1 /*
2 * Copyright (c) 2008, 2015, 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 assert(speciesData() == speciesData(form));
58 }
59
60 //
61 // BMH API and internals
62 //
63
64 static BoundMethodHandle bindSingle(MethodType type, LambdaForm form, BasicType xtype, Object x) {
65 // for some type signatures, there exist pre-defined concrete BMH classes
66 try {
67 switch (xtype) {
68 case L_TYPE:
69 return bindSingle(type, form, x); // Use known fast path.
70 case I_TYPE:
71 return (BoundMethodHandle) SpeciesData.EMPTY.extendWith(I_TYPE).constructor().invokeBasic(type, form, ValueConversions.widenSubword(x));
72 case J_TYPE:
73 return (BoundMethodHandle) SpeciesData.EMPTY.extendWith(J_TYPE).constructor().invokeBasic(type, form, (long) x);
74 case F_TYPE:
75 return (BoundMethodHandle) SpeciesData.EMPTY.extendWith(F_TYPE).constructor().invokeBasic(type, form, (float) x);
76 case D_TYPE:
77 return (BoundMethodHandle) SpeciesData.EMPTY.extendWith(D_TYPE).constructor().invokeBasic(type, form, (double) x);
78 default : throw newInternalError("unexpected xtype: " + xtype);
79 }
80 } catch (Throwable t) {
81 throw newInternalError(t);
82 }
83 }
84
85 /*non-public*/
86 LambdaFormEditor editor() {
87 return form.editor();
88 }
89
90 static BoundMethodHandle bindSingle(MethodType type, LambdaForm form, Object x) {
91 return Species_L.make(type, form, x);
92 }
93
94 @Override // there is a default binder in the super class, for 'L' types only
95 /*non-public*/
96 BoundMethodHandle bindArgumentL(int pos, Object value) {
97 return editor().bindArgumentL(this, pos, value);
98 }
99 /*non-public*/
100 BoundMethodHandle bindArgumentI(int pos, int value) {
101 return editor().bindArgumentI(this, pos, value);
102 }
103 /*non-public*/
104 BoundMethodHandle bindArgumentJ(int pos, long value) {
105 return editor().bindArgumentJ(this, pos, value);
106 }
107 /*non-public*/
108 BoundMethodHandle bindArgumentF(int pos, float value) {
109 return editor().bindArgumentF(this, pos, value);
110 }
111 /*non-public*/
112 BoundMethodHandle bindArgumentD(int pos, double value) {
113 return editor().bindArgumentD(this, pos, value);
114 }
115
116 @Override
117 BoundMethodHandle rebind() {
118 if (!tooComplex()) {
119 return this;
120 }
121 return makeReinvoker(this);
122 }
123
124 private boolean tooComplex() {
125 return (fieldCount() > FIELD_COUNT_THRESHOLD ||
126 form.expressionCount() > FORM_EXPRESSION_THRESHOLD);
127 }
128 private static final int FIELD_COUNT_THRESHOLD = 12; // largest convenient BMH field count
129 private static final int FORM_EXPRESSION_THRESHOLD = 24; // largest convenient BMH expression count
130
131 /**
132 * A reinvoker MH has this form:
133 * {@code lambda (bmh, arg*) { thismh = bmh[0]; invokeBasic(thismh, arg*) }}
134 */
135 static BoundMethodHandle makeReinvoker(MethodHandle target) {
136 LambdaForm form = DelegatingMethodHandle.makeReinvokerForm(
137 target, MethodTypeForm.LF_REBIND,
138 Species_L.SPECIES_DATA, Species_L.SPECIES_DATA.getterFunction(0));
139 return Species_L.make(target.type(), form, target);
140 }
141
142 /**
143 * Return the {@link SpeciesData} instance representing this BMH species. All subclasses must provide a
144 * static field containing this value, and they must accordingly implement this method.
145 */
146 /*non-public*/ abstract SpeciesData speciesData();
147
148 /*non-public*/ static SpeciesData speciesData(LambdaForm form) {
149 Object c = form.names[0].constraint;
150 if (c instanceof SpeciesData)
151 return (SpeciesData) c;
152 // if there is no BMH constraint, then use the null constraint
153 return SpeciesData.EMPTY;
154 }
155
156 /**
157 * Return the number of fields in this BMH. Equivalent to speciesData().fieldCount().
158 */
159 /*non-public*/ abstract int fieldCount();
160
161 @Override
162 Object internalProperties() {
163 return "\n& BMH="+internalValues();
164 }
165
166 @Override
167 final Object internalValues() {
168 Object[] boundValues = new Object[speciesData().fieldCount()];
169 for (int i = 0; i < boundValues.length; ++i) {
170 boundValues[i] = arg(i);
171 }
172 return Arrays.asList(boundValues);
173 }
174
175 /*non-public*/ final Object arg(int i) {
176 try {
177 switch (speciesData().fieldType(i)) {
178 case L_TYPE: return speciesData().getters[i].invokeBasic(this);
179 case I_TYPE: return (int) speciesData().getters[i].invokeBasic(this);
180 case J_TYPE: return (long) speciesData().getters[i].invokeBasic(this);
181 case F_TYPE: return (float) speciesData().getters[i].invokeBasic(this);
182 case D_TYPE: return (double) speciesData().getters[i].invokeBasic(this);
183 }
184 } catch (Throwable ex) {
185 throw newInternalError(ex);
186 }
187 throw new InternalError("unexpected type: " + speciesData().typeChars+"."+i);
188 }
189
190 //
191 // cloning API
192 //
193
194 /*non-public*/ abstract BoundMethodHandle copyWith(MethodType mt, LambdaForm lf);
195 /*non-public*/ abstract BoundMethodHandle copyWithExtendL(MethodType mt, LambdaForm lf, Object narg);
196 /*non-public*/ abstract BoundMethodHandle copyWithExtendI(MethodType mt, LambdaForm lf, int narg);
197 /*non-public*/ abstract BoundMethodHandle copyWithExtendJ(MethodType mt, LambdaForm lf, long narg);
198 /*non-public*/ abstract BoundMethodHandle copyWithExtendF(MethodType mt, LambdaForm lf, float narg);
199 /*non-public*/ abstract BoundMethodHandle copyWithExtendD(MethodType mt, LambdaForm lf, double narg);
200
201 //
202 // concrete BMH classes required to close bootstrap loops
203 //
204
205 private // make it private to force users to access the enclosing class first
206 static final class Species_L extends BoundMethodHandle {
207 final Object argL0;
208 private Species_L(MethodType mt, LambdaForm lf, Object argL0) {
209 super(mt, lf);
210 this.argL0 = argL0;
211 }
212 @Override
213 /*non-public*/ SpeciesData speciesData() {
214 return SPECIES_DATA;
215 }
216 @Override
217 /*non-public*/ int fieldCount() {
218 return 1;
219 }
220 /*non-public*/ static final SpeciesData SPECIES_DATA = SpeciesData.getForClass("L", Species_L.class);
221 /*non-public*/ static BoundMethodHandle make(MethodType mt, LambdaForm lf, Object argL0) {
222 return new Species_L(mt, lf, argL0);
223 }
224 @Override
225 /*non-public*/ final BoundMethodHandle copyWith(MethodType mt, LambdaForm lf) {
226 return new Species_L(mt, lf, argL0);
227 }
228 @Override
229 /*non-public*/ final BoundMethodHandle copyWithExtendL(MethodType mt, LambdaForm lf, Object narg) {
230 try {
231 return (BoundMethodHandle) SPECIES_DATA.extendWith(L_TYPE).constructor().invokeBasic(mt, lf, argL0, narg);
232 } catch (Throwable ex) {
233 throw uncaughtException(ex);
234 }
235 }
236 @Override
237 /*non-public*/ final BoundMethodHandle copyWithExtendI(MethodType mt, LambdaForm lf, int narg) {
238 try {
239 return (BoundMethodHandle) SPECIES_DATA.extendWith(I_TYPE).constructor().invokeBasic(mt, lf, argL0, narg);
240 } catch (Throwable ex) {
241 throw uncaughtException(ex);
242 }
243 }
244 @Override
245 /*non-public*/ final BoundMethodHandle copyWithExtendJ(MethodType mt, LambdaForm lf, long narg) {
246 try {
247 return (BoundMethodHandle) SPECIES_DATA.extendWith(J_TYPE).constructor().invokeBasic(mt, lf, argL0, narg);
248 } catch (Throwable ex) {
249 throw uncaughtException(ex);
250 }
251 }
252 @Override
253 /*non-public*/ final BoundMethodHandle copyWithExtendF(MethodType mt, LambdaForm lf, float narg) {
254 try {
255 return (BoundMethodHandle) SPECIES_DATA.extendWith(F_TYPE).constructor().invokeBasic(mt, lf, argL0, narg);
256 } catch (Throwable ex) {
257 throw uncaughtException(ex);
258 }
259 }
260 @Override
261 /*non-public*/ final BoundMethodHandle copyWithExtendD(MethodType mt, LambdaForm lf, double narg) {
262 try {
263 return (BoundMethodHandle) SPECIES_DATA.extendWith(D_TYPE).constructor().invokeBasic(mt, lf, argL0, narg);
264 } catch (Throwable ex) {
265 throw uncaughtException(ex);
266 }
267 }
268 }
269
270 //
271 // BMH species meta-data
272 //
273
274 /**
275 * Meta-data wrapper for concrete BMH types.
276 * Each BMH type corresponds to a given sequence of basic field types (LIJFD).
277 * The fields are immutable; their values are fully specified at object construction.
278 * Each BMH type supplies an array of getter functions which may be used in lambda forms.
279 * A BMH is constructed by cloning a shorter BMH and adding one or more new field values.
280 * The shortest possible BMH has zero fields; its class is SimpleMethodHandle.
281 * BMH species are not interrelated by subtyping, even though it would appear that
282 * a shorter BMH could serve as a supertype of a longer one which extends it.
283 */
284 static class SpeciesData {
285 private final String typeChars;
286 private final BasicType[] typeCodes;
287 private final Class<? extends BoundMethodHandle> clazz;
288 // Bootstrapping requires circular relations MH -> BMH -> SpeciesData -> MH
289 // Therefore, we need a non-final link in the chain. Use array elements.
290 @Stable private final MethodHandle[] constructor;
291 @Stable private final MethodHandle[] getters;
292 @Stable private final NamedFunction[] nominalGetters;
293 @Stable private final SpeciesData[] extensions;
294
295 /*non-public*/ int fieldCount() {
296 return typeCodes.length;
297 }
298 /*non-public*/ BasicType fieldType(int i) {
299 return typeCodes[i];
300 }
301 /*non-public*/ char fieldTypeChar(int i) {
302 return typeChars.charAt(i);
303 }
304 Object fieldSignature() {
305 return typeChars;
306 }
307 public Class<? extends BoundMethodHandle> fieldHolder() {
308 return clazz;
309 }
310 public String toString() {
311 return "SpeciesData<"+fieldSignature()+">";
312 }
313
314 /**
315 * Return a {@link LambdaForm.Name} containing a {@link LambdaForm.NamedFunction} that
316 * represents a MH bound to a generic invoker, which in turn forwards to the corresponding
317 * getter.
318 */
319 NamedFunction getterFunction(int i) {
320 NamedFunction nf = nominalGetters[i];
321 assert(nf.memberDeclaringClassOrNull() == fieldHolder());
322 assert(nf.returnType() == fieldType(i));
323 return nf;
324 }
325
326 NamedFunction[] getterFunctions() {
327 return nominalGetters;
328 }
329
330 MethodHandle[] getterHandles() { return getters; }
331
332 MethodHandle constructor() {
333 return constructor[0];
334 }
335
336 static final SpeciesData EMPTY = new SpeciesData("", BoundMethodHandle.class);
337
338 private SpeciesData(String types, Class<? extends BoundMethodHandle> clazz) {
339 this.typeChars = types;
340 this.typeCodes = basicTypes(types);
341 this.clazz = clazz;
342 if (!INIT_DONE) {
343 this.constructor = new MethodHandle[1]; // only one ctor
344 this.getters = new MethodHandle[types.length()];
345 this.nominalGetters = new NamedFunction[types.length()];
346 } else {
347 this.constructor = Factory.makeCtors(clazz, types, null);
348 this.getters = Factory.makeGetters(clazz, types, null);
349 this.nominalGetters = Factory.makeNominalGetters(types, null, this.getters);
350 }
351 this.extensions = new SpeciesData[ARG_TYPE_LIMIT];
352 }
353
354 private void initForBootstrap() {
355 assert(!INIT_DONE);
356 if (constructor() == null) {
357 String types = typeChars;
358 Factory.makeCtors(clazz, types, this.constructor);
359 Factory.makeGetters(clazz, types, this.getters);
360 Factory.makeNominalGetters(types, this.nominalGetters, this.getters);
361 }
362 }
363
364 private SpeciesData(String typeChars) {
365 // Placeholder only.
366 this.typeChars = typeChars;
367 this.typeCodes = basicTypes(typeChars);
368 this.clazz = null;
369 this.constructor = null;
370 this.getters = null;
371 this.nominalGetters = null;
372 this.extensions = null;
373 }
374 private boolean isPlaceholder() { return clazz == null; }
375
376 private static final HashMap<String, SpeciesData> CACHE = new HashMap<>();
377 static { CACHE.put("", EMPTY); } // make bootstrap predictable
378 private static final boolean INIT_DONE; // set after <clinit> finishes...
379
380 SpeciesData extendWith(byte type) {
381 return extendWith(BasicType.basicType(type));
382 }
383
384 SpeciesData extendWith(BasicType type) {
385 int ord = type.ordinal();
386 SpeciesData d = extensions[ord];
387 if (d != null) return d;
388 extensions[ord] = d = get(typeChars+type.basicTypeChar());
389 return d;
390 }
391
392 private static SpeciesData get(String types) {
393 // Acquire cache lock for query.
394 SpeciesData d = lookupCache(types);
395 if (!d.isPlaceholder())
396 return d;
397 synchronized (d) {
398 // Use synch. on the placeholder to prevent multiple instantiation of one species.
399 // Creating this class forces a recursive call to getForClass.
400 if (lookupCache(types).isPlaceholder())
401 Factory.generateConcreteBMHClass(types);
402 }
403 // Reacquire cache lock.
404 d = lookupCache(types);
405 // Class loading must have upgraded the cache.
406 assert(d != null && !d.isPlaceholder());
407 if (OBSERVE_BMH_SPECIES_CREATION) {
408 if (d == null) {
409 throw new IllegalStateException("d == null");
410 }
411 if (d.isPlaceholder()) {
412 throw new IllegalStateException("d is place holder");
413 }
414 }
415 return d;
416 }
417 static SpeciesData getForClass(String types, Class<? extends BoundMethodHandle> clazz) {
418 // clazz is a new class which is initializing its SPECIES_DATA field
419 return updateCache(types, new SpeciesData(types, clazz));
420 }
421 private static synchronized SpeciesData lookupCache(String types) {
422 SpeciesData d = CACHE.get(types);
423 if (d != null) return d;
424 d = new SpeciesData(types);
425 assert(d.isPlaceholder());
426 if (OBSERVE_BMH_SPECIES_CREATION && !d.isPlaceholder()) {
427 throw new IllegalStateException("d is not place holder");
428 }
429 CACHE.put(types, d);
430 return d;
431 }
432 private static synchronized SpeciesData updateCache(String types, SpeciesData d) {
433 SpeciesData d2;
434 assert((d2 = CACHE.get(types)) == null || d2.isPlaceholder());
435 assert(!d.isPlaceholder());
436 if (OBSERVE_BMH_SPECIES_CREATION) {
437 d2 = CACHE.get(types);
438 if (d2 != null && !d2.isPlaceholder()) {
439 throw new IllegalStateException("non-null d2 is not place holder");
440 }
441 if (d.isPlaceholder()) {
442 throw new IllegalStateException("d is place holder");
443 }
444 }
445 CACHE.put(types, d);
446 return d;
447 }
448
449 static {
450 // pre-fill the BMH speciesdata cache with BMH's inner classes
451 final Class<BoundMethodHandle> rootCls = BoundMethodHandle.class;
452 try {
453 for (Class<?> c : rootCls.getDeclaredClasses()) {
454 if (rootCls.isAssignableFrom(c)) {
455 final Class<? extends BoundMethodHandle> cbmh = c.asSubclass(BoundMethodHandle.class);
456 SpeciesData d = Factory.speciesDataFromConcreteBMHClass(cbmh);
457 assert(d != null) : cbmh.getName();
458 assert(d.clazz == cbmh);
459 assert(d == lookupCache(d.typeChars));
460 }
461 }
462 } catch (Throwable e) {
463 throw newInternalError(e);
464 }
465
466 for (SpeciesData d : CACHE.values()) {
467 d.initForBootstrap();
468 }
469 // Note: Do not simplify this, because INIT_DONE must not be
470 // a compile-time constant during bootstrapping.
471 INIT_DONE = Boolean.TRUE;
472 }
473 }
474
475 static SpeciesData getSpeciesData(String types) {
476 return SpeciesData.get(types);
477 }
478
479 /**
480 * Generation of concrete BMH classes.
481 *
482 * A concrete BMH species is fit for binding a number of values adhering to a
483 * given type pattern. Reference types are erased.
484 *
485 * BMH species are cached by type pattern.
486 *
487 * A BMH species has a number of fields with the concrete (possibly erased) types of
488 * bound values. Setters are provided as an API in BMH. Getters are exposed as MHs,
489 * which can be included as names in lambda forms.
490 */
491 static class Factory {
492
493 static final String JLO_SIG = "Ljava/lang/Object;";
494 static final String JLS_SIG = "Ljava/lang/String;";
495 static final String JLC_SIG = "Ljava/lang/Class;";
496 static final String MH = "java/lang/invoke/MethodHandle";
497 static final String MH_SIG = "L"+MH+";";
498 static final String BMH = "java/lang/invoke/BoundMethodHandle";
499 static final String BMH_SIG = "L"+BMH+";";
500 static final String SPECIES_DATA = "java/lang/invoke/BoundMethodHandle$SpeciesData";
501 static final String SPECIES_DATA_SIG = "L"+SPECIES_DATA+";";
502
503 static final String SPECIES_PREFIX_NAME = "Species_";
504 static final String SPECIES_PREFIX_PATH = BMH + "$" + SPECIES_PREFIX_NAME;
505
506 static final String BMHSPECIES_DATA_EWI_SIG = "(B)" + SPECIES_DATA_SIG;
507 static final String BMHSPECIES_DATA_GFC_SIG = "(" + JLS_SIG + JLC_SIG + ")" + SPECIES_DATA_SIG;
508 static final String MYSPECIES_DATA_SIG = "()" + SPECIES_DATA_SIG;
509 static final String VOID_SIG = "()V";
510 static final String INT_SIG = "()I";
511
512 static final String SIG_INCIPIT = "(Ljava/lang/invoke/MethodType;Ljava/lang/invoke/LambdaForm;";
513
514 static final String[] E_THROWABLE = new String[] { "java/lang/Throwable" };
515
516 /**
517 * Generate a concrete subclass of BMH for a given combination of bound types.
518 *
519 * A concrete BMH species adheres to the following schema:
520 *
521 * <pre>
522 * class Species_[[types]] extends BoundMethodHandle {
523 * [[fields]]
524 * final SpeciesData speciesData() { return SpeciesData.get("[[types]]"); }
525 * }
526 * </pre>
527 *
528 * The {@code [[types]]} signature is precisely the string that is passed to this
529 * method.
530 *
531 * The {@code [[fields]]} section consists of one field definition per character in
532 * the type signature, adhering to the naming schema described in the definition of
533 * {@link #makeFieldName}.
534 *
535 * For example, a concrete BMH species for two reference and one integral bound values
536 * would have the following shape:
537 *
538 * <pre>
539 * class BoundMethodHandle { ... private static
540 * final class Species_LLI extends BoundMethodHandle {
541 * final Object argL0;
542 * final Object argL1;
543 * final int argI2;
544 * private Species_LLI(MethodType mt, LambdaForm lf, Object argL0, Object argL1, int argI2) {
545 * super(mt, lf);
546 * this.argL0 = argL0;
547 * this.argL1 = argL1;
548 * this.argI2 = argI2;
549 * }
550 * final SpeciesData speciesData() { return SPECIES_DATA; }
551 * final int fieldCount() { return 3; }
552 * static final SpeciesData SPECIES_DATA = SpeciesData.getForClass("LLI", Species_LLI.class);
553 * static BoundMethodHandle make(MethodType mt, LambdaForm lf, Object argL0, Object argL1, int argI2) {
554 * return new Species_LLI(mt, lf, argL0, argL1, argI2);
555 * }
556 * final BoundMethodHandle copyWith(MethodType mt, LambdaForm lf) {
557 * return new Species_LLI(mt, lf, argL0, argL1, argI2);
558 * }
559 * final BoundMethodHandle copyWithExtendL(MethodType mt, LambdaForm lf, Object narg) {
560 * return SPECIES_DATA.extendWith(L_TYPE).constructor().invokeBasic(mt, lf, argL0, argL1, argI2, narg);
561 * }
562 * final BoundMethodHandle copyWithExtendI(MethodType mt, LambdaForm lf, int narg) {
563 * return SPECIES_DATA.extendWith(I_TYPE).constructor().invokeBasic(mt, lf, argL0, argL1, argI2, narg);
564 * }
565 * final BoundMethodHandle copyWithExtendJ(MethodType mt, LambdaForm lf, long narg) {
566 * return SPECIES_DATA.extendWith(J_TYPE).constructor().invokeBasic(mt, lf, argL0, argL1, argI2, narg);
567 * }
568 * final BoundMethodHandle copyWithExtendF(MethodType mt, LambdaForm lf, float narg) {
569 * return SPECIES_DATA.extendWith(F_TYPE).constructor().invokeBasic(mt, lf, argL0, argL1, argI2, narg);
570 * }
571 * public final BoundMethodHandle copyWithExtendD(MethodType mt, LambdaForm lf, double narg) {
572 * return SPECIES_DATA.extendWith(D_TYPE).constructor().invokeBasic(mt, lf, argL0, argL1, argI2, narg);
573 * }
574 * }
575 * </pre>
576 *
577 * @param types the type signature, wherein reference types are erased to 'L'
578 * @return the generated concrete BMH class
579 */
580 static Class<? extends BoundMethodHandle> generateConcreteBMHClass(String types) {
581 final ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES);
582
583 String shortTypes = LambdaForm.shortenSignature(types);
584 final String className = SPECIES_PREFIX_PATH + shortTypes;
585 final String sourceFile = SPECIES_PREFIX_NAME + shortTypes;
586 final int NOT_ACC_PUBLIC = 0; // not ACC_PUBLIC
587 cw.visit(V1_6, NOT_ACC_PUBLIC + ACC_FINAL + ACC_SUPER, className, null, BMH, null);
588 cw.visitSource(sourceFile, null);
589
590 // emit static types and SPECIES_DATA fields
591 cw.visitField(NOT_ACC_PUBLIC + ACC_STATIC, "SPECIES_DATA", SPECIES_DATA_SIG, null, null).visitEnd();
592
593 // emit bound argument fields
594 for (int i = 0; i < types.length(); ++i) {
595 final char t = types.charAt(i);
596 final String fieldName = makeFieldName(types, i);
597 final String fieldDesc = t == 'L' ? JLO_SIG : String.valueOf(t);
598 cw.visitField(ACC_FINAL, fieldName, fieldDesc, null, null).visitEnd();
599 }
600
601 MethodVisitor mv;
602
603 // emit constructor
604 mv = cw.visitMethod(ACC_PRIVATE, "<init>", makeSignature(types, true), null, null);
605 mv.visitCode();
606 mv.visitVarInsn(ALOAD, 0); // this
607 mv.visitVarInsn(ALOAD, 1); // type
608 mv.visitVarInsn(ALOAD, 2); // form
609
610 mv.visitMethodInsn(INVOKESPECIAL, BMH, "<init>", makeSignature("", true), false);
611
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(ALOAD, 0);
616 mv.visitVarInsn(typeLoadOp(t), j + 3); // parameters start at 3
617 mv.visitFieldInsn(PUTFIELD, className, makeFieldName(types, i), typeSig(t));
618 if (t == 'J' || t == 'D') {
619 ++j; // adjust argument register access
620 }
621 }
622
623 mv.visitInsn(RETURN);
624 mv.visitMaxs(0, 0);
625 mv.visitEnd();
626
627 // emit implementation of speciesData()
628 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_FINAL, "speciesData", MYSPECIES_DATA_SIG, null, null);
629 mv.visitCode();
630 mv.visitFieldInsn(GETSTATIC, className, "SPECIES_DATA", SPECIES_DATA_SIG);
631 mv.visitInsn(ARETURN);
632 mv.visitMaxs(0, 0);
633 mv.visitEnd();
634
635 // emit implementation of fieldCount()
636 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_FINAL, "fieldCount", INT_SIG, null, null);
637 mv.visitCode();
638 int fc = types.length();
639 if (fc <= (ICONST_5 - ICONST_0)) {
640 mv.visitInsn(ICONST_0 + fc);
641 } else {
642 mv.visitIntInsn(SIPUSH, fc);
643 }
644 mv.visitInsn(IRETURN);
645 mv.visitMaxs(0, 0);
646 mv.visitEnd();
647 // emit make() ...factory method wrapping constructor
648 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_STATIC, "make", makeSignature(types, false), null, null);
649 mv.visitCode();
650 // make instance
651 mv.visitTypeInsn(NEW, className);
652 mv.visitInsn(DUP);
653 // load mt, lf
654 mv.visitVarInsn(ALOAD, 0); // type
655 mv.visitVarInsn(ALOAD, 1); // form
656 // load factory method arguments
657 for (int i = 0, j = 0; i < types.length(); ++i, ++j) {
658 // i counts the arguments, j counts corresponding argument slots
659 char t = types.charAt(i);
660 mv.visitVarInsn(typeLoadOp(t), j + 2); // parameters start at 3
661 if (t == 'J' || t == 'D') {
662 ++j; // adjust argument register access
663 }
664 }
665
666 // finally, invoke the constructor and return
667 mv.visitMethodInsn(INVOKESPECIAL, className, "<init>", makeSignature(types, true), false);
668 mv.visitInsn(ARETURN);
669 mv.visitMaxs(0, 0);
670 mv.visitEnd();
671
672 // emit copyWith()
673 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_FINAL, "copyWith", makeSignature("", false), null, null);
674 mv.visitCode();
675 // make instance
676 mv.visitTypeInsn(NEW, className);
677 mv.visitInsn(DUP);
678 // load mt, lf
679 mv.visitVarInsn(ALOAD, 1);
680 mv.visitVarInsn(ALOAD, 2);
681 // put fields on the stack
682 emitPushFields(types, className, mv);
683 // finally, invoke the constructor and return
684 mv.visitMethodInsn(INVOKESPECIAL, className, "<init>", makeSignature(types, true), false);
685 mv.visitInsn(ARETURN);
686 mv.visitMaxs(0, 0);
687 mv.visitEnd();
688
689 // for each type, emit copyWithExtendT()
690 for (BasicType type : BasicType.ARG_TYPES) {
691 int ord = type.ordinal();
692 char btChar = type.basicTypeChar();
693 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_FINAL, "copyWithExtend" + btChar, makeSignature(String.valueOf(btChar), false), null, E_THROWABLE);
694 mv.visitCode();
695 // return SPECIES_DATA.extendWith(t).constructor().invokeBasic(mt, lf, argL0, ..., narg)
696 // obtain constructor
697 mv.visitFieldInsn(GETSTATIC, className, "SPECIES_DATA", SPECIES_DATA_SIG);
698 int iconstInsn = ICONST_0 + ord;
699 assert(iconstInsn <= ICONST_5);
700 mv.visitInsn(iconstInsn);
701 mv.visitMethodInsn(INVOKEVIRTUAL, SPECIES_DATA, "extendWith", BMHSPECIES_DATA_EWI_SIG, false);
702 mv.visitMethodInsn(INVOKEVIRTUAL, SPECIES_DATA, "constructor", "()" + MH_SIG, false);
703 // load mt, lf
704 mv.visitVarInsn(ALOAD, 1);
705 mv.visitVarInsn(ALOAD, 2);
706 // put fields on the stack
707 emitPushFields(types, className, mv);
708 // put narg on stack
709 mv.visitVarInsn(typeLoadOp(btChar), 3);
710 // finally, invoke the constructor and return
711 mv.visitMethodInsn(INVOKEVIRTUAL, MH, "invokeBasic", makeSignature(types + btChar, false), false);
712 mv.visitInsn(ARETURN);
713 mv.visitMaxs(0, 0);
714 mv.visitEnd();
715 }
716
717 // emit class initializer
718 mv = cw.visitMethod(NOT_ACC_PUBLIC | ACC_STATIC, "<clinit>", VOID_SIG, null, null);
719 mv.visitCode();
720 mv.visitLdcInsn(types);
721 mv.visitLdcInsn(Type.getObjectType(className));
722 mv.visitMethodInsn(INVOKESTATIC, SPECIES_DATA, "getForClass", BMHSPECIES_DATA_GFC_SIG, false);
723 mv.visitFieldInsn(PUTSTATIC, className, "SPECIES_DATA", SPECIES_DATA_SIG);
724 mv.visitInsn(RETURN);
725 mv.visitMaxs(0, 0);
726 mv.visitEnd();
727
728 cw.visitEnd();
729
730 // load class
731 final byte[] classFile = cw.toByteArray();
732 InvokerBytecodeGenerator.maybeDump(className, classFile);
733 Class<? extends BoundMethodHandle> bmhClass =
734 //UNSAFE.defineAnonymousClass(BoundMethodHandle.class, classFile, null).asSubclass(BoundMethodHandle.class);
735 UNSAFE.defineClass(className, classFile, 0, classFile.length,
736 BoundMethodHandle.class.getClassLoader(), null)
737 .asSubclass(BoundMethodHandle.class);
738 UNSAFE.ensureClassInitialized(bmhClass);
739
740 return bmhClass;
741 }
742
743 private static int typeLoadOp(char t) {
744 switch (t) {
745 case 'L': return ALOAD;
746 case 'I': return ILOAD;
747 case 'J': return LLOAD;
748 case 'F': return FLOAD;
749 case 'D': return DLOAD;
750 default : throw newInternalError("unrecognized type " + t);
751 }
752 }
753
754 private static void emitPushFields(String types, String className, MethodVisitor mv) {
755 for (int i = 0; i < types.length(); ++i) {
756 char tc = types.charAt(i);
757 mv.visitVarInsn(ALOAD, 0);
758 mv.visitFieldInsn(GETFIELD, className, makeFieldName(types, i), typeSig(tc));
759 }
760 }
761
762 static String typeSig(char t) {
763 return t == 'L' ? JLO_SIG : String.valueOf(t);
764 }
765
766 //
767 // Getter MH generation.
768 //
769
770 private static MethodHandle makeGetter(Class<?> cbmhClass, String types, int index) {
771 String fieldName = makeFieldName(types, index);
772 Class<?> fieldType = Wrapper.forBasicType(types.charAt(index)).primitiveType();
773 try {
774 return LOOKUP.findGetter(cbmhClass, fieldName, fieldType);
775 } catch (NoSuchFieldException | IllegalAccessException e) {
776 throw newInternalError(e);
777 }
778 }
779
780 static MethodHandle[] makeGetters(Class<?> cbmhClass, String types, MethodHandle[] mhs) {
781 if (mhs == null) mhs = new MethodHandle[types.length()];
782 for (int i = 0; i < mhs.length; ++i) {
783 mhs[i] = makeGetter(cbmhClass, types, i);
784 assert(mhs[i].internalMemberName().getDeclaringClass() == cbmhClass);
785 }
786 return mhs;
787 }
788
789 static MethodHandle[] makeCtors(Class<? extends BoundMethodHandle> cbmh, String types, MethodHandle mhs[]) {
790 if (mhs == null) mhs = new MethodHandle[1];
791 if (types.equals("")) return mhs; // hack for empty BMH species
792 mhs[0] = makeCbmhCtor(cbmh, types);
793 return mhs;
794 }
795
796 static NamedFunction[] makeNominalGetters(String types, NamedFunction[] nfs, MethodHandle[] getters) {
797 if (nfs == null) nfs = new NamedFunction[types.length()];
798 for (int i = 0; i < nfs.length; ++i) {
799 nfs[i] = new NamedFunction(getters[i]);
800 }
801 return nfs;
802 }
803
804 //
805 // Auxiliary methods.
806 //
807
808 static SpeciesData speciesDataFromConcreteBMHClass(Class<? extends BoundMethodHandle> cbmh) {
809 try {
810 Field F_SPECIES_DATA = cbmh.getDeclaredField("SPECIES_DATA");
811 return (SpeciesData) F_SPECIES_DATA.get(null);
812 } catch (ReflectiveOperationException ex) {
813 throw newInternalError(ex);
814 }
815 }
816
817 /**
818 * Field names in concrete BMHs adhere to this pattern:
819 * arg + type + index
820 * where type is a single character (L, I, J, F, D).
821 */
822 private static String makeFieldName(String types, int index) {
823 assert index >= 0 && index < types.length();
824 return "arg" + types.charAt(index) + index;
825 }
826
827 private static String makeSignature(String types, boolean ctor) {
828 StringBuilder buf = new StringBuilder(SIG_INCIPIT);
829 for (char c : types.toCharArray()) {
830 buf.append(typeSig(c));
831 }
832 return buf.append(')').append(ctor ? "V" : BMH_SIG).toString();
833 }
834
835 static MethodHandle makeCbmhCtor(Class<? extends BoundMethodHandle> cbmh, String types) {
836 try {
837 return LOOKUP.findStatic(cbmh, "make", MethodType.fromDescriptor(makeSignature(types, false), null));
838 } catch (NoSuchMethodException | IllegalAccessException | IllegalArgumentException | TypeNotPresentException e) {
839 throw newInternalError(e);
840 }
841 }
842 }
843
844 private static final Lookup LOOKUP = Lookup.IMPL_LOOKUP;
845
846 /**
847 * All subclasses must provide such a value describing their type signature.
848 */
849 static final SpeciesData SPECIES_DATA = SpeciesData.EMPTY;
850
851 private static final SpeciesData[] SPECIES_DATA_CACHE = new SpeciesData[5];
852 private static SpeciesData checkCache(int size, String types) {
853 int idx = size - 1;
854 SpeciesData data = SPECIES_DATA_CACHE[idx];
855 if (data != null) return data;
856 SPECIES_DATA_CACHE[idx] = data = getSpeciesData(types);
857 return data;
858 }
859 static SpeciesData speciesData_L() { return checkCache(1, "L"); }
860 static SpeciesData speciesData_LL() { return checkCache(2, "LL"); }
861 static SpeciesData speciesData_LLL() { return checkCache(3, "LLL"); }
862 static SpeciesData speciesData_LLLL() { return checkCache(4, "LLLL"); }
863 static SpeciesData speciesData_LLLLL() { return checkCache(5, "LLLLL"); }
864 }