1 /*
2 * Copyright (c) 2008, 2016, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.lang.invoke;
27
28 import jdk.internal.loader.BootLoader;
29 import jdk.internal.org.objectweb.asm.ClassWriter;
30 import jdk.internal.org.objectweb.asm.FieldVisitor;
31 import jdk.internal.org.objectweb.asm.MethodVisitor;
32 import jdk.internal.vm.annotation.Stable;
33 import sun.invoke.util.ValueConversions;
34 import sun.invoke.util.Wrapper;
35
36 import java.lang.invoke.LambdaForm.NamedFunction;
37 import java.lang.invoke.MethodHandles.Lookup;
38 import java.lang.reflect.Field;
39 import java.util.Map;
40 import java.util.concurrent.ConcurrentHashMap;
41 import java.util.concurrent.ConcurrentMap;
42 import java.util.function.Function;
43
44 import static java.lang.invoke.LambdaForm.BasicType;
45 import static java.lang.invoke.LambdaForm.BasicType.*;
46 import static java.lang.invoke.MethodHandleStatics.*;
47 import static jdk.internal.org.objectweb.asm.Opcodes.*;
48
49 /**
50 * The flavor of method handle which emulates an invoke instruction
51 * on a predetermined argument. The JVM dispatches to the correct method
52 * when the handle is created, not when it is invoked.
53 *
54 * All bound arguments are encapsulated in dedicated species.
55 */
56 /*non-public*/ abstract class BoundMethodHandle extends MethodHandle {
57
58 /*non-public*/ BoundMethodHandle(MethodType type, LambdaForm form) {
59 super(type, form);
60 assert(speciesData() == speciesData(form));
61 }
62
63 //
64 // BMH API and internals
65 //
66
67 static BoundMethodHandle bindSingle(MethodType type, LambdaForm form, BasicType xtype, Object x) {
68 // for some type signatures, there exist pre-defined concrete BMH classes
69 try {
70 switch (xtype) {
71 case L_TYPE:
72 return bindSingle(type, form, x); // Use known fast path.
73 case I_TYPE:
74 return (BoundMethodHandle) SpeciesData.EMPTY.extendWith(I_TYPE).constructor().invokeBasic(type, form, ValueConversions.widenSubword(x));
75 case J_TYPE:
76 return (BoundMethodHandle) SpeciesData.EMPTY.extendWith(J_TYPE).constructor().invokeBasic(type, form, (long) x);
77 case F_TYPE:
78 return (BoundMethodHandle) SpeciesData.EMPTY.extendWith(F_TYPE).constructor().invokeBasic(type, form, (float) x);
79 case D_TYPE:
80 return (BoundMethodHandle) SpeciesData.EMPTY.extendWith(D_TYPE).constructor().invokeBasic(type, form, (double) x);
81 default : throw newInternalError("unexpected xtype: " + xtype);
82 }
83 } catch (Throwable t) {
84 throw newInternalError(t);
85 }
86 }
87
88 /*non-public*/
89 LambdaFormEditor editor() {
90 return form.editor();
91 }
92
93 static BoundMethodHandle bindSingle(MethodType type, LambdaForm form, Object x) {
94 return Species_L.make(type, form, x);
95 }
96
97 @Override // there is a default binder in the super class, for 'L' types only
98 /*non-public*/
99 BoundMethodHandle bindArgumentL(int pos, Object value) {
100 return editor().bindArgumentL(this, pos, value);
101 }
102 /*non-public*/
103 BoundMethodHandle bindArgumentI(int pos, int value) {
104 return editor().bindArgumentI(this, pos, value);
105 }
106 /*non-public*/
107 BoundMethodHandle bindArgumentJ(int pos, long value) {
108 return editor().bindArgumentJ(this, pos, value);
109 }
110 /*non-public*/
111 BoundMethodHandle bindArgumentF(int pos, float value) {
112 return editor().bindArgumentF(this, pos, value);
113 }
114 /*non-public*/
115 BoundMethodHandle bindArgumentD(int pos, double value) {
116 return editor().bindArgumentD(this, pos, value);
117 }
118
119 @Override
120 BoundMethodHandle rebind() {
121 if (!tooComplex()) {
122 return this;
123 }
124 return makeReinvoker(this);
125 }
126
127 private boolean tooComplex() {
128 return (fieldCount() > FIELD_COUNT_THRESHOLD ||
129 form.expressionCount() > FORM_EXPRESSION_THRESHOLD);
130 }
131 private static final int FIELD_COUNT_THRESHOLD = 12; // largest convenient BMH field count
132 private static final int FORM_EXPRESSION_THRESHOLD = 24; // largest convenient BMH expression count
133
134 /**
135 * A reinvoker MH has this form:
136 * {@code lambda (bmh, arg*) { thismh = bmh[0]; invokeBasic(thismh, arg*) }}
137 */
138 static BoundMethodHandle makeReinvoker(MethodHandle target) {
139 LambdaForm form = DelegatingMethodHandle.makeReinvokerForm(
140 target, MethodTypeForm.LF_REBIND,
141 Species_L.SPECIES_DATA, Species_L.SPECIES_DATA.getterFunction(0));
142 return Species_L.make(target.type(), form, target);
143 }
144
145 /**
146 * Return the {@link SpeciesData} instance representing this BMH species. All subclasses must provide a
147 * static field containing this value, and they must accordingly implement this method.
148 */
149 /*non-public*/ abstract SpeciesData speciesData();
150
151 /*non-public*/ static SpeciesData speciesData(LambdaForm form) {
152 Object c = form.names[0].constraint;
153 if (c instanceof SpeciesData)
154 return (SpeciesData) c;
155 // if there is no BMH constraint, then use the null constraint
156 return SpeciesData.EMPTY;
157 }
158
159 /**
160 * Return the number of fields in this BMH. Equivalent to speciesData().fieldCount().
161 */
162 /*non-public*/ abstract int fieldCount();
163
164 @Override
165 Object internalProperties() {
166 return "\n& BMH="+internalValues();
167 }
168
169 @Override
170 final String internalValues() {
171 int count = speciesData().fieldCount();
172 if (count == 1) {
173 return "[" + arg(0) + "]";
174 }
175 StringBuilder sb = new StringBuilder("[");
176 for (int i = 0; i < count; ++i) {
177 sb.append("\n ").append(i).append(": ( ").append(arg(i)).append(" )");
178 }
179 return sb.append("\n]").toString();
180 }
181
182 /*non-public*/ final Object arg(int i) {
183 try {
184 switch (speciesData().fieldType(i)) {
185 case L_TYPE: return speciesData().getters[i].invokeBasic(this);
186 case I_TYPE: return (int) speciesData().getters[i].invokeBasic(this);
187 case J_TYPE: return (long) speciesData().getters[i].invokeBasic(this);
188 case F_TYPE: return (float) speciesData().getters[i].invokeBasic(this);
189 case D_TYPE: return (double) speciesData().getters[i].invokeBasic(this);
190 }
191 } catch (Throwable ex) {
192 throw newInternalError(ex);
193 }
194 throw new InternalError("unexpected type: " + speciesData().typeChars+"."+i);
195 }
196
197 //
198 // cloning API
199 //
200
201 /*non-public*/ abstract BoundMethodHandle copyWith(MethodType mt, LambdaForm lf);
202 /*non-public*/ abstract BoundMethodHandle copyWithExtendL(MethodType mt, LambdaForm lf, Object narg);
203 /*non-public*/ abstract BoundMethodHandle copyWithExtendI(MethodType mt, LambdaForm lf, int narg);
204 /*non-public*/ abstract BoundMethodHandle copyWithExtendJ(MethodType mt, LambdaForm lf, long narg);
205 /*non-public*/ abstract BoundMethodHandle copyWithExtendF(MethodType mt, LambdaForm lf, float narg);
206 /*non-public*/ abstract BoundMethodHandle copyWithExtendD(MethodType mt, LambdaForm lf, double narg);
207
208 //
209 // concrete BMH classes required to close bootstrap loops
210 //
211
212 private // make it private to force users to access the enclosing class first
213 static final class Species_L extends BoundMethodHandle {
214 final Object argL0;
215 private Species_L(MethodType mt, LambdaForm lf, Object argL0) {
216 super(mt, lf);
217 this.argL0 = argL0;
218 }
219 @Override
220 /*non-public*/ SpeciesData speciesData() {
221 return SPECIES_DATA;
222 }
223 @Override
224 /*non-public*/ int fieldCount() {
225 return 1;
226 }
227 /*non-public*/ static final SpeciesData SPECIES_DATA = new SpeciesData("L", Species_L.class);
228 /*non-public*/ static BoundMethodHandle make(MethodType mt, LambdaForm lf, Object argL0) {
229 return new Species_L(mt, lf, argL0);
230 }
231 @Override
232 /*non-public*/ final BoundMethodHandle copyWith(MethodType mt, LambdaForm lf) {
233 return new Species_L(mt, lf, argL0);
234 }
235 @Override
236 /*non-public*/ final BoundMethodHandle copyWithExtendL(MethodType mt, LambdaForm lf, Object narg) {
237 try {
238 return (BoundMethodHandle) SPECIES_DATA.extendWith(L_TYPE).constructor().invokeBasic(mt, lf, argL0, narg);
239 } catch (Throwable ex) {
240 throw uncaughtException(ex);
241 }
242 }
243 @Override
244 /*non-public*/ final BoundMethodHandle copyWithExtendI(MethodType mt, LambdaForm lf, int narg) {
245 try {
246 return (BoundMethodHandle) SPECIES_DATA.extendWith(I_TYPE).constructor().invokeBasic(mt, lf, argL0, narg);
247 } catch (Throwable ex) {
248 throw uncaughtException(ex);
249 }
250 }
251 @Override
252 /*non-public*/ final BoundMethodHandle copyWithExtendJ(MethodType mt, LambdaForm lf, long narg) {
253 try {
254 return (BoundMethodHandle) SPECIES_DATA.extendWith(J_TYPE).constructor().invokeBasic(mt, lf, argL0, narg);
255 } catch (Throwable ex) {
256 throw uncaughtException(ex);
257 }
258 }
259 @Override
260 /*non-public*/ final BoundMethodHandle copyWithExtendF(MethodType mt, LambdaForm lf, float narg) {
261 try {
262 return (BoundMethodHandle) SPECIES_DATA.extendWith(F_TYPE).constructor().invokeBasic(mt, lf, argL0, narg);
263 } catch (Throwable ex) {
264 throw uncaughtException(ex);
265 }
266 }
267 @Override
268 /*non-public*/ final BoundMethodHandle copyWithExtendD(MethodType mt, LambdaForm lf, double narg) {
269 try {
270 return (BoundMethodHandle) SPECIES_DATA.extendWith(D_TYPE).constructor().invokeBasic(mt, lf, argL0, narg);
271 } catch (Throwable ex) {
272 throw uncaughtException(ex);
273 }
274 }
275 }
276
277 //
278 // BMH species meta-data
279 //
280
281 /**
282 * Meta-data wrapper for concrete BMH types.
283 * Each BMH type corresponds to a given sequence of basic field types (LIJFD).
284 * The fields are immutable; their values are fully specified at object construction.
285 * Each BMH type supplies an array of getter functions which may be used in lambda forms.
286 * A BMH is constructed by cloning a shorter BMH and adding one or more new field values.
287 * The shortest possible BMH has zero fields; its class is SimpleMethodHandle.
288 * BMH species are not interrelated by subtyping, even though it would appear that
289 * a shorter BMH could serve as a supertype of a longer one which extends it.
290 */
291 static class SpeciesData {
292 private final String typeChars;
293 private final BasicType[] typeCodes;
294 private final Class<? extends BoundMethodHandle> clazz;
295 // Bootstrapping requires circular relations MH -> BMH -> SpeciesData -> MH
296 // Therefore, we need a non-final link in the chain. Use array elements.
297 @Stable private final MethodHandle[] constructor;
298 @Stable private final MethodHandle[] getters;
299 @Stable private final NamedFunction[] nominalGetters;
300 @Stable private final SpeciesData[] extensions;
301
302 /*non-public*/ int fieldCount() {
303 return typeCodes.length;
304 }
305 /*non-public*/ BasicType fieldType(int i) {
306 return typeCodes[i];
307 }
308 /*non-public*/ char fieldTypeChar(int i) {
309 return typeChars.charAt(i);
310 }
311 Object fieldSignature() {
312 return typeChars;
313 }
314 public Class<? extends BoundMethodHandle> fieldHolder() {
315 return clazz;
316 }
317 public String toString() {
318 return "SpeciesData<"+fieldSignature()+">";
319 }
320
321 /**
322 * Return a {@link LambdaForm.Name} containing a {@link LambdaForm.NamedFunction} that
323 * represents a MH bound to a generic invoker, which in turn forwards to the corresponding
324 * getter.
325 */
326 NamedFunction getterFunction(int i) {
327 NamedFunction nf = nominalGetters[i];
328 assert(nf.memberDeclaringClassOrNull() == fieldHolder());
329 assert(nf.returnType() == fieldType(i));
330 return nf;
331 }
332
333 NamedFunction[] getterFunctions() {
334 return nominalGetters;
335 }
336
337 MethodHandle[] getterHandles() { return getters; }
338
339 MethodHandle constructor() {
340 return constructor[0];
341 }
342
343 static final SpeciesData EMPTY = new SpeciesData("", BoundMethodHandle.class);
344
345 SpeciesData(String types, Class<? extends BoundMethodHandle> clazz) {
346 this.typeChars = types;
347 this.typeCodes = basicTypes(types);
348 this.clazz = clazz;
349 if (!INIT_DONE) {
350 this.constructor = new MethodHandle[1]; // only one ctor
351 this.getters = new MethodHandle[types.length()];
352 this.nominalGetters = new NamedFunction[types.length()];
353 } else {
354 this.constructor = Factory.makeCtors(clazz, types, null);
355 this.getters = Factory.makeGetters(clazz, types, null);
356 this.nominalGetters = Factory.makeNominalGetters(types, null, this.getters);
357 }
358 this.extensions = new SpeciesData[ARG_TYPE_LIMIT];
359 }
360
361 private void initForBootstrap() {
362 assert(!INIT_DONE);
363 if (constructor() == null) {
364 String types = typeChars;
365 CACHE.put(types, this);
366 Factory.makeCtors(clazz, types, this.constructor);
367 Factory.makeGetters(clazz, types, this.getters);
368 Factory.makeNominalGetters(types, this.nominalGetters, this.getters);
369 }
370 }
371
372 private static final ConcurrentMap<String, SpeciesData> CACHE = new ConcurrentHashMap<>();
373 private static final boolean INIT_DONE; // set after <clinit> finishes...
374
375 SpeciesData extendWith(byte type) {
376 return extendWith(BasicType.basicType(type));
377 }
378
379 SpeciesData extendWith(BasicType type) {
380 int ord = type.ordinal();
381 SpeciesData d = extensions[ord];
382 if (d != null) return d;
383 extensions[ord] = d = get(typeChars+type.basicTypeChar());
384 return d;
385 }
386
387 private static SpeciesData get(String types) {
388 return CACHE.computeIfAbsent(types, new Function<String, SpeciesData>() {
389 @Override
390 public SpeciesData apply(String types) {
391 Class<? extends BoundMethodHandle> bmhcl = Factory.getConcreteBMHClass(types);
392 // SpeciesData instantiation may throw VirtualMachineError because of
393 // code cache overflow...
394 SpeciesData speciesData = new SpeciesData(types, bmhcl);
395 // CHM.computeIfAbsent ensures only one SpeciesData will be set
396 // successfully on the concrete BMH class if ever
397 Factory.setSpeciesDataToConcreteBMHClass(bmhcl, speciesData);
398 // the concrete BMH class is published via SpeciesData instance
399 // returned here only after it's SPECIES_DATA field is set
400 return speciesData;
401 }
402 });
403 }
404
405 /**
406 * This is to be called when assertions are enabled. It checks whether SpeciesData for all of the statically
407 * defined species subclasses of BoundMethodHandle has been added to the SpeciesData cache. See below in the
408 * static initializer for
409 */
410 static boolean speciesDataCachePopulated() {
411 Class<BoundMethodHandle> rootCls = BoundMethodHandle.class;
412 try {
413 for (Class<?> c : rootCls.getDeclaredClasses()) {
414 if (rootCls.isAssignableFrom(c)) {
415 final Class<? extends BoundMethodHandle> cbmh = c.asSubclass(BoundMethodHandle.class);
416 SpeciesData d = Factory.getSpeciesDataFromConcreteBMHClass(cbmh);
417 assert(d != null) : cbmh.getName();
418 assert(d.clazz == cbmh);
419 assert(CACHE.get(d.typeChars) == d);
420 }
421 }
422 } catch (Throwable e) {
423 throw newInternalError(e);
424 }
425 return true;
426 }
427
428 static {
429 // Pre-fill the BMH species-data cache with EMPTY and all BMH's inner subclasses.
430 EMPTY.initForBootstrap();
431 Species_L.SPECIES_DATA.initForBootstrap();
432 // check that all static SpeciesData instances have been initialized
433 assert speciesDataCachePopulated();
434 // Note: Do not simplify this, because INIT_DONE must not be
435 // a compile-time constant during bootstrapping.
436 INIT_DONE = Boolean.TRUE;
437 }
438 }
439
440 static SpeciesData getSpeciesData(String types) {
441 return SpeciesData.get(types);
442 }
443
444 /**
445 * Generation of concrete BMH classes.
446 *
447 * A concrete BMH species is fit for binding a number of values adhering to a
448 * given type pattern. Reference types are erased.
449 *
450 * BMH species are cached by type pattern.
451 *
452 * A BMH species has a number of fields with the concrete (possibly erased) types of
453 * bound values. Setters are provided as an API in BMH. Getters are exposed as MHs,
454 * which can be included as names in lambda forms.
455 */
456 static class Factory {
457
458 static final String JLO_SIG = "Ljava/lang/Object;";
459 static final String JLS_SIG = "Ljava/lang/String;";
460 static final String JLC_SIG = "Ljava/lang/Class;";
461 static final String MH = "java/lang/invoke/MethodHandle";
462 static final String MH_SIG = "L"+MH+";";
463 static final String BMH = "java/lang/invoke/BoundMethodHandle";
464 static final String BMH_SIG = "L"+BMH+";";
465 static final String SPECIES_DATA = "java/lang/invoke/BoundMethodHandle$SpeciesData";
466 static final String SPECIES_DATA_SIG = "L"+SPECIES_DATA+";";
467 static final String STABLE_SIG = "Ljdk/internal/vm/annotation/Stable;";
468
469 static final String SPECIES_PREFIX_NAME = "Species_";
470 static final String SPECIES_PREFIX_PATH = BMH + "$" + SPECIES_PREFIX_NAME;
471 static final String SPECIES_CLASS_PREFIX = SPECIES_PREFIX_PATH.replace('/', '.');
472
473 static final String BMHSPECIES_DATA_EWI_SIG = "(B)" + SPECIES_DATA_SIG;
474 static final String BMHSPECIES_DATA_GFC_SIG = "(" + JLS_SIG + JLC_SIG + ")" + SPECIES_DATA_SIG;
475 static final String MYSPECIES_DATA_SIG = "()" + SPECIES_DATA_SIG;
476 static final String VOID_SIG = "()V";
477 static final String INT_SIG = "()I";
478
479 static final String SIG_INCIPIT = "(Ljava/lang/invoke/MethodType;Ljava/lang/invoke/LambdaForm;";
480
481 static final String[] E_THROWABLE = new String[] { "java/lang/Throwable" };
482
483 static final ConcurrentMap<String, Class<? extends BoundMethodHandle>> CLASS_CACHE = new ConcurrentHashMap<>();
484
485 /**
486 * Get a concrete subclass of BMH for a given combination of bound types.
487 *
488 * @param types the type signature, wherein reference types are erased to 'L'
489 * @return the concrete BMH class
490 */
491 static Class<? extends BoundMethodHandle> getConcreteBMHClass(String types) {
492 // CHM.computeIfAbsent ensures generateConcreteBMHClass is called
493 // only once per key.
494 return CLASS_CACHE.computeIfAbsent(
495 types, new Function<String, Class<? extends BoundMethodHandle>>() {
496 @Override
497 public Class<? extends BoundMethodHandle> apply(String types) {
498 String shortTypes = LambdaForm.shortenSignature(types);
499 String className = SPECIES_CLASS_PREFIX + shortTypes;
500 Class<?> c = BootLoader.loadClassOrNull(className);
501 if (c != null) {
502 return c.asSubclass(BoundMethodHandle.class);
503 } else {
504 // Not pregenerated, generate the class
505 return generateConcreteBMHClass(shortTypes, types);
506 }
507 }
508 });
509 }
510
511 /**
512 * Generate a concrete subclass of BMH for a given combination of bound types.
513 *
514 * A concrete BMH species adheres to the following schema:
515 *
516 * <pre>
517 * class Species_[[types]] extends BoundMethodHandle {
518 * [[fields]]
519 * final SpeciesData speciesData() { return SpeciesData.get("[[types]]"); }
520 * }
521 * </pre>
522 *
523 * The {@code [[types]]} signature is precisely the string that is passed to this
524 * method.
525 *
526 * The {@code [[fields]]} section consists of one field definition per character in
527 * the type signature, adhering to the naming schema described in the definition of
528 * {@link #makeFieldName}.
529 *
530 * For example, a concrete BMH species for two reference and one integral bound values
531 * would have the following shape:
532 *
533 * <pre>
534 * class BoundMethodHandle { ... private static
535 * final class Species_LLI extends BoundMethodHandle {
536 * final Object argL0;
537 * final Object argL1;
538 * final int argI2;
539 * private Species_LLI(MethodType mt, LambdaForm lf, Object argL0, Object argL1, int argI2) {
540 * super(mt, lf);
541 * this.argL0 = argL0;
542 * this.argL1 = argL1;
543 * this.argI2 = argI2;
544 * }
545 * final SpeciesData speciesData() { return SPECIES_DATA; }
546 * final int fieldCount() { return 3; }
547 * @Stable static SpeciesData SPECIES_DATA; // injected afterwards
548 * static BoundMethodHandle make(MethodType mt, LambdaForm lf, Object argL0, Object argL1, int argI2) {
549 * return new Species_LLI(mt, lf, argL0, argL1, argI2);
550 * }
551 * final BoundMethodHandle copyWith(MethodType mt, LambdaForm lf) {
552 * return new Species_LLI(mt, lf, argL0, argL1, argI2);
553 * }
554 * final BoundMethodHandle copyWithExtendL(MethodType mt, LambdaForm lf, Object narg) {
555 * return SPECIES_DATA.extendWith(L_TYPE).constructor().invokeBasic(mt, lf, argL0, argL1, argI2, narg);
556 * }
557 * final BoundMethodHandle copyWithExtendI(MethodType mt, LambdaForm lf, int narg) {
558 * return SPECIES_DATA.extendWith(I_TYPE).constructor().invokeBasic(mt, lf, argL0, argL1, argI2, narg);
559 * }
560 * final BoundMethodHandle copyWithExtendJ(MethodType mt, LambdaForm lf, long narg) {
561 * return SPECIES_DATA.extendWith(J_TYPE).constructor().invokeBasic(mt, lf, argL0, argL1, argI2, narg);
562 * }
563 * final BoundMethodHandle copyWithExtendF(MethodType mt, LambdaForm lf, float narg) {
564 * return SPECIES_DATA.extendWith(F_TYPE).constructor().invokeBasic(mt, lf, argL0, argL1, argI2, narg);
565 * }
566 * public final BoundMethodHandle copyWithExtendD(MethodType mt, LambdaForm lf, double narg) {
567 * return SPECIES_DATA.extendWith(D_TYPE).constructor().invokeBasic(mt, lf, argL0, argL1, argI2, narg);
568 * }
569 * }
570 * </pre>
571 *
572 * @param types the type signature, wherein reference types are erased to 'L'
573 * @return the generated concrete BMH class
574 */
575 static Class<? extends BoundMethodHandle> generateConcreteBMHClass(String shortTypes,
576 String types) {
577 final String className = speciesInternalClassName(shortTypes);
578 byte[] classFile = generateConcreteBMHClassBytes(shortTypes, types, className);
579
580 // load class
581 InvokerBytecodeGenerator.maybeDump(className, classFile);
582 Class<? extends BoundMethodHandle> bmhClass =
583 UNSAFE.defineClass(className, classFile, 0, classFile.length,
584 BoundMethodHandle.class.getClassLoader(), null)
585 .asSubclass(BoundMethodHandle.class);
586
587 return bmhClass;
588 }
589
590 static String speciesInternalClassName(String shortTypes) {
591 return SPECIES_PREFIX_PATH + shortTypes;
592 }
593
594 static byte[] generateConcreteBMHClassBytes(final String shortTypes,
595 final String types, final String className) {
596 final String sourceFile = SPECIES_PREFIX_NAME + shortTypes;
597
598 final ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES);
599 final int NOT_ACC_PUBLIC = 0; // not ACC_PUBLIC
600 cw.visit(V1_6, NOT_ACC_PUBLIC + ACC_FINAL + ACC_SUPER, className, null, BMH, null);
601 cw.visitSource(sourceFile, null);
602
603 // emit static types and SPECIES_DATA fields
604 FieldVisitor fw = cw.visitField(NOT_ACC_PUBLIC + ACC_STATIC, "SPECIES_DATA", SPECIES_DATA_SIG, null, null);
605 fw.visitAnnotation(STABLE_SIG, true);
606 fw.visitEnd();
607
608 // emit bound argument fields
609 for (int i = 0; i < types.length(); ++i) {
610 final char t = types.charAt(i);
611 final String fieldName = makeFieldName(types, i);
612 final String fieldDesc = t == 'L' ? JLO_SIG : String.valueOf(t);
613 cw.visitField(ACC_FINAL, fieldName, fieldDesc, null, null).visitEnd();
614 }
615
616 MethodVisitor mv;
617
618 // emit constructor
619 mv = cw.visitMethod(ACC_PRIVATE, "<init>", makeSignature(types, true), null, null);
620 mv.visitCode();
621 mv.visitVarInsn(ALOAD, 0); // this
622 mv.visitVarInsn(ALOAD, 1); // type
623 mv.visitVarInsn(ALOAD, 2); // form
624
625 mv.visitMethodInsn(INVOKESPECIAL, BMH, "<init>", makeSignature("", true), false);
626
627 for (int i = 0, j = 0; i < types.length(); ++i, ++j) {
628 // i counts the arguments, j counts corresponding argument slots
629 char t = types.charAt(i);
630 mv.visitVarInsn(ALOAD, 0);
631 mv.visitVarInsn(typeLoadOp(t), j + 3); // parameters start at 3
632 mv.visitFieldInsn(PUTFIELD, className, makeFieldName(types, i), typeSig(t));
633 if (t == 'J' || t == 'D') {
634 ++j; // adjust argument register access
635 }
636 }
637
638 mv.visitInsn(RETURN);
639 mv.visitMaxs(0, 0);
640 mv.visitEnd();
641
642 // emit implementation of speciesData()
643 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_FINAL, "speciesData", MYSPECIES_DATA_SIG, null, null);
644 mv.visitCode();
645 mv.visitFieldInsn(GETSTATIC, className, "SPECIES_DATA", SPECIES_DATA_SIG);
646 mv.visitInsn(ARETURN);
647 mv.visitMaxs(0, 0);
648 mv.visitEnd();
649
650 // emit implementation of fieldCount()
651 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_FINAL, "fieldCount", INT_SIG, null, null);
652 mv.visitCode();
653 int fc = types.length();
654 if (fc <= (ICONST_5 - ICONST_0)) {
655 mv.visitInsn(ICONST_0 + fc);
656 } else {
657 mv.visitIntInsn(SIPUSH, fc);
658 }
659 mv.visitInsn(IRETURN);
660 mv.visitMaxs(0, 0);
661 mv.visitEnd();
662 // emit make() ...factory method wrapping constructor
663 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_STATIC, "make", makeSignature(types, false), null, null);
664 mv.visitCode();
665 // make instance
666 mv.visitTypeInsn(NEW, className);
667 mv.visitInsn(DUP);
668 // load mt, lf
669 mv.visitVarInsn(ALOAD, 0); // type
670 mv.visitVarInsn(ALOAD, 1); // form
671 // load factory method arguments
672 for (int i = 0, j = 0; i < types.length(); ++i, ++j) {
673 // i counts the arguments, j counts corresponding argument slots
674 char t = types.charAt(i);
675 mv.visitVarInsn(typeLoadOp(t), j + 2); // parameters start at 3
676 if (t == 'J' || t == 'D') {
677 ++j; // adjust argument register access
678 }
679 }
680
681 // finally, invoke the constructor and return
682 mv.visitMethodInsn(INVOKESPECIAL, className, "<init>", makeSignature(types, true), false);
683 mv.visitInsn(ARETURN);
684 mv.visitMaxs(0, 0);
685 mv.visitEnd();
686
687 // emit copyWith()
688 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_FINAL, "copyWith", makeSignature("", false), null, null);
689 mv.visitCode();
690 // make instance
691 mv.visitTypeInsn(NEW, className);
692 mv.visitInsn(DUP);
693 // load mt, lf
694 mv.visitVarInsn(ALOAD, 1);
695 mv.visitVarInsn(ALOAD, 2);
696 // put fields on the stack
697 emitPushFields(types, className, mv);
698 // finally, invoke the constructor and return
699 mv.visitMethodInsn(INVOKESPECIAL, className, "<init>", makeSignature(types, true), false);
700 mv.visitInsn(ARETURN);
701 mv.visitMaxs(0, 0);
702 mv.visitEnd();
703
704 // for each type, emit copyWithExtendT()
705 for (BasicType type : BasicType.ARG_TYPES) {
706 int ord = type.ordinal();
707 char btChar = type.basicTypeChar();
708 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_FINAL, "copyWithExtend" + btChar, makeSignature(String.valueOf(btChar), false), null, E_THROWABLE);
709 mv.visitCode();
710 // return SPECIES_DATA.extendWith(t).constructor().invokeBasic(mt, lf, argL0, ..., narg)
711 // obtain constructor
712 mv.visitFieldInsn(GETSTATIC, className, "SPECIES_DATA", SPECIES_DATA_SIG);
713 int iconstInsn = ICONST_0 + ord;
714 assert(iconstInsn <= ICONST_5);
715 mv.visitInsn(iconstInsn);
716 mv.visitMethodInsn(INVOKEVIRTUAL, SPECIES_DATA, "extendWith", BMHSPECIES_DATA_EWI_SIG, false);
717 mv.visitMethodInsn(INVOKEVIRTUAL, SPECIES_DATA, "constructor", "()" + MH_SIG, false);
718 // load mt, lf
719 mv.visitVarInsn(ALOAD, 1);
720 mv.visitVarInsn(ALOAD, 2);
721 // put fields on the stack
722 emitPushFields(types, className, mv);
723 // put narg on stack
724 mv.visitVarInsn(typeLoadOp(btChar), 3);
725 // finally, invoke the constructor and return
726 mv.visitMethodInsn(INVOKEVIRTUAL, MH, "invokeBasic", makeSignature(types + btChar, false), false);
727 mv.visitInsn(ARETURN);
728 mv.visitMaxs(0, 0);
729 mv.visitEnd();
730 }
731
732 cw.visitEnd();
733
734 return cw.toByteArray();
735 }
736
737 private static int typeLoadOp(char t) {
738 switch (t) {
739 case 'L': return ALOAD;
740 case 'I': return ILOAD;
741 case 'J': return LLOAD;
742 case 'F': return FLOAD;
743 case 'D': return DLOAD;
744 default : throw newInternalError("unrecognized type " + t);
745 }
746 }
747
748 private static void emitPushFields(String types, String className, MethodVisitor mv) {
749 for (int i = 0; i < types.length(); ++i) {
750 char tc = types.charAt(i);
751 mv.visitVarInsn(ALOAD, 0);
752 mv.visitFieldInsn(GETFIELD, className, makeFieldName(types, i), typeSig(tc));
753 }
754 }
755
756 static String typeSig(char t) {
757 return t == 'L' ? JLO_SIG : String.valueOf(t);
758 }
759
760 //
761 // Getter MH generation.
762 //
763
764 private static MethodHandle makeGetter(Class<?> cbmhClass, String types, int index) {
765 String fieldName = makeFieldName(types, index);
766 Class<?> fieldType = Wrapper.forBasicType(types.charAt(index)).primitiveType();
767 try {
768 return LOOKUP.findGetter(cbmhClass, fieldName, fieldType);
769 } catch (NoSuchFieldException | IllegalAccessException e) {
770 throw newInternalError(e);
771 }
772 }
773
774 static MethodHandle[] makeGetters(Class<?> cbmhClass, String types, MethodHandle[] mhs) {
775 if (mhs == null) mhs = new MethodHandle[types.length()];
776 for (int i = 0; i < mhs.length; ++i) {
777 mhs[i] = makeGetter(cbmhClass, types, i);
778 assert(mhs[i].internalMemberName().getDeclaringClass() == cbmhClass);
779 }
780 return mhs;
781 }
782
783 static MethodHandle[] makeCtors(Class<? extends BoundMethodHandle> cbmh, String types, MethodHandle mhs[]) {
784 if (mhs == null) mhs = new MethodHandle[1];
785 if (types.equals("")) return mhs; // hack for empty BMH species
786 mhs[0] = makeCbmhCtor(cbmh, types);
787 return mhs;
788 }
789
790 static NamedFunction[] makeNominalGetters(String types, NamedFunction[] nfs, MethodHandle[] getters) {
791 if (nfs == null) nfs = new NamedFunction[types.length()];
792 for (int i = 0; i < nfs.length; ++i) {
793 nfs[i] = new NamedFunction(getters[i]);
794 }
795 return nfs;
796 }
797
798 //
799 // Auxiliary methods.
800 //
801
802 static SpeciesData getSpeciesDataFromConcreteBMHClass(Class<? extends BoundMethodHandle> cbmh) {
803 try {
804 Field F_SPECIES_DATA = cbmh.getDeclaredField("SPECIES_DATA");
805 return (SpeciesData) F_SPECIES_DATA.get(null);
806 } catch (ReflectiveOperationException ex) {
807 throw newInternalError(ex);
808 }
809 }
810
811 static void setSpeciesDataToConcreteBMHClass(Class<? extends BoundMethodHandle> cbmh, SpeciesData speciesData) {
812 try {
813 Field F_SPECIES_DATA = cbmh.getDeclaredField("SPECIES_DATA");
814 // ## FIXME: annotation parser can't create proxy classes until module system is fully initialzed
815 // assert F_SPECIES_DATA.getDeclaredAnnotation(Stable.class) != null;
816 F_SPECIES_DATA.set(null, speciesData);
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 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[6];
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 static SpeciesData speciesData_LLLLLL() { return checkCache(6, "LLLLLL"); }
870 }