1 /*
2 * Copyright (c) 2012, 2019, 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 MethodType mt = invokerType.erase();
127 // Create an array to map name indexes to locals indexes.
128 localsMap[0] = 0; // localsMap has at least one element
129 for (int i = 1, index = 0; i < localsMap.length; i++) {
130 Wrapper w = Wrapper.forBasicType(mt.parameterType(i - 1));
131 index += w.stackSlots();
132 localsMap[i] = index;
133 }
134 }
135
136 /** For generating customized code for a single LambdaForm. */
137 private InvokerBytecodeGenerator(String className, LambdaForm form, MethodType invokerType) {
138 this(className, form.lambdaName(), form, invokerType);
139 }
140
141 /** For generating customized code for a single LambdaForm. */
142 InvokerBytecodeGenerator(String className, String invokerName,
143 LambdaForm form, MethodType invokerType) {
144 this(form, form.names.length,
145 className, invokerName, invokerType);
146 // Create an array to map name indexes to locals indexes.
147 Name[] names = form.names;
148 for (int i = 0, index = 0; i < localsMap.length; i++) {
149 localsMap[i] = index;
150 if (i < names.length) {
151 BasicType type = names[i].type();
152 index += type.basicTypeSlots();
153 }
154 }
155 }
156
157 /** instance counters for dumped classes */
158 private static final HashMap<String,Integer> DUMP_CLASS_FILES_COUNTERS;
159 /** debugging flag for saving generated class files */
160 private static final File DUMP_CLASS_FILES_DIR;
161
162 static {
163 if (DUMP_CLASS_FILES) {
164 DUMP_CLASS_FILES_COUNTERS = new HashMap<>();
165 try {
166 File dumpDir = new File("DUMP_CLASS_FILES");
167 if (!dumpDir.exists()) {
168 dumpDir.mkdirs();
169 }
170 DUMP_CLASS_FILES_DIR = dumpDir;
171 System.out.println("Dumping class files to "+DUMP_CLASS_FILES_DIR+"/...");
172 } catch (Exception e) {
173 throw newInternalError(e);
174 }
175 } else {
176 DUMP_CLASS_FILES_COUNTERS = null;
177 DUMP_CLASS_FILES_DIR = null;
178 }
179 }
180
181 private void maybeDump(final byte[] classFile) {
182 if (DUMP_CLASS_FILES) {
183 maybeDump(CLASS_PREFIX + className, classFile);
184 }
185 }
186
187 // Also used from BoundMethodHandle
188 static void maybeDump(final String className, final byte[] classFile) {
189 if (DUMP_CLASS_FILES) {
190 java.security.AccessController.doPrivileged(
191 new java.security.PrivilegedAction<>() {
192 public Void run() {
193 try {
194 String dumpName = className.replace('.','/');
195 File dumpFile = new File(DUMP_CLASS_FILES_DIR, dumpName+".class");
196 System.out.println("dump: " + dumpFile);
197 dumpFile.getParentFile().mkdirs();
198 FileOutputStream file = new FileOutputStream(dumpFile);
199 file.write(classFile);
200 file.close();
201 return null;
202 } catch (IOException ex) {
203 throw newInternalError(ex);
204 }
205 }
206 });
207 }
208 }
209
210 private static String makeDumpableClassName(String className) {
211 Integer ctr;
212 synchronized (DUMP_CLASS_FILES_COUNTERS) {
213 ctr = DUMP_CLASS_FILES_COUNTERS.get(className);
214 if (ctr == null) ctr = 0;
215 DUMP_CLASS_FILES_COUNTERS.put(className, ctr+1);
216 }
217 String sfx = ctr.toString();
218 while (sfx.length() < 3)
219 sfx = "0"+sfx;
220 className += sfx;
221 return className;
222 }
223
224 class CpPatch {
225 final int index;
226 final Object value;
227 CpPatch(int index, Object value) {
228 this.index = index;
229 this.value = value;
230 }
231 public String toString() {
232 return "CpPatch/index="+index+",value="+value;
233 }
234 }
235
236 private final ArrayList<CpPatch> cpPatches = new ArrayList<>();
237
238 private int cph = 0; // for counting constant placeholders
239
240 String constantPlaceholder(Object arg) {
241 String cpPlaceholder = "CONSTANT_PLACEHOLDER_" + cph++;
242 if (DUMP_CLASS_FILES) cpPlaceholder += " <<" + debugString(arg) + ">>";
243 // TODO check if arg is already in the constant pool
244 // insert placeholder in CP and remember the patch
245 int index = cw.newConst((Object) cpPlaceholder);
246 cpPatches.add(new CpPatch(index, arg));
247 return cpPlaceholder;
248 }
249
250 Object[] cpPatches(byte[] classFile) {
251 int size = getConstantPoolSize(classFile);
252 Object[] res = new Object[size];
253 for (CpPatch p : cpPatches) {
254 if (p.index >= size)
255 throw new InternalError("in cpool["+size+"]: "+p+"\n"+Arrays.toString(Arrays.copyOf(classFile, 20)));
256 res[p.index] = p.value;
257 }
258 return res;
259 }
260
261 private static String debugString(Object arg) {
262 if (arg instanceof MethodHandle) {
263 MethodHandle mh = (MethodHandle) arg;
264 MemberName member = mh.internalMemberName();
265 if (member != null)
266 return member.toString();
267 return mh.debugString();
268 }
269 return arg.toString();
270 }
271
272 /**
273 * Extract the number of constant pool entries from a given class file.
274 *
275 * @param classFile the bytes of the class file in question.
276 * @return the number of entries in the constant pool.
277 */
278 private static int getConstantPoolSize(byte[] classFile) {
279 // The first few bytes:
280 // u4 magic;
281 // u2 minor_version;
282 // u2 major_version;
283 // u2 constant_pool_count;
284 return ((classFile[8] & 0xFF) << 8) | (classFile[9] & 0xFF);
285 }
286
287 /**
288 * Extract the MemberName of a newly-defined method.
289 */
290 private MemberName loadMethod(byte[] classFile) {
291 Class<?> invokerClass = loadAndInitializeInvokerClass(classFile, cpPatches(classFile));
292 return resolveInvokerMember(invokerClass, invokerName, invokerType);
293 }
294
295 /**
296 * Define a given class as anonymous class in the runtime system.
297 */
298 private static Class<?> loadAndInitializeInvokerClass(byte[] classBytes, Object[] patches) {
299 Class<?> invokerClass = UNSAFE.defineAnonymousClass(HOST_CLASS, classBytes, patches);
300 UNSAFE.ensureClassInitialized(invokerClass); // Make sure the class is initialized; VM might complain.
301 return invokerClass;
302 }
303
304 private static MemberName resolveInvokerMember(Class<?> invokerClass, String name, MethodType type) {
305 MemberName member = new MemberName(invokerClass, name, type, REF_invokeStatic);
306 try {
307 member = MEMBERNAME_FACTORY.resolveOrFail(REF_invokeStatic, member, HOST_CLASS, ReflectiveOperationException.class);
308 } catch (ReflectiveOperationException e) {
309 throw newInternalError(e);
310 }
311 return member;
312 }
313
314 /**
315 * Set up class file generation.
316 */
317 private ClassWriter classFilePrologue() {
318 final int NOT_ACC_PUBLIC = 0; // not ACC_PUBLIC
319 cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES);
320 cw.visit(Opcodes.V1_8, NOT_ACC_PUBLIC + Opcodes.ACC_FINAL + Opcodes.ACC_SUPER,
321 CLASS_PREFIX + className, null, INVOKER_SUPER_NAME, null);
322 cw.visitSource(SOURCE_PREFIX + className, null);
323 return cw;
324 }
325
326 private void methodPrologue() {
327 String invokerDesc = invokerType.toMethodDescriptorString();
328 mv = cw.visitMethod(Opcodes.ACC_STATIC, invokerName, invokerDesc, null, null);
329 }
330
331 /**
332 * Tear down class file generation.
333 */
334 private void methodEpilogue() {
335 mv.visitMaxs(0, 0);
336 mv.visitEnd();
337 }
338
339 /*
340 * Low-level emit helpers.
341 */
342 private void emitConst(Object con) {
343 if (con == null) {
344 mv.visitInsn(Opcodes.ACONST_NULL);
345 return;
346 }
347 if (con instanceof Integer) {
348 emitIconstInsn((int) con);
349 return;
350 }
351 if (con instanceof Byte) {
352 emitIconstInsn((byte)con);
353 return;
354 }
355 if (con instanceof Short) {
356 emitIconstInsn((short)con);
357 return;
358 }
359 if (con instanceof Character) {
360 emitIconstInsn((char)con);
361 return;
362 }
363 if (con instanceof Long) {
364 long x = (long) con;
365 short sx = (short)x;
366 if (x == sx) {
367 if (sx >= 0 && sx <= 1) {
368 mv.visitInsn(Opcodes.LCONST_0 + (int) sx);
369 } else {
370 emitIconstInsn((int) x);
371 mv.visitInsn(Opcodes.I2L);
372 }
373 return;
374 }
375 }
376 if (con instanceof Float) {
377 float x = (float) con;
378 short sx = (short)x;
379 if (x == sx) {
380 if (sx >= 0 && sx <= 2) {
381 mv.visitInsn(Opcodes.FCONST_0 + (int) sx);
382 } else {
383 emitIconstInsn((int) x);
384 mv.visitInsn(Opcodes.I2F);
385 }
386 return;
387 }
388 }
389 if (con instanceof Double) {
390 double x = (double) con;
391 short sx = (short)x;
392 if (x == sx) {
393 if (sx >= 0 && sx <= 1) {
394 mv.visitInsn(Opcodes.DCONST_0 + (int) sx);
395 } else {
396 emitIconstInsn((int) x);
397 mv.visitInsn(Opcodes.I2D);
398 }
399 return;
400 }
401 }
402 if (con instanceof Boolean) {
403 emitIconstInsn((boolean) con ? 1 : 0);
404 return;
405 }
406 // fall through:
407 mv.visitLdcInsn(con);
408 }
409
410 private void emitIconstInsn(final int cst) {
411 if (cst >= -1 && cst <= 5) {
412 mv.visitInsn(Opcodes.ICONST_0 + cst);
413 } else if (cst >= Byte.MIN_VALUE && cst <= Byte.MAX_VALUE) {
414 mv.visitIntInsn(Opcodes.BIPUSH, cst);
415 } else if (cst >= Short.MIN_VALUE && cst <= Short.MAX_VALUE) {
416 mv.visitIntInsn(Opcodes.SIPUSH, cst);
417 } else {
418 mv.visitLdcInsn(cst);
419 }
420 }
421
422 /*
423 * NOTE: These load/store methods use the localsMap to find the correct index!
424 */
425 private void emitLoadInsn(BasicType type, int index) {
426 int opcode = loadInsnOpcode(type);
427 mv.visitVarInsn(opcode, localsMap[index]);
428 }
429
430 private int loadInsnOpcode(BasicType type) throws InternalError {
431 switch (type) {
432 case I_TYPE: return Opcodes.ILOAD;
433 case J_TYPE: return Opcodes.LLOAD;
434 case F_TYPE: return Opcodes.FLOAD;
435 case D_TYPE: return Opcodes.DLOAD;
436 case L_TYPE: return Opcodes.ALOAD;
437 default:
438 throw new InternalError("unknown type: " + type);
439 }
440 }
441 private void emitAloadInsn(int index) {
442 emitLoadInsn(L_TYPE, index);
443 }
444
445 private void emitStoreInsn(BasicType type, int index) {
446 int opcode = storeInsnOpcode(type);
447 mv.visitVarInsn(opcode, localsMap[index]);
448 }
449
450 private int storeInsnOpcode(BasicType type) throws InternalError {
451 switch (type) {
452 case I_TYPE: return Opcodes.ISTORE;
453 case J_TYPE: return Opcodes.LSTORE;
454 case F_TYPE: return Opcodes.FSTORE;
455 case D_TYPE: return Opcodes.DSTORE;
456 case L_TYPE: return Opcodes.ASTORE;
457 default:
458 throw new InternalError("unknown type: " + type);
459 }
460 }
461 private void emitAstoreInsn(int index) {
462 emitStoreInsn(L_TYPE, index);
463 }
464
465 private byte arrayTypeCode(Wrapper elementType) {
466 switch (elementType) {
467 case BOOLEAN: return Opcodes.T_BOOLEAN;
468 case BYTE: return Opcodes.T_BYTE;
469 case CHAR: return Opcodes.T_CHAR;
470 case SHORT: return Opcodes.T_SHORT;
471 case INT: return Opcodes.T_INT;
472 case LONG: return Opcodes.T_LONG;
473 case FLOAT: return Opcodes.T_FLOAT;
474 case DOUBLE: return Opcodes.T_DOUBLE;
475 case OBJECT: return 0; // in place of Opcodes.T_OBJECT
476 default: throw new InternalError();
477 }
478 }
479
480 private int arrayInsnOpcode(byte tcode, int aaop) throws InternalError {
481 assert(aaop == Opcodes.AASTORE || aaop == Opcodes.AALOAD);
482 int xas;
483 switch (tcode) {
484 case Opcodes.T_BOOLEAN: xas = Opcodes.BASTORE; break;
485 case Opcodes.T_BYTE: xas = Opcodes.BASTORE; break;
486 case Opcodes.T_CHAR: xas = Opcodes.CASTORE; break;
487 case Opcodes.T_SHORT: xas = Opcodes.SASTORE; break;
488 case Opcodes.T_INT: xas = Opcodes.IASTORE; break;
489 case Opcodes.T_LONG: xas = Opcodes.LASTORE; break;
490 case Opcodes.T_FLOAT: xas = Opcodes.FASTORE; break;
491 case Opcodes.T_DOUBLE: xas = Opcodes.DASTORE; break;
492 case 0: xas = Opcodes.AASTORE; break;
493 default: throw new InternalError();
494 }
495 return xas - Opcodes.AASTORE + aaop;
496 }
497
498 /**
499 * Emit a boxing call.
500 *
501 * @param wrapper primitive type class to box.
502 */
503 private void emitBoxing(Wrapper wrapper) {
504 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName();
505 String name = "valueOf";
506 String desc = "(" + wrapper.basicTypeChar() + ")L" + owner + ";";
507 mv.visitMethodInsn(Opcodes.INVOKESTATIC, owner, name, desc, false);
508 }
509
510 /**
511 * Emit an unboxing call (plus preceding checkcast).
512 *
513 * @param wrapper wrapper type class to unbox.
514 */
515 private void emitUnboxing(Wrapper wrapper) {
516 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName();
517 String name = wrapper.primitiveSimpleName() + "Value";
518 String desc = "()" + wrapper.basicTypeChar();
519 emitReferenceCast(wrapper.wrapperType(), null);
520 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, owner, name, desc, false);
521 }
522
523 /**
524 * Emit an implicit conversion for an argument which must be of the given pclass.
525 * This is usually a no-op, except when pclass is a subword type or a reference other than Object or an interface.
526 *
527 * @param ptype type of value present on stack
528 * @param pclass type of value required on stack
529 * @param arg compile-time representation of value on stack (Node, constant) or null if none
530 */
531 private void emitImplicitConversion(BasicType ptype, Class<?> pclass, Object arg) {
532 assert(basicType(pclass) == ptype); // boxing/unboxing handled by caller
533 if (pclass == ptype.basicTypeClass() && ptype != L_TYPE)
534 return; // nothing to do
535 switch (ptype) {
536 case L_TYPE:
537 if (VerifyType.isNullConversion(Object.class, pclass, false)) {
538 if (PROFILE_LEVEL > 0)
539 emitReferenceCast(Object.class, arg);
540 return;
541 }
542 emitReferenceCast(pclass, arg);
543 return;
544 case I_TYPE:
545 if (!VerifyType.isNullConversion(int.class, pclass, false))
546 emitPrimCast(ptype.basicTypeWrapper(), Wrapper.forPrimitiveType(pclass));
547 return;
548 }
549 throw newInternalError("bad implicit conversion: tc="+ptype+": "+pclass);
550 }
551
552 /** Update localClasses type map. Return true if the information is already present. */
553 private boolean assertStaticType(Class<?> cls, Name n) {
554 int local = n.index();
555 Class<?> aclass = localClasses[local];
556 if (aclass != null && (aclass == cls || cls.isAssignableFrom(aclass))) {
557 return true; // type info is already present
558 } else if (aclass == null || aclass.isAssignableFrom(cls)) {
559 localClasses[local] = cls; // type info can be improved
560 }
561 return false;
562 }
563
564 private void emitReferenceCast(Class<?> cls, Object arg) {
565 Name writeBack = null; // local to write back result
566 if (arg instanceof Name) {
567 Name n = (Name) arg;
568 if (lambdaForm.useCount(n) > 1) {
569 // This guy gets used more than once.
570 writeBack = n;
571 if (assertStaticType(cls, n)) {
572 return; // this cast was already performed
573 }
574 }
575 }
576 if (isStaticallyNameable(cls)) {
577 String sig = getInternalName(cls);
578 mv.visitTypeInsn(Opcodes.CHECKCAST, sig);
579 } else {
580 mv.visitLdcInsn(constantPlaceholder(cls));
581 mv.visitTypeInsn(Opcodes.CHECKCAST, CLS);
582 mv.visitInsn(Opcodes.SWAP);
583 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, CLS, "cast", LL_SIG, false);
584 if (Object[].class.isAssignableFrom(cls))
585 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJARY);
586 else if (PROFILE_LEVEL > 0)
587 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJ);
588 }
589 if (writeBack != null) {
590 mv.visitInsn(Opcodes.DUP);
591 emitAstoreInsn(writeBack.index());
592 }
593 }
594
595 /**
596 * Emits an actual return instruction conforming to the given return type.
597 */
598 private void emitReturnInsn(BasicType type) {
599 int opcode;
600 switch (type) {
601 case I_TYPE: opcode = Opcodes.IRETURN; break;
602 case J_TYPE: opcode = Opcodes.LRETURN; break;
603 case F_TYPE: opcode = Opcodes.FRETURN; break;
604 case D_TYPE: opcode = Opcodes.DRETURN; break;
605 case L_TYPE: opcode = Opcodes.ARETURN; break;
606 case V_TYPE: opcode = Opcodes.RETURN; break;
607 default:
608 throw new InternalError("unknown return type: " + type);
609 }
610 mv.visitInsn(opcode);
611 }
612
613 private String getInternalName(Class<?> c) {
614 if (c == Object.class) return OBJ;
615 else if (c == Object[].class) return OBJARY;
616 else if (c == Class.class) return CLS;
617 else if (c == MethodHandle.class) return MH;
618 assert(VerifyAccess.isTypeVisible(c, Object.class)) : c.getName();
619
620 if (c == lastClass) {
621 return lastInternalName;
622 }
623 lastClass = c;
624 return lastInternalName = c.getName().replace('.', '/');
625 }
626
627 private static MemberName resolveFrom(String name, MethodType type, Class<?> holder) {
628 MemberName member = new MemberName(holder, name, type, REF_invokeStatic);
629 MemberName resolvedMember = MemberName.getFactory().resolveOrNull(REF_invokeStatic, member, holder);
630 if (TRACE_RESOLVE) {
631 System.out.println("[LF_RESOLVE] " + holder.getName() + " " + name + " " +
632 shortenSignature(basicTypeSignature(type)) + (resolvedMember != null ? " (success)" : " (fail)") );
633 }
634 return resolvedMember;
635 }
636
637 private static MemberName lookupPregenerated(LambdaForm form, MethodType invokerType) {
638 if (form.customized != null) {
639 // No pre-generated version for customized LF
640 return null;
641 }
642 String name = form.kind.methodName;
643 switch (form.kind) {
644 case BOUND_REINVOKER: {
645 name = name + "_" + BoundMethodHandle.speciesDataFor(form).key();
646 return resolveFrom(name, invokerType, DelegatingMethodHandle.Holder.class);
647 }
648 case DELEGATE: return resolveFrom(name, invokerType, DelegatingMethodHandle.Holder.class);
649 case ZERO: // fall-through
650 case IDENTITY: {
651 name = name + "_" + form.returnType().basicTypeChar();
652 return resolveFrom(name, invokerType, LambdaForm.Holder.class);
653 }
654 case EXACT_INVOKER: // fall-through
655 case EXACT_LINKER: // fall-through
656 case LINK_TO_CALL_SITE: // fall-through
657 case LINK_TO_TARGET_METHOD: // fall-through
658 case GENERIC_INVOKER: // fall-through
659 case GENERIC_LINKER: return resolveFrom(name, invokerType.basicType(), Invokers.Holder.class);
660 case GET_REFERENCE: // fall-through
661 case GET_BOOLEAN: // fall-through
662 case GET_BYTE: // fall-through
663 case GET_CHAR: // fall-through
664 case GET_SHORT: // fall-through
665 case GET_INT: // fall-through
666 case GET_LONG: // fall-through
667 case GET_FLOAT: // fall-through
668 case GET_DOUBLE: // fall-through
669 case PUT_REFERENCE: // fall-through
670 case PUT_BOOLEAN: // fall-through
671 case PUT_BYTE: // fall-through
672 case PUT_CHAR: // fall-through
673 case PUT_SHORT: // fall-through
674 case PUT_INT: // fall-through
675 case PUT_LONG: // fall-through
676 case PUT_FLOAT: // fall-through
677 case PUT_DOUBLE: // fall-through
678 case DIRECT_NEW_INVOKE_SPECIAL: // fall-through
679 case DIRECT_INVOKE_INTERFACE: // fall-through
680 case DIRECT_INVOKE_SPECIAL: // fall-through
681 case DIRECT_INVOKE_SPECIAL_IFC: // fall-through
682 case DIRECT_INVOKE_STATIC: // fall-through
683 case DIRECT_INVOKE_STATIC_INIT: // fall-through
684 case DIRECT_INVOKE_VIRTUAL: return resolveFrom(name, invokerType, DirectMethodHandle.Holder.class);
685 }
686 return null;
687 }
688
689 /**
690 * Generate customized bytecode for a given LambdaForm.
691 */
692 static MemberName generateCustomizedCode(LambdaForm form, MethodType invokerType) {
693 MemberName pregenerated = lookupPregenerated(form, invokerType);
694 if (pregenerated != null) return pregenerated; // pre-generated bytecode
695
696 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("MH", form, invokerType);
697 return g.loadMethod(g.generateCustomizedCodeBytes());
698 }
699
700 /** Generates code to check that actual receiver and LambdaForm matches */
701 private boolean checkActualReceiver() {
702 // Expects MethodHandle on the stack and actual receiver MethodHandle in slot #0
703 mv.visitInsn(Opcodes.DUP);
704 mv.visitVarInsn(Opcodes.ALOAD, localsMap[0]);
705 mv.visitMethodInsn(Opcodes.INVOKESTATIC, MHI, "assertSame", LLV_SIG, false);
706 return true;
707 }
708
709 static String className(String cn) {
710 assert checkClassName(cn): "Class not found: " + cn;
711 return cn;
712 }
713
714 static boolean checkClassName(String cn) {
715 Type tp = Type.getType(cn);
716 // additional sanity so only valid "L;" descriptors work
717 if (tp.getSort() != Type.OBJECT) {
718 return false;
719 }
720 try {
721 Class<?> c = Class.forName(tp.getClassName(), false, null);
722 return true;
723 } catch (ClassNotFoundException e) {
724 return false;
725 }
726 }
727
728 static final String DONTINLINE_SIG = className("Ljdk/internal/vm/annotation/DontInline;");
729 static final String FORCEINLINE_SIG = className("Ljdk/internal/vm/annotation/ForceInline;");
730 static final String HIDDEN_SIG = className("Ljdk/internal/vm/annotation/Hidden;");
731 static final String INJECTEDPROFILE_SIG = className("Ljava/lang/invoke/InjectedProfile;");
732 static final String LF_COMPILED_SIG = className("Ljava/lang/invoke/LambdaForm$Compiled;");
733
734 /**
735 * Generate an invoker method for the passed {@link LambdaForm}.
736 */
737 private byte[] generateCustomizedCodeBytes() {
738 classFilePrologue();
739 addMethod();
740 bogusMethod(lambdaForm);
741
742 final byte[] classFile = toByteArray();
743 maybeDump(classFile);
744 return classFile;
745 }
746
747 void setClassWriter(ClassWriter cw) {
748 this.cw = cw;
749 }
750
751 void addMethod() {
752 methodPrologue();
753
754 // Suppress this method in backtraces displayed to the user.
755 mv.visitAnnotation(HIDDEN_SIG, true);
756
757 // Mark this method as a compiled LambdaForm
758 mv.visitAnnotation(LF_COMPILED_SIG, true);
759
760 if (lambdaForm.forceInline) {
761 // Force inlining of this invoker method.
762 mv.visitAnnotation(FORCEINLINE_SIG, true);
763 } else {
764 mv.visitAnnotation(DONTINLINE_SIG, true);
765 }
766
767 constantPlaceholder(lambdaForm); // keep LambdaForm instance & its compiled form lifetime tightly coupled.
768
769 if (lambdaForm.customized != null) {
770 // Since LambdaForm is customized for a particular MethodHandle, it's safe to substitute
771 // receiver MethodHandle (at slot #0) with an embedded constant and use it instead.
772 // It enables more efficient code generation in some situations, since embedded constants
773 // are compile-time constants for JIT compiler.
774 mv.visitLdcInsn(constantPlaceholder(lambdaForm.customized));
775 mv.visitTypeInsn(Opcodes.CHECKCAST, MH);
776 assert(checkActualReceiver()); // expects MethodHandle on top of the stack
777 mv.visitVarInsn(Opcodes.ASTORE, localsMap[0]);
778 }
779
780 // iterate over the form's names, generating bytecode instructions for each
781 // start iterating at the first name following the arguments
782 Name onStack = null;
783 for (int i = lambdaForm.arity; i < lambdaForm.names.length; i++) {
784 Name name = lambdaForm.names[i];
785
786 emitStoreResult(onStack);
787 onStack = name; // unless otherwise modified below
788 MethodHandleImpl.Intrinsic intr = name.function.intrinsicName();
789 switch (intr) {
790 case SELECT_ALTERNATIVE:
791 assert lambdaForm.isSelectAlternative(i);
792 if (PROFILE_GWT) {
793 assert(name.arguments[0] instanceof Name &&
794 ((Name)name.arguments[0]).refersTo(MethodHandleImpl.class, "profileBoolean"));
795 mv.visitAnnotation(INJECTEDPROFILE_SIG, true);
796 }
797 onStack = emitSelectAlternative(name, lambdaForm.names[i+1]);
798 i++; // skip MH.invokeBasic of the selectAlternative result
799 continue;
800 case GUARD_WITH_CATCH:
801 assert lambdaForm.isGuardWithCatch(i);
802 onStack = emitGuardWithCatch(i);
803 i += 2; // jump to the end of GWC idiom
804 continue;
805 case TRY_FINALLY:
806 assert lambdaForm.isTryFinally(i);
807 onStack = emitTryFinally(i);
808 i += 2; // jump to the end of the TF idiom
809 continue;
810 case LOOP:
811 assert lambdaForm.isLoop(i);
812 onStack = emitLoop(i);
813 i += 2; // jump to the end of the LOOP idiom
814 continue;
815 case NEW_ARRAY:
816 Class<?> rtype = name.function.methodType().returnType();
817 if (isStaticallyNameable(rtype)) {
818 emitNewArray(name);
819 continue;
820 }
821 break;
822 case ARRAY_LOAD:
823 emitArrayLoad(name);
824 continue;
825 case ARRAY_STORE:
826 emitArrayStore(name);
827 continue;
828 case ARRAY_LENGTH:
829 emitArrayLength(name);
830 continue;
831 case IDENTITY:
832 assert(name.arguments.length == 1);
833 emitPushArguments(name, 0);
834 continue;
835 case ZERO:
836 assert(name.arguments.length == 0);
837 emitConst(name.type.basicTypeWrapper().zero());
838 continue;
839 case NONE:
840 // no intrinsic associated
841 break;
842 default:
843 throw newInternalError("Unknown intrinsic: "+intr);
844 }
845
846 MemberName member = name.function.member();
847 if (isStaticallyInvocable(member)) {
848 emitStaticInvoke(member, name);
849 } else {
850 emitInvoke(name);
851 }
852 }
853
854 // return statement
855 emitReturn(onStack);
856
857 methodEpilogue();
858 }
859
860 /*
861 * @throws BytecodeGenerationException if something goes wrong when
862 * generating the byte code
863 */
864 private byte[] toByteArray() {
865 try {
866 return cw.toByteArray();
867 } catch (RuntimeException e) {
868 throw new BytecodeGenerationException(e);
869 }
870 }
871
872 @SuppressWarnings("serial")
873 static final class BytecodeGenerationException extends RuntimeException {
874 BytecodeGenerationException(Exception cause) {
875 super(cause);
876 }
877 }
878
879 void emitArrayLoad(Name name) { emitArrayOp(name, Opcodes.AALOAD); }
880 void emitArrayStore(Name name) { emitArrayOp(name, Opcodes.AASTORE); }
881 void emitArrayLength(Name name) { emitArrayOp(name, Opcodes.ARRAYLENGTH); }
882
883 void emitArrayOp(Name name, int arrayOpcode) {
884 assert arrayOpcode == Opcodes.AALOAD || arrayOpcode == Opcodes.AASTORE || arrayOpcode == Opcodes.ARRAYLENGTH;
885 Class<?> elementType = name.function.methodType().parameterType(0).getComponentType();
886 assert elementType != null;
887 emitPushArguments(name, 0);
888 if (arrayOpcode != Opcodes.ARRAYLENGTH && elementType.isPrimitive()) {
889 Wrapper w = Wrapper.forPrimitiveType(elementType);
890 arrayOpcode = arrayInsnOpcode(arrayTypeCode(w), arrayOpcode);
891 }
892 mv.visitInsn(arrayOpcode);
893 }
894
895 /**
896 * Emit an invoke for the given name.
897 */
898 void emitInvoke(Name name) {
899 assert(!name.isLinkerMethodInvoke()); // should use the static path for these
900 if (true) {
901 // push receiver
902 MethodHandle target = name.function.resolvedHandle();
903 assert(target != null) : name.exprString();
904 mv.visitLdcInsn(constantPlaceholder(target));
905 emitReferenceCast(MethodHandle.class, target);
906 } else {
907 // load receiver
908 emitAloadInsn(0);
909 emitReferenceCast(MethodHandle.class, null);
910 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", LF_SIG);
911 mv.visitFieldInsn(Opcodes.GETFIELD, LF, "names", LFN_SIG);
912 // TODO more to come
913 }
914
915 // push arguments
916 emitPushArguments(name, 0);
917
918 // invocation
919 MethodType type = name.function.methodType();
920 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false);
921 }
922
923 private static Class<?>[] STATICALLY_INVOCABLE_PACKAGES = {
924 // Sample classes from each package we are willing to bind to statically:
925 java.lang.Object.class,
926 java.util.Arrays.class,
927 jdk.internal.misc.Unsafe.class
928 //MethodHandle.class already covered
929 };
930
931 static boolean isStaticallyInvocable(NamedFunction ... functions) {
932 for (NamedFunction nf : functions) {
933 if (!isStaticallyInvocable(nf.member())) {
934 return false;
935 }
936 }
937 return true;
938 }
939
940 static boolean isStaticallyInvocable(Name name) {
941 return isStaticallyInvocable(name.function.member());
942 }
943
944 static boolean isStaticallyInvocable(MemberName member) {
945 if (member == null) return false;
946 if (member.isConstructor()) return false;
947 Class<?> cls = member.getDeclaringClass();
948 // Fast-path non-private members declared by MethodHandles, which is a common
949 // case
950 if (MethodHandle.class.isAssignableFrom(cls) && !member.isPrivate()) {
951 assert(isStaticallyInvocableType(member.getMethodOrFieldType()));
952 return true;
953 }
954 if (cls.isArray() || cls.isPrimitive())
955 return false; // FIXME
956 if (cls.isAnonymousClass() || cls.isLocalClass())
957 return false; // inner class of some sort
958 if (cls.getClassLoader() != MethodHandle.class.getClassLoader())
959 return false; // not on BCP
960 if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: switch to supported API once it is added
961 return false;
962 if (!isStaticallyInvocableType(member.getMethodOrFieldType()))
963 return false;
964 if (!member.isPrivate() && VerifyAccess.isSamePackage(MethodHandle.class, cls))
965 return true; // in java.lang.invoke package
966 if (member.isPublic() && isStaticallyNameable(cls))
967 return true;
968 return false;
969 }
970
971 private static boolean isStaticallyInvocableType(MethodType mtype) {
972 if (!isStaticallyNameable(mtype.returnType()))
973 return false;
974 for (Class<?> ptype : mtype.parameterArray())
975 if (!isStaticallyNameable(ptype))
976 return false;
977 return true;
978 }
979
980 static boolean isStaticallyNameable(Class<?> cls) {
981 if (cls == Object.class)
982 return true;
983 if (MethodHandle.class.isAssignableFrom(cls)) {
984 assert(!ReflectUtil.isVMAnonymousClass(cls));
985 return true;
986 }
987 while (cls.isArray())
988 cls = cls.getComponentType();
989 if (cls.isPrimitive())
990 return true; // int[].class, for example
991 if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: switch to supported API once it is added
992 return false;
993 // could use VerifyAccess.isClassAccessible but the following is a safe approximation
994 if (cls.getClassLoader() != Object.class.getClassLoader())
995 return false;
996 if (VerifyAccess.isSamePackage(MethodHandle.class, cls))
997 return true;
998 if (!Modifier.isPublic(cls.getModifiers()))
999 return false;
1000 for (Class<?> pkgcls : STATICALLY_INVOCABLE_PACKAGES) {
1001 if (VerifyAccess.isSamePackage(pkgcls, cls))
1002 return true;
1003 }
1004 return false;
1005 }
1006
1007 void emitStaticInvoke(Name name) {
1008 emitStaticInvoke(name.function.member(), name);
1009 }
1010
1011 /**
1012 * Emit an invoke for the given name, using the MemberName directly.
1013 */
1014 void emitStaticInvoke(MemberName member, Name name) {
1015 assert(member.equals(name.function.member()));
1016 Class<?> defc = member.getDeclaringClass();
1017 String cname = getInternalName(defc);
1018 String mname = member.getName();
1019 String mtype;
1020 byte refKind = member.getReferenceKind();
1021 if (refKind == REF_invokeSpecial) {
1022 // in order to pass the verifier, we need to convert this to invokevirtual in all cases
1023 assert(member.canBeStaticallyBound()) : member;
1024 refKind = REF_invokeVirtual;
1025 }
1026
1027 assert(!(member.getDeclaringClass().isInterface() && refKind == REF_invokeVirtual));
1028
1029 // push arguments
1030 emitPushArguments(name, 0);
1031
1032 // invocation
1033 if (member.isMethod()) {
1034 mtype = member.getMethodType().toMethodDescriptorString();
1035 mv.visitMethodInsn(refKindOpcode(refKind), cname, mname, mtype,
1036 member.getDeclaringClass().isInterface());
1037 } else {
1038 mtype = MethodType.toFieldDescriptorString(member.getFieldType());
1039 mv.visitFieldInsn(refKindOpcode(refKind), cname, mname, mtype);
1040 }
1041 // Issue a type assertion for the result, so we can avoid casts later.
1042 if (name.type == L_TYPE) {
1043 Class<?> rtype = member.getInvocationType().returnType();
1044 assert(!rtype.isPrimitive());
1045 if (rtype != Object.class && !rtype.isInterface()) {
1046 assertStaticType(rtype, name);
1047 }
1048 }
1049 }
1050
1051 void emitNewArray(Name name) throws InternalError {
1052 Class<?> rtype = name.function.methodType().returnType();
1053 if (name.arguments.length == 0) {
1054 // The array will be a constant.
1055 Object emptyArray;
1056 try {
1057 emptyArray = name.function.resolvedHandle().invoke();
1058 } catch (Throwable ex) {
1059 throw uncaughtException(ex);
1060 }
1061 assert(java.lang.reflect.Array.getLength(emptyArray) == 0);
1062 assert(emptyArray.getClass() == rtype); // exact typing
1063 mv.visitLdcInsn(constantPlaceholder(emptyArray));
1064 emitReferenceCast(rtype, emptyArray);
1065 return;
1066 }
1067 Class<?> arrayElementType = rtype.getComponentType();
1068 assert(arrayElementType != null);
1069 emitIconstInsn(name.arguments.length);
1070 int xas = Opcodes.AASTORE;
1071 if (!arrayElementType.isPrimitive()) {
1072 mv.visitTypeInsn(Opcodes.ANEWARRAY, getInternalName(arrayElementType));
1073 } else {
1074 byte tc = arrayTypeCode(Wrapper.forPrimitiveType(arrayElementType));
1075 xas = arrayInsnOpcode(tc, xas);
1076 mv.visitIntInsn(Opcodes.NEWARRAY, tc);
1077 }
1078 // store arguments
1079 for (int i = 0; i < name.arguments.length; i++) {
1080 mv.visitInsn(Opcodes.DUP);
1081 emitIconstInsn(i);
1082 emitPushArgument(name, i);
1083 mv.visitInsn(xas);
1084 }
1085 // the array is left on the stack
1086 assertStaticType(rtype, name);
1087 }
1088 int refKindOpcode(byte refKind) {
1089 switch (refKind) {
1090 case REF_invokeVirtual: return Opcodes.INVOKEVIRTUAL;
1091 case REF_invokeStatic: return Opcodes.INVOKESTATIC;
1092 case REF_invokeSpecial: return Opcodes.INVOKESPECIAL;
1093 case REF_invokeInterface: return Opcodes.INVOKEINTERFACE;
1094 case REF_getField: return Opcodes.GETFIELD;
1095 case REF_putField: return Opcodes.PUTFIELD;
1096 case REF_getStatic: return Opcodes.GETSTATIC;
1097 case REF_putStatic: return Opcodes.PUTSTATIC;
1098 }
1099 throw new InternalError("refKind="+refKind);
1100 }
1101
1102 /**
1103 * Emit bytecode for the selectAlternative idiom.
1104 *
1105 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithTest):
1106 * <blockquote><pre>{@code
1107 * Lambda(a0:L,a1:I)=>{
1108 * t2:I=foo.test(a1:I);
1109 * t3:L=MethodHandleImpl.selectAlternative(t2:I,(MethodHandle(int)int),(MethodHandle(int)int));
1110 * t4:I=MethodHandle.invokeBasic(t3:L,a1:I);t4:I}
1111 * }</pre></blockquote>
1112 */
1113 private Name emitSelectAlternative(Name selectAlternativeName, Name invokeBasicName) {
1114 assert isStaticallyInvocable(invokeBasicName);
1115
1116 Name receiver = (Name) invokeBasicName.arguments[0];
1117
1118 Label L_fallback = new Label();
1119 Label L_done = new Label();
1120
1121 // load test result
1122 emitPushArgument(selectAlternativeName, 0);
1123
1124 // if_icmpne L_fallback
1125 mv.visitJumpInsn(Opcodes.IFEQ, L_fallback);
1126
1127 // invoke selectAlternativeName.arguments[1]
1128 Class<?>[] preForkClasses = localClasses.clone();
1129 emitPushArgument(selectAlternativeName, 1); // get 2nd argument of selectAlternative
1130 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot
1131 emitStaticInvoke(invokeBasicName);
1132
1133 // goto L_done
1134 mv.visitJumpInsn(Opcodes.GOTO, L_done);
1135
1136 // L_fallback:
1137 mv.visitLabel(L_fallback);
1138
1139 // invoke selectAlternativeName.arguments[2]
1140 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length);
1141 emitPushArgument(selectAlternativeName, 2); // get 3rd argument of selectAlternative
1142 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot
1143 emitStaticInvoke(invokeBasicName);
1144
1145 // L_done:
1146 mv.visitLabel(L_done);
1147 // for now do not bother to merge typestate; just reset to the dominator state
1148 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length);
1149
1150 return invokeBasicName; // return what's on stack
1151 }
1152
1153 /**
1154 * Emit bytecode for the guardWithCatch idiom.
1155 *
1156 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithCatch):
1157 * <blockquote><pre>{@code
1158 * guardWithCatch=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L,a5:L,a6:L,a7:L)=>{
1159 * t8:L=MethodHandle.invokeBasic(a4:L,a6:L,a7:L);
1160 * t9:L=MethodHandleImpl.guardWithCatch(a1:L,a2:L,a3:L,t8:L);
1161 * t10:I=MethodHandle.invokeBasic(a5:L,t9:L);t10:I}
1162 * }</pre></blockquote>
1163 *
1164 * It is compiled into bytecode equivalent of the following code:
1165 * <blockquote><pre>{@code
1166 * try {
1167 * return a1.invokeBasic(a6, a7);
1168 * } catch (Throwable e) {
1169 * if (!a2.isInstance(e)) throw e;
1170 * return a3.invokeBasic(ex, a6, a7);
1171 * }}</pre></blockquote>
1172 */
1173 private Name emitGuardWithCatch(int pos) {
1174 Name args = lambdaForm.names[pos];
1175 Name invoker = lambdaForm.names[pos+1];
1176 Name result = lambdaForm.names[pos+2];
1177
1178 Label L_startBlock = new Label();
1179 Label L_endBlock = new Label();
1180 Label L_handler = new Label();
1181 Label L_done = new Label();
1182
1183 Class<?> returnType = result.function.resolvedHandle().type().returnType();
1184 MethodType type = args.function.resolvedHandle().type()
1185 .dropParameterTypes(0,1)
1186 .changeReturnType(returnType);
1187
1188 mv.visitTryCatchBlock(L_startBlock, L_endBlock, L_handler, "java/lang/Throwable");
1189
1190 // Normal case
1191 mv.visitLabel(L_startBlock);
1192 // load target
1193 emitPushArgument(invoker, 0);
1194 emitPushArguments(args, 1); // skip 1st argument: method handle
1195 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false);
1196 mv.visitLabel(L_endBlock);
1197 mv.visitJumpInsn(Opcodes.GOTO, L_done);
1198
1199 // Exceptional case
1200 mv.visitLabel(L_handler);
1201
1202 // Check exception's type
1203 mv.visitInsn(Opcodes.DUP);
1204 // load exception class
1205 emitPushArgument(invoker, 1);
1206 mv.visitInsn(Opcodes.SWAP);
1207 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/Class", "isInstance", "(Ljava/lang/Object;)Z", false);
1208 Label L_rethrow = new Label();
1209 mv.visitJumpInsn(Opcodes.IFEQ, L_rethrow);
1210
1211 // Invoke catcher
1212 // load catcher
1213 emitPushArgument(invoker, 2);
1214 mv.visitInsn(Opcodes.SWAP);
1215 emitPushArguments(args, 1); // skip 1st argument: method handle
1216 MethodType catcherType = type.insertParameterTypes(0, Throwable.class);
1217 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", catcherType.basicType().toMethodDescriptorString(), false);
1218 mv.visitJumpInsn(Opcodes.GOTO, L_done);
1219
1220 mv.visitLabel(L_rethrow);
1221 mv.visitInsn(Opcodes.ATHROW);
1222
1223 mv.visitLabel(L_done);
1224
1225 return result;
1226 }
1227
1228 /**
1229 * Emit bytecode for the tryFinally idiom.
1230 * <p>
1231 * The pattern looks like (Cf. MethodHandleImpl.makeTryFinally):
1232 * <blockquote><pre>{@code
1233 * // a0: BMH
1234 * // a1: target, a2: cleanup
1235 * // a3: box, a4: unbox
1236 * // a5 (and following): arguments
1237 * tryFinally=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L,a5:L)=>{
1238 * t6:L=MethodHandle.invokeBasic(a3:L,a5:L); // box the arguments into an Object[]
1239 * t7:L=MethodHandleImpl.tryFinally(a1:L,a2:L,t6:L); // call the tryFinally executor
1240 * t8:L=MethodHandle.invokeBasic(a4:L,t7:L);t8:L} // unbox the result; return the result
1241 * }</pre></blockquote>
1242 * <p>
1243 * It is compiled into bytecode equivalent to the following code:
1244 * <blockquote><pre>{@code
1245 * Throwable t;
1246 * Object r;
1247 * try {
1248 * r = a1.invokeBasic(a5);
1249 * } catch (Throwable thrown) {
1250 * t = thrown;
1251 * throw t;
1252 * } finally {
1253 * r = a2.invokeBasic(t, r, a5);
1254 * }
1255 * return r;
1256 * }</pre></blockquote>
1257 * <p>
1258 * Specifically, the bytecode will have the following form (the stack effects are given for the beginnings of
1259 * blocks, and for the situations after executing the given instruction - the code will have a slightly different
1260 * shape if the return type is {@code void}):
1261 * <blockquote><pre>{@code
1262 * TRY: (--)
1263 * load target (-- target)
1264 * load args (-- args... target)
1265 * INVOKEVIRTUAL MethodHandle.invokeBasic (depends)
1266 * FINALLY_NORMAL: (-- r_2nd* r)
1267 * store returned value (--)
1268 * load cleanup (-- cleanup)
1269 * ACONST_NULL (-- t cleanup)
1270 * load returned value (-- r_2nd* r t cleanup)
1271 * load args (-- args... r_2nd* r t cleanup)
1272 * INVOKEVIRTUAL MethodHandle.invokeBasic (-- r_2nd* r)
1273 * GOTO DONE
1274 * CATCH: (-- t)
1275 * DUP (-- t t)
1276 * FINALLY_EXCEPTIONAL: (-- t t)
1277 * load cleanup (-- cleanup t t)
1278 * SWAP (-- t cleanup t)
1279 * load default for r (-- r_2nd* r t cleanup t)
1280 * load args (-- args... r_2nd* r t cleanup t)
1281 * INVOKEVIRTUAL MethodHandle.invokeBasic (-- r_2nd* r t)
1282 * POP/POP2* (-- t)
1283 * ATHROW
1284 * DONE: (-- r)
1285 * }</pre></blockquote>
1286 * * = depends on whether the return type takes up 2 stack slots.
1287 */
1288 private Name emitTryFinally(int pos) {
1289 Name args = lambdaForm.names[pos];
1290 Name invoker = lambdaForm.names[pos+1];
1291 Name result = lambdaForm.names[pos+2];
1292
1293 Label lFrom = new Label();
1294 Label lTo = new Label();
1295 Label lCatch = new Label();
1296 Label lDone = new Label();
1297
1298 Class<?> returnType = result.function.resolvedHandle().type().returnType();
1299 BasicType basicReturnType = BasicType.basicType(returnType);
1300 boolean isNonVoid = returnType != void.class;
1301
1302 MethodType type = args.function.resolvedHandle().type()
1303 .dropParameterTypes(0,1)
1304 .changeReturnType(returnType);
1305 MethodType cleanupType = type.insertParameterTypes(0, Throwable.class);
1306 if (isNonVoid) {
1307 cleanupType = cleanupType.insertParameterTypes(1, returnType);
1308 }
1309 String cleanupDesc = cleanupType.basicType().toMethodDescriptorString();
1310
1311 // exception handler table
1312 mv.visitTryCatchBlock(lFrom, lTo, lCatch, "java/lang/Throwable");
1313
1314 // TRY:
1315 mv.visitLabel(lFrom);
1316 emitPushArgument(invoker, 0); // load target
1317 emitPushArguments(args, 1); // load args (skip 0: method handle)
1318 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false);
1319 mv.visitLabel(lTo);
1320
1321 // FINALLY_NORMAL:
1322 int index = extendLocalsMap(new Class<?>[]{ returnType });
1323 if (isNonVoid) {
1324 emitStoreInsn(basicReturnType, index);
1325 }
1326 emitPushArgument(invoker, 1); // load cleanup
1327 mv.visitInsn(Opcodes.ACONST_NULL);
1328 if (isNonVoid) {
1329 emitLoadInsn(basicReturnType, index);
1330 }
1331 emitPushArguments(args, 1); // load args (skip 0: method handle)
1332 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", cleanupDesc, false);
1333 mv.visitJumpInsn(Opcodes.GOTO, lDone);
1334
1335 // CATCH:
1336 mv.visitLabel(lCatch);
1337 mv.visitInsn(Opcodes.DUP);
1338
1339 // FINALLY_EXCEPTIONAL:
1340 emitPushArgument(invoker, 1); // load cleanup
1341 mv.visitInsn(Opcodes.SWAP);
1342 if (isNonVoid) {
1343 emitZero(BasicType.basicType(returnType)); // load default for result
1344 }
1345 emitPushArguments(args, 1); // load args (skip 0: method handle)
1346 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", cleanupDesc, false);
1347 if (isNonVoid) {
1348 emitPopInsn(basicReturnType);
1349 }
1350 mv.visitInsn(Opcodes.ATHROW);
1351
1352 // DONE:
1353 mv.visitLabel(lDone);
1354
1355 return result;
1356 }
1357
1358 private void emitPopInsn(BasicType type) {
1359 mv.visitInsn(popInsnOpcode(type));
1360 }
1361
1362 private static int popInsnOpcode(BasicType type) {
1363 switch (type) {
1364 case I_TYPE:
1365 case F_TYPE:
1366 case L_TYPE:
1367 return Opcodes.POP;
1368 case J_TYPE:
1369 case D_TYPE:
1370 return Opcodes.POP2;
1371 default:
1372 throw new InternalError("unknown type: " + type);
1373 }
1374 }
1375
1376 /**
1377 * Emit bytecode for the loop idiom.
1378 * <p>
1379 * The pattern looks like (Cf. MethodHandleImpl.loop):
1380 * <blockquote><pre>{@code
1381 * // a0: BMH
1382 * // a1: LoopClauses (containing an array of arrays: inits, steps, preds, finis)
1383 * // a2: box, a3: unbox
1384 * // a4 (and following): arguments
1385 * loop=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L)=>{
1386 * t5:L=MethodHandle.invokeBasic(a2:L,a4:L); // box the arguments into an Object[]
1387 * t6:L=MethodHandleImpl.loop(bt:L,a1:L,t5:L); // call the loop executor (with supplied types in bt)
1388 * t7:L=MethodHandle.invokeBasic(a3:L,t6:L);t7:L} // unbox the result; return the result
1389 * }</pre></blockquote>
1390 * <p>
1391 * It is compiled into bytecode equivalent to the code seen in {@link MethodHandleImpl#loop(BasicType[],
1392 * MethodHandleImpl.LoopClauses, Object...)}, with the difference that no arrays
1393 * will be used for local state storage. Instead, the local state will be mapped to actual stack slots.
1394 * <p>
1395 * Bytecode generation applies an unrolling scheme to enable better bytecode generation regarding local state type
1396 * handling. The generated bytecode will have the following form ({@code void} types are ignored for convenience).
1397 * Assume there are {@code C} clauses in the loop.
1398 * <blockquote><pre>{@code
1399 * PREINIT: ALOAD_1
1400 * CHECKCAST LoopClauses
1401 * GETFIELD LoopClauses.clauses
1402 * ASTORE clauseDataIndex // place the clauses 2-dimensional array on the stack
1403 * INIT: (INIT_SEQ for clause 1)
1404 * ...
1405 * (INIT_SEQ for clause C)
1406 * LOOP: (LOOP_SEQ for clause 1)
1407 * ...
1408 * (LOOP_SEQ for clause C)
1409 * GOTO LOOP
1410 * DONE: ...
1411 * }</pre></blockquote>
1412 * <p>
1413 * The {@code INIT_SEQ_x} sequence for clause {@code x} (with {@code x} ranging from {@code 0} to {@code C-1}) has
1414 * the following shape. Assume slot {@code vx} is used to hold the state for clause {@code x}.
1415 * <blockquote><pre>{@code
1416 * INIT_SEQ_x: ALOAD clauseDataIndex
1417 * ICONST_0
1418 * AALOAD // load the inits array
1419 * ICONST x
1420 * AALOAD // load the init handle for clause x
1421 * load args
1422 * INVOKEVIRTUAL MethodHandle.invokeBasic
1423 * store vx
1424 * }</pre></blockquote>
1425 * <p>
1426 * The {@code LOOP_SEQ_x} sequence for clause {@code x} (with {@code x} ranging from {@code 0} to {@code C-1}) has
1427 * the following shape. Again, assume slot {@code vx} is used to hold the state for clause {@code x}.
1428 * <blockquote><pre>{@code
1429 * LOOP_SEQ_x: ALOAD clauseDataIndex
1430 * ICONST_1
1431 * AALOAD // load the steps array
1432 * ICONST x
1433 * AALOAD // load the step handle for clause x
1434 * load locals
1435 * load args
1436 * INVOKEVIRTUAL MethodHandle.invokeBasic
1437 * store vx
1438 * ALOAD clauseDataIndex
1439 * ICONST_2
1440 * AALOAD // load the preds array
1441 * ICONST x
1442 * AALOAD // load the pred handle for clause x
1443 * load locals
1444 * load args
1445 * INVOKEVIRTUAL MethodHandle.invokeBasic
1446 * IFNE LOOP_SEQ_x+1 // predicate returned false -> jump to next clause
1447 * ALOAD clauseDataIndex
1448 * ICONST_3
1449 * AALOAD // load the finis array
1450 * ICONST x
1451 * AALOAD // load the fini handle for clause x
1452 * load locals
1453 * load args
1454 * INVOKEVIRTUAL MethodHandle.invokeBasic
1455 * GOTO DONE // jump beyond end of clauses to return from loop
1456 * }</pre></blockquote>
1457 */
1458 private Name emitLoop(int pos) {
1459 Name args = lambdaForm.names[pos];
1460 Name invoker = lambdaForm.names[pos+1];
1461 Name result = lambdaForm.names[pos+2];
1462
1463 // extract clause and loop-local state types
1464 // find the type info in the loop invocation
1465 BasicType[] loopClauseTypes = (BasicType[]) invoker.arguments[0];
1466 Class<?>[] loopLocalStateTypes = Stream.of(loopClauseTypes).
1467 filter(bt -> bt != BasicType.V_TYPE).map(BasicType::basicTypeClass).toArray(Class<?>[]::new);
1468 Class<?>[] localTypes = new Class<?>[loopLocalStateTypes.length + 1];
1469 localTypes[0] = MethodHandleImpl.LoopClauses.class;
1470 System.arraycopy(loopLocalStateTypes, 0, localTypes, 1, loopLocalStateTypes.length);
1471
1472 final int clauseDataIndex = extendLocalsMap(localTypes);
1473 final int firstLoopStateIndex = clauseDataIndex + 1;
1474
1475 Class<?> returnType = result.function.resolvedHandle().type().returnType();
1476 MethodType loopType = args.function.resolvedHandle().type()
1477 .dropParameterTypes(0,1)
1478 .changeReturnType(returnType);
1479 MethodType loopHandleType = loopType.insertParameterTypes(0, loopLocalStateTypes);
1480 MethodType predType = loopHandleType.changeReturnType(boolean.class);
1481 MethodType finiType = loopHandleType;
1482
1483 final int nClauses = loopClauseTypes.length;
1484
1485 // indices to invoker arguments to load method handle arrays
1486 final int inits = 1;
1487 final int steps = 2;
1488 final int preds = 3;
1489 final int finis = 4;
1490
1491 Label lLoop = new Label();
1492 Label lDone = new Label();
1493 Label lNext;
1494
1495 // PREINIT:
1496 emitPushArgument(MethodHandleImpl.LoopClauses.class, invoker.arguments[1]);
1497 mv.visitFieldInsn(Opcodes.GETFIELD, LOOP_CLAUSES, "clauses", MHARY2);
1498 emitAstoreInsn(clauseDataIndex);
1499
1500 // INIT:
1501 for (int c = 0, state = 0; c < nClauses; ++c) {
1502 MethodType cInitType = loopType.changeReturnType(loopClauseTypes[c].basicTypeClass());
1503 emitLoopHandleInvoke(invoker, inits, c, args, false, cInitType, loopLocalStateTypes, clauseDataIndex,
1504 firstLoopStateIndex);
1505 if (cInitType.returnType() != void.class) {
1506 emitStoreInsn(BasicType.basicType(cInitType.returnType()), firstLoopStateIndex + state);
1507 ++state;
1508 }
1509 }
1510
1511 // LOOP:
1512 mv.visitLabel(lLoop);
1513
1514 for (int c = 0, state = 0; c < nClauses; ++c) {
1515 lNext = new Label();
1516
1517 MethodType stepType = loopHandleType.changeReturnType(loopClauseTypes[c].basicTypeClass());
1518 boolean isVoid = stepType.returnType() == void.class;
1519
1520 // invoke loop step
1521 emitLoopHandleInvoke(invoker, steps, c, args, true, stepType, loopLocalStateTypes, clauseDataIndex,
1522 firstLoopStateIndex);
1523 if (!isVoid) {
1524 emitStoreInsn(BasicType.basicType(stepType.returnType()), firstLoopStateIndex + state);
1525 ++state;
1526 }
1527
1528 // invoke loop predicate
1529 emitLoopHandleInvoke(invoker, preds, c, args, true, predType, loopLocalStateTypes, clauseDataIndex,
1530 firstLoopStateIndex);
1531 mv.visitJumpInsn(Opcodes.IFNE, lNext);
1532
1533 // invoke fini
1534 emitLoopHandleInvoke(invoker, finis, c, args, true, finiType, loopLocalStateTypes, clauseDataIndex,
1535 firstLoopStateIndex);
1536 mv.visitJumpInsn(Opcodes.GOTO, lDone);
1537
1538 // this is the beginning of the next loop clause
1539 mv.visitLabel(lNext);
1540 }
1541
1542 mv.visitJumpInsn(Opcodes.GOTO, lLoop);
1543
1544 // DONE:
1545 mv.visitLabel(lDone);
1546
1547 return result;
1548 }
1549
1550 private int extendLocalsMap(Class<?>[] types) {
1551 int firstSlot = localsMap.length - 1;
1552 localsMap = Arrays.copyOf(localsMap, localsMap.length + types.length);
1553 localClasses = Arrays.copyOf(localClasses, localClasses.length + types.length);
1554 System.arraycopy(types, 0, localClasses, firstSlot, types.length);
1555 int index = localsMap[firstSlot - 1] + 1;
1556 int lastSlots = 0;
1557 for (int i = 0; i < types.length; ++i) {
1558 localsMap[firstSlot + i] = index;
1559 lastSlots = BasicType.basicType(localClasses[firstSlot + i]).basicTypeSlots();
1560 index += lastSlots;
1561 }
1562 localsMap[localsMap.length - 1] = index - lastSlots;
1563 return firstSlot;
1564 }
1565
1566 private void emitLoopHandleInvoke(Name holder, int handles, int clause, Name args, boolean pushLocalState,
1567 MethodType type, Class<?>[] loopLocalStateTypes, int clauseDataSlot,
1568 int firstLoopStateSlot) {
1569 // load handle for clause
1570 emitPushClauseArray(clauseDataSlot, handles);
1571 emitIconstInsn(clause);
1572 mv.visitInsn(Opcodes.AALOAD);
1573 // load loop state (preceding the other arguments)
1574 if (pushLocalState) {
1575 for (int s = 0; s < loopLocalStateTypes.length; ++s) {
1576 emitLoadInsn(BasicType.basicType(loopLocalStateTypes[s]), firstLoopStateSlot + s);
1577 }
1578 }
1579 // load loop args (skip 0: method handle)
1580 emitPushArguments(args, 1);
1581 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.toMethodDescriptorString(), false);
1582 }
1583
1584 private void emitPushClauseArray(int clauseDataSlot, int which) {
1585 emitAloadInsn(clauseDataSlot);
1586 emitIconstInsn(which - 1);
1587 mv.visitInsn(Opcodes.AALOAD);
1588 }
1589
1590 private void emitZero(BasicType type) {
1591 switch (type) {
1592 case I_TYPE: mv.visitInsn(Opcodes.ICONST_0); break;
1593 case J_TYPE: mv.visitInsn(Opcodes.LCONST_0); break;
1594 case F_TYPE: mv.visitInsn(Opcodes.FCONST_0); break;
1595 case D_TYPE: mv.visitInsn(Opcodes.DCONST_0); break;
1596 case L_TYPE: mv.visitInsn(Opcodes.ACONST_NULL); break;
1597 default: throw new InternalError("unknown type: " + type);
1598 }
1599 }
1600
1601 private void emitPushArguments(Name args, int start) {
1602 MethodType type = args.function.methodType();
1603 for (int i = start; i < args.arguments.length; i++) {
1604 emitPushArgument(type.parameterType(i), args.arguments[i]);
1605 }
1606 }
1607
1608 private void emitPushArgument(Name name, int paramIndex) {
1609 Object arg = name.arguments[paramIndex];
1610 Class<?> ptype = name.function.methodType().parameterType(paramIndex);
1611 emitPushArgument(ptype, arg);
1612 }
1613
1614 private void emitPushArgument(Class<?> ptype, Object arg) {
1615 BasicType bptype = basicType(ptype);
1616 if (arg instanceof Name) {
1617 Name n = (Name) arg;
1618 emitLoadInsn(n.type, n.index());
1619 emitImplicitConversion(n.type, ptype, n);
1620 } else if ((arg == null || arg instanceof String) && bptype == L_TYPE) {
1621 emitConst(arg);
1622 } else {
1623 if (Wrapper.isWrapperType(arg.getClass()) && bptype != L_TYPE) {
1624 emitConst(arg);
1625 } else {
1626 mv.visitLdcInsn(constantPlaceholder(arg));
1627 emitImplicitConversion(L_TYPE, ptype, arg);
1628 }
1629 }
1630 }
1631
1632 /**
1633 * Store the name to its local, if necessary.
1634 */
1635 private void emitStoreResult(Name name) {
1636 if (name != null && name.type != V_TYPE) {
1637 // non-void: actually assign
1638 emitStoreInsn(name.type, name.index());
1639 }
1640 }
1641
1642 /**
1643 * Emits a return statement from a LF invoker. If required, the result type is cast to the correct return type.
1644 */
1645 private void emitReturn(Name onStack) {
1646 // return statement
1647 Class<?> rclass = invokerType.returnType();
1648 BasicType rtype = lambdaForm.returnType();
1649 assert(rtype == basicType(rclass)); // must agree
1650 if (rtype == V_TYPE) {
1651 // void
1652 mv.visitInsn(Opcodes.RETURN);
1653 // it doesn't matter what rclass is; the JVM will discard any value
1654 } else {
1655 LambdaForm.Name rn = lambdaForm.names[lambdaForm.result];
1656
1657 // put return value on the stack if it is not already there
1658 if (rn != onStack) {
1659 emitLoadInsn(rtype, lambdaForm.result);
1660 }
1661
1662 emitImplicitConversion(rtype, rclass, rn);
1663
1664 // generate actual return statement
1665 emitReturnInsn(rtype);
1666 }
1667 }
1668
1669 /**
1670 * Emit a type conversion bytecode casting from "from" to "to".
1671 */
1672 private void emitPrimCast(Wrapper from, Wrapper to) {
1673 // Here's how.
1674 // - indicates forbidden
1675 // <-> indicates implicit
1676 // to ----> boolean byte short char int long float double
1677 // from boolean <-> - - - - - - -
1678 // byte - <-> i2s i2c <-> i2l i2f i2d
1679 // short - i2b <-> i2c <-> i2l i2f i2d
1680 // char - i2b i2s <-> <-> i2l i2f i2d
1681 // int - i2b i2s i2c <-> i2l i2f i2d
1682 // long - l2i,i2b l2i,i2s l2i,i2c l2i <-> l2f l2d
1683 // float - f2i,i2b f2i,i2s f2i,i2c f2i f2l <-> f2d
1684 // double - d2i,i2b d2i,i2s d2i,i2c d2i d2l d2f <->
1685 if (from == to) {
1686 // no cast required, should be dead code anyway
1687 return;
1688 }
1689 if (from.isSubwordOrInt()) {
1690 // cast from {byte,short,char,int} to anything
1691 emitI2X(to);
1692 } else {
1693 // cast from {long,float,double} to anything
1694 if (to.isSubwordOrInt()) {
1695 // cast to {byte,short,char,int}
1696 emitX2I(from);
1697 if (to.bitWidth() < 32) {
1698 // targets other than int require another conversion
1699 emitI2X(to);
1700 }
1701 } else {
1702 // cast to {long,float,double} - this is verbose
1703 boolean error = false;
1704 switch (from) {
1705 case LONG:
1706 switch (to) {
1707 case FLOAT: mv.visitInsn(Opcodes.L2F); break;
1708 case DOUBLE: mv.visitInsn(Opcodes.L2D); break;
1709 default: error = true; break;
1710 }
1711 break;
1712 case FLOAT:
1713 switch (to) {
1714 case LONG : mv.visitInsn(Opcodes.F2L); break;
1715 case DOUBLE: mv.visitInsn(Opcodes.F2D); break;
1716 default: error = true; break;
1717 }
1718 break;
1719 case DOUBLE:
1720 switch (to) {
1721 case LONG : mv.visitInsn(Opcodes.D2L); break;
1722 case FLOAT: mv.visitInsn(Opcodes.D2F); break;
1723 default: error = true; break;
1724 }
1725 break;
1726 default:
1727 error = true;
1728 break;
1729 }
1730 if (error) {
1731 throw new IllegalStateException("unhandled prim cast: " + from + "2" + to);
1732 }
1733 }
1734 }
1735 }
1736
1737 private void emitI2X(Wrapper type) {
1738 switch (type) {
1739 case BYTE: mv.visitInsn(Opcodes.I2B); break;
1740 case SHORT: mv.visitInsn(Opcodes.I2S); break;
1741 case CHAR: mv.visitInsn(Opcodes.I2C); break;
1742 case INT: /* naught */ break;
1743 case LONG: mv.visitInsn(Opcodes.I2L); break;
1744 case FLOAT: mv.visitInsn(Opcodes.I2F); break;
1745 case DOUBLE: mv.visitInsn(Opcodes.I2D); break;
1746 case BOOLEAN:
1747 // For compatibility with ValueConversions and explicitCastArguments:
1748 mv.visitInsn(Opcodes.ICONST_1);
1749 mv.visitInsn(Opcodes.IAND);
1750 break;
1751 default: throw new InternalError("unknown type: " + type);
1752 }
1753 }
1754
1755 private void emitX2I(Wrapper type) {
1756 switch (type) {
1757 case LONG: mv.visitInsn(Opcodes.L2I); break;
1758 case FLOAT: mv.visitInsn(Opcodes.F2I); break;
1759 case DOUBLE: mv.visitInsn(Opcodes.D2I); break;
1760 default: throw new InternalError("unknown type: " + type);
1761 }
1762 }
1763
1764 /**
1765 * Generate bytecode for a LambdaForm.vmentry which calls interpretWithArguments.
1766 */
1767 static MemberName generateLambdaFormInterpreterEntryPoint(MethodType mt) {
1768 assert(isValidSignature(basicTypeSignature(mt)));
1769 String name = "interpret_"+basicTypeChar(mt.returnType());
1770 MethodType type = mt; // includes leading argument
1771 type = type.changeParameterType(0, MethodHandle.class);
1772 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("LFI", name, type);
1773 return g.loadMethod(g.generateLambdaFormInterpreterEntryPointBytes());
1774 }
1775
1776 private byte[] generateLambdaFormInterpreterEntryPointBytes() {
1777 classFilePrologue();
1778 methodPrologue();
1779
1780 // Suppress this method in backtraces displayed to the user.
1781 mv.visitAnnotation(HIDDEN_SIG, true);
1782
1783 // Don't inline the interpreter entry.
1784 mv.visitAnnotation(DONTINLINE_SIG, true);
1785
1786 // create parameter array
1787 emitIconstInsn(invokerType.parameterCount());
1788 mv.visitTypeInsn(Opcodes.ANEWARRAY, "java/lang/Object");
1789
1790 // fill parameter array
1791 for (int i = 0; i < invokerType.parameterCount(); i++) {
1792 Class<?> ptype = invokerType.parameterType(i);
1793 mv.visitInsn(Opcodes.DUP);
1794 emitIconstInsn(i);
1795 emitLoadInsn(basicType(ptype), i);
1796 // box if primitive type
1797 if (ptype.isPrimitive()) {
1798 emitBoxing(Wrapper.forPrimitiveType(ptype));
1799 }
1800 mv.visitInsn(Opcodes.AASTORE);
1801 }
1802 // invoke
1803 emitAloadInsn(0);
1804 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", "Ljava/lang/invoke/LambdaForm;");
1805 mv.visitInsn(Opcodes.SWAP); // swap form and array; avoid local variable
1806 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, LF, "interpretWithArguments", "([Ljava/lang/Object;)Ljava/lang/Object;", false);
1807
1808 // maybe unbox
1809 Class<?> rtype = invokerType.returnType();
1810 if (rtype.isPrimitive() && rtype != void.class) {
1811 emitUnboxing(Wrapper.forPrimitiveType(rtype));
1812 }
1813
1814 // return statement
1815 emitReturnInsn(basicType(rtype));
1816
1817 methodEpilogue();
1818 bogusMethod(invokerType);
1819
1820 final byte[] classFile = cw.toByteArray();
1821 maybeDump(classFile);
1822 return classFile;
1823 }
1824
1825 /**
1826 * Generate bytecode for a NamedFunction invoker.
1827 */
1828 static MemberName generateNamedFunctionInvoker(MethodTypeForm typeForm) {
1829 MethodType invokerType = NamedFunction.INVOKER_METHOD_TYPE;
1830 String invokerName = "invoke_" + shortenSignature(basicTypeSignature(typeForm.erasedType()));
1831 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("NFI", invokerName, invokerType);
1832 return g.loadMethod(g.generateNamedFunctionInvokerImpl(typeForm));
1833 }
1834
1835 private byte[] generateNamedFunctionInvokerImpl(MethodTypeForm typeForm) {
1836 MethodType dstType = typeForm.erasedType();
1837 classFilePrologue();
1838 methodPrologue();
1839
1840 // Suppress this method in backtraces displayed to the user.
1841 mv.visitAnnotation(HIDDEN_SIG, true);
1842
1843 // Force inlining of this invoker method.
1844 mv.visitAnnotation(FORCEINLINE_SIG, true);
1845
1846 // Load receiver
1847 emitAloadInsn(0);
1848
1849 // Load arguments from array
1850 for (int i = 0; i < dstType.parameterCount(); i++) {
1851 emitAloadInsn(1);
1852 emitIconstInsn(i);
1853 mv.visitInsn(Opcodes.AALOAD);
1854
1855 // Maybe unbox
1856 Class<?> dptype = dstType.parameterType(i);
1857 if (dptype.isPrimitive()) {
1858 Wrapper dstWrapper = Wrapper.forBasicType(dptype);
1859 Wrapper srcWrapper = dstWrapper.isSubwordOrInt() ? Wrapper.INT : dstWrapper; // narrow subword from int
1860 emitUnboxing(srcWrapper);
1861 emitPrimCast(srcWrapper, dstWrapper);
1862 }
1863 }
1864
1865 // Invoke
1866 String targetDesc = dstType.basicType().toMethodDescriptorString();
1867 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", targetDesc, false);
1868
1869 // Box primitive types
1870 Class<?> rtype = dstType.returnType();
1871 if (rtype != void.class && rtype.isPrimitive()) {
1872 Wrapper srcWrapper = Wrapper.forBasicType(rtype);
1873 Wrapper dstWrapper = srcWrapper.isSubwordOrInt() ? Wrapper.INT : srcWrapper; // widen subword to int
1874 // boolean casts not allowed
1875 emitPrimCast(srcWrapper, dstWrapper);
1876 emitBoxing(dstWrapper);
1877 }
1878
1879 // If the return type is void we return a null reference.
1880 if (rtype == void.class) {
1881 mv.visitInsn(Opcodes.ACONST_NULL);
1882 }
1883 emitReturnInsn(L_TYPE); // NOTE: NamedFunction invokers always return a reference value.
1884
1885 methodEpilogue();
1886 bogusMethod(dstType);
1887
1888 final byte[] classFile = cw.toByteArray();
1889 maybeDump(classFile);
1890 return classFile;
1891 }
1892
1893 /**
1894 * Emit a bogus method that just loads some string constants. This is to get the constants into the constant pool
1895 * for debugging purposes.
1896 */
1897 private void bogusMethod(Object os) {
1898 if (DUMP_CLASS_FILES) {
1899 mv = cw.visitMethod(Opcodes.ACC_STATIC, "dummy", "()V", null, null);
1900 mv.visitLdcInsn(os.toString());
1901 mv.visitInsn(Opcodes.POP);
1902 mv.visitInsn(Opcodes.RETURN);
1903 mv.visitMaxs(0, 0);
1904 mv.visitEnd();
1905 }
1906 }
1907 }