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