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$Name"; 55 private static final String CLS = "java/lang/Class"; 56 private static final String OBJ = "java/lang/Object"; 57 private static final String OBJARY = "[Ljava/lang/Object;"; 58 59 private static final String MH_SIG = "L" + MH + ";"; 60 private static final String LF_SIG = "L" + LF + ";"; 61 private static final String LFN_SIG = "L" + LFN + ";"; 62 private static final String LL_SIG = "(L" + OBJ + ";)L" + OBJ + ";"; 63 private static final String LLV_SIG = "(L" + OBJ + ";L" + OBJ + ";)V"; 64 65 /** Name of its super class*/ 66 private static final String superName = OBJ; 67 68 /** Name of new class */ 69 private final String className; 70 71 /** Name of the source file (for stack trace printing). */ 72 private final String sourceFile; 73 74 private final LambdaForm lambdaForm; 75 private final String invokerName; 76 private final MethodType invokerType; 77 78 /** Info about local variables in compiled lambda form */ 79 private final int[] localsMap; // index 80 private final BasicType[] localTypes; // basic type 81 private final Class<?>[] localClasses; // type 82 83 /** ASM bytecode generation. */ 84 private ClassWriter cw; 85 private MethodVisitor mv; 86 87 private static final MemberName.Factory MEMBERNAME_FACTORY = MemberName.getFactory(); 88 private static final Class<?> HOST_CLASS = LambdaForm.class; 89 90 /** Main constructor; other constructors delegate to this one. */ 91 private InvokerBytecodeGenerator(LambdaForm lambdaForm, int localsMapSize, 92 String className, String invokerName, MethodType invokerType) { 93 if (invokerName.contains(".")) { 94 int p = invokerName.indexOf('.'); 95 className = invokerName.substring(0, p); 96 invokerName = invokerName.substring(p+1); 97 } 98 if (DUMP_CLASS_FILES) { 99 className = makeDumpableClassName(className); 100 } 101 this.className = LF + "$" + className; 102 this.sourceFile = "LambdaForm$" + className; 103 this.lambdaForm = lambdaForm; 104 this.invokerName = invokerName; 105 this.invokerType = invokerType; 106 this.localsMap = new int[localsMapSize+1]; 107 // last entry of localsMap is count of allocated local slots 108 this.localTypes = new BasicType[localsMapSize+1]; 109 this.localClasses = new Class<?>[localsMapSize+1]; 110 } 111 112 /** For generating LambdaForm interpreter entry points. */ 113 private InvokerBytecodeGenerator(String className, String invokerName, MethodType invokerType) { 114 this(null, invokerType.parameterCount(), 115 className, invokerName, invokerType); 116 // Create an array to map name indexes to locals indexes. 117 localTypes[localTypes.length - 1] = V_TYPE; 118 for (int i = 0; i < localsMap.length; i++) { 119 localsMap[i] = invokerType.parameterSlotCount() - invokerType.parameterSlotDepth(i); 120 if (i < invokerType.parameterCount()) 121 localTypes[i] = basicType(invokerType.parameterType(i)); 122 } 123 } 124 125 /** For generating customized code for a single LambdaForm. */ 126 private InvokerBytecodeGenerator(String className, LambdaForm form, MethodType invokerType) { 127 this(form, form.names.length, 128 className, form.debugName, invokerType); 129 // Create an array to map name indexes to locals indexes. 130 Name[] names = form.names; 131 for (int i = 0, index = 0; i < localsMap.length; i++) { 132 localsMap[i] = index; 133 if (i < names.length) { 134 BasicType type = names[i].type(); 135 index += type.basicTypeSlots(); 136 localTypes[i] = type; 137 } 138 } 139 } 140 141 142 /** instance counters for dumped classes */ 143 private static final HashMap<String,Integer> DUMP_CLASS_FILES_COUNTERS; 144 /** debugging flag for saving generated class files */ 145 private static final File DUMP_CLASS_FILES_DIR; 146 147 static { 148 if (DUMP_CLASS_FILES) { 149 DUMP_CLASS_FILES_COUNTERS = new HashMap<>(); 150 try { 151 File dumpDir = new File("DUMP_CLASS_FILES"); 152 if (!dumpDir.exists()) { 153 dumpDir.mkdirs(); 154 } 155 DUMP_CLASS_FILES_DIR = dumpDir; 156 System.out.println("Dumping class files to "+DUMP_CLASS_FILES_DIR+"/..."); 157 } catch (Exception e) { 158 throw newInternalError(e); 159 } 160 } else { 161 DUMP_CLASS_FILES_COUNTERS = null; 162 DUMP_CLASS_FILES_DIR = null; 163 } 164 } 165 166 static void maybeDump(final String className, final byte[] classFile) { 167 if (DUMP_CLASS_FILES) { 168 java.security.AccessController.doPrivileged( 169 new java.security.PrivilegedAction<>() { 170 public Void run() { 171 try { 172 String dumpName = className; 173 //dumpName = dumpName.replace('/', '-'); 174 File dumpFile = new File(DUMP_CLASS_FILES_DIR, dumpName+".class"); 175 System.out.println("dump: " + dumpFile); 176 dumpFile.getParentFile().mkdirs(); 177 FileOutputStream file = new FileOutputStream(dumpFile); 178 file.write(classFile); 179 file.close(); 180 return null; 181 } catch (IOException ex) { 182 throw newInternalError(ex); 183 } 184 } 185 }); 186 } 187 188 } 189 190 private static String makeDumpableClassName(String className) { 191 Integer ctr; 192 synchronized (DUMP_CLASS_FILES_COUNTERS) { 193 ctr = DUMP_CLASS_FILES_COUNTERS.get(className); 194 if (ctr == null) ctr = 0; 195 DUMP_CLASS_FILES_COUNTERS.put(className, ctr+1); 196 } 197 String sfx = ctr.toString(); 198 while (sfx.length() < 3) 199 sfx = "0"+sfx; 200 className += sfx; 201 return className; 202 } 203 204 class CpPatch { 205 final int index; 206 final String placeholder; 207 final Object value; 208 CpPatch(int index, String placeholder, Object value) { 209 this.index = index; 210 this.placeholder = placeholder; 211 this.value = value; 212 } 213 public String toString() { 214 return "CpPatch/index="+index+",placeholder="+placeholder+",value="+value; 215 } 216 } 217 218 Map<Object, CpPatch> cpPatches = new HashMap<>(); 219 220 int cph = 0; // for counting constant placeholders 221 222 String constantPlaceholder(Object arg) { 223 String cpPlaceholder = "CONSTANT_PLACEHOLDER_" + cph++; 224 if (DUMP_CLASS_FILES) cpPlaceholder += " <<" + debugString(arg) + ">>"; // debugging aid 225 if (cpPatches.containsKey(cpPlaceholder)) { 226 throw new InternalError("observed CP placeholder twice: " + cpPlaceholder); 227 } 228 // insert placeholder in CP and remember the patch 229 int index = cw.newConst((Object) cpPlaceholder); // TODO check if already in the constant pool 230 cpPatches.put(cpPlaceholder, new CpPatch(index, cpPlaceholder, arg)); 231 return cpPlaceholder; 232 } 233 234 Object[] cpPatches(byte[] classFile) { 235 int size = getConstantPoolSize(classFile); 236 Object[] res = new Object[size]; 237 for (CpPatch p : cpPatches.values()) { 238 if (p.index >= size) 239 throw new InternalError("in cpool["+size+"]: "+p+"\n"+Arrays.toString(Arrays.copyOf(classFile, 20))); 240 res[p.index] = p.value; 241 } 242 return res; 243 } 244 245 private static String debugString(Object arg) { 246 if (arg instanceof MethodHandle) { 247 MethodHandle mh = (MethodHandle) arg; 248 MemberName member = mh.internalMemberName(); 249 if (member != null) 250 return member.toString(); 251 return mh.debugString(); 252 } 253 return arg.toString(); 254 } 255 256 /** 257 * Extract the number of constant pool entries from a given class file. 258 * 259 * @param classFile the bytes of the class file in question. 260 * @return the number of entries in the constant pool. 261 */ 262 private static int getConstantPoolSize(byte[] classFile) { 263 // The first few bytes: 264 // u4 magic; 265 // u2 minor_version; 266 // u2 major_version; 267 // u2 constant_pool_count; 268 return ((classFile[8] & 0xFF) << 8) | (classFile[9] & 0xFF); 269 } 270 271 /** 272 * Extract the MemberName of a newly-defined method. 273 */ 274 private MemberName loadMethod(byte[] classFile) { 275 Class<?> invokerClass = loadAndInitializeInvokerClass(classFile, cpPatches(classFile)); 276 return resolveInvokerMember(invokerClass, invokerName, invokerType); 277 } 278 279 /** 280 * Define a given class as anonymous class in the runtime system. 281 */ 282 private static Class<?> loadAndInitializeInvokerClass(byte[] classBytes, Object[] patches) { 283 Class<?> invokerClass = UNSAFE.defineAnonymousClass(HOST_CLASS, classBytes, patches); 284 UNSAFE.ensureClassInitialized(invokerClass); // Make sure the class is initialized; VM might complain. 285 return invokerClass; 286 } 287 288 private static MemberName resolveInvokerMember(Class<?> invokerClass, String name, MethodType type) { 289 MemberName member = new MemberName(invokerClass, name, type, REF_invokeStatic); 290 //System.out.println("resolveInvokerMember => "+member); 291 //for (Method m : invokerClass.getDeclaredMethods()) System.out.println(" "+m); 292 try { 293 member = MEMBERNAME_FACTORY.resolveOrFail(REF_invokeStatic, member, HOST_CLASS, ReflectiveOperationException.class); 294 } catch (ReflectiveOperationException e) { 295 throw newInternalError(e); 296 } 297 //System.out.println("resolveInvokerMember => "+member); 298 return member; 299 } 300 301 /** 302 * Set up class file generation. 303 */ 304 private void classFilePrologue() { 305 final int NOT_ACC_PUBLIC = 0; // not ACC_PUBLIC 306 cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES); 307 cw.visit(Opcodes.V1_8, NOT_ACC_PUBLIC + Opcodes.ACC_FINAL + Opcodes.ACC_SUPER, className, null, superName, null); 308 cw.visitSource(sourceFile, null); 309 310 String invokerDesc = invokerType.toMethodDescriptorString(); 311 mv = cw.visitMethod(Opcodes.ACC_STATIC, invokerName, invokerDesc, null, null); 312 } 313 314 /** 315 * Tear down class file generation. 316 */ 317 private void classFileEpilogue() { 318 mv.visitMaxs(0, 0); 319 mv.visitEnd(); 320 } 321 322 /* 323 * Low-level emit helpers. 324 */ 325 private void emitConst(Object con) { 326 if (con == null) { 327 mv.visitInsn(Opcodes.ACONST_NULL); 328 return; 329 } 330 if (con instanceof Integer) { 331 emitIconstInsn((int) con); 332 return; 333 } 334 if (con instanceof Long) { 335 long x = (long) con; 336 if (x == (short) x) { 337 emitIconstInsn((int) x); 338 mv.visitInsn(Opcodes.I2L); 339 return; 340 } 341 } 342 if (con instanceof Float) { 343 float x = (float) con; 344 if (x == (short) x) { 345 emitIconstInsn((int) x); 346 mv.visitInsn(Opcodes.I2F); 347 return; 348 } 349 } 350 if (con instanceof Double) { 351 double x = (double) con; 352 if (x == (short) x) { 353 emitIconstInsn((int) x); 354 mv.visitInsn(Opcodes.I2D); 355 return; 356 } 357 } 358 if (con instanceof Boolean) { 359 emitIconstInsn((boolean) con ? 1 : 0); 360 return; 361 } 362 // fall through: 363 mv.visitLdcInsn(con); 364 } 365 366 private void emitIconstInsn(int i) { 367 int opcode; 368 switch (i) { 369 case 0: opcode = Opcodes.ICONST_0; break; 370 case 1: opcode = Opcodes.ICONST_1; break; 371 case 2: opcode = Opcodes.ICONST_2; break; 372 case 3: opcode = Opcodes.ICONST_3; break; 373 case 4: opcode = Opcodes.ICONST_4; break; 374 case 5: opcode = Opcodes.ICONST_5; break; 375 default: 376 if (i == (byte) i) { 377 mv.visitIntInsn(Opcodes.BIPUSH, i & 0xFF); 378 } else if (i == (short) i) { 379 mv.visitIntInsn(Opcodes.SIPUSH, (char) i); 380 } else { 381 mv.visitLdcInsn(i); 382 } 383 return; 384 } 385 mv.visitInsn(opcode); 386 } 387 388 /* 389 * NOTE: These load/store methods use the localsMap to find the correct index! 390 */ 391 private void emitLoadInsn(BasicType type, int index) { 392 int opcode = loadInsnOpcode(type); 393 mv.visitVarInsn(opcode, localsMap[index]); 394 } 395 396 private int loadInsnOpcode(BasicType type) throws InternalError { 397 switch (type) { 398 case I_TYPE: return Opcodes.ILOAD; 399 case J_TYPE: return Opcodes.LLOAD; 400 case F_TYPE: return Opcodes.FLOAD; 401 case D_TYPE: return Opcodes.DLOAD; 402 case L_TYPE: return Opcodes.ALOAD; 403 default: 404 throw new InternalError("unknown type: " + type); 405 } 406 } 407 private void emitAloadInsn(int index) { 408 emitLoadInsn(L_TYPE, index); 409 } 410 411 private void emitStoreInsn(BasicType type, int index) { 412 int opcode = storeInsnOpcode(type); 413 mv.visitVarInsn(opcode, localsMap[index]); 414 } 415 416 private int storeInsnOpcode(BasicType type) throws InternalError { 417 switch (type) { 418 case I_TYPE: return Opcodes.ISTORE; 419 case J_TYPE: return Opcodes.LSTORE; 420 case F_TYPE: return Opcodes.FSTORE; 421 case D_TYPE: return Opcodes.DSTORE; 422 case L_TYPE: return Opcodes.ASTORE; 423 default: 424 throw new InternalError("unknown type: " + type); 425 } 426 } 427 private void emitAstoreInsn(int index) { 428 emitStoreInsn(L_TYPE, index); 429 } 430 431 private byte arrayTypeCode(Wrapper elementType) { 432 switch (elementType) { 433 case BOOLEAN: return Opcodes.T_BOOLEAN; 434 case BYTE: return Opcodes.T_BYTE; 435 case CHAR: return Opcodes.T_CHAR; 436 case SHORT: return Opcodes.T_SHORT; 437 case INT: return Opcodes.T_INT; 438 case LONG: return Opcodes.T_LONG; 439 case FLOAT: return Opcodes.T_FLOAT; 440 case DOUBLE: return Opcodes.T_DOUBLE; 441 case OBJECT: return 0; // in place of Opcodes.T_OBJECT 442 default: throw new InternalError(); 443 } 444 } 445 446 private int arrayInsnOpcode(byte tcode, int aaop) throws InternalError { 447 assert(aaop == Opcodes.AASTORE || aaop == Opcodes.AALOAD); 448 int xas; 449 switch (tcode) { 450 case Opcodes.T_BOOLEAN: xas = Opcodes.BASTORE; break; 451 case Opcodes.T_BYTE: xas = Opcodes.BASTORE; break; 452 case Opcodes.T_CHAR: xas = Opcodes.CASTORE; break; 453 case Opcodes.T_SHORT: xas = Opcodes.SASTORE; break; 454 case Opcodes.T_INT: xas = Opcodes.IASTORE; break; 455 case Opcodes.T_LONG: xas = Opcodes.LASTORE; break; 456 case Opcodes.T_FLOAT: xas = Opcodes.FASTORE; break; 457 case Opcodes.T_DOUBLE: xas = Opcodes.DASTORE; break; 458 case 0: xas = Opcodes.AASTORE; break; 459 default: throw new InternalError(); 460 } 461 return xas - Opcodes.AASTORE + aaop; 462 } 463 464 465 private void freeFrameLocal(int oldFrameLocal) { 466 int i = indexForFrameLocal(oldFrameLocal); 467 if (i < 0) return; 468 BasicType type = localTypes[i]; 469 int newFrameLocal = makeLocalTemp(type); 470 mv.visitVarInsn(loadInsnOpcode(type), oldFrameLocal); 471 mv.visitVarInsn(storeInsnOpcode(type), newFrameLocal); 472 assert(localsMap[i] == oldFrameLocal); 473 localsMap[i] = newFrameLocal; 474 assert(indexForFrameLocal(oldFrameLocal) < 0); 475 } 476 private int indexForFrameLocal(int frameLocal) { 477 for (int i = 0; i < localsMap.length; i++) { 478 if (localsMap[i] == frameLocal && localTypes[i] != V_TYPE) 479 return i; 480 } 481 return -1; 482 } 483 private int makeLocalTemp(BasicType type) { 484 int frameLocal = localsMap[localsMap.length - 1]; 485 localsMap[localsMap.length - 1] = frameLocal + type.basicTypeSlots(); 486 return frameLocal; 487 } 488 489 /** 490 * Emit a boxing call. 491 * 492 * @param wrapper primitive type class to box. 493 */ 494 private void emitBoxing(Wrapper wrapper) { 495 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName(); 496 String name = "valueOf"; 497 String desc = "(" + wrapper.basicTypeChar() + ")L" + owner + ";"; 498 mv.visitMethodInsn(Opcodes.INVOKESTATIC, owner, name, desc, false); 499 } 500 501 /** 502 * Emit an unboxing call (plus preceding checkcast). 503 * 504 * @param wrapper wrapper type class to unbox. 505 */ 506 private void emitUnboxing(Wrapper wrapper) { 507 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName(); 508 String name = wrapper.primitiveSimpleName() + "Value"; 509 String desc = "()" + wrapper.basicTypeChar(); 510 emitReferenceCast(wrapper.wrapperType(), null); 511 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, owner, name, desc, false); 512 } 513 514 /** 515 * Emit an implicit conversion for an argument which must be of the given pclass. 516 * This is usually a no-op, except when pclass is a subword type or a reference other than Object or an interface. 517 * 518 * @param ptype type of value present on stack 519 * @param pclass type of value required on stack 520 * @param arg compile-time representation of value on stack (Node, constant) or null if none 521 */ 522 private void emitImplicitConversion(BasicType ptype, Class<?> pclass, Object arg) { 523 assert(basicType(pclass) == ptype); // boxing/unboxing handled by caller 524 if (pclass == ptype.basicTypeClass() && ptype != L_TYPE) 525 return; // nothing to do 526 switch (ptype) { 527 case L_TYPE: 528 if (VerifyType.isNullConversion(Object.class, pclass, false)) { 529 if (PROFILE_LEVEL > 0) 530 emitReferenceCast(Object.class, arg); 531 return; 532 } 533 emitReferenceCast(pclass, arg); 534 return; 535 case I_TYPE: 536 if (!VerifyType.isNullConversion(int.class, pclass, false)) 537 emitPrimCast(ptype.basicTypeWrapper(), Wrapper.forPrimitiveType(pclass)); 538 return; 539 } 540 throw newInternalError("bad implicit conversion: tc="+ptype+": "+pclass); 541 } 542 543 /** Update localClasses type map. Return true if the information is already present. */ 544 private boolean assertStaticType(Class<?> cls, Name n) { 545 int local = n.index(); 546 Class<?> aclass = localClasses[local]; 547 if (aclass != null && (aclass == cls || cls.isAssignableFrom(aclass))) { 548 return true; // type info is already present 549 } else if (aclass == null || aclass.isAssignableFrom(cls)) { 550 localClasses[local] = cls; // type info can be improved 551 } 552 return false; 553 } 554 555 private void emitReferenceCast(Class<?> cls, Object arg) { 556 Name writeBack = null; // local to write back result 557 if (arg instanceof Name) { 558 Name n = (Name) arg; 559 if (assertStaticType(cls, n)) 560 return; // this cast was already performed 561 if (lambdaForm.useCount(n) > 1) { 562 // This guy gets used more than once. 563 writeBack = n; 564 } 565 } 566 if (isStaticallyNameable(cls)) { 567 String sig = getInternalName(cls); 568 mv.visitTypeInsn(Opcodes.CHECKCAST, sig); 569 } else { 570 mv.visitLdcInsn(constantPlaceholder(cls)); 571 mv.visitTypeInsn(Opcodes.CHECKCAST, CLS); 572 mv.visitInsn(Opcodes.SWAP); 573 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, CLS, "cast", LL_SIG, false); 574 if (Object[].class.isAssignableFrom(cls)) 575 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJARY); 576 else if (PROFILE_LEVEL > 0) 577 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJ); 578 } 579 if (writeBack != null) { 580 mv.visitInsn(Opcodes.DUP); 581 emitAstoreInsn(writeBack.index()); 582 } 583 } 584 585 /** 586 * Emits an actual return instruction conforming to the given return type. 587 */ 588 private void emitReturnInsn(BasicType type) { 589 int opcode; 590 switch (type) { 591 case I_TYPE: opcode = Opcodes.IRETURN; break; 592 case J_TYPE: opcode = Opcodes.LRETURN; break; 593 case F_TYPE: opcode = Opcodes.FRETURN; break; 594 case D_TYPE: opcode = Opcodes.DRETURN; break; 595 case L_TYPE: opcode = Opcodes.ARETURN; break; 596 case V_TYPE: opcode = Opcodes.RETURN; break; 597 default: 598 throw new InternalError("unknown return type: " + type); 599 } 600 mv.visitInsn(opcode); 601 } 602 603 private static String getInternalName(Class<?> c) { 604 if (c == Object.class) return OBJ; 605 else if (c == Object[].class) return OBJARY; 606 else if (c == Class.class) return CLS; 607 else if (c == MethodHandle.class) return MH; 608 assert(VerifyAccess.isTypeVisible(c, Object.class)) : c.getName(); 609 return c.getName().replace('.', '/'); 610 } 611 612 /** 613 * Generate customized bytecode for a given LambdaForm. 614 */ 615 static MemberName generateCustomizedCode(LambdaForm form, MethodType invokerType) { 616 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("MH", form, invokerType); 617 return g.loadMethod(g.generateCustomizedCodeBytes()); 618 } 619 620 /** Generates code to check that actual receiver and LambdaForm matches */ 621 private boolean checkActualReceiver() { 622 // Expects MethodHandle on the stack and actual receiver MethodHandle in slot #0 623 mv.visitInsn(Opcodes.DUP); 624 mv.visitVarInsn(Opcodes.ALOAD, localsMap[0]); 625 mv.visitMethodInsn(Opcodes.INVOKESTATIC, MHI, "assertSame", LLV_SIG, false); 626 return true; 627 } 628 629 /** 630 * Generate an invoker method for the passed {@link LambdaForm}. 631 */ 632 private byte[] generateCustomizedCodeBytes() { 633 classFilePrologue(); 634 635 // Suppress this method in backtraces displayed to the user. 636 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true); 637 638 // Mark this method as a compiled LambdaForm 639 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Compiled;", true); 640 641 if (lambdaForm.forceInline) { 642 // Force inlining of this invoker method. 643 mv.visitAnnotation("Ljava/lang/invoke/ForceInline;", true); 644 } else { 645 mv.visitAnnotation("Ljava/lang/invoke/DontInline;", true); 646 } 647 648 if (lambdaForm.customized != null) { 649 // Since LambdaForm is customized for a particular MethodHandle, it's safe to substitute 650 // receiver MethodHandle (at slot #0) with an embedded constant and use it instead. 651 // It enables more efficient code generation in some situations, since embedded constants 652 // are compile-time constants for JIT compiler. 653 mv.visitLdcInsn(constantPlaceholder(lambdaForm.customized)); 654 mv.visitTypeInsn(Opcodes.CHECKCAST, MH); 655 assert(checkActualReceiver()); // expects MethodHandle on top of the stack 656 mv.visitVarInsn(Opcodes.ASTORE, localsMap[0]); 657 } 658 659 // iterate over the form's names, generating bytecode instructions for each 660 // start iterating at the first name following the arguments 661 Name onStack = null; 662 for (int i = lambdaForm.arity; i < lambdaForm.names.length; i++) { 663 Name name = lambdaForm.names[i]; 664 665 emitStoreResult(onStack); 666 onStack = name; // unless otherwise modified below 667 MethodHandleImpl.Intrinsic intr = name.function.intrinsicName(); 668 switch (intr) { 669 case SELECT_ALTERNATIVE: 670 assert isSelectAlternative(i); 671 if (PROFILE_GWT) { 672 assert(name.arguments[0] instanceof Name && 673 nameRefersTo((Name)name.arguments[0], MethodHandleImpl.class, "profileBoolean")); 674 mv.visitAnnotation("Ljava/lang/invoke/InjectedProfile;", true); 675 } 676 onStack = emitSelectAlternative(name, lambdaForm.names[i+1]); 677 i++; // skip MH.invokeBasic of the selectAlternative result 678 continue; 679 case GUARD_WITH_CATCH: 680 assert isGuardWithCatch(i); 681 onStack = emitGuardWithCatch(i); 682 i = i+2; // Jump to the end of GWC idiom 683 continue; 684 case NEW_ARRAY: 685 Class<?> rtype = name.function.methodType().returnType(); 686 if (isStaticallyNameable(rtype)) { 687 emitNewArray(name); 688 continue; 689 } 690 break; 691 case ARRAY_LOAD: 692 emitArrayLoad(name); 693 continue; 694 case ARRAY_STORE: 695 emitArrayStore(name); 696 continue; 697 case IDENTITY: 698 assert(name.arguments.length == 1); 699 emitPushArguments(name); 700 continue; 701 case ZERO: 702 assert(name.arguments.length == 0); 703 emitConst(name.type.basicTypeWrapper().zero()); 704 continue; 705 case NONE: 706 // no intrinsic associated 707 break; 708 default: 709 throw newInternalError("Unknown intrinsic: "+intr); 710 } 711 712 MemberName member = name.function.member(); 713 if (isStaticallyInvocable(member)) { 714 emitStaticInvoke(member, name); 715 } else { 716 emitInvoke(name); 717 } 718 } 719 720 // return statement 721 emitReturn(onStack); 722 723 classFileEpilogue(); 724 bogusMethod(lambdaForm); 725 726 final byte[] classFile = cw.toByteArray(); 727 maybeDump(className, classFile); 728 return classFile; 729 } 730 731 void emitArrayLoad(Name name) { emitArrayOp(name, Opcodes.AALOAD); } 732 void emitArrayStore(Name name) { emitArrayOp(name, Opcodes.AASTORE); } 733 734 void emitArrayOp(Name name, int arrayOpcode) { 735 assert arrayOpcode == Opcodes.AALOAD || arrayOpcode == Opcodes.AASTORE; 736 Class<?> elementType = name.function.methodType().parameterType(0).getComponentType(); 737 assert elementType != null; 738 emitPushArguments(name); 739 if (elementType.isPrimitive()) { 740 Wrapper w = Wrapper.forPrimitiveType(elementType); 741 arrayOpcode = arrayInsnOpcode(arrayTypeCode(w), arrayOpcode); 742 } 743 mv.visitInsn(arrayOpcode); 744 } 745 746 /** 747 * Emit an invoke for the given name. 748 */ 749 void emitInvoke(Name name) { 750 assert(!isLinkerMethodInvoke(name)); // should use the static path for these 751 if (true) { 752 // push receiver 753 MethodHandle target = name.function.resolvedHandle; 754 assert(target != null) : name.exprString(); 755 mv.visitLdcInsn(constantPlaceholder(target)); 756 emitReferenceCast(MethodHandle.class, target); 757 } else { 758 // load receiver 759 emitAloadInsn(0); 760 emitReferenceCast(MethodHandle.class, null); 761 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", LF_SIG); 762 mv.visitFieldInsn(Opcodes.GETFIELD, LF, "names", LFN_SIG); 763 // TODO more to come 764 } 765 766 // push arguments 767 emitPushArguments(name); 768 769 // invocation 770 MethodType type = name.function.methodType(); 771 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false); 772 } 773 774 private static Class<?>[] STATICALLY_INVOCABLE_PACKAGES = { 775 // Sample classes from each package we are willing to bind to statically: 776 java.lang.Object.class, 777 java.util.Arrays.class, 778 sun.misc.Unsafe.class 779 //MethodHandle.class already covered 780 }; 781 782 static boolean isStaticallyInvocable(Name name) { 783 return isStaticallyInvocable(name.function.member()); 784 } 785 786 static boolean isStaticallyInvocable(MemberName member) { 787 if (member == null) return false; 788 if (member.isConstructor()) return false; 789 Class<?> cls = member.getDeclaringClass(); 790 if (cls.isArray() || cls.isPrimitive()) 791 return false; // FIXME 792 if (cls.isAnonymousClass() || cls.isLocalClass()) 793 return false; // inner class of some sort 794 if (cls.getClassLoader() != MethodHandle.class.getClassLoader()) 795 return false; // not on BCP 796 if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: switch to supported API once it is added 797 return false; 798 MethodType mtype = member.getMethodOrFieldType(); 799 if (!isStaticallyNameable(mtype.returnType())) 800 return false; 801 for (Class<?> ptype : mtype.parameterArray()) 802 if (!isStaticallyNameable(ptype)) 803 return false; 804 if (!member.isPrivate() && VerifyAccess.isSamePackage(MethodHandle.class, cls)) 805 return true; // in java.lang.invoke package 806 if (member.isPublic() && isStaticallyNameable(cls)) 807 return true; 808 return false; 809 } 810 811 static boolean isStaticallyNameable(Class<?> cls) { 812 if (cls == Object.class) 813 return true; 814 while (cls.isArray()) 815 cls = cls.getComponentType(); 816 if (cls.isPrimitive()) 817 return true; // int[].class, for example 818 if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: switch to supported API once it is added 819 return false; 820 // could use VerifyAccess.isClassAccessible but the following is a safe approximation 821 if (cls.getClassLoader() != Object.class.getClassLoader()) 822 return false; 823 if (VerifyAccess.isSamePackage(MethodHandle.class, cls)) 824 return true; 825 if (!Modifier.isPublic(cls.getModifiers())) 826 return false; 827 for (Class<?> pkgcls : STATICALLY_INVOCABLE_PACKAGES) { 828 if (VerifyAccess.isSamePackage(pkgcls, cls)) 829 return true; 830 } 831 return false; 832 } 833 834 void emitStaticInvoke(Name name) { 835 emitStaticInvoke(name.function.member(), name); 836 } 837 838 /** 839 * Emit an invoke for the given name, using the MemberName directly. 840 */ 841 void emitStaticInvoke(MemberName member, Name name) { 842 assert(member.equals(name.function.member())); 843 Class<?> defc = member.getDeclaringClass(); 844 String cname = getInternalName(defc); 845 String mname = member.getName(); 846 String mtype; 847 byte refKind = member.getReferenceKind(); 848 if (refKind == REF_invokeSpecial) { 849 // in order to pass the verifier, we need to convert this to invokevirtual in all cases 850 assert(member.canBeStaticallyBound()) : member; 851 refKind = REF_invokeVirtual; 852 } 853 854 assert(!(member.getDeclaringClass().isInterface() && refKind == REF_invokeVirtual)); 855 856 // push arguments 857 emitPushArguments(name); 858 859 // invocation 860 if (member.isMethod()) { 861 mtype = member.getMethodType().toMethodDescriptorString(); 862 mv.visitMethodInsn(refKindOpcode(refKind), cname, mname, mtype, 863 member.getDeclaringClass().isInterface()); 864 } else { 865 mtype = MethodType.toFieldDescriptorString(member.getFieldType()); 866 mv.visitFieldInsn(refKindOpcode(refKind), cname, mname, mtype); 867 } 868 // Issue a type assertion for the result, so we can avoid casts later. 869 if (name.type == L_TYPE) { 870 Class<?> rtype = member.getInvocationType().returnType(); 871 assert(!rtype.isPrimitive()); 872 if (rtype != Object.class && !rtype.isInterface()) { 873 assertStaticType(rtype, name); 874 } 875 } 876 } 877 878 void emitNewArray(Name name) throws InternalError { 879 Class<?> rtype = name.function.methodType().returnType(); 880 if (name.arguments.length == 0) { 881 // The array will be a constant. 882 Object emptyArray; 883 try { 884 emptyArray = name.function.resolvedHandle.invoke(); 885 } catch (Throwable ex) { 886 throw newInternalError(ex); 887 } 888 assert(java.lang.reflect.Array.getLength(emptyArray) == 0); 889 assert(emptyArray.getClass() == rtype); // exact typing 890 mv.visitLdcInsn(constantPlaceholder(emptyArray)); 891 emitReferenceCast(rtype, emptyArray); 892 return; 893 } 894 Class<?> arrayElementType = rtype.getComponentType(); 895 assert(arrayElementType != null); 896 emitIconstInsn(name.arguments.length); 897 int xas = Opcodes.AASTORE; 898 if (!arrayElementType.isPrimitive()) { 899 mv.visitTypeInsn(Opcodes.ANEWARRAY, getInternalName(arrayElementType)); 900 } else { 901 byte tc = arrayTypeCode(Wrapper.forPrimitiveType(arrayElementType)); 902 xas = arrayInsnOpcode(tc, xas); 903 mv.visitIntInsn(Opcodes.NEWARRAY, tc); 904 } 905 // store arguments 906 for (int i = 0; i < name.arguments.length; i++) { 907 mv.visitInsn(Opcodes.DUP); 908 emitIconstInsn(i); 909 emitPushArgument(name, i); 910 mv.visitInsn(xas); 911 } 912 // the array is left on the stack 913 assertStaticType(rtype, name); 914 } 915 int refKindOpcode(byte refKind) { 916 switch (refKind) { 917 case REF_invokeVirtual: return Opcodes.INVOKEVIRTUAL; 918 case REF_invokeStatic: return Opcodes.INVOKESTATIC; 919 case REF_invokeSpecial: return Opcodes.INVOKESPECIAL; 920 case REF_invokeInterface: return Opcodes.INVOKEINTERFACE; 921 case REF_getField: return Opcodes.GETFIELD; 922 case REF_putField: return Opcodes.PUTFIELD; 923 case REF_getStatic: return Opcodes.GETSTATIC; 924 case REF_putStatic: return Opcodes.PUTSTATIC; 925 } 926 throw new InternalError("refKind="+refKind); 927 } 928 929 /** 930 * Check if MemberName is a call to a method named {@code name} in class {@code declaredClass}. 931 */ 932 private boolean memberRefersTo(MemberName member, Class<?> declaringClass, String name) { 933 return member != null && 934 member.getDeclaringClass() == declaringClass && 935 member.getName().equals(name); 936 } 937 private boolean nameRefersTo(Name name, Class<?> declaringClass, String methodName) { 938 return name.function != null && 939 memberRefersTo(name.function.member(), declaringClass, methodName); 940 } 941 942 /** 943 * Check if MemberName is a call to MethodHandle.invokeBasic. 944 */ 945 private boolean isInvokeBasic(Name name) { 946 if (name.function == null) 947 return false; 948 if (name.arguments.length < 1) 949 return false; // must have MH argument 950 MemberName member = name.function.member(); 951 return memberRefersTo(member, MethodHandle.class, "invokeBasic") && 952 !member.isPublic() && !member.isStatic(); 953 } 954 955 /** 956 * Check if MemberName is a call to MethodHandle.linkToStatic, etc. 957 */ 958 private boolean isLinkerMethodInvoke(Name name) { 959 if (name.function == null) 960 return false; 961 if (name.arguments.length < 1) 962 return false; // must have MH argument 963 MemberName member = name.function.member(); 964 return member != null && 965 member.getDeclaringClass() == MethodHandle.class && 966 !member.isPublic() && member.isStatic() && 967 member.getName().startsWith("linkTo"); 968 } 969 970 /** 971 * Check if i-th name is a call to MethodHandleImpl.selectAlternative. 972 */ 973 private boolean isSelectAlternative(int pos) { 974 // selectAlternative idiom: 975 // t_{n}:L=MethodHandleImpl.selectAlternative(...) 976 // t_{n+1}:?=MethodHandle.invokeBasic(t_{n}, ...) 977 if (pos+1 >= lambdaForm.names.length) return false; 978 Name name0 = lambdaForm.names[pos]; 979 Name name1 = lambdaForm.names[pos+1]; 980 return nameRefersTo(name0, MethodHandleImpl.class, "selectAlternative") && 981 isInvokeBasic(name1) && 982 name1.lastUseIndex(name0) == 0 && // t_{n+1}:?=MethodHandle.invokeBasic(t_{n}, ...) 983 lambdaForm.lastUseIndex(name0) == pos+1; // t_{n} is local: used only in t_{n+1} 984 } 985 986 /** 987 * Check if i-th name is a start of GuardWithCatch idiom. 988 */ 989 private boolean isGuardWithCatch(int pos) { 990 // GuardWithCatch idiom: 991 // t_{n}:L=MethodHandle.invokeBasic(...) 992 // t_{n+1}:L=MethodHandleImpl.guardWithCatch(*, *, *, t_{n}); 993 // t_{n+2}:?=MethodHandle.invokeBasic(t_{n+1}) 994 if (pos+2 >= lambdaForm.names.length) return false; 995 Name name0 = lambdaForm.names[pos]; 996 Name name1 = lambdaForm.names[pos+1]; 997 Name name2 = lambdaForm.names[pos+2]; 998 return nameRefersTo(name1, MethodHandleImpl.class, "guardWithCatch") && 999 isInvokeBasic(name0) && 1000 isInvokeBasic(name2) && 1001 name1.lastUseIndex(name0) == 3 && // t_{n+1}:L=MethodHandleImpl.guardWithCatch(*, *, *, t_{n}); 1002 lambdaForm.lastUseIndex(name0) == pos+1 && // t_{n} is local: used only in t_{n+1} 1003 name2.lastUseIndex(name1) == 1 && // t_{n+2}:?=MethodHandle.invokeBasic(t_{n+1}) 1004 lambdaForm.lastUseIndex(name1) == pos+2; // t_{n+1} is local: used only in t_{n+2} 1005 } 1006 1007 /** 1008 * Emit bytecode for the selectAlternative idiom. 1009 * 1010 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithTest): 1011 * <blockquote><pre>{@code 1012 * Lambda(a0:L,a1:I)=>{ 1013 * t2:I=foo.test(a1:I); 1014 * t3:L=MethodHandleImpl.selectAlternative(t2:I,(MethodHandle(int)int),(MethodHandle(int)int)); 1015 * t4:I=MethodHandle.invokeBasic(t3:L,a1:I);t4:I} 1016 * }</pre></blockquote> 1017 */ 1018 private Name emitSelectAlternative(Name selectAlternativeName, Name invokeBasicName) { 1019 assert isStaticallyInvocable(invokeBasicName); 1020 1021 Name receiver = (Name) invokeBasicName.arguments[0]; 1022 1023 Label L_fallback = new Label(); 1024 Label L_done = new Label(); 1025 1026 // load test result 1027 emitPushArgument(selectAlternativeName, 0); 1028 1029 // if_icmpne L_fallback 1030 mv.visitJumpInsn(Opcodes.IFEQ, L_fallback); 1031 1032 // invoke selectAlternativeName.arguments[1] 1033 Class<?>[] preForkClasses = localClasses.clone(); 1034 emitPushArgument(selectAlternativeName, 1); // get 2nd argument of selectAlternative 1035 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot 1036 emitStaticInvoke(invokeBasicName); 1037 1038 // goto L_done 1039 mv.visitJumpInsn(Opcodes.GOTO, L_done); 1040 1041 // L_fallback: 1042 mv.visitLabel(L_fallback); 1043 1044 // invoke selectAlternativeName.arguments[2] 1045 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length); 1046 emitPushArgument(selectAlternativeName, 2); // get 3rd argument of selectAlternative 1047 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot 1048 emitStaticInvoke(invokeBasicName); 1049 1050 // L_done: 1051 mv.visitLabel(L_done); 1052 // for now do not bother to merge typestate; just reset to the dominator state 1053 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length); 1054 1055 return invokeBasicName; // return what's on stack 1056 } 1057 1058 /** 1059 * Emit bytecode for the guardWithCatch idiom. 1060 * 1061 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithCatch): 1062 * <blockquote><pre>{@code 1063 * guardWithCatch=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L,a5:L,a6:L,a7:L)=>{ 1064 * t8:L=MethodHandle.invokeBasic(a4:L,a6:L,a7:L); 1065 * t9:L=MethodHandleImpl.guardWithCatch(a1:L,a2:L,a3:L,t8:L); 1066 * t10:I=MethodHandle.invokeBasic(a5:L,t9:L);t10:I} 1067 * }</pre></blockquote> 1068 * 1069 * It is compiled into bytecode equivalent of the following code: 1070 * <blockquote><pre>{@code 1071 * try { 1072 * return a1.invokeBasic(a6, a7); 1073 * } catch (Throwable e) { 1074 * if (!a2.isInstance(e)) throw e; 1075 * return a3.invokeBasic(ex, a6, a7); 1076 * }} 1077 */ 1078 private Name emitGuardWithCatch(int pos) { 1079 Name args = lambdaForm.names[pos]; 1080 Name invoker = lambdaForm.names[pos+1]; 1081 Name result = lambdaForm.names[pos+2]; 1082 1083 Label L_startBlock = new Label(); 1084 Label L_endBlock = new Label(); 1085 Label L_handler = new Label(); 1086 Label L_done = new Label(); 1087 1088 Class<?> returnType = result.function.resolvedHandle.type().returnType(); 1089 MethodType type = args.function.resolvedHandle.type() 1090 .dropParameterTypes(0,1) 1091 .changeReturnType(returnType); 1092 1093 mv.visitTryCatchBlock(L_startBlock, L_endBlock, L_handler, "java/lang/Throwable"); 1094 1095 // Normal case 1096 mv.visitLabel(L_startBlock); 1097 // load target 1098 emitPushArgument(invoker, 0); 1099 emitPushArguments(args, 1); // skip 1st argument: method handle 1100 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false); 1101 mv.visitLabel(L_endBlock); 1102 mv.visitJumpInsn(Opcodes.GOTO, L_done); 1103 1104 // Exceptional case 1105 mv.visitLabel(L_handler); 1106 1107 // Check exception's type 1108 mv.visitInsn(Opcodes.DUP); 1109 // load exception class 1110 emitPushArgument(invoker, 1); 1111 mv.visitInsn(Opcodes.SWAP); 1112 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/Class", "isInstance", "(Ljava/lang/Object;)Z", false); 1113 Label L_rethrow = new Label(); 1114 mv.visitJumpInsn(Opcodes.IFEQ, L_rethrow); 1115 1116 // Invoke catcher 1117 // load catcher 1118 emitPushArgument(invoker, 2); 1119 mv.visitInsn(Opcodes.SWAP); 1120 emitPushArguments(args, 1); // skip 1st argument: method handle 1121 MethodType catcherType = type.insertParameterTypes(0, Throwable.class); 1122 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", catcherType.basicType().toMethodDescriptorString(), false); 1123 mv.visitJumpInsn(Opcodes.GOTO, L_done); 1124 1125 mv.visitLabel(L_rethrow); 1126 mv.visitInsn(Opcodes.ATHROW); 1127 1128 mv.visitLabel(L_done); 1129 1130 return result; 1131 } 1132 1133 private void emitPushArguments(Name args) { 1134 emitPushArguments(args, 0); 1135 } 1136 1137 private void emitPushArguments(Name args, int start) { 1138 for (int i = start; i < args.arguments.length; i++) { 1139 emitPushArgument(args, i); 1140 } 1141 } 1142 1143 private void emitPushArgument(Name name, int paramIndex) { 1144 Object arg = name.arguments[paramIndex]; 1145 Class<?> ptype = name.function.methodType().parameterType(paramIndex); 1146 emitPushArgument(ptype, arg); 1147 } 1148 1149 private void emitPushArgument(Class<?> ptype, Object arg) { 1150 BasicType bptype = basicType(ptype); 1151 if (arg instanceof Name) { 1152 Name n = (Name) arg; 1153 emitLoadInsn(n.type, n.index()); 1154 emitImplicitConversion(n.type, ptype, n); 1155 } else if ((arg == null || arg instanceof String) && bptype == L_TYPE) { 1156 emitConst(arg); 1157 } else { 1158 if (Wrapper.isWrapperType(arg.getClass()) && bptype != L_TYPE) { 1159 emitConst(arg); 1160 } else { 1161 mv.visitLdcInsn(constantPlaceholder(arg)); 1162 emitImplicitConversion(L_TYPE, ptype, arg); 1163 } 1164 } 1165 } 1166 1167 /** 1168 * Store the name to its local, if necessary. 1169 */ 1170 private void emitStoreResult(Name name) { 1171 if (name != null && name.type != V_TYPE) { 1172 // non-void: actually assign 1173 emitStoreInsn(name.type, name.index()); 1174 } 1175 } 1176 1177 /** 1178 * Emits a return statement from a LF invoker. If required, the result type is cast to the correct return type. 1179 */ 1180 private void emitReturn(Name onStack) { 1181 // return statement 1182 Class<?> rclass = invokerType.returnType(); 1183 BasicType rtype = lambdaForm.returnType(); 1184 assert(rtype == basicType(rclass)); // must agree 1185 if (rtype == V_TYPE) { 1186 // void 1187 mv.visitInsn(Opcodes.RETURN); 1188 // it doesn't matter what rclass is; the JVM will discard any value 1189 } else { 1190 LambdaForm.Name rn = lambdaForm.names[lambdaForm.result]; 1191 1192 // put return value on the stack if it is not already there 1193 if (rn != onStack) { 1194 emitLoadInsn(rtype, lambdaForm.result); 1195 } 1196 1197 emitImplicitConversion(rtype, rclass, rn); 1198 1199 // generate actual return statement 1200 emitReturnInsn(rtype); 1201 } 1202 } 1203 1204 /** 1205 * Emit a type conversion bytecode casting from "from" to "to". 1206 */ 1207 private void emitPrimCast(Wrapper from, Wrapper to) { 1208 // Here's how. 1209 // - indicates forbidden 1210 // <-> indicates implicit 1211 // to ----> boolean byte short char int long float double 1212 // from boolean <-> - - - - - - - 1213 // byte - <-> i2s i2c <-> i2l i2f i2d 1214 // short - i2b <-> i2c <-> i2l i2f i2d 1215 // char - i2b i2s <-> <-> i2l i2f i2d 1216 // int - i2b i2s i2c <-> i2l i2f i2d 1217 // long - l2i,i2b l2i,i2s l2i,i2c l2i <-> l2f l2d 1218 // float - f2i,i2b f2i,i2s f2i,i2c f2i f2l <-> f2d 1219 // double - d2i,i2b d2i,i2s d2i,i2c d2i d2l d2f <-> 1220 if (from == to) { 1221 // no cast required, should be dead code anyway 1222 return; 1223 } 1224 if (from.isSubwordOrInt()) { 1225 // cast from {byte,short,char,int} to anything 1226 emitI2X(to); 1227 } else { 1228 // cast from {long,float,double} to anything 1229 if (to.isSubwordOrInt()) { 1230 // cast to {byte,short,char,int} 1231 emitX2I(from); 1232 if (to.bitWidth() < 32) { 1233 // targets other than int require another conversion 1234 emitI2X(to); 1235 } 1236 } else { 1237 // cast to {long,float,double} - this is verbose 1238 boolean error = false; 1239 switch (from) { 1240 case LONG: 1241 switch (to) { 1242 case FLOAT: mv.visitInsn(Opcodes.L2F); break; 1243 case DOUBLE: mv.visitInsn(Opcodes.L2D); break; 1244 default: error = true; break; 1245 } 1246 break; 1247 case FLOAT: 1248 switch (to) { 1249 case LONG : mv.visitInsn(Opcodes.F2L); break; 1250 case DOUBLE: mv.visitInsn(Opcodes.F2D); break; 1251 default: error = true; break; 1252 } 1253 break; 1254 case DOUBLE: 1255 switch (to) { 1256 case LONG : mv.visitInsn(Opcodes.D2L); break; 1257 case FLOAT: mv.visitInsn(Opcodes.D2F); break; 1258 default: error = true; break; 1259 } 1260 break; 1261 default: 1262 error = true; 1263 break; 1264 } 1265 if (error) { 1266 throw new IllegalStateException("unhandled prim cast: " + from + "2" + to); 1267 } 1268 } 1269 } 1270 } 1271 1272 private void emitI2X(Wrapper type) { 1273 switch (type) { 1274 case BYTE: mv.visitInsn(Opcodes.I2B); break; 1275 case SHORT: mv.visitInsn(Opcodes.I2S); break; 1276 case CHAR: mv.visitInsn(Opcodes.I2C); break; 1277 case INT: /* naught */ break; 1278 case LONG: mv.visitInsn(Opcodes.I2L); break; 1279 case FLOAT: mv.visitInsn(Opcodes.I2F); break; 1280 case DOUBLE: mv.visitInsn(Opcodes.I2D); break; 1281 case BOOLEAN: 1282 // For compatibility with ValueConversions and explicitCastArguments: 1283 mv.visitInsn(Opcodes.ICONST_1); 1284 mv.visitInsn(Opcodes.IAND); 1285 break; 1286 default: throw new InternalError("unknown type: " + type); 1287 } 1288 } 1289 1290 private void emitX2I(Wrapper type) { 1291 switch (type) { 1292 case LONG: mv.visitInsn(Opcodes.L2I); break; 1293 case FLOAT: mv.visitInsn(Opcodes.F2I); break; 1294 case DOUBLE: mv.visitInsn(Opcodes.D2I); break; 1295 default: throw new InternalError("unknown type: " + type); 1296 } 1297 } 1298 1299 /** 1300 * Generate bytecode for a LambdaForm.vmentry which calls interpretWithArguments. 1301 */ 1302 static MemberName generateLambdaFormInterpreterEntryPoint(String sig) { 1303 assert(isValidSignature(sig)); 1304 String name = "interpret_"+signatureReturn(sig).basicTypeChar(); 1305 MethodType type = signatureType(sig); // sig includes leading argument 1306 type = type.changeParameterType(0, MethodHandle.class); 1307 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("LFI", name, type); 1308 return g.loadMethod(g.generateLambdaFormInterpreterEntryPointBytes()); 1309 } 1310 1311 private byte[] generateLambdaFormInterpreterEntryPointBytes() { 1312 classFilePrologue(); 1313 1314 // Suppress this method in backtraces displayed to the user. 1315 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true); 1316 1317 // Don't inline the interpreter entry. 1318 mv.visitAnnotation("Ljava/lang/invoke/DontInline;", true); 1319 1320 // create parameter array 1321 emitIconstInsn(invokerType.parameterCount()); 1322 mv.visitTypeInsn(Opcodes.ANEWARRAY, "java/lang/Object"); 1323 1324 // fill parameter array 1325 for (int i = 0; i < invokerType.parameterCount(); i++) { 1326 Class<?> ptype = invokerType.parameterType(i); 1327 mv.visitInsn(Opcodes.DUP); 1328 emitIconstInsn(i); 1329 emitLoadInsn(basicType(ptype), i); 1330 // box if primitive type 1331 if (ptype.isPrimitive()) { 1332 emitBoxing(Wrapper.forPrimitiveType(ptype)); 1333 } 1334 mv.visitInsn(Opcodes.AASTORE); 1335 } 1336 // invoke 1337 emitAloadInsn(0); 1338 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", "Ljava/lang/invoke/LambdaForm;"); 1339 mv.visitInsn(Opcodes.SWAP); // swap form and array; avoid local variable 1340 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, LF, "interpretWithArguments", "([Ljava/lang/Object;)Ljava/lang/Object;", false); 1341 1342 // maybe unbox 1343 Class<?> rtype = invokerType.returnType(); 1344 if (rtype.isPrimitive() && rtype != void.class) { 1345 emitUnboxing(Wrapper.forPrimitiveType(rtype)); 1346 } 1347 1348 // return statement 1349 emitReturnInsn(basicType(rtype)); 1350 1351 classFileEpilogue(); 1352 bogusMethod(invokerType); 1353 1354 final byte[] classFile = cw.toByteArray(); 1355 maybeDump(className, classFile); 1356 return classFile; 1357 } 1358 1359 /** 1360 * Generate bytecode for a NamedFunction invoker. 1361 */ 1362 static MemberName generateNamedFunctionInvoker(MethodTypeForm typeForm) { 1363 MethodType invokerType = NamedFunction.INVOKER_METHOD_TYPE; 1364 String invokerName = "invoke_" + shortenSignature(basicTypeSignature(typeForm.erasedType())); 1365 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("NFI", invokerName, invokerType); 1366 return g.loadMethod(g.generateNamedFunctionInvokerImpl(typeForm)); 1367 } 1368 1369 private byte[] generateNamedFunctionInvokerImpl(MethodTypeForm typeForm) { 1370 MethodType dstType = typeForm.erasedType(); 1371 classFilePrologue(); 1372 1373 // Suppress this method in backtraces displayed to the user. 1374 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true); 1375 1376 // Force inlining of this invoker method. 1377 mv.visitAnnotation("Ljava/lang/invoke/ForceInline;", true); 1378 1379 // Load receiver 1380 emitAloadInsn(0); 1381 1382 // Load arguments from array 1383 for (int i = 0; i < dstType.parameterCount(); i++) { 1384 emitAloadInsn(1); 1385 emitIconstInsn(i); 1386 mv.visitInsn(Opcodes.AALOAD); 1387 1388 // Maybe unbox 1389 Class<?> dptype = dstType.parameterType(i); 1390 if (dptype.isPrimitive()) { 1391 Class<?> sptype = dstType.basicType().wrap().parameterType(i); 1392 Wrapper dstWrapper = Wrapper.forBasicType(dptype); 1393 Wrapper srcWrapper = dstWrapper.isSubwordOrInt() ? Wrapper.INT : dstWrapper; // narrow subword from int 1394 emitUnboxing(srcWrapper); 1395 emitPrimCast(srcWrapper, dstWrapper); 1396 } 1397 } 1398 1399 // Invoke 1400 String targetDesc = dstType.basicType().toMethodDescriptorString(); 1401 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", targetDesc, false); 1402 1403 // Box primitive types 1404 Class<?> rtype = dstType.returnType(); 1405 if (rtype != void.class && rtype.isPrimitive()) { 1406 Wrapper srcWrapper = Wrapper.forBasicType(rtype); 1407 Wrapper dstWrapper = srcWrapper.isSubwordOrInt() ? Wrapper.INT : srcWrapper; // widen subword to int 1408 // boolean casts not allowed 1409 emitPrimCast(srcWrapper, dstWrapper); 1410 emitBoxing(dstWrapper); 1411 } 1412 1413 // If the return type is void we return a null reference. 1414 if (rtype == void.class) { 1415 mv.visitInsn(Opcodes.ACONST_NULL); 1416 } 1417 emitReturnInsn(L_TYPE); // NOTE: NamedFunction invokers always return a reference value. 1418 1419 classFileEpilogue(); 1420 bogusMethod(dstType); 1421 1422 final byte[] classFile = cw.toByteArray(); 1423 maybeDump(className, classFile); 1424 return classFile; 1425 } 1426 1427 /** 1428 * Emit a bogus method that just loads some string constants. This is to get the constants into the constant pool 1429 * for debugging purposes. 1430 */ 1431 private void bogusMethod(Object... os) { 1432 if (DUMP_CLASS_FILES) { 1433 mv = cw.visitMethod(Opcodes.ACC_STATIC, "dummy", "()V", null, null); 1434 for (Object o : os) { 1435 mv.visitLdcInsn(o.toString()); 1436 mv.visitInsn(Opcodes.POP); 1437 } 1438 mv.visitInsn(Opcodes.RETURN); 1439 mv.visitMaxs(0, 0); 1440 mv.visitEnd(); 1441 } 1442 } 1443 }