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 LINK_TO_CALL_SITE: // fall-through
653 case LINK_TO_TARGET_METHOD: // fall-through
654 case GENERIC_INVOKER: // fall-through
655 case GENERIC_LINKER: return resolveFrom(name, invokerType.basicType(), Invokers.Holder.class);
656 case GET_REFERENCE: // fall-through
657 case GET_BOOLEAN: // fall-through
658 case GET_BYTE: // fall-through
659 case GET_CHAR: // fall-through
660 case GET_SHORT: // fall-through
661 case GET_INT: // fall-through
662 case GET_LONG: // fall-through
663 case GET_FLOAT: // fall-through
664 case GET_DOUBLE: // fall-through
665 case PUT_REFERENCE: // fall-through
666 case PUT_BOOLEAN: // fall-through
667 case PUT_BYTE: // fall-through
668 case PUT_CHAR: // fall-through
669 case PUT_SHORT: // fall-through
670 case PUT_INT: // fall-through
671 case PUT_LONG: // fall-through
672 case PUT_FLOAT: // fall-through
673 case PUT_DOUBLE: // fall-through
674 case DIRECT_NEW_INVOKE_SPECIAL: // fall-through
675 case DIRECT_INVOKE_INTERFACE: // fall-through
676 case DIRECT_INVOKE_SPECIAL: // fall-through
677 case DIRECT_INVOKE_SPECIAL_IFC: // fall-through
678 case DIRECT_INVOKE_STATIC: // fall-through
679 case DIRECT_INVOKE_STATIC_INIT: // fall-through
680 case DIRECT_INVOKE_VIRTUAL: return resolveFrom(name, invokerType, DirectMethodHandle.Holder.class);
681 }
682 return null;
683 }
684
685 /**
686 * Generate customized bytecode for a given LambdaForm.
687 */
688 static MemberName generateCustomizedCode(LambdaForm form, MethodType invokerType) {
689 MemberName pregenerated = lookupPregenerated(form, invokerType);
690 if (pregenerated != null) return pregenerated; // pre-generated bytecode
691
692 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("MH", form, invokerType);
693 return g.loadMethod(g.generateCustomizedCodeBytes());
694 }
695
696 /** Generates code to check that actual receiver and LambdaForm matches */
697 private boolean checkActualReceiver() {
698 // Expects MethodHandle on the stack and actual receiver MethodHandle in slot #0
699 mv.visitInsn(Opcodes.DUP);
700 mv.visitVarInsn(Opcodes.ALOAD, localsMap[0]);
701 mv.visitMethodInsn(Opcodes.INVOKESTATIC, MHI, "assertSame", LLV_SIG, false);
702 return true;
703 }
704
705 static String className(String cn) {
706 assert checkClassName(cn): "Class not found: " + cn;
707 return cn;
708 }
709
710 static boolean checkClassName(String cn) {
711 Type tp = Type.getType(cn);
712 // additional sanity so only valid "L;" descriptors work
713 if (tp.getSort() != Type.OBJECT) {
714 return false;
715 }
716 try {
717 Class<?> c = Class.forName(tp.getClassName(), false, null);
718 return true;
719 } catch (ClassNotFoundException e) {
720 return false;
721 }
722 }
723
724 static final String LF_HIDDEN_SIG = className("Ljava/lang/invoke/LambdaForm$Hidden;");
725 static final String LF_COMPILED_SIG = className("Ljava/lang/invoke/LambdaForm$Compiled;");
726 static final String FORCEINLINE_SIG = className("Ljdk/internal/vm/annotation/ForceInline;");
727 static final String DONTINLINE_SIG = className("Ljdk/internal/vm/annotation/DontInline;");
728 static final String INJECTEDPROFILE_SIG = className("Ljava/lang/invoke/InjectedProfile;");
729
730 /**
731 * Generate an invoker method for the passed {@link LambdaForm}.
732 */
733 private byte[] generateCustomizedCodeBytes() {
734 classFilePrologue();
735 addMethod();
736 bogusMethod(lambdaForm);
737
738 final byte[] classFile = toByteArray();
739 maybeDump(classFile);
740 return classFile;
741 }
742
743 void setClassWriter(ClassWriter cw) {
744 this.cw = cw;
745 }
746
747 void addMethod() {
748 methodPrologue();
749
750 // Suppress this method in backtraces displayed to the user.
751 mv.visitAnnotation(LF_HIDDEN_SIG, true);
752
753 // Mark this method as a compiled LambdaForm
754 mv.visitAnnotation(LF_COMPILED_SIG, true);
755
756 if (lambdaForm.forceInline) {
757 // Force inlining of this invoker method.
758 mv.visitAnnotation(FORCEINLINE_SIG, true);
759 } else {
760 mv.visitAnnotation(DONTINLINE_SIG, true);
761 }
762
763 constantPlaceholder(lambdaForm); // keep LambdaForm instance & its compiled form lifetime tightly coupled.
764
765 if (lambdaForm.customized != null) {
766 // Since LambdaForm is customized for a particular MethodHandle, it's safe to substitute
767 // receiver MethodHandle (at slot #0) with an embedded constant and use it instead.
768 // It enables more efficient code generation in some situations, since embedded constants
769 // are compile-time constants for JIT compiler.
770 mv.visitLdcInsn(constantPlaceholder(lambdaForm.customized));
771 mv.visitTypeInsn(Opcodes.CHECKCAST, MH);
772 assert(checkActualReceiver()); // expects MethodHandle on top of the stack
773 mv.visitVarInsn(Opcodes.ASTORE, localsMap[0]);
774 }
775
776 // iterate over the form's names, generating bytecode instructions for each
777 // start iterating at the first name following the arguments
778 Name onStack = null;
779 for (int i = lambdaForm.arity; i < lambdaForm.names.length; i++) {
780 Name name = lambdaForm.names[i];
781
782 emitStoreResult(onStack);
783 onStack = name; // unless otherwise modified below
784 MethodHandleImpl.Intrinsic intr = name.function.intrinsicName();
785 switch (intr) {
786 case SELECT_ALTERNATIVE:
787 assert lambdaForm.isSelectAlternative(i);
788 if (PROFILE_GWT) {
789 assert(name.arguments[0] instanceof Name &&
790 ((Name)name.arguments[0]).refersTo(MethodHandleImpl.class, "profileBoolean"));
791 mv.visitAnnotation(INJECTEDPROFILE_SIG, true);
792 }
793 onStack = emitSelectAlternative(name, lambdaForm.names[i+1]);
794 i++; // skip MH.invokeBasic of the selectAlternative result
795 continue;
796 case GUARD_WITH_CATCH:
797 assert lambdaForm.isGuardWithCatch(i);
798 onStack = emitGuardWithCatch(i);
799 i += 2; // jump to the end of GWC idiom
800 continue;
801 case TRY_FINALLY:
802 assert lambdaForm.isTryFinally(i);
803 onStack = emitTryFinally(i);
804 i += 2; // jump to the end of the TF idiom
805 continue;
806 case LOOP:
807 assert lambdaForm.isLoop(i);
808 onStack = emitLoop(i);
809 i += 2; // jump to the end of the LOOP idiom
810 continue;
811 case NEW_ARRAY:
812 Class<?> rtype = name.function.methodType().returnType();
813 if (isStaticallyNameable(rtype)) {
814 emitNewArray(name);
815 continue;
816 }
817 break;
818 case ARRAY_LOAD:
819 emitArrayLoad(name);
820 continue;
821 case ARRAY_STORE:
822 emitArrayStore(name);
823 continue;
824 case ARRAY_LENGTH:
825 emitArrayLength(name);
826 continue;
827 case IDENTITY:
828 assert(name.arguments.length == 1);
829 emitPushArguments(name, 0);
830 continue;
831 case ZERO:
832 assert(name.arguments.length == 0);
833 emitConst(name.type.basicTypeWrapper().zero());
834 continue;
835 case NONE:
836 // no intrinsic associated
837 break;
838 default:
839 throw newInternalError("Unknown intrinsic: "+intr);
840 }
841
842 MemberName member = name.function.member();
843 if (isStaticallyInvocable(member)) {
844 emitStaticInvoke(member, name);
845 } else {
846 emitInvoke(name);
847 }
848 }
849
850 // return statement
851 emitReturn(onStack);
852
853 methodEpilogue();
854 }
855
856 /*
857 * @throws BytecodeGenerationException if something goes wrong when
858 * generating the byte code
859 */
860 private byte[] toByteArray() {
861 try {
862 return cw.toByteArray();
863 } catch (RuntimeException e) {
864 throw new BytecodeGenerationException(e);
865 }
866 }
867
868 @SuppressWarnings("serial")
869 static final class BytecodeGenerationException extends RuntimeException {
870 BytecodeGenerationException(Exception cause) {
871 super(cause);
872 }
873 }
874
875 void emitArrayLoad(Name name) { emitArrayOp(name, Opcodes.AALOAD); }
876 void emitArrayStore(Name name) { emitArrayOp(name, Opcodes.AASTORE); }
877 void emitArrayLength(Name name) { emitArrayOp(name, Opcodes.ARRAYLENGTH); }
878
879 void emitArrayOp(Name name, int arrayOpcode) {
880 assert arrayOpcode == Opcodes.AALOAD || arrayOpcode == Opcodes.AASTORE || arrayOpcode == Opcodes.ARRAYLENGTH;
881 Class<?> elementType = name.function.methodType().parameterType(0).getComponentType();
882 assert elementType != null;
883 emitPushArguments(name, 0);
884 if (arrayOpcode != Opcodes.ARRAYLENGTH && elementType.isPrimitive()) {
885 Wrapper w = Wrapper.forPrimitiveType(elementType);
886 arrayOpcode = arrayInsnOpcode(arrayTypeCode(w), arrayOpcode);
887 }
888 mv.visitInsn(arrayOpcode);
889 }
890
891 /**
892 * Emit an invoke for the given name.
893 */
894 void emitInvoke(Name name) {
895 assert(!name.isLinkerMethodInvoke()); // should use the static path for these
896 if (true) {
897 // push receiver
898 MethodHandle target = name.function.resolvedHandle();
899 assert(target != null) : name.exprString();
900 mv.visitLdcInsn(constantPlaceholder(target));
901 emitReferenceCast(MethodHandle.class, target);
902 } else {
903 // load receiver
904 emitAloadInsn(0);
905 emitReferenceCast(MethodHandle.class, null);
906 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", LF_SIG);
907 mv.visitFieldInsn(Opcodes.GETFIELD, LF, "names", LFN_SIG);
908 // TODO more to come
909 }
910
911 // push arguments
912 emitPushArguments(name, 0);
913
914 // invocation
915 MethodType type = name.function.methodType();
916 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false);
917 }
918
919 private static Class<?>[] STATICALLY_INVOCABLE_PACKAGES = {
920 // Sample classes from each package we are willing to bind to statically:
921 java.lang.Object.class,
922 java.util.Arrays.class,
923 jdk.internal.misc.Unsafe.class
924 //MethodHandle.class already covered
925 };
926
927 static boolean isStaticallyInvocable(NamedFunction ... functions) {
928 for (NamedFunction nf : functions) {
929 if (!isStaticallyInvocable(nf.member())) {
930 return false;
931 }
932 }
933 return true;
934 }
935
936 static boolean isStaticallyInvocable(Name name) {
937 return isStaticallyInvocable(name.function.member());
938 }
939
940 static boolean isStaticallyInvocable(MemberName member) {
941 if (member == null) return false;
942 if (member.isConstructor()) return false;
943 Class<?> cls = member.getDeclaringClass();
944 // Fast-path non-private members declared by MethodHandles, which is a common
945 // case
946 if (MethodHandle.class.isAssignableFrom(cls) && !member.isPrivate()) {
947 assert(isStaticallyInvocableType(member.getMethodOrFieldType()));
948 return true;
949 }
950 if (cls.isArray() || cls.isPrimitive())
951 return false; // FIXME
952 if (cls.isAnonymousClass() || cls.isLocalClass())
953 return false; // inner class of some sort
954 if (cls.getClassLoader() != MethodHandle.class.getClassLoader())
955 return false; // not on BCP
956 if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: switch to supported API once it is added
957 return false;
958 if (!isStaticallyInvocableType(member.getMethodOrFieldType()))
959 return false;
960 if (!member.isPrivate() && VerifyAccess.isSamePackage(MethodHandle.class, cls))
961 return true; // in java.lang.invoke package
962 if (member.isPublic() && isStaticallyNameable(cls))
963 return true;
964 return false;
965 }
966
967 private static boolean isStaticallyInvocableType(MethodType mtype) {
968 if (!isStaticallyNameable(mtype.returnType()))
969 return false;
970 for (Class<?> ptype : mtype.parameterArray())
971 if (!isStaticallyNameable(ptype))
972 return false;
973 return true;
974 }
975
976 static boolean isStaticallyNameable(Class<?> cls) {
977 if (cls == Object.class)
978 return true;
979 if (MethodHandle.class.isAssignableFrom(cls)) {
980 assert(!ReflectUtil.isVMAnonymousClass(cls));
981 return true;
982 }
983 while (cls.isArray())
984 cls = cls.getComponentType();
985 if (cls.isPrimitive())
986 return true; // int[].class, for example
987 if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: switch to supported API once it is added
988 return false;
989 // could use VerifyAccess.isClassAccessible but the following is a safe approximation
990 if (cls.getClassLoader() != Object.class.getClassLoader())
991 return false;
992 if (VerifyAccess.isSamePackage(MethodHandle.class, cls))
993 return true;
994 if (!Modifier.isPublic(cls.getModifiers()))
995 return false;
996 for (Class<?> pkgcls : STATICALLY_INVOCABLE_PACKAGES) {
997 if (VerifyAccess.isSamePackage(pkgcls, cls))
998 return true;
999 }
1000 return false;
1001 }
1002
1003 void emitStaticInvoke(Name name) {
1004 emitStaticInvoke(name.function.member(), name);
1005 }
1006
1007 /**
1008 * Emit an invoke for the given name, using the MemberName directly.
1009 */
1010 void emitStaticInvoke(MemberName member, Name name) {
1011 assert(member.equals(name.function.member()));
1012 Class<?> defc = member.getDeclaringClass();
1013 String cname = getInternalName(defc);
1014 String mname = member.getName();
1015 String mtype;
1016 byte refKind = member.getReferenceKind();
1017 if (refKind == REF_invokeSpecial) {
1018 // in order to pass the verifier, we need to convert this to invokevirtual in all cases
1019 assert(member.canBeStaticallyBound()) : member;
1020 refKind = REF_invokeVirtual;
1021 }
1022
1023 assert(!(member.getDeclaringClass().isInterface() && refKind == REF_invokeVirtual));
1024
1025 // push arguments
1026 emitPushArguments(name, 0);
1027
1028 // invocation
1029 if (member.isMethod()) {
1030 mtype = member.getMethodType().toMethodDescriptorString();
1031 mv.visitMethodInsn(refKindOpcode(refKind), cname, mname, mtype,
1032 member.getDeclaringClass().isInterface());
1033 } else {
1034 mtype = MethodType.toFieldDescriptorString(member.getFieldType());
1035 mv.visitFieldInsn(refKindOpcode(refKind), cname, mname, mtype);
1036 }
1037 // Issue a type assertion for the result, so we can avoid casts later.
1038 if (name.type == L_TYPE) {
1039 Class<?> rtype = member.getInvocationType().returnType();
1040 assert(!rtype.isPrimitive());
1041 if (rtype != Object.class && !rtype.isInterface()) {
1042 assertStaticType(rtype, name);
1043 }
1044 }
1045 }
1046
1047 void emitNewArray(Name name) throws InternalError {
1048 Class<?> rtype = name.function.methodType().returnType();
1049 if (name.arguments.length == 0) {
1050 // The array will be a constant.
1051 Object emptyArray;
1052 try {
1053 emptyArray = name.function.resolvedHandle().invoke();
1054 } catch (Throwable ex) {
1055 throw uncaughtException(ex);
1056 }
1057 assert(java.lang.reflect.Array.getLength(emptyArray) == 0);
1058 assert(emptyArray.getClass() == rtype); // exact typing
1059 mv.visitLdcInsn(constantPlaceholder(emptyArray));
1060 emitReferenceCast(rtype, emptyArray);
1061 return;
1062 }
1063 Class<?> arrayElementType = rtype.getComponentType();
1064 assert(arrayElementType != null);
1065 emitIconstInsn(name.arguments.length);
1066 int xas = Opcodes.AASTORE;
1067 if (!arrayElementType.isPrimitive()) {
1068 mv.visitTypeInsn(Opcodes.ANEWARRAY, getInternalName(arrayElementType));
1069 } else {
1070 byte tc = arrayTypeCode(Wrapper.forPrimitiveType(arrayElementType));
1071 xas = arrayInsnOpcode(tc, xas);
1072 mv.visitIntInsn(Opcodes.NEWARRAY, tc);
1073 }
1074 // store arguments
1075 for (int i = 0; i < name.arguments.length; i++) {
1076 mv.visitInsn(Opcodes.DUP);
1077 emitIconstInsn(i);
1078 emitPushArgument(name, i);
1079 mv.visitInsn(xas);
1080 }
1081 // the array is left on the stack
1082 assertStaticType(rtype, name);
1083 }
1084 int refKindOpcode(byte refKind) {
1085 switch (refKind) {
1086 case REF_invokeVirtual: return Opcodes.INVOKEVIRTUAL;
1087 case REF_invokeStatic: return Opcodes.INVOKESTATIC;
1088 case REF_invokeSpecial: return Opcodes.INVOKESPECIAL;
1089 case REF_invokeInterface: return Opcodes.INVOKEINTERFACE;
1090 case REF_getField: return Opcodes.GETFIELD;
1091 case REF_putField: return Opcodes.PUTFIELD;
1092 case REF_getStatic: return Opcodes.GETSTATIC;
1093 case REF_putStatic: return Opcodes.PUTSTATIC;
1094 }
1095 throw new InternalError("refKind="+refKind);
1096 }
1097
1098 /**
1099 * Emit bytecode for the selectAlternative idiom.
1100 *
1101 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithTest):
1102 * <blockquote><pre>{@code
1103 * Lambda(a0:L,a1:I)=>{
1104 * t2:I=foo.test(a1:I);
1105 * t3:L=MethodHandleImpl.selectAlternative(t2:I,(MethodHandle(int)int),(MethodHandle(int)int));
1106 * t4:I=MethodHandle.invokeBasic(t3:L,a1:I);t4:I}
1107 * }</pre></blockquote>
1108 */
1109 private Name emitSelectAlternative(Name selectAlternativeName, Name invokeBasicName) {
1110 assert isStaticallyInvocable(invokeBasicName);
1111
1112 Name receiver = (Name) invokeBasicName.arguments[0];
1113
1114 Label L_fallback = new Label();
1115 Label L_done = new Label();
1116
1117 // load test result
1118 emitPushArgument(selectAlternativeName, 0);
1119
1120 // if_icmpne L_fallback
1121 mv.visitJumpInsn(Opcodes.IFEQ, L_fallback);
1122
1123 // invoke selectAlternativeName.arguments[1]
1124 Class<?>[] preForkClasses = localClasses.clone();
1125 emitPushArgument(selectAlternativeName, 1); // get 2nd argument of selectAlternative
1126 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot
1127 emitStaticInvoke(invokeBasicName);
1128
1129 // goto L_done
1130 mv.visitJumpInsn(Opcodes.GOTO, L_done);
1131
1132 // L_fallback:
1133 mv.visitLabel(L_fallback);
1134
1135 // invoke selectAlternativeName.arguments[2]
1136 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length);
1137 emitPushArgument(selectAlternativeName, 2); // get 3rd argument of selectAlternative
1138 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot
1139 emitStaticInvoke(invokeBasicName);
1140
1141 // L_done:
1142 mv.visitLabel(L_done);
1143 // for now do not bother to merge typestate; just reset to the dominator state
1144 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length);
1145
1146 return invokeBasicName; // return what's on stack
1147 }
1148
1149 /**
1150 * Emit bytecode for the guardWithCatch idiom.
1151 *
1152 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithCatch):
1153 * <blockquote><pre>{@code
1154 * guardWithCatch=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L,a5:L,a6:L,a7:L)=>{
1155 * t8:L=MethodHandle.invokeBasic(a4:L,a6:L,a7:L);
1156 * t9:L=MethodHandleImpl.guardWithCatch(a1:L,a2:L,a3:L,t8:L);
1157 * t10:I=MethodHandle.invokeBasic(a5:L,t9:L);t10:I}
1158 * }</pre></blockquote>
1159 *
1160 * It is compiled into bytecode equivalent of the following code:
1161 * <blockquote><pre>{@code
1162 * try {
1163 * return a1.invokeBasic(a6, a7);
1164 * } catch (Throwable e) {
1165 * if (!a2.isInstance(e)) throw e;
1166 * return a3.invokeBasic(ex, a6, a7);
1167 * }}
1168 */
1169 private Name emitGuardWithCatch(int pos) {
1170 Name args = lambdaForm.names[pos];
1171 Name invoker = lambdaForm.names[pos+1];
1172 Name result = lambdaForm.names[pos+2];
1173
1174 Label L_startBlock = new Label();
1175 Label L_endBlock = new Label();
1176 Label L_handler = new Label();
1177 Label L_done = new Label();
1178
1179 Class<?> returnType = result.function.resolvedHandle().type().returnType();
1180 MethodType type = args.function.resolvedHandle().type()
1181 .dropParameterTypes(0,1)
1182 .changeReturnType(returnType);
1183
1184 mv.visitTryCatchBlock(L_startBlock, L_endBlock, L_handler, "java/lang/Throwable");
1185
1186 // Normal case
1187 mv.visitLabel(L_startBlock);
1188 // load target
1189 emitPushArgument(invoker, 0);
1190 emitPushArguments(args, 1); // skip 1st argument: method handle
1191 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false);
1192 mv.visitLabel(L_endBlock);
1193 mv.visitJumpInsn(Opcodes.GOTO, L_done);
1194
1195 // Exceptional case
1196 mv.visitLabel(L_handler);
1197
1198 // Check exception's type
1199 mv.visitInsn(Opcodes.DUP);
1200 // load exception class
1201 emitPushArgument(invoker, 1);
1202 mv.visitInsn(Opcodes.SWAP);
1203 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/Class", "isInstance", "(Ljava/lang/Object;)Z", false);
1204 Label L_rethrow = new Label();
1205 mv.visitJumpInsn(Opcodes.IFEQ, L_rethrow);
1206
1207 // Invoke catcher
1208 // load catcher
1209 emitPushArgument(invoker, 2);
1210 mv.visitInsn(Opcodes.SWAP);
1211 emitPushArguments(args, 1); // skip 1st argument: method handle
1212 MethodType catcherType = type.insertParameterTypes(0, Throwable.class);
1213 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", catcherType.basicType().toMethodDescriptorString(), false);
1214 mv.visitJumpInsn(Opcodes.GOTO, L_done);
1215
1216 mv.visitLabel(L_rethrow);
1217 mv.visitInsn(Opcodes.ATHROW);
1218
1219 mv.visitLabel(L_done);
1220
1221 return result;
1222 }
1223
1224 /**
1225 * Emit bytecode for the tryFinally idiom.
1226 * <p>
1227 * The pattern looks like (Cf. MethodHandleImpl.makeTryFinally):
1228 * <blockquote><pre>{@code
1229 * // a0: BMH
1230 * // a1: target, a2: cleanup
1231 * // a3: box, a4: unbox
1232 * // a5 (and following): arguments
1233 * tryFinally=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L,a5:L)=>{
1234 * t6:L=MethodHandle.invokeBasic(a3:L,a5:L); // box the arguments into an Object[]
1235 * t7:L=MethodHandleImpl.tryFinally(a1:L,a2:L,t6:L); // call the tryFinally executor
1236 * t8:L=MethodHandle.invokeBasic(a4:L,t7:L);t8:L} // unbox the result; return the result
1237 * }</pre></blockquote>
1238 * <p>
1239 * It is compiled into bytecode equivalent to the following code:
1240 * <blockquote><pre>{@code
1241 * Throwable t;
1242 * Object r;
1243 * try {
1244 * r = a1.invokeBasic(a5);
1245 * } catch (Throwable thrown) {
1246 * t = thrown;
1247 * throw t;
1248 * } finally {
1249 * r = a2.invokeBasic(t, r, a5);
1250 * }
1251 * return r;
1252 * }</pre></blockquote>
1253 * <p>
1254 * Specifically, the bytecode will have the following form (the stack effects are given for the beginnings of
1255 * blocks, and for the situations after executing the given instruction - the code will have a slightly different
1256 * shape if the return type is {@code void}):
1257 * <blockquote><pre>{@code
1258 * TRY: (--)
1259 * load target (-- target)
1260 * load args (-- args... target)
1261 * INVOKEVIRTUAL MethodHandle.invokeBasic (depends)
1262 * FINALLY_NORMAL: (-- r)
1263 * load cleanup (-- cleanup r)
1264 * SWAP (-- r cleanup)
1265 * ACONST_NULL (-- t r cleanup)
1266 * SWAP (-- r t cleanup)
1267 * load args (-- args... r t cleanup)
1268 * INVOKEVIRTUAL MethodHandle.invokeBasic (-- r)
1269 * GOTO DONE
1270 * CATCH: (-- t)
1271 * DUP (-- t t)
1272 * FINALLY_EXCEPTIONAL: (-- t t)
1273 * load cleanup (-- cleanup t t)
1274 * SWAP (-- t cleanup t)
1275 * load default for r (-- r t cleanup t)
1276 * load args (-- args... r t cleanup t)
1277 * INVOKEVIRTUAL MethodHandle.invokeBasic (-- r t)
1278 * POP (-- t)
1279 * ATHROW
1280 * DONE: (-- r)
1281 * }</pre></blockquote>
1282 */
1283 private Name emitTryFinally(int pos) {
1284 Name args = lambdaForm.names[pos];
1285 Name invoker = lambdaForm.names[pos+1];
1286 Name result = lambdaForm.names[pos+2];
1287
1288 Label lFrom = new Label();
1289 Label lTo = new Label();
1290 Label lCatch = new Label();
1291 Label lDone = new Label();
1292
1293 Class<?> returnType = result.function.resolvedHandle().type().returnType();
1294 boolean isNonVoid = returnType != void.class;
1295 MethodType type = args.function.resolvedHandle().type()
1296 .dropParameterTypes(0,1)
1297 .changeReturnType(returnType);
1298 MethodType cleanupType = type.insertParameterTypes(0, Throwable.class);
1299 if (isNonVoid) {
1300 cleanupType = cleanupType.insertParameterTypes(1, returnType);
1301 }
1302 String cleanupDesc = cleanupType.basicType().toMethodDescriptorString();
1303
1304 // exception handler table
1305 mv.visitTryCatchBlock(lFrom, lTo, lCatch, "java/lang/Throwable");
1306
1307 // TRY:
1308 mv.visitLabel(lFrom);
1309 emitPushArgument(invoker, 0); // load target
1310 emitPushArguments(args, 1); // load args (skip 0: method handle)
1311 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false);
1312 mv.visitLabel(lTo);
1313
1314 // FINALLY_NORMAL:
1315 emitPushArgument(invoker, 1); // load cleanup
1316 if (isNonVoid) {
1317 mv.visitInsn(Opcodes.SWAP);
1318 }
1319 mv.visitInsn(Opcodes.ACONST_NULL);
1320 if (isNonVoid) {
1321 mv.visitInsn(Opcodes.SWAP);
1322 }
1323 emitPushArguments(args, 1); // load args (skip 0: method handle)
1324 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", cleanupDesc, false);
1325 mv.visitJumpInsn(Opcodes.GOTO, lDone);
1326
1327 // CATCH:
1328 mv.visitLabel(lCatch);
1329 mv.visitInsn(Opcodes.DUP);
1330
1331 // FINALLY_EXCEPTIONAL:
1332 emitPushArgument(invoker, 1); // load cleanup
1333 mv.visitInsn(Opcodes.SWAP);
1334 if (isNonVoid) {
1335 emitZero(BasicType.basicType(returnType)); // load default for result
1336 }
1337 emitPushArguments(args, 1); // load args (skip 0: method handle)
1338 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", cleanupDesc, false);
1339 if (isNonVoid) {
1340 mv.visitInsn(Opcodes.POP);
1341 }
1342 mv.visitInsn(Opcodes.ATHROW);
1343
1344 // DONE:
1345 mv.visitLabel(lDone);
1346
1347 return result;
1348 }
1349
1350 /**
1351 * Emit bytecode for the loop idiom.
1352 * <p>
1353 * The pattern looks like (Cf. MethodHandleImpl.loop):
1354 * <blockquote><pre>{@code
1355 * // a0: BMH
1356 * // a1: LoopClauses (containing an array of arrays: inits, steps, preds, finis)
1357 * // a2: box, a3: unbox
1358 * // a4 (and following): arguments
1359 * loop=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L)=>{
1360 * t5:L=MethodHandle.invokeBasic(a2:L,a4:L); // box the arguments into an Object[]
1361 * t6:L=MethodHandleImpl.loop(bt:L,a1:L,t5:L); // call the loop executor (with supplied types in bt)
1362 * t7:L=MethodHandle.invokeBasic(a3:L,t6:L);t7:L} // unbox the result; return the result
1363 * }</pre></blockquote>
1364 * <p>
1365 * It is compiled into bytecode equivalent to the code seen in {@link MethodHandleImpl#loop(BasicType[],
1366 * MethodHandleImpl.LoopClauses, Object...)}, with the difference that no arrays
1367 * will be used for local state storage. Instead, the local state will be mapped to actual stack slots.
1368 * <p>
1369 * Bytecode generation applies an unrolling scheme to enable better bytecode generation regarding local state type
1370 * handling. The generated bytecode will have the following form ({@code void} types are ignored for convenience).
1371 * Assume there are {@code C} clauses in the loop.
1372 * <blockquote><pre>{@code
1373 * PREINIT: ALOAD_1
1374 * CHECKCAST LoopClauses
1375 * GETFIELD LoopClauses.clauses
1376 * ASTORE clauseDataIndex // place the clauses 2-dimensional array on the stack
1377 * INIT: (INIT_SEQ for clause 1)
1378 * ...
1379 * (INIT_SEQ for clause C)
1380 * LOOP: (LOOP_SEQ for clause 1)
1381 * ...
1382 * (LOOP_SEQ for clause C)
1383 * GOTO LOOP
1384 * DONE: ...
1385 * }</pre></blockquote>
1386 * <p>
1387 * The {@code INIT_SEQ_x} sequence for clause {@code x} (with {@code x} ranging from {@code 0} to {@code C-1}) has
1388 * the following shape. Assume slot {@code vx} is used to hold the state for clause {@code x}.
1389 * <blockquote><pre>{@code
1390 * INIT_SEQ_x: ALOAD clauseDataIndex
1391 * ICONST_0
1392 * AALOAD // load the inits array
1393 * ICONST x
1394 * AALOAD // load the init handle for clause x
1395 * load args
1396 * INVOKEVIRTUAL MethodHandle.invokeBasic
1397 * store vx
1398 * }</pre></blockquote>
1399 * <p>
1400 * The {@code LOOP_SEQ_x} sequence for clause {@code x} (with {@code x} ranging from {@code 0} to {@code C-1}) has
1401 * the following shape. Again, assume slot {@code vx} is used to hold the state for clause {@code x}.
1402 * <blockquote><pre>{@code
1403 * LOOP_SEQ_x: ALOAD clauseDataIndex
1404 * ICONST_1
1405 * AALOAD // load the steps array
1406 * ICONST x
1407 * AALOAD // load the step handle for clause x
1408 * load locals
1409 * load args
1410 * INVOKEVIRTUAL MethodHandle.invokeBasic
1411 * store vx
1412 * ALOAD clauseDataIndex
1413 * ICONST_2
1414 * AALOAD // load the preds array
1415 * ICONST x
1416 * AALOAD // load the pred handle for clause x
1417 * load locals
1418 * load args
1419 * INVOKEVIRTUAL MethodHandle.invokeBasic
1420 * IFNE LOOP_SEQ_x+1 // predicate returned false -> jump to next clause
1421 * ALOAD clauseDataIndex
1422 * ICONST_3
1423 * AALOAD // load the finis array
1424 * ICONST x
1425 * AALOAD // load the fini handle for clause x
1426 * load locals
1427 * load args
1428 * INVOKEVIRTUAL MethodHandle.invokeBasic
1429 * GOTO DONE // jump beyond end of clauses to return from loop
1430 * }</pre></blockquote>
1431 */
1432 private Name emitLoop(int pos) {
1433 Name args = lambdaForm.names[pos];
1434 Name invoker = lambdaForm.names[pos+1];
1435 Name result = lambdaForm.names[pos+2];
1436
1437 // extract clause and loop-local state types
1438 // find the type info in the loop invocation
1439 BasicType[] loopClauseTypes = (BasicType[]) invoker.arguments[0];
1440 Class<?>[] loopLocalStateTypes = Stream.of(loopClauseTypes).
1441 filter(bt -> bt != BasicType.V_TYPE).map(BasicType::basicTypeClass).toArray(Class<?>[]::new);
1442 Class<?>[] localTypes = new Class<?>[loopLocalStateTypes.length + 1];
1443 localTypes[0] = MethodHandleImpl.LoopClauses.class;
1444 System.arraycopy(loopLocalStateTypes, 0, localTypes, 1, loopLocalStateTypes.length);
1445
1446 final int clauseDataIndex = extendLocalsMap(localTypes);
1447 final int firstLoopStateIndex = clauseDataIndex + 1;
1448
1449 Class<?> returnType = result.function.resolvedHandle().type().returnType();
1450 MethodType loopType = args.function.resolvedHandle().type()
1451 .dropParameterTypes(0,1)
1452 .changeReturnType(returnType);
1453 MethodType loopHandleType = loopType.insertParameterTypes(0, loopLocalStateTypes);
1454 MethodType predType = loopHandleType.changeReturnType(boolean.class);
1455 MethodType finiType = loopHandleType;
1456
1457 final int nClauses = loopClauseTypes.length;
1458
1459 // indices to invoker arguments to load method handle arrays
1460 final int inits = 1;
1461 final int steps = 2;
1462 final int preds = 3;
1463 final int finis = 4;
1464
1465 Label lLoop = new Label();
1466 Label lDone = new Label();
1467 Label lNext;
1468
1469 // PREINIT:
1470 emitPushArgument(MethodHandleImpl.LoopClauses.class, invoker.arguments[1]);
1471 mv.visitFieldInsn(Opcodes.GETFIELD, LOOP_CLAUSES, "clauses", MHARY2);
1472 emitAstoreInsn(clauseDataIndex);
1473
1474 // INIT:
1475 for (int c = 0, state = 0; c < nClauses; ++c) {
1476 MethodType cInitType = loopType.changeReturnType(loopClauseTypes[c].basicTypeClass());
1477 emitLoopHandleInvoke(invoker, inits, c, args, false, cInitType, loopLocalStateTypes, clauseDataIndex,
1478 firstLoopStateIndex);
1479 if (cInitType.returnType() != void.class) {
1480 emitStoreInsn(BasicType.basicType(cInitType.returnType()), firstLoopStateIndex + state);
1481 ++state;
1482 }
1483 }
1484
1485 // LOOP:
1486 mv.visitLabel(lLoop);
1487
1488 for (int c = 0, state = 0; c < nClauses; ++c) {
1489 lNext = new Label();
1490
1491 MethodType stepType = loopHandleType.changeReturnType(loopClauseTypes[c].basicTypeClass());
1492 boolean isVoid = stepType.returnType() == void.class;
1493
1494 // invoke loop step
1495 emitLoopHandleInvoke(invoker, steps, c, args, true, stepType, loopLocalStateTypes, clauseDataIndex,
1496 firstLoopStateIndex);
1497 if (!isVoid) {
1498 emitStoreInsn(BasicType.basicType(stepType.returnType()), firstLoopStateIndex + state);
1499 ++state;
1500 }
1501
1502 // invoke loop predicate
1503 emitLoopHandleInvoke(invoker, preds, c, args, true, predType, loopLocalStateTypes, clauseDataIndex,
1504 firstLoopStateIndex);
1505 mv.visitJumpInsn(Opcodes.IFNE, lNext);
1506
1507 // invoke fini
1508 emitLoopHandleInvoke(invoker, finis, c, args, true, finiType, loopLocalStateTypes, clauseDataIndex,
1509 firstLoopStateIndex);
1510 mv.visitJumpInsn(Opcodes.GOTO, lDone);
1511
1512 // this is the beginning of the next loop clause
1513 mv.visitLabel(lNext);
1514 }
1515
1516 mv.visitJumpInsn(Opcodes.GOTO, lLoop);
1517
1518 // DONE:
1519 mv.visitLabel(lDone);
1520
1521 return result;
1522 }
1523
1524 private int extendLocalsMap(Class<?>[] types) {
1525 int firstSlot = localsMap.length - 1;
1526 localsMap = Arrays.copyOf(localsMap, localsMap.length + types.length);
1527 localClasses = Arrays.copyOf(localClasses, localClasses.length + types.length);
1528 System.arraycopy(types, 0, localClasses, firstSlot, types.length);
1529 int index = localsMap[firstSlot - 1] + 1;
1530 int lastSlots = 0;
1531 for (int i = 0; i < types.length; ++i) {
1532 localsMap[firstSlot + i] = index;
1533 lastSlots = BasicType.basicType(localClasses[firstSlot + i]).basicTypeSlots();
1534 index += lastSlots;
1535 }
1536 localsMap[localsMap.length - 1] = index - lastSlots;
1537 return firstSlot;
1538 }
1539
1540 private void emitLoopHandleInvoke(Name holder, int handles, int clause, Name args, boolean pushLocalState,
1541 MethodType type, Class<?>[] loopLocalStateTypes, int clauseDataSlot,
1542 int firstLoopStateSlot) {
1543 // load handle for clause
1544 emitPushClauseArray(clauseDataSlot, handles);
1545 emitIconstInsn(clause);
1546 mv.visitInsn(Opcodes.AALOAD);
1547 // load loop state (preceding the other arguments)
1548 if (pushLocalState) {
1549 for (int s = 0; s < loopLocalStateTypes.length; ++s) {
1550 emitLoadInsn(BasicType.basicType(loopLocalStateTypes[s]), firstLoopStateSlot + s);
1551 }
1552 }
1553 // load loop args (skip 0: method handle)
1554 emitPushArguments(args, 1);
1555 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.toMethodDescriptorString(), false);
1556 }
1557
1558 private void emitPushClauseArray(int clauseDataSlot, int which) {
1559 emitAloadInsn(clauseDataSlot);
1560 emitIconstInsn(which - 1);
1561 mv.visitInsn(Opcodes.AALOAD);
1562 }
1563
1564 private void emitZero(BasicType type) {
1565 switch (type) {
1566 case I_TYPE: mv.visitInsn(Opcodes.ICONST_0); break;
1567 case J_TYPE: mv.visitInsn(Opcodes.LCONST_0); break;
1568 case F_TYPE: mv.visitInsn(Opcodes.FCONST_0); break;
1569 case D_TYPE: mv.visitInsn(Opcodes.DCONST_0); break;
1570 case L_TYPE: mv.visitInsn(Opcodes.ACONST_NULL); break;
1571 default: throw new InternalError("unknown type: " + type);
1572 }
1573 }
1574
1575 private void emitPushArguments(Name args, int start) {
1576 MethodType type = args.function.methodType();
1577 for (int i = start; i < args.arguments.length; i++) {
1578 emitPushArgument(type.parameterType(i), args.arguments[i]);
1579 }
1580 }
1581
1582 private void emitPushArgument(Name name, int paramIndex) {
1583 Object arg = name.arguments[paramIndex];
1584 Class<?> ptype = name.function.methodType().parameterType(paramIndex);
1585 emitPushArgument(ptype, arg);
1586 }
1587
1588 private void emitPushArgument(Class<?> ptype, Object arg) {
1589 BasicType bptype = basicType(ptype);
1590 if (arg instanceof Name) {
1591 Name n = (Name) arg;
1592 emitLoadInsn(n.type, n.index());
1593 emitImplicitConversion(n.type, ptype, n);
1594 } else if ((arg == null || arg instanceof String) && bptype == L_TYPE) {
1595 emitConst(arg);
1596 } else {
1597 if (Wrapper.isWrapperType(arg.getClass()) && bptype != L_TYPE) {
1598 emitConst(arg);
1599 } else {
1600 mv.visitLdcInsn(constantPlaceholder(arg));
1601 emitImplicitConversion(L_TYPE, ptype, arg);
1602 }
1603 }
1604 }
1605
1606 /**
1607 * Store the name to its local, if necessary.
1608 */
1609 private void emitStoreResult(Name name) {
1610 if (name != null && name.type != V_TYPE) {
1611 // non-void: actually assign
1612 emitStoreInsn(name.type, name.index());
1613 }
1614 }
1615
1616 /**
1617 * Emits a return statement from a LF invoker. If required, the result type is cast to the correct return type.
1618 */
1619 private void emitReturn(Name onStack) {
1620 // return statement
1621 Class<?> rclass = invokerType.returnType();
1622 BasicType rtype = lambdaForm.returnType();
1623 assert(rtype == basicType(rclass)); // must agree
1624 if (rtype == V_TYPE) {
1625 // void
1626 mv.visitInsn(Opcodes.RETURN);
1627 // it doesn't matter what rclass is; the JVM will discard any value
1628 } else {
1629 LambdaForm.Name rn = lambdaForm.names[lambdaForm.result];
1630
1631 // put return value on the stack if it is not already there
1632 if (rn != onStack) {
1633 emitLoadInsn(rtype, lambdaForm.result);
1634 }
1635
1636 emitImplicitConversion(rtype, rclass, rn);
1637
1638 // generate actual return statement
1639 emitReturnInsn(rtype);
1640 }
1641 }
1642
1643 /**
1644 * Emit a type conversion bytecode casting from "from" to "to".
1645 */
1646 private void emitPrimCast(Wrapper from, Wrapper to) {
1647 // Here's how.
1648 // - indicates forbidden
1649 // <-> indicates implicit
1650 // to ----> boolean byte short char int long float double
1651 // from boolean <-> - - - - - - -
1652 // byte - <-> i2s i2c <-> i2l i2f i2d
1653 // short - i2b <-> i2c <-> i2l i2f i2d
1654 // char - i2b i2s <-> <-> i2l i2f i2d
1655 // int - i2b i2s i2c <-> i2l i2f i2d
1656 // long - l2i,i2b l2i,i2s l2i,i2c l2i <-> l2f l2d
1657 // float - f2i,i2b f2i,i2s f2i,i2c f2i f2l <-> f2d
1658 // double - d2i,i2b d2i,i2s d2i,i2c d2i d2l d2f <->
1659 if (from == to) {
1660 // no cast required, should be dead code anyway
1661 return;
1662 }
1663 if (from.isSubwordOrInt()) {
1664 // cast from {byte,short,char,int} to anything
1665 emitI2X(to);
1666 } else {
1667 // cast from {long,float,double} to anything
1668 if (to.isSubwordOrInt()) {
1669 // cast to {byte,short,char,int}
1670 emitX2I(from);
1671 if (to.bitWidth() < 32) {
1672 // targets other than int require another conversion
1673 emitI2X(to);
1674 }
1675 } else {
1676 // cast to {long,float,double} - this is verbose
1677 boolean error = false;
1678 switch (from) {
1679 case LONG:
1680 switch (to) {
1681 case FLOAT: mv.visitInsn(Opcodes.L2F); break;
1682 case DOUBLE: mv.visitInsn(Opcodes.L2D); break;
1683 default: error = true; break;
1684 }
1685 break;
1686 case FLOAT:
1687 switch (to) {
1688 case LONG : mv.visitInsn(Opcodes.F2L); break;
1689 case DOUBLE: mv.visitInsn(Opcodes.F2D); break;
1690 default: error = true; break;
1691 }
1692 break;
1693 case DOUBLE:
1694 switch (to) {
1695 case LONG : mv.visitInsn(Opcodes.D2L); break;
1696 case FLOAT: mv.visitInsn(Opcodes.D2F); break;
1697 default: error = true; break;
1698 }
1699 break;
1700 default:
1701 error = true;
1702 break;
1703 }
1704 if (error) {
1705 throw new IllegalStateException("unhandled prim cast: " + from + "2" + to);
1706 }
1707 }
1708 }
1709 }
1710
1711 private void emitI2X(Wrapper type) {
1712 switch (type) {
1713 case BYTE: mv.visitInsn(Opcodes.I2B); break;
1714 case SHORT: mv.visitInsn(Opcodes.I2S); break;
1715 case CHAR: mv.visitInsn(Opcodes.I2C); break;
1716 case INT: /* naught */ break;
1717 case LONG: mv.visitInsn(Opcodes.I2L); break;
1718 case FLOAT: mv.visitInsn(Opcodes.I2F); break;
1719 case DOUBLE: mv.visitInsn(Opcodes.I2D); break;
1720 case BOOLEAN:
1721 // For compatibility with ValueConversions and explicitCastArguments:
1722 mv.visitInsn(Opcodes.ICONST_1);
1723 mv.visitInsn(Opcodes.IAND);
1724 break;
1725 default: throw new InternalError("unknown type: " + type);
1726 }
1727 }
1728
1729 private void emitX2I(Wrapper type) {
1730 switch (type) {
1731 case LONG: mv.visitInsn(Opcodes.L2I); break;
1732 case FLOAT: mv.visitInsn(Opcodes.F2I); break;
1733 case DOUBLE: mv.visitInsn(Opcodes.D2I); break;
1734 default: throw new InternalError("unknown type: " + type);
1735 }
1736 }
1737
1738 /**
1739 * Generate bytecode for a LambdaForm.vmentry which calls interpretWithArguments.
1740 */
1741 static MemberName generateLambdaFormInterpreterEntryPoint(MethodType mt) {
1742 assert(isValidSignature(basicTypeSignature(mt)));
1743 String name = "interpret_"+basicTypeChar(mt.returnType());
1744 MethodType type = mt; // includes leading argument
1745 type = type.changeParameterType(0, MethodHandle.class);
1746 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("LFI", name, type);
1747 return g.loadMethod(g.generateLambdaFormInterpreterEntryPointBytes());
1748 }
1749
1750 private byte[] generateLambdaFormInterpreterEntryPointBytes() {
1751 classFilePrologue();
1752 methodPrologue();
1753
1754 // Suppress this method in backtraces displayed to the user.
1755 mv.visitAnnotation(LF_HIDDEN_SIG, true);
1756
1757 // Don't inline the interpreter entry.
1758 mv.visitAnnotation(DONTINLINE_SIG, true);
1759
1760 // create parameter array
1761 emitIconstInsn(invokerType.parameterCount());
1762 mv.visitTypeInsn(Opcodes.ANEWARRAY, "java/lang/Object");
1763
1764 // fill parameter array
1765 for (int i = 0; i < invokerType.parameterCount(); i++) {
1766 Class<?> ptype = invokerType.parameterType(i);
1767 mv.visitInsn(Opcodes.DUP);
1768 emitIconstInsn(i);
1769 emitLoadInsn(basicType(ptype), i);
1770 // box if primitive type
1771 if (ptype.isPrimitive()) {
1772 emitBoxing(Wrapper.forPrimitiveType(ptype));
1773 }
1774 mv.visitInsn(Opcodes.AASTORE);
1775 }
1776 // invoke
1777 emitAloadInsn(0);
1778 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", "Ljava/lang/invoke/LambdaForm;");
1779 mv.visitInsn(Opcodes.SWAP); // swap form and array; avoid local variable
1780 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, LF, "interpretWithArguments", "([Ljava/lang/Object;)Ljava/lang/Object;", false);
1781
1782 // maybe unbox
1783 Class<?> rtype = invokerType.returnType();
1784 if (rtype.isPrimitive() && rtype != void.class) {
1785 emitUnboxing(Wrapper.forPrimitiveType(rtype));
1786 }
1787
1788 // return statement
1789 emitReturnInsn(basicType(rtype));
1790
1791 methodEpilogue();
1792 bogusMethod(invokerType);
1793
1794 final byte[] classFile = cw.toByteArray();
1795 maybeDump(classFile);
1796 return classFile;
1797 }
1798
1799 /**
1800 * Generate bytecode for a NamedFunction invoker.
1801 */
1802 static MemberName generateNamedFunctionInvoker(MethodTypeForm typeForm) {
1803 MethodType invokerType = NamedFunction.INVOKER_METHOD_TYPE;
1804 String invokerName = "invoke_" + shortenSignature(basicTypeSignature(typeForm.erasedType()));
1805 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("NFI", invokerName, invokerType);
1806 return g.loadMethod(g.generateNamedFunctionInvokerImpl(typeForm));
1807 }
1808
1809 private byte[] generateNamedFunctionInvokerImpl(MethodTypeForm typeForm) {
1810 MethodType dstType = typeForm.erasedType();
1811 classFilePrologue();
1812 methodPrologue();
1813
1814 // Suppress this method in backtraces displayed to the user.
1815 mv.visitAnnotation(LF_HIDDEN_SIG, true);
1816
1817 // Force inlining of this invoker method.
1818 mv.visitAnnotation(FORCEINLINE_SIG, true);
1819
1820 // Load receiver
1821 emitAloadInsn(0);
1822
1823 // Load arguments from array
1824 for (int i = 0; i < dstType.parameterCount(); i++) {
1825 emitAloadInsn(1);
1826 emitIconstInsn(i);
1827 mv.visitInsn(Opcodes.AALOAD);
1828
1829 // Maybe unbox
1830 Class<?> dptype = dstType.parameterType(i);
1831 if (dptype.isPrimitive()) {
1832 Wrapper dstWrapper = Wrapper.forBasicType(dptype);
1833 Wrapper srcWrapper = dstWrapper.isSubwordOrInt() ? Wrapper.INT : dstWrapper; // narrow subword from int
1834 emitUnboxing(srcWrapper);
1835 emitPrimCast(srcWrapper, dstWrapper);
1836 }
1837 }
1838
1839 // Invoke
1840 String targetDesc = dstType.basicType().toMethodDescriptorString();
1841 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", targetDesc, false);
1842
1843 // Box primitive types
1844 Class<?> rtype = dstType.returnType();
1845 if (rtype != void.class && rtype.isPrimitive()) {
1846 Wrapper srcWrapper = Wrapper.forBasicType(rtype);
1847 Wrapper dstWrapper = srcWrapper.isSubwordOrInt() ? Wrapper.INT : srcWrapper; // widen subword to int
1848 // boolean casts not allowed
1849 emitPrimCast(srcWrapper, dstWrapper);
1850 emitBoxing(dstWrapper);
1851 }
1852
1853 // If the return type is void we return a null reference.
1854 if (rtype == void.class) {
1855 mv.visitInsn(Opcodes.ACONST_NULL);
1856 }
1857 emitReturnInsn(L_TYPE); // NOTE: NamedFunction invokers always return a reference value.
1858
1859 methodEpilogue();
1860 bogusMethod(dstType);
1861
1862 final byte[] classFile = cw.toByteArray();
1863 maybeDump(classFile);
1864 return classFile;
1865 }
1866
1867 /**
1868 * Emit a bogus method that just loads some string constants. This is to get the constants into the constant pool
1869 * for debugging purposes.
1870 */
1871 private void bogusMethod(Object os) {
1872 if (DUMP_CLASS_FILES) {
1873 mv = cw.visitMethod(Opcodes.ACC_STATIC, "dummy", "()V", null, null);
1874 mv.visitLdcInsn(os.toString());
1875 mv.visitInsn(Opcodes.POP);
1876 mv.visitInsn(Opcodes.RETURN);
1877 mv.visitMaxs(0, 0);
1878 mv.visitEnd();
1879 }
1880 }
1881 }