1 /* 2 * Copyright (c) 2012, 2019, 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 MethodType mt = invokerType.erase(); 127 // Create an array to map name indexes to locals indexes. 128 localsMap[0] = 0; // localsMap has at least one element 129 for (int i = 1, index = 0; i < localsMap.length; i++) { 130 Wrapper w = Wrapper.forBasicType(mt.parameterType(i - 1)); 131 index += w.stackSlots(); 132 localsMap[i] = index; 133 } 134 } 135 136 /** For generating customized code for a single LambdaForm. */ 137 private InvokerBytecodeGenerator(String className, LambdaForm form, MethodType invokerType) { 138 this(className, form.lambdaName(), form, invokerType); 139 } 140 141 /** For generating customized code for a single LambdaForm. */ 142 InvokerBytecodeGenerator(String className, String invokerName, 143 LambdaForm form, MethodType invokerType) { 144 this(form, form.names.length, 145 className, invokerName, invokerType); 146 // Create an array to map name indexes to locals indexes. 147 Name[] names = form.names; 148 for (int i = 0, index = 0; i < localsMap.length; i++) { 149 localsMap[i] = index; 150 if (i < names.length) { 151 BasicType type = names[i].type(); 152 index += type.basicTypeSlots(); 153 } 154 } 155 } 156 157 /** instance counters for dumped classes */ 158 private static final HashMap<String,Integer> DUMP_CLASS_FILES_COUNTERS; 159 /** debugging flag for saving generated class files */ 160 private static final File DUMP_CLASS_FILES_DIR; 161 162 static { 163 if (DUMP_CLASS_FILES) { 164 DUMP_CLASS_FILES_COUNTERS = new HashMap<>(); 165 try { 166 File dumpDir = new File("DUMP_CLASS_FILES"); 167 if (!dumpDir.exists()) { 168 dumpDir.mkdirs(); 169 } 170 DUMP_CLASS_FILES_DIR = dumpDir; 171 System.out.println("Dumping class files to "+DUMP_CLASS_FILES_DIR+"/..."); 172 } catch (Exception e) { 173 throw newInternalError(e); 174 } 175 } else { 176 DUMP_CLASS_FILES_COUNTERS = null; 177 DUMP_CLASS_FILES_DIR = null; 178 } 179 } 180 181 private void maybeDump(final byte[] classFile) { 182 if (DUMP_CLASS_FILES) { 183 maybeDump(CLASS_PREFIX + className, classFile); 184 } 185 } 186 187 // Also used from BoundMethodHandle 188 static void maybeDump(final String className, final byte[] classFile) { 189 if (DUMP_CLASS_FILES) { 190 java.security.AccessController.doPrivileged( 191 new java.security.PrivilegedAction<>() { 192 public Void run() { 193 try { 194 String dumpName = className.replace('.','/'); 195 File dumpFile = new File(DUMP_CLASS_FILES_DIR, dumpName+".class"); 196 System.out.println("dump: " + dumpFile); 197 dumpFile.getParentFile().mkdirs(); 198 FileOutputStream file = new FileOutputStream(dumpFile); 199 file.write(classFile); 200 file.close(); 201 return null; 202 } catch (IOException ex) { 203 throw newInternalError(ex); 204 } 205 } 206 }); 207 } 208 } 209 210 private static String makeDumpableClassName(String className) { 211 Integer ctr; 212 synchronized (DUMP_CLASS_FILES_COUNTERS) { 213 ctr = DUMP_CLASS_FILES_COUNTERS.get(className); 214 if (ctr == null) ctr = 0; 215 DUMP_CLASS_FILES_COUNTERS.put(className, ctr+1); 216 } 217 String sfx = ctr.toString(); 218 while (sfx.length() < 3) 219 sfx = "0"+sfx; 220 className += sfx; 221 return className; 222 } 223 224 class CpPatch { 225 final int index; 226 final Object value; 227 CpPatch(int index, Object value) { 228 this.index = index; 229 this.value = value; 230 } 231 public String toString() { 232 return "CpPatch/index="+index+",value="+value; 233 } 234 } 235 236 private final ArrayList<CpPatch> cpPatches = new ArrayList<>(); 237 238 private int cph = 0; // for counting constant placeholders 239 240 String constantPlaceholder(Object arg) { 241 String cpPlaceholder = "CONSTANT_PLACEHOLDER_" + cph++; 242 if (DUMP_CLASS_FILES) cpPlaceholder += " <<" + debugString(arg) + ">>"; 243 // TODO check if arg is already in the constant pool 244 // insert placeholder in CP and remember the patch 245 int index = cw.newConst((Object) cpPlaceholder); 246 cpPatches.add(new CpPatch(index, arg)); 247 return cpPlaceholder; 248 } 249 250 Object[] cpPatches(byte[] classFile) { 251 int size = getConstantPoolSize(classFile); 252 Object[] res = new Object[size]; 253 for (CpPatch p : cpPatches) { 254 if (p.index >= size) 255 throw new InternalError("in cpool["+size+"]: "+p+"\n"+Arrays.toString(Arrays.copyOf(classFile, 20))); 256 res[p.index] = p.value; 257 } 258 return res; 259 } 260 261 private static String debugString(Object arg) { 262 if (arg instanceof MethodHandle) { 263 MethodHandle mh = (MethodHandle) arg; 264 MemberName member = mh.internalMemberName(); 265 if (member != null) 266 return member.toString(); 267 return mh.debugString(); 268 } 269 return arg.toString(); 270 } 271 272 /** 273 * Extract the number of constant pool entries from a given class file. 274 * 275 * @param classFile the bytes of the class file in question. 276 * @return the number of entries in the constant pool. 277 */ 278 private static int getConstantPoolSize(byte[] classFile) { 279 // The first few bytes: 280 // u4 magic; 281 // u2 minor_version; 282 // u2 major_version; 283 // u2 constant_pool_count; 284 return ((classFile[8] & 0xFF) << 8) | (classFile[9] & 0xFF); 285 } 286 287 /** 288 * Extract the MemberName of a newly-defined method. 289 */ 290 private MemberName loadMethod(byte[] classFile) { 291 Class<?> invokerClass = loadAndInitializeInvokerClass(classFile, cpPatches(classFile)); 292 return resolveInvokerMember(invokerClass, invokerName, invokerType); 293 } 294 295 /** 296 * Define a given class as anonymous class in the runtime system. 297 */ 298 private static Class<?> loadAndInitializeInvokerClass(byte[] classBytes, Object[] patches) { 299 Class<?> invokerClass = UNSAFE.defineAnonymousClass(HOST_CLASS, classBytes, patches); 300 UNSAFE.ensureClassInitialized(invokerClass); // Make sure the class is initialized; VM might complain. 301 return invokerClass; 302 } 303 304 private static MemberName resolveInvokerMember(Class<?> invokerClass, String name, MethodType type) { 305 MemberName member = new MemberName(invokerClass, name, type, REF_invokeStatic); 306 try { 307 member = MEMBERNAME_FACTORY.resolveOrFail(REF_invokeStatic, member, HOST_CLASS, ReflectiveOperationException.class); 308 } catch (ReflectiveOperationException e) { 309 throw newInternalError(e); 310 } 311 return member; 312 } 313 314 /** 315 * Set up class file generation. 316 */ 317 private ClassWriter classFilePrologue() { 318 final int NOT_ACC_PUBLIC = 0; // not ACC_PUBLIC 319 cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES); 320 cw.visit(Opcodes.V1_8, NOT_ACC_PUBLIC + Opcodes.ACC_FINAL + Opcodes.ACC_SUPER, 321 CLASS_PREFIX + className, null, INVOKER_SUPER_NAME, null); 322 cw.visitSource(SOURCE_PREFIX + className, null); 323 return cw; 324 } 325 326 private void methodPrologue() { 327 String invokerDesc = invokerType.toMethodDescriptorString(); 328 mv = cw.visitMethod(Opcodes.ACC_STATIC, invokerName, invokerDesc, null, null); 329 } 330 331 /** 332 * Tear down class file generation. 333 */ 334 private void methodEpilogue() { 335 mv.visitMaxs(0, 0); 336 mv.visitEnd(); 337 } 338 339 /* 340 * Low-level emit helpers. 341 */ 342 private void emitConst(Object con) { 343 if (con == null) { 344 mv.visitInsn(Opcodes.ACONST_NULL); 345 return; 346 } 347 if (con instanceof Integer) { 348 emitIconstInsn((int) con); 349 return; 350 } 351 if (con instanceof Byte) { 352 emitIconstInsn((byte)con); 353 return; 354 } 355 if (con instanceof Short) { 356 emitIconstInsn((short)con); 357 return; 358 } 359 if (con instanceof Character) { 360 emitIconstInsn((char)con); 361 return; 362 } 363 if (con instanceof Long) { 364 long x = (long) con; 365 short sx = (short)x; 366 if (x == sx) { 367 if (sx >= 0 && sx <= 1) { 368 mv.visitInsn(Opcodes.LCONST_0 + (int) sx); 369 } else { 370 emitIconstInsn((int) x); 371 mv.visitInsn(Opcodes.I2L); 372 } 373 return; 374 } 375 } 376 if (con instanceof Float) { 377 float x = (float) con; 378 short sx = (short)x; 379 if (x == sx) { 380 if (sx >= 0 && sx <= 2) { 381 mv.visitInsn(Opcodes.FCONST_0 + (int) sx); 382 } else { 383 emitIconstInsn((int) x); 384 mv.visitInsn(Opcodes.I2F); 385 } 386 return; 387 } 388 } 389 if (con instanceof Double) { 390 double x = (double) con; 391 short sx = (short)x; 392 if (x == sx) { 393 if (sx >= 0 && sx <= 1) { 394 mv.visitInsn(Opcodes.DCONST_0 + (int) sx); 395 } else { 396 emitIconstInsn((int) x); 397 mv.visitInsn(Opcodes.I2D); 398 } 399 return; 400 } 401 } 402 if (con instanceof Boolean) { 403 emitIconstInsn((boolean) con ? 1 : 0); 404 return; 405 } 406 // fall through: 407 mv.visitLdcInsn(con); 408 } 409 410 private void emitIconstInsn(final int cst) { 411 if (cst >= -1 && cst <= 5) { 412 mv.visitInsn(Opcodes.ICONST_0 + cst); 413 } else if (cst >= Byte.MIN_VALUE && cst <= Byte.MAX_VALUE) { 414 mv.visitIntInsn(Opcodes.BIPUSH, cst); 415 } else if (cst >= Short.MIN_VALUE && cst <= Short.MAX_VALUE) { 416 mv.visitIntInsn(Opcodes.SIPUSH, cst); 417 } else { 418 mv.visitLdcInsn(cst); 419 } 420 } 421 422 /* 423 * NOTE: These load/store methods use the localsMap to find the correct index! 424 */ 425 private void emitLoadInsn(BasicType type, int index) { 426 int opcode = loadInsnOpcode(type); 427 mv.visitVarInsn(opcode, localsMap[index]); 428 } 429 430 private int loadInsnOpcode(BasicType type) throws InternalError { 431 switch (type) { 432 case I_TYPE: return Opcodes.ILOAD; 433 case J_TYPE: return Opcodes.LLOAD; 434 case F_TYPE: return Opcodes.FLOAD; 435 case D_TYPE: return Opcodes.DLOAD; 436 case L_TYPE: return Opcodes.ALOAD; 437 default: 438 throw new InternalError("unknown type: " + type); 439 } 440 } 441 private void emitAloadInsn(int index) { 442 emitLoadInsn(L_TYPE, index); 443 } 444 445 private void emitStoreInsn(BasicType type, int index) { 446 int opcode = storeInsnOpcode(type); 447 mv.visitVarInsn(opcode, localsMap[index]); 448 } 449 450 private int storeInsnOpcode(BasicType type) throws InternalError { 451 switch (type) { 452 case I_TYPE: return Opcodes.ISTORE; 453 case J_TYPE: return Opcodes.LSTORE; 454 case F_TYPE: return Opcodes.FSTORE; 455 case D_TYPE: return Opcodes.DSTORE; 456 case L_TYPE: return Opcodes.ASTORE; 457 default: 458 throw new InternalError("unknown type: " + type); 459 } 460 } 461 private void emitAstoreInsn(int index) { 462 emitStoreInsn(L_TYPE, index); 463 } 464 465 private byte arrayTypeCode(Wrapper elementType) { 466 switch (elementType) { 467 case BOOLEAN: return Opcodes.T_BOOLEAN; 468 case BYTE: return Opcodes.T_BYTE; 469 case CHAR: return Opcodes.T_CHAR; 470 case SHORT: return Opcodes.T_SHORT; 471 case INT: return Opcodes.T_INT; 472 case LONG: return Opcodes.T_LONG; 473 case FLOAT: return Opcodes.T_FLOAT; 474 case DOUBLE: return Opcodes.T_DOUBLE; 475 case OBJECT: return 0; // in place of Opcodes.T_OBJECT 476 default: throw new InternalError(); 477 } 478 } 479 480 private int arrayInsnOpcode(byte tcode, int aaop) throws InternalError { 481 assert(aaop == Opcodes.AASTORE || aaop == Opcodes.AALOAD); 482 int xas; 483 switch (tcode) { 484 case Opcodes.T_BOOLEAN: xas = Opcodes.BASTORE; break; 485 case Opcodes.T_BYTE: xas = Opcodes.BASTORE; break; 486 case Opcodes.T_CHAR: xas = Opcodes.CASTORE; break; 487 case Opcodes.T_SHORT: xas = Opcodes.SASTORE; break; 488 case Opcodes.T_INT: xas = Opcodes.IASTORE; break; 489 case Opcodes.T_LONG: xas = Opcodes.LASTORE; break; 490 case Opcodes.T_FLOAT: xas = Opcodes.FASTORE; break; 491 case Opcodes.T_DOUBLE: xas = Opcodes.DASTORE; break; 492 case 0: xas = Opcodes.AASTORE; break; 493 default: throw new InternalError(); 494 } 495 return xas - Opcodes.AASTORE + aaop; 496 } 497 498 /** 499 * Emit a boxing call. 500 * 501 * @param wrapper primitive type class to box. 502 */ 503 private void emitBoxing(Wrapper wrapper) { 504 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName(); 505 String name = "valueOf"; 506 String desc = "(" + wrapper.basicTypeChar() + ")L" + owner + ";"; 507 mv.visitMethodInsn(Opcodes.INVOKESTATIC, owner, name, desc, false); 508 } 509 510 /** 511 * Emit an unboxing call (plus preceding checkcast). 512 * 513 * @param wrapper wrapper type class to unbox. 514 */ 515 private void emitUnboxing(Wrapper wrapper) { 516 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName(); 517 String name = wrapper.primitiveSimpleName() + "Value"; 518 String desc = "()" + wrapper.basicTypeChar(); 519 emitReferenceCast(wrapper.wrapperType(), null); 520 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, owner, name, desc, false); 521 } 522 523 /** 524 * Emit an implicit conversion for an argument which must be of the given pclass. 525 * This is usually a no-op, except when pclass is a subword type or a reference other than Object or an interface. 526 * 527 * @param ptype type of value present on stack 528 * @param pclass type of value required on stack 529 * @param arg compile-time representation of value on stack (Node, constant) or null if none 530 */ 531 private void emitImplicitConversion(BasicType ptype, Class<?> pclass, Object arg) { 532 assert(basicType(pclass) == ptype); // boxing/unboxing handled by caller 533 if (pclass == ptype.basicTypeClass() && ptype != L_TYPE) 534 return; // nothing to do 535 switch (ptype) { 536 case L_TYPE: 537 if (VerifyType.isNullConversion(Object.class, pclass, false)) { 538 if (PROFILE_LEVEL > 0) 539 emitReferenceCast(Object.class, arg); 540 return; 541 } 542 emitReferenceCast(pclass, arg); 543 return; 544 case I_TYPE: 545 if (!VerifyType.isNullConversion(int.class, pclass, false)) 546 emitPrimCast(ptype.basicTypeWrapper(), Wrapper.forPrimitiveType(pclass)); 547 return; 548 } 549 throw newInternalError("bad implicit conversion: tc="+ptype+": "+pclass); 550 } 551 552 /** Update localClasses type map. Return true if the information is already present. */ 553 private boolean assertStaticType(Class<?> cls, Name n) { 554 int local = n.index(); 555 Class<?> aclass = localClasses[local]; 556 if (aclass != null && (aclass == cls || cls.isAssignableFrom(aclass))) { 557 return true; // type info is already present 558 } else if (aclass == null || aclass.isAssignableFrom(cls)) { 559 localClasses[local] = cls; // type info can be improved 560 } 561 return false; 562 } 563 564 private void emitReferenceCast(Class<?> cls, Object arg) { 565 Name writeBack = null; // local to write back result 566 if (arg instanceof Name) { 567 Name n = (Name) arg; 568 if (lambdaForm.useCount(n) > 1) { 569 // This guy gets used more than once. 570 writeBack = n; 571 if (assertStaticType(cls, n)) { 572 return; // this cast was already performed 573 } 574 } 575 } 576 if (isStaticallyNameable(cls)) { 577 String sig = getInternalName(cls); 578 mv.visitTypeInsn(Opcodes.CHECKCAST, sig); 579 } else { 580 mv.visitLdcInsn(constantPlaceholder(cls)); 581 mv.visitTypeInsn(Opcodes.CHECKCAST, CLS); 582 mv.visitInsn(Opcodes.SWAP); 583 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, CLS, "cast", LL_SIG, false); 584 if (Object[].class.isAssignableFrom(cls)) 585 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJARY); 586 else if (PROFILE_LEVEL > 0) 587 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJ); 588 } 589 if (writeBack != null) { 590 mv.visitInsn(Opcodes.DUP); 591 emitAstoreInsn(writeBack.index()); 592 } 593 } 594 595 /** 596 * Emits an actual return instruction conforming to the given return type. 597 */ 598 private void emitReturnInsn(BasicType type) { 599 int opcode; 600 switch (type) { 601 case I_TYPE: opcode = Opcodes.IRETURN; break; 602 case J_TYPE: opcode = Opcodes.LRETURN; break; 603 case F_TYPE: opcode = Opcodes.FRETURN; break; 604 case D_TYPE: opcode = Opcodes.DRETURN; break; 605 case L_TYPE: opcode = Opcodes.ARETURN; break; 606 case V_TYPE: opcode = Opcodes.RETURN; break; 607 default: 608 throw new InternalError("unknown return type: " + type); 609 } 610 mv.visitInsn(opcode); 611 } 612 613 private String getInternalName(Class<?> c) { 614 if (c == Object.class) return OBJ; 615 else if (c == Object[].class) return OBJARY; 616 else if (c == Class.class) return CLS; 617 else if (c == MethodHandle.class) return MH; 618 assert(VerifyAccess.isTypeVisible(c, Object.class)) : c.getName(); 619 620 if (c == lastClass) { 621 return lastInternalName; 622 } 623 lastClass = c; 624 return lastInternalName = c.getName().replace('.', '/'); 625 } 626 627 private static MemberName resolveFrom(String name, MethodType type, Class<?> holder) { 628 MemberName member = new MemberName(holder, name, type, REF_invokeStatic); 629 MemberName resolvedMember = MemberName.getFactory().resolveOrNull(REF_invokeStatic, member, holder); 630 if (TRACE_RESOLVE) { 631 System.out.println("[LF_RESOLVE] " + holder.getName() + " " + name + " " + 632 shortenSignature(basicTypeSignature(type)) + (resolvedMember != null ? " (success)" : " (fail)") ); 633 } 634 return resolvedMember; 635 } 636 637 private static MemberName lookupPregenerated(LambdaForm form, MethodType invokerType) { 638 if (form.customized != null) { 639 // No pre-generated version for customized LF 640 return null; 641 } 642 String name = form.kind.methodName; 643 switch (form.kind) { 644 case BOUND_REINVOKER: { 645 name = name + "_" + BoundMethodHandle.speciesDataFor(form).key(); 646 return resolveFrom(name, invokerType, DelegatingMethodHandle.Holder.class); 647 } 648 case DELEGATE: return resolveFrom(name, invokerType, DelegatingMethodHandle.Holder.class); 649 case ZERO: // fall-through 650 case IDENTITY: { 651 name = name + "_" + form.returnType().basicTypeChar(); 652 return resolveFrom(name, invokerType, LambdaForm.Holder.class); 653 } 654 case EXACT_INVOKER: // fall-through 655 case EXACT_LINKER: // fall-through 656 case LINK_TO_CALL_SITE: // fall-through 657 case LINK_TO_TARGET_METHOD: // fall-through 658 case GENERIC_INVOKER: // fall-through 659 case GENERIC_LINKER: return resolveFrom(name, invokerType.basicType(), Invokers.Holder.class); 660 case GET_REFERENCE: // fall-through 661 case GET_BOOLEAN: // fall-through 662 case GET_BYTE: // fall-through 663 case GET_CHAR: // fall-through 664 case GET_SHORT: // fall-through 665 case GET_INT: // fall-through 666 case GET_LONG: // fall-through 667 case GET_FLOAT: // fall-through 668 case GET_DOUBLE: // fall-through 669 case PUT_REFERENCE: // fall-through 670 case PUT_BOOLEAN: // fall-through 671 case PUT_BYTE: // fall-through 672 case PUT_CHAR: // fall-through 673 case PUT_SHORT: // fall-through 674 case PUT_INT: // fall-through 675 case PUT_LONG: // fall-through 676 case PUT_FLOAT: // fall-through 677 case PUT_DOUBLE: // fall-through 678 case DIRECT_NEW_INVOKE_SPECIAL: // fall-through 679 case DIRECT_INVOKE_INTERFACE: // fall-through 680 case DIRECT_INVOKE_SPECIAL: // fall-through 681 case DIRECT_INVOKE_SPECIAL_IFC: // fall-through 682 case DIRECT_INVOKE_STATIC: // fall-through 683 case DIRECT_INVOKE_STATIC_INIT: // fall-through 684 case DIRECT_INVOKE_VIRTUAL: return resolveFrom(name, invokerType, DirectMethodHandle.Holder.class); 685 } 686 return null; 687 } 688 689 /** 690 * Generate customized bytecode for a given LambdaForm. 691 */ 692 static MemberName generateCustomizedCode(LambdaForm form, MethodType invokerType) { 693 MemberName pregenerated = lookupPregenerated(form, invokerType); 694 if (pregenerated != null) return pregenerated; // pre-generated bytecode 695 696 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("MH", form, invokerType); 697 return g.loadMethod(g.generateCustomizedCodeBytes()); 698 } 699 700 /** Generates code to check that actual receiver and LambdaForm matches */ 701 private boolean checkActualReceiver() { 702 // Expects MethodHandle on the stack and actual receiver MethodHandle in slot #0 703 mv.visitInsn(Opcodes.DUP); 704 mv.visitVarInsn(Opcodes.ALOAD, localsMap[0]); 705 mv.visitMethodInsn(Opcodes.INVOKESTATIC, MHI, "assertSame", LLV_SIG, false); 706 return true; 707 } 708 709 static String className(String cn) { 710 assert checkClassName(cn): "Class not found: " + cn; 711 return cn; 712 } 713 714 static boolean checkClassName(String cn) { 715 Type tp = Type.getType(cn); 716 // additional sanity so only valid "L;" descriptors work 717 if (tp.getSort() != Type.OBJECT) { 718 return false; 719 } 720 try { 721 Class<?> c = Class.forName(tp.getClassName(), false, null); 722 return true; 723 } catch (ClassNotFoundException e) { 724 return false; 725 } 726 } 727 728 static final String DONTINLINE_SIG = className("Ljdk/internal/vm/annotation/DontInline;"); 729 static final String FORCEINLINE_SIG = className("Ljdk/internal/vm/annotation/ForceInline;"); 730 static final String HIDDEN_SIG = className("Ljdk/internal/vm/annotation/Hidden;"); 731 static final String INJECTEDPROFILE_SIG = className("Ljava/lang/invoke/InjectedProfile;"); 732 static final String LF_COMPILED_SIG = className("Ljava/lang/invoke/LambdaForm$Compiled;"); 733 734 /** 735 * Generate an invoker method for the passed {@link LambdaForm}. 736 */ 737 private byte[] generateCustomizedCodeBytes() { 738 classFilePrologue(); 739 addMethod(); 740 bogusMethod(lambdaForm); 741 742 final byte[] classFile = toByteArray(); 743 maybeDump(classFile); 744 return classFile; 745 } 746 747 void setClassWriter(ClassWriter cw) { 748 this.cw = cw; 749 } 750 751 void addMethod() { 752 methodPrologue(); 753 754 // Suppress this method in backtraces displayed to the user. 755 mv.visitAnnotation(HIDDEN_SIG, true); 756 757 // Mark this method as a compiled LambdaForm 758 mv.visitAnnotation(LF_COMPILED_SIG, true); 759 760 if (lambdaForm.forceInline) { 761 // Force inlining of this invoker method. 762 mv.visitAnnotation(FORCEINLINE_SIG, true); 763 } else { 764 mv.visitAnnotation(DONTINLINE_SIG, true); 765 } 766 767 constantPlaceholder(lambdaForm); // keep LambdaForm instance & its compiled form lifetime tightly coupled. 768 769 if (lambdaForm.customized != null) { 770 // Since LambdaForm is customized for a particular MethodHandle, it's safe to substitute 771 // receiver MethodHandle (at slot #0) with an embedded constant and use it instead. 772 // It enables more efficient code generation in some situations, since embedded constants 773 // are compile-time constants for JIT compiler. 774 mv.visitLdcInsn(constantPlaceholder(lambdaForm.customized)); 775 mv.visitTypeInsn(Opcodes.CHECKCAST, MH); 776 assert(checkActualReceiver()); // expects MethodHandle on top of the stack 777 mv.visitVarInsn(Opcodes.ASTORE, localsMap[0]); 778 } 779 780 // iterate over the form's names, generating bytecode instructions for each 781 // start iterating at the first name following the arguments 782 Name onStack = null; 783 for (int i = lambdaForm.arity; i < lambdaForm.names.length; i++) { 784 Name name = lambdaForm.names[i]; 785 786 emitStoreResult(onStack); 787 onStack = name; // unless otherwise modified below 788 MethodHandleImpl.Intrinsic intr = name.function.intrinsicName(); 789 switch (intr) { 790 case SELECT_ALTERNATIVE: 791 assert lambdaForm.isSelectAlternative(i); 792 if (PROFILE_GWT) { 793 assert(name.arguments[0] instanceof Name && 794 ((Name)name.arguments[0]).refersTo(MethodHandleImpl.class, "profileBoolean")); 795 mv.visitAnnotation(INJECTEDPROFILE_SIG, true); 796 } 797 onStack = emitSelectAlternative(name, lambdaForm.names[i+1]); 798 i++; // skip MH.invokeBasic of the selectAlternative result 799 continue; 800 case GUARD_WITH_CATCH: 801 assert lambdaForm.isGuardWithCatch(i); 802 onStack = emitGuardWithCatch(i); 803 i += 2; // jump to the end of GWC idiom 804 continue; 805 case TRY_FINALLY: 806 assert lambdaForm.isTryFinally(i); 807 onStack = emitTryFinally(i); 808 i += 2; // jump to the end of the TF idiom 809 continue; 810 case LOOP: 811 assert lambdaForm.isLoop(i); 812 onStack = emitLoop(i); 813 i += 2; // jump to the end of the LOOP idiom 814 continue; 815 case NEW_ARRAY: 816 Class<?> rtype = name.function.methodType().returnType(); 817 if (isStaticallyNameable(rtype)) { 818 emitNewArray(name); 819 continue; 820 } 821 break; 822 case ARRAY_LOAD: 823 emitArrayLoad(name); 824 continue; 825 case ARRAY_STORE: 826 emitArrayStore(name); 827 continue; 828 case ARRAY_LENGTH: 829 emitArrayLength(name); 830 continue; 831 case IDENTITY: 832 assert(name.arguments.length == 1); 833 emitPushArguments(name, 0); 834 continue; 835 case ZERO: 836 assert(name.arguments.length == 0); 837 emitConst(name.type.basicTypeWrapper().zero()); 838 continue; 839 case NONE: 840 // no intrinsic associated 841 break; 842 default: 843 throw newInternalError("Unknown intrinsic: "+intr); 844 } 845 846 MemberName member = name.function.member(); 847 if (isStaticallyInvocable(member)) { 848 emitStaticInvoke(member, name); 849 } else { 850 emitInvoke(name); 851 } 852 } 853 854 // return statement 855 emitReturn(onStack); 856 857 methodEpilogue(); 858 } 859 860 /* 861 * @throws BytecodeGenerationException if something goes wrong when 862 * generating the byte code 863 */ 864 private byte[] toByteArray() { 865 try { 866 return cw.toByteArray(); 867 } catch (RuntimeException e) { 868 throw new BytecodeGenerationException(e); 869 } 870 } 871 872 @SuppressWarnings("serial") 873 static final class BytecodeGenerationException extends RuntimeException { 874 BytecodeGenerationException(Exception cause) { 875 super(cause); 876 } 877 } 878 879 void emitArrayLoad(Name name) { emitArrayOp(name, Opcodes.AALOAD); } 880 void emitArrayStore(Name name) { emitArrayOp(name, Opcodes.AASTORE); } 881 void emitArrayLength(Name name) { emitArrayOp(name, Opcodes.ARRAYLENGTH); } 882 883 void emitArrayOp(Name name, int arrayOpcode) { 884 assert arrayOpcode == Opcodes.AALOAD || arrayOpcode == Opcodes.AASTORE || arrayOpcode == Opcodes.ARRAYLENGTH; 885 Class<?> elementType = name.function.methodType().parameterType(0).getComponentType(); 886 assert elementType != null; 887 emitPushArguments(name, 0); 888 if (arrayOpcode != Opcodes.ARRAYLENGTH && elementType.isPrimitive()) { 889 Wrapper w = Wrapper.forPrimitiveType(elementType); 890 arrayOpcode = arrayInsnOpcode(arrayTypeCode(w), arrayOpcode); 891 } 892 mv.visitInsn(arrayOpcode); 893 } 894 895 /** 896 * Emit an invoke for the given name. 897 */ 898 void emitInvoke(Name name) { 899 assert(!name.isLinkerMethodInvoke()); // should use the static path for these 900 if (true) { 901 // push receiver 902 MethodHandle target = name.function.resolvedHandle(); 903 assert(target != null) : name.exprString(); 904 mv.visitLdcInsn(constantPlaceholder(target)); 905 emitReferenceCast(MethodHandle.class, target); 906 } else { 907 // load receiver 908 emitAloadInsn(0); 909 emitReferenceCast(MethodHandle.class, null); 910 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", LF_SIG); 911 mv.visitFieldInsn(Opcodes.GETFIELD, LF, "names", LFN_SIG); 912 // TODO more to come 913 } 914 915 // push arguments 916 emitPushArguments(name, 0); 917 918 // invocation 919 MethodType type = name.function.methodType(); 920 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false); 921 } 922 923 private static Class<?>[] STATICALLY_INVOCABLE_PACKAGES = { 924 // Sample classes from each package we are willing to bind to statically: 925 java.lang.Object.class, 926 java.util.Arrays.class, 927 jdk.internal.misc.Unsafe.class 928 //MethodHandle.class already covered 929 }; 930 931 static boolean isStaticallyInvocable(NamedFunction ... functions) { 932 for (NamedFunction nf : functions) { 933 if (!isStaticallyInvocable(nf.member())) { 934 return false; 935 } 936 } 937 return true; 938 } 939 940 static boolean isStaticallyInvocable(Name name) { 941 return isStaticallyInvocable(name.function.member()); 942 } 943 944 static boolean isStaticallyInvocable(MemberName member) { 945 if (member == null) return false; 946 if (member.isConstructor()) return false; 947 Class<?> cls = member.getDeclaringClass(); 948 // Fast-path non-private members declared by MethodHandles, which is a common 949 // case 950 if (MethodHandle.class.isAssignableFrom(cls) && !member.isPrivate()) { 951 assert(isStaticallyInvocableType(member.getMethodOrFieldType())); 952 return true; 953 } 954 if (cls.isArray() || cls.isPrimitive()) 955 return false; // FIXME 956 if (cls.isAnonymousClass() || cls.isLocalClass()) 957 return false; // inner class of some sort 958 if (cls.getClassLoader() != MethodHandle.class.getClassLoader()) 959 return false; // not on BCP 960 if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: switch to supported API once it is added 961 return false; 962 if (!isStaticallyInvocableType(member.getMethodOrFieldType())) 963 return false; 964 if (!member.isPrivate() && VerifyAccess.isSamePackage(MethodHandle.class, cls)) 965 return true; // in java.lang.invoke package 966 if (member.isPublic() && isStaticallyNameable(cls)) 967 return true; 968 return false; 969 } 970 971 private static boolean isStaticallyInvocableType(MethodType mtype) { 972 if (!isStaticallyNameable(mtype.returnType())) 973 return false; 974 for (Class<?> ptype : mtype.parameterArray()) 975 if (!isStaticallyNameable(ptype)) 976 return false; 977 return true; 978 } 979 980 static boolean isStaticallyNameable(Class<?> cls) { 981 if (cls == Object.class) 982 return true; 983 if (MethodHandle.class.isAssignableFrom(cls)) { 984 assert(!ReflectUtil.isVMAnonymousClass(cls)); 985 return true; 986 } 987 while (cls.isArray()) 988 cls = cls.getComponentType(); 989 if (cls.isPrimitive()) 990 return true; // int[].class, for example 991 if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: switch to supported API once it is added 992 return false; 993 // could use VerifyAccess.isClassAccessible but the following is a safe approximation 994 if (cls.getClassLoader() != Object.class.getClassLoader()) 995 return false; 996 if (VerifyAccess.isSamePackage(MethodHandle.class, cls)) 997 return true; 998 if (!Modifier.isPublic(cls.getModifiers())) 999 return false; 1000 for (Class<?> pkgcls : STATICALLY_INVOCABLE_PACKAGES) { 1001 if (VerifyAccess.isSamePackage(pkgcls, cls)) 1002 return true; 1003 } 1004 return false; 1005 } 1006 1007 void emitStaticInvoke(Name name) { 1008 emitStaticInvoke(name.function.member(), name); 1009 } 1010 1011 /** 1012 * Emit an invoke for the given name, using the MemberName directly. 1013 */ 1014 void emitStaticInvoke(MemberName member, Name name) { 1015 assert(member.equals(name.function.member())); 1016 Class<?> defc = member.getDeclaringClass(); 1017 String cname = getInternalName(defc); 1018 String mname = member.getName(); 1019 String mtype; 1020 byte refKind = member.getReferenceKind(); 1021 if (refKind == REF_invokeSpecial) { 1022 // in order to pass the verifier, we need to convert this to invokevirtual in all cases 1023 assert(member.canBeStaticallyBound()) : member; 1024 refKind = REF_invokeVirtual; 1025 } 1026 1027 assert(!(member.getDeclaringClass().isInterface() && refKind == REF_invokeVirtual)); 1028 1029 // push arguments 1030 emitPushArguments(name, 0); 1031 1032 // invocation 1033 if (member.isMethod()) { 1034 mtype = member.getMethodType().toMethodDescriptorString(); 1035 mv.visitMethodInsn(refKindOpcode(refKind), cname, mname, mtype, 1036 member.getDeclaringClass().isInterface()); 1037 } else { 1038 mtype = MethodType.toFieldDescriptorString(member.getFieldType()); 1039 mv.visitFieldInsn(refKindOpcode(refKind), cname, mname, mtype); 1040 } 1041 // Issue a type assertion for the result, so we can avoid casts later. 1042 if (name.type == L_TYPE) { 1043 Class<?> rtype = member.getInvocationType().returnType(); 1044 assert(!rtype.isPrimitive()); 1045 if (rtype != Object.class && !rtype.isInterface()) { 1046 assertStaticType(rtype, name); 1047 } 1048 } 1049 } 1050 1051 void emitNewArray(Name name) throws InternalError { 1052 Class<?> rtype = name.function.methodType().returnType(); 1053 if (name.arguments.length == 0) { 1054 // The array will be a constant. 1055 Object emptyArray; 1056 try { 1057 emptyArray = name.function.resolvedHandle().invoke(); 1058 } catch (Throwable ex) { 1059 throw uncaughtException(ex); 1060 } 1061 assert(java.lang.reflect.Array.getLength(emptyArray) == 0); 1062 assert(emptyArray.getClass() == rtype); // exact typing 1063 mv.visitLdcInsn(constantPlaceholder(emptyArray)); 1064 emitReferenceCast(rtype, emptyArray); 1065 return; 1066 } 1067 Class<?> arrayElementType = rtype.getComponentType(); 1068 assert(arrayElementType != null); 1069 emitIconstInsn(name.arguments.length); 1070 int xas = Opcodes.AASTORE; 1071 if (!arrayElementType.isPrimitive()) { 1072 mv.visitTypeInsn(Opcodes.ANEWARRAY, getInternalName(arrayElementType)); 1073 } else { 1074 byte tc = arrayTypeCode(Wrapper.forPrimitiveType(arrayElementType)); 1075 xas = arrayInsnOpcode(tc, xas); 1076 mv.visitIntInsn(Opcodes.NEWARRAY, tc); 1077 } 1078 // store arguments 1079 for (int i = 0; i < name.arguments.length; i++) { 1080 mv.visitInsn(Opcodes.DUP); 1081 emitIconstInsn(i); 1082 emitPushArgument(name, i); 1083 mv.visitInsn(xas); 1084 } 1085 // the array is left on the stack 1086 assertStaticType(rtype, name); 1087 } 1088 int refKindOpcode(byte refKind) { 1089 switch (refKind) { 1090 case REF_invokeVirtual: return Opcodes.INVOKEVIRTUAL; 1091 case REF_invokeStatic: return Opcodes.INVOKESTATIC; 1092 case REF_invokeSpecial: return Opcodes.INVOKESPECIAL; 1093 case REF_invokeInterface: return Opcodes.INVOKEINTERFACE; 1094 case REF_getField: return Opcodes.GETFIELD; 1095 case REF_putField: return Opcodes.PUTFIELD; 1096 case REF_getStatic: return Opcodes.GETSTATIC; 1097 case REF_putStatic: return Opcodes.PUTSTATIC; 1098 } 1099 throw new InternalError("refKind="+refKind); 1100 } 1101 1102 /** 1103 * Emit bytecode for the selectAlternative idiom. 1104 * 1105 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithTest): 1106 * <blockquote><pre>{@code 1107 * Lambda(a0:L,a1:I)=>{ 1108 * t2:I=foo.test(a1:I); 1109 * t3:L=MethodHandleImpl.selectAlternative(t2:I,(MethodHandle(int)int),(MethodHandle(int)int)); 1110 * t4:I=MethodHandle.invokeBasic(t3:L,a1:I);t4:I} 1111 * }</pre></blockquote> 1112 */ 1113 private Name emitSelectAlternative(Name selectAlternativeName, Name invokeBasicName) { 1114 assert isStaticallyInvocable(invokeBasicName); 1115 1116 Name receiver = (Name) invokeBasicName.arguments[0]; 1117 1118 Label L_fallback = new Label(); 1119 Label L_done = new Label(); 1120 1121 // load test result 1122 emitPushArgument(selectAlternativeName, 0); 1123 1124 // if_icmpne L_fallback 1125 mv.visitJumpInsn(Opcodes.IFEQ, L_fallback); 1126 1127 // invoke selectAlternativeName.arguments[1] 1128 Class<?>[] preForkClasses = localClasses.clone(); 1129 emitPushArgument(selectAlternativeName, 1); // get 2nd argument of selectAlternative 1130 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot 1131 emitStaticInvoke(invokeBasicName); 1132 1133 // goto L_done 1134 mv.visitJumpInsn(Opcodes.GOTO, L_done); 1135 1136 // L_fallback: 1137 mv.visitLabel(L_fallback); 1138 1139 // invoke selectAlternativeName.arguments[2] 1140 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length); 1141 emitPushArgument(selectAlternativeName, 2); // get 3rd argument of selectAlternative 1142 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot 1143 emitStaticInvoke(invokeBasicName); 1144 1145 // L_done: 1146 mv.visitLabel(L_done); 1147 // for now do not bother to merge typestate; just reset to the dominator state 1148 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length); 1149 1150 return invokeBasicName; // return what's on stack 1151 } 1152 1153 /** 1154 * Emit bytecode for the guardWithCatch idiom. 1155 * 1156 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithCatch): 1157 * <blockquote><pre>{@code 1158 * guardWithCatch=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L,a5:L,a6:L,a7:L)=>{ 1159 * t8:L=MethodHandle.invokeBasic(a4:L,a6:L,a7:L); 1160 * t9:L=MethodHandleImpl.guardWithCatch(a1:L,a2:L,a3:L,t8:L); 1161 * t10:I=MethodHandle.invokeBasic(a5:L,t9:L);t10:I} 1162 * }</pre></blockquote> 1163 * 1164 * It is compiled into bytecode equivalent of the following code: 1165 * <blockquote><pre>{@code 1166 * try { 1167 * return a1.invokeBasic(a6, a7); 1168 * } catch (Throwable e) { 1169 * if (!a2.isInstance(e)) throw e; 1170 * return a3.invokeBasic(ex, a6, a7); 1171 * }}</pre></blockquote> 1172 */ 1173 private Name emitGuardWithCatch(int pos) { 1174 Name args = lambdaForm.names[pos]; 1175 Name invoker = lambdaForm.names[pos+1]; 1176 Name result = lambdaForm.names[pos+2]; 1177 1178 Label L_startBlock = new Label(); 1179 Label L_endBlock = new Label(); 1180 Label L_handler = new Label(); 1181 Label L_done = new Label(); 1182 1183 Class<?> returnType = result.function.resolvedHandle().type().returnType(); 1184 MethodType type = args.function.resolvedHandle().type() 1185 .dropParameterTypes(0,1) 1186 .changeReturnType(returnType); 1187 1188 mv.visitTryCatchBlock(L_startBlock, L_endBlock, L_handler, "java/lang/Throwable"); 1189 1190 // Normal case 1191 mv.visitLabel(L_startBlock); 1192 // load target 1193 emitPushArgument(invoker, 0); 1194 emitPushArguments(args, 1); // skip 1st argument: method handle 1195 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false); 1196 mv.visitLabel(L_endBlock); 1197 mv.visitJumpInsn(Opcodes.GOTO, L_done); 1198 1199 // Exceptional case 1200 mv.visitLabel(L_handler); 1201 1202 // Check exception's type 1203 mv.visitInsn(Opcodes.DUP); 1204 // load exception class 1205 emitPushArgument(invoker, 1); 1206 mv.visitInsn(Opcodes.SWAP); 1207 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/Class", "isInstance", "(Ljava/lang/Object;)Z", false); 1208 Label L_rethrow = new Label(); 1209 mv.visitJumpInsn(Opcodes.IFEQ, L_rethrow); 1210 1211 // Invoke catcher 1212 // load catcher 1213 emitPushArgument(invoker, 2); 1214 mv.visitInsn(Opcodes.SWAP); 1215 emitPushArguments(args, 1); // skip 1st argument: method handle 1216 MethodType catcherType = type.insertParameterTypes(0, Throwable.class); 1217 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", catcherType.basicType().toMethodDescriptorString(), false); 1218 mv.visitJumpInsn(Opcodes.GOTO, L_done); 1219 1220 mv.visitLabel(L_rethrow); 1221 mv.visitInsn(Opcodes.ATHROW); 1222 1223 mv.visitLabel(L_done); 1224 1225 return result; 1226 } 1227 1228 /** 1229 * Emit bytecode for the tryFinally idiom. 1230 * <p> 1231 * The pattern looks like (Cf. MethodHandleImpl.makeTryFinally): 1232 * <blockquote><pre>{@code 1233 * // a0: BMH 1234 * // a1: target, a2: cleanup 1235 * // a3: box, a4: unbox 1236 * // a5 (and following): arguments 1237 * tryFinally=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L,a5:L)=>{ 1238 * t6:L=MethodHandle.invokeBasic(a3:L,a5:L); // box the arguments into an Object[] 1239 * t7:L=MethodHandleImpl.tryFinally(a1:L,a2:L,t6:L); // call the tryFinally executor 1240 * t8:L=MethodHandle.invokeBasic(a4:L,t7:L);t8:L} // unbox the result; return the result 1241 * }</pre></blockquote> 1242 * <p> 1243 * It is compiled into bytecode equivalent to the following code: 1244 * <blockquote><pre>{@code 1245 * Throwable t; 1246 * Object r; 1247 * try { 1248 * r = a1.invokeBasic(a5); 1249 * } catch (Throwable thrown) { 1250 * t = thrown; 1251 * throw t; 1252 * } finally { 1253 * r = a2.invokeBasic(t, r, a5); 1254 * } 1255 * return r; 1256 * }</pre></blockquote> 1257 * <p> 1258 * Specifically, the bytecode will have the following form (the stack effects are given for the beginnings of 1259 * blocks, and for the situations after executing the given instruction - the code will have a slightly different 1260 * shape if the return type is {@code void}): 1261 * <blockquote><pre>{@code 1262 * TRY: (--) 1263 * load target (-- target) 1264 * load args (-- args... target) 1265 * INVOKEVIRTUAL MethodHandle.invokeBasic (depends) 1266 * FINALLY_NORMAL: (-- r_2nd* r) 1267 * store returned value (--) 1268 * load cleanup (-- cleanup) 1269 * ACONST_NULL (-- t cleanup) 1270 * load returned value (-- r_2nd* r t cleanup) 1271 * load args (-- args... r_2nd* r t cleanup) 1272 * INVOKEVIRTUAL MethodHandle.invokeBasic (-- r_2nd* r) 1273 * GOTO DONE 1274 * CATCH: (-- t) 1275 * DUP (-- t t) 1276 * FINALLY_EXCEPTIONAL: (-- t t) 1277 * load cleanup (-- cleanup t t) 1278 * SWAP (-- t cleanup t) 1279 * load default for r (-- r_2nd* r t cleanup t) 1280 * load args (-- args... r_2nd* r t cleanup t) 1281 * INVOKEVIRTUAL MethodHandle.invokeBasic (-- r_2nd* r t) 1282 * POP/POP2* (-- t) 1283 * ATHROW 1284 * DONE: (-- r) 1285 * }</pre></blockquote> 1286 * * = depends on whether the return type takes up 2 stack slots. 1287 */ 1288 private Name emitTryFinally(int pos) { 1289 Name args = lambdaForm.names[pos]; 1290 Name invoker = lambdaForm.names[pos+1]; 1291 Name result = lambdaForm.names[pos+2]; 1292 1293 Label lFrom = new Label(); 1294 Label lTo = new Label(); 1295 Label lCatch = new Label(); 1296 Label lDone = new Label(); 1297 1298 Class<?> returnType = result.function.resolvedHandle().type().returnType(); 1299 BasicType basicReturnType = BasicType.basicType(returnType); 1300 boolean isNonVoid = returnType != void.class; 1301 1302 MethodType type = args.function.resolvedHandle().type() 1303 .dropParameterTypes(0,1) 1304 .changeReturnType(returnType); 1305 MethodType cleanupType = type.insertParameterTypes(0, Throwable.class); 1306 if (isNonVoid) { 1307 cleanupType = cleanupType.insertParameterTypes(1, returnType); 1308 } 1309 String cleanupDesc = cleanupType.basicType().toMethodDescriptorString(); 1310 1311 // exception handler table 1312 mv.visitTryCatchBlock(lFrom, lTo, lCatch, "java/lang/Throwable"); 1313 1314 // TRY: 1315 mv.visitLabel(lFrom); 1316 emitPushArgument(invoker, 0); // load target 1317 emitPushArguments(args, 1); // load args (skip 0: method handle) 1318 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false); 1319 mv.visitLabel(lTo); 1320 1321 // FINALLY_NORMAL: 1322 int index = extendLocalsMap(new Class<?>[]{ returnType }); 1323 if (isNonVoid) { 1324 emitStoreInsn(basicReturnType, index); 1325 } 1326 emitPushArgument(invoker, 1); // load cleanup 1327 mv.visitInsn(Opcodes.ACONST_NULL); 1328 if (isNonVoid) { 1329 emitLoadInsn(basicReturnType, index); 1330 } 1331 emitPushArguments(args, 1); // load args (skip 0: method handle) 1332 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", cleanupDesc, false); 1333 mv.visitJumpInsn(Opcodes.GOTO, lDone); 1334 1335 // CATCH: 1336 mv.visitLabel(lCatch); 1337 mv.visitInsn(Opcodes.DUP); 1338 1339 // FINALLY_EXCEPTIONAL: 1340 emitPushArgument(invoker, 1); // load cleanup 1341 mv.visitInsn(Opcodes.SWAP); 1342 if (isNonVoid) { 1343 emitZero(BasicType.basicType(returnType)); // load default for result 1344 } 1345 emitPushArguments(args, 1); // load args (skip 0: method handle) 1346 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", cleanupDesc, false); 1347 if (isNonVoid) { 1348 emitPopInsn(basicReturnType); 1349 } 1350 mv.visitInsn(Opcodes.ATHROW); 1351 1352 // DONE: 1353 mv.visitLabel(lDone); 1354 1355 return result; 1356 } 1357 1358 private void emitPopInsn(BasicType type) { 1359 mv.visitInsn(popInsnOpcode(type)); 1360 } 1361 1362 private static int popInsnOpcode(BasicType type) { 1363 switch (type) { 1364 case I_TYPE: 1365 case F_TYPE: 1366 case L_TYPE: 1367 return Opcodes.POP; 1368 case J_TYPE: 1369 case D_TYPE: 1370 return Opcodes.POP2; 1371 default: 1372 throw new InternalError("unknown type: " + type); 1373 } 1374 } 1375 1376 /** 1377 * Emit bytecode for the loop idiom. 1378 * <p> 1379 * The pattern looks like (Cf. MethodHandleImpl.loop): 1380 * <blockquote><pre>{@code 1381 * // a0: BMH 1382 * // a1: LoopClauses (containing an array of arrays: inits, steps, preds, finis) 1383 * // a2: box, a3: unbox 1384 * // a4 (and following): arguments 1385 * loop=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L)=>{ 1386 * t5:L=MethodHandle.invokeBasic(a2:L,a4:L); // box the arguments into an Object[] 1387 * t6:L=MethodHandleImpl.loop(bt:L,a1:L,t5:L); // call the loop executor (with supplied types in bt) 1388 * t7:L=MethodHandle.invokeBasic(a3:L,t6:L);t7:L} // unbox the result; return the result 1389 * }</pre></blockquote> 1390 * <p> 1391 * It is compiled into bytecode equivalent to the code seen in {@link MethodHandleImpl#loop(BasicType[], 1392 * MethodHandleImpl.LoopClauses, Object...)}, with the difference that no arrays 1393 * will be used for local state storage. Instead, the local state will be mapped to actual stack slots. 1394 * <p> 1395 * Bytecode generation applies an unrolling scheme to enable better bytecode generation regarding local state type 1396 * handling. The generated bytecode will have the following form ({@code void} types are ignored for convenience). 1397 * Assume there are {@code C} clauses in the loop. 1398 * <blockquote><pre>{@code 1399 * PREINIT: ALOAD_1 1400 * CHECKCAST LoopClauses 1401 * GETFIELD LoopClauses.clauses 1402 * ASTORE clauseDataIndex // place the clauses 2-dimensional array on the stack 1403 * INIT: (INIT_SEQ for clause 1) 1404 * ... 1405 * (INIT_SEQ for clause C) 1406 * LOOP: (LOOP_SEQ for clause 1) 1407 * ... 1408 * (LOOP_SEQ for clause C) 1409 * GOTO LOOP 1410 * DONE: ... 1411 * }</pre></blockquote> 1412 * <p> 1413 * The {@code INIT_SEQ_x} sequence for clause {@code x} (with {@code x} ranging from {@code 0} to {@code C-1}) has 1414 * the following shape. Assume slot {@code vx} is used to hold the state for clause {@code x}. 1415 * <blockquote><pre>{@code 1416 * INIT_SEQ_x: ALOAD clauseDataIndex 1417 * ICONST_0 1418 * AALOAD // load the inits array 1419 * ICONST x 1420 * AALOAD // load the init handle for clause x 1421 * load args 1422 * INVOKEVIRTUAL MethodHandle.invokeBasic 1423 * store vx 1424 * }</pre></blockquote> 1425 * <p> 1426 * The {@code LOOP_SEQ_x} sequence for clause {@code x} (with {@code x} ranging from {@code 0} to {@code C-1}) has 1427 * the following shape. Again, assume slot {@code vx} is used to hold the state for clause {@code x}. 1428 * <blockquote><pre>{@code 1429 * LOOP_SEQ_x: ALOAD clauseDataIndex 1430 * ICONST_1 1431 * AALOAD // load the steps array 1432 * ICONST x 1433 * AALOAD // load the step handle for clause x 1434 * load locals 1435 * load args 1436 * INVOKEVIRTUAL MethodHandle.invokeBasic 1437 * store vx 1438 * ALOAD clauseDataIndex 1439 * ICONST_2 1440 * AALOAD // load the preds array 1441 * ICONST x 1442 * AALOAD // load the pred handle for clause x 1443 * load locals 1444 * load args 1445 * INVOKEVIRTUAL MethodHandle.invokeBasic 1446 * IFNE LOOP_SEQ_x+1 // predicate returned false -> jump to next clause 1447 * ALOAD clauseDataIndex 1448 * ICONST_3 1449 * AALOAD // load the finis array 1450 * ICONST x 1451 * AALOAD // load the fini handle for clause x 1452 * load locals 1453 * load args 1454 * INVOKEVIRTUAL MethodHandle.invokeBasic 1455 * GOTO DONE // jump beyond end of clauses to return from loop 1456 * }</pre></blockquote> 1457 */ 1458 private Name emitLoop(int pos) { 1459 Name args = lambdaForm.names[pos]; 1460 Name invoker = lambdaForm.names[pos+1]; 1461 Name result = lambdaForm.names[pos+2]; 1462 1463 // extract clause and loop-local state types 1464 // find the type info in the loop invocation 1465 BasicType[] loopClauseTypes = (BasicType[]) invoker.arguments[0]; 1466 Class<?>[] loopLocalStateTypes = Stream.of(loopClauseTypes). 1467 filter(bt -> bt != BasicType.V_TYPE).map(BasicType::basicTypeClass).toArray(Class<?>[]::new); 1468 Class<?>[] localTypes = new Class<?>[loopLocalStateTypes.length + 1]; 1469 localTypes[0] = MethodHandleImpl.LoopClauses.class; 1470 System.arraycopy(loopLocalStateTypes, 0, localTypes, 1, loopLocalStateTypes.length); 1471 1472 final int clauseDataIndex = extendLocalsMap(localTypes); 1473 final int firstLoopStateIndex = clauseDataIndex + 1; 1474 1475 Class<?> returnType = result.function.resolvedHandle().type().returnType(); 1476 MethodType loopType = args.function.resolvedHandle().type() 1477 .dropParameterTypes(0,1) 1478 .changeReturnType(returnType); 1479 MethodType loopHandleType = loopType.insertParameterTypes(0, loopLocalStateTypes); 1480 MethodType predType = loopHandleType.changeReturnType(boolean.class); 1481 MethodType finiType = loopHandleType; 1482 1483 final int nClauses = loopClauseTypes.length; 1484 1485 // indices to invoker arguments to load method handle arrays 1486 final int inits = 1; 1487 final int steps = 2; 1488 final int preds = 3; 1489 final int finis = 4; 1490 1491 Label lLoop = new Label(); 1492 Label lDone = new Label(); 1493 Label lNext; 1494 1495 // PREINIT: 1496 emitPushArgument(MethodHandleImpl.LoopClauses.class, invoker.arguments[1]); 1497 mv.visitFieldInsn(Opcodes.GETFIELD, LOOP_CLAUSES, "clauses", MHARY2); 1498 emitAstoreInsn(clauseDataIndex); 1499 1500 // INIT: 1501 for (int c = 0, state = 0; c < nClauses; ++c) { 1502 MethodType cInitType = loopType.changeReturnType(loopClauseTypes[c].basicTypeClass()); 1503 emitLoopHandleInvoke(invoker, inits, c, args, false, cInitType, loopLocalStateTypes, clauseDataIndex, 1504 firstLoopStateIndex); 1505 if (cInitType.returnType() != void.class) { 1506 emitStoreInsn(BasicType.basicType(cInitType.returnType()), firstLoopStateIndex + state); 1507 ++state; 1508 } 1509 } 1510 1511 // LOOP: 1512 mv.visitLabel(lLoop); 1513 1514 for (int c = 0, state = 0; c < nClauses; ++c) { 1515 lNext = new Label(); 1516 1517 MethodType stepType = loopHandleType.changeReturnType(loopClauseTypes[c].basicTypeClass()); 1518 boolean isVoid = stepType.returnType() == void.class; 1519 1520 // invoke loop step 1521 emitLoopHandleInvoke(invoker, steps, c, args, true, stepType, loopLocalStateTypes, clauseDataIndex, 1522 firstLoopStateIndex); 1523 if (!isVoid) { 1524 emitStoreInsn(BasicType.basicType(stepType.returnType()), firstLoopStateIndex + state); 1525 ++state; 1526 } 1527 1528 // invoke loop predicate 1529 emitLoopHandleInvoke(invoker, preds, c, args, true, predType, loopLocalStateTypes, clauseDataIndex, 1530 firstLoopStateIndex); 1531 mv.visitJumpInsn(Opcodes.IFNE, lNext); 1532 1533 // invoke fini 1534 emitLoopHandleInvoke(invoker, finis, c, args, true, finiType, loopLocalStateTypes, clauseDataIndex, 1535 firstLoopStateIndex); 1536 mv.visitJumpInsn(Opcodes.GOTO, lDone); 1537 1538 // this is the beginning of the next loop clause 1539 mv.visitLabel(lNext); 1540 } 1541 1542 mv.visitJumpInsn(Opcodes.GOTO, lLoop); 1543 1544 // DONE: 1545 mv.visitLabel(lDone); 1546 1547 return result; 1548 } 1549 1550 private int extendLocalsMap(Class<?>[] types) { 1551 int firstSlot = localsMap.length - 1; 1552 localsMap = Arrays.copyOf(localsMap, localsMap.length + types.length); 1553 localClasses = Arrays.copyOf(localClasses, localClasses.length + types.length); 1554 System.arraycopy(types, 0, localClasses, firstSlot, types.length); 1555 int index = localsMap[firstSlot - 1] + 1; 1556 int lastSlots = 0; 1557 for (int i = 0; i < types.length; ++i) { 1558 localsMap[firstSlot + i] = index; 1559 lastSlots = BasicType.basicType(localClasses[firstSlot + i]).basicTypeSlots(); 1560 index += lastSlots; 1561 } 1562 localsMap[localsMap.length - 1] = index - lastSlots; 1563 return firstSlot; 1564 } 1565 1566 private void emitLoopHandleInvoke(Name holder, int handles, int clause, Name args, boolean pushLocalState, 1567 MethodType type, Class<?>[] loopLocalStateTypes, int clauseDataSlot, 1568 int firstLoopStateSlot) { 1569 // load handle for clause 1570 emitPushClauseArray(clauseDataSlot, handles); 1571 emitIconstInsn(clause); 1572 mv.visitInsn(Opcodes.AALOAD); 1573 // load loop state (preceding the other arguments) 1574 if (pushLocalState) { 1575 for (int s = 0; s < loopLocalStateTypes.length; ++s) { 1576 emitLoadInsn(BasicType.basicType(loopLocalStateTypes[s]), firstLoopStateSlot + s); 1577 } 1578 } 1579 // load loop args (skip 0: method handle) 1580 emitPushArguments(args, 1); 1581 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.toMethodDescriptorString(), false); 1582 } 1583 1584 private void emitPushClauseArray(int clauseDataSlot, int which) { 1585 emitAloadInsn(clauseDataSlot); 1586 emitIconstInsn(which - 1); 1587 mv.visitInsn(Opcodes.AALOAD); 1588 } 1589 1590 private void emitZero(BasicType type) { 1591 switch (type) { 1592 case I_TYPE: mv.visitInsn(Opcodes.ICONST_0); break; 1593 case J_TYPE: mv.visitInsn(Opcodes.LCONST_0); break; 1594 case F_TYPE: mv.visitInsn(Opcodes.FCONST_0); break; 1595 case D_TYPE: mv.visitInsn(Opcodes.DCONST_0); break; 1596 case L_TYPE: mv.visitInsn(Opcodes.ACONST_NULL); break; 1597 default: throw new InternalError("unknown type: " + type); 1598 } 1599 } 1600 1601 private void emitPushArguments(Name args, int start) { 1602 MethodType type = args.function.methodType(); 1603 for (int i = start; i < args.arguments.length; i++) { 1604 emitPushArgument(type.parameterType(i), args.arguments[i]); 1605 } 1606 } 1607 1608 private void emitPushArgument(Name name, int paramIndex) { 1609 Object arg = name.arguments[paramIndex]; 1610 Class<?> ptype = name.function.methodType().parameterType(paramIndex); 1611 emitPushArgument(ptype, arg); 1612 } 1613 1614 private void emitPushArgument(Class<?> ptype, Object arg) { 1615 BasicType bptype = basicType(ptype); 1616 if (arg instanceof Name) { 1617 Name n = (Name) arg; 1618 emitLoadInsn(n.type, n.index()); 1619 emitImplicitConversion(n.type, ptype, n); 1620 } else if ((arg == null || arg instanceof String) && bptype == L_TYPE) { 1621 emitConst(arg); 1622 } else { 1623 if (Wrapper.isWrapperType(arg.getClass()) && bptype != L_TYPE) { 1624 emitConst(arg); 1625 } else { 1626 mv.visitLdcInsn(constantPlaceholder(arg)); 1627 emitImplicitConversion(L_TYPE, ptype, arg); 1628 } 1629 } 1630 } 1631 1632 /** 1633 * Store the name to its local, if necessary. 1634 */ 1635 private void emitStoreResult(Name name) { 1636 if (name != null && name.type != V_TYPE) { 1637 // non-void: actually assign 1638 emitStoreInsn(name.type, name.index()); 1639 } 1640 } 1641 1642 /** 1643 * Emits a return statement from a LF invoker. If required, the result type is cast to the correct return type. 1644 */ 1645 private void emitReturn(Name onStack) { 1646 // return statement 1647 Class<?> rclass = invokerType.returnType(); 1648 BasicType rtype = lambdaForm.returnType(); 1649 assert(rtype == basicType(rclass)); // must agree 1650 if (rtype == V_TYPE) { 1651 // void 1652 mv.visitInsn(Opcodes.RETURN); 1653 // it doesn't matter what rclass is; the JVM will discard any value 1654 } else { 1655 LambdaForm.Name rn = lambdaForm.names[lambdaForm.result]; 1656 1657 // put return value on the stack if it is not already there 1658 if (rn != onStack) { 1659 emitLoadInsn(rtype, lambdaForm.result); 1660 } 1661 1662 emitImplicitConversion(rtype, rclass, rn); 1663 1664 // generate actual return statement 1665 emitReturnInsn(rtype); 1666 } 1667 } 1668 1669 /** 1670 * Emit a type conversion bytecode casting from "from" to "to". 1671 */ 1672 private void emitPrimCast(Wrapper from, Wrapper to) { 1673 // Here's how. 1674 // - indicates forbidden 1675 // <-> indicates implicit 1676 // to ----> boolean byte short char int long float double 1677 // from boolean <-> - - - - - - - 1678 // byte - <-> i2s i2c <-> i2l i2f i2d 1679 // short - i2b <-> i2c <-> i2l i2f i2d 1680 // char - i2b i2s <-> <-> i2l i2f i2d 1681 // int - i2b i2s i2c <-> i2l i2f i2d 1682 // long - l2i,i2b l2i,i2s l2i,i2c l2i <-> l2f l2d 1683 // float - f2i,i2b f2i,i2s f2i,i2c f2i f2l <-> f2d 1684 // double - d2i,i2b d2i,i2s d2i,i2c d2i d2l d2f <-> 1685 if (from == to) { 1686 // no cast required, should be dead code anyway 1687 return; 1688 } 1689 if (from.isSubwordOrInt()) { 1690 // cast from {byte,short,char,int} to anything 1691 emitI2X(to); 1692 } else { 1693 // cast from {long,float,double} to anything 1694 if (to.isSubwordOrInt()) { 1695 // cast to {byte,short,char,int} 1696 emitX2I(from); 1697 if (to.bitWidth() < 32) { 1698 // targets other than int require another conversion 1699 emitI2X(to); 1700 } 1701 } else { 1702 // cast to {long,float,double} - this is verbose 1703 boolean error = false; 1704 switch (from) { 1705 case LONG: 1706 switch (to) { 1707 case FLOAT: mv.visitInsn(Opcodes.L2F); break; 1708 case DOUBLE: mv.visitInsn(Opcodes.L2D); break; 1709 default: error = true; break; 1710 } 1711 break; 1712 case FLOAT: 1713 switch (to) { 1714 case LONG : mv.visitInsn(Opcodes.F2L); break; 1715 case DOUBLE: mv.visitInsn(Opcodes.F2D); break; 1716 default: error = true; break; 1717 } 1718 break; 1719 case DOUBLE: 1720 switch (to) { 1721 case LONG : mv.visitInsn(Opcodes.D2L); break; 1722 case FLOAT: mv.visitInsn(Opcodes.D2F); break; 1723 default: error = true; break; 1724 } 1725 break; 1726 default: 1727 error = true; 1728 break; 1729 } 1730 if (error) { 1731 throw new IllegalStateException("unhandled prim cast: " + from + "2" + to); 1732 } 1733 } 1734 } 1735 } 1736 1737 private void emitI2X(Wrapper type) { 1738 switch (type) { 1739 case BYTE: mv.visitInsn(Opcodes.I2B); break; 1740 case SHORT: mv.visitInsn(Opcodes.I2S); break; 1741 case CHAR: mv.visitInsn(Opcodes.I2C); break; 1742 case INT: /* naught */ break; 1743 case LONG: mv.visitInsn(Opcodes.I2L); break; 1744 case FLOAT: mv.visitInsn(Opcodes.I2F); break; 1745 case DOUBLE: mv.visitInsn(Opcodes.I2D); break; 1746 case BOOLEAN: 1747 // For compatibility with ValueConversions and explicitCastArguments: 1748 mv.visitInsn(Opcodes.ICONST_1); 1749 mv.visitInsn(Opcodes.IAND); 1750 break; 1751 default: throw new InternalError("unknown type: " + type); 1752 } 1753 } 1754 1755 private void emitX2I(Wrapper type) { 1756 switch (type) { 1757 case LONG: mv.visitInsn(Opcodes.L2I); break; 1758 case FLOAT: mv.visitInsn(Opcodes.F2I); break; 1759 case DOUBLE: mv.visitInsn(Opcodes.D2I); break; 1760 default: throw new InternalError("unknown type: " + type); 1761 } 1762 } 1763 1764 /** 1765 * Generate bytecode for a LambdaForm.vmentry which calls interpretWithArguments. 1766 */ 1767 static MemberName generateLambdaFormInterpreterEntryPoint(MethodType mt) { 1768 assert(isValidSignature(basicTypeSignature(mt))); 1769 String name = "interpret_"+basicTypeChar(mt.returnType()); 1770 MethodType type = mt; // includes leading argument 1771 type = type.changeParameterType(0, MethodHandle.class); 1772 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("LFI", name, type); 1773 return g.loadMethod(g.generateLambdaFormInterpreterEntryPointBytes()); 1774 } 1775 1776 private byte[] generateLambdaFormInterpreterEntryPointBytes() { 1777 classFilePrologue(); 1778 methodPrologue(); 1779 1780 // Suppress this method in backtraces displayed to the user. 1781 mv.visitAnnotation(HIDDEN_SIG, true); 1782 1783 // Don't inline the interpreter entry. 1784 mv.visitAnnotation(DONTINLINE_SIG, true); 1785 1786 // create parameter array 1787 emitIconstInsn(invokerType.parameterCount()); 1788 mv.visitTypeInsn(Opcodes.ANEWARRAY, "java/lang/Object"); 1789 1790 // fill parameter array 1791 for (int i = 0; i < invokerType.parameterCount(); i++) { 1792 Class<?> ptype = invokerType.parameterType(i); 1793 mv.visitInsn(Opcodes.DUP); 1794 emitIconstInsn(i); 1795 emitLoadInsn(basicType(ptype), i); 1796 // box if primitive type 1797 if (ptype.isPrimitive()) { 1798 emitBoxing(Wrapper.forPrimitiveType(ptype)); 1799 } 1800 mv.visitInsn(Opcodes.AASTORE); 1801 } 1802 // invoke 1803 emitAloadInsn(0); 1804 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", "Ljava/lang/invoke/LambdaForm;"); 1805 mv.visitInsn(Opcodes.SWAP); // swap form and array; avoid local variable 1806 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, LF, "interpretWithArguments", "([Ljava/lang/Object;)Ljava/lang/Object;", false); 1807 1808 // maybe unbox 1809 Class<?> rtype = invokerType.returnType(); 1810 if (rtype.isPrimitive() && rtype != void.class) { 1811 emitUnboxing(Wrapper.forPrimitiveType(rtype)); 1812 } 1813 1814 // return statement 1815 emitReturnInsn(basicType(rtype)); 1816 1817 methodEpilogue(); 1818 bogusMethod(invokerType); 1819 1820 final byte[] classFile = cw.toByteArray(); 1821 maybeDump(classFile); 1822 return classFile; 1823 } 1824 1825 /** 1826 * Generate bytecode for a NamedFunction invoker. 1827 */ 1828 static MemberName generateNamedFunctionInvoker(MethodTypeForm typeForm) { 1829 MethodType invokerType = NamedFunction.INVOKER_METHOD_TYPE; 1830 String invokerName = "invoke_" + shortenSignature(basicTypeSignature(typeForm.erasedType())); 1831 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("NFI", invokerName, invokerType); 1832 return g.loadMethod(g.generateNamedFunctionInvokerImpl(typeForm)); 1833 } 1834 1835 private byte[] generateNamedFunctionInvokerImpl(MethodTypeForm typeForm) { 1836 MethodType dstType = typeForm.erasedType(); 1837 classFilePrologue(); 1838 methodPrologue(); 1839 1840 // Suppress this method in backtraces displayed to the user. 1841 mv.visitAnnotation(HIDDEN_SIG, true); 1842 1843 // Force inlining of this invoker method. 1844 mv.visitAnnotation(FORCEINLINE_SIG, true); 1845 1846 // Load receiver 1847 emitAloadInsn(0); 1848 1849 // Load arguments from array 1850 for (int i = 0; i < dstType.parameterCount(); i++) { 1851 emitAloadInsn(1); 1852 emitIconstInsn(i); 1853 mv.visitInsn(Opcodes.AALOAD); 1854 1855 // Maybe unbox 1856 Class<?> dptype = dstType.parameterType(i); 1857 if (dptype.isPrimitive()) { 1858 Wrapper dstWrapper = Wrapper.forBasicType(dptype); 1859 Wrapper srcWrapper = dstWrapper.isSubwordOrInt() ? Wrapper.INT : dstWrapper; // narrow subword from int 1860 emitUnboxing(srcWrapper); 1861 emitPrimCast(srcWrapper, dstWrapper); 1862 } 1863 } 1864 1865 // Invoke 1866 String targetDesc = dstType.basicType().toMethodDescriptorString(); 1867 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", targetDesc, false); 1868 1869 // Box primitive types 1870 Class<?> rtype = dstType.returnType(); 1871 if (rtype != void.class && rtype.isPrimitive()) { 1872 Wrapper srcWrapper = Wrapper.forBasicType(rtype); 1873 Wrapper dstWrapper = srcWrapper.isSubwordOrInt() ? Wrapper.INT : srcWrapper; // widen subword to int 1874 // boolean casts not allowed 1875 emitPrimCast(srcWrapper, dstWrapper); 1876 emitBoxing(dstWrapper); 1877 } 1878 1879 // If the return type is void we return a null reference. 1880 if (rtype == void.class) { 1881 mv.visitInsn(Opcodes.ACONST_NULL); 1882 } 1883 emitReturnInsn(L_TYPE); // NOTE: NamedFunction invokers always return a reference value. 1884 1885 methodEpilogue(); 1886 bogusMethod(dstType); 1887 1888 final byte[] classFile = cw.toByteArray(); 1889 maybeDump(classFile); 1890 return classFile; 1891 } 1892 1893 /** 1894 * Emit a bogus method that just loads some string constants. This is to get the constants into the constant pool 1895 * for debugging purposes. 1896 */ 1897 private void bogusMethod(Object os) { 1898 if (DUMP_CLASS_FILES) { 1899 mv = cw.visitMethod(Opcodes.ACC_STATIC, "dummy", "()V", null, null); 1900 mv.visitLdcInsn(os.toString()); 1901 mv.visitInsn(Opcodes.POP); 1902 mv.visitInsn(Opcodes.RETURN); 1903 mv.visitMaxs(0, 0); 1904 mv.visitEnd(); 1905 } 1906 } 1907 }