1 /* 2 * Copyright (c) 2012, 2014, 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$Name"; 55 private static final String CLS = "java/lang/Class"; 56 private static final String OBJ = "java/lang/Object"; 57 private static final String OBJARY = "[Ljava/lang/Object;"; 58 59 private static final String LF_SIG = "L" + LF + ";"; 60 private static final String LFN_SIG = "L" + LFN + ";"; 61 private static final String LL_SIG = "(L" + OBJ + ";)L" + OBJ + ";"; 62 private static final String CLL_SIG = "(L" + CLS + ";L" + OBJ + ";)L" + OBJ + ";"; 63 64 /** Name of its super class*/ 65 private static final String superName = OBJ; 66 67 /** Name of new class */ 68 private final String className; 69 70 /** Name of the source file (for stack trace printing). */ 71 private final String sourceFile; 72 73 private final LambdaForm lambdaForm; 74 private final String invokerName; 75 private final MethodType invokerType; 76 77 /** Info about local variables in compiled lambda form */ 78 private final int[] localsMap; // index 79 private final BasicType[] localTypes; // basic type 80 private final Class<?>[] localClasses; // type 81 82 /** ASM bytecode generation. */ 83 private ClassWriter cw; 84 private MethodVisitor mv; 85 86 private static final MemberName.Factory MEMBERNAME_FACTORY = MemberName.getFactory(); 87 private static final Class<?> HOST_CLASS = LambdaForm.class; 88 89 /** Main constructor; other constructors delegate to this one. */ 90 private InvokerBytecodeGenerator(LambdaForm lambdaForm, int localsMapSize, 91 String className, String invokerName, MethodType invokerType) { 92 if (invokerName.contains(".")) { 93 int p = invokerName.indexOf('.'); 94 className = invokerName.substring(0, p); 95 invokerName = invokerName.substring(p+1); 96 } 97 if (DUMP_CLASS_FILES) { 98 className = makeDumpableClassName(className); 99 } 100 this.className = LF + "$" + className; 101 this.sourceFile = "LambdaForm$" + className; 102 this.lambdaForm = lambdaForm; 103 this.invokerName = invokerName; 104 this.invokerType = invokerType; 105 this.localsMap = new int[localsMapSize+1]; 106 // last entry of localsMap is count of allocated local slots 107 this.localTypes = new BasicType[localsMapSize+1]; 108 this.localClasses = new Class<?>[localsMapSize+1]; 109 } 110 111 /** For generating LambdaForm interpreter entry points. */ 112 private InvokerBytecodeGenerator(String className, String invokerName, MethodType invokerType) { 113 this(null, invokerType.parameterCount(), 114 className, invokerName, invokerType); 115 // Create an array to map name indexes to locals indexes. 116 localTypes[localTypes.length - 1] = V_TYPE; 117 for (int i = 0; i < localsMap.length; i++) { 118 localsMap[i] = invokerType.parameterSlotCount() - invokerType.parameterSlotDepth(i); 119 if (i < invokerType.parameterCount()) 120 localTypes[i] = basicType(invokerType.parameterType(i)); 121 } 122 } 123 124 /** For generating customized code for a single LambdaForm. */ 125 private InvokerBytecodeGenerator(String className, LambdaForm form, MethodType invokerType) { 126 this(form, form.names.length, 127 className, form.debugName, invokerType); 128 // Create an array to map name indexes to locals indexes. 129 Name[] names = form.names; 130 for (int i = 0, index = 0; i < localsMap.length; i++) { 131 localsMap[i] = index; 132 if (i < names.length) { 133 BasicType type = names[i].type(); 134 index += type.basicTypeSlots(); 135 localTypes[i] = type; 136 } 137 } 138 } 139 140 141 /** instance counters for dumped classes */ 142 private final static HashMap<String,Integer> DUMP_CLASS_FILES_COUNTERS; 143 /** debugging flag for saving generated class files */ 144 private final static File DUMP_CLASS_FILES_DIR; 145 146 static { 147 if (DUMP_CLASS_FILES) { 148 DUMP_CLASS_FILES_COUNTERS = new HashMap<>(); 149 try { 150 File dumpDir = new File("DUMP_CLASS_FILES"); 151 if (!dumpDir.exists()) { 152 dumpDir.mkdirs(); 153 } 154 DUMP_CLASS_FILES_DIR = dumpDir; 155 System.out.println("Dumping class files to "+DUMP_CLASS_FILES_DIR+"/..."); 156 } catch (Exception e) { 157 throw newInternalError(e); 158 } 159 } else { 160 DUMP_CLASS_FILES_COUNTERS = null; 161 DUMP_CLASS_FILES_DIR = null; 162 } 163 } 164 165 static void maybeDump(final String className, final byte[] classFile) { 166 if (DUMP_CLASS_FILES) { 167 java.security.AccessController.doPrivileged( 168 new java.security.PrivilegedAction<Void>() { 169 public Void run() { 170 try { 171 String dumpName = className; 172 //dumpName = dumpName.replace('/', '-'); 173 File dumpFile = new File(DUMP_CLASS_FILES_DIR, dumpName+".class"); 174 System.out.println("dump: " + dumpFile); 175 dumpFile.getParentFile().mkdirs(); 176 FileOutputStream file = new FileOutputStream(dumpFile); 177 file.write(classFile); 178 file.close(); 179 return null; 180 } catch (IOException ex) { 181 throw newInternalError(ex); 182 } 183 } 184 }); 185 } 186 187 } 188 189 private static String makeDumpableClassName(String className) { 190 Integer ctr; 191 synchronized (DUMP_CLASS_FILES_COUNTERS) { 192 ctr = DUMP_CLASS_FILES_COUNTERS.get(className); 193 if (ctr == null) ctr = 0; 194 DUMP_CLASS_FILES_COUNTERS.put(className, ctr+1); 195 } 196 String sfx = ctr.toString(); 197 while (sfx.length() < 3) 198 sfx = "0"+sfx; 199 className += sfx; 200 return className; 201 } 202 203 class CpPatch { 204 final int index; 205 final String placeholder; 206 final Object value; 207 CpPatch(int index, String placeholder, Object value) { 208 this.index = index; 209 this.placeholder = placeholder; 210 this.value = value; 211 } 212 public String toString() { 213 return "CpPatch/index="+index+",placeholder="+placeholder+",value="+value; 214 } 215 } 216 217 Map<Object, CpPatch> cpPatches = new HashMap<>(); 218 219 int cph = 0; // for counting constant placeholders 220 221 String constantPlaceholder(Object arg) { 222 String cpPlaceholder = "CONSTANT_PLACEHOLDER_" + cph++; 223 if (DUMP_CLASS_FILES) cpPlaceholder += " <<" + debugString(arg) + ">>"; // debugging aid 224 if (cpPatches.containsKey(cpPlaceholder)) { 225 throw new InternalError("observed CP placeholder twice: " + cpPlaceholder); 226 } 227 // insert placeholder in CP and remember the patch 228 int index = cw.newConst((Object) cpPlaceholder); // TODO check if already in the constant pool 229 cpPatches.put(cpPlaceholder, new CpPatch(index, cpPlaceholder, arg)); 230 return cpPlaceholder; 231 } 232 233 Object[] cpPatches(byte[] classFile) { 234 int size = getConstantPoolSize(classFile); 235 Object[] res = new Object[size]; 236 for (CpPatch p : cpPatches.values()) { 237 if (p.index >= size) 238 throw new InternalError("in cpool["+size+"]: "+p+"\n"+Arrays.toString(Arrays.copyOf(classFile, 20))); 239 res[p.index] = p.value; 240 } 241 return res; 242 } 243 244 private static String debugString(Object arg) { 245 if (arg instanceof MethodHandle) { 246 MethodHandle mh = (MethodHandle) arg; 247 MemberName member = mh.internalMemberName(); 248 if (member != null) 249 return member.toString(); 250 return mh.debugString(); 251 } 252 return arg.toString(); 253 } 254 255 /** 256 * Extract the number of constant pool entries from a given class file. 257 * 258 * @param classFile the bytes of the class file in question. 259 * @return the number of entries in the constant pool. 260 */ 261 private static int getConstantPoolSize(byte[] classFile) { 262 // The first few bytes: 263 // u4 magic; 264 // u2 minor_version; 265 // u2 major_version; 266 // u2 constant_pool_count; 267 return ((classFile[8] & 0xFF) << 8) | (classFile[9] & 0xFF); 268 } 269 270 /** 271 * Extract the MemberName of a newly-defined method. 272 */ 273 private MemberName loadMethod(byte[] classFile) { 274 Class<?> invokerClass = loadAndInitializeInvokerClass(classFile, cpPatches(classFile)); 275 return resolveInvokerMember(invokerClass, invokerName, invokerType); 276 } 277 278 /** 279 * Define a given class as anonymous class in the runtime system. 280 */ 281 private static Class<?> loadAndInitializeInvokerClass(byte[] classBytes, Object[] patches) { 282 Class<?> invokerClass = UNSAFE.defineAnonymousClass(HOST_CLASS, classBytes, patches); 283 UNSAFE.ensureClassInitialized(invokerClass); // Make sure the class is initialized; VM might complain. 284 return invokerClass; 285 } 286 287 private static MemberName resolveInvokerMember(Class<?> invokerClass, String name, MethodType type) { 288 MemberName member = new MemberName(invokerClass, name, type, REF_invokeStatic); 289 try { 290 member = MEMBERNAME_FACTORY.resolveOrFail(REF_invokeStatic, member, HOST_CLASS, ReflectiveOperationException.class); 291 } catch (ReflectiveOperationException e) { 292 throw newInternalError(e); 293 } 294 return member; 295 } 296 297 /** 298 * Set up class file generation. 299 */ 300 private void classFilePrologue() { 301 final int NOT_ACC_PUBLIC = 0; // not ACC_PUBLIC 302 cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES); 303 cw.visit(Opcodes.V1_8, NOT_ACC_PUBLIC + Opcodes.ACC_FINAL + Opcodes.ACC_SUPER, className, null, superName, null); 304 cw.visitSource(sourceFile, null); 305 306 String invokerDesc = invokerType.toMethodDescriptorString(); 307 mv = cw.visitMethod(Opcodes.ACC_STATIC, invokerName, invokerDesc, null, null); 308 } 309 310 /** 311 * Tear down class file generation. 312 */ 313 private void classFileEpilogue() { 314 mv.visitMaxs(0, 0); 315 mv.visitEnd(); 316 } 317 318 /* 319 * Low-level emit helpers. 320 */ 321 private void emitConst(Object con) { 322 if (con == null) { 323 mv.visitInsn(Opcodes.ACONST_NULL); 324 return; 325 } 326 if (con instanceof Integer) { 327 emitIconstInsn((int) con); 328 return; 329 } 330 if (con instanceof Long) { 331 long x = (long) con; 332 if (x == (short) x) { 333 emitIconstInsn((int) x); 334 mv.visitInsn(Opcodes.I2L); 335 return; 336 } 337 } 338 if (con instanceof Float) { 339 float x = (float) con; 340 if (x == (short) x) { 341 emitIconstInsn((int) x); 342 mv.visitInsn(Opcodes.I2F); 343 return; 344 } 345 } 346 if (con instanceof Double) { 347 double x = (double) con; 348 if (x == (short) x) { 349 emitIconstInsn((int) x); 350 mv.visitInsn(Opcodes.I2D); 351 return; 352 } 353 } 354 if (con instanceof Boolean) { 355 emitIconstInsn((boolean) con ? 1 : 0); 356 return; 357 } 358 // fall through: 359 mv.visitLdcInsn(con); 360 } 361 362 private void emitIconstInsn(int i) { 363 int opcode; 364 switch (i) { 365 case 0: opcode = Opcodes.ICONST_0; break; 366 case 1: opcode = Opcodes.ICONST_1; break; 367 case 2: opcode = Opcodes.ICONST_2; break; 368 case 3: opcode = Opcodes.ICONST_3; break; 369 case 4: opcode = Opcodes.ICONST_4; break; 370 case 5: opcode = Opcodes.ICONST_5; break; 371 default: 372 if (i == (byte) i) { 373 mv.visitIntInsn(Opcodes.BIPUSH, i & 0xFF); 374 } else if (i == (short) i) { 375 mv.visitIntInsn(Opcodes.SIPUSH, (char) i); 376 } else { 377 mv.visitLdcInsn(i); 378 } 379 return; 380 } 381 mv.visitInsn(opcode); 382 } 383 384 /* 385 * NOTE: These load/store methods use the localsMap to find the correct index! 386 */ 387 private void emitLoadInsn(BasicType type, int index) { 388 int opcode = loadInsnOpcode(type); 389 mv.visitVarInsn(opcode, localsMap[index]); 390 } 391 392 private int loadInsnOpcode(BasicType type) throws InternalError { 393 switch (type) { 394 case I_TYPE: return Opcodes.ILOAD; 395 case J_TYPE: return Opcodes.LLOAD; 396 case F_TYPE: return Opcodes.FLOAD; 397 case D_TYPE: return Opcodes.DLOAD; 398 case L_TYPE: return Opcodes.ALOAD; 399 default: 400 throw new InternalError("unknown type: " + type); 401 } 402 } 403 private void emitAloadInsn(int index) { 404 emitLoadInsn(L_TYPE, index); 405 } 406 407 private void emitStoreInsn(BasicType type, int index) { 408 int opcode = storeInsnOpcode(type); 409 mv.visitVarInsn(opcode, localsMap[index]); 410 } 411 412 private int storeInsnOpcode(BasicType type) throws InternalError { 413 switch (type) { 414 case I_TYPE: return Opcodes.ISTORE; 415 case J_TYPE: return Opcodes.LSTORE; 416 case F_TYPE: return Opcodes.FSTORE; 417 case D_TYPE: return Opcodes.DSTORE; 418 case L_TYPE: return Opcodes.ASTORE; 419 default: 420 throw new InternalError("unknown type: " + type); 421 } 422 } 423 private void emitAstoreInsn(int index) { 424 emitStoreInsn(L_TYPE, index); 425 } 426 427 private byte arrayTypeCode(Wrapper elementType) { 428 switch (elementType) { 429 case BOOLEAN: return Opcodes.T_BOOLEAN; 430 case BYTE: return Opcodes.T_BYTE; 431 case CHAR: return Opcodes.T_CHAR; 432 case SHORT: return Opcodes.T_SHORT; 433 case INT: return Opcodes.T_INT; 434 case LONG: return Opcodes.T_LONG; 435 case FLOAT: return Opcodes.T_FLOAT; 436 case DOUBLE: return Opcodes.T_DOUBLE; 437 case OBJECT: return 0; // in place of Opcodes.T_OBJECT 438 default: throw new InternalError(); 439 } 440 } 441 442 private int arrayInsnOpcode(byte tcode, int aaop) throws InternalError { 443 assert(aaop == Opcodes.AASTORE || aaop == Opcodes.AALOAD); 444 int xas; 445 switch (tcode) { 446 case Opcodes.T_BOOLEAN: xas = Opcodes.BASTORE; break; 447 case Opcodes.T_BYTE: xas = Opcodes.BASTORE; break; 448 case Opcodes.T_CHAR: xas = Opcodes.CASTORE; break; 449 case Opcodes.T_SHORT: xas = Opcodes.SASTORE; break; 450 case Opcodes.T_INT: xas = Opcodes.IASTORE; break; 451 case Opcodes.T_LONG: xas = Opcodes.LASTORE; break; 452 case Opcodes.T_FLOAT: xas = Opcodes.FASTORE; break; 453 case Opcodes.T_DOUBLE: xas = Opcodes.DASTORE; break; 454 case 0: xas = Opcodes.AASTORE; break; 455 default: throw new InternalError(); 456 } 457 return xas - Opcodes.AASTORE + aaop; 458 } 459 460 461 private void freeFrameLocal(int oldFrameLocal) { 462 int i = indexForFrameLocal(oldFrameLocal); 463 if (i < 0) return; 464 BasicType type = localTypes[i]; 465 int newFrameLocal = makeLocalTemp(type); 466 mv.visitVarInsn(loadInsnOpcode(type), oldFrameLocal); 467 mv.visitVarInsn(storeInsnOpcode(type), newFrameLocal); 468 assert(localsMap[i] == oldFrameLocal); 469 localsMap[i] = newFrameLocal; 470 assert(indexForFrameLocal(oldFrameLocal) < 0); 471 } 472 private int indexForFrameLocal(int frameLocal) { 473 for (int i = 0; i < localsMap.length; i++) { 474 if (localsMap[i] == frameLocal && localTypes[i] != V_TYPE) 475 return i; 476 } 477 return -1; 478 } 479 private int makeLocalTemp(BasicType type) { 480 int frameLocal = localsMap[localsMap.length - 1]; 481 localsMap[localsMap.length - 1] = frameLocal + type.basicTypeSlots(); 482 return frameLocal; 483 } 484 485 /** 486 * Emit a boxing call. 487 * 488 * @param wrapper primitive type class to box. 489 */ 490 private void emitBoxing(Wrapper wrapper) { 491 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName(); 492 String name = "valueOf"; 493 String desc = "(" + wrapper.basicTypeChar() + ")L" + owner + ";"; 494 mv.visitMethodInsn(Opcodes.INVOKESTATIC, owner, name, desc, false); 495 } 496 497 /** 498 * Emit an unboxing call (plus preceding checkcast). 499 * 500 * @param wrapper wrapper type class to unbox. 501 */ 502 private void emitUnboxing(Wrapper wrapper) { 503 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName(); 504 String name = wrapper.primitiveSimpleName() + "Value"; 505 String desc = "()" + wrapper.basicTypeChar(); 506 emitReferenceCast(wrapper.wrapperType(), null); 507 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, owner, name, desc, false); 508 } 509 510 /** 511 * Emit an implicit conversion for an argument which must be of the given pclass. 512 * This is usually a no-op, except when pclass is a subword type or a reference other than Object or an interface. 513 * 514 * @param ptype type of value present on stack 515 * @param pclass type of value required on stack 516 * @param arg compile-time representation of value on stack (Node, constant) or null if none 517 */ 518 private void emitImplicitConversion(BasicType ptype, Class<?> pclass, Object arg) { 519 assert(basicType(pclass) == ptype); // boxing/unboxing handled by caller 520 if (pclass == ptype.basicTypeClass() && ptype != L_TYPE) 521 return; // nothing to do 522 switch (ptype) { 523 case L_TYPE: 524 if (VerifyType.isNullConversion(Object.class, pclass, false)) { 525 if (PROFILE_LEVEL > 0) 526 emitReferenceCast(Object.class, arg); 527 return; 528 } 529 emitReferenceCast(pclass, arg); 530 return; 531 case I_TYPE: 532 if (!VerifyType.isNullConversion(int.class, pclass, false)) 533 emitPrimCast(ptype.basicTypeWrapper(), Wrapper.forPrimitiveType(pclass)); 534 return; 535 } 536 throw newInternalError("bad implicit conversion: tc="+ptype+": "+pclass); 537 } 538 539 /** Update localClasses type map. Return true if the information is already present. */ 540 private boolean assertStaticType(Class<?> cls, Name n) { 541 int local = n.index(); 542 Class<?> aclass = localClasses[local]; 543 if (aclass != null && (aclass == cls || cls.isAssignableFrom(aclass))) { 544 return true; // type info is already present 545 } else if (aclass == null || aclass.isAssignableFrom(cls)) { 546 localClasses[local] = cls; // type info can be improved 547 } 548 return false; 549 } 550 551 private void emitReferenceCast(Class<?> cls, Object arg) { 552 Name writeBack = null; // local to write back result 553 if (arg instanceof Name) { 554 Name n = (Name) arg; 555 if (assertStaticType(cls, n)) 556 return; // this cast was already performed 557 if (lambdaForm.useCount(n) > 1) { 558 // This guy gets used more than once. 559 writeBack = n; 560 } 561 } 562 if (isStaticallyNameable(cls)) { 563 String sig = getInternalName(cls); 564 mv.visitTypeInsn(Opcodes.CHECKCAST, sig); 565 } else { 566 mv.visitLdcInsn(constantPlaceholder(cls)); 567 mv.visitTypeInsn(Opcodes.CHECKCAST, CLS); 568 mv.visitInsn(Opcodes.SWAP); 569 mv.visitMethodInsn(Opcodes.INVOKESTATIC, MHI, "castReference", CLL_SIG, false); 570 if (Object[].class.isAssignableFrom(cls)) 571 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJARY); 572 else if (PROFILE_LEVEL > 0) 573 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJ); 574 } 575 if (writeBack != null) { 576 mv.visitInsn(Opcodes.DUP); 577 emitAstoreInsn(writeBack.index()); 578 } 579 } 580 581 /** 582 * Emits an actual return instruction conforming to the given return type. 583 */ 584 private void emitReturnInsn(BasicType type) { 585 int opcode; 586 switch (type) { 587 case I_TYPE: opcode = Opcodes.IRETURN; break; 588 case J_TYPE: opcode = Opcodes.LRETURN; break; 589 case F_TYPE: opcode = Opcodes.FRETURN; break; 590 case D_TYPE: opcode = Opcodes.DRETURN; break; 591 case L_TYPE: opcode = Opcodes.ARETURN; break; 592 case V_TYPE: opcode = Opcodes.RETURN; break; 593 default: 594 throw new InternalError("unknown return type: " + type); 595 } 596 mv.visitInsn(opcode); 597 } 598 599 private static String getInternalName(Class<?> c) { 600 if (c == Object.class) return OBJ; 601 else if (c == Object[].class) return OBJARY; 602 else if (c == Class.class) return CLS; 603 else if (c == MethodHandle.class) return MH; 604 assert(VerifyAccess.isTypeVisible(c, Object.class)) : c.getName(); 605 return c.getName().replace('.', '/'); 606 } 607 608 /** 609 * Generate customized bytecode for a given LambdaForm. 610 */ 611 static MemberName generateCustomizedCode(LambdaForm form, MethodType invokerType) { 612 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("MH", form, invokerType); 613 return g.loadMethod(g.generateCustomizedCodeBytes()); 614 } 615 616 /** 617 * Generate an invoker method for the passed {@link LambdaForm}. 618 */ 619 private byte[] generateCustomizedCodeBytes() { 620 classFilePrologue(); 621 622 // Suppress this method in backtraces displayed to the user. 623 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true); 624 625 // Mark this method as a compiled LambdaForm 626 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Compiled;", true); 627 628 if (lambdaForm.forceInline) { 629 // Force inlining of this invoker method. 630 mv.visitAnnotation("Ljava/lang/invoke/ForceInline;", true); 631 } else { 632 mv.visitAnnotation("Ljava/lang/invoke/DontInline;", true); 633 } 634 635 636 // iterate over the form's names, generating bytecode instructions for each 637 // start iterating at the first name following the arguments 638 Name onStack = null; 639 for (int i = lambdaForm.arity; i < lambdaForm.names.length; i++) { 640 Name name = lambdaForm.names[i]; 641 642 emitStoreResult(onStack); 643 onStack = name; // unless otherwise modified below 644 MethodHandleImpl.Intrinsic intr = name.function.intrinsicName(); 645 switch (intr) { 646 case SELECT_ALTERNATIVE: 647 assert isSelectAlternative(i); 648 onStack = emitSelectAlternative(name, lambdaForm.names[i+1]); 649 i++; // skip MH.invokeBasic of the selectAlternative result 650 continue; 651 case GUARD_WITH_CATCH: 652 assert isGuardWithCatch(i); 653 onStack = emitGuardWithCatch(i); 654 i = i+2; // Jump to the end of GWC idiom 655 continue; 656 case NEW_ARRAY: 657 Class<?> rtype = name.function.methodType().returnType(); 658 if (isStaticallyNameable(rtype)) { 659 emitNewArray(name); 660 continue; 661 } 662 break; 663 case ARRAY_LOAD: 664 emitArrayLoad(name); 665 continue; 666 case ARRAY_STORE: 667 emitArrayStore(name); 668 continue; 669 case IDENTITY: 670 assert(name.arguments.length == 1); 671 emitPushArguments(name); 672 continue; 673 case ZERO: 674 assert(name.arguments.length == 0); 675 emitConst(name.type.basicTypeWrapper().zero()); 676 continue; 677 case NONE: 678 // no intrinsic associated 679 break; 680 default: 681 throw newInternalError("Unknown intrinsic: "+intr); 682 } 683 684 MemberName member = name.function.member(); 685 if (isStaticallyInvocable(member)) { 686 emitStaticInvoke(member, name); 687 } else { 688 emitInvoke(name); 689 } 690 } 691 692 // return statement 693 emitReturn(onStack); 694 695 classFileEpilogue(); 696 bogusMethod(lambdaForm); 697 698 final byte[] classFile = cw.toByteArray(); 699 maybeDump(className, classFile); 700 return classFile; 701 } 702 703 void emitArrayLoad(Name name) { emitArrayOp(name, Opcodes.AALOAD); } 704 void emitArrayStore(Name name) { emitArrayOp(name, Opcodes.AASTORE); } 705 706 void emitArrayOp(Name name, int arrayOpcode) { 707 assert arrayOpcode == Opcodes.AALOAD || arrayOpcode == Opcodes.AASTORE; 708 Class<?> elementType = name.function.methodType().parameterType(0).getComponentType(); 709 assert elementType != null; 710 emitPushArguments(name); 711 if (elementType.isPrimitive()) { 712 Wrapper w = Wrapper.forPrimitiveType(elementType); 713 arrayOpcode = arrayInsnOpcode(arrayTypeCode(w), arrayOpcode); 714 } 715 mv.visitInsn(arrayOpcode); 716 } 717 718 /** 719 * Emit an invoke for the given name. 720 */ 721 void emitInvoke(Name name) { 722 assert(!isLinkerMethodInvoke(name)); // should use the static path for these 723 if (true) { 724 // push receiver 725 MethodHandle target = name.function.resolvedHandle; 726 assert(target != null) : name.exprString(); 727 mv.visitLdcInsn(constantPlaceholder(target)); 728 emitReferenceCast(MethodHandle.class, target); 729 } else { 730 // load receiver 731 emitAloadInsn(0); 732 emitReferenceCast(MethodHandle.class, null); 733 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", LF_SIG); 734 mv.visitFieldInsn(Opcodes.GETFIELD, LF, "names", LFN_SIG); 735 // TODO more to come 736 } 737 738 // push arguments 739 emitPushArguments(name); 740 741 // invocation 742 MethodType type = name.function.methodType(); 743 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false); 744 } 745 746 static private Class<?>[] STATICALLY_INVOCABLE_PACKAGES = { 747 // Sample classes from each package we are willing to bind to statically: 748 java.lang.Object.class, 749 java.util.Arrays.class, 750 sun.misc.Unsafe.class 751 //MethodHandle.class already covered 752 }; 753 754 static boolean isStaticallyInvocable(Name name) { 755 return isStaticallyInvocable(name.function.member()); 756 } 757 758 static boolean isStaticallyInvocable(MemberName member) { 759 if (member == null) return false; 760 if (member.isConstructor()) return false; 761 Class<?> cls = member.getDeclaringClass(); 762 if (cls.isArray() || cls.isPrimitive()) 763 return false; // FIXME 764 if (cls.isAnonymousClass() || cls.isLocalClass()) 765 return false; // inner class of some sort 766 if (cls.getClassLoader() != MethodHandle.class.getClassLoader()) 767 return false; // not on BCP 768 if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: switch to supported API once it is added 769 return false; 770 MethodType mtype = member.getMethodOrFieldType(); 771 if (!isStaticallyNameable(mtype.returnType())) 772 return false; 773 for (Class<?> ptype : mtype.parameterArray()) 774 if (!isStaticallyNameable(ptype)) 775 return false; 776 if (!member.isPrivate() && VerifyAccess.isSamePackage(MethodHandle.class, cls)) 777 return true; // in java.lang.invoke package 778 if (member.isPublic() && isStaticallyNameable(cls)) 779 return true; 780 return false; 781 } 782 783 static boolean isStaticallyNameable(Class<?> cls) { 784 if (cls == Object.class) 785 return true; 786 while (cls.isArray()) 787 cls = cls.getComponentType(); 788 if (cls.isPrimitive()) 789 return true; // int[].class, for example 790 if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: switch to supported API once it is added 791 return false; 792 // could use VerifyAccess.isClassAccessible but the following is a safe approximation 793 if (cls.getClassLoader() != Object.class.getClassLoader()) 794 return false; 795 if (VerifyAccess.isSamePackage(MethodHandle.class, cls)) 796 return true; 797 if (!Modifier.isPublic(cls.getModifiers())) 798 return false; 799 for (Class<?> pkgcls : STATICALLY_INVOCABLE_PACKAGES) { 800 if (VerifyAccess.isSamePackage(pkgcls, cls)) 801 return true; 802 } 803 return false; 804 } 805 806 void emitStaticInvoke(Name name) { 807 emitStaticInvoke(name.function.member(), name); 808 } 809 810 /** 811 * Emit an invoke for the given name, using the MemberName directly. 812 */ 813 void emitStaticInvoke(MemberName member, Name name) { 814 assert(member.equals(name.function.member())); 815 Class<?> defc = member.getDeclaringClass(); 816 String cname = getInternalName(defc); 817 String mname = member.getName(); 818 String mtype; 819 byte refKind = member.getReferenceKind(); 820 if (refKind == REF_invokeSpecial) { 821 // in order to pass the verifier, we need to convert this to invokevirtual in all cases 822 assert(member.canBeStaticallyBound()) : member; 823 refKind = REF_invokeVirtual; 824 } 825 826 if (member.getDeclaringClass().isInterface() && refKind == REF_invokeVirtual) { 827 // Methods from Object declared in an interface can be resolved by JVM to invokevirtual kind. 828 // Need to convert it back to invokeinterface to pass verification and make the invocation works as expected. 829 refKind = REF_invokeInterface; 830 } 831 832 // push arguments 833 emitPushArguments(name); 834 835 // invocation 836 if (member.isMethod()) { 837 mtype = member.getMethodType().toMethodDescriptorString(); 838 mv.visitMethodInsn(refKindOpcode(refKind), cname, mname, mtype, 839 member.getDeclaringClass().isInterface()); 840 } else { 841 mtype = MethodType.toFieldDescriptorString(member.getFieldType()); 842 mv.visitFieldInsn(refKindOpcode(refKind), cname, mname, mtype); 843 } 844 // Issue a type assertion for the result, so we can avoid casts later. 845 if (name.type == L_TYPE) { 846 Class<?> rtype = member.getInvocationType().returnType(); 847 assert(!rtype.isPrimitive()); 848 if (rtype != Object.class && !rtype.isInterface()) { 849 assertStaticType(rtype, name); 850 } 851 } 852 } 853 854 void emitNewArray(Name name) throws InternalError { 855 Class<?> rtype = name.function.methodType().returnType(); 856 if (name.arguments.length == 0) { 857 // The array will be a constant. 858 Object emptyArray; 859 try { 860 emptyArray = name.function.resolvedHandle.invoke(); 861 } catch (Throwable ex) { 862 throw newInternalError(ex); 863 } 864 assert(java.lang.reflect.Array.getLength(emptyArray) == 0); 865 assert(emptyArray.getClass() == rtype); // exact typing 866 mv.visitLdcInsn(constantPlaceholder(emptyArray)); 867 emitReferenceCast(rtype, emptyArray); 868 return; 869 } 870 Class<?> arrayElementType = rtype.getComponentType(); 871 assert(arrayElementType != null); 872 emitIconstInsn(name.arguments.length); 873 int xas = Opcodes.AASTORE; 874 if (!arrayElementType.isPrimitive()) { 875 mv.visitTypeInsn(Opcodes.ANEWARRAY, getInternalName(arrayElementType)); 876 } else { 877 byte tc = arrayTypeCode(Wrapper.forPrimitiveType(arrayElementType)); 878 xas = arrayInsnOpcode(tc, xas); 879 mv.visitIntInsn(Opcodes.NEWARRAY, tc); 880 } 881 // store arguments 882 for (int i = 0; i < name.arguments.length; i++) { 883 mv.visitInsn(Opcodes.DUP); 884 emitIconstInsn(i); 885 emitPushArgument(name, i); 886 mv.visitInsn(xas); 887 } 888 // the array is left on the stack 889 assertStaticType(rtype, name); 890 } 891 int refKindOpcode(byte refKind) { 892 switch (refKind) { 893 case REF_invokeVirtual: return Opcodes.INVOKEVIRTUAL; 894 case REF_invokeStatic: return Opcodes.INVOKESTATIC; 895 case REF_invokeSpecial: return Opcodes.INVOKESPECIAL; 896 case REF_invokeInterface: return Opcodes.INVOKEINTERFACE; 897 case REF_getField: return Opcodes.GETFIELD; 898 case REF_putField: return Opcodes.PUTFIELD; 899 case REF_getStatic: return Opcodes.GETSTATIC; 900 case REF_putStatic: return Opcodes.PUTSTATIC; 901 } 902 throw new InternalError("refKind="+refKind); 903 } 904 905 /** 906 * Check if MemberName is a call to a method named {@code name} in class {@code declaredClass}. 907 */ 908 private boolean memberRefersTo(MemberName member, Class<?> declaringClass, String name) { 909 return member != null && 910 member.getDeclaringClass() == declaringClass && 911 member.getName().equals(name); 912 } 913 private boolean nameRefersTo(Name name, Class<?> declaringClass, String methodName) { 914 return name.function != null && 915 memberRefersTo(name.function.member(), declaringClass, methodName); 916 } 917 918 /** 919 * Check if MemberName is a call to MethodHandle.invokeBasic. 920 */ 921 private boolean isInvokeBasic(Name name) { 922 if (name.function == null) 923 return false; 924 if (name.arguments.length < 1) 925 return false; // must have MH argument 926 MemberName member = name.function.member(); 927 return memberRefersTo(member, MethodHandle.class, "invokeBasic") && 928 !member.isPublic() && !member.isStatic(); 929 } 930 931 /** 932 * Check if MemberName is a call to MethodHandle.linkToStatic, etc. 933 */ 934 private boolean isLinkerMethodInvoke(Name name) { 935 if (name.function == null) 936 return false; 937 if (name.arguments.length < 1) 938 return false; // must have MH argument 939 MemberName member = name.function.member(); 940 return member != null && 941 member.getDeclaringClass() == MethodHandle.class && 942 !member.isPublic() && member.isStatic() && 943 member.getName().startsWith("linkTo"); 944 } 945 946 /** 947 * Check if i-th name is a call to MethodHandleImpl.selectAlternative. 948 */ 949 private boolean isSelectAlternative(int pos) { 950 // selectAlternative idiom: 951 // t_{n}:L=MethodHandleImpl.selectAlternative(...) 952 // t_{n+1}:?=MethodHandle.invokeBasic(t_{n}, ...) 953 if (pos+1 >= lambdaForm.names.length) return false; 954 Name name0 = lambdaForm.names[pos]; 955 Name name1 = lambdaForm.names[pos+1]; 956 return nameRefersTo(name0, MethodHandleImpl.class, "selectAlternative") && 957 isInvokeBasic(name1) && 958 name1.lastUseIndex(name0) == 0 && // t_{n+1}:?=MethodHandle.invokeBasic(t_{n}, ...) 959 lambdaForm.lastUseIndex(name0) == pos+1; // t_{n} is local: used only in t_{n+1} 960 } 961 962 /** 963 * Check if i-th name is a start of GuardWithCatch idiom. 964 */ 965 private boolean isGuardWithCatch(int pos) { 966 // GuardWithCatch idiom: 967 // t_{n}:L=MethodHandle.invokeBasic(...) 968 // t_{n+1}:L=MethodHandleImpl.guardWithCatch(*, *, *, t_{n}); 969 // t_{n+2}:?=MethodHandle.invokeBasic(t_{n+1}) 970 if (pos+2 >= lambdaForm.names.length) return false; 971 Name name0 = lambdaForm.names[pos]; 972 Name name1 = lambdaForm.names[pos+1]; 973 Name name2 = lambdaForm.names[pos+2]; 974 return nameRefersTo(name1, MethodHandleImpl.class, "guardWithCatch") && 975 isInvokeBasic(name0) && 976 isInvokeBasic(name2) && 977 name1.lastUseIndex(name0) == 3 && // t_{n+1}:L=MethodHandleImpl.guardWithCatch(*, *, *, t_{n}); 978 lambdaForm.lastUseIndex(name0) == pos+1 && // t_{n} is local: used only in t_{n+1} 979 name2.lastUseIndex(name1) == 1 && // t_{n+2}:?=MethodHandle.invokeBasic(t_{n+1}) 980 lambdaForm.lastUseIndex(name1) == pos+2; // t_{n+1} is local: used only in t_{n+2} 981 } 982 983 /** 984 * Emit bytecode for the selectAlternative idiom. 985 * 986 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithTest): 987 * <blockquote><pre>{@code 988 * Lambda(a0:L,a1:I)=>{ 989 * t2:I=foo.test(a1:I); 990 * t3:L=MethodHandleImpl.selectAlternative(t2:I,(MethodHandle(int)int),(MethodHandle(int)int)); 991 * t4:I=MethodHandle.invokeBasic(t3:L,a1:I);t4:I} 992 * }</pre></blockquote> 993 */ 994 private Name emitSelectAlternative(Name selectAlternativeName, Name invokeBasicName) { 995 assert isStaticallyInvocable(invokeBasicName); 996 997 Name receiver = (Name) invokeBasicName.arguments[0]; 998 999 Label L_fallback = new Label(); 1000 Label L_done = new Label(); 1001 1002 // load test result 1003 emitPushArgument(selectAlternativeName, 0); 1004 1005 // if_icmpne L_fallback 1006 mv.visitJumpInsn(Opcodes.IFEQ, L_fallback); 1007 1008 // invoke selectAlternativeName.arguments[1] 1009 Class<?>[] preForkClasses = localClasses.clone(); 1010 emitPushArgument(selectAlternativeName, 1); // get 2nd argument of selectAlternative 1011 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot 1012 emitStaticInvoke(invokeBasicName); 1013 1014 // goto L_done 1015 mv.visitJumpInsn(Opcodes.GOTO, L_done); 1016 1017 // L_fallback: 1018 mv.visitLabel(L_fallback); 1019 1020 // invoke selectAlternativeName.arguments[2] 1021 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length); 1022 emitPushArgument(selectAlternativeName, 2); // get 3rd argument of selectAlternative 1023 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot 1024 emitStaticInvoke(invokeBasicName); 1025 1026 // L_done: 1027 mv.visitLabel(L_done); 1028 // for now do not bother to merge typestate; just reset to the dominator state 1029 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length); 1030 1031 return invokeBasicName; // return what's on stack 1032 } 1033 1034 /** 1035 * Emit bytecode for the guardWithCatch idiom. 1036 * 1037 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithCatch): 1038 * <blockquote><pre>{@code 1039 * guardWithCatch=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L,a5:L,a6:L,a7:L)=>{ 1040 * t8:L=MethodHandle.invokeBasic(a4:L,a6:L,a7:L); 1041 * t9:L=MethodHandleImpl.guardWithCatch(a1:L,a2:L,a3:L,t8:L); 1042 * t10:I=MethodHandle.invokeBasic(a5:L,t9:L);t10:I} 1043 * }</pre></blockquote> 1044 * 1045 * It is compiled into bytecode equivalent of the following code: 1046 * <blockquote><pre>{@code 1047 * try { 1048 * return a1.invokeBasic(a6, a7); 1049 * } catch (Throwable e) { 1050 * if (!a2.isInstance(e)) throw e; 1051 * return a3.invokeBasic(ex, a6, a7); 1052 * }} 1053 */ 1054 private Name emitGuardWithCatch(int pos) { 1055 Name args = lambdaForm.names[pos]; 1056 Name invoker = lambdaForm.names[pos+1]; 1057 Name result = lambdaForm.names[pos+2]; 1058 1059 Label L_startBlock = new Label(); 1060 Label L_endBlock = new Label(); 1061 Label L_handler = new Label(); 1062 Label L_done = new Label(); 1063 1064 Class<?> returnType = result.function.resolvedHandle.type().returnType(); 1065 MethodType type = args.function.resolvedHandle.type() 1066 .dropParameterTypes(0,1) 1067 .changeReturnType(returnType); 1068 1069 mv.visitTryCatchBlock(L_startBlock, L_endBlock, L_handler, "java/lang/Throwable"); 1070 1071 // Normal case 1072 mv.visitLabel(L_startBlock); 1073 // load target 1074 emitPushArgument(invoker, 0); 1075 emitPushArguments(args, 1); // skip 1st argument: method handle 1076 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false); 1077 mv.visitLabel(L_endBlock); 1078 mv.visitJumpInsn(Opcodes.GOTO, L_done); 1079 1080 // Exceptional case 1081 mv.visitLabel(L_handler); 1082 1083 // Check exception's type 1084 mv.visitInsn(Opcodes.DUP); 1085 // load exception class 1086 emitPushArgument(invoker, 1); 1087 mv.visitInsn(Opcodes.SWAP); 1088 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/Class", "isInstance", "(Ljava/lang/Object;)Z", false); 1089 Label L_rethrow = new Label(); 1090 mv.visitJumpInsn(Opcodes.IFEQ, L_rethrow); 1091 1092 // Invoke catcher 1093 // load catcher 1094 emitPushArgument(invoker, 2); 1095 mv.visitInsn(Opcodes.SWAP); 1096 emitPushArguments(args, 1); // skip 1st argument: method handle 1097 MethodType catcherType = type.insertParameterTypes(0, Throwable.class); 1098 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", catcherType.basicType().toMethodDescriptorString(), false); 1099 mv.visitJumpInsn(Opcodes.GOTO, L_done); 1100 1101 mv.visitLabel(L_rethrow); 1102 mv.visitInsn(Opcodes.ATHROW); 1103 1104 mv.visitLabel(L_done); 1105 1106 return result; 1107 } 1108 1109 private void emitPushArguments(Name args) { 1110 emitPushArguments(args, 0); 1111 } 1112 1113 private void emitPushArguments(Name args, int start) { 1114 for (int i = start; i < args.arguments.length; i++) { 1115 emitPushArgument(args, i); 1116 } 1117 } 1118 1119 private void emitPushArgument(Name name, int paramIndex) { 1120 Object arg = name.arguments[paramIndex]; 1121 Class<?> ptype = name.function.methodType().parameterType(paramIndex); 1122 emitPushArgument(ptype, arg); 1123 } 1124 1125 private void emitPushArgument(Class<?> ptype, Object arg) { 1126 BasicType bptype = basicType(ptype); 1127 if (arg instanceof Name) { 1128 Name n = (Name) arg; 1129 emitLoadInsn(n.type, n.index()); 1130 emitImplicitConversion(n.type, ptype, n); 1131 } else if ((arg == null || arg instanceof String) && bptype == L_TYPE) { 1132 emitConst(arg); 1133 } else { 1134 if (Wrapper.isWrapperType(arg.getClass()) && bptype != L_TYPE) { 1135 emitConst(arg); 1136 } else { 1137 mv.visitLdcInsn(constantPlaceholder(arg)); 1138 emitImplicitConversion(L_TYPE, ptype, arg); 1139 } 1140 } 1141 } 1142 1143 /** 1144 * Store the name to its local, if necessary. 1145 */ 1146 private void emitStoreResult(Name name) { 1147 if (name != null && name.type != V_TYPE) { 1148 // non-void: actually assign 1149 emitStoreInsn(name.type, name.index()); 1150 } 1151 } 1152 1153 /** 1154 * Emits a return statement from a LF invoker. If required, the result type is cast to the correct return type. 1155 */ 1156 private void emitReturn(Name onStack) { 1157 // return statement 1158 Class<?> rclass = invokerType.returnType(); 1159 BasicType rtype = lambdaForm.returnType(); 1160 assert(rtype == basicType(rclass)); // must agree 1161 if (rtype == V_TYPE) { 1162 // void 1163 mv.visitInsn(Opcodes.RETURN); 1164 // it doesn't matter what rclass is; the JVM will discard any value 1165 } else { 1166 LambdaForm.Name rn = lambdaForm.names[lambdaForm.result]; 1167 1168 // put return value on the stack if it is not already there 1169 if (rn != onStack) { 1170 emitLoadInsn(rtype, lambdaForm.result); 1171 } 1172 1173 emitImplicitConversion(rtype, rclass, rn); 1174 1175 // generate actual return statement 1176 emitReturnInsn(rtype); 1177 } 1178 } 1179 1180 /** 1181 * Emit a type conversion bytecode casting from "from" to "to". 1182 */ 1183 private void emitPrimCast(Wrapper from, Wrapper to) { 1184 // Here's how. 1185 // - indicates forbidden 1186 // <-> indicates implicit 1187 // to ----> boolean byte short char int long float double 1188 // from boolean <-> - - - - - - - 1189 // byte - <-> i2s i2c <-> i2l i2f i2d 1190 // short - i2b <-> i2c <-> i2l i2f i2d 1191 // char - i2b i2s <-> <-> i2l i2f i2d 1192 // int - i2b i2s i2c <-> i2l i2f i2d 1193 // long - l2i,i2b l2i,i2s l2i,i2c l2i <-> l2f l2d 1194 // float - f2i,i2b f2i,i2s f2i,i2c f2i f2l <-> f2d 1195 // double - d2i,i2b d2i,i2s d2i,i2c d2i d2l d2f <-> 1196 if (from == to) { 1197 // no cast required, should be dead code anyway 1198 return; 1199 } 1200 if (from.isSubwordOrInt()) { 1201 // cast from {byte,short,char,int} to anything 1202 emitI2X(to); 1203 } else { 1204 // cast from {long,float,double} to anything 1205 if (to.isSubwordOrInt()) { 1206 // cast to {byte,short,char,int} 1207 emitX2I(from); 1208 if (to.bitWidth() < 32) { 1209 // targets other than int require another conversion 1210 emitI2X(to); 1211 } 1212 } else { 1213 // cast to {long,float,double} - this is verbose 1214 boolean error = false; 1215 switch (from) { 1216 case LONG: 1217 switch (to) { 1218 case FLOAT: mv.visitInsn(Opcodes.L2F); break; 1219 case DOUBLE: mv.visitInsn(Opcodes.L2D); break; 1220 default: error = true; break; 1221 } 1222 break; 1223 case FLOAT: 1224 switch (to) { 1225 case LONG : mv.visitInsn(Opcodes.F2L); break; 1226 case DOUBLE: mv.visitInsn(Opcodes.F2D); break; 1227 default: error = true; break; 1228 } 1229 break; 1230 case DOUBLE: 1231 switch (to) { 1232 case LONG : mv.visitInsn(Opcodes.D2L); break; 1233 case FLOAT: mv.visitInsn(Opcodes.D2F); break; 1234 default: error = true; break; 1235 } 1236 break; 1237 default: 1238 error = true; 1239 break; 1240 } 1241 if (error) { 1242 throw new IllegalStateException("unhandled prim cast: " + from + "2" + to); 1243 } 1244 } 1245 } 1246 } 1247 1248 private void emitI2X(Wrapper type) { 1249 switch (type) { 1250 case BYTE: mv.visitInsn(Opcodes.I2B); break; 1251 case SHORT: mv.visitInsn(Opcodes.I2S); break; 1252 case CHAR: mv.visitInsn(Opcodes.I2C); break; 1253 case INT: /* naught */ break; 1254 case LONG: mv.visitInsn(Opcodes.I2L); break; 1255 case FLOAT: mv.visitInsn(Opcodes.I2F); break; 1256 case DOUBLE: mv.visitInsn(Opcodes.I2D); break; 1257 case BOOLEAN: 1258 // For compatibility with ValueConversions and explicitCastArguments: 1259 mv.visitInsn(Opcodes.ICONST_1); 1260 mv.visitInsn(Opcodes.IAND); 1261 break; 1262 default: throw new InternalError("unknown type: " + type); 1263 } 1264 } 1265 1266 private void emitX2I(Wrapper type) { 1267 switch (type) { 1268 case LONG: mv.visitInsn(Opcodes.L2I); break; 1269 case FLOAT: mv.visitInsn(Opcodes.F2I); break; 1270 case DOUBLE: mv.visitInsn(Opcodes.D2I); break; 1271 default: throw new InternalError("unknown type: " + type); 1272 } 1273 } 1274 1275 /** 1276 * Generate bytecode for a LambdaForm.vmentry which calls interpretWithArguments. 1277 */ 1278 static MemberName generateLambdaFormInterpreterEntryPoint(String sig) { 1279 assert(isValidSignature(sig)); 1280 String name = "interpret_"+signatureReturn(sig).basicTypeChar(); 1281 MethodType type = signatureType(sig); // sig includes leading argument 1282 type = type.changeParameterType(0, MethodHandle.class); 1283 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("LFI", name, type); 1284 return g.loadMethod(g.generateLambdaFormInterpreterEntryPointBytes()); 1285 } 1286 1287 private byte[] generateLambdaFormInterpreterEntryPointBytes() { 1288 classFilePrologue(); 1289 1290 // Suppress this method in backtraces displayed to the user. 1291 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true); 1292 1293 // Don't inline the interpreter entry. 1294 mv.visitAnnotation("Ljava/lang/invoke/DontInline;", true); 1295 1296 // create parameter array 1297 emitIconstInsn(invokerType.parameterCount()); 1298 mv.visitTypeInsn(Opcodes.ANEWARRAY, "java/lang/Object"); 1299 1300 // fill parameter array 1301 for (int i = 0; i < invokerType.parameterCount(); i++) { 1302 Class<?> ptype = invokerType.parameterType(i); 1303 mv.visitInsn(Opcodes.DUP); 1304 emitIconstInsn(i); 1305 emitLoadInsn(basicType(ptype), i); 1306 // box if primitive type 1307 if (ptype.isPrimitive()) { 1308 emitBoxing(Wrapper.forPrimitiveType(ptype)); 1309 } 1310 mv.visitInsn(Opcodes.AASTORE); 1311 } 1312 // invoke 1313 emitAloadInsn(0); 1314 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", "Ljava/lang/invoke/LambdaForm;"); 1315 mv.visitInsn(Opcodes.SWAP); // swap form and array; avoid local variable 1316 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, LF, "interpretWithArguments", "([Ljava/lang/Object;)Ljava/lang/Object;", false); 1317 1318 // maybe unbox 1319 Class<?> rtype = invokerType.returnType(); 1320 if (rtype.isPrimitive() && rtype != void.class) { 1321 emitUnboxing(Wrapper.forPrimitiveType(rtype)); 1322 } 1323 1324 // return statement 1325 emitReturnInsn(basicType(rtype)); 1326 1327 classFileEpilogue(); 1328 bogusMethod(invokerType); 1329 1330 final byte[] classFile = cw.toByteArray(); 1331 maybeDump(className, classFile); 1332 return classFile; 1333 } 1334 1335 /** 1336 * Generate bytecode for a NamedFunction invoker. 1337 */ 1338 static MemberName generateNamedFunctionInvoker(MethodTypeForm typeForm) { 1339 MethodType invokerType = NamedFunction.INVOKER_METHOD_TYPE; 1340 String invokerName = "invoke_" + shortenSignature(basicTypeSignature(typeForm.erasedType())); 1341 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("NFI", invokerName, invokerType); 1342 return g.loadMethod(g.generateNamedFunctionInvokerImpl(typeForm)); 1343 } 1344 1345 private byte[] generateNamedFunctionInvokerImpl(MethodTypeForm typeForm) { 1346 MethodType dstType = typeForm.erasedType(); 1347 classFilePrologue(); 1348 1349 // Suppress this method in backtraces displayed to the user. 1350 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true); 1351 1352 // Force inlining of this invoker method. 1353 mv.visitAnnotation("Ljava/lang/invoke/ForceInline;", true); 1354 1355 // Load receiver 1356 emitAloadInsn(0); 1357 1358 // Load arguments from array 1359 for (int i = 0; i < dstType.parameterCount(); i++) { 1360 emitAloadInsn(1); 1361 emitIconstInsn(i); 1362 mv.visitInsn(Opcodes.AALOAD); 1363 1364 // Maybe unbox 1365 Class<?> dptype = dstType.parameterType(i); 1366 if (dptype.isPrimitive()) { 1367 Class<?> sptype = dstType.basicType().wrap().parameterType(i); 1368 Wrapper dstWrapper = Wrapper.forBasicType(dptype); 1369 Wrapper srcWrapper = dstWrapper.isSubwordOrInt() ? Wrapper.INT : dstWrapper; // narrow subword from int 1370 emitUnboxing(srcWrapper); 1371 emitPrimCast(srcWrapper, dstWrapper); 1372 } 1373 } 1374 1375 // Invoke 1376 String targetDesc = dstType.basicType().toMethodDescriptorString(); 1377 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", targetDesc, false); 1378 1379 // Box primitive types 1380 Class<?> rtype = dstType.returnType(); 1381 if (rtype != void.class && rtype.isPrimitive()) { 1382 Wrapper srcWrapper = Wrapper.forBasicType(rtype); 1383 Wrapper dstWrapper = srcWrapper.isSubwordOrInt() ? Wrapper.INT : srcWrapper; // widen subword to int 1384 // boolean casts not allowed 1385 emitPrimCast(srcWrapper, dstWrapper); 1386 emitBoxing(dstWrapper); 1387 } 1388 1389 // If the return type is void we return a null reference. 1390 if (rtype == void.class) { 1391 mv.visitInsn(Opcodes.ACONST_NULL); 1392 } 1393 emitReturnInsn(L_TYPE); // NOTE: NamedFunction invokers always return a reference value. 1394 1395 classFileEpilogue(); 1396 bogusMethod(dstType); 1397 1398 final byte[] classFile = cw.toByteArray(); 1399 maybeDump(className, classFile); 1400 return classFile; 1401 } 1402 1403 /** 1404 * Emit a bogus method that just loads some string constants. This is to get the constants into the constant pool 1405 * for debugging purposes. 1406 */ 1407 private void bogusMethod(Object... os) { 1408 if (DUMP_CLASS_FILES) { 1409 mv = cw.visitMethod(Opcodes.ACC_STATIC, "dummy", "()V", null, null); 1410 for (Object o : os) { 1411 mv.visitLdcInsn(o.toString()); 1412 mv.visitInsn(Opcodes.POP); 1413 } 1414 mv.visitInsn(Opcodes.RETURN); 1415 mv.visitMaxs(0, 0); 1416 mv.visitEnd(); 1417 } 1418 } 1419 }