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