1 /*
2 * Copyright (c) 2012, 2016, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.lang.invoke;
27
28 import jdk.internal.org.objectweb.asm.ClassWriter;
29 import jdk.internal.org.objectweb.asm.Label;
30 import jdk.internal.org.objectweb.asm.MethodVisitor;
31 import jdk.internal.org.objectweb.asm.Opcodes;
32 import jdk.internal.org.objectweb.asm.Type;
33 import sun.invoke.util.VerifyAccess;
34 import sun.invoke.util.VerifyType;
35 import sun.invoke.util.Wrapper;
36 import sun.reflect.misc.ReflectUtil;
37
38 import java.io.File;
39 import java.io.FileOutputStream;
40 import java.io.IOException;
41 import java.lang.reflect.Modifier;
42 import java.util.ArrayList;
43 import java.util.Arrays;
44 import java.util.HashMap;
45 import java.util.stream.Stream;
46
47 import static java.lang.invoke.LambdaForm.BasicType;
48 import static java.lang.invoke.LambdaForm.BasicType.*;
49 import static java.lang.invoke.LambdaForm.*;
50 import static java.lang.invoke.MethodHandleNatives.Constants.*;
51 import static java.lang.invoke.MethodHandleStatics.*;
52
53 /**
54 * Code generation backend for LambdaForm.
55 * <p>
56 * @author John Rose, JSR 292 EG
57 */
58 class InvokerBytecodeGenerator {
59 /** Define class names for convenience. */
60 private static final String MH = "java/lang/invoke/MethodHandle";
61 private static final String MHI = "java/lang/invoke/MethodHandleImpl";
62 private static final String LF = "java/lang/invoke/LambdaForm";
63 private static final String LFN = "java/lang/invoke/LambdaForm$Name";
64 private static final String CLS = "java/lang/Class";
65 private static final String OBJ = "java/lang/Object";
66 private static final String OBJARY = "[Ljava/lang/Object;";
67
68 private static final String LOOP_CLAUSES = MHI + "$LoopClauses";
69 private static final String MHARY2 = "[[L" + MH + ";";
70
71 private static final String LF_SIG = "L" + LF + ";";
72 private static final String LFN_SIG = "L" + LFN + ";";
73 private static final String LL_SIG = "(L" + OBJ + ";)L" + OBJ + ";";
74 private static final String LLV_SIG = "(L" + OBJ + ";L" + OBJ + ";)V";
75 private static final String CLASS_PREFIX = LF + "$";
76 private static final String SOURCE_PREFIX = "LambdaForm$";
77
78 /** Name of its super class*/
79 static final String INVOKER_SUPER_NAME = OBJ;
80
81 /** Name of new class */
82 private final String className;
83
84 private final LambdaForm lambdaForm;
85 private final String invokerName;
86 private final MethodType invokerType;
87
88 /** Info about local variables in compiled lambda form */
89 private int[] localsMap; // index
90 private Class<?>[] localClasses; // type
91
92 /** ASM bytecode generation. */
93 private ClassWriter cw;
94 private MethodVisitor mv;
95
96 private static final MemberName.Factory MEMBERNAME_FACTORY = MemberName.getFactory();
97 private static final Class<?> HOST_CLASS = LambdaForm.class;
98
99 /** Main constructor; other constructors delegate to this one. */
100 private InvokerBytecodeGenerator(LambdaForm lambdaForm, int localsMapSize,
101 String className, String invokerName, MethodType invokerType) {
102 int p = invokerName.indexOf('.');
103 if (p > -1) {
104 className = invokerName.substring(0, p);
105 invokerName = invokerName.substring(p + 1);
106 }
107 if (DUMP_CLASS_FILES) {
108 className = makeDumpableClassName(className);
109 }
110 this.className = className;
111 this.lambdaForm = lambdaForm;
112 this.invokerName = invokerName;
113 this.invokerType = invokerType;
114 this.localsMap = new int[localsMapSize+1]; // last entry of localsMap is count of allocated local slots
115 this.localClasses = new Class<?>[localsMapSize+1];
116 }
117
118 /** For generating LambdaForm interpreter entry points. */
119 private InvokerBytecodeGenerator(String className, String invokerName, MethodType invokerType) {
120 this(null, invokerType.parameterCount(),
121 className, invokerName, invokerType);
122 // Create an array to map name indexes to locals indexes.
123 for (int i = 0; i < localsMap.length; i++) {
124 localsMap[i] = invokerType.parameterSlotCount() - invokerType.parameterSlotDepth(i);
125 }
126 }
127
128 /** For generating customized code for a single LambdaForm. */
129 private InvokerBytecodeGenerator(String className, LambdaForm form, MethodType invokerType) {
130 this(className, form.lambdaName(), form, invokerType);
131 }
132
133 /** For generating customized code for a single LambdaForm. */
134 InvokerBytecodeGenerator(String className, String invokerName,
135 LambdaForm form, MethodType invokerType) {
136 this(form, form.names.length,
137 className, invokerName, invokerType);
138 // Create an array to map name indexes to locals indexes.
139 Name[] names = form.names;
140 for (int i = 0, index = 0; i < localsMap.length; i++) {
141 localsMap[i] = index;
142 if (i < names.length) {
143 BasicType type = names[i].type();
144 index += type.basicTypeSlots();
145 }
146 }
147 }
148
149 /** instance counters for dumped classes */
150 private static final HashMap<String,Integer> DUMP_CLASS_FILES_COUNTERS;
151 /** debugging flag for saving generated class files */
152 private static final File DUMP_CLASS_FILES_DIR;
153
154 static {
155 if (DUMP_CLASS_FILES) {
156 DUMP_CLASS_FILES_COUNTERS = new HashMap<>();
157 try {
158 File dumpDir = new File("DUMP_CLASS_FILES");
159 if (!dumpDir.exists()) {
160 dumpDir.mkdirs();
161 }
162 DUMP_CLASS_FILES_DIR = dumpDir;
163 System.out.println("Dumping class files to "+DUMP_CLASS_FILES_DIR+"/...");
164 } catch (Exception e) {
165 throw newInternalError(e);
166 }
167 } else {
168 DUMP_CLASS_FILES_COUNTERS = null;
169 DUMP_CLASS_FILES_DIR = null;
170 }
171 }
172
173 private void maybeDump(final byte[] classFile) {
174 if (DUMP_CLASS_FILES) {
175 maybeDump(CLASS_PREFIX + className, classFile);
176 }
177 }
178
179 // Also used from BoundMethodHandle
180 static void maybeDump(final String className, final byte[] classFile) {
181 if (DUMP_CLASS_FILES) {
182 java.security.AccessController.doPrivileged(
183 new java.security.PrivilegedAction<>() {
184 public Void run() {
185 try {
186 String dumpName = className.replace('.','/');
187 //dumpName = dumpName.replace('/', '-');
188 File dumpFile = new File(DUMP_CLASS_FILES_DIR, dumpName+".class");
189 System.out.println("dump: " + dumpFile);
190 dumpFile.getParentFile().mkdirs();
191 FileOutputStream file = new FileOutputStream(dumpFile);
192 file.write(classFile);
193 file.close();
194 return null;
195 } catch (IOException ex) {
196 throw newInternalError(ex);
197 }
198 }
199 });
200 }
201 }
202
203 private static String makeDumpableClassName(String className) {
204 Integer ctr;
205 synchronized (DUMP_CLASS_FILES_COUNTERS) {
206 ctr = DUMP_CLASS_FILES_COUNTERS.get(className);
207 if (ctr == null) ctr = 0;
208 DUMP_CLASS_FILES_COUNTERS.put(className, ctr+1);
209 }
210 String sfx = ctr.toString();
211 while (sfx.length() < 3)
212 sfx = "0"+sfx;
213 className += sfx;
214 return className;
215 }
216
217 class CpPatch {
218 final int index;
219 final Object value;
220 CpPatch(int index, Object value) {
221 this.index = index;
222 this.value = value;
223 }
224 public String toString() {
225 return "CpPatch/index="+index+",value="+value;
226 }
227 }
228
229 private final ArrayList<CpPatch> cpPatches = new ArrayList<>();
230
231 private int cph = 0; // for counting constant placeholders
232
233 String constantPlaceholder(Object arg) {
234 String cpPlaceholder = "CONSTANT_PLACEHOLDER_" + cph++;
235 if (DUMP_CLASS_FILES) cpPlaceholder += " <<" + debugString(arg) + ">>";
236 // TODO check if arg is already in the constant pool
237 // insert placeholder in CP and remember the patch
238 int index = cw.newConst((Object) cpPlaceholder);
239 cpPatches.add(new CpPatch(index, arg));
240 return cpPlaceholder;
241 }
242
243 Object[] cpPatches(byte[] classFile) {
244 int size = getConstantPoolSize(classFile);
245 Object[] res = new Object[size];
246 for (CpPatch p : cpPatches) {
247 if (p.index >= size)
248 throw new InternalError("in cpool["+size+"]: "+p+"\n"+Arrays.toString(Arrays.copyOf(classFile, 20)));
249 res[p.index] = p.value;
250 }
251 return res;
252 }
253
254 private static String debugString(Object arg) {
255 if (arg instanceof MethodHandle) {
256 MethodHandle mh = (MethodHandle) arg;
257 MemberName member = mh.internalMemberName();
258 if (member != null)
259 return member.toString();
260 return mh.debugString();
261 }
262 return arg.toString();
263 }
264
265 /**
266 * Extract the number of constant pool entries from a given class file.
267 *
268 * @param classFile the bytes of the class file in question.
269 * @return the number of entries in the constant pool.
270 */
271 private static int getConstantPoolSize(byte[] classFile) {
272 // The first few bytes:
273 // u4 magic;
274 // u2 minor_version;
275 // u2 major_version;
276 // u2 constant_pool_count;
277 return ((classFile[8] & 0xFF) << 8) | (classFile[9] & 0xFF);
278 }
279
280 /**
281 * Extract the MemberName of a newly-defined method.
282 */
283 private MemberName loadMethod(byte[] classFile) {
284 Class<?> invokerClass = loadAndInitializeInvokerClass(classFile, cpPatches(classFile));
285 return resolveInvokerMember(invokerClass, invokerName, invokerType);
286 }
287
288 /**
289 * Define a given class as anonymous class in the runtime system.
290 */
291 private static Class<?> loadAndInitializeInvokerClass(byte[] classBytes, Object[] patches) {
292 Class<?> invokerClass = UNSAFE.defineAnonymousClass(HOST_CLASS, classBytes, patches);
293 UNSAFE.ensureClassInitialized(invokerClass); // Make sure the class is initialized; VM might complain.
294 return invokerClass;
295 }
296
297 private static MemberName resolveInvokerMember(Class<?> invokerClass, String name, MethodType type) {
298 MemberName member = new MemberName(invokerClass, name, type, REF_invokeStatic);
299 try {
300 member = MEMBERNAME_FACTORY.resolveOrFail(REF_invokeStatic, member, HOST_CLASS, ReflectiveOperationException.class);
301 } catch (ReflectiveOperationException e) {
302 throw newInternalError(e);
303 }
304 return member;
305 }
306
307 /**
308 * Set up class file generation.
309 */
310 private ClassWriter classFilePrologue() {
311 final int NOT_ACC_PUBLIC = 0; // not ACC_PUBLIC
312 cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES);
313 cw.visit(Opcodes.V1_8, NOT_ACC_PUBLIC + Opcodes.ACC_FINAL + Opcodes.ACC_SUPER,
314 CLASS_PREFIX + className, null, INVOKER_SUPER_NAME, null);
315 cw.visitSource(SOURCE_PREFIX + className, null);
316 return cw;
317 }
318
319 private void methodPrologue() {
320 String invokerDesc = invokerType.toMethodDescriptorString();
321 mv = cw.visitMethod(Opcodes.ACC_STATIC, invokerName, invokerDesc, null, null);
322 }
323
324 /**
325 * Tear down class file generation.
326 */
327 private void methodEpilogue() {
328 mv.visitMaxs(0, 0);
329 mv.visitEnd();
330 }
331
332 /*
333 * Low-level emit helpers.
334 */
335 private void emitConst(Object con) {
336 if (con == null) {
337 mv.visitInsn(Opcodes.ACONST_NULL);
338 return;
339 }
340 if (con instanceof Integer) {
341 emitIconstInsn((int) con);
342 return;
343 }
344 if (con instanceof Byte) {
345 emitIconstInsn((byte)con);
346 return;
347 }
348 if (con instanceof Short) {
349 emitIconstInsn((short)con);
350 return;
351 }
352 if (con instanceof Character) {
353 emitIconstInsn((char)con);
354 return;
355 }
356 if (con instanceof Long) {
357 long x = (long) con;
358 short sx = (short)x;
359 if (x == sx) {
360 if (sx >= 0 && sx <= 1) {
361 mv.visitInsn(Opcodes.LCONST_0 + (int) sx);
362 } else {
363 emitIconstInsn((int) x);
364 mv.visitInsn(Opcodes.I2L);
365 }
366 return;
367 }
368 }
369 if (con instanceof Float) {
370 float x = (float) con;
371 short sx = (short)x;
372 if (x == sx) {
373 if (sx >= 0 && sx <= 2) {
374 mv.visitInsn(Opcodes.FCONST_0 + (int) sx);
375 } else {
376 emitIconstInsn((int) x);
377 mv.visitInsn(Opcodes.I2F);
378 }
379 return;
380 }
381 }
382 if (con instanceof Double) {
383 double x = (double) con;
384 short sx = (short)x;
385 if (x == sx) {
386 if (sx >= 0 && sx <= 1) {
387 mv.visitInsn(Opcodes.DCONST_0 + (int) sx);
388 } else {
389 emitIconstInsn((int) x);
390 mv.visitInsn(Opcodes.I2D);
391 }
392 return;
393 }
394 }
395 if (con instanceof Boolean) {
396 emitIconstInsn((boolean) con ? 1 : 0);
397 return;
398 }
399 // fall through:
400 mv.visitLdcInsn(con);
401 }
402
403 private void emitIconstInsn(final int cst) {
404 if (cst >= -1 && cst <= 5) {
405 mv.visitInsn(Opcodes.ICONST_0 + cst);
406 } else if (cst >= Byte.MIN_VALUE && cst <= Byte.MAX_VALUE) {
407 mv.visitIntInsn(Opcodes.BIPUSH, cst);
408 } else if (cst >= Short.MIN_VALUE && cst <= Short.MAX_VALUE) {
409 mv.visitIntInsn(Opcodes.SIPUSH, cst);
410 } else {
411 mv.visitLdcInsn(cst);
412 }
413 }
414
415 /*
416 * NOTE: These load/store methods use the localsMap to find the correct index!
417 */
418 private void emitLoadInsn(BasicType type, int index) {
419 int opcode = loadInsnOpcode(type);
420 mv.visitVarInsn(opcode, localsMap[index]);
421 }
422
423 private int loadInsnOpcode(BasicType type) throws InternalError {
424 switch (type) {
425 case I_TYPE: return Opcodes.ILOAD;
426 case J_TYPE: return Opcodes.LLOAD;
427 case F_TYPE: return Opcodes.FLOAD;
428 case D_TYPE: return Opcodes.DLOAD;
429 case L_TYPE: return Opcodes.ALOAD;
430 default:
431 throw new InternalError("unknown type: " + type);
432 }
433 }
434 private void emitAloadInsn(int index) {
435 emitLoadInsn(L_TYPE, index);
436 }
437
438 private void emitStoreInsn(BasicType type, int index) {
439 int opcode = storeInsnOpcode(type);
440 mv.visitVarInsn(opcode, localsMap[index]);
441 }
442
443 private int storeInsnOpcode(BasicType type) throws InternalError {
444 switch (type) {
445 case I_TYPE: return Opcodes.ISTORE;
446 case J_TYPE: return Opcodes.LSTORE;
447 case F_TYPE: return Opcodes.FSTORE;
448 case D_TYPE: return Opcodes.DSTORE;
449 case L_TYPE: return Opcodes.ASTORE;
450 default:
451 throw new InternalError("unknown type: " + type);
452 }
453 }
454 private void emitAstoreInsn(int index) {
455 emitStoreInsn(L_TYPE, index);
456 }
457
458 private byte arrayTypeCode(Wrapper elementType) {
459 switch (elementType) {
460 case BOOLEAN: return Opcodes.T_BOOLEAN;
461 case BYTE: return Opcodes.T_BYTE;
462 case CHAR: return Opcodes.T_CHAR;
463 case SHORT: return Opcodes.T_SHORT;
464 case INT: return Opcodes.T_INT;
465 case LONG: return Opcodes.T_LONG;
466 case FLOAT: return Opcodes.T_FLOAT;
467 case DOUBLE: return Opcodes.T_DOUBLE;
468 case OBJECT: return 0; // in place of Opcodes.T_OBJECT
469 default: throw new InternalError();
470 }
471 }
472
473 private int arrayInsnOpcode(byte tcode, int aaop) throws InternalError {
474 assert(aaop == Opcodes.AASTORE || aaop == Opcodes.AALOAD);
475 int xas;
476 switch (tcode) {
477 case Opcodes.T_BOOLEAN: xas = Opcodes.BASTORE; break;
478 case Opcodes.T_BYTE: xas = Opcodes.BASTORE; break;
479 case Opcodes.T_CHAR: xas = Opcodes.CASTORE; break;
480 case Opcodes.T_SHORT: xas = Opcodes.SASTORE; break;
481 case Opcodes.T_INT: xas = Opcodes.IASTORE; break;
482 case Opcodes.T_LONG: xas = Opcodes.LASTORE; break;
483 case Opcodes.T_FLOAT: xas = Opcodes.FASTORE; break;
484 case Opcodes.T_DOUBLE: xas = Opcodes.DASTORE; break;
485 case 0: xas = Opcodes.AASTORE; break;
486 default: throw new InternalError();
487 }
488 return xas - Opcodes.AASTORE + aaop;
489 }
490
491 /**
492 * Emit a boxing call.
493 *
494 * @param wrapper primitive type class to box.
495 */
496 private void emitBoxing(Wrapper wrapper) {
497 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName();
498 String name = "valueOf";
499 String desc = "(" + wrapper.basicTypeChar() + ")L" + owner + ";";
500 mv.visitMethodInsn(Opcodes.INVOKESTATIC, owner, name, desc, false);
501 }
502
503 /**
504 * Emit an unboxing call (plus preceding checkcast).
505 *
506 * @param wrapper wrapper type class to unbox.
507 */
508 private void emitUnboxing(Wrapper wrapper) {
509 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName();
510 String name = wrapper.primitiveSimpleName() + "Value";
511 String desc = "()" + wrapper.basicTypeChar();
512 emitReferenceCast(wrapper.wrapperType(), null);
513 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, owner, name, desc, false);
514 }
515
516 /**
517 * Emit an implicit conversion for an argument which must be of the given pclass.
518 * This is usually a no-op, except when pclass is a subword type or a reference other than Object or an interface.
519 *
520 * @param ptype type of value present on stack
521 * @param pclass type of value required on stack
522 * @param arg compile-time representation of value on stack (Node, constant) or null if none
523 */
524 private void emitImplicitConversion(BasicType ptype, Class<?> pclass, Object arg) {
525 assert(basicType(pclass) == ptype); // boxing/unboxing handled by caller
526 if (pclass == ptype.basicTypeClass() && ptype != L_TYPE)
527 return; // nothing to do
528 switch (ptype) {
529 case L_TYPE:
530 if (VerifyType.isNullConversion(Object.class, pclass, false)) {
531 if (PROFILE_LEVEL > 0)
532 emitReferenceCast(Object.class, arg);
533 return;
534 }
535 emitReferenceCast(pclass, arg);
536 return;
537 case I_TYPE:
538 if (!VerifyType.isNullConversion(int.class, pclass, false))
539 emitPrimCast(ptype.basicTypeWrapper(), Wrapper.forPrimitiveType(pclass));
540 return;
541 }
542 throw newInternalError("bad implicit conversion: tc="+ptype+": "+pclass);
543 }
544
545 /** Update localClasses type map. Return true if the information is already present. */
546 private boolean assertStaticType(Class<?> cls, Name n) {
547 int local = n.index();
548 Class<?> aclass = localClasses[local];
549 if (aclass != null && (aclass == cls || cls.isAssignableFrom(aclass))) {
550 return true; // type info is already present
551 } else if (aclass == null || aclass.isAssignableFrom(cls)) {
552 localClasses[local] = cls; // type info can be improved
553 }
554 return false;
555 }
556
557 private void emitReferenceCast(Class<?> cls, Object arg) {
558 Name writeBack = null; // local to write back result
559 if (arg instanceof Name) {
560 Name n = (Name) arg;
561 if (lambdaForm.useCount(n) > 1) {
562 // This guy gets used more than once.
563 writeBack = n;
564 if (assertStaticType(cls, n)) {
565 return; // this cast was already performed
566 }
567 }
568 }
569 if (isStaticallyNameable(cls)) {
570 String sig = getInternalName(cls);
571 mv.visitTypeInsn(Opcodes.CHECKCAST, sig);
572 } else {
573 mv.visitLdcInsn(constantPlaceholder(cls));
574 mv.visitTypeInsn(Opcodes.CHECKCAST, CLS);
575 mv.visitInsn(Opcodes.SWAP);
576 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, CLS, "cast", LL_SIG, false);
577 if (Object[].class.isAssignableFrom(cls))
578 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJARY);
579 else if (PROFILE_LEVEL > 0)
580 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJ);
581 }
582 if (writeBack != null) {
583 mv.visitInsn(Opcodes.DUP);
584 emitAstoreInsn(writeBack.index());
585 }
586 }
587
588 /**
589 * Emits an actual return instruction conforming to the given return type.
590 */
591 private void emitReturnInsn(BasicType type) {
592 int opcode;
593 switch (type) {
594 case I_TYPE: opcode = Opcodes.IRETURN; break;
595 case J_TYPE: opcode = Opcodes.LRETURN; break;
596 case F_TYPE: opcode = Opcodes.FRETURN; break;
597 case D_TYPE: opcode = Opcodes.DRETURN; break;
598 case L_TYPE: opcode = Opcodes.ARETURN; break;
599 case V_TYPE: opcode = Opcodes.RETURN; break;
600 default:
601 throw new InternalError("unknown return type: " + type);
602 }
603 mv.visitInsn(opcode);
604 }
605
606 private static String getInternalName(Class<?> c) {
607 if (c == Object.class) return OBJ;
608 else if (c == Object[].class) return OBJARY;
609 else if (c == Class.class) return CLS;
610 else if (c == MethodHandle.class) return MH;
611 assert(VerifyAccess.isTypeVisible(c, Object.class)) : c.getName();
612 return c.getName().replace('.', '/');
613 }
614
615 private static MemberName resolveFrom(String name, MethodType type, Class<?> holder) {
616 MemberName member = new MemberName(holder, name, type, REF_invokeStatic);
617 MemberName resolvedMember = MemberName.getFactory().resolveOrNull(REF_invokeStatic, member, holder);
618 if (TRACE_RESOLVE) {
619 System.out.println("[LF_RESOLVE] " + holder.getName() + " " + name + " " +
620 shortenSignature(basicTypeSignature(type)) + (resolvedMember != null ? " (success)" : " (fail)") );
621 }
622 return resolvedMember;
623 }
624
625 private static MemberName lookupPregenerated(LambdaForm form, MethodType invokerType) {
626 if (form.customized != null) {
627 // No pre-generated version for customized LF
628 return null;
629 }
630 String name = form.kind.methodName;
631 switch (form.kind) {
632 case BOUND_REINVOKER: {
633 name = name + "_" + BoundMethodHandle.formSpeciesData(form).key();
634 return resolveFrom(name, invokerType, DelegatingMethodHandle.Holder.class);
635 }
636 case DELEGATE: return resolveFrom(name, invokerType, DelegatingMethodHandle.Holder.class);
637 case ZERO: // fall-through
638 case IDENTITY: {
639 name = name + "_" + form.returnType().basicTypeChar();
640 return resolveFrom(name, invokerType, LambdaForm.Holder.class);
641 }
642 case EXACT_INVOKER: // fall-through
643 case EXACT_LINKER: // fall-through
644 case GENERIC_INVOKER: // fall-through
645 case GENERIC_LINKER: return resolveFrom(name, invokerType.basicType(), Invokers.Holder.class);
646 case GET_OBJECT: // fall-through
647 case GET_BOOLEAN: // fall-through
648 case GET_BYTE: // fall-through
649 case GET_CHAR: // fall-through
650 case GET_SHORT: // fall-through
651 case GET_INT: // fall-through
652 case GET_LONG: // fall-through
653 case GET_FLOAT: // fall-through
654 case GET_DOUBLE: // fall-through
655 case PUT_OBJECT: // fall-through
656 case PUT_BOOLEAN: // fall-through
657 case PUT_BYTE: // fall-through
658 case PUT_CHAR: // fall-through
659 case PUT_SHORT: // fall-through
660 case PUT_INT: // fall-through
661 case PUT_LONG: // fall-through
662 case PUT_FLOAT: // fall-through
663 case PUT_DOUBLE: // fall-through
664 case DIRECT_INVOKE_INTERFACE: // fall-through
665 case DIRECT_INVOKE_SPECIAL: // fall-through
666 case DIRECT_INVOKE_STATIC: // fall-through
667 case DIRECT_INVOKE_STATIC_INIT: // fall-through
668 case DIRECT_INVOKE_VIRTUAL: return resolveFrom(name, invokerType, DirectMethodHandle.Holder.class);
669 }
670 return null;
671 }
672
673 /**
674 * Generate customized bytecode for a given LambdaForm.
675 */
676 static MemberName generateCustomizedCode(LambdaForm form, MethodType invokerType) {
677 MemberName pregenerated = lookupPregenerated(form, invokerType);
678 if (pregenerated != null) return pregenerated; // pre-generated bytecode
679
680 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("MH", form, invokerType);
681 return g.loadMethod(g.generateCustomizedCodeBytes());
682 }
683
684 /** Generates code to check that actual receiver and LambdaForm matches */
685 private boolean checkActualReceiver() {
686 // Expects MethodHandle on the stack and actual receiver MethodHandle in slot #0
687 mv.visitInsn(Opcodes.DUP);
688 mv.visitVarInsn(Opcodes.ALOAD, localsMap[0]);
689 mv.visitMethodInsn(Opcodes.INVOKESTATIC, MHI, "assertSame", LLV_SIG, false);
690 return true;
691 }
692
693 static String className(String cn) {
694 assert checkClassName(cn): "Class not found: " + cn;
695 return cn;
696 }
697
698 static boolean checkClassName(String cn) {
699 Type tp = Type.getType(cn);
700 // additional sanity so only valid "L;" descriptors work
701 if (tp.getSort() != Type.OBJECT) {
702 return false;
703 }
704 try {
705 Class<?> c = Class.forName(tp.getClassName(), false, null);
706 return true;
707 } catch (ClassNotFoundException e) {
708 return false;
709 }
710 }
711
712 static final String LF_HIDDEN_SIG = className("Ljava/lang/invoke/LambdaForm$Hidden;");
713 static final String LF_COMPILED_SIG = className("Ljava/lang/invoke/LambdaForm$Compiled;");
714 static final String FORCEINLINE_SIG = className("Ljdk/internal/vm/annotation/ForceInline;");
715 static final String DONTINLINE_SIG = className("Ljdk/internal/vm/annotation/DontInline;");
716 static final String INJECTEDPROFILE_SIG = className("Ljava/lang/invoke/InjectedProfile;");
717
718 /**
719 * Generate an invoker method for the passed {@link LambdaForm}.
720 */
721 private byte[] generateCustomizedCodeBytes() {
722 classFilePrologue();
723 addMethod();
724 bogusMethod(lambdaForm);
725
726 final byte[] classFile = toByteArray();
727 maybeDump(classFile);
728 return classFile;
729 }
730
731 void setClassWriter(ClassWriter cw) {
732 this.cw = cw;
733 }
734
735 void addMethod() {
736 methodPrologue();
737
738 // Suppress this method in backtraces displayed to the user.
739 mv.visitAnnotation(LF_HIDDEN_SIG, true);
740
741 // Mark this method as a compiled LambdaForm
742 mv.visitAnnotation(LF_COMPILED_SIG, true);
743
744 if (lambdaForm.forceInline) {
745 // Force inlining of this invoker method.
746 mv.visitAnnotation(FORCEINLINE_SIG, true);
747 } else {
748 mv.visitAnnotation(DONTINLINE_SIG, true);
749 }
750
751 constantPlaceholder(lambdaForm); // keep LambdaForm instance & its compiled form lifetime tightly coupled.
752
753 if (lambdaForm.customized != null) {
754 // Since LambdaForm is customized for a particular MethodHandle, it's safe to substitute
755 // receiver MethodHandle (at slot #0) with an embedded constant and use it instead.
756 // It enables more efficient code generation in some situations, since embedded constants
757 // are compile-time constants for JIT compiler.
758 mv.visitLdcInsn(constantPlaceholder(lambdaForm.customized));
759 mv.visitTypeInsn(Opcodes.CHECKCAST, MH);
760 assert(checkActualReceiver()); // expects MethodHandle on top of the stack
761 mv.visitVarInsn(Opcodes.ASTORE, localsMap[0]);
762 }
763
764 // iterate over the form's names, generating bytecode instructions for each
765 // start iterating at the first name following the arguments
766 Name onStack = null;
767 for (int i = lambdaForm.arity; i < lambdaForm.names.length; i++) {
768 Name name = lambdaForm.names[i];
769
770 emitStoreResult(onStack);
771 onStack = name; // unless otherwise modified below
772 MethodHandleImpl.Intrinsic intr = name.function.intrinsicName();
773 switch (intr) {
774 case SELECT_ALTERNATIVE:
775 assert lambdaForm.isSelectAlternative(i);
776 if (PROFILE_GWT) {
777 assert(name.arguments[0] instanceof Name &&
778 ((Name)name.arguments[0]).refersTo(MethodHandleImpl.class, "profileBoolean"));
779 mv.visitAnnotation(INJECTEDPROFILE_SIG, true);
780 }
781 onStack = emitSelectAlternative(name, lambdaForm.names[i+1]);
782 i++; // skip MH.invokeBasic of the selectAlternative result
783 continue;
784 case GUARD_WITH_CATCH:
785 assert lambdaForm.isGuardWithCatch(i);
786 onStack = emitGuardWithCatch(i);
787 i += 2; // jump to the end of GWC idiom
788 continue;
789 case TRY_FINALLY:
790 assert lambdaForm.isTryFinally(i);
791 onStack = emitTryFinally(i);
792 i += 2; // jump to the end of the TF idiom
793 continue;
794 case LOOP:
795 assert lambdaForm.isLoop(i);
796 onStack = emitLoop(i);
797 i += 2; // jump to the end of the LOOP idiom
798 continue;
799 case NEW_ARRAY:
800 Class<?> rtype = name.function.methodType().returnType();
801 if (isStaticallyNameable(rtype)) {
802 emitNewArray(name);
803 continue;
804 }
805 break;
806 case ARRAY_LOAD:
807 emitArrayLoad(name);
808 continue;
809 case ARRAY_STORE:
810 emitArrayStore(name);
811 continue;
812 case ARRAY_LENGTH:
813 emitArrayLength(name);
814 continue;
815 case IDENTITY:
816 assert(name.arguments.length == 1);
817 emitPushArguments(name, 0);
818 continue;
819 case ZERO:
820 assert(name.arguments.length == 0);
821 emitConst(name.type.basicTypeWrapper().zero());
822 continue;
823 case NONE:
824 // no intrinsic associated
825 break;
826 default:
827 throw newInternalError("Unknown intrinsic: "+intr);
828 }
829
830 MemberName member = name.function.member();
831 if (isStaticallyInvocable(member)) {
832 emitStaticInvoke(member, name);
833 } else {
834 emitInvoke(name);
835 }
836 }
837
838 // return statement
839 emitReturn(onStack);
840
841 methodEpilogue();
842 }
843
844 /*
845 * @throws BytecodeGenerationException if something goes wrong when
846 * generating the byte code
847 */
848 private byte[] toByteArray() {
849 try {
850 return cw.toByteArray();
851 } catch (RuntimeException e) {
852 throw new BytecodeGenerationException(e);
853 }
854 }
855
856 @SuppressWarnings("serial")
857 static final class BytecodeGenerationException extends RuntimeException {
858 BytecodeGenerationException(Exception cause) {
859 super(cause);
860 }
861 }
862
863 void emitArrayLoad(Name name) { emitArrayOp(name, Opcodes.AALOAD); }
864 void emitArrayStore(Name name) { emitArrayOp(name, Opcodes.AASTORE); }
865 void emitArrayLength(Name name) { emitArrayOp(name, Opcodes.ARRAYLENGTH); }
866
867 void emitArrayOp(Name name, int arrayOpcode) {
868 assert arrayOpcode == Opcodes.AALOAD || arrayOpcode == Opcodes.AASTORE || arrayOpcode == Opcodes.ARRAYLENGTH;
869 Class<?> elementType = name.function.methodType().parameterType(0).getComponentType();
870 assert elementType != null;
871 emitPushArguments(name, 0);
872 if (arrayOpcode != Opcodes.ARRAYLENGTH && elementType.isPrimitive()) {
873 Wrapper w = Wrapper.forPrimitiveType(elementType);
874 arrayOpcode = arrayInsnOpcode(arrayTypeCode(w), arrayOpcode);
875 }
876 mv.visitInsn(arrayOpcode);
877 }
878
879 /**
880 * Emit an invoke for the given name.
881 */
882 void emitInvoke(Name name) {
883 assert(!name.isLinkerMethodInvoke()); // should use the static path for these
884 if (true) {
885 // push receiver
886 MethodHandle target = name.function.resolvedHandle();
887 assert(target != null) : name.exprString();
888 mv.visitLdcInsn(constantPlaceholder(target));
889 emitReferenceCast(MethodHandle.class, target);
890 } else {
891 // load receiver
892 emitAloadInsn(0);
893 emitReferenceCast(MethodHandle.class, null);
894 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", LF_SIG);
895 mv.visitFieldInsn(Opcodes.GETFIELD, LF, "names", LFN_SIG);
896 // TODO more to come
897 }
898
899 // push arguments
900 emitPushArguments(name, 0);
901
902 // invocation
903 MethodType type = name.function.methodType();
904 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false);
905 }
906
907 private static Class<?>[] STATICALLY_INVOCABLE_PACKAGES = {
908 // Sample classes from each package we are willing to bind to statically:
909 java.lang.Object.class,
910 java.util.Arrays.class,
911 jdk.internal.misc.Unsafe.class
912 //MethodHandle.class already covered
913 };
914
915 static boolean isStaticallyInvocable(NamedFunction ... functions) {
916 for (NamedFunction nf : functions) {
917 if (!isStaticallyInvocable(nf.member())) {
918 return false;
919 }
920 }
921 return true;
922 }
923
924 static boolean isStaticallyInvocable(Name name) {
925 return isStaticallyInvocable(name.function.member());
926 }
927
928 static boolean isStaticallyInvocable(MemberName member) {
929 if (member == null) return false;
930 if (member.isConstructor()) return false;
931 Class<?> cls = member.getDeclaringClass();
932 if (cls.isArray() || cls.isPrimitive())
933 return false; // FIXME
934 if (cls.isAnonymousClass() || cls.isLocalClass())
935 return false; // inner class of some sort
936 if (cls.getClassLoader() != MethodHandle.class.getClassLoader())
937 return false; // not on BCP
938 if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: switch to supported API once it is added
939 return false;
940 MethodType mtype = member.getMethodOrFieldType();
941 if (!isStaticallyNameable(mtype.returnType()))
942 return false;
943 for (Class<?> ptype : mtype.parameterArray())
944 if (!isStaticallyNameable(ptype))
945 return false;
946 if (!member.isPrivate() && VerifyAccess.isSamePackage(MethodHandle.class, cls))
947 return true; // in java.lang.invoke package
948 if (member.isPublic() && isStaticallyNameable(cls))
949 return true;
950 return false;
951 }
952
953 static boolean isStaticallyNameable(Class<?> cls) {
954 if (cls == Object.class)
955 return true;
956 while (cls.isArray())
957 cls = cls.getComponentType();
958 if (cls.isPrimitive())
959 return true; // int[].class, for example
960 if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: switch to supported API once it is added
961 return false;
962 // could use VerifyAccess.isClassAccessible but the following is a safe approximation
963 if (cls.getClassLoader() != Object.class.getClassLoader())
964 return false;
965 if (VerifyAccess.isSamePackage(MethodHandle.class, cls))
966 return true;
967 if (!Modifier.isPublic(cls.getModifiers()))
968 return false;
969 for (Class<?> pkgcls : STATICALLY_INVOCABLE_PACKAGES) {
970 if (VerifyAccess.isSamePackage(pkgcls, cls))
971 return true;
972 }
973 return false;
974 }
975
976 void emitStaticInvoke(Name name) {
977 emitStaticInvoke(name.function.member(), name);
978 }
979
980 /**
981 * Emit an invoke for the given name, using the MemberName directly.
982 */
983 void emitStaticInvoke(MemberName member, Name name) {
984 assert(member.equals(name.function.member()));
985 Class<?> defc = member.getDeclaringClass();
986 String cname = getInternalName(defc);
987 String mname = member.getName();
988 String mtype;
989 byte refKind = member.getReferenceKind();
990 if (refKind == REF_invokeSpecial) {
991 // in order to pass the verifier, we need to convert this to invokevirtual in all cases
992 assert(member.canBeStaticallyBound()) : member;
993 refKind = REF_invokeVirtual;
994 }
995
996 assert(!(member.getDeclaringClass().isInterface() && refKind == REF_invokeVirtual));
997
998 // push arguments
999 emitPushArguments(name, 0);
1000
1001 // invocation
1002 if (member.isMethod()) {
1003 mtype = member.getMethodType().toMethodDescriptorString();
1004 mv.visitMethodInsn(refKindOpcode(refKind), cname, mname, mtype,
1005 member.getDeclaringClass().isInterface());
1006 } else {
1007 mtype = MethodType.toFieldDescriptorString(member.getFieldType());
1008 mv.visitFieldInsn(refKindOpcode(refKind), cname, mname, mtype);
1009 }
1010 // Issue a type assertion for the result, so we can avoid casts later.
1011 if (name.type == L_TYPE) {
1012 Class<?> rtype = member.getInvocationType().returnType();
1013 assert(!rtype.isPrimitive());
1014 if (rtype != Object.class && !rtype.isInterface()) {
1015 assertStaticType(rtype, name);
1016 }
1017 }
1018 }
1019
1020 void emitNewArray(Name name) throws InternalError {
1021 Class<?> rtype = name.function.methodType().returnType();
1022 if (name.arguments.length == 0) {
1023 // The array will be a constant.
1024 Object emptyArray;
1025 try {
1026 emptyArray = name.function.resolvedHandle().invoke();
1027 } catch (Throwable ex) {
1028 throw uncaughtException(ex);
1029 }
1030 assert(java.lang.reflect.Array.getLength(emptyArray) == 0);
1031 assert(emptyArray.getClass() == rtype); // exact typing
1032 mv.visitLdcInsn(constantPlaceholder(emptyArray));
1033 emitReferenceCast(rtype, emptyArray);
1034 return;
1035 }
1036 Class<?> arrayElementType = rtype.getComponentType();
1037 assert(arrayElementType != null);
1038 emitIconstInsn(name.arguments.length);
1039 int xas = Opcodes.AASTORE;
1040 if (!arrayElementType.isPrimitive()) {
1041 mv.visitTypeInsn(Opcodes.ANEWARRAY, getInternalName(arrayElementType));
1042 } else {
1043 byte tc = arrayTypeCode(Wrapper.forPrimitiveType(arrayElementType));
1044 xas = arrayInsnOpcode(tc, xas);
1045 mv.visitIntInsn(Opcodes.NEWARRAY, tc);
1046 }
1047 // store arguments
1048 for (int i = 0; i < name.arguments.length; i++) {
1049 mv.visitInsn(Opcodes.DUP);
1050 emitIconstInsn(i);
1051 emitPushArgument(name, i);
1052 mv.visitInsn(xas);
1053 }
1054 // the array is left on the stack
1055 assertStaticType(rtype, name);
1056 }
1057 int refKindOpcode(byte refKind) {
1058 switch (refKind) {
1059 case REF_invokeVirtual: return Opcodes.INVOKEVIRTUAL;
1060 case REF_invokeStatic: return Opcodes.INVOKESTATIC;
1061 case REF_invokeSpecial: return Opcodes.INVOKESPECIAL;
1062 case REF_invokeInterface: return Opcodes.INVOKEINTERFACE;
1063 case REF_getField: return Opcodes.GETFIELD;
1064 case REF_putField: return Opcodes.PUTFIELD;
1065 case REF_getStatic: return Opcodes.GETSTATIC;
1066 case REF_putStatic: return Opcodes.PUTSTATIC;
1067 }
1068 throw new InternalError("refKind="+refKind);
1069 }
1070
1071 /**
1072 * Emit bytecode for the selectAlternative idiom.
1073 *
1074 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithTest):
1075 * <blockquote><pre>{@code
1076 * Lambda(a0:L,a1:I)=>{
1077 * t2:I=foo.test(a1:I);
1078 * t3:L=MethodHandleImpl.selectAlternative(t2:I,(MethodHandle(int)int),(MethodHandle(int)int));
1079 * t4:I=MethodHandle.invokeBasic(t3:L,a1:I);t4:I}
1080 * }</pre></blockquote>
1081 */
1082 private Name emitSelectAlternative(Name selectAlternativeName, Name invokeBasicName) {
1083 assert isStaticallyInvocable(invokeBasicName);
1084
1085 Name receiver = (Name) invokeBasicName.arguments[0];
1086
1087 Label L_fallback = new Label();
1088 Label L_done = new Label();
1089
1090 // load test result
1091 emitPushArgument(selectAlternativeName, 0);
1092
1093 // if_icmpne L_fallback
1094 mv.visitJumpInsn(Opcodes.IFEQ, L_fallback);
1095
1096 // invoke selectAlternativeName.arguments[1]
1097 Class<?>[] preForkClasses = localClasses.clone();
1098 emitPushArgument(selectAlternativeName, 1); // get 2nd argument of selectAlternative
1099 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot
1100 emitStaticInvoke(invokeBasicName);
1101
1102 // goto L_done
1103 mv.visitJumpInsn(Opcodes.GOTO, L_done);
1104
1105 // L_fallback:
1106 mv.visitLabel(L_fallback);
1107
1108 // invoke selectAlternativeName.arguments[2]
1109 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length);
1110 emitPushArgument(selectAlternativeName, 2); // get 3rd argument of selectAlternative
1111 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot
1112 emitStaticInvoke(invokeBasicName);
1113
1114 // L_done:
1115 mv.visitLabel(L_done);
1116 // for now do not bother to merge typestate; just reset to the dominator state
1117 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length);
1118
1119 return invokeBasicName; // return what's on stack
1120 }
1121
1122 /**
1123 * Emit bytecode for the guardWithCatch idiom.
1124 *
1125 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithCatch):
1126 * <blockquote><pre>{@code
1127 * guardWithCatch=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L,a5:L,a6:L,a7:L)=>{
1128 * t8:L=MethodHandle.invokeBasic(a4:L,a6:L,a7:L);
1129 * t9:L=MethodHandleImpl.guardWithCatch(a1:L,a2:L,a3:L,t8:L);
1130 * t10:I=MethodHandle.invokeBasic(a5:L,t9:L);t10:I}
1131 * }</pre></blockquote>
1132 *
1133 * It is compiled into bytecode equivalent of the following code:
1134 * <blockquote><pre>{@code
1135 * try {
1136 * return a1.invokeBasic(a6, a7);
1137 * } catch (Throwable e) {
1138 * if (!a2.isInstance(e)) throw e;
1139 * return a3.invokeBasic(ex, a6, a7);
1140 * }}
1141 */
1142 private Name emitGuardWithCatch(int pos) {
1143 Name args = lambdaForm.names[pos];
1144 Name invoker = lambdaForm.names[pos+1];
1145 Name result = lambdaForm.names[pos+2];
1146
1147 Label L_startBlock = new Label();
1148 Label L_endBlock = new Label();
1149 Label L_handler = new Label();
1150 Label L_done = new Label();
1151
1152 Class<?> returnType = result.function.resolvedHandle().type().returnType();
1153 MethodType type = args.function.resolvedHandle().type()
1154 .dropParameterTypes(0,1)
1155 .changeReturnType(returnType);
1156
1157 mv.visitTryCatchBlock(L_startBlock, L_endBlock, L_handler, "java/lang/Throwable");
1158
1159 // Normal case
1160 mv.visitLabel(L_startBlock);
1161 // load target
1162 emitPushArgument(invoker, 0);
1163 emitPushArguments(args, 1); // skip 1st argument: method handle
1164 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false);
1165 mv.visitLabel(L_endBlock);
1166 mv.visitJumpInsn(Opcodes.GOTO, L_done);
1167
1168 // Exceptional case
1169 mv.visitLabel(L_handler);
1170
1171 // Check exception's type
1172 mv.visitInsn(Opcodes.DUP);
1173 // load exception class
1174 emitPushArgument(invoker, 1);
1175 mv.visitInsn(Opcodes.SWAP);
1176 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/Class", "isInstance", "(Ljava/lang/Object;)Z", false);
1177 Label L_rethrow = new Label();
1178 mv.visitJumpInsn(Opcodes.IFEQ, L_rethrow);
1179
1180 // Invoke catcher
1181 // load catcher
1182 emitPushArgument(invoker, 2);
1183 mv.visitInsn(Opcodes.SWAP);
1184 emitPushArguments(args, 1); // skip 1st argument: method handle
1185 MethodType catcherType = type.insertParameterTypes(0, Throwable.class);
1186 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", catcherType.basicType().toMethodDescriptorString(), false);
1187 mv.visitJumpInsn(Opcodes.GOTO, L_done);
1188
1189 mv.visitLabel(L_rethrow);
1190 mv.visitInsn(Opcodes.ATHROW);
1191
1192 mv.visitLabel(L_done);
1193
1194 return result;
1195 }
1196
1197 /**
1198 * Emit bytecode for the tryFinally idiom.
1199 * <p>
1200 * The pattern looks like (Cf. MethodHandleImpl.makeTryFinally):
1201 * <blockquote><pre>{@code
1202 * // a0: BMH
1203 * // a1: target, a2: cleanup
1204 * // a3: box, a4: unbox
1205 * // a5 (and following): arguments
1206 * tryFinally=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L,a5:L)=>{
1207 * t6:L=MethodHandle.invokeBasic(a3:L,a5:L); // box the arguments into an Object[]
1208 * t7:L=MethodHandleImpl.tryFinally(a1:L,a2:L,t6:L); // call the tryFinally executor
1209 * t8:L=MethodHandle.invokeBasic(a4:L,t7:L);t8:L} // unbox the result; return the result
1210 * }</pre></blockquote>
1211 * <p>
1212 * It is compiled into bytecode equivalent to the following code:
1213 * <blockquote><pre>{@code
1214 * Throwable t;
1215 * Object r;
1216 * try {
1217 * r = a1.invokeBasic(a5);
1218 * } catch (Throwable thrown) {
1219 * t = thrown;
1220 * throw t;
1221 * } finally {
1222 * r = a2.invokeBasic(t, r, a5);
1223 * }
1224 * return r;
1225 * }</pre></blockquote>
1226 * <p>
1227 * Specifically, the bytecode will have the following form (the stack effects are given for the beginnings of
1228 * blocks, and for the situations after executing the given instruction - the code will have a slightly different
1229 * shape if the return type is {@code void}):
1230 * <blockquote><pre>{@code
1231 * TRY: (--)
1232 * load target (-- target)
1233 * load args (-- args... target)
1234 * INVOKEVIRTUAL MethodHandle.invokeBasic (depends)
1235 * FINALLY_NORMAL: (-- r)
1236 * load cleanup (-- cleanup r)
1237 * SWAP (-- r cleanup)
1238 * ACONST_NULL (-- t r cleanup)
1239 * SWAP (-- r t cleanup)
1240 * load args (-- args... r t cleanup)
1241 * INVOKEVIRTUAL MethodHandle.invokeBasic (-- r)
1242 * GOTO DONE
1243 * CATCH: (-- t)
1244 * DUP (-- t t)
1245 * FINALLY_EXCEPTIONAL: (-- t t)
1246 * load cleanup (-- cleanup t t)
1247 * SWAP (-- t cleanup t)
1248 * load default for r (-- r t cleanup t)
1249 * load args (-- args... r t cleanup t)
1250 * INVOKEVIRTUAL MethodHandle.invokeBasic (-- r t)
1251 * POP (-- t)
1252 * ATHROW
1253 * DONE: (-- r)
1254 * }</pre></blockquote>
1255 */
1256 private Name emitTryFinally(int pos) {
1257 Name args = lambdaForm.names[pos];
1258 Name invoker = lambdaForm.names[pos+1];
1259 Name result = lambdaForm.names[pos+2];
1260
1261 Label lFrom = new Label();
1262 Label lTo = new Label();
1263 Label lCatch = new Label();
1264 Label lDone = new Label();
1265
1266 Class<?> returnType = result.function.resolvedHandle().type().returnType();
1267 boolean isNonVoid = returnType != void.class;
1268 MethodType type = args.function.resolvedHandle().type()
1269 .dropParameterTypes(0,1)
1270 .changeReturnType(returnType);
1271 MethodType cleanupType = type.insertParameterTypes(0, Throwable.class);
1272 if (isNonVoid) {
1273 cleanupType = cleanupType.insertParameterTypes(1, returnType);
1274 }
1275 String cleanupDesc = cleanupType.basicType().toMethodDescriptorString();
1276
1277 // exception handler table
1278 mv.visitTryCatchBlock(lFrom, lTo, lCatch, "java/lang/Throwable");
1279
1280 // TRY:
1281 mv.visitLabel(lFrom);
1282 emitPushArgument(invoker, 0); // load target
1283 emitPushArguments(args, 1); // load args (skip 0: method handle)
1284 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false);
1285 mv.visitLabel(lTo);
1286
1287 // FINALLY_NORMAL:
1288 emitPushArgument(invoker, 1); // load cleanup
1289 if (isNonVoid) {
1290 mv.visitInsn(Opcodes.SWAP);
1291 }
1292 mv.visitInsn(Opcodes.ACONST_NULL);
1293 if (isNonVoid) {
1294 mv.visitInsn(Opcodes.SWAP);
1295 }
1296 emitPushArguments(args, 1); // load args (skip 0: method handle)
1297 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", cleanupDesc, false);
1298 mv.visitJumpInsn(Opcodes.GOTO, lDone);
1299
1300 // CATCH:
1301 mv.visitLabel(lCatch);
1302 mv.visitInsn(Opcodes.DUP);
1303
1304 // FINALLY_EXCEPTIONAL:
1305 emitPushArgument(invoker, 1); // load cleanup
1306 mv.visitInsn(Opcodes.SWAP);
1307 if (isNonVoid) {
1308 emitZero(BasicType.basicType(returnType)); // load default for result
1309 }
1310 emitPushArguments(args, 1); // load args (skip 0: method handle)
1311 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", cleanupDesc, false);
1312 if (isNonVoid) {
1313 mv.visitInsn(Opcodes.POP);
1314 }
1315 mv.visitInsn(Opcodes.ATHROW);
1316
1317 // DONE:
1318 mv.visitLabel(lDone);
1319
1320 return result;
1321 }
1322
1323 /**
1324 * Emit bytecode for the loop idiom.
1325 * <p>
1326 * The pattern looks like (Cf. MethodHandleImpl.loop):
1327 * <blockquote><pre>{@code
1328 * // a0: BMH
1329 * // a1: LoopClauses (containing an array of arrays: inits, steps, preds, finis)
1330 * // a2: box, a3: unbox
1331 * // a4 (and following): arguments
1332 * loop=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L)=>{
1333 * t5:L=MethodHandle.invokeBasic(a2:L,a4:L); // box the arguments into an Object[]
1334 * t6:L=MethodHandleImpl.loop(bt:L,a1:L,t5:L); // call the loop executor (with supplied types in bt)
1335 * t7:L=MethodHandle.invokeBasic(a3:L,t6:L);t7:L} // unbox the result; return the result
1336 * }</pre></blockquote>
1337 * <p>
1338 * It is compiled into bytecode equivalent to the code seen in {@link MethodHandleImpl#loop(BasicType[],
1339 * MethodHandleImpl.LoopClauses, Object...)}, with the difference that no arrays
1340 * will be used for local state storage. Instead, the local state will be mapped to actual stack slots.
1341 * <p>
1342 * Bytecode generation applies an unrolling scheme to enable better bytecode generation regarding local state type
1343 * handling. The generated bytecode will have the following form ({@code void} types are ignored for convenience).
1344 * Assume there are {@code C} clauses in the loop.
1345 * <blockquote><pre>{@code
1346 * PREINIT: ALOAD_1
1347 * CHECKCAST LoopClauses
1348 * GETFIELD LoopClauses.clauses
1349 * ASTORE clauseDataIndex // place the clauses 2-dimensional array on the stack
1350 * INIT: (INIT_SEQ for clause 1)
1351 * ...
1352 * (INIT_SEQ for clause C)
1353 * LOOP: (LOOP_SEQ for clause 1)
1354 * ...
1355 * (LOOP_SEQ for clause C)
1356 * GOTO LOOP
1357 * DONE: ...
1358 * }</pre></blockquote>
1359 * <p>
1360 * The {@code INIT_SEQ_x} sequence for clause {@code x} (with {@code x} ranging from {@code 0} to {@code C-1}) has
1361 * the following shape. Assume slot {@code vx} is used to hold the state for clause {@code x}.
1362 * <blockquote><pre>{@code
1363 * INIT_SEQ_x: ALOAD clauseDataIndex
1364 * ICONST_0
1365 * AALOAD // load the inits array
1366 * ICONST x
1367 * AALOAD // load the init handle for clause x
1368 * load args
1369 * INVOKEVIRTUAL MethodHandle.invokeBasic
1370 * store vx
1371 * }</pre></blockquote>
1372 * <p>
1373 * The {@code LOOP_SEQ_x} sequence for clause {@code x} (with {@code x} ranging from {@code 0} to {@code C-1}) has
1374 * the following shape. Again, assume slot {@code vx} is used to hold the state for clause {@code x}.
1375 * <blockquote><pre>{@code
1376 * LOOP_SEQ_x: ALOAD clauseDataIndex
1377 * ICONST_1
1378 * AALOAD // load the steps array
1379 * ICONST x
1380 * AALOAD // load the step handle for clause x
1381 * load locals
1382 * load args
1383 * INVOKEVIRTUAL MethodHandle.invokeBasic
1384 * store vx
1385 * ALOAD clauseDataIndex
1386 * ICONST_2
1387 * AALOAD // load the preds array
1388 * ICONST x
1389 * AALOAD // load the pred handle for clause x
1390 * load locals
1391 * load args
1392 * INVOKEVIRTUAL MethodHandle.invokeBasic
1393 * IFNE LOOP_SEQ_x+1 // predicate returned false -> jump to next clause
1394 * ALOAD clauseDataIndex
1395 * ICONST_3
1396 * AALOAD // load the finis array
1397 * ICONST x
1398 * AALOAD // load the fini handle for clause x
1399 * load locals
1400 * load args
1401 * INVOKEVIRTUAL MethodHandle.invokeBasic
1402 * GOTO DONE // jump beyond end of clauses to return from loop
1403 * }</pre></blockquote>
1404 */
1405 private Name emitLoop(int pos) {
1406 Name args = lambdaForm.names[pos];
1407 Name invoker = lambdaForm.names[pos+1];
1408 Name result = lambdaForm.names[pos+2];
1409
1410 // extract clause and loop-local state types
1411 // find the type info in the loop invocation
1412 BasicType[] loopClauseTypes = (BasicType[]) invoker.arguments[0];
1413 Class<?>[] loopLocalStateTypes = Stream.of(loopClauseTypes).
1414 filter(bt -> bt != BasicType.V_TYPE).map(BasicType::basicTypeClass).toArray(Class<?>[]::new);
1415 Class<?>[] localTypes = new Class<?>[loopLocalStateTypes.length + 1];
1416 localTypes[0] = MethodHandleImpl.LoopClauses.class;
1417 System.arraycopy(loopLocalStateTypes, 0, localTypes, 1, loopLocalStateTypes.length);
1418
1419 final int clauseDataIndex = extendLocalsMap(localTypes);
1420 final int firstLoopStateIndex = clauseDataIndex + 1;
1421
1422 Class<?> returnType = result.function.resolvedHandle().type().returnType();
1423 MethodType loopType = args.function.resolvedHandle().type()
1424 .dropParameterTypes(0,1)
1425 .changeReturnType(returnType);
1426 MethodType loopHandleType = loopType.insertParameterTypes(0, loopLocalStateTypes);
1427 MethodType predType = loopHandleType.changeReturnType(boolean.class);
1428 MethodType finiType = loopHandleType;
1429
1430 final int nClauses = loopClauseTypes.length;
1431
1432 // indices to invoker arguments to load method handle arrays
1433 final int inits = 1;
1434 final int steps = 2;
1435 final int preds = 3;
1436 final int finis = 4;
1437
1438 Label lLoop = new Label();
1439 Label lDone = new Label();
1440 Label lNext;
1441
1442 // PREINIT:
1443 emitPushArgument(MethodHandleImpl.LoopClauses.class, invoker.arguments[1]);
1444 mv.visitFieldInsn(Opcodes.GETFIELD, LOOP_CLAUSES, "clauses", MHARY2);
1445 emitAstoreInsn(clauseDataIndex);
1446
1447 // INIT:
1448 for (int c = 0, state = 0; c < nClauses; ++c) {
1449 MethodType cInitType = loopType.changeReturnType(loopClauseTypes[c].basicTypeClass());
1450 emitLoopHandleInvoke(invoker, inits, c, args, false, cInitType, loopLocalStateTypes, clauseDataIndex,
1451 firstLoopStateIndex);
1452 if (cInitType.returnType() != void.class) {
1453 emitStoreInsn(BasicType.basicType(cInitType.returnType()), firstLoopStateIndex + state);
1454 ++state;
1455 }
1456 }
1457
1458 // LOOP:
1459 mv.visitLabel(lLoop);
1460
1461 for (int c = 0, state = 0; c < nClauses; ++c) {
1462 lNext = new Label();
1463
1464 MethodType stepType = loopHandleType.changeReturnType(loopClauseTypes[c].basicTypeClass());
1465 boolean isVoid = stepType.returnType() == void.class;
1466
1467 // invoke loop step
1468 emitLoopHandleInvoke(invoker, steps, c, args, true, stepType, loopLocalStateTypes, clauseDataIndex,
1469 firstLoopStateIndex);
1470 if (!isVoid) {
1471 emitStoreInsn(BasicType.basicType(stepType.returnType()), firstLoopStateIndex + state);
1472 ++state;
1473 }
1474
1475 // invoke loop predicate
1476 emitLoopHandleInvoke(invoker, preds, c, args, true, predType, loopLocalStateTypes, clauseDataIndex,
1477 firstLoopStateIndex);
1478 mv.visitJumpInsn(Opcodes.IFNE, lNext);
1479
1480 // invoke fini
1481 emitLoopHandleInvoke(invoker, finis, c, args, true, finiType, loopLocalStateTypes, clauseDataIndex,
1482 firstLoopStateIndex);
1483 mv.visitJumpInsn(Opcodes.GOTO, lDone);
1484
1485 // this is the beginning of the next loop clause
1486 mv.visitLabel(lNext);
1487 }
1488
1489 mv.visitJumpInsn(Opcodes.GOTO, lLoop);
1490
1491 // DONE:
1492 mv.visitLabel(lDone);
1493
1494 return result;
1495 }
1496
1497 private int extendLocalsMap(Class<?>[] types) {
1498 int firstSlot = localsMap.length - 1;
1499 localsMap = Arrays.copyOf(localsMap, localsMap.length + types.length);
1500 localClasses = Arrays.copyOf(localClasses, localClasses.length + types.length);
1501 System.arraycopy(types, 0, localClasses, firstSlot, types.length);
1502 int index = localsMap[firstSlot - 1] + 1;
1503 int lastSlots = 0;
1504 for (int i = 0; i < types.length; ++i) {
1505 localsMap[firstSlot + i] = index;
1506 lastSlots = BasicType.basicType(localClasses[firstSlot + i]).basicTypeSlots();
1507 index += lastSlots;
1508 }
1509 localsMap[localsMap.length - 1] = index - lastSlots;
1510 return firstSlot;
1511 }
1512
1513 private void emitLoopHandleInvoke(Name holder, int handles, int clause, Name args, boolean pushLocalState,
1514 MethodType type, Class<?>[] loopLocalStateTypes, int clauseDataSlot,
1515 int firstLoopStateSlot) {
1516 // load handle for clause
1517 emitPushClauseArray(clauseDataSlot, handles);
1518 emitIconstInsn(clause);
1519 mv.visitInsn(Opcodes.AALOAD);
1520 // load loop state (preceding the other arguments)
1521 if (pushLocalState) {
1522 for (int s = 0; s < loopLocalStateTypes.length; ++s) {
1523 emitLoadInsn(BasicType.basicType(loopLocalStateTypes[s]), firstLoopStateSlot + s);
1524 }
1525 }
1526 // load loop args (skip 0: method handle)
1527 emitPushArguments(args, 1);
1528 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.toMethodDescriptorString(), false);
1529 }
1530
1531 private void emitPushClauseArray(int clauseDataSlot, int which) {
1532 emitAloadInsn(clauseDataSlot);
1533 emitIconstInsn(which - 1);
1534 mv.visitInsn(Opcodes.AALOAD);
1535 }
1536
1537 private void emitZero(BasicType type) {
1538 switch (type) {
1539 case I_TYPE: mv.visitInsn(Opcodes.ICONST_0); break;
1540 case J_TYPE: mv.visitInsn(Opcodes.LCONST_0); break;
1541 case F_TYPE: mv.visitInsn(Opcodes.FCONST_0); break;
1542 case D_TYPE: mv.visitInsn(Opcodes.DCONST_0); break;
1543 case L_TYPE: mv.visitInsn(Opcodes.ACONST_NULL); break;
1544 default: throw new InternalError("unknown type: " + type);
1545 }
1546 }
1547
1548 private void emitPushArguments(Name args, int start) {
1549 MethodType type = args.function.methodType();
1550 for (int i = start; i < args.arguments.length; i++) {
1551 emitPushArgument(type.parameterType(i), args.arguments[i]);
1552 }
1553 }
1554
1555 private void emitPushArgument(Name name, int paramIndex) {
1556 Object arg = name.arguments[paramIndex];
1557 Class<?> ptype = name.function.methodType().parameterType(paramIndex);
1558 emitPushArgument(ptype, arg);
1559 }
1560
1561 private void emitPushArgument(Class<?> ptype, Object arg) {
1562 BasicType bptype = basicType(ptype);
1563 if (arg instanceof Name) {
1564 Name n = (Name) arg;
1565 emitLoadInsn(n.type, n.index());
1566 emitImplicitConversion(n.type, ptype, n);
1567 } else if ((arg == null || arg instanceof String) && bptype == L_TYPE) {
1568 emitConst(arg);
1569 } else {
1570 if (Wrapper.isWrapperType(arg.getClass()) && bptype != L_TYPE) {
1571 emitConst(arg);
1572 } else {
1573 mv.visitLdcInsn(constantPlaceholder(arg));
1574 emitImplicitConversion(L_TYPE, ptype, arg);
1575 }
1576 }
1577 }
1578
1579 /**
1580 * Store the name to its local, if necessary.
1581 */
1582 private void emitStoreResult(Name name) {
1583 if (name != null && name.type != V_TYPE) {
1584 // non-void: actually assign
1585 emitStoreInsn(name.type, name.index());
1586 }
1587 }
1588
1589 /**
1590 * Emits a return statement from a LF invoker. If required, the result type is cast to the correct return type.
1591 */
1592 private void emitReturn(Name onStack) {
1593 // return statement
1594 Class<?> rclass = invokerType.returnType();
1595 BasicType rtype = lambdaForm.returnType();
1596 assert(rtype == basicType(rclass)); // must agree
1597 if (rtype == V_TYPE) {
1598 // void
1599 mv.visitInsn(Opcodes.RETURN);
1600 // it doesn't matter what rclass is; the JVM will discard any value
1601 } else {
1602 LambdaForm.Name rn = lambdaForm.names[lambdaForm.result];
1603
1604 // put return value on the stack if it is not already there
1605 if (rn != onStack) {
1606 emitLoadInsn(rtype, lambdaForm.result);
1607 }
1608
1609 emitImplicitConversion(rtype, rclass, rn);
1610
1611 // generate actual return statement
1612 emitReturnInsn(rtype);
1613 }
1614 }
1615
1616 /**
1617 * Emit a type conversion bytecode casting from "from" to "to".
1618 */
1619 private void emitPrimCast(Wrapper from, Wrapper to) {
1620 // Here's how.
1621 // - indicates forbidden
1622 // <-> indicates implicit
1623 // to ----> boolean byte short char int long float double
1624 // from boolean <-> - - - - - - -
1625 // byte - <-> i2s i2c <-> i2l i2f i2d
1626 // short - i2b <-> i2c <-> i2l i2f i2d
1627 // char - i2b i2s <-> <-> i2l i2f i2d
1628 // int - i2b i2s i2c <-> i2l i2f i2d
1629 // long - l2i,i2b l2i,i2s l2i,i2c l2i <-> l2f l2d
1630 // float - f2i,i2b f2i,i2s f2i,i2c f2i f2l <-> f2d
1631 // double - d2i,i2b d2i,i2s d2i,i2c d2i d2l d2f <->
1632 if (from == to) {
1633 // no cast required, should be dead code anyway
1634 return;
1635 }
1636 if (from.isSubwordOrInt()) {
1637 // cast from {byte,short,char,int} to anything
1638 emitI2X(to);
1639 } else {
1640 // cast from {long,float,double} to anything
1641 if (to.isSubwordOrInt()) {
1642 // cast to {byte,short,char,int}
1643 emitX2I(from);
1644 if (to.bitWidth() < 32) {
1645 // targets other than int require another conversion
1646 emitI2X(to);
1647 }
1648 } else {
1649 // cast to {long,float,double} - this is verbose
1650 boolean error = false;
1651 switch (from) {
1652 case LONG:
1653 switch (to) {
1654 case FLOAT: mv.visitInsn(Opcodes.L2F); break;
1655 case DOUBLE: mv.visitInsn(Opcodes.L2D); break;
1656 default: error = true; break;
1657 }
1658 break;
1659 case FLOAT:
1660 switch (to) {
1661 case LONG : mv.visitInsn(Opcodes.F2L); break;
1662 case DOUBLE: mv.visitInsn(Opcodes.F2D); break;
1663 default: error = true; break;
1664 }
1665 break;
1666 case DOUBLE:
1667 switch (to) {
1668 case LONG : mv.visitInsn(Opcodes.D2L); break;
1669 case FLOAT: mv.visitInsn(Opcodes.D2F); break;
1670 default: error = true; break;
1671 }
1672 break;
1673 default:
1674 error = true;
1675 break;
1676 }
1677 if (error) {
1678 throw new IllegalStateException("unhandled prim cast: " + from + "2" + to);
1679 }
1680 }
1681 }
1682 }
1683
1684 private void emitI2X(Wrapper type) {
1685 switch (type) {
1686 case BYTE: mv.visitInsn(Opcodes.I2B); break;
1687 case SHORT: mv.visitInsn(Opcodes.I2S); break;
1688 case CHAR: mv.visitInsn(Opcodes.I2C); break;
1689 case INT: /* naught */ break;
1690 case LONG: mv.visitInsn(Opcodes.I2L); break;
1691 case FLOAT: mv.visitInsn(Opcodes.I2F); break;
1692 case DOUBLE: mv.visitInsn(Opcodes.I2D); break;
1693 case BOOLEAN:
1694 // For compatibility with ValueConversions and explicitCastArguments:
1695 mv.visitInsn(Opcodes.ICONST_1);
1696 mv.visitInsn(Opcodes.IAND);
1697 break;
1698 default: throw new InternalError("unknown type: " + type);
1699 }
1700 }
1701
1702 private void emitX2I(Wrapper type) {
1703 switch (type) {
1704 case LONG: mv.visitInsn(Opcodes.L2I); break;
1705 case FLOAT: mv.visitInsn(Opcodes.F2I); break;
1706 case DOUBLE: mv.visitInsn(Opcodes.D2I); break;
1707 default: throw new InternalError("unknown type: " + type);
1708 }
1709 }
1710
1711 /**
1712 * Generate bytecode for a LambdaForm.vmentry which calls interpretWithArguments.
1713 */
1714 static MemberName generateLambdaFormInterpreterEntryPoint(MethodType mt) {
1715 assert(isValidSignature(basicTypeSignature(mt)));
1716 String name = "interpret_"+basicTypeChar(mt.returnType());
1717 MethodType type = mt; // includes leading argument
1718 type = type.changeParameterType(0, MethodHandle.class);
1719 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("LFI", name, type);
1720 return g.loadMethod(g.generateLambdaFormInterpreterEntryPointBytes());
1721 }
1722
1723 private byte[] generateLambdaFormInterpreterEntryPointBytes() {
1724 classFilePrologue();
1725 methodPrologue();
1726
1727 // Suppress this method in backtraces displayed to the user.
1728 mv.visitAnnotation(LF_HIDDEN_SIG, true);
1729
1730 // Don't inline the interpreter entry.
1731 mv.visitAnnotation(DONTINLINE_SIG, true);
1732
1733 // create parameter array
1734 emitIconstInsn(invokerType.parameterCount());
1735 mv.visitTypeInsn(Opcodes.ANEWARRAY, "java/lang/Object");
1736
1737 // fill parameter array
1738 for (int i = 0; i < invokerType.parameterCount(); i++) {
1739 Class<?> ptype = invokerType.parameterType(i);
1740 mv.visitInsn(Opcodes.DUP);
1741 emitIconstInsn(i);
1742 emitLoadInsn(basicType(ptype), i);
1743 // box if primitive type
1744 if (ptype.isPrimitive()) {
1745 emitBoxing(Wrapper.forPrimitiveType(ptype));
1746 }
1747 mv.visitInsn(Opcodes.AASTORE);
1748 }
1749 // invoke
1750 emitAloadInsn(0);
1751 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", "Ljava/lang/invoke/LambdaForm;");
1752 mv.visitInsn(Opcodes.SWAP); // swap form and array; avoid local variable
1753 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, LF, "interpretWithArguments", "([Ljava/lang/Object;)Ljava/lang/Object;", false);
1754
1755 // maybe unbox
1756 Class<?> rtype = invokerType.returnType();
1757 if (rtype.isPrimitive() && rtype != void.class) {
1758 emitUnboxing(Wrapper.forPrimitiveType(rtype));
1759 }
1760
1761 // return statement
1762 emitReturnInsn(basicType(rtype));
1763
1764 methodEpilogue();
1765 bogusMethod(invokerType);
1766
1767 final byte[] classFile = cw.toByteArray();
1768 maybeDump(classFile);
1769 return classFile;
1770 }
1771
1772 /**
1773 * Generate bytecode for a NamedFunction invoker.
1774 */
1775 static MemberName generateNamedFunctionInvoker(MethodTypeForm typeForm) {
1776 MethodType invokerType = NamedFunction.INVOKER_METHOD_TYPE;
1777 String invokerName = "invoke_" + shortenSignature(basicTypeSignature(typeForm.erasedType()));
1778 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("NFI", invokerName, invokerType);
1779 return g.loadMethod(g.generateNamedFunctionInvokerImpl(typeForm));
1780 }
1781
1782 private byte[] generateNamedFunctionInvokerImpl(MethodTypeForm typeForm) {
1783 MethodType dstType = typeForm.erasedType();
1784 classFilePrologue();
1785 methodPrologue();
1786
1787 // Suppress this method in backtraces displayed to the user.
1788 mv.visitAnnotation(LF_HIDDEN_SIG, true);
1789
1790 // Force inlining of this invoker method.
1791 mv.visitAnnotation(FORCEINLINE_SIG, true);
1792
1793 // Load receiver
1794 emitAloadInsn(0);
1795
1796 // Load arguments from array
1797 for (int i = 0; i < dstType.parameterCount(); i++) {
1798 emitAloadInsn(1);
1799 emitIconstInsn(i);
1800 mv.visitInsn(Opcodes.AALOAD);
1801
1802 // Maybe unbox
1803 Class<?> dptype = dstType.parameterType(i);
1804 if (dptype.isPrimitive()) {
1805 Wrapper dstWrapper = Wrapper.forBasicType(dptype);
1806 Wrapper srcWrapper = dstWrapper.isSubwordOrInt() ? Wrapper.INT : dstWrapper; // narrow subword from int
1807 emitUnboxing(srcWrapper);
1808 emitPrimCast(srcWrapper, dstWrapper);
1809 }
1810 }
1811
1812 // Invoke
1813 String targetDesc = dstType.basicType().toMethodDescriptorString();
1814 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", targetDesc, false);
1815
1816 // Box primitive types
1817 Class<?> rtype = dstType.returnType();
1818 if (rtype != void.class && rtype.isPrimitive()) {
1819 Wrapper srcWrapper = Wrapper.forBasicType(rtype);
1820 Wrapper dstWrapper = srcWrapper.isSubwordOrInt() ? Wrapper.INT : srcWrapper; // widen subword to int
1821 // boolean casts not allowed
1822 emitPrimCast(srcWrapper, dstWrapper);
1823 emitBoxing(dstWrapper);
1824 }
1825
1826 // If the return type is void we return a null reference.
1827 if (rtype == void.class) {
1828 mv.visitInsn(Opcodes.ACONST_NULL);
1829 }
1830 emitReturnInsn(L_TYPE); // NOTE: NamedFunction invokers always return a reference value.
1831
1832 methodEpilogue();
1833 bogusMethod(dstType);
1834
1835 final byte[] classFile = cw.toByteArray();
1836 maybeDump(classFile);
1837 return classFile;
1838 }
1839
1840 /**
1841 * Emit a bogus method that just loads some string constants. This is to get the constants into the constant pool
1842 * for debugging purposes.
1843 */
1844 private void bogusMethod(Object... os) {
1845 if (DUMP_CLASS_FILES) {
1846 mv = cw.visitMethod(Opcodes.ACC_STATIC, "dummy", "()V", null, null);
1847 for (Object o : os) {
1848 mv.visitLdcInsn(o.toString());
1849 mv.visitInsn(Opcodes.POP);
1850 }
1851 mv.visitInsn(Opcodes.RETURN);
1852 mv.visitMaxs(0, 0);
1853 mv.visitEnd();
1854 }
1855 }
1856 }