1 /* 2 * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package java.lang.invoke; 27 28 import java.io.*; 29 import java.util.*; 30 import java.lang.reflect.Modifier; 31 32 import jdk.internal.org.objectweb.asm.*; 33 34 import static java.lang.invoke.LambdaForm.*; 35 import static java.lang.invoke.LambdaForm.BasicType.*; 36 import static java.lang.invoke.MethodHandleStatics.*; 37 import static java.lang.invoke.MethodHandleNatives.Constants.*; 38 39 import sun.invoke.util.VerifyAccess; 40 import sun.invoke.util.VerifyType; 41 import sun.invoke.util.Wrapper; 42 import sun.reflect.misc.ReflectUtil; 43 44 /** 45 * Code generation backend for LambdaForm. 46 * <p> 47 * @author John Rose, JSR 292 EG 48 */ 49 class InvokerBytecodeGenerator { 50 /** Define class names for convenience. */ 51 private static final String MH = "java/lang/invoke/MethodHandle"; 52 private static final String MHI = "java/lang/invoke/MethodHandleImpl"; 53 private static final String LF = "java/lang/invoke/LambdaForm"; 54 private static final String LFN = "java/lang/invoke/LambdaForm$Name"; 55 private static final String CLS = "java/lang/Class"; 56 private static final String OBJ = "java/lang/Object"; 57 private static final String OBJARY = "[Ljava/lang/Object;"; 58 59 private static final String MH_SIG = "L" + MH + ";"; 60 private static final String LF_SIG = "L" + LF + ";"; 61 private static final String LFN_SIG = "L" + LFN + ";"; 62 private static final String LL_SIG = "(L" + OBJ + ";)L" + OBJ + ";"; 63 private static final String LLV_SIG = "(L" + OBJ + ";L" + OBJ + ";)V"; 64 private static final String CLL_SIG = "(L" + CLS + ";L" + OBJ + ";)L" + OBJ + ";"; 65 66 /** Name of its super class*/ 67 private static final String superName = OBJ; 68 69 /** Name of new class */ 70 private final String className; 71 72 /** Name of the source file (for stack trace printing). */ 73 private final String sourceFile; 74 75 private final LambdaForm lambdaForm; 76 private final String invokerName; 77 private final MethodType invokerType; 78 79 /** Info about local variables in compiled lambda form */ 80 private final int[] localsMap; // index 81 private final BasicType[] localTypes; // basic type 82 private final Class<?>[] localClasses; // type 83 84 /** ASM bytecode generation. */ 85 private ClassWriter cw; 86 private MethodVisitor mv; 87 88 private static final MemberName.Factory MEMBERNAME_FACTORY = MemberName.getFactory(); 89 private static final Class<?> HOST_CLASS = LambdaForm.class; 90 91 /** Main constructor; other constructors delegate to this one. */ InvokerBytecodeGenerator(LambdaForm lambdaForm, int localsMapSize, String className, String invokerName, MethodType invokerType)92 private InvokerBytecodeGenerator(LambdaForm lambdaForm, int localsMapSize, 93 String className, String invokerName, MethodType invokerType) { 94 if (invokerName.contains(".")) { 95 int p = invokerName.indexOf("."); 96 className = invokerName.substring(0, p); 97 invokerName = invokerName.substring(p+1); 98 } 99 if (DUMP_CLASS_FILES) { 100 className = makeDumpableClassName(className); 101 } 102 this.className = LF + "$" + className; 103 this.sourceFile = "LambdaForm$" + className; 104 this.lambdaForm = lambdaForm; 105 this.invokerName = invokerName; 106 this.invokerType = invokerType; 107 this.localsMap = new int[localsMapSize+1]; 108 // last entry of localsMap is count of allocated local slots 109 this.localTypes = new BasicType[localsMapSize+1]; 110 this.localClasses = new Class<?>[localsMapSize+1]; 111 } 112 113 /** For generating LambdaForm interpreter entry points. */ InvokerBytecodeGenerator(String className, String invokerName, MethodType invokerType)114 private InvokerBytecodeGenerator(String className, String invokerName, MethodType invokerType) { 115 this(null, invokerType.parameterCount(), 116 className, invokerName, invokerType); 117 // Create an array to map name indexes to locals indexes. 118 localTypes[localTypes.length - 1] = V_TYPE; 119 for (int i = 0; i < localsMap.length; i++) { 120 localsMap[i] = invokerType.parameterSlotCount() - invokerType.parameterSlotDepth(i); 121 if (i < invokerType.parameterCount()) 122 localTypes[i] = basicType(invokerType.parameterType(i)); 123 } 124 } 125 126 /** For generating customized code for a single LambdaForm. */ InvokerBytecodeGenerator(String className, LambdaForm form, MethodType invokerType)127 private InvokerBytecodeGenerator(String className, LambdaForm form, MethodType invokerType) { 128 this(form, form.names.length, 129 className, form.debugName, invokerType); 130 // Create an array to map name indexes to locals indexes. 131 Name[] names = form.names; 132 for (int i = 0, index = 0; i < localsMap.length; i++) { 133 localsMap[i] = index; 134 if (i < names.length) { 135 BasicType type = names[i].type(); 136 index += type.basicTypeSlots(); 137 localTypes[i] = type; 138 } 139 } 140 } 141 142 143 /** instance counters for dumped classes */ 144 private final static HashMap<String,Integer> DUMP_CLASS_FILES_COUNTERS; 145 /** debugging flag for saving generated class files */ 146 private final static File DUMP_CLASS_FILES_DIR; 147 148 static { 149 if (DUMP_CLASS_FILES) { 150 DUMP_CLASS_FILES_COUNTERS = new HashMap<>(); 151 try { 152 File dumpDir = new File("DUMP_CLASS_FILES"); 153 if (!dumpDir.exists()) { dumpDir.mkdirs()154 dumpDir.mkdirs(); 155 } 156 DUMP_CLASS_FILES_DIR = dumpDir; 157 System.out.println("Dumping class files to "+DUMP_CLASS_FILES_DIR+"/..."); 158 } catch (Exception e) { 159 throw newInternalError(e); 160 } 161 } else { 162 DUMP_CLASS_FILES_COUNTERS = null; 163 DUMP_CLASS_FILES_DIR = null; 164 } 165 } 166 maybeDump(final String className, final byte[] classFile)167 static void maybeDump(final String className, final byte[] classFile) { 168 if (DUMP_CLASS_FILES) { 169 java.security.AccessController.doPrivileged( 170 new java.security.PrivilegedAction<Void>() { 171 public Void run() { 172 try { 173 String dumpName = className; 174 //dumpName = dumpName.replace('/', '-'); 175 File dumpFile = new File(DUMP_CLASS_FILES_DIR, dumpName+".class"); 176 System.out.println("dump: " + dumpFile); 177 dumpFile.getParentFile().mkdirs(); 178 FileOutputStream file = new FileOutputStream(dumpFile); 179 file.write(classFile); 180 file.close(); 181 return null; 182 } catch (IOException ex) { 183 throw newInternalError(ex); 184 } 185 } 186 }); 187 } 188 189 } 190 makeDumpableClassName(String className)191 private static String makeDumpableClassName(String className) { 192 Integer ctr; 193 synchronized (DUMP_CLASS_FILES_COUNTERS) { 194 ctr = DUMP_CLASS_FILES_COUNTERS.get(className); 195 if (ctr == null) ctr = 0; 196 DUMP_CLASS_FILES_COUNTERS.put(className, ctr+1); 197 } 198 String sfx = ctr.toString(); 199 while (sfx.length() < 3) 200 sfx = "0"+sfx; 201 className += sfx; 202 return className; 203 } 204 205 class CpPatch { 206 final int index; 207 final String placeholder; 208 final Object value; CpPatch(int index, String placeholder, Object value)209 CpPatch(int index, String placeholder, Object value) { 210 this.index = index; 211 this.placeholder = placeholder; 212 this.value = value; 213 } toString()214 public String toString() { 215 return "CpPatch/index="+index+",placeholder="+placeholder+",value="+value; 216 } 217 } 218 219 Map<Object, CpPatch> cpPatches = new HashMap<>(); 220 221 int cph = 0; // for counting constant placeholders 222 constantPlaceholder(Object arg)223 String constantPlaceholder(Object arg) { 224 String cpPlaceholder = "CONSTANT_PLACEHOLDER_" + cph++; 225 if (DUMP_CLASS_FILES) cpPlaceholder += " <<" + debugString(arg) + ">>"; // debugging aid 226 if (cpPatches.containsKey(cpPlaceholder)) { 227 throw new InternalError("observed CP placeholder twice: " + cpPlaceholder); 228 } 229 // insert placeholder in CP and remember the patch 230 int index = cw.newConst((Object) cpPlaceholder); // TODO check if aready in the constant pool 231 cpPatches.put(cpPlaceholder, new CpPatch(index, cpPlaceholder, arg)); 232 return cpPlaceholder; 233 } 234 cpPatches(byte[] classFile)235 Object[] cpPatches(byte[] classFile) { 236 int size = getConstantPoolSize(classFile); 237 Object[] res = new Object[size]; 238 for (CpPatch p : cpPatches.values()) { 239 if (p.index >= size) 240 throw new InternalError("in cpool["+size+"]: "+p+"\n"+Arrays.toString(Arrays.copyOf(classFile, 20))); 241 res[p.index] = p.value; 242 } 243 return res; 244 } 245 debugString(Object arg)246 private static String debugString(Object arg) { 247 if (arg instanceof MethodHandle) { 248 MethodHandle mh = (MethodHandle) arg; 249 MemberName member = mh.internalMemberName(); 250 if (member != null) 251 return member.toString(); 252 return mh.debugString(); 253 } 254 return arg.toString(); 255 } 256 257 /** 258 * Extract the number of constant pool entries from a given class file. 259 * 260 * @param classFile the bytes of the class file in question. 261 * @return the number of entries in the constant pool. 262 */ getConstantPoolSize(byte[] classFile)263 private static int getConstantPoolSize(byte[] classFile) { 264 // The first few bytes: 265 // u4 magic; 266 // u2 minor_version; 267 // u2 major_version; 268 // u2 constant_pool_count; 269 return ((classFile[8] & 0xFF) << 8) | (classFile[9] & 0xFF); 270 } 271 272 /** 273 * Extract the MemberName of a newly-defined method. 274 */ loadMethod(byte[] classFile)275 private MemberName loadMethod(byte[] classFile) { 276 Class<?> invokerClass = loadAndInitializeInvokerClass(classFile, cpPatches(classFile)); 277 return resolveInvokerMember(invokerClass, invokerName, invokerType); 278 } 279 280 /** 281 * Define a given class as anonymous class in the runtime system. 282 */ loadAndInitializeInvokerClass(byte[] classBytes, Object[] patches)283 private static Class<?> loadAndInitializeInvokerClass(byte[] classBytes, Object[] patches) { 284 Class<?> invokerClass = UNSAFE.defineAnonymousClass(HOST_CLASS, classBytes, patches); 285 UNSAFE.ensureClassInitialized(invokerClass); // Make sure the class is initialized; VM might complain. 286 return invokerClass; 287 } 288 resolveInvokerMember(Class<?> invokerClass, String name, MethodType type)289 private static MemberName resolveInvokerMember(Class<?> invokerClass, String name, MethodType type) { 290 MemberName member = new MemberName(invokerClass, name, type, REF_invokeStatic); 291 //System.out.println("resolveInvokerMember => "+member); 292 //for (Method m : invokerClass.getDeclaredMethods()) System.out.println(" "+m); 293 try { 294 member = MEMBERNAME_FACTORY.resolveOrFail(REF_invokeStatic, member, HOST_CLASS, ReflectiveOperationException.class); 295 } catch (ReflectiveOperationException e) { 296 throw newInternalError(e); 297 } 298 //System.out.println("resolveInvokerMember => "+member); 299 return member; 300 } 301 302 /** 303 * Set up class file generation. 304 */ classFilePrologue()305 private void classFilePrologue() { 306 final int NOT_ACC_PUBLIC = 0; // not ACC_PUBLIC 307 cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES); 308 cw.visit(Opcodes.V1_8, NOT_ACC_PUBLIC + Opcodes.ACC_FINAL + Opcodes.ACC_SUPER, className, null, superName, null); 309 cw.visitSource(sourceFile, null); 310 311 String invokerDesc = invokerType.toMethodDescriptorString(); 312 mv = cw.visitMethod(Opcodes.ACC_STATIC, invokerName, invokerDesc, null, null); 313 } 314 315 /** 316 * Tear down class file generation. 317 */ classFileEpilogue()318 private void classFileEpilogue() { 319 mv.visitMaxs(0, 0); 320 mv.visitEnd(); 321 } 322 323 /* 324 * Low-level emit helpers. 325 */ emitConst(Object con)326 private void emitConst(Object con) { 327 if (con == null) { 328 mv.visitInsn(Opcodes.ACONST_NULL); 329 return; 330 } 331 if (con instanceof Integer) { 332 emitIconstInsn((int) con); 333 return; 334 } 335 if (con instanceof Long) { 336 long x = (long) con; 337 if (x == (short) x) { 338 emitIconstInsn((int) x); 339 mv.visitInsn(Opcodes.I2L); 340 return; 341 } 342 } 343 if (con instanceof Float) { 344 float x = (float) con; 345 if (x == (short) x) { 346 emitIconstInsn((int) x); 347 mv.visitInsn(Opcodes.I2F); 348 return; 349 } 350 } 351 if (con instanceof Double) { 352 double x = (double) con; 353 if (x == (short) x) { 354 emitIconstInsn((int) x); 355 mv.visitInsn(Opcodes.I2D); 356 return; 357 } 358 } 359 if (con instanceof Boolean) { 360 emitIconstInsn((boolean) con ? 1 : 0); 361 return; 362 } 363 // fall through: 364 mv.visitLdcInsn(con); 365 } 366 emitIconstInsn(int i)367 private void emitIconstInsn(int i) { 368 int opcode; 369 switch (i) { 370 case 0: opcode = Opcodes.ICONST_0; break; 371 case 1: opcode = Opcodes.ICONST_1; break; 372 case 2: opcode = Opcodes.ICONST_2; break; 373 case 3: opcode = Opcodes.ICONST_3; break; 374 case 4: opcode = Opcodes.ICONST_4; break; 375 case 5: opcode = Opcodes.ICONST_5; break; 376 default: 377 if (i == (byte) i) { 378 mv.visitIntInsn(Opcodes.BIPUSH, i & 0xFF); 379 } else if (i == (short) i) { 380 mv.visitIntInsn(Opcodes.SIPUSH, (char) i); 381 } else { 382 mv.visitLdcInsn(i); 383 } 384 return; 385 } 386 mv.visitInsn(opcode); 387 } 388 389 /* 390 * NOTE: These load/store methods use the localsMap to find the correct index! 391 */ emitLoadInsn(BasicType type, int index)392 private void emitLoadInsn(BasicType type, int index) { 393 int opcode = loadInsnOpcode(type); 394 mv.visitVarInsn(opcode, localsMap[index]); 395 } 396 loadInsnOpcode(BasicType type)397 private int loadInsnOpcode(BasicType type) throws InternalError { 398 switch (type) { 399 case I_TYPE: return Opcodes.ILOAD; 400 case J_TYPE: return Opcodes.LLOAD; 401 case F_TYPE: return Opcodes.FLOAD; 402 case D_TYPE: return Opcodes.DLOAD; 403 case L_TYPE: return Opcodes.ALOAD; 404 default: 405 throw new InternalError("unknown type: " + type); 406 } 407 } emitAloadInsn(int index)408 private void emitAloadInsn(int index) { 409 emitLoadInsn(L_TYPE, index); 410 } 411 emitStoreInsn(BasicType type, int index)412 private void emitStoreInsn(BasicType type, int index) { 413 int opcode = storeInsnOpcode(type); 414 mv.visitVarInsn(opcode, localsMap[index]); 415 } 416 storeInsnOpcode(BasicType type)417 private int storeInsnOpcode(BasicType type) throws InternalError { 418 switch (type) { 419 case I_TYPE: return Opcodes.ISTORE; 420 case J_TYPE: return Opcodes.LSTORE; 421 case F_TYPE: return Opcodes.FSTORE; 422 case D_TYPE: return Opcodes.DSTORE; 423 case L_TYPE: return Opcodes.ASTORE; 424 default: 425 throw new InternalError("unknown type: " + type); 426 } 427 } emitAstoreInsn(int index)428 private void emitAstoreInsn(int index) { 429 emitStoreInsn(L_TYPE, index); 430 } 431 arrayTypeCode(Wrapper elementType)432 private byte arrayTypeCode(Wrapper elementType) { 433 switch (elementType) { 434 case BOOLEAN: return Opcodes.T_BOOLEAN; 435 case BYTE: return Opcodes.T_BYTE; 436 case CHAR: return Opcodes.T_CHAR; 437 case SHORT: return Opcodes.T_SHORT; 438 case INT: return Opcodes.T_INT; 439 case LONG: return Opcodes.T_LONG; 440 case FLOAT: return Opcodes.T_FLOAT; 441 case DOUBLE: return Opcodes.T_DOUBLE; 442 case OBJECT: return 0; // in place of Opcodes.T_OBJECT 443 default: throw new InternalError(); 444 } 445 } 446 arrayInsnOpcode(byte tcode, int aaop)447 private int arrayInsnOpcode(byte tcode, int aaop) throws InternalError { 448 assert(aaop == Opcodes.AASTORE || aaop == Opcodes.AALOAD); 449 int xas; 450 switch (tcode) { 451 case Opcodes.T_BOOLEAN: xas = Opcodes.BASTORE; break; 452 case Opcodes.T_BYTE: xas = Opcodes.BASTORE; break; 453 case Opcodes.T_CHAR: xas = Opcodes.CASTORE; break; 454 case Opcodes.T_SHORT: xas = Opcodes.SASTORE; break; 455 case Opcodes.T_INT: xas = Opcodes.IASTORE; break; 456 case Opcodes.T_LONG: xas = Opcodes.LASTORE; break; 457 case Opcodes.T_FLOAT: xas = Opcodes.FASTORE; break; 458 case Opcodes.T_DOUBLE: xas = Opcodes.DASTORE; break; 459 case 0: xas = Opcodes.AASTORE; break; 460 default: throw new InternalError(); 461 } 462 return xas - Opcodes.AASTORE + aaop; 463 } 464 465 freeFrameLocal(int oldFrameLocal)466 private void freeFrameLocal(int oldFrameLocal) { 467 int i = indexForFrameLocal(oldFrameLocal); 468 if (i < 0) return; 469 BasicType type = localTypes[i]; 470 int newFrameLocal = makeLocalTemp(type); 471 mv.visitVarInsn(loadInsnOpcode(type), oldFrameLocal); 472 mv.visitVarInsn(storeInsnOpcode(type), newFrameLocal); 473 assert(localsMap[i] == oldFrameLocal); 474 localsMap[i] = newFrameLocal; 475 assert(indexForFrameLocal(oldFrameLocal) < 0); 476 } 477 private int indexForFrameLocal(int frameLocal) { 478 for (int i = 0; i < localsMap.length; i++) { 479 if (localsMap[i] == frameLocal && localTypes[i] != V_TYPE) 480 return i; 481 } 482 return -1; 483 } 484 private int makeLocalTemp(BasicType type) { 485 int frameLocal = localsMap[localsMap.length - 1]; 486 localsMap[localsMap.length - 1] = frameLocal + type.basicTypeSlots(); 487 return frameLocal; 488 } 489 490 /** 491 * Emit a boxing call. 492 * 493 * @param wrapper primitive type class to box. 494 */ 495 private void emitBoxing(Wrapper wrapper) { 496 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName(); 497 String name = "valueOf"; 498 String desc = "(" + wrapper.basicTypeChar() + ")L" + owner + ";"; 499 mv.visitMethodInsn(Opcodes.INVOKESTATIC, owner, name, desc, false); 500 } 501 502 /** 503 * Emit an unboxing call (plus preceding checkcast). 504 * 505 * @param wrapper wrapper type class to unbox. 506 */ 507 private void emitUnboxing(Wrapper wrapper) { 508 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName(); 509 String name = wrapper.primitiveSimpleName() + "Value"; 510 String desc = "()" + wrapper.basicTypeChar(); 511 emitReferenceCast(wrapper.wrapperType(), null); 512 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, owner, name, desc, false); 513 } 514 515 /** 516 * Emit an implicit conversion for an argument which must be of the given pclass. 517 * This is usually a no-op, except when pclass is a subword type or a reference other than Object or an interface. 518 * 519 * @param ptype type of value present on stack 520 * @param pclass type of value required on stack 521 * @param arg compile-time representation of value on stack (Node, constant) or null if none 522 */ 523 private void emitImplicitConversion(BasicType ptype, Class<?> pclass, Object arg) { 524 assert(basicType(pclass) == ptype); // boxing/unboxing handled by caller 525 if (pclass == ptype.basicTypeClass() && ptype != L_TYPE) 526 return; // nothing to do 527 switch (ptype) { 528 case L_TYPE: 529 if (VerifyType.isNullConversion(Object.class, pclass, false)) { 530 if (PROFILE_LEVEL > 0) 531 emitReferenceCast(Object.class, arg); 532 return; 533 } 534 emitReferenceCast(pclass, arg); 535 return; 536 case I_TYPE: 537 if (!VerifyType.isNullConversion(int.class, pclass, false)) 538 emitPrimCast(ptype.basicTypeWrapper(), Wrapper.forPrimitiveType(pclass)); 539 return; 540 } 541 throw newInternalError("bad implicit conversion: tc="+ptype+": "+pclass); 542 } 543 544 /** Update localClasses type map. Return true if the information is already present. */ 545 private boolean assertStaticType(Class<?> cls, Name n) { 546 int local = n.index(); 547 Class<?> aclass = localClasses[local]; 548 if (aclass != null && (aclass == cls || cls.isAssignableFrom(aclass))) { 549 return true; // type info is already present 550 } else if (aclass == null || aclass.isAssignableFrom(cls)) { 551 localClasses[local] = cls; // type info can be improved 552 } 553 return false; 554 } 555 556 private void emitReferenceCast(Class<?> cls, Object arg) { 557 Name writeBack = null; // local to write back result 558 if (arg instanceof Name) { 559 Name n = (Name) arg; 560 if (assertStaticType(cls, n)) 561 return; // this cast was already performed 562 if (lambdaForm.useCount(n) > 1) { 563 // This guy gets used more than once. 564 writeBack = n; 565 } 566 } 567 if (isStaticallyNameable(cls)) { 568 String sig = getInternalName(cls); mv.visitTypeInsn(Opcodes.CHECKCAST, sig)569 mv.visitTypeInsn(Opcodes.CHECKCAST, sig); 570 } else { constantPlaceholder(cls)571 mv.visitLdcInsn(constantPlaceholder(cls)); mv.visitTypeInsn(Opcodes.CHECKCAST, CLS)572 mv.visitTypeInsn(Opcodes.CHECKCAST, CLS); 573 mv.visitInsn(Opcodes.SWAP); mv.visitMethodInsn(Opcodes.INVOKESTATIC, MHI, R, CLL_SIG, false)574 mv.visitMethodInsn(Opcodes.INVOKESTATIC, MHI, "castReference", CLL_SIG, false); 575 if (Object[].class.isAssignableFrom(cls)) mv.visitTypeInsn(Opcodes.CHECKCAST, OBJARY)576 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJARY); 577 else if (PROFILE_LEVEL > 0) mv.visitTypeInsn(Opcodes.CHECKCAST, OBJ)578 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJ); 579 } 580 if (writeBack != null) { 581 mv.visitInsn(Opcodes.DUP); writeBack.index()582 emitAstoreInsn(writeBack.index()); 583 } 584 } 585 586 /** 587 * Emits an actual return instruction conforming to the given return type. 588 */ emitReturnInsn(BasicType type)589 private void emitReturnInsn(BasicType type) { 590 int opcode; 591 switch (type) { 592 case I_TYPE: opcode = Opcodes.IRETURN; break; 593 case J_TYPE: opcode = Opcodes.LRETURN; break; 594 case F_TYPE: opcode = Opcodes.FRETURN; break; 595 case D_TYPE: opcode = Opcodes.DRETURN; break; 596 case L_TYPE: opcode = Opcodes.ARETURN; break; 597 case V_TYPE: opcode = Opcodes.RETURN; break; 598 default: 599 throw new InternalError("unknown return type: " + type); 600 } 601 mv.visitInsn(opcode); 602 } 603 getInternalName(Class<?> c)604 private static String getInternalName(Class<?> c) { 605 if (c == Object.class) return OBJ; 606 else if (c == Object[].class) return OBJARY; 607 else if (c == Class.class) return CLS; 608 else if (c == MethodHandle.class) return MH; 609 assert(VerifyAccess.isTypeVisible(c, Object.class)) : c.getName(); 610 return c.getName().replace('.', '/'); 611 } 612 613 /** 614 * Generate customized bytecode for a given LambdaForm. 615 */ generateCustomizedCode(LambdaForm form, MethodType invokerType)616 static MemberName generateCustomizedCode(LambdaForm form, MethodType invokerType) { 617 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("MH", form, invokerType); 618 return g.loadMethod(g.generateCustomizedCodeBytes()); 619 } 620 621 /** Generates code to check that actual receiver and LambdaForm matches */ checkActualReceiver()622 private boolean checkActualReceiver() { 623 // Expects MethodHandle on the stack and actual receiver MethodHandle in slot #0 624 mv.visitInsn(Opcodes.DUP); 625 mv.visitVarInsn(Opcodes.ALOAD, localsMap[0]); 626 mv.visitMethodInsn(Opcodes.INVOKESTATIC, MHI, "assertSame", LLV_SIG, false); 627 return true; 628 } 629 630 /** 631 * Generate an invoker method for the passed {@link LambdaForm}. 632 */ generateCustomizedCodeBytes()633 private byte[] generateCustomizedCodeBytes() { 634 classFilePrologue(); 635 636 // Suppress this method in backtraces displayed to the user. 637 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true); 638 639 // Mark this method as a compiled LambdaForm 640 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Compiled;", true); 641 642 if (lambdaForm.forceInline) { 643 // Force inlining of this invoker method. 644 mv.visitAnnotation("Ljava/lang/invoke/ForceInline;", true); 645 } else { 646 mv.visitAnnotation("Ljava/lang/invoke/DontInline;", true); 647 } 648 649 if (lambdaForm.customized != null) { 650 // Since LambdaForm is customized for a particular MethodHandle, it's safe to substitute 651 // receiver MethodHandle (at slot #0) with an embedded constant and use it instead. 652 // It enables more efficient code generation in some situations, since embedded constants 653 // are compile-time constants for JIT compiler. 654 mv.visitLdcInsn(constantPlaceholder(lambdaForm.customized)); 655 mv.visitTypeInsn(Opcodes.CHECKCAST, MH); 656 assert(checkActualReceiver()); // expects MethodHandle on top of the stack 657 mv.visitVarInsn(Opcodes.ASTORE, localsMap[0]); 658 } 659 660 // iterate over the form's names, generating bytecode instructions for each 661 // start iterating at the first name following the arguments 662 Name onStack = null; 663 for (int i = lambdaForm.arity; i < lambdaForm.names.length; i++) { 664 Name name = lambdaForm.names[i]; 665 666 emitStoreResult(onStack); 667 onStack = name; // unless otherwise modified below 668 MethodHandleImpl.Intrinsic intr = name.function.intrinsicName(); 669 switch (intr) { 670 case SELECT_ALTERNATIVE: 671 assert isSelectAlternative(i); 672 if (PROFILE_GWT) { 673 assert(name.arguments[0] instanceof Name && 674 nameRefersTo((Name)name.arguments[0], MethodHandleImpl.class, "profileBoolean")); 675 mv.visitAnnotation("Ljava/lang/invoke/InjectedProfile;", true); 676 } 677 onStack = emitSelectAlternative(name, lambdaForm.names[i+1]); 678 i++; // skip MH.invokeBasic of the selectAlternative result 679 continue; 680 case GUARD_WITH_CATCH: 681 assert isGuardWithCatch(i); 682 onStack = emitGuardWithCatch(i); 683 i = i+2; // Jump to the end of GWC idiom 684 continue; 685 case NEW_ARRAY: 686 Class<?> rtype = name.function.methodType().returnType(); 687 if (isStaticallyNameable(rtype)) { 688 emitNewArray(name); 689 continue; 690 } 691 break; 692 case ARRAY_LOAD: 693 emitArrayLoad(name); 694 continue; 695 case ARRAY_STORE: 696 emitArrayStore(name); 697 continue; 698 case IDENTITY: 699 assert(name.arguments.length == 1); 700 emitPushArguments(name); 701 continue; 702 case ZERO: 703 assert(name.arguments.length == 0); 704 emitConst(name.type.basicTypeWrapper().zero()); 705 continue; 706 case NONE: 707 // no intrinsic associated 708 break; 709 default: 710 throw newInternalError("Unknown intrinsic: "+intr); 711 } 712 713 MemberName member = name.function.member(); 714 if (isStaticallyInvocable(member)) { 715 emitStaticInvoke(member, name); 716 } else { 717 emitInvoke(name); 718 } 719 } 720 721 // return statement 722 emitReturn(onStack); 723 724 classFileEpilogue(); 725 bogusMethod(lambdaForm); 726 727 final byte[] classFile = cw.toByteArray(); 728 maybeDump(className, classFile); 729 return classFile; 730 } 731 emitArrayLoad(Name name)732 void emitArrayLoad(Name name) { emitArrayOp(name, Opcodes.AALOAD); } emitArrayStore(Name name)733 void emitArrayStore(Name name) { emitArrayOp(name, Opcodes.AASTORE); } 734 emitArrayOp(Name name, int arrayOpcode)735 void emitArrayOp(Name name, int arrayOpcode) { 736 assert arrayOpcode == Opcodes.AALOAD || arrayOpcode == Opcodes.AASTORE; 737 Class<?> elementType = name.function.methodType().parameterType(0).getComponentType(); 738 assert elementType != null; 739 emitPushArguments(name); 740 if (elementType.isPrimitive()) { 741 Wrapper w = Wrapper.forPrimitiveType(elementType); 742 arrayOpcode = arrayInsnOpcode(arrayTypeCode(w), arrayOpcode); 743 } 744 mv.visitInsn(arrayOpcode); 745 } 746 747 /** 748 * Emit an invoke for the given name. 749 */ emitInvoke(Name name)750 void emitInvoke(Name name) { 751 assert(!isLinkerMethodInvoke(name)); // should use the static path for these 752 if (true) { 753 // push receiver 754 MethodHandle target = name.function.resolvedHandle; 755 assert(target != null) : name.exprString(); 756 mv.visitLdcInsn(constantPlaceholder(target)); 757 emitReferenceCast(MethodHandle.class, target); 758 } else { 759 // load receiver 760 emitAloadInsn(0); 761 emitReferenceCast(MethodHandle.class, null); 762 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", LF_SIG); 763 mv.visitFieldInsn(Opcodes.GETFIELD, LF, "names", LFN_SIG); 764 // TODO more to come 765 } 766 767 // push arguments 768 emitPushArguments(name); 769 770 // invocation 771 MethodType type = name.function.methodType(); 772 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false); 773 } 774 775 static private Class<?>[] STATICALLY_INVOCABLE_PACKAGES = { 776 // Sample classes from each package we are willing to bind to statically: 777 java.lang.Object.class, 778 java.util.Arrays.class, 779 sun.misc.Unsafe.class 780 //MethodHandle.class already covered 781 }; 782 isStaticallyInvocable(Name name)783 static boolean isStaticallyInvocable(Name name) { 784 return isStaticallyInvocable(name.function.member()); 785 } 786 isStaticallyInvocable(MemberName member)787 static boolean isStaticallyInvocable(MemberName member) { 788 if (member == null) return false; 789 if (member.isConstructor()) return false; 790 Class<?> cls = member.getDeclaringClass(); 791 if (cls.isArray() || cls.isPrimitive()) 792 return false; // FIXME 793 if (cls.isAnonymousClass() || cls.isLocalClass()) 794 return false; // inner class of some sort 795 if (cls.getClassLoader() != MethodHandle.class.getClassLoader()) 796 return false; // not on BCP 797 if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: switch to supported API once it is added 798 return false; 799 MethodType mtype = member.getMethodOrFieldType(); 800 if (!isStaticallyNameable(mtype.returnType())) 801 return false; 802 for (Class<?> ptype : mtype.parameterArray()) 803 if (!isStaticallyNameable(ptype)) 804 return false; 805 if (!member.isPrivate() && VerifyAccess.isSamePackage(MethodHandle.class, cls)) 806 return true; // in java.lang.invoke package 807 if (member.isPublic() && isStaticallyNameable(cls)) 808 return true; 809 return false; 810 } 811 isStaticallyNameable(Class<?> cls)812 static boolean isStaticallyNameable(Class<?> cls) { 813 if (cls == Object.class) 814 return true; 815 while (cls.isArray()) 816 cls = cls.getComponentType(); 817 if (cls.isPrimitive()) 818 return true; // int[].class, for example 819 if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: switch to supported API once it is added 820 return false; 821 // could use VerifyAccess.isClassAccessible but the following is a safe approximation 822 if (cls.getClassLoader() != Object.class.getClassLoader()) 823 return false; 824 if (VerifyAccess.isSamePackage(MethodHandle.class, cls)) 825 return true; 826 if (!Modifier.isPublic(cls.getModifiers())) 827 return false; 828 for (Class<?> pkgcls : STATICALLY_INVOCABLE_PACKAGES) { 829 if (VerifyAccess.isSamePackage(pkgcls, cls)) 830 return true; 831 } 832 return false; 833 } 834 emitStaticInvoke(Name name)835 void emitStaticInvoke(Name name) { 836 emitStaticInvoke(name.function.member(), name); 837 } 838 839 /** 840 * Emit an invoke for the given name, using the MemberName directly. 841 */ emitStaticInvoke(MemberName member, Name name)842 void emitStaticInvoke(MemberName member, Name name) { 843 assert(member.equals(name.function.member())); 844 Class<?> defc = member.getDeclaringClass(); 845 String cname = getInternalName(defc); 846 String mname = member.getName(); 847 String mtype; 848 byte refKind = member.getReferenceKind(); 849 if (refKind == REF_invokeSpecial) { 850 // in order to pass the verifier, we need to convert this to invokevirtual in all cases 851 assert(member.canBeStaticallyBound()) : member; 852 refKind = REF_invokeVirtual; 853 } 854 855 if (member.getDeclaringClass().isInterface() && refKind == REF_invokeVirtual) { 856 // Methods from Object declared in an interface can be resolved by JVM to invokevirtual kind. 857 // Need to convert it back to invokeinterface to pass verification and make the invocation works as expected. 858 refKind = REF_invokeInterface; 859 } 860 861 // push arguments 862 emitPushArguments(name); 863 864 // invocation 865 if (member.isMethod()) { 866 mtype = member.getMethodType().toMethodDescriptorString(); 867 mv.visitMethodInsn(refKindOpcode(refKind), cname, mname, mtype, 868 member.getDeclaringClass().isInterface()); 869 } else { 870 mtype = MethodType.toFieldDescriptorString(member.getFieldType()); 871 mv.visitFieldInsn(refKindOpcode(refKind), cname, mname, mtype); 872 } 873 // Issue a type assertion for the result, so we can avoid casts later. 874 if (name.type == L_TYPE) { 875 Class<?> rtype = member.getInvocationType().returnType(); 876 assert(!rtype.isPrimitive()); 877 if (rtype != Object.class && !rtype.isInterface()) { 878 assertStaticType(rtype, name); 879 } 880 } 881 } 882 emitNewArray(Name name)883 void emitNewArray(Name name) throws InternalError { 884 Class<?> rtype = name.function.methodType().returnType(); 885 if (name.arguments.length == 0) { 886 // The array will be a constant. 887 Object emptyArray; 888 try { 889 emptyArray = name.function.resolvedHandle.invoke(); 890 } catch (Throwable ex) { 891 throw newInternalError(ex); 892 } 893 assert(java.lang.reflect.Array.getLength(emptyArray) == 0); 894 assert(emptyArray.getClass() == rtype); // exact typing 895 mv.visitLdcInsn(constantPlaceholder(emptyArray)); 896 emitReferenceCast(rtype, emptyArray); 897 return; 898 } 899 Class<?> arrayElementType = rtype.getComponentType(); 900 assert(arrayElementType != null); 901 emitIconstInsn(name.arguments.length); 902 int xas = Opcodes.AASTORE; 903 if (!arrayElementType.isPrimitive()) { 904 mv.visitTypeInsn(Opcodes.ANEWARRAY, getInternalName(arrayElementType)); 905 } else { 906 byte tc = arrayTypeCode(Wrapper.forPrimitiveType(arrayElementType)); 907 xas = arrayInsnOpcode(tc, xas); 908 mv.visitIntInsn(Opcodes.NEWARRAY, tc); 909 } 910 // store arguments 911 for (int i = 0; i < name.arguments.length; i++) { 912 mv.visitInsn(Opcodes.DUP); 913 emitIconstInsn(i); 914 emitPushArgument(name, i); 915 mv.visitInsn(xas); 916 } 917 // the array is left on the stack 918 assertStaticType(rtype, name); 919 } refKindOpcode(byte refKind)920 int refKindOpcode(byte refKind) { 921 switch (refKind) { 922 case REF_invokeVirtual: return Opcodes.INVOKEVIRTUAL; 923 case REF_invokeStatic: return Opcodes.INVOKESTATIC; 924 case REF_invokeSpecial: return Opcodes.INVOKESPECIAL; 925 case REF_invokeInterface: return Opcodes.INVOKEINTERFACE; 926 case REF_getField: return Opcodes.GETFIELD; 927 case REF_putField: return Opcodes.PUTFIELD; 928 case REF_getStatic: return Opcodes.GETSTATIC; 929 case REF_putStatic: return Opcodes.PUTSTATIC; 930 } 931 throw new InternalError("refKind="+refKind); 932 } 933 934 /** 935 * Check if MemberName is a call to a method named {@code name} in class {@code declaredClass}. 936 */ memberRefersTo(MemberName member, Class<?> declaringClass, String name)937 private boolean memberRefersTo(MemberName member, Class<?> declaringClass, String name) { 938 return member != null && 939 member.getDeclaringClass() == declaringClass && 940 member.getName().equals(name); 941 } nameRefersTo(Name name, Class<?> declaringClass, String methodName)942 private boolean nameRefersTo(Name name, Class<?> declaringClass, String methodName) { 943 return name.function != null && 944 memberRefersTo(name.function.member(), declaringClass, methodName); 945 } 946 947 /** 948 * Check if MemberName is a call to MethodHandle.invokeBasic. 949 */ isInvokeBasic(Name name)950 private boolean isInvokeBasic(Name name) { 951 if (name.function == null) 952 return false; 953 if (name.arguments.length < 1) 954 return false; // must have MH argument 955 MemberName member = name.function.member(); 956 return memberRefersTo(member, MethodHandle.class, "invokeBasic") && 957 !member.isPublic() && !member.isStatic(); 958 } 959 960 /** 961 * Check if MemberName is a call to MethodHandle.linkToStatic, etc. 962 */ isLinkerMethodInvoke(Name name)963 private boolean isLinkerMethodInvoke(Name name) { 964 if (name.function == null) 965 return false; 966 if (name.arguments.length < 1) 967 return false; // must have MH argument 968 MemberName member = name.function.member(); 969 return member != null && 970 member.getDeclaringClass() == MethodHandle.class && 971 !member.isPublic() && member.isStatic() && 972 member.getName().startsWith("linkTo"); 973 } 974 975 /** 976 * Check if i-th name is a call to MethodHandleImpl.selectAlternative. 977 */ isSelectAlternative(int pos)978 private boolean isSelectAlternative(int pos) { 979 // selectAlternative idiom: 980 // t_{n}:L=MethodHandleImpl.selectAlternative(...) 981 // t_{n+1}:?=MethodHandle.invokeBasic(t_{n}, ...) 982 if (pos+1 >= lambdaForm.names.length) return false; 983 Name name0 = lambdaForm.names[pos]; 984 Name name1 = lambdaForm.names[pos+1]; 985 return nameRefersTo(name0, MethodHandleImpl.class, "selectAlternative") && 986 isInvokeBasic(name1) && 987 name1.lastUseIndex(name0) == 0 && // t_{n+1}:?=MethodHandle.invokeBasic(t_{n}, ...) 988 lambdaForm.lastUseIndex(name0) == pos+1; // t_{n} is local: used only in t_{n+1} 989 } 990 991 /** 992 * Check if i-th name is a start of GuardWithCatch idiom. 993 */ isGuardWithCatch(int pos)994 private boolean isGuardWithCatch(int pos) { 995 // GuardWithCatch idiom: 996 // t_{n}:L=MethodHandle.invokeBasic(...) 997 // t_{n+1}:L=MethodHandleImpl.guardWithCatch(*, *, *, t_{n}); 998 // t_{n+2}:?=MethodHandle.invokeBasic(t_{n+1}) 999 if (pos+2 >= lambdaForm.names.length) return false; 1000 Name name0 = lambdaForm.names[pos]; 1001 Name name1 = lambdaForm.names[pos+1]; 1002 Name name2 = lambdaForm.names[pos+2]; 1003 return nameRefersTo(name1, MethodHandleImpl.class, "guardWithCatch") && 1004 isInvokeBasic(name0) && 1005 isInvokeBasic(name2) && 1006 name1.lastUseIndex(name0) == 3 && // t_{n+1}:L=MethodHandleImpl.guardWithCatch(*, *, *, t_{n}); 1007 lambdaForm.lastUseIndex(name0) == pos+1 && // t_{n} is local: used only in t_{n+1} 1008 name2.lastUseIndex(name1) == 1 && // t_{n+2}:?=MethodHandle.invokeBasic(t_{n+1}) 1009 lambdaForm.lastUseIndex(name1) == pos+2; // t_{n+1} is local: used only in t_{n+2} 1010 } 1011 1012 /** 1013 * Emit bytecode for the selectAlternative idiom. 1014 * 1015 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithTest): 1016 * <blockquote><pre>{@code 1017 * Lambda(a0:L,a1:I)=>{ 1018 * t2:I=foo.test(a1:I); 1019 * t3:L=MethodHandleImpl.selectAlternative(t2:I,(MethodHandle(int)int),(MethodHandle(int)int)); 1020 * t4:I=MethodHandle.invokeBasic(t3:L,a1:I);t4:I} 1021 * }</pre></blockquote> 1022 */ emitSelectAlternative(Name selectAlternativeName, Name invokeBasicName)1023 private Name emitSelectAlternative(Name selectAlternativeName, Name invokeBasicName) { 1024 assert isStaticallyInvocable(invokeBasicName); 1025 1026 Name receiver = (Name) invokeBasicName.arguments[0]; 1027 1028 Label L_fallback = new Label(); 1029 Label L_done = new Label(); 1030 1031 // load test result 1032 emitPushArgument(selectAlternativeName, 0); 1033 1034 // if_icmpne L_fallback 1035 mv.visitJumpInsn(Opcodes.IFEQ, L_fallback); 1036 1037 // invoke selectAlternativeName.arguments[1] 1038 Class<?>[] preForkClasses = localClasses.clone(); 1039 emitPushArgument(selectAlternativeName, 1); // get 2nd argument of selectAlternative 1040 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot 1041 emitStaticInvoke(invokeBasicName); 1042 1043 // goto L_done 1044 mv.visitJumpInsn(Opcodes.GOTO, L_done); 1045 1046 // L_fallback: 1047 mv.visitLabel(L_fallback); 1048 1049 // invoke selectAlternativeName.arguments[2] 1050 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length); 1051 emitPushArgument(selectAlternativeName, 2); // get 3rd argument of selectAlternative 1052 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot 1053 emitStaticInvoke(invokeBasicName); 1054 1055 // L_done: 1056 mv.visitLabel(L_done); 1057 // for now do not bother to merge typestate; just reset to the dominator state 1058 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length); 1059 1060 return invokeBasicName; // return what's on stack 1061 } 1062 1063 /** 1064 * Emit bytecode for the guardWithCatch idiom. 1065 * 1066 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithCatch): 1067 * <blockquote><pre>{@code 1068 * guardWithCatch=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L,a5:L,a6:L,a7:L)=>{ 1069 * t8:L=MethodHandle.invokeBasic(a4:L,a6:L,a7:L); 1070 * t9:L=MethodHandleImpl.guardWithCatch(a1:L,a2:L,a3:L,t8:L); 1071 * t10:I=MethodHandle.invokeBasic(a5:L,t9:L);t10:I} 1072 * }</pre></blockquote> 1073 * 1074 * It is compiled into bytecode equivalent of the following code: 1075 * <blockquote><pre>{@code 1076 * try { 1077 * return a1.invokeBasic(a6, a7); 1078 * } catch (Throwable e) { 1079 * if (!a2.isInstance(e)) throw e; 1080 * return a3.invokeBasic(ex, a6, a7); 1081 * }} 1082 */ emitGuardWithCatch(int pos)1083 private Name emitGuardWithCatch(int pos) { 1084 Name args = lambdaForm.names[pos]; 1085 Name invoker = lambdaForm.names[pos+1]; 1086 Name result = lambdaForm.names[pos+2]; 1087 1088 Label L_startBlock = new Label(); 1089 Label L_endBlock = new Label(); 1090 Label L_handler = new Label(); 1091 Label L_done = new Label(); 1092 1093 Class<?> returnType = result.function.resolvedHandle.type().returnType(); 1094 MethodType type = args.function.resolvedHandle.type() 1095 .dropParameterTypes(0,1) 1096 .changeReturnType(returnType); 1097 1098 mv.visitTryCatchBlock(L_startBlock, L_endBlock, L_handler, "java/lang/Throwable"); 1099 1100 // Normal case 1101 mv.visitLabel(L_startBlock); 1102 // load target 1103 emitPushArgument(invoker, 0); 1104 emitPushArguments(args, 1); // skip 1st argument: method handle 1105 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false); 1106 mv.visitLabel(L_endBlock); 1107 mv.visitJumpInsn(Opcodes.GOTO, L_done); 1108 1109 // Exceptional case 1110 mv.visitLabel(L_handler); 1111 1112 // Check exception's type 1113 mv.visitInsn(Opcodes.DUP); 1114 // load exception class 1115 emitPushArgument(invoker, 1); 1116 mv.visitInsn(Opcodes.SWAP); 1117 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/Class", "isInstance", "(Ljava/lang/Object;)Z", false); 1118 Label L_rethrow = new Label(); 1119 mv.visitJumpInsn(Opcodes.IFEQ, L_rethrow); 1120 1121 // Invoke catcher 1122 // load catcher 1123 emitPushArgument(invoker, 2); 1124 mv.visitInsn(Opcodes.SWAP); 1125 emitPushArguments(args, 1); // skip 1st argument: method handle 1126 MethodType catcherType = type.insertParameterTypes(0, Throwable.class); 1127 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", catcherType.basicType().toMethodDescriptorString(), false); 1128 mv.visitJumpInsn(Opcodes.GOTO, L_done); 1129 1130 mv.visitLabel(L_rethrow); 1131 mv.visitInsn(Opcodes.ATHROW); 1132 1133 mv.visitLabel(L_done); 1134 1135 return result; 1136 } 1137 emitPushArguments(Name args)1138 private void emitPushArguments(Name args) { 1139 emitPushArguments(args, 0); 1140 } 1141 emitPushArguments(Name args, int start)1142 private void emitPushArguments(Name args, int start) { 1143 for (int i = start; i < args.arguments.length; i++) { 1144 emitPushArgument(args, i); 1145 } 1146 } 1147 emitPushArgument(Name name, int paramIndex)1148 private void emitPushArgument(Name name, int paramIndex) { 1149 Object arg = name.arguments[paramIndex]; 1150 Class<?> ptype = name.function.methodType().parameterType(paramIndex); 1151 emitPushArgument(ptype, arg); 1152 } 1153 emitPushArgument(Class<?> ptype, Object arg)1154 private void emitPushArgument(Class<?> ptype, Object arg) { 1155 BasicType bptype = basicType(ptype); 1156 if (arg instanceof Name) { 1157 Name n = (Name) arg; 1158 emitLoadInsn(n.type, n.index()); 1159 emitImplicitConversion(n.type, ptype, n); 1160 } else if ((arg == null || arg instanceof String) && bptype == L_TYPE) { 1161 emitConst(arg); 1162 } else { 1163 if (Wrapper.isWrapperType(arg.getClass()) && bptype != L_TYPE) { 1164 emitConst(arg); 1165 } else { 1166 mv.visitLdcInsn(constantPlaceholder(arg)); 1167 emitImplicitConversion(L_TYPE, ptype, arg); 1168 } 1169 } 1170 } 1171 1172 /** 1173 * Store the name to its local, if necessary. 1174 */ emitStoreResult(Name name)1175 private void emitStoreResult(Name name) { 1176 if (name != null && name.type != V_TYPE) { 1177 // non-void: actually assign 1178 emitStoreInsn(name.type, name.index()); 1179 } 1180 } 1181 1182 /** 1183 * Emits a return statement from a LF invoker. If required, the result type is cast to the correct return type. 1184 */ emitReturn(Name onStack)1185 private void emitReturn(Name onStack) { 1186 // return statement 1187 Class<?> rclass = invokerType.returnType(); 1188 BasicType rtype = lambdaForm.returnType(); 1189 assert(rtype == basicType(rclass)); // must agree 1190 if (rtype == V_TYPE) { 1191 // void 1192 mv.visitInsn(Opcodes.RETURN); 1193 // it doesn't matter what rclass is; the JVM will discard any value 1194 } else { 1195 LambdaForm.Name rn = lambdaForm.names[lambdaForm.result]; 1196 1197 // put return value on the stack if it is not already there 1198 if (rn != onStack) { 1199 emitLoadInsn(rtype, lambdaForm.result); 1200 } 1201 1202 emitImplicitConversion(rtype, rclass, rn); 1203 1204 // generate actual return statement 1205 emitReturnInsn(rtype); 1206 } 1207 } 1208 1209 /** 1210 * Emit a type conversion bytecode casting from "from" to "to". 1211 */ emitPrimCast(Wrapper from, Wrapper to)1212 private void emitPrimCast(Wrapper from, Wrapper to) { 1213 // Here's how. 1214 // - indicates forbidden 1215 // <-> indicates implicit 1216 // to ----> boolean byte short char int long float double 1217 // from boolean <-> - - - - - - - 1218 // byte - <-> i2s i2c <-> i2l i2f i2d 1219 // short - i2b <-> i2c <-> i2l i2f i2d 1220 // char - i2b i2s <-> <-> i2l i2f i2d 1221 // int - i2b i2s i2c <-> i2l i2f i2d 1222 // long - l2i,i2b l2i,i2s l2i,i2c l2i <-> l2f l2d 1223 // float - f2i,i2b f2i,i2s f2i,i2c f2i f2l <-> f2d 1224 // double - d2i,i2b d2i,i2s d2i,i2c d2i d2l d2f <-> 1225 if (from == to) { 1226 // no cast required, should be dead code anyway 1227 return; 1228 } 1229 if (from.isSubwordOrInt()) { 1230 // cast from {byte,short,char,int} to anything 1231 emitI2X(to); 1232 } else { 1233 // cast from {long,float,double} to anything 1234 if (to.isSubwordOrInt()) { 1235 // cast to {byte,short,char,int} 1236 emitX2I(from); 1237 if (to.bitWidth() < 32) { 1238 // targets other than int require another conversion 1239 emitI2X(to); 1240 } 1241 } else { 1242 // cast to {long,float,double} - this is verbose 1243 boolean error = false; 1244 switch (from) { 1245 case LONG: 1246 switch (to) { 1247 case FLOAT: mv.visitInsn(Opcodes.L2F); break; 1248 case DOUBLE: mv.visitInsn(Opcodes.L2D); break; 1249 default: error = true; break; 1250 } 1251 break; 1252 case FLOAT: 1253 switch (to) { 1254 case LONG : mv.visitInsn(Opcodes.F2L); break; 1255 case DOUBLE: mv.visitInsn(Opcodes.F2D); break; 1256 default: error = true; break; 1257 } 1258 break; 1259 case DOUBLE: 1260 switch (to) { 1261 case LONG : mv.visitInsn(Opcodes.D2L); break; 1262 case FLOAT: mv.visitInsn(Opcodes.D2F); break; 1263 default: error = true; break; 1264 } 1265 break; 1266 default: 1267 error = true; 1268 break; 1269 } 1270 if (error) { 1271 throw new IllegalStateException("unhandled prim cast: " + from + "2" + to); 1272 } 1273 } 1274 } 1275 } 1276 emitI2X(Wrapper type)1277 private void emitI2X(Wrapper type) { 1278 switch (type) { 1279 case BYTE: mv.visitInsn(Opcodes.I2B); break; 1280 case SHORT: mv.visitInsn(Opcodes.I2S); break; 1281 case CHAR: mv.visitInsn(Opcodes.I2C); break; 1282 case INT: /* naught */ break; 1283 case LONG: mv.visitInsn(Opcodes.I2L); break; 1284 case FLOAT: mv.visitInsn(Opcodes.I2F); break; 1285 case DOUBLE: mv.visitInsn(Opcodes.I2D); break; 1286 case BOOLEAN: 1287 // For compatibility with ValueConversions and explicitCastArguments: 1288 mv.visitInsn(Opcodes.ICONST_1); 1289 mv.visitInsn(Opcodes.IAND); 1290 break; 1291 default: throw new InternalError("unknown type: " + type); 1292 } 1293 } 1294 emitX2I(Wrapper type)1295 private void emitX2I(Wrapper type) { 1296 switch (type) { 1297 case LONG: mv.visitInsn(Opcodes.L2I); break; 1298 case FLOAT: mv.visitInsn(Opcodes.F2I); break; 1299 case DOUBLE: mv.visitInsn(Opcodes.D2I); break; 1300 default: throw new InternalError("unknown type: " + type); 1301 } 1302 } 1303 1304 /** 1305 * Generate bytecode for a LambdaForm.vmentry which calls interpretWithArguments. 1306 */ generateLambdaFormInterpreterEntryPoint(String sig)1307 static MemberName generateLambdaFormInterpreterEntryPoint(String sig) { 1308 assert(isValidSignature(sig)); 1309 String name = "interpret_"+signatureReturn(sig).basicTypeChar(); 1310 MethodType type = signatureType(sig); // sig includes leading argument 1311 type = type.changeParameterType(0, MethodHandle.class); 1312 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("LFI", name, type); 1313 return g.loadMethod(g.generateLambdaFormInterpreterEntryPointBytes()); 1314 } 1315 generateLambdaFormInterpreterEntryPointBytes()1316 private byte[] generateLambdaFormInterpreterEntryPointBytes() { 1317 classFilePrologue(); 1318 1319 // Suppress this method in backtraces displayed to the user. 1320 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true); 1321 1322 // Don't inline the interpreter entry. 1323 mv.visitAnnotation("Ljava/lang/invoke/DontInline;", true); 1324 1325 // create parameter array 1326 emitIconstInsn(invokerType.parameterCount()); 1327 mv.visitTypeInsn(Opcodes.ANEWARRAY, "java/lang/Object"); 1328 1329 // fill parameter array 1330 for (int i = 0; i < invokerType.parameterCount(); i++) { 1331 Class<?> ptype = invokerType.parameterType(i); 1332 mv.visitInsn(Opcodes.DUP); 1333 emitIconstInsn(i); 1334 emitLoadInsn(basicType(ptype), i); 1335 // box if primitive type 1336 if (ptype.isPrimitive()) { 1337 emitBoxing(Wrapper.forPrimitiveType(ptype)); 1338 } 1339 mv.visitInsn(Opcodes.AASTORE); 1340 } 1341 // invoke 1342 emitAloadInsn(0); 1343 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", "Ljava/lang/invoke/LambdaForm;"); 1344 mv.visitInsn(Opcodes.SWAP); // swap form and array; avoid local variable 1345 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, LF, "interpretWithArguments", "([Ljava/lang/Object;)Ljava/lang/Object;", false); 1346 1347 // maybe unbox 1348 Class<?> rtype = invokerType.returnType(); 1349 if (rtype.isPrimitive() && rtype != void.class) { 1350 emitUnboxing(Wrapper.forPrimitiveType(rtype)); 1351 } 1352 1353 // return statement 1354 emitReturnInsn(basicType(rtype)); 1355 1356 classFileEpilogue(); 1357 bogusMethod(invokerType); 1358 1359 final byte[] classFile = cw.toByteArray(); 1360 maybeDump(className, classFile); 1361 return classFile; 1362 } 1363 1364 /** 1365 * Generate bytecode for a NamedFunction invoker. 1366 */ generateNamedFunctionInvoker(MethodTypeForm typeForm)1367 static MemberName generateNamedFunctionInvoker(MethodTypeForm typeForm) { 1368 MethodType invokerType = NamedFunction.INVOKER_METHOD_TYPE; 1369 String invokerName = "invoke_" + shortenSignature(basicTypeSignature(typeForm.erasedType())); 1370 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("NFI", invokerName, invokerType); 1371 return g.loadMethod(g.generateNamedFunctionInvokerImpl(typeForm)); 1372 } 1373 generateNamedFunctionInvokerImpl(MethodTypeForm typeForm)1374 private byte[] generateNamedFunctionInvokerImpl(MethodTypeForm typeForm) { 1375 MethodType dstType = typeForm.erasedType(); 1376 classFilePrologue(); 1377 1378 // Suppress this method in backtraces displayed to the user. 1379 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true); 1380 1381 // Force inlining of this invoker method. 1382 mv.visitAnnotation("Ljava/lang/invoke/ForceInline;", true); 1383 1384 // Load receiver 1385 emitAloadInsn(0); 1386 1387 // Load arguments from array 1388 for (int i = 0; i < dstType.parameterCount(); i++) { 1389 emitAloadInsn(1); 1390 emitIconstInsn(i); 1391 mv.visitInsn(Opcodes.AALOAD); 1392 1393 // Maybe unbox 1394 Class<?> dptype = dstType.parameterType(i); 1395 if (dptype.isPrimitive()) { 1396 Class<?> sptype = dstType.basicType().wrap().parameterType(i); 1397 Wrapper dstWrapper = Wrapper.forBasicType(dptype); 1398 Wrapper srcWrapper = dstWrapper.isSubwordOrInt() ? Wrapper.INT : dstWrapper; // narrow subword from int 1399 emitUnboxing(srcWrapper); 1400 emitPrimCast(srcWrapper, dstWrapper); 1401 } 1402 } 1403 1404 // Invoke 1405 String targetDesc = dstType.basicType().toMethodDescriptorString(); 1406 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", targetDesc, false); 1407 1408 // Box primitive types 1409 Class<?> rtype = dstType.returnType(); 1410 if (rtype != void.class && rtype.isPrimitive()) { 1411 Wrapper srcWrapper = Wrapper.forBasicType(rtype); 1412 Wrapper dstWrapper = srcWrapper.isSubwordOrInt() ? Wrapper.INT : srcWrapper; // widen subword to int 1413 // boolean casts not allowed 1414 emitPrimCast(srcWrapper, dstWrapper); 1415 emitBoxing(dstWrapper); 1416 } 1417 1418 // If the return type is void we return a null reference. 1419 if (rtype == void.class) { 1420 mv.visitInsn(Opcodes.ACONST_NULL); 1421 } 1422 emitReturnInsn(L_TYPE); // NOTE: NamedFunction invokers always return a reference value. 1423 1424 classFileEpilogue(); 1425 bogusMethod(dstType); 1426 1427 final byte[] classFile = cw.toByteArray(); 1428 maybeDump(className, classFile); 1429 return classFile; 1430 } 1431 1432 /** 1433 * Emit a bogus method that just loads some string constants. This is to get the constants into the constant pool 1434 * for debugging purposes. 1435 */ bogusMethod(Object... os)1436 private void bogusMethod(Object... os) { 1437 if (DUMP_CLASS_FILES) { 1438 mv = cw.visitMethod(Opcodes.ACC_STATIC, "dummy", "()V", null, null); 1439 for (Object o : os) { 1440 mv.visitLdcInsn(o.toString()); 1441 mv.visitInsn(Opcodes.POP); 1442 } 1443 mv.visitInsn(Opcodes.RETURN); 1444 mv.visitMaxs(0, 0); 1445 mv.visitEnd(); 1446 } 1447 } 1448 } 1449