1 /*
2 * Copyright (c) 2008, 2013, 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 static jdk.internal.org.objectweb.asm.Opcodes.*;
29 import static java.lang.invoke.LambdaForm.*;
30 import static java.lang.invoke.LambdaForm.BasicType.*;
31 import static java.lang.invoke.MethodHandleStatics.*;
32
33 import java.lang.invoke.LambdaForm.NamedFunction;
34 import java.lang.invoke.MethodHandles.Lookup;
35 import java.lang.reflect.Field;
36 import java.util.Arrays;
37 import java.util.HashMap;
38
39 import sun.invoke.util.ValueConversions;
40 import sun.invoke.util.Wrapper;
41
42 import jdk.internal.org.objectweb.asm.ClassWriter;
43 import jdk.internal.org.objectweb.asm.MethodVisitor;
44 import jdk.internal.org.objectweb.asm.Type;
45
46 /**
47 * The flavor of method handle which emulates an invoke instruction
48 * on a predetermined argument. The JVM dispatches to the correct method
49 * when the handle is created, not when it is invoked.
50 *
51 * All bound arguments are encapsulated in dedicated species.
52 */
53 /* non-public */ abstract class BoundMethodHandle extends MethodHandle {
54
55 /* non-public */ BoundMethodHandle(MethodType type, LambdaForm form) {
56 super(type, form);
57 }
58
59 //
60 // BMH API and internals
61 //
62
63 static BoundMethodHandle bindSingle(MethodType type, LambdaForm form, BasicType xtype, Object x) {
64 // for some type signatures, there exist pre-defined concrete BMH classes
65 try {
66 switch (xtype) {
67 case L_TYPE:
68 return bindSingle(type, form, x); // Use known fast path.
69 case I_TYPE:
70 return (BoundMethodHandle) SpeciesData.EMPTY.extendWith(I_TYPE).constructor().invokeBasic(type, form, ValueConversions.widenSubword(x));
71 case J_TYPE:
72 return (BoundMethodHandle) SpeciesData.EMPTY.extendWith(J_TYPE).constructor().invokeBasic(type, form, (long) x);
73 case F_TYPE:
74 return (BoundMethodHandle) SpeciesData.EMPTY.extendWith(F_TYPE).constructor().invokeBasic(type, form, (float) x);
75 case D_TYPE:
76 return (BoundMethodHandle) SpeciesData.EMPTY.extendWith(D_TYPE).constructor().invokeBasic(type, form, (double) x);
77 default : throw newInternalError("unexpected xtype: " + xtype);
78 }
79 } catch (Throwable t) {
80 throw newInternalError(t);
81 }
82 }
83
84 static BoundMethodHandle bindSingle(MethodType type, LambdaForm form, Object x) {
85 return Species_L.make(type, form, x);
86 }
87
88 @Override // there is a default binder in the super class, for 'L' types only
89 /*non-public*/
90 BoundMethodHandle bindArgumentL(int pos, Object value) {
91 MethodType type = type().dropParameterTypes(pos, pos+1);
92 LambdaForm form = internalForm().bind(1+pos, speciesData());
93 return copyWithExtendL(type, form, value);
94 }
95 /*non-public*/
96 BoundMethodHandle bindArgumentI(int pos, int value) {
97 MethodType type = type().dropParameterTypes(pos, pos+1);
98 LambdaForm form = internalForm().bind(1+pos, speciesData());
99 return copyWithExtendI(type, form, value);
100 }
101 /*non-public*/
102 BoundMethodHandle bindArgumentJ(int pos, long value) {
103 MethodType type = type().dropParameterTypes(pos, pos+1);
104 LambdaForm form = internalForm().bind(1+pos, speciesData());
105 return copyWithExtendJ(type, form, value);
106 }
107 /*non-public*/
108 BoundMethodHandle bindArgumentF(int pos, float value) {
109 MethodType type = type().dropParameterTypes(pos, pos+1);
110 LambdaForm form = internalForm().bind(1+pos, speciesData());
111 return copyWithExtendF(type, form, value);
112 }
113 /*non-public*/
114 BoundMethodHandle bindArgumentD(int pos, double value) {
115 MethodType type = type().dropParameterTypes(pos, pos + 1);
116 LambdaForm form = internalForm().bind(1+pos, speciesData());
117 return copyWithExtendD(type, form, value);
118 }
119
120 /**
121 * Return the {@link SpeciesData} instance representing this BMH species. All subclasses must provide a
122 * static field containing this value, and they must accordingly implement this method.
123 */
124 /*non-public*/ abstract SpeciesData speciesData();
125
126 /**
127 * Return the number of fields in this BMH. Equivalent to speciesData().fieldCount().
128 */
129 /*non-public*/ abstract int fieldCount();
130
131 @Override
132 Object internalProperties() {
133 return "\n& BMH="+internalValues();
134 }
135
136 @Override
137 final Object internalValues() {
138 Object[] boundValues = new Object[speciesData().fieldCount()];
139 for (int i = 0; i < boundValues.length; ++i) {
140 boundValues[i] = arg(i);
141 }
142 return Arrays.asList(boundValues);
143 }
144
145 /*non-public*/ final Object arg(int i) {
146 try {
147 switch (speciesData().fieldType(i)) {
148 case L_TYPE: return speciesData().getters[i].invokeBasic(this);
149 case I_TYPE: return (int) speciesData().getters[i].invokeBasic(this);
150 case J_TYPE: return (long) speciesData().getters[i].invokeBasic(this);
151 case F_TYPE: return (float) speciesData().getters[i].invokeBasic(this);
152 case D_TYPE: return (double) speciesData().getters[i].invokeBasic(this);
153 }
154 } catch (Throwable ex) {
155 throw newInternalError(ex);
156 }
157 throw new InternalError("unexpected type: " + speciesData().typeChars+"."+i);
158 }
159
160 //
161 // cloning API
162 //
163
164 /*non-public*/ abstract BoundMethodHandle copyWith(MethodType mt, LambdaForm lf);
165 /*non-public*/ abstract BoundMethodHandle copyWithExtendL(MethodType mt, LambdaForm lf, Object narg);
166 /*non-public*/ abstract BoundMethodHandle copyWithExtendI(MethodType mt, LambdaForm lf, int narg);
167 /*non-public*/ abstract BoundMethodHandle copyWithExtendJ(MethodType mt, LambdaForm lf, long narg);
168 /*non-public*/ abstract BoundMethodHandle copyWithExtendF(MethodType mt, LambdaForm lf, float narg);
169 /*non-public*/ abstract BoundMethodHandle copyWithExtendD(MethodType mt, LambdaForm lf, double narg);
170
171 // The following is a grossly irregular hack:
172 @Override MethodHandle reinvokerTarget() {
173 try {
174 return (MethodHandle) arg(0);
175 } catch (Throwable ex) {
176 throw newInternalError(ex);
177 }
178 }
179
180 //
181 // concrete BMH classes required to close bootstrap loops
182 //
183
184 private // make it private to force users to access the enclosing class first
185 static final class Species_L extends BoundMethodHandle {
186 final Object argL0;
187 private Species_L(MethodType mt, LambdaForm lf, Object argL0) {
188 super(mt, lf);
189 this.argL0 = argL0;
190 }
191 // The following is a grossly irregular hack:
192 @Override MethodHandle reinvokerTarget() { return (MethodHandle) argL0; }
193 @Override
194 /*non-public*/ SpeciesData speciesData() {
195 return SPECIES_DATA;
196 }
197 @Override
198 /*non-public*/ int fieldCount() {
199 return 1;
200 }
201 /*non-public*/ static final SpeciesData SPECIES_DATA = SpeciesData.getForClass("L", Species_L.class);
202 /*non-public*/ static BoundMethodHandle make(MethodType mt, LambdaForm lf, Object argL0) {
203 return new Species_L(mt, lf, argL0);
204 }
205 @Override
206 /*non-public*/ final BoundMethodHandle copyWith(MethodType mt, LambdaForm lf) {
207 return new Species_L(mt, lf, argL0);
208 }
209 @Override
210 /*non-public*/ final BoundMethodHandle copyWithExtendL(MethodType mt, LambdaForm lf, Object narg) {
211 try {
212 return (BoundMethodHandle) SPECIES_DATA.extendWith(L_TYPE).constructor().invokeBasic(mt, lf, argL0, narg);
213 } catch (Throwable ex) {
214 throw uncaughtException(ex);
215 }
216 }
217 @Override
218 /*non-public*/ final BoundMethodHandle copyWithExtendI(MethodType mt, LambdaForm lf, int narg) {
219 try {
220 return (BoundMethodHandle) SPECIES_DATA.extendWith(I_TYPE).constructor().invokeBasic(mt, lf, argL0, narg);
221 } catch (Throwable ex) {
222 throw uncaughtException(ex);
223 }
224 }
225 @Override
226 /*non-public*/ final BoundMethodHandle copyWithExtendJ(MethodType mt, LambdaForm lf, long narg) {
227 try {
228 return (BoundMethodHandle) SPECIES_DATA.extendWith(J_TYPE).constructor().invokeBasic(mt, lf, argL0, narg);
229 } catch (Throwable ex) {
230 throw uncaughtException(ex);
231 }
232 }
233 @Override
234 /*non-public*/ final BoundMethodHandle copyWithExtendF(MethodType mt, LambdaForm lf, float narg) {
235 try {
236 return (BoundMethodHandle) SPECIES_DATA.extendWith(F_TYPE).constructor().invokeBasic(mt, lf, argL0, narg);
237 } catch (Throwable ex) {
238 throw uncaughtException(ex);
239 }
240 }
241 @Override
242 /*non-public*/ final BoundMethodHandle copyWithExtendD(MethodType mt, LambdaForm lf, double narg) {
243 try {
244 return (BoundMethodHandle) SPECIES_DATA.extendWith(D_TYPE).constructor().invokeBasic(mt, lf, argL0, narg);
245 } catch (Throwable ex) {
246 throw uncaughtException(ex);
247 }
248 }
249 }
250
251 //
252 // BMH species meta-data
253 //
254
255 /**
256 * Meta-data wrapper for concrete BMH types.
257 * Each BMH type corresponds to a given sequence of basic field types (LIJFD).
258 * The fields are immutable; their values are fully specified at object construction.
259 * Each BMH type supplies an array of getter functions which may be used in lambda forms.
260 * A BMH is constructed by cloning a shorter BMH and adding one or more new field values.
261 * As a degenerate and common case, the "shorter BMH" can be missing, and contributes zero prior fields.
262 */
263 static class SpeciesData {
264 final String typeChars;
265 final BasicType[] typeCodes;
266 final Class<? extends BoundMethodHandle> clazz;
267 // Bootstrapping requires circular relations MH -> BMH -> SpeciesData -> MH
268 // Therefore, we need a non-final link in the chain. Use array elements.
269 final MethodHandle[] constructor;
270 final MethodHandle[] getters;
271 final NamedFunction[] nominalGetters;
272 final SpeciesData[] extensions;
273
274 /*non-public*/ int fieldCount() {
275 return typeCodes.length;
276 }
277 /*non-public*/ BasicType fieldType(int i) {
278 return typeCodes[i];
279 }
280 /*non-public*/ char fieldTypeChar(int i) {
281 return typeChars.charAt(i);
282 }
283
284 public String toString() {
285 return "SpeciesData["+(isPlaceholder() ? "<placeholder>" : clazz.getSimpleName())+":"+typeChars+"]";
286 }
287
288 /**
289 * Return a {@link LambdaForm.Name} containing a {@link LambdaForm.NamedFunction} that
290 * represents a MH bound to a generic invoker, which in turn forwards to the corresponding
291 * getter.
292 */
293 NamedFunction getterFunction(int i) {
294 return nominalGetters[i];
295 }
296
297 MethodHandle constructor() {
298 return constructor[0];
299 }
300
301 static final SpeciesData EMPTY = new SpeciesData("", BoundMethodHandle.class);
302
303 private SpeciesData(String types, Class<? extends BoundMethodHandle> clazz) {
304 this.typeChars = types;
305 this.typeCodes = basicTypes(types);
306 this.clazz = clazz;
307 if (!INIT_DONE) {
308 this.constructor = new MethodHandle[1]; // only one ctor
309 this.getters = new MethodHandle[types.length()];
310 this.nominalGetters = new NamedFunction[types.length()];
311 } else {
312 this.constructor = Factory.makeCtors(clazz, types, null);
313 this.getters = Factory.makeGetters(clazz, types, null);
314 this.nominalGetters = Factory.makeNominalGetters(types, null, this.getters);
315 }
316 this.extensions = new SpeciesData[ARG_TYPE_LIMIT];
317 }
318
319 private void initForBootstrap() {
320 assert(!INIT_DONE);
321 if (constructor() == null) {
322 String types = typeChars;
323 Factory.makeCtors(clazz, types, this.constructor);
324 Factory.makeGetters(clazz, types, this.getters);
325 Factory.makeNominalGetters(types, this.nominalGetters, this.getters);
326 }
327 }
328
329 private SpeciesData(String typeChars) {
330 // Placeholder only.
331 this.typeChars = typeChars;
332 this.typeCodes = basicTypes(typeChars);
333 this.clazz = null;
334 this.constructor = null;
335 this.getters = null;
336 this.nominalGetters = null;
337 this.extensions = null;
338 }
339 private boolean isPlaceholder() { return clazz == null; }
340
341 private static final HashMap<String, SpeciesData> CACHE = new HashMap<>();
342 static { CACHE.put("", EMPTY); } // make bootstrap predictable
343 private static final boolean INIT_DONE; // set after <clinit> finishes...
344
345 SpeciesData extendWith(byte type) {
346 return extendWith(BasicType.basicType(type));
347 }
348
349 SpeciesData extendWith(BasicType type) {
350 int ord = type.ordinal();
351 SpeciesData d = extensions[ord];
352 if (d != null) return d;
353 extensions[ord] = d = get(typeChars+type.basicTypeChar());
354 return d;
355 }
356
357 private static SpeciesData get(String types) {
358 // Acquire cache lock for query.
359 SpeciesData d = lookupCache(types);
360 if (!d.isPlaceholder())
361 return d;
362 synchronized (d) {
363 // Use synch. on the placeholder to prevent multiple instantiation of one species.
364 // Creating this class forces a recursive call to getForClass.
365 if (lookupCache(types).isPlaceholder())
366 Factory.generateConcreteBMHClass(types);
367 }
368 // Reacquire cache lock.
369 d = lookupCache(types);
370 // Class loading must have upgraded the cache.
371 assert(d != null && !d.isPlaceholder());
372 return d;
373 }
374 static SpeciesData getForClass(String types, Class<? extends BoundMethodHandle> clazz) {
375 // clazz is a new class which is initializing its SPECIES_DATA field
376 return updateCache(types, new SpeciesData(types, clazz));
377 }
378 private static synchronized SpeciesData lookupCache(String types) {
379 SpeciesData d = CACHE.get(types);
380 if (d != null) return d;
381 d = new SpeciesData(types);
382 assert(d.isPlaceholder());
383 CACHE.put(types, d);
384 return d;
385 }
386 private static synchronized SpeciesData updateCache(String types, SpeciesData d) {
387 SpeciesData d2;
388 assert((d2 = CACHE.get(types)) == null || d2.isPlaceholder());
389 assert(!d.isPlaceholder());
390 CACHE.put(types, d);
391 return d;
392 }
393
394 static {
395 // pre-fill the BMH speciesdata cache with BMH's inner classes
396 final Class<BoundMethodHandle> rootCls = BoundMethodHandle.class;
397 try {
398 for (Class<?> c : rootCls.getDeclaredClasses()) {
399 if (rootCls.isAssignableFrom(c)) {
400 final Class<? extends BoundMethodHandle> cbmh = c.asSubclass(BoundMethodHandle.class);
401 SpeciesData d = Factory.speciesDataFromConcreteBMHClass(cbmh);
402 assert(d != null) : cbmh.getName();
403 assert(d.clazz == cbmh);
404 assert(d == lookupCache(d.typeChars));
405 }
406 }
407 } catch (Throwable e) {
408 throw newInternalError(e);
409 }
410
411 for (SpeciesData d : CACHE.values()) {
412 d.initForBootstrap();
413 }
414 // Note: Do not simplify this, because INIT_DONE must not be
415 // a compile-time constant during bootstrapping.
416 INIT_DONE = Boolean.TRUE;
417 }
418 }
419
420 static SpeciesData getSpeciesData(String types) {
421 return SpeciesData.get(types);
422 }
423
424 /**
425 * Generation of concrete BMH classes.
426 *
427 * A concrete BMH species is fit for binding a number of values adhering to a
428 * given type pattern. Reference types are erased.
429 *
430 * BMH species are cached by type pattern.
431 *
432 * A BMH species has a number of fields with the concrete (possibly erased) types of
433 * bound values. Setters are provided as an API in BMH. Getters are exposed as MHs,
434 * which can be included as names in lambda forms.
435 */
436 static class Factory {
437
438 static final String JLO_SIG = "Ljava/lang/Object;";
439 static final String JLS_SIG = "Ljava/lang/String;";
440 static final String JLC_SIG = "Ljava/lang/Class;";
441 static final String MH = "java/lang/invoke/MethodHandle";
442 static final String MH_SIG = "L"+MH+";";
443 static final String BMH = "java/lang/invoke/BoundMethodHandle";
444 static final String BMH_SIG = "L"+BMH+";";
445 static final String SPECIES_DATA = "java/lang/invoke/BoundMethodHandle$SpeciesData";
446 static final String SPECIES_DATA_SIG = "L"+SPECIES_DATA+";";
447
448 static final String SPECIES_PREFIX_NAME = "Species_";
449 static final String SPECIES_PREFIX_PATH = BMH + "$" + SPECIES_PREFIX_NAME;
450
451 static final String BMHSPECIES_DATA_EWI_SIG = "(B)" + SPECIES_DATA_SIG;
452 static final String BMHSPECIES_DATA_GFC_SIG = "(" + JLS_SIG + JLC_SIG + ")" + SPECIES_DATA_SIG;
453 static final String MYSPECIES_DATA_SIG = "()" + SPECIES_DATA_SIG;
454 static final String VOID_SIG = "()V";
455 static final String INT_SIG = "()I";
456
457 static final String SIG_INCIPIT = "(Ljava/lang/invoke/MethodType;Ljava/lang/invoke/LambdaForm;";
458
459 static final String[] E_THROWABLE = new String[] { "java/lang/Throwable" };
460
461 /**
462 * Generate a concrete subclass of BMH for a given combination of bound types.
463 *
464 * A concrete BMH species adheres to the following schema:
465 *
466 * <pre>
467 * class Species_[[types]] extends BoundMethodHandle {
468 * [[fields]]
469 * final SpeciesData speciesData() { return SpeciesData.get("[[types]]"); }
470 * }
471 * </pre>
472 *
473 * The {@code [[types]]} signature is precisely the string that is passed to this
474 * method.
475 *
476 * The {@code [[fields]]} section consists of one field definition per character in
477 * the type signature, adhering to the naming schema described in the definition of
478 * {@link #makeFieldName}.
479 *
480 * For example, a concrete BMH species for two reference and one integral bound values
481 * would have the following shape:
482 *
483 * <pre>
484 * class BoundMethodHandle { ... private static
485 * final class Species_LLI extends BoundMethodHandle {
486 * final Object argL0;
487 * final Object argL1;
488 * final int argI2;
489 * private Species_LLI(MethodType mt, LambdaForm lf, Object argL0, Object argL1, int argI2) {
490 * super(mt, lf);
491 * this.argL0 = argL0;
492 * this.argL1 = argL1;
493 * this.argI2 = argI2;
494 * }
495 * final SpeciesData speciesData() { return SPECIES_DATA; }
496 * final int fieldCount() { return 3; }
497 * static final SpeciesData SPECIES_DATA = SpeciesData.getForClass("LLI", Species_LLI.class);
498 * static BoundMethodHandle make(MethodType mt, LambdaForm lf, Object argL0, Object argL1, int argI2) {
499 * return new Species_LLI(mt, lf, argL0, argL1, argI2);
500 * }
501 * final BoundMethodHandle copyWith(MethodType mt, LambdaForm lf) {
502 * return new Species_LLI(mt, lf, argL0, argL1, argI2);
503 * }
504 * final BoundMethodHandle copyWithExtendL(MethodType mt, LambdaForm lf, Object narg) {
505 * return SPECIES_DATA.extendWith(L_TYPE).constructor().invokeBasic(mt, lf, argL0, argL1, argI2, narg);
506 * }
507 * final BoundMethodHandle copyWithExtendI(MethodType mt, LambdaForm lf, int narg) {
508 * return SPECIES_DATA.extendWith(I_TYPE).constructor().invokeBasic(mt, lf, argL0, argL1, argI2, narg);
509 * }
510 * final BoundMethodHandle copyWithExtendJ(MethodType mt, LambdaForm lf, long narg) {
511 * return SPECIES_DATA.extendWith(J_TYPE).constructor().invokeBasic(mt, lf, argL0, argL1, argI2, narg);
512 * }
513 * final BoundMethodHandle copyWithExtendF(MethodType mt, LambdaForm lf, float narg) {
514 * return SPECIES_DATA.extendWith(F_TYPE).constructor().invokeBasic(mt, lf, argL0, argL1, argI2, narg);
515 * }
516 * public final BoundMethodHandle copyWithExtendD(MethodType mt, LambdaForm lf, double narg) {
517 * return SPECIES_DATA.extendWith(D_TYPE).constructor().invokeBasic(mt, lf, argL0, argL1, argI2, narg);
518 * }
519 * }
520 * </pre>
521 *
522 * @param types the type signature, wherein reference types are erased to 'L'
523 * @return the generated concrete BMH class
524 */
525 static Class<? extends BoundMethodHandle> generateConcreteBMHClass(String types) {
526 final ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES);
527
528 String shortTypes = LambdaForm.shortenSignature(types);
529 final String className = SPECIES_PREFIX_PATH + shortTypes;
530 final String sourceFile = SPECIES_PREFIX_NAME + shortTypes;
531 final int NOT_ACC_PUBLIC = 0; // not ACC_PUBLIC
532 cw.visit(V1_6, NOT_ACC_PUBLIC + ACC_FINAL + ACC_SUPER, className, null, BMH, null);
533 cw.visitSource(sourceFile, null);
534
535 // emit static types and SPECIES_DATA fields
536 cw.visitField(NOT_ACC_PUBLIC + ACC_STATIC, "SPECIES_DATA", SPECIES_DATA_SIG, null, null).visitEnd();
537
538 // emit bound argument fields
539 for (int i = 0; i < types.length(); ++i) {
540 final char t = types.charAt(i);
541 final String fieldName = makeFieldName(types, i);
542 final String fieldDesc = t == 'L' ? JLO_SIG : String.valueOf(t);
543 cw.visitField(ACC_FINAL, fieldName, fieldDesc, null, null).visitEnd();
544 }
545
546 MethodVisitor mv;
547
548 // emit constructor
549 mv = cw.visitMethod(ACC_PRIVATE, "<init>", makeSignature(types, true), null, null);
550 mv.visitCode();
551 mv.visitVarInsn(ALOAD, 0); // this
552 mv.visitVarInsn(ALOAD, 1); // type
553 mv.visitVarInsn(ALOAD, 2); // form
554
555 mv.visitMethodInsn(INVOKESPECIAL, BMH, "<init>", makeSignature("", true), false);
556
557 for (int i = 0, j = 0; i < types.length(); ++i, ++j) {
558 // i counts the arguments, j counts corresponding argument slots
559 char t = types.charAt(i);
560 mv.visitVarInsn(ALOAD, 0);
561 mv.visitVarInsn(typeLoadOp(t), j + 3); // parameters start at 3
562 mv.visitFieldInsn(PUTFIELD, className, makeFieldName(types, i), typeSig(t));
563 if (t == 'J' || t == 'D') {
564 ++j; // adjust argument register access
565 }
566 }
567
568 mv.visitInsn(RETURN);
569 mv.visitMaxs(0, 0);
570 mv.visitEnd();
571
572 // emit implementation of reinvokerTarget()
573 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_FINAL, "reinvokerTarget", "()" + MH_SIG, null, null);
574 mv.visitCode();
575 mv.visitVarInsn(ALOAD, 0);
576 mv.visitFieldInsn(GETFIELD, className, "argL0", JLO_SIG);
577 mv.visitTypeInsn(CHECKCAST, MH);
578 mv.visitInsn(ARETURN);
579 mv.visitMaxs(0, 0);
580 mv.visitEnd();
581
582 // emit implementation of speciesData()
583 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_FINAL, "speciesData", MYSPECIES_DATA_SIG, null, null);
584 mv.visitCode();
585 mv.visitFieldInsn(GETSTATIC, className, "SPECIES_DATA", SPECIES_DATA_SIG);
586 mv.visitInsn(ARETURN);
587 mv.visitMaxs(0, 0);
588 mv.visitEnd();
589
590 // emit implementation of fieldCount()
591 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_FINAL, "fieldCount", INT_SIG, null, null);
592 mv.visitCode();
593 int fc = types.length();
594 if (fc <= (ICONST_5 - ICONST_0)) {
595 mv.visitInsn(ICONST_0 + fc);
596 } else {
597 mv.visitIntInsn(SIPUSH, fc);
598 }
599 mv.visitInsn(IRETURN);
600 mv.visitMaxs(0, 0);
601 mv.visitEnd();
602 // emit make() ...factory method wrapping constructor
603 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_STATIC, "make", makeSignature(types, false), null, null);
604 mv.visitCode();
605 // make instance
606 mv.visitTypeInsn(NEW, className);
607 mv.visitInsn(DUP);
608 // load mt, lf
609 mv.visitVarInsn(ALOAD, 0); // type
610 mv.visitVarInsn(ALOAD, 1); // form
611 // load factory method arguments
612 for (int i = 0, j = 0; i < types.length(); ++i, ++j) {
613 // i counts the arguments, j counts corresponding argument slots
614 char t = types.charAt(i);
615 mv.visitVarInsn(typeLoadOp(t), j + 2); // parameters start at 3
616 if (t == 'J' || t == 'D') {
617 ++j; // adjust argument register access
618 }
619 }
620
621 // finally, invoke the constructor and return
622 mv.visitMethodInsn(INVOKESPECIAL, className, "<init>", makeSignature(types, true), false);
623 mv.visitInsn(ARETURN);
624 mv.visitMaxs(0, 0);
625 mv.visitEnd();
626
627 // emit copyWith()
628 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_FINAL, "copyWith", makeSignature("", false), null, null);
629 mv.visitCode();
630 // make instance
631 mv.visitTypeInsn(NEW, className);
632 mv.visitInsn(DUP);
633 // load mt, lf
634 mv.visitVarInsn(ALOAD, 1);
635 mv.visitVarInsn(ALOAD, 2);
636 // put fields on the stack
637 emitPushFields(types, className, mv);
638 // finally, invoke the constructor and return
639 mv.visitMethodInsn(INVOKESPECIAL, className, "<init>", makeSignature(types, true), false);
640 mv.visitInsn(ARETURN);
641 mv.visitMaxs(0, 0);
642 mv.visitEnd();
643
644 // for each type, emit copyWithExtendT()
645 for (BasicType type : BasicType.ARG_TYPES) {
646 int ord = type.ordinal();
647 char btChar = type.basicTypeChar();
648 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_FINAL, "copyWithExtend" + btChar, makeSignature(String.valueOf(btChar), false), null, E_THROWABLE);
649 mv.visitCode();
650 // return SPECIES_DATA.extendWith(t).constructor().invokeBasic(mt, lf, argL0, ..., narg)
651 // obtain constructor
652 mv.visitFieldInsn(GETSTATIC, className, "SPECIES_DATA", SPECIES_DATA_SIG);
653 int iconstInsn = ICONST_0 + ord;
654 assert(iconstInsn <= ICONST_5);
655 mv.visitInsn(iconstInsn);
656 mv.visitMethodInsn(INVOKEVIRTUAL, SPECIES_DATA, "extendWith", BMHSPECIES_DATA_EWI_SIG, false);
657 mv.visitMethodInsn(INVOKEVIRTUAL, SPECIES_DATA, "constructor", "()" + MH_SIG, false);
658 // load mt, lf
659 mv.visitVarInsn(ALOAD, 1);
660 mv.visitVarInsn(ALOAD, 2);
661 // put fields on the stack
662 emitPushFields(types, className, mv);
663 // put narg on stack
664 mv.visitVarInsn(typeLoadOp(btChar), 3);
665 // finally, invoke the constructor and return
666 mv.visitMethodInsn(INVOKEVIRTUAL, MH, "invokeBasic", makeSignature(types + btChar, false), false);
667 mv.visitInsn(ARETURN);
668 mv.visitMaxs(0, 0);
669 mv.visitEnd();
670 }
671
672 // emit class initializer
673 mv = cw.visitMethod(NOT_ACC_PUBLIC | ACC_STATIC, "<clinit>", VOID_SIG, null, null);
674 mv.visitCode();
675 mv.visitLdcInsn(types);
676 mv.visitLdcInsn(Type.getObjectType(className));
677 mv.visitMethodInsn(INVOKESTATIC, SPECIES_DATA, "getForClass", BMHSPECIES_DATA_GFC_SIG, false);
678 mv.visitFieldInsn(PUTSTATIC, className, "SPECIES_DATA", SPECIES_DATA_SIG);
679 mv.visitInsn(RETURN);
680 mv.visitMaxs(0, 0);
681 mv.visitEnd();
682
683 cw.visitEnd();
684
685 // load class
686 final byte[] classFile = cw.toByteArray();
687 InvokerBytecodeGenerator.maybeDump(className, classFile);
688 Class<? extends BoundMethodHandle> bmhClass =
689 //UNSAFE.defineAnonymousClass(BoundMethodHandle.class, classFile, null).asSubclass(BoundMethodHandle.class);
690 UNSAFE.defineClass(className, classFile, 0, classFile.length,
691 BoundMethodHandle.class.getClassLoader(), null)
692 .asSubclass(BoundMethodHandle.class);
693 UNSAFE.ensureClassInitialized(bmhClass);
694
695 return bmhClass;
696 }
697
698 private static int typeLoadOp(char t) {
699 switch (t) {
700 case 'L': return ALOAD;
701 case 'I': return ILOAD;
702 case 'J': return LLOAD;
703 case 'F': return FLOAD;
704 case 'D': return DLOAD;
705 default : throw newInternalError("unrecognized type " + t);
706 }
707 }
708
709 private static void emitPushFields(String types, String className, MethodVisitor mv) {
710 for (int i = 0; i < types.length(); ++i) {
711 char tc = types.charAt(i);
712 mv.visitVarInsn(ALOAD, 0);
713 mv.visitFieldInsn(GETFIELD, className, makeFieldName(types, i), typeSig(tc));
714 }
715 }
716
717 static String typeSig(char t) {
718 return t == 'L' ? JLO_SIG : String.valueOf(t);
719 }
720
721 //
722 // Getter MH generation.
723 //
724
725 private static MethodHandle makeGetter(Class<?> cbmhClass, String types, int index) {
726 String fieldName = makeFieldName(types, index);
727 Class<?> fieldType = Wrapper.forBasicType(types.charAt(index)).primitiveType();
728 try {
729 return LOOKUP.findGetter(cbmhClass, fieldName, fieldType);
730 } catch (NoSuchFieldException | IllegalAccessException e) {
731 throw newInternalError(e);
732 }
733 }
734
735 static MethodHandle[] makeGetters(Class<?> cbmhClass, String types, MethodHandle[] mhs) {
736 if (mhs == null) mhs = new MethodHandle[types.length()];
737 for (int i = 0; i < mhs.length; ++i) {
738 mhs[i] = makeGetter(cbmhClass, types, i);
739 assert(mhs[i].internalMemberName().getDeclaringClass() == cbmhClass);
740 }
741 return mhs;
742 }
743
744 static MethodHandle[] makeCtors(Class<? extends BoundMethodHandle> cbmh, String types, MethodHandle mhs[]) {
745 if (mhs == null) mhs = new MethodHandle[1];
746 if (types.equals("")) return mhs; // hack for empty BMH species
747 mhs[0] = makeCbmhCtor(cbmh, types);
748 return mhs;
749 }
750
751 static NamedFunction[] makeNominalGetters(String types, NamedFunction[] nfs, MethodHandle[] getters) {
752 if (nfs == null) nfs = new NamedFunction[types.length()];
753 for (int i = 0; i < nfs.length; ++i) {
754 nfs[i] = new NamedFunction(getters[i]);
755 }
756 return nfs;
757 }
758
759 //
760 // Auxiliary methods.
761 //
762
763 static SpeciesData speciesDataFromConcreteBMHClass(Class<? extends BoundMethodHandle> cbmh) {
764 try {
765 Field F_SPECIES_DATA = cbmh.getDeclaredField("SPECIES_DATA");
766 return (SpeciesData) F_SPECIES_DATA.get(null);
767 } catch (ReflectiveOperationException ex) {
768 throw newInternalError(ex);
769 }
770 }
771
772 /**
773 * Field names in concrete BMHs adhere to this pattern:
774 * arg + type + index
775 * where type is a single character (L, I, J, F, D).
776 */
777 private static String makeFieldName(String types, int index) {
778 assert index >= 0 && index < types.length();
779 return "arg" + types.charAt(index) + index;
780 }
781
782 private static String makeSignature(String types, boolean ctor) {
783 StringBuilder buf = new StringBuilder(SIG_INCIPIT);
784 for (char c : types.toCharArray()) {
785 buf.append(typeSig(c));
786 }
787 return buf.append(')').append(ctor ? "V" : BMH_SIG).toString();
788 }
789
790 static MethodHandle makeCbmhCtor(Class<? extends BoundMethodHandle> cbmh, String types) {
791 try {
792 return LOOKUP.findStatic(cbmh, "make", MethodType.fromMethodDescriptorString(makeSignature(types, false), null));
793 } catch (NoSuchMethodException | IllegalAccessException | IllegalArgumentException | TypeNotPresentException e) {
794 throw newInternalError(e);
795 }
796 }
797 }
798
799 private static final Lookup LOOKUP = Lookup.IMPL_LOOKUP;
800
801 /**
802 * All subclasses must provide such a value describing their type signature.
803 */
804 static final SpeciesData SPECIES_DATA = SpeciesData.EMPTY;
805
806 private static final SpeciesData[] SPECIES_DATA_CACHE = new SpeciesData[5];
807 private static SpeciesData checkCache(int size, String types) {
808 int idx = size - 1;
809 SpeciesData data = SPECIES_DATA_CACHE[idx];
810 if (data != null) return data;
811 SPECIES_DATA_CACHE[idx] = data = getSpeciesData(types);
812 return data;
813 }
814 static SpeciesData speciesData_L() { return checkCache(1, "L"); }
815 static SpeciesData speciesData_LL() { return checkCache(2, "LL"); }
816 static SpeciesData speciesData_LLL() { return checkCache(3, "LLL"); }
817 static SpeciesData speciesData_LLLL() { return checkCache(4, "LLLL"); }
818 static SpeciesData speciesData_LLLLL() { return checkCache(5, "LLLLL"); }
819 }