1/* 2 * Copyright (c) 2012, 2016, 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 26package java.lang.invoke; 27 28import jdk.internal.org.objectweb.asm.ClassWriter; 29import jdk.internal.org.objectweb.asm.Label; 30import jdk.internal.org.objectweb.asm.MethodVisitor; 31import jdk.internal.org.objectweb.asm.Opcodes; 32import jdk.internal.org.objectweb.asm.Type; 33import sun.invoke.util.VerifyAccess; 34import sun.invoke.util.VerifyType; 35import sun.invoke.util.Wrapper; 36import sun.reflect.misc.ReflectUtil; 37 38import java.io.File; 39import java.io.FileOutputStream; 40import java.io.IOException; 41import java.lang.reflect.Modifier; 42import java.util.ArrayList; 43import java.util.Arrays; 44import java.util.HashMap; 45import java.util.stream.Stream; 46 47import static java.lang.invoke.LambdaForm.BasicType; 48import static java.lang.invoke.LambdaForm.BasicType.*; 49import static java.lang.invoke.LambdaForm.*; 50import static java.lang.invoke.MethodHandleNatives.Constants.*; 51import static java.lang.invoke.MethodHandleStatics.*; 52 53/** 54 * Code generation backend for LambdaForm. 55 * <p> 56 * @author John Rose, JSR 292 EG 57 */ 58class InvokerBytecodeGenerator { 59 /** Define class names for convenience. */ 60 private static final String MH = "java/lang/invoke/MethodHandle"; 61 private static final String MHI = "java/lang/invoke/MethodHandleImpl"; 62 private static final String LF = "java/lang/invoke/LambdaForm"; 63 private static final String LFN = "java/lang/invoke/LambdaForm$Name"; 64 private static final String CLS = "java/lang/Class"; 65 private static final String OBJ = "java/lang/Object"; 66 private static final String OBJARY = "[Ljava/lang/Object;"; 67 68 private static final String LOOP_CLAUSES = MHI + "$LoopClauses"; 69 private static final String MHARY2 = "[[L" + MH + ";"; 70 71 private static final String LF_SIG = "L" + LF + ";"; 72 private static final String LFN_SIG = "L" + LFN + ";"; 73 private static final String LL_SIG = "(L" + OBJ + ";)L" + OBJ + ";"; 74 private static final String LLV_SIG = "(L" + OBJ + ";L" + OBJ + ";)V"; 75 private static final String CLASS_PREFIX = LF + "$"; 76 private static final String SOURCE_PREFIX = "LambdaForm$"; 77 78 /** Name of its super class*/ 79 static final String INVOKER_SUPER_NAME = OBJ; 80 81 /** Name of new class */ 82 private final String className; 83 84 private final LambdaForm lambdaForm; 85 private final String invokerName; 86 private final MethodType invokerType; 87 88 /** Info about local variables in compiled lambda form */ 89 private int[] localsMap; // index 90 private Class<?>[] localClasses; // type 91 92 /** ASM bytecode generation. */ 93 private ClassWriter cw; 94 private MethodVisitor mv; 95 96 private static final MemberName.Factory MEMBERNAME_FACTORY = MemberName.getFactory(); 97 private static final Class<?> HOST_CLASS = LambdaForm.class; 98 99 /** Main constructor; other constructors delegate to this one. */ 100 private InvokerBytecodeGenerator(LambdaForm lambdaForm, int localsMapSize, 101 String className, String invokerName, MethodType invokerType) { 102 int p = invokerName.indexOf('.'); 103 if (p > -1) { 104 className = invokerName.substring(0, p); 105 invokerName = invokerName.substring(p + 1); 106 } 107 if (DUMP_CLASS_FILES) { 108 className = makeDumpableClassName(className); 109 } 110 this.className = className; 111 this.lambdaForm = lambdaForm; 112 this.invokerName = invokerName; 113 this.invokerType = invokerType; 114 this.localsMap = new int[localsMapSize+1]; // last entry of localsMap is count of allocated local slots 115 this.localClasses = new Class<?>[localsMapSize+1]; 116 } 117 118 /** For generating LambdaForm interpreter entry points. */ 119 private InvokerBytecodeGenerator(String className, String invokerName, MethodType invokerType) { 120 this(null, invokerType.parameterCount(), 121 className, invokerName, invokerType); 122 // Create an array to map name indexes to locals indexes. 123 for (int i = 0; i < localsMap.length; i++) { 124 localsMap[i] = invokerType.parameterSlotCount() - invokerType.parameterSlotDepth(i); 125 } 126 } 127 128 /** For generating customized code for a single LambdaForm. */ 129 private InvokerBytecodeGenerator(String className, LambdaForm form, MethodType invokerType) { 130 this(className, form.lambdaName(), form, invokerType); 131 } 132 133 /** For generating customized code for a single LambdaForm. */ 134 InvokerBytecodeGenerator(String className, String invokerName, 135 LambdaForm form, MethodType invokerType) { 136 this(form, form.names.length, 137 className, invokerName, invokerType); 138 // Create an array to map name indexes to locals indexes. 139 Name[] names = form.names; 140 for (int i = 0, index = 0; i < localsMap.length; i++) { 141 localsMap[i] = index; 142 if (i < names.length) { 143 BasicType type = names[i].type(); 144 index += type.basicTypeSlots(); 145 } 146 } 147 } 148 149 /** instance counters for dumped classes */ 150 private static final HashMap<String,Integer> DUMP_CLASS_FILES_COUNTERS; 151 /** debugging flag for saving generated class files */ 152 private static final File DUMP_CLASS_FILES_DIR; 153 154 static { 155 if (DUMP_CLASS_FILES) { 156 DUMP_CLASS_FILES_COUNTERS = new HashMap<>(); 157 try { 158 File dumpDir = new File("DUMP_CLASS_FILES"); 159 if (!dumpDir.exists()) { 160 dumpDir.mkdirs(); 161 } 162 DUMP_CLASS_FILES_DIR = dumpDir; 163 System.out.println("Dumping class files to "+DUMP_CLASS_FILES_DIR+"/..."); 164 } catch (Exception e) { 165 throw newInternalError(e); 166 } 167 } else { 168 DUMP_CLASS_FILES_COUNTERS = null; 169 DUMP_CLASS_FILES_DIR = null; 170 } 171 } 172 173 private void maybeDump(final byte[] classFile) { 174 if (DUMP_CLASS_FILES) { 175 maybeDump(CLASS_PREFIX + className, classFile); 176 } 177 } 178 179 // Also used from BoundMethodHandle 180 static void maybeDump(final String className, final byte[] classFile) { 181 if (DUMP_CLASS_FILES) { 182 java.security.AccessController.doPrivileged( 183 new java.security.PrivilegedAction<>() { 184 public Void run() { 185 try { 186 String dumpName = className; 187 //dumpName = dumpName.replace('/', '-'); 188 File dumpFile = new File(DUMP_CLASS_FILES_DIR, dumpName+".class"); 189 System.out.println("dump: " + dumpFile); 190 dumpFile.getParentFile().mkdirs(); 191 FileOutputStream file = new FileOutputStream(dumpFile); 192 file.write(classFile); 193 file.close(); 194 return null; 195 } catch (IOException ex) { 196 throw newInternalError(ex); 197 } 198 } 199 }); 200 } 201 } 202 203 private static String makeDumpableClassName(String className) { 204 Integer ctr; 205 synchronized (DUMP_CLASS_FILES_COUNTERS) { 206 ctr = DUMP_CLASS_FILES_COUNTERS.get(className); 207 if (ctr == null) ctr = 0; 208 DUMP_CLASS_FILES_COUNTERS.put(className, ctr+1); 209 } 210 String sfx = ctr.toString(); 211 while (sfx.length() < 3) 212 sfx = "0"+sfx; 213 className += sfx; 214 return className; 215 } 216 217 class CpPatch { 218 final int index; 219 final Object value; 220 CpPatch(int index, Object value) { 221 this.index = index; 222 this.value = value; 223 } 224 public String toString() { 225 return "CpPatch/index="+index+",value="+value; 226 } 227 } 228 229 private final ArrayList<CpPatch> cpPatches = new ArrayList<>(); 230 231 private int cph = 0; // for counting constant placeholders 232 233 String constantPlaceholder(Object arg) { 234 String cpPlaceholder = "CONSTANT_PLACEHOLDER_" + cph++; 235 if (DUMP_CLASS_FILES) cpPlaceholder += " <<" + debugString(arg) + ">>"; 236 // TODO check if arg is already in the constant pool 237 // insert placeholder in CP and remember the patch 238 int index = cw.newConst((Object) cpPlaceholder); 239 cpPatches.add(new CpPatch(index, arg)); 240 return cpPlaceholder; 241 } 242 243 Object[] cpPatches(byte[] classFile) { 244 int size = getConstantPoolSize(classFile); 245 Object[] res = new Object[size]; 246 for (CpPatch p : cpPatches) { 247 if (p.index >= size) 248 throw new InternalError("in cpool["+size+"]: "+p+"\n"+Arrays.toString(Arrays.copyOf(classFile, 20))); 249 res[p.index] = p.value; 250 } 251 return res; 252 } 253 254 private static String debugString(Object arg) { 255 if (arg instanceof MethodHandle) { 256 MethodHandle mh = (MethodHandle) arg; 257 MemberName member = mh.internalMemberName(); 258 if (member != null) 259 return member.toString(); 260 return mh.debugString(); 261 } 262 return arg.toString(); 263 } 264 265 /** 266 * Extract the number of constant pool entries from a given class file. 267 * 268 * @param classFile the bytes of the class file in question. 269 * @return the number of entries in the constant pool. 270 */ 271 private static int getConstantPoolSize(byte[] classFile) { 272 // The first few bytes: 273 // u4 magic; 274 // u2 minor_version; 275 // u2 major_version; 276 // u2 constant_pool_count; 277 return ((classFile[8] & 0xFF) << 8) | (classFile[9] & 0xFF); 278 } 279 280 /** 281 * Extract the MemberName of a newly-defined method. 282 */ 283 private MemberName loadMethod(byte[] classFile) { 284 Class<?> invokerClass = loadAndInitializeInvokerClass(classFile, cpPatches(classFile)); 285 return resolveInvokerMember(invokerClass, invokerName, invokerType); 286 } 287 288 /** 289 * Define a given class as anonymous class in the runtime system. 290 */ 291 private static Class<?> loadAndInitializeInvokerClass(byte[] classBytes, Object[] patches) { 292 Class<?> invokerClass = UNSAFE.defineAnonymousClass(HOST_CLASS, classBytes, patches); 293 UNSAFE.ensureClassInitialized(invokerClass); // Make sure the class is initialized; VM might complain. 294 return invokerClass; 295 } 296 297 private static MemberName resolveInvokerMember(Class<?> invokerClass, String name, MethodType type) { 298 MemberName member = new MemberName(invokerClass, name, type, REF_invokeStatic); 299 try { 300 member = MEMBERNAME_FACTORY.resolveOrFail(REF_invokeStatic, member, HOST_CLASS, ReflectiveOperationException.class); 301 } catch (ReflectiveOperationException e) { 302 throw newInternalError(e); 303 } 304 return member; 305 } 306 307 /** 308 * Set up class file generation. 309 */ 310 private ClassWriter classFilePrologue() { 311 final int NOT_ACC_PUBLIC = 0; // not ACC_PUBLIC 312 cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES); 313 cw.visit(Opcodes.V1_8, NOT_ACC_PUBLIC + Opcodes.ACC_FINAL + Opcodes.ACC_SUPER, 314 CLASS_PREFIX + className, null, INVOKER_SUPER_NAME, null); 315 cw.visitSource(SOURCE_PREFIX + className, null); 316 return cw; 317 } 318 319 private void methodPrologue() { 320 String invokerDesc = invokerType.toMethodDescriptorString(); 321 mv = cw.visitMethod(Opcodes.ACC_STATIC, invokerName, invokerDesc, null, null); 322 } 323 324 /** 325 * Tear down class file generation. 326 */ 327 private void methodEpilogue() { 328 mv.visitMaxs(0, 0); 329 mv.visitEnd(); 330 } 331 332 /* 333 * Low-level emit helpers. 334 */ 335 private void emitConst(Object con) { 336 if (con == null) { 337 mv.visitInsn(Opcodes.ACONST_NULL); 338 return; 339 } 340 if (con instanceof Integer) { 341 emitIconstInsn((int) con); 342 return; 343 } 344 if (con instanceof Byte) { 345 emitIconstInsn((byte)con); 346 return; 347 } 348 if (con instanceof Short) { 349 emitIconstInsn((short)con); 350 return; 351 } 352 if (con instanceof Character) { 353 emitIconstInsn((char)con); 354 return; 355 } 356 if (con instanceof Long) { 357 long x = (long) con; 358 short sx = (short)x; 359 if (x == sx) { 360 if (sx >= 0 && sx <= 1) { 361 mv.visitInsn(Opcodes.LCONST_0 + (int) sx); 362 } else { 363 emitIconstInsn((int) x); 364 mv.visitInsn(Opcodes.I2L); 365 } 366 return; 367 } 368 } 369 if (con instanceof Float) { 370 float x = (float) con; 371 short sx = (short)x; 372 if (x == sx) { 373 if (sx >= 0 && sx <= 2) { 374 mv.visitInsn(Opcodes.FCONST_0 + (int) sx); 375 } else { 376 emitIconstInsn((int) x); 377 mv.visitInsn(Opcodes.I2F); 378 } 379 return; 380 } 381 } 382 if (con instanceof Double) { 383 double x = (double) con; 384 short sx = (short)x; 385 if (x == sx) { 386 if (sx >= 0 && sx <= 1) { 387 mv.visitInsn(Opcodes.DCONST_0 + (int) sx); 388 } else { 389 emitIconstInsn((int) x); 390 mv.visitInsn(Opcodes.I2D); 391 } 392 return; 393 } 394 } 395 if (con instanceof Boolean) { 396 emitIconstInsn((boolean) con ? 1 : 0); 397 return; 398 } 399 // fall through: 400 mv.visitLdcInsn(con); 401 } 402 403 private void emitIconstInsn(final int cst) { 404 if (cst >= -1 && cst <= 5) { 405 mv.visitInsn(Opcodes.ICONST_0 + cst); 406 } else if (cst >= Byte.MIN_VALUE && cst <= Byte.MAX_VALUE) { 407 mv.visitIntInsn(Opcodes.BIPUSH, cst); 408 } else if (cst >= Short.MIN_VALUE && cst <= Short.MAX_VALUE) { 409 mv.visitIntInsn(Opcodes.SIPUSH, cst); 410 } else { 411 mv.visitLdcInsn(cst); 412 } 413 } 414 415 /* 416 * NOTE: These load/store methods use the localsMap to find the correct index! 417 */ 418 private void emitLoadInsn(BasicType type, int index) { 419 int opcode = loadInsnOpcode(type); 420 mv.visitVarInsn(opcode, localsMap[index]); 421 } 422 423 private int loadInsnOpcode(BasicType type) throws InternalError { 424 switch (type) { 425 case I_TYPE: return Opcodes.ILOAD; 426 case J_TYPE: return Opcodes.LLOAD; 427 case F_TYPE: return Opcodes.FLOAD; 428 case D_TYPE: return Opcodes.DLOAD; 429 case L_TYPE: return Opcodes.ALOAD; 430 default: 431 throw new InternalError("unknown type: " + type); 432 } 433 } 434 private void emitAloadInsn(int index) { 435 emitLoadInsn(L_TYPE, index); 436 } 437 438 private void emitStoreInsn(BasicType type, int index) { 439 int opcode = storeInsnOpcode(type); 440 mv.visitVarInsn(opcode, localsMap[index]); 441 } 442 443 private int storeInsnOpcode(BasicType type) throws InternalError { 444 switch (type) { 445 case I_TYPE: return Opcodes.ISTORE; 446 case J_TYPE: return Opcodes.LSTORE; 447 case F_TYPE: return Opcodes.FSTORE; 448 case D_TYPE: return Opcodes.DSTORE; 449 case L_TYPE: return Opcodes.ASTORE; 450 default: 451 throw new InternalError("unknown type: " + type); 452 } 453 } 454 private void emitAstoreInsn(int index) { 455 emitStoreInsn(L_TYPE, index); 456 } 457 458 private byte arrayTypeCode(Wrapper elementType) { 459 switch (elementType) { 460 case BOOLEAN: return Opcodes.T_BOOLEAN; 461 case BYTE: return Opcodes.T_BYTE; 462 case CHAR: return Opcodes.T_CHAR; 463 case SHORT: return Opcodes.T_SHORT; 464 case INT: return Opcodes.T_INT; 465 case LONG: return Opcodes.T_LONG; 466 case FLOAT: return Opcodes.T_FLOAT; 467 case DOUBLE: return Opcodes.T_DOUBLE; 468 case OBJECT: return 0; // in place of Opcodes.T_OBJECT 469 default: throw new InternalError(); 470 } 471 } 472 473 private int arrayInsnOpcode(byte tcode, int aaop) throws InternalError { 474 assert(aaop == Opcodes.AASTORE || aaop == Opcodes.AALOAD); 475 int xas; 476 switch (tcode) { 477 case Opcodes.T_BOOLEAN: xas = Opcodes.BASTORE; break; 478 case Opcodes.T_BYTE: xas = Opcodes.BASTORE; break; 479 case Opcodes.T_CHAR: xas = Opcodes.CASTORE; break; 480 case Opcodes.T_SHORT: xas = Opcodes.SASTORE; break; 481 case Opcodes.T_INT: xas = Opcodes.IASTORE; break; 482 case Opcodes.T_LONG: xas = Opcodes.LASTORE; break; 483 case Opcodes.T_FLOAT: xas = Opcodes.FASTORE; break; 484 case Opcodes.T_DOUBLE: xas = Opcodes.DASTORE; break; 485 case 0: xas = Opcodes.AASTORE; break; 486 default: throw new InternalError(); 487 } 488 return xas - Opcodes.AASTORE + aaop; 489 } 490 491 /** 492 * Emit a boxing call. 493 * 494 * @param wrapper primitive type class to box. 495 */ 496 private void emitBoxing(Wrapper wrapper) { 497 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName(); 498 String name = "valueOf"; 499 String desc = "(" + wrapper.basicTypeChar() + ")L" + owner + ";"; 500 mv.visitMethodInsn(Opcodes.INVOKESTATIC, owner, name, desc, false); 501 } 502 503 /** 504 * Emit an unboxing call (plus preceding checkcast). 505 * 506 * @param wrapper wrapper type class to unbox. 507 */ 508 private void emitUnboxing(Wrapper wrapper) { 509 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName(); 510 String name = wrapper.primitiveSimpleName() + "Value"; 511 String desc = "()" + wrapper.basicTypeChar(); 512 emitReferenceCast(wrapper.wrapperType(), null); 513 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, owner, name, desc, false); 514 } 515 516 /** 517 * Emit an implicit conversion for an argument which must be of the given pclass. 518 * This is usually a no-op, except when pclass is a subword type or a reference other than Object or an interface. 519 * 520 * @param ptype type of value present on stack 521 * @param pclass type of value required on stack 522 * @param arg compile-time representation of value on stack (Node, constant) or null if none 523 */ 524 private void emitImplicitConversion(BasicType ptype, Class<?> pclass, Object arg) { 525 assert(basicType(pclass) == ptype); // boxing/unboxing handled by caller 526 if (pclass == ptype.basicTypeClass() && ptype != L_TYPE) 527 return; // nothing to do 528 switch (ptype) { 529 case L_TYPE: 530 if (VerifyType.isNullConversion(Object.class, pclass, false)) { 531 if (PROFILE_LEVEL > 0) 532 emitReferenceCast(Object.class, arg); 533 return; 534 } 535 emitReferenceCast(pclass, arg); 536 return; 537 case I_TYPE: 538 if (!VerifyType.isNullConversion(int.class, pclass, false)) 539 emitPrimCast(ptype.basicTypeWrapper(), Wrapper.forPrimitiveType(pclass)); 540 return; 541 } 542 throw newInternalError("bad implicit conversion: tc="+ptype+": "+pclass); 543 } 544 545 /** Update localClasses type map. Return true if the information is already present. */ 546 private boolean assertStaticType(Class<?> cls, Name n) { 547 int local = n.index(); 548 Class<?> aclass = localClasses[local]; 549 if (aclass != null && (aclass == cls || cls.isAssignableFrom(aclass))) { 550 return true; // type info is already present 551 } else if (aclass == null || aclass.isAssignableFrom(cls)) { 552 localClasses[local] = cls; // type info can be improved 553 } 554 return false; 555 } 556 557 private void emitReferenceCast(Class<?> cls, Object arg) { 558 Name writeBack = null; // local to write back result 559 if (arg instanceof Name) { 560 Name n = (Name) arg; 561 if (lambdaForm.useCount(n) > 1) { 562 // This guy gets used more than once. 563 writeBack = n; 564 if (assertStaticType(cls, n)) { 565 return; // this cast was already performed 566 } 567 } 568 } 569 if (isStaticallyNameable(cls)) { 570 String sig = getInternalName(cls); 571 mv.visitTypeInsn(Opcodes.CHECKCAST, sig); 572 } else { 573 mv.visitLdcInsn(constantPlaceholder(cls)); 574 mv.visitTypeInsn(Opcodes.CHECKCAST, CLS); 575 mv.visitInsn(Opcodes.SWAP); 576 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, CLS, "cast", LL_SIG, false); 577 if (Object[].class.isAssignableFrom(cls)) 578 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJARY); 579 else if (PROFILE_LEVEL > 0) 580 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJ); 581 } 582 if (writeBack != null) { 583 mv.visitInsn(Opcodes.DUP); 584 emitAstoreInsn(writeBack.index()); 585 } 586 } 587 588 /** 589 * Emits an actual return instruction conforming to the given return type. 590 */ 591 private void emitReturnInsn(BasicType type) { 592 int opcode; 593 switch (type) { 594 case I_TYPE: opcode = Opcodes.IRETURN; break; 595 case J_TYPE: opcode = Opcodes.LRETURN; break; 596 case F_TYPE: opcode = Opcodes.FRETURN; break; 597 case D_TYPE: opcode = Opcodes.DRETURN; break; 598 case L_TYPE: opcode = Opcodes.ARETURN; break; 599 case V_TYPE: opcode = Opcodes.RETURN; break; 600 default: 601 throw new InternalError("unknown return type: " + type); 602 } 603 mv.visitInsn(opcode); 604 } 605 606 private static String getInternalName(Class<?> c) { 607 if (c == Object.class) return OBJ; 608 else if (c == Object[].class) return OBJARY; 609 else if (c == Class.class) return CLS; 610 else if (c == MethodHandle.class) return MH; 611 assert(VerifyAccess.isTypeVisible(c, Object.class)) : c.getName(); 612 return c.getName().replace('.', '/'); 613 } 614 615 private static MemberName resolveFrom(String name, MethodType type, Class<?> holder) { 616 MemberName member = new MemberName(holder, name, type, REF_invokeStatic); 617 MemberName resolvedMember = MemberName.getFactory().resolveOrNull(REF_invokeStatic, member, holder); 618 if (TRACE_RESOLVE) { 619 System.out.println("[LF_RESOLVE] " + holder.getName() + " " + name + " " + 620 shortenSignature(basicTypeSignature(type)) + (resolvedMember != null ? " (success)" : " (fail)") ); 621 } 622 return resolvedMember; 623 } 624 625 private static MemberName lookupPregenerated(LambdaForm form, MethodType invokerType) { 626 if (form.customized != null) { 627 // No pre-generated version for customized LF 628 return null; 629 } 630 String name = form.kind.methodName; 631 switch (form.kind) { 632 case BOUND_REINVOKER: { 633 name = name + "_" + BoundMethodHandle.speciesData(form).fieldSignature(); 634 return resolveFrom(name, invokerType, DelegatingMethodHandle.Holder.class); 635 } 636 case DELEGATE: return resolveFrom(name, invokerType, DelegatingMethodHandle.Holder.class); 637 case ZERO: // fall-through 638 case IDENTITY: { 639 name = name + "_" + form.returnType().basicTypeChar(); 640 return resolveFrom(name, invokerType, LambdaForm.Holder.class); 641 } 642 case EXACT_INVOKER: // fall-through 643 case EXACT_LINKER: // fall-through 644 case GENERIC_INVOKER: // fall-through 645 case GENERIC_LINKER: return resolveFrom(name, invokerType.basicType(), Invokers.Holder.class); 646 case GET_OBJECT: // fall-through 647 case GET_BOOLEAN: // fall-through 648 case GET_BYTE: // fall-through 649 case GET_CHAR: // fall-through 650 case GET_SHORT: // fall-through 651 case GET_INT: // fall-through 652 case GET_LONG: // fall-through 653 case GET_FLOAT: // fall-through 654 case GET_DOUBLE: // fall-through 655 case PUT_OBJECT: // fall-through 656 case PUT_BOOLEAN: // fall-through 657 case PUT_BYTE: // fall-through 658 case PUT_CHAR: // fall-through 659 case PUT_SHORT: // fall-through 660 case PUT_INT: // fall-through 661 case PUT_LONG: // fall-through 662 case PUT_FLOAT: // fall-through 663 case PUT_DOUBLE: // fall-through 664 case DIRECT_INVOKE_INTERFACE: // fall-through 665 case DIRECT_INVOKE_SPECIAL: // fall-through 666 case DIRECT_INVOKE_STATIC: // fall-through 667 case DIRECT_INVOKE_STATIC_INIT: // fall-through 668 case DIRECT_INVOKE_VIRTUAL: return resolveFrom(name, invokerType, DirectMethodHandle.Holder.class); 669 } 670 return null; 671 } 672 673 /** 674 * Generate customized bytecode for a given LambdaForm. 675 */ 676 static MemberName generateCustomizedCode(LambdaForm form, MethodType invokerType) { 677 MemberName pregenerated = lookupPregenerated(form, invokerType); 678 if (pregenerated != null) return pregenerated; // pre-generated bytecode 679 680 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("MH", form, invokerType); 681 return g.loadMethod(g.generateCustomizedCodeBytes()); 682 } 683 684 /** Generates code to check that actual receiver and LambdaForm matches */ 685 private boolean checkActualReceiver() { 686 // Expects MethodHandle on the stack and actual receiver MethodHandle in slot #0 687 mv.visitInsn(Opcodes.DUP); 688 mv.visitVarInsn(Opcodes.ALOAD, localsMap[0]); 689 mv.visitMethodInsn(Opcodes.INVOKESTATIC, MHI, "assertSame", LLV_SIG, false); 690 return true; 691 } 692 693 static String className(String cn) { 694 assert checkClassName(cn): "Class not found: " + cn; 695 return cn; 696 } 697 698 static boolean checkClassName(String cn) { 699 Type tp = Type.getType(cn); 700 // additional sanity so only valid "L;" descriptors work 701 if (tp.getSort() != Type.OBJECT) { 702 return false; 703 } 704 try { 705 Class<?> c = Class.forName(tp.getClassName(), false, null); 706 return true; 707 } catch (ClassNotFoundException e) { 708 return false; 709 } 710 } 711 712 static final String LF_HIDDEN_SIG = className("Ljava/lang/invoke/LambdaForm$Hidden;"); 713 static final String LF_COMPILED_SIG = className("Ljava/lang/invoke/LambdaForm$Compiled;"); 714 static final String FORCEINLINE_SIG = className("Ljdk/internal/vm/annotation/ForceInline;"); 715 static final String DONTINLINE_SIG = className("Ljdk/internal/vm/annotation/DontInline;"); 716 static final String INJECTEDPROFILE_SIG = className("Ljava/lang/invoke/InjectedProfile;"); 717 718 /** 719 * Generate an invoker method for the passed {@link LambdaForm}. 720 */ 721 private byte[] generateCustomizedCodeBytes() { 722 classFilePrologue(); 723 addMethod(); 724 bogusMethod(lambdaForm); 725 726 final byte[] classFile = toByteArray(); 727 maybeDump(classFile); 728 return classFile; 729 } 730 731 void setClassWriter(ClassWriter cw) { 732 this.cw = cw; 733 } 734 735 void addMethod() { 736 methodPrologue(); 737 738 // Suppress this method in backtraces displayed to the user. 739 mv.visitAnnotation(LF_HIDDEN_SIG, true); 740 741 // Mark this method as a compiled LambdaForm 742 mv.visitAnnotation(LF_COMPILED_SIG, true); 743 744 if (lambdaForm.forceInline) { 745 // Force inlining of this invoker method. 746 mv.visitAnnotation(FORCEINLINE_SIG, true); 747 } else { 748 mv.visitAnnotation(DONTINLINE_SIG, true); 749 } 750 751 constantPlaceholder(lambdaForm); // keep LambdaForm instance & its compiled form lifetime tightly coupled. 752 753 if (lambdaForm.customized != null) { 754 // Since LambdaForm is customized for a particular MethodHandle, it's safe to substitute 755 // receiver MethodHandle (at slot #0) with an embedded constant and use it instead. 756 // It enables more efficient code generation in some situations, since embedded constants 757 // are compile-time constants for JIT compiler. 758 mv.visitLdcInsn(constantPlaceholder(lambdaForm.customized)); 759 mv.visitTypeInsn(Opcodes.CHECKCAST, MH); 760 assert(checkActualReceiver()); // expects MethodHandle on top of the stack 761 mv.visitVarInsn(Opcodes.ASTORE, localsMap[0]); 762 } 763 764 // iterate over the form's names, generating bytecode instructions for each 765 // start iterating at the first name following the arguments 766 Name onStack = null; 767 for (int i = lambdaForm.arity; i < lambdaForm.names.length; i++) { 768 Name name = lambdaForm.names[i]; 769 770 emitStoreResult(onStack); 771 onStack = name; // unless otherwise modified below 772 MethodHandleImpl.Intrinsic intr = name.function.intrinsicName(); 773 switch (intr) { 774 case SELECT_ALTERNATIVE: 775 assert lambdaForm.isSelectAlternative(i); 776 if (PROFILE_GWT) { 777 assert(name.arguments[0] instanceof Name && 778 ((Name)name.arguments[0]).refersTo(MethodHandleImpl.class, "profileBoolean")); 779 mv.visitAnnotation(INJECTEDPROFILE_SIG, true); 780 } 781 onStack = emitSelectAlternative(name, lambdaForm.names[i+1]); 782 i++; // skip MH.invokeBasic of the selectAlternative result 783 continue; 784 case GUARD_WITH_CATCH: 785 assert lambdaForm.isGuardWithCatch(i); 786 onStack = emitGuardWithCatch(i); 787 i += 2; // jump to the end of GWC idiom 788 continue; 789 case TRY_FINALLY: 790 assert lambdaForm.isTryFinally(i); 791 onStack = emitTryFinally(i); 792 i += 2; // jump to the end of the TF idiom 793 continue; 794 case LOOP: 795 assert lambdaForm.isLoop(i); 796 onStack = emitLoop(i); 797 i += 2; // jump to the end of the LOOP idiom 798 continue; 799 case NEW_ARRAY: 800 Class<?> rtype = name.function.methodType().returnType(); 801 if (isStaticallyNameable(rtype)) { 802 emitNewArray(name); 803 continue; 804 } 805 break; 806 case ARRAY_LOAD: 807 emitArrayLoad(name); 808 continue; 809 case ARRAY_STORE: 810 emitArrayStore(name); 811 continue; 812 case ARRAY_LENGTH: 813 emitArrayLength(name); 814 continue; 815 case IDENTITY: 816 assert(name.arguments.length == 1); 817 emitPushArguments(name, 0); 818 continue; 819 case ZERO: 820 assert(name.arguments.length == 0); 821 emitConst(name.type.basicTypeWrapper().zero()); 822 continue; 823 case NONE: 824 // no intrinsic associated 825 break; 826 default: 827 throw newInternalError("Unknown intrinsic: "+intr); 828 } 829 830 MemberName member = name.function.member(); 831 if (isStaticallyInvocable(member)) { 832 emitStaticInvoke(member, name); 833 } else { 834 emitInvoke(name); 835 } 836 } 837 838 // return statement 839 emitReturn(onStack); 840 841 methodEpilogue(); 842 } 843 844 /* 845 * @throws BytecodeGenerationException if something goes wrong when 846 * generating the byte code 847 */ 848 private byte[] toByteArray() { 849 try { 850 return cw.toByteArray(); 851 } catch (RuntimeException e) { 852 throw new BytecodeGenerationException(e); 853 } 854 } 855 856 @SuppressWarnings("serial") 857 static final class BytecodeGenerationException extends RuntimeException { 858 BytecodeGenerationException(Exception cause) { 859 super(cause); 860 } 861 } 862 863 void emitArrayLoad(Name name) { emitArrayOp(name, Opcodes.AALOAD); } 864 void emitArrayStore(Name name) { emitArrayOp(name, Opcodes.AASTORE); } 865 void emitArrayLength(Name name) { emitArrayOp(name, Opcodes.ARRAYLENGTH); } 866 867 void emitArrayOp(Name name, int arrayOpcode) { 868 assert arrayOpcode == Opcodes.AALOAD || arrayOpcode == Opcodes.AASTORE || arrayOpcode == Opcodes.ARRAYLENGTH; 869 Class<?> elementType = name.function.methodType().parameterType(0).getComponentType(); 870 assert elementType != null; 871 emitPushArguments(name, 0); 872 if (arrayOpcode != Opcodes.ARRAYLENGTH && elementType.isPrimitive()) { 873 Wrapper w = Wrapper.forPrimitiveType(elementType); 874 arrayOpcode = arrayInsnOpcode(arrayTypeCode(w), arrayOpcode); 875 } 876 mv.visitInsn(arrayOpcode); 877 } 878 879 /** 880 * Emit an invoke for the given name. 881 */ 882 void emitInvoke(Name name) { 883 assert(!name.isLinkerMethodInvoke()); // should use the static path for these 884 if (true) { 885 // push receiver 886 MethodHandle target = name.function.resolvedHandle(); 887 assert(target != null) : name.exprString(); 888 mv.visitLdcInsn(constantPlaceholder(target)); 889 emitReferenceCast(MethodHandle.class, target); 890 } else { 891 // load receiver 892 emitAloadInsn(0); 893 emitReferenceCast(MethodHandle.class, null); 894 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", LF_SIG); 895 mv.visitFieldInsn(Opcodes.GETFIELD, LF, "names", LFN_SIG); 896 // TODO more to come 897 } 898 899 // push arguments 900 emitPushArguments(name, 0); 901 902 // invocation 903 MethodType type = name.function.methodType(); 904 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false); 905 } 906 907 private static Class<?>[] STATICALLY_INVOCABLE_PACKAGES = { 908 // Sample classes from each package we are willing to bind to statically: 909 java.lang.Object.class, 910 java.util.Arrays.class, 911 jdk.internal.misc.Unsafe.class 912 //MethodHandle.class already covered 913 }; 914 915 static boolean isStaticallyInvocable(NamedFunction ... functions) { 916 for (NamedFunction nf : functions) { 917 if (!isStaticallyInvocable(nf.member())) { 918 return false; 919 } 920 } 921 return true; 922 } 923 924 static boolean isStaticallyInvocable(Name name) { 925 return isStaticallyInvocable(name.function.member()); 926 } 927 928 static boolean isStaticallyInvocable(MemberName member) { 929 if (member == null) return false; 930 if (member.isConstructor()) return false; 931 Class<?> cls = member.getDeclaringClass(); 932 if (cls.isArray() || cls.isPrimitive()) 933 return false; // FIXME 934 if (cls.isAnonymousClass() || cls.isLocalClass()) 935 return false; // inner class of some sort 936 if (cls.getClassLoader() != MethodHandle.class.getClassLoader()) 937 return false; // not on BCP 938 if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: switch to supported API once it is added 939 return false; 940 MethodType mtype = member.getMethodOrFieldType(); 941 if (!isStaticallyNameable(mtype.returnType())) 942 return false; 943 for (Class<?> ptype : mtype.parameterArray()) 944 if (!isStaticallyNameable(ptype)) 945 return false; 946 if (!member.isPrivate() && VerifyAccess.isSamePackage(MethodHandle.class, cls)) 947 return true; // in java.lang.invoke package 948 if (member.isPublic() && isStaticallyNameable(cls)) 949 return true; 950 return false; 951 } 952 953 static boolean isStaticallyNameable(Class<?> cls) { 954 if (cls == Object.class) 955 return true; 956 while (cls.isArray()) 957 cls = cls.getComponentType(); 958 if (cls.isPrimitive()) 959 return true; // int[].class, for example 960 if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: switch to supported API once it is added 961 return false; 962 // could use VerifyAccess.isClassAccessible but the following is a safe approximation 963 if (cls.getClassLoader() != Object.class.getClassLoader()) 964 return false; 965 if (VerifyAccess.isSamePackage(MethodHandle.class, cls)) 966 return true; 967 if (!Modifier.isPublic(cls.getModifiers())) 968 return false; 969 for (Class<?> pkgcls : STATICALLY_INVOCABLE_PACKAGES) { 970 if (VerifyAccess.isSamePackage(pkgcls, cls)) 971 return true; 972 } 973 return false; 974 } 975 976 void emitStaticInvoke(Name name) { 977 emitStaticInvoke(name.function.member(), name); 978 } 979 980 /** 981 * Emit an invoke for the given name, using the MemberName directly. 982 */ 983 void emitStaticInvoke(MemberName member, Name name) { 984 assert(member.equals(name.function.member())); 985 Class<?> defc = member.getDeclaringClass(); 986 String cname = getInternalName(defc); 987 String mname = member.getName(); 988 String mtype; 989 byte refKind = member.getReferenceKind(); 990 if (refKind == REF_invokeSpecial) { 991 // in order to pass the verifier, we need to convert this to invokevirtual in all cases 992 assert(member.canBeStaticallyBound()) : member; 993 refKind = REF_invokeVirtual; 994 } 995 996 assert(!(member.getDeclaringClass().isInterface() && refKind == REF_invokeVirtual)); 997 998 // push arguments 999 emitPushArguments(name, 0); 1000 1001 // invocation 1002 if (member.isMethod()) { 1003 mtype = member.getMethodType().toMethodDescriptorString(); 1004 mv.visitMethodInsn(refKindOpcode(refKind), cname, mname, mtype, 1005 member.getDeclaringClass().isInterface()); 1006 } else { 1007 mtype = MethodType.toFieldDescriptorString(member.getFieldType()); 1008 mv.visitFieldInsn(refKindOpcode(refKind), cname, mname, mtype); 1009 } 1010 // Issue a type assertion for the result, so we can avoid casts later. 1011 if (name.type == L_TYPE) { 1012 Class<?> rtype = member.getInvocationType().returnType(); 1013 assert(!rtype.isPrimitive()); 1014 if (rtype != Object.class && !rtype.isInterface()) { 1015 assertStaticType(rtype, name); 1016 } 1017 } 1018 } 1019 1020 void emitNewArray(Name name) throws InternalError { 1021 Class<?> rtype = name.function.methodType().returnType(); 1022 if (name.arguments.length == 0) { 1023 // The array will be a constant. 1024 Object emptyArray; 1025 try { 1026 emptyArray = name.function.resolvedHandle().invoke(); 1027 } catch (Throwable ex) { 1028 throw uncaughtException(ex); 1029 } 1030 assert(java.lang.reflect.Array.getLength(emptyArray) == 0); 1031 assert(emptyArray.getClass() == rtype); // exact typing 1032 mv.visitLdcInsn(constantPlaceholder(emptyArray)); 1033 emitReferenceCast(rtype, emptyArray); 1034 return; 1035 } 1036 Class<?> arrayElementType = rtype.getComponentType(); 1037 assert(arrayElementType != null); 1038 emitIconstInsn(name.arguments.length); 1039 int xas = Opcodes.AASTORE; 1040 if (!arrayElementType.isPrimitive()) { 1041 mv.visitTypeInsn(Opcodes.ANEWARRAY, getInternalName(arrayElementType)); 1042 } else { 1043 byte tc = arrayTypeCode(Wrapper.forPrimitiveType(arrayElementType)); 1044 xas = arrayInsnOpcode(tc, xas); 1045 mv.visitIntInsn(Opcodes.NEWARRAY, tc); 1046 } 1047 // store arguments 1048 for (int i = 0; i < name.arguments.length; i++) { 1049 mv.visitInsn(Opcodes.DUP); 1050 emitIconstInsn(i); 1051 emitPushArgument(name, i); 1052 mv.visitInsn(xas); 1053 } 1054 // the array is left on the stack 1055 assertStaticType(rtype, name); 1056 } 1057 int refKindOpcode(byte refKind) { 1058 switch (refKind) { 1059 case REF_invokeVirtual: return Opcodes.INVOKEVIRTUAL; 1060 case REF_invokeStatic: return Opcodes.INVOKESTATIC; 1061 case REF_invokeSpecial: return Opcodes.INVOKESPECIAL; 1062 case REF_invokeInterface: return Opcodes.INVOKEINTERFACE; 1063 case REF_getField: return Opcodes.GETFIELD; 1064 case REF_putField: return Opcodes.PUTFIELD; 1065 case REF_getStatic: return Opcodes.GETSTATIC; 1066 case REF_putStatic: return Opcodes.PUTSTATIC; 1067 } 1068 throw new InternalError("refKind="+refKind); 1069 } 1070 1071 /** 1072 * Emit bytecode for the selectAlternative idiom. 1073 * 1074 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithTest): 1075 * <blockquote><pre>{@code 1076 * Lambda(a0:L,a1:I)=>{ 1077 * t2:I=foo.test(a1:I); 1078 * t3:L=MethodHandleImpl.selectAlternative(t2:I,(MethodHandle(int)int),(MethodHandle(int)int)); 1079 * t4:I=MethodHandle.invokeBasic(t3:L,a1:I);t4:I} 1080 * }</pre></blockquote> 1081 */ 1082 private Name emitSelectAlternative(Name selectAlternativeName, Name invokeBasicName) { 1083 assert isStaticallyInvocable(invokeBasicName); 1084 1085 Name receiver = (Name) invokeBasicName.arguments[0]; 1086 1087 Label L_fallback = new Label(); 1088 Label L_done = new Label(); 1089 1090 // load test result 1091 emitPushArgument(selectAlternativeName, 0); 1092 1093 // if_icmpne L_fallback 1094 mv.visitJumpInsn(Opcodes.IFEQ, L_fallback); 1095 1096 // invoke selectAlternativeName.arguments[1] 1097 Class<?>[] preForkClasses = localClasses.clone(); 1098 emitPushArgument(selectAlternativeName, 1); // get 2nd argument of selectAlternative 1099 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot 1100 emitStaticInvoke(invokeBasicName); 1101 1102 // goto L_done 1103 mv.visitJumpInsn(Opcodes.GOTO, L_done); 1104 1105 // L_fallback: 1106 mv.visitLabel(L_fallback); 1107 1108 // invoke selectAlternativeName.arguments[2] 1109 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length); 1110 emitPushArgument(selectAlternativeName, 2); // get 3rd argument of selectAlternative 1111 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot 1112 emitStaticInvoke(invokeBasicName); 1113 1114 // L_done: 1115 mv.visitLabel(L_done); 1116 // for now do not bother to merge typestate; just reset to the dominator state 1117 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length); 1118 1119 return invokeBasicName; // return what's on stack 1120 } 1121 1122 /** 1123 * Emit bytecode for the guardWithCatch idiom. 1124 * 1125 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithCatch): 1126 * <blockquote><pre>{@code 1127 * guardWithCatch=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L,a5:L,a6:L,a7:L)=>{ 1128 * t8:L=MethodHandle.invokeBasic(a4:L,a6:L,a7:L); 1129 * t9:L=MethodHandleImpl.guardWithCatch(a1:L,a2:L,a3:L,t8:L); 1130 * t10:I=MethodHandle.invokeBasic(a5:L,t9:L);t10:I} 1131 * }</pre></blockquote> 1132 * 1133 * It is compiled into bytecode equivalent of the following code: 1134 * <blockquote><pre>{@code 1135 * try { 1136 * return a1.invokeBasic(a6, a7); 1137 * } catch (Throwable e) { 1138 * if (!a2.isInstance(e)) throw e; 1139 * return a3.invokeBasic(ex, a6, a7); 1140 * }} 1141 */ 1142 private Name emitGuardWithCatch(int pos) { 1143 Name args = lambdaForm.names[pos]; 1144 Name invoker = lambdaForm.names[pos+1]; 1145 Name result = lambdaForm.names[pos+2]; 1146 1147 Label L_startBlock = new Label(); 1148 Label L_endBlock = new Label(); 1149 Label L_handler = new Label(); 1150 Label L_done = new Label(); 1151 1152 Class<?> returnType = result.function.resolvedHandle().type().returnType(); 1153 MethodType type = args.function.resolvedHandle().type() 1154 .dropParameterTypes(0,1) 1155 .changeReturnType(returnType); 1156 1157 mv.visitTryCatchBlock(L_startBlock, L_endBlock, L_handler, "java/lang/Throwable"); 1158 1159 // Normal case 1160 mv.visitLabel(L_startBlock); 1161 // load target 1162 emitPushArgument(invoker, 0); 1163 emitPushArguments(args, 1); // skip 1st argument: method handle 1164 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false); 1165 mv.visitLabel(L_endBlock); 1166 mv.visitJumpInsn(Opcodes.GOTO, L_done); 1167 1168 // Exceptional case 1169 mv.visitLabel(L_handler); 1170 1171 // Check exception's type 1172 mv.visitInsn(Opcodes.DUP); 1173 // load exception class 1174 emitPushArgument(invoker, 1); 1175 mv.visitInsn(Opcodes.SWAP); 1176 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/Class", "isInstance", "(Ljava/lang/Object;)Z", false); 1177 Label L_rethrow = new Label(); 1178 mv.visitJumpInsn(Opcodes.IFEQ, L_rethrow); 1179 1180 // Invoke catcher 1181 // load catcher 1182 emitPushArgument(invoker, 2); 1183 mv.visitInsn(Opcodes.SWAP); 1184 emitPushArguments(args, 1); // skip 1st argument: method handle 1185 MethodType catcherType = type.insertParameterTypes(0, Throwable.class); 1186 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", catcherType.basicType().toMethodDescriptorString(), false); 1187 mv.visitJumpInsn(Opcodes.GOTO, L_done); 1188 1189 mv.visitLabel(L_rethrow); 1190 mv.visitInsn(Opcodes.ATHROW); 1191 1192 mv.visitLabel(L_done); 1193 1194 return result; 1195 } 1196 1197 /** 1198 * Emit bytecode for the tryFinally idiom. 1199 * <p> 1200 * The pattern looks like (Cf. MethodHandleImpl.makeTryFinally): 1201 * <blockquote><pre>{@code 1202 * // a0: BMH 1203 * // a1: target, a2: cleanup 1204 * // a3: box, a4: unbox 1205 * // a5 (and following): arguments 1206 * tryFinally=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L,a5:L)=>{ 1207 * t6:L=MethodHandle.invokeBasic(a3:L,a5:L); // box the arguments into an Object[] 1208 * t7:L=MethodHandleImpl.tryFinally(a1:L,a2:L,t6:L); // call the tryFinally executor 1209 * t8:L=MethodHandle.invokeBasic(a4:L,t7:L);t8:L} // unbox the result; return the result 1210 * }</pre></blockquote> 1211 * <p> 1212 * It is compiled into bytecode equivalent to the following code: 1213 * <blockquote><pre>{@code 1214 * Throwable t; 1215 * Object r; 1216 * try { 1217 * r = a1.invokeBasic(a5); 1218 * } catch (Throwable thrown) { 1219 * t = thrown; 1220 * throw t; 1221 * } finally { 1222 * r = a2.invokeBasic(t, r, a5); 1223 * } 1224 * return r; 1225 * }</pre></blockquote> 1226 * <p> 1227 * Specifically, the bytecode will have the following form (the stack effects are given for the beginnings of 1228 * blocks, and for the situations after executing the given instruction - the code will have a slightly different 1229 * shape if the return type is {@code void}): 1230 * <blockquote><pre>{@code 1231 * TRY: (--) 1232 * load target (-- target) 1233 * load args (-- args... target) 1234 * INVOKEVIRTUAL MethodHandle.invokeBasic (depends) 1235 * FINALLY_NORMAL: (-- r) 1236 * load cleanup (-- cleanup r) 1237 * SWAP (-- r cleanup) 1238 * ACONST_NULL (-- t r cleanup) 1239 * SWAP (-- r t cleanup) 1240 * load args (-- args... r t cleanup) 1241 * INVOKEVIRTUAL MethodHandle.invokeBasic (-- r) 1242 * GOTO DONE 1243 * CATCH: (-- t) 1244 * DUP (-- t t) 1245 * FINALLY_EXCEPTIONAL: (-- t t) 1246 * load cleanup (-- cleanup t t) 1247 * SWAP (-- t cleanup t) 1248 * load default for r (-- r t cleanup t) 1249 * load args (-- args... r t cleanup t) 1250 * INVOKEVIRTUAL MethodHandle.invokeBasic (-- r t) 1251 * POP (-- t) 1252 * ATHROW 1253 * DONE: (-- r) 1254 * }</pre></blockquote> 1255 */ 1256 private Name emitTryFinally(int pos) { 1257 Name args = lambdaForm.names[pos]; 1258 Name invoker = lambdaForm.names[pos+1]; 1259 Name result = lambdaForm.names[pos+2]; 1260 1261 Label lFrom = new Label(); 1262 Label lTo = new Label(); 1263 Label lCatch = new Label(); 1264 Label lDone = new Label(); 1265 1266 Class<?> returnType = result.function.resolvedHandle().type().returnType(); 1267 boolean isNonVoid = returnType != void.class; 1268 MethodType type = args.function.resolvedHandle().type() 1269 .dropParameterTypes(0,1) 1270 .changeReturnType(returnType); 1271 MethodType cleanupType = type.insertParameterTypes(0, Throwable.class); 1272 if (isNonVoid) { 1273 cleanupType = cleanupType.insertParameterTypes(1, returnType); 1274 } 1275 String cleanupDesc = cleanupType.basicType().toMethodDescriptorString(); 1276 1277 // exception handler table 1278 mv.visitTryCatchBlock(lFrom, lTo, lCatch, "java/lang/Throwable"); 1279 1280 // TRY: 1281 mv.visitLabel(lFrom); 1282 emitPushArgument(invoker, 0); // load target 1283 emitPushArguments(args, 1); // load args (skip 0: method handle) 1284 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false); 1285 mv.visitLabel(lTo); 1286 1287 // FINALLY_NORMAL: 1288 emitPushArgument(invoker, 1); // load cleanup 1289 if (isNonVoid) { 1290 mv.visitInsn(Opcodes.SWAP); 1291 } 1292 mv.visitInsn(Opcodes.ACONST_NULL); 1293 if (isNonVoid) { 1294 mv.visitInsn(Opcodes.SWAP); 1295 } 1296 emitPushArguments(args, 1); // load args (skip 0: method handle) 1297 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", cleanupDesc, false); 1298 mv.visitJumpInsn(Opcodes.GOTO, lDone); 1299 1300 // CATCH: 1301 mv.visitLabel(lCatch); 1302 mv.visitInsn(Opcodes.DUP); 1303 1304 // FINALLY_EXCEPTIONAL: 1305 emitPushArgument(invoker, 1); // load cleanup 1306 mv.visitInsn(Opcodes.SWAP); 1307 if (isNonVoid) { 1308 emitZero(BasicType.basicType(returnType)); // load default for result 1309 } 1310 emitPushArguments(args, 1); // load args (skip 0: method handle) 1311 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", cleanupDesc, false); 1312 if (isNonVoid) { 1313 mv.visitInsn(Opcodes.POP); 1314 } 1315 mv.visitInsn(Opcodes.ATHROW); 1316 1317 // DONE: 1318 mv.visitLabel(lDone); 1319 1320 return result; 1321 } 1322 1323 /** 1324 * Emit bytecode for the loop idiom. 1325 * <p> 1326 * The pattern looks like (Cf. MethodHandleImpl.loop): 1327 * <blockquote><pre>{@code 1328 * // a0: BMH 1329 * // a1: LoopClauses (containing an array of arrays: inits, steps, preds, finis) 1330 * // a2: box, a3: unbox 1331 * // a4 (and following): arguments 1332 * loop=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L)=>{ 1333 * t5:L=MethodHandle.invokeBasic(a2:L,a4:L); // box the arguments into an Object[] 1334 * t6:L=MethodHandleImpl.loop(bt:L,a1:L,t5:L); // call the loop executor (with supplied types in bt) 1335 * t7:L=MethodHandle.invokeBasic(a3:L,t6:L);t7:L} // unbox the result; return the result 1336 * }</pre></blockquote> 1337 * <p> 1338 * It is compiled into bytecode equivalent to the code seen in {@link MethodHandleImpl#loop(BasicType[], 1339 * MethodHandleImpl.LoopClauses, Object...)}, with the difference that no arrays 1340 * will be used for local state storage. Instead, the local state will be mapped to actual stack slots. 1341 * <p> 1342 * Bytecode generation applies an unrolling scheme to enable better bytecode generation regarding local state type 1343 * handling. The generated bytecode will have the following form ({@code void} types are ignored for convenience). 1344 * Assume there are {@code C} clauses in the loop. 1345 * <blockquote><pre>{@code 1346 * PREINIT: ALOAD_1 1347 * CHECKCAST LoopClauses 1348 * GETFIELD LoopClauses.clauses 1349 * ASTORE clauseDataIndex // place the clauses 2-dimensional array on the stack 1350 * INIT: (INIT_SEQ for clause 1) 1351 * ... 1352 * (INIT_SEQ for clause C) 1353 * LOOP: (LOOP_SEQ for clause 1) 1354 * ... 1355 * (LOOP_SEQ for clause C) 1356 * GOTO LOOP 1357 * DONE: ... 1358 * }</pre></blockquote> 1359 * <p> 1360 * The {@code INIT_SEQ_x} sequence for clause {@code x} (with {@code x} ranging from {@code 0} to {@code C-1}) has 1361 * the following shape. Assume slot {@code vx} is used to hold the state for clause {@code x}. 1362 * <blockquote><pre>{@code 1363 * INIT_SEQ_x: ALOAD clauseDataIndex 1364 * ICONST_0 1365 * AALOAD // load the inits array 1366 * ICONST x 1367 * AALOAD // load the init handle for clause x 1368 * load args 1369 * INVOKEVIRTUAL MethodHandle.invokeBasic 1370 * store vx 1371 * }</pre></blockquote> 1372 * <p> 1373 * The {@code LOOP_SEQ_x} sequence for clause {@code x} (with {@code x} ranging from {@code 0} to {@code C-1}) has 1374 * the following shape. Again, assume slot {@code vx} is used to hold the state for clause {@code x}. 1375 * <blockquote><pre>{@code 1376 * LOOP_SEQ_x: ALOAD clauseDataIndex 1377 * ICONST_1 1378 * AALOAD // load the steps array 1379 * ICONST x 1380 * AALOAD // load the step handle for clause x 1381 * load locals 1382 * load args 1383 * INVOKEVIRTUAL MethodHandle.invokeBasic 1384 * store vx 1385 * ALOAD clauseDataIndex 1386 * ICONST_2 1387 * AALOAD // load the preds array 1388 * ICONST x 1389 * AALOAD // load the pred handle for clause x 1390 * load locals 1391 * load args 1392 * INVOKEVIRTUAL MethodHandle.invokeBasic 1393 * IFNE LOOP_SEQ_x+1 // predicate returned false -> jump to next clause 1394 * ALOAD clauseDataIndex 1395 * ICONST_3 1396 * AALOAD // load the finis array 1397 * ICONST x 1398 * AALOAD // load the fini handle for clause x 1399 * load locals 1400 * load args 1401 * INVOKEVIRTUAL MethodHandle.invokeBasic 1402 * GOTO DONE // jump beyond end of clauses to return from loop 1403 * }</pre></blockquote> 1404 */ 1405 private Name emitLoop(int pos) { 1406 Name args = lambdaForm.names[pos]; 1407 Name invoker = lambdaForm.names[pos+1]; 1408 Name result = lambdaForm.names[pos+2]; 1409 1410 // extract clause and loop-local state types 1411 // find the type info in the loop invocation 1412 BasicType[] loopClauseTypes = (BasicType[]) invoker.arguments[0]; 1413 Class<?>[] loopLocalStateTypes = Stream.of(loopClauseTypes). 1414 filter(bt -> bt != BasicType.V_TYPE).map(BasicType::basicTypeClass).toArray(Class<?>[]::new); 1415 Class<?>[] localTypes = new Class<?>[loopLocalStateTypes.length + 1]; 1416 localTypes[0] = MethodHandleImpl.LoopClauses.class; 1417 System.arraycopy(loopLocalStateTypes, 0, localTypes, 1, loopLocalStateTypes.length); 1418 1419 final int clauseDataIndex = extendLocalsMap(localTypes); 1420 final int firstLoopStateIndex = clauseDataIndex + 1; 1421 1422 Class<?> returnType = result.function.resolvedHandle().type().returnType(); 1423 MethodType loopType = args.function.resolvedHandle().type() 1424 .dropParameterTypes(0,1) 1425 .changeReturnType(returnType); 1426 MethodType loopHandleType = loopType.insertParameterTypes(0, loopLocalStateTypes); 1427 MethodType predType = loopHandleType.changeReturnType(boolean.class); 1428 MethodType finiType = loopHandleType; 1429 1430 final int nClauses = loopClauseTypes.length; 1431 1432 // indices to invoker arguments to load method handle arrays 1433 final int inits = 1; 1434 final int steps = 2; 1435 final int preds = 3; 1436 final int finis = 4; 1437 1438 Label lLoop = new Label(); 1439 Label lDone = new Label(); 1440 Label lNext; 1441 1442 // PREINIT: 1443 emitPushArgument(MethodHandleImpl.LoopClauses.class, invoker.arguments[1]); 1444 mv.visitFieldInsn(Opcodes.GETFIELD, LOOP_CLAUSES, "clauses", MHARY2); 1445 emitAstoreInsn(clauseDataIndex); 1446 1447 // INIT: 1448 for (int c = 0, state = 0; c < nClauses; ++c) { 1449 MethodType cInitType = loopType.changeReturnType(loopClauseTypes[c].basicTypeClass()); 1450 emitLoopHandleInvoke(invoker, inits, c, args, false, cInitType, loopLocalStateTypes, clauseDataIndex, 1451 firstLoopStateIndex); 1452 if (cInitType.returnType() != void.class) { 1453 emitStoreInsn(BasicType.basicType(cInitType.returnType()), firstLoopStateIndex + state); 1454 ++state; 1455 } 1456 } 1457 1458 // LOOP: 1459 mv.visitLabel(lLoop); 1460 1461 for (int c = 0, state = 0; c < nClauses; ++c) { 1462 lNext = new Label(); 1463 1464 MethodType stepType = loopHandleType.changeReturnType(loopClauseTypes[c].basicTypeClass()); 1465 boolean isVoid = stepType.returnType() == void.class; 1466 1467 // invoke loop step 1468 emitLoopHandleInvoke(invoker, steps, c, args, true, stepType, loopLocalStateTypes, clauseDataIndex, 1469 firstLoopStateIndex); 1470 if (!isVoid) { 1471 emitStoreInsn(BasicType.basicType(stepType.returnType()), firstLoopStateIndex + state); 1472 ++state; 1473 } 1474 1475 // invoke loop predicate 1476 emitLoopHandleInvoke(invoker, preds, c, args, true, predType, loopLocalStateTypes, clauseDataIndex, 1477 firstLoopStateIndex); 1478 mv.visitJumpInsn(Opcodes.IFNE, lNext); 1479 1480 // invoke fini 1481 emitLoopHandleInvoke(invoker, finis, c, args, true, finiType, loopLocalStateTypes, clauseDataIndex, 1482 firstLoopStateIndex); 1483 mv.visitJumpInsn(Opcodes.GOTO, lDone); 1484 1485 // this is the beginning of the next loop clause 1486 mv.visitLabel(lNext); 1487 } 1488 1489 mv.visitJumpInsn(Opcodes.GOTO, lLoop); 1490 1491 // DONE: 1492 mv.visitLabel(lDone); 1493 1494 return result; 1495 } 1496 1497 private int extendLocalsMap(Class<?>[] types) { 1498 int firstSlot = localsMap.length - 1; 1499 localsMap = Arrays.copyOf(localsMap, localsMap.length + types.length); 1500 localClasses = Arrays.copyOf(localClasses, localClasses.length + types.length); 1501 System.arraycopy(types, 0, localClasses, firstSlot, types.length); 1502 int index = localsMap[firstSlot - 1] + 1; 1503 int lastSlots = 0; 1504 for (int i = 0; i < types.length; ++i) { 1505 localsMap[firstSlot + i] = index; 1506 lastSlots = BasicType.basicType(localClasses[firstSlot + i]).basicTypeSlots(); 1507 index += lastSlots; 1508 } 1509 localsMap[localsMap.length - 1] = index - lastSlots; 1510 return firstSlot; 1511 } 1512 1513 private void emitLoopHandleInvoke(Name holder, int handles, int clause, Name args, boolean pushLocalState, 1514 MethodType type, Class<?>[] loopLocalStateTypes, int clauseDataSlot, 1515 int firstLoopStateSlot) { 1516 // load handle for clause 1517 emitPushClauseArray(clauseDataSlot, handles); 1518 emitIconstInsn(clause); 1519 mv.visitInsn(Opcodes.AALOAD); 1520 // load loop state (preceding the other arguments) 1521 if (pushLocalState) { 1522 for (int s = 0; s < loopLocalStateTypes.length; ++s) { 1523 emitLoadInsn(BasicType.basicType(loopLocalStateTypes[s]), firstLoopStateSlot + s); 1524 } 1525 } 1526 // load loop args (skip 0: method handle) 1527 emitPushArguments(args, 1); 1528 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.toMethodDescriptorString(), false); 1529 } 1530 1531 private void emitPushClauseArray(int clauseDataSlot, int which) { 1532 emitAloadInsn(clauseDataSlot); 1533 emitIconstInsn(which - 1); 1534 mv.visitInsn(Opcodes.AALOAD); 1535 } 1536 1537 private void emitZero(BasicType type) { 1538 switch (type) { 1539 case I_TYPE: mv.visitInsn(Opcodes.ICONST_0); break; 1540 case J_TYPE: mv.visitInsn(Opcodes.LCONST_0); break; 1541 case F_TYPE: mv.visitInsn(Opcodes.FCONST_0); break; 1542 case D_TYPE: mv.visitInsn(Opcodes.DCONST_0); break; 1543 case L_TYPE: mv.visitInsn(Opcodes.ACONST_NULL); break; 1544 default: throw new InternalError("unknown type: " + type); 1545 } 1546 } 1547 1548 private void emitPushArguments(Name args, int start) { 1549 MethodType type = args.function.methodType(); 1550 for (int i = start; i < args.arguments.length; i++) { 1551 emitPushArgument(type.parameterType(i), args.arguments[i]); 1552 } 1553 } 1554 1555 private void emitPushArgument(Name name, int paramIndex) { 1556 Object arg = name.arguments[paramIndex]; 1557 Class<?> ptype = name.function.methodType().parameterType(paramIndex); 1558 emitPushArgument(ptype, arg); 1559 } 1560 1561 private void emitPushArgument(Class<?> ptype, Object arg) { 1562 BasicType bptype = basicType(ptype); 1563 if (arg instanceof Name) { 1564 Name n = (Name) arg; 1565 emitLoadInsn(n.type, n.index()); 1566 emitImplicitConversion(n.type, ptype, n); 1567 } else if ((arg == null || arg instanceof String) && bptype == L_TYPE) { 1568 emitConst(arg); 1569 } else { 1570 if (Wrapper.isWrapperType(arg.getClass()) && bptype != L_TYPE) { 1571 emitConst(arg); 1572 } else { 1573 mv.visitLdcInsn(constantPlaceholder(arg)); 1574 emitImplicitConversion(L_TYPE, ptype, arg); 1575 } 1576 } 1577 } 1578 1579 /** 1580 * Store the name to its local, if necessary. 1581 */ 1582 private void emitStoreResult(Name name) { 1583 if (name != null && name.type != V_TYPE) { 1584 // non-void: actually assign 1585 emitStoreInsn(name.type, name.index()); 1586 } 1587 } 1588 1589 /** 1590 * Emits a return statement from a LF invoker. If required, the result type is cast to the correct return type. 1591 */ 1592 private void emitReturn(Name onStack) { 1593 // return statement 1594 Class<?> rclass = invokerType.returnType(); 1595 BasicType rtype = lambdaForm.returnType(); 1596 assert(rtype == basicType(rclass)); // must agree 1597 if (rtype == V_TYPE) { 1598 // void 1599 mv.visitInsn(Opcodes.RETURN); 1600 // it doesn't matter what rclass is; the JVM will discard any value 1601 } else { 1602 LambdaForm.Name rn = lambdaForm.names[lambdaForm.result]; 1603 1604 // put return value on the stack if it is not already there 1605 if (rn != onStack) { 1606 emitLoadInsn(rtype, lambdaForm.result); 1607 } 1608 1609 emitImplicitConversion(rtype, rclass, rn); 1610 1611 // generate actual return statement 1612 emitReturnInsn(rtype); 1613 } 1614 } 1615 1616 /** 1617 * Emit a type conversion bytecode casting from "from" to "to". 1618 */ 1619 private void emitPrimCast(Wrapper from, Wrapper to) { 1620 // Here's how. 1621 // - indicates forbidden 1622 // <-> indicates implicit 1623 // to ----> boolean byte short char int long float double 1624 // from boolean <-> - - - - - - - 1625 // byte - <-> i2s i2c <-> i2l i2f i2d 1626 // short - i2b <-> i2c <-> i2l i2f i2d 1627 // char - i2b i2s <-> <-> i2l i2f i2d 1628 // int - i2b i2s i2c <-> i2l i2f i2d 1629 // long - l2i,i2b l2i,i2s l2i,i2c l2i <-> l2f l2d 1630 // float - f2i,i2b f2i,i2s f2i,i2c f2i f2l <-> f2d 1631 // double - d2i,i2b d2i,i2s d2i,i2c d2i d2l d2f <-> 1632 if (from == to) { 1633 // no cast required, should be dead code anyway 1634 return; 1635 } 1636 if (from.isSubwordOrInt()) { 1637 // cast from {byte,short,char,int} to anything 1638 emitI2X(to); 1639 } else { 1640 // cast from {long,float,double} to anything 1641 if (to.isSubwordOrInt()) { 1642 // cast to {byte,short,char,int} 1643 emitX2I(from); 1644 if (to.bitWidth() < 32) { 1645 // targets other than int require another conversion 1646 emitI2X(to); 1647 } 1648 } else { 1649 // cast to {long,float,double} - this is verbose 1650 boolean error = false; 1651 switch (from) { 1652 case LONG: 1653 switch (to) { 1654 case FLOAT: mv.visitInsn(Opcodes.L2F); break; 1655 case DOUBLE: mv.visitInsn(Opcodes.L2D); break; 1656 default: error = true; break; 1657 } 1658 break; 1659 case FLOAT: 1660 switch (to) { 1661 case LONG : mv.visitInsn(Opcodes.F2L); break; 1662 case DOUBLE: mv.visitInsn(Opcodes.F2D); break; 1663 default: error = true; break; 1664 } 1665 break; 1666 case DOUBLE: 1667 switch (to) { 1668 case LONG : mv.visitInsn(Opcodes.D2L); break; 1669 case FLOAT: mv.visitInsn(Opcodes.D2F); break; 1670 default: error = true; break; 1671 } 1672 break; 1673 default: 1674 error = true; 1675 break; 1676 } 1677 if (error) { 1678 throw new IllegalStateException("unhandled prim cast: " + from + "2" + to); 1679 } 1680 } 1681 } 1682 } 1683 1684 private void emitI2X(Wrapper type) { 1685 switch (type) { 1686 case BYTE: mv.visitInsn(Opcodes.I2B); break; 1687 case SHORT: mv.visitInsn(Opcodes.I2S); break; 1688 case CHAR: mv.visitInsn(Opcodes.I2C); break; 1689 case INT: /* naught */ break; 1690 case LONG: mv.visitInsn(Opcodes.I2L); break; 1691 case FLOAT: mv.visitInsn(Opcodes.I2F); break; 1692 case DOUBLE: mv.visitInsn(Opcodes.I2D); break; 1693 case BOOLEAN: 1694 // For compatibility with ValueConversions and explicitCastArguments: 1695 mv.visitInsn(Opcodes.ICONST_1); 1696 mv.visitInsn(Opcodes.IAND); 1697 break; 1698 default: throw new InternalError("unknown type: " + type); 1699 } 1700 } 1701 1702 private void emitX2I(Wrapper type) { 1703 switch (type) { 1704 case LONG: mv.visitInsn(Opcodes.L2I); break; 1705 case FLOAT: mv.visitInsn(Opcodes.F2I); break; 1706 case DOUBLE: mv.visitInsn(Opcodes.D2I); break; 1707 default: throw new InternalError("unknown type: " + type); 1708 } 1709 } 1710 1711 /** 1712 * Generate bytecode for a LambdaForm.vmentry which calls interpretWithArguments. 1713 */ 1714 static MemberName generateLambdaFormInterpreterEntryPoint(MethodType mt) { 1715 assert(isValidSignature(basicTypeSignature(mt))); 1716 String name = "interpret_"+basicTypeChar(mt.returnType()); 1717 MethodType type = mt; // includes leading argument 1718 type = type.changeParameterType(0, MethodHandle.class); 1719 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("LFI", name, type); 1720 return g.loadMethod(g.generateLambdaFormInterpreterEntryPointBytes()); 1721 } 1722 1723 private byte[] generateLambdaFormInterpreterEntryPointBytes() { 1724 classFilePrologue(); 1725 methodPrologue(); 1726 1727 // Suppress this method in backtraces displayed to the user. 1728 mv.visitAnnotation(LF_HIDDEN_SIG, true); 1729 1730 // Don't inline the interpreter entry. 1731 mv.visitAnnotation(DONTINLINE_SIG, true); 1732 1733 // create parameter array 1734 emitIconstInsn(invokerType.parameterCount()); 1735 mv.visitTypeInsn(Opcodes.ANEWARRAY, "java/lang/Object"); 1736 1737 // fill parameter array 1738 for (int i = 0; i < invokerType.parameterCount(); i++) { 1739 Class<?> ptype = invokerType.parameterType(i); 1740 mv.visitInsn(Opcodes.DUP); 1741 emitIconstInsn(i); 1742 emitLoadInsn(basicType(ptype), i); 1743 // box if primitive type 1744 if (ptype.isPrimitive()) { 1745 emitBoxing(Wrapper.forPrimitiveType(ptype)); 1746 } 1747 mv.visitInsn(Opcodes.AASTORE); 1748 } 1749 // invoke 1750 emitAloadInsn(0); 1751 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", "Ljava/lang/invoke/LambdaForm;"); 1752 mv.visitInsn(Opcodes.SWAP); // swap form and array; avoid local variable 1753 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, LF, "interpretWithArguments", "([Ljava/lang/Object;)Ljava/lang/Object;", false); 1754 1755 // maybe unbox 1756 Class<?> rtype = invokerType.returnType(); 1757 if (rtype.isPrimitive() && rtype != void.class) { 1758 emitUnboxing(Wrapper.forPrimitiveType(rtype)); 1759 } 1760 1761 // return statement 1762 emitReturnInsn(basicType(rtype)); 1763 1764 methodEpilogue(); 1765 bogusMethod(invokerType); 1766 1767 final byte[] classFile = cw.toByteArray(); 1768 maybeDump(classFile); 1769 return classFile; 1770 } 1771 1772 /** 1773 * Generate bytecode for a NamedFunction invoker. 1774 */ 1775 static MemberName generateNamedFunctionInvoker(MethodTypeForm typeForm) { 1776 MethodType invokerType = NamedFunction.INVOKER_METHOD_TYPE; 1777 String invokerName = "invoke_" + shortenSignature(basicTypeSignature(typeForm.erasedType())); 1778 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("NFI", invokerName, invokerType); 1779 return g.loadMethod(g.generateNamedFunctionInvokerImpl(typeForm)); 1780 } 1781 1782 private byte[] generateNamedFunctionInvokerImpl(MethodTypeForm typeForm) { 1783 MethodType dstType = typeForm.erasedType(); 1784 classFilePrologue(); 1785 methodPrologue(); 1786 1787 // Suppress this method in backtraces displayed to the user. 1788 mv.visitAnnotation(LF_HIDDEN_SIG, true); 1789 1790 // Force inlining of this invoker method. 1791 mv.visitAnnotation(FORCEINLINE_SIG, true); 1792 1793 // Load receiver 1794 emitAloadInsn(0); 1795 1796 // Load arguments from array 1797 for (int i = 0; i < dstType.parameterCount(); i++) { 1798 emitAloadInsn(1); 1799 emitIconstInsn(i); 1800 mv.visitInsn(Opcodes.AALOAD); 1801 1802 // Maybe unbox 1803 Class<?> dptype = dstType.parameterType(i); 1804 if (dptype.isPrimitive()) { 1805 Wrapper dstWrapper = Wrapper.forBasicType(dptype); 1806 Wrapper srcWrapper = dstWrapper.isSubwordOrInt() ? Wrapper.INT : dstWrapper; // narrow subword from int 1807 emitUnboxing(srcWrapper); 1808 emitPrimCast(srcWrapper, dstWrapper); 1809 } 1810 } 1811 1812 // Invoke 1813 String targetDesc = dstType.basicType().toMethodDescriptorString(); 1814 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", targetDesc, false); 1815 1816 // Box primitive types 1817 Class<?> rtype = dstType.returnType(); 1818 if (rtype != void.class && rtype.isPrimitive()) { 1819 Wrapper srcWrapper = Wrapper.forBasicType(rtype); 1820 Wrapper dstWrapper = srcWrapper.isSubwordOrInt() ? Wrapper.INT : srcWrapper; // widen subword to int 1821 // boolean casts not allowed 1822 emitPrimCast(srcWrapper, dstWrapper); 1823 emitBoxing(dstWrapper); 1824 } 1825 1826 // If the return type is void we return a null reference. 1827 if (rtype == void.class) { 1828 mv.visitInsn(Opcodes.ACONST_NULL); 1829 } 1830 emitReturnInsn(L_TYPE); // NOTE: NamedFunction invokers always return a reference value. 1831 1832 methodEpilogue(); 1833 bogusMethod(dstType); 1834 1835 final byte[] classFile = cw.toByteArray(); 1836 maybeDump(classFile); 1837 return classFile; 1838 } 1839 1840 /** 1841 * Emit a bogus method that just loads some string constants. This is to get the constants into the constant pool 1842 * for debugging purposes. 1843 */ 1844 private void bogusMethod(Object... os) { 1845 if (DUMP_CLASS_FILES) { 1846 mv = cw.visitMethod(Opcodes.ACC_STATIC, "dummy", "()V", null, null); 1847 for (Object o : os) { 1848 mv.visitLdcInsn(o.toString()); 1849 mv.visitInsn(Opcodes.POP); 1850 } 1851 mv.visitInsn(Opcodes.RETURN); 1852 mv.visitMaxs(0, 0); 1853 mv.visitEnd(); 1854 } 1855 } 1856} 1857