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 /** Internal name lookup cache. */
97 private HashMap<Class<?>, String> nameMap;
98
99 private static final MemberName.Factory MEMBERNAME_FACTORY = MemberName.getFactory();
100 private static final Class<?> HOST_CLASS = LambdaForm.class;
101
102 /** Main constructor; other constructors delegate to this one. */
103 private InvokerBytecodeGenerator(LambdaForm lambdaForm, int localsMapSize,
104 String className, String invokerName, MethodType invokerType) {
105 int p = invokerName.indexOf('.');
106 if (p > -1) {
107 className = invokerName.substring(0, p);
108 invokerName = invokerName.substring(p + 1);
109 }
110 if (DUMP_CLASS_FILES) {
111 className = makeDumpableClassName(className);
112 }
113 this.className = className;
114 this.lambdaForm = lambdaForm;
115 this.invokerName = invokerName;
116 this.invokerType = invokerType;
117 this.localsMap = new int[localsMapSize+1]; // last entry of localsMap is count of allocated local slots
118 this.localClasses = new Class<?>[localsMapSize+1];
119 }
120
121 /** For generating LambdaForm interpreter entry points. */
122 private InvokerBytecodeGenerator(String className, String invokerName, MethodType invokerType) {
123 this(null, invokerType.parameterCount(),
124 className, invokerName, invokerType);
125 // Create an array to map name indexes to locals indexes.
126 for (int i = 0; i < localsMap.length; i++) {
127 localsMap[i] = invokerType.parameterSlotCount() - invokerType.parameterSlotDepth(i);
128 }
129 }
130
131 /** For generating customized code for a single LambdaForm. */
132 private InvokerBytecodeGenerator(String className, LambdaForm form, MethodType invokerType) {
133 this(className, form.lambdaName(), form, invokerType);
134 }
135
136 /** For generating customized code for a single LambdaForm. */
137 InvokerBytecodeGenerator(String className, String invokerName,
138 LambdaForm form, MethodType invokerType) {
139 this(form, form.names.length,
140 className, invokerName, invokerType);
141 // Create an array to map name indexes to locals indexes.
142 Name[] names = form.names;
143 for (int i = 0, index = 0; i < localsMap.length; i++) {
144 localsMap[i] = index;
145 if (i < names.length) {
146 BasicType type = names[i].type();
147 index += type.basicTypeSlots();
148 }
149 }
150 }
151
152 /** instance counters for dumped classes */
153 private static final HashMap<String,Integer> DUMP_CLASS_FILES_COUNTERS;
154 /** debugging flag for saving generated class files */
155 private static final File DUMP_CLASS_FILES_DIR;
156
157 static {
158 if (DUMP_CLASS_FILES) {
159 DUMP_CLASS_FILES_COUNTERS = new HashMap<>();
160 try {
161 File dumpDir = new File("DUMP_CLASS_FILES");
162 if (!dumpDir.exists()) {
163 dumpDir.mkdirs();
164 }
165 DUMP_CLASS_FILES_DIR = dumpDir;
166 System.out.println("Dumping class files to "+DUMP_CLASS_FILES_DIR+"/...");
167 } catch (Exception e) {
168 throw newInternalError(e);
169 }
170 } else {
171 DUMP_CLASS_FILES_COUNTERS = null;
172 DUMP_CLASS_FILES_DIR = null;
173 }
174 }
175
176 private void maybeDump(final byte[] classFile) {
177 if (DUMP_CLASS_FILES) {
178 maybeDump(CLASS_PREFIX + className, classFile);
179 }
180 }
181
182 // Also used from BoundMethodHandle
183 static void maybeDump(final String className, final byte[] classFile) {
184 if (DUMP_CLASS_FILES) {
185 java.security.AccessController.doPrivileged(
186 new java.security.PrivilegedAction<>() {
187 public Void run() {
188 try {
189 String dumpName = className.replace('.','/');
190 File dumpFile = new File(DUMP_CLASS_FILES_DIR, dumpName+".class");
191 System.out.println("dump: " + dumpFile);
192 dumpFile.getParentFile().mkdirs();
193 FileOutputStream file = new FileOutputStream(dumpFile);
194 file.write(classFile);
195 file.close();
196 return null;
197 } catch (IOException ex) {
198 throw newInternalError(ex);
199 }
200 }
201 });
202 }
203 }
204
205 private static String makeDumpableClassName(String className) {
206 Integer ctr;
207 synchronized (DUMP_CLASS_FILES_COUNTERS) {
208 ctr = DUMP_CLASS_FILES_COUNTERS.get(className);
209 if (ctr == null) ctr = 0;
210 DUMP_CLASS_FILES_COUNTERS.put(className, ctr+1);
211 }
212 String sfx = ctr.toString();
213 while (sfx.length() < 3)
214 sfx = "0"+sfx;
215 className += sfx;
216 return className;
217 }
218
219 class CpPatch {
220 final int index;
221 final Object value;
222 CpPatch(int index, Object value) {
223 this.index = index;
224 this.value = value;
225 }
226 public String toString() {
227 return "CpPatch/index="+index+",value="+value;
228 }
229 }
230
231 private final ArrayList<CpPatch> cpPatches = new ArrayList<>();
232
233 private int cph = 0; // for counting constant placeholders
234
235 String constantPlaceholder(Object arg) {
236 String cpPlaceholder = "CONSTANT_PLACEHOLDER_" + cph++;
237 if (DUMP_CLASS_FILES) cpPlaceholder += " <<" + debugString(arg) + ">>";
238 // TODO check if arg is already in the constant pool
239 // insert placeholder in CP and remember the patch
240 int index = cw.newConst((Object) cpPlaceholder);
241 cpPatches.add(new CpPatch(index, arg));
242 return cpPlaceholder;
243 }
244
245 Object[] cpPatches(byte[] classFile) {
246 int size = getConstantPoolSize(classFile);
247 Object[] res = new Object[size];
248 for (CpPatch p : cpPatches) {
249 if (p.index >= size)
250 throw new InternalError("in cpool["+size+"]: "+p+"\n"+Arrays.toString(Arrays.copyOf(classFile, 20)));
251 res[p.index] = p.value;
252 }
253 return res;
254 }
255
256 private static String debugString(Object arg) {
257 if (arg instanceof MethodHandle) {
258 MethodHandle mh = (MethodHandle) arg;
259 MemberName member = mh.internalMemberName();
260 if (member != null)
261 return member.toString();
262 return mh.debugString();
263 }
264 return arg.toString();
265 }
266
267 /**
268 * Extract the number of constant pool entries from a given class file.
269 *
270 * @param classFile the bytes of the class file in question.
271 * @return the number of entries in the constant pool.
272 */
273 private static int getConstantPoolSize(byte[] classFile) {
274 // The first few bytes:
275 // u4 magic;
276 // u2 minor_version;
277 // u2 major_version;
278 // u2 constant_pool_count;
279 return ((classFile[8] & 0xFF) << 8) | (classFile[9] & 0xFF);
280 }
281
282 /**
283 * Extract the MemberName of a newly-defined method.
284 */
285 private MemberName loadMethod(byte[] classFile) {
286 Class<?> invokerClass = loadAndInitializeInvokerClass(classFile, cpPatches(classFile));
287 return resolveInvokerMember(invokerClass, invokerName, invokerType);
288 }
289
290 /**
291 * Define a given class as anonymous class in the runtime system.
292 */
293 private static Class<?> loadAndInitializeInvokerClass(byte[] classBytes, Object[] patches) {
294 Class<?> invokerClass = UNSAFE.defineAnonymousClass(HOST_CLASS, classBytes, patches);
295 UNSAFE.ensureClassInitialized(invokerClass); // Make sure the class is initialized; VM might complain.
296 return invokerClass;
297 }
298
299 private static MemberName resolveInvokerMember(Class<?> invokerClass, String name, MethodType type) {
300 MemberName member = new MemberName(invokerClass, name, type, REF_invokeStatic);
301 try {
302 member = MEMBERNAME_FACTORY.resolveOrFail(REF_invokeStatic, member, HOST_CLASS, ReflectiveOperationException.class);
303 } catch (ReflectiveOperationException e) {
304 throw newInternalError(e);
305 }
306 return member;
307 }
308
309 /**
310 * Set up class file generation.
311 */
312 private ClassWriter classFilePrologue() {
313 final int NOT_ACC_PUBLIC = 0; // not ACC_PUBLIC
314 cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES);
315 cw.visit(Opcodes.V1_8, NOT_ACC_PUBLIC + Opcodes.ACC_FINAL + Opcodes.ACC_SUPER,
316 CLASS_PREFIX + className, null, INVOKER_SUPER_NAME, null);
317 cw.visitSource(SOURCE_PREFIX + className, null);
318 return cw;
319 }
320
321 private void methodPrologue() {
322 String invokerDesc = invokerType.toMethodDescriptorString();
323 mv = cw.visitMethod(Opcodes.ACC_STATIC, invokerName, invokerDesc, null, null);
324 }
325
326 /**
327 * Tear down class file generation.
328 */
329 private void methodEpilogue() {
330 mv.visitMaxs(0, 0);
331 mv.visitEnd();
332 }
333
334 /*
335 * Low-level emit helpers.
336 */
337 private void emitConst(Object con) {
338 if (con == null) {
339 mv.visitInsn(Opcodes.ACONST_NULL);
340 return;
341 }
342 if (con instanceof Integer) {
343 emitIconstInsn((int) con);
344 return;
345 }
346 if (con instanceof Byte) {
347 emitIconstInsn((byte)con);
348 return;
349 }
350 if (con instanceof Short) {
351 emitIconstInsn((short)con);
352 return;
353 }
354 if (con instanceof Character) {
355 emitIconstInsn((char)con);
356 return;
357 }
358 if (con instanceof Long) {
359 long x = (long) con;
360 short sx = (short)x;
361 if (x == sx) {
362 if (sx >= 0 && sx <= 1) {
363 mv.visitInsn(Opcodes.LCONST_0 + (int) sx);
364 } else {
365 emitIconstInsn((int) x);
366 mv.visitInsn(Opcodes.I2L);
367 }
368 return;
369 }
370 }
371 if (con instanceof Float) {
372 float x = (float) con;
373 short sx = (short)x;
374 if (x == sx) {
375 if (sx >= 0 && sx <= 2) {
376 mv.visitInsn(Opcodes.FCONST_0 + (int) sx);
377 } else {
378 emitIconstInsn((int) x);
379 mv.visitInsn(Opcodes.I2F);
380 }
381 return;
382 }
383 }
384 if (con instanceof Double) {
385 double x = (double) con;
386 short sx = (short)x;
387 if (x == sx) {
388 if (sx >= 0 && sx <= 1) {
389 mv.visitInsn(Opcodes.DCONST_0 + (int) sx);
390 } else {
391 emitIconstInsn((int) x);
392 mv.visitInsn(Opcodes.I2D);
393 }
394 return;
395 }
396 }
397 if (con instanceof Boolean) {
398 emitIconstInsn((boolean) con ? 1 : 0);
399 return;
400 }
401 // fall through:
402 mv.visitLdcInsn(con);
403 }
404
405 private void emitIconstInsn(final int cst) {
406 if (cst >= -1 && cst <= 5) {
407 mv.visitInsn(Opcodes.ICONST_0 + cst);
408 } else if (cst >= Byte.MIN_VALUE && cst <= Byte.MAX_VALUE) {
409 mv.visitIntInsn(Opcodes.BIPUSH, cst);
410 } else if (cst >= Short.MIN_VALUE && cst <= Short.MAX_VALUE) {
411 mv.visitIntInsn(Opcodes.SIPUSH, cst);
412 } else {
413 mv.visitLdcInsn(cst);
414 }
415 }
416
417 /*
418 * NOTE: These load/store methods use the localsMap to find the correct index!
419 */
420 private void emitLoadInsn(BasicType type, int index) {
421 int opcode = loadInsnOpcode(type);
422 mv.visitVarInsn(opcode, localsMap[index]);
423 }
424
425 private int loadInsnOpcode(BasicType type) throws InternalError {
426 switch (type) {
427 case I_TYPE: return Opcodes.ILOAD;
428 case J_TYPE: return Opcodes.LLOAD;
429 case F_TYPE: return Opcodes.FLOAD;
430 case D_TYPE: return Opcodes.DLOAD;
431 case L_TYPE: return Opcodes.ALOAD;
432 default:
433 throw new InternalError("unknown type: " + type);
434 }
435 }
436 private void emitAloadInsn(int index) {
437 emitLoadInsn(L_TYPE, index);
438 }
439
440 private void emitStoreInsn(BasicType type, int index) {
441 int opcode = storeInsnOpcode(type);
442 mv.visitVarInsn(opcode, localsMap[index]);
443 }
444
445 private int storeInsnOpcode(BasicType type) throws InternalError {
446 switch (type) {
447 case I_TYPE: return Opcodes.ISTORE;
448 case J_TYPE: return Opcodes.LSTORE;
449 case F_TYPE: return Opcodes.FSTORE;
450 case D_TYPE: return Opcodes.DSTORE;
451 case L_TYPE: return Opcodes.ASTORE;
452 default:
453 throw new InternalError("unknown type: " + type);
454 }
455 }
456 private void emitAstoreInsn(int index) {
457 emitStoreInsn(L_TYPE, index);
458 }
459
460 private byte arrayTypeCode(Wrapper elementType) {
461 switch (elementType) {
462 case BOOLEAN: return Opcodes.T_BOOLEAN;
463 case BYTE: return Opcodes.T_BYTE;
464 case CHAR: return Opcodes.T_CHAR;
465 case SHORT: return Opcodes.T_SHORT;
466 case INT: return Opcodes.T_INT;
467 case LONG: return Opcodes.T_LONG;
468 case FLOAT: return Opcodes.T_FLOAT;
469 case DOUBLE: return Opcodes.T_DOUBLE;
470 case OBJECT: return 0; // in place of Opcodes.T_OBJECT
471 default: throw new InternalError();
472 }
473 }
474
475 private int arrayInsnOpcode(byte tcode, int aaop) throws InternalError {
476 assert(aaop == Opcodes.AASTORE || aaop == Opcodes.AALOAD);
477 int xas;
478 switch (tcode) {
479 case Opcodes.T_BOOLEAN: xas = Opcodes.BASTORE; break;
480 case Opcodes.T_BYTE: xas = Opcodes.BASTORE; break;
481 case Opcodes.T_CHAR: xas = Opcodes.CASTORE; break;
482 case Opcodes.T_SHORT: xas = Opcodes.SASTORE; break;
483 case Opcodes.T_INT: xas = Opcodes.IASTORE; break;
484 case Opcodes.T_LONG: xas = Opcodes.LASTORE; break;
485 case Opcodes.T_FLOAT: xas = Opcodes.FASTORE; break;
486 case Opcodes.T_DOUBLE: xas = Opcodes.DASTORE; break;
487 case 0: xas = Opcodes.AASTORE; break;
488 default: throw new InternalError();
489 }
490 return xas - Opcodes.AASTORE + aaop;
491 }
492
493 /**
494 * Emit a boxing call.
495 *
496 * @param wrapper primitive type class to box.
497 */
498 private void emitBoxing(Wrapper wrapper) {
499 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName();
500 String name = "valueOf";
501 String desc = "(" + wrapper.basicTypeChar() + ")L" + owner + ";";
502 mv.visitMethodInsn(Opcodes.INVOKESTATIC, owner, name, desc, false);
503 }
504
505 /**
506 * Emit an unboxing call (plus preceding checkcast).
507 *
508 * @param wrapper wrapper type class to unbox.
509 */
510 private void emitUnboxing(Wrapper wrapper) {
511 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName();
512 String name = wrapper.primitiveSimpleName() + "Value";
513 String desc = "()" + wrapper.basicTypeChar();
514 emitReferenceCast(wrapper.wrapperType(), null);
515 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, owner, name, desc, false);
516 }
517
518 /**
519 * Emit an implicit conversion for an argument which must be of the given pclass.
520 * This is usually a no-op, except when pclass is a subword type or a reference other than Object or an interface.
521 *
522 * @param ptype type of value present on stack
523 * @param pclass type of value required on stack
524 * @param arg compile-time representation of value on stack (Node, constant) or null if none
525 */
526 private void emitImplicitConversion(BasicType ptype, Class<?> pclass, Object arg) {
527 assert(basicType(pclass) == ptype); // boxing/unboxing handled by caller
528 if (pclass == ptype.basicTypeClass() && ptype != L_TYPE)
529 return; // nothing to do
530 switch (ptype) {
531 case L_TYPE:
532 if (VerifyType.isNullConversion(Object.class, pclass, false)) {
533 if (PROFILE_LEVEL > 0)
534 emitReferenceCast(Object.class, arg);
535 return;
536 }
537 emitReferenceCast(pclass, arg);
538 return;
539 case I_TYPE:
540 if (!VerifyType.isNullConversion(int.class, pclass, false))
541 emitPrimCast(ptype.basicTypeWrapper(), Wrapper.forPrimitiveType(pclass));
542 return;
543 }
544 throw newInternalError("bad implicit conversion: tc="+ptype+": "+pclass);
545 }
546
547 /** Update localClasses type map. Return true if the information is already present. */
548 private boolean assertStaticType(Class<?> cls, Name n) {
549 int local = n.index();
550 Class<?> aclass = localClasses[local];
551 if (aclass != null && (aclass == cls || cls.isAssignableFrom(aclass))) {
552 return true; // type info is already present
553 } else if (aclass == null || aclass.isAssignableFrom(cls)) {
554 localClasses[local] = cls; // type info can be improved
555 }
556 return false;
557 }
558
559 private void emitReferenceCast(Class<?> cls, Object arg) {
560 Name writeBack = null; // local to write back result
561 if (arg instanceof Name) {
562 Name n = (Name) arg;
563 if (lambdaForm.useCount(n) > 1) {
564 // This guy gets used more than once.
565 writeBack = n;
566 if (assertStaticType(cls, n)) {
567 return; // this cast was already performed
568 }
569 }
570 }
571 if (isStaticallyNameable(cls)) {
572 String sig = getInternalName(cls);
573 mv.visitTypeInsn(Opcodes.CHECKCAST, sig);
574 } else {
575 mv.visitLdcInsn(constantPlaceholder(cls));
576 mv.visitTypeInsn(Opcodes.CHECKCAST, CLS);
577 mv.visitInsn(Opcodes.SWAP);
578 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, CLS, "cast", LL_SIG, false);
579 if (Object[].class.isAssignableFrom(cls))
580 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJARY);
581 else if (PROFILE_LEVEL > 0)
582 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJ);
583 }
584 if (writeBack != null) {
585 mv.visitInsn(Opcodes.DUP);
586 emitAstoreInsn(writeBack.index());
587 }
588 }
589
590 /**
591 * Emits an actual return instruction conforming to the given return type.
592 */
593 private void emitReturnInsn(BasicType type) {
594 int opcode;
595 switch (type) {
596 case I_TYPE: opcode = Opcodes.IRETURN; break;
597 case J_TYPE: opcode = Opcodes.LRETURN; break;
598 case F_TYPE: opcode = Opcodes.FRETURN; break;
599 case D_TYPE: opcode = Opcodes.DRETURN; break;
600 case L_TYPE: opcode = Opcodes.ARETURN; break;
601 case V_TYPE: opcode = Opcodes.RETURN; break;
602 default:
603 throw new InternalError("unknown return type: " + type);
604 }
605 mv.visitInsn(opcode);
606 }
607
608 private String getInternalName(Class<?> c) {
609 if (c == Object.class) return OBJ;
610 else if (c == Object[].class) return OBJARY;
611 else if (c == Class.class) return CLS;
612 else if (c == MethodHandle.class) return MH;
613 assert(VerifyAccess.isTypeVisible(c, Object.class)) : c.getName();
614
615 String name;
616 if (nameMap == null) {
617 nameMap = new HashMap<>(2);
618 name = null;
619 } else {
620 name = nameMap.get(c);
621 }
622 if (name == null) {
623 name = c.getName().replace('.', '/');
624 nameMap.put(c, name);
625 }
626 return name;
627 }
628
629 private static MemberName resolveFrom(String name, MethodType type, Class<?> holder) {
630 MemberName member = new MemberName(holder, name, type, REF_invokeStatic);
631 MemberName resolvedMember = MemberName.getFactory().resolveOrNull(REF_invokeStatic, member, holder);
632 if (TRACE_RESOLVE) {
633 System.out.println("[LF_RESOLVE] " + holder.getName() + " " + name + " " +
634 shortenSignature(basicTypeSignature(type)) + (resolvedMember != null ? " (success)" : " (fail)") );
635 }
636 return resolvedMember;
637 }
638
639 private static MemberName lookupPregenerated(LambdaForm form, MethodType invokerType) {
640 if (form.customized != null) {
641 // No pre-generated version for customized LF
642 return null;
643 }
644 String name = form.kind.methodName;
645 switch (form.kind) {
646 case BOUND_REINVOKER: {
647 name = name + "_" + BoundMethodHandle.speciesDataFor(form).key();
648 return resolveFrom(name, invokerType, DelegatingMethodHandle.Holder.class);
649 }
650 case DELEGATE: return resolveFrom(name, invokerType, DelegatingMethodHandle.Holder.class);
651 case ZERO: // fall-through
652 case IDENTITY: {
653 name = name + "_" + form.returnType().basicTypeChar();
654 return resolveFrom(name, invokerType, LambdaForm.Holder.class);
655 }
656 case EXACT_INVOKER: // fall-through
657 case EXACT_LINKER: // fall-through
658 case GENERIC_INVOKER: // fall-through
659 case GENERIC_LINKER: return resolveFrom(name, invokerType.basicType(), Invokers.Holder.class);
660 case GET_OBJECT: // fall-through
661 case GET_BOOLEAN: // fall-through
662 case GET_BYTE: // fall-through
663 case GET_CHAR: // fall-through
664 case GET_SHORT: // fall-through
665 case GET_INT: // fall-through
666 case GET_LONG: // fall-through
667 case GET_FLOAT: // fall-through
668 case GET_DOUBLE: // fall-through
669 case PUT_OBJECT: // fall-through
670 case PUT_BOOLEAN: // fall-through
671 case PUT_BYTE: // fall-through
672 case PUT_CHAR: // fall-through
673 case PUT_SHORT: // fall-through
674 case PUT_INT: // fall-through
675 case PUT_LONG: // fall-through
676 case PUT_FLOAT: // fall-through
677 case PUT_DOUBLE: // fall-through
678 case DIRECT_INVOKE_INTERFACE: // fall-through
679 case DIRECT_INVOKE_SPECIAL: // fall-through
680 case DIRECT_INVOKE_STATIC: // fall-through
681 case DIRECT_INVOKE_STATIC_INIT: // fall-through
682 case DIRECT_INVOKE_VIRTUAL: return resolveFrom(name, invokerType, DirectMethodHandle.Holder.class);
683 }
684 return null;
685 }
686
687 /**
688 * Generate customized bytecode for a given LambdaForm.
689 */
690 static MemberName generateCustomizedCode(LambdaForm form, MethodType invokerType) {
691 MemberName pregenerated = lookupPregenerated(form, invokerType);
692 if (pregenerated != null) return pregenerated; // pre-generated bytecode
693
694 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("MH", form, invokerType);
695 return g.loadMethod(g.generateCustomizedCodeBytes());
696 }
697
698 /** Generates code to check that actual receiver and LambdaForm matches */
699 private boolean checkActualReceiver() {
700 // Expects MethodHandle on the stack and actual receiver MethodHandle in slot #0
701 mv.visitInsn(Opcodes.DUP);
702 mv.visitVarInsn(Opcodes.ALOAD, localsMap[0]);
703 mv.visitMethodInsn(Opcodes.INVOKESTATIC, MHI, "assertSame", LLV_SIG, false);
704 return true;
705 }
706
707 static String className(String cn) {
708 assert checkClassName(cn): "Class not found: " + cn;
709 return cn;
710 }
711
712 static boolean checkClassName(String cn) {
713 Type tp = Type.getType(cn);
714 // additional sanity so only valid "L;" descriptors work
715 if (tp.getSort() != Type.OBJECT) {
716 return false;
717 }
718 try {
719 Class<?> c = Class.forName(tp.getClassName(), false, null);
720 return true;
721 } catch (ClassNotFoundException e) {
722 return false;
723 }
724 }
725
726 static final String LF_HIDDEN_SIG = className("Ljava/lang/invoke/LambdaForm$Hidden;");
727 static final String LF_COMPILED_SIG = className("Ljava/lang/invoke/LambdaForm$Compiled;");
728 static final String FORCEINLINE_SIG = className("Ljdk/internal/vm/annotation/ForceInline;");
729 static final String DONTINLINE_SIG = className("Ljdk/internal/vm/annotation/DontInline;");
730 static final String INJECTEDPROFILE_SIG = className("Ljava/lang/invoke/InjectedProfile;");
731
732 /**
733 * Generate an invoker method for the passed {@link LambdaForm}.
734 */
735 private byte[] generateCustomizedCodeBytes() {
736 classFilePrologue();
737 addMethod();
738 bogusMethod(lambdaForm);
739
740 final byte[] classFile = toByteArray();
741 maybeDump(classFile);
742 return classFile;
743 }
744
745 void setClassWriter(ClassWriter cw) {
746 this.cw = cw;
747 }
748
749 void addMethod() {
750 methodPrologue();
751
752 // Suppress this method in backtraces displayed to the user.
753 mv.visitAnnotation(LF_HIDDEN_SIG, true);
754
755 // Mark this method as a compiled LambdaForm
756 mv.visitAnnotation(LF_COMPILED_SIG, true);
757
758 if (lambdaForm.forceInline) {
759 // Force inlining of this invoker method.
760 mv.visitAnnotation(FORCEINLINE_SIG, true);
761 } else {
762 mv.visitAnnotation(DONTINLINE_SIG, true);
763 }
764
765 constantPlaceholder(lambdaForm); // keep LambdaForm instance & its compiled form lifetime tightly coupled.
766
767 if (lambdaForm.customized != null) {
768 // Since LambdaForm is customized for a particular MethodHandle, it's safe to substitute
769 // receiver MethodHandle (at slot #0) with an embedded constant and use it instead.
770 // It enables more efficient code generation in some situations, since embedded constants
771 // are compile-time constants for JIT compiler.
772 mv.visitLdcInsn(constantPlaceholder(lambdaForm.customized));
773 mv.visitTypeInsn(Opcodes.CHECKCAST, MH);
774 assert(checkActualReceiver()); // expects MethodHandle on top of the stack
775 mv.visitVarInsn(Opcodes.ASTORE, localsMap[0]);
776 }
777
778 // iterate over the form's names, generating bytecode instructions for each
779 // start iterating at the first name following the arguments
780 Name onStack = null;
781 for (int i = lambdaForm.arity; i < lambdaForm.names.length; i++) {
782 Name name = lambdaForm.names[i];
783
784 emitStoreResult(onStack);
785 onStack = name; // unless otherwise modified below
786 MethodHandleImpl.Intrinsic intr = name.function.intrinsicName();
787 switch (intr) {
788 case SELECT_ALTERNATIVE:
789 assert lambdaForm.isSelectAlternative(i);
790 if (PROFILE_GWT) {
791 assert(name.arguments[0] instanceof Name &&
792 ((Name)name.arguments[0]).refersTo(MethodHandleImpl.class, "profileBoolean"));
793 mv.visitAnnotation(INJECTEDPROFILE_SIG, true);
794 }
795 onStack = emitSelectAlternative(name, lambdaForm.names[i+1]);
796 i++; // skip MH.invokeBasic of the selectAlternative result
797 continue;
798 case GUARD_WITH_CATCH:
799 assert lambdaForm.isGuardWithCatch(i);
800 onStack = emitGuardWithCatch(i);
801 i += 2; // jump to the end of GWC idiom
802 continue;
803 case TRY_FINALLY:
804 assert lambdaForm.isTryFinally(i);
805 onStack = emitTryFinally(i);
806 i += 2; // jump to the end of the TF idiom
807 continue;
808 case LOOP:
809 assert lambdaForm.isLoop(i);
810 onStack = emitLoop(i);
811 i += 2; // jump to the end of the LOOP idiom
812 continue;
813 case NEW_ARRAY:
814 Class<?> rtype = name.function.methodType().returnType();
815 if (isStaticallyNameable(rtype)) {
816 emitNewArray(name);
817 continue;
818 }
819 break;
820 case ARRAY_LOAD:
821 emitArrayLoad(name);
822 continue;
823 case ARRAY_STORE:
824 emitArrayStore(name);
825 continue;
826 case ARRAY_LENGTH:
827 emitArrayLength(name);
828 continue;
829 case IDENTITY:
830 assert(name.arguments.length == 1);
831 emitPushArguments(name, 0);
832 continue;
833 case ZERO:
834 assert(name.arguments.length == 0);
835 emitConst(name.type.basicTypeWrapper().zero());
836 continue;
837 case NONE:
838 // no intrinsic associated
839 break;
840 default:
841 throw newInternalError("Unknown intrinsic: "+intr);
842 }
843
844 MemberName member = name.function.member();
845 if (isStaticallyInvocable(member)) {
846 emitStaticInvoke(member, name);
847 } else {
848 emitInvoke(name);
849 }
850 }
851
852 // return statement
853 emitReturn(onStack);
854
855 methodEpilogue();
856 }
857
858 /*
859 * @throws BytecodeGenerationException if something goes wrong when
860 * generating the byte code
861 */
862 private byte[] toByteArray() {
863 try {
864 return cw.toByteArray();
865 } catch (RuntimeException e) {
866 throw new BytecodeGenerationException(e);
867 }
868 }
869
870 @SuppressWarnings("serial")
871 static final class BytecodeGenerationException extends RuntimeException {
872 BytecodeGenerationException(Exception cause) {
873 super(cause);
874 }
875 }
876
877 void emitArrayLoad(Name name) { emitArrayOp(name, Opcodes.AALOAD); }
878 void emitArrayStore(Name name) { emitArrayOp(name, Opcodes.AASTORE); }
879 void emitArrayLength(Name name) { emitArrayOp(name, Opcodes.ARRAYLENGTH); }
880
881 void emitArrayOp(Name name, int arrayOpcode) {
882 assert arrayOpcode == Opcodes.AALOAD || arrayOpcode == Opcodes.AASTORE || arrayOpcode == Opcodes.ARRAYLENGTH;
883 Class<?> elementType = name.function.methodType().parameterType(0).getComponentType();
884 assert elementType != null;
885 emitPushArguments(name, 0);
886 if (arrayOpcode != Opcodes.ARRAYLENGTH && elementType.isPrimitive()) {
887 Wrapper w = Wrapper.forPrimitiveType(elementType);
888 arrayOpcode = arrayInsnOpcode(arrayTypeCode(w), arrayOpcode);
889 }
890 mv.visitInsn(arrayOpcode);
891 }
892
893 /**
894 * Emit an invoke for the given name.
895 */
896 void emitInvoke(Name name) {
897 assert(!name.isLinkerMethodInvoke()); // should use the static path for these
898 if (true) {
899 // push receiver
900 MethodHandle target = name.function.resolvedHandle();
901 assert(target != null) : name.exprString();
902 mv.visitLdcInsn(constantPlaceholder(target));
903 emitReferenceCast(MethodHandle.class, target);
904 } else {
905 // load receiver
906 emitAloadInsn(0);
907 emitReferenceCast(MethodHandle.class, null);
908 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", LF_SIG);
909 mv.visitFieldInsn(Opcodes.GETFIELD, LF, "names", LFN_SIG);
910 // TODO more to come
911 }
912
913 // push arguments
914 emitPushArguments(name, 0);
915
916 // invocation
917 MethodType type = name.function.methodType();
918 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false);
919 }
920
921 private static Class<?>[] STATICALLY_INVOCABLE_PACKAGES = {
922 // Sample classes from each package we are willing to bind to statically:
923 java.lang.Object.class,
924 java.util.Arrays.class,
925 jdk.internal.misc.Unsafe.class
926 //MethodHandle.class already covered
927 };
928
929 static boolean isStaticallyInvocable(NamedFunction ... functions) {
930 for (NamedFunction nf : functions) {
931 if (!isStaticallyInvocable(nf.member())) {
932 return false;
933 }
934 }
935 return true;
936 }
937
938 static boolean isStaticallyInvocable(Name name) {
939 return isStaticallyInvocable(name.function.member());
940 }
941
942 static boolean isStaticallyInvocable(MemberName member) {
943 if (member == null) return false;
944 if (member.isConstructor()) return false;
945 Class<?> cls = member.getDeclaringClass();
946 // Fast-path non-private members declared by MethodHandles, which is a common
947 // case
948 if (MethodHandle.class.isAssignableFrom(cls) && !member.isPrivate()) {
949 assert(isStaticallyInvocableType(member.getMethodOrFieldType()));
950 return true;
951 }
952 if (cls.isArray() || cls.isPrimitive())
953 return false; // FIXME
954 if (cls.isAnonymousClass() || cls.isLocalClass())
955 return false; // inner class of some sort
956 if (cls.getClassLoader() != MethodHandle.class.getClassLoader())
957 return false; // not on BCP
958 if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: switch to supported API once it is added
959 return false;
960 if (!isStaticallyInvocableType(member.getMethodOrFieldType()))
961 return false;
962 if (!member.isPrivate() && VerifyAccess.isSamePackage(MethodHandle.class, cls))
963 return true; // in java.lang.invoke package
964 if (member.isPublic() && isStaticallyNameable(cls))
965 return true;
966 return false;
967 }
968
969 private static boolean isStaticallyInvocableType(MethodType mtype) {
970 if (!isStaticallyNameable(mtype.returnType()))
971 return false;
972 for (Class<?> ptype : mtype.parameterArray())
973 if (!isStaticallyNameable(ptype))
974 return false;
975 return true;
976 }
977
978 static boolean isStaticallyNameable(Class<?> cls) {
979 if (cls == Object.class)
980 return true;
981 if (MethodHandle.class.isAssignableFrom(cls)) {
982 assert(!ReflectUtil.isVMAnonymousClass(cls));
983 return true;
984 }
985 while (cls.isArray())
986 cls = cls.getComponentType();
987 if (cls.isPrimitive())
988 return true; // int[].class, for example
989 if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: switch to supported API once it is added
990 return false;
991 // could use VerifyAccess.isClassAccessible but the following is a safe approximation
992 if (cls.getClassLoader() != Object.class.getClassLoader())
993 return false;
994 if (VerifyAccess.isSamePackage(MethodHandle.class, cls))
995 return true;
996 if (!Modifier.isPublic(cls.getModifiers()))
997 return false;
998 for (Class<?> pkgcls : STATICALLY_INVOCABLE_PACKAGES) {
999 if (VerifyAccess.isSamePackage(pkgcls, cls))
1000 return true;
1001 }
1002 return false;
1003 }
1004
1005 void emitStaticInvoke(Name name) {
1006 emitStaticInvoke(name.function.member(), name);
1007 }
1008
1009 /**
1010 * Emit an invoke for the given name, using the MemberName directly.
1011 */
1012 void emitStaticInvoke(MemberName member, Name name) {
1013 assert(member.equals(name.function.member()));
1014 Class<?> defc = member.getDeclaringClass();
1015 String cname = getInternalName(defc);
1016 String mname = member.getName();
1017 String mtype;
1018 byte refKind = member.getReferenceKind();
1019 if (refKind == REF_invokeSpecial) {
1020 // in order to pass the verifier, we need to convert this to invokevirtual in all cases
1021 assert(member.canBeStaticallyBound()) : member;
1022 refKind = REF_invokeVirtual;
1023 }
1024
1025 assert(!(member.getDeclaringClass().isInterface() && refKind == REF_invokeVirtual));
1026
1027 // push arguments
1028 emitPushArguments(name, 0);
1029
1030 // invocation
1031 if (member.isMethod()) {
1032 mtype = member.getMethodType().toMethodDescriptorString();
1033 mv.visitMethodInsn(refKindOpcode(refKind), cname, mname, mtype,
1034 member.getDeclaringClass().isInterface());
1035 } else {
1036 mtype = MethodType.toFieldDescriptorString(member.getFieldType());
1037 mv.visitFieldInsn(refKindOpcode(refKind), cname, mname, mtype);
1038 }
1039 // Issue a type assertion for the result, so we can avoid casts later.
1040 if (name.type == L_TYPE) {
1041 Class<?> rtype = member.getInvocationType().returnType();
1042 assert(!rtype.isPrimitive());
1043 if (rtype != Object.class && !rtype.isInterface()) {
1044 assertStaticType(rtype, name);
1045 }
1046 }
1047 }
1048
1049 void emitNewArray(Name name) throws InternalError {
1050 Class<?> rtype = name.function.methodType().returnType();
1051 if (name.arguments.length == 0) {
1052 // The array will be a constant.
1053 Object emptyArray;
1054 try {
1055 emptyArray = name.function.resolvedHandle().invoke();
1056 } catch (Throwable ex) {
1057 throw uncaughtException(ex);
1058 }
1059 assert(java.lang.reflect.Array.getLength(emptyArray) == 0);
1060 assert(emptyArray.getClass() == rtype); // exact typing
1061 mv.visitLdcInsn(constantPlaceholder(emptyArray));
1062 emitReferenceCast(rtype, emptyArray);
1063 return;
1064 }
1065 Class<?> arrayElementType = rtype.getComponentType();
1066 assert(arrayElementType != null);
1067 emitIconstInsn(name.arguments.length);
1068 int xas = Opcodes.AASTORE;
1069 if (!arrayElementType.isPrimitive()) {
1070 mv.visitTypeInsn(Opcodes.ANEWARRAY, getInternalName(arrayElementType));
1071 } else {
1072 byte tc = arrayTypeCode(Wrapper.forPrimitiveType(arrayElementType));
1073 xas = arrayInsnOpcode(tc, xas);
1074 mv.visitIntInsn(Opcodes.NEWARRAY, tc);
1075 }
1076 // store arguments
1077 for (int i = 0; i < name.arguments.length; i++) {
1078 mv.visitInsn(Opcodes.DUP);
1079 emitIconstInsn(i);
1080 emitPushArgument(name, i);
1081 mv.visitInsn(xas);
1082 }
1083 // the array is left on the stack
1084 assertStaticType(rtype, name);
1085 }
1086 int refKindOpcode(byte refKind) {
1087 switch (refKind) {
1088 case REF_invokeVirtual: return Opcodes.INVOKEVIRTUAL;
1089 case REF_invokeStatic: return Opcodes.INVOKESTATIC;
1090 case REF_invokeSpecial: return Opcodes.INVOKESPECIAL;
1091 case REF_invokeInterface: return Opcodes.INVOKEINTERFACE;
1092 case REF_getField: return Opcodes.GETFIELD;
1093 case REF_putField: return Opcodes.PUTFIELD;
1094 case REF_getStatic: return Opcodes.GETSTATIC;
1095 case REF_putStatic: return Opcodes.PUTSTATIC;
1096 }
1097 throw new InternalError("refKind="+refKind);
1098 }
1099
1100 /**
1101 * Emit bytecode for the selectAlternative idiom.
1102 *
1103 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithTest):
1104 * <blockquote><pre>{@code
1105 * Lambda(a0:L,a1:I)=>{
1106 * t2:I=foo.test(a1:I);
1107 * t3:L=MethodHandleImpl.selectAlternative(t2:I,(MethodHandle(int)int),(MethodHandle(int)int));
1108 * t4:I=MethodHandle.invokeBasic(t3:L,a1:I);t4:I}
1109 * }</pre></blockquote>
1110 */
1111 private Name emitSelectAlternative(Name selectAlternativeName, Name invokeBasicName) {
1112 assert isStaticallyInvocable(invokeBasicName);
1113
1114 Name receiver = (Name) invokeBasicName.arguments[0];
1115
1116 Label L_fallback = new Label();
1117 Label L_done = new Label();
1118
1119 // load test result
1120 emitPushArgument(selectAlternativeName, 0);
1121
1122 // if_icmpne L_fallback
1123 mv.visitJumpInsn(Opcodes.IFEQ, L_fallback);
1124
1125 // invoke selectAlternativeName.arguments[1]
1126 Class<?>[] preForkClasses = localClasses.clone();
1127 emitPushArgument(selectAlternativeName, 1); // get 2nd argument of selectAlternative
1128 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot
1129 emitStaticInvoke(invokeBasicName);
1130
1131 // goto L_done
1132 mv.visitJumpInsn(Opcodes.GOTO, L_done);
1133
1134 // L_fallback:
1135 mv.visitLabel(L_fallback);
1136
1137 // invoke selectAlternativeName.arguments[2]
1138 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length);
1139 emitPushArgument(selectAlternativeName, 2); // get 3rd argument of selectAlternative
1140 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot
1141 emitStaticInvoke(invokeBasicName);
1142
1143 // L_done:
1144 mv.visitLabel(L_done);
1145 // for now do not bother to merge typestate; just reset to the dominator state
1146 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length);
1147
1148 return invokeBasicName; // return what's on stack
1149 }
1150
1151 /**
1152 * Emit bytecode for the guardWithCatch idiom.
1153 *
1154 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithCatch):
1155 * <blockquote><pre>{@code
1156 * guardWithCatch=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L,a5:L,a6:L,a7:L)=>{
1157 * t8:L=MethodHandle.invokeBasic(a4:L,a6:L,a7:L);
1158 * t9:L=MethodHandleImpl.guardWithCatch(a1:L,a2:L,a3:L,t8:L);
1159 * t10:I=MethodHandle.invokeBasic(a5:L,t9:L);t10:I}
1160 * }</pre></blockquote>
1161 *
1162 * It is compiled into bytecode equivalent of the following code:
1163 * <blockquote><pre>{@code
1164 * try {
1165 * return a1.invokeBasic(a6, a7);
1166 * } catch (Throwable e) {
1167 * if (!a2.isInstance(e)) throw e;
1168 * return a3.invokeBasic(ex, a6, a7);
1169 * }}
1170 */
1171 private Name emitGuardWithCatch(int pos) {
1172 Name args = lambdaForm.names[pos];
1173 Name invoker = lambdaForm.names[pos+1];
1174 Name result = lambdaForm.names[pos+2];
1175
1176 Label L_startBlock = new Label();
1177 Label L_endBlock = new Label();
1178 Label L_handler = new Label();
1179 Label L_done = new Label();
1180
1181 Class<?> returnType = result.function.resolvedHandle().type().returnType();
1182 MethodType type = args.function.resolvedHandle().type()
1183 .dropParameterTypes(0,1)
1184 .changeReturnType(returnType);
1185
1186 mv.visitTryCatchBlock(L_startBlock, L_endBlock, L_handler, "java/lang/Throwable");
1187
1188 // Normal case
1189 mv.visitLabel(L_startBlock);
1190 // load target
1191 emitPushArgument(invoker, 0);
1192 emitPushArguments(args, 1); // skip 1st argument: method handle
1193 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false);
1194 mv.visitLabel(L_endBlock);
1195 mv.visitJumpInsn(Opcodes.GOTO, L_done);
1196
1197 // Exceptional case
1198 mv.visitLabel(L_handler);
1199
1200 // Check exception's type
1201 mv.visitInsn(Opcodes.DUP);
1202 // load exception class
1203 emitPushArgument(invoker, 1);
1204 mv.visitInsn(Opcodes.SWAP);
1205 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/Class", "isInstance", "(Ljava/lang/Object;)Z", false);
1206 Label L_rethrow = new Label();
1207 mv.visitJumpInsn(Opcodes.IFEQ, L_rethrow);
1208
1209 // Invoke catcher
1210 // load catcher
1211 emitPushArgument(invoker, 2);
1212 mv.visitInsn(Opcodes.SWAP);
1213 emitPushArguments(args, 1); // skip 1st argument: method handle
1214 MethodType catcherType = type.insertParameterTypes(0, Throwable.class);
1215 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", catcherType.basicType().toMethodDescriptorString(), false);
1216 mv.visitJumpInsn(Opcodes.GOTO, L_done);
1217
1218 mv.visitLabel(L_rethrow);
1219 mv.visitInsn(Opcodes.ATHROW);
1220
1221 mv.visitLabel(L_done);
1222
1223 return result;
1224 }
1225
1226 /**
1227 * Emit bytecode for the tryFinally idiom.
1228 * <p>
1229 * The pattern looks like (Cf. MethodHandleImpl.makeTryFinally):
1230 * <blockquote><pre>{@code
1231 * // a0: BMH
1232 * // a1: target, a2: cleanup
1233 * // a3: box, a4: unbox
1234 * // a5 (and following): arguments
1235 * tryFinally=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L,a5:L)=>{
1236 * t6:L=MethodHandle.invokeBasic(a3:L,a5:L); // box the arguments into an Object[]
1237 * t7:L=MethodHandleImpl.tryFinally(a1:L,a2:L,t6:L); // call the tryFinally executor
1238 * t8:L=MethodHandle.invokeBasic(a4:L,t7:L);t8:L} // unbox the result; return the result
1239 * }</pre></blockquote>
1240 * <p>
1241 * It is compiled into bytecode equivalent to the following code:
1242 * <blockquote><pre>{@code
1243 * Throwable t;
1244 * Object r;
1245 * try {
1246 * r = a1.invokeBasic(a5);
1247 * } catch (Throwable thrown) {
1248 * t = thrown;
1249 * throw t;
1250 * } finally {
1251 * r = a2.invokeBasic(t, r, a5);
1252 * }
1253 * return r;
1254 * }</pre></blockquote>
1255 * <p>
1256 * Specifically, the bytecode will have the following form (the stack effects are given for the beginnings of
1257 * blocks, and for the situations after executing the given instruction - the code will have a slightly different
1258 * shape if the return type is {@code void}):
1259 * <blockquote><pre>{@code
1260 * TRY: (--)
1261 * load target (-- target)
1262 * load args (-- args... target)
1263 * INVOKEVIRTUAL MethodHandle.invokeBasic (depends)
1264 * FINALLY_NORMAL: (-- r)
1265 * load cleanup (-- cleanup r)
1266 * SWAP (-- r cleanup)
1267 * ACONST_NULL (-- t r cleanup)
1268 * SWAP (-- r t cleanup)
1269 * load args (-- args... r t cleanup)
1270 * INVOKEVIRTUAL MethodHandle.invokeBasic (-- r)
1271 * GOTO DONE
1272 * CATCH: (-- t)
1273 * DUP (-- t t)
1274 * FINALLY_EXCEPTIONAL: (-- t t)
1275 * load cleanup (-- cleanup t t)
1276 * SWAP (-- t cleanup t)
1277 * load default for r (-- r t cleanup t)
1278 * load args (-- args... r t cleanup t)
1279 * INVOKEVIRTUAL MethodHandle.invokeBasic (-- r t)
1280 * POP (-- t)
1281 * ATHROW
1282 * DONE: (-- r)
1283 * }</pre></blockquote>
1284 */
1285 private Name emitTryFinally(int pos) {
1286 Name args = lambdaForm.names[pos];
1287 Name invoker = lambdaForm.names[pos+1];
1288 Name result = lambdaForm.names[pos+2];
1289
1290 Label lFrom = new Label();
1291 Label lTo = new Label();
1292 Label lCatch = new Label();
1293 Label lDone = new Label();
1294
1295 Class<?> returnType = result.function.resolvedHandle().type().returnType();
1296 boolean isNonVoid = returnType != void.class;
1297 MethodType type = args.function.resolvedHandle().type()
1298 .dropParameterTypes(0,1)
1299 .changeReturnType(returnType);
1300 MethodType cleanupType = type.insertParameterTypes(0, Throwable.class);
1301 if (isNonVoid) {
1302 cleanupType = cleanupType.insertParameterTypes(1, returnType);
1303 }
1304 String cleanupDesc = cleanupType.basicType().toMethodDescriptorString();
1305
1306 // exception handler table
1307 mv.visitTryCatchBlock(lFrom, lTo, lCatch, "java/lang/Throwable");
1308
1309 // TRY:
1310 mv.visitLabel(lFrom);
1311 emitPushArgument(invoker, 0); // load target
1312 emitPushArguments(args, 1); // load args (skip 0: method handle)
1313 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false);
1314 mv.visitLabel(lTo);
1315
1316 // FINALLY_NORMAL:
1317 emitPushArgument(invoker, 1); // load cleanup
1318 if (isNonVoid) {
1319 mv.visitInsn(Opcodes.SWAP);
1320 }
1321 mv.visitInsn(Opcodes.ACONST_NULL);
1322 if (isNonVoid) {
1323 mv.visitInsn(Opcodes.SWAP);
1324 }
1325 emitPushArguments(args, 1); // load args (skip 0: method handle)
1326 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", cleanupDesc, false);
1327 mv.visitJumpInsn(Opcodes.GOTO, lDone);
1328
1329 // CATCH:
1330 mv.visitLabel(lCatch);
1331 mv.visitInsn(Opcodes.DUP);
1332
1333 // FINALLY_EXCEPTIONAL:
1334 emitPushArgument(invoker, 1); // load cleanup
1335 mv.visitInsn(Opcodes.SWAP);
1336 if (isNonVoid) {
1337 emitZero(BasicType.basicType(returnType)); // load default for result
1338 }
1339 emitPushArguments(args, 1); // load args (skip 0: method handle)
1340 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", cleanupDesc, false);
1341 if (isNonVoid) {
1342 mv.visitInsn(Opcodes.POP);
1343 }
1344 mv.visitInsn(Opcodes.ATHROW);
1345
1346 // DONE:
1347 mv.visitLabel(lDone);
1348
1349 return result;
1350 }
1351
1352 /**
1353 * Emit bytecode for the loop idiom.
1354 * <p>
1355 * The pattern looks like (Cf. MethodHandleImpl.loop):
1356 * <blockquote><pre>{@code
1357 * // a0: BMH
1358 * // a1: LoopClauses (containing an array of arrays: inits, steps, preds, finis)
1359 * // a2: box, a3: unbox
1360 * // a4 (and following): arguments
1361 * loop=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L)=>{
1362 * t5:L=MethodHandle.invokeBasic(a2:L,a4:L); // box the arguments into an Object[]
1363 * t6:L=MethodHandleImpl.loop(bt:L,a1:L,t5:L); // call the loop executor (with supplied types in bt)
1364 * t7:L=MethodHandle.invokeBasic(a3:L,t6:L);t7:L} // unbox the result; return the result
1365 * }</pre></blockquote>
1366 * <p>
1367 * It is compiled into bytecode equivalent to the code seen in {@link MethodHandleImpl#loop(BasicType[],
1368 * MethodHandleImpl.LoopClauses, Object...)}, with the difference that no arrays
1369 * will be used for local state storage. Instead, the local state will be mapped to actual stack slots.
1370 * <p>
1371 * Bytecode generation applies an unrolling scheme to enable better bytecode generation regarding local state type
1372 * handling. The generated bytecode will have the following form ({@code void} types are ignored for convenience).
1373 * Assume there are {@code C} clauses in the loop.
1374 * <blockquote><pre>{@code
1375 * PREINIT: ALOAD_1
1376 * CHECKCAST LoopClauses
1377 * GETFIELD LoopClauses.clauses
1378 * ASTORE clauseDataIndex // place the clauses 2-dimensional array on the stack
1379 * INIT: (INIT_SEQ for clause 1)
1380 * ...
1381 * (INIT_SEQ for clause C)
1382 * LOOP: (LOOP_SEQ for clause 1)
1383 * ...
1384 * (LOOP_SEQ for clause C)
1385 * GOTO LOOP
1386 * DONE: ...
1387 * }</pre></blockquote>
1388 * <p>
1389 * The {@code INIT_SEQ_x} sequence for clause {@code x} (with {@code x} ranging from {@code 0} to {@code C-1}) has
1390 * the following shape. Assume slot {@code vx} is used to hold the state for clause {@code x}.
1391 * <blockquote><pre>{@code
1392 * INIT_SEQ_x: ALOAD clauseDataIndex
1393 * ICONST_0
1394 * AALOAD // load the inits array
1395 * ICONST x
1396 * AALOAD // load the init handle for clause x
1397 * load args
1398 * INVOKEVIRTUAL MethodHandle.invokeBasic
1399 * store vx
1400 * }</pre></blockquote>
1401 * <p>
1402 * The {@code LOOP_SEQ_x} sequence for clause {@code x} (with {@code x} ranging from {@code 0} to {@code C-1}) has
1403 * the following shape. Again, assume slot {@code vx} is used to hold the state for clause {@code x}.
1404 * <blockquote><pre>{@code
1405 * LOOP_SEQ_x: ALOAD clauseDataIndex
1406 * ICONST_1
1407 * AALOAD // load the steps array
1408 * ICONST x
1409 * AALOAD // load the step handle for clause x
1410 * load locals
1411 * load args
1412 * INVOKEVIRTUAL MethodHandle.invokeBasic
1413 * store vx
1414 * ALOAD clauseDataIndex
1415 * ICONST_2
1416 * AALOAD // load the preds array
1417 * ICONST x
1418 * AALOAD // load the pred handle for clause x
1419 * load locals
1420 * load args
1421 * INVOKEVIRTUAL MethodHandle.invokeBasic
1422 * IFNE LOOP_SEQ_x+1 // predicate returned false -> jump to next clause
1423 * ALOAD clauseDataIndex
1424 * ICONST_3
1425 * AALOAD // load the finis array
1426 * ICONST x
1427 * AALOAD // load the fini handle for clause x
1428 * load locals
1429 * load args
1430 * INVOKEVIRTUAL MethodHandle.invokeBasic
1431 * GOTO DONE // jump beyond end of clauses to return from loop
1432 * }</pre></blockquote>
1433 */
1434 private Name emitLoop(int pos) {
1435 Name args = lambdaForm.names[pos];
1436 Name invoker = lambdaForm.names[pos+1];
1437 Name result = lambdaForm.names[pos+2];
1438
1439 // extract clause and loop-local state types
1440 // find the type info in the loop invocation
1441 BasicType[] loopClauseTypes = (BasicType[]) invoker.arguments[0];
1442 Class<?>[] loopLocalStateTypes = Stream.of(loopClauseTypes).
1443 filter(bt -> bt != BasicType.V_TYPE).map(BasicType::basicTypeClass).toArray(Class<?>[]::new);
1444 Class<?>[] localTypes = new Class<?>[loopLocalStateTypes.length + 1];
1445 localTypes[0] = MethodHandleImpl.LoopClauses.class;
1446 System.arraycopy(loopLocalStateTypes, 0, localTypes, 1, loopLocalStateTypes.length);
1447
1448 final int clauseDataIndex = extendLocalsMap(localTypes);
1449 final int firstLoopStateIndex = clauseDataIndex + 1;
1450
1451 Class<?> returnType = result.function.resolvedHandle().type().returnType();
1452 MethodType loopType = args.function.resolvedHandle().type()
1453 .dropParameterTypes(0,1)
1454 .changeReturnType(returnType);
1455 MethodType loopHandleType = loopType.insertParameterTypes(0, loopLocalStateTypes);
1456 MethodType predType = loopHandleType.changeReturnType(boolean.class);
1457 MethodType finiType = loopHandleType;
1458
1459 final int nClauses = loopClauseTypes.length;
1460
1461 // indices to invoker arguments to load method handle arrays
1462 final int inits = 1;
1463 final int steps = 2;
1464 final int preds = 3;
1465 final int finis = 4;
1466
1467 Label lLoop = new Label();
1468 Label lDone = new Label();
1469 Label lNext;
1470
1471 // PREINIT:
1472 emitPushArgument(MethodHandleImpl.LoopClauses.class, invoker.arguments[1]);
1473 mv.visitFieldInsn(Opcodes.GETFIELD, LOOP_CLAUSES, "clauses", MHARY2);
1474 emitAstoreInsn(clauseDataIndex);
1475
1476 // INIT:
1477 for (int c = 0, state = 0; c < nClauses; ++c) {
1478 MethodType cInitType = loopType.changeReturnType(loopClauseTypes[c].basicTypeClass());
1479 emitLoopHandleInvoke(invoker, inits, c, args, false, cInitType, loopLocalStateTypes, clauseDataIndex,
1480 firstLoopStateIndex);
1481 if (cInitType.returnType() != void.class) {
1482 emitStoreInsn(BasicType.basicType(cInitType.returnType()), firstLoopStateIndex + state);
1483 ++state;
1484 }
1485 }
1486
1487 // LOOP:
1488 mv.visitLabel(lLoop);
1489
1490 for (int c = 0, state = 0; c < nClauses; ++c) {
1491 lNext = new Label();
1492
1493 MethodType stepType = loopHandleType.changeReturnType(loopClauseTypes[c].basicTypeClass());
1494 boolean isVoid = stepType.returnType() == void.class;
1495
1496 // invoke loop step
1497 emitLoopHandleInvoke(invoker, steps, c, args, true, stepType, loopLocalStateTypes, clauseDataIndex,
1498 firstLoopStateIndex);
1499 if (!isVoid) {
1500 emitStoreInsn(BasicType.basicType(stepType.returnType()), firstLoopStateIndex + state);
1501 ++state;
1502 }
1503
1504 // invoke loop predicate
1505 emitLoopHandleInvoke(invoker, preds, c, args, true, predType, loopLocalStateTypes, clauseDataIndex,
1506 firstLoopStateIndex);
1507 mv.visitJumpInsn(Opcodes.IFNE, lNext);
1508
1509 // invoke fini
1510 emitLoopHandleInvoke(invoker, finis, c, args, true, finiType, loopLocalStateTypes, clauseDataIndex,
1511 firstLoopStateIndex);
1512 mv.visitJumpInsn(Opcodes.GOTO, lDone);
1513
1514 // this is the beginning of the next loop clause
1515 mv.visitLabel(lNext);
1516 }
1517
1518 mv.visitJumpInsn(Opcodes.GOTO, lLoop);
1519
1520 // DONE:
1521 mv.visitLabel(lDone);
1522
1523 return result;
1524 }
1525
1526 private int extendLocalsMap(Class<?>[] types) {
1527 int firstSlot = localsMap.length - 1;
1528 localsMap = Arrays.copyOf(localsMap, localsMap.length + types.length);
1529 localClasses = Arrays.copyOf(localClasses, localClasses.length + types.length);
1530 System.arraycopy(types, 0, localClasses, firstSlot, types.length);
1531 int index = localsMap[firstSlot - 1] + 1;
1532 int lastSlots = 0;
1533 for (int i = 0; i < types.length; ++i) {
1534 localsMap[firstSlot + i] = index;
1535 lastSlots = BasicType.basicType(localClasses[firstSlot + i]).basicTypeSlots();
1536 index += lastSlots;
1537 }
1538 localsMap[localsMap.length - 1] = index - lastSlots;
1539 return firstSlot;
1540 }
1541
1542 private void emitLoopHandleInvoke(Name holder, int handles, int clause, Name args, boolean pushLocalState,
1543 MethodType type, Class<?>[] loopLocalStateTypes, int clauseDataSlot,
1544 int firstLoopStateSlot) {
1545 // load handle for clause
1546 emitPushClauseArray(clauseDataSlot, handles);
1547 emitIconstInsn(clause);
1548 mv.visitInsn(Opcodes.AALOAD);
1549 // load loop state (preceding the other arguments)
1550 if (pushLocalState) {
1551 for (int s = 0; s < loopLocalStateTypes.length; ++s) {
1552 emitLoadInsn(BasicType.basicType(loopLocalStateTypes[s]), firstLoopStateSlot + s);
1553 }
1554 }
1555 // load loop args (skip 0: method handle)
1556 emitPushArguments(args, 1);
1557 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.toMethodDescriptorString(), false);
1558 }
1559
1560 private void emitPushClauseArray(int clauseDataSlot, int which) {
1561 emitAloadInsn(clauseDataSlot);
1562 emitIconstInsn(which - 1);
1563 mv.visitInsn(Opcodes.AALOAD);
1564 }
1565
1566 private void emitZero(BasicType type) {
1567 switch (type) {
1568 case I_TYPE: mv.visitInsn(Opcodes.ICONST_0); break;
1569 case J_TYPE: mv.visitInsn(Opcodes.LCONST_0); break;
1570 case F_TYPE: mv.visitInsn(Opcodes.FCONST_0); break;
1571 case D_TYPE: mv.visitInsn(Opcodes.DCONST_0); break;
1572 case L_TYPE: mv.visitInsn(Opcodes.ACONST_NULL); break;
1573 default: throw new InternalError("unknown type: " + type);
1574 }
1575 }
1576
1577 private void emitPushArguments(Name args, int start) {
1578 MethodType type = args.function.methodType();
1579 for (int i = start; i < args.arguments.length; i++) {
1580 emitPushArgument(type.parameterType(i), args.arguments[i]);
1581 }
1582 }
1583
1584 private void emitPushArgument(Name name, int paramIndex) {
1585 Object arg = name.arguments[paramIndex];
1586 Class<?> ptype = name.function.methodType().parameterType(paramIndex);
1587 emitPushArgument(ptype, arg);
1588 }
1589
1590 private void emitPushArgument(Class<?> ptype, Object arg) {
1591 BasicType bptype = basicType(ptype);
1592 if (arg instanceof Name) {
1593 Name n = (Name) arg;
1594 emitLoadInsn(n.type, n.index());
1595 emitImplicitConversion(n.type, ptype, n);
1596 } else if ((arg == null || arg instanceof String) && bptype == L_TYPE) {
1597 emitConst(arg);
1598 } else {
1599 if (Wrapper.isWrapperType(arg.getClass()) && bptype != L_TYPE) {
1600 emitConst(arg);
1601 } else {
1602 mv.visitLdcInsn(constantPlaceholder(arg));
1603 emitImplicitConversion(L_TYPE, ptype, arg);
1604 }
1605 }
1606 }
1607
1608 /**
1609 * Store the name to its local, if necessary.
1610 */
1611 private void emitStoreResult(Name name) {
1612 if (name != null && name.type != V_TYPE) {
1613 // non-void: actually assign
1614 emitStoreInsn(name.type, name.index());
1615 }
1616 }
1617
1618 /**
1619 * Emits a return statement from a LF invoker. If required, the result type is cast to the correct return type.
1620 */
1621 private void emitReturn(Name onStack) {
1622 // return statement
1623 Class<?> rclass = invokerType.returnType();
1624 BasicType rtype = lambdaForm.returnType();
1625 assert(rtype == basicType(rclass)); // must agree
1626 if (rtype == V_TYPE) {
1627 // void
1628 mv.visitInsn(Opcodes.RETURN);
1629 // it doesn't matter what rclass is; the JVM will discard any value
1630 } else {
1631 LambdaForm.Name rn = lambdaForm.names[lambdaForm.result];
1632
1633 // put return value on the stack if it is not already there
1634 if (rn != onStack) {
1635 emitLoadInsn(rtype, lambdaForm.result);
1636 }
1637
1638 emitImplicitConversion(rtype, rclass, rn);
1639
1640 // generate actual return statement
1641 emitReturnInsn(rtype);
1642 }
1643 }
1644
1645 /**
1646 * Emit a type conversion bytecode casting from "from" to "to".
1647 */
1648 private void emitPrimCast(Wrapper from, Wrapper to) {
1649 // Here's how.
1650 // - indicates forbidden
1651 // <-> indicates implicit
1652 // to ----> boolean byte short char int long float double
1653 // from boolean <-> - - - - - - -
1654 // byte - <-> i2s i2c <-> i2l i2f i2d
1655 // short - i2b <-> i2c <-> i2l i2f i2d
1656 // char - i2b i2s <-> <-> i2l i2f i2d
1657 // int - i2b i2s i2c <-> i2l i2f i2d
1658 // long - l2i,i2b l2i,i2s l2i,i2c l2i <-> l2f l2d
1659 // float - f2i,i2b f2i,i2s f2i,i2c f2i f2l <-> f2d
1660 // double - d2i,i2b d2i,i2s d2i,i2c d2i d2l d2f <->
1661 if (from == to) {
1662 // no cast required, should be dead code anyway
1663 return;
1664 }
1665 if (from.isSubwordOrInt()) {
1666 // cast from {byte,short,char,int} to anything
1667 emitI2X(to);
1668 } else {
1669 // cast from {long,float,double} to anything
1670 if (to.isSubwordOrInt()) {
1671 // cast to {byte,short,char,int}
1672 emitX2I(from);
1673 if (to.bitWidth() < 32) {
1674 // targets other than int require another conversion
1675 emitI2X(to);
1676 }
1677 } else {
1678 // cast to {long,float,double} - this is verbose
1679 boolean error = false;
1680 switch (from) {
1681 case LONG:
1682 switch (to) {
1683 case FLOAT: mv.visitInsn(Opcodes.L2F); break;
1684 case DOUBLE: mv.visitInsn(Opcodes.L2D); break;
1685 default: error = true; break;
1686 }
1687 break;
1688 case FLOAT:
1689 switch (to) {
1690 case LONG : mv.visitInsn(Opcodes.F2L); break;
1691 case DOUBLE: mv.visitInsn(Opcodes.F2D); break;
1692 default: error = true; break;
1693 }
1694 break;
1695 case DOUBLE:
1696 switch (to) {
1697 case LONG : mv.visitInsn(Opcodes.D2L); break;
1698 case FLOAT: mv.visitInsn(Opcodes.D2F); break;
1699 default: error = true; break;
1700 }
1701 break;
1702 default:
1703 error = true;
1704 break;
1705 }
1706 if (error) {
1707 throw new IllegalStateException("unhandled prim cast: " + from + "2" + to);
1708 }
1709 }
1710 }
1711 }
1712
1713 private void emitI2X(Wrapper type) {
1714 switch (type) {
1715 case BYTE: mv.visitInsn(Opcodes.I2B); break;
1716 case SHORT: mv.visitInsn(Opcodes.I2S); break;
1717 case CHAR: mv.visitInsn(Opcodes.I2C); break;
1718 case INT: /* naught */ break;
1719 case LONG: mv.visitInsn(Opcodes.I2L); break;
1720 case FLOAT: mv.visitInsn(Opcodes.I2F); break;
1721 case DOUBLE: mv.visitInsn(Opcodes.I2D); break;
1722 case BOOLEAN:
1723 // For compatibility with ValueConversions and explicitCastArguments:
1724 mv.visitInsn(Opcodes.ICONST_1);
1725 mv.visitInsn(Opcodes.IAND);
1726 break;
1727 default: throw new InternalError("unknown type: " + type);
1728 }
1729 }
1730
1731 private void emitX2I(Wrapper type) {
1732 switch (type) {
1733 case LONG: mv.visitInsn(Opcodes.L2I); break;
1734 case FLOAT: mv.visitInsn(Opcodes.F2I); break;
1735 case DOUBLE: mv.visitInsn(Opcodes.D2I); break;
1736 default: throw new InternalError("unknown type: " + type);
1737 }
1738 }
1739
1740 /**
1741 * Generate bytecode for a LambdaForm.vmentry which calls interpretWithArguments.
1742 */
1743 static MemberName generateLambdaFormInterpreterEntryPoint(MethodType mt) {
1744 assert(isValidSignature(basicTypeSignature(mt)));
1745 String name = "interpret_"+basicTypeChar(mt.returnType());
1746 MethodType type = mt; // includes leading argument
1747 type = type.changeParameterType(0, MethodHandle.class);
1748 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("LFI", name, type);
1749 return g.loadMethod(g.generateLambdaFormInterpreterEntryPointBytes());
1750 }
1751
1752 private byte[] generateLambdaFormInterpreterEntryPointBytes() {
1753 classFilePrologue();
1754 methodPrologue();
1755
1756 // Suppress this method in backtraces displayed to the user.
1757 mv.visitAnnotation(LF_HIDDEN_SIG, true);
1758
1759 // Don't inline the interpreter entry.
1760 mv.visitAnnotation(DONTINLINE_SIG, true);
1761
1762 // create parameter array
1763 emitIconstInsn(invokerType.parameterCount());
1764 mv.visitTypeInsn(Opcodes.ANEWARRAY, "java/lang/Object");
1765
1766 // fill parameter array
1767 for (int i = 0; i < invokerType.parameterCount(); i++) {
1768 Class<?> ptype = invokerType.parameterType(i);
1769 mv.visitInsn(Opcodes.DUP);
1770 emitIconstInsn(i);
1771 emitLoadInsn(basicType(ptype), i);
1772 // box if primitive type
1773 if (ptype.isPrimitive()) {
1774 emitBoxing(Wrapper.forPrimitiveType(ptype));
1775 }
1776 mv.visitInsn(Opcodes.AASTORE);
1777 }
1778 // invoke
1779 emitAloadInsn(0);
1780 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", "Ljava/lang/invoke/LambdaForm;");
1781 mv.visitInsn(Opcodes.SWAP); // swap form and array; avoid local variable
1782 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, LF, "interpretWithArguments", "([Ljava/lang/Object;)Ljava/lang/Object;", false);
1783
1784 // maybe unbox
1785 Class<?> rtype = invokerType.returnType();
1786 if (rtype.isPrimitive() && rtype != void.class) {
1787 emitUnboxing(Wrapper.forPrimitiveType(rtype));
1788 }
1789
1790 // return statement
1791 emitReturnInsn(basicType(rtype));
1792
1793 methodEpilogue();
1794 bogusMethod(invokerType);
1795
1796 final byte[] classFile = cw.toByteArray();
1797 maybeDump(classFile);
1798 return classFile;
1799 }
1800
1801 /**
1802 * Generate bytecode for a NamedFunction invoker.
1803 */
1804 static MemberName generateNamedFunctionInvoker(MethodTypeForm typeForm) {
1805 MethodType invokerType = NamedFunction.INVOKER_METHOD_TYPE;
1806 String invokerName = "invoke_" + shortenSignature(basicTypeSignature(typeForm.erasedType()));
1807 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("NFI", invokerName, invokerType);
1808 return g.loadMethod(g.generateNamedFunctionInvokerImpl(typeForm));
1809 }
1810
1811 private byte[] generateNamedFunctionInvokerImpl(MethodTypeForm typeForm) {
1812 MethodType dstType = typeForm.erasedType();
1813 classFilePrologue();
1814 methodPrologue();
1815
1816 // Suppress this method in backtraces displayed to the user.
1817 mv.visitAnnotation(LF_HIDDEN_SIG, true);
1818
1819 // Force inlining of this invoker method.
1820 mv.visitAnnotation(FORCEINLINE_SIG, true);
1821
1822 // Load receiver
1823 emitAloadInsn(0);
1824
1825 // Load arguments from array
1826 for (int i = 0; i < dstType.parameterCount(); i++) {
1827 emitAloadInsn(1);
1828 emitIconstInsn(i);
1829 mv.visitInsn(Opcodes.AALOAD);
1830
1831 // Maybe unbox
1832 Class<?> dptype = dstType.parameterType(i);
1833 if (dptype.isPrimitive()) {
1834 Wrapper dstWrapper = Wrapper.forBasicType(dptype);
1835 Wrapper srcWrapper = dstWrapper.isSubwordOrInt() ? Wrapper.INT : dstWrapper; // narrow subword from int
1836 emitUnboxing(srcWrapper);
1837 emitPrimCast(srcWrapper, dstWrapper);
1838 }
1839 }
1840
1841 // Invoke
1842 String targetDesc = dstType.basicType().toMethodDescriptorString();
1843 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", targetDesc, false);
1844
1845 // Box primitive types
1846 Class<?> rtype = dstType.returnType();
1847 if (rtype != void.class && rtype.isPrimitive()) {
1848 Wrapper srcWrapper = Wrapper.forBasicType(rtype);
1849 Wrapper dstWrapper = srcWrapper.isSubwordOrInt() ? Wrapper.INT : srcWrapper; // widen subword to int
1850 // boolean casts not allowed
1851 emitPrimCast(srcWrapper, dstWrapper);
1852 emitBoxing(dstWrapper);
1853 }
1854
1855 // If the return type is void we return a null reference.
1856 if (rtype == void.class) {
1857 mv.visitInsn(Opcodes.ACONST_NULL);
1858 }
1859 emitReturnInsn(L_TYPE); // NOTE: NamedFunction invokers always return a reference value.
1860
1861 methodEpilogue();
1862 bogusMethod(dstType);
1863
1864 final byte[] classFile = cw.toByteArray();
1865 maybeDump(classFile);
1866 return classFile;
1867 }
1868
1869 /**
1870 * Emit a bogus method that just loads some string constants. This is to get the constants into the constant pool
1871 * for debugging purposes.
1872 */
1873 private void bogusMethod(Object... os) {
1874 if (DUMP_CLASS_FILES) {
1875 mv = cw.visitMethod(Opcodes.ACC_STATIC, "dummy", "()V", null, null);
1876 for (Object o : os) {
1877 mv.visitLdcInsn(o.toString());
1878 mv.visitInsn(Opcodes.POP);
1879 }
1880 mv.visitInsn(Opcodes.RETURN);
1881 mv.visitMaxs(0, 0);
1882 mv.visitEnd();
1883 }
1884 }
1885 }