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 private static final HashMap<String, VirtualMachineError> FAILED_SPECIES_CACHE = new HashMap<>();
378 static { CACHE.put("", EMPTY); } // make bootstrap predictable
379 private static final boolean INIT_DONE; // set after <clinit> finishes...
380
381 SpeciesData extendWith(byte type) {
382 return extendWith(BasicType.basicType(type));
383 }
384
385 SpeciesData extendWith(BasicType type) {
386 int ord = type.ordinal();
387 SpeciesData d = extensions[ord];
388 if (d != null) return d;
389 extensions[ord] = d = get(typeChars+type.basicTypeChar());
390 return d;
391 }
392
393 private static SpeciesData get(String types) {
394 // Acquire cache lock for query.
395 SpeciesData d = lookupCache(types);
396 if (!d.isPlaceholder())
397 return d;
398 synchronized (d) {
399 VirtualMachineError previousFailure;
400 if ((previousFailure = FAILED_SPECIES_CACHE.get(types)) != null) {
401 throw new InternalError("species creation for " + types + " failed previously", previousFailure);
402 }
403 // Use synch. on the placeholder to prevent multiple instantiation of one species.
404 SpeciesData d2 = lookupCache(types);
405 if (d2.isPlaceholder()) {
406 try {
407 Class<? extends BoundMethodHandle> bmhcl = Factory.generateConcreteBMHClass(types);
408 // install new SpeciesData into cache
409 d2 = Factory.speciesDataFromConcreteBMHClass(bmhcl);
410 assert(!d2.isPlaceholder());
411 updateCache(d2.typeChars, d2);
412 } catch (VirtualMachineError vme) {
413 // The species is not registered in the cache if something went wrong during class definition or
414 // initialization. Register it in the failure cache for future reference, and throw the VME.
415 FAILED_SPECIES_CACHE.put(types, vme);
416 throw vme;
417 }
418 }
419 d = d2;
420 }
421 return d;
422 }
423 static SpeciesData getForClass(String types, Class<? extends BoundMethodHandle> clazz) {
424 // clazz is a new class which is initializing its SPECIES_DATA field
425 return new SpeciesData(types, clazz);
426 }
427 private static synchronized SpeciesData lookupCache(String types) {
428 SpeciesData d = CACHE.get(types);
429 if (d != null) return d;
430 d = new SpeciesData(types);
431 assert(d.isPlaceholder());
432 CACHE.put(types, d);
433 return d;
434 }
435 private static synchronized SpeciesData updateCache(String types, SpeciesData d) {
436 SpeciesData d2;
437 assert((d2 = CACHE.get(types)) == null || d2.isPlaceholder());
438 assert(!d.isPlaceholder());
439 CACHE.put(types, d);
440 return d;
441 }
442
443 /**
444 * This is to be called when assertions are enabled. It checks whether SpeciesData for all of the statically
445 * defined species subclasses of BoundMethodHandle has been added to the SpeciesData cache. See below in the
446 * static initializer for
447 */
448 static boolean speciesDataCachePopulated() {
449 Class<BoundMethodHandle> rootCls = BoundMethodHandle.class;
450 try {
451 for (Class<?> c : rootCls.getDeclaredClasses()) {
452 if (rootCls.isAssignableFrom(c)) {
453 final Class<? extends BoundMethodHandle> cbmh = c.asSubclass(BoundMethodHandle.class);
454 SpeciesData d = Factory.speciesDataFromConcreteBMHClass(cbmh);
455 assert(d != null) : cbmh.getName();
456 assert(d.clazz == cbmh);
457 assert(CACHE.get(d.typeChars) == d);
458 }
459 }
460 } catch (Throwable e) {
461 throw newInternalError(e);
462 }
463 return true;
464 }
465
466 static {
467 // Pre-fill the BMH species-data cache with BMH's inner subclasses. All of these classes' SPECIES_DATA
468 // fields must be added to the staticSpeciesData array to ensure proper cache population.
469 SpeciesData[] staticSpeciesData = new SpeciesData[]{Species_L.SPECIES_DATA};
470 for (SpeciesData d : staticSpeciesData) {
471 updateCache(d.typeChars, d);
472 }
473 for (SpeciesData d : CACHE.values()) {
474 d.initForBootstrap();
475 }
476 assert speciesDataCachePopulated();
477 // Note: Do not simplify this, because INIT_DONE must not be
478 // a compile-time constant during bootstrapping.
479 INIT_DONE = Boolean.TRUE;
480 }
481 }
482
483 static SpeciesData getSpeciesData(String types) {
484 return SpeciesData.get(types);
485 }
486
487 /**
488 * Generation of concrete BMH classes.
489 *
490 * A concrete BMH species is fit for binding a number of values adhering to a
491 * given type pattern. Reference types are erased.
492 *
493 * BMH species are cached by type pattern.
494 *
495 * A BMH species has a number of fields with the concrete (possibly erased) types of
496 * bound values. Setters are provided as an API in BMH. Getters are exposed as MHs,
497 * which can be included as names in lambda forms.
498 */
499 static class Factory {
500
501 static final String JLO_SIG = "Ljava/lang/Object;";
502 static final String JLS_SIG = "Ljava/lang/String;";
503 static final String JLC_SIG = "Ljava/lang/Class;";
504 static final String MH = "java/lang/invoke/MethodHandle";
505 static final String MH_SIG = "L"+MH+";";
506 static final String BMH = "java/lang/invoke/BoundMethodHandle";
507 static final String BMH_SIG = "L"+BMH+";";
508 static final String SPECIES_DATA = "java/lang/invoke/BoundMethodHandle$SpeciesData";
509 static final String SPECIES_DATA_SIG = "L"+SPECIES_DATA+";";
510
511 static final String SPECIES_PREFIX_NAME = "Species_";
512 static final String SPECIES_PREFIX_PATH = BMH + "$" + SPECIES_PREFIX_NAME;
513
514 static final String BMHSPECIES_DATA_EWI_SIG = "(B)" + SPECIES_DATA_SIG;
515 static final String BMHSPECIES_DATA_GFC_SIG = "(" + JLS_SIG + JLC_SIG + ")" + SPECIES_DATA_SIG;
516 static final String MYSPECIES_DATA_SIG = "()" + SPECIES_DATA_SIG;
517 static final String VOID_SIG = "()V";
518 static final String INT_SIG = "()I";
519
520 static final String SIG_INCIPIT = "(Ljava/lang/invoke/MethodType;Ljava/lang/invoke/LambdaForm;";
521
522 static final String[] E_THROWABLE = new String[] { "java/lang/Throwable" };
523
524 /**
525 * Generate a concrete subclass of BMH for a given combination of bound types.
526 *
527 * A concrete BMH species adheres to the following schema:
528 *
529 * <pre>
530 * class Species_[[types]] extends BoundMethodHandle {
531 * [[fields]]
532 * final SpeciesData speciesData() { return SpeciesData.get("[[types]]"); }
533 * }
534 * </pre>
535 *
536 * The {@code [[types]]} signature is precisely the string that is passed to this
537 * method.
538 *
539 * The {@code [[fields]]} section consists of one field definition per character in
540 * the type signature, adhering to the naming schema described in the definition of
541 * {@link #makeFieldName}.
542 *
543 * For example, a concrete BMH species for two reference and one integral bound values
544 * would have the following shape:
545 *
546 * <pre>
547 * class BoundMethodHandle { ... private static
548 * final class Species_LLI extends BoundMethodHandle {
549 * final Object argL0;
550 * final Object argL1;
551 * final int argI2;
552 * private Species_LLI(MethodType mt, LambdaForm lf, Object argL0, Object argL1, int argI2) {
553 * super(mt, lf);
554 * this.argL0 = argL0;
555 * this.argL1 = argL1;
556 * this.argI2 = argI2;
557 * }
558 * final SpeciesData speciesData() { return SPECIES_DATA; }
559 * final int fieldCount() { return 3; }
560 * static final SpeciesData SPECIES_DATA = SpeciesData.getForClass("LLI", Species_LLI.class);
561 * static BoundMethodHandle make(MethodType mt, LambdaForm lf, Object argL0, Object argL1, int argI2) {
562 * return new Species_LLI(mt, lf, argL0, argL1, argI2);
563 * }
564 * final BoundMethodHandle copyWith(MethodType mt, LambdaForm lf) {
565 * return new Species_LLI(mt, lf, argL0, argL1, argI2);
566 * }
567 * final BoundMethodHandle copyWithExtendL(MethodType mt, LambdaForm lf, Object narg) {
568 * return SPECIES_DATA.extendWith(L_TYPE).constructor().invokeBasic(mt, lf, argL0, argL1, argI2, narg);
569 * }
570 * final BoundMethodHandle copyWithExtendI(MethodType mt, LambdaForm lf, int narg) {
571 * return SPECIES_DATA.extendWith(I_TYPE).constructor().invokeBasic(mt, lf, argL0, argL1, argI2, narg);
572 * }
573 * final BoundMethodHandle copyWithExtendJ(MethodType mt, LambdaForm lf, long narg) {
574 * return SPECIES_DATA.extendWith(J_TYPE).constructor().invokeBasic(mt, lf, argL0, argL1, argI2, narg);
575 * }
576 * final BoundMethodHandle copyWithExtendF(MethodType mt, LambdaForm lf, float narg) {
577 * return SPECIES_DATA.extendWith(F_TYPE).constructor().invokeBasic(mt, lf, argL0, argL1, argI2, narg);
578 * }
579 * public final BoundMethodHandle copyWithExtendD(MethodType mt, LambdaForm lf, double narg) {
580 * return SPECIES_DATA.extendWith(D_TYPE).constructor().invokeBasic(mt, lf, argL0, argL1, argI2, narg);
581 * }
582 * }
583 * </pre>
584 *
585 * @param types the type signature, wherein reference types are erased to 'L'
586 * @return the generated concrete BMH class
587 */
588 static Class<? extends BoundMethodHandle> generateConcreteBMHClass(String types) {
589 final ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES);
590
591 String shortTypes = LambdaForm.shortenSignature(types);
592 final String className = SPECIES_PREFIX_PATH + shortTypes;
593 final String sourceFile = SPECIES_PREFIX_NAME + shortTypes;
594 final int NOT_ACC_PUBLIC = 0; // not ACC_PUBLIC
595 cw.visit(V1_6, NOT_ACC_PUBLIC + ACC_FINAL + ACC_SUPER, className, null, BMH, null);
596 cw.visitSource(sourceFile, null);
597
598 // emit static types and SPECIES_DATA fields
599 cw.visitField(NOT_ACC_PUBLIC + ACC_STATIC, "SPECIES_DATA", SPECIES_DATA_SIG, null, null).visitEnd();
600
601 // emit bound argument fields
602 for (int i = 0; i < types.length(); ++i) {
603 final char t = types.charAt(i);
604 final String fieldName = makeFieldName(types, i);
605 final String fieldDesc = t == 'L' ? JLO_SIG : String.valueOf(t);
606 cw.visitField(ACC_FINAL, fieldName, fieldDesc, null, null).visitEnd();
607 }
608
609 MethodVisitor mv;
610
611 // emit constructor
612 mv = cw.visitMethod(ACC_PRIVATE, "<init>", makeSignature(types, true), null, null);
613 mv.visitCode();
614 mv.visitVarInsn(ALOAD, 0); // this
615 mv.visitVarInsn(ALOAD, 1); // type
616 mv.visitVarInsn(ALOAD, 2); // form
617 mv.visitMethodInsn(INVOKESPECIAL, BMH, "<init>", makeSignature("", true), false);
618 for (int i = 0, j = 0; i < types.length(); ++i, ++j) {
619 // i counts the arguments, j counts corresponding argument slots
620 char t = types.charAt(i);
621 mv.visitVarInsn(ALOAD, 0);
622 mv.visitVarInsn(typeLoadOp(t), j + 3); // parameters start at 3
623 mv.visitFieldInsn(PUTFIELD, className, makeFieldName(types, i), typeSig(t));
624 if (t == 'J' || t == 'D') {
625 ++j; // adjust argument register access
626 }
627 }
628 mv.visitInsn(RETURN);
629 mv.visitMaxs(0, 0);
630 mv.visitEnd();
631
632 // emit implementation of speciesData()
633 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_FINAL, "speciesData", MYSPECIES_DATA_SIG, null, null);
634 mv.visitCode();
635 mv.visitFieldInsn(GETSTATIC, className, "SPECIES_DATA", SPECIES_DATA_SIG);
636 mv.visitInsn(ARETURN);
637 mv.visitMaxs(0, 0);
638 mv.visitEnd();
639
640 // emit implementation of fieldCount()
641 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_FINAL, "fieldCount", INT_SIG, null, null);
642 mv.visitCode();
643 int fc = types.length();
644 if (fc <= (ICONST_5 - ICONST_0)) {
645 mv.visitInsn(ICONST_0 + fc);
646 } else {
647 mv.visitIntInsn(SIPUSH, fc);
648 }
649 mv.visitInsn(IRETURN);
650 mv.visitMaxs(0, 0);
651 mv.visitEnd();
652
653 // emit make() ...factory method wrapping constructor
654 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_STATIC, "make", makeSignature(types, false), null, null);
655 mv.visitCode();
656 // make instance
657 mv.visitTypeInsn(NEW, className);
658 mv.visitInsn(DUP);
659 // load mt, lf
660 mv.visitVarInsn(ALOAD, 0); // type
661 mv.visitVarInsn(ALOAD, 1); // form
662 // load factory method arguments
663 for (int i = 0, j = 0; i < types.length(); ++i, ++j) {
664 // i counts the arguments, j counts corresponding argument slots
665 char t = types.charAt(i);
666 mv.visitVarInsn(typeLoadOp(t), j + 2); // parameters start at 3
667 if (t == 'J' || t == 'D') {
668 ++j; // adjust argument register access
669 }
670 }
671 // finally, invoke the constructor and return
672 mv.visitMethodInsn(INVOKESPECIAL, className, "<init>", makeSignature(types, true), false);
673 mv.visitInsn(ARETURN);
674 mv.visitMaxs(0, 0);
675 mv.visitEnd();
676
677 // emit copyWith()
678 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_FINAL, "copyWith", makeSignature("", false), null, null);
679 mv.visitCode();
680 // make instance
681 mv.visitTypeInsn(NEW, className);
682 mv.visitInsn(DUP);
683 // load mt, lf
684 mv.visitVarInsn(ALOAD, 1);
685 mv.visitVarInsn(ALOAD, 2);
686 // put fields on the stack
687 emitPushFields(types, className, mv);
688 // finally, invoke the constructor and return
689 mv.visitMethodInsn(INVOKESPECIAL, className, "<init>", makeSignature(types, true), false);
690 mv.visitInsn(ARETURN);
691 mv.visitMaxs(0, 0);
692 mv.visitEnd();
693
694 // for each type, emit copyWithExtendT()
695 for (BasicType type : BasicType.ARG_TYPES) {
696 int ord = type.ordinal();
697 char btChar = type.basicTypeChar();
698 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_FINAL, "copyWithExtend" + btChar, makeSignature(String.valueOf(btChar), false), null, E_THROWABLE);
699 mv.visitCode();
700 // return SPECIES_DATA.extendWith(t).constructor().invokeBasic(mt, lf, argL0, ..., narg)
701 // obtain constructor
702 mv.visitFieldInsn(GETSTATIC, className, "SPECIES_DATA", SPECIES_DATA_SIG);
703 int iconstInsn = ICONST_0 + ord;
704 assert(iconstInsn <= ICONST_5);
705 mv.visitInsn(iconstInsn);
706 mv.visitMethodInsn(INVOKEVIRTUAL, SPECIES_DATA, "extendWith", BMHSPECIES_DATA_EWI_SIG, false);
707 mv.visitMethodInsn(INVOKEVIRTUAL, SPECIES_DATA, "constructor", "()" + MH_SIG, false);
708 // load mt, lf
709 mv.visitVarInsn(ALOAD, 1);
710 mv.visitVarInsn(ALOAD, 2);
711 // put fields on the stack
712 emitPushFields(types, className, mv);
713 // put narg on stack
714 mv.visitVarInsn(typeLoadOp(btChar), 3);
715 // finally, invoke the constructor and return
716 mv.visitMethodInsn(INVOKEVIRTUAL, MH, "invokeBasic", makeSignature(types + btChar, false), false);
717 mv.visitInsn(ARETURN);
718 mv.visitMaxs(0, 0);
719 mv.visitEnd();
720 }
721
722 // emit class initializer
723 mv = cw.visitMethod(NOT_ACC_PUBLIC | ACC_STATIC, "<clinit>", VOID_SIG, null, null);
724 mv.visitCode();
725 mv.visitLdcInsn(types);
726 mv.visitLdcInsn(Type.getObjectType(className));
727 mv.visitMethodInsn(INVOKESTATIC, SPECIES_DATA, "getForClass", BMHSPECIES_DATA_GFC_SIG, false);
728 mv.visitFieldInsn(PUTSTATIC, className, "SPECIES_DATA", SPECIES_DATA_SIG);
729 mv.visitInsn(RETURN);
730 mv.visitMaxs(0, 0);
731 mv.visitEnd();
732
733 cw.visitEnd();
734
735 // load class
736 final byte[] classFile = cw.toByteArray();
737 InvokerBytecodeGenerator.maybeDump(className, classFile);
738 Class<? extends BoundMethodHandle> bmhClass =
739 //UNSAFE.defineAnonymousClass(BoundMethodHandle.class, classFile, null).asSubclass(BoundMethodHandle.class);
740 UNSAFE.defineClass(className, classFile, 0, classFile.length,
741 BoundMethodHandle.class.getClassLoader(), null)
742 .asSubclass(BoundMethodHandle.class);
743 UNSAFE.ensureClassInitialized(bmhClass);
744
745 return bmhClass;
746 }
747
748 private static int typeLoadOp(char t) {
749 switch (t) {
750 case 'L': return ALOAD;
751 case 'I': return ILOAD;
752 case 'J': return LLOAD;
753 case 'F': return FLOAD;
754 case 'D': return DLOAD;
755 default : throw newInternalError("unrecognized type " + t);
756 }
757 }
758
759 private static void emitPushFields(String types, String className, MethodVisitor mv) {
760 for (int i = 0; i < types.length(); ++i) {
761 char tc = types.charAt(i);
762 mv.visitVarInsn(ALOAD, 0);
763 mv.visitFieldInsn(GETFIELD, className, makeFieldName(types, i), typeSig(tc));
764 }
765 }
766
767 static String typeSig(char t) {
768 return t == 'L' ? JLO_SIG : String.valueOf(t);
769 }
770
771 //
772 // Getter MH generation.
773 //
774
775 private static MethodHandle makeGetter(Class<?> cbmhClass, String types, int index) {
776 String fieldName = makeFieldName(types, index);
777 Class<?> fieldType = Wrapper.forBasicType(types.charAt(index)).primitiveType();
778 try {
779 return LOOKUP.findGetter(cbmhClass, fieldName, fieldType);
780 } catch (NoSuchFieldException | IllegalAccessException e) {
781 throw newInternalError(e);
782 }
783 }
784
785 static MethodHandle[] makeGetters(Class<?> cbmhClass, String types, MethodHandle[] mhs) {
786 if (mhs == null) mhs = new MethodHandle[types.length()];
787 for (int i = 0; i < mhs.length; ++i) {
788 mhs[i] = makeGetter(cbmhClass, types, i);
789 assert(mhs[i].internalMemberName().getDeclaringClass() == cbmhClass);
790 }
791 return mhs;
792 }
793
794 static MethodHandle[] makeCtors(Class<? extends BoundMethodHandle> cbmh, String types, MethodHandle mhs[]) {
795 if (mhs == null) mhs = new MethodHandle[1];
796 if (types.equals("")) return mhs; // hack for empty BMH species
797 mhs[0] = makeCbmhCtor(cbmh, types);
798 return mhs;
799 }
800
801 static NamedFunction[] makeNominalGetters(String types, NamedFunction[] nfs, MethodHandle[] getters) {
802 if (nfs == null) nfs = new NamedFunction[types.length()];
803 for (int i = 0; i < nfs.length; ++i) {
804 nfs[i] = new NamedFunction(getters[i]);
805 }
806 return nfs;
807 }
808
809 //
810 // Auxiliary methods.
811 //
812
813 static SpeciesData speciesDataFromConcreteBMHClass(Class<? extends BoundMethodHandle> cbmh) {
814 try {
815 Field F_SPECIES_DATA = cbmh.getDeclaredField("SPECIES_DATA");
816 return (SpeciesData) F_SPECIES_DATA.get(null);
817 } catch (ReflectiveOperationException ex) {
818 throw newInternalError(ex);
819 }
820 }
821
822 /**
823 * Field names in concrete BMHs adhere to this pattern:
824 * arg + type + index
825 * where type is a single character (L, I, J, F, D).
826 */
827 private static String makeFieldName(String types, int index) {
828 assert index >= 0 && index < types.length();
829 return "arg" + types.charAt(index) + index;
830 }
831
832 private static String makeSignature(String types, boolean ctor) {
833 StringBuilder buf = new StringBuilder(SIG_INCIPIT);
834 for (char c : types.toCharArray()) {
835 buf.append(typeSig(c));
836 }
837 return buf.append(')').append(ctor ? "V" : BMH_SIG).toString();
838 }
839
840 static MethodHandle makeCbmhCtor(Class<? extends BoundMethodHandle> cbmh, String types) {
841 try {
842 return LOOKUP.findStatic(cbmh, "make", MethodType.fromDescriptor(makeSignature(types, false), null));
843 } catch (NoSuchMethodException | IllegalAccessException | IllegalArgumentException | TypeNotPresentException e) {
844 throw newInternalError(e);
845 }
846 }
847 }
848
849 private static final Lookup LOOKUP = Lookup.IMPL_LOOKUP;
850
851 /**
852 * All subclasses must provide such a value describing their type signature.
853 */
854 static final SpeciesData SPECIES_DATA = SpeciesData.EMPTY;
855
856 private static final SpeciesData[] SPECIES_DATA_CACHE = new SpeciesData[5];
857 private static SpeciesData checkCache(int size, String types) {
858 int idx = size - 1;
859 SpeciesData data = SPECIES_DATA_CACHE[idx];
860 if (data != null) return data;
861 SPECIES_DATA_CACHE[idx] = data = getSpeciesData(types);
862 return data;
863 }
864 static SpeciesData speciesData_L() { return checkCache(1, "L"); }
865 static SpeciesData speciesData_LL() { return checkCache(2, "LL"); }
866 static SpeciesData speciesData_LLL() { return checkCache(3, "LLL"); }
867 static SpeciesData speciesData_LLLL() { return checkCache(4, "LLLL"); }
868 static SpeciesData speciesData_LLLLL() { return checkCache(5, "LLLLL"); }
869 }