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 26 package java.lang.invoke; 27 28 import jdk.internal.org.objectweb.asm.ClassWriter; 29 import jdk.internal.org.objectweb.asm.Label; 30 import jdk.internal.org.objectweb.asm.MethodVisitor; 31 import jdk.internal.org.objectweb.asm.Opcodes; 32 import jdk.internal.org.objectweb.asm.Type; 33 import sun.invoke.util.VerifyAccess; 34 import sun.invoke.util.VerifyType; 35 import sun.invoke.util.Wrapper; 36 import sun.reflect.misc.ReflectUtil; 37 38 import java.io.File; 39 import java.io.FileOutputStream; 40 import java.io.IOException; 41 import java.lang.reflect.Modifier; 42 import java.util.ArrayList; 43 import java.util.Arrays; 44 import java.util.HashMap; 45 import java.util.stream.Stream; 46 47 import static java.lang.invoke.LambdaForm.BasicType; 48 import static java.lang.invoke.LambdaForm.BasicType.*; 49 import static java.lang.invoke.LambdaForm.*; 50 import static java.lang.invoke.MethodHandleNatives.Constants.*; 51 import static java.lang.invoke.MethodHandleStatics.*; 52 53 /** 54 * Code generation backend for LambdaForm. 55 * <p> 56 * @author John Rose, JSR 292 EG 57 */ 58 class 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 /** Single element internal class name lookup cache. */ 97 private Class<?> lastClass; 98 private String lastInternalName; 99 100 private static final MemberName.Factory MEMBERNAME_FACTORY = MemberName.getFactory(); 101 private static final Class<?> HOST_CLASS = LambdaForm.class; 102 103 /** Main constructor; other constructors delegate to this one. */ 104 private InvokerBytecodeGenerator(LambdaForm lambdaForm, int localsMapSize, 105 String className, String invokerName, MethodType invokerType) { 106 int p = invokerName.indexOf('.'); 107 if (p > -1) { 108 className = invokerName.substring(0, p); 109 invokerName = invokerName.substring(p + 1); 110 } 111 if (DUMP_CLASS_FILES) { 112 className = makeDumpableClassName(className); 113 } 114 this.className = className; 115 this.lambdaForm = lambdaForm; 116 this.invokerName = invokerName; 117 this.invokerType = invokerType; 118 this.localsMap = new int[localsMapSize+1]; // last entry of localsMap is count of allocated local slots 119 this.localClasses = new Class<?>[localsMapSize+1]; 120 } 121 122 /** For generating LambdaForm interpreter entry points. */ 123 private InvokerBytecodeGenerator(String className, String invokerName, MethodType invokerType) { 124 this(null, invokerType.parameterCount(), 125 className, invokerName, invokerType); 126 // Create an array to map name indexes to locals indexes. 127 for (int i = 0; i < localsMap.length; i++) { 128 localsMap[i] = invokerType.parameterSlotCount() - invokerType.parameterSlotDepth(i); 129 } 130 } 131 132 /** For generating customized code for a single LambdaForm. */ 133 private InvokerBytecodeGenerator(String className, LambdaForm form, MethodType invokerType) { 134 this(className, form.lambdaName(), form, invokerType); 135 } 136 137 /** For generating customized code for a single LambdaForm. */ 138 InvokerBytecodeGenerator(String className, String invokerName, 139 LambdaForm form, MethodType invokerType) { 140 this(form, form.names.length, 141 className, invokerName, invokerType); 142 // Create an array to map name indexes to locals indexes. 143 Name[] names = form.names; 144 for (int i = 0, index = 0; i < localsMap.length; i++) { 145 localsMap[i] = index; 146 if (i < names.length) { 147 BasicType type = names[i].type(); 148 index += type.basicTypeSlots(); 149 } 150 } 151 } 152 153 /** instance counters for dumped classes */ 154 private static final HashMap<String,Integer> DUMP_CLASS_FILES_COUNTERS; 155 /** debugging flag for saving generated class files */ 156 private static final File DUMP_CLASS_FILES_DIR; 157 158 static { 159 if (DUMP_CLASS_FILES) { 160 DUMP_CLASS_FILES_COUNTERS = new HashMap<>(); 161 try { 162 File dumpDir = new File("DUMP_CLASS_FILES"); 163 if (!dumpDir.exists()) { 164 dumpDir.mkdirs(); 165 } 166 DUMP_CLASS_FILES_DIR = dumpDir; 167 System.out.println("Dumping class files to "+DUMP_CLASS_FILES_DIR+"/..."); 168 } catch (Exception e) { 169 throw newInternalError(e); 170 } 171 } else { 172 DUMP_CLASS_FILES_COUNTERS = null; 173 DUMP_CLASS_FILES_DIR = null; 174 } 175 } 176 177 private void maybeDump(final byte[] classFile) { 178 if (DUMP_CLASS_FILES) { 179 maybeDump(CLASS_PREFIX + className, classFile); 180 } 181 } 182 183 // Also used from BoundMethodHandle 184 static void maybeDump(final String className, final byte[] classFile) { 185 if (DUMP_CLASS_FILES) { 186 java.security.AccessController.doPrivileged( 187 new java.security.PrivilegedAction<>() { 188 public Void run() { 189 try { 190 String dumpName = className.replace('.','/'); 191 File dumpFile = new File(DUMP_CLASS_FILES_DIR, dumpName+".class"); 192 System.out.println("dump: " + dumpFile); 193 dumpFile.getParentFile().mkdirs(); 194 FileOutputStream file = new FileOutputStream(dumpFile); 195 file.write(classFile); 196 file.close(); 197 return null; 198 } catch (IOException ex) { 199 throw newInternalError(ex); 200 } 201 } 202 }); 203 } 204 } 205 206 private static String makeDumpableClassName(String className) { 207 Integer ctr; 208 synchronized (DUMP_CLASS_FILES_COUNTERS) { 209 ctr = DUMP_CLASS_FILES_COUNTERS.get(className); 210 if (ctr == null) ctr = 0; 211 DUMP_CLASS_FILES_COUNTERS.put(className, ctr+1); 212 } 213 String sfx = ctr.toString(); 214 while (sfx.length() < 3) 215 sfx = "0"+sfx; 216 className += sfx; 217 return className; 218 } 219 220 class CpPatch { 221 final int index; 222 final Object value; 223 CpPatch(int index, Object value) { 224 this.index = index; 225 this.value = value; 226 } 227 public String toString() { 228 return "CpPatch/index="+index+",value="+value; 229 } 230 } 231 232 private final ArrayList<CpPatch> cpPatches = new ArrayList<>(); 233 234 private int cph = 0; // for counting constant placeholders 235 236 String constantPlaceholder(Object arg) { 237 String cpPlaceholder = "CONSTANT_PLACEHOLDER_" + cph++; 238 if (DUMP_CLASS_FILES) cpPlaceholder += " <<" + debugString(arg) + ">>"; 239 // TODO check if arg is already in the constant pool 240 // insert placeholder in CP and remember the patch 241 int index = cw.newConst((Object) cpPlaceholder); 242 cpPatches.add(new CpPatch(index, arg)); 243 return cpPlaceholder; 244 } 245 246 Object[] cpPatches(byte[] classFile) { 247 int size = getConstantPoolSize(classFile); 248 Object[] res = new Object[size]; 249 for (CpPatch p : cpPatches) { 250 if (p.index >= size) 251 throw new InternalError("in cpool["+size+"]: "+p+"\n"+Arrays.toString(Arrays.copyOf(classFile, 20))); 252 res[p.index] = p.value; 253 } 254 return res; 255 } 256 257 private static String debugString(Object arg) { 258 if (arg instanceof MethodHandle) { 259 MethodHandle mh = (MethodHandle) arg; 260 MemberName member = mh.internalMemberName(); 261 if (member != null) 262 return member.toString(); 263 return mh.debugString(); 264 } 265 return arg.toString(); 266 } 267 268 /** 269 * Extract the number of constant pool entries from a given class file. 270 * 271 * @param classFile the bytes of the class file in question. 272 * @return the number of entries in the constant pool. 273 */ 274 private static int getConstantPoolSize(byte[] classFile) { 275 // The first few bytes: 276 // u4 magic; 277 // u2 minor_version; 278 // u2 major_version; 279 // u2 constant_pool_count; 280 return ((classFile[8] & 0xFF) << 8) | (classFile[9] & 0xFF); 281 } 282 283 /** 284 * Extract the MemberName of a newly-defined method. 285 */ 286 private MemberName loadMethod(byte[] classFile) { 287 Class<?> invokerClass = loadAndInitializeInvokerClass(classFile, cpPatches(classFile)); 288 return resolveInvokerMember(invokerClass, invokerName, invokerType); 289 } 290 291 /** 292 * Define a given class as anonymous class in the runtime system. 293 */ 294 private static Class<?> loadAndInitializeInvokerClass(byte[] classBytes, Object[] patches) { 295 Class<?> invokerClass = UNSAFE.defineAnonymousClass(HOST_CLASS, classBytes, patches); 296 UNSAFE.ensureClassInitialized(invokerClass); // Make sure the class is initialized; VM might complain. 297 return invokerClass; 298 } 299 300 private static MemberName resolveInvokerMember(Class<?> invokerClass, String name, MethodType type) { 301 MemberName member = new MemberName(invokerClass, name, type, REF_invokeStatic); 302 try { 303 member = MEMBERNAME_FACTORY.resolveOrFail(REF_invokeStatic, member, HOST_CLASS, ReflectiveOperationException.class); 304 } catch (ReflectiveOperationException e) { 305 throw newInternalError(e); 306 } 307 return member; 308 } 309 310 /** 311 * Set up class file generation. 312 */ 313 private ClassWriter classFilePrologue() { 314 final int NOT_ACC_PUBLIC = 0; // not ACC_PUBLIC 315 cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES); 316 cw.visit(Opcodes.V1_8, NOT_ACC_PUBLIC + Opcodes.ACC_FINAL + Opcodes.ACC_SUPER, 317 CLASS_PREFIX + className, null, INVOKER_SUPER_NAME, null); 318 cw.visitSource(SOURCE_PREFIX + className, null); 319 return cw; 320 } 321 322 private void methodPrologue() { 323 String invokerDesc = invokerType.toMethodDescriptorString(); 324 mv = cw.visitMethod(Opcodes.ACC_STATIC, invokerName, invokerDesc, null, null); 325 } 326 327 /** 328 * Tear down class file generation. 329 */ 330 private void methodEpilogue() { 331 mv.visitMaxs(0, 0); 332 mv.visitEnd(); 333 } 334 335 /* 336 * Low-level emit helpers. 337 */ 338 private void emitConst(Object con) { 339 if (con == null) { 340 mv.visitInsn(Opcodes.ACONST_NULL); 341 return; 342 } 343 if (con instanceof Integer) { 344 emitIconstInsn((int) con); 345 return; 346 } 347 if (con instanceof Byte) { 348 emitIconstInsn((byte)con); 349 return; 350 } 351 if (con instanceof Short) { 352 emitIconstInsn((short)con); 353 return; 354 } 355 if (con instanceof Character) { 356 emitIconstInsn((char)con); 357 return; 358 } 359 if (con instanceof Long) { 360 long x = (long) con; 361 short sx = (short)x; 362 if (x == sx) { 363 if (sx >= 0 && sx <= 1) { 364 mv.visitInsn(Opcodes.LCONST_0 + (int) sx); 365 } else { 366 emitIconstInsn((int) x); 367 mv.visitInsn(Opcodes.I2L); 368 } 369 return; 370 } 371 } 372 if (con instanceof Float) { 373 float x = (float) con; 374 short sx = (short)x; 375 if (x == sx) { 376 if (sx >= 0 && sx <= 2) { 377 mv.visitInsn(Opcodes.FCONST_0 + (int) sx); 378 } else { 379 emitIconstInsn((int) x); 380 mv.visitInsn(Opcodes.I2F); 381 } 382 return; 383 } 384 } 385 if (con instanceof Double) { 386 double x = (double) con; 387 short sx = (short)x; 388 if (x == sx) { 389 if (sx >= 0 && sx <= 1) { 390 mv.visitInsn(Opcodes.DCONST_0 + (int) sx); 391 } else { 392 emitIconstInsn((int) x); 393 mv.visitInsn(Opcodes.I2D); 394 } 395 return; 396 } 397 } 398 if (con instanceof Boolean) { 399 emitIconstInsn((boolean) con ? 1 : 0); 400 return; 401 } 402 // fall through: 403 mv.visitLdcInsn(con); 404 } 405 406 private void emitIconstInsn(final int cst) { 407 if (cst >= -1 && cst <= 5) { 408 mv.visitInsn(Opcodes.ICONST_0 + cst); 409 } else if (cst >= Byte.MIN_VALUE && cst <= Byte.MAX_VALUE) { 410 mv.visitIntInsn(Opcodes.BIPUSH, cst); 411 } else if (cst >= Short.MIN_VALUE && cst <= Short.MAX_VALUE) { 412 mv.visitIntInsn(Opcodes.SIPUSH, cst); 413 } else { 414 mv.visitLdcInsn(cst); 415 } 416 } 417 418 /* 419 * NOTE: These load/store methods use the localsMap to find the correct index! 420 */ 421 private void emitLoadInsn(BasicType type, int index) { 422 int opcode = loadInsnOpcode(type); 423 mv.visitVarInsn(opcode, localsMap[index]); 424 } 425 426 private int loadInsnOpcode(BasicType type) throws InternalError { 427 switch (type) { 428 case I_TYPE: return Opcodes.ILOAD; 429 case J_TYPE: return Opcodes.LLOAD; 430 case F_TYPE: return Opcodes.FLOAD; 431 case D_TYPE: return Opcodes.DLOAD; 432 case L_TYPE: return Opcodes.ALOAD; 433 default: 434 throw new InternalError("unknown type: " + type); 435 } 436 } 437 private void emitAloadInsn(int index) { 438 emitLoadInsn(L_TYPE, index); 439 } 440 441 private void emitStoreInsn(BasicType type, int index) { 442 int opcode = storeInsnOpcode(type); 443 mv.visitVarInsn(opcode, localsMap[index]); 444 } 445 446 private int storeInsnOpcode(BasicType type) throws InternalError { 447 switch (type) { 448 case I_TYPE: return Opcodes.ISTORE; 449 case J_TYPE: return Opcodes.LSTORE; 450 case F_TYPE: return Opcodes.FSTORE; 451 case D_TYPE: return Opcodes.DSTORE; 452 case L_TYPE: return Opcodes.ASTORE; 453 default: 454 throw new InternalError("unknown type: " + type); 455 } 456 } 457 private void emitAstoreInsn(int index) { 458 emitStoreInsn(L_TYPE, index); 459 } 460 461 private byte arrayTypeCode(Wrapper elementType) { 462 switch (elementType) { 463 case BOOLEAN: return Opcodes.T_BOOLEAN; 464 case BYTE: return Opcodes.T_BYTE; 465 case CHAR: return Opcodes.T_CHAR; 466 case SHORT: return Opcodes.T_SHORT; 467 case INT: return Opcodes.T_INT; 468 case LONG: return Opcodes.T_LONG; 469 case FLOAT: return Opcodes.T_FLOAT; 470 case DOUBLE: return Opcodes.T_DOUBLE; 471 case OBJECT: return 0; // in place of Opcodes.T_OBJECT 472 default: throw new InternalError(); 473 } 474 } 475 476 private int arrayInsnOpcode(byte tcode, int aaop) throws InternalError { 477 assert(aaop == Opcodes.AASTORE || aaop == Opcodes.AALOAD); 478 int xas; 479 switch (tcode) { 480 case Opcodes.T_BOOLEAN: xas = Opcodes.BASTORE; break; 481 case Opcodes.T_BYTE: xas = Opcodes.BASTORE; break; 482 case Opcodes.T_CHAR: xas = Opcodes.CASTORE; break; 483 case Opcodes.T_SHORT: xas = Opcodes.SASTORE; break; 484 case Opcodes.T_INT: xas = Opcodes.IASTORE; break; 485 case Opcodes.T_LONG: xas = Opcodes.LASTORE; break; 486 case Opcodes.T_FLOAT: xas = Opcodes.FASTORE; break; 487 case Opcodes.T_DOUBLE: xas = Opcodes.DASTORE; break; 488 case 0: xas = Opcodes.AASTORE; break; 489 default: throw new InternalError(); 490 } 491 return xas - Opcodes.AASTORE + aaop; 492 } 493 494 /** 495 * Emit a boxing call. 496 * 497 * @param wrapper primitive type class to box. 498 */ 499 private void emitBoxing(Wrapper wrapper) { 500 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName(); 501 String name = "valueOf"; 502 String desc = "(" + wrapper.basicTypeChar() + ")L" + owner + ";"; 503 mv.visitMethodInsn(Opcodes.INVOKESTATIC, owner, name, desc, false); 504 } 505 506 /** 507 * Emit an unboxing call (plus preceding checkcast). 508 * 509 * @param wrapper wrapper type class to unbox. 510 */ 511 private void emitUnboxing(Wrapper wrapper) { 512 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName(); 513 String name = wrapper.primitiveSimpleName() + "Value"; 514 String desc = "()" + wrapper.basicTypeChar(); 515 emitReferenceCast(wrapper.wrapperType(), null); 516 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, owner, name, desc, false); 517 } 518 519 /** 520 * Emit an implicit conversion for an argument which must be of the given pclass. 521 * This is usually a no-op, except when pclass is a subword type or a reference other than Object or an interface. 522 * 523 * @param ptype type of value present on stack 524 * @param pclass type of value required on stack 525 * @param arg compile-time representation of value on stack (Node, constant) or null if none 526 */ 527 private void emitImplicitConversion(BasicType ptype, Class<?> pclass, Object arg) { 528 assert(basicType(pclass) == ptype); // boxing/unboxing handled by caller 529 if (pclass == ptype.basicTypeClass() && ptype != L_TYPE) 530 return; // nothing to do 531 switch (ptype) { 532 case L_TYPE: 533 if (VerifyType.isNullConversion(Object.class, pclass, false)) { 534 if (PROFILE_LEVEL > 0) 535 emitReferenceCast(Object.class, arg); 536 return; 537 } 538 emitReferenceCast(pclass, arg); 539 return; 540 case I_TYPE: 541 if (!VerifyType.isNullConversion(int.class, pclass, false)) 542 emitPrimCast(ptype.basicTypeWrapper(), Wrapper.forPrimitiveType(pclass)); 543 return; 544 } 545 throw newInternalError("bad implicit conversion: tc="+ptype+": "+pclass); 546 } 547 548 /** Update localClasses type map. Return true if the information is already present. */ 549 private boolean assertStaticType(Class<?> cls, Name n) { 550 int local = n.index(); 551 Class<?> aclass = localClasses[local]; 552 if (aclass != null && (aclass == cls || cls.isAssignableFrom(aclass))) { 553 return true; // type info is already present 554 } else if (aclass == null || aclass.isAssignableFrom(cls)) { 555 localClasses[local] = cls; // type info can be improved 556 } 557 return false; 558 } 559 560 private void emitReferenceCast(Class<?> cls, Object arg) { 561 Name writeBack = null; // local to write back result 562 if (arg instanceof Name) { 563 Name n = (Name) arg; 564 if (lambdaForm.useCount(n) > 1) { 565 // This guy gets used more than once. 566 writeBack = n; 567 if (assertStaticType(cls, n)) { 568 return; // this cast was already performed 569 } 570 } 571 } 572 if (isStaticallyNameable(cls)) { 573 String sig = getInternalName(cls); 574 mv.visitTypeInsn(Opcodes.CHECKCAST, sig); 575 } else { 576 mv.visitLdcInsn(constantPlaceholder(cls)); 577 mv.visitTypeInsn(Opcodes.CHECKCAST, CLS); 578 mv.visitInsn(Opcodes.SWAP); 579 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, CLS, "cast", LL_SIG, false); 580 if (Object[].class.isAssignableFrom(cls)) 581 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJARY); 582 else if (PROFILE_LEVEL > 0) 583 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJ); 584 } 585 if (writeBack != null) { 586 mv.visitInsn(Opcodes.DUP); 587 emitAstoreInsn(writeBack.index()); 588 } 589 } 590 591 /** 592 * Emits an actual return instruction conforming to the given return type. 593 */ 594 private void emitReturnInsn(BasicType type) { 595 int opcode; 596 switch (type) { 597 case I_TYPE: opcode = Opcodes.IRETURN; break; 598 case J_TYPE: opcode = Opcodes.LRETURN; break; 599 case F_TYPE: opcode = Opcodes.FRETURN; break; 600 case D_TYPE: opcode = Opcodes.DRETURN; break; 601 case L_TYPE: opcode = Opcodes.ARETURN; break; 602 case V_TYPE: opcode = Opcodes.RETURN; break; 603 default: 604 throw new InternalError("unknown return type: " + type); 605 } 606 mv.visitInsn(opcode); 607 } 608 609 private String getInternalName(Class<?> c) { 610 if (c == Object.class) return OBJ; 611 else if (c == Object[].class) return OBJARY; 612 else if (c == Class.class) return CLS; 613 else if (c == MethodHandle.class) return MH; 614 assert(VerifyAccess.isTypeVisible(c, Object.class)) : c.getName(); 615 616 if (c == lastClass) { 617 return lastInternalName; 618 } 619 lastClass = c; 620 return lastInternalName = c.getName().replace('.', '/'); 621 } 622 623 private static MemberName resolveFrom(String name, MethodType type, Class<?> holder) { 624 MemberName member = new MemberName(holder, name, type, REF_invokeStatic); 625 MemberName resolvedMember = MemberName.getFactory().resolveOrNull(REF_invokeStatic, member, holder); 626 if (TRACE_RESOLVE) { 627 System.out.println("[LF_RESOLVE] " + holder.getName() + " " + name + " " + 628 shortenSignature(basicTypeSignature(type)) + (resolvedMember != null ? " (success)" : " (fail)") ); 629 } 630 return resolvedMember; 631 } 632 633 private static MemberName lookupPregenerated(LambdaForm form, MethodType invokerType) { 634 if (form.customized != null) { 635 // No pre-generated version for customized LF 636 return null; 637 } 638 String name = form.kind.methodName; 639 switch (form.kind) { 640 case BOUND_REINVOKER: { 641 name = name + "_" + BoundMethodHandle.speciesDataFor(form).key(); 642 return resolveFrom(name, invokerType, DelegatingMethodHandle.Holder.class); 643 } 644 case DELEGATE: return resolveFrom(name, invokerType, DelegatingMethodHandle.Holder.class); 645 case ZERO: // fall-through 646 case IDENTITY: { 647 name = name + "_" + form.returnType().basicTypeChar(); 648 return resolveFrom(name, invokerType, LambdaForm.Holder.class); 649 } 650 case EXACT_INVOKER: // fall-through 651 case EXACT_LINKER: // fall-through 652 case GENERIC_INVOKER: // fall-through 653 case GENERIC_LINKER: return resolveFrom(name, invokerType.basicType(), Invokers.Holder.class); 654 case GET_OBJECT: // fall-through 655 case GET_BOOLEAN: // fall-through 656 case GET_BYTE: // fall-through 657 case GET_CHAR: // fall-through 658 case GET_SHORT: // fall-through 659 case GET_INT: // fall-through 660 case GET_LONG: // fall-through 661 case GET_FLOAT: // fall-through 662 case GET_DOUBLE: // fall-through 663 case PUT_OBJECT: // fall-through 664 case PUT_BOOLEAN: // fall-through 665 case PUT_BYTE: // fall-through 666 case PUT_CHAR: // fall-through 667 case PUT_SHORT: // fall-through 668 case PUT_INT: // fall-through 669 case PUT_LONG: // fall-through 670 case PUT_FLOAT: // fall-through 671 case PUT_DOUBLE: // fall-through 672 case DIRECT_NEW_INVOKE_SPECIAL: // fall-through 673 case DIRECT_INVOKE_INTERFACE: // fall-through 674 case DIRECT_INVOKE_SPECIAL: // fall-through 675 case DIRECT_INVOKE_STATIC: // fall-through 676 case DIRECT_INVOKE_STATIC_INIT: // fall-through 677 case DIRECT_INVOKE_VIRTUAL: return resolveFrom(name, invokerType, DirectMethodHandle.Holder.class); 678 } 679 return null; 680 } 681 682 /** 683 * Generate customized bytecode for a given LambdaForm. 684 */ 685 static MemberName generateCustomizedCode(LambdaForm form, MethodType invokerType) { 686 MemberName pregenerated = lookupPregenerated(form, invokerType); 687 if (pregenerated != null) return pregenerated; // pre-generated bytecode 688 689 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("MH", form, invokerType); 690 return g.loadMethod(g.generateCustomizedCodeBytes()); 691 } 692 693 /** Generates code to check that actual receiver and LambdaForm matches */ 694 private boolean checkActualReceiver() { 695 // Expects MethodHandle on the stack and actual receiver MethodHandle in slot #0 696 mv.visitInsn(Opcodes.DUP); 697 mv.visitVarInsn(Opcodes.ALOAD, localsMap[0]); 698 mv.visitMethodInsn(Opcodes.INVOKESTATIC, MHI, "assertSame", LLV_SIG, false); 699 return true; 700 } 701 702 static String className(String cn) { 703 assert checkClassName(cn): "Class not found: " + cn; 704 return cn; 705 } 706 707 static boolean checkClassName(String cn) { 708 Type tp = Type.getType(cn); 709 // additional sanity so only valid "L;" descriptors work 710 if (tp.getSort() != Type.OBJECT) { 711 return false; 712 } 713 try { 714 Class<?> c = Class.forName(tp.getClassName(), false, null); 715 return true; 716 } catch (ClassNotFoundException e) { 717 return false; 718 } 719 } 720 721 static final String LF_HIDDEN_SIG = className("Ljava/lang/invoke/LambdaForm$Hidden;"); 722 static final String LF_COMPILED_SIG = className("Ljava/lang/invoke/LambdaForm$Compiled;"); 723 static final String FORCEINLINE_SIG = className("Ljdk/internal/vm/annotation/ForceInline;"); 724 static final String DONTINLINE_SIG = className("Ljdk/internal/vm/annotation/DontInline;"); 725 static final String INJECTEDPROFILE_SIG = className("Ljava/lang/invoke/InjectedProfile;"); 726 727 /** 728 * Generate an invoker method for the passed {@link LambdaForm}. 729 */ 730 private byte[] generateCustomizedCodeBytes() { 731 classFilePrologue(); 732 addMethod(); 733 bogusMethod(lambdaForm); 734 735 final byte[] classFile = toByteArray(); 736 maybeDump(classFile); 737 return classFile; 738 } 739 740 void setClassWriter(ClassWriter cw) { 741 this.cw = cw; 742 } 743 744 void addMethod() { 745 methodPrologue(); 746 747 // Suppress this method in backtraces displayed to the user. 748 mv.visitAnnotation(LF_HIDDEN_SIG, true); 749 750 // Mark this method as a compiled LambdaForm 751 mv.visitAnnotation(LF_COMPILED_SIG, true); 752 753 if (lambdaForm.forceInline) { 754 // Force inlining of this invoker method. 755 mv.visitAnnotation(FORCEINLINE_SIG, true); 756 } else { 757 mv.visitAnnotation(DONTINLINE_SIG, true); 758 } 759 760 constantPlaceholder(lambdaForm); // keep LambdaForm instance & its compiled form lifetime tightly coupled. 761 762 if (lambdaForm.customized != null) { 763 // Since LambdaForm is customized for a particular MethodHandle, it's safe to substitute 764 // receiver MethodHandle (at slot #0) with an embedded constant and use it instead. 765 // It enables more efficient code generation in some situations, since embedded constants 766 // are compile-time constants for JIT compiler. 767 mv.visitLdcInsn(constantPlaceholder(lambdaForm.customized)); 768 mv.visitTypeInsn(Opcodes.CHECKCAST, MH); 769 assert(checkActualReceiver()); // expects MethodHandle on top of the stack 770 mv.visitVarInsn(Opcodes.ASTORE, localsMap[0]); 771 } 772 773 // iterate over the form's names, generating bytecode instructions for each 774 // start iterating at the first name following the arguments 775 Name onStack = null; 776 for (int i = lambdaForm.arity; i < lambdaForm.names.length; i++) { 777 Name name = lambdaForm.names[i]; 778 779 emitStoreResult(onStack); 780 onStack = name; // unless otherwise modified below 781 MethodHandleImpl.Intrinsic intr = name.function.intrinsicName(); 782 switch (intr) { 783 case SELECT_ALTERNATIVE: 784 assert lambdaForm.isSelectAlternative(i); 785 if (PROFILE_GWT) { 786 assert(name.arguments[0] instanceof Name && 787 ((Name)name.arguments[0]).refersTo(MethodHandleImpl.class, "profileBoolean")); 788 mv.visitAnnotation(INJECTEDPROFILE_SIG, true); 789 } 790 onStack = emitSelectAlternative(name, lambdaForm.names[i+1]); 791 i++; // skip MH.invokeBasic of the selectAlternative result 792 continue; 793 case GUARD_WITH_CATCH: 794 assert lambdaForm.isGuardWithCatch(i); 795 onStack = emitGuardWithCatch(i); 796 i += 2; // jump to the end of GWC idiom 797 continue; 798 case TRY_FINALLY: 799 assert lambdaForm.isTryFinally(i); 800 onStack = emitTryFinally(i); 801 i += 2; // jump to the end of the TF idiom 802 continue; 803 case LOOP: 804 assert lambdaForm.isLoop(i); 805 onStack = emitLoop(i); 806 i += 2; // jump to the end of the LOOP idiom 807 continue; 808 case NEW_ARRAY: 809 Class<?> rtype = name.function.methodType().returnType(); 810 if (isStaticallyNameable(rtype)) { 811 emitNewArray(name); 812 continue; 813 } 814 break; 815 case ARRAY_LOAD: 816 emitArrayLoad(name); 817 continue; 818 case ARRAY_STORE: 819 emitArrayStore(name); 820 continue; 821 case ARRAY_LENGTH: 822 emitArrayLength(name); 823 continue; 824 case IDENTITY: 825 assert(name.arguments.length == 1); 826 emitPushArguments(name, 0); 827 continue; 828 case ZERO: 829 assert(name.arguments.length == 0); 830 emitConst(name.type.basicTypeWrapper().zero()); 831 continue; 832 case NONE: 833 // no intrinsic associated 834 break; 835 default: 836 throw newInternalError("Unknown intrinsic: "+intr); 837 } 838 839 MemberName member = name.function.member(); 840 if (isStaticallyInvocable(member)) { 841 emitStaticInvoke(member, name); 842 } else { 843 emitInvoke(name); 844 } 845 } 846 847 // return statement 848 emitReturn(onStack); 849 850 methodEpilogue(); 851 } 852 853 /* 854 * @throws BytecodeGenerationException if something goes wrong when 855 * generating the byte code 856 */ 857 private byte[] toByteArray() { 858 try { 859 return cw.toByteArray(); 860 } catch (RuntimeException e) { 861 throw new BytecodeGenerationException(e); 862 } 863 } 864 865 @SuppressWarnings("serial") 866 static final class BytecodeGenerationException extends RuntimeException { 867 BytecodeGenerationException(Exception cause) { 868 super(cause); 869 } 870 } 871 872 void emitArrayLoad(Name name) { emitArrayOp(name, Opcodes.AALOAD); } 873 void emitArrayStore(Name name) { emitArrayOp(name, Opcodes.AASTORE); } 874 void emitArrayLength(Name name) { emitArrayOp(name, Opcodes.ARRAYLENGTH); } 875 876 void emitArrayOp(Name name, int arrayOpcode) { 877 assert arrayOpcode == Opcodes.AALOAD || arrayOpcode == Opcodes.AASTORE || arrayOpcode == Opcodes.ARRAYLENGTH; 878 Class<?> elementType = name.function.methodType().parameterType(0).getComponentType(); 879 assert elementType != null; 880 emitPushArguments(name, 0); 881 if (arrayOpcode != Opcodes.ARRAYLENGTH && elementType.isPrimitive()) { 882 Wrapper w = Wrapper.forPrimitiveType(elementType); 883 arrayOpcode = arrayInsnOpcode(arrayTypeCode(w), arrayOpcode); 884 } 885 mv.visitInsn(arrayOpcode); 886 } 887 888 /** 889 * Emit an invoke for the given name. 890 */ 891 void emitInvoke(Name name) { 892 assert(!name.isLinkerMethodInvoke()); // should use the static path for these 893 if (true) { 894 // push receiver 895 MethodHandle target = name.function.resolvedHandle(); 896 assert(target != null) : name.exprString(); 897 mv.visitLdcInsn(constantPlaceholder(target)); 898 emitReferenceCast(MethodHandle.class, target); 899 } else { 900 // load receiver 901 emitAloadInsn(0); 902 emitReferenceCast(MethodHandle.class, null); 903 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", LF_SIG); 904 mv.visitFieldInsn(Opcodes.GETFIELD, LF, "names", LFN_SIG); 905 // TODO more to come 906 } 907 908 // push arguments 909 emitPushArguments(name, 0); 910 911 // invocation 912 MethodType type = name.function.methodType(); 913 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false); 914 } 915 916 private static Class<?>[] STATICALLY_INVOCABLE_PACKAGES = { 917 // Sample classes from each package we are willing to bind to statically: 918 java.lang.Object.class, 919 java.util.Arrays.class, 920 jdk.internal.misc.Unsafe.class 921 //MethodHandle.class already covered 922 }; 923 924 static boolean isStaticallyInvocable(NamedFunction ... functions) { 925 for (NamedFunction nf : functions) { 926 if (!isStaticallyInvocable(nf.member())) { 927 return false; 928 } 929 } 930 return true; 931 } 932 933 static boolean isStaticallyInvocable(Name name) { 934 return isStaticallyInvocable(name.function.member()); 935 } 936 937 static boolean isStaticallyInvocable(MemberName member) { 938 if (member == null) return false; 939 if (member.isConstructor()) return false; 940 Class<?> cls = member.getDeclaringClass(); 941 // Fast-path non-private members declared by MethodHandles, which is a common 942 // case 943 if (MethodHandle.class.isAssignableFrom(cls) && !member.isPrivate()) { 944 assert(isStaticallyInvocableType(member.getMethodOrFieldType())); 945 return true; 946 } 947 if (cls.isArray() || cls.isPrimitive()) 948 return false; // FIXME 949 if (cls.isAnonymousClass() || cls.isLocalClass()) 950 return false; // inner class of some sort 951 if (cls.getClassLoader() != MethodHandle.class.getClassLoader()) 952 return false; // not on BCP 953 if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: switch to supported API once it is added 954 return false; 955 if (!isStaticallyInvocableType(member.getMethodOrFieldType())) 956 return false; 957 if (!member.isPrivate() && VerifyAccess.isSamePackage(MethodHandle.class, cls)) 958 return true; // in java.lang.invoke package 959 if (member.isPublic() && isStaticallyNameable(cls)) 960 return true; 961 return false; 962 } 963 964 private static boolean isStaticallyInvocableType(MethodType mtype) { 965 if (!isStaticallyNameable(mtype.returnType())) 966 return false; 967 for (Class<?> ptype : mtype.parameterArray()) 968 if (!isStaticallyNameable(ptype)) 969 return false; 970 return true; 971 } 972 973 static boolean isStaticallyNameable(Class<?> cls) { 974 if (cls == Object.class) 975 return true; 976 if (MethodHandle.class.isAssignableFrom(cls)) { 977 assert(!ReflectUtil.isVMAnonymousClass(cls)); 978 return true; 979 } 980 while (cls.isArray()) 981 cls = cls.getComponentType(); 982 if (cls.isPrimitive()) 983 return true; // int[].class, for example 984 if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: switch to supported API once it is added 985 return false; 986 // could use VerifyAccess.isClassAccessible but the following is a safe approximation 987 if (cls.getClassLoader() != Object.class.getClassLoader()) 988 return false; 989 if (VerifyAccess.isSamePackage(MethodHandle.class, cls)) 990 return true; 991 if (!Modifier.isPublic(cls.getModifiers())) 992 return false; 993 for (Class<?> pkgcls : STATICALLY_INVOCABLE_PACKAGES) { 994 if (VerifyAccess.isSamePackage(pkgcls, cls)) 995 return true; 996 } 997 return false; 998 } 999 1000 void emitStaticInvoke(Name name) { 1001 emitStaticInvoke(name.function.member(), name); 1002 } 1003 1004 /** 1005 * Emit an invoke for the given name, using the MemberName directly. 1006 */ 1007 void emitStaticInvoke(MemberName member, Name name) { 1008 assert(member.equals(name.function.member())); 1009 Class<?> defc = member.getDeclaringClass(); 1010 String cname = getInternalName(defc); 1011 String mname = member.getName(); 1012 String mtype; 1013 byte refKind = member.getReferenceKind(); 1014 if (refKind == REF_invokeSpecial) { 1015 // in order to pass the verifier, we need to convert this to invokevirtual in all cases 1016 assert(member.canBeStaticallyBound()) : member; 1017 refKind = REF_invokeVirtual; 1018 } 1019 1020 assert(!(member.getDeclaringClass().isInterface() && refKind == REF_invokeVirtual)); 1021 1022 // push arguments 1023 emitPushArguments(name, 0); 1024 1025 // invocation 1026 if (member.isMethod()) { 1027 mtype = member.getMethodType().toMethodDescriptorString(); 1028 mv.visitMethodInsn(refKindOpcode(refKind), cname, mname, mtype, 1029 member.getDeclaringClass().isInterface()); 1030 } else { 1031 mtype = MethodType.toFieldDescriptorString(member.getFieldType()); 1032 mv.visitFieldInsn(refKindOpcode(refKind), cname, mname, mtype); 1033 } 1034 // Issue a type assertion for the result, so we can avoid casts later. 1035 if (name.type == L_TYPE) { 1036 Class<?> rtype = member.getInvocationType().returnType(); 1037 assert(!rtype.isPrimitive()); 1038 if (rtype != Object.class && !rtype.isInterface()) { 1039 assertStaticType(rtype, name); 1040 } 1041 } 1042 } 1043 1044 void emitNewArray(Name name) throws InternalError { 1045 Class<?> rtype = name.function.methodType().returnType(); 1046 if (name.arguments.length == 0) { 1047 // The array will be a constant. 1048 Object emptyArray; 1049 try { 1050 emptyArray = name.function.resolvedHandle().invoke(); 1051 } catch (Throwable ex) { 1052 throw uncaughtException(ex); 1053 } 1054 assert(java.lang.reflect.Array.getLength(emptyArray) == 0); 1055 assert(emptyArray.getClass() == rtype); // exact typing 1056 mv.visitLdcInsn(constantPlaceholder(emptyArray)); 1057 emitReferenceCast(rtype, emptyArray); 1058 return; 1059 } 1060 Class<?> arrayElementType = rtype.getComponentType(); 1061 assert(arrayElementType != null); 1062 emitIconstInsn(name.arguments.length); 1063 int xas = Opcodes.AASTORE; 1064 if (!arrayElementType.isPrimitive()) { 1065 mv.visitTypeInsn(Opcodes.ANEWARRAY, getInternalName(arrayElementType)); 1066 } else { 1067 byte tc = arrayTypeCode(Wrapper.forPrimitiveType(arrayElementType)); 1068 xas = arrayInsnOpcode(tc, xas); 1069 mv.visitIntInsn(Opcodes.NEWARRAY, tc); 1070 } 1071 // store arguments 1072 for (int i = 0; i < name.arguments.length; i++) { 1073 mv.visitInsn(Opcodes.DUP); 1074 emitIconstInsn(i); 1075 emitPushArgument(name, i); 1076 mv.visitInsn(xas); 1077 } 1078 // the array is left on the stack 1079 assertStaticType(rtype, name); 1080 } 1081 int refKindOpcode(byte refKind) { 1082 switch (refKind) { 1083 case REF_invokeVirtual: return Opcodes.INVOKEVIRTUAL; 1084 case REF_invokeStatic: return Opcodes.INVOKESTATIC; 1085 case REF_invokeSpecial: return Opcodes.INVOKESPECIAL; 1086 case REF_invokeInterface: return Opcodes.INVOKEINTERFACE; 1087 case REF_getField: return Opcodes.GETFIELD; 1088 case REF_putField: return Opcodes.PUTFIELD; 1089 case REF_getStatic: return Opcodes.GETSTATIC; 1090 case REF_putStatic: return Opcodes.PUTSTATIC; 1091 } 1092 throw new InternalError("refKind="+refKind); 1093 } 1094 1095 /** 1096 * Emit bytecode for the selectAlternative idiom. 1097 * 1098 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithTest): 1099 * <blockquote><pre>{@code 1100 * Lambda(a0:L,a1:I)=>{ 1101 * t2:I=foo.test(a1:I); 1102 * t3:L=MethodHandleImpl.selectAlternative(t2:I,(MethodHandle(int)int),(MethodHandle(int)int)); 1103 * t4:I=MethodHandle.invokeBasic(t3:L,a1:I);t4:I} 1104 * }</pre></blockquote> 1105 */ 1106 private Name emitSelectAlternative(Name selectAlternativeName, Name invokeBasicName) { 1107 assert isStaticallyInvocable(invokeBasicName); 1108 1109 Name receiver = (Name) invokeBasicName.arguments[0]; 1110 1111 Label L_fallback = new Label(); 1112 Label L_done = new Label(); 1113 1114 // load test result 1115 emitPushArgument(selectAlternativeName, 0); 1116 1117 // if_icmpne L_fallback 1118 mv.visitJumpInsn(Opcodes.IFEQ, L_fallback); 1119 1120 // invoke selectAlternativeName.arguments[1] 1121 Class<?>[] preForkClasses = localClasses.clone(); 1122 emitPushArgument(selectAlternativeName, 1); // get 2nd argument of selectAlternative 1123 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot 1124 emitStaticInvoke(invokeBasicName); 1125 1126 // goto L_done 1127 mv.visitJumpInsn(Opcodes.GOTO, L_done); 1128 1129 // L_fallback: 1130 mv.visitLabel(L_fallback); 1131 1132 // invoke selectAlternativeName.arguments[2] 1133 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length); 1134 emitPushArgument(selectAlternativeName, 2); // get 3rd argument of selectAlternative 1135 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot 1136 emitStaticInvoke(invokeBasicName); 1137 1138 // L_done: 1139 mv.visitLabel(L_done); 1140 // for now do not bother to merge typestate; just reset to the dominator state 1141 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length); 1142 1143 return invokeBasicName; // return what's on stack 1144 } 1145 1146 /** 1147 * Emit bytecode for the guardWithCatch idiom. 1148 * 1149 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithCatch): 1150 * <blockquote><pre>{@code 1151 * guardWithCatch=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L,a5:L,a6:L,a7:L)=>{ 1152 * t8:L=MethodHandle.invokeBasic(a4:L,a6:L,a7:L); 1153 * t9:L=MethodHandleImpl.guardWithCatch(a1:L,a2:L,a3:L,t8:L); 1154 * t10:I=MethodHandle.invokeBasic(a5:L,t9:L);t10:I} 1155 * }</pre></blockquote> 1156 * 1157 * It is compiled into bytecode equivalent of the following code: 1158 * <blockquote><pre>{@code 1159 * try { 1160 * return a1.invokeBasic(a6, a7); 1161 * } catch (Throwable e) { 1162 * if (!a2.isInstance(e)) throw e; 1163 * return a3.invokeBasic(ex, a6, a7); 1164 * }} 1165 */ 1166 private Name emitGuardWithCatch(int pos) { 1167 Name args = lambdaForm.names[pos]; 1168 Name invoker = lambdaForm.names[pos+1]; 1169 Name result = lambdaForm.names[pos+2]; 1170 1171 Label L_startBlock = new Label(); 1172 Label L_endBlock = new Label(); 1173 Label L_handler = new Label(); 1174 Label L_done = new Label(); 1175 1176 Class<?> returnType = result.function.resolvedHandle().type().returnType(); 1177 MethodType type = args.function.resolvedHandle().type() 1178 .dropParameterTypes(0,1) 1179 .changeReturnType(returnType); 1180 1181 mv.visitTryCatchBlock(L_startBlock, L_endBlock, L_handler, "java/lang/Throwable"); 1182 1183 // Normal case 1184 mv.visitLabel(L_startBlock); 1185 // load target 1186 emitPushArgument(invoker, 0); 1187 emitPushArguments(args, 1); // skip 1st argument: method handle 1188 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false); 1189 mv.visitLabel(L_endBlock); 1190 mv.visitJumpInsn(Opcodes.GOTO, L_done); 1191 1192 // Exceptional case 1193 mv.visitLabel(L_handler); 1194 1195 // Check exception's type 1196 mv.visitInsn(Opcodes.DUP); 1197 // load exception class 1198 emitPushArgument(invoker, 1); 1199 mv.visitInsn(Opcodes.SWAP); 1200 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/Class", "isInstance", "(Ljava/lang/Object;)Z", false); 1201 Label L_rethrow = new Label(); 1202 mv.visitJumpInsn(Opcodes.IFEQ, L_rethrow); 1203 1204 // Invoke catcher 1205 // load catcher 1206 emitPushArgument(invoker, 2); 1207 mv.visitInsn(Opcodes.SWAP); 1208 emitPushArguments(args, 1); // skip 1st argument: method handle 1209 MethodType catcherType = type.insertParameterTypes(0, Throwable.class); 1210 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", catcherType.basicType().toMethodDescriptorString(), false); 1211 mv.visitJumpInsn(Opcodes.GOTO, L_done); 1212 1213 mv.visitLabel(L_rethrow); 1214 mv.visitInsn(Opcodes.ATHROW); 1215 1216 mv.visitLabel(L_done); 1217 1218 return result; 1219 } 1220 1221 /** 1222 * Emit bytecode for the tryFinally idiom. 1223 * <p> 1224 * The pattern looks like (Cf. MethodHandleImpl.makeTryFinally): 1225 * <blockquote><pre>{@code 1226 * // a0: BMH 1227 * // a1: target, a2: cleanup 1228 * // a3: box, a4: unbox 1229 * // a5 (and following): arguments 1230 * tryFinally=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L,a5:L)=>{ 1231 * t6:L=MethodHandle.invokeBasic(a3:L,a5:L); // box the arguments into an Object[] 1232 * t7:L=MethodHandleImpl.tryFinally(a1:L,a2:L,t6:L); // call the tryFinally executor 1233 * t8:L=MethodHandle.invokeBasic(a4:L,t7:L);t8:L} // unbox the result; return the result 1234 * }</pre></blockquote> 1235 * <p> 1236 * It is compiled into bytecode equivalent to the following code: 1237 * <blockquote><pre>{@code 1238 * Throwable t; 1239 * Object r; 1240 * try { 1241 * r = a1.invokeBasic(a5); 1242 * } catch (Throwable thrown) { 1243 * t = thrown; 1244 * throw t; 1245 * } finally { 1246 * r = a2.invokeBasic(t, r, a5); 1247 * } 1248 * return r; 1249 * }</pre></blockquote> 1250 * <p> 1251 * Specifically, the bytecode will have the following form (the stack effects are given for the beginnings of 1252 * blocks, and for the situations after executing the given instruction - the code will have a slightly different 1253 * shape if the return type is {@code void}): 1254 * <blockquote><pre>{@code 1255 * TRY: (--) 1256 * load target (-- target) 1257 * load args (-- args... target) 1258 * INVOKEVIRTUAL MethodHandle.invokeBasic (depends) 1259 * FINALLY_NORMAL: (-- r) 1260 * load cleanup (-- cleanup r) 1261 * SWAP (-- r cleanup) 1262 * ACONST_NULL (-- t r cleanup) 1263 * SWAP (-- r t cleanup) 1264 * load args (-- args... r t cleanup) 1265 * INVOKEVIRTUAL MethodHandle.invokeBasic (-- r) 1266 * GOTO DONE 1267 * CATCH: (-- t) 1268 * DUP (-- t t) 1269 * FINALLY_EXCEPTIONAL: (-- t t) 1270 * load cleanup (-- cleanup t t) 1271 * SWAP (-- t cleanup t) 1272 * load default for r (-- r t cleanup t) 1273 * load args (-- args... r t cleanup t) 1274 * INVOKEVIRTUAL MethodHandle.invokeBasic (-- r t) 1275 * POP (-- t) 1276 * ATHROW 1277 * DONE: (-- r) 1278 * }</pre></blockquote> 1279 */ 1280 private Name emitTryFinally(int pos) { 1281 Name args = lambdaForm.names[pos]; 1282 Name invoker = lambdaForm.names[pos+1]; 1283 Name result = lambdaForm.names[pos+2]; 1284 1285 Label lFrom = new Label(); 1286 Label lTo = new Label(); 1287 Label lCatch = new Label(); 1288 Label lDone = new Label(); 1289 1290 Class<?> returnType = result.function.resolvedHandle().type().returnType(); 1291 boolean isNonVoid = returnType != void.class; 1292 MethodType type = args.function.resolvedHandle().type() 1293 .dropParameterTypes(0,1) 1294 .changeReturnType(returnType); 1295 MethodType cleanupType = type.insertParameterTypes(0, Throwable.class); 1296 if (isNonVoid) { 1297 cleanupType = cleanupType.insertParameterTypes(1, returnType); 1298 } 1299 String cleanupDesc = cleanupType.basicType().toMethodDescriptorString(); 1300 1301 // exception handler table 1302 mv.visitTryCatchBlock(lFrom, lTo, lCatch, "java/lang/Throwable"); 1303 1304 // TRY: 1305 mv.visitLabel(lFrom); 1306 emitPushArgument(invoker, 0); // load target 1307 emitPushArguments(args, 1); // load args (skip 0: method handle) 1308 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false); 1309 mv.visitLabel(lTo); 1310 1311 // FINALLY_NORMAL: 1312 emitPushArgument(invoker, 1); // load cleanup 1313 if (isNonVoid) { 1314 mv.visitInsn(Opcodes.SWAP); 1315 } 1316 mv.visitInsn(Opcodes.ACONST_NULL); 1317 if (isNonVoid) { 1318 mv.visitInsn(Opcodes.SWAP); 1319 } 1320 emitPushArguments(args, 1); // load args (skip 0: method handle) 1321 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", cleanupDesc, false); 1322 mv.visitJumpInsn(Opcodes.GOTO, lDone); 1323 1324 // CATCH: 1325 mv.visitLabel(lCatch); 1326 mv.visitInsn(Opcodes.DUP); 1327 1328 // FINALLY_EXCEPTIONAL: 1329 emitPushArgument(invoker, 1); // load cleanup 1330 mv.visitInsn(Opcodes.SWAP); 1331 if (isNonVoid) { 1332 emitZero(BasicType.basicType(returnType)); // load default for result 1333 } 1334 emitPushArguments(args, 1); // load args (skip 0: method handle) 1335 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", cleanupDesc, false); 1336 if (isNonVoid) { 1337 mv.visitInsn(Opcodes.POP); 1338 } 1339 mv.visitInsn(Opcodes.ATHROW); 1340 1341 // DONE: 1342 mv.visitLabel(lDone); 1343 1344 return result; 1345 } 1346 1347 /** 1348 * Emit bytecode for the loop idiom. 1349 * <p> 1350 * The pattern looks like (Cf. MethodHandleImpl.loop): 1351 * <blockquote><pre>{@code 1352 * // a0: BMH 1353 * // a1: LoopClauses (containing an array of arrays: inits, steps, preds, finis) 1354 * // a2: box, a3: unbox 1355 * // a4 (and following): arguments 1356 * loop=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L)=>{ 1357 * t5:L=MethodHandle.invokeBasic(a2:L,a4:L); // box the arguments into an Object[] 1358 * t6:L=MethodHandleImpl.loop(bt:L,a1:L,t5:L); // call the loop executor (with supplied types in bt) 1359 * t7:L=MethodHandle.invokeBasic(a3:L,t6:L);t7:L} // unbox the result; return the result 1360 * }</pre></blockquote> 1361 * <p> 1362 * It is compiled into bytecode equivalent to the code seen in {@link MethodHandleImpl#loop(BasicType[], 1363 * MethodHandleImpl.LoopClauses, Object...)}, with the difference that no arrays 1364 * will be used for local state storage. Instead, the local state will be mapped to actual stack slots. 1365 * <p> 1366 * Bytecode generation applies an unrolling scheme to enable better bytecode generation regarding local state type 1367 * handling. The generated bytecode will have the following form ({@code void} types are ignored for convenience). 1368 * Assume there are {@code C} clauses in the loop. 1369 * <blockquote><pre>{@code 1370 * PREINIT: ALOAD_1 1371 * CHECKCAST LoopClauses 1372 * GETFIELD LoopClauses.clauses 1373 * ASTORE clauseDataIndex // place the clauses 2-dimensional array on the stack 1374 * INIT: (INIT_SEQ for clause 1) 1375 * ... 1376 * (INIT_SEQ for clause C) 1377 * LOOP: (LOOP_SEQ for clause 1) 1378 * ... 1379 * (LOOP_SEQ for clause C) 1380 * GOTO LOOP 1381 * DONE: ... 1382 * }</pre></blockquote> 1383 * <p> 1384 * The {@code INIT_SEQ_x} sequence for clause {@code x} (with {@code x} ranging from {@code 0} to {@code C-1}) has 1385 * the following shape. Assume slot {@code vx} is used to hold the state for clause {@code x}. 1386 * <blockquote><pre>{@code 1387 * INIT_SEQ_x: ALOAD clauseDataIndex 1388 * ICONST_0 1389 * AALOAD // load the inits array 1390 * ICONST x 1391 * AALOAD // load the init handle for clause x 1392 * load args 1393 * INVOKEVIRTUAL MethodHandle.invokeBasic 1394 * store vx 1395 * }</pre></blockquote> 1396 * <p> 1397 * The {@code LOOP_SEQ_x} sequence for clause {@code x} (with {@code x} ranging from {@code 0} to {@code C-1}) has 1398 * the following shape. Again, assume slot {@code vx} is used to hold the state for clause {@code x}. 1399 * <blockquote><pre>{@code 1400 * LOOP_SEQ_x: ALOAD clauseDataIndex 1401 * ICONST_1 1402 * AALOAD // load the steps array 1403 * ICONST x 1404 * AALOAD // load the step handle for clause x 1405 * load locals 1406 * load args 1407 * INVOKEVIRTUAL MethodHandle.invokeBasic 1408 * store vx 1409 * ALOAD clauseDataIndex 1410 * ICONST_2 1411 * AALOAD // load the preds array 1412 * ICONST x 1413 * AALOAD // load the pred handle for clause x 1414 * load locals 1415 * load args 1416 * INVOKEVIRTUAL MethodHandle.invokeBasic 1417 * IFNE LOOP_SEQ_x+1 // predicate returned false -> jump to next clause 1418 * ALOAD clauseDataIndex 1419 * ICONST_3 1420 * AALOAD // load the finis array 1421 * ICONST x 1422 * AALOAD // load the fini handle for clause x 1423 * load locals 1424 * load args 1425 * INVOKEVIRTUAL MethodHandle.invokeBasic 1426 * GOTO DONE // jump beyond end of clauses to return from loop 1427 * }</pre></blockquote> 1428 */ 1429 private Name emitLoop(int pos) { 1430 Name args = lambdaForm.names[pos]; 1431 Name invoker = lambdaForm.names[pos+1]; 1432 Name result = lambdaForm.names[pos+2]; 1433 1434 // extract clause and loop-local state types 1435 // find the type info in the loop invocation 1436 BasicType[] loopClauseTypes = (BasicType[]) invoker.arguments[0]; 1437 Class<?>[] loopLocalStateTypes = Stream.of(loopClauseTypes). 1438 filter(bt -> bt != BasicType.V_TYPE).map(BasicType::basicTypeClass).toArray(Class<?>[]::new); 1439 Class<?>[] localTypes = new Class<?>[loopLocalStateTypes.length + 1]; 1440 localTypes[0] = MethodHandleImpl.LoopClauses.class; 1441 System.arraycopy(loopLocalStateTypes, 0, localTypes, 1, loopLocalStateTypes.length); 1442 1443 final int clauseDataIndex = extendLocalsMap(localTypes); 1444 final int firstLoopStateIndex = clauseDataIndex + 1; 1445 1446 Class<?> returnType = result.function.resolvedHandle().type().returnType(); 1447 MethodType loopType = args.function.resolvedHandle().type() 1448 .dropParameterTypes(0,1) 1449 .changeReturnType(returnType); 1450 MethodType loopHandleType = loopType.insertParameterTypes(0, loopLocalStateTypes); 1451 MethodType predType = loopHandleType.changeReturnType(boolean.class); 1452 MethodType finiType = loopHandleType; 1453 1454 final int nClauses = loopClauseTypes.length; 1455 1456 // indices to invoker arguments to load method handle arrays 1457 final int inits = 1; 1458 final int steps = 2; 1459 final int preds = 3; 1460 final int finis = 4; 1461 1462 Label lLoop = new Label(); 1463 Label lDone = new Label(); 1464 Label lNext; 1465 1466 // PREINIT: 1467 emitPushArgument(MethodHandleImpl.LoopClauses.class, invoker.arguments[1]); 1468 mv.visitFieldInsn(Opcodes.GETFIELD, LOOP_CLAUSES, "clauses", MHARY2); 1469 emitAstoreInsn(clauseDataIndex); 1470 1471 // INIT: 1472 for (int c = 0, state = 0; c < nClauses; ++c) { 1473 MethodType cInitType = loopType.changeReturnType(loopClauseTypes[c].basicTypeClass()); 1474 emitLoopHandleInvoke(invoker, inits, c, args, false, cInitType, loopLocalStateTypes, clauseDataIndex, 1475 firstLoopStateIndex); 1476 if (cInitType.returnType() != void.class) { 1477 emitStoreInsn(BasicType.basicType(cInitType.returnType()), firstLoopStateIndex + state); 1478 ++state; 1479 } 1480 } 1481 1482 // LOOP: 1483 mv.visitLabel(lLoop); 1484 1485 for (int c = 0, state = 0; c < nClauses; ++c) { 1486 lNext = new Label(); 1487 1488 MethodType stepType = loopHandleType.changeReturnType(loopClauseTypes[c].basicTypeClass()); 1489 boolean isVoid = stepType.returnType() == void.class; 1490 1491 // invoke loop step 1492 emitLoopHandleInvoke(invoker, steps, c, args, true, stepType, loopLocalStateTypes, clauseDataIndex, 1493 firstLoopStateIndex); 1494 if (!isVoid) { 1495 emitStoreInsn(BasicType.basicType(stepType.returnType()), firstLoopStateIndex + state); 1496 ++state; 1497 } 1498 1499 // invoke loop predicate 1500 emitLoopHandleInvoke(invoker, preds, c, args, true, predType, loopLocalStateTypes, clauseDataIndex, 1501 firstLoopStateIndex); 1502 mv.visitJumpInsn(Opcodes.IFNE, lNext); 1503 1504 // invoke fini 1505 emitLoopHandleInvoke(invoker, finis, c, args, true, finiType, loopLocalStateTypes, clauseDataIndex, 1506 firstLoopStateIndex); 1507 mv.visitJumpInsn(Opcodes.GOTO, lDone); 1508 1509 // this is the beginning of the next loop clause 1510 mv.visitLabel(lNext); 1511 } 1512 1513 mv.visitJumpInsn(Opcodes.GOTO, lLoop); 1514 1515 // DONE: 1516 mv.visitLabel(lDone); 1517 1518 return result; 1519 } 1520 1521 private int extendLocalsMap(Class<?>[] types) { 1522 int firstSlot = localsMap.length - 1; 1523 localsMap = Arrays.copyOf(localsMap, localsMap.length + types.length); 1524 localClasses = Arrays.copyOf(localClasses, localClasses.length + types.length); 1525 System.arraycopy(types, 0, localClasses, firstSlot, types.length); 1526 int index = localsMap[firstSlot - 1] + 1; 1527 int lastSlots = 0; 1528 for (int i = 0; i < types.length; ++i) { 1529 localsMap[firstSlot + i] = index; 1530 lastSlots = BasicType.basicType(localClasses[firstSlot + i]).basicTypeSlots(); 1531 index += lastSlots; 1532 } 1533 localsMap[localsMap.length - 1] = index - lastSlots; 1534 return firstSlot; 1535 } 1536 1537 private void emitLoopHandleInvoke(Name holder, int handles, int clause, Name args, boolean pushLocalState, 1538 MethodType type, Class<?>[] loopLocalStateTypes, int clauseDataSlot, 1539 int firstLoopStateSlot) { 1540 // load handle for clause 1541 emitPushClauseArray(clauseDataSlot, handles); 1542 emitIconstInsn(clause); 1543 mv.visitInsn(Opcodes.AALOAD); 1544 // load loop state (preceding the other arguments) 1545 if (pushLocalState) { 1546 for (int s = 0; s < loopLocalStateTypes.length; ++s) { 1547 emitLoadInsn(BasicType.basicType(loopLocalStateTypes[s]), firstLoopStateSlot + s); 1548 } 1549 } 1550 // load loop args (skip 0: method handle) 1551 emitPushArguments(args, 1); 1552 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.toMethodDescriptorString(), false); 1553 } 1554 1555 private void emitPushClauseArray(int clauseDataSlot, int which) { 1556 emitAloadInsn(clauseDataSlot); 1557 emitIconstInsn(which - 1); 1558 mv.visitInsn(Opcodes.AALOAD); 1559 } 1560 1561 private void emitZero(BasicType type) { 1562 switch (type) { 1563 case I_TYPE: mv.visitInsn(Opcodes.ICONST_0); break; 1564 case J_TYPE: mv.visitInsn(Opcodes.LCONST_0); break; 1565 case F_TYPE: mv.visitInsn(Opcodes.FCONST_0); break; 1566 case D_TYPE: mv.visitInsn(Opcodes.DCONST_0); break; 1567 case L_TYPE: mv.visitInsn(Opcodes.ACONST_NULL); break; 1568 default: throw new InternalError("unknown type: " + type); 1569 } 1570 } 1571 1572 private void emitPushArguments(Name args, int start) { 1573 MethodType type = args.function.methodType(); 1574 for (int i = start; i < args.arguments.length; i++) { 1575 emitPushArgument(type.parameterType(i), args.arguments[i]); 1576 } 1577 } 1578 1579 private void emitPushArgument(Name name, int paramIndex) { 1580 Object arg = name.arguments[paramIndex]; 1581 Class<?> ptype = name.function.methodType().parameterType(paramIndex); 1582 emitPushArgument(ptype, arg); 1583 } 1584 1585 private void emitPushArgument(Class<?> ptype, Object arg) { 1586 BasicType bptype = basicType(ptype); 1587 if (arg instanceof Name) { 1588 Name n = (Name) arg; 1589 emitLoadInsn(n.type, n.index()); 1590 emitImplicitConversion(n.type, ptype, n); 1591 } else if ((arg == null || arg instanceof String) && bptype == L_TYPE) { 1592 emitConst(arg); 1593 } else { 1594 if (Wrapper.isWrapperType(arg.getClass()) && bptype != L_TYPE) { 1595 emitConst(arg); 1596 } else { 1597 mv.visitLdcInsn(constantPlaceholder(arg)); 1598 emitImplicitConversion(L_TYPE, ptype, arg); 1599 } 1600 } 1601 } 1602 1603 /** 1604 * Store the name to its local, if necessary. 1605 */ 1606 private void emitStoreResult(Name name) { 1607 if (name != null && name.type != V_TYPE) { 1608 // non-void: actually assign 1609 emitStoreInsn(name.type, name.index()); 1610 } 1611 } 1612 1613 /** 1614 * Emits a return statement from a LF invoker. If required, the result type is cast to the correct return type. 1615 */ 1616 private void emitReturn(Name onStack) { 1617 // return statement 1618 Class<?> rclass = invokerType.returnType(); 1619 BasicType rtype = lambdaForm.returnType(); 1620 assert(rtype == basicType(rclass)); // must agree 1621 if (rtype == V_TYPE) { 1622 // void 1623 mv.visitInsn(Opcodes.RETURN); 1624 // it doesn't matter what rclass is; the JVM will discard any value 1625 } else { 1626 LambdaForm.Name rn = lambdaForm.names[lambdaForm.result]; 1627 1628 // put return value on the stack if it is not already there 1629 if (rn != onStack) { 1630 emitLoadInsn(rtype, lambdaForm.result); 1631 } 1632 1633 emitImplicitConversion(rtype, rclass, rn); 1634 1635 // generate actual return statement 1636 emitReturnInsn(rtype); 1637 } 1638 } 1639 1640 /** 1641 * Emit a type conversion bytecode casting from "from" to "to". 1642 */ 1643 private void emitPrimCast(Wrapper from, Wrapper to) { 1644 // Here's how. 1645 // - indicates forbidden 1646 // <-> indicates implicit 1647 // to ----> boolean byte short char int long float double 1648 // from boolean <-> - - - - - - - 1649 // byte - <-> i2s i2c <-> i2l i2f i2d 1650 // short - i2b <-> i2c <-> i2l i2f i2d 1651 // char - i2b i2s <-> <-> i2l i2f i2d 1652 // int - i2b i2s i2c <-> i2l i2f i2d 1653 // long - l2i,i2b l2i,i2s l2i,i2c l2i <-> l2f l2d 1654 // float - f2i,i2b f2i,i2s f2i,i2c f2i f2l <-> f2d 1655 // double - d2i,i2b d2i,i2s d2i,i2c d2i d2l d2f <-> 1656 if (from == to) { 1657 // no cast required, should be dead code anyway 1658 return; 1659 } 1660 if (from.isSubwordOrInt()) { 1661 // cast from {byte,short,char,int} to anything 1662 emitI2X(to); 1663 } else { 1664 // cast from {long,float,double} to anything 1665 if (to.isSubwordOrInt()) { 1666 // cast to {byte,short,char,int} 1667 emitX2I(from); 1668 if (to.bitWidth() < 32) { 1669 // targets other than int require another conversion 1670 emitI2X(to); 1671 } 1672 } else { 1673 // cast to {long,float,double} - this is verbose 1674 boolean error = false; 1675 switch (from) { 1676 case LONG: 1677 switch (to) { 1678 case FLOAT: mv.visitInsn(Opcodes.L2F); break; 1679 case DOUBLE: mv.visitInsn(Opcodes.L2D); break; 1680 default: error = true; break; 1681 } 1682 break; 1683 case FLOAT: 1684 switch (to) { 1685 case LONG : mv.visitInsn(Opcodes.F2L); break; 1686 case DOUBLE: mv.visitInsn(Opcodes.F2D); break; 1687 default: error = true; break; 1688 } 1689 break; 1690 case DOUBLE: 1691 switch (to) { 1692 case LONG : mv.visitInsn(Opcodes.D2L); break; 1693 case FLOAT: mv.visitInsn(Opcodes.D2F); break; 1694 default: error = true; break; 1695 } 1696 break; 1697 default: 1698 error = true; 1699 break; 1700 } 1701 if (error) { 1702 throw new IllegalStateException("unhandled prim cast: " + from + "2" + to); 1703 } 1704 } 1705 } 1706 } 1707 1708 private void emitI2X(Wrapper type) { 1709 switch (type) { 1710 case BYTE: mv.visitInsn(Opcodes.I2B); break; 1711 case SHORT: mv.visitInsn(Opcodes.I2S); break; 1712 case CHAR: mv.visitInsn(Opcodes.I2C); break; 1713 case INT: /* naught */ break; 1714 case LONG: mv.visitInsn(Opcodes.I2L); break; 1715 case FLOAT: mv.visitInsn(Opcodes.I2F); break; 1716 case DOUBLE: mv.visitInsn(Opcodes.I2D); break; 1717 case BOOLEAN: 1718 // For compatibility with ValueConversions and explicitCastArguments: 1719 mv.visitInsn(Opcodes.ICONST_1); 1720 mv.visitInsn(Opcodes.IAND); 1721 break; 1722 default: throw new InternalError("unknown type: " + type); 1723 } 1724 } 1725 1726 private void emitX2I(Wrapper type) { 1727 switch (type) { 1728 case LONG: mv.visitInsn(Opcodes.L2I); break; 1729 case FLOAT: mv.visitInsn(Opcodes.F2I); break; 1730 case DOUBLE: mv.visitInsn(Opcodes.D2I); break; 1731 default: throw new InternalError("unknown type: " + type); 1732 } 1733 } 1734 1735 /** 1736 * Generate bytecode for a LambdaForm.vmentry which calls interpretWithArguments. 1737 */ 1738 static MemberName generateLambdaFormInterpreterEntryPoint(MethodType mt) { 1739 assert(isValidSignature(basicTypeSignature(mt))); 1740 String name = "interpret_"+basicTypeChar(mt.returnType()); 1741 MethodType type = mt; // includes leading argument 1742 type = type.changeParameterType(0, MethodHandle.class); 1743 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("LFI", name, type); 1744 return g.loadMethod(g.generateLambdaFormInterpreterEntryPointBytes()); 1745 } 1746 1747 private byte[] generateLambdaFormInterpreterEntryPointBytes() { 1748 classFilePrologue(); 1749 methodPrologue(); 1750 1751 // Suppress this method in backtraces displayed to the user. 1752 mv.visitAnnotation(LF_HIDDEN_SIG, true); 1753 1754 // Don't inline the interpreter entry. 1755 mv.visitAnnotation(DONTINLINE_SIG, true); 1756 1757 // create parameter array 1758 emitIconstInsn(invokerType.parameterCount()); 1759 mv.visitTypeInsn(Opcodes.ANEWARRAY, "java/lang/Object"); 1760 1761 // fill parameter array 1762 for (int i = 0; i < invokerType.parameterCount(); i++) { 1763 Class<?> ptype = invokerType.parameterType(i); 1764 mv.visitInsn(Opcodes.DUP); 1765 emitIconstInsn(i); 1766 emitLoadInsn(basicType(ptype), i); 1767 // box if primitive type 1768 if (ptype.isPrimitive()) { 1769 emitBoxing(Wrapper.forPrimitiveType(ptype)); 1770 } 1771 mv.visitInsn(Opcodes.AASTORE); 1772 } 1773 // invoke 1774 emitAloadInsn(0); 1775 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", "Ljava/lang/invoke/LambdaForm;"); 1776 mv.visitInsn(Opcodes.SWAP); // swap form and array; avoid local variable 1777 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, LF, "interpretWithArguments", "([Ljava/lang/Object;)Ljava/lang/Object;", false); 1778 1779 // maybe unbox 1780 Class<?> rtype = invokerType.returnType(); 1781 if (rtype.isPrimitive() && rtype != void.class) { 1782 emitUnboxing(Wrapper.forPrimitiveType(rtype)); 1783 } 1784 1785 // return statement 1786 emitReturnInsn(basicType(rtype)); 1787 1788 methodEpilogue(); 1789 bogusMethod(invokerType); 1790 1791 final byte[] classFile = cw.toByteArray(); 1792 maybeDump(classFile); 1793 return classFile; 1794 } 1795 1796 /** 1797 * Generate bytecode for a NamedFunction invoker. 1798 */ 1799 static MemberName generateNamedFunctionInvoker(MethodTypeForm typeForm) { 1800 MethodType invokerType = NamedFunction.INVOKER_METHOD_TYPE; 1801 String invokerName = "invoke_" + shortenSignature(basicTypeSignature(typeForm.erasedType())); 1802 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("NFI", invokerName, invokerType); 1803 return g.loadMethod(g.generateNamedFunctionInvokerImpl(typeForm)); 1804 } 1805 1806 private byte[] generateNamedFunctionInvokerImpl(MethodTypeForm typeForm) { 1807 MethodType dstType = typeForm.erasedType(); 1808 classFilePrologue(); 1809 methodPrologue(); 1810 1811 // Suppress this method in backtraces displayed to the user. 1812 mv.visitAnnotation(LF_HIDDEN_SIG, true); 1813 1814 // Force inlining of this invoker method. 1815 mv.visitAnnotation(FORCEINLINE_SIG, true); 1816 1817 // Load receiver 1818 emitAloadInsn(0); 1819 1820 // Load arguments from array 1821 for (int i = 0; i < dstType.parameterCount(); i++) { 1822 emitAloadInsn(1); 1823 emitIconstInsn(i); 1824 mv.visitInsn(Opcodes.AALOAD); 1825 1826 // Maybe unbox 1827 Class<?> dptype = dstType.parameterType(i); 1828 if (dptype.isPrimitive()) { 1829 Wrapper dstWrapper = Wrapper.forBasicType(dptype); 1830 Wrapper srcWrapper = dstWrapper.isSubwordOrInt() ? Wrapper.INT : dstWrapper; // narrow subword from int 1831 emitUnboxing(srcWrapper); 1832 emitPrimCast(srcWrapper, dstWrapper); 1833 } 1834 } 1835 1836 // Invoke 1837 String targetDesc = dstType.basicType().toMethodDescriptorString(); 1838 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", targetDesc, false); 1839 1840 // Box primitive types 1841 Class<?> rtype = dstType.returnType(); 1842 if (rtype != void.class && rtype.isPrimitive()) { 1843 Wrapper srcWrapper = Wrapper.forBasicType(rtype); 1844 Wrapper dstWrapper = srcWrapper.isSubwordOrInt() ? Wrapper.INT : srcWrapper; // widen subword to int 1845 // boolean casts not allowed 1846 emitPrimCast(srcWrapper, dstWrapper); 1847 emitBoxing(dstWrapper); 1848 } 1849 1850 // If the return type is void we return a null reference. 1851 if (rtype == void.class) { 1852 mv.visitInsn(Opcodes.ACONST_NULL); 1853 } 1854 emitReturnInsn(L_TYPE); // NOTE: NamedFunction invokers always return a reference value. 1855 1856 methodEpilogue(); 1857 bogusMethod(dstType); 1858 1859 final byte[] classFile = cw.toByteArray(); 1860 maybeDump(classFile); 1861 return classFile; 1862 } 1863 1864 /** 1865 * Emit a bogus method that just loads some string constants. This is to get the constants into the constant pool 1866 * for debugging purposes. 1867 */ 1868 private void bogusMethod(Object os) { 1869 if (DUMP_CLASS_FILES) { 1870 mv = cw.visitMethod(Opcodes.ACC_STATIC, "dummy", "()V", null, null); 1871 mv.visitLdcInsn(os.toString()); 1872 mv.visitInsn(Opcodes.POP); 1873 mv.visitInsn(Opcodes.RETURN); 1874 mv.visitMaxs(0, 0); 1875 mv.visitEnd(); 1876 } 1877 } 1878 }