) { 659 // Since LambdaForm is customized for a particular MethodHandle, it's safe to substitute 660 // receiver MethodHandle (at slot #0) with an embedded constant and use it instead. 661 // It enables more efficient code generation in some situations, since embedded constants 662 // are compile-time constants for JIT compiler. 663 mv.visitLdcInsn(constantPlaceholder(lambdaForm.customized)); 664 mv.visitTypeInsn(Opcodes.CHECKCAST, MH); 665 assert(checkActualReceiver()); // expects MethodHandle on top of the stack 666 mv.visitVarInsn(Opcodes.ASTORE, localsMap[0]); 667 } 668 669 // iterate over the form's names, generating bytecode instructions for each 670 // start iterating at the first name following the arguments 671 Name onStack = null; 672 for (int i = lambdaForm.arity; i < lambdaForm.names.length; i++) { 673 Name name = lambdaForm.names[i]; 674 675 emitStoreResult(onStack); 676 onStack = name; // unless otherwise modified below 677 MethodHandleImpl.Intrinsic intr = name.function.intrinsicName(); 678 switch (intr) { 679 case SELECT_ALTERNATIVE: 680 assert isSelectAlternative(i); 681 if (PROFILE_GWT) { 682 assert(name.arguments[0] instanceof Name && 683 nameRefersTo((Name)name.arguments[0], MethodHandleImpl.class, "profileBoolean")); 684 mv.visitAnnotation(INJECTEDPROFILE_SIG, true); 685 } 686 onStack = emitSelectAlternative(name, lambdaForm.names[i+1]); 687 i++; // skip MH.invokeBasic of the selectAlternative result 688 continue; 689 case GUARD_WITH_CATCH: 690 assert isGuardWithCatch(i); 691 onStack = emitGuardWithCatch(i); 692 i = i+2; // Jump to the end of GWC idiom 693 continue; 694 case NEW_ARRAY: 695 Class<?> rtype = name.function.methodType().returnType(); 696 if (isStaticallyNameable(rtype)) { 697 emitNewArray(name); 698 continue; 699 } 700 break; 701 case ARRAY_LOAD: 702 emitArrayLoad(name); 703 continue; 704 case ARRAY_STORE: 705 emitArrayStore(name); 706 continue; 707 case IDENTITY: 708 assert(name.arguments.length == 1); 709 emitPushArguments(name); 710 continue; 711 case ZERO: 712 assert(name.arguments.length == 0); 713 emitConst(name.type.basicTypeWrapper().zero()); 714 continue; 715 case NONE: 716 // no intrinsic associated 717 break; 718 default: 719 throw newInternalError("Unknown intrinsic: "+intr); 720 } 721 722 MemberName member = name.function.member(); 723 if (isStaticallyInvocable(member)) { 724 emitStaticInvoke(member, name); 725 } else { 726 emitInvoke(name); 727 } 728 } 729 730 // return statement 731 emitReturn(onStack); 732 733 classFileEpilogue(); 734 bogusMethod(lambdaForm); 735 736 final byte[] classFile = cw.toByteArray(); 737 maybeDump(className, classFile); 738 return classFile; 739 } 740 741 void emitArrayLoad(Name name) { emitArrayOp(name, Opcodes.AALOAD); } 742 void emitArrayStore(Name name) { emitArrayOp(name, Opcodes.AASTORE); } 743 744 void emitArrayOp(Name name, int arrayOpcode) { 745 assert arrayOpcode == Opcodes.AALOAD || arrayOpcode == Opcodes.AASTORE; 746 Class<?> elementType = name.function.methodType().parameterType(0).getComponentType(); 747 assert elementType != null; 748 emitPushArguments(name); 749 if (elementType.isPrimitive()) { 750 Wrapper w = Wrapper.forPrimitiveType(elementType); 751 arrayOpcode = arrayInsnOpcode(arrayTypeCode(w), arrayOpcode); 752 } 753 mv.visitInsn(arrayOpcode); 754 } 755 756 /** 757 * Emit an invoke for the given name. 758 */ 759 void emitInvoke(Name name) { 760 assert(!isLinkerMethodInvoke(name)); // should use the static path for these 761 if (true) { 762 // push receiver 763 MethodHandle target = name.function.resolvedHandle(); 764 assert(target != null) : name.exprString(); 765 mv.visitLdcInsn(constantPlaceholder(target)); 766 emitReferenceCast(MethodHandle.class, target); 767 } else { 768 // load receiver 769 emitAloadInsn(0); 770 emitReferenceCast(MethodHandle.class, null); 771 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", LF_SIG); 772 mv.visitFieldInsn(Opcodes.GETFIELD, LF, "names", LFN_SIG); 773 // TODO more to come 774 } 775 776 // push arguments 777 emitPushArguments(name); 778 779 // invocation 780 MethodType type = name.function.methodType(); 781 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false); 782 } 783 784 private static Class<?>[] STATICALLY_INVOCABLE_PACKAGES = { 785 // Sample classes from each package we are willing to bind to statically: 786 java.lang.Object.class, 787 java.util.Arrays.class, 788 jdk.internal.misc.Unsafe.class 789 //MethodHandle.class already covered 790 }; 791 792 static boolean isStaticallyInvocable(NamedFunction[] functions) { 793 for (NamedFunction nf : functions) { 794 if (!isStaticallyInvocable(nf.member())) { 795 return false; 796 } 797 } 798 return true; 799 } 800 801 static boolean isStaticallyInvocable(Name name) { 802 return isStaticallyInvocable(name.function.member()); 803 } 804 805 static boolean isStaticallyInvocable(MemberName member) { 806 if (member == null) return false; 807 if (member.isConstructor()) return false; 808 Class<?> cls = member.getDeclaringClass(); 809 if (cls.isArray() || cls.isPrimitive()) 810 return false; // FIXME 811 if (cls.isAnonymousClass() || cls.isLocalClass()) 812 return false; // inner class of some sort 813 if (cls.getClassLoader() != MethodHandle.class.getClassLoader()) 814 return false; // not on BCP 815 if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: switch to supported API once it is added 816 return false; 817 MethodType mtype = member.getMethodOrFieldType(); 818 if (!isStaticallyNameable(mtype.returnType())) 819 return false; 820 for (Class<?> ptype : mtype.parameterArray()) 821 if (!isStaticallyNameable(ptype)) 822 return false; 823 if (!member.isPrivate() && VerifyAccess.isSamePackage(MethodHandle.class, cls)) 824 return true; // in java.lang.invoke package 825 if (member.isPublic() && isStaticallyNameable(cls)) 826 return true; 827 return false; 828 } 829 830 static boolean isStaticallyNameable(Class<?> cls) { 831 if (cls == Object.class) 832 return true; 833 while (cls.isArray()) 834 cls = cls.getComponentType(); 835 if (cls.isPrimitive()) 836 return true; // int[].class, for example 837 if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: switch to supported API once it is added 838 return false; 839 // could use VerifyAccess.isClassAccessible but the following is a safe approximation 840 if (cls.getClassLoader() != Object.class.getClassLoader()) 841 return false; 842 if (VerifyAccess.isSamePackage(MethodHandle.class, cls)) 843 return true; 844 if (!Modifier.isPublic(cls.getModifiers())) 845 return false; 846 for (Class<?> pkgcls : STATICALLY_INVOCABLE_PACKAGES) { 847 if (VerifyAccess.isSamePackage(pkgcls, cls)) 848 return true; 849 } 850 return false; 851 } 852 853 void emitStaticInvoke(Name name) { 854 emitStaticInvoke(name.function.member(), name); 855 } 856 857 /** 858 * Emit an invoke for the given name, using the MemberName directly. 859 */ 860 void emitStaticInvoke(MemberName member, Name name) { 861 assert(member.equals(name.function.member())); 862 Class<?> defc = member.getDeclaringClass(); 863 String cname = getInternalName(defc); 864 String mname = member.getName(); 865 String mtype; 866 byte refKind = member.getReferenceKind(); 867 if (refKind == REF_invokeSpecial) { 868 // in order to pass the verifier, we need to convert this to invokevirtual in all cases 869 assert(member.canBeStaticallyBound()) : member; 870 refKind = REF_invokeVirtual; 871 } 872 873 assert(!(member.getDeclaringClass().isInterface() && refKind == REF_invokeVirtual)); 874 875 // push arguments 876 emitPushArguments(name); 877 878 // invocation 879 if (member.isMethod()) { 880 mtype = member.getMethodType().toMethodDescriptorString(); 881 mv.visitMethodInsn(refKindOpcode(refKind), cname, mname, mtype, 882 member.getDeclaringClass().isInterface()); 883 } else { 884 mtype = MethodType.toFieldDescriptorString(member.getFieldType()); 885 mv.visitFieldInsn(refKindOpcode(refKind), cname, mname, mtype); 886 } 887 // Issue a type assertion for the result, so we can avoid casts later. 888 if (name.type == L_TYPE) { 889 Class<?> rtype = member.getInvocationType().returnType(); 890 assert(!rtype.isPrimitive()); 891 if (rtype != Object.class && !rtype.isInterface()) { 892 assertStaticType(rtype, name); 893 } 894 } 895 } 896 897 void emitNewArray(Name name) throws InternalError { 898 Class<?> rtype = name.function.methodType().returnType(); 899 if (name.arguments.length == 0) { 900 // The array will be a constant. 901 Object emptyArray; 902 try { 903 emptyArray = name.function.resolvedHandle().invoke(); 904 } catch (Throwable ex) { 905 throw newInternalError(ex); 906 } 907 assert(java.lang.reflect.Array.getLength(emptyArray) == 0); 908 assert(emptyArray.getClass() == rtype); // exact typing 909 mv.visitLdcInsn(constantPlaceholder(emptyArray)); 910 emitReferenceCast(rtype, emptyArray); 911 return; 912 } 913 Class<?> arrayElementType = rtype.getComponentType(); 914 assert(arrayElementType != null); 915 emitIconstInsn(name.arguments.length); 916 int xas = Opcodes.AASTORE; 917 if (!arrayElementType.isPrimitive()) { 918 mv.visitTypeInsn(Opcodes.ANEWARRAY, getInternalName(arrayElementType)); 919 } else { 920 byte tc = arrayTypeCode(Wrapper.forPrimitiveType(arrayElementType)); 921 xas = arrayInsnOpcode(tc, xas); 922 mv.visitIntInsn(Opcodes.NEWARRAY, tc); 923 } 924 // store arguments 925 for (int i = 0; i < name.arguments.length; i++) { 926 mv.visitInsn(Opcodes.DUP); 927 emitIconstInsn(i); 928 emitPushArgument(name, i); 929 mv.visitInsn(xas); 930 } 931 // the array is left on the stack 932 assertStaticType(rtype, name); 933 } 934 int refKindOpcode(byte refKind) { 935 switch (refKind) { 936 case REF_invokeVirtual: return Opcodes.INVOKEVIRTUAL; 937 case REF_invokeStatic: return Opcodes.INVOKESTATIC; 938 case REF_invokeSpecial: return Opcodes.INVOKESPECIAL; 939 case REF_invokeInterface: return Opcodes.INVOKEINTERFACE; 940 case REF_getField: return Opcodes.GETFIELD; 941 case REF_putField: return Opcodes.PUTFIELD; 942 case REF_getStatic: return Opcodes.GETSTATIC; 943 case REF_putStatic: return Opcodes.PUTSTATIC; 944 } 945 throw new InternalError("refKind="+refKind); 946 } 947 948 /** 949 * Check if MemberName is a call to a method named {@code name} in class {@code declaredClass}. 950 */ 951 private boolean memberRefersTo(MemberName member, Class<?> declaringClass, String name) { 952 return member != null && 953 member.getDeclaringClass() == declaringClass && 954 member.getName().equals(name); 955 } 956 private boolean nameRefersTo(Name name, Class<?> declaringClass, String methodName) { 957 return name.function != null && 958 memberRefersTo(name.function.member(), declaringClass, methodName); 959 } 960 961 /** 962 * Check if MemberName is a call to MethodHandle.invokeBasic. 963 */ 964 private boolean isInvokeBasic(Name name) { 965 if (name.function == null) 966 return false; 967 if (name.arguments.length < 1) 968 return false; // must have MH argument 969 MemberName member = name.function.member(); 970 return memberRefersTo(member, MethodHandle.class, "invokeBasic") && 971 !member.isPublic() && !member.isStatic(); 972 } 973 974 /** 975 * Check if MemberName is a call to MethodHandle.linkToStatic, etc. 976 */ 977 private boolean isLinkerMethodInvoke(Name name) { 978 if (name.function == null) 979 return false; 980 if (name.arguments.length < 1) 981 return false; // must have MH argument 982 MemberName member = name.function.member(); 983 return member != null && 984 member.getDeclaringClass() == MethodHandle.class && 985 !member.isPublic() && member.isStatic() && 986 member.getName().startsWith("linkTo"); 987 } 988 989 /** 990 * Check if i-th name is a call to MethodHandleImpl.selectAlternative. 991 */ 992 private boolean isSelectAlternative(int pos) { 993 // selectAlternative idiom: 994 // t_{n}:L=MethodHandleImpl.selectAlternative(...) 995 // t_{n+1}:?=MethodHandle.invokeBasic(t_{n}, ...) 996 if (pos+1 >= lambdaForm.names.length) return false; 997 Name name0 = lambdaForm.names[pos]; 998 Name name1 = lambdaForm.names[pos+1]; 999 return nameRefersTo(name0, MethodHandleImpl.class, "selectAlternative") && 1000 isInvokeBasic(name1) && 1001 name1.lastUseIndex(name0) == 0 && // t_{n+1}:?=MethodHandle.invokeBasic(t_{n}, ...) 1002 lambdaForm.lastUseIndex(name0) == pos+1; // t_{n} is local: used only in t_{n+1} 1003 } 1004 1005 /** 1006 * Check if i-th name is a start of GuardWithCatch idiom. 1007 */ 1008 private boolean isGuardWithCatch(int pos) { 1009 // GuardWithCatch idiom: 1010 // t_{n}:L=MethodHandle.invokeBasic(...) 1011 // t_{n+1}:L=MethodHandleImpl.guardWithCatch(*, *, *, t_{n}); 1012 // t_{n+2}:?=MethodHandle.invokeBasic(t_{n+1}) 1013 if (pos+2 >= lambdaForm.names.length) return false; 1014 Name name0 = lambdaForm.names[pos]; 1015 Name name1 = lambdaForm.names[pos+1]; 1016 Name name2 = lambdaForm.names[pos+2]; 1017 return nameRefersTo(name1, MethodHandleImpl.class, "guardWithCatch") && 1018 isInvokeBasic(name0) && 1019 isInvokeBasic(name2) && 1020 name1.lastUseIndex(name0) == 3 && // t_{n+1}:L=MethodHandleImpl.guardWithCatch(*, *, *, t_{n}); 1021 lambdaForm.lastUseIndex(name0) == pos+1 && // t_{n} is local: used only in t_{n+1} 1022 name2.lastUseIndex(name1) == 1 && // t_{n+2}:?=MethodHandle.invokeBasic(t_{n+1}) 1023 lambdaForm.lastUseIndex(name1) == pos+2; // t_{n+1} is local: used only in t_{n+2} 1024 } 1025 1026 /** 1027 * Emit bytecode for the selectAlternative idiom. 1028 * 1029 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithTest): 1030 * <blockquote><pre>{@code 1031 * Lambda(a0:L,a1:I)=>{ 1032 * t2:I=foo.test(a1:I); 1033 * t3:L=MethodHandleImpl.selectAlternative(t2:I,(MethodHandle(int)int),(MethodHandle(int)int)); 1034 * t4:I=MethodHandle.invokeBasic(t3:L,a1:I);t4:I} 1035 * }</pre></blockquote> 1036 */ 1037 private Name emitSelectAlternative(Name selectAlternativeName, Name invokeBasicName) { 1038 assert isStaticallyInvocable(invokeBasicName); 1039 1040 Name receiver = (Name) invokeBasicName.arguments[0]; 1041 1042 Label L_fallback = new Label(); 1043 Label L_done = new Label(); 1044 1045 // load test result 1046 emitPushArgument(selectAlternativeName, 0); 1047 1048 // if_icmpne L_fallback 1049 mv.visitJumpInsn(Opcodes.IFEQ, L_fallback); 1050 1051 // invoke selectAlternativeName.arguments[1] 1052 Class<?>[] preForkClasses = localClasses.clone(); 1053 emitPushArgument(selectAlternativeName, 1); // get 2nd argument of selectAlternative 1054 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot 1055 emitStaticInvoke(invokeBasicName); 1056 1057 // goto L_done 1058 mv.visitJumpInsn(Opcodes.GOTO, L_done); 1059 1060 // L_fallback: 1061 mv.visitLabel(L_fallback); 1062 1063 // invoke selectAlternativeName.arguments[2] 1064 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length); 1065 emitPushArgument(selectAlternativeName, 2); // get 3rd argument of selectAlternative 1066 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot 1067 emitStaticInvoke(invokeBasicName); 1068 1069 // L_done: 1070 mv.visitLabel(L_done); 1071 // for now do not bother to merge typestate; just reset to the dominator state 1072 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length); 1073 1074 return invokeBasicName; // return what's on stack 1075 } 1076 1077 /** 1078 * Emit bytecode for the guardWithCatch idiom. 1079 * 1080 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithCatch): 1081 * <blockquote><pre>{@code 1082 * guardWithCatch=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L,a5:L,a6:L,a7:L)=>{ 1083 * t8:L=MethodHandle.invokeBasic(a4:L,a6:L,a7:L); 1084 * t9:L=MethodHandleImpl.guardWithCatch(a1:L,a2:L,a3:L,t8:L); 1085 * t10:I=MethodHandle.invokeBasic(a5:L,t9:L);t10:I} 1086 * }</pre></blockquote> 1087 * 1088 * It is compiled into bytecode equivalent of the following code: 1089 * <blockquote><pre>{@code 1090 * try { 1091 * return a1.invokeBasic(a6, a7); 1092 * } catch (Throwable e) { 1093 * if (!a2.isInstance(e)) throw e; 1094 * return a3.invokeBasic(ex, a6, a7); 1095 * }} 1096 */ 1097 private Name emitGuardWithCatch(int pos) { 1098 Name args = lambdaForm.names[pos]; 1099 Name invoker = lambdaForm.names[pos+1]; 1100 Name result = lambdaForm.names[pos+2]; 1101 1102 Label L_startBlock = new Label(); 1103 Label L_endBlock = new Label(); 1104 Label L_handler = new Label(); 1105 Label L_done = new Label(); 1106 1107 Class<?> returnType = result.function.resolvedHandle().type().returnType(); 1108 MethodType type = args.function.resolvedHandle().type() 1109 .dropParameterTypes(0,1) 1110 .changeReturnType(returnType); 1111 1112 mv.visitTryCatchBlock(L_startBlock, L_endBlock, L_handler, "java/lang/Throwable"); 1113 1114 // Normal case 1115 mv.visitLabel(L_startBlock); 1116 // load target 1117 emitPushArgument(invoker, 0); 1118 emitPushArguments(args, 1); // skip 1st argument: method handle 1119 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false); 1120 mv.visitLabel(L_endBlock); 1121 mv.visitJumpInsn(Opcodes.GOTO, L_done); 1122 1123 // Exceptional case 1124 mv.visitLabel(L_handler); 1125 1126 // Check exception's type 1127 mv.visitInsn(Opcodes.DUP); 1128 // load exception class 1129 emitPushArgument(invoker, 1); 1130 mv.visitInsn(Opcodes.SWAP); 1131 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/Class", "isInstance", "(Ljava/lang/Object;)Z", false); 1132 Label L_rethrow = new Label(); 1133 mv.visitJumpInsn(Opcodes.IFEQ, L_rethrow); 1134 1135 // Invoke catcher 1136 // load catcher 1137 emitPushArgument(invoker, 2); 1138 mv.visitInsn(Opcodes.SWAP); 1139 emitPushArguments(args, 1); // skip 1st argument: method handle 1140 MethodType catcherType = type.insertParameterTypes(0, Throwable.class); 1141 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", catcherType.basicType().toMethodDescriptorString(), false); 1142 mv.visitJumpInsn(Opcodes.GOTO, L_done); 1143 1144 mv.visitLabel(L_rethrow); 1145 mv.visitInsn(Opcodes.ATHROW); 1146 1147 mv.visitLabel(L_done); 1148 1149 return result; 1150 } 1151 1152 private void emitPushArguments(Name args) { 1153 emitPushArguments(args, 0); 1154 } 1155 1156 private void emitPushArguments(Name args, int start) { 1157 for (int i = start; i < args.arguments.length; i++) { 1158 emitPushArgument(args, i); 1159 } 1160 } 1161 1162 private void emitPushArgument(Name name, int paramIndex) { 1163 Object arg = name.arguments[paramIndex]; 1164 Class<?> ptype = name.function.methodType().parameterType(paramIndex); 1165 emitPushArgument(ptype, arg); 1166 } 1167 1168 private void emitPushArgument(Class<?> ptype, Object arg) { 1169 BasicType bptype = basicType(ptype); 1170 if (arg instanceof Name) { 1171 Name n = (Name) arg; 1172 emitLoadInsn(n.type, n.index()); 1173 emitImplicitConversion(n.type, ptype, n); 1174 } else if ((arg == null || arg instanceof String) && bptype == L_TYPE) { 1175 emitConst(arg); 1176 } else { 1177 if (Wrapper.isWrapperType(arg.getClass()) && bptype != L_TYPE) { 1178 emitConst(arg); 1179 } else { 1180 mv.visitLdcInsn(constantPlaceholder(arg)); 1181 emitImplicitConversion(L_TYPE, ptype, arg); 1182 } 1183 } 1184 } 1185 1186 /** 1187 * Store the name to its local, if necessary. 1188 */ 1189 private void emitStoreResult(Name name) { 1190 if (name != null && name.type != V_TYPE) { 1191 // non-void: actually assign 1192 emitStoreInsn(name.type, name.index()); 1193 } 1194 } 1195 1196 /** 1197 * Emits a return statement from a LF invoker. If required, the result type is cast to the correct return type. 1198 */ 1199 private void emitReturn(Name onStack) { 1200 // return statement 1201 Class<?> rclass = invokerType.returnType(); 1202 BasicType rtype = lambdaForm.returnType(); 1203 assert(rtype == basicType(rclass)); // must agree 1204 if (rtype == V_TYPE) { 1205 // void 1206 mv.visitInsn(Opcodes.RETURN); 1207 // it doesn't matter what rclass is; the JVM will discard any value 1208 } else { 1209 LambdaForm.Name rn = lambdaForm.names[lambdaForm.result]; 1210 1211 // put return value on the stack if it is not already there 1212 if (rn != onStack) { 1213 emitLoadInsn(rtype, lambdaForm.result); 1214 } 1215 1216 emitImplicitConversion(rtype, rclass, rn); 1217 1218 // generate actual return statement 1219 emitReturnInsn(rtype); 1220 } 1221 } 1222 1223 /** 1224 * Emit a type conversion bytecode casting from "from" to "to". 1225 */ 1226 private void emitPrimCast(Wrapper from, Wrapper to) { 1227 // Here's how. 1228 // - indicates forbidden 1229 // <-> indicates implicit 1230 // to ----> boolean byte short char int long float double 1231 // from boolean <-> - - - - - - - 1232 // byte - <-> i2s i2c <-> i2l i2f i2d 1233 // short - i2b <-> i2c <-> i2l i2f i2d 1234 // char - i2b i2s <-> <-> i2l i2f i2d 1235 // int - i2b i2s i2c <-> i2l i2f i2d 1236 // long - l2i,i2b l2i,i2s l2i,i2c l2i <-> l2f l2d 1237 // float - f2i,i2b f2i,i2s f2i,i2c f2i f2l <-> f2d 1238 // double - d2i,i2b d2i,i2s d2i,i2c d2i d2l d2f <-> 1239 if (from == to) { 1240 // no cast required, should be dead code anyway 1241 return; 1242 } 1243 if (from.isSubwordOrInt()) { 1244 // cast from {byte,short,char,int} to anything 1245 emitI2X(to); 1246 } else { 1247 // cast from {long,float,double} to anything 1248 if (to.isSubwordOrInt()) { 1249 // cast to {byte,short,char,int} 1250 emitX2I(from); 1251 if (to.bitWidth() < 32) { 1252 // targets other than int require another conversion 1253 emitI2X(to); 1254 } 1255 } else { 1256 // cast to {long,float,double} - this is verbose 1257 boolean error = false; 1258 switch (from) { 1259 case LONG: 1260 switch (to) { 1261 case FLOAT: mv.visitInsn(Opcodes.L2F); break; 1262 case DOUBLE: mv.visitInsn(Opcodes.L2D); break; 1263 default: error = true; break; 1264 } 1265 break; 1266 case FLOAT: 1267 switch (to) { 1268 case LONG : mv.visitInsn(Opcodes.F2L); break; 1269 case DOUBLE: mv.visitInsn(Opcodes.F2D); break; 1270 default: error = true; break; 1271 } 1272 break; 1273 case DOUBLE: 1274 switch (to) { 1275 case LONG : mv.visitInsn(Opcodes.D2L); break; 1276 case FLOAT: mv.visitInsn(Opcodes.D2F); break; 1277 default: error = true; break; 1278 } 1279 break; 1280 default: 1281 error = true; 1282 break; 1283 } 1284 if (error) { 1285 throw new IllegalStateException("unhandled prim cast: " + from + "2" + to); 1286 } 1287 } 1288 } 1289 } 1290 1291 private void emitI2X(Wrapper type) { 1292 switch (type) { 1293 case BYTE: mv.visitInsn(Opcodes.I2B); break; 1294 case SHORT: mv.visitInsn(Opcodes.I2S); break; 1295 case CHAR: mv.visitInsn(Opcodes.I2C); break; 1296 case INT: /* naught */ break; 1297 case LONG: mv.visitInsn(Opcodes.I2L); break; 1298 case FLOAT: mv.visitInsn(Opcodes.I2F); break; 1299 case DOUBLE: mv.visitInsn(Opcodes.I2D); break; 1300 case BOOLEAN: 1301 // For compatibility with ValueConversions and explicitCastArguments: 1302 mv.visitInsn(Opcodes.ICONST_1); 1303 mv.visitInsn(Opcodes.IAND); 1304 break; 1305 default: throw new InternalError("unknown type: " + type); 1306 } 1307 } 1308 1309 private void emitX2I(Wrapper type) { 1310 switch (type) { 1311 case LONG: mv.visitInsn(Opcodes.L2I); break; 1312 case FLOAT: mv.visitInsn(Opcodes.F2I); break; 1313 case DOUBLE: mv.visitInsn(Opcodes.D2I); break; 1314 default: throw new InternalError("unknown type: " + type); 1315 } 1316 } 1317 1318 /** 1319 * Generate bytecode for a LambdaForm.vmentry which calls interpretWithArguments. 1320 */ 1321 static MemberName generateLambdaFormInterpreterEntryPoint(MethodType mt) { 1322 assert(isValidSignature(basicTypeSignature(mt))); 1323 String name = "interpret_"+basicTypeChar(mt.returnType()); 1324 MethodType type = mt; // includes leading argument 1325 type = type.changeParameterType(0, MethodHandle.class); 1326 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("LFI", name, type); 1327 return g.loadMethod(g.generateLambdaFormInterpreterEntryPointBytes()); 1328 } 1329 1330 private byte[] generateLambdaFormInterpreterEntryPointBytes() { 1331 classFilePrologue(); 1332 1333 // Suppress this method in backtraces displayed to the user. 1334 mv.visitAnnotation(LF_HIDDEN_SIG, true); 1335 1336 // Don't inline the interpreter entry. 1337 mv.visitAnnotation(DONTINLINE_SIG, true); 1338 1339 // create parameter array 1340 emitIconstInsn(invokerType.parameterCount()); 1341 mv.visitTypeInsn(Opcodes.ANEWARRAY, "java/lang/Object"); 1342 1343 // fill parameter array 1344 for (int i = 0; i < invokerType.parameterCount(); i++) { 1345 Class<?> ptype = invokerType.parameterType(i); 1346 mv.visitInsn(Opcodes.DUP); 1347 emitIconstInsn(i); 1348 emitLoadInsn(basicType(ptype), i); 1349 // box if primitive type 1350 if (ptype.isPrimitive()) { 1351 emitBoxing(Wrapper.forPrimitiveType(ptype)); 1352 } 1353 mv.visitInsn(Opcodes.AASTORE); 1354 } 1355 // invoke 1356 emitAloadInsn(0); 1357 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", "Ljava/lang/invoke/LambdaForm;"); 1358 mv.visitInsn(Opcodes.SWAP); // swap form and array; avoid local variable 1359 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, LF, "interpretWithArguments", "([Ljava/lang/Object;)Ljava/lang/Object;", false); 1360 1361 // maybe unbox 1362 Class<?> rtype = invokerType.returnType(); 1363 if (rtype.isPrimitive() && rtype != void.class) { 1364 emitUnboxing(Wrapper.forPrimitiveType(rtype)); 1365 } 1366 1367 // return statement 1368 emitReturnInsn(basicType(rtype)); 1369 1370 classFileEpilogue(); 1371 bogusMethod(invokerType); 1372 1373 final byte[] classFile = cw.toByteArray(); 1374 maybeDump(className, classFile); 1375 return classFile; 1376 } 1377 1378 /** 1379 * Generate bytecode for a NamedFunction invoker. 1380 */ 1381 static MemberName generateNamedFunctionInvoker(MethodTypeForm typeForm) { 1382 MethodType invokerType = NamedFunction.INVOKER_METHOD_TYPE; 1383 String invokerName = "invoke_" + shortenSignature(basicTypeSignature(typeForm.erasedType())); 1384 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("NFI", invokerName, invokerType); 1385 return g.loadMethod(g.generateNamedFunctionInvokerImpl(typeForm)); 1386 } 1387 1388 private byte[] generateNamedFunctionInvokerImpl(MethodTypeForm typeForm) { 1389 MethodType dstType = typeForm.erasedType(); 1390 classFilePrologue(); 1391 1392 // Suppress this method in backtraces displayed to the user. 1393 mv.visitAnnotation(LF_HIDDEN_SIG, true); 1394 1395 // Force inlining of this invoker method. 1396 mv.visitAnnotation(FORCEINLINE_SIG, true); 1397 1398 // Load receiver 1399 emitAloadInsn(0); 1400 1401 // Load arguments from array 1402 for (int i = 0; i < dstType.parameterCount(); i++) { 1403 emitAloadInsn(1); 1404 emitIconstInsn(i); 1405 mv.visitInsn(Opcodes.AALOAD); 1406 1407 // Maybe unbox 1408 Class<?> dptype = dstType.parameterType(i); 1409 if (dptype.isPrimitive()) { 1410 Class<?> sptype = dstType.basicType().wrap().parameterType(i); 1411 Wrapper dstWrapper = Wrapper.forBasicType(dptype); 1412 Wrapper srcWrapper = dstWrapper.isSubwordOrInt() ? Wrapper.INT : dstWrapper; // narrow subword from int 1413 emitUnboxing(srcWrapper); 1414 emitPrimCast(srcWrapper, dstWrapper); 1415 } 1416 } 1417 1418 // Invoke 1419 String targetDesc = dstType.basicType().toMethodDescriptorString(); 1420 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", targetDesc, false); 1421 1422 // Box primitive types 1423 Class<?> rtype = dstType.returnType(); 1424 if (rtype != void.class && rtype.isPrimitive()) { 1425 Wrapper srcWrapper = Wrapper.forBasicType(rtype); 1426 Wrapper dstWrapper = srcWrapper.isSubwordOrInt() ? Wrapper.INT : srcWrapper; // widen subword to int 1427 // boolean casts not allowed 1428 emitPrimCast(srcWrapper, dstWrapper); 1429 emitBoxing(dstWrapper); 1430 } 1431 1432 // If the return type is void we return a null reference. 1433 if (rtype == void.class) { 1434 mv.visitInsn(Opcodes.ACONST_NULL); 1435 } 1436 emitReturnInsn(L_TYPE); // NOTE: NamedFunction invokers always return a reference value. 1437 1438 classFileEpilogue(); 1439 bogusMethod(dstType); 1440 1441 final byte[] classFile = cw.toByteArray(); 1442 maybeDump(className, classFile); 1443 return classFile; 1444 } 1445 1446 /** 1447 * Emit a bogus method that just loads some string constants. This is to get the constants into the constant pool 1448 * for debugging purposes. 1449 */ 1450 private void bogusMethod(Object... os) { 1451 if (DUMP_CLASS_FILES) { 1452 mv = cw.visitMethod(Opcodes.ACC_STATIC, "dummy", "()V", null, null); 1453 for (Object o : os) { 1454 mv.visitLdcInsn(o.toString()); 1455 mv.visitInsn(Opcodes.POP); 1456 } 1457 mv.visitInsn(Opcodes.RETURN); 1458 mv.visitMaxs(0, 0); 1459 mv.visitEnd(); 1460 } 1461 } 1462 }